channel.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2006, Digium, Inc.
 *
 * Mark Spencer <[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.
 */

/*! \file
 *
 * \brief Channel Management
 *
 * \author Mark Spencer <[email protected]>
 */

/*** MODULEINFO
 <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/_private.h"

#include <sys/time.h>
#include <signal.h>
#include <math.h>

#include "asterisk/paths.h" /* use ast_config_AST_SYSTEM_NAME */

#include "asterisk/pbx.h"
#include "asterisk/frame.h"
#include "asterisk/mod_format.h"
#include "asterisk/sched.h"
#include "asterisk/channel.h"
#include "asterisk/musiconhold.h"
#include "asterisk/say.h"
#include "asterisk/file.h"
#include "asterisk/cli.h"
#include "asterisk/translate.h"
#include "asterisk/manager.h"
#include "asterisk/chanvars.h"
#include "asterisk/linkedlists.h"
#include "asterisk/indications.h"
#include "asterisk/causes.h"
#include "asterisk/callerid.h"
#include "asterisk/utils.h"
#include "asterisk/lock.h"
#include "asterisk/app.h"
#include "asterisk/transcap.h"
#include "asterisk/devicestate.h"
#include "asterisk/threadstorage.h"
#include "asterisk/slinfactory.h"
#include "asterisk/audiohook.h"
#include "asterisk/framehook.h"
#include "asterisk/timing.h"
#include "asterisk/autochan.h"
#include "asterisk/stringfields.h"
#include "asterisk/global_datastores.h"
#include "asterisk/channel_internal.h"
#include "asterisk/features.h"
#include "asterisk/bridge.h"
#include "asterisk/test.h"
#include "asterisk/stasis_channels.h"
#include "asterisk/max_forwards.h"
#include "asterisk/stream.h"
#include "asterisk/message.h"

/*** DOCUMENTATION
 ***/

#if defined(KEEP_TILL_CHANNEL_PARTY_NUMBER_INFO_NEEDED)
#if defined(HAVE_PRI)
#include "libpri.h"
#endif /* defined(HAVE_PRI) */
#endif /* defined(KEEP_TILL_CHANNEL_PARTY_NUMBER_INFO_NEEDED) */

/* uncomment if you have problems with 'monitoring' synchronized files */
#if 0
#define MONITOR_CONSTANT_DELAY
#define MONITOR_DELAY 150 * 8 /*!< 150 ms of MONITORING DELAY */
#endif

static int chancount;

unsigned long global_fin, global_fout;

AST_THREADSTORAGE(state2str_threadbuf);
#define STATE2STR_BUFSIZE 32

/*! Default amount of time to use when emulating a DTMF digit as a begin and end
 * 100ms */
#define AST_DEFAULT_EMULATE_DTMF_DURATION 100

/*! Default amount of time to use when emulating an MF digit as a begin and end
 * 55ms */
#define DEFAULT_EMULATE_MF_DURATION 55

#define DEFAULT_AMA_FLAGS AST_AMA_DOCUMENTATION

/*! Minimum amount of time between the end of the last digit and the beginning
 * of a new one - 45ms */
#define AST_MIN_DTMF_GAP 45

/*! \brief List of channel drivers */
struct chanlist {
 const struct ast_channel_tech *tech;
 AST_LIST_ENTRY(chanlist) list;
};

/*! \brief the list of registered channel types */
static AST_RWLIST_HEAD_STATIC(backends, chanlist);

/*! \brief All active channels on the system */
static struct ao2_container *channels;

/*! \brief map AST_CAUSE's to readable string representations
 *
 * \ref causes.h
*/
struct causes_map {
 int cause;
 const char *name;
 const char *desc;
};

static const struct causes_map causes[] = {
 { AST_CAUSE_UNALLOCATED, "UNALLOCATED", "Unallocated (unassigned) number" },
 { AST_CAUSE_NO_ROUTE_TRANSIT_NET, "NO_ROUTE_TRANSIT_NET", "No route to specified transmit network" },
 { AST_CAUSE_NO_ROUTE_DESTINATION, "NO_ROUTE_DESTINATION", "No route to destination" },
 { AST_CAUSE_MISDIALLED_TRUNK_PREFIX, "MISDIALLED_TRUNK_PREFIX", "Misdialed trunk prefix" },
 { AST_CAUSE_CHANNEL_UNACCEPTABLE, "CHANNEL_UNACCEPTABLE", "Channel unacceptable" },
 { AST_CAUSE_CALL_AWARDED_DELIVERED, "CALL_AWARDED_DELIVERED", "Call awarded and being delivered in an established channel" },
 { AST_CAUSE_PRE_EMPTED, "PRE_EMPTED", "Pre-empted" },
 { AST_CAUSE_NUMBER_PORTED_NOT_HERE, "NUMBER_PORTED_NOT_HERE", "Number ported elsewhere" },
 { AST_CAUSE_NORMAL_CLEARING, "NORMAL_CLEARING", "Normal Clearing" },
 { AST_CAUSE_USER_BUSY, "USER_BUSY", "User busy" },
 { AST_CAUSE_NO_USER_RESPONSE, "NO_USER_RESPONSE", "No user responding" },
 { AST_CAUSE_NO_ANSWER, "NO_ANSWER", "User alerting, no answer" },
 { AST_CAUSE_SUBSCRIBER_ABSENT, "SUBSCRIBER_ABSENT", "Subscriber absent" },
 { AST_CAUSE_CALL_REJECTED, "CALL_REJECTED", "Call Rejected" },
 { AST_CAUSE_NUMBER_CHANGED, "NUMBER_CHANGED", "Number changed" },
 { AST_CAUSE_REDIRECTED_TO_NEW_DESTINATION, "REDIRECTED_TO_NEW_DESTINATION", "Redirected to new destination" },
 { AST_CAUSE_ANSWERED_ELSEWHERE, "ANSWERED_ELSEWHERE", "Answered elsewhere" },
 { AST_CAUSE_DESTINATION_OUT_OF_ORDER, "DESTINATION_OUT_OF_ORDER", "Destination out of order" },
 { AST_CAUSE_INVALID_NUMBER_FORMAT, "INVALID_NUMBER_FORMAT", "Invalid number format" },
 { AST_CAUSE_FACILITY_REJECTED, "FACILITY_REJECTED", "Facility rejected" },
 { AST_CAUSE_RESPONSE_TO_STATUS_ENQUIRY, "RESPONSE_TO_STATUS_ENQUIRY", "Response to STATus ENQuiry" },
 { AST_CAUSE_NORMAL_UNSPECIFIED, "NORMAL_UNSPECIFIED", "Normal, unspecified" },
 { AST_CAUSE_NORMAL_CIRCUIT_CONGESTION, "NORMAL_CIRCUIT_CONGESTION", "Circuit/channel congestion" },
 { AST_CAUSE_NETWORK_OUT_OF_ORDER, "NETWORK_OUT_OF_ORDER", "Network out of order" },
 { AST_CAUSE_NORMAL_TEMPORARY_FAILURE, "NORMAL_TEMPORARY_FAILURE", "Temporary failure" },
 { AST_CAUSE_SWITCH_CONGESTION, "SWITCH_CONGESTION", "Switching equipment congestion" },
 { AST_CAUSE_ACCESS_INFO_DISCARDED, "ACCESS_INFO_DISCARDED", "Access information discarded" },
 { AST_CAUSE_REQUESTED_CHAN_UNAVAIL, "REQUESTED_CHAN_UNAVAIL", "Requested channel not available" },
 { AST_CAUSE_FACILITY_NOT_SUBSCRIBED, "FACILITY_NOT_SUBSCRIBED", "Facility not subscribed" },
 { AST_CAUSE_OUTGOING_CALL_BARRED, "OUTGOING_CALL_BARRED", "Outgoing call barred" },
 { AST_CAUSE_INCOMING_CALL_BARRED, "INCOMING_CALL_BARRED", "Incoming call barred" },
 { AST_CAUSE_BEARERCAPABILITY_NOTAUTH, "BEARERCAPABILITY_NOTAUTH", "Bearer capability not authorized" },
 { AST_CAUSE_BEARERCAPABILITY_NOTAVAIL, "BEARERCAPABILITY_NOTAVAIL", "Bearer capability not available" },
 { AST_CAUSE_BEARERCAPABILITY_NOTIMPL, "BEARERCAPABILITY_NOTIMPL", "Bearer capability not implemented" },
 { AST_CAUSE_CHAN_NOT_IMPLEMENTED, "CHAN_NOT_IMPLEMENTED", "Channel not implemented" },
 { AST_CAUSE_FACILITY_NOT_IMPLEMENTED, "FACILITY_NOT_IMPLEMENTED", "Facility not implemented" },
 { AST_CAUSE_INVALID_CALL_REFERENCE, "INVALID_CALL_REFERENCE", "Invalid call reference value" },
 { AST_CAUSE_INCOMPATIBLE_DESTINATION, "INCOMPATIBLE_DESTINATION", "Incompatible destination" },
 { AST_CAUSE_INVALID_MSG_UNSPECIFIED, "INVALID_MSG_UNSPECIFIED", "Invalid message unspecified" },
 { AST_CAUSE_MANDATORY_IE_MISSING, "MANDATORY_IE_MISSING", "Mandatory information element is missing" },
 { AST_CAUSE_MESSAGE_TYPE_NONEXIST, "MESSAGE_TYPE_NONEXIST", "Message type nonexist." },
 { AST_CAUSE_WRONG_MESSAGE, "WRONG_MESSAGE", "Wrong message" },
 { AST_CAUSE_IE_NONEXIST, "IE_NONEXIST", "Info. element nonexist or not implemented" },
 { AST_CAUSE_INVALID_IE_CONTENTS, "INVALID_IE_CONTENTS", "Invalid information element contents" },
 { AST_CAUSE_WRONG_CALL_STATE, "WRONG_CALL_STATE", "Message not compatible with call state" },
 { AST_CAUSE_RECOVERY_ON_TIMER_EXPIRE, "RECOVERY_ON_TIMER_EXPIRE", "Recover on timer expiry" },
 { AST_CAUSE_MANDATORY_IE_LENGTH_ERROR, "MANDATORY_IE_LENGTH_ERROR", "Mandatory IE length error" },
 { AST_CAUSE_PROTOCOL_ERROR, "PROTOCOL_ERROR", "Protocol error, unspecified" },
 { AST_CAUSE_INTERWORKING, "INTERWORKING", "Interworking, unspecified" },
};

struct ast_variable *ast_channeltype_list(void)
{
 struct chanlist *cl;
 struct ast_variable *var = NULL, *prev = NULL;

 AST_RWLIST_RDLOCK(&backends);
 AST_RWLIST_TRAVERSE(&backends, cl, list) {
 if (prev) {
 if ((prev->next = ast_variable_new(cl->tech->type, cl->tech->description, "")))
 prev = prev->next;
 } else {
 var = ast_variable_new(cl->tech->type, cl->tech->description, "");
 prev = var;
 }
 }
 AST_RWLIST_UNLOCK(&backends);

 return var;
}

#if defined(KEEP_TILL_CHANNEL_PARTY_NUMBER_INFO_NEEDED)
static const char *party_number_ton2str(int ton)
{
#if defined(HAVE_PRI)
 switch ((ton >> 4) & 0x07) {
 case PRI_TON_INTERNATIONAL:
 return "International";
 case PRI_TON_NATIONAL:
 return "National";
 case PRI_TON_NET_SPECIFIC:
 return "Network Specific";
 case PRI_TON_SUBSCRIBER:
 return "Subscriber";
 case PRI_TON_ABBREVIATED:
 return "Abbreviated";
 case PRI_TON_RESERVED:
 return "Reserved";
 case PRI_TON_UNKNOWN:
 default:
 break;
 }
#endif /* defined(HAVE_PRI) */
 return "Unknown";
}
#endif /* defined(KEEP_TILL_CHANNEL_PARTY_NUMBER_INFO_NEEDED) */

#if defined(KEEP_TILL_CHANNEL_PARTY_NUMBER_INFO_NEEDED)
static const char *party_number_plan2str(int plan)
{
#if defined(HAVE_PRI)
 switch (plan & 0x0F) {
 default:
 case PRI_NPI_UNKNOWN:
 break;
 case PRI_NPI_E163_E164:
 return "Public (E.163/E.164)";
 case PRI_NPI_X121:
 return "Data (X.121)";
 case PRI_NPI_F69:
 return "Telex (F.69)";
 case PRI_NPI_NATIONAL:
 return "National Standard";
 case PRI_NPI_PRIVATE:
 return "Private";
 case PRI_NPI_RESERVED:
 return "Reserved";
 }
#endif /* defined(HAVE_PRI) */
 return "Unknown";
}
#endif /* defined(KEEP_TILL_CHANNEL_PARTY_NUMBER_INFO_NEEDED) */

/*! \brief Show channel types - CLI command */
static char *handle_cli_core_show_channeltypes(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
#define FORMAT "%-15.15s %-40.40s %-13.13s %-13.13s %-13.13s %-13.13s\n"
 struct chanlist *cl;
 int count_chan = 0;

 switch (cmd) {
 case CLI_INIT:
 e->command = "core show channeltypes";
 e->usage =
 "Usage: core show channeltypes\n"
 " Lists available channel types registered in your\n"
 " Asterisk server.\n";
 return NULL;
 case CLI_GENERATE:
 return NULL;
 }

 if (a->argc != 3)
 return CLI_SHOWUSAGE;

 ast_cli(a->fd, FORMAT, "Type", "Description", "Devicestate", "Presencestate", "Indications", "Transfer");
 ast_cli(a->fd, FORMAT, "-------------", "-------------", "-------------", "-------------", "-------------", "-------------");

 AST_RWLIST_RDLOCK(&backends);
 AST_RWLIST_TRAVERSE(&backends, cl, list) {
 ast_cli(a->fd, FORMAT, cl->tech->type, cl->tech->description,
 (cl->tech->devicestate) ? "yes" : "no",
 (cl->tech->presencestate) ? "yes" : "no",
 (cl->tech->indicate) ? "yes" : "no",
 (cl->tech->transfer) ? "yes" : "no");
 count_chan++;
 }
 AST_RWLIST_UNLOCK(&backends);

 ast_cli(a->fd, "----------\n%d channel drivers registered.\n", count_chan);

 return CLI_SUCCESS;

