res_pjsip_session.c

Go to the documentation of this file.

/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 2013, Digium, Inc.
*
* Mark Michelson <[email protected]>
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/

/*** MODULEINFO
 <depend>pjproject</depend>
 <depend>res_pjsip</depend>
 <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include <pjsip.h>
#include <pjsip_ua.h>
#include <pjlib.h>
#include <pjmedia.h>

#include "asterisk/res_pjsip.h"
#include "asterisk/res_pjsip_session.h"
#include "asterisk/res_pjsip_session_caps.h"
#include "asterisk/callerid.h"
#include "asterisk/datastore.h"
#include "asterisk/module.h"
#include "asterisk/logger.h"
#include "asterisk/res_pjsip.h"
#include "asterisk/astobj2.h"
#include "asterisk/lock.h"
#include "asterisk/uuid.h"
#include "asterisk/pbx.h"
#include "asterisk/taskprocessor.h"
#include "asterisk/causes.h"
#include "asterisk/sdp_srtp.h"
#include "asterisk/dsp.h"
#include "asterisk/acl.h"
#include "asterisk/features_config.h"
#include "asterisk/pickup.h"
#include "asterisk/test.h"
#include "asterisk/stream.h"
#include "asterisk/vector.h"

#define SDP_HANDLER_BUCKETS 11

#define MOD_DATA_ON_RESPONSE "on_response"
#define MOD_DATA_NAT_HOOK "nat_hook"

/* Most common case is one audio and one video stream */
#define DEFAULT_NUM_SESSION_MEDIA 2

/* Some forward declarations */
static void handle_session_begin(struct ast_sip_session *session);
static void handle_session_end(struct ast_sip_session *session);
static void handle_session_destroy(struct ast_sip_session *session);
static void handle_incoming_request(struct ast_sip_session *session, pjsip_rx_data *rdata);
static void handle_incoming_response(struct ast_sip_session *session, pjsip_rx_data *rdata,
 enum ast_sip_session_response_priority response_priority);
static int handle_incoming(struct ast_sip_session *session, pjsip_rx_data *rdata,
 enum ast_sip_session_response_priority response_priority);
static void handle_outgoing_request(struct ast_sip_session *session, pjsip_tx_data *tdata);
static void handle_outgoing_response(struct ast_sip_session *session, pjsip_tx_data *tdata);
static int sip_session_refresh(struct ast_sip_session *session,
 ast_sip_session_request_creation_cb on_request_creation,
 ast_sip_session_sdp_creation_cb on_sdp_creation,
 ast_sip_session_response_cb on_response,
 enum ast_sip_session_refresh_method method, int generate_new_sdp,
 struct ast_sip_session_media_state *pending_media_state,
 struct ast_sip_session_media_state *active_media_state,
 int queued);

/*! \brief NAT hook for modifying outgoing messages with SDP */
static struct ast_sip_nat_hook *nat_hook;

/*!
 * \brief Registered SDP stream handlers
 *
 * This container is keyed on stream types. Each
 * object in the container is a linked list of
 * handlers for the stream type.
 */
static struct ao2_container *sdp_handlers;

/*!
 * These are the objects in the sdp_handlers container
 */
struct sdp_handler_list {
 /* The list of handlers to visit */
 AST_LIST_HEAD_NOLOCK(, ast_sip_session_sdp_handler) list;
 /* The handlers in this list handle streams of this type */
 char stream_type[1];
};

static struct pjmedia_sdp_session *create_local_sdp(pjsip_inv_session *inv, struct ast_sip_session *session, const pjmedia_sdp_session *offer);

static int sdp_handler_list_hash(const void *obj, int flags)
{
 const struct sdp_handler_list *handler_list = obj;
 const char *stream_type = flags & OBJ_KEY ? obj : handler_list->stream_type;

 return ast_str_hash(stream_type);
}

const char *ast_sip_session_get_name(const struct ast_sip_session *session)
{
 if (!session) {
 return "(null session)";
 }
 if (session->channel) {
 return ast_channel_name(session->channel);
 } else if (session->endpoint) {
 return ast_sorcery_object_get_id(session->endpoint);
 } else {
 return "unknown";
 }
}

static int sdp_handler_list_cmp(void *obj, void *arg, int flags)
{
 struct sdp_handler_list *handler_list1 = obj;
 struct sdp_handler_list *handler_list2 = arg;
 const char *stream_type2 = flags & OBJ_KEY ? arg : handler_list2->stream_type;

 return strcmp(handler_list1->stream_type, stream_type2) ? 0 : CMP_MATCH | CMP_STOP;
}

int ast_sip_session_register_sdp_handler(struct ast_sip_session_sdp_handler *handler, const char *stream_type)
{
 RAII_VAR(struct sdp_handler_list *, handler_list,
 ao2_find(sdp_handlers, stream_type, OBJ_KEY), ao2_cleanup);
 SCOPED_AO2LOCK(lock, sdp_handlers);

 if (handler_list) {
 struct ast_sip_session_sdp_handler *iter;
 /* Check if this handler is already registered for this stream type */
 AST_LIST_TRAVERSE(&handler_list->list, iter, next) {
 if (!strcmp(iter->id, handler->id)) {
 ast_log(LOG_WARNING, "Handler '%s' already registered for stream type '%s'.\n", handler->id, stream_type);
 return -1;
 }
 }
 AST_LIST_INSERT_TAIL(&handler_list->list, handler, next);
 ast_debug(1, "Registered SDP stream handler '%s' for stream type '%s'\n", handler->id, stream_type);

 return 0;
 }

 /* No stream of this type has been registered yet, so we need to create a new list */
 handler_list = ao2_alloc(sizeof(*handler_list) + strlen(stream_type), NULL);
 if (!handler_list) {
 return -1;
 }
 /* Safe use of strcpy */
 strcpy(handler_list->stream_type, stream_type);
 AST_LIST_HEAD_INIT_NOLOCK(&handler_list->list);
 AST_LIST_INSERT_TAIL(&handler_list->list, handler, next);
 if (!ao2_link(sdp_handlers, handler_list)) {
 return -1;
 }
 ast_debug(1, "Registered SDP stream handler '%s' for stream type '%s'\n", handler->id, stream_type);

 return 0;
}

static int remove_handler(void *obj, void *arg, void *data, int flags)
{
 struct sdp_handler_list *handler_list = obj;
 struct ast_sip_session_sdp_handler *handler = data;
 struct ast_sip_session_sdp_handler *iter;
 const char *stream_type = arg;

 AST_LIST_TRAVERSE_SAFE_BEGIN(&handler_list->list, iter, next) {
 if (!strcmp(iter->id, handler->id)) {
 AST_LIST_REMOVE_CURRENT(next);
 ast_debug(1, "Unregistered SDP stream handler '%s' for stream type '%s'\n", handler->id, stream_type);
 }
 }
 AST_LIST_TRAVERSE_SAFE_END;

 if (AST_LIST_EMPTY(&handler_list->list)) {
 ast_debug(3, "No more handlers exist for stream type '%s'\n", stream_type);
 return CMP_MATCH;
 } else {
 return CMP_STOP;
 }
}

void ast_sip_session_unregister_sdp_handler(struct ast_sip_session_sdp_handler *handler, const char *stream_type)
{
 ao2_callback_data(sdp_handlers, OBJ_KEY | OBJ_UNLINK | OBJ_NODATA, remove_handler, (void *)stream_type, handler);
}

static int media_stats_local_ssrc_cmp(
 const struct ast_rtp_instance_stats *vec_elem, const struct ast_rtp_instance_stats *srch)
{
 if (vec_elem->local_ssrc == srch->local_ssrc) {
 return 1;
 }

 return 0;
}

static struct ast_sip_session_media_state *internal_sip_session_media_state_alloc(
 size_t sessions, size_t read_callbacks)
{
 struct ast_sip_session_media_state *media_state;

 media_state = ast_calloc(1, sizeof(*media_state));
 if (!media_state) {
 return NULL;
 }

 if (AST_VECTOR_INIT(&media_state->sessions, sessions) < 0) {
 ast_free(media_state);
 return NULL;
 }

 if (AST_VECTOR_INIT(&media_state->read_callbacks, read_callbacks) < 0) {
 AST_VECTOR_FREE(&media_state->sessions);
 ast_free(media_state);
 return NULL;
 }

 return media_state;
}

struct ast_sip_session_media_state *ast_sip_session_media_state_alloc(void)
{
 return internal_sip_session_media_state_alloc(
 DEFAULT_NUM_SESSION_MEDIA, DEFAULT_NUM_SESSION_MEDIA);
}

void ast_sip_session_media_stats_save(struct ast_sip_session *sip_session, struct ast_sip_session_media_state *media_state)
{
 int i;
 int ret;

 if (!media_state || !sip_session) {
 return;
 }

 for (i = 0; i < AST_VECTOR_SIZE(&media_state->sessions); i++) {
 struct ast_rtp_instance_stats *stats_tmp = NULL;
 struct ast_sip_session_media *media = AST_VECTOR_GET(&media_state->sessions, i);
 if (!media || !media->rtp) {
 continue;
 }

 stats_tmp = ast_calloc(1, sizeof(struct ast_rtp_instance_stats));
 if (!stats_tmp) {
 return;
 }

 ret = ast_rtp_instance_get_stats(media->rtp, stats_tmp, AST_RTP_INSTANCE_STAT_ALL);
 if (ret) {
 ast_free(stats_tmp);
 continue;
 }

 /* remove all the duplicated stats if exist */
 AST_VECTOR_REMOVE_CMP_UNORDERED(&sip_session->media_stats, stats_tmp, media_stats_local_ssrc_cmp, ast_free);

 AST_VECTOR_APPEND(&sip_session->media_stats, stats_tmp);
 }
}

void ast_sip_session_media_state_reset(struct ast_sip_session_media_state *media_state)
{
 int index;

 if (!media_state) {
 return;
 }

 AST_VECTOR_RESET(&media_state->sessions, ao2_cleanup);
 AST_VECTOR_RESET(&media_state->read_callbacks, AST_VECTOR_ELEM_CLEANUP_NOOP);

 for (index = 0; index < AST_MEDIA_TYPE_END; ++index) {
 media_state->default_session[index] = NULL;
 }

 ast_stream_topology_free(media_state->topology);
 media_state->topology = NULL;
}

struct ast_sip_session_media_state *ast_sip_session_media_state_clone(const struct ast_sip_session_media_state *media_state)
{
 struct ast_sip_session_media_state *cloned;
 int index;

 if (!media_state) {
 return NULL;
 }

 cloned = internal_sip_session_media_state_alloc(
 AST_VECTOR_SIZE(&media_state->sessions),
 AST_VECTOR_SIZE(&media_state->read_callbacks));
 if (!cloned) {
 return NULL;
 }

 if (media_state->topology) {
 cloned->topology = ast_stream_topology_clone(media_state->topology);
 if (!cloned->topology) {
 ast_sip_session_media_state_free(cloned);
 return NULL;
 }
 }

 for (index = 0; index < AST_VECTOR_SIZE(&media_state->sessions); ++index) {
 struct ast_sip_session_media *session_media = AST_VECTOR_GET(&media_state->sessions, index);
 enum ast_media_type type = ast_stream_get_type(ast_stream_topology_get_stream(cloned->topology, index));

 ao2_bump(session_media);
 if (AST_VECTOR_REPLACE(&cloned->sessions, index, session_media)) {
 ao2_cleanup(session_media);
 }
 if (ast_stream_get_state(ast_stream_topology_get_stream(cloned->topology, index)) != AST_STREAM_STATE_REMOVED &&
 !cloned->default_session[type]) {
 cloned->default_session[type] = session_media;
 }
 }

 for (index = 0; index < AST_VECTOR_SIZE(&media_state->read_callbacks); ++index) {
 struct ast_sip_session_media_read_callback_state *read_callback = AST_VECTOR_GET_ADDR(&media_state->read_callbacks, index);

 AST_VECTOR_REPLACE(&cloned->read_callbacks, index, *read_callback);
 }

 return cloned;
}

void ast_sip_session_media_state_free(struct ast_sip_session_media_state *media_state)
{
 if (!media_state) {
 return;
 }

 /* This will reset the internal state so we only have to free persistent things */
 ast_sip_session_media_state_reset(media_state);

 AST_VECTOR_FREE(&media_state->sessions);
 AST_VECTOR_FREE(&media_state->read_callbacks);

 ast_free(media_state);
}

int ast_sip_session_is_pending_stream_default(const struct ast_sip_session *session, const struct ast_stream *stream)
{
 int index;

 if (!session->pending_media_state->topology) {
 ast_log(LOG_WARNING, "Pending topology was NULL for channel '%s'\n",
 session->channel ? ast_channel_name(session->channel) : "unknown");
 return 0;
 }

 if (ast_stream_get_state(stream) == AST_STREAM_STATE_REMOVED) {
 return 0;
 }

 for (index = 0; index < ast_stream_topology_get_count(session->pending_media_state->topology); ++index) {
 if (ast_stream_get_type(ast_stream_topology_get_stream(session->pending_media_state->topology, index)) !=
 ast_stream_get_type(stream)) {
 continue;
 }

 return ast_stream_topology_get_stream(session->pending_media_state->topology, index) == stream ? 1 : 0;
 }

 return 0;
}

int ast_sip_session_media_add_read_callback(struct ast_sip_session *session, struct ast_sip_session_media *session_media,
 int fd, ast_sip_session_media_read_cb callback)
{
 struct ast_sip_session_media_read_callback_state callback_state = {
 .fd = fd,
 .read_callback = callback,
 .session = session_media,
 };

 /* The contents of the vector are whole structs and not pointers */
 return AST_VECTOR_APPEND(&session->pending_media_state->read_callbacks, callback_state);
}

int ast_sip_session_media_set_write_callback(struct ast_sip_session *session, struct ast_sip_session_media *session_media,
 ast_sip_session_media_write_cb callback)
{
 if (session_media->write_callback) {
 if (session_media->write_callback == callback) {
 return 0;
 }

 return -1;
 }

 session_media->write_callback = callback;

 return 0;
}

struct ast_sip_session_media *ast_sip_session_media_get_transport(struct ast_sip_session *session, struct ast_sip_session_media *session_media)
{
 int index;

 if (!session->endpoint->media.bundle || ast_strlen_zero(session_media->mid)) {
 return session_media;
 }

 for (index = 0; index < AST_VECTOR_SIZE(&session->pending_media_state->sessions); ++index) {
 struct ast_sip_session_media *bundle_group_session_media;

 bundle_group_session_media = AST_VECTOR_GET(&session->pending_media_state->sessions, index);

 /* The first session which is in the bundle group is considered the authoritative session for transport */
 if (bundle_group_session_media->bundle_group == session_media->bundle_group) {
 return bundle_group_session_media;
 }
 }

 return session_media;
}

/*!
 * \brief Set an SDP stream handler for a corresponding session media.
 *
 * \note Always use this function to set the SDP handler for a session media.
 *
 * This function will properly free resources on the SDP handler currently being
 * used by the session media, then set the session media to use the new SDP
 * handler.
 */
static void session_media_set_handler(struct ast_sip_session_media *session_media,
 struct ast_sip_session_sdp_handler *handler)
{
 ast_assert(session_media->handler != handler);

 if (session_media->handler) {
 session_media->handler->stream_destroy(session_media);
 }
 session_media->handler = handler;
}

static int stream_destroy(void *obj, void *arg, int flags)
{
 struct sdp_handler_list *handler_list = obj;
 struct ast_sip_session_media *session_media = arg;
 struct ast_sip_session_sdp_handler *handler;

 AST_LIST_TRAVERSE(&handler_list->list, handler, next) {
 handler->stream_destroy(session_media);
 }

 return 0;
}

static void session_media_dtor(void *obj)
{
 struct ast_sip_session_media *session_media = obj;

 /* It is possible for multiple handlers to have allocated memory on the
 * session media (usually through a stream changing types). Therefore, we
 * traverse all the SDP handlers and let them all call stream_destroy on
 * the session_media
 */
 ao2_callback(sdp_handlers, 0, stream_destroy, session_media);

 if (session_media->srtp) {
 ast_sdp_srtp_destroy(session_media->srtp);
 }

 ast_free(session_media->mid);
 ast_free(session_media->remote_mslabel);
 ast_free(session_media->remote_label);
 ast_free(session_media->stream_name);
}

struct ast_sip_session_media *ast_sip_session_media_state_add(struct ast_sip_session *session,
 struct ast_sip_session_media_state *media_state, enum ast_media_type type, int position)
{
 struct ast_sip_session_media *session_media = NULL;
 struct ast_sip_session_media *current_session_media = NULL;
 SCOPE_ENTER(1, "%s Adding position %d\n", ast_sip_session_get_name(session), position);

 /* It is possible for this media state to already contain a session for the stream. If this
 * is the case we simply return it.
 */
 if (position < AST_VECTOR_SIZE(&media_state->sessions)) {
 current_session_media = AST_VECTOR_GET(&media_state->sessions, position);
 if (current_session_media && current_session_media->type == type) {
 SCOPE_EXIT_RTN_VALUE(current_session_media, "Using existing media_session\n");
 }
 }

 /* Determine if we can reuse the session media from the active media state if present */
 if (position < AST_VECTOR_SIZE(&session->active_media_state->sessions)) {
 session_media = AST_VECTOR_GET(&session->active_media_state->sessions, position);
 /* A stream can never exist without an accompanying media session */
 if (session_media->type == type) {
 ao2_ref(session_media, +1);
 ast_trace(1, "Reusing existing media session\n");
 /*
 * If this session_media was previously removed, its bundle group was probably reset
 * to -1 so if bundling is enabled on the endpoint, we need to reset it to 0, set
 * the bundled flag and reset its mid.
 */
 if (session->endpoint->media.bundle && session_media->bundle_group == -1) {
 session_media->bundled = session->endpoint->media.webrtc;
 session_media->bundle_group = 0;
 ast_free(session_media->mid);
 if (ast_asprintf(&session_media->mid, "%s-%d", ast_codec_media_type2str(type), position) < 0) {
 ao2_ref(session_media, -1);
 SCOPE_EXIT_RTN_VALUE(NULL, "Couldn't alloc mid\n");
 }
 }
 } else {
 ast_trace(1, "Can't reuse existing media session because the types are different. %s <> %s\n",
 ast_codec_media_type2str(type), ast_codec_media_type2str(session_media->type));
 session_media = NULL;
 }
 }

 if (!session_media) {
 /* No existing media session we can use so create a new one */
 session_media = ao2_alloc_options(sizeof(*session_media), session_media_dtor, AO2_ALLOC_OPT_LOCK_NOLOCK);
 if (!session_media) {
 return NULL;
 }
 ast_trace(1, "Creating new media session\n");

 session_media->encryption = session->endpoint->media.rtp.encryption;
 session_media->remote_ice = session->endpoint->media.rtp.ice_support;
 session_media->remote_rtcp_mux = session->endpoint->media.rtcp_mux;
 session_media->keepalive_sched_id = -1;
 session_media->timeout_sched_id = -1;
 session_media->type = type;
 session_media->stream_num = position;

 if (session->endpoint->media.bundle) {
 /* This is a new stream so create a new mid based on media type and position, which makes it unique.
 * If this is the result of an offer the mid will just end up getting replaced.
 */
 if (ast_asprintf(&session_media->mid, "%s-%d", ast_codec_media_type2str(type), position) < 0) {
 ao2_ref(session_media, -1);
 SCOPE_EXIT_RTN_VALUE(NULL, "Couldn't alloc mid\n");
 }
 session_media->bundle_group = 0;

 /* Some WebRTC clients can't handle an offer to bundle media streams. Instead they expect them to
 * already be bundled. Every client handles this scenario though so if WebRTC is enabled just go
 * ahead and treat the streams as having already been bundled.
 */
 session_media->bundled = session->endpoint->media.webrtc;
 } else {
 session_media->bundle_group = -1;
 }
 }

 ast_free(session_media->stream_name);
 session_media->stream_name = ast_strdup(ast_stream_get_name(ast_stream_topology_get_stream(media_state->topology, position)));

 if (AST_VECTOR_REPLACE(&media_state->sessions, position, session_media)) {
 ao2_ref(session_media, -1);

 SCOPE_EXIT_RTN_VALUE(NULL, "Couldn't replace media_session\n");
 }

 ao2_cleanup(current_session_media);

 /* If this stream will be active in some way and it is the first of this type then consider this the default media session to match */
 if (!media_state->default_session[type] && ast_stream_get_state(ast_stream_topology_get_stream(media_state->topology, position)) != AST_STREAM_STATE_REMOVED) {
 ast_trace(1, "Setting media session as default for %s\n", ast_codec_media_type2str(session_media->type));

 media_state->default_session[type] = session_media;
 }

 SCOPE_EXIT_RTN_VALUE(session_media, "Done\n");
}

static int is_stream_limitation_reached(enum ast_media_type type, const struct ast_sip_endpoint *endpoint, int *type_streams)
{
 switch (type) {
 case AST_MEDIA_TYPE_AUDIO:
 return !(type_streams[type] < endpoint->media.max_audio_streams);
 case AST_MEDIA_TYPE_VIDEO:
 return !(type_streams[type] < endpoint->media.max_video_streams);
 case AST_MEDIA_TYPE_IMAGE:
 /* We don't have an option for image (T.38) streams so cap it to one. */
 return (type_streams[type] > 0);
 case AST_MEDIA_TYPE_UNKNOWN:
 case AST_MEDIA_TYPE_TEXT:
 default:
 /* We don't want any unknown or "other" streams on our endpoint,
 * so always just say we've reached the limit
 */
 return 1;
 }
}

static int get_mid_bundle_group(const pjmedia_sdp_session *sdp, const char *mid)
{
 int bundle_group = 0;
 int index;

 for (index = 0; index < sdp->attr_count; ++index) {
 pjmedia_sdp_attr *attr = sdp->attr[index];
 char value[pj_strlen(&attr->value) + 1], *mids = value, *attr_mid;

 if (pj_strcmp2(&attr->name, "group") || pj_strncmp2(&attr->value, "BUNDLE", 6)) {
 continue;
 }

 ast_copy_pj_str(value, &attr->value, sizeof(value));

 /* Skip the BUNDLE at the front */
 mids += 7;

 while ((attr_mid = strsep(&mids, " "))) {
 if (!strcmp(attr_mid, mid)) {
 /* The ordering of attributes determines our internal identification of the bundle group based on number,
 * with -1 being not in a bundle group. Since this is only exposed internally for response purposes it's
 * actually even fine if things move around.
 */
 return bundle_group;
 }
 }

 bundle_group++;
 }

 return -1;
}

static int set_mid_and_bundle_group(struct ast_sip_session *session,
 struct ast_sip_session_media *session_media,
 const pjmedia_sdp_session *sdp,
 const struct pjmedia_sdp_media *stream)
{
 pjmedia_sdp_attr *attr;

 if (!session->endpoint->media.bundle) {
 return 0;
 }

 /* By default on an incoming negotiation we assume no mid and bundle group is present */
 ast_free(session_media->mid);
 session_media->mid = NULL;
 session_media->bundle_group = -1;
 session_media->bundled = 0;

 /* Grab the media identifier for the stream */
 attr = pjmedia_sdp_media_find_attr2(stream, "mid", NULL);
 if (!attr) {
 return 0;
 }

 session_media->mid = ast_calloc(1, attr->value.slen + 1);
 if (!session_media->mid) {
 return 0;
 }
 ast_copy_pj_str(session_media->mid, &attr->value, attr->value.slen + 1);

 /* Determine what bundle group this is part of */
 session_media->bundle_group = get_mid_bundle_group(sdp, session_media->mid);

 /* If this is actually part of a bundle group then the other side requested or accepted the bundle request */
 session_media->bundled = session_media->bundle_group != -1;

 return 0;
}

static void set_remote_mslabel_and_stream_group(struct ast_sip_session *session,
 struct ast_sip_session_media *session_media,
 const pjmedia_sdp_session *sdp,
 const struct pjmedia_sdp_media *stream,
 struct ast_stream *asterisk_stream)
{
 int index;

 ast_free(session_media->remote_mslabel);
 session_media->remote_mslabel = NULL;
 ast_free(session_media->remote_label);
 session_media->remote_label = NULL;

 for (index = 0; index < stream->attr_count; ++index) {
 pjmedia_sdp_attr *attr = stream->attr[index];
 char attr_value[pj_strlen(&attr->value) + 1];
 char *ssrc_attribute_name, *ssrc_attribute_value = NULL;
 char *msid, *tmp = attr_value;
 static const pj_str_t STR_msid = { "msid", 4 };
 static const pj_str_t STR_ssrc = { "ssrc", 4 };
 static const pj_str_t STR_label = { "label", 5 };

 if (!pj_strcmp(&attr->name, &STR_label)) {
 ast_copy_pj_str(attr_value, &attr->value, sizeof(attr_value));
 session_media->remote_label = ast_strdup(attr_value);
 } else if (!pj_strcmp(&attr->name, &STR_msid)) {
 ast_copy_pj_str(attr_value, &attr->value, sizeof(attr_value));
 msid = strsep(&tmp, " ");
 session_media->remote_mslabel = ast_strdup(msid);
 break;
 } else if (!pj_strcmp(&attr->name, &STR_ssrc)) {
 ast_copy_pj_str(attr_value, &attr->value, sizeof(attr_value));

 if ((ssrc_attribute_name = strchr(attr_value, ' '))) {
 /* This has an actual attribute */
 *ssrc_attribute_name++ = '\0';
 ssrc_attribute_value = strchr(ssrc_attribute_name, ':');
 if (ssrc_attribute_value) {
 /* Values are actually optional according to the spec */
 *ssrc_attribute_value++ = '\0';
 }

 if (!strcasecmp(ssrc_attribute_name, "mslabel") && !ast_strlen_zero(ssrc_attribute_value)) {
 session_media->remote_mslabel = ast_strdup(ssrc_attribute_value);
 break;
 }
 }
 }
 }

 if (ast_strlen_zero(session_media->remote_mslabel)) {
 return;
 }

 /* Iterate through the existing streams looking for a match and if so then group this with it */
 for (index = 0; index < AST_VECTOR_SIZE(&session->pending_media_state->sessions); ++index) {
 struct ast_sip_session_media *group_session_media;

 group_session_media = AST_VECTOR_GET(&session->pending_media_state->sessions, index);

 if (ast_strlen_zero(group_session_media->remote_mslabel) ||
 strcmp(group_session_media->remote_mslabel, session_media->remote_mslabel)) {
 continue;
 }

 ast_stream_set_group(asterisk_stream, index);
 break;
 }
}

static void remove_stream_from_bundle(struct ast_sip_session_media *session_media,
 struct ast_stream *stream)
{
 ast_stream_set_state(stream, AST_STREAM_STATE_REMOVED);
 ast_free(session_media->mid);
 session_media->mid = NULL;
 session_media->bundle_group = -1;
 session_media->bundled = 0;
}

static int handle_incoming_sdp(struct ast_sip_session *session, const pjmedia_sdp_session *sdp)
{
 int i;
 int handled = 0;
 int type_streams[AST_MEDIA_TYPE_END] = {0};
 SCOPE_ENTER(3, "%s: Media count: %d\n", ast_sip_session_get_name(session), sdp->media_count);

 if (session->inv_session && session->inv_session->state == PJSIP_INV_STATE_DISCONNECTED) {
 SCOPE_EXIT_LOG_RTN_VALUE(-1, LOG_ERROR, "%s: Failed to handle incoming SDP. Session has been already disconnected\n",
 ast_sip_session_get_name(session));
 }

 /* It is possible for SDP deferral to have already created a pending topology */
 if (!session->pending_media_state->topology) {
 session->pending_media_state->topology = ast_stream_topology_alloc();
 if (!session->pending_media_state->topology) {
 SCOPE_EXIT_LOG_RTN_VALUE(-1, LOG_ERROR, "%s: Couldn't alloc pending topology\n",
 ast_sip_session_get_name(session));
 }
 }

 for (i = 0; i < sdp->media_count; ++i) {
 /* See if there are registered handlers for this media stream type */
 char media[20];
 struct ast_sip_session_sdp_handler *handler;
 RAII_VAR(struct sdp_handler_list *, handler_list, NULL, ao2_cleanup);
 struct ast_sip_session_media *session_media = NULL;
 int res;
 enum ast_media_type type;
 struct ast_stream *stream = NULL;
 pjmedia_sdp_media *remote_stream = sdp->media[i];
 SCOPE_ENTER(4, "%s: Processing stream %d\n", ast_sip_session_get_name(session), i);

 /* We need a null-terminated version of the media string */
 ast_copy_pj_str(media, &sdp->media[i]->desc.media, sizeof(media));
 type = ast_media_type_from_str(media);

 /* See if we have an already existing stream, which can occur from SDP deferral checking */
 if (i < ast_stream_topology_get_count(session->pending_media_state->topology)) {
 stream = ast_stream_topology_get_stream(session->pending_media_state->topology, i);
 ast_trace(-1, "%s: Using existing pending stream %s\n", ast_sip_session_get_name(session),
 ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));
 }
 if (!stream) {
 struct ast_stream *existing_stream = NULL;
 char *stream_name = NULL, *stream_name_allocated = NULL;
 const char *stream_label = NULL;

 if (session->active_media_state->topology &&
 (i < ast_stream_topology_get_count(session->active_media_state->topology))) {
 existing_stream = ast_stream_topology_get_stream(session->active_media_state->topology, i);
 ast_trace(-1, "%s: Found existing active stream %s\n", ast_sip_session_get_name(session),
 ast_str_tmp(128, ast_stream_to_str(existing_stream, &STR_TMP)));

 if (ast_stream_get_state(existing_stream) != AST_STREAM_STATE_REMOVED) {
 stream_name = (char *)ast_stream_get_name(existing_stream);
 stream_label = ast_stream_get_metadata(existing_stream, "SDP:LABEL");
 }
 }

 if (ast_strlen_zero(stream_name)) {
 if (ast_asprintf(&stream_name_allocated, "%s-%d", ast_codec_media_type2str(type), i) < 0) {
 handled = 0;
 SCOPE_EXIT_LOG_EXPR(goto end, LOG_ERROR, "%s: Couldn't alloc stream name\n",
 ast_sip_session_get_name(session));

