res_pjsip_outbound_registration.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * Joshua Colp <[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>
 <use type="module">res_statsd</use>
 <support_level>core</support_level>
 ***/

#include "asterisk.h"

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

#include "asterisk/res_pjsip.h"
#include "asterisk/res_pjsip_cli.h"
#include "asterisk/module.h"
#include "asterisk/taskprocessor.h"
#include "asterisk/cli.h"
#include "asterisk/stasis_system.h"
#include "asterisk/threadstorage.h"
#include "asterisk/threadpool.h"
#include "asterisk/statsd.h"
#include "res_pjsip/include/res_pjsip_private.h"
#include "asterisk/vector.h"
#include "asterisk/pbx.h"

/*** DOCUMENTATION
 <configInfo name="res_pjsip_outbound_registration" language="en_US">
 <synopsis>SIP resource for outbound registrations</synopsis>
 <description><para>
 <emphasis>Outbound Registration</emphasis>
 </para>
 <para>This module allows <literal>res_pjsip</literal> to register to other SIP servers.</para>
 </description>
 <configFile name="pjsip.conf">
 <configObject name="registration">
 <synopsis>The configuration for outbound registration</synopsis>
 <description><para>
 Registration is <emphasis>COMPLETELY</emphasis> separate from the rest of
 <literal>pjsip.conf</literal>. A minimal configuration consists of
 setting a <literal>server_uri</literal> and a <literal>client_uri</literal>.
 </para></description>
 <configOption name="auth_rejection_permanent" default="yes">
 <synopsis>Determines whether failed authentication challenges are treated
 as permanent failures.</synopsis>
 <description><para>If this option is enabled and an authentication challenge fails,
 registration will not be attempted again until the configuration is reloaded.</para></description>
 </configOption>
 <configOption name="client_uri">
 <synopsis>Client SIP URI used when attemping outbound registration</synopsis>
 <description><para>
 This is the address-of-record for the outbound registration (i.e. the URI in
 the To header of the REGISTER).</para>
 <para>For registration with an ITSP, the client SIP URI may need to consist of
 an account name or number and the provider's hostname for their registrar, e.g.
 [email protected]. This may differ between providers.</para>
 <para>For registration to generic registrars, the client SIP URI will depend
 on networking specifics and configuration of the registrar.
 </para></description>
 </configOption>
 <configOption name="contact_user">
 <synopsis>Contact User to use in request</synopsis>
 </configOption>
 <configOption name="contact_header_params">
 <synopsis>Header parameters to place in the Contact header</synopsis>
 </configOption>
 <configOption name="expiration" default="3600">
 <synopsis>Expiration time for registrations in seconds</synopsis>
 </configOption>
 <configOption name="max_retries" default="10">
 <synopsis>Maximum number of registration attempts.</synopsis>
 <description><para>
 This sets the maximum number of registration attempts that are made before
 stopping any further attempts. If set to 0 then upon failure no further attempts
 are made.
 </para></description>
 </configOption>
 <configOption name="outbound_auth" default="">
 <synopsis>Authentication object(s) to be used for outbound registrations.</synopsis>
 <description><para>
 This is a comma-delimited list of <replaceable>auth</replaceable>
 sections defined in <filename>pjsip.conf</filename> used to respond
 to outbound authentication challenges.</para>
 <note><para>
 Using the same auth section for inbound and outbound
 authentication is not recommended. There is a difference in
 meaning for an empty realm setting between inbound and outbound
 authentication uses. See the auth realm description for details.
 </para></note>
 </description>
 </configOption>
 <configOption name="outbound_proxy" default="">
 <synopsis>Full SIP URI of the outbound proxy used to send registrations</synopsis>
 </configOption>
 <configOption name="retry_interval" default="60">
 <synopsis>Interval in seconds between retries if outbound registration is unsuccessful</synopsis>
 </configOption>
 <configOption name="forbidden_retry_interval" default="0">
 <synopsis>Interval used when receiving a 403 Forbidden response.</synopsis>
 <description><para>
 If a 403 Forbidden is received, chan_pjsip will wait
 <replaceable>forbidden_retry_interval</replaceable> seconds before
 attempting registration again. If 0 is specified, chan_pjsip will not
 retry after receiving a 403 Forbidden response. Setting this to a non-zero
 value goes against a "SHOULD NOT" in RFC3261, but can be used to work around
 buggy registrars.
 </para></description>
 </configOption>
 <configOption name="fatal_retry_interval" default="0">
 <synopsis>Interval used when receiving a Fatal response.</synopsis>
 <description><para>
 If a fatal response is received, chan_pjsip will wait
 <replaceable>fatal_retry_interval</replaceable> seconds before
 attempting registration again. If 0 is specified, chan_pjsip will not
 retry after receiving a fatal (non-temporary 4xx, 5xx, 6xx) response.
 Setting this to a non-zero value may go against a "SHOULD NOT" in RFC3261,
 but can be used to work around buggy registrars.</para>
 <note><para>if also set the <replaceable>forbidden_retry_interval</replaceable>
 takes precedence over this one when a 403 is received.
 Also, if <replaceable>auth_rejection_permanent</replaceable> equals 'yes' then
 a 401 and 407 become subject to this retry interval.</para></note>
 </description>
 </configOption>
 <configOption name="server_uri">
 <synopsis>SIP URI of the server to register against</synopsis>
 <description><para>
 This is the URI at which to find the registrar to send the outbound REGISTER. This URI
 is used as the request URI of the outbound REGISTER request from Asterisk.</para>
 <para>For registration with an ITSP, the setting may often be just the domain of
 the registrar, e.g. sip:sip.example.com.
 </para></description>
 </configOption>
 <configOption name="transport">
 <synopsis>Transport used for outbound authentication</synopsis>
 <description>
 <note><para>A <replaceable>transport</replaceable> configured in
 <literal>pjsip.conf</literal>. As with other <literal>res_pjsip</literal> modules, this will use the first available transport of the appropriate type if unconfigured.</para></note>
 </description>
 </configOption>
 <configOption name="line">
 <synopsis>Whether to add a 'line' parameter to the Contact for inbound call matching</synopsis>
 <description><para>
 When enabled this option will cause a 'line' parameter to be added to the Contact
 header placed into the outgoing registration request. If the remote server sends a call
 this line parameter will be used to establish a relationship to the outbound registration,
 ultimately causing the configured endpoint to be used.
 </para></description>
 </configOption>
 <configOption name="endpoint">
 <synopsis>Endpoint to use for incoming related calls</synopsis>
 <description><para>
 When line support is enabled this configured endpoint name is used for incoming calls
 that are related to the outbound registration.
 </para></description>
 </configOption>
 <configOption name="type">
 <synopsis>Must be of type 'registration'.</synopsis>
 </configOption>
 <configOption name="support_path">
 <synopsis>Enables advertising SIP Path support for outbound REGISTER requests.</synopsis>
 <description><para>
 When this option is enabled, outbound REGISTER requests will advertise
 support for Path headers so that intervening proxies can add to the Path
 header as necessary.
 </para></description>
 </configOption>
 <configOption name="support_outbound">
 <synopsis>Enables advertising SIP Outbound support (RFC5626) for outbound REGISTER requests.</synopsis>
 </configOption>
 </configObject>
 </configFile>
 </configInfo>
 <manager name="PJSIPUnregister" language="en_US">
 <synopsis>
 Unregister an outbound registration.
 </synopsis>
 <syntax>
 <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
 <parameter name="Registration" required="true">
 <para>The outbound registration to unregister or '*all' to unregister them all.</para>
 </parameter>
 </syntax>
 <description>
 <para>
 Unregisters the specified (or all) outbound registration(s) and stops future registration attempts.
 Call PJSIPRegister to start registration and schedule re-registrations according to configuration.
 </para>
 </description>
 </manager>
 <manager name="PJSIPRegister" language="en_US">
 <synopsis>
 Register an outbound registration.
 </synopsis>
 <syntax>
 <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
 <parameter name="Registration" required="true">
 <para>The outbound registration to register or '*all' to register them all.</para>
 </parameter>
 </syntax>
 <description>
 <para>
 Unregisters the specified (or all) outbound registration(s) then starts registration and schedules re-registrations
 according to configuration.
 </para>
 </description>
 </manager>
 <manager name="PJSIPShowRegistrationsOutbound" language="en_US">
 <synopsis>
 Lists PJSIP outbound registrations.
 </synopsis>
 <syntax />
 <description>
 <para>
 In response <literal>OutboundRegistrationDetail</literal> events showing configuration and status
 information are raised for each outbound registration object. <literal>AuthDetail</literal>
 events are raised for each associated auth object as well. Once all events are completed an
 <literal>OutboundRegistrationDetailComplete</literal> is issued.
 </para>
 </description>
 </manager>
 ***/

/* forward declarations */
static int set_outbound_initial_authentication_credentials(pjsip_regc *regc,
 const struct ast_sip_auth_vector *auth_vector);

/*! \brief Some thread local storage used to determine if the running thread invoked the callback */
AST_THREADSTORAGE(register_callback_invoked);

/*! \brief Amount of buffer time (in seconds) before expiration that we re-register at */
#define REREGISTER_BUFFER_TIME 10

/*! \brief Size of the buffer for creating a unique string for the line */
#define LINE_PARAMETER_SIZE 8

/*! \brief Various states that an outbound registration may be in */
enum sip_outbound_registration_status {
 /*! \brief Currently unregistered */
 SIP_REGISTRATION_UNREGISTERED = 0,
 /*! \brief Registered, yay! */
 SIP_REGISTRATION_REGISTERED,
 /*! \brief Registration was rejected, but response was temporal */
 SIP_REGISTRATION_REJECTED_TEMPORARY,
 /*! \brief Registration was rejected, permanently */
 SIP_REGISTRATION_REJECTED_PERMANENT,
 /*! \brief Registration is stopping. */
 SIP_REGISTRATION_STOPPING,
 /*! \brief Registration has been stopped */
 SIP_REGISTRATION_STOPPED,
};

/*!
 * \internal
 * \brief Convert the internal registration state to an external status string.
 * \since 13.5.0
 *
 * \param state Current outbound registration state.
 *
 * \return External registration status string.
 */
static const char *sip_outbound_registration_status_str(enum sip_outbound_registration_status state)
{
 const char *str;

 str = "Unregistered";
 switch (state) {
 case SIP_REGISTRATION_STOPPING:
 case SIP_REGISTRATION_STOPPED:
 case SIP_REGISTRATION_UNREGISTERED:
 break;
 case SIP_REGISTRATION_REGISTERED:
 str = "Registered";
 break;
 case SIP_REGISTRATION_REJECTED_TEMPORARY:
 case SIP_REGISTRATION_REJECTED_PERMANENT:
 str = "Rejected";
 break;
 }
 return str;
}

/*! \brief Outbound registration information */
struct sip_outbound_registration {
 /*! \brief Sorcery object details */
 SORCERY_OBJECT(details);
 /*! \brief Stringfields */
 AST_DECLARE_STRING_FIELDS(
 /*! \brief URI for the registrar */
 AST_STRING_FIELD(server_uri);
 /*! \brief URI for the AOR */
 AST_STRING_FIELD(client_uri);
 /*! \brief Optional user for contact header */
 AST_STRING_FIELD(contact_user);
 /*! \bried Optional header parameters for contact */
 AST_STRING_FIELD(contact_header_params);
 /*! \brief Explicit transport to use for registration */
 AST_STRING_FIELD(transport);
 /*! \brief Outbound proxy to use */
 AST_STRING_FIELD(outbound_proxy);
 /*! \brief Endpoint to use for related incoming calls */
 AST_STRING_FIELD(endpoint);
 );
 /*! \brief Requested expiration time */
 unsigned int expiration;
 /*! \brief Interval at which retries should occur for temporal responses */
 unsigned int retry_interval;
 /*! \brief Interval at which retries should occur for permanent responses */
 unsigned int forbidden_retry_interval;
 /*! \brief Interval at which retries should occur for all permanent responses */
 unsigned int fatal_retry_interval;
 /*! \brief Treat authentication challenges that we cannot handle as permanent failures */
 unsigned int auth_rejection_permanent;
 /*! \brief Maximum number of retries permitted */
 unsigned int max_retries;
 /*! \brief Whether to add a line parameter to the outbound Contact or not */
 unsigned int line;
 /*! \brief Configured authentication credentials */
 struct ast_sip_auth_vector outbound_auths;
 /*! \brief Whether Path support is enabled */
 unsigned int support_path;
 /*! \brief Whether Outbound support is enabled */
 unsigned int support_outbound;
};