#undef FORMAT
}

static char *complete_channeltypes(struct ast_cli_args *a)
{
 struct chanlist *cl;
 int wordlen;

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

 wordlen = strlen(a->word);

 AST_RWLIST_RDLOCK(&backends);
 AST_RWLIST_TRAVERSE(&backends, cl, list) {
 if (!strncasecmp(a->word, cl->tech->type, wordlen)) {
 ast_cli_completion_add(ast_strdup(cl->tech->type));
 }
 }
 AST_RWLIST_UNLOCK(&backends);

 return NULL;
}

/*! \brief Show details about a channel driver - CLI command */
static char *handle_cli_core_show_channeltype(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
 struct chanlist *cl = NULL;
 struct ast_str *codec_buf = ast_str_alloca(AST_FORMAT_CAP_NAMES_LEN);

 switch (cmd) {
 case CLI_INIT:
 e->command = "core show channeltype";
 e->usage =
 "Usage: core show channeltype <name>\n"
 " Show details about the specified channel type, <name>.\n";
 return NULL;
 case CLI_GENERATE:
 return complete_channeltypes(a);
 }

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

 AST_RWLIST_RDLOCK(&backends);

 AST_RWLIST_TRAVERSE(&backends, cl, list) {
 if (!strncasecmp(cl->tech->type, a->argv[3], strlen(cl->tech->type)))
 break;
 }


 if (!cl) {
 ast_cli(a->fd, "\n%s is not a registered channel driver.\n", a->argv[3]);
 AST_RWLIST_UNLOCK(&backends);
 return CLI_FAILURE;
 }

 ast_cli(a->fd,
 "-- Info about channel driver: %s --\n"
 " Device State: %s\n"
 "Presence State: %s\n"
 " Indication: %s\n"
 " Transfer : %s\n"
 " Capabilities: %s\n"
 " Digit Begin: %s\n"
 " Digit End: %s\n"
 " Send HTML : %s\n"
 " Image Support: %s\n"
 " Text Support: %s\n",
 cl->tech->type,
 (cl->tech->devicestate) ? "yes" : "no",
 (cl->tech->presencestate) ? "yes" : "no",
 (cl->tech->indicate) ? "yes" : "no",
 (cl->tech->transfer) ? "yes" : "no",
 ast_format_cap_get_names(cl->tech->capabilities, &codec_buf),
 (cl->tech->send_digit_begin) ? "yes" : "no",
 (cl->tech->send_digit_end) ? "yes" : "no",
 (cl->tech->send_html) ? "yes" : "no",
 (cl->tech->send_image) ? "yes" : "no",
 (cl->tech->send_text) ? "yes" : "no"

 );

 AST_RWLIST_UNLOCK(&backends);

 return CLI_SUCCESS;
}

static struct ast_cli_entry cli_channel[] = {
 AST_CLI_DEFINE(handle_cli_core_show_channeltypes, "List available channel types"),
 AST_CLI_DEFINE(handle_cli_core_show_channeltype, "Give more details on that channel type")
};

static struct ast_frame *kill_read(struct ast_channel *chan)
{
 /* Hangup channel. */
 return NULL;
}

static struct ast_frame *kill_exception(struct ast_channel *chan)
{
 /* Hangup channel. */
 return NULL;
}

static int kill_write(struct ast_channel *chan, struct ast_frame *frame)
{
 /* Hangup channel. */
 return -1;
}

static int kill_fixup(struct ast_channel *oldchan, struct ast_channel *newchan)
{
 /* No problem fixing up the channel. */
 return 0;
}

static int kill_hangup(struct ast_channel *chan)
{
 ast_channel_tech_pvt_set(chan, NULL);
 return 0;
}

/*!
 * \brief Kill the channel channel driver technology descriptor.
 *
 * \details
 * The purpose of this channel technology is to encourage the
 * channel to hangup as quickly as possible.
 *
 * \note Used by DTMF atxfer and zombie channels.
 */
const struct ast_channel_tech ast_kill_tech = {
 .type = "Kill",
 .description = "Kill channel (should not see this)",
 .read = kill_read,
 .exception = kill_exception,
 .write = kill_write,
 .fixup = kill_fixup,
 .hangup = kill_hangup,
};

/*! \brief Checks to see if a channel is needing hang up */
int ast_check_hangup(struct ast_channel *chan)
{
 if (ast_channel_softhangup_internal_flag(chan)) /* yes if soft hangup flag set */
 return 1;
 if (ast_tvzero(*ast_channel_whentohangup(chan))) /* no if no hangup scheduled */
 return 0;
 if (ast_tvdiff_ms(*ast_channel_whentohangup(chan), ast_tvnow()) > 0) /* no if hangup time has not come yet. */
 return 0;
 ast_debug(4, "Hangup time has come: %" PRIi64 "\n", ast_tvdiff_ms(*ast_channel_whentohangup(chan), ast_tvnow()));
 ast_test_suite_event_notify("HANGUP_TIME", "Channel: %s", ast_channel_name(chan));
 ast_channel_softhangup_internal_flag_add(chan, AST_SOFTHANGUP_TIMEOUT); /* record event */
 return 1;
}

int ast_check_hangup_locked(struct ast_channel *chan)
{
 int res;
 ast_channel_lock(chan);
 res = ast_check_hangup(chan);
 ast_channel_unlock(chan);
 return res;
}

void ast_channel_softhangup_withcause_locked(struct ast_channel *chan, int causecode)
{
 ast_channel_lock(chan);

 if (causecode > 0) {
 ast_debug(1, "Setting hangupcause of channel %s to %d (is %d now)\n",
 ast_channel_name(chan), causecode, ast_channel_hangupcause(chan));

 ast_channel_hangupcause_set(chan, causecode);
 }

 ast_softhangup_nolock(chan, AST_SOFTHANGUP_EXPLICIT);

 ast_channel_unlock(chan);
}

static int ast_channel_softhangup_cb(void *obj, void *arg, int flags)
{
 struct ast_channel *chan = obj;

 ast_softhangup(chan, AST_SOFTHANGUP_SHUTDOWN);

 return 0;
}

void ast_softhangup_all(void)
{
 ao2_callback(channels, OBJ_NODATA | OBJ_MULTIPLE, ast_channel_softhangup_cb, NULL);
}

/*! \brief returns number of active/allocated channels */
int ast_active_channels(void)
{
 return channels ? ao2_container_count(channels) : 0;
}

int ast_undestroyed_channels(void)
{
 return ast_atomic_fetchadd_int(&chancount, 0);
}

/*! \brief Set when to hangup channel */
void ast_channel_setwhentohangup_tv(struct ast_channel *chan, struct timeval offset)
{
 if (ast_tvzero(offset)) {
 ast_channel_whentohangup_set(chan, &offset);
 } else {
 struct timeval tv = ast_tvadd(offset, ast_tvnow());
 ast_channel_whentohangup_set(chan, &tv);
 }
 ast_queue_frame(chan, &ast_null_frame);
 return;
}

/*! \brief Compare a offset with when to hangup channel */
int ast_channel_cmpwhentohangup_tv(struct ast_channel *chan, struct timeval offset)
{
 struct timeval whentohangup;

 if (ast_tvzero(*ast_channel_whentohangup(chan)))
 return ast_tvzero(offset) ? 0 : -1;

 if (ast_tvzero(offset))
 return 1;

 whentohangup = ast_tvadd(offset, ast_tvnow());

 return ast_tvdiff_ms(whentohangup, *ast_channel_whentohangup(chan));
}

/*! \brief Register a new telephony channel in Asterisk */
int ast_channel_register(const struct ast_channel_tech *tech)
{
 struct chanlist *chan;

 AST_RWLIST_WRLOCK(&backends);

 AST_RWLIST_TRAVERSE(&backends, chan, list) {
 if (!strcasecmp(tech->type, chan->tech->type)) {
 ast_log(LOG_WARNING, "Already have a handler for type '%s'\n", tech->type);
 AST_RWLIST_UNLOCK(&backends);
 return -1;
 }
 }

 if (!(chan = ast_calloc(1, sizeof(*chan)))) {
 AST_RWLIST_UNLOCK(&backends);
 return -1;
 }
 chan->tech = tech;
 AST_RWLIST_INSERT_HEAD(&backends, chan, list);

 ast_debug(1, "Registered handler for '%s' (%s)\n", chan->tech->type, chan->tech->description);

 ast_verb(2, "Registered channel type '%s' (%s)\n", chan->tech->type, chan->tech->description);

 AST_RWLIST_UNLOCK(&backends);

 return 0;
}

/*! \brief Unregister channel driver */
void ast_channel_unregister(const struct ast_channel_tech *tech)
{
 struct chanlist *chan;

 ast_debug(1, "Unregistering channel type '%s'\n", tech->type);

 AST_RWLIST_WRLOCK(&backends);

 AST_RWLIST_TRAVERSE_SAFE_BEGIN(&backends, chan, list) {
 if (chan->tech == tech) {
 AST_LIST_REMOVE_CURRENT(list);
 ast_free(chan);
 ast_verb(2, "Unregistered channel type '%s'\n", tech->type);
 break;
 }
 }
 AST_LIST_TRAVERSE_SAFE_END;

 AST_RWLIST_UNLOCK(&backends);
}

/*! \brief Get handle to channel driver based on name */
const struct ast_channel_tech *ast_get_channel_tech(const char *name)
{
 struct chanlist *chanls;
 const struct ast_channel_tech *ret = NULL;

 AST_RWLIST_RDLOCK(&backends);

 AST_RWLIST_TRAVERSE(&backends, chanls, list) {
 if (!strcasecmp(name, chanls->tech->type)) {
 ret = chanls->tech;
 break;
 }
 }

 AST_RWLIST_UNLOCK(&backends);

 return ret;
}

/*! \brief Gives the string form of a given hangup cause */
const char *ast_cause2str(int cause)
{
 int x;

 for (x = 0; x < ARRAY_LEN(causes); x++) {
 if (causes[x].cause == cause)
 return causes[x].desc;
 }

 return "Unknown";
}

/*! \brief Convert a symbolic hangup cause to number */
int ast_str2cause(const char *name)
{
 int x;

 for (x = 0; x < ARRAY_LEN(causes); x++)
 if (!strncasecmp(causes[x].name, name, strlen(causes[x].name)))
 return causes[x].cause;

 return -1;
}

/*! \brief Gives the string form of a given channel state.
 *
 * \note This function is not reentrant.
 *
 * \param state
 */
const char *ast_state2str(enum ast_channel_state state)
{
 char *buf;

 switch (state) {
 case AST_STATE_DOWN:
 return "Down";
 case AST_STATE_RESERVED:
 return "Rsrvd";
 case AST_STATE_OFFHOOK:
 return "OffHook";
 case AST_STATE_DIALING:
 return "Dialing";
 case AST_STATE_RING:
 return "Ring";
 case AST_STATE_RINGING:
 return "Ringing";
 case AST_STATE_UP:
 return "Up";
 case AST_STATE_BUSY:
 return "Busy";
 case AST_STATE_DIALING_OFFHOOK:
 return "Dialing Offhook";
 case AST_STATE_PRERING:
 return "Pre-ring";
 case AST_STATE_MUTE:
 return "Mute";
 default:
 if (!(buf = ast_threadstorage_get(&state2str_threadbuf, STATE2STR_BUFSIZE)))
 return "Unknown";
 snprintf(buf, STATE2STR_BUFSIZE, "Unknown (%u)", state);
 return buf;
 }
}

/*! \brief Gives the string form of a given transfer capability */
char *ast_transfercapability2str(int transfercapability)
{
 switch (transfercapability) {
 case AST_TRANS_CAP_SPEECH:
 return "SPEECH";
 case AST_TRANS_CAP_DIGITAL:
 return "DIGITAL";
 case AST_TRANS_CAP_RESTRICTED_DIGITAL:
 return "RESTRICTED_DIGITAL";
 case AST_TRANS_CAP_3_1K_AUDIO:
 return "3K1AUDIO";
 case AST_TRANS_CAP_DIGITAL_W_TONES:
 return "DIGITAL_W_TONES";
 case AST_TRANS_CAP_VIDEO:
 return "VIDEO";
 default:
 return "UNKNOWN";
 }
}

/*! \brief Channel technology used to extract a channel from a running application. The
 * channel created with this technology will be immediately hung up - most external
 * applications won't ever want to see this.
 */
static const struct ast_channel_tech surrogate_tech = {
 .type = "Surrogate",
 .description = "Surrogate channel used to pull channel from an application",
 .properties = AST_CHAN_TP_INTERNAL,
};

static const struct ast_channel_tech null_tech = {
 .type = "NULL",
 .description = "Null channel (should not see this)",
};

static void ast_channel_destructor(void *obj);
static void ast_dummy_channel_destructor(void *obj);
static int ast_channel_by_uniqueid_cb(void *obj, void *arg, void *data, int flags);

static int does_id_conflict(const char *uniqueid)
{
 struct ast_channel *conflict;
 size_t length = 0;

 if (ast_strlen_zero(uniqueid)) {
 return 0;
 }

 conflict = ast_channel_callback(ast_channel_by_uniqueid_cb, (char *) uniqueid, &length, OBJ_NOLOCK);
 if (conflict) {
 ast_log(LOG_ERROR, "Channel Unique ID '%s' already in use by channel %s(%p)\n",
 uniqueid, ast_channel_name(conflict), conflict);
 ast_channel_unref(conflict);
 return 1;
 }

 return 0;
}

/*! \brief Create a new channel structure */
static struct ast_channel *__attribute__((format(printf, 15, 0)))
__ast_channel_alloc_ap(int needqueue, int state, const char *cid_num, const char *cid_name,
 const char *acctcode, const char *exten, const char *context, const struct ast_assigned_ids *assignedids,
 const struct ast_channel *requestor, enum ama_flags amaflag, struct ast_endpoint *endpoint,
 const char *file, int line,
 const char *function, const char *name_fmt, va_list ap)
{
 struct ast_channel *tmp;
 struct varshead *headp;
 char *tech = "", *tech2 = NULL;
 struct ast_format_cap *nativeformats;
 struct ast_sched_context *schedctx;
 struct ast_timer *timer;
 struct timeval now;
 const struct ast_channel_tech *channel_tech;
 struct ast_stream_topology *topology;