 }
 stream_name = stream_name_allocated;
 ast_trace(-1, "%s: Using %s for new stream name\n", ast_sip_session_get_name(session),
 stream_name);
 }

 stream = ast_stream_alloc(stream_name, type);
 ast_free(stream_name_allocated);
 if (!stream) {
 handled = 0;
 SCOPE_EXIT_LOG_EXPR(goto end, LOG_ERROR, "%s: Couldn't alloc stream\n",
 ast_sip_session_get_name(session));
 }

 if (!ast_strlen_zero(stream_label)) {
 ast_stream_set_metadata(stream, "SDP:LABEL", stream_label);
 ast_trace(-1, "%s: Using %s for new stream label\n", ast_sip_session_get_name(session),
 stream_label);

 }

 if (ast_stream_topology_set_stream(session->pending_media_state->topology, i, stream)) {
 ast_stream_free(stream);
 handled = 0;
 SCOPE_EXIT_LOG_EXPR(goto end, LOG_ERROR, "%s: Couldn't set stream in topology\n",
 ast_sip_session_get_name(session));
 }

 /* For backwards compatibility with the core the default audio stream is always sendrecv */
 if (!ast_sip_session_is_pending_stream_default(session, stream) || strcmp(media, "audio")) {
 if (pjmedia_sdp_media_find_attr2(remote_stream, "sendonly", NULL)) {
 /* Stream state reflects our state of a stream, so in the case of
 * sendonly and recvonly we store the opposite since that is what ours
 * is.
 */
 ast_stream_set_state(stream, AST_STREAM_STATE_RECVONLY);
 } else if (pjmedia_sdp_media_find_attr2(remote_stream, "recvonly", NULL)) {
 ast_stream_set_state(stream, AST_STREAM_STATE_SENDONLY);
 } else if (pjmedia_sdp_media_find_attr2(remote_stream, "inactive", NULL)) {
 ast_stream_set_state(stream, AST_STREAM_STATE_INACTIVE);
 } else {
 ast_stream_set_state(stream, AST_STREAM_STATE_SENDRECV);
 }
 } else {
 ast_stream_set_state(stream, AST_STREAM_STATE_SENDRECV);
 }
 ast_trace(-1, "%s: Using new stream %s\n", ast_sip_session_get_name(session),
 ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));
 }

 session_media = ast_sip_session_media_state_add(session, session->pending_media_state, ast_media_type_from_str(media), i);
 if (!session_media) {
 SCOPE_EXIT_LOG_EXPR(goto end, LOG_ERROR, "%s: Couldn't alloc session media\n",
 ast_sip_session_get_name(session));
 }

 /* If this stream is already declined mark it as such, or mark it as such if we've reached the limit */
 if (!remote_stream->desc.port || is_stream_limitation_reached(type, session->endpoint, type_streams)) {
 remove_stream_from_bundle(session_media, stream);
 SCOPE_EXIT_EXPR(continue, "%s: Declining incoming SDP media stream %s'\n",
 ast_sip_session_get_name(session), ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));
 }

 set_mid_and_bundle_group(session, session_media, sdp, remote_stream);
 set_remote_mslabel_and_stream_group(session, session_media, sdp, remote_stream, stream);

 if (session_media->handler) {
 handler = session_media->handler;
 ast_trace(-1, "%s: Negotiating incoming SDP media stream %s using %s SDP handler\n",
 ast_sip_session_get_name(session), ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)),
 session_media->handler->id);
 res = handler->negotiate_incoming_sdp_stream(session, session_media, sdp, i, stream);
 if (res < 0) {
 /* Catastrophic failure. Abort! */
 SCOPE_EXIT_LOG_EXPR(goto end, LOG_ERROR, "%s: Couldn't negotiate stream %s\n",
 ast_sip_session_get_name(session), ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));
 } else if (res == 0) {
 remove_stream_from_bundle(session_media, stream);
 SCOPE_EXIT_EXPR(continue, "%s: Declining incoming SDP media stream %s\n",
 ast_sip_session_get_name(session), ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));
 } else if (res > 0) {
 handled = 1;
 ++type_streams[type];
 /* Handled by this handler. Move to the next stream */
 SCOPE_EXIT_EXPR(continue, "%s: Media stream %s handled by %s\n",
 ast_sip_session_get_name(session), ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)),
 session_media->handler->id);
 }
 }

 handler_list = ao2_find(sdp_handlers, media, OBJ_KEY);
 if (!handler_list) {
 SCOPE_EXIT_EXPR(continue, "%s: Media stream %s has no registered handlers\n",
 ast_sip_session_get_name(session), ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));
 }
 AST_LIST_TRAVERSE(&handler_list->list, handler, next) {
 if (handler == session_media->handler) {
 continue;
 }
 ast_trace(-1, "%s: Negotiating incoming SDP media stream %s using %s SDP handler\n",
 ast_sip_session_get_name(session), ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)),
 handler->id);

 res = handler->negotiate_incoming_sdp_stream(session, session_media, sdp, i, stream);
 if (res < 0) {
 /* Catastrophic failure. Abort! */
 handled = 0;
 SCOPE_EXIT_LOG_EXPR(goto end, LOG_ERROR, "%s: Couldn't negotiate stream %s\n",
 ast_sip_session_get_name(session), ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));
 } else if (res == 0) {
 remove_stream_from_bundle(session_media, stream);
 ast_trace(-1, "%s: Declining incoming SDP media stream %s\n",
 ast_sip_session_get_name(session), ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));
 continue;
 } else if (res > 0) {
 session_media_set_handler(session_media, handler);
 handled = 1;
 ++type_streams[type];
 ast_trace(-1, "%s: Media stream %s handled by %s\n",
 ast_sip_session_get_name(session), ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)),
 session_media->handler->id);
 break;
 }
 }

 SCOPE_EXIT("%s: Done with stream %s\n", ast_sip_session_get_name(session),
 ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));
 }

end:
 SCOPE_EXIT_RTN_VALUE(handled ? 0 : -1, "%s: Handled? %s\n", ast_sip_session_get_name(session),
 handled ? "yes" : "no");
}

static int handle_negotiated_sdp_session_media(struct ast_sip_session_media *session_media,
 struct ast_sip_session *session, const pjmedia_sdp_session *local,
 const pjmedia_sdp_session *remote, int index, struct ast_stream *asterisk_stream)
{
 /* See if there are registered handlers for this media stream type */
 struct pjmedia_sdp_media *local_stream = local->media[index];
 char media[20];
 struct ast_sip_session_sdp_handler *handler;
 RAII_VAR(struct sdp_handler_list *, handler_list, NULL, ao2_cleanup);
 int res;
 SCOPE_ENTER(1, "%s\n", session ? ast_sip_session_get_name(session) : "unknown");

 /* We need a null-terminated version of the media string */
 ast_copy_pj_str(media, &local->media[index]->desc.media, sizeof(media));

 /* For backwards compatibility we only reflect the stream state correctly on
 * the non-default streams and any non-audio streams. This is because the stream
 * state of the default audio stream is also used for signaling that someone has
 * placed us on hold. This situation is not handled currently and can result in
 * the remote side being sorted of placed on hold too.
 */
 if (!ast_sip_session_is_pending_stream_default(session, asterisk_stream) || strcmp(media, "audio")) {
 /* Determine the state of the stream based on our local SDP */
 if (pjmedia_sdp_media_find_attr2(local_stream, "sendonly", NULL)) {
 ast_stream_set_state(asterisk_stream, AST_STREAM_STATE_SENDONLY);
 } else if (pjmedia_sdp_media_find_attr2(local_stream, "recvonly", NULL)) {
 ast_stream_set_state(asterisk_stream, AST_STREAM_STATE_RECVONLY);
 } else if (pjmedia_sdp_media_find_attr2(local_stream, "inactive", NULL)) {
 ast_stream_set_state(asterisk_stream, AST_STREAM_STATE_INACTIVE);
 } else {
 ast_stream_set_state(asterisk_stream, AST_STREAM_STATE_SENDRECV);
 }
 } else {
 ast_stream_set_state(asterisk_stream, AST_STREAM_STATE_SENDRECV);
 }

 set_mid_and_bundle_group(session, session_media, remote, remote->media[index]);
 set_remote_mslabel_and_stream_group(session, session_media, remote, remote->media[index], asterisk_stream);

 handler = session_media->handler;
 if (handler) {
 ast_debug(4, "%s: Applying negotiated SDP media stream '%s' using %s SDP handler\n",
 ast_sip_session_get_name(session), ast_codec_media_type2str(session_media->type),
 handler->id);
 res = handler->apply_negotiated_sdp_stream(session, session_media, local, remote, index, asterisk_stream);
 if (res >= 0) {
 ast_debug(4, "%s: Applied negotiated SDP media stream '%s' using %s SDP handler\n",
 ast_sip_session_get_name(session), ast_codec_media_type2str(session_media->type),
 handler->id);
 SCOPE_EXIT_RTN_VALUE(0, "%s: Applied negotiated SDP media stream '%s' using %s SDP handler\n",
 ast_sip_session_get_name(session), ast_codec_media_type2str(session_media->type),
 handler->id);
 }
 SCOPE_EXIT_RTN_VALUE(-1, "%s: Failed to apply negotiated SDP media stream '%s' using %s SDP handler\n",
 ast_sip_session_get_name(session), ast_codec_media_type2str(session_media->type),
 handler->id);
 }

 handler_list = ao2_find(sdp_handlers, media, OBJ_KEY);
 if (!handler_list) {
 ast_debug(4, "%s: No registered SDP handlers for media type '%s'\n", ast_sip_session_get_name(session), media);
 return -1;
 }
 AST_LIST_TRAVERSE(&handler_list->list, handler, next) {
 if (handler == session_media->handler) {
 continue;
 }
 ast_debug(4, "%s: Applying negotiated SDP media stream '%s' using %s SDP handler\n",
 ast_sip_session_get_name(session), ast_codec_media_type2str(session_media->type),
 handler->id);
 res = handler->apply_negotiated_sdp_stream(session, session_media, local, remote, index, asterisk_stream);
 if (res < 0) {
 /* Catastrophic failure. Abort! */
 SCOPE_EXIT_RTN_VALUE(-1, "%s: Handler '%s' returned %d\n",
 ast_sip_session_get_name(session), handler->id, res);
 }
 if (res > 0) {
 ast_debug(4, "%s: Applied negotiated SDP media stream '%s' using %s SDP handler\n",
 ast_sip_session_get_name(session), ast_codec_media_type2str(session_media->type),
 handler->id);
 /* Handled by this handler. Move to the next stream */
 session_media_set_handler(session_media, handler);
 SCOPE_EXIT_RTN_VALUE(0, "%s: Handler '%s' handled this sdp stream\n",
 ast_sip_session_get_name(session), handler->id);
 }
 }

 res = 0;
 if (session_media->handler && session_media->handler->stream_stop) {
 ast_debug(4, "%s: Stopping SDP media stream '%s' as it is not currently negotiated\n",
 ast_sip_session_get_name(session), ast_codec_media_type2str(session_media->type));
 session_media->handler->stream_stop(session_media);
 }

 SCOPE_EXIT_RTN_VALUE(0, "%s: Media type '%s' %s\n",
 ast_sip_session_get_name(session), ast_codec_media_type2str(session_media->type),
 res ? "not negotiated. Stopped" : "handled");
}

static int handle_negotiated_sdp(struct ast_sip_session *session, const pjmedia_sdp_session *local, const pjmedia_sdp_session *remote)
{
 int i;
 struct ast_stream_topology *topology;
 unsigned int changed = 0; /* 0 = unchanged, 1 = new source, 2 = new topology */
 SCOPE_ENTER(1, "%s\n", ast_sip_session_get_name(session));

 if (!session->pending_media_state->topology) {
 if (session->active_media_state->topology) {
 /*
 * This happens when we have negotiated media after receiving a 183,
 * and we're now receiving a 200 with a new SDP. In this case, there
 * is active_media_state, but the pending_media_state has been reset.
 */
 struct ast_sip_session_media_state *active_media_state_clone;

 active_media_state_clone =
 ast_sip_session_media_state_clone(session->active_media_state);
 if (!active_media_state_clone) {
 ast_log(LOG_WARNING, "%s: Unable to clone active media state\n",
 ast_sip_session_get_name(session));
 return -1;
 }

 ast_sip_session_media_state_free(session->pending_media_state);
 session->pending_media_state = active_media_state_clone;
 } else {
 ast_log(LOG_WARNING, "%s: No pending or active media state\n",
 ast_sip_session_get_name(session));
 return -1;
 }
 }

 /* If we're handling negotiated streams, then we should already have set
 * up session media instances (and Asterisk streams) that correspond to
 * the local SDP, and there should be the same number of session medias
 * and streams as there are local SDP streams
 */
 if (ast_stream_topology_get_count(session->pending_media_state->topology) != local->media_count
 || AST_VECTOR_SIZE(&session->pending_media_state->sessions) != local->media_count) {
 ast_log(LOG_WARNING, "%s: Local SDP contains %d media streams while we expected it to contain %u\n",
 ast_sip_session_get_name(session),
 ast_stream_topology_get_count(session->pending_media_state->topology), local->media_count);
 SCOPE_EXIT_RTN_VALUE(-1, "Media stream count mismatch\n");
 }

 for (i = 0; i < local->media_count; ++i) {
 struct ast_sip_session_media *session_media;
 struct ast_stream *stream;

 if (!remote->media[i]) {
 continue;
 }

 session_media = AST_VECTOR_GET(&session->pending_media_state->sessions, i);
 stream = ast_stream_topology_get_stream(session->pending_media_state->topology, i);

 /* Make sure that this stream is in the correct state. If we need to change
 * the state to REMOVED, then our work here is done, so go ahead and move on
 * to the next stream.
 */
 if (!remote->media[i]->desc.port) {
 ast_stream_set_state(stream, AST_STREAM_STATE_REMOVED);
 continue;
 }

 /* If the stream state is REMOVED, nothing needs to be done, so move on to the
 * next stream. This can occur if an internal thing has requested it to be
 * removed, or if we remove it as a result of the stream limit being reached.
 */
 if (ast_stream_get_state(stream) == AST_STREAM_STATE_REMOVED) {
 /*
 * Defer removing the handler until we are ready to activate
 * the new topology. The channel's thread may still be using
 * the stream and we could crash before we are ready.
 */
 continue;
 }

 if (handle_negotiated_sdp_session_media(session_media, session, local, remote, i, stream)) {
 SCOPE_EXIT_RTN_VALUE(-1, "Unable to handle negotiated session media\n");
 }

 changed |= session_media->changed;
 session_media->changed = 0;
 }

 /* Apply the pending media state to the channel and make it active */
 ast_channel_lock(session->channel);

 /* Now update the stream handler for any declined/removed streams */
 for (i = 0; i < local->media_count; ++i) {
 struct ast_sip_session_media *session_media;
 struct ast_stream *stream;

 if (!remote->media[i]) {
 continue;
 }

 session_media = AST_VECTOR_GET(&session->pending_media_state->sessions, i);
 stream = ast_stream_topology_get_stream(session->pending_media_state->topology, i);

 if (ast_stream_get_state(stream) == AST_STREAM_STATE_REMOVED
 && session_media->handler) {
 /*
 * This stream is no longer being used and the channel's thread
 * is held off because we have the channel lock so release any
 * resources the handler may have on it.
 */
 session_media_set_handler(session_media, NULL);
 }
 }

 /* Update the topology on the channel to match the accepted one */
 topology = ast_stream_topology_clone(session->pending_media_state->topology);
 if (topology) {
 ast_channel_set_stream_topology(session->channel, topology);
 /* If this is a remotely done renegotiation that has changed the stream topology notify what is
 * currently handling this channel. Note that fax uses its own process, so if we are transitioning
 * between audio and fax or vice versa we don't notify.
 */
 if (pjmedia_sdp_neg_was_answer_remote(session->inv_session->neg) == PJ_FALSE &&
 session->active_media_state && session->active_media_state->topology &&
 !ast_stream_topology_equal(session->active_media_state->topology, topology) &&
 !session->active_media_state->default_session[AST_MEDIA_TYPE_IMAGE] &&
 !session->pending_media_state->default_session[AST_MEDIA_TYPE_IMAGE]) {
 changed = 2;
 }
 }

 /* Remove all current file descriptors from the channel */
 for (i = 0; i < AST_VECTOR_SIZE(&session->active_media_state->read_callbacks); ++i) {
 ast_channel_internal_fd_clear(session->channel, i + AST_EXTENDED_FDS);
 }

 /* Add all the file descriptors from the pending media state */
 for (i = 0; i < AST_VECTOR_SIZE(&session->pending_media_state->read_callbacks); ++i) {
 struct ast_sip_session_media_read_callback_state *callback_state;

 callback_state = AST_VECTOR_GET_ADDR(&session->pending_media_state->read_callbacks, i);
 ast_channel_internal_fd_set(session->channel, i + AST_EXTENDED_FDS, callback_state->fd);
 }

 /* Active and pending flip flop as needed */
 ast_sip_session_media_stats_save(session, session->active_media_state);
 SWAP(session->active_media_state, session->pending_media_state);
 ast_sip_session_media_state_reset(session->pending_media_state);

 ast_channel_unlock(session->channel);

 if (changed == 1) {
 struct ast_frame f = { AST_FRAME_CONTROL, .subclass.integer = AST_CONTROL_STREAM_TOPOLOGY_SOURCE_CHANGED };

 ast_queue_frame(session->channel, &f);
 } else if (changed == 2) {
 ast_channel_stream_topology_changed_externally(session->channel);
 } else {
 ast_queue_frame(session->channel, &ast_null_frame);
 }

 SCOPE_EXIT_RTN_VALUE(0);
}

#define DATASTORE_BUCKETS 53
#define MEDIA_BUCKETS 7

static void session_datastore_destroy(void *obj)
{
 struct ast_datastore *datastore = obj;

 /* Using the destroy function (if present) destroy the data */
 if (datastore->info->destroy != NULL && datastore->data != NULL) {
 datastore->info->destroy(datastore->data);
 datastore->data = NULL;
 }

 ast_free((void *) datastore->uid);
 datastore->uid = NULL;
}

struct ast_datastore *ast_sip_session_alloc_datastore(const struct ast_datastore_info *info, const char *uid)
{
 RAII_VAR(struct ast_datastore *, datastore, NULL, ao2_cleanup);
 char uuid_buf[AST_UUID_STR_LEN];
 const char *uid_ptr = uid;

 if (!info) {
 return NULL;
 }

 datastore = ao2_alloc(sizeof(*datastore), session_datastore_destroy);
 if (!datastore) {
 return NULL;
 }

 datastore->info = info;
 if (ast_strlen_zero(uid)) {
 /* They didn't provide an ID so we'll provide one ourself */
 uid_ptr = ast_uuid_generate_str(uuid_buf, sizeof(uuid_buf));
 }

 datastore->uid = ast_strdup(uid_ptr);
 if (!datastore->uid) {
 return NULL;
 }

 ao2_ref(datastore, +1);
 return datastore;
}

int ast_sip_session_add_datastore(struct ast_sip_session *session, struct ast_datastore *datastore)
{
 ast_assert(datastore != NULL);
 ast_assert(datastore->info != NULL);
 ast_assert(ast_strlen_zero(datastore->uid) == 0);

 if (!ao2_link(session->datastores, datastore)) {
 return -1;
 }
 return 0;
}

struct ast_datastore *ast_sip_session_get_datastore(struct ast_sip_session *session, const char *name)
{
 return ao2_find(session->datastores, name, OBJ_KEY);
}

void ast_sip_session_remove_datastore(struct ast_sip_session *session, const char *name)
{
 ao2_callback(session->datastores, OBJ_KEY | OBJ_UNLINK | OBJ_NODATA, NULL, (void *) name);
}

enum delayed_method {
 DELAYED_METHOD_INVITE,
 DELAYED_METHOD_UPDATE,
 DELAYED_METHOD_BYE,
};

/*!
 * \internal
 * \brief Convert delayed method enum value to a string.
 * \since 13.3.0
 *
 * \param method Delayed method enum value to convert to a string.
 *
 * \return String value of delayed method.
 */
static const char *delayed_method2str(enum delayed_method method)
{
 const char *str = "<unknown>";

 switch (method) {
 case DELAYED_METHOD_INVITE:
 str = "INVITE";
 break;
 case DELAYED_METHOD_UPDATE:
 str = "UPDATE";
 break;
 case DELAYED_METHOD_BYE:
 str = "BYE";
 break;
 }

 return str;
}

/*!
 * \brief Structure used for sending delayed requests
 *
 * Requests are typically delayed because the current transaction
 * state of an INVITE. Once the pending INVITE transaction terminates,
 * the delayed request will be sent
 */
struct ast_sip_session_delayed_request {
 /*! Method of the request */
 enum delayed_method method;
 /*! Callback to call when the delayed request is created. */
 ast_sip_session_request_creation_cb on_request_creation;
 /*! Callback to call when the delayed request SDP is created */
 ast_sip_session_sdp_creation_cb on_sdp_creation;
 /*! Callback to call when the delayed request receives a response */
 ast_sip_session_response_cb on_response;
 /*! Whether to generate new SDP */
 int generate_new_sdp;
 /*! Requested media state for the SDP */
 struct ast_sip_session_media_state *pending_media_state;
 /*! Active media state at the time of the original request */
 struct ast_sip_session_media_state *active_media_state;

 AST_LIST_ENTRY(ast_sip_session_delayed_request) next;
};

static struct ast_sip_session_delayed_request *delayed_request_alloc(
 enum delayed_method method,
 ast_sip_session_request_creation_cb on_request_creation,
 ast_sip_session_sdp_creation_cb on_sdp_creation,
 ast_sip_session_response_cb on_response,
 int generate_new_sdp,
 struct ast_sip_session_media_state *pending_media_state,
 struct ast_sip_session_media_state *active_media_state)
{
 struct ast_sip_session_delayed_request *delay = ast_calloc(1, sizeof(*delay));

 if (!delay) {
 return NULL;
 }
 delay->method = method;
 delay->on_request_creation = on_request_creation;
 delay->on_sdp_creation = on_sdp_creation;
 delay->on_response = on_response;
 delay->generate_new_sdp = generate_new_sdp;
 delay->pending_media_state = pending_media_state;
 delay->active_media_state = active_media_state;
 return delay;
}

static void delayed_request_free(struct ast_sip_session_delayed_request *delay)
{
 ast_sip_session_media_state_free(delay->pending_media_state);
 ast_sip_session_media_state_free(delay->active_media_state);
 ast_free(delay);
}

/*!
 * \internal
 * \brief Send a delayed request
 *
 * \retval -1 failure
 * \retval 0 success
 * \retval 1 refresh request not sent as no change would occur
 */
static int send_delayed_request(struct ast_sip_session *session, struct ast_sip_session_delayed_request *delay)
{
 int res;
 SCOPE_ENTER(3, "%s: sending delayed %s request\n",
 ast_sip_session_get_name(session),
 delayed_method2str(delay->method));

 switch (delay->method) {
 case DELAYED_METHOD_INVITE:
 res = sip_session_refresh(session, delay->on_request_creation,
 delay->on_sdp_creation, delay->on_response,
 AST_SIP_SESSION_REFRESH_METHOD_INVITE, delay->generate_new_sdp, delay->pending_media_state,
 delay->active_media_state, 1);
 /* Ownership of media state transitions to ast_sip_session_refresh */
 delay->pending_media_state = NULL;
 delay->active_media_state = NULL;
 SCOPE_EXIT_RTN_VALUE(res, "%s\n", ast_sip_session_get_name(session));
 case DELAYED_METHOD_UPDATE:
 res = sip_session_refresh(session, delay->on_request_creation,
 delay->on_sdp_creation, delay->on_response,
 AST_SIP_SESSION_REFRESH_METHOD_UPDATE, delay->generate_new_sdp, delay->pending_media_state,
 delay->active_media_state, 1);
 /* Ownership of media state transitions to ast_sip_session_refresh */
 delay->pending_media_state = NULL;
 delay->active_media_state = NULL;
 SCOPE_EXIT_RTN_VALUE(res, "%s\n", ast_sip_session_get_name(session));
 case DELAYED_METHOD_BYE:
 ast_sip_session_terminate(session, 0);
 SCOPE_EXIT_RTN_VALUE(0, "%s: Terminating session on delayed BYE\n", ast_sip_session_get_name(session));
 }

 SCOPE_EXIT_LOG_RTN_VALUE(-1, LOG_WARNING, "%s: Don't know how to send delayed %s(%d) request.\n",
 ast_sip_session_get_name(session),
 delayed_method2str(delay->method), delay->method);
}

/*!
 * \internal
 * \brief The current INVITE transaction is in the PROCEEDING state.
 * \since 13.3.0
 *
 * \param vsession Session object.
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
static int invite_proceeding(void *vsession)
{
 struct ast_sip_session *session = vsession;
 struct ast_sip_session_delayed_request *delay;
 int found = 0;
 int res = 0;
 SCOPE_ENTER(3, "%s\n", ast_sip_session_get_name(session));

 AST_LIST_TRAVERSE_SAFE_BEGIN(&session->delayed_requests, delay, next) {
 switch (delay->method) {
 case DELAYED_METHOD_INVITE:
 break;
 case DELAYED_METHOD_UPDATE:
 AST_LIST_REMOVE_CURRENT(next);
 ast_trace(-1, "%s: Sending delayed %s request\n", ast_sip_session_get_name(session),
 delayed_method2str(delay->method));
 res = send_delayed_request(session, delay);
 delayed_request_free(delay);
 if (!res) {
 found = 1;
 }
 break;
 case DELAYED_METHOD_BYE:
 /* A BYE is pending so don't bother anymore. */
 found = 1;
 break;
 }
 if (found) {
 break;
 }
 }
 AST_LIST_TRAVERSE_SAFE_END;

 ao2_ref(session, -1);
 SCOPE_EXIT_RTN_VALUE(res, "%s\n", ast_sip_session_get_name(session));
}

/*!
 * \internal
 * \brief The current INVITE transaction is in the TERMINATED state.
 * \since 13.3.0
 *
 * \param vsession Session object.
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
static int invite_terminated(void *vsession)
{
 struct ast_sip_session *session = vsession;
 struct ast_sip_session_delayed_request *delay;
 int found = 0;
 int res = 0;
 int timer_running;
 SCOPE_ENTER(3, "%s\n", ast_sip_session_get_name(session));

 /* re-INVITE collision timer running? */
 timer_running = pj_timer_entry_running(&session->rescheduled_reinvite);

 AST_LIST_TRAVERSE_SAFE_BEGIN(&session->delayed_requests, delay, next) {
 switch (delay->method) {
 case DELAYED_METHOD_INVITE:
 if (!timer_running) {
 found = 1;
 }
 break;
 case DELAYED_METHOD_UPDATE:
 case DELAYED_METHOD_BYE:
 found = 1;
 break;
 }
 if (found) {
 AST_LIST_REMOVE_CURRENT(next);
 ast_trace(-1, "%s: Sending delayed %s request\n", ast_sip_session_get_name(session),
 delayed_method2str(delay->method));
 res = send_delayed_request(session, delay);
 delayed_request_free(delay);
 if (!res) {
 break;
 }
 }
 }
 AST_LIST_TRAVERSE_SAFE_END;

 ao2_ref(session, -1);
 SCOPE_EXIT_RTN_VALUE(res, "%s\n", ast_sip_session_get_name(session));
}

/*!
 * \internal
 * \brief INVITE collision timeout.
 * \since 13.3.0
 *
 * \param vsession Session object.
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
static int invite_collision_timeout(void *vsession)
{
 struct ast_sip_session *session = vsession;
 int res;
 SCOPE_ENTER(3, "%s\n", ast_sip_session_get_name(session));

 if (session->inv_session->invite_tsx) {
 /*
 * INVITE transaction still active. Let it send
 * the collision re-INVITE when it terminates.
 */
 ao2_ref(session, -1);
 res = 0;
 } else {
 res = invite_terminated(session);
 }