/*! \brief Outbound registration client state information (persists for lifetime of regc) */
struct sip_outbound_registration_client_state {
 /*! \brief Current state of this registration */
 enum sip_outbound_registration_status status;
 /*!
 * \brief Outbound registration client
 * \note May only be accessed within the serializer thread
 * because it might get destroyed and set to NULL for
 * module unload.
 */
 pjsip_regc *client;
 /*!
 * \brief Last tdata sent
 * We need the original tdata to resend a request on auth failure
 * or timeout. On an auth failure, we use the original tdata
 * to initialize the new tdata for the authorized response. On a timeout
 * we need it to skip failed SRV entries if any.
 */
 pjsip_tx_data *last_tdata;
 /*! \brief Timer entry for retrying on temporal responses */
 pj_timer_entry timer;
 /*! \brief Optional line parameter placed into Contact */
 char line[LINE_PARAMETER_SIZE];
 /*! \brief Current number of retries */
 unsigned int retries;
 /*! \brief Maximum number of retries permitted */
 unsigned int max_retries;
 /*! \brief Interval at which retries should occur for temporal responses */
 unsigned int retry_interval;
 /*! \brief Interval at which retries should occur for permanent responses */
 unsigned int forbidden_retry_interval;
 /*! \brief Interval at which retries should occur for all permanent responses */
 unsigned int fatal_retry_interval;
 /*! \brief Treat authentication challenges that we cannot handle as permanent failures */
 unsigned int auth_rejection_permanent;
 /*! \brief Determines whether SIP Path support should be advertised */
 unsigned int support_path;
 /*! \brief Determines whether SIP Outbound support should be advertised */
 unsigned int support_outbound;
 /*! CSeq number of last sent auth request. */
 unsigned int auth_cseq;
 /*! \brief Serializer for stuff and things */
 struct ast_taskprocessor *serializer;
 /*! \brief Configured authentication credentials */
 struct ast_sip_auth_vector outbound_auths;
 /*! \brief Registration should be destroyed after completion of transaction */
 unsigned int destroy:1;
 /*! \brief Non-zero if we have attempted sending a REGISTER with authentication */
 unsigned int auth_attempted:1;
 /*! \brief The name of the transport to be used for the registration */
 char *transport_name;
 /*! \brief The name of the registration sorcery object */
 char *registration_name;
};

/*! \brief Outbound registration state information (persists for lifetime that registration should exist) */
struct sip_outbound_registration_state {
 /*! \brief Outbound registration configuration object */
 struct sip_outbound_registration *registration;
 /*! \brief Client state information */
 struct sip_outbound_registration_client_state *client_state;
};

/*! Time needs to be long enough for a transaction to timeout if nothing replies. */
#define MAX_UNLOAD_TIMEOUT_TIME 35 /* Seconds */

/*! Shutdown group to monitor sip_outbound_registration_client_state serializers. */
static struct ast_serializer_shutdown_group *shutdown_group;

/*! \brief Default number of state container buckets */
#define DEFAULT_STATE_BUCKETS 53
static AO2_GLOBAL_OBJ_STATIC(current_states);

/*! subscription id for network change events */
static struct stasis_subscription *network_change_sub;

/*! \brief hashing function for state objects */
static int registration_state_hash(const void *obj, const int flags)
{
 const struct sip_outbound_registration_state *object;
 const char *key;

 switch (flags & OBJ_SEARCH_MASK) {
 case OBJ_SEARCH_KEY:
 key = obj;
 break;
 case OBJ_SEARCH_OBJECT:
 object = obj;
 key = ast_sorcery_object_get_id(object->registration);
 break;
 default:
 ast_assert(0);
 return 0;
 }
 return ast_str_hash(key);
}

/*! \brief comparator function for state objects */
static int registration_state_cmp(void *obj, void *arg, int flags)
{
 const struct sip_outbound_registration_state *object_left = obj;
 const struct sip_outbound_registration_state *object_right = arg;
 const char *right_key = arg;
 int cmp;

 switch (flags & OBJ_SEARCH_MASK) {
 case OBJ_SEARCH_OBJECT:
 right_key = ast_sorcery_object_get_id(object_right->registration);
 /* Fall through */
 case OBJ_SEARCH_KEY:
 cmp = strcmp(ast_sorcery_object_get_id(object_left->registration), right_key);
 break;
 case OBJ_SEARCH_PARTIAL_KEY:
 /* Not supported by container. */
 ast_assert(0);
 return 0;
 default:
 cmp = 0;
 break;
 }
 if (cmp) {
 return 0;
 }
 return CMP_MATCH;
}

static struct sip_outbound_registration_state *get_state(const char *id)
{
 struct sip_outbound_registration_state *state = NULL;
 struct ao2_container *states;

 states = ao2_global_obj_ref(current_states);
 if (states) {
 state = ao2_find(states, id, OBJ_SEARCH_KEY);
 ao2_ref(states, -1);
 }
 return state;
}

static struct ao2_container *get_registrations(void)
{
 struct ao2_container *registrations = ast_sorcery_retrieve_by_fields(
 ast_sip_get_sorcery(), "registration",
 AST_RETRIEVE_FLAG_MULTIPLE | AST_RETRIEVE_FLAG_ALL, NULL);

 return registrations;
}

/*! \brief Callback function for matching an outbound registration based on line */
static int line_identify_relationship(void *obj, void *arg, int flags)
{
 struct sip_outbound_registration_state *state = obj;
 pjsip_param *line = arg;

 return !pj_strcmp2(&line->value, state->client_state->line) ? CMP_MATCH : 0;
}

static struct pjsip_param *get_uri_option_line(const void *uri)
{
 pjsip_sip_uri *pjuri;
 static const pj_str_t LINE_STR = { "line", 4 };

 if (!PJSIP_URI_SCHEME_IS_SIP(uri) && !PJSIP_URI_SCHEME_IS_SIPS(uri)) {
 return NULL;
 }
 pjuri = pjsip_uri_get_uri(uri);
 return pjsip_param_find(&pjuri->other_param, &LINE_STR);
}

/*! \brief Endpoint identifier which uses the 'line' parameter to establish a relationship to an outgoing registration */
static struct ast_sip_endpoint *line_identify(pjsip_rx_data *rdata)
{
 pjsip_param *line;
 RAII_VAR(struct ao2_container *, states, NULL, ao2_cleanup);
 RAII_VAR(struct sip_outbound_registration_state *, state, NULL, ao2_cleanup);

 if (!(line = get_uri_option_line(rdata->msg_info.to->uri))
 && !(line = get_uri_option_line(rdata->msg_info.msg->line.req.uri))) {
 return NULL;
 }

 states = ao2_global_obj_ref(current_states);
 if (!states) {
 return NULL;
 }

 state = ao2_callback(states, 0, line_identify_relationship, line);
 if (!state || ast_strlen_zero(state->registration->endpoint)) {
 return NULL;
 }

 ast_debug(3, "Determined relationship to outbound registration '%s' based on line '%s', using configured endpoint '%s'\n",
 ast_sorcery_object_get_id(state->registration), state->client_state->line, state->registration->endpoint);

 return ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "endpoint", state->registration->endpoint);
}

static struct ast_sip_endpoint_identifier line_identifier = {
 .identify_endpoint = line_identify,
};

/*! \brief Helper function which cancels the timer on a client */
static void cancel_registration(struct sip_outbound_registration_client_state *client_state)
{
 if (pj_timer_heap_cancel_if_active(pjsip_endpt_get_timer_heap(ast_sip_get_pjsip_endpoint()),
 &client_state->timer, client_state->timer.id)) {
 /* The timer was successfully cancelled, drop the refcount of client_state */
 ao2_ref(client_state, -1);
 }
}

static pj_str_t PATH_NAME = { "path", 4 };
static pj_str_t OUTBOUND_NAME = { "outbound", 8 };

/*! \brief Helper function which sends a message and cleans up, if needed, on failure */
static pj_status_t registration_client_send(struct sip_outbound_registration_client_state *client_state,
 pjsip_tx_data *tdata)
{
 pj_status_t status;
 int *callback_invoked;
 pjsip_tpselector selector = { .type = PJSIP_TPSELECTOR_NONE, };

 callback_invoked = ast_threadstorage_get(&register_callback_invoked, sizeof(int));
 if (!callback_invoked) {
 pjsip_tx_data_dec_ref(tdata);
 return PJ_ENOMEM;
 }
 *callback_invoked = 0;

 /* Due to the message going out the callback may now be invoked, so bump the count */
 ao2_ref(client_state, +1);
 /*
 * We also bump tdata in expectation of saving it to client_state->last_tdata.
 * We have to do it BEFORE pjsip_regc_send because if it succeeds, it decrements
 * the ref count on its own.
 */
 pjsip_tx_data_add_ref(tdata);

 /*
 * Set the transport in case transports were reloaded.
 * When pjproject removes the extraneous error messages produced,
 * we can check status and only set the transport and resend if there was an error
 */
 ast_sip_set_tpselector_from_transport_name(client_state->transport_name, &selector);
 pjsip_regc_set_transport(client_state->client, &selector);
 ast_sip_tpselector_unref(&selector);

 status = pjsip_regc_send(client_state->client, tdata);

 /*
 * If the attempt to send the message failed and the callback was not invoked we need to
 * drop the references we just added
 */
 if ((status != PJ_SUCCESS) && !(*callback_invoked)) {
 pjsip_tx_data_dec_ref(tdata);
 ao2_ref(client_state, -1);
 return status;
 }

 /*
 * Decref the old last_data before replacing it.
 * BTW, it's quite possible that last_data == tdata
 * if we're trying successive servers in an SRV set.
 */
 if (client_state->last_tdata) {
 pjsip_tx_data_dec_ref(client_state->last_tdata);
 }
 client_state->last_tdata = tdata;

 return status;
}

/*! \brief Helper function to add string to Supported header */
static int add_to_supported_header(pjsip_tx_data *tdata, pj_str_t *name)
{
 pjsip_supported_hdr *hdr;
 int i;

 hdr = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_SUPPORTED, NULL);
 if (!hdr) {
 /* insert a new Supported header */
 hdr = pjsip_supported_hdr_create(tdata->pool);
 if (!hdr) {
 pjsip_tx_data_dec_ref(tdata);
 return 0;
 }

 pjsip_msg_add_hdr(tdata->msg, (pjsip_hdr *)hdr);
 }

 /* Don't add the value if it's already there */
 for (i = 0; i < hdr->count; ++i) {
 if (pj_stricmp(&hdr->values[i], name) == 0) {
 return 1;
 }
 }

 if (hdr->count >= PJSIP_GENERIC_ARRAY_MAX_COUNT) {
 return 0;
 }

 /* add on to the existing Supported header */
 pj_strassign(&hdr->values[hdr->count++], name);

 return 1;
}

/*! \brief Helper function to add configured supported headers */
static int add_configured_supported_headers(struct sip_outbound_registration_client_state *client_state, pjsip_tx_data *tdata)
{
 if (client_state->support_path) {
 if (!add_to_supported_header(tdata, &PATH_NAME)) {
 return 0;
 }
 }

 if (client_state->support_outbound) {
 if (!add_to_supported_header(tdata, &OUTBOUND_NAME)) {
 return 0;
 }
 }

 return 1;
}

/*! \brief Callback function for registering */
static int handle_client_registration(void *data)
{
 RAII_VAR(struct sip_outbound_registration_client_state *, client_state, data, ao2_cleanup);
 pjsip_tx_data *tdata;

 if (set_outbound_initial_authentication_credentials(client_state->client, &client_state->outbound_auths)) {
 ast_log(LOG_WARNING, "Failed to set initial authentication credentials\n");
 }

 if (client_state->status == SIP_REGISTRATION_STOPPED
 || pjsip_regc_register(client_state->client, PJ_FALSE, &tdata) != PJ_SUCCESS) {
 return 0;
 }

 if (DEBUG_ATLEAST(1)) {
 pjsip_regc_info info;

 pjsip_regc_get_info(client_state->client, &info);
 ast_log(LOG_DEBUG, "Outbound REGISTER attempt %u to '%.*s' with client '%.*s'\n",
 client_state->retries + 1,
 (int) info.server_uri.slen, info.server_uri.ptr,
 (int) info.client_uri.slen, info.client_uri.ptr);
 }

 if (!add_configured_supported_headers(client_state, tdata)) {
 ast_log(LOG_WARNING, "Failed to set supported headers\n");
 return -1;
 }

 registration_client_send(client_state, tdata);

 return 0;
}

/*! \brief Timer callback function, used just for registrations */
static void sip_outbound_registration_timer_cb(pj_timer_heap_t *timer_heap, struct pj_timer_entry *entry)
{
 struct sip_outbound_registration_client_state *client_state = entry->user_data;

 entry->id = 0;