 /* If shutting down, don't allocate any new channels */
 if (ast_shutting_down()) {
 ast_log(LOG_WARNING, "Channel allocation failed: Refusing due to active shutdown\n");
 return NULL;
 }

 tmp = __ast_channel_internal_alloc(ast_channel_destructor, assignedids, requestor,
 file, line, function);
 if (!tmp) {
 /* Channel structure allocation failure. */
 return NULL;
 }

 ast_channel_stage_snapshot(tmp);

 /*
 * Init file descriptors to unopened state so
 * the destructor can know not to close them.
 */
 ast_channel_timingfd_set(tmp, -1);
 ast_channel_internal_alertpipe_clear(tmp);
 ast_channel_internal_fd_clear_all(tmp);

 nativeformats = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
 if (!nativeformats) {
 /*
 * Aborting the channel creation. We do not need to complete staging
 * the channel snapshot because the channel has not been finalized or
 * linked into the channels container yet. Nobody else knows about
 * this channel nor will anybody ever know about it.
 */
 return ast_channel_unref(tmp);
 }
 ast_format_cap_append(nativeformats, ast_format_none, 0);
 ast_channel_nativeformats_set(tmp, nativeformats);
 ao2_ref(nativeformats, -1);

 ast_channel_set_rawwriteformat(tmp, ast_format_none);
 ast_channel_set_rawreadformat(tmp, ast_format_none);
 ast_channel_set_writeformat(tmp, ast_format_none);
 ast_channel_set_readformat(tmp, ast_format_none);

 if (!(schedctx = ast_sched_context_create())) {
 ast_log(LOG_WARNING, "Channel allocation failed: Unable to create schedule context\n");
 /* See earlier channel creation abort comment above. */
 return ast_channel_unref(tmp);
 }
 ast_channel_sched_set(tmp, schedctx);

 ast_party_dialed_init(ast_channel_dialed(tmp));
 ast_party_caller_init(ast_channel_caller(tmp));
 ast_party_connected_line_init(ast_channel_connected(tmp));
 ast_party_connected_line_init(ast_channel_connected_indicated(tmp));
 ast_party_redirecting_init(ast_channel_redirecting(tmp));

 if (cid_name) {
 ast_channel_caller(tmp)->id.name.valid = 1;
 ast_channel_caller(tmp)->id.name.str = ast_strdup(cid_name);
 if (!ast_channel_caller(tmp)->id.name.str) {
 /* See earlier channel creation abort comment above. */
 return ast_channel_unref(tmp);
 }
 }
 if (cid_num) {
 ast_channel_caller(tmp)->id.number.valid = 1;
 ast_channel_caller(tmp)->id.number.str = ast_strdup(cid_num);
 if (!ast_channel_caller(tmp)->id.number.str) {
 /* See earlier channel creation abort comment above. */
 return ast_channel_unref(tmp);
 }
 }

 if ((timer = ast_timer_open())) {
 ast_channel_timer_set(tmp, timer);
 if (strcmp(ast_timer_get_name(ast_channel_timer(tmp)), "timerfd")) {
 needqueue = 0;
 }
 ast_channel_timingfd_set(tmp, ast_timer_fd(ast_channel_timer(tmp)));
 }

 if (needqueue && ast_channel_internal_alertpipe_init(tmp)) {
 /* See earlier channel creation abort comment above. */
 return ast_channel_unref(tmp);
 }

 if (!(topology = ast_stream_topology_alloc())) {
 return ast_channel_unref(tmp);
 }
 ast_channel_internal_set_stream_topology(tmp, topology);

 /* Always watch the alertpipe */
 ast_channel_set_fd(tmp, AST_ALERT_FD, ast_channel_internal_alert_readfd(tmp));
 /* And timing pipe */
 ast_channel_set_fd(tmp, AST_TIMING_FD, ast_channel_timingfd(tmp));

 /* Initial state */
 ast_channel_state_set(tmp, state);
 ast_channel_hold_state_set(tmp, AST_CONTROL_UNHOLD);

 ast_channel_streamid_set(tmp, -1);
 ast_channel_vstreamid_set(tmp, -1);

 ast_channel_fin_set(tmp, global_fin);
 ast_channel_fout_set(tmp, global_fout);

 now = ast_tvnow();
 ast_channel_creationtime_set(tmp, &now);

 ast_channel_internal_setup_topics(tmp);

 if (!ast_strlen_zero(name_fmt)) {
 char *slash, *slash2;
 /* Almost every channel is calling this function, and setting the name via the ast_string_field_build() call.
 * And they all use slightly different formats for their name string.
 * This means, to set the name here, we have to accept variable args, and call the string_field_build from here.
 * This means, that the stringfields must have a routine that takes the va_lists directly, and
 * uses them to build the string, instead of forming the va_lists internally from the vararg ... list.
 * This new function was written so this can be accomplished.
 */
 ast_channel_name_build_va(tmp, name_fmt, ap);
 tech = ast_strdupa(ast_channel_name(tmp));
 if ((slash = strchr(tech, '/'))) {
 if ((slash2 = strchr(slash + 1, '/'))) {
 tech2 = slash + 1;
 *slash2 = '\0';
 }
 *slash = '\0';
 }
 } else {
 /*
 * Start the string with '-' so it becomes an empty string
 * in the destructor.
 */
 ast_channel_name_set(tmp, "-**Unknown**");
 }

 if (amaflag != AST_AMA_NONE) {
 ast_channel_amaflags_set(tmp, amaflag);
 } else {
 ast_channel_amaflags_set(tmp, DEFAULT_AMA_FLAGS);
 }

 if (!ast_strlen_zero(acctcode)) {
 ast_channel_accountcode_set(tmp, acctcode);
 }
 ast_channel_language_set(tmp, ast_defaultlanguage);

 ast_channel_context_set(tmp, S_OR(context, "default"));
 ast_channel_exten_set(tmp, S_OR(exten, "s"));
 ast_channel_priority_set(tmp, 1);

 headp = ast_channel_varshead(tmp);
 AST_LIST_HEAD_INIT_NOLOCK(headp);

 ast_pbx_hangup_handler_init(tmp);
 AST_LIST_HEAD_INIT_NOLOCK(ast_channel_datastores(tmp));
 AST_LIST_HEAD_INIT_NOLOCK(ast_channel_autochans(tmp));

 channel_tech = ast_get_channel_tech(tech);
 if (!channel_tech && !ast_strlen_zero(tech2)) {
 channel_tech = ast_get_channel_tech(tech2);
 }
 if (channel_tech) {
 ast_channel_tech_set(tmp, channel_tech);
 } else {
 ast_channel_tech_set(tmp, &null_tech);
 }

 /* You might scream "locking inversion" at seeing this but it is actually perfectly fine.
 * Since the channel was just created nothing can know about it yet or even acquire it.
 */
 ast_channel_lock(tmp);

 ao2_lock(channels);

 if (assignedids && (does_id_conflict(assignedids->uniqueid) || does_id_conflict(assignedids->uniqueid2))) {
 ast_channel_internal_errno_set(AST_CHANNEL_ERROR_ID_EXISTS);
 ao2_unlock(channels);
 ast_channel_unlock(tmp);
 /* See earlier channel creation abort comment above. */
 return ast_channel_unref(tmp);
 }

 /* Finalize and link into the channels container. */
 ast_channel_internal_finalize(tmp);
 ast_atomic_fetchadd_int(&chancount, +1);
 ao2_link_flags(channels, tmp, OBJ_NOLOCK);

 ao2_unlock(channels);

 if (endpoint) {
 ast_endpoint_add_channel(endpoint, tmp);
 }

 /*
 * And now, since the channel structure is built, and has its name, let
 * the world know of its existance
 */
 ast_channel_stage_snapshot_done(tmp);

 ast_debug(1, "Channel %p '%s' allocated\n", tmp, ast_channel_name(tmp));

 return tmp;
}

struct ast_channel *__ast_channel_alloc(int needqueue, int state, const char *cid_num,
 const char *cid_name, const char *acctcode,
 const char *exten, const char *context, const struct ast_assigned_ids *assignedids,
 const struct ast_channel *requestor, enum ama_flags amaflag,
 struct ast_endpoint *endpoint,
 const char *file, int line, const char *function,
 const char *name_fmt, ...)
{
 va_list ap;
 struct ast_channel *result;

 va_start(ap, name_fmt);
 result = __ast_channel_alloc_ap(needqueue, state, cid_num, cid_name, acctcode, exten, context,
 assignedids, requestor, amaflag, endpoint, file, line, function, name_fmt, ap);
 va_end(ap);

 return result;
}

/* only do the minimum amount of work needed here to make a channel
 * structure that can be used to expand channel vars */
struct ast_channel *__ast_dummy_channel_alloc(const char *file, int line, const char *function)
{
 struct ast_channel *tmp;
 struct varshead *headp;

 tmp = __ast_channel_internal_alloc(ast_dummy_channel_destructor, NULL, NULL,
 file, line, function);
 if (!tmp) {
 /* Dummy channel structure allocation failure. */
 return NULL;
 }

 ast_pbx_hangup_handler_init(tmp);
 AST_LIST_HEAD_INIT_NOLOCK(ast_channel_datastores(tmp));

 /*
 * Init file descriptors to unopened state just in case
 * autoservice is called on the channel or something tries to
 * read a frame from it.
 */
 ast_channel_timingfd_set(tmp, -1);
 ast_channel_internal_alertpipe_clear(tmp);
 ast_channel_internal_fd_clear_all(tmp);

 ast_channel_hold_state_set(tmp, AST_CONTROL_UNHOLD);

 ast_channel_internal_setup_topics(tmp);

 headp = ast_channel_varshead(tmp);
 AST_LIST_HEAD_INIT_NOLOCK(headp);

 return tmp;
}

static int __ast_queue_frame(struct ast_channel *chan, struct ast_frame *fin, int head, struct ast_frame *after)
{
 struct ast_frame *f;
 struct ast_frame *cur;
 unsigned int new_frames = 0;
 unsigned int new_voice_frames = 0;
 unsigned int queued_frames = 0;
 unsigned int queued_voice_frames = 0;
 AST_LIST_HEAD_NOLOCK(,ast_frame) frames;

 ast_channel_lock(chan);

 /*
 * Check the last frame on the queue if we are queuing the new
 * frames after it.
 */
 cur = AST_LIST_LAST(ast_channel_readq(chan));
 if (cur && cur->frametype == AST_FRAME_CONTROL && !head && (!after || after == cur)) {
 switch (cur->subclass.integer) {
 case AST_CONTROL_END_OF_Q:
 if (fin->frametype == AST_FRAME_CONTROL
 && fin->subclass.integer == AST_CONTROL_HANGUP) {
 /*
 * Destroy the end-of-Q marker frame so we can queue the hangup
 * frame in its place.
 */
 AST_LIST_REMOVE(ast_channel_readq(chan), cur, frame_list);
 ast_frfree(cur);

 /*
 * This has degenerated to a normal queue append anyway. Since
 * we just destroyed the last frame in the queue we must make
 * sure that "after" is NULL or bad things will happen.
 */
 after = NULL;
 break;
 }
 /* Fall through */
 case AST_CONTROL_HANGUP:
 /* Don't queue anything. */
 ast_channel_unlock(chan);
 return 0;
 default:
 break;
 }
 }

 /* Build copies of all the new frames and count them */
 AST_LIST_HEAD_INIT_NOLOCK(&frames);
 for (cur = fin; cur; cur = AST_LIST_NEXT(cur, frame_list)) {
 if (!(f = ast_frdup(cur))) {
 if (AST_LIST_FIRST(&frames)) {
 ast_frfree(AST_LIST_FIRST(&frames));
 }
 ast_channel_unlock(chan);
 return -1;
 }

 AST_LIST_INSERT_TAIL(&frames, f, frame_list);
 new_frames++;
 if (f->frametype == AST_FRAME_VOICE) {
 new_voice_frames++;
 }
 }

 /* Count how many frames exist on the queue */
 AST_LIST_TRAVERSE(ast_channel_readq(chan), cur, frame_list) {
 queued_frames++;
 if (cur->frametype == AST_FRAME_VOICE) {
 queued_voice_frames++;
 }
 }

 if ((queued_frames + new_frames > 128 || queued_voice_frames + new_voice_frames > 96)) {
 int count = 0;
 ast_log(LOG_WARNING, "Exceptionally long %squeue length queuing to %s\n", queued_frames + new_frames > 128 ? "" : "voice ", ast_channel_name(chan));
 AST_LIST_TRAVERSE_SAFE_BEGIN(ast_channel_readq(chan), cur, frame_list) {
 /* Save the most recent frame */
 if (!AST_LIST_NEXT(cur, frame_list)) {
 break;
 } else if (cur->frametype == AST_FRAME_VOICE || cur->frametype == AST_FRAME_VIDEO || cur->frametype == AST_FRAME_NULL) {
 if (++count > 64) {
 break;
 }
 AST_LIST_REMOVE_CURRENT(frame_list);
 ast_frfree(cur);

 /* Read from the alert pipe for each flushed frame. */
 ast_channel_internal_alert_read(chan);
 }
 }
 AST_LIST_TRAVERSE_SAFE_END;
 }

 if (after) {
 AST_LIST_INSERT_LIST_AFTER(ast_channel_readq(chan), &frames, after, frame_list);
 } else {
 if (head) {
 AST_LIST_APPEND_LIST(&frames, ast_channel_readq(chan), frame_list);
 AST_LIST_HEAD_INIT_NOLOCK(ast_channel_readq(chan));
 }
 AST_LIST_APPEND_LIST(ast_channel_readq(chan), &frames, frame_list);
 }

 if (ast_channel_alert_writable(chan)) {
 /* Write to the alert pipe for each added frame */
 while (new_frames--) {
 if (ast_channel_alert_write(chan)) {
 ast_log(LOG_WARNING, "Unable to write to alert pipe on %s (qlen = %u): %s!\n",
 ast_channel_name(chan), queued_frames, strerror(errno));
 break;
 }
 }
 } else if (ast_channel_timingfd(chan) > -1) {
 ast_timer_enable_continuous(ast_channel_timer(chan));
 } else if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING)) {
 pthread_kill(ast_channel_blocker(chan), SIGURG);
 }

 ast_channel_unlock(chan);

 return 0;
}

int ast_queue_frame(struct ast_channel *chan, struct ast_frame *fin)
{
 return __ast_queue_frame(chan, fin, 0, NULL);
}

int ast_queue_frame_head(struct ast_channel *chan, struct ast_frame *fin)
{
 return __ast_queue_frame(chan, fin, 1, NULL);
}