 SCOPE_EXIT_RTN_VALUE(res, "%s\n", ast_sip_session_get_name(session));
}

/*!
 * \internal
 * \brief The current UPDATE transaction is in the COMPLETED state.
 * \since 13.3.0
 *
 * \param vsession Session object.
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
static int update_completed(void *vsession)
{
 struct ast_sip_session *session = vsession;
 int res;

 if (session->inv_session->invite_tsx) {
 res = invite_proceeding(session);
 } else {
 res = invite_terminated(session);
 }

 return res;
}

static void check_delayed_requests(struct ast_sip_session *session,
 int (*cb)(void *vsession))
{
 ao2_ref(session, +1);
 if (ast_sip_push_task(session->serializer, cb, session)) {
 ao2_ref(session, -1);
 }
}

static int delay_request(struct ast_sip_session *session,
 ast_sip_session_request_creation_cb on_request,
 ast_sip_session_sdp_creation_cb on_sdp_creation,
 ast_sip_session_response_cb on_response,
 int generate_new_sdp,
 enum delayed_method method,
 struct ast_sip_session_media_state *pending_media_state,
 struct ast_sip_session_media_state *active_media_state,
 int queue_head)
{
 struct ast_sip_session_delayed_request *delay = delayed_request_alloc(method,
 on_request, on_sdp_creation, on_response, generate_new_sdp, pending_media_state,
 active_media_state);
 SCOPE_ENTER(3, "%s\n", ast_sip_session_get_name(session));

 if (!delay) {
 ast_sip_session_media_state_free(pending_media_state);
 ast_sip_session_media_state_free(active_media_state);
 SCOPE_EXIT_LOG_RTN_VALUE(-1, LOG_ERROR, "Unable to allocate delay request\n");
 }

 if (method == DELAYED_METHOD_BYE || queue_head) {
 /* Send BYE as early as possible */
 AST_LIST_INSERT_HEAD(&session->delayed_requests, delay, next);
 } else {
 AST_LIST_INSERT_TAIL(&session->delayed_requests, delay, next);
 }
 SCOPE_EXIT_RTN_VALUE(0);
}

static pjmedia_sdp_session *generate_session_refresh_sdp(struct ast_sip_session *session)
{
 pjsip_inv_session *inv_session = session->inv_session;
 const pjmedia_sdp_session *previous_sdp = NULL;
 SCOPE_ENTER(3, "%s\n", ast_sip_session_get_name(session));

 if (inv_session->neg) {
 if (pjmedia_sdp_neg_was_answer_remote(inv_session->neg)) {
 pjmedia_sdp_neg_get_active_remote(inv_session->neg, &previous_sdp);
 } else {
 pjmedia_sdp_neg_get_active_local(inv_session->neg, &previous_sdp);
 }
 }
 SCOPE_EXIT_RTN_VALUE(create_local_sdp(inv_session, session, previous_sdp));
}

static void set_from_header(struct ast_sip_session *session)
{
 struct ast_party_id effective_id;
 struct ast_party_id connected_id;
 pj_pool_t *dlg_pool;
 pjsip_fromto_hdr *dlg_info;
 pjsip_contact_hdr *dlg_contact;
 pjsip_name_addr *dlg_info_name_addr;
 pjsip_sip_uri *dlg_info_uri;
 pjsip_sip_uri *dlg_contact_uri;
 int restricted;
 const char *pjsip_from_domain;

 if (!session->channel || session->saved_from_hdr) {
 return;
 }

 /* We need to save off connected_id for RPID/PAI generation */
 ast_party_id_init(&connected_id);
 ast_channel_lock(session->channel);
 effective_id = ast_channel_connected_effective_id(session->channel);
 ast_party_id_copy(&connected_id, &effective_id);
 ast_channel_unlock(session->channel);

 restricted =
 ((ast_party_id_presentation(&connected_id) & AST_PRES_RESTRICTION) != AST_PRES_ALLOWED);

 /* Now set up dlg->local.info so pjsip can correctly generate From */

 dlg_pool = session->inv_session->dlg->pool;
 dlg_info = session->inv_session->dlg->local.info;
 dlg_contact = session->inv_session->dlg->local.contact;
 dlg_info_name_addr = (pjsip_name_addr *) dlg_info->uri;
 dlg_info_uri = pjsip_uri_get_uri(dlg_info_name_addr);
 dlg_contact_uri = (pjsip_sip_uri*)pjsip_uri_get_uri(dlg_contact->uri);

 if (session->endpoint->id.trust_outbound || !restricted) {
 ast_sip_modify_id_header(dlg_pool, dlg_info, &connected_id);
 if (ast_sip_get_use_callerid_contact() && ast_strlen_zero(session->endpoint->contact_user)) {
 pj_strdup2(dlg_pool, &dlg_contact_uri->user, S_COR(connected_id.number.valid, connected_id.number.str, ""));
 }
 }

 ast_party_id_free(&connected_id);

 if (!ast_strlen_zero(session->endpoint->fromuser)) {
 dlg_info_name_addr->display.ptr = NULL;
 dlg_info_name_addr->display.slen = 0;
 pj_strdup2(dlg_pool, &dlg_info_uri->user, session->endpoint->fromuser);
 }

 if (!ast_strlen_zero(session->endpoint->fromdomain)) {
 pj_strdup2(dlg_pool, &dlg_info_uri->host, session->endpoint->fromdomain);
 }

 /*
 * Channel variable for compatibility with chan_sip SIPFROMDOMAIN
 */
 ast_channel_lock(session->channel);
 pjsip_from_domain = pbx_builtin_getvar_helper(session->channel, "SIPFROMDOMAIN");
 if (!ast_strlen_zero(pjsip_from_domain)) {
 ast_debug(3, "%s: From header domain reset by channel variable SIPFROMDOMAIN (%s)\n",
 ast_sip_session_get_name(session), pjsip_from_domain);
 pj_strdup2(dlg_pool, &dlg_info_uri->host, pjsip_from_domain);
 }
 ast_channel_unlock(session->channel);

 /* We need to save off the non-anonymized From for RPID/PAI generation (for domain) */
 session->saved_from_hdr = pjsip_hdr_clone(dlg_pool, dlg_info);
 ast_sip_add_usereqphone(session->endpoint, dlg_pool, session->saved_from_hdr->uri);

 /* In chan_sip, fromuser and fromdomain trump restricted so we only
 * anonymize if they're not set.
 */
 if (restricted) {
 /* fromuser doesn't provide a display name so we always set it */
 pj_strdup2(dlg_pool, &dlg_info_name_addr->display, "Anonymous");

 if (ast_strlen_zero(session->endpoint->fromuser)) {
 pj_strdup2(dlg_pool, &dlg_info_uri->user, "anonymous");
 }

 if (ast_sip_get_use_callerid_contact() && ast_strlen_zero(session->endpoint->contact_user)) {
 pj_strdup2(dlg_pool, &dlg_contact_uri->user, "anonymous");
 }

 if (ast_strlen_zero(session->endpoint->fromdomain)) {
 pj_strdup2(dlg_pool, &dlg_info_uri->host, "anonymous.invalid");
 }
 } else {
 ast_sip_add_usereqphone(session->endpoint, dlg_pool, dlg_info->uri);
 }
}

/*
 * Helper macros for merging and validating media states
 */
#define STREAM_REMOVED(_stream) (ast_stream_get_state(_stream) == AST_STREAM_STATE_REMOVED)
#define STATE_REMOVED(_stream_state) (_stream_state == AST_STREAM_STATE_REMOVED)
#define STATE_NONE(_stream_state) (_stream_state == AST_STREAM_STATE_END)
#define GET_STREAM_SAFE(_topology, _i) (_i < ast_stream_topology_get_count(_topology) ? ast_stream_topology_get_stream(_topology, _i) : NULL)
#define GET_STREAM_STATE_SAFE(_stream) (_stream ? ast_stream_get_state(_stream) : AST_STREAM_STATE_END)
#define GET_STREAM_NAME_SAFE(_stream) (_stream ? ast_stream_get_name(_stream) : "")

/*!
 * \internal
 * \brief Validate a media state
 *
 * \param state Media state
 *
 * \retval 1 The media state is valid
 * \retval 0 The media state is NOT valid
 *
 */
static int is_media_state_valid(const char *session_name, struct ast_sip_session_media_state *state)
{
 int stream_count = ast_stream_topology_get_count(state->topology);
 int session_count = AST_VECTOR_SIZE(&state->sessions);
 int i;
 int res = 0;
 SCOPE_ENTER(3, "%s: Topology: %s\n", session_name,
 ast_str_tmp(256, ast_stream_topology_to_str(state->topology, &STR_TMP)));

 if (session_count != stream_count) {
 SCOPE_EXIT_RTN_VALUE(0, "%s: %d media sessions but %d streams\n", session_name,
 session_count, stream_count);
 }

 for (i = 0; i < stream_count; i++) {
 struct ast_sip_session_media *media = NULL;
 struct ast_stream *stream = ast_stream_topology_get_stream(state->topology, i);
 const char *stream_name = NULL;
 int j;
 SCOPE_ENTER(4, "%s: Checking stream %s\n", session_name, ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));

 if (!stream) {
 SCOPE_EXIT_EXPR(goto end, "%s: stream %d is null\n", session_name, i);
 }
 stream_name = ast_stream_get_name(stream);

 for (j = 0; j < stream_count; j++) {
 struct ast_stream *possible_dup = ast_stream_topology_get_stream(state->topology, j);
 if (j == i || !possible_dup) {
 continue;
 }
 if (!STREAM_REMOVED(stream) && ast_strings_equal(stream_name, GET_STREAM_NAME_SAFE(possible_dup))) {
 SCOPE_EXIT_EXPR(goto end, "%s: stream %i %s is duplicated to %d\n", session_name,
 i, stream_name, j);
 }
 }

 media = AST_VECTOR_GET(&state->sessions, i);
 if (!media) {
 SCOPE_EXIT_EXPR(continue, "%s: media %d is null\n", session_name, i);
 }

 for (j = 0; j < session_count; j++) {
 struct ast_sip_session_media *possible_dup = AST_VECTOR_GET(&state->sessions, j);
 if (j == i || !possible_dup) {
 continue;
 }
 if (!ast_strlen_zero(media->label) && !ast_strlen_zero(possible_dup->label)
 && ast_strings_equal(media->label, possible_dup->label)) {
 SCOPE_EXIT_EXPR(goto end, "%s: media %d %s is duplicated to %d\n", session_name,
 i, media->label, j);
 }
 }

 if (media->stream_num != i) {
 SCOPE_EXIT_EXPR(goto end, "%s: media %d has stream_num %d\n", session_name,
 i, media->stream_num);
 }

 if (media->type != ast_stream_get_type(stream)) {
 SCOPE_EXIT_EXPR(goto end, "%s: media %d has type %s but stream has type %s\n", stream_name,
 i, ast_codec_media_type2str(media->type), ast_codec_media_type2str(ast_stream_get_type(stream)));
 }
 SCOPE_EXIT("%s: Done with stream %s\n", session_name, ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));
 }

 res = 1;
end:
 SCOPE_EXIT_RTN_VALUE(res, "%s: %s\n", session_name, res ? "Valid" : "NOT Valid");
}

/*!
 * \internal
 * \brief Merge media states for a delayed session refresh
 *
 * \param session_name For log messages
 * \param delayed_pending_state The pending media state at the time the resuest was queued
 * \param delayed_active_state The active media state at the time the resuest was queued
 * \param current_active_state The current active media state
 * \param run_validation Whether to run validation on the resulting media state or not
 *
 * \returns New merged topology or NULL if there's an error
 *
 */
static struct ast_sip_session_media_state *resolve_refresh_media_states(
 const char *session_name,
 struct ast_sip_session_media_state *delayed_pending_state,
 struct ast_sip_session_media_state *delayed_active_state,
 struct ast_sip_session_media_state *current_active_state,
 int run_post_validation)
{
 RAII_VAR(struct ast_sip_session_media_state *, new_pending_state, NULL, ast_sip_session_media_state_free);
 struct ast_sip_session_media_state *returned_media_state = NULL;
 struct ast_stream_topology *delayed_pending = delayed_pending_state->topology;
 struct ast_stream_topology *delayed_active = delayed_active_state->topology;
 struct ast_stream_topology *current_active = current_active_state->topology;
 struct ast_stream_topology *new_pending = NULL;
 int i;
 int max_stream_count;
 int res;
 SCOPE_ENTER(2, "%s: DP: %s DA: %s CA: %s\n", session_name,
 ast_str_tmp(256, ast_stream_topology_to_str(delayed_pending, &STR_TMP)),
 ast_str_tmp(256, ast_stream_topology_to_str(delayed_active, &STR_TMP)),
 ast_str_tmp(256, ast_stream_topology_to_str(current_active, &STR_TMP))
 );

 max_stream_count = MAX(ast_stream_topology_get_count(delayed_pending),
 ast_stream_topology_get_count(delayed_active));
 max_stream_count = MAX(max_stream_count, ast_stream_topology_get_count(current_active));

 /*
 * The new_pending_state is always based on the currently negotiated state because
 * the stream ordering in its topology must be preserved.
 */
 new_pending_state = ast_sip_session_media_state_clone(current_active_state);
 if (!new_pending_state) {
 SCOPE_EXIT_LOG_RTN_VALUE(NULL, LOG_ERROR, "%s: Couldn't clone current_active_state to new_pending_state\n", session_name);
 }
 new_pending = new_pending_state->topology;

 for (i = 0; i < max_stream_count; i++) {
 struct ast_stream *dp_stream = GET_STREAM_SAFE(delayed_pending, i);
 struct ast_stream *da_stream = GET_STREAM_SAFE(delayed_active, i);
 struct ast_stream *ca_stream = GET_STREAM_SAFE(current_active, i);
 struct ast_stream *np_stream = GET_STREAM_SAFE(new_pending, i);
 struct ast_stream *found_da_stream = NULL;
 struct ast_stream *found_np_stream = NULL;
 enum ast_stream_state dp_state = GET_STREAM_STATE_SAFE(dp_stream);
 enum ast_stream_state da_state = GET_STREAM_STATE_SAFE(da_stream);
 enum ast_stream_state ca_state = GET_STREAM_STATE_SAFE(ca_stream);
 enum ast_stream_state np_state = GET_STREAM_STATE_SAFE(np_stream);
 enum ast_stream_state found_da_state = AST_STREAM_STATE_END;
 enum ast_stream_state found_np_state = AST_STREAM_STATE_END;
 const char *da_name = GET_STREAM_NAME_SAFE(da_stream);
 const char *dp_name = GET_STREAM_NAME_SAFE(dp_stream);
 const char *ca_name = GET_STREAM_NAME_SAFE(ca_stream);
 const char *np_name = GET_STREAM_NAME_SAFE(np_stream);
 const char *found_da_name __attribute__((unused)) = "";
 const char *found_np_name __attribute__((unused)) = "";
 int found_da_slot __attribute__((unused)) = -1;
 int found_np_slot = -1;
 int removed_np_slot = -1;
 int j;
 SCOPE_ENTER(3, "%s: slot: %d DP: %s DA: %s CA: %s\n", session_name, i,
 ast_str_tmp(128, ast_stream_to_str(dp_stream, &STR_TMP)),
 ast_str_tmp(128, ast_stream_to_str(da_stream, &STR_TMP)),
 ast_str_tmp(128, ast_stream_to_str(ca_stream, &STR_TMP)));

 if (STATE_NONE(da_state) && STATE_NONE(dp_state) && STATE_NONE(ca_state)) {
 SCOPE_EXIT_EXPR(break, "%s: All gone\n", session_name);
 }

 /*
 * Simple cases are handled first to avoid having to search the NP and DA
 * topologies for streams with the same name but not in the same position.
 */

 if (STATE_NONE(dp_state) && !STATE_NONE(da_state)) {
 /*
 * The slot in the delayed pending topology can't be empty if the delayed
 * active topology has a stream there. Streams can't just go away. They
 * can be reused or marked "removed" but they can't go away.
 */
 SCOPE_EXIT_LOG_RTN_VALUE(NULL, LOG_WARNING, "%s: DP slot is empty but DA is not\n", session_name);
 }

 if (STATE_NONE(dp_state)) {
 /*
 * The current active topology can certainly have streams that weren't
 * in existence when the delayed request was queued. In this case,
 * no action is needed since we already copied the current active topology
 * to the new pending one.
 */
 SCOPE_EXIT_EXPR(continue, "%s: No DP stream so use CA stream as is\n", session_name);
 }

 if (ast_strings_equal(dp_name, da_name) && ast_strings_equal(da_name, ca_name)) {
 /*
 * The delayed pending stream in this slot matches by name, the streams
 * in the same slot in the other two topologies. Easy case.
 */
 ast_trace(-1, "%s: Same stream in all 3 states\n", session_name);
 if (dp_state == da_state && da_state == ca_state) {
 /* All the same state, no need to update. */
 SCOPE_EXIT_EXPR(continue, "%s: All in the same state so nothing to do\n", session_name);
 }
 if (da_state != ca_state) {
 /*
 * Something set the CA state between the time this request was queued
 * and now. The CA state wins so we don't do anything.
 */
 SCOPE_EXIT_EXPR(continue, "%s: Ignoring request to change state from %s to %s\n",
 session_name, ast_stream_state2str(ca_state), ast_stream_state2str(dp_state));
 }
 if (dp_state != da_state) {
 /* DP needs to update the state */
 ast_stream_set_state(np_stream, dp_state);
 SCOPE_EXIT_EXPR(continue, "%s: Changed NP stream state from %s to %s\n",
 session_name, ast_stream_state2str(ca_state), ast_stream_state2str(dp_state));
 }
 }

 /*
 * We're done with the simple cases. For the rest, we need to identify if the
 * DP stream we're trying to take action on is already in the other topologies
 * possibly in a different slot. To do that, if the stream in the DA or CA slots
 * doesn't match the current DP stream, we need to iterate over the topology
 * looking for a stream with the same name.
 */

 /*
 * Since we already copied all of the CA streams to the NP topology, we'll use it
 * instead of CA because we'll be updating the NP as we go.
 */
 if (!ast_strings_equal(dp_name, np_name)) {
 /*
 * The NP stream in this slot doesn't have the same name as the DP stream
 * so we need to see if it's in another NP slot. We're not going to stop
 * when we find a matching stream because we also want to find the first
 * removed removed slot, if any, so we can re-use this slot. We'll break
 * early if we find both before we reach the end.
 */
 ast_trace(-1, "%s: Checking if DP is already in NP somewhere\n", session_name);
 for (j = 0; j < ast_stream_topology_get_count(new_pending); j++) {
 struct ast_stream *possible_existing = ast_stream_topology_get_stream(new_pending, j);
 const char *possible_existing_name = GET_STREAM_NAME_SAFE(possible_existing);

 ast_trace(-1, "%s: Checking %s against %s\n", session_name, dp_name, possible_existing_name);
 if (found_np_slot == -1 && ast_strings_equal(dp_name, possible_existing_name)) {
 ast_trace(-1, "%s: Pending stream %s slot %d is in NP slot %d\n", session_name,
 dp_name, i, j);
 found_np_slot = j;
 found_np_stream = possible_existing;
 found_np_state = ast_stream_get_state(possible_existing);
 found_np_name = ast_stream_get_name(possible_existing);
 }
 if (STREAM_REMOVED(possible_existing) && removed_np_slot == -1) {
 removed_np_slot = j;
 }
 if (removed_np_slot >= 0 && found_np_slot >= 0) {
 break;
 }
 }
 } else {
 /* Makes the subsequent code easier */
 found_np_slot = i;
 found_np_stream = np_stream;
 found_np_state = np_state;
 found_np_name = np_name;
 }

 if (!ast_strings_equal(dp_name, da_name)) {
 /*
 * The DA stream in this slot doesn't have the same name as the DP stream
 * so we need to see if it's in another DA slot. In real life, the DA stream
 * in this slot could have a different name but there shouldn't be a case
 * where the DP stream is another slot in the DA topology. Just in case though.
 * We don't care about removed slots in the DA topology.
 */
 ast_trace(-1, "%s: Checking if DP is already in DA somewhere\n", session_name);
 for (j = 0; j < ast_stream_topology_get_count(delayed_active); j++) {
 struct ast_stream *possible_existing = ast_stream_topology_get_stream(delayed_active, j);
 const char *possible_existing_name = GET_STREAM_NAME_SAFE(possible_existing);

 ast_trace(-1, "%s: Checking %s against %s\n", session_name, dp_name, possible_existing_name);
 if (ast_strings_equal(dp_name, possible_existing_name)) {
 ast_trace(-1, "%s: Pending stream %s slot %d is already in delayed active slot %d\n",
 session_name, dp_name, i, j);
 found_da_slot = j;
 found_da_stream = possible_existing;
 found_da_state = ast_stream_get_state(possible_existing);
 found_da_name = ast_stream_get_name(possible_existing);
 break;
 }
 }
 } else {
 /* Makes the subsequent code easier */
 found_da_slot = i;
 found_da_stream = da_stream;
 found_da_state = da_state;
 found_da_name = da_name;
 }

 ast_trace(-1, "%s: Found NP slot: %d Found removed NP slot: %d Found DA slot: %d\n",
 session_name, found_np_slot, removed_np_slot, found_da_slot);

 /*
 * Now we know whether the DP stream is new or changing state and we know if the DP
 * stream exists in the other topologies and if so, where in those topologies it exists.
 */

 if (!found_da_stream) {
 /*
 * The DP stream isn't in the DA topology which would imply that the intention of the
 * request was to add the stream, not change its state. It's possible though that
 * the stream was added by another request between the time this request was queued
 * and now so we need to check the CA topology as well.
 */
 ast_trace(-1, "%s: There was no corresponding DA stream so the request was to add a stream\n", session_name);

 if (found_np_stream) {
 /*
 * We found it in the CA topology. Since the intention was to add it
 * and it's already there, there's nothing to do.
 */
 SCOPE_EXIT_EXPR(continue, "%s: New stream requested but it's already in CA\n", session_name);
 } else {
 /* OK, it's not in either which would again imply that the intention of the
 * request was to add the stream.
 */
 ast_trace(-1, "%s: There was no corresponding NP stream\n", session_name);
 if (STATE_REMOVED(dp_state)) {
 /*
 * How can DP request to remove a stream that doesn't seem to exist anythere?
 * It's not. It's possible that the stream was already removed and the slot
 * reused in the CA topology, but it would still have to exist in the DA
 * topology. Bail.
 */
 SCOPE_EXIT_LOG_RTN_VALUE(NULL, LOG_ERROR,
 "%s: Attempting to remove stream %d:%s but it doesn't exist anywhere.\n", session_name, i, dp_name);
 } else {
 /*
 * We're now sure we want to add the the stream. Since we can re-use
 * slots in the CA topology that have streams marked as "removed", we
 * use the slot we saved in removed_np_slot if it exists.
 */
 ast_trace(-1, "%s: Checking for open slot\n", session_name);
 if (removed_np_slot >= 0) {
 struct ast_sip_session_media *old_media = AST_VECTOR_GET(&new_pending_state->sessions, removed_np_slot);
 res = ast_stream_topology_set_stream(new_pending, removed_np_slot, ast_stream_clone(dp_stream, NULL));
 if (res != 0) {
 SCOPE_EXIT_LOG_RTN_VALUE(NULL, LOG_WARNING, "%s: Couldn't set stream in new topology\n", session_name);
 }
 /*
 * Since we're reusing the removed_np_slot slot for something else, we need
 * to free and remove any session media already in it.
 * ast_stream_topology_set_stream() took care of freeing the old stream.
 */
 res = AST_VECTOR_REPLACE(&new_pending_state->sessions, removed_np_slot, NULL);
 if (res != 0) {
 SCOPE_EXIT_LOG_RTN_VALUE(NULL, LOG_WARNING, "%s: Couldn't replace media session\n", session_name);
 }

 ao2_cleanup(old_media);
 SCOPE_EXIT_EXPR(continue, "%s: Replaced removed stream in slot %d\n",
 session_name, removed_np_slot);
 } else {
 int new_slot = ast_stream_topology_append_stream(new_pending, ast_stream_clone(dp_stream, NULL));
 if (new_slot < 0) {
 SCOPE_EXIT_LOG_RTN_VALUE(NULL, LOG_WARNING, "%s: Couldn't append stream in new topology\n", session_name);
 }

 res = AST_VECTOR_REPLACE(&new_pending_state->sessions, new_slot, NULL);
 if (res != 0) {
 SCOPE_EXIT_LOG_RTN_VALUE(NULL, LOG_WARNING, "%s: Couldn't replace media session\n", session_name);
 }
 SCOPE_EXIT_EXPR(continue, "%s: Appended new stream to slot %d\n",
 session_name, new_slot);
 }
 }
 }
 } else {
 /*
 * The DP stream exists in the DA topology so it's a change of some sort.
 */
 ast_trace(-1, "%s: There was a corresponding DA stream so the request was to change/remove a stream\n", session_name);
 if (dp_state == found_da_state) {
 /* No change? Let's see if it's in CA */
 if (!found_np_stream) {
 /*
 * The DP and DA state are the same which would imply that the stream
 * already exists but it's not in the CA topology. It's possible that
 * between the time this request was queued and now the stream was removed
 * from the CA topology and the slot used for something else. Nothing
 * we can do here.
 */
 SCOPE_EXIT_EXPR(continue, "%s: Stream doesn't exist in CA so nothing to do\n", session_name);
 } else if (dp_state == found_np_state) {
 SCOPE_EXIT_EXPR(continue, "%s: States are the same all around so nothing to do\n", session_name);
 } else {
 SCOPE_EXIT_EXPR(continue, "%s: Something changed the CA state so we're going to leave it as is\n", session_name);
 }
 } else {
 /* We have a state change. */
 ast_trace(-1, "%s: Requesting state change to %s\n", session_name, ast_stream_state2str(dp_state));
 if (!found_np_stream) {
 SCOPE_EXIT_EXPR(continue, "%s: Stream doesn't exist in CA so nothing to do\n", session_name);
 } else if (da_state == found_np_state) {
 ast_stream_set_state(found_np_stream, dp_state);
 SCOPE_EXIT_EXPR(continue, "%s: Changed NP stream state from %s to %s\n",
 session_name, ast_stream_state2str(found_np_state), ast_stream_state2str(dp_state));
 } else {
 SCOPE_EXIT_EXPR(continue, "%s: Something changed the CA state so we're going to leave it as is\n",
 session_name);
 }
 }
 }

 SCOPE_EXIT("%s: Done with slot %d\n", session_name, i);
 }

 ast_trace(-1, "%s: Resetting default media states\n", session_name);
 for (i = 0; i < AST_MEDIA_TYPE_END; i++) {
 int j;
 new_pending_state->default_session[i] = NULL;
 for (j = 0; j < AST_VECTOR_SIZE(&new_pending_state->sessions); j++) {
 struct ast_sip_session_media *media = AST_VECTOR_GET(&new_pending_state->sessions, j);
 struct ast_stream *stream = ast_stream_topology_get_stream(new_pending_state->topology, j);

 if (media && media->type == i && !STREAM_REMOVED(stream)) {
 new_pending_state->default_session[i] = media;
 break;
 }
 }
 }

 if (run_post_validation) {
 ast_trace(-1, "%s: Running post-validation\n", session_name);
 if (!is_media_state_valid(session_name, new_pending_state)) {
 SCOPE_EXIT_LOG_RTN_VALUE(NULL, LOG_ERROR, "State not consistent\n");
 }
 }

 /*
 * We need to move the new pending state to another variable and set new_pending_state to NULL
 * so RAII_VAR doesn't free it.
 */
 returned_media_state = new_pending_state;
 new_pending_state = NULL;
 SCOPE_EXIT_RTN_VALUE(returned_media_state, "%s: NP: %s\n", session_name,
 ast_str_tmp(256, ast_stream_topology_to_str(new_pending, &STR_TMP)));
}

static int sip_session_refresh(struct ast_sip_session *session,
 ast_sip_session_request_creation_cb on_request_creation,
 ast_sip_session_sdp_creation_cb on_sdp_creation,
 ast_sip_session_response_cb on_response,
 enum ast_sip_session_refresh_method method, int generate_new_sdp,
 struct ast_sip_session_media_state *pending_media_state,
 struct ast_sip_session_media_state *active_media_state,
 int queued)
{
 pjsip_inv_session *inv_session = session->inv_session;
 pjmedia_sdp_session *new_sdp = NULL;
 pjsip_tx_data *tdata;
 int res = -1;
 SCOPE_ENTER(3, "%s: New SDP? %s Queued? %s DP: %s DA: %s\n", ast_sip_session_get_name(session),
 generate_new_sdp ? "yes" : "no", queued ? "yes" : "no",
 pending_media_state ? ast_str_tmp(256, ast_stream_topology_to_str(pending_media_state->topology, &STR_TMP)) : "none",
 active_media_state ? ast_str_tmp(256, ast_stream_topology_to_str(active_media_state->topology, &STR_TMP)) : "none");

 if (pending_media_state && (!pending_media_state->topology || !generate_new_sdp)) {

 ast_sip_session_media_state_free(pending_media_state);
 ast_sip_session_media_state_free(active_media_state);
 SCOPE_EXIT_RTN_VALUE(-1, "%s: Not sending reinvite because %s%s\n", ast_sip_session_get_name(session),
 pending_media_state->topology == NULL ? "pending topology is null " : "",
 !generate_new_sdp ? "generate_new_sdp is false" : "");
 }

 if (inv_session->state == PJSIP_INV_STATE_DISCONNECTED) {
 /* Don't try to do anything with a hung-up call */
 ast_sip_session_media_state_free(pending_media_state);
 ast_sip_session_media_state_free(active_media_state);
 SCOPE_EXIT_RTN_VALUE(0, "%s: Not sending reinvite because of disconnected state\n",
 ast_sip_session_get_name(session));
 }

 /* If the dialog has not yet been established we have to defer until it has */
 if (inv_session->dlg->state != PJSIP_DIALOG_STATE_ESTABLISHED) {
 res = delay_request(session, on_request_creation, on_sdp_creation, on_response,
 generate_new_sdp,
 method == AST_SIP_SESSION_REFRESH_METHOD_INVITE
 ? DELAYED_METHOD_INVITE : DELAYED_METHOD_UPDATE,
 pending_media_state, active_media_state ? active_media_state : ast_sip_session_media_state_clone(session->active_media_state), queued);
 SCOPE_EXIT_RTN_VALUE(res, "%s: Delay sending reinvite because dialog has not been established\n",
 ast_sip_session_get_name(session));
 }

 if (method == AST_SIP_SESSION_REFRESH_METHOD_INVITE) {
 if (inv_session->invite_tsx) {
 /* We can't send a reinvite yet, so delay it */
 res = delay_request(session, on_request_creation, on_sdp_creation,
 on_response, generate_new_sdp, DELAYED_METHOD_INVITE, pending_media_state,
 active_media_state ? active_media_state : ast_sip_session_media_state_clone(session->active_media_state), queued);
 SCOPE_EXIT_RTN_VALUE(res, "%s: Delay sending reinvite because of outstanding transaction\n",
 ast_sip_session_get_name(session));
 } else if (inv_session->state != PJSIP_INV_STATE_CONFIRMED) {
 /* Initial INVITE transaction failed to progress us to a confirmed state
 * which means re-invites are not possible
 */
 ast_sip_session_media_state_free(pending_media_state);
 ast_sip_session_media_state_free(active_media_state);
 SCOPE_EXIT_RTN_VALUE(0, "%s: Not sending reinvite because not in confirmed state\n",
 ast_sip_session_get_name(session));
 }
 }

 if (generate_new_sdp) {
 /* SDP can only be generated if current negotiation has already completed */
 if (inv_session->neg
 && pjmedia_sdp_neg_get_state(inv_session->neg)
 != PJMEDIA_SDP_NEG_STATE_DONE) {
 res = delay_request(session, on_request_creation, on_sdp_creation,
 on_response, generate_new_sdp,
 method == AST_SIP_SESSION_REFRESH_METHOD_INVITE
 ? DELAYED_METHOD_INVITE : DELAYED_METHOD_UPDATE, pending_media_state,
 active_media_state ? active_media_state : ast_sip_session_media_state_clone(session->active_media_state), queued);
 SCOPE_EXIT_RTN_VALUE(res, "%s: Delay session refresh with new SDP because SDP negotiation is not yet done\n",
 ast_sip_session_get_name(session));
 }