 /*
 * Transfer client_state reference to serializer task so the
 * nominal path will not dec the client_state ref in this
 * pjproject callback thread.
 */
 if (ast_sip_push_task(client_state->serializer, handle_client_registration, client_state)) {
 ast_log(LOG_WARNING, "Scheduled outbound registration could not be executed.\n");
 ao2_ref(client_state, -1);
 }
}

/*! \brief Helper function which sets up the timer to re-register in a specific amount of time */
static void schedule_registration(struct sip_outbound_registration_client_state *client_state, unsigned int seconds)
{
 pj_time_val delay = { .sec = seconds, };
 pjsip_regc_info info;

 cancel_registration(client_state);

 pjsip_regc_get_info(client_state->client, &info);
 ast_debug(1, "Scheduling outbound registration to server '%.*s' from client '%.*s' in %d seconds\n",
 (int) info.server_uri.slen, info.server_uri.ptr,
 (int) info.client_uri.slen, info.client_uri.ptr,
 seconds);

 ao2_ref(client_state, +1);
 if (pjsip_endpt_schedule_timer(ast_sip_get_pjsip_endpoint(), &client_state->timer, &delay) != PJ_SUCCESS) {
 ast_log(LOG_WARNING, "Failed to schedule registration to server '%.*s' from client '%.*s'\n",
 (int) info.server_uri.slen, info.server_uri.ptr,
 (int) info.client_uri.slen, info.client_uri.ptr);
 ao2_ref(client_state, -1);
 }
}

static void update_client_state_status(struct sip_outbound_registration_client_state *client_state, enum sip_outbound_registration_status status)
{
 const char *status_old;
 const char *status_new;

 if (client_state->status == status) {
 /* Status state did not change at all. */
 return;
 }

 status_old = sip_outbound_registration_status_str(client_state->status);
 status_new = sip_outbound_registration_status_str(status);
 client_state->status = status;

 if (!strcmp(status_old, status_new)) {
 /*
 * The internal status state may have changed but the status
 * state we tell the world did not change at all.
 */
 return;
 }

 ast_statsd_log_string_va("PJSIP.registrations.state.%s", AST_STATSD_GAUGE, "-1", 1.0,
 status_old);
 ast_statsd_log_string_va("PJSIP.registrations.state.%s", AST_STATSD_GAUGE, "+1", 1.0,
 status_new);
}

/*! \brief Callback function for unregistering (potentially) and destroying state */
static int handle_client_state_destruction(void *data)
{
 struct sip_outbound_registration_client_state *client_state = data;

 cancel_registration(client_state);

 if (client_state->client) {
 pjsip_regc_info info;
 pjsip_tx_data *tdata;

 pjsip_regc_get_info(client_state->client, &info);

 if (info.is_busy == PJ_TRUE) {
 /* If a client transaction is in progress we defer until it is complete */
 ast_debug(1,
 "Registration transaction is busy with server '%.*s' from client '%.*s'.\n",
 (int) info.server_uri.slen, info.server_uri.ptr,
 (int) info.client_uri.slen, info.client_uri.ptr);
 client_state->destroy = 1;
 ao2_ref(client_state, -1);
 return 0;
 }

 switch (client_state->status) {
 case SIP_REGISTRATION_UNREGISTERED:
 break;
 case SIP_REGISTRATION_REGISTERED:
 ast_debug(1,
 "Trying to unregister with server '%.*s' from client '%.*s' before destruction.\n",
 (int) info.server_uri.slen, info.server_uri.ptr,
 (int) info.client_uri.slen, info.client_uri.ptr);

 update_client_state_status(client_state, SIP_REGISTRATION_STOPPING);
 client_state->destroy = 1;
 if (pjsip_regc_unregister(client_state->client, &tdata) == PJ_SUCCESS
 && add_configured_supported_headers(client_state, tdata)
 && registration_client_send(client_state, tdata) == PJ_SUCCESS) {
 ao2_ref(client_state, -1);
 return 0;
 }
 break;
 case SIP_REGISTRATION_REJECTED_TEMPORARY:
 case SIP_REGISTRATION_REJECTED_PERMANENT:
 case SIP_REGISTRATION_STOPPING:
 case SIP_REGISTRATION_STOPPED:
 break;
 }

 pjsip_regc_destroy(client_state->client);
 client_state->client = NULL;
 }

 update_client_state_status(client_state, SIP_REGISTRATION_STOPPED);
 ast_sip_auth_vector_destroy(&client_state->outbound_auths);
 ao2_ref(client_state, -1);

 return 0;
}

/*! \brief Structure for registration response */
struct registration_response {
 /*! \brief Response code for the registration attempt */
 int code;
 /*! \brief Expiration time for registration */
 int expiration;
 /*! \brief Retry-After value */
 int retry_after;
 /*! \brief Outbound registration client state */
 struct sip_outbound_registration_client_state *client_state;
 /*! \brief The response message */
 pjsip_rx_data *rdata;
 /*! \brief Request for which the response was received */
 pjsip_tx_data *old_request;
};

/*! \brief Registration response structure destructor */
static void registration_response_destroy(void *obj)
{
 struct registration_response *response = obj;

 if (response->rdata) {
 pjsip_rx_data_free_cloned(response->rdata);
 }

 if (response->old_request) {
 pjsip_tx_data_dec_ref(response->old_request);
 }

 ao2_cleanup(response->client_state);
}

/*! \brief Helper function which determines if a response code is temporal or not */
static int sip_outbound_registration_is_temporal(unsigned int code,
 struct sip_outbound_registration_client_state *client_state)
{
 /* Shamelessly taken from pjsua */
 if (code == PJSIP_SC_REQUEST_TIMEOUT ||
 code == PJSIP_SC_INTERNAL_SERVER_ERROR ||
 code == PJSIP_SC_BAD_GATEWAY ||
 code == PJSIP_SC_SERVICE_UNAVAILABLE ||
 code == PJSIP_SC_SERVER_TIMEOUT ||
 ((code == PJSIP_SC_UNAUTHORIZED ||
 code == PJSIP_SC_PROXY_AUTHENTICATION_REQUIRED) &&
 !client_state->auth_rejection_permanent) ||
 PJSIP_IS_STATUS_IN_CLASS(code, 600)) {
 return 1;
 } else {
 return 0;
 }
}

static void schedule_retry(struct registration_response *response, unsigned int interval,
 const char *server_uri, const char *client_uri)
{
 update_client_state_status(response->client_state, SIP_REGISTRATION_REJECTED_TEMPORARY);
 schedule_registration(response->client_state, interval);

 if (response->rdata) {
 ast_log(LOG_WARNING, "Temporal response '%d' received from '%s' on "
 "registration attempt to '%s', retrying in '%u'\n",
 response->code, server_uri, client_uri, interval);
 } else {
 ast_log(LOG_WARNING, "No response received from '%s' on "
 "registration attempt to '%s', retrying in '%u'\n",
 server_uri, client_uri, interval);
 }
}

static int reregister_immediately_cb(void *obj)
{
 struct sip_outbound_registration_state *state = obj;

 if (state->client_state->status != SIP_REGISTRATION_REGISTERED) {
 ao2_ref(state, -1);
 return 0;
 }

 if (DEBUG_ATLEAST(1)) {
 pjsip_regc_info info;

 pjsip_regc_get_info(state->client_state->client, &info);
 ast_log(LOG_DEBUG,
 "Outbound registration transport to server '%.*s' from client '%.*s' shutdown\n",
 (int) info.server_uri.slen, info.server_uri.ptr,
 (int) info.client_uri.slen, info.client_uri.ptr);
 }

 cancel_registration(state->client_state);

 ao2_ref(state->client_state, +1);
 handle_client_registration(state->client_state);

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

/*!
 * \internal
 * \brief The reliable transport we registered using has shutdown.
 * \since 13.18.0
 *
 * \param obj What is needed to initiate a reregister attempt.
 *
 * \note Normally executed by the pjsip monitor thread.
 *
 * \return Nothing
 */
static void registration_transport_shutdown_cb(void *obj)
{
 const char *registration_name = obj;
 struct sip_outbound_registration_state *state;

 state = get_state(registration_name);
 if (!state) {
 /* Registration no longer exists or shutting down. */
 return;
 }
 if (ast_sip_push_task(state->client_state->serializer, reregister_immediately_cb, state)) {
 ao2_ref(state, -1);
 }
}

static int monitor_matcher(void *a, void *b)
{
 char *ma = a;
 char *mb = b;

 return strcmp(ma, mb) == 0;
}

static void registration_transport_monitor_setup(pjsip_transport *transport, const char *registration_name)
{
 char *monitor;

 if (!PJSIP_TRANSPORT_IS_RELIABLE(transport)) {
 return;
 }
 monitor = ao2_alloc_options(strlen(registration_name) + 1, NULL,
 AO2_ALLOC_OPT_LOCK_NOLOCK);
 if (!monitor) {
 return;
 }
 strcpy(monitor, registration_name);/* Safe */

 /*
 * We'll ignore if the transport has already been shutdown before we
 * register the monitor. We might get into a message spamming infinite
 * loop of registration, shutdown, reregistration...
 */
 ast_sip_transport_monitor_register(transport, registration_transport_shutdown_cb,
 monitor);
 ao2_ref(monitor, -1);
}

static void save_response_fields_to_transport(struct registration_response *response)
{
 static const pj_str_t associated_uri_str = { "P-Associated-URI", 16 };
 static const pj_str_t service_route_str = { "Service-Route", 13 };
 pjsip_hdr *header = NULL;
 pjsip_msg *msg = response->rdata->msg_info.msg;
 struct ast_sip_service_route_vector *service_routes = NULL;

 /* If no transport is specified then we can't update any */
 if (ast_strlen_zero(response->client_state->transport_name)) {
 return;
 }

 ast_sip_transport_state_set_transport(response->client_state->transport_name, response->rdata->tp_info.transport);

 while ((header = pjsip_msg_find_hdr_by_name(msg, &service_route_str, header ? header->next : NULL))) {
 char *service_route;
 size_t size;