/*! \brief Queue a hangup frame for channel */
int ast_queue_hangup(struct ast_channel *chan)
{
 struct ast_frame f = { AST_FRAME_CONTROL, .subclass.integer = AST_CONTROL_HANGUP };
 int res;

 /* Yeah, let's not change a lock-critical value without locking */
 ast_channel_lock(chan);
 ast_channel_softhangup_internal_flag_add(chan, AST_SOFTHANGUP_DEV);
 ast_channel_publish_blob(chan, ast_channel_hangup_request_type(), NULL);

 res = ast_queue_frame(chan, &f);
 ast_channel_unlock(chan);
 return res;
}

/*! \brief Queue a hangup frame for channel */
int ast_queue_hangup_with_cause(struct ast_channel *chan, int cause)
{
 RAII_VAR(struct ast_json *, blob, NULL, ast_json_unref);
 struct ast_frame f = { AST_FRAME_CONTROL, .subclass.integer = AST_CONTROL_HANGUP };
 int res;

 if (cause >= 0) {
 f.data.uint32 = cause;
 }
 ast_log(LOG_WARNING, "Queuing hangup with cause: %d !!!\n", cause);
 /* Yeah, let's not change a lock-critical value without locking */
 ast_channel_lock(chan);
 ast_channel_softhangup_internal_flag_add(chan, AST_SOFTHANGUP_DEV);
 if (cause < 0) {
 f.data.uint32 = ast_channel_hangupcause(chan);
 }
 blob = ast_json_pack("{s: i}",
 "cause", cause);
 ast_channel_publish_blob(chan, ast_channel_hangup_request_type(), blob);

 res = ast_queue_frame(chan, &f);
 ast_channel_unlock(chan);
 return res;
}

int ast_queue_hold(struct ast_channel *chan, const char *musicclass)
{
 struct ast_frame f = { AST_FRAME_CONTROL, .subclass.integer = AST_CONTROL_HOLD };
 struct ast_json *blob = NULL;
 int res;

 if (!ast_strlen_zero(musicclass)) {
 f.data.ptr = (void *) musicclass;
 f.datalen = strlen(musicclass) + 1;

 blob = ast_json_pack("{s: s}",
 "musicclass", musicclass);
 }

 ast_channel_lock(chan);
 ast_channel_publish_blob(chan, ast_channel_hold_type(), blob);
 ast_channel_unlock(chan);

 res = ast_queue_frame(chan, &f);

 ast_json_unref(blob);

 return res;
}

int ast_queue_unhold(struct ast_channel *chan)
{
 struct ast_frame f = { AST_FRAME_CONTROL, .subclass.integer = AST_CONTROL_UNHOLD };
 int res;

 ast_channel_lock(chan);
 ast_channel_publish_blob(chan, ast_channel_unhold_type(), NULL);
 ast_channel_unlock(chan);

 res = ast_queue_frame(chan, &f);

 return res;
}

/*! \brief Queue a control frame */
int ast_queue_control(struct ast_channel *chan, enum ast_control_frame_type control)
{
 struct ast_frame f = { AST_FRAME_CONTROL, .subclass.integer = control };
 return ast_queue_frame(chan, &f);
}

/*! \brief Queue a control frame with payload */
int ast_queue_control_data(struct ast_channel *chan, enum ast_control_frame_type control,
 const void *data, size_t datalen)
{
 struct ast_frame f = { AST_FRAME_CONTROL, .subclass.integer = control, .data.ptr = (void *) data, .datalen = datalen };
 return ast_queue_frame(chan, &f);
}

/*! \brief Queue an ANSWER control frame with topology */
int ast_queue_answer(struct ast_channel *chan, const struct ast_stream_topology *topology)
{
 struct ast_frame f = {
 AST_FRAME_CONTROL,
 .subclass.integer = AST_CONTROL_ANSWER,
 .subclass.topology = (struct ast_stream_topology *)topology,
 };
 return ast_queue_frame(chan, &f);
}

/*! \brief Set defer DTMF flag on channel */
int ast_channel_defer_dtmf(struct ast_channel *chan)
{
 int pre = 0;

 if (chan) {
 ast_channel_lock(chan);
 pre = ast_test_flag(ast_channel_flags(chan), AST_FLAG_DEFER_DTMF);
 ast_set_flag(ast_channel_flags(chan), AST_FLAG_DEFER_DTMF);
 ast_channel_unlock(chan);
 }
 return pre;
}

/*! \brief Unset defer DTMF flag on channel */
void ast_channel_undefer_dtmf(struct ast_channel *chan)
{
 if (chan) {
 ast_channel_clear_flag(chan, AST_FLAG_DEFER_DTMF);
 }
}

struct ast_channel *ast_channel_callback(ao2_callback_data_fn *cb_fn, void *arg,
 void *data, int ao2_flags)
{
 return ao2_callback_data(channels, ao2_flags, cb_fn, arg, data);
}

static int ast_channel_by_name_cb(void *obj, void *arg, void *data, int flags)
{
 struct ast_channel *chan = obj;
 const char *name = arg;
 size_t name_len = *(size_t *) data;
 int ret = CMP_MATCH;

 if (ast_strlen_zero(name)) {
 ast_log(LOG_ERROR, "BUG! Must supply a channel name or partial name to match!\n");
 return CMP_STOP;
 }

 ast_channel_lock(chan);
 if ((!name_len && strcasecmp(ast_channel_name(chan), name))
 || (name_len && strncasecmp(ast_channel_name(chan), name, name_len))) {
 ret = 0; /* name match failed, keep looking */
 }
 ast_channel_unlock(chan);

 return ret;
}

static int ast_channel_by_exten_cb(void *obj, void *arg, void *data, int flags)
{
 struct ast_channel *chan = obj;
 char *context = arg;
 char *exten = data;
 int ret = CMP_MATCH;

 if (ast_strlen_zero(exten) || ast_strlen_zero(context)) {
 ast_log(LOG_ERROR, "BUG! Must have a context and extension to match!\n");
 return CMP_STOP;
 }

 ast_channel_lock(chan);
 if (strcasecmp(ast_channel_context(chan), context) && strcasecmp(ast_channel_macrocontext(chan), context)) {
 ret = 0; /* Context match failed, continue */
 } else if (strcasecmp(ast_channel_exten(chan), exten) && strcasecmp(ast_channel_macroexten(chan), exten)) {
 ret = 0; /* Extension match failed, continue */
 }
 ast_channel_unlock(chan);

 return ret;
}

static int ast_channel_by_uniqueid_cb(void *obj, void *arg, void *data, int flags)
{
 struct ast_channel *chan = obj;
 char *uniqueid = arg;
 size_t id_len = *(size_t *) data;
 int ret = CMP_MATCH;

 if (ast_strlen_zero(uniqueid)) {
 ast_log(LOG_ERROR, "BUG! Must supply a uniqueid or partial uniqueid to match!\n");
 return CMP_STOP;
 }

 ast_channel_lock(chan);
 if ((!id_len && strcasecmp(ast_channel_uniqueid(chan), uniqueid))
 || (id_len && strncasecmp(ast_channel_uniqueid(chan), uniqueid, id_len))) {
 ret = 0; /* uniqueid match failed, keep looking */
 }
 ast_channel_unlock(chan);

 return ret;
}

struct ast_channel_iterator {
 /* storage for non-dynamically allocated iterator */
 struct ao2_iterator simple_iterator;
 /* pointer to the actual iterator (simple_iterator or a dynamically
 * allocated iterator)
 */
 struct ao2_iterator *active_iterator;
};

struct ast_channel_iterator *ast_channel_iterator_destroy(struct ast_channel_iterator *i)
{
 ao2_iterator_destroy(i->active_iterator);
 ast_free(i);

 return NULL;
}

struct ast_channel_iterator *ast_channel_iterator_by_exten_new(const char *exten, const char *context)
{
 struct ast_channel_iterator *i;
 char *l_exten = (char *) exten;
 char *l_context = (char *) context;

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

 i->active_iterator = (void *) ast_channel_callback(ast_channel_by_exten_cb,
 l_context, l_exten, OBJ_MULTIPLE);
 if (!i->active_iterator) {
 ast_free(i);
 return NULL;
 }

 return i;
}

struct ast_channel_iterator *ast_channel_iterator_by_name_new(const char *name, size_t name_len)
{
 struct ast_channel_iterator *i;
 char *l_name = (char *) name;

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

 i->active_iterator = (void *) ast_channel_callback(ast_channel_by_name_cb,
 l_name, &name_len,
 OBJ_MULTIPLE | (name_len == 0 /* match the whole word, so optimize */ ? OBJ_KEY : 0));
 if (!i->active_iterator) {
 ast_free(i);
 return NULL;
 }

 return i;
}

struct ast_channel_iterator *ast_channel_iterator_all_new(void)
{
 struct ast_channel_iterator *i;

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

 i->simple_iterator = ao2_iterator_init(channels, 0);
 i->active_iterator = &i->simple_iterator;

 return i;
}

struct ast_channel *ast_channel_iterator_next(struct ast_channel_iterator *i)
{
 return ao2_iterator_next(i->active_iterator);
}

/* Legacy function, not currently used for lookups, but we need a cmp_fn */
static int ast_channel_cmp_cb(void *obj, void *arg, int flags)
{
 ast_log(LOG_ERROR, "BUG! Should never be called!\n");
 return CMP_STOP;
}

struct ast_channel *ast_channel_get_by_name_prefix(const char *name, size_t name_len)
{
 struct ast_channel *chan;
 char *l_name = (char *) name;

 chan = ast_channel_callback(ast_channel_by_name_cb, l_name, &name_len,
 (name_len == 0) /* optimize if it is a complete name match */ ? OBJ_KEY : 0);
 if (chan) {
 return chan;
 }

 if (ast_strlen_zero(l_name)) {
 /* We didn't have a name to search for so quit. */
 return NULL;
 }

 /* Now try a search for uniqueid. */
 return ast_channel_callback(ast_channel_by_uniqueid_cb, l_name, &name_len, 0);
}

struct ast_channel *ast_channel_get_by_name(const char *name)
{
 return ast_channel_get_by_name_prefix(name, 0);
}

struct ast_channel *ast_channel_get_by_exten(const char *exten, const char *context)
{
 char *l_exten = (char *) exten;
 char *l_context = (char *) context;

 return ast_channel_callback(ast_channel_by_exten_cb, l_context, l_exten, 0);
}

int ast_is_deferrable_frame(const struct ast_frame *frame)
{
 /* Do not add a default entry in this switch statement. Each new
 * frame type should be addressed directly as to whether it should
 * be queued up or not.
 */
 switch (frame->frametype) {
 case AST_FRAME_BRIDGE_ACTION:
 case AST_FRAME_BRIDGE_ACTION_SYNC:
 case AST_FRAME_CONTROL:
 case AST_FRAME_TEXT:
 case AST_FRAME_TEXT_DATA:
 case AST_FRAME_IMAGE:
 case AST_FRAME_HTML:
 return 1;

 case AST_FRAME_DTMF_END:
 case AST_FRAME_DTMF_BEGIN:
 case AST_FRAME_VOICE:
 case AST_FRAME_VIDEO:
 case AST_FRAME_NULL:
 case AST_FRAME_IAX:
 case AST_FRAME_CNG:
 case AST_FRAME_MODEM:
 case AST_FRAME_RTCP:
 return 0;
 }
 return 0;
}

/*! \brief Wait, look for hangups and condition arg */
static int safe_sleep_conditional(struct ast_channel *chan, int timeout_ms, int (*cond)(void*), void *data, unsigned int generate_silence)
{
 struct ast_frame *f;
 struct ast_silence_generator *silgen = NULL;
 int res = 0;
 struct timeval start;
 int ms;
 AST_LIST_HEAD_NOLOCK(, ast_frame) deferred_frames;

 AST_LIST_HEAD_INIT_NOLOCK(&deferred_frames);

 /* If no other generator is present, start silencegen while waiting */
 if (generate_silence && ast_opt_transmit_silence && !ast_channel_generatordata(chan)) {
 silgen = ast_channel_start_silence_generator(chan);
 }

 start = ast_tvnow();
 while ((ms = ast_remaining_ms(start, timeout_ms))) {
 struct ast_frame *dup_f = NULL;

 if (cond && ((*cond)(data) == 0)) {
 break;
 }
 ms = ast_waitfor(chan, ms);
 if (ms < 0) {
 res = -1;
 break;
 }
 if (ms > 0) {
 f = ast_read(chan);
 if (!f) {
 res = -1;
 break;
 }

 if (!ast_is_deferrable_frame(f)) {
 ast_frfree(f);
 continue;
 }

 if ((dup_f = ast_frisolate(f))) {
 if (dup_f != f) {
 ast_frfree(f);
 }
 AST_LIST_INSERT_HEAD(&deferred_frames, dup_f, frame_list);
 }
 }
 }

 /* stop silgen if present */
 if (silgen) {
 ast_channel_stop_silence_generator(chan, silgen);
 }

 /* We need to free all the deferred frames, but we only need to
 * queue the deferred frames if there was no error and no
 * hangup was received
 */
 ast_channel_lock(chan);
 while ((f = AST_LIST_REMOVE_HEAD(&deferred_frames, frame_list))) {
 if (!res) {
 ast_queue_frame_head(chan, f);
 }
 ast_frfree(f);
 }
 ast_channel_unlock(chan);

 return res;
}

int ast_safe_sleep_conditional(struct ast_channel *chan, int timeout_ms, int (*cond)(void*), void *data)
{
 return safe_sleep_conditional(chan, timeout_ms, cond, data, 1);
}