 /* If an explicitly requested media state has been provided use it instead of any pending one */
 if (pending_media_state) {
 int index;
 int type_streams[AST_MEDIA_TYPE_END] = {0};

 ast_trace(-1, "%s: Pending media state exists\n", ast_sip_session_get_name(session));

 /* Media state conveys a desired media state, so if there are outstanding
 * delayed requests we need to ensure we go into the queue and not jump
 * ahead. If we sent this media state now then updates could go out of
 * order.
 */
 if (!queued && !AST_LIST_EMPTY(&session->delayed_requests)) {
 res = delay_request(session, on_request_creation, on_sdp_creation,
 on_response, generate_new_sdp,
 method == AST_SIP_SESSION_REFRESH_METHOD_INVITE
 ? DELAYED_METHOD_INVITE : DELAYED_METHOD_UPDATE, pending_media_state,
 active_media_state ? active_media_state : ast_sip_session_media_state_clone(session->active_media_state), queued);
 SCOPE_EXIT_RTN_VALUE(res, "%s: Delay sending reinvite because of outstanding requests\n",
 ast_sip_session_get_name(session));
 }

 /*
 * Attempt to resolve only if objects are available, and it's not
 * switching to or from an image type.
 */
 if (active_media_state && active_media_state->topology &&
 (!active_media_state->default_session[AST_MEDIA_TYPE_IMAGE] ==
 !pending_media_state->default_session[AST_MEDIA_TYPE_IMAGE])) {

 struct ast_sip_session_media_state *new_pending_state;

 ast_trace(-1, "%s: Active media state exists and is%s equal to pending\n", ast_sip_session_get_name(session),
 !ast_stream_topology_equal(active_media_state->topology,pending_media_state->topology) ? " not" : "");
 ast_trace(-1, "%s: DP: %s\n", ast_sip_session_get_name(session), ast_str_tmp(256, ast_stream_topology_to_str(pending_media_state->topology, &STR_TMP)));
 ast_trace(-1, "%s: DA: %s\n", ast_sip_session_get_name(session), ast_str_tmp(256, ast_stream_topology_to_str(active_media_state->topology, &STR_TMP)));
 ast_trace(-1, "%s: CP: %s\n", ast_sip_session_get_name(session), ast_str_tmp(256, ast_stream_topology_to_str(session->pending_media_state->topology, &STR_TMP)));
 ast_trace(-1, "%s: CA: %s\n", ast_sip_session_get_name(session), ast_str_tmp(256, ast_stream_topology_to_str(session->active_media_state->topology, &STR_TMP)));

 new_pending_state = resolve_refresh_media_states(ast_sip_session_get_name(session),
 pending_media_state, active_media_state, session->active_media_state, 1);
 if (new_pending_state) {
 ast_trace(-1, "%s: NP: %s\n", ast_sip_session_get_name(session), ast_str_tmp(256, ast_stream_topology_to_str(new_pending_state->topology, &STR_TMP)));
 ast_sip_session_media_state_free(pending_media_state);
 pending_media_state = new_pending_state;
 } else {
 ast_sip_session_media_state_reset(pending_media_state);
 ast_sip_session_media_state_free(active_media_state);
 SCOPE_EXIT_LOG_RTN_VALUE(-1, LOG_WARNING, "%s: Unable to merge media states\n", ast_sip_session_get_name(session));
 }
 }

 /* Prune the media state so the number of streams fit within the configured limits - we do it here
 * so that the index of the resulting streams in the SDP match. If we simply left the streams out
 * of the SDP when producing it we'd be in trouble. We also enforce formats here for media types that
 * are configurable on the endpoint.
 */
 ast_trace(-1, "%s: Pruning and checking formats of streams\n", ast_sip_session_get_name(session));

 for (index = 0; index < ast_stream_topology_get_count(pending_media_state->topology); ++index) {
 struct ast_stream *existing_stream = NULL;
 struct ast_stream *stream = ast_stream_topology_get_stream(pending_media_state->topology, index);
 SCOPE_ENTER(4, "%s: Checking stream %s\n", ast_sip_session_get_name(session),
 ast_stream_get_name(stream));

 if (session->active_media_state->topology &&
 index < ast_stream_topology_get_count(session->active_media_state->topology)) {
 existing_stream = ast_stream_topology_get_stream(session->active_media_state->topology, index);
 ast_trace(-1, "%s: Found existing stream %s\n", ast_sip_session_get_name(session),
 ast_stream_get_name(existing_stream));
 }

 if (is_stream_limitation_reached(ast_stream_get_type(stream), session->endpoint, type_streams)) {
 if (index < AST_VECTOR_SIZE(&pending_media_state->sessions)) {
 struct ast_sip_session_media *session_media = AST_VECTOR_GET(&pending_media_state->sessions, index);

 ao2_cleanup(session_media);
 AST_VECTOR_REMOVE(&pending_media_state->sessions, index, 1);
 }

 ast_stream_topology_del_stream(pending_media_state->topology, index);
 ast_trace(-1, "%s: Dropped overlimit stream %s\n", ast_sip_session_get_name(session),
 ast_stream_get_name(stream));

 /* A stream has potentially moved into our spot so we need to jump back so we process it */
 index -= 1;
 SCOPE_EXIT_EXPR(continue);
 }

 /* No need to do anything with stream if it's media state is removed */
 if (ast_stream_get_state(stream) == AST_STREAM_STATE_REMOVED) {
 /* If there is no existing stream we can just not have this stream in the topology at all. */
 if (!existing_stream) {
 ast_trace(-1, "%s: Dropped removed stream %s\n", ast_sip_session_get_name(session),
 ast_stream_get_name(stream));
 ast_stream_topology_del_stream(pending_media_state->topology, index);
 /* TODO: Do we need to remove the corresponding media state? */
 index -= 1;
 }
 SCOPE_EXIT_EXPR(continue);
 }

 /* Enforce the configured allowed codecs on audio and video streams */
 if ((ast_stream_get_type(stream) == AST_MEDIA_TYPE_AUDIO || ast_stream_get_type(stream) == AST_MEDIA_TYPE_VIDEO) &&
 !ast_stream_get_metadata(stream, "pjsip_session_refresh")) {
 struct ast_format_cap *joint_cap;

 joint_cap = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
 if (!joint_cap) {
 ast_sip_session_media_state_free(pending_media_state);
 ast_sip_session_media_state_free(active_media_state);
 res = -1;
 SCOPE_EXIT_LOG_EXPR(goto end, LOG_ERROR, "%s: Unable to alloc format caps\n", ast_sip_session_get_name(session));
 }
 ast_format_cap_get_compatible(ast_stream_get_formats(stream), session->endpoint->media.codecs, joint_cap);
 if (!ast_format_cap_count(joint_cap)) {
 ao2_ref(joint_cap, -1);

 if (!existing_stream) {
 /* If there is no existing stream we can just not have this stream in the topology
 * at all.
 */
 ast_stream_topology_del_stream(pending_media_state->topology, index);
 index -= 1;
 SCOPE_EXIT_EXPR(continue, "%s: Dropped incompatible stream %s\n",
 ast_sip_session_get_name(session), ast_stream_get_name(stream));
 } else if (ast_stream_get_state(stream) != ast_stream_get_state(existing_stream) ||
 strcmp(ast_stream_get_name(stream), ast_stream_get_name(existing_stream))) {
 /* If the underlying stream is a different type or different name then we have to
 * mark it as removed, as it is replacing an existing stream. We do this so order
 * is preserved.
 */
 ast_stream_set_state(stream, AST_STREAM_STATE_REMOVED);
 SCOPE_EXIT_EXPR(continue, "%s: Dropped incompatible stream %s\n",
 ast_sip_session_get_name(session), ast_stream_get_name(stream));
 } else {
 /* However if the stream is otherwise remaining the same we can keep the formats
 * that exist on it already which allows media to continue to flow. We don't modify
 * the format capabilities but do need to cast it so that ao2_bump can raise the
 * reference count.
 */
 joint_cap = ao2_bump((struct ast_format_cap *)ast_stream_get_formats(existing_stream));
 }
 }
 ast_stream_set_formats(stream, joint_cap);
 ao2_cleanup(joint_cap);
 }

 ++type_streams[ast_stream_get_type(stream)];

 SCOPE_EXIT();
 }

 if (session->active_media_state->topology) {
 /* SDP is a fun thing. Take for example the fact that streams are never removed. They just become
 * declined. To better handle this in the case where something requests a topology change for fewer
 * streams than are currently present we fill in the topology to match the current number of streams
 * that are active.
 */

 for (index = ast_stream_topology_get_count(pending_media_state->topology);
 index < ast_stream_topology_get_count(session->active_media_state->topology); ++index) {
 struct ast_stream *stream = ast_stream_topology_get_stream(session->active_media_state->topology, index);
 struct ast_stream *cloned;
 int position;
 SCOPE_ENTER(4, "%s: Stream %s not in pending\n", ast_sip_session_get_name(session),
 ast_stream_get_name(stream));

 cloned = ast_stream_clone(stream, NULL);
 if (!cloned) {
 ast_sip_session_media_state_free(pending_media_state);
 ast_sip_session_media_state_free(active_media_state);
 res = -1;
 SCOPE_EXIT_LOG_EXPR(goto end, LOG_ERROR, "%s: Unable to clone stream %s\n",
 ast_sip_session_get_name(session), ast_stream_get_name(stream));
 }

 ast_stream_set_state(cloned, AST_STREAM_STATE_REMOVED);
 position = ast_stream_topology_append_stream(pending_media_state->topology, cloned);
 if (position < 0) {
 ast_stream_free(cloned);
 ast_sip_session_media_state_free(pending_media_state);
 ast_sip_session_media_state_free(active_media_state);
 res = -1;
 SCOPE_EXIT_LOG_EXPR(goto end, LOG_ERROR, "%s: Unable to append cloned stream\n",
 ast_sip_session_get_name(session));
 }
 SCOPE_EXIT("%s: Appended empty stream in position %d to make counts match\n",
 ast_sip_session_get_name(session), position);
 }

 /*
 * We can suppress this re-invite if the pending topology is equal to the currently
 * active topology.
 */
 if (ast_stream_topology_equal(session->active_media_state->topology, pending_media_state->topology)) {
 ast_trace(-1, "%s: CA: %s\n", ast_sip_session_get_name(session), ast_str_tmp(256, ast_stream_topology_to_str(session->active_media_state->topology, &STR_TMP)));
 ast_trace(-1, "%s: NP: %s\n", ast_sip_session_get_name(session), ast_str_tmp(256, ast_stream_topology_to_str(pending_media_state->topology, &STR_TMP)));
 ast_sip_session_media_state_free(pending_media_state);
 ast_sip_session_media_state_free(active_media_state);
 /* For external consumers we return 0 to say success, but internally for
 * send_delayed_request we return a separate value to indicate that this
 * session refresh would be redundant so we didn't send it
 */
 SCOPE_EXIT_RTN_VALUE(queued ? 1 : 0, "%s: Topologies are equal. Not sending re-invite\n",
 ast_sip_session_get_name(session));
 }
 }

 ast_sip_session_media_state_free(session->pending_media_state);
 session->pending_media_state = pending_media_state;
 }

 new_sdp = generate_session_refresh_sdp(session);
 if (!new_sdp) {
 ast_sip_session_media_state_reset(session->pending_media_state);
 ast_sip_session_media_state_free(active_media_state);
 SCOPE_EXIT_LOG_RTN_VALUE(-1, LOG_WARNING, "%s: Failed to generate session refresh SDP. Not sending session refresh\n",
 ast_sip_session_get_name(session));
 }
 if (on_sdp_creation) {
 if (on_sdp_creation(session, new_sdp)) {
 ast_sip_session_media_state_reset(session->pending_media_state);
 ast_sip_session_media_state_free(active_media_state);
 SCOPE_EXIT_LOG_RTN_VALUE(-1, LOG_WARNING, "%s: on_sdp_creation failed\n", ast_sip_session_get_name(session));
 }
 }
 }

 if (method == AST_SIP_SESSION_REFRESH_METHOD_INVITE) {
 if (pjsip_inv_reinvite(inv_session, NULL, new_sdp, &tdata)) {
 if (generate_new_sdp) {
 ast_sip_session_media_state_reset(session->pending_media_state);
 }
 ast_sip_session_media_state_free(active_media_state);
 SCOPE_EXIT_LOG_RTN_VALUE(-1, LOG_WARNING, "%s: Failed to create reinvite properly\n", ast_sip_session_get_name(session));
 }
 } else if (pjsip_inv_update(inv_session, NULL, new_sdp, &tdata)) {
 if (generate_new_sdp) {
 ast_sip_session_media_state_reset(session->pending_media_state);
 }
 ast_sip_session_media_state_free(active_media_state);
 SCOPE_EXIT_LOG_RTN_VALUE(-1, LOG_WARNING, "%s: Failed to create UPDATE properly\n", ast_sip_session_get_name(session));
 }
 if (on_request_creation) {
 if (on_request_creation(session, tdata)) {
 if (generate_new_sdp) {
 ast_sip_session_media_state_reset(session->pending_media_state);
 }
 ast_sip_session_media_state_free(active_media_state);
 SCOPE_EXIT_LOG_RTN_VALUE(-1, LOG_WARNING, "%s: on_request_creation failed.\n", ast_sip_session_get_name(session));
 }
 }
 ast_sip_session_send_request_with_cb(session, tdata, on_response);
 ast_sip_session_media_state_free(active_media_state);

end:
 SCOPE_EXIT_RTN_VALUE(res, "%s: Sending session refresh SDP via %s\n", ast_sip_session_get_name(session),
 method == AST_SIP_SESSION_REFRESH_METHOD_INVITE ? "re-INVITE" : "UPDATE");
}

int ast_sip_session_refresh(struct ast_sip_session *session,
 ast_sip_session_request_creation_cb on_request_creation,
 ast_sip_session_sdp_creation_cb on_sdp_creation,
 ast_sip_session_response_cb on_response,
 enum ast_sip_session_refresh_method method, int generate_new_sdp,
 struct ast_sip_session_media_state *media_state)
{
 return sip_session_refresh(session, on_request_creation, on_sdp_creation,
 on_response, method, generate_new_sdp, media_state, NULL, 0);
}

int ast_sip_session_regenerate_answer(struct ast_sip_session *session,
 ast_sip_session_sdp_creation_cb on_sdp_creation)
{
 pjsip_inv_session *inv_session = session->inv_session;
 pjmedia_sdp_session *new_answer = NULL;
 const pjmedia_sdp_session *previous_offer = NULL;
 SCOPE_ENTER(1, "%s\n", ast_sip_session_get_name(session));

 /* The SDP answer can only be regenerated if it is still pending to be sent */
 if (!inv_session->neg || (pjmedia_sdp_neg_get_state(inv_session->neg) != PJMEDIA_SDP_NEG_STATE_REMOTE_OFFER &&
 pjmedia_sdp_neg_get_state(inv_session->neg) != PJMEDIA_SDP_NEG_STATE_WAIT_NEGO)) {
 ast_log(LOG_WARNING, "Requested to regenerate local SDP answer for channel '%s' but negotiation in state '%s'\n",
 ast_channel_name(session->channel), pjmedia_sdp_neg_state_str(pjmedia_sdp_neg_get_state(inv_session->neg)));
 SCOPE_EXIT_RTN_VALUE(-1, "Bad negotiation state\n");
 }

 pjmedia_sdp_neg_get_neg_remote(inv_session->neg, &previous_offer);
 if (pjmedia_sdp_neg_get_state(inv_session->neg) == PJMEDIA_SDP_NEG_STATE_WAIT_NEGO) {
 /* Transition the SDP negotiator back to when it received the remote offer */
 pjmedia_sdp_neg_negotiate(inv_session->pool, inv_session->neg, 0);
 pjmedia_sdp_neg_set_remote_offer(inv_session->pool, inv_session->neg, previous_offer);
 }

 new_answer = create_local_sdp(inv_session, session, previous_offer);
 if (!new_answer) {
 ast_log(LOG_WARNING, "Could not create a new local SDP answer for channel '%s'\n",
 ast_channel_name(session->channel));
 SCOPE_EXIT_RTN_VALUE(-1, "Couldn't create new SDP\n");
 }

 if (on_sdp_creation) {
 if (on_sdp_creation(session, new_answer)) {
 SCOPE_EXIT_RTN_VALUE(-1, "Callback failed\n");
 }
 }

 pjsip_inv_set_sdp_answer(inv_session, new_answer);

 SCOPE_EXIT_RTN_VALUE(0);
}

void ast_sip_session_send_response(struct ast_sip_session *session, pjsip_tx_data *tdata)
{
 handle_outgoing_response(session, tdata);
 pjsip_inv_send_msg(session->inv_session, tdata);
 return;
}

static pj_bool_t session_on_rx_request(pjsip_rx_data *rdata);
static pj_bool_t session_on_rx_response(pjsip_rx_data *rdata);
static void session_on_tsx_state(pjsip_transaction *tsx, pjsip_event *e);

static pjsip_module session_module = {
 .name = {"Session Module", 14},
 .priority = PJSIP_MOD_PRIORITY_APPLICATION,
 .on_rx_request = session_on_rx_request,
 .on_rx_response = session_on_rx_response,
 .on_tsx_state = session_on_tsx_state,
};

/*! \brief Determine whether the SDP provided requires deferral of negotiating or not
 *
 * \retval 1 re-invite should be deferred and resumed later
 * \retval 0 re-invite should not be deferred
 */
static int sdp_requires_deferral(struct ast_sip_session *session, const pjmedia_sdp_session *sdp)
{
 int i;

 if (!session->pending_media_state->topology) {
 session->pending_media_state->topology = ast_stream_topology_alloc();
 if (!session->pending_media_state->topology) {
 return -1;
 }
 }

 for (i = 0; i < sdp->media_count; ++i) {
 /* See if there are registered handlers for this media stream type */
 char media[20];
 struct ast_sip_session_sdp_handler *handler;
 RAII_VAR(struct sdp_handler_list *, handler_list, NULL, ao2_cleanup);
 struct ast_stream *existing_stream = NULL;
 struct ast_stream *stream;
 enum ast_media_type type;
 struct ast_sip_session_media *session_media = NULL;
 enum ast_sip_session_sdp_stream_defer res;
 pjmedia_sdp_media *remote_stream = sdp->media[i];

 /* We need a null-terminated version of the media string */
 ast_copy_pj_str(media, &sdp->media[i]->desc.media, sizeof(media));

 if (session->active_media_state->topology &&
 (i < ast_stream_topology_get_count(session->active_media_state->topology))) {
 existing_stream = ast_stream_topology_get_stream(session->active_media_state->topology, i);
 }

 type = ast_media_type_from_str(media);
 stream = ast_stream_alloc(existing_stream ? ast_stream_get_name(existing_stream) : ast_codec_media_type2str(type), type);
 if (!stream) {
 return -1;
 }

 /* As this is only called on an incoming SDP offer before processing it is not possible
 * for streams and their media sessions to exist.
 */
 if (ast_stream_topology_set_stream(session->pending_media_state->topology, i, stream)) {
 ast_stream_free(stream);
 return -1;
 }

 if (existing_stream) {
 const char *stream_label = ast_stream_get_metadata(existing_stream, "SDP:LABEL");

 if (!ast_strlen_zero(stream_label)) {
 ast_stream_set_metadata(stream, "SDP:LABEL", stream_label);
 }
 }

 session_media = ast_sip_session_media_state_add(session, session->pending_media_state, ast_media_type_from_str(media), i);
 if (!session_media) {
 return -1;
 }

 /* For backwards compatibility with the core the default audio stream is always sendrecv */
 if (!ast_sip_session_is_pending_stream_default(session, stream) || strcmp(media, "audio")) {
 if (pjmedia_sdp_media_find_attr2(remote_stream, "sendonly", NULL)) {
 /* Stream state reflects our state of a stream, so in the case of
 * sendonly and recvonly we store the opposite since that is what ours
 * is.
 */
 ast_stream_set_state(stream, AST_STREAM_STATE_RECVONLY);
 } else if (pjmedia_sdp_media_find_attr2(remote_stream, "recvonly", NULL)) {
 ast_stream_set_state(stream, AST_STREAM_STATE_SENDONLY);
 } else if (pjmedia_sdp_media_find_attr2(remote_stream, "inactive", NULL)) {
 ast_stream_set_state(stream, AST_STREAM_STATE_INACTIVE);
 } else {
 ast_stream_set_state(stream, AST_STREAM_STATE_SENDRECV);
 }
 } else {
 ast_stream_set_state(stream, AST_STREAM_STATE_SENDRECV);
 }

 if (session_media->handler) {
 handler = session_media->handler;
 if (handler->defer_incoming_sdp_stream) {
 res = handler->defer_incoming_sdp_stream(session, session_media, sdp,
 sdp->media[i]);
 switch (res) {
 case AST_SIP_SESSION_SDP_DEFER_NOT_HANDLED:
 break;
 case AST_SIP_SESSION_SDP_DEFER_ERROR:
 return 0;
 case AST_SIP_SESSION_SDP_DEFER_NOT_NEEDED:
 break;
 case AST_SIP_SESSION_SDP_DEFER_NEEDED:
 return 1;
 }
 }
 /* Handled by this handler. Move to the next stream */
 continue;
 }

 handler_list = ao2_find(sdp_handlers, media, OBJ_KEY);
 if (!handler_list) {
 ast_debug(3, "%s: No registered SDP handlers for media type '%s'\n", ast_sip_session_get_name(session), media);
 continue;
 }
 AST_LIST_TRAVERSE(&handler_list->list, handler, next) {
 if (handler == session_media->handler) {
 continue;
 }
 if (!handler->defer_incoming_sdp_stream) {
 continue;
 }
 res = handler->defer_incoming_sdp_stream(session, session_media, sdp,
 sdp->media[i]);
 switch (res) {
 case AST_SIP_SESSION_SDP_DEFER_NOT_HANDLED:
 continue;
 case AST_SIP_SESSION_SDP_DEFER_ERROR:
 session_media_set_handler(session_media, handler);
 return 0;
 case AST_SIP_SESSION_SDP_DEFER_NOT_NEEDED:
 /* Handled by this handler. */
 session_media_set_handler(session_media, handler);
 break;
 case AST_SIP_SESSION_SDP_DEFER_NEEDED:
 /* Handled by this handler. */
 session_media_set_handler(session_media, handler);
 return 1;
 }
 /* Move to the next stream */
 break;
 }
 }
 return 0;
}

static pj_bool_t session_reinvite_on_rx_request(pjsip_rx_data *rdata)
{
 pjsip_dialog *dlg;
 RAII_VAR(struct ast_sip_session *, session, NULL, ao2_cleanup);
 pjsip_rdata_sdp_info *sdp_info;
 int deferred;

 if (rdata->msg_info.msg->line.req.method.id != PJSIP_INVITE_METHOD ||
 !(dlg = pjsip_ua_find_dialog(&rdata->msg_info.cid->id, &rdata->msg_info.to->tag, &rdata->msg_info.from->tag, PJ_FALSE)) ||
 !(session = ast_sip_dialog_get_session(dlg)) ||
 !session->channel) {
 return PJ_FALSE;
 }

 if (session->inv_session->invite_tsx) {
 /* There's a transaction in progress so bail now and let pjproject send 491 */
 return PJ_FALSE;
 }

 if (session->deferred_reinvite) {
 pj_str_t key, deferred_key;
 pjsip_tx_data *tdata;

 /* We use memory from the new request on purpose so the deferred reinvite pool does not grow uncontrollably */
 pjsip_tsx_create_key(rdata->tp_info.pool, &key, PJSIP_ROLE_UAS, &rdata->msg_info.cseq->method, rdata);
 pjsip_tsx_create_key(rdata->tp_info.pool, &deferred_key, PJSIP_ROLE_UAS, &session->deferred_reinvite->msg_info.cseq->method,
 session->deferred_reinvite);

 /* If this is a retransmission ignore it */
 if (!pj_strcmp(&key, &deferred_key)) {
 return PJ_TRUE;
 }

 /* Otherwise this is a new re-invite, so reject it */
 if (pjsip_dlg_create_response(dlg, rdata, 491, NULL, &tdata) == PJ_SUCCESS) {
 if (pjsip_endpt_send_response2(ast_sip_get_pjsip_endpoint(), rdata, tdata, NULL, NULL) != PJ_SUCCESS) {
 pjsip_tx_data_dec_ref(tdata);
 }
 }

 return PJ_TRUE;
 }

 if (!(sdp_info = pjsip_rdata_get_sdp_info(rdata)) ||
 (sdp_info->sdp_err != PJ_SUCCESS)) {
 return PJ_FALSE;
 }

 if (!sdp_info->sdp) {
 return PJ_FALSE;
 }

 deferred = sdp_requires_deferral(session, sdp_info->sdp);
 if (deferred == -1) {
 ast_sip_session_media_state_reset(session->pending_media_state);
 return PJ_FALSE;
 } else if (!deferred) {
 return PJ_FALSE;
 }

 pjsip_rx_data_clone(rdata, 0, &session->deferred_reinvite);

 return PJ_TRUE;
}

void ast_sip_session_resume_reinvite(struct ast_sip_session *session)
{
 if (!session->deferred_reinvite) {
 return;
 }

 if (session->channel) {
 pjsip_endpt_process_rx_data(ast_sip_get_pjsip_endpoint(),
 session->deferred_reinvite, NULL, NULL);
 }
 pjsip_rx_data_free_cloned(session->deferred_reinvite);
 session->deferred_reinvite = NULL;
}

static pjsip_module session_reinvite_module = {
 .name = { "Session Re-Invite Module", 24 },
 .priority = PJSIP_MOD_PRIORITY_UA_PROXY_LAYER - 1,
 .on_rx_request = session_reinvite_on_rx_request,
};

void ast_sip_session_send_request_with_cb(struct ast_sip_session *session, pjsip_tx_data *tdata,
 ast_sip_session_response_cb on_response)
{
 pjsip_inv_session *inv_session = session->inv_session;

 /* For every request except BYE we disallow sending of the message when
 * the session has been disconnected. A BYE request is special though
 * because it can be sent again after the session is disconnected except
 * with credentials.
 */
 if (inv_session->state == PJSIP_INV_STATE_DISCONNECTED &&
 tdata->msg->line.req.method.id != PJSIP_BYE_METHOD) {
 return;
 }

 ast_sip_mod_data_set(tdata->pool, tdata->mod_data, session_module.id,
 MOD_DATA_ON_RESPONSE, on_response);

 handle_outgoing_request(session, tdata);
 pjsip_inv_send_msg(session->inv_session, tdata);

 return;
}

void ast_sip_session_send_request(struct ast_sip_session *session, pjsip_tx_data *tdata)
{
 ast_sip_session_send_request_with_cb(session, tdata, NULL);
}

int ast_sip_session_create_invite(struct ast_sip_session *session, pjsip_tx_data **tdata)
{
 pjmedia_sdp_session *offer;
 SCOPE_ENTER(1, "%s\n", ast_sip_session_get_name(session));

 if (!(offer = create_local_sdp(session->inv_session, session, NULL))) {
 pjsip_inv_terminate(session->inv_session, 500, PJ_FALSE);
 SCOPE_EXIT_RTN_VALUE(-1, "Couldn't create offer\n");
 }

 pjsip_inv_set_local_sdp(session->inv_session, offer);
 pjmedia_sdp_neg_set_prefer_remote_codec_order(session->inv_session->neg, PJ_FALSE);
#ifdef PJMEDIA_SDP_NEG_ANSWER_MULTIPLE_CODECS
 if (!session->endpoint->preferred_codec_only) {
 pjmedia_sdp_neg_set_answer_multiple_codecs(session->inv_session->neg, PJ_TRUE);
 }
#endif

 /*
 * We MUST call set_from_header() before pjsip_inv_invite. If we don't, the
 * From in the initial INVITE will be wrong but the rest of the messages will be OK.
 */
 set_from_header(session);

 if (pjsip_inv_invite(session->inv_session, tdata) != PJ_SUCCESS) {
 SCOPE_EXIT_RTN_VALUE(-1, "pjsip_inv_invite failed\n");
 }