 /* The below code takes the approach that if we can't store all service routes then we
 * store none at all. This gives a predictable failure condition instead of storing a
 * partial list and having partial route headers.
 */
 size = pj_strlen(&((pjsip_generic_string_hdr*)header)->hvalue) + 1;
 service_route = ast_malloc(size);
 if (!service_route) {
 if (service_routes) {
 ast_sip_service_route_vector_destroy(service_routes);
 service_routes = NULL;
 }
 break;
 }

 ast_copy_pj_str(service_route, &((pjsip_generic_string_hdr*)header)->hvalue, size);

 if (!service_routes) {
 service_routes = ast_sip_service_route_vector_alloc();
 if (!service_routes) {
 ast_free(service_route);
 break;
 }
 }

 if (AST_VECTOR_APPEND(service_routes, service_route)) {
 ast_free(service_route);
 ast_sip_service_route_vector_destroy(service_routes);
 service_routes = NULL;
 break;
 }
 }

 /* If any service routes were handled then store them on the transport */
 if (service_routes) {
 ast_sip_transport_state_set_service_routes(response->client_state->transport_name, service_routes);
 }

 /* If an associated URI is present in the response we need to use it on any outgoing
 * traffic on the transport.
 */
 header = pjsip_msg_find_hdr_by_name(msg, &associated_uri_str, NULL);
 if (header) {
 char value[pj_strlen(&((pjsip_generic_string_hdr*)header)->hvalue) + 1];

 ast_copy_pj_str(value, &((pjsip_generic_string_hdr*)header)->hvalue, sizeof(value));
 ast_sip_transport_state_set_preferred_identity(response->client_state->transport_name, value);
 }
}


/*! \brief Callback function for handling a response to a registration attempt */
static int handle_registration_response(void *data)
{
 struct registration_response *response = data;
 pjsip_regc_info info;
 char server_uri[PJSIP_MAX_URL_SIZE];
 char client_uri[PJSIP_MAX_URL_SIZE];

 if (response->client_state->status == SIP_REGISTRATION_STOPPED) {
 ao2_ref(response, -1);
 return 0;
 }

 pjsip_regc_get_info(response->client_state->client, &info);
 ast_copy_pj_str(server_uri, &info.server_uri, sizeof(server_uri));
 ast_copy_pj_str(client_uri, &info.client_uri, sizeof(client_uri));

 ast_debug(1, "Processing REGISTER response %d from server '%s' for client '%s'\n",
 response->code, server_uri, client_uri);

 if (response->code == 408 || response->code == 503) {
 if ((ast_sip_failover_request(response->old_request))) {
 int res = registration_client_send(response->client_state, response->old_request);
 /* The tdata ref was stolen */
 response->old_request = NULL;
 if (res == PJ_SUCCESS) {
 ao2_ref(response, -1);
 return 0;
 }
 }
 } else if ((response->code == 401 || response->code == 407)
 && (!response->client_state->auth_attempted
 || response->rdata->msg_info.cseq->cseq != response->client_state->auth_cseq)) {
 int res;
 pjsip_cseq_hdr *cseq_hdr;
 pjsip_tx_data *tdata;

 if (!ast_sip_create_request_with_auth(&response->client_state->outbound_auths,
 response->rdata, response->old_request, &tdata)) {
 response->client_state->auth_attempted = 1;
 ast_debug(1, "Sending authenticated REGISTER to server '%s' from client '%s'\n",
 server_uri, client_uri);
 pjsip_tx_data_add_ref(tdata);
 res = registration_client_send(response->client_state, tdata);

 /* Save the cseq that actually got sent. */
 cseq_hdr = (pjsip_cseq_hdr *) pjsip_msg_find_hdr(tdata->msg, PJSIP_H_CSEQ,
 NULL);
 response->client_state->auth_cseq = cseq_hdr->cseq;
 pjsip_tx_data_dec_ref(tdata);
 if (res == PJ_SUCCESS) {
 ao2_ref(response, -1);
 return 0;
 }
 } else {
 ast_log(LOG_WARNING, "Failed to create authenticated REGISTER request to server '%s' from client '%s'\n",
 server_uri, client_uri);
 }
 /* Otherwise, fall through so the failure is processed appropriately */
 }

 response->client_state->auth_attempted = 0;

 if (PJSIP_IS_STATUS_IN_CLASS(response->code, 200)) {
 /* Check if this is in regards to registering or unregistering */
 if (response->expiration) {
 int next_registration_round;

 /* If the registration went fine simply reschedule registration for the future */
 ast_debug(1, "Outbound registration to '%s' with client '%s' successful\n", server_uri, client_uri);
 update_client_state_status(response->client_state, SIP_REGISTRATION_REGISTERED);
 response->client_state->retries = 0;
 next_registration_round = response->expiration - REREGISTER_BUFFER_TIME;
 if (next_registration_round < 0) {
 /* Re-register immediately. */
 next_registration_round = 0;
 }
 schedule_registration(response->client_state, next_registration_round);

 /* See if we should monitor for transport shutdown */
 registration_transport_monitor_setup(response->rdata->tp_info.transport,
 response->client_state->registration_name);
 } else {
 ast_debug(1, "Outbound unregistration to '%s' with client '%s' successful\n", server_uri, client_uri);
 update_client_state_status(response->client_state, SIP_REGISTRATION_UNREGISTERED);
 ast_sip_transport_monitor_unregister(response->rdata->tp_info.transport,
 registration_transport_shutdown_cb, response->client_state->registration_name,
 monitor_matcher);
 }

 save_response_fields_to_transport(response);
 } else if (response->client_state->destroy) {
 /* We need to deal with the pending destruction instead. */
 } else if (response->retry_after) {
 /* If we have been instructed to retry after a period of time, schedule it as such */
 schedule_retry(response, response->retry_after, server_uri, client_uri);
 } else if (response->client_state->retry_interval
 && sip_outbound_registration_is_temporal(response->code, response->client_state)) {
 if (response->client_state->retries == response->client_state->max_retries) {
 /* If we received enough temporal responses to exceed our maximum give up permanently */
 update_client_state_status(response->client_state, SIP_REGISTRATION_REJECTED_PERMANENT);
 ast_log(LOG_WARNING, "Maximum retries reached when attempting outbound registration to '%s' with client '%s', stopping registration attempt\n",
 server_uri, client_uri);
 } else {
 /* On the other hand if we can still try some more do so */
 response->client_state->retries++;
 schedule_retry(response, response->client_state->retry_interval, server_uri, client_uri);
 }
 } else {
 if (response->code == 403
 && response->client_state->forbidden_retry_interval
 && response->client_state->retries < response->client_state->max_retries) {
 /* A forbidden response retry interval is configured and there are retries remaining */
 update_client_state_status(response->client_state, SIP_REGISTRATION_REJECTED_TEMPORARY);
 response->client_state->retries++;
 schedule_registration(response->client_state, response->client_state->forbidden_retry_interval);
 ast_log(LOG_WARNING, "403 Forbidden fatal response received from '%s' on registration attempt to '%s', retrying in '%u' seconds\n",
 server_uri, client_uri, response->client_state->forbidden_retry_interval);
 } else if (response->client_state->fatal_retry_interval
 && response->client_state->retries < response->client_state->max_retries) {
 /* Some kind of fatal failure response received, so retry according to configured interval */
 update_client_state_status(response->client_state, SIP_REGISTRATION_REJECTED_TEMPORARY);
 response->client_state->retries++;
 schedule_registration(response->client_state, response->client_state->fatal_retry_interval);
 ast_log(LOG_WARNING, "'%d' fatal response received from '%s' on registration attempt to '%s', retrying in '%u' seconds\n",
 response->code, server_uri, client_uri, response->client_state->fatal_retry_interval);
 } else {
 /* Finally if there's no hope of registering give up */
 update_client_state_status(response->client_state, SIP_REGISTRATION_REJECTED_PERMANENT);
 if (response->rdata) {
 ast_log(LOG_WARNING, "Fatal response '%d' received from '%s' on registration attempt to '%s', stopping outbound registration\n",
 response->code, server_uri, client_uri);
 } else {
 ast_log(LOG_WARNING, "Fatal registration attempt to '%s', stopping outbound registration\n", client_uri);
 }
 }
 }

 ast_system_publish_registry("PJSIP", client_uri, server_uri,
 sip_outbound_registration_status_str(response->client_state->status), NULL);

 if (response->client_state->destroy) {
 /* We have a pending deferred destruction to complete now. */
 ao2_ref(response->client_state, +1);
 handle_client_state_destruction(response->client_state);
 }

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

/*! \brief Callback function for outbound registration client */
static void sip_outbound_registration_response_cb(struct pjsip_regc_cbparam *param)
{
 struct sip_outbound_registration_client_state *client_state = param->token;
 struct registration_response *response;
 int *callback_invoked;

 callback_invoked = ast_threadstorage_get(&register_callback_invoked, sizeof(int));

 ast_assert(callback_invoked != NULL);
 ast_assert(client_state != NULL);

 *callback_invoked = 1;

 response = ao2_alloc(sizeof(*response), registration_response_destroy);
 if (!response) {
 ao2_ref(client_state, -1);
 return;
 }
 response->code = param->code;
 response->expiration = param->expiration;
 /*
 * Transfer client_state reference to response so the
 * nominal path will not dec the client_state ref in this
 * pjproject callback thread.
 */
 response->client_state = client_state;

 ast_debug(1, "Received REGISTER response %d(%.*s)\n",
 param->code, (int) param->reason.slen, param->reason.ptr);

 if (param->rdata) {
 struct pjsip_retry_after_hdr *retry_after;
 pjsip_transaction *tsx;

 retry_after = pjsip_msg_find_hdr(param->rdata->msg_info.msg, PJSIP_H_RETRY_AFTER,
 NULL);
 response->retry_after = retry_after ? retry_after->ivalue : 0;

 /*
 * If we got a response from the server, we have to use the tdata
 * from the transaction, not the tdata saved when we sent the
 * request. If we use the saved tdata, we won't process responses
 * like 423 Interval Too Brief correctly and we'll wind up sending
 * the bad Expires value again.
 */
 pjsip_tx_data_dec_ref(client_state->last_tdata);

 tsx = pjsip_rdata_get_tsx(param->rdata);
 response->old_request = tsx->last_tx;
 pjsip_tx_data_add_ref(response->old_request);
 pjsip_rx_data_clone(param->rdata, 0, &response->rdata);
 } else {
 /* old_request steals the reference */
 response->old_request = client_state->last_tdata;
 }
 client_state->last_tdata = NULL;

 /*
 * Transfer response reference to serializer task so the
 * nominal path will not dec the response ref in this
 * pjproject callback thread.
 */
 if (ast_sip_push_task(client_state->serializer, handle_registration_response, response)) {
 ast_log(LOG_WARNING, "Failed to pass incoming registration response to threadpool\n");
 ao2_cleanup(response);
 }
}

/*! \brief Destructor function for registration state */
static void sip_outbound_registration_state_destroy(void *obj)
{
 struct sip_outbound_registration_state *state = obj;

 ast_debug(3, "Destroying registration state for registration to server '%s' from client '%s'\n",
 state->registration ? state->registration->server_uri : "",
 state->registration ? state->registration->client_uri : "");
 ao2_cleanup(state->registration);

 if (!state->client_state) {
 /* Nothing to do */
 } else if (!state->client_state->serializer) {
 ao2_ref(state->client_state, -1);
 } else if (ast_sip_push_task(state->client_state->serializer,
 handle_client_state_destruction, state->client_state)) {
 ast_log(LOG_WARNING, "Failed to pass outbound registration client destruction to threadpool\n");
 ao2_ref(state->client_state, -1);
 }
}

/*! \brief Destructor function for client registration state */
static void sip_outbound_registration_client_state_destroy(void *obj)
{
 struct sip_outbound_registration_client_state *client_state = obj;

 ast_statsd_log_string("PJSIP.registrations.count", AST_STATSD_GAUGE, "-1", 1.0);
 ast_statsd_log_string_va("PJSIP.registrations.state.%s", AST_STATSD_GAUGE, "-1", 1.0,
 sip_outbound_registration_status_str(client_state->status));

 ast_taskprocessor_unreference(client_state->serializer);
 ast_free(client_state->transport_name);
 ast_free(client_state->registration_name);
 if (client_state->last_tdata) {
 pjsip_tx_data_dec_ref(client_state->last_tdata);
 }
}