/*! \brief Wait, look for hangups */
int ast_safe_sleep(struct ast_channel *chan, int ms)
{
 return safe_sleep_conditional(chan, ms, NULL, NULL, 1);
}

int ast_safe_sleep_without_silence(struct ast_channel *chan, int ms)
{
 return safe_sleep_conditional(chan, ms, NULL, NULL, 0);
}

struct ast_channel *ast_channel_release(struct ast_channel *chan)
{
 /* Safe, even if already unlinked. */
 ao2_unlink(channels, chan);
 return ast_channel_unref(chan);
}

void ast_party_name_init(struct ast_party_name *init)
{
 init->str = NULL;
 init->char_set = AST_PARTY_CHAR_SET_ISO8859_1;
 init->presentation = AST_PRES_ALLOWED_USER_NUMBER_NOT_SCREENED;
 init->valid = 0;
}

void ast_party_name_copy(struct ast_party_name *dest, const struct ast_party_name *src)
{
 if (dest == src) {
 /* Don't copy to self */
 return;
 }

 ast_free(dest->str);
 dest->str = ast_strdup(src->str);
 dest->char_set = src->char_set;
 dest->presentation = src->presentation;
 dest->valid = src->valid;
}

void ast_party_name_set_init(struct ast_party_name *init, const struct ast_party_name *guide)
{
 init->str = NULL;
 init->char_set = guide->char_set;
 init->presentation = guide->presentation;
 init->valid = guide->valid;
}

void ast_party_name_set(struct ast_party_name *dest, const struct ast_party_name *src)
{
 if (dest == src) {
 /* Don't set to self */
 return;
 }

 if (src->str && src->str != dest->str) {
 ast_free(dest->str);
 dest->str = ast_strdup(src->str);
 }

 dest->char_set = src->char_set;
 dest->presentation = src->presentation;
 dest->valid = src->valid;
}

void ast_party_name_free(struct ast_party_name *doomed)
{
 ast_free(doomed->str);
 doomed->str = NULL;
}

void ast_party_number_init(struct ast_party_number *init)
{
 init->str = NULL;
 init->plan = 0;/* Unknown */
 init->presentation = AST_PRES_ALLOWED_USER_NUMBER_NOT_SCREENED;
 init->valid = 0;
}

void ast_party_number_copy(struct ast_party_number *dest, const struct ast_party_number *src)
{
 if (dest == src) {
 /* Don't copy to self */
 return;
 }

 ast_free(dest->str);
 dest->str = ast_strdup(src->str);
 dest->plan = src->plan;
 dest->presentation = src->presentation;
 dest->valid = src->valid;
}

void ast_party_number_set_init(struct ast_party_number *init, const struct ast_party_number *guide)
{
 init->str = NULL;
 init->plan = guide->plan;
 init->presentation = guide->presentation;
 init->valid = guide->valid;
}

void ast_party_number_set(struct ast_party_number *dest, const struct ast_party_number *src)
{
 if (dest == src) {
 /* Don't set to self */
 return;
 }

 if (src->str && src->str != dest->str) {
 ast_free(dest->str);
 dest->str = ast_strdup(src->str);
 }

 dest->plan = src->plan;
 dest->presentation = src->presentation;
 dest->valid = src->valid;
}

void ast_party_number_free(struct ast_party_number *doomed)
{
 ast_free(doomed->str);
 doomed->str = NULL;
}

void ast_party_subaddress_init(struct ast_party_subaddress *init)
{
 init->str = NULL;
 init->type = 0;
 init->odd_even_indicator = 0;
 init->valid = 0;
}

void ast_party_subaddress_copy(struct ast_party_subaddress *dest, const struct ast_party_subaddress *src)
{
 if (dest == src) {
 /* Don't copy to self */
 return;
 }

 ast_free(dest->str);
 dest->str = ast_strdup(src->str);
 dest->type = src->type;
 dest->odd_even_indicator = src->odd_even_indicator;
 dest->valid = src->valid;
}

void ast_party_subaddress_set_init(struct ast_party_subaddress *init, const struct ast_party_subaddress *guide)
{
 init->str = NULL;
 init->type = guide->type;
 init->odd_even_indicator = guide->odd_even_indicator;
 init->valid = guide->valid;
}

void ast_party_subaddress_set(struct ast_party_subaddress *dest, const struct ast_party_subaddress *src)
{
 if (dest == src) {
 /* Don't set to self */
 return;
 }

 if (src->str && src->str != dest->str) {
 ast_free(dest->str);
 dest->str = ast_strdup(src->str);
 }

 dest->type = src->type;
 dest->odd_even_indicator = src->odd_even_indicator;
 dest->valid = src->valid;
}

void ast_party_subaddress_free(struct ast_party_subaddress *doomed)
{
 ast_free(doomed->str);
 doomed->str = NULL;
}

void ast_set_party_id_all(struct ast_set_party_id *update_id)
{
 update_id->name = 1;
 update_id->number = 1;
 update_id->subaddress = 1;
}

void ast_party_id_init(struct ast_party_id *init)
{
 ast_party_name_init(&init->name);
 ast_party_number_init(&init->number);
 ast_party_subaddress_init(&init->subaddress);
 init->tag = NULL;
}

void ast_party_id_copy(struct ast_party_id *dest, const struct ast_party_id *src)
{
 if (dest == src) {
 /* Don't copy to self */
 return;
 }

 ast_party_name_copy(&dest->name, &src->name);
 ast_party_number_copy(&dest->number, &src->number);
 ast_party_subaddress_copy(&dest->subaddress, &src->subaddress);

 ast_free(dest->tag);
 dest->tag = ast_strdup(src->tag);
}

void ast_party_id_set_init(struct ast_party_id *init, const struct ast_party_id *guide)
{
 ast_party_name_set_init(&init->name, &guide->name);
 ast_party_number_set_init(&init->number, &guide->number);
 ast_party_subaddress_set_init(&init->subaddress, &guide->subaddress);
 init->tag = NULL;
}

void ast_party_id_set(struct ast_party_id *dest, const struct ast_party_id *src, const struct ast_set_party_id *update)
{
 if (dest == src) {
 /* Don't set to self */
 return;
 }

 if (!update || update->name) {
 ast_party_name_set(&dest->name, &src->name);
 }
 if (!update || update->number) {
 ast_party_number_set(&dest->number, &src->number);
 }
 if (!update || update->subaddress) {
 ast_party_subaddress_set(&dest->subaddress, &src->subaddress);
 }

 if (src->tag && src->tag != dest->tag) {
 ast_free(dest->tag);
 dest->tag = ast_strdup(src->tag);
 }
}

void ast_party_id_free(struct ast_party_id *doomed)
{
 ast_party_name_free(&doomed->name);
 ast_party_number_free(&doomed->number);
 ast_party_subaddress_free(&doomed->subaddress);

 ast_free(doomed->tag);
 doomed->tag = NULL;
}

int ast_party_id_presentation(const struct ast_party_id *id)
{
 int number_priority;
 int number_value;
 int number_screening;
 int name_priority;
 int name_value;

 /* Determine name presentation priority. */
 if (!id->name.valid) {
 name_value = AST_PRES_UNAVAILABLE;
 name_priority = 3;
 } else {
 name_value = id->name.presentation & AST_PRES_RESTRICTION;
 switch (name_value) {
 case AST_PRES_RESTRICTED:
 name_priority = 0;
 break;
 case AST_PRES_ALLOWED:
 name_priority = 1;
 break;
 case AST_PRES_UNAVAILABLE:
 name_priority = 2;
 break;
 default:
 name_value = AST_PRES_UNAVAILABLE;
 name_priority = 3;
 break;
 }
 }

 /* Determine number presentation priority. */
 if (!id->number.valid) {
 number_screening = AST_PRES_USER_NUMBER_UNSCREENED;
 number_value = AST_PRES_UNAVAILABLE;
 number_priority = 3;
 } else {
 number_screening = id->number.presentation & AST_PRES_NUMBER_TYPE;
 number_value = id->number.presentation & AST_PRES_RESTRICTION;
 switch (number_value) {
 case AST_PRES_RESTRICTED:
 number_priority = 0;
 break;
 case AST_PRES_ALLOWED:
 number_priority = 1;
 break;
 case AST_PRES_UNAVAILABLE:
 number_priority = 2;
 break;
 default:
 number_screening = AST_PRES_USER_NUMBER_UNSCREENED;
 number_value = AST_PRES_UNAVAILABLE;
 number_priority = 3;
 break;
 }
 }

 /* Select the wining presentation value. */
 if (name_priority < number_priority) {
 number_value = name_value;
 }
 if (number_value == AST_PRES_UNAVAILABLE) {
 return AST_PRES_NUMBER_NOT_AVAILABLE;
 }

 return number_value | number_screening;
}

void ast_party_id_invalidate(struct ast_party_id *id)
{
 id->name.valid = 0;
 id->number.valid = 0;
 id->subaddress.valid = 0;
}

void ast_party_id_reset(struct ast_party_id *id)
{
 ast_party_id_free(id);
 ast_party_id_init(id);
}

struct ast_party_id ast_party_id_merge(struct ast_party_id *base, struct ast_party_id *overlay)
{
 struct ast_party_id merged;

 merged = *base;
 if (overlay->name.valid) {
 merged.name = overlay->name;
 }
 if (overlay->number.valid) {
 merged.number = overlay->number;
 }
 if (overlay->subaddress.valid) {
 merged.subaddress = overlay->subaddress;
 }
 /* Note the actual structure is returned and not a pointer to it! */
 return merged;
}

void ast_party_id_merge_copy(struct ast_party_id *dest, struct ast_party_id *base, struct ast_party_id *overlay)
{
 struct ast_party_id merged;

 merged = ast_party_id_merge(base, overlay);
 ast_party_id_copy(dest, &merged);
}

void ast_party_dialed_init(struct ast_party_dialed *init)
{
 init->number.str = NULL;
 init->number.plan = 0;/* Unknown */
 ast_party_subaddress_init(&init->subaddress);
 init->transit_network_select = 0;
}

void ast_party_dialed_copy(struct ast_party_dialed *dest, const struct ast_party_dialed *src)
{
 if (dest == src) {
 /* Don't copy to self */
 return;
 }

 ast_free(dest->number.str);
 dest->number.str = ast_strdup(src->number.str);
 dest->number.plan = src->number.plan;
 ast_party_subaddress_copy(&dest->subaddress, &src->subaddress);
 dest->transit_network_select = src->transit_network_select;
}

void ast_party_dialed_set_init(struct ast_party_dialed *init, const struct ast_party_dialed *guide)
{
 init->number.str = NULL;
 init->number.plan = guide->number.plan;
 ast_party_subaddress_set_init(&init->subaddress, &guide->subaddress);
 init->transit_network_select = guide->transit_network_select;
}

void ast_party_dialed_set(struct ast_party_dialed *dest, const struct ast_party_dialed *src)
{
 if (src->number.str && src->number.str != dest->number.str) {
 ast_free(dest->number.str);
 dest->number.str = ast_strdup(src->number.str);
 }
 dest->number.plan = src->number.plan;

 ast_party_subaddress_set(&dest->subaddress, &src->subaddress);

 dest->transit_network_select = src->transit_network_select;
}

void ast_party_dialed_free(struct ast_party_dialed *doomed)
{
 ast_free(doomed->number.str);
 doomed->number.str = NULL;
 ast_party_subaddress_free(&doomed->subaddress);
}

void ast_party_caller_init(struct ast_party_caller *init)
{
 ast_party_id_init(&init->id);
 ast_party_id_init(&init->ani);
 ast_party_id_init(&init->priv);
 init->ani2 = 0;
}

void ast_party_caller_copy(struct ast_party_caller *dest, const struct ast_party_caller *src)
{
 if (dest == src) {
 /* Don't copy to self */
 return;
 }

 ast_party_id_copy(&dest->id, &src->id);
 ast_party_id_copy(&dest->ani, &src->ani);
 ast_party_id_copy(&dest->priv, &src->priv);
 dest->ani2 = src->ani2;
}

void ast_party_caller_set_init(struct ast_party_caller *init, const struct ast_party_caller *guide)
{
 ast_party_id_set_init(&init->id, &guide->id);
 ast_party_id_set_init(&init->ani, &guide->ani);
 ast_party_id_set_init(&init->priv, &guide->priv);
 init->ani2 = guide->ani2;
}

void ast_party_caller_set(struct ast_party_caller *dest, const struct ast_party_caller *src, const struct ast_set_party_caller *update)
{
 ast_party_id_set(&dest->id, &src->id, update ? &update->id : NULL);
 ast_party_id_set(&dest->ani, &src->ani, update ? &update->ani : NULL);
 ast_party_id_set(&dest->priv, &src->priv, update ? &update->priv : NULL);
 dest->ani2 = src->ani2;
}

void ast_party_caller_free(struct ast_party_caller *doomed)
{
 ast_party_id_free(&doomed->id);
 ast_party_id_free(&doomed->ani);
 ast_party_id_free(&doomed->priv);
}

void ast_party_connected_line_init(struct ast_party_connected_line *init)
{
 ast_party_id_init(&init->id);
 ast_party_id_init(&init->ani);
 ast_party_id_init(&init->priv);
 init->ani2 = 0;
 init->source = AST_CONNECTED_LINE_UPDATE_SOURCE_UNKNOWN;
}

void ast_party_connected_line_copy(struct ast_party_connected_line *dest, const struct ast_party_connected_line *src)
{
 if (dest == src) {
 /* Don't copy to self */
 return;
 }

 ast_party_id_copy(&dest->id, &src->id);
 ast_party_id_copy(&dest->ani, &src->ani);
 ast_party_id_copy(&dest->priv, &src->priv);
 dest->ani2 = src->ani2;
 dest->source = src->source;
}

void ast_party_connected_line_set_init(struct ast_party_connected_line *init, const struct ast_party_connected_line *guide)
{
 ast_party_id_set_init(&init->id, &guide->id);
 ast_party_id_set_init(&init->ani, &guide->ani);
 ast_party_id_set_init(&init->priv, &guide->priv);
 init->ani2 = guide->ani2;
 init->source = guide->source;
}