 SCOPE_EXIT_RTN_VALUE(0);
}

static int datastore_hash(const void *obj, int flags)
{
 const struct ast_datastore *datastore = obj;
 const char *uid = flags & OBJ_KEY ? obj : datastore->uid;

 ast_assert(uid != NULL);

 return ast_str_hash(uid);
}

static int datastore_cmp(void *obj, void *arg, int flags)
{
 const struct ast_datastore *datastore1 = obj;
 const struct ast_datastore *datastore2 = arg;
 const char *uid2 = flags & OBJ_KEY ? arg : datastore2->uid;

 ast_assert(datastore1->uid != NULL);
 ast_assert(uid2 != NULL);

 return strcmp(datastore1->uid, uid2) ? 0 : CMP_MATCH | CMP_STOP;
}

static void session_destructor(void *obj)
{
 struct ast_sip_session *session = obj;
 struct ast_sip_session_delayed_request *delay;

#ifdef TEST_FRAMEWORK
 /* We dup the endpoint ID in case the endpoint gets freed out from under us */
 const char *endpoint_name = session->endpoint ?
 ast_strdupa(ast_sorcery_object_get_id(session->endpoint)) : "<none>";
#endif

 ast_debug(3, "%s: Destroying SIP session\n", ast_sip_session_get_name(session));

 ast_test_suite_event_notify("SESSION_DESTROYING",
 "Endpoint: %s\r\n"
 "AOR: %s\r\n"
 "Contact: %s"
 , endpoint_name
 , session->aor ? ast_sorcery_object_get_id(session->aor) : "<none>"
 , session->contact ? ast_sorcery_object_get_id(session->contact) : "<none>"
 );

 /* fire session destroy handler */
 handle_session_destroy(session);

 /* remove all registered supplements */
 ast_sip_session_remove_supplements(session);
 AST_LIST_HEAD_DESTROY(&session->supplements);

 /* remove all saved media stats */
 AST_VECTOR_RESET(&session->media_stats, ast_free);
 AST_VECTOR_FREE(&session->media_stats);

 ast_taskprocessor_unreference(session->serializer);
 ao2_cleanup(session->datastores);
 ast_sip_session_media_state_free(session->active_media_state);
 ast_sip_session_media_state_free(session->pending_media_state);

 while ((delay = AST_LIST_REMOVE_HEAD(&session->delayed_requests, next))) {
 delayed_request_free(delay);
 }
 ast_party_id_free(&session->id);
 ao2_cleanup(session->endpoint);
 ao2_cleanup(session->aor);
 ao2_cleanup(session->contact);
 ao2_cleanup(session->direct_media_cap);

 ast_dsp_free(session->dsp);

 if (session->inv_session) {
 struct pjsip_dialog *dlg = session->inv_session->dlg;

 /* The INVITE session uses the dialog pool for memory, so we need to
 * decrement its reference first before that of the dialog.
 */

#ifdef HAVE_PJSIP_INV_SESSION_REF
 pjsip_inv_dec_ref(session->inv_session);
#endif
 pjsip_dlg_dec_session(dlg, &session_module);
 }

 ast_test_suite_event_notify("SESSION_DESTROYED", "Endpoint: %s", endpoint_name);
}

/*! \brief Destructor for SIP channel */
static void sip_channel_destroy(void *obj)
{
 struct ast_sip_channel_pvt *channel = obj;

 ao2_cleanup(channel->pvt);
 ao2_cleanup(channel->session);
}

struct ast_sip_channel_pvt *ast_sip_channel_pvt_alloc(void *pvt, struct ast_sip_session *session)
{
 struct ast_sip_channel_pvt *channel = ao2_alloc(sizeof(*channel), sip_channel_destroy);

 if (!channel) {
 return NULL;
 }

 ao2_ref(pvt, +1);
 channel->pvt = pvt;
 ao2_ref(session, +1);
 channel->session = session;

 return channel;
}

struct ast_sip_session *ast_sip_session_alloc(struct ast_sip_endpoint *endpoint,
 struct ast_sip_contact *contact, pjsip_inv_session *inv_session, pjsip_rx_data *rdata)
{
 RAII_VAR(struct ast_sip_session *, session, NULL, ao2_cleanup);
 struct ast_sip_session *ret_session;
 int dsp_features = 0;

 session = ao2_alloc(sizeof(*session), session_destructor);
 if (!session) {
 return NULL;
 }

 AST_LIST_HEAD_INIT(&session->supplements);
 AST_LIST_HEAD_INIT_NOLOCK(&session->delayed_requests);
 ast_party_id_init(&session->id);

 session->direct_media_cap = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
 if (!session->direct_media_cap) {
 return NULL;
 }
 session->datastores = ao2_container_alloc_hash(AO2_ALLOC_OPT_LOCK_MUTEX, 0,
 DATASTORE_BUCKETS, datastore_hash, NULL, datastore_cmp);
 if (!session->datastores) {
 return NULL;
 }
 session->active_media_state = ast_sip_session_media_state_alloc();
 if (!session->active_media_state) {
 return NULL;
 }
 session->pending_media_state = ast_sip_session_media_state_alloc();
 if (!session->pending_media_state) {
 return NULL;
 }
 if (AST_VECTOR_INIT(&session->media_stats, 1) < 0) {
 return NULL;
 }

 if (endpoint->dtmf == AST_SIP_DTMF_INBAND || endpoint->dtmf == AST_SIP_DTMF_AUTO) {
 dsp_features |= DSP_FEATURE_DIGIT_DETECT;
 }
 if (endpoint->faxdetect) {
 dsp_features |= DSP_FEATURE_FAX_DETECT;
 }
 if (dsp_features) {
 session->dsp = ast_dsp_new();
 if (!session->dsp) {
 return NULL;
 }

 ast_dsp_set_features(session->dsp, dsp_features);
 }

 session->endpoint = ao2_bump(endpoint);

 if (rdata) {
 /*
 * We must continue using the serializer that the original
 * INVITE came in on for the dialog. There may be
 * retransmissions already enqueued in the original
 * serializer that can result in reentrancy and message
 * sequencing problems.
 */
 session->serializer = ast_sip_get_distributor_serializer(rdata);
 } else {
 char tps_name[AST_TASKPROCESSOR_MAX_NAME + 1];

 /* Create name with seq number appended. */
 ast_taskprocessor_build_name(tps_name, sizeof(tps_name), "pjsip/outsess/%s",
 ast_sorcery_object_get_id(endpoint));

 session->serializer = ast_sip_create_serializer(tps_name);
 }
 if (!session->serializer) {
 return NULL;
 }
 ast_sip_dialog_set_serializer(inv_session->dlg, session->serializer);
 ast_sip_dialog_set_endpoint(inv_session->dlg, endpoint);

 /* When a PJSIP INVITE session is created it is created with a reference
 * count of 1, with that reference being managed by the underlying state
 * of the INVITE session itself. When the INVITE session transitions to
 * a DISCONNECTED state that reference is released. This means we can not
 * rely on that reference to ensure the INVITE session remains for the
 * lifetime of our session. To ensure it does we add our own reference
 * and release it when our own session goes away, ensuring that the INVITE
 * session remains for the lifetime of session.
 */

#ifdef HAVE_PJSIP_INV_SESSION_REF
 if (pjsip_inv_add_ref(inv_session) != PJ_SUCCESS) {
 ast_log(LOG_ERROR, "Can't increase the session reference counter\n");
 return NULL;
 }
#endif

 pjsip_dlg_inc_session(inv_session->dlg, &session_module);
 inv_session->mod_data[session_module.id] = ao2_bump(session);
 session->contact = ao2_bump(contact);
 session->inv_session = inv_session;

 session->dtmf = endpoint->dtmf;
 session->moh_passthrough = endpoint->moh_passthrough;

 if (ast_sip_session_add_supplements(session)) {
 /* Release the ref held by session->inv_session */
 ao2_ref(session, -1);
 return NULL;
 }

 session->authentication_challenge_count = 0;

 /* Fire seesion begin handlers */
 handle_session_begin(session);

 /* Avoid unnecessary ref manipulation to return a session */
 ret_session = session;
 session = NULL;
 return ret_session;
}

/*! \brief struct controlling the suspension of the session's serializer. */
struct ast_sip_session_suspender {
 ast_cond_t cond_suspended;
 ast_cond_t cond_complete;
 int suspended;
 int complete;
};

static void sip_session_suspender_dtor(void *vdoomed)
{
 struct ast_sip_session_suspender *doomed = vdoomed;

 ast_cond_destroy(&doomed->cond_suspended);
 ast_cond_destroy(&doomed->cond_complete);
}

/*!
 * \internal
 * \brief Block the session serializer thread task.
 *
 * \param data Pushed serializer task data for suspension.
 *
 * \retval 0
 */
static int sip_session_suspend_task(void *data)
{
 struct ast_sip_session_suspender *suspender = data;

 ao2_lock(suspender);

 /* Signal that the serializer task is now suspended. */
 suspender->suspended = 1;
 ast_cond_signal(&suspender->cond_suspended);

 /* Wait for the serializer suspension to be completed. */
 while (!suspender->complete) {
 ast_cond_wait(&suspender->cond_complete, ao2_object_get_lockaddr(suspender));
 }

 ao2_unlock(suspender);
 ao2_ref(suspender, -1);

 return 0;
}

void ast_sip_session_suspend(struct ast_sip_session *session)
{
 struct ast_sip_session_suspender *suspender;
 int res;

 ast_assert(session->suspended == NULL);

 if (ast_taskprocessor_is_task(session->serializer)) {
 /* I am the session's serializer thread so I cannot suspend. */
 return;
 }

 if (ast_taskprocessor_is_suspended(session->serializer)) {
 /* The serializer already suspended. */
 return;
 }

 suspender = ao2_alloc(sizeof(*suspender), sip_session_suspender_dtor);
 if (!suspender) {
 /* We will just have to hope that the system does not deadlock */
 return;
 }
 ast_cond_init(&suspender->cond_suspended, NULL);
 ast_cond_init(&suspender->cond_complete, NULL);

 ao2_ref(suspender, +1);
 res = ast_sip_push_task(session->serializer, sip_session_suspend_task, suspender);
 if (res) {
 /* We will just have to hope that the system does not deadlock */
 ao2_ref(suspender, -2);
 return;
 }

 session->suspended = suspender;

 /* Wait for the serializer to get suspended. */
 ao2_lock(suspender);
 while (!suspender->suspended) {
 ast_cond_wait(&suspender->cond_suspended, ao2_object_get_lockaddr(suspender));
 }
 ao2_unlock(suspender);

 ast_taskprocessor_suspend(session->serializer);
}

void ast_sip_session_unsuspend(struct ast_sip_session *session)
{
 struct ast_sip_session_suspender *suspender = session->suspended;

 if (!suspender) {
 /* Nothing to do */
 return;
 }
 session->suspended = NULL;

 /* Signal that the serializer task suspension is now complete. */
 ao2_lock(suspender);
 suspender->complete = 1;
 ast_cond_signal(&suspender->cond_complete);
 ao2_unlock(suspender);

 ao2_ref(suspender, -1);

 ast_taskprocessor_unsuspend(session->serializer);
}

/*!
 * \internal
 * \brief Handle initial INVITE challenge response message.
 * \since 13.5.0
 *
 * \param rdata PJSIP receive response message data.
 *
 * \retval PJ_FALSE Did not handle message.
 * \retval PJ_TRUE Handled message.
 */
static pj_bool_t outbound_invite_auth(pjsip_rx_data *rdata)
{
 pjsip_transaction *tsx;
 pjsip_dialog *dlg;
 pjsip_inv_session *inv;
 pjsip_tx_data *tdata;
 struct ast_sip_session *session;

 if (rdata->msg_info.msg->line.status.code != 401
 && rdata->msg_info.msg->line.status.code != 407) {
 /* Doesn't pertain to us. Move on */
 return PJ_FALSE;
 }

 tsx = pjsip_rdata_get_tsx(rdata);
 dlg = pjsip_rdata_get_dlg(rdata);
 if (!dlg || !tsx) {
 return PJ_FALSE;
 }

 if (tsx->method.id != PJSIP_INVITE_METHOD) {
 /* Not an INVITE that needs authentication */
 return PJ_FALSE;
 }

 inv = pjsip_dlg_get_inv_session(dlg);
 session = inv->mod_data[session_module.id];

 if (PJSIP_INV_STATE_CONFIRMED <= inv->state) {
 /*
 * We cannot handle reINVITE authentication at this
 * time because the reINVITE transaction is still in
 * progress.
 */
 ast_debug(3, "%s: A reINVITE is being challenged\n", ast_sip_session_get_name(session));
 return PJ_FALSE;
 }
 ast_debug(3, "%s: Initial INVITE is being challenged.\n", ast_sip_session_get_name(session));

 if (++session->authentication_challenge_count > MAX_RX_CHALLENGES) {
 ast_debug(3, "%s: Initial INVITE reached maximum number of auth attempts.\n", ast_sip_session_get_name(session));
 return PJ_FALSE;
 }

 if (ast_sip_create_request_with_auth(&session->endpoint->outbound_auths, rdata,
 tsx->last_tx, &tdata)) {
 return PJ_FALSE;
 }

 /*
 * Restart the outgoing initial INVITE transaction to deal
 * with authentication.
 */
 pjsip_inv_uac_restart(inv, PJ_FALSE);

 ast_sip_session_send_request(session, tdata);
 return PJ_TRUE;
}

static pjsip_module outbound_invite_auth_module = {
 .name = {"Outbound INVITE Auth", 20},
 .priority = PJSIP_MOD_PRIORITY_DIALOG_USAGE,
 .on_rx_response = outbound_invite_auth,
};

/*!
 * \internal
 * \brief Setup outbound initial INVITE authentication.
 * \since 13.5.0
 *
 * \param dlg PJSIP dialog to attach outbound authentication.
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
static int setup_outbound_invite_auth(pjsip_dialog *dlg)
{
 pj_status_t status;

 ++dlg->sess_count;
 status = pjsip_dlg_add_usage(dlg, &outbound_invite_auth_module, NULL);
 --dlg->sess_count;

 return status != PJ_SUCCESS ? -1 : 0;
}

struct ast_sip_session *ast_sip_session_create_outgoing(struct ast_sip_endpoint *endpoint,
 struct ast_sip_contact *contact, const char *location, const char *request_user,
 struct ast_stream_topology *req_topology)
{
 const char *uri = NULL;
 RAII_VAR(struct ast_sip_aor *, found_aor, NULL, ao2_cleanup);
 RAII_VAR(struct ast_sip_contact *, found_contact, NULL, ao2_cleanup);
 pjsip_timer_setting timer;
 pjsip_dialog *dlg;
 struct pjsip_inv_session *inv_session;
 RAII_VAR(struct ast_sip_session *, session, NULL, ao2_cleanup);
 struct ast_sip_session *ret_session;
 SCOPE_ENTER(1, "%s %s Topology: %s\n", ast_sorcery_object_get_id(endpoint), request_user,
 ast_str_tmp(256, ast_stream_topology_to_str(req_topology, &STR_TMP)));

 /* If no location has been provided use the AOR list from the endpoint itself */
 if (location || !contact) {
 location = S_OR(location, endpoint->aors);

 ast_sip_location_retrieve_contact_and_aor_from_list_filtered(location, AST_SIP_CONTACT_FILTER_REACHABLE,
 &found_aor, &found_contact);
 if (!found_contact || ast_strlen_zero(found_contact->uri)) {
 uri = location;
 } else {
 uri = found_contact->uri;
 }
 } else {
 uri = contact->uri;
 }

 /* If we still have no URI to dial fail to create the session */
 if (ast_strlen_zero(uri)) {
 ast_log(LOG_ERROR, "Endpoint '%s': No URI available. Is endpoint registered?\n",
 ast_sorcery_object_get_id(endpoint));
 SCOPE_EXIT_RTN_VALUE(NULL, "No URI\n");
 }

 if (!(dlg = ast_sip_create_dialog_uac(endpoint, uri, request_user))) {
 SCOPE_EXIT_RTN_VALUE(NULL, "Couldn't create dialog\n");
 }

 if (setup_outbound_invite_auth(dlg)) {
 pjsip_dlg_terminate(dlg);
 SCOPE_EXIT_RTN_VALUE(NULL, "Couldn't setup auth\n");
 }

 if (pjsip_inv_create_uac(dlg, NULL, endpoint->extensions.flags, &inv_session) != PJ_SUCCESS) {
 pjsip_dlg_terminate(dlg);
 SCOPE_EXIT_RTN_VALUE(NULL, "Couldn't create uac\n");
 }
#if defined(HAVE_PJSIP_REPLACE_MEDIA_STREAM) || defined(PJMEDIA_SDP_NEG_ALLOW_MEDIA_CHANGE)
 inv_session->sdp_neg_flags = PJMEDIA_SDP_NEG_ALLOW_MEDIA_CHANGE;
#endif

 pjsip_timer_setting_default(&timer);
 timer.min_se = endpoint->extensions.timer.min_se;
 timer.sess_expires = endpoint->extensions.timer.sess_expires;
 pjsip_timer_init_session(inv_session, &timer);

 session = ast_sip_session_alloc(endpoint, found_contact ? found_contact : contact,
 inv_session, NULL);
 if (!session) {
 pjsip_inv_terminate(inv_session, 500, PJ_FALSE);
 return NULL;
 }
 session->aor = ao2_bump(found_aor);
 session->call_direction = AST_SIP_SESSION_OUTGOING_CALL;

 ast_party_id_copy(&session->id, &endpoint->id.self);

 if (ast_stream_topology_get_count(req_topology) > 0) {
 /* get joint caps between req_topology and endpoint topology */
 int i;

 for (i = 0; i < ast_stream_topology_get_count(req_topology); ++i) {
 struct ast_stream *req_stream;
 struct ast_stream *clone_stream;

 req_stream = ast_stream_topology_get_stream(req_topology, i);

 if (ast_stream_get_state(req_stream) == AST_STREAM_STATE_REMOVED) {
 continue;
 }

 clone_stream = ast_sip_session_create_joint_call_stream(session, req_stream);
 if (!clone_stream || ast_stream_get_format_count(clone_stream) == 0) {
 ast_stream_free(clone_stream);
 continue;
 }

 if (!session->pending_media_state->topology) {
 session->pending_media_state->topology = ast_stream_topology_alloc();
 if (!session->pending_media_state->topology) {
 pjsip_inv_terminate(inv_session, 500, PJ_FALSE);
 ao2_ref(session, -1);
 SCOPE_EXIT_RTN_VALUE(NULL, "Couldn't create topology\n");
 }
 }

 if (ast_stream_topology_append_stream(session->pending_media_state->topology, clone_stream) < 0) {
 ast_stream_free(clone_stream);
 continue;
 }
 }
 }

 if (!session->pending_media_state->topology) {
 /* Use the configured topology on the endpoint as the pending one */
 session->pending_media_state->topology = ast_stream_topology_clone(endpoint->media.topology);
 if (!session->pending_media_state->topology) {
 pjsip_inv_terminate(inv_session, 500, PJ_FALSE);
 ao2_ref(session, -1);
 SCOPE_EXIT_RTN_VALUE(NULL, "Couldn't clone topology\n");
 }
 }

 if (pjsip_dlg_add_usage(dlg, &session_module, NULL) != PJ_SUCCESS) {
 pjsip_inv_terminate(inv_session, 500, PJ_FALSE);
 /* Since we are not notifying ourselves that the INVITE session is being terminated
 * we need to manually drop its reference to session
 */
 ao2_ref(session, -1);
 SCOPE_EXIT_RTN_VALUE(NULL, "Couldn't add usage\n");
 }

 /* Avoid unnecessary ref manipulation to return a session */
 ret_session = session;
 session = NULL;
 SCOPE_EXIT_RTN_VALUE(ret_session);
}

static int session_end(void *vsession);
static int session_end_completion(void *vsession);

void ast_sip_session_terminate(struct ast_sip_session *session, int response)
{
 pj_status_t status;
 pjsip_tx_data *packet = NULL;
 SCOPE_ENTER(1, "%s Response %d\n", ast_sip_session_get_name(session), response);

 if (session->defer_terminate) {
 session->terminate_while_deferred = 1;
 SCOPE_EXIT_RTN("Deferred\n");
 }

 if (!response) {
 response = 603;
 }

 /* The media sessions need to exist for the lifetime of the underlying channel
 * to ensure that anything (such as bridge_native_rtp) has access to them as
 * appropriate. Since ast_sip_session_terminate is called by chan_pjsip and other
 * places when the session is to be terminated we terminate any existing
 * media sessions here.
 */
 ast_sip_session_media_stats_save(session, session->active_media_state);
 SWAP(session->active_media_state, session->pending_media_state);
 ast_sip_session_media_state_reset(session->pending_media_state);

 switch (session->inv_session->state) {
 case PJSIP_INV_STATE_NULL:
 if (!session->inv_session->invite_tsx) {
 /*
 * Normally, it's pjproject's transaction cleanup that ultimately causes the
 * final session reference to be released but if both STATE and invite_tsx are NULL,
 * we never created a transaction in the first place. In this case, we need to
 * do the cleanup ourselves.
 */
 /* Transfer the inv_session session reference to the session_end_task */
 session->inv_session->mod_data[session_module.id] = NULL;
 pjsip_inv_terminate(session->inv_session, response, PJ_TRUE);
 session_end(session);
 /*
 * session_end_completion will cleanup the final session reference unless
 * ast_sip_session_terminate's caller is holding one.
 */
 session_end_completion(session);
 } else {
 pjsip_inv_terminate(session->inv_session, response, PJ_TRUE);
 }
 break;
 case PJSIP_INV_STATE_CONFIRMED:
 if (session->inv_session->invite_tsx) {
 ast_debug(3, "%s: Delay sending BYE because of outstanding transaction...\n",
 ast_sip_session_get_name(session));
 /* If this is delayed the only thing that will happen is a BYE request so we don't
 * actually need to store the response code for when it happens.
 */
 delay_request(session, NULL, NULL, NULL, 0, DELAYED_METHOD_BYE, NULL, NULL, 1);
 break;
 }
 /* Fall through */
 default:
 status = pjsip_inv_end_session(session->inv_session, response, NULL, &packet);
 if (status == PJ_SUCCESS && packet) {
 struct ast_sip_session_delayed_request *delay;

 /* Flush any delayed requests so they cannot overlap this transaction. */
 while ((delay = AST_LIST_REMOVE_HEAD(&session->delayed_requests, next))) {
 delayed_request_free(delay);
 }

 if (packet->msg->type == PJSIP_RESPONSE_MSG) {
 ast_sip_session_send_response(session, packet);
 } else {
 ast_sip_session_send_request(session, packet);
 }
 }
 break;
 }
 SCOPE_EXIT_RTN();
}

static int session_termination_task(void *data)
{
 struct ast_sip_session *session = data;

 if (session->defer_terminate) {
 session->defer_terminate = 0;
 if (session->inv_session) {
 ast_sip_session_terminate(session, 0);
 }
 }

 ao2_ref(session, -1);
 return 0;
}

static void session_termination_cb(pj_timer_heap_t *timer_heap, struct pj_timer_entry *entry)
{
 struct ast_sip_session *session = entry->user_data;

 if (ast_sip_push_task(session->serializer, session_termination_task, session)) {
 ao2_cleanup(session);
 }
}

int ast_sip_session_defer_termination(struct ast_sip_session *session)
{
 pj_time_val delay = { .sec = 60, };
 int res;

 /* The session should not have an active deferred termination request. */
 ast_assert(!session->defer_terminate);

 session->defer_terminate = 1;

 session->defer_end = 1;
 session->ended_while_deferred = 0;

 ao2_ref(session, +1);
 pj_timer_entry_init(&session->scheduled_termination, 0, session, session_termination_cb);

 res = (pjsip_endpt_schedule_timer(ast_sip_get_pjsip_endpoint(),
 &session->scheduled_termination, &delay) != PJ_SUCCESS) ? -1 : 0;
 if (res) {
 session->defer_terminate = 0;
 ao2_ref(session, -1);
 }
 return res;
}

/*!
 * \internal
 * \brief Stop the defer termination timer if it is still running.
 * \since 13.5.0
 *
 * \param session Which session to stop the timer.
 *
 * \return Nothing
 */
static void sip_session_defer_termination_stop_timer(struct ast_sip_session *session)
{
 if (pj_timer_heap_cancel_if_active(pjsip_endpt_get_timer_heap(ast_sip_get_pjsip_endpoint()),
 &session->scheduled_termination, session->scheduled_termination.id)) {
 ao2_ref(session, -1);
 }
}

void ast_sip_session_defer_termination_cancel(struct ast_sip_session *session)
{
 if (!session->defer_terminate) {
 /* Already canceled or timer fired. */
 return;
 }

 session->defer_terminate = 0;

 if (session->terminate_while_deferred) {
 /* Complete the termination started by the upper layer. */
 ast_sip_session_terminate(session, 0);
 }

 /* Stop the termination timer if it is still running. */
 sip_session_defer_termination_stop_timer(session);
}

void ast_sip_session_end_if_deferred(struct ast_sip_session *session)
{
 if (!session->defer_end) {
 return;
 }

 session->defer_end = 0;

 if (session->ended_while_deferred) {
 /* Complete the session end started by the remote hangup. */
 ast_debug(3, "%s: Ending session after being deferred\n", ast_sip_session_get_name(session));
 session->ended_while_deferred = 0;
 session_end(session);
 }
}

struct ast_sip_session *ast_sip_dialog_get_session(pjsip_dialog *dlg)
{
 pjsip_inv_session *inv_session = pjsip_dlg_get_inv_session(dlg);
 struct ast_sip_session *session;

 if (!inv_session ||
 !(session = inv_session->mod_data[session_module.id])) {
 return NULL;
 }

 ao2_ref(session, +1);

 return session;
}

enum sip_get_destination_result {
 /*! The extension was successfully found */
 SIP_GET_DEST_EXTEN_FOUND,
 /*! The extension specified in the RURI was not found */
 SIP_GET_DEST_EXTEN_NOT_FOUND,
 /*! The extension specified in the RURI was a partial match */
 SIP_GET_DEST_EXTEN_PARTIAL,
 /*! The RURI is of an unsupported scheme */
 SIP_GET_DEST_UNSUPPORTED_URI,
};

/*!
 * \brief Determine where in the dialplan a call should go
 *
 * This uses the username in the request URI to try to match
 * an extension in the endpoint's configured context in order
 * to route the call.
 *
 * \param session The inbound SIP session
 * \param rdata The SIP INVITE
 */
static enum sip_get_destination_result get_destination(struct ast_sip_session *session, pjsip_rx_data *rdata)
{
 pjsip_uri *ruri = rdata->msg_info.msg->line.req.uri;
 pjsip_sip_uri *sip_ruri;
 struct ast_features_pickup_config *pickup_cfg;
 const char *pickupexten;

 if (!PJSIP_URI_SCHEME_IS_SIP(ruri) && !PJSIP_URI_SCHEME_IS_SIPS(ruri)) {
 return SIP_GET_DEST_UNSUPPORTED_URI;
 }

 sip_ruri = pjsip_uri_get_uri(ruri);
 ast_copy_pj_str(session->exten, &sip_ruri->user, sizeof(session->exten));

 /*
 * We may want to match in the dialplan without any user
 * options getting in the way.
 */
 AST_SIP_USER_OPTIONS_TRUNCATE_CHECK(session->exten);

 pickup_cfg = ast_get_chan_features_pickup_config(NULL); /* session->channel doesn't exist yet, using NULL */
 if (!pickup_cfg) {
 ast_log(LOG_ERROR, "%s: Unable to retrieve pickup configuration options. Unable to detect call pickup extension\n",
 ast_sip_session_get_name(session));
 pickupexten = "";
 } else {
 pickupexten = ast_strdupa(pickup_cfg->pickupexten);
 ao2_ref(pickup_cfg, -1);
 }

 if (!strcmp(session->exten, pickupexten) ||
 ast_exists_extension(NULL, session->endpoint->context, session->exten, 1, NULL)) {
 /*
 * Save off the INVITE Request-URI in case it is
 * needed: CHANNEL(pjsip,request_uri)
 */
 session->request_uri = pjsip_uri_clone(session->inv_session->pool, ruri);

 return SIP_GET_DEST_EXTEN_FOUND;
 }

 /*
 * Check for partial match via overlap dialling (if enabled)
 */
 if (session->endpoint->allow_overlap && (
 !strncmp(session->exten, pickupexten, strlen(session->exten)) ||
 ast_canmatch_extension(NULL, session->endpoint->context, session->exten, 1, NULL))) {
 /* Overlap partial match */
 return SIP_GET_DEST_EXTEN_PARTIAL;
 }

 return SIP_GET_DEST_EXTEN_NOT_FOUND;
}

/*
 * /internal
 * /brief Process initial answer for an incoming invite
 *
 * This function should only be called during the setup, and handling of a
 * new incoming invite. Most, if not all of the time, this will be called
 * when an error occurs and we need to respond as such.
 *
 * When a SIP session termination code is given for the answer it's assumed
 * this call then will be the final bit of processing before ending session
 * setup. As such, we've been holding a lock, and a reference on the invite
 * session's dialog. So before returning this function removes that reference,
 * and unlocks the dialog.
 *
 * \param inv_session The session on which to answer
 * \param rdata The original request
 * \param answer_code The answer's numeric code
 * \param terminate_code The termination code if the answer fails
 * \param notify Whether or not to call on_state_changed
 *
 * \retval 0 if invite successfully answered, -1 if an error occurred
 */
static int new_invite_initial_answer(pjsip_inv_session *inv_session, pjsip_rx_data *rdata,
 int answer_code, int terminate_code, pj_bool_t notify)
{
 pjsip_tx_data *tdata = NULL;
 int res = 0;

 if (inv_session->state != PJSIP_INV_STATE_DISCONNECTED) {
 if (pjsip_inv_initial_answer(
 inv_session, rdata, answer_code, NULL, NULL, &tdata) != PJ_SUCCESS) {

 pjsip_inv_terminate(inv_session, terminate_code ? terminate_code : answer_code, notify);
 res = -1;
 } else {
 pjsip_inv_send_msg(inv_session, tdata);
 }
 }

 if (answer_code >= 300) {
 /*
 * A session is ending. The dialog has a reference that needs to be
 * removed and holds a lock that needs to be unlocked before returning.
 */
 pjsip_dlg_dec_lock(inv_session->dlg);
 }

 return res;
}

/*
 * /internal
 * /brief Create and initialize a pjsip invite session

 * pjsip_inv_session adds, and maintains a reference to the dialog upon a successful
 * invite session creation until the session is destroyed. However, we'll wait to
 * remove the reference that was added for the dialog when it gets created since we're
 * not ready to unlock the dialog in this function.
 *
 * So, if this function successfully returns that means it returns with its newly
 * created, and associated dialog locked and with two references (i.e. dialog's
 * reference count should be 2).
 *
 * \param endpoint A pointer to the endpoint
 * \param rdata The request that is starting the dialog
 *
 * \retval A pjsip invite session object
 * \retval NULL on error
 */
static pjsip_inv_session *pre_session_setup(pjsip_rx_data *rdata, const struct ast_sip_endpoint *endpoint)
{
 pjsip_tx_data *tdata;
 pjsip_dialog *dlg;
 pjsip_inv_session *inv_session;
 unsigned int options = endpoint->extensions.flags;
 pj_status_t dlg_status = PJ_EUNKNOWN;

 if (pjsip_inv_verify_request(rdata, &options, NULL, NULL, ast_sip_get_pjsip_endpoint(), &tdata) != PJ_SUCCESS) {
 if (tdata) {
 if (pjsip_endpt_send_response2(ast_sip_get_pjsip_endpoint(), rdata, tdata, NULL, NULL) != PJ_SUCCESS) {
 pjsip_tx_data_dec_ref(tdata);
 }
 } else {
 pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 500, NULL, NULL, NULL);
 }
 return NULL;
 }

 dlg = ast_sip_create_dialog_uas_locked(endpoint, rdata, &dlg_status);
 if (!dlg) {
 if (dlg_status != PJ_EEXISTS) {
 pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 500, NULL, NULL, NULL);
 }
 return NULL;
 }