/*! \brief Allocator function for registration state */
static struct sip_outbound_registration_state *sip_outbound_registration_state_alloc(struct sip_outbound_registration *registration)
{
 struct sip_outbound_registration_state *state;
 char tps_name[AST_TASKPROCESSOR_MAX_NAME + 1];

 state = ao2_alloc(sizeof(*state), sip_outbound_registration_state_destroy);
 if (!state) {
 return NULL;
 }
 state->client_state = ao2_alloc(sizeof(*state->client_state),
 sip_outbound_registration_client_state_destroy);
 if (!state->client_state) {
 ao2_cleanup(state);
 return NULL;
 }

 state->client_state->status = SIP_REGISTRATION_UNREGISTERED;
 pj_timer_entry_init(&state->client_state->timer, 0, state->client_state,
 sip_outbound_registration_timer_cb);
 state->client_state->transport_name = ast_strdup(registration->transport);
 state->client_state->registration_name =
 ast_strdup(ast_sorcery_object_get_id(registration));

 ast_statsd_log_string("PJSIP.registrations.count", AST_STATSD_GAUGE, "+1", 1.0);
 ast_statsd_log_string_va("PJSIP.registrations.state.%s", AST_STATSD_GAUGE, "+1", 1.0,
 sip_outbound_registration_status_str(state->client_state->status));

 if (!state->client_state->transport_name
 || !state->client_state->registration_name) {
 ao2_cleanup(state);
 return NULL;
 }

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

 state->client_state->serializer = ast_sip_create_serializer_group(tps_name,
 shutdown_group);
 if (!state->client_state->serializer) {
 ao2_cleanup(state);
 return NULL;
 }

 state->registration = ao2_bump(registration);
 return state;
}

/*! \brief Destructor function for registration information */
static void sip_outbound_registration_destroy(void *obj)
{
 struct sip_outbound_registration *registration = obj;

 ast_sip_auth_vector_destroy(&registration->outbound_auths);

 ast_string_field_free_memory(registration);
}

/*! \brief Allocator function for registration information */
static void *sip_outbound_registration_alloc(const char *name)
{
 struct sip_outbound_registration *registration;

 registration = ast_sorcery_generic_alloc(sizeof(*registration),
 sip_outbound_registration_destroy);
 if (!registration || ast_string_field_init(registration, 256)) {
 ao2_cleanup(registration);
 return NULL;
 }

 return registration;
}

/*! \brief Helper function which populates a pj_str_t with a contact header */
static int sip_dialog_create_contact(pj_pool_t *pool, pj_str_t *contact, const char *user,
 const pj_str_t *target, pjsip_tpselector *selector, const char *line, const char *header_params)
{
 pj_str_t tmp, local_addr;
 pjsip_uri *uri;
 pjsip_sip_uri *sip_uri;
 pjsip_transport_type_e type;
 int local_port;

 pj_strdup_with_null(pool, &tmp, target);

 if (!(uri = pjsip_parse_uri(pool, tmp.ptr, tmp.slen, 0)) ||
 (!PJSIP_URI_SCHEME_IS_SIP(uri) && !PJSIP_URI_SCHEME_IS_SIPS(uri))) {
 return -1;
 }

 sip_uri = pjsip_uri_get_uri(uri);

 type = pjsip_transport_get_type_from_name(&sip_uri->transport_param);
 if (PJSIP_URI_SCHEME_IS_SIPS(sip_uri)) {
 if (type == PJSIP_TRANSPORT_UNSPECIFIED
 || !(pjsip_transport_get_flag_from_type(type) & PJSIP_TRANSPORT_SECURE)) {
 type = PJSIP_TRANSPORT_TLS;
 }
 } else if (!sip_uri->transport_param.slen) {
 type = PJSIP_TRANSPORT_UDP;
 } else if (type == PJSIP_TRANSPORT_UNSPECIFIED) {
 return -1;
 }

 if (pj_strchr(&sip_uri->host, ':')) {
 type |= PJSIP_TRANSPORT_IPV6;
 }

 if (pjsip_tpmgr_find_local_addr(pjsip_endpt_get_tpmgr(ast_sip_get_pjsip_endpoint()),
 pool, type, selector, &local_addr, &local_port) != PJ_SUCCESS) {
 return -1;
 }

 if (!pj_strchr(&sip_uri->host, ':') && pj_strchr(&local_addr, ':')) {
 type |= PJSIP_TRANSPORT_IPV6;
 }

 contact->ptr = pj_pool_alloc(pool, PJSIP_MAX_URL_SIZE);
 contact->slen = pj_ansi_snprintf(contact->ptr, PJSIP_MAX_URL_SIZE,
 "<%s:%s@%s%.*s%s:%d%s%s%s%s>%s%s",
 ((pjsip_transport_get_flag_from_type(type) & PJSIP_TRANSPORT_SECURE) && PJSIP_URI_SCHEME_IS_SIPS(uri)) ? "sips" : "sip",
 user,
 (type & PJSIP_TRANSPORT_IPV6) ? "[" : "",
 (int)local_addr.slen,
 local_addr.ptr,
 (type & PJSIP_TRANSPORT_IPV6) ? "]" : "",
 local_port,
 (type != PJSIP_TRANSPORT_UDP && type != PJSIP_TRANSPORT_UDP6) ? ";transport=" : "",
 (type != PJSIP_TRANSPORT_UDP && type != PJSIP_TRANSPORT_UDP6) ? pjsip_transport_get_type_name(type) : "",
 !ast_strlen_zero(line) ? ";line=" : "",
 S_OR(line, ""),
 !ast_strlen_zero(header_params) ? ";" : "",
 S_OR(header_params, ""));

 return 0;
}

/*!
 * \internal
 * \brief Check if a registration can be reused
 *
 * This checks if the existing outbound registration's configuration differs from a newly-applied
 * outbound registration to see if the applied one.
 *
 * \param existing The pre-existing outbound registration
 * \param applied The newly-created registration
 */
static int can_reuse_registration(struct sip_outbound_registration *existing,
 struct sip_outbound_registration *applied)
{
 int rc = 1;
 struct ast_sorcery *sorcery = ast_sip_get_sorcery();
 struct ast_variable *ve = ast_sorcery_objectset_create(sorcery, existing);
 struct ast_variable *va = ast_sorcery_objectset_create(sorcery, applied);
 struct ast_variable *vc = NULL;

 if (ast_sorcery_changeset_create(ve, va, &vc) || vc != NULL) {
 rc = 0;
 ast_debug(4, "Registration '%s' changed. Can't re-use.\n", ast_sorcery_object_get_id(existing));
 } else {
 ast_debug(4, "Registration '%s' didn't change. Can re-use\n", ast_sorcery_object_get_id(existing));
 }

 ast_variables_destroy(ve);
 ast_variables_destroy(va);
 ast_variables_destroy(vc);

 return rc;
}

/* \brief Get google oauth2 access token using refresh token */
static const char *fetch_google_access_token(const struct ast_sip_auth *auth)
{
 char *cmd = NULL;
 const char *token;
 const char *url = "https://www.googleapis.com/oauth2/v3/token";
 char buf[4096];
 int res;
 struct ast_json_error error;
 struct ast_json *json;

 /* set timeout to be shorter than default 180s (also checks func_curl is available) */
 if (ast_func_write(NULL, "CURLOPT(conntimeout)", "10")) {
 ast_log(LOG_ERROR, "CURL is unavailable. This is required for Google OAuth 2.0 authentication. Please ensure it is loaded.\n");
 return NULL;
 }

 res = ast_asprintf(&cmd,
 "CURL(%s,client_id=%s&client_secret=%s&refresh_token=%s&grant_type=refresh_token)",
 url, auth->oauth_clientid, auth->oauth_secret, auth->refresh_token);
 if (res < 0) {
 return NULL;
 }

 ast_debug(2, "Performing Google OAuth 2.0 authentication using command: %s\n", cmd);

 buf[0] = '\0';
 res = ast_func_read(NULL, cmd, buf, sizeof(buf));
 ast_free(cmd);
 if (res) {
 ast_log(LOG_ERROR, "Could not retrieve Google OAuth 2.0 authentication\n");
 return NULL;
 }

 ast_debug(2, "Google OAuth 2.0 authentication returned: %s\n", buf);

 json = ast_json_load_string(buf, &error);
 if (!json) {
 ast_log(LOG_ERROR, "Could not parse Google OAuth 2.0 authentication: %d(%d) %s: '%s'\n",
 error.line, error.column, error.text, buf);
 return NULL;
 }

 token = ast_json_string_get(ast_json_object_get(json, "access_token"));
 if (!token) {
 ast_log(LOG_ERROR, "Could not find Google OAuth 2.0 access_token in: '%s'\n",
 buf);
 }
 token = ast_strdup(token);
 ast_json_unref(json);
 return token;
}

/*!
 * \internal
 * \brief Set pjsip registration context with any authentication credentials that need to be
 * sent in the initial registration request
 *
 * \param regc The pjsip registration context
 * \param auth_vector The vector of configured authentication credentials
 */
static int set_outbound_initial_authentication_credentials(pjsip_regc *regc,
 const struct ast_sip_auth_vector *auth_vector)
{
 size_t auth_size = AST_VECTOR_SIZE(auth_vector);
 struct ast_sip_auth *auths[auth_size];
 const char *access_token;
 pjsip_cred_info auth_creds[1];
 pjsip_auth_clt_pref prefs;
 int res = 0;
 int idx;

 memset(auths, 0, sizeof(auths));
 if (ast_sip_retrieve_auths(auth_vector, auths)) {
 res = -1;
 goto cleanup;
 }

 for (idx = 0; idx < auth_size; ++idx) {
 switch (auths[idx]->type) {
 case AST_SIP_AUTH_TYPE_GOOGLE_OAUTH:
 pj_cstr(&auth_creds[0].username, auths[idx]->auth_user);
 pj_cstr(&auth_creds[0].scheme, "Bearer");
 pj_cstr(&auth_creds[0].realm, auths[idx]->realm);
 ast_debug(2, "Obtaining Google OAuth access token\n");
 access_token = fetch_google_access_token(auths[idx]);
 if (!access_token) {
 ast_log(LOG_WARNING, "Obtaining Google OAuth access token failed\n");
 access_token = auths[idx]->auth_pass;
 res = -1;
 }
 ast_debug(2, "Setting data to '%s'\n", access_token);

 pj_cstr(&auth_creds[0].data, access_token);
 auth_creds[0].data_type = PJSIP_CRED_DATA_PLAIN_PASSWD;

 pjsip_regc_set_credentials(regc, 1, auth_creds);