void ast_party_connected_line_set(struct ast_party_connected_line *dest, const struct ast_party_connected_line *src, const struct ast_set_party_connected_line *update)
{
 ast_party_id_set(&dest->id, &src->id, update ? &update->id : NULL);
 ast_party_id_set(&dest->ani, &src->ani, update ? &update->ani : NULL);
 ast_party_id_set(&dest->priv, &src->priv, update ? &update->priv : NULL);
 dest->ani2 = src->ani2;
 dest->source = src->source;
}

void ast_party_connected_line_collect_caller(struct ast_party_connected_line *connected, struct ast_party_caller *caller)
{
 connected->id = caller->id;
 connected->ani = caller->ani;
 connected->priv = caller->priv;
 connected->ani2 = caller->ani2;
 connected->source = AST_CONNECTED_LINE_UPDATE_SOURCE_UNKNOWN;
}

void ast_party_connected_line_free(struct ast_party_connected_line *doomed)
{
 ast_party_id_free(&doomed->id);
 ast_party_id_free(&doomed->ani);
 ast_party_id_free(&doomed->priv);
}

void ast_party_redirecting_reason_init(struct ast_party_redirecting_reason *init)
{
 init->str = NULL;
 init->code = AST_REDIRECTING_REASON_UNKNOWN;
}

void ast_party_redirecting_reason_copy(struct ast_party_redirecting_reason *dest, const struct ast_party_redirecting_reason *src)
{
 if (dest == src) {
 return;
 }

 ast_free(dest->str);
 dest->str = ast_strdup(src->str);
 dest->code = src->code;
}

void ast_party_redirecting_reason_set_init(struct ast_party_redirecting_reason *init, const struct ast_party_redirecting_reason *guide)
{
 init->str = NULL;
 init->code = guide->code;
}

void ast_party_redirecting_reason_set(struct ast_party_redirecting_reason *dest, const struct ast_party_redirecting_reason *src)
{
 if (dest == src) {
 return;
 }

 if (src->str && src->str != dest->str) {
 ast_free(dest->str);
 dest->str = ast_strdup(src->str);
 }

 dest->code = src->code;
}

void ast_party_redirecting_reason_free(struct ast_party_redirecting_reason *doomed)
{
 ast_free(doomed->str);
}


void ast_party_redirecting_init(struct ast_party_redirecting *init)
{
 ast_party_id_init(&init->orig);
 ast_party_id_init(&init->from);
 ast_party_id_init(&init->to);
 ast_party_id_init(&init->priv_orig);
 ast_party_id_init(&init->priv_from);
 ast_party_id_init(&init->priv_to);
 ast_party_redirecting_reason_init(&init->reason);
 ast_party_redirecting_reason_init(&init->orig_reason);
 init->count = 0;
}

void ast_party_redirecting_copy(struct ast_party_redirecting *dest, const struct ast_party_redirecting *src)
{
 if (dest == src) {
 /* Don't copy to self */
 return;
 }

 ast_party_id_copy(&dest->orig, &src->orig);
 ast_party_id_copy(&dest->from, &src->from);
 ast_party_id_copy(&dest->to, &src->to);
 ast_party_id_copy(&dest->priv_orig, &src->priv_orig);
 ast_party_id_copy(&dest->priv_from, &src->priv_from);
 ast_party_id_copy(&dest->priv_to, &src->priv_to);
 ast_party_redirecting_reason_copy(&dest->reason, &src->reason);
 ast_party_redirecting_reason_copy(&dest->orig_reason, &src->orig_reason);
 dest->count = src->count;
}

void ast_party_redirecting_set_init(struct ast_party_redirecting *init, const struct ast_party_redirecting *guide)
{
 ast_party_id_set_init(&init->orig, &guide->orig);
 ast_party_id_set_init(&init->from, &guide->from);
 ast_party_id_set_init(&init->to, &guide->to);
 ast_party_id_set_init(&init->priv_orig, &guide->priv_orig);
 ast_party_id_set_init(&init->priv_from, &guide->priv_from);
 ast_party_id_set_init(&init->priv_to, &guide->priv_to);
 ast_party_redirecting_reason_set_init(&init->reason, &guide->reason);
 ast_party_redirecting_reason_set_init(&init->orig_reason, &guide->orig_reason);
 init->count = guide->count;
}

void ast_party_redirecting_set(struct ast_party_redirecting *dest, const struct ast_party_redirecting *src, const struct ast_set_party_redirecting *update)
{
 ast_party_id_set(&dest->orig, &src->orig, update ? &update->orig : NULL);
 ast_party_id_set(&dest->from, &src->from, update ? &update->from : NULL);
 ast_party_id_set(&dest->to, &src->to, update ? &update->to : NULL);
 ast_party_id_set(&dest->priv_orig, &src->priv_orig, update ? &update->priv_orig : NULL);
 ast_party_id_set(&dest->priv_from, &src->priv_from, update ? &update->priv_from : NULL);
 ast_party_id_set(&dest->priv_to, &src->priv_to, update ? &update->priv_to : NULL);
 ast_party_redirecting_reason_set(&dest->reason, &src->reason);
 ast_party_redirecting_reason_set(&dest->orig_reason, &src->orig_reason);
 dest->count = src->count;
}

void ast_party_redirecting_free(struct ast_party_redirecting *doomed)
{
 ast_party_id_free(&doomed->orig);
 ast_party_id_free(&doomed->from);
 ast_party_id_free(&doomed->to);
 ast_party_id_free(&doomed->priv_orig);
 ast_party_id_free(&doomed->priv_from);
 ast_party_id_free(&doomed->priv_to);
 ast_party_redirecting_reason_free(&doomed->reason);
 ast_party_redirecting_reason_free(&doomed->orig_reason);
}

/*! \brief Free a channel structure */
static void ast_channel_destructor(void *obj)
{
 struct ast_channel *chan = obj;
 struct ast_var_t *vardata;
 struct ast_frame *f;
 struct varshead *headp;
 struct ast_datastore *datastore;
 char device_name[AST_CHANNEL_NAME];
 ast_callid callid;

 ast_debug(1, "Channel %p '%s' destroying\n", chan, ast_channel_name(chan));

 /* Stop monitoring */
 if (ast_channel_monitor(chan)) {
 ast_channel_monitor(chan)->stop(chan, 0);
 }

 /* If there is native format music-on-hold state, free it */
 if (ast_channel_music_state(chan)) {
 ast_moh_cleanup(chan);
 }

 ast_pbx_hangup_handler_destroy(chan);

 /* Things that may possibly raise Stasis messages shouldn't occur after this point */
 ast_set_flag(ast_channel_flags(chan), AST_FLAG_DEAD);

 if (ast_channel_internal_is_finalized(chan)) {
 /* A channel snapshot should not be in the process of being staged now. */
 ast_assert(!ast_test_flag(ast_channel_flags(chan), AST_FLAG_SNAPSHOT_STAGE));

 ast_channel_lock(chan);
 ast_channel_publish_final_snapshot(chan);
 ast_channel_unlock(chan);
 }

 ast_channel_lock(chan);

 /* Get rid of each of the data stores on the channel */
 while ((datastore = AST_LIST_REMOVE_HEAD(ast_channel_datastores(chan), entry)))
 /* Free the data store */
 ast_datastore_free(datastore);

 /* While the channel is locked, take the reference to its callid while we tear down the call. */
 callid = ast_channel_callid(chan);
 ast_channel_callid_cleanup(chan);

 ast_channel_unlock(chan);

 /* Lock and unlock the channel just to be sure nobody has it locked still
 due to a reference that was stored in a datastore. (i.e. app_chanspy) */
 ast_channel_lock(chan);
 ast_channel_unlock(chan);

 if (ast_channel_tech_pvt(chan)) {
 ast_log_callid(LOG_WARNING, callid, "Channel '%s' may not have been hung up properly\n", ast_channel_name(chan));
 ast_free(ast_channel_tech_pvt(chan));
 }

 if (ast_channel_sched(chan)) {
 ast_sched_context_destroy(ast_channel_sched(chan));
 }

 if (ast_channel_internal_is_finalized(chan)) {
 char *dashptr;

 ast_copy_string(device_name, ast_channel_name(chan), sizeof(device_name));
 if ((dashptr = strrchr(device_name, '-'))) {
 *dashptr = '\0';
 }
 } else {
 device_name[0] = '\0';
 }

 /* Free translators */
 if (ast_channel_readtrans(chan))
 ast_translator_free_path(ast_channel_readtrans(chan));
 if (ast_channel_writetrans(chan))
 ast_translator_free_path(ast_channel_writetrans(chan));
 if (ast_channel_pbx(chan))
 ast_log_callid(LOG_WARNING, callid, "PBX may not have been terminated properly on '%s'\n", ast_channel_name(chan));

 /* Free formats */
 ast_channel_set_oldwriteformat(chan, NULL);
 ast_channel_set_rawreadformat(chan, NULL);
 ast_channel_set_rawwriteformat(chan, NULL);
 ast_channel_set_readformat(chan, NULL);
 ast_channel_set_writeformat(chan, NULL);

 ast_party_dialed_free(ast_channel_dialed(chan));
 ast_party_caller_free(ast_channel_caller(chan));
 ast_party_connected_line_free(ast_channel_connected(chan));
 ast_party_connected_line_free(ast_channel_connected_indicated(chan));
 ast_party_redirecting_free(ast_channel_redirecting(chan));

 /* Close pipes if appropriate */
 ast_channel_internal_alertpipe_close(chan);
 if (ast_channel_timer(chan)) {
 ast_timer_close(ast_channel_timer(chan));
 ast_channel_timer_set(chan, NULL);
 }
 while ((f = AST_LIST_REMOVE_HEAD(ast_channel_readq(chan), frame_list)))
 ast_frfree(f);

 /* loop over the variables list, freeing all data and deleting list items */
 /* no need to lock the list, as the channel is already locked */
 headp = ast_channel_varshead(chan);
 while ((vardata = AST_LIST_REMOVE_HEAD(headp, entries)))
 ast_var_delete(vardata);

 ast_app_group_discard(chan);

 /* Destroy the jitterbuffer */
 ast_jb_destroy(chan);

 if (ast_channel_cdr(chan)) {
 ast_cdr_free(ast_channel_cdr(chan));
 ast_channel_cdr_set(chan, NULL);
 }

 if (ast_channel_zone(chan)) {
 ast_channel_zone_set(chan, ast_tone_zone_unref(ast_channel_zone(chan)));
 }

 ast_channel_internal_cleanup(chan);

 if (device_name[0]) {
 /*
 * We have a device name to notify of a new state.
 *
 * Queue an unknown state, because, while we know that this particular
 * instance is dead, we don't know the state of all other possible
 * instances.
 */
 ast_devstate_changed_literal(AST_DEVICE_UNKNOWN, (ast_test_flag(ast_channel_flags(chan), AST_FLAG_DISABLE_DEVSTATE_CACHE) ? AST_DEVSTATE_NOT_CACHABLE : AST_DEVSTATE_CACHABLE), device_name);
 }

 ast_channel_nativeformats_set(chan, NULL);

 ast_channel_named_callgroups_set(chan, NULL);
 ast_channel_named_pickupgroups_set(chan, NULL);

 ast_atomic_fetchadd_int(&chancount, -1);
}

/*! \brief Free a dummy channel structure */
static void ast_dummy_channel_destructor(void *obj)
{
 struct ast_channel *chan = obj;
 struct ast_datastore *datastore;
 struct ast_var_t *vardata;
 struct varshead *headp;

 ast_pbx_hangup_handler_destroy(chan);

 /* Get rid of each of the data stores on the channel */
 while ((datastore = AST_LIST_REMOVE_HEAD(ast_channel_datastores(chan), entry))) {
 /* Free the data store */
 ast_datastore_free(datastore);
 }

 ast_party_dialed_free(ast_channel_dialed(chan));
 ast_party_caller_free(ast_channel_caller(chan));
 ast_party_connected_line_free(ast_channel_connected(chan));
 ast_party_connected_line_free(ast_channel_connected_indicated(chan));
 ast_party_redirecting_free(ast_channel_redirecting(chan));

 /* loop over the variables list, freeing all data and deleting list items */
 /* no need to lock the list, as the channel is already locked */
 headp = ast_channel_varshead(chan);
 while ((vardata = AST_LIST_REMOVE_HEAD(headp, entries)))
 ast_var_delete(vardata);

 if (ast_channel_cdr(chan)) {
 ast_cdr_free(ast_channel_cdr(chan));
 ast_channel_cdr_set(chan, NULL);
 }

 ast_channel_internal_cleanup(chan);
}

int ast_channel_datastore_inherit(struct ast_channel *from, struct ast_channel *to)
{
 struct ast_datastore *datastore = NULL, *datastore2;

 AST_LIST_TRAVERSE(ast_channel_datastores(from), datastore, entry) {
 if (datastore->inheritance > 0) {
 datastore2 = ast_datastore_alloc(datastore->info, datastore->uid);
 if (datastore2) {
 datastore2->data = datastore->info->duplicate ? datastore->info->duplicate(datastore->data) : NULL;
 datastore2->inheritance = datastore->inheritance == DATASTORE_INHERIT_FOREVER ? DATASTORE_INHERIT_FOREVER : datastore->inheritance - 1;
 AST_LIST_INSERT_TAIL(ast_channel_datastores(to), datastore2, entry);
 }
 }
 }
 return 0;
}

int ast_channel_datastore_add(struct ast_channel *chan, struct ast_datastore *datastore)
{
 int res = 0;

 AST_LIST_INSERT_HEAD(ast_channel_datastores(chan), datastore, entry);

 return res;
}

int ast_channel_datastore_remove(struct ast_channel *chan, struct ast_datastore *datastore)
{
 return AST_LIST_REMOVE(ast_channel_datastores(chan), datastore, entry) ? 0 : -1;
}

struct ast_datastore *ast_channel_datastore_find(struct ast_channel *chan, const struct ast_datastore_info *info, const char *uid)
{
 struct ast_datastore *datastore = NULL;

 if (info == NULL)
 return NULL;