 /*
 * The returned dialog holds a lock and has a reference added. Any paths where the
 * dialog invite session is not returned must unlock the dialog and remove its reference.
 */

 if (pjsip_inv_create_uas(dlg, rdata, NULL, options, &inv_session) != PJ_SUCCESS) {
 pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 500, NULL, NULL, NULL);
 /*
 * The acquired dialog holds a lock, and a reference. Since the dialog is not
 * going to be returned here it must first be unlocked and de-referenced. This
 * must be done prior to calling dialog termination.
 */
 pjsip_dlg_dec_lock(dlg);
 pjsip_dlg_terminate(dlg);
 return NULL;
 }

#if defined(HAVE_PJSIP_REPLACE_MEDIA_STREAM) || defined(PJMEDIA_SDP_NEG_ALLOW_MEDIA_CHANGE)
 inv_session->sdp_neg_flags = PJMEDIA_SDP_NEG_ALLOW_MEDIA_CHANGE;
#endif
 if (pjsip_dlg_add_usage(dlg, &session_module, NULL) != PJ_SUCCESS) {
 /* Dialog's lock and a reference are removed in new_invite_initial_answer */
 new_invite_initial_answer(inv_session, rdata, 500, 500, PJ_FALSE);
 /* Remove 2nd reference added at inv_session creation */
 pjsip_dlg_dec_session(inv_session->dlg, &session_module);
 return NULL;
 }

 return inv_session;
}

struct new_invite {
 /*! \brief Session created for the new INVITE */
 struct ast_sip_session *session;

 /*! \brief INVITE request itself */
 pjsip_rx_data *rdata;
};

static int check_sdp_content_type_supported(pjsip_media_type *content_type)
{
 pjsip_media_type app_sdp;
 pjsip_media_type_init2(&app_sdp, "application", "sdp");

 if (!pjsip_media_type_cmp(content_type, &app_sdp, 0)) {
 return 1;
 }

 return 0;
}

static int check_content_disposition_in_multipart(pjsip_multipart_part *part)
{
 pjsip_hdr *hdr = part->hdr.next;
 static const pj_str_t str_handling_required = {"handling=required", 16};

 while (hdr != &part->hdr) {
 if (hdr->type == PJSIP_H_OTHER) {
 pjsip_generic_string_hdr *generic_hdr = (pjsip_generic_string_hdr*)hdr;

 if (!pj_stricmp2(&hdr->name, "Content-Disposition") &&
 pj_stristr(&generic_hdr->hvalue, &str_handling_required) &&
 !check_sdp_content_type_supported(&part->body->content_type)) {
 return 1;
 }
 }
 hdr = hdr->next;
 }

 return 0;
}

/**
 * if there is required media we don't understand, return 1
 */
static int check_content_disposition(pjsip_rx_data *rdata)
{
 pjsip_msg_body *body = rdata->msg_info.msg->body;
 pjsip_ctype_hdr *ctype_hdr = rdata->msg_info.ctype;

 if (body && ctype_hdr &&
 !pj_stricmp2(&ctype_hdr->media.type, "multipart") &&
 (!pj_stricmp2(&ctype_hdr->media.subtype, "mixed") ||
 !pj_stricmp2(&ctype_hdr->media.subtype, "alternative"))) {
 pjsip_multipart_part *part = pjsip_multipart_get_first_part(body);
 while (part != NULL) {
 if (check_content_disposition_in_multipart(part)) {
 return 1;
 }
 part = pjsip_multipart_get_next_part(body, part);
 }
 }
 return 0;
}

static int new_invite(struct new_invite *invite)
{
 pjsip_tx_data *tdata = NULL;
 pjsip_timer_setting timer;
 pjsip_rdata_sdp_info *sdp_info;
 pjmedia_sdp_session *local = NULL;
 char buffer[AST_SOCKADDR_BUFLEN];
 SCOPE_ENTER(3, "%s\n", ast_sip_session_get_name(invite->session));


 /* From this point on, any calls to pjsip_inv_terminate have the last argument as PJ_TRUE
 * so that we will be notified so we can destroy the session properly
 */

 if (invite->session->inv_session->state == PJSIP_INV_STATE_DISCONNECTED) {
 ast_trace_log(-1, LOG_ERROR, "%s: Session already DISCONNECTED [reason=%d (%s)]\n",
 ast_sip_session_get_name(invite->session),
 invite->session->inv_session->cause,
 pjsip_get_status_text(invite->session->inv_session->cause)->ptr);
 SCOPE_EXIT_RTN_VALUE(-1);
 }

 switch (get_destination(invite->session, invite->rdata)) {
 case SIP_GET_DEST_EXTEN_FOUND:
 /* Things worked. Keep going */
 break;
 case SIP_GET_DEST_UNSUPPORTED_URI:
 ast_trace(-1, "%s: Call (%s:%s) to extension '%s' - unsupported uri\n",
 ast_sip_session_get_name(invite->session),
 invite->rdata->tp_info.transport->type_name,
 pj_sockaddr_print(&invite->rdata->pkt_info.src_addr, buffer, sizeof(buffer), 3),
 invite->session->exten);
 if (pjsip_inv_initial_answer(invite->session->inv_session, invite->rdata, 416, NULL, NULL, &tdata) == PJ_SUCCESS) {
 ast_sip_session_send_response(invite->session, tdata);
 } else {
 pjsip_inv_terminate(invite->session->inv_session, 416, PJ_TRUE);
 }
 goto end;
 case SIP_GET_DEST_EXTEN_PARTIAL:
 ast_trace(-1, "%s: Call (%s:%s) to extension '%s' - partial match\n",
 ast_sip_session_get_name(invite->session),
 invite->rdata->tp_info.transport->type_name,
 pj_sockaddr_print(&invite->rdata->pkt_info.src_addr, buffer, sizeof(buffer), 3),
 invite->session->exten);

 if (pjsip_inv_initial_answer(invite->session->inv_session, invite->rdata, 484, NULL, NULL, &tdata) == PJ_SUCCESS) {
 ast_sip_session_send_response(invite->session, tdata);
 } else {
 pjsip_inv_terminate(invite->session->inv_session, 484, PJ_TRUE);
 }
 goto end;
 case SIP_GET_DEST_EXTEN_NOT_FOUND:
 default:
 ast_trace_log(-1, LOG_NOTICE, "%s: Call (%s:%s) to extension '%s' rejected because extension not found in context '%s'.\n",
 ast_sip_session_get_name(invite->session),
 invite->rdata->tp_info.transport->type_name,
 pj_sockaddr_print(&invite->rdata->pkt_info.src_addr, buffer, sizeof(buffer), 3),
 invite->session->exten,
 invite->session->endpoint->context);

 if (pjsip_inv_initial_answer(invite->session->inv_session, invite->rdata, 404, NULL, NULL, &tdata) == PJ_SUCCESS) {
 ast_sip_session_send_response(invite->session, tdata);
 } else {
 pjsip_inv_terminate(invite->session->inv_session, 404, PJ_TRUE);
 }
 goto end;
 };

 if (check_content_disposition(invite->rdata)) {
 if (pjsip_inv_initial_answer(invite->session->inv_session, invite->rdata, 415, NULL, NULL, &tdata) == PJ_SUCCESS) {
 ast_sip_session_send_response(invite->session, tdata);
 } else {
 pjsip_inv_terminate(invite->session->inv_session, 415, PJ_TRUE);
 }
 goto end;
 }

 pjsip_timer_setting_default(&timer);
 timer.min_se = invite->session->endpoint->extensions.timer.min_se;
 timer.sess_expires = invite->session->endpoint->extensions.timer.sess_expires;
 pjsip_timer_init_session(invite->session->inv_session, &timer);

 /*
 * At this point, we've verified what we can that won't take awhile,
 * so let's go ahead and send a 100 Trying out to stop any
 * retransmissions.
 */
 ast_trace(-1, "%s: Call (%s:%s) to extension '%s' sending 100 Trying\n",
 ast_sip_session_get_name(invite->session),
 invite->rdata->tp_info.transport->type_name,
 pj_sockaddr_print(&invite->rdata->pkt_info.src_addr, buffer, sizeof(buffer), 3),
 invite->session->exten);
 if (pjsip_inv_initial_answer(invite->session->inv_session, invite->rdata, 100, NULL, NULL, &tdata) != PJ_SUCCESS) {
 pjsip_inv_terminate(invite->session->inv_session, 500, PJ_TRUE);
 goto end;
 }
 ast_sip_session_send_response(invite->session, tdata);

 sdp_info = pjsip_rdata_get_sdp_info(invite->rdata);
 if (sdp_info && (sdp_info->sdp_err == PJ_SUCCESS) && sdp_info->sdp) {
 if (handle_incoming_sdp(invite->session, sdp_info->sdp)) {
 tdata = NULL;
 if (pjsip_inv_end_session(invite->session->inv_session, 488, NULL, &tdata) == PJ_SUCCESS
 && tdata) {
 ast_sip_session_send_response(invite->session, tdata);
 }
 goto end;
 }
 /* We are creating a local SDP which is an answer to their offer */
 local = create_local_sdp(invite->session->inv_session, invite->session, sdp_info->sdp);
 } else {
 /* We are creating a local SDP which is an offer */
 local = create_local_sdp(invite->session->inv_session, invite->session, NULL);
 }

 /* If we were unable to create a local SDP terminate the session early, it won't go anywhere */
 if (!local) {
 tdata = NULL;
 if (pjsip_inv_end_session(invite->session->inv_session, 500, NULL, &tdata) == PJ_SUCCESS
 && tdata) {
 ast_sip_session_send_response(invite->session, tdata);
 }
 goto end;
 }

 pjsip_inv_set_local_sdp(invite->session->inv_session, local);
 pjmedia_sdp_neg_set_prefer_remote_codec_order(invite->session->inv_session->neg, PJ_FALSE);
#ifdef PJMEDIA_SDP_NEG_ANSWER_MULTIPLE_CODECS
 if (!invite->session->endpoint->preferred_codec_only) {
 pjmedia_sdp_neg_set_answer_multiple_codecs(invite->session->inv_session->neg, PJ_TRUE);
 }
#endif

 handle_incoming_request(invite->session, invite->rdata);

end:
 SCOPE_EXIT_RTN_VALUE(0, "%s\n", ast_sip_session_get_name(invite->session));
}

static void handle_new_invite_request(pjsip_rx_data *rdata)
{
 RAII_VAR(struct ast_sip_endpoint *, endpoint,
 ast_pjsip_rdata_get_endpoint(rdata), ao2_cleanup);
 pjsip_inv_session *inv_session = NULL;
 struct ast_sip_session *session;
 struct new_invite invite;
 char *req_uri = TRACE_ATLEAST(1) ? ast_alloca(256) : "";
 int res = TRACE_ATLEAST(1) ? pjsip_uri_print(PJSIP_URI_IN_REQ_URI, rdata->msg_info.msg->line.req.uri, req_uri, 256) : 0;
 SCOPE_ENTER(1, "Request: %s\n", res ? req_uri : "");

 ast_assert(endpoint != NULL);

 inv_session = pre_session_setup(rdata, endpoint);
 if (!inv_session) {
 /* pre_session_setup() returns a response on failure */
 SCOPE_EXIT_RTN("Failure in pre session setup\n");
 }

 /*
 * Upon a successful pre_session_setup the associated dialog is returned locked
 * and with an added reference. Well actually two references. One added when the
 * dialog itself was created, and another added when the pjsip invite session was
 * created and the dialog was added to it.
 *
 * In order to ensure the dialog's, and any of its internal attributes, lifetimes
 * we'll hold the lock and maintain the reference throughout the entire new invite
 * handling process. See ast_sip_create_dialog_uas_locked for more details but,
 * basically we do this to make sure a transport failure does not destroy the dialog
 * and/or transaction out from underneath us between pjsip calls. Alternatively, we
 * could probably release the lock if we needed to, but then we'd have to re-lock and
 * check the dialog and transaction prior to every pjsip call.
 *
 * That means any off nominal/failure paths in this function must remove the associated
 * dialog reference added at dialog creation, and remove the lock. As well the
 * referenced pjsip invite session must be "cleaned up", which should also then
 * remove its reference to the dialog at that time.
 *
 * Nominally we'll unlock the dialog, and release the reference when all new invite
 * process handling has successfully completed.
 */

 session = ast_sip_session_alloc(endpoint, NULL, inv_session, rdata);
 if (!session) {
 /* Dialog's lock and reference are removed in new_invite_initial_answer */
 if (!new_invite_initial_answer(inv_session, rdata, 500, 500, PJ_FALSE)) {
 /* Terminate the session if it wasn't done in the answer */
 pjsip_inv_terminate(inv_session, 500, PJ_FALSE);
 }
 SCOPE_EXIT_RTN("Couldn't create session\n");
 }
 session->call_direction = AST_SIP_SESSION_INCOMING_CALL;

 /*
 * The current thread is supposed be the session serializer to prevent
 * any initial INVITE retransmissions from trying to setup the same
 * call again.
 */
 ast_assert(ast_taskprocessor_is_task(session->serializer));

 invite.session = session;
 invite.rdata = rdata;
 new_invite(&invite);

 /*
 * The dialog lock and reference added at dialog creation time must be
 * maintained throughout the new invite process. Since we're pretty much
 * done at this point with things it's safe to go ahead and remove the lock
 * and the reference here. See ast_sip_create_dialog_uas_locked for more info.
 *
 * Note, any future functionality added that does work using the dialog must
 * be done before this.
 */
 pjsip_dlg_dec_lock(inv_session->dlg);

 SCOPE_EXIT("Request: %s Session: %s\n", req_uri, ast_sip_session_get_name(session));
 ao2_ref(session, -1);
}

static pj_bool_t does_method_match(const pj_str_t *message_method, const char *supplement_method)
{
 pj_str_t method;

 if (ast_strlen_zero(supplement_method)) {
 return PJ_TRUE;
 }

 pj_cstr(&method, supplement_method);

 return pj_stristr(&method, message_method) ? PJ_TRUE : PJ_FALSE;
}

static pj_bool_t has_supplement(const struct ast_sip_session *session, const pjsip_rx_data *rdata)
{
 struct ast_sip_session_supplement *supplement;
 struct pjsip_method *method = &rdata->msg_info.msg->line.req.method;

 if (!session) {
 return PJ_FALSE;
 }

 AST_LIST_TRAVERSE(&session->supplements, supplement, next) {
 if (does_method_match(&method->name, supplement->method)) {
 return PJ_TRUE;
 }
 }
 return PJ_FALSE;
}

/*!
 * \internal
 * Added for debugging purposes
 */
static void session_on_tsx_state(pjsip_transaction *tsx, pjsip_event *e)
{

 pjsip_dialog *dlg = pjsip_tsx_get_dlg(tsx);
 pjsip_inv_session *inv_session = (dlg ? pjsip_dlg_get_inv_session(dlg) : NULL);
 struct ast_sip_session *session = (inv_session ? inv_session->mod_data[session_module.id] : NULL);
 SCOPE_ENTER(1, "%s TSX State: %s Inv State: %s\n", ast_sip_session_get_name(session),
 pjsip_tsx_state_str(tsx->state), inv_session ? pjsip_inv_state_name(inv_session->state) : "unknown");

 if (session) {
 ast_trace(2, "Topology: Pending: %s Active: %s\n",
 ast_str_tmp(256, ast_stream_topology_to_str(session->pending_media_state->topology, &STR_TMP)),
 ast_str_tmp(256, ast_stream_topology_to_str(session->active_media_state->topology, &STR_TMP)));
 }

 SCOPE_EXIT_RTN();
}

/*!
 * \internal
 * Added for debugging purposes
 */
static pj_bool_t session_on_rx_response(pjsip_rx_data *rdata)
{

 struct pjsip_status_line status = rdata->msg_info.msg->line.status;
 pjsip_dialog *dlg = pjsip_rdata_get_dlg(rdata);
 pjsip_inv_session *inv_session = dlg ? pjsip_dlg_get_inv_session(dlg) : NULL;
 struct ast_sip_session *session = (inv_session ? inv_session->mod_data[session_module.id] : NULL);
 SCOPE_ENTER(1, "%s Method: %.*s Status: %d\n", ast_sip_session_get_name(session),
 (int)rdata->msg_info.cseq->method.name.slen, rdata->msg_info.cseq->method.name.ptr, status.code);

 SCOPE_EXIT_RTN_VALUE(PJ_FALSE);
}

/*!
 * \brief Called when a new SIP request comes into PJSIP
 *
 * This function is called under two circumstances
 * 1) An out-of-dialog request is received by PJSIP
 * 2) An in-dialog request that the inv_session layer does not
 * handle is received (such as an in-dialog INFO)
 *
 * Except for INVITEs, there is very little we actually do in this function
 * 1) For requests we don't handle, we return PJ_FALSE
 * 2) For new INVITEs, handle them now to prevent retransmissions from
 * trying to setup the same call again.
 * 3) For in-dialog requests we handle, we process them in the
 * .on_state_changed = session_inv_on_state_changed or
 * .on_tsx_state_changed = session_inv_on_tsx_state_changed
 * callbacks instead.
 */
static pj_bool_t session_on_rx_request(pjsip_rx_data *rdata)
{
 pj_status_t handled = PJ_FALSE;
 struct pjsip_request_line req = rdata->msg_info.msg->line.req;
 pjsip_dialog *dlg = pjsip_rdata_get_dlg(rdata);
 pjsip_inv_session *inv_session = (dlg ? pjsip_dlg_get_inv_session(dlg) : NULL);
 struct ast_sip_session *session = (inv_session ? inv_session->mod_data[session_module.id] : NULL);
 char *req_uri = TRACE_ATLEAST(1) ? ast_alloca(256) : "";
 int res = TRACE_ATLEAST(1) ? pjsip_uri_print(PJSIP_URI_IN_REQ_URI, rdata->msg_info.msg->line.req.uri, req_uri, 256) : 0;
 SCOPE_ENTER(1, "%s Request: %.*s %s\n", ast_sip_session_get_name(session),
 (int) pj_strlen(&req.method.name), pj_strbuf(&req.method.name), res ? req_uri : "");

 switch (req.method.id) {
 case PJSIP_INVITE_METHOD:
 if (dlg) {
 ast_log(LOG_WARNING, "on_rx_request called for INVITE in mid-dialog?\n");
 break;
 }
 handled = PJ_TRUE;
 handle_new_invite_request(rdata);
 break;
 default:
 /* Handle other in-dialog methods if their supplements have been registered */
 handled = dlg && (inv_session = pjsip_dlg_get_inv_session(dlg)) &&
 has_supplement(inv_session->mod_data[session_module.id], rdata);
 break;
 }

 SCOPE_EXIT_RTN_VALUE(handled, "%s Handled request %.*s %s ? %s\n", ast_sip_session_get_name(session),
 (int) pj_strlen(&req.method.name), pj_strbuf(&req.method.name), req_uri,
 handled == PJ_TRUE ? "yes" : "no");
}

static void resend_reinvite(pj_timer_heap_t *timer, pj_timer_entry *entry)
{
 struct ast_sip_session *session = entry->user_data;

 ast_debug(3, "%s: re-INVITE collision timer expired.\n",
 ast_sip_session_get_name(session));

 if (AST_LIST_EMPTY(&session->delayed_requests)) {
 /* No delayed request pending, so just return */
 ao2_ref(session, -1);
 return;
 }
 if (ast_sip_push_task(session->serializer, invite_collision_timeout, session)) {
 /*
 * Uh oh. We now have nothing in the foreseeable future
 * to trigger sending the delayed requests.
 */
 ao2_ref(session, -1);
 }
}

static void reschedule_reinvite(struct ast_sip_session *session, ast_sip_session_response_cb on_response)
{
 pjsip_inv_session *inv = session->inv_session;
 pj_time_val tv;
 struct ast_sip_session_media_state *pending_media_state = NULL;
 struct ast_sip_session_media_state *active_media_state = NULL;
 const char *session_name = ast_sip_session_get_name(session);
 int use_pending = 0;
 int use_active = 0;

 SCOPE_ENTER(3, "%s\n", session_name);

 /*
 * If the two media state topologies are the same this means that the session refresh request
 * did not specify a desired topology, so it does not care. If that is the case we don't even
 * pass one in here resulting in the current topology being used. It's possible though that
 * either one of the topologies could be NULL so we have to test for that before we check for
 * equality.
 */

 /* We only want to clone a media state if its topology is not null */
 use_pending = session->pending_media_state->topology != NULL;
 use_active = session->active_media_state->topology != NULL;

 /*
 * If both media states have topologies, we can test for equality. If they're equal we're not going to
 * clone either states.
 */
 if (use_pending && use_active && ast_stream_topology_equal(session->active_media_state->topology, session->pending_media_state->topology)) {
 use_pending = 0;
 use_active = 0;
 }

 if (use_pending) {
 pending_media_state = ast_sip_session_media_state_clone(session->pending_media_state);
 if (!pending_media_state) {
 SCOPE_EXIT_LOG_RTN(LOG_ERROR, "%s: Failed to clone pending media state\n", session_name);
 }
 }

 if (use_active) {
 active_media_state = ast_sip_session_media_state_clone(session->active_media_state);
 if (!active_media_state) {
 ast_sip_session_media_state_free(pending_media_state);
 SCOPE_EXIT_LOG_RTN(LOG_ERROR, "%s: Failed to clone active media state\n", session_name);
 }
 }

 if (delay_request(session, NULL, NULL, on_response, 1, DELAYED_METHOD_INVITE, pending_media_state,
 active_media_state, 1)) {
 ast_sip_session_media_state_free(pending_media_state);
 ast_sip_session_media_state_free(active_media_state);
 SCOPE_EXIT_LOG_RTN(LOG_ERROR, "%s: Failed to add delayed request\n", session_name);
 }

 if (pj_timer_entry_running(&session->rescheduled_reinvite)) {
 /* Timer already running. Something weird is going on. */
 SCOPE_EXIT_LOG_RTN(LOG_ERROR, "%s: re-INVITE collision while timer running!!!\n", session_name);
 }

 tv.sec = 0;
 if (inv->role == PJSIP_ROLE_UAC) {
 tv.msec = 2100 + ast_random() % 2000;
 } else {
 tv.msec = ast_random() % 2000;
 }
 pj_timer_entry_init(&session->rescheduled_reinvite, 0, session, resend_reinvite);

 ao2_ref(session, +1);
 if (pjsip_endpt_schedule_timer(ast_sip_get_pjsip_endpoint(),
 &session->rescheduled_reinvite, &tv) != PJ_SUCCESS) {
 ao2_ref(session, -1);
 SCOPE_EXIT_LOG_RTN(LOG_ERROR, "%s: Couldn't schedule timer\n", session_name);
 }

 SCOPE_EXIT_RTN();
}

static void __print_debug_details(const char *function, pjsip_inv_session *inv, pjsip_transaction *tsx, pjsip_event *e)
{
 int id = session_module.id;
 struct ast_sip_session *session = NULL;

 if (!DEBUG_ATLEAST(5)) {
 /* Debug not spamy enough */
 return;
 }

 ast_log(LOG_DEBUG, "Function %s called on event %s\n",
 function, pjsip_event_str(e->type));
 if (!inv) {
 ast_log(LOG_DEBUG, "Transaction %p does not belong to an inv_session?\n", tsx);
 ast_log(LOG_DEBUG, "The transaction state is %s\n",
 pjsip_tsx_state_str(tsx->state));
 return;
 }
 if (id > -1) {
 session = inv->mod_data[session_module.id];
 }
 if (!session) {
 ast_log(LOG_DEBUG, "inv_session %p has no ast session\n", inv);
 } else {
 ast_log(LOG_DEBUG, "The state change pertains to the endpoint '%s(%s)'\n",
 ast_sorcery_object_get_id(session->endpoint),
 session->channel ? ast_channel_name(session->channel) : "");
 }
 if (inv->invite_tsx) {
 ast_log(LOG_DEBUG, "The inv session still has an invite_tsx (%p)\n",
 inv->invite_tsx);
 } else {
 ast_log(LOG_DEBUG, "The inv session does NOT have an invite_tsx\n");
 }
 if (tsx) {
 ast_log(LOG_DEBUG, "The %s %.*s transaction involved in this state change is %p\n",
 pjsip_role_name(tsx->role),
 (int) pj_strlen(&tsx->method.name), pj_strbuf(&tsx->method.name),
 tsx);
 ast_log(LOG_DEBUG, "The current transaction state is %s\n",
 pjsip_tsx_state_str(tsx->state));
 ast_log(LOG_DEBUG, "The transaction state change event is %s\n",
 pjsip_event_str(e->body.tsx_state.type));
 } else {
 ast_log(LOG_DEBUG, "There is no transaction involved in this state change\n");
 }
 ast_log(LOG_DEBUG, "The current inv state is %s\n", pjsip_inv_state_name(inv->state));
}

#define print_debug_details(inv, tsx, e) __print_debug_details(__PRETTY_FUNCTION__, (inv), (tsx), (e))

static void handle_incoming_request(struct ast_sip_session *session, pjsip_rx_data *rdata)
{
 struct ast_sip_session_supplement *supplement;
 struct pjsip_request_line req = rdata->msg_info.msg->line.req;
 SCOPE_ENTER(3, "%s: Method is %.*s\n", ast_sip_session_get_name(session), (int) pj_strlen(&req.method.name), pj_strbuf(&req.method.name));

 AST_LIST_TRAVERSE(&session->supplements, supplement, next) {
 if (supplement->incoming_request && does_method_match(&req.method.name, supplement->method)) {
 if (supplement->incoming_request(session, rdata)) {
 break;
 }
 }
 }

 SCOPE_EXIT("%s\n", ast_sip_session_get_name(session));
}

static void handle_session_begin(struct ast_sip_session *session)
{
 struct ast_sip_session_supplement *iter;

 AST_LIST_TRAVERSE(&session->supplements, iter, next) {
 if (iter->session_begin) {
 iter->session_begin(session);
 }
 }
}

static void handle_session_destroy(struct ast_sip_session *session)
{
 struct ast_sip_session_supplement *iter;

 AST_LIST_TRAVERSE(&session->supplements, iter, next) {
 if (iter->session_destroy) {
 iter->session_destroy(session);
 }
 }
}

static void handle_session_end(struct ast_sip_session *session)
{
 struct ast_sip_session_supplement *iter;

 /* Session is dead. Notify the supplements. */
 AST_LIST_TRAVERSE(&session->supplements, iter, next) {
 if (iter->session_end) {
 iter->session_end(session);
 }
 }
}

static void handle_incoming_response(struct ast_sip_session *session, pjsip_rx_data *rdata,
 enum ast_sip_session_response_priority response_priority)
{
 struct ast_sip_session_supplement *supplement;
 struct pjsip_status_line status = rdata->msg_info.msg->line.status;
 SCOPE_ENTER(3, "%s: Response is %d %.*s\n", ast_sip_session_get_name(session),
 status.code, (int) pj_strlen(&status.reason), pj_strbuf(&status.reason));

 AST_LIST_TRAVERSE(&session->supplements, supplement, next) {
 if (!(supplement->response_priority & response_priority)) {
 continue;
 }
 if (supplement->incoming_response && does_method_match(&rdata->msg_info.cseq->method.name, supplement->method)) {
 supplement->incoming_response(session, rdata);
 }
 }

 SCOPE_EXIT("%s\n", ast_sip_session_get_name(session));
}

static int handle_incoming(struct ast_sip_session *session, pjsip_rx_data *rdata,
 enum ast_sip_session_response_priority response_priority)
{
 if (rdata->msg_info.msg->type == PJSIP_REQUEST_MSG) {
 handle_incoming_request(session, rdata);
 } else {
 handle_incoming_response(session, rdata, response_priority);
 }

 return 0;
}

static void handle_outgoing_request(struct ast_sip_session *session, pjsip_tx_data *tdata)
{
 struct ast_sip_session_supplement *supplement;
 struct pjsip_request_line req = tdata->msg->line.req;
 SCOPE_ENTER(3, "%s: Method is %.*s\n", ast_sip_session_get_name(session),
 (int) pj_strlen(&req.method.name), pj_strbuf(&req.method.name));

 ast_sip_message_apply_transport(session->endpoint->transport, tdata);