 /* for oauth, send auth without waiting for unauthorized response */
 prefs.initial_auth = PJ_TRUE;
 pj_cstr(&prefs.algorithm, "oauth");
 pjsip_regc_set_prefs(regc, &prefs);

 if (access_token != auths[idx]->auth_pass) {
 ast_free((char *) access_token);
 }
 break;
 default:
 /* other cases handled after receiving auth rejection */
 break;
 }
 }

cleanup:
 ast_sip_cleanup_auths(auths, auth_size);
 return res;
}

/*! \brief Helper function that allocates a pjsip registration client and configures it */
static int sip_outbound_registration_regc_alloc(void *data)
{
 struct sip_outbound_registration_state *state = data;
 RAII_VAR(struct sip_outbound_registration *, registration,
 ao2_bump(state->registration), ao2_cleanup);
 pj_pool_t *pool;
 pj_str_t tmp;
 pjsip_uri *uri;
 pj_str_t server_uri, client_uri, contact_uri;
 pjsip_tpselector selector = { .type = PJSIP_TPSELECTOR_NONE, };

 pool = pjsip_endpt_create_pool(ast_sip_get_pjsip_endpoint(), "URI Validation", 256, 256);
 if (!pool) {
 ast_log(LOG_ERROR, "Could not create pool for URI validation on outbound registration '%s'\n",
 ast_sorcery_object_get_id(registration));
 return -1;
 }

 pj_strdup2_with_null(pool, &tmp, registration->server_uri);
 uri = pjsip_parse_uri(pool, tmp.ptr, tmp.slen, 0);
 if (!uri) {
 ast_log(LOG_ERROR, "Invalid server URI '%s' specified on outbound registration '%s'\n",
 registration->server_uri, ast_sorcery_object_get_id(registration));
 pjsip_endpt_release_pool(ast_sip_get_pjsip_endpoint(), pool);
 return -1;
 }

 pj_strdup2_with_null(pool, &tmp, registration->client_uri);
 uri = pjsip_parse_uri(pool, tmp.ptr, tmp.slen, 0);
 if (!uri) {
 ast_log(LOG_ERROR, "Invalid client URI '%s' specified on outbound registration '%s'\n",
 registration->client_uri, ast_sorcery_object_get_id(registration));
 pjsip_endpt_release_pool(ast_sip_get_pjsip_endpoint(), pool);
 return -1;
 }

 if (!ast_strlen_zero(registration->outbound_proxy)) {
 pj_strdup2_with_null(pool, &tmp, registration->outbound_proxy);
 uri = pjsip_parse_uri(pool, tmp.ptr, tmp.slen, 0);
 if (!uri) {
 ast_log(LOG_ERROR, "Invalid outbound proxy URI '%s' specified on outbound registration '%s'\n",
 registration->outbound_proxy, ast_sorcery_object_get_id(registration));
 pjsip_endpt_release_pool(ast_sip_get_pjsip_endpoint(), pool);
 return -1;
 }
 }

 pjsip_endpt_release_pool(ast_sip_get_pjsip_endpoint(), pool);


 ast_assert(state->client_state->client == NULL);
 if (pjsip_regc_create(ast_sip_get_pjsip_endpoint(), state->client_state,
 sip_outbound_registration_response_cb,
 &state->client_state->client) != PJ_SUCCESS) {
 return -1;
 }

 ast_sip_set_tpselector_from_transport_name(registration->transport, &selector);
 pjsip_regc_set_transport(state->client_state->client, &selector);

 if (!ast_strlen_zero(registration->outbound_proxy)) {
 pjsip_route_hdr route_set, *route;
 static const pj_str_t ROUTE_HNAME = { "Route", 5 };
 pj_str_t tmp;

 pj_list_init(&route_set);

 pj_strdup2_with_null(pjsip_regc_get_pool(state->client_state->client), &tmp,
 registration->outbound_proxy);
 route = pjsip_parse_hdr(pjsip_regc_get_pool(state->client_state->client),
 &ROUTE_HNAME, tmp.ptr, tmp.slen, NULL);
 if (!route) {
 ast_sip_tpselector_unref(&selector);
 return -1;
 }
 pj_list_insert_nodes_before(&route_set, route);

 pjsip_regc_set_route_set(state->client_state->client, &route_set);
 }

 if (state->registration->line) {
 ast_generate_random_string(state->client_state->line, sizeof(state->client_state->line));
 }

 pj_cstr(&server_uri, registration->server_uri);

 if (sip_dialog_create_contact(pjsip_regc_get_pool(state->client_state->client),
 &contact_uri, S_OR(registration->contact_user, "s"), &server_uri, &selector,
 state->client_state->line, registration->contact_header_params)) {
 ast_sip_tpselector_unref(&selector);
 return -1;
 }

 ast_sip_tpselector_unref(&selector);

 pj_cstr(&client_uri, registration->client_uri);
 if (pjsip_regc_init(state->client_state->client, &server_uri, &client_uri,
 &client_uri, 1, &contact_uri, registration->expiration) != PJ_SUCCESS) {
 return -1;
 }

 return 0;
}

/*! \brief Helper function which performs a single registration */
static int sip_outbound_registration_perform(void *data)
{
 struct sip_outbound_registration_state *state = data;
 struct sip_outbound_registration *registration = ao2_bump(state->registration);
 size_t i;

 /* Just in case the client state is being reused for this registration, free the auth information */
 ast_sip_auth_vector_destroy(&state->client_state->outbound_auths);

 AST_VECTOR_INIT(&state->client_state->outbound_auths, AST_VECTOR_SIZE(&registration->outbound_auths));
 for (i = 0; i < AST_VECTOR_SIZE(&registration->outbound_auths); ++i) {
 char *name = ast_strdup(AST_VECTOR_GET(&registration->outbound_auths, i));

 if (name && AST_VECTOR_APPEND(&state->client_state->outbound_auths, name)) {
 ast_free(name);
 }
 }
 state->client_state->retry_interval = registration->retry_interval;
 state->client_state->forbidden_retry_interval = registration->forbidden_retry_interval;
 state->client_state->fatal_retry_interval = registration->fatal_retry_interval;
 state->client_state->max_retries = registration->max_retries;
 state->client_state->retries = 0;
 state->client_state->support_path = registration->support_path;
 state->client_state->support_outbound = registration->support_outbound;
 state->client_state->auth_rejection_permanent = registration->auth_rejection_permanent;

 pjsip_regc_update_expires(state->client_state->client, registration->expiration);

 schedule_registration(state->client_state, (ast_random() % 10) + 1);

 ao2_ref(registration, -1);
 ao2_ref(state, -1);
 return 0;
}

/*! \brief Apply function which finds or allocates a state structure */
static int sip_outbound_registration_apply(const struct ast_sorcery *sorcery, void *obj)
{
 RAII_VAR(struct ao2_container *, states, ao2_global_obj_ref(current_states), ao2_cleanup);
 RAII_VAR(struct sip_outbound_registration_state *, state, NULL, ao2_cleanup);
 RAII_VAR(struct sip_outbound_registration_state *, new_state, NULL, ao2_cleanup);
 struct sip_outbound_registration *applied = obj;

 if (!states) {
 /* Global container has gone. Likely shutting down. */
 return -1;
 }
 state = ao2_find(states, ast_sorcery_object_get_id(applied), OBJ_SEARCH_KEY);

 ast_debug(4, "Applying configuration to outbound registration '%s'\n", ast_sorcery_object_get_id(applied));

 if (ast_strlen_zero(applied->server_uri)) {
 ast_log(LOG_ERROR, "No server URI specified on outbound registration '%s'\n",
 ast_sorcery_object_get_id(applied));
 return -1;
 } else if (ast_sip_validate_uri_length(applied->server_uri)) {
 ast_log(LOG_ERROR, "Server URI or hostname length exceeds pjproject limit or is not a sip(s) uri: '%s'\n",
 ast_sorcery_object_get_id(applied));
 return -1;
 } else if (ast_strlen_zero(applied->client_uri)) {
 ast_log(LOG_ERROR, "No client URI specified on outbound registration '%s'\n",
 ast_sorcery_object_get_id(applied));
 return -1;
 } else if (ast_sip_validate_uri_length(applied->client_uri)) {
 ast_log(LOG_ERROR, "Client URI or hostname length exceeds pjproject limit or is not a sip(s) uri: '%s'\n",
 ast_sorcery_object_get_id(applied));
 return -1;
 } else if (applied->line && ast_strlen_zero(applied->endpoint)) {
 ast_log(LOG_ERROR, "Line support has been enabled on outbound registration '%s' without providing an endpoint\n",
 ast_sorcery_object_get_id(applied));
 return -1;
 } else if (!ast_strlen_zero(applied->endpoint) && !applied->line) {
 ast_log(LOG_ERROR, "An endpoint has been specified on outbound registration '%s' without enabling line support\n",
 ast_sorcery_object_get_id(applied));
 return -1;
 }

 if (state && can_reuse_registration(state->registration, applied)) {
 ast_debug(4,
 "No change between old configuration and new configuration on outbound registration '%s'. Using previous state\n",
 ast_sorcery_object_get_id(applied));

 /*
 * This is OK to replace without relinking the state in the
 * current_states container since state->registration and
 * applied have the same key.
 */
 ao2_lock(states);
 ao2_replace(state->registration, applied);
 ao2_unlock(states);
 return 0;
 }

 if (!(new_state = sip_outbound_registration_state_alloc(applied))) {
 return -1;
 }

 if (ast_sip_push_task_wait_serializer(new_state->client_state->serializer,
 sip_outbound_registration_regc_alloc, new_state)) {
 return -1;
 }

 if (ast_sip_push_task(new_state->client_state->serializer,
 sip_outbound_registration_perform, ao2_bump(new_state))) {
 ast_log(LOG_ERROR, "Failed to perform outbound registration on '%s'\n",
 ast_sorcery_object_get_id(new_state->registration));
 ao2_ref(new_state, -1);
 return -1;
 }

 ao2_lock(states);
 if (state) {
 ao2_unlink(states, state);
 }
 ao2_link(states, new_state);
 ao2_unlock(states);

 return 0;
}

static int outbound_auth_handler(const struct aco_option *opt, struct ast_variable *var, void *obj)
{
 struct sip_outbound_registration *registration = obj;

 return ast_sip_auth_vector_init(&registration->outbound_auths, var->value);
}

static int outbound_auths_to_str(const void *obj, const intptr_t *args, char **buf)
{
 const struct sip_outbound_registration *registration = obj;

 return ast_sip_auths_to_str(&registration->outbound_auths, buf);
}

static int outbound_auths_to_var_list(const void *obj, struct ast_variable **fields)
{
 const struct sip_outbound_registration *registration = obj;
 int i;
 struct ast_variable *head = NULL;

 for (i = 0; i < AST_VECTOR_SIZE(&registration->outbound_auths) ; i++) {
 ast_variable_list_append(&head, ast_variable_new("outbound_auth",
 AST_VECTOR_GET(&registration->outbound_auths, i), ""));
 }

 if (head) {
 *fields = head;
 }

 return 0;
}

static int unregister_task(void *obj)
{
 struct sip_outbound_registration_state *state = obj;
 struct pjsip_regc *client = state->client_state->client;
 pjsip_tx_data *tdata;
 pjsip_regc_info info;

 pjsip_regc_get_info(client, &info);
 ast_debug(1, "Unregistering contacts with server '%s' from client '%s'\n",
 state->registration->server_uri, state->registration->client_uri);

 cancel_registration(state->client_state);

 if (pjsip_regc_unregister(client, &tdata) == PJ_SUCCESS
 && add_configured_supported_headers(state->client_state, tdata)) {
 registration_client_send(state->client_state, tdata);
 }