 AST_LIST_TRAVERSE(ast_channel_datastores(chan), datastore, entry) {
 if (datastore->info != info) {
 continue;
 }

 if (uid == NULL) {
 /* matched by type only */
 break;
 }

 if ((datastore->uid != NULL) && !strcasecmp(uid, datastore->uid)) {
 /* Matched by type AND uid */
 break;
 }
 }

 return datastore;
}

/*! Set the file descriptor on the channel */
void ast_channel_set_fd(struct ast_channel *chan, int which, int fd)
{
 ast_channel_internal_fd_set(chan, which, fd);
 return;
}

void ast_channel_clear_softhangup(struct ast_channel *chan, int flag)
{
 ast_channel_lock(chan);

 ast_channel_softhangup_internal_flag_clear(chan, flag);

 if (!ast_channel_softhangup_internal_flag(chan)) {
 struct ast_frame *fr;

 /* If we have completely cleared the softhangup flag,
 * then we need to fully abort the hangup process. This requires
 * pulling the END_OF_Q frame out of the channel frame queue if it
 * still happens to be there. */

 fr = AST_LIST_LAST(ast_channel_readq(chan));
 if (fr && fr->frametype == AST_FRAME_CONTROL &&
 fr->subclass.integer == AST_CONTROL_END_OF_Q) {
 AST_LIST_REMOVE(ast_channel_readq(chan), fr, frame_list);
 ast_frfree(fr);
 }
 }

 ast_channel_unlock(chan);
}

/*! \brief Softly hangup a channel, don't lock */
int ast_softhangup_nolock(struct ast_channel *chan, int cause)
{
 ast_debug(1, "Soft-Hanging (%#04x) up channel '%s'\n", (unsigned)cause, ast_channel_name(chan));
 /* Inform channel driver that we need to be hung up, if it cares */
 ast_channel_softhangup_internal_flag_add(chan, cause);
 ast_queue_frame(chan, &ast_null_frame);
 /* Interrupt any poll call or such */
 if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING))
 pthread_kill(ast_channel_blocker(chan), SIGURG);
 return 0;
}

/*! \brief Softly hangup a channel, lock */
int ast_softhangup(struct ast_channel *chan, int cause)
{
 RAII_VAR(struct ast_json *, blob, NULL, ast_json_unref);
 int res;

 ast_channel_lock(chan);
 res = ast_softhangup_nolock(chan, cause);
 blob = ast_json_pack("{s: i, s: b}",
 "cause", cause,
 "soft", 1);
 ast_channel_publish_blob(chan, ast_channel_hangup_request_type(), blob);
 ast_channel_unlock(chan);

 return res;
}

static void free_translation(struct ast_channel *clonechan)
{
 if (ast_channel_writetrans(clonechan)) {
 ast_translator_free_path(ast_channel_writetrans(clonechan));
 }
 if (ast_channel_readtrans(clonechan)) {
 ast_translator_free_path(ast_channel_readtrans(clonechan));
 }
 ast_channel_writetrans_set(clonechan, NULL);
 ast_channel_readtrans_set(clonechan, NULL);
}

void ast_set_hangupsource(struct ast_channel *chan, const char *source, int force)
{
 RAII_VAR(struct ast_channel *, bridge, ast_channel_bridge_peer(chan), ast_channel_cleanup);

 ast_channel_lock(chan);
 if (force || ast_strlen_zero(ast_channel_hangupsource(chan))) {
 ast_channel_hangupsource_set(chan, source);
 }
 ast_channel_unlock(chan);

 if (bridge) {
 ast_channel_lock(bridge);
 if (force || ast_strlen_zero(ast_channel_hangupsource(bridge))) {
 ast_channel_hangupsource_set(bridge, source);
 }
 ast_channel_unlock(bridge);
 }
}

int ast_channel_has_audio_frame_or_monitor(struct ast_channel *chan)
{
 return ast_channel_monitor(chan)
 || !ast_audiohook_write_list_empty(ast_channel_audiohooks(chan))
 || !ast_framehook_list_contains_no_active(ast_channel_framehooks(chan));
}

int ast_channel_has_hook_requiring_audio(struct ast_channel *chan)
{
 return ast_channel_monitor(chan)
 || !ast_audiohook_write_list_empty(ast_channel_audiohooks(chan))
 || !ast_framehook_list_contains_no_active_of_type(ast_channel_framehooks(chan), AST_FRAME_VOICE);
}

static void destroy_hooks(struct ast_channel *chan)
{
 if (ast_channel_audiohooks(chan)) {
 ast_audiohook_detach_list(ast_channel_audiohooks(chan));
 ast_channel_audiohooks_set(chan, NULL);
 }

 ast_framehook_list_destroy(chan);
}

/*! \brief Hangup a channel */
void ast_hangup(struct ast_channel *chan)
{
 /* Be NULL safe for RAII_VAR() usage. */
 if (!chan) {
 return;
 }

 ast_debug(1, "Channel %p '%s' hanging up. Refs: %d\n", chan, ast_channel_name(chan),
 ao2_ref(chan, 0));

 ast_autoservice_stop(chan);

 ast_channel_lock(chan);

 while (ast_channel_masq(chan) || ast_channel_masqr(chan)) {
 CHANNEL_DEADLOCK_AVOIDANCE(chan);
 }

 /* Mark as a zombie so a masquerade cannot be setup on this channel. */
 ast_set_flag(ast_channel_flags(chan), AST_FLAG_ZOMBIE);

 ast_channel_unlock(chan);

 /*
 * XXX if running the hangup handlers here causes problems
 * because the handlers take too long to execute, we could move
 * the meat of this function into another thread. A thread
 * where channels go to die.
 *
 * If this is done, ast_autoservice_chan_hangup_peer() will no
 * longer be needed.
 */
 ast_pbx_hangup_handler_run(chan);
 ao2_unlink(channels, chan);
 ast_channel_lock(chan);

 destroy_hooks(chan);

 free_translation(chan);
 /* Close audio stream */
 if (ast_channel_stream(chan)) {
 ast_closestream(ast_channel_stream(chan));
 ast_channel_stream_set(chan, NULL);
 }
 /* Close video stream */
 if (ast_channel_vstream(chan)) {
 ast_closestream(ast_channel_vstream(chan));
 ast_channel_vstream_set(chan, NULL);
 }
 if (ast_channel_sched(chan)) {
 ast_sched_context_destroy(ast_channel_sched(chan));
 ast_channel_sched_set(chan, NULL);
 }

 if (ast_channel_generatordata(chan)) { /* Clear any tone stuff remaining */
 if (ast_channel_generator(chan) && ast_channel_generator(chan)->release) {
 ast_channel_generator(chan)->release(chan, ast_channel_generatordata(chan));
 }
 }
 ast_channel_generatordata_set(chan, NULL);
 ast_channel_generator_set(chan, NULL);

 if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING)) {
 ast_log(LOG_WARNING, "Hard hangup called by thread LWP %d on %s, while blocked by thread LWP %d in procedure %s! Expect a failure\n",
 ast_get_tid(), ast_channel_name(chan), ast_channel_blocker_tid(chan),
 ast_channel_blockproc(chan));
 ast_assert(0);
 }

 if (ast_channel_tech(chan)->hangup) {
 ast_channel_tech(chan)->hangup(chan);
 }

 ast_channel_unlock(chan);

 ast_cc_offer(chan);

 ast_channel_unref(chan);
}

/*!
 * \internal
 * \brief Set channel answered time if not already set.
 * \since 13.11.0
 *
 * \param chan Channel to set answered time.
 *
 * \return Nothing
 */
static void set_channel_answer_time(struct ast_channel *chan)
{
 if (ast_tvzero(ast_channel_answertime(chan))) {
 struct timeval answertime;

 answertime = ast_tvnow();
 ast_channel_answertime_set(chan, &answertime);
 }
}


int ast_raw_answer_with_stream_topology(struct ast_channel *chan, struct ast_stream_topology *topology)
{
 int res = 0;
 SCOPE_TRACE(1, "%s\n", ast_channel_name(chan));

 ast_channel_lock(chan);

 /* You can't answer an outbound call */
 if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_OUTGOING)) {
 ast_channel_unlock(chan);
 return 0;
 }

 /* Stop if we're a zombie or need a soft hangup */
 if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_ZOMBIE) || ast_check_hangup(chan)) {
 ast_channel_unlock(chan);
 return -1;
 }

 /*
 * Mark when incoming channel answered so we can know how
 * long the channel has been up.
 */
 set_channel_answer_time(chan);

 ast_channel_unlock(chan);

 switch (ast_channel_state(chan)) {
 case AST_STATE_RINGING:
 case AST_STATE_RING:
 ast_channel_lock(chan);
 if (ast_channel_tech(chan)->answer_with_stream_topology) {
 res = ast_channel_tech(chan)->answer_with_stream_topology(chan, topology);

 } else if (ast_channel_tech(chan)->answer) {
 res = ast_channel_tech(chan)->answer(chan);
 }
 ast_setstate(chan, AST_STATE_UP);
 ast_channel_unlock(chan);
 break;
 case AST_STATE_UP:
 break;
 default:
 break;
 }

 ast_indicate(chan, -1);

 return res;
}

int ast_raw_answer(struct ast_channel *chan)
{
 return ast_raw_answer_with_stream_topology(chan, NULL);
}

int __ast_answer(struct ast_channel *chan, unsigned int delay)
{
 int res = 0;
 enum ast_channel_state old_state;
 SCOPE_TRACE(1, "%s\n", ast_channel_name(chan));

 old_state = ast_channel_state(chan);
 if ((res = ast_raw_answer(chan))) {
 return res;
 }

 switch (old_state) {
 case AST_STATE_RINGING:
 case AST_STATE_RING:
 /* wait for media to start flowing, but don't wait any longer
 * than 'delay' or 500 milliseconds, whichever is longer
 */
 do {
 AST_LIST_HEAD_NOLOCK(, ast_frame) frames;
 struct ast_frame *cur;
 struct ast_frame *new_frame;
 int timeout_ms = MAX(delay, 500);
 unsigned int done = 0;
 struct timeval start;

 AST_LIST_HEAD_INIT_NOLOCK(&frames);

 start = ast_tvnow();
 for (;;) {
 int ms = ast_remaining_ms(start, timeout_ms);
 ms = ast_waitfor(chan, ms);
 if (ms < 0) {
 ast_log(LOG_WARNING, "Error condition occurred when polling channel %s for a voice frame: %s\n", ast_channel_name(chan), strerror(errno));
 res = -1;
 break;
 }
 if (ms == 0) {
 ast_debug(2, "Didn't receive a media frame from %s within %u ms of answering. Continuing anyway\n", ast_channel_name(chan), MAX(delay, 500));
 break;
 }
 cur = ast_read(chan);
 if (!cur || ((cur->frametype == AST_FRAME_CONTROL) &&
 (cur->subclass.integer == AST_CONTROL_HANGUP))) {
 if (cur) {
 ast_frfree(cur);
 }
 res = -1;
 ast_debug(2, "Hangup of channel %s detected in answer routine\n", ast_channel_name(chan));
 break;
 }

 if ((new_frame = ast_frisolate(cur)) != cur) {
 ast_frfree(cur);
 }

 AST_LIST_INSERT_HEAD(&frames, new_frame, frame_list);

 /* if a specific delay period was requested, continue
 * until that delay has passed. don't stop just because
 * incoming media has arrived.
 */
 if (delay) {
 continue;
 }

 switch (new_frame->frametype) {
 /* all of these frametypes qualify as 'media' */
 case AST_FRAME_VOICE:
 case AST_FRAME_VIDEO:
 case AST_FRAME_TEXT:
 case AST_FRAME_TEXT_DATA:
 case AST_FRAME_DTMF_BEGIN:
 case AST_FRAME_DTMF_END:
 case AST_FRAME_IMAGE:
 case AST_FRAME_HTML:
 case AST_FRAME_MODEM:
 case AST_FRAME_RTCP:
 done = 1;
 break;
 case AST_FRAME_CONTROL:
 case AST_FRAME_IAX:
 case AST_FRAME_BRIDGE_ACTION:
 case AST_FRAME_BRIDGE_ACTION_SYNC:
 case AST_FRAME_NULL:
 case AST_FRAME_CNG:
 break;
 }

 if (done) {
 break;
 }
 }

 ast_channel_lock(chan);
 while ((cur = AST_LIST_REMOVE_HEAD(&frames, frame_list))) {
 if (res == 0) {
 ast_queue_frame_head(chan, cur);
 }
 ast_frfree(cur);
 }
 ast_channel_unlock(chan);
 } while (0);
 break;
 default:
 break;
 }

 return res;
}

int ast_answer(struct ast_channel *chan)
{
 SCOPE_TRACE(1, "%s\n", ast_channel_name(chan));
 return __ast_answer(chan, 0);
}

inline int ast_auto_answer(struct ast_channel *chan)
{
 if (ast_channel_state(chan) == AST_STATE_UP) {
 /* Already answered */
 return 0;
 }
 return ast_answer(chan);
}

int64_t ast_channel_get_duration_ms(struct ast_channel *chan)
{
 ast_assert(NULL != chan);

 if (ast_tvzero(ast_channel_creationtime(chan))) {
 return 0;
 }
 return ast_tvdiff_ms(ast_tvnow(), ast_channel_creationtime(chan));
}

int ast_channel_get_duration(struct ast_channel *chan)
{
 return (ast_channel_get_duration_ms(chan) / 1000);
}

int64_t ast_channel_get_up_time_ms(struct ast_channel *chan)
{
 ast_assert(NULL != chan);

 if (ast_tvzero(ast_channel_answertime(chan))) {
 return 0;
 }
 return ast_tvdiff_ms(ast_tvnow(), ast_channel_answertime(chan));
}

int ast_channel_get_up_time(struct ast_channel *chan)
{
 return (ast_channel_get_up_time_ms(chan) / 1000);
}