 AST_LIST_TRAVERSE(&session->supplements, supplement, next) {
 if (supplement->outgoing_request && does_method_match(&req.method.name, supplement->method)) {
 supplement->outgoing_request(session, tdata);
 }
 }
 SCOPE_EXIT("%s\n", ast_sip_session_get_name(session));
}

static void handle_outgoing_response(struct ast_sip_session *session, pjsip_tx_data *tdata)
{
 struct ast_sip_session_supplement *supplement;
 struct pjsip_status_line status = tdata->msg->line.status;
 pjsip_cseq_hdr *cseq = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_CSEQ, NULL);
 SCOPE_ENTER(3, "%s: Method is %.*s, Response is %d %.*s\n", ast_sip_session_get_name(session),
 (int) pj_strlen(&cseq->method.name),
 pj_strbuf(&cseq->method.name), status.code, (int) pj_strlen(&status.reason),
 pj_strbuf(&status.reason));


 if (!cseq) {
 SCOPE_EXIT_LOG_RTN(LOG_ERROR, "%s: Cannot send response due to missing sequence header",
 ast_sip_session_get_name(session));
 }

 ast_sip_message_apply_transport(session->endpoint->transport, tdata);

 AST_LIST_TRAVERSE(&session->supplements, supplement, next) {
 if (supplement->outgoing_response && does_method_match(&cseq->method.name, supplement->method)) {
 supplement->outgoing_response(session, tdata);
 }
 }

 SCOPE_EXIT("%s\n", ast_sip_session_get_name(session));
}

static int session_end(void *vsession)
{
 struct ast_sip_session *session = vsession;

 /* Stop the scheduled termination */
 sip_session_defer_termination_stop_timer(session);

 /* Session is dead. Notify the supplements. */
 handle_session_end(session);

 return 0;
}

/*!
 * \internal
 * \brief Complete ending session activities.
 * \since 13.5.0
 *
 * \param vsession Which session to complete stopping.
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
static int session_end_completion(void *vsession)
{
 struct ast_sip_session *session = vsession;

 ast_sip_dialog_set_serializer(session->inv_session->dlg, NULL);
 ast_sip_dialog_set_endpoint(session->inv_session->dlg, NULL);

 /* Now we can release the ref that was held by session->inv_session */
 ao2_cleanup(session);
 return 0;
}

static int check_request_status(pjsip_inv_session *inv, pjsip_event *e)
{
 struct ast_sip_session *session = inv->mod_data[session_module.id];
 pjsip_transaction *tsx = e->body.tsx_state.tsx;

 if (tsx->status_code != 503 && tsx->status_code != 408) {
 return 0;
 }

 if (!ast_sip_failover_request(tsx->last_tx)) {
 return 0;
 }

 pjsip_inv_uac_restart(inv, PJ_FALSE);
 /*
 * Bump the ref since it will be on a new transaction and
 * we don't want it to go away along with the old transaction.
 */
 pjsip_tx_data_add_ref(tsx->last_tx);
 ast_sip_session_send_request(session, tsx->last_tx);
 return 1;
}

static void handle_incoming_before_media(pjsip_inv_session *inv,
 struct ast_sip_session *session, pjsip_rx_data *rdata)
{
 pjsip_msg *msg;
 ast_debug(3, "%s: Received %s\n", ast_sip_session_get_name(session), rdata->msg_info.msg->type == PJSIP_REQUEST_MSG ?
 "request" : "response");


 handle_incoming(session, rdata, AST_SIP_SESSION_BEFORE_MEDIA);
 msg = rdata->msg_info.msg;
 if (msg->type == PJSIP_REQUEST_MSG
 && msg->line.req.method.id == PJSIP_ACK_METHOD
 && pjmedia_sdp_neg_get_state(inv->neg) != PJMEDIA_SDP_NEG_STATE_DONE) {
 pjsip_tx_data *tdata;

 /*
 * SDP negotiation failed on an incoming call that delayed
 * negotiation and then gave us an invalid SDP answer. We
 * need to send a BYE to end the call because of the invalid
 * SDP answer.
 */
 ast_debug(1,
 "%s: Ending session due to incomplete SDP negotiation. %s\n",
 ast_sip_session_get_name(session),
 pjsip_rx_data_get_info(rdata));
 if (pjsip_inv_end_session(inv, 400, NULL, &tdata) == PJ_SUCCESS
 && tdata) {
 ast_sip_session_send_request(session, tdata);
 }
 }
}

static void session_inv_on_state_changed(pjsip_inv_session *inv, pjsip_event *e)
{
 pjsip_event_id_e type;
 struct ast_sip_session *session = inv->mod_data[session_module.id];
 SCOPE_ENTER(1, "%s Event: %s Inv State: %s\n", ast_sip_session_get_name(session),
 pjsip_event_str(e->type), pjsip_inv_state_name(inv->state));

 if (ast_shutdown_final()) {
 SCOPE_EXIT_RTN("Shutting down\n");
 }

 if (e) {
 print_debug_details(inv, NULL, e);
 type = e->type;
 } else {
 type = PJSIP_EVENT_UNKNOWN;
 }

 session = inv->mod_data[session_module.id];
 if (!session) {
 SCOPE_EXIT_RTN("No session\n");
 }

 switch(type) {
 case PJSIP_EVENT_TX_MSG:
 break;
 case PJSIP_EVENT_RX_MSG:
 handle_incoming_before_media(inv, session, e->body.rx_msg.rdata);
 break;
 case PJSIP_EVENT_TSX_STATE:
 ast_debug(3, "%s: Source of transaction state change is %s\n", ast_sip_session_get_name(session),
 pjsip_event_str(e->body.tsx_state.type));
 /* Transaction state changes are prompted by some other underlying event. */
 switch(e->body.tsx_state.type) {
 case PJSIP_EVENT_TX_MSG:
 break;
 case PJSIP_EVENT_RX_MSG:
 if (!check_request_status(inv, e)) {
 handle_incoming_before_media(inv, session, e->body.tsx_state.src.rdata);
 }
 break;
 case PJSIP_EVENT_TRANSPORT_ERROR:
 case PJSIP_EVENT_TIMER:
 /*
 * Check the request status on transport error or timeout. A transport
 * error can occur when a TCP socket closes and that can be the result
 * of a 503. Also we may need to failover on a timeout (408).
 */
 check_request_status(inv, e);
 break;
 case PJSIP_EVENT_USER:
 case PJSIP_EVENT_UNKNOWN:
 case PJSIP_EVENT_TSX_STATE:
 /* Inception? */
 break;
 }
 break;
 case PJSIP_EVENT_TRANSPORT_ERROR:
 case PJSIP_EVENT_TIMER:
 case PJSIP_EVENT_UNKNOWN:
 case PJSIP_EVENT_USER:
 default:
 break;
 }

 if (inv->state == PJSIP_INV_STATE_DISCONNECTED) {
 if (session->defer_end) {
 ast_debug(3, "%s: Deferring session end\n", ast_sip_session_get_name(session));
 session->ended_while_deferred = 1;
 SCOPE_EXIT_RTN("Deferring\n");
 }

 if (ast_sip_push_task(session->serializer, session_end, session)) {
 /* Do it anyway even though this is not the right thread. */
 session_end(session);
 }
 }

 SCOPE_EXIT_RTN();
}

static void session_inv_on_new_session(pjsip_inv_session *inv, pjsip_event *e)
{
 /* XXX STUB */
}

static int session_end_if_disconnected(int id, pjsip_inv_session *inv)
{
 struct ast_sip_session *session;

 if (inv->state != PJSIP_INV_STATE_DISCONNECTED) {
 return 0;
 }

 /*
 * We are locking because ast_sip_dialog_get_session() needs
 * the dialog locked to get the session by other threads.
 */
 pjsip_dlg_inc_lock(inv->dlg);
 session = inv->mod_data[id];
 inv->mod_data[id] = NULL;
 pjsip_dlg_dec_lock(inv->dlg);

 /*
 * Pass the session ref held by session->inv_session to
 * session_end_completion().
 */
 if (session
 && ast_sip_push_task(session->serializer, session_end_completion, session)) {
 /* Do it anyway even though this is not the right thread. */
 session_end_completion(session);
 }

 return 1;
}

static void session_inv_on_tsx_state_changed(pjsip_inv_session *inv, pjsip_transaction *tsx, pjsip_event *e)
{
 ast_sip_session_response_cb cb;
 int id = session_module.id;
 pjsip_tx_data *tdata;
 struct ast_sip_session *session = inv->mod_data[session_module.id];
 SCOPE_ENTER(1, "%s TSX State: %s Inv State: %s\n", ast_sip_session_get_name(session),
 pjsip_tsx_state_str(tsx->state), pjsip_inv_state_name(inv->state));

 if (ast_shutdown_final()) {
 SCOPE_EXIT_RTN("Shutting down\n");
 }

 session = inv->mod_data[id];

 print_debug_details(inv, tsx, e);
 if (!session) {
 /* The session has ended. Ignore the transaction change. */
 SCOPE_EXIT_RTN("Session ended\n");
 }

 /*
 * If the session is disconnected really nothing else to do unless currently transacting
 * a BYE. If a BYE then hold off destruction until the transaction timeout occurs. This
 * has to be done for BYEs because sometimes the dialog can be in a disconnected
 * state but the BYE request transaction has not yet completed.
 */
 if (tsx->method.id != PJSIP_BYE_METHOD && session_end_if_disconnected(id, inv)) {
 SCOPE_EXIT_RTN("Disconnected\n");
 }

 switch (e->body.tsx_state.type) {
 case PJSIP_EVENT_TX_MSG:
 /* When we create an outgoing request, we do not have access to the transaction that
 * is created. Instead, We have to place transaction-specific data in the tdata. Here,
 * we transfer the data into the transaction. This way, when we receive a response, we
 * can dig this data out again
 */
 tsx->mod_data[id] = e->body.tsx_state.src.tdata->mod_data[id];
 break;
 case PJSIP_EVENT_RX_MSG:
 cb = ast_sip_mod_data_get(tsx->mod_data, id, MOD_DATA_ON_RESPONSE);
 /* As the PJSIP invite session implementation responds with a 200 OK before we have a
 * chance to be invoked session supplements for BYE requests actually end up executing
 * in the invite session state callback as well. To prevent session supplements from
 * running on the BYE request again we explicitly squash invocation of them here.
 */
 if ((e->body.tsx_state.src.rdata->msg_info.msg->type != PJSIP_REQUEST_MSG) ||
 (tsx->method.id != PJSIP_BYE_METHOD)) {
 handle_incoming(session, e->body.tsx_state.src.rdata,
 AST_SIP_SESSION_AFTER_MEDIA);
 }
 if (tsx->method.id == PJSIP_INVITE_METHOD) {
 if (tsx->role == PJSIP_ROLE_UAC) {
 if (tsx->state == PJSIP_TSX_STATE_COMPLETED) {
 /* This means we got a non 2XX final response to our outgoing INVITE */
 if (tsx->status_code == PJSIP_SC_REQUEST_PENDING) {
 reschedule_reinvite(session, cb);
 SCOPE_EXIT_RTN("Non 2XX final response\n");
 }
 if (inv->state == PJSIP_INV_STATE_CONFIRMED) {
 ast_debug(1, "%s: reINVITE received final response code %d\n",
 ast_sip_session_get_name(session),
 tsx->status_code);
 if ((tsx->status_code == 401 || tsx->status_code == 407)
 && ++session->authentication_challenge_count < MAX_RX_CHALLENGES
 && !ast_sip_create_request_with_auth(
 &session->endpoint->outbound_auths,
 e->body.tsx_state.src.rdata, tsx->last_tx, &tdata)) {
 /* Send authed reINVITE */
 ast_sip_session_send_request_with_cb(session, tdata, cb);
 SCOPE_EXIT_RTN("Sending authed reinvite\n");
 }
 /* Per RFC3261 14.1 a response to a re-INVITE should only terminate
 * the dialog if a 481 or 408 occurs. All other responses should leave
 * the dialog untouched.
 */
 if (tsx->status_code == 481 || tsx->status_code == 408) {
 if (pjsip_inv_end_session(inv, 500, NULL, &tdata) == PJ_SUCCESS
 && tdata) {
 ast_sip_session_send_request(session, tdata);
 }
 }
 }
 } else if (tsx->state == PJSIP_TSX_STATE_TERMINATED) {
 if (!inv->cancelling
 && inv->role == PJSIP_ROLE_UAC
 && inv->state == PJSIP_INV_STATE_CONFIRMED
 && pjmedia_sdp_neg_was_answer_remote(inv->neg)
 && pjmedia_sdp_neg_get_state(inv->neg) == PJMEDIA_SDP_NEG_STATE_DONE
 && (session->channel && ast_channel_hangupcause(session->channel) == AST_CAUSE_BEARERCAPABILITY_NOTAVAIL)
 ) {
 /*
 * We didn't send a CANCEL but the UAS sent us the 200 OK with an invalid or unacceptable codec SDP.
 * In this case the SDP negotiation is incomplete and PJPROJECT has already sent the ACK.
 * So, we send the BYE with 503 status code here. And the actual hangup cause code is already set
 * to AST_CAUSE_BEARERCAPABILITY_NOTAVAIL by the session_inv_on_media_update(), setting the 503
 * status code doesn't affect to hangup cause code.
 */
 ast_debug(1, "Endpoint '%s(%s)': Ending session due to 200 OK with incomplete SDP negotiation. %s\n",
 ast_sorcery_object_get_id(session->endpoint),
 session->channel ? ast_channel_name(session->channel) : "",
 pjsip_rx_data_get_info(e->body.tsx_state.src.rdata));
 pjsip_inv_end_session(session->inv_session, 503, NULL, &tdata);
 SCOPE_EXIT_RTN("Incomplete SDP negotiation\n");
 }

 if (inv->cancelling && tsx->status_code == PJSIP_SC_OK) {
 int sdp_negotiation_done =
 pjmedia_sdp_neg_get_state(inv->neg) == PJMEDIA_SDP_NEG_STATE_DONE;

 /*
 * We can get here for the following reasons.
 *
 * 1) The race condition detailed in RFC5407 section 3.1.2.
 * We sent a CANCEL at the same time that the UAS sent us a
 * 200 OK with a valid SDP for the original INVITE. As a
 * result, we have now received a 200 OK for a cancelled
 * call and the SDP negotiation is complete. We need to
 * immediately send a BYE to end the dialog.
 *
 * 2) We sent a CANCEL and hit the race condition but the
 * UAS sent us an invalid SDP with the 200 OK. In this case
 * the SDP negotiation is incomplete and PJPROJECT has
 * already sent the BYE for us because of the invalid SDP.
 */
 ast_test_suite_event_notify("PJSIP_SESSION_CANCELED",
 "Endpoint: %s\r\n"
 "Channel: %s\r\n"
 "Message: %s\r\n"
 "SDP: %s",
 ast_sorcery_object_get_id(session->endpoint),
 session->channel ? ast_channel_name(session->channel) : "",
 pjsip_rx_data_get_info(e->body.tsx_state.src.rdata),
 sdp_negotiation_done ? "complete" : "incomplete");
 if (!sdp_negotiation_done) {
 ast_debug(1, "%s: Incomplete SDP negotiation cancelled session. %s\n",
 ast_sip_session_get_name(session),
 pjsip_rx_data_get_info(e->body.tsx_state.src.rdata));
 } else if (pjsip_inv_end_session(inv, 500, NULL, &tdata) == PJ_SUCCESS
 && tdata) {
 ast_debug(1, "%s: Ending session due to RFC5407 race condition. %s\n",
 ast_sip_session_get_name(session),
 pjsip_rx_data_get_info(e->body.tsx_state.src.rdata));
 ast_sip_session_send_request(session, tdata);
 }
 }
 }
 }
 } else {
 /* All other methods */
 if (tsx->role == PJSIP_ROLE_UAC) {
 if (tsx->state == PJSIP_TSX_STATE_COMPLETED) {
 /* This means we got a final response to our outgoing method */
 ast_debug(1, "%s: %.*s received final response code %d\n",
 ast_sip_session_get_name(session),
 (int) pj_strlen(&tsx->method.name), pj_strbuf(&tsx->method.name),
 tsx->status_code);
 if ((tsx->status_code == 401 || tsx->status_code == 407)
 && ++session->authentication_challenge_count < MAX_RX_CHALLENGES
 && !ast_sip_create_request_with_auth(
 &session->endpoint->outbound_auths,
 e->body.tsx_state.src.rdata, tsx->last_tx, &tdata)) {
 /* Send authed version of the method */
 ast_sip_session_send_request_with_cb(session, tdata, cb);
 SCOPE_EXIT_RTN("Sending authed %.*s\n",
 (int) pj_strlen(&tsx->method.name), pj_strbuf(&tsx->method.name));
 }
 }
 }
 }
 if (cb) {
 cb(session, e->body.tsx_state.src.rdata);
 }
 break;
 case PJSIP_EVENT_TRANSPORT_ERROR:
 case PJSIP_EVENT_TIMER:
 /*
 * The timer event is run by the pjsip monitor thread and not
 * by the session serializer.
 */
 if (session_end_if_disconnected(id, inv)) {
 SCOPE_EXIT_RTN("Disconnected\n");
 }
 break;
 case PJSIP_EVENT_USER:
 case PJSIP_EVENT_UNKNOWN:
 case PJSIP_EVENT_TSX_STATE:
 /* Inception? */
 break;
 }

 if (AST_LIST_EMPTY(&session->delayed_requests)) {
 /* No delayed request pending, so just return */
 SCOPE_EXIT_RTN("Nothing delayed\n");
 }

 if (tsx->method.id == PJSIP_INVITE_METHOD) {
 if (tsx->state == PJSIP_TSX_STATE_PROCEEDING) {
 ast_debug(3, "%s: INVITE delay check. tsx-state:%s\n",
 ast_sip_session_get_name(session),
 pjsip_tsx_state_str(tsx->state));
 check_delayed_requests(session, invite_proceeding);
 } else if (tsx->state == PJSIP_TSX_STATE_TERMINATED) {
 /*
 * Terminated INVITE transactions always should result in
 * queuing delayed requests, no matter what event caused
 * the transaction to terminate.
 */
 ast_debug(3, "%s: INVITE delay check. tsx-state:%s\n",
 ast_sip_session_get_name(session),
 pjsip_tsx_state_str(tsx->state));
 check_delayed_requests(session, invite_terminated);
 }
 } else if (tsx->role == PJSIP_ROLE_UAC
 && tsx->state == PJSIP_TSX_STATE_COMPLETED
 && !pj_strcmp2(&tsx->method.name, "UPDATE")) {
 ast_debug(3, "%s: UPDATE delay check. tsx-state:%s\n",
 ast_sip_session_get_name(session),
 pjsip_tsx_state_str(tsx->state));
 check_delayed_requests(session, update_completed);
 }

 SCOPE_EXIT_RTN();
}

static int add_sdp_streams(struct ast_sip_session_media *session_media,
 struct ast_sip_session *session, pjmedia_sdp_session *answer,
 const struct pjmedia_sdp_session *remote,
 struct ast_stream *stream)
{
 struct ast_sip_session_sdp_handler *handler = session_media->handler;
 RAII_VAR(struct sdp_handler_list *, handler_list, NULL, ao2_cleanup);
 int res = 0;
 SCOPE_ENTER(1, "%s Stream: %s\n", ast_sip_session_get_name(session),
 ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));

 if (handler) {
 /* if an already assigned handler reports a catastrophic error, fail */
 res = handler->create_outgoing_sdp_stream(session, session_media, answer, remote, stream);
 if (res < 0) {
 SCOPE_EXIT_RTN_VALUE(-1, "Coudn't create sdp stream\n");
 }
 SCOPE_EXIT_RTN_VALUE(0, "Had handler\n");
 }

 handler_list = ao2_find(sdp_handlers, ast_codec_media_type2str(session_media->type), OBJ_KEY);
 if (!handler_list) {
 SCOPE_EXIT_RTN_VALUE(0, "No handlers\n");
 }

 /* no handler for this stream type and we have a list to search */
 AST_LIST_TRAVERSE(&handler_list->list, handler, next) {
 if (handler == session_media->handler) {
 continue;
 }
 res = handler->create_outgoing_sdp_stream(session, session_media, answer, remote, stream);
 if (res < 0) {
 /* catastrophic error */
 SCOPE_EXIT_RTN_VALUE(-1, "Coudn't create sdp stream\n");
 }
 if (res > 0) {
 /* Handled by this handler. Move to the next stream */
 session_media_set_handler(session_media, handler);
 SCOPE_EXIT_RTN_VALUE(0, "Handled\n");
 }
 }

 /* streams that weren't handled won't be included in generated outbound SDP */
 SCOPE_EXIT_RTN_VALUE(0, "Not handled\n");
}

/*! \brief Bundle group building structure */
struct sip_session_media_bundle_group {
 /*! \brief The media identifiers in this bundle group */
 char *mids[PJMEDIA_MAX_SDP_MEDIA];
 /*! \brief SDP attribute string */
 struct ast_str *attr_string;
};

static int add_bundle_groups(struct ast_sip_session *session, pj_pool_t *pool, pjmedia_sdp_session *answer)
{
 pj_str_t stmp;
 pjmedia_sdp_attr *attr;
 struct sip_session_media_bundle_group bundle_groups[PJMEDIA_MAX_SDP_MEDIA];
 int index, mid_id;
 struct sip_session_media_bundle_group *bundle_group;

 if (session->endpoint->media.webrtc) {
 attr = pjmedia_sdp_attr_create(pool, "msid-semantic", pj_cstr(&stmp, "WMS *"));
 pjmedia_sdp_attr_add(&answer->attr_count, answer->attr, attr);
 }

 if (!session->endpoint->media.bundle) {
 return 0;
 }

 memset(bundle_groups, 0, sizeof(bundle_groups));

 /* Build the bundle group layout so we can then add it to the SDP */
 for (index = 0; index < AST_VECTOR_SIZE(&session->pending_media_state->sessions); ++index) {
 struct ast_sip_session_media *session_media = AST_VECTOR_GET(&session->pending_media_state->sessions, index);

 /* If this stream is not part of a bundle group we can't add it */
 if (session_media->bundle_group == -1) {
 continue;
 }

 bundle_group = &bundle_groups[session_media->bundle_group];

 /* If this is the first mid then we need to allocate the attribute string and place BUNDLE in front */
 if (!bundle_group->mids[0]) {
 bundle_group->mids[0] = session_media->mid;
 bundle_group->attr_string = ast_str_create(64);
 if (!bundle_group->attr_string) {
 continue;
 }

 ast_str_set(&bundle_group->attr_string, 0, "BUNDLE %s", session_media->mid);
 continue;
 }

 for (mid_id = 1; mid_id < PJMEDIA_MAX_SDP_MEDIA; ++mid_id) {
 if (!bundle_group->mids[mid_id]) {
 bundle_group->mids[mid_id] = session_media->mid;
 ast_str_append(&bundle_group->attr_string, 0, " %s", session_media->mid);
 break;
 } else if (!strcmp(bundle_group->mids[mid_id], session_media->mid)) {
 break;
 }
 }
 }

 /* Add all bundle groups that have mids to the SDP */
 for (index = 0; index < PJMEDIA_MAX_SDP_MEDIA; ++index) {
 bundle_group = &bundle_groups[index];

 if (!bundle_group->attr_string) {
 continue;
 }

 attr = pjmedia_sdp_attr_create(pool, "group", pj_cstr(&stmp, ast_str_buffer(bundle_group->attr_string)));
 pjmedia_sdp_attr_add(&answer->attr_count, answer->attr, attr);

 ast_free(bundle_group->attr_string);
 }

 return 0;
}

static struct pjmedia_sdp_session *create_local_sdp(pjsip_inv_session *inv, struct ast_sip_session *session, const pjmedia_sdp_session *offer)
{
 static const pj_str_t STR_IN = { "IN", 2 };
 static const pj_str_t STR_IP4 = { "IP4", 3 };
 static const pj_str_t STR_IP6 = { "IP6", 3 };
 pjmedia_sdp_session *local;
 int i;
 int stream;
 SCOPE_ENTER(3, "%s\n", ast_sip_session_get_name(session));

 if (inv->state == PJSIP_INV_STATE_DISCONNECTED) {
 SCOPE_EXIT_LOG_RTN_VALUE(NULL, LOG_ERROR, "%s: Failed to create session SDP. Session has been already disconnected\n",
 ast_sip_session_get_name(session));
 }

 if (!inv->pool_prov || !(local = PJ_POOL_ZALLOC_T(inv->pool_prov, pjmedia_sdp_session))) {
 SCOPE_EXIT_LOG_RTN_VALUE(NULL, LOG_ERROR, "%s: Pool allocation failure\n", ast_sip_session_get_name(session));
 }

 if (!offer) {
 local->origin.version = local->origin.id = (pj_uint32_t)(ast_random());
 } else {
 local->origin.version = offer->origin.version + 1;
 local->origin.id = offer->origin.id;
 }

 pj_strdup2(inv->pool_prov, &local->origin.user, session->endpoint->media.sdpowner);
 pj_strdup2(inv->pool_prov, &local->name, session->endpoint->media.sdpsession);

 if (!session->pending_media_state->topology || !ast_stream_topology_get_count(session->pending_media_state->topology)) {
 /* We've encountered a situation where we have been told to create a local SDP but noone has given us any indication
 * of what kind of stream topology they would like. We try to not alter the current state of the SDP negotiation
 * by using what is currently negotiated. If this is unavailable we fall back to what is configured on the endpoint.
 */
 ast_stream_topology_free(session->pending_media_state->topology);
 if (session->active_media_state->topology) {
 session->pending_media_state->topology = ast_stream_topology_clone(session->active_media_state->topology);
 } else {
 session->pending_media_state->topology = ast_stream_topology_clone(session->endpoint->media.topology);
 }
 if (!session->pending_media_state->topology) {
 SCOPE_EXIT_LOG_RTN_VALUE(NULL, LOG_ERROR, "%s: No pending media state topology\n", ast_sip_session_get_name(session));
 }
 }

 ast_trace(-1, "%s: Processing streams\n", ast_sip_session_get_name(session));

 for (i = 0; i < ast_stream_topology_get_count(session->pending_media_state->topology); ++i) {
 struct ast_sip_session_media *session_media;
 struct ast_stream *stream = ast_stream_topology_get_stream(session->pending_media_state->topology, i);
 unsigned int streams = local->media_count;
 SCOPE_ENTER(4, "%s: Processing stream %s\n", ast_sip_session_get_name(session),
 ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));

 /* This code does not enforce any maximum stream count limitations as that is done on either
 * the handling of an incoming SDP offer or on the handling of a session refresh.
 */

 session_media = ast_sip_session_media_state_add(session, session->pending_media_state, ast_stream_get_type(stream), i);
 if (!session_media) {
 local = NULL;
 SCOPE_EXIT_LOG_EXPR(goto end, LOG_ERROR, "%s: Couldn't alloc/add session media for stream %s\n",
 ast_sip_session_get_name(session), ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));
 }

 if (add_sdp_streams(session_media, session, local, offer, stream)) {
 local = NULL;
 SCOPE_EXIT_LOG_EXPR(goto end, LOG_ERROR, "%s: Couldn't add sdp streams for stream %s\n",
 ast_sip_session_get_name(session), ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));
 }

 /* If a stream was actually added then add any additional details */
 if (streams != local->media_count) {
 pjmedia_sdp_media *media = local->media[streams];
 pj_str_t stmp;
 pjmedia_sdp_attr *attr;

 /* Add the media identifier if present */
 if (!ast_strlen_zero(session_media->mid)) {
 attr = pjmedia_sdp_attr_create(inv->pool_prov, "mid", pj_cstr(&stmp, session_media->mid));
 pjmedia_sdp_attr_add(&media->attr_count, media->attr, attr);
 }

 ast_trace(-1, "%s: Stream %s added%s%s\n", ast_sip_session_get_name(session),
 ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)),
 S_COR(!ast_strlen_zero(session_media->mid), " with mid ", ""), S_OR(session_media->mid, ""));

 }

 /* Ensure that we never exceed the maximum number of streams PJMEDIA will allow. */
 if (local->media_count == PJMEDIA_MAX_SDP_MEDIA) {
 SCOPE_EXIT_EXPR(break, "%s: Stream %s exceeded max pjmedia count of %d\n",
 ast_sip_session_get_name(session), ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)),
 PJMEDIA_MAX_SDP_MEDIA);
 }

 SCOPE_EXIT("%s: Done with %s\n", ast_sip_session_get_name(session),
 ast_str_tmp(128, ast_stream_to_str(stream, &STR_TMP)));

 }

 /* Add any bundle groups that are present on the media state */
 ast_trace(-1, "%s: Adding bundle groups (if available)\n", ast_sip_session_get_name(session));
 if (add_bundle_groups(session, inv->pool_prov, local)) {
 SCOPE_EXIT_LOG_RTN_VALUE(NULL, LOG_ERROR, "%s: Couldn't add bundle groups\n", ast_sip_session_get_name(session));
 }