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

static int queue_unregister(struct sip_outbound_registration_state *state)
{
 ao2_ref(state, +1);
 if (ast_sip_push_task(state->client_state->serializer, unregister_task, state)) {
 ao2_ref(state, -1);
 return -1;
 }

 return 0;
}

static int queue_register(struct sip_outbound_registration_state *state)
{
 ao2_ref(state, +1);
 if (ast_sip_push_task(state->client_state->serializer, sip_outbound_registration_perform, state)) {
 ao2_ref(state, -1);
 return -1;
 }

 return 0;
}

static void unregister_all(void)
{
 struct ao2_container *states;

 states = ao2_global_obj_ref(current_states);
 if (!states) {
 return;
 }

 /* Clean out all the states and let sorcery handle recreating the registrations */
 ao2_callback(states, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL, NULL);
 ao2_ref(states, -1);
}

static void reregister_all(void)
{
 unregister_all();
 ast_sorcery_load_object(ast_sip_get_sorcery(), "registration");
}

static char *cli_complete_registration(const char *line, const char *word,
 int pos, int state)
{
 char *result = NULL;
 int wordlen;
 int which = 0;
 struct sip_outbound_registration *registration;
 struct ao2_container *registrations;
 struct ao2_iterator i;

 if (pos != 3) {
 return NULL;
 }

 wordlen = strlen(word);
 if (wordlen == 0 && ++which > state) {
 return ast_strdup("*all");
 }

 registrations = ast_sorcery_retrieve_by_fields(ast_sip_get_sorcery(), "registration",
 AST_RETRIEVE_FLAG_MULTIPLE | AST_RETRIEVE_FLAG_ALL, NULL);
 if (!registrations) {
 return NULL;
 }

 i = ao2_iterator_init(registrations, 0);
 while ((registration = ao2_iterator_next(&i))) {
 const char *name = ast_sorcery_object_get_id(registration);

 if (!strncasecmp(word, name, wordlen) && ++which > state) {
 result = ast_strdup(name);
 }

 ao2_ref(registration, -1);
 if (result) {
 break;
 }
 }
 ao2_iterator_destroy(&i);

 ao2_ref(registrations, -1);
 return result;
}

static char *cli_unregister(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
 struct sip_outbound_registration_state *state;
 const char *registration_name;

 switch (cmd) {
 case CLI_INIT:
 e->command = "pjsip send unregister";
 e->usage =
 "Usage: pjsip send unregister <registration> | *all\n"
 " Unregisters the specified (or all) outbound registration(s) "
 "and stops future registration attempts.\n";
 return NULL;
 case CLI_GENERATE:
 return cli_complete_registration(a->line, a->word, a->pos, a->n);
 }

 if (a->argc != 4) {
 return CLI_SHOWUSAGE;
 }

 registration_name = a->argv[3];

 if (strcmp(registration_name, "*all") == 0) {
 unregister_all();
 ast_cli(a->fd, "Unregister all queued\n");
 return CLI_SUCCESS;
 }

 state = get_state(registration_name);
 if (!state) {
 ast_cli(a->fd, "Unable to retrieve registration %s\n", registration_name);
 return CLI_FAILURE;
 }

 if (queue_unregister(state)) {
 ast_cli(a->fd, "Failed to queue unregistration\n");
 }

 ao2_ref(state, -1);
 return CLI_SUCCESS;
}

static char *cli_register(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
 struct sip_outbound_registration_state *state;
 const char *registration_name;

 switch (cmd) {
 case CLI_INIT:
 e->command = "pjsip send register";
 e->usage =
 "Usage: pjsip send register <registration> | *all \n"
 " Unregisters the specified (or all) outbound "
 "registration(s) then starts registration(s) and schedules re-registrations.\n";
 return NULL;
 case CLI_GENERATE:
 return cli_complete_registration(a->line, a->word, a->pos, a->n);
 }

 if (a->argc != 4) {
 return CLI_SHOWUSAGE;
 }

 registration_name = a->argv[3];

 if (strcmp(registration_name, "*all") == 0) {
 reregister_all();
 ast_cli(a->fd, "Re-register all queued\n");
 return CLI_SUCCESS;
 }

 state = get_state(registration_name);
 if (!state) {
 ast_cli(a->fd, "Unable to retrieve registration %s\n", registration_name);
 return CLI_FAILURE;
 }

 /* We need to serialize the unregister and register so they need
 * to be queued as separate tasks.
 */
 if (queue_unregister(state)) {
 ast_cli(a->fd, "Failed to queue unregistration\n");
 } else if (queue_register(state)) {
 ast_cli(a->fd, "Failed to queue registration\n");
 }

 ao2_ref(state, -1);
 return CLI_SUCCESS;
}

static int ami_unregister(struct mansession *s, const struct message *m)
{
 const char *registration_name = astman_get_header(m, "Registration");
 struct sip_outbound_registration_state *state;

 if (ast_strlen_zero(registration_name)) {
 astman_send_error(s, m, "Registration parameter missing.");
 return 0;
 }

 if (strcmp(registration_name, "*all") == 0) {
 unregister_all();
 astman_send_ack(s, m, "Unregistrations queued.");
 return 0;
 }

 state = get_state(registration_name);
 if (!state) {
 astman_send_error(s, m, "Unable to retrieve registration entry\n");
 return 0;
 }

 if (queue_unregister(state)) {
 astman_send_ack(s, m, "Failed to queue unregistration");
 } else {
 astman_send_ack(s, m, "Unregistration sent");
 }

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

static int ami_register(struct mansession *s, const struct message *m)
{
 const char *registration_name = astman_get_header(m, "Registration");
 struct sip_outbound_registration_state *state;

 if (ast_strlen_zero(registration_name)) {
 astman_send_error(s, m, "Registration parameter missing.");
 return 0;
 }

 if (strcmp(registration_name, "*all") == 0) {
 reregister_all();
 astman_send_ack(s, m, "Reregistrations queued.");
 return 0;
 }

 state = get_state(registration_name);
 if (!state) {
 astman_send_error(s, m, "Unable to retrieve registration entry\n");
 return 0;
 }

 /* We need to serialize the unregister and register so they need
 * to be queued as separate tasks.
 */
 if (queue_unregister(state)) {
 astman_send_ack(s, m, "Failed to queue unregistration");
 } else if (queue_register(state)) {
 astman_send_ack(s, m, "Failed to queue unregistration");
 } else {
 astman_send_ack(s, m, "Reregistration sent");
 }

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

struct sip_ami_outbound {
 struct ast_sip_ami *ami;
 int registered;
 int not_registered;
 struct sip_outbound_registration *registration;
};

static int ami_outbound_registration_task(void *obj)
{
 struct sip_ami_outbound *ami = obj;
 struct ast_str *buf;
 struct sip_outbound_registration_state *state;

 buf = ast_sip_create_ami_event("OutboundRegistrationDetail", ami->ami);
 if (!buf) {
 return -1;
 }

 ast_sip_sorcery_object_to_ami(ami->registration, &buf);

 if ((state = get_state(ast_sorcery_object_get_id(ami->registration)))) {
 pjsip_regc_info info;

 if (state->client_state->status == SIP_REGISTRATION_REGISTERED) {
 ++ami->registered;
 } else {
 ++ami->not_registered;
 }

 ast_str_append(&buf, 0, "Status: %s\r\n",
 sip_outbound_registration_status_str(state->client_state->status));

 pjsip_regc_get_info(state->client_state->client, &info);
 ast_str_append(&buf, 0, "NextReg: %d\r\n", info.next_reg);
 ao2_ref(state, -1);
 }

 astman_append(ami->ami->s, "%s\r\n", ast_str_buffer(buf));
 ast_free(buf);

 return ast_sip_format_auths_ami(&ami->registration->outbound_auths, ami->ami);
}

static int ami_outbound_registration_detail(void *obj, void *arg, int flags)
{
 struct sip_ami_outbound *ami = arg;

 ami->registration = obj;
 return ast_sip_push_task_wait_servant(NULL, ami_outbound_registration_task, ami);
}

static int ami_show_outbound_registrations(struct mansession *s,
 const struct message *m)
{
 struct ast_sip_ami ami = { .s = s, .m = m, .action_id = astman_get_header(m, "ActionID"), };
 struct sip_ami_outbound ami_outbound = { .ami = &ami };
 struct ao2_container *regs;

 regs = get_registrations();
 if (!regs) {
 astman_send_error(s, m, "Unable to retrieve "
 "outbound registrations\n");
 return -1;
 }

 astman_send_listack(s, m, "Following are Events for each Outbound registration",
 "start");

 ao2_callback(regs, OBJ_NODATA, ami_outbound_registration_detail, &ami_outbound);

 astman_send_list_complete_start(s, m, "OutboundRegistrationDetailComplete",
 ami_outbound.registered + ami_outbound.not_registered);
 astman_append(s,
 "Registered: %d\r\n"
 "NotRegistered: %d\r\n",
 ami_outbound.registered,
 ami_outbound.not_registered);
 astman_send_list_complete_end(s);

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

static struct ao2_container *cli_get_container(const char *regex)
{
 RAII_VAR(struct ao2_container *, container, NULL, ao2_cleanup);
 struct ao2_container *s_container;

 container = ast_sorcery_retrieve_by_regex(ast_sip_get_sorcery(), "registration", regex);
 if (!container) {
 return NULL;
 }

 s_container = ao2_container_alloc_list(AO2_ALLOC_OPT_LOCK_NOLOCK, 0,
 ast_sorcery_object_id_sort, ast_sorcery_object_id_compare);
 if (!s_container) {
 return NULL;
 }

 if (ao2_container_dup(s_container, container, 0)) {
 ao2_ref(s_container, -1);
 return NULL;
 }

 return s_container;
}

static int cli_iterator(void *container, ao2_callback_fn callback, void *args)
{
 ao2_callback(container, OBJ_NODATA, callback, args);

 return 0;
}

static void *cli_retrieve_by_id(const char *id)
{
 struct ao2_container *states;
 void *obj = ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "registration", id);

 if (!obj) {
 /* if the object no longer exists then remove its state */
 states = ao2_global_obj_ref(current_states);
 if (states) {
 ao2_find(states, id, OBJ_SEARCH_KEY | OBJ_UNLINK | OBJ_NODATA);
 ao2_ref(states, -1);
 }
 }

 return obj;
}

static int cli_print_header(void *obj, void *arg, int flags)
{
 struct ast_sip_cli_context *context = arg;

 ast_assert(context->output_buffer != NULL);

 ast_str_append(&context->output_buffer, 0,
 " <Registration/ServerURI..............................> <Auth..........> <Status.......>\n");

 return 0;
}

static int cli_print_body(void *obj, void *arg, int flags)
{
 struct sip_outbound_registration *registration = obj;
 struct ast_sip_cli_context *context = arg;
 const char *id = ast_sorcery_object_get_id(registration);
 struct sip_outbound_registration_state *state = get_state(id);
#define REGISTRATION_URI_FIELD_LEN 53

 ast_assert(context->output_buffer != NULL);

 ast_str_append(&context->output_buffer, 0, " %-s/%-*.*s %-16s %-16s\n",
 id,
 (int) (REGISTRATION_URI_FIELD_LEN - strlen(id)),
 (int) (REGISTRATION_URI_FIELD_LEN - strlen(id)),
 registration->server_uri,
 AST_VECTOR_SIZE(&registration->outbound_auths)
 ? AST_VECTOR_GET(&registration->outbound_auths, 0)
 : "n/a",
 (state ? sip_outbound_registration_status_str(state->client_state->status) : "Unregistered"));
 ao2_cleanup(state);

 if (context->show_details
 || (context->show_details_only_level_0 && context->indent_level == 0)) {
 ast_str_append(&context->output_buffer, 0, "\n");
 ast_sip_cli_print_sorcery_objectset(registration, context, 0);
 }

 return 0;
}

/*
 * A function pointer to callback needs to be within the
 * module in order to avoid problems with an undefined
 * symbol when the module is loaded.
 */
static char *my_cli_traverse_objects(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
 return ast_sip_cli_traverse_objects(e, cmd, a);
}

static struct ast_cli_entry cli_outbound_registration[] = {
 AST_CLI_DEFINE(cli_unregister, "Unregisters outbound registration target"),
 AST_CLI_DEFINE(cli_register, "Registers an outbound registration target"),
 AST_CLI_DEFINE(my_cli_traverse_objects, "List PJSIP Registrations",
 .command = "pjsip list registrations",
 .usage = "Usage: pjsip list registrations [ like <pattern> ]\n"
 " List the configured PJSIP Registrations\n"
 " Optional regular expression pattern is used to filter the list.\n"),
 AST_CLI_DEFINE(my_cli_traverse_objects, "Show PJSIP Registrations",
 .command = "pjsip show registrations",
 .usage = "Usage: pjsip show registrations [ like <pattern> ]\n"
 " Show the configured PJSIP Registrations\n"
 " Optional regular expression pattern is used to filter the list.\n"),
 AST_CLI_DEFINE(my_cli_traverse_objects, "Show PJSIP Registration",
 .command = "pjsip show registration",
 .usage = "Usage: pjsip show registration <id>\n"
 " Show the configured PJSIP Registration\n"),
};

static struct ast_sip_cli_formatter_entry *cli_formatter;

static void auth_observer(const char *type)
{
 struct sip_outbound_registration *registration;
 struct sip_outbound_registration_state *state;
 struct ao2_container *regs;
 const char *registration_id;
 struct ao2_iterator i;

 ast_debug(4, "Auths updated. Checking for any outbound registrations that are in permanent rejected state so they can be retried\n");

 regs = ast_sorcery_retrieve_by_fields(ast_sip_get_sorcery(), "registration",
 AST_RETRIEVE_FLAG_MULTIPLE | AST_RETRIEVE_FLAG_ALL, NULL);
 if (!regs || ao2_container_count(regs) == 0) {
 ao2_cleanup(regs);
 return;
 }

 i = ao2_iterator_init(regs, 0);
 for (; (registration = ao2_iterator_next(&i)); ao2_ref(registration, -1)) {
 registration_id = ast_sorcery_object_get_id(registration);
 state = get_state(registration_id);
 if (state && state->client_state->status == SIP_REGISTRATION_REJECTED_PERMANENT) {
 ast_debug(4, "Trying outbound registration '%s' again\n", registration_id);

 if (ast_sip_push_task(state->client_state->serializer,
 sip_outbound_registration_perform, ao2_bump(state))) {
 ast_log(LOG_ERROR, "Failed to perform outbound registration on '%s'\n", registration_id);
 ao2_ref(state, -1);
 }
 }
 ao2_cleanup(state);
 }
 ao2_iterator_destroy(&i);
 ao2_cleanup(regs);
}

static const struct ast_sorcery_observer observer_callbacks_auth = {
 .loaded = auth_observer,
};

static int check_state(void *obj, void *arg, int flags)
{
 struct sip_outbound_registration_state *state = obj;
 struct sip_outbound_registration *registration;

 registration = ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "registration",
 ast_sorcery_object_get_id(state->registration));
 if (!registration) {
 /* This is a dead registration */
 return CMP_MATCH;
 }

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

/*!
 * \internal
 * \brief Observer to purge dead registration states.
 *
 * \param name Module name owning the sorcery instance.
 * \param sorcery Instance being observed.
 * \param object_type Name of object being observed.
 * \param reloaded Non-zero if the object is being reloaded.
 *
 * \return Nothing
 */
static void registration_loaded_observer(const char *name, const struct ast_sorcery *sorcery, const char *object_type, int reloaded)
{
 struct ao2_container *states;

 if (strcmp(object_type, "registration")) {
 /* Not interested */
 return;
 }

 states = ao2_global_obj_ref(current_states);
 if (!states) {
 /* Global container has gone. Likely shutting down. */
 return;
 }

 /*
 * Refresh the current configured registrations. We don't need to hold
 * onto the objects, as the apply handler will cause their states to
 * be created appropriately.
 */
 ao2_cleanup(get_registrations());

 /* Now to purge dead registrations. */
 ao2_callback(states, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, check_state, NULL);
 ao2_ref(states, -1);
}

static const struct ast_sorcery_instance_observer observer_callbacks_registrations = {
 .object_type_loaded = registration_loaded_observer,
};

static void registration_deleted_observer(const void *obj)
{
 const struct sip_outbound_registration *registration = obj;
 struct ao2_container *states;

 states = ao2_global_obj_ref(current_states);
 if (!states) {
 /* Global container has gone. Likely shutting down. */
 return;
 }

 ao2_find(states, ast_sorcery_object_get_id(registration), OBJ_UNLINK | OBJ_NODATA | OBJ_SEARCH_KEY);

 ao2_ref(states, -1);
}

static const struct ast_sorcery_observer registration_observer = {
 .deleted = registration_deleted_observer,
};

static void network_change_stasis_cb(void *data, struct stasis_subscription *sub, struct stasis_message *message)
{
 /* This callback is only concerned with network change messages from the system topic. */
 if (stasis_message_type(message) != ast_network_change_type()) {
 return;
 }
 ast_debug(3, "Received network change event\n");

 reregister_all();
}

static int unload_module(void)
{
 int remaining;

 network_change_sub = stasis_unsubscribe_and_join(network_change_sub);

 ast_manager_unregister("PJSIPShowRegistrationsOutbound");
 ast_manager_unregister("PJSIPUnregister");
 ast_manager_unregister("PJSIPRegister");

 ast_cli_unregister_multiple(cli_outbound_registration, ARRAY_LEN(cli_outbound_registration));
 ast_sip_unregister_cli_formatter(cli_formatter);
 cli_formatter = NULL;

 ast_sip_unregister_endpoint_identifier(&line_identifier);

 ast_sorcery_observer_remove(ast_sip_get_sorcery(), "auth", &observer_callbacks_auth);
 ast_sorcery_instance_observer_remove(ast_sip_get_sorcery(), &observer_callbacks_registrations);

 ast_sorcery_object_unregister(ast_sip_get_sorcery(), "registration");

 ao2_global_obj_release(current_states);

 ast_sip_transport_monitor_unregister_all(registration_transport_shutdown_cb, NULL, NULL);

 /* Wait for registration serializers to get destroyed. */
 ast_debug(2, "Waiting for registration transactions to complete for unload.\n");
 remaining = ast_serializer_shutdown_group_join(shutdown_group, MAX_UNLOAD_TIMEOUT_TIME);
 if (remaining) {
 /*
 * NOTE: We probably have a sip_outbound_registration_client_state
 * ref leak if the remaining count cannot reach zero after a few
 * minutes of trying to unload.
 */
 ast_log(LOG_WARNING, "Unload incomplete. Could not stop %d outbound registrations. Try again later.\n",
 remaining);
 return -1;
 }

 ast_debug(2, "Successful shutdown.\n");

 ao2_cleanup(shutdown_group);
 shutdown_group = NULL;

 return 0;
}

static int load_module(void)
{
 struct ao2_container *new_states;

 shutdown_group = ast_serializer_shutdown_group_alloc();
 if (!shutdown_group) {
 return AST_MODULE_LOAD_DECLINE;
 }

 /* Create outbound registration states container. */
 new_states = ao2_container_alloc_hash(AO2_ALLOC_OPT_LOCK_MUTEX, 0,
 DEFAULT_STATE_BUCKETS, registration_state_hash, NULL, registration_state_cmp);
 if (!new_states) {
 ast_log(LOG_ERROR, "Unable to allocate registration states container\n");
 unload_module();
 return AST_MODULE_LOAD_DECLINE;
 }
 ao2_global_obj_replace_unref(current_states, new_states);
 ao2_ref(new_states, -1);

 /*
 * Register sorcery object descriptions.
 */
 ast_sorcery_apply_config(ast_sip_get_sorcery(), "res_pjsip_outbound_registration");
 ast_sorcery_apply_default(ast_sip_get_sorcery(), "registration", "config", "pjsip.conf,criteria=type=registration");

 if (ast_sorcery_object_register(ast_sip_get_sorcery(), "registration", sip_outbound_registration_alloc, NULL, sip_outbound_registration_apply)) {
 unload_module();
 return AST_MODULE_LOAD_DECLINE;
 }

 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "type", "", OPT_NOOP_T, 0, 0);
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "server_uri", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, server_uri));
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "client_uri", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, client_uri));
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "contact_user", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, contact_user));
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "contact_header_params", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, contact_header_params));
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "transport", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, transport));
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "outbound_proxy", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, outbound_proxy));
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "expiration", "3600", OPT_UINT_T, 0, FLDSET(struct sip_outbound_registration, expiration));
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "retry_interval", "60", OPT_UINT_T, 0, FLDSET(struct sip_outbound_registration, retry_interval));
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "forbidden_retry_interval", "0", OPT_UINT_T, 0, FLDSET(struct sip_outbound_registration, forbidden_retry_interval));
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "fatal_retry_interval", "0", OPT_UINT_T, 0, FLDSET(struct sip_outbound_registration, fatal_retry_interval));
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "max_retries", "10", OPT_UINT_T, 0, FLDSET(struct sip_outbound_registration, max_retries));
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "auth_rejection_permanent", "yes", OPT_BOOL_T, 1, FLDSET(struct sip_outbound_registration, auth_rejection_permanent));
 ast_sorcery_object_field_register_custom(ast_sip_get_sorcery(), "registration", "outbound_auth", "", outbound_auth_handler, outbound_auths_to_str, outbound_auths_to_var_list, 0, 0);
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "support_path", "no", OPT_BOOL_T, 1, FLDSET(struct sip_outbound_registration, support_path));
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "support_outbound", "no", OPT_YESNO_T, 1, FLDSET(struct sip_outbound_registration, support_outbound));
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "line", "no", OPT_BOOL_T, 1, FLDSET(struct sip_outbound_registration, line));
 ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "endpoint", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, endpoint));

 /*
 * Register sorcery observers.
 */
 if (ast_sorcery_instance_observer_add(ast_sip_get_sorcery(),
 &observer_callbacks_registrations)
 || ast_sorcery_observer_add(ast_sip_get_sorcery(), "auth",
 &observer_callbacks_auth)
 || ast_sorcery_observer_add(ast_sip_get_sorcery(), "registration",
 &registration_observer)) {
 ast_log(LOG_ERROR, "Unable to register observers.\n");
 unload_module();
 return AST_MODULE_LOAD_DECLINE;
 }

 /* Register how this module identifies endpoints. */
 ast_sip_register_endpoint_identifier(&line_identifier);

 /* Register CLI commands. */
 cli_formatter = ao2_alloc(sizeof(struct ast_sip_cli_formatter_entry), NULL);
 if (!cli_formatter) {
 ast_log(LOG_ERROR, "Unable to allocate memory for cli formatter\n");
 unload_module();
 return AST_MODULE_LOAD_DECLINE;
 }
 cli_formatter->name = "registration";
 cli_formatter->print_header = cli_print_header;
 cli_formatter->print_body = cli_print_body;
 cli_formatter->get_container = cli_get_container;
 cli_formatter->iterate = cli_iterator;
 cli_formatter->get_id = ast_sorcery_object_get_id;
 cli_formatter->retrieve_by_id = cli_retrieve_by_id;
 ast_sip_register_cli_formatter(cli_formatter);
 ast_cli_register_multiple(cli_outbound_registration, ARRAY_LEN(cli_outbound_registration));

 /* Register AMI actions. */
 ast_manager_register_xml("PJSIPUnregister", EVENT_FLAG_SYSTEM | EVENT_FLAG_REPORTING, ami_unregister);
 ast_manager_register_xml("PJSIPRegister", EVENT_FLAG_SYSTEM | EVENT_FLAG_REPORTING, ami_register);
 ast_manager_register_xml("PJSIPShowRegistrationsOutbound", EVENT_FLAG_SYSTEM | EVENT_FLAG_REPORTING, ami_show_outbound_registrations);

 /* Clear any previous statsd gauges in case we weren't shutdown cleanly */
 ast_statsd_log("PJSIP.registrations.count", AST_STATSD_GAUGE, 0);
 ast_statsd_log("PJSIP.registrations.state.Registered", AST_STATSD_GAUGE, 0);
 ast_statsd_log("PJSIP.registrations.state.Unregistered", AST_STATSD_GAUGE, 0);
 ast_statsd_log("PJSIP.registrations.state.Rejected", AST_STATSD_GAUGE, 0);

 /* Load configuration objects */
 ast_sorcery_load_object(ast_sip_get_sorcery(), "registration");

 network_change_sub = stasis_subscribe(ast_system_topic(),
 network_change_stasis_cb, NULL);
 stasis_subscription_accept_message_type(network_change_sub, ast_network_change_type());
 stasis_subscription_set_filter(network_change_sub, STASIS_SUBSCRIPTION_FILTER_SELECTIVE);

 return AST_MODULE_LOAD_SUCCESS;
}

static int reload_module(void)
{
 ast_sorcery_reload_object(ast_sip_get_sorcery(), "registration");
 return 0;
}

AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PJSIP Outbound Registration Support",
 .support_level = AST_MODULE_SUPPORT_CORE,
 .load = load_module,
 .reload = reload_module,
 .unload = unload_module,
 .load_pri = AST_MODPRI_APP_DEPEND,
 .requires = "res_pjsip",
 .optional_modules = "res_statsd",
);