 /* Use the connection details of an available media if possible for SDP level */
 ast_trace(-1, "%s: Copying connection details\n", ast_sip_session_get_name(session));

 for (stream = 0; stream < local->media_count; stream++) {
 SCOPE_ENTER(4, "%s: Processing media %d\n", ast_sip_session_get_name(session), stream);
 if (!local->media[stream]->conn) {
 SCOPE_EXIT_EXPR(continue, "%s: Media %d has no connection info\n", ast_sip_session_get_name(session), stream);
 }

 if (local->conn) {
 if (!pj_strcmp(&local->conn->net_type, &local->media[stream]->conn->net_type) &&
 !pj_strcmp(&local->conn->addr_type, &local->media[stream]->conn->addr_type) &&
 !pj_strcmp(&local->conn->addr, &local->media[stream]->conn->addr)) {
 local->media[stream]->conn = NULL;
 }
 SCOPE_EXIT_EXPR(continue, "%s: Media %d has good existing connection info\n", ast_sip_session_get_name(session), stream);
 }

 /* This stream's connection info will serve as the connection details for SDP level */
 local->conn = local->media[stream]->conn;
 local->media[stream]->conn = NULL;

 SCOPE_EXIT_EXPR(continue, "%s: Media %d reset\n", ast_sip_session_get_name(session), stream);
 }

 /* If no SDP level connection details are present then create some */
 if (!local->conn) {
 ast_trace(-1, "%s: Creating connection details\n", ast_sip_session_get_name(session));

 local->conn = pj_pool_zalloc(inv->pool_prov, sizeof(struct pjmedia_sdp_conn));
 local->conn->net_type = STR_IN;
 local->conn->addr_type = session->endpoint->media.rtp.ipv6 ? STR_IP6 : STR_IP4;

 if (!ast_strlen_zero(session->endpoint->media.address)) {
 pj_strdup2(inv->pool_prov, &local->conn->addr, session->endpoint->media.address);
 } else {
 pj_strdup2(inv->pool_prov, &local->conn->addr, ast_sip_get_host_ip_string(session->endpoint->media.rtp.ipv6 ? pj_AF_INET6() : pj_AF_INET()));
 }
 }

 pj_strassign(&local->origin.net_type, &local->conn->net_type);
 pj_strassign(&local->origin.addr_type, &local->conn->addr_type);
 pj_strassign(&local->origin.addr, &local->conn->addr);

end:
 SCOPE_EXIT_RTN_VALUE(local, "%s\n", ast_sip_session_get_name(session));
}

static void session_inv_on_rx_offer(pjsip_inv_session *inv, const pjmedia_sdp_session *offer)
{
 struct ast_sip_session *session = inv->mod_data[session_module.id];
 pjmedia_sdp_session *answer;
 SCOPE_ENTER(3, "%s\n", ast_sip_session_get_name(session));

 if (ast_shutdown_final()) {
 SCOPE_EXIT_RTN("%s: Shutdown in progress\n", ast_sip_session_get_name(session));
 }

 session = inv->mod_data[session_module.id];
 if (handle_incoming_sdp(session, offer)) {
 ast_sip_session_media_state_reset(session->pending_media_state);
 SCOPE_EXIT_RTN("%s: handle_incoming_sdp failed\n", ast_sip_session_get_name(session));
 }

 if ((answer = create_local_sdp(inv, session, offer))) {
 pjsip_inv_set_sdp_answer(inv, answer);
 SCOPE_EXIT_RTN("%s: Set SDP answer\n", ast_sip_session_get_name(session));
 }
 SCOPE_EXIT_RTN("%s: create_local_sdp failed\n", ast_sip_session_get_name(session));
}

static void session_inv_on_create_offer(pjsip_inv_session *inv, pjmedia_sdp_session **p_offer)
{
 struct ast_sip_session *session = inv->mod_data[session_module.id];
 const pjmedia_sdp_session *previous_sdp = NULL;
 pjmedia_sdp_session *offer;
 int i;

 if (inv->neg) {
 if (pjmedia_sdp_neg_was_answer_remote(inv->neg)) {
 pjmedia_sdp_neg_get_active_remote(inv->neg, &previous_sdp);
 } else {
 pjmedia_sdp_neg_get_active_local(inv->neg, &previous_sdp);
 }
 }

 offer = create_local_sdp(inv, session, previous_sdp);
 if (!offer) {
 return;
 }

 ast_queue_unhold(session->channel);

 /*
 * Some devices indicate hold with deferred SDP reinvites (i.e. no SDP in the reinvite).
 * When hold is initially indicated, we
 * - Receive an INVITE with no SDP
 * - Send a 200 OK with SDP, indicating sendrecv in the media streams
 * - Receive an ACK with SDP, indicating sendonly in the media streams
 *
 * At this point, the pjmedia negotiator saves the state of the media direction so that
 * if we are to send any offers, we'll offer recvonly in the media streams. This is
 * problematic if the device is attempting to unhold, though. If the device unholds
 * by sending a reinvite with no SDP, then we will respond with a 200 OK with recvonly.
 * According to RFC 3264, if an offerer offers recvonly, then the answerer MUST respond
 * with sendonly or inactive. The result of this is that the stream is not off hold.
 *
 * Therefore, in this case, when we receive a reinvite while the stream is on hold, we
 * need to be sure to offer sendrecv. This way, the answerer can respond with sendrecv
 * in order to get the stream off hold. If this is actually a different purpose reinvite
 * (like a session timer refresh), then the answerer can respond to our sendrecv with
 * sendonly, keeping the stream on hold.
 */
 for (i = 0; i < offer->media_count; ++i) {
 pjmedia_sdp_media *m = offer->media[i];
 pjmedia_sdp_attr *recvonly;
 pjmedia_sdp_attr *inactive;
 pjmedia_sdp_attr *sendonly;

 recvonly = pjmedia_sdp_attr_find2(m->attr_count, m->attr, "recvonly", NULL);
 inactive = pjmedia_sdp_attr_find2(m->attr_count, m->attr, "inactive", NULL);
 sendonly = pjmedia_sdp_attr_find2(m->attr_count, m->attr, "sendonly", NULL);
 if (recvonly || inactive || sendonly) {
 pjmedia_sdp_attr *to_remove = recvonly ?: inactive ?: sendonly;
 pjmedia_sdp_attr *sendrecv;

 pjmedia_sdp_attr_remove(&m->attr_count, m->attr, to_remove);

 sendrecv = pjmedia_sdp_attr_create(session->inv_session->pool, "sendrecv", NULL);
 pjmedia_sdp_media_add_attr(m, sendrecv);
 }
 }

 *p_offer = offer;
}

static void session_inv_on_media_update(pjsip_inv_session *inv, pj_status_t status)
{
 struct ast_sip_session *session = inv->mod_data[session_module.id];
 const pjmedia_sdp_session *local, *remote;
 SCOPE_ENTER(3, "%s\n", ast_sip_session_get_name(session));

 if (ast_shutdown_final()) {
 SCOPE_EXIT_RTN("%s: Shutdown in progress\n", ast_sip_session_get_name(session));
 }

 session = inv->mod_data[session_module.id];
 if (!session || !session->channel) {
 /*
 * If we don't have a session or channel then we really
 * don't care about media updates.
 * Just ignore
 */
 SCOPE_EXIT_RTN("%s: No channel or session\n", ast_sip_session_get_name(session));
 }

 if (session->endpoint) {
 int bail = 0;

 /*
 * If following_fork is set, then this is probably the result of a
 * forked INVITE and SDP asnwers coming from the different fork UAS
 * destinations. In this case updated_sdp_answer will also be set.
 *
 * If only updated_sdp_answer is set, then this is the non-forking
 * scenario where the same UAS just needs to change something like
 * the media port.
 */

 if (inv->following_fork) {
 if (session->endpoint->media.rtp.follow_early_media_fork) {
 ast_trace(-1, "%s: Following early media fork with different To tags\n", ast_sip_session_get_name(session));
 } else {
 ast_trace(-1, "%s: Not following early media fork with different To tags\n", ast_sip_session_get_name(session));
 bail = 1;
 }
 }
#ifdef HAVE_PJSIP_INV_ACCEPT_MULTIPLE_SDP_ANSWERS
 else if (inv->updated_sdp_answer) {
 if (session->endpoint->media.rtp.accept_multiple_sdp_answers) {
 ast_trace(-1, "%s: Accepting updated SDP with same To tag\n", ast_sip_session_get_name(session));
 } else {
 ast_trace(-1, "%s: Ignoring updated SDP answer with same To tag\n", ast_sip_session_get_name(session));
 bail = 1;
 }
 }
#endif
 if (bail) {
 SCOPE_EXIT_RTN("%s: Bailing\n", ast_sip_session_get_name(session));
 }
 }

 if ((status != PJ_SUCCESS) || (pjmedia_sdp_neg_get_active_local(inv->neg, &local) != PJ_SUCCESS) ||
 (pjmedia_sdp_neg_get_active_remote(inv->neg, &remote) != PJ_SUCCESS)) {
 ast_channel_hangupcause_set(session->channel, AST_CAUSE_BEARERCAPABILITY_NOTAVAIL);
 ast_set_hangupsource(session->channel, ast_channel_name(session->channel), 0);
 ast_queue_hangup(session->channel);
 SCOPE_EXIT_RTN("%s: Couldn't get active or local or remote negotiator. Hanging up\n", ast_sip_session_get_name(session));
 }

 if (handle_negotiated_sdp(session, local, remote)) {
 ast_sip_session_media_state_reset(session->pending_media_state);
 SCOPE_EXIT_RTN("%s: handle_negotiated_sdp failed. Resetting pending media state\n", ast_sip_session_get_name(session));
 }
 SCOPE_EXIT_RTN("%s\n", ast_sip_session_get_name(session));
}

static pjsip_redirect_op session_inv_on_redirected(pjsip_inv_session *inv, const pjsip_uri *target, const pjsip_event *e)
{
 struct ast_sip_session *session;
 const pjsip_sip_uri *uri;

 if (ast_shutdown_final()) {
 return PJSIP_REDIRECT_STOP;
 }

 session = inv->mod_data[session_module.id];
 if (!session || !session->channel) {
 return PJSIP_REDIRECT_STOP;
 }

 if (session->endpoint->redirect_method == AST_SIP_REDIRECT_URI_PJSIP) {
 return PJSIP_REDIRECT_ACCEPT;
 }

 if (!PJSIP_URI_SCHEME_IS_SIP(target) && !PJSIP_URI_SCHEME_IS_SIPS(target)) {
 return PJSIP_REDIRECT_STOP;
 }

 handle_incoming(session, e->body.rx_msg.rdata, AST_SIP_SESSION_BEFORE_REDIRECTING);

 uri = pjsip_uri_get_uri(target);

 if (session->endpoint->redirect_method == AST_SIP_REDIRECT_USER) {
 char exten[AST_MAX_EXTENSION];

 ast_copy_pj_str(exten, &uri->user, sizeof(exten));

 /*
 * We may want to match in the dialplan without any user
 * options getting in the way.
 */
 AST_SIP_USER_OPTIONS_TRUNCATE_CHECK(exten);

 ast_channel_call_forward_set(session->channel, exten);
 } else if (session->endpoint->redirect_method == AST_SIP_REDIRECT_URI_CORE) {
 char target_uri[PJSIP_MAX_URL_SIZE];
 /* PJSIP/ + endpoint length + / + max URL size */
 char forward[8 + strlen(ast_sorcery_object_get_id(session->endpoint)) + PJSIP_MAX_URL_SIZE];

 pjsip_uri_print(PJSIP_URI_IN_REQ_URI, uri, target_uri, sizeof(target_uri));
 sprintf(forward, "PJSIP/%s/%s", ast_sorcery_object_get_id(session->endpoint), target_uri);
 ast_channel_call_forward_set(session->channel, forward);
 }

 return PJSIP_REDIRECT_STOP;
}

static pjsip_inv_callback inv_callback = {
 .on_state_changed = session_inv_on_state_changed,
 .on_new_session = session_inv_on_new_session,
 .on_tsx_state_changed = session_inv_on_tsx_state_changed,
 .on_rx_offer = session_inv_on_rx_offer,
 .on_create_offer = session_inv_on_create_offer,
 .on_media_update = session_inv_on_media_update,
 .on_redirected = session_inv_on_redirected,
};

/*! \brief Hook for modifying outgoing messages with SDP to contain the proper address information */
static void session_outgoing_nat_hook(pjsip_tx_data *tdata, struct ast_sip_transport *transport)
{
 RAII_VAR(struct ast_sip_transport_state *, transport_state, ast_sip_get_transport_state(ast_sorcery_object_get_id(transport)), ao2_cleanup);
 struct ast_sip_nat_hook *hook = ast_sip_mod_data_get(
 tdata->mod_data, session_module.id, MOD_DATA_NAT_HOOK);
 struct pjmedia_sdp_session *sdp;
 pjsip_dialog *dlg = pjsip_tdata_get_dlg(tdata);
 RAII_VAR(struct ast_sip_session *, session, dlg ? ast_sip_dialog_get_session(dlg) : NULL, ao2_cleanup);
 int stream;

 /* SDP produced by us directly will never be multipart */
 if (!transport_state || hook || !tdata->msg->body ||
 !ast_sip_is_content_type(&tdata->msg->body->content_type, "application", "sdp") ||
 ast_strlen_zero(transport->external_media_address)) {
 return;
 }

 sdp = tdata->msg->body->data;

 if (sdp->conn) {
 char host[NI_MAXHOST];
 struct ast_sockaddr our_sdp_addr = { { 0, } };

 ast_copy_pj_str(host, &sdp->conn->addr, sizeof(host));
 ast_sockaddr_parse(&our_sdp_addr, host, PARSE_PORT_FORBID);

 /* Reversed check here. We don't check the remote
 * endpoint being in our local net, but whether our
 * outgoing session IP is local. If it is, we'll do
 * rewriting. No localnet configured? Always rewrite. */
 if (ast_sip_transport_is_local(transport_state, &our_sdp_addr) || !transport_state->localnet) {
 ast_debug(5, "%s: Setting external media address to %s\n", ast_sip_session_get_name(session),
 ast_sockaddr_stringify_host(&transport_state->external_media_address));
 pj_strdup2(tdata->pool, &sdp->conn->addr, ast_sockaddr_stringify_host(&transport_state->external_media_address));
 pj_strassign(&sdp->origin.addr, &sdp->conn->addr);
 }
 }

 for (stream = 0; stream < sdp->media_count; ++stream) {
 /* See if there are registered handlers for this media stream type */
 char media[20];
 struct ast_sip_session_sdp_handler *handler;
 RAII_VAR(struct sdp_handler_list *, handler_list, NULL, ao2_cleanup);

 /* We need a null-terminated version of the media string */
 ast_copy_pj_str(media, &sdp->media[stream]->desc.media, sizeof(media));

 handler_list = ao2_find(sdp_handlers, media, OBJ_KEY);
 if (!handler_list) {
 ast_debug(4, "%s: No registered SDP handlers for media type '%s'\n", ast_sip_session_get_name(session),
 media);
 continue;
 }
 AST_LIST_TRAVERSE(&handler_list->list, handler, next) {
 if (handler->change_outgoing_sdp_stream_media_address) {
 handler->change_outgoing_sdp_stream_media_address(tdata, sdp->media[stream], transport);
 }
 }
 }

 /* We purposely do this so that the hook will not be invoked multiple times, ie: if a retransmit occurs */
 ast_sip_mod_data_set(tdata->pool, tdata->mod_data, session_module.id, MOD_DATA_NAT_HOOK, nat_hook);
}

#ifdef TEST_FRAMEWORK

static struct ast_stream *test_stream_alloc(const char *name, enum ast_media_type type, enum ast_stream_state state)
{
 struct ast_stream *stream;

 stream = ast_stream_alloc(name, type);
 if (!stream) {
 return NULL;
 }
 ast_stream_set_state(stream, state);

 return stream;
}

static struct ast_sip_session_media *test_media_add(
 struct ast_sip_session_media_state *media_state, const char *name, enum ast_media_type type,
 enum ast_stream_state state, int position)
{
 struct ast_sip_session_media *session_media = NULL;
 struct ast_stream *stream = NULL;

 stream = test_stream_alloc(name, type, state);
 if (!stream) {
 return NULL;
 }

 if (position >= 0 && position < ast_stream_topology_get_count(media_state->topology)) {
 ast_stream_topology_set_stream(media_state->topology, position, stream);
 } else {
 position = ast_stream_topology_append_stream(media_state->topology, stream);
 }

 session_media = ao2_alloc_options(sizeof(*session_media), session_media_dtor, AO2_ALLOC_OPT_LOCK_NOLOCK);
 if (!session_media) {
 return NULL;
 }

 session_media->keepalive_sched_id = -1;
 session_media->timeout_sched_id = -1;
 session_media->type = type;
 session_media->stream_num = position;
 session_media->bundle_group = -1;
 strcpy(session_media->label, name);

 if (AST_VECTOR_REPLACE(&media_state->sessions, position, session_media)) {
 ao2_ref(session_media, -1);

 return NULL;
 }

 /* If this stream will be active in some way and it is the first of this type then consider this the default media session to match */
 if (!media_state->default_session[type] && ast_stream_get_state(ast_stream_topology_get_stream(media_state->topology, position)) != AST_STREAM_STATE_REMOVED) {
 media_state->default_session[type] = session_media;
 }

 return session_media;
}

static int test_is_media_session_equal(struct ast_sip_session_media *left, struct ast_sip_session_media *right)
{
 if (left == right) {
 return 1;
 }

 if (!left) {
 return 1;
 }

 if (!right) {
 return 0;
 }
 return memcmp(left, right, sizeof(*left)) == 0;
}

static int test_is_media_state_equal(struct ast_sip_session_media_state *left, struct ast_sip_session_media_state *right,
 int assert_on_failure)
{
 int i;
 SCOPE_ENTER(2);

 if (left == right) {
 SCOPE_EXIT_RTN_VALUE(1, "equal\n");
 }

 if (!(left && right)) {
 ast_assert(!assert_on_failure);
 SCOPE_EXIT_RTN_VALUE(0, "one is null: left: %p right: %p\n", left, right);
 }

 if (!ast_stream_topology_equal(left->topology, right->topology)) {
 ast_assert(!assert_on_failure);
 SCOPE_EXIT_RTN_VALUE(0, "topologies differ\n");
 }
 if (AST_VECTOR_SIZE(&left->sessions) != AST_VECTOR_SIZE(&right->sessions)) {
 ast_assert(!assert_on_failure);
 SCOPE_EXIT_RTN_VALUE(0, "session vector sizes different: left %zu != right %zu\n",
 AST_VECTOR_SIZE(&left->sessions),
 AST_VECTOR_SIZE(&right->sessions));
 }
 if (AST_VECTOR_SIZE(&left->read_callbacks) != AST_VECTOR_SIZE(&right->read_callbacks)) {
 ast_assert(!assert_on_failure);
 SCOPE_EXIT_RTN_VALUE(0, "read_callback vector sizes different: left %zu != right %zu\n",
 AST_VECTOR_SIZE(&left->read_callbacks),
 AST_VECTOR_SIZE(&right->read_callbacks));
 }

 for (i = 0; i < AST_VECTOR_SIZE(&left->sessions) ; i++) {
 if (!test_is_media_session_equal(AST_VECTOR_GET(&left->sessions, i), AST_VECTOR_GET(&right->sessions, i))) {
 ast_assert(!assert_on_failure);
 SCOPE_EXIT_RTN_VALUE(0, "Media session %d different\n", i);
 }
 }

 for (i = 0; i < AST_VECTOR_SIZE(&left->read_callbacks) ; i++) {
 if (memcmp(AST_VECTOR_GET_ADDR(&left->read_callbacks, i),
 AST_VECTOR_GET_ADDR(&right->read_callbacks, i),
 sizeof(struct ast_sip_session_media_read_callback_state)) != 0) {
 ast_assert(!assert_on_failure);
 SCOPE_EXIT_RTN_VALUE(0, "read_callback %d different\n", i);
 }
 }

 for (i = 0; i < AST_MEDIA_TYPE_END; i++) {
 if (!(left->default_session[i] && right->default_session[i])) {
 continue;
 }
 if (!left->default_session[i] || !right->default_session[i]
 || left->default_session[i]->stream_num != right->default_session[i]->stream_num) {
 ast_assert(!assert_on_failure);
 SCOPE_EXIT_RTN_VALUE(0, "Default media session %d different. Left: %s Right: %s\n", i,
 left->default_session[i] ? left->default_session[i]->label : "null",
 right->default_session[i] ? right->default_session[i]->label : "null");
 }
 }

 SCOPE_EXIT_RTN_VALUE(1, "equal\n");
}

AST_TEST_DEFINE(test_resolve_refresh_media_states)
{
#define FREE_STATE() \
({ \
 ast_sip_session_media_state_free(new_pending_state); \
 new_pending_state = NULL; \
 ast_sip_session_media_state_free(delayed_pending_state); \
 delayed_pending_state = NULL; \
 ast_sip_session_media_state_free(delayed_active_state); \
 delayed_active_state = NULL; \
 ast_sip_session_media_state_free(current_active_state); \
 current_active_state = NULL; \
 ast_sip_session_media_state_free(expected_pending_state); \
 expected_pending_state = NULL; \
})

#define RESET_STATE(__num) \
({ \
 testnum=__num; \
 ast_trace(-1, "Test %d\n", testnum); \
 test_failed = 0; \
 delayed_pending_state = ast_sip_session_media_state_alloc(); \
 delayed_pending_state->topology = ast_stream_topology_alloc(); \
 delayed_active_state = ast_sip_session_media_state_alloc(); \
 delayed_active_state->topology = ast_stream_topology_alloc(); \
 current_active_state = ast_sip_session_media_state_alloc(); \
 current_active_state->topology = ast_stream_topology_alloc(); \
 expected_pending_state = ast_sip_session_media_state_alloc(); \
 expected_pending_state->topology = ast_stream_topology_alloc(); \
})

#define CHECKER() \
({ \
 new_pending_state = resolve_refresh_media_states("unittest", delayed_pending_state, delayed_active_state, current_active_state, 1); \
 if (!test_is_media_state_equal(new_pending_state, expected_pending_state, 0)) { \
 res = AST_TEST_FAIL; \
 test_failed = 1; \
 ast_test_status_update(test, "da: %s\n", ast_str_tmp(256, ast_stream_topology_to_str(delayed_active_state->topology, &STR_TMP))); \
 ast_test_status_update(test, "dp: %s\n", ast_str_tmp(256, ast_stream_topology_to_str(delayed_pending_state->topology, &STR_TMP))); \
 ast_test_status_update(test, "ca: %s\n", ast_str_tmp(256, ast_stream_topology_to_str(current_active_state->topology, &STR_TMP))); \
 ast_test_status_update(test, "ep: %s\n", ast_str_tmp(256, ast_stream_topology_to_str(expected_pending_state->topology, &STR_TMP))); \
 ast_test_status_update(test, "np: %s\n", ast_str_tmp(256, ast_stream_topology_to_str(new_pending_state->topology, &STR_TMP))); \
 } \
 ast_test_status_update(test, "Test %d %s\n", testnum, test_failed ? "FAILED" : "passed"); \
 ast_trace(-1, "Test %d %s\n", testnum, test_failed ? "FAILED" : "passed"); \
 test_failed = 0; \
 FREE_STATE(); \
})


 struct ast_sip_session_media_state * delayed_pending_state = NULL;
 struct ast_sip_session_media_state * delayed_active_state = NULL;
 struct ast_sip_session_media_state * current_active_state = NULL;
 struct ast_sip_session_media_state * new_pending_state = NULL;
 struct ast_sip_session_media_state * expected_pending_state = NULL;
 enum ast_test_result_state res = AST_TEST_PASS;
 int test_failed = 0;
 int testnum = 0;
 SCOPE_ENTER(1);

 switch (cmd) {
 case TEST_INIT:
 info->name = "merge_refresh_topologies";
 info->category = "/res/res_pjsip_session/";
 info->summary = "Test merging of delayed request topologies";
 info->description = "Test merging of delayed request topologies";
 SCOPE_EXIT_RTN_VALUE(AST_TEST_NOT_RUN);
 case TEST_EXECUTE:
 break;
 }

 RESET_STATE(1);
 test_media_add(delayed_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(delayed_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(current_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(expected_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 CHECKER();

 RESET_STATE(2);
 test_media_add(delayed_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(delayed_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(current_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(expected_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 CHECKER();

 RESET_STATE(3);
 test_media_add(delayed_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(delayed_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(current_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo5", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(expected_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo5", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 CHECKER();

 RESET_STATE(4);
 test_media_add(delayed_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(delayed_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(current_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_REMOVED, -1);

 test_media_add(expected_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 CHECKER();

 RESET_STATE(5);
 test_media_add(delayed_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(delayed_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_REMOVED, -1);

 test_media_add(current_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_REMOVED, -1);

 test_media_add(expected_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_REMOVED, -1);
 CHECKER();

 RESET_STATE(6);
 test_media_add(delayed_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(delayed_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(current_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_REMOVED, -1);
 test_media_add(current_active_state, "myvideo4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(expected_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 CHECKER();

 RESET_STATE(7);
 test_media_add(delayed_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(delayed_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(current_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo5", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo6", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(expected_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo5", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo6", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 CHECKER();

 RESET_STATE(8);
 test_media_add(delayed_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(delayed_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(current_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_REMOVED, -1);

 test_media_add(expected_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 CHECKER();

 RESET_STATE(9);
 test_media_add(delayed_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(delayed_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(current_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_REMOVED, -1);
 test_media_add(current_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_REMOVED, -1);

 test_media_add(expected_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 CHECKER();

 RESET_STATE(10);
 test_media_add(delayed_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(delayed_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_REMOVED, -1);
 test_media_add(delayed_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_REMOVED, -1);

 test_media_add(current_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(expected_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_REMOVED, -1);
 test_media_add(expected_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_REMOVED, -1);
 test_media_add(expected_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 CHECKER();

 RESET_STATE(11);
 test_media_add(delayed_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "myvideo4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(delayed_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(current_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "myvideo4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(expected_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "myvideo3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 CHECKER();

 RESET_STATE(12);
 test_media_add(delayed_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "292-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "296-2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(delayed_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "292-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "296-2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "297-4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "294-5", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(current_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "292-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "296-2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "290-3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "297-4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(expected_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "292-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "296-2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "290-3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "297-4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "294-5", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 CHECKER();

 RESET_STATE(13);
 test_media_add(delayed_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "293-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "292-2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "294-3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "295-4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "296-5", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(delayed_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "293-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "292-2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "294-3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "295-4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "296-5", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "298-7", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(current_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "293-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "292-2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "294-3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "295-4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "296-5", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "290-6", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(expected_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "293-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "292-2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "294-3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "295-4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "296-5", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "290-6", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "298-7", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 CHECKER();

 RESET_STATE(14);
 test_media_add(delayed_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "298-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "297-2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(delayed_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "298-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "294-4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "295-5", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(current_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "298-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "297-2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "291-3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "294-4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(expected_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "298-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "297-2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "291-3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "294-4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "295-5", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 CHECKER();

 RESET_STATE(15);
 test_media_add(delayed_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "298-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_active_state, "297-2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(delayed_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "298-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDONLY, -1);
 test_media_add(delayed_pending_state, "294-4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(delayed_pending_state, "295-5", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(current_active_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "297-2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "291-3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "294-4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(current_active_state, "298-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);

 test_media_add(expected_pending_state, "audio", AST_MEDIA_TYPE_AUDIO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "297-2", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "291-3", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "294-4", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 test_media_add(expected_pending_state, "298-1", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDONLY, -1);
 test_media_add(expected_pending_state, "295-5", AST_MEDIA_TYPE_VIDEO, AST_STREAM_STATE_SENDRECV, -1);
 CHECKER();

 SCOPE_EXIT_RTN_VALUE(res);
}
#endif /* TEST_FRAMEWORK */

static int load_module(void)
{
 pjsip_endpoint *endpt;

 if (!ast_sip_get_sorcery() || !ast_sip_get_pjsip_endpoint()) {
 return AST_MODULE_LOAD_DECLINE;
 }
 if (!(nat_hook = ast_sorcery_alloc(ast_sip_get_sorcery(), "nat_hook", NULL))) {
 return AST_MODULE_LOAD_DECLINE;
 }
 nat_hook->outgoing_external_message = session_outgoing_nat_hook;
 ast_sorcery_create(ast_sip_get_sorcery(), nat_hook);
 sdp_handlers = ao2_container_alloc_hash(AO2_ALLOC_OPT_LOCK_MUTEX, 0,
 SDP_HANDLER_BUCKETS, sdp_handler_list_hash, NULL, sdp_handler_list_cmp);
 if (!sdp_handlers) {
 return AST_MODULE_LOAD_DECLINE;
 }
 endpt = ast_sip_get_pjsip_endpoint();
 pjsip_inv_usage_init(endpt, &inv_callback);
 pjsip_100rel_init_module(endpt);
 pjsip_timer_init_module(endpt);
 if (ast_sip_register_service(&session_module)) {
 return AST_MODULE_LOAD_DECLINE;
 }
 ast_sip_register_service(&session_reinvite_module);
 ast_sip_register_service(&outbound_invite_auth_module);

 ast_module_shutdown_ref(ast_module_info->self);
#ifdef TEST_FRAMEWORK
 AST_TEST_REGISTER(test_resolve_refresh_media_states);
#endif
 return AST_MODULE_LOAD_SUCCESS;
}

static int unload_module(void)
{
#ifdef TEST_FRAMEWORK
 AST_TEST_UNREGISTER(test_resolve_refresh_media_states);
#endif
 ast_sip_unregister_service(&outbound_invite_auth_module);
 ast_sip_unregister_service(&session_reinvite_module);
 ast_sip_unregister_service(&session_module);
 ast_sorcery_delete(ast_sip_get_sorcery(), nat_hook);
 ao2_cleanup(nat_hook);
 ao2_cleanup(sdp_handlers);
 return 0;
}

AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER, "PJSIP Session resource",
 .support_level = AST_MODULE_SUPPORT_CORE,
 .load = load_module,
 .unload = unload_module,
 .load_pri = AST_MODPRI_APP_DEPEND,
 .requires = "res_pjsip",
);