/*!
 * \brief Determine whether or not we have to trigger dtmf emulating using 50 fps timer events
 * especially when no voice frames are received during dtmf processing (direct media or muted
 * sender case using SIP INFO)
 */
static inline int should_trigger_dtmf_emulating(struct ast_channel *chan)
{
 if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_DEFER_DTMF | AST_FLAG_EMULATE_DTMF)) {
 /* We're in the middle of emulating a digit, or DTMF has been
 * explicitly deferred. Trigger dtmf with periodic 50 pfs timer events, then. */
 return 1;
 }

 if (!ast_tvzero(*ast_channel_dtmf_tv(chan)) &&
 ast_tvdiff_ms(ast_tvnow(), *ast_channel_dtmf_tv(chan)) < 2*AST_MIN_DTMF_GAP) {
 /*
 * We're not in the middle of a digit, but it hasn't been long enough
 * since the last digit, so we'll have to trigger DTMF furtheron.
 * Using 2 times AST_MIN_DTMF_GAP to trigger readq reading for possible
 * buffered next dtmf event
 */
 return 1;
 }

 return 0;
}

static void deactivate_generator_nolock(struct ast_channel *chan)
{
 if (ast_channel_generatordata(chan)) {
 struct ast_generator *generator = ast_channel_generator(chan);

 if (generator && generator->release) {
 generator->release(chan, ast_channel_generatordata(chan));
 }
 ast_channel_generatordata_set(chan, NULL);
 ast_channel_generator_set(chan, NULL);
 ast_channel_set_fd(chan, AST_GENERATOR_FD, -1);
 ast_clear_flag(ast_channel_flags(chan), AST_FLAG_WRITE_INT);
 ast_settimeout(chan, 0, NULL, NULL);
 }
}

void ast_deactivate_generator(struct ast_channel *chan)
{
 ast_channel_lock(chan);
 deactivate_generator_nolock(chan);
 if (should_trigger_dtmf_emulating(chan)) {
 /* if in the middle of dtmf emulation keep 50 tick per sec timer on rolling */
 ast_timer_set_rate(ast_channel_timer(chan), 50);
 }
 ast_channel_unlock(chan);
}

static void generator_write_format_change(struct ast_channel *chan)
{
 struct ast_generator *generator;

 ast_channel_lock(chan);
 generator = ast_channel_generator(chan);
 if (generator && generator->write_format_change) {
 generator->write_format_change(chan, ast_channel_generatordata(chan));
 }
 ast_channel_unlock(chan);
}

static int generator_force(const void *data)
{
 /* Called if generator doesn't have data */
 void *tmp;
 int res;
 int (*generate)(struct ast_channel *chan, void *tmp, int datalen, int samples) = NULL;
 struct ast_channel *chan = (struct ast_channel *)data;

 ast_channel_lock(chan);
 tmp = ast_channel_generatordata(chan);
 ast_channel_generatordata_set(chan, NULL);
 if (ast_channel_generator(chan))
 generate = ast_channel_generator(chan)->generate;
 ast_channel_unlock(chan);

 if (!tmp || !generate) {
 return 0;
 }

 res = generate(chan, tmp, 0, ast_format_get_sample_rate(ast_channel_writeformat(chan)) / 50);

 ast_channel_lock(chan);
 if (ast_channel_generator(chan) && generate == ast_channel_generator(chan)->generate) {
 ast_channel_generatordata_set(chan, tmp);
 }
 ast_channel_unlock(chan);

 if (res) {
 ast_debug(1, "Auto-deactivating generator\n");
 ast_deactivate_generator(chan);
 }

 return 0;
}

int ast_activate_generator(struct ast_channel *chan, struct ast_generator *gen, void *params)
{
 int res = 0;
 void *generatordata = NULL;

 ast_channel_lock(chan);
 if (ast_channel_generatordata(chan)) {
 struct ast_generator *generator_old = ast_channel_generator(chan);

 if (generator_old && generator_old->release) {
 generator_old->release(chan, ast_channel_generatordata(chan));
 }
 }
 if (gen->alloc && !(generatordata = gen->alloc(chan, params))) {
 res = -1;
 }
 ast_channel_generatordata_set(chan, generatordata);
 if (!res) {
 ast_settimeout(chan, 50, generator_force, chan);
 ast_channel_generator_set(chan, gen);
 }
 ast_channel_unlock(chan);

 ast_prod(chan);

 return res;
}

/*! \brief Wait for x amount of time on a file descriptor to have input. */
int ast_waitfor_n_fd(int *fds, int n, int *ms, int *exception)
{
 int winner = -1;
 ast_waitfor_nandfds(NULL, 0, fds, n, exception, &winner, ms);
 return winner;
}

/*! \brief Wait for x amount of time on a file descriptor to have input. */
struct ast_channel *ast_waitfor_nandfds(struct ast_channel **c, int n, int *fds, int nfds,
 int *exception, int *outfd, int *ms)
{
 struct timeval start = { 0 , 0 };
 struct pollfd *pfds = NULL;
 int res;
 long rms;
 int x, y, max;
 int sz = nfds;
 struct timeval now = { 0, 0 };
 struct timeval whentohangup = { 0, 0 }, diff;
 struct ast_channel *winner = NULL;
 struct fdmap {
 int chan;
 int fdno;
 } *fdmap = NULL;

 if (outfd) {
 *outfd = -99999;
 }
 if (exception) {
 *exception = 0;
 }

 for (x = 0; x < n; x++) {
 ast_channel_lock(c[x]);
 if (!ast_tvzero(*ast_channel_whentohangup(c[x]))) {
 if (ast_tvzero(whentohangup))
 now = ast_tvnow();
 diff = ast_tvsub(*ast_channel_whentohangup(c[x]), now);
 if (diff.tv_sec < 0 || ast_tvzero(diff)) {
 ast_test_suite_event_notify("HANGUP_TIME", "Channel: %s", ast_channel_name(c[x]));
 /* Should already be hungup */
 ast_channel_softhangup_internal_flag_add(c[x], AST_SOFTHANGUP_TIMEOUT);
 ast_channel_unlock(c[x]);
 return c[x];
 }
 if (ast_tvzero(whentohangup) || ast_tvcmp(diff, whentohangup) < 0)
 whentohangup = diff;
 }
 sz += ast_channel_fd_count(c[x]);
 ast_channel_unlock(c[x]);
 }

 if (!sz) {
 return NULL;
 }

 pfds = ast_alloca(sizeof(*pfds) * sz);
 fdmap = ast_alloca(sizeof(*fdmap) * sz);

 /* Wait full interval */
 rms = *ms;
 /* INT_MAX, not LONG_MAX, because it matters on 64-bit */
 if (!ast_tvzero(whentohangup) && whentohangup.tv_sec < INT_MAX / 1000) {
 rms = whentohangup.tv_sec * 1000 + whentohangup.tv_usec / 1000; /* timeout in milliseconds */
 if (*ms >= 0 && *ms < rms) { /* original *ms still smaller */
 rms = *ms;
 }
 } else if (!ast_tvzero(whentohangup) && rms < 0) {
 /* Tiny corner case... call would need to last >24 days */
 rms = INT_MAX;
 }
 /*
 * Build the pollfd array, putting the channels' fds first,
 * followed by individual fds. Order is important because
 * individual fd's must have priority over channel fds.
 */
 max = 0;
 for (x = 0; x < n; x++) {
 ast_channel_lock(c[x]);
 for (y = 0; y < ast_channel_fd_count(c[x]); y++) {
 fdmap[max].fdno = y; /* fd y is linked to this pfds */
 fdmap[max].chan = x; /* channel x is linked to this pfds */
 max += ast_add_fd(&pfds[max], ast_channel_fd(c[x], y));
 }
 CHECK_BLOCKING(c[x]);
 ast_channel_unlock(c[x]);
 }
 /* Add the individual fds */
 for (x = 0; x < nfds; x++) {
 fdmap[max].chan = -1;
 max += ast_add_fd(&pfds[max], fds[x]);
 }

 if (*ms > 0) {
 start = ast_tvnow();
 }

 if (sizeof(int) == 4) { /* XXX fix timeout > 600000 on linux x86-32 */
 do {
 int kbrms = rms;
 if (kbrms > 600000) {
 kbrms = 600000;
 }
 res = ast_poll(pfds, max, kbrms);
 if (!res) {
 rms -= kbrms;
 }
 } while (!res && (rms > 0));
 } else {
 res = ast_poll(pfds, max, rms);
 }
 for (x = 0; x < n; x++) {
 ast_channel_lock(c[x]);
 ast_clear_flag(ast_channel_flags(c[x]), AST_FLAG_BLOCKING);
 ast_channel_unlock(c[x]);
 }
 if (res < 0) { /* Simulate a timeout if we were interrupted */
 if (errno != EINTR) {
 *ms = -1;
 }
 return NULL;
 }
 if (!ast_tvzero(whentohangup)) { /* if we have a timeout, check who expired */
 now = ast_tvnow();
 for (x = 0; x < n; x++) {
 if (!ast_tvzero(*ast_channel_whentohangup(c[x])) && ast_tvcmp(*ast_channel_whentohangup(c[x]), now) <= 0) {
 ast_test_suite_event_notify("HANGUP_TIME", "Channel: %s", ast_channel_name(c[x]));
 ast_channel_softhangup_internal_flag_add(c[x], AST_SOFTHANGUP_TIMEOUT);
 if (winner == NULL) {
 winner = c[x];
 }
 }
 }
 }
 if (res == 0) { /* no fd ready, reset timeout and done */
 *ms = 0; /* XXX use 0 since we may not have an exact timeout. */
 return winner;
 }
 /*
 * Then check if any channel or fd has a pending event.
 * Remember to check channels first and fds last, as they
 * must have priority on setting 'winner'
 */
 for (x = 0; x < max; x++) {
 res = pfds[x].revents;
 if (res == 0) {
 continue;
 }
 if (fdmap[x].chan >= 0) { /* this is a channel */
 winner = c[fdmap[x].chan]; /* override previous winners */
 ast_channel_lock(winner);
 if (res & POLLPRI) {
 ast_set_flag(ast_channel_flags(winner), AST_FLAG_EXCEPTION);
 } else {
 ast_clear_flag(ast_channel_flags(winner), AST_FLAG_EXCEPTION);
 }
 ast_channel_fdno_set(winner, fdmap[x].fdno);
 ast_channel_unlock(winner);
 } else { /* this is an fd */
 if (outfd) {
 *outfd = pfds[x].fd;
 }
 if (exception) {
 *exception = (res & POLLPRI) ? -1 : 0;
 }
 winner = NULL;
 }
 }
 if (*ms > 0) {
 *ms -= ast_tvdiff_ms(ast_tvnow(), start);
 if (*ms < 0) {
 *ms = 0;
 }
 }
 return winner;
}

struct ast_channel *ast_waitfor_n(struct ast_channel **c, int n, int *ms)
{
 return ast_waitfor_nandfds(c, n, NULL, 0, NULL, NULL, ms);
}

int ast_waitfor(struct ast_channel *c, int ms)
{
 if (ms < 0) {
 do {
 ms = 100000;
 ast_waitfor_nandfds(&c, 1, NULL, 0, NULL, NULL, &ms);
 } while (!ms);
 } else {
 ast_waitfor_nandfds(&c, 1, NULL, 0, NULL, NULL, &ms);
 }
 return ms;
}

int ast_waitfordigit(struct ast_channel *c, int ms)
{
 return ast_waitfordigit_full(c, ms, NULL, -1, -1);
}

int ast_settimeout(struct ast_channel *c, unsigned int rate, int (*func)(const void *data), void *data)
{
 return ast_settimeout_full(c, rate, func, data, 0);
}

int ast_settimeout_full(struct ast_channel *c, unsigned int rate, int (*func)(const void *data), void *data, unsigned int is_ao2_obj)
{
 int res;
 unsigned int real_rate = rate, max_rate;

 ast_channel_lock(c);

 if (ast_channel_timingfd(c) == -1) {
 ast_channel_unlock(c);
 return -1;
 }

 if (!func) {
 rate = 0;
 data = NULL;
 }

 if (rate && rate > (max_rate = ast_timer_get_max_rate(ast_channel_timer(c)))) {
 real_rate = max_rate;
 }

 ast_debug(1, "Scheduling timer at (%u requested / %u actual) timer ticks per second\n", rate, real_rate);

 res = ast_timer_set_rate(ast_channel_timer(c), real_rate);

 if (ast_channel_timingdata(c) && ast_test_flag(ast_channel_flags(c), AST_FLAG_TIMINGDATA_IS_AO2_OBJ)) {
 ao2_ref(ast_channel_timingdata(c), -1);
 }

 ast_channel_timingfunc_set(c, func);
 ast_channel_timingdata_set(c, data);

 if (data && is_ao2_obj) {
 ao2_ref(data, 1);
 ast_set_flag(ast_channel_flags(c), AST_FLAG_TIMINGDATA_IS_AO2_OBJ);
 } else {
 ast_clear_flag(ast_channel_flags(c), AST_FLAG_TIMINGDATA_IS_AO2_OBJ);
 }

 if (func == NULL && rate == 0 && ast_channel_fdno(c) == AST_TIMING_FD) {
 /* Clearing the timing func and setting the rate to 0
 * means that we don't want to be reading from the timingfd
 * any more. Setting c->fdno to -1 means we won't have any
 * errant reads from the timingfd, meaning we won't potentially
 * miss any important frames.
 */
 ast_channel_fdno_set(c, -1);
 }

 ast_channel_unlock(c);

 return res;
}

int ast_waitfordigit_full(struct ast_channel *c, int timeout_ms, const char *breakon, int audiofd, int cmdfd)
{
 struct timeval start = ast_tvnow();
 int ms;

 /* Stop if we're a zombie or need a soft hangup */
 if (ast_test_flag(ast_channel_flags(c), AST_FLAG_ZOMBIE) || ast_check_hangup(c))
 return -1;

 /* Only look for the end of DTMF, don't bother with the beginning and don't emulate things */
 ast_channel_set_flag(c, AST_FLAG_END_DTMF_ONLY);

 /* Wait for a digit, no more than timeout_ms milliseconds total.
 * Or, wait indefinitely if timeout_ms is <0.
 */
 while ((ms = ast_remaining_ms(start, timeout_ms))) {
 struct ast_channel *rchan;
 int outfd = -1;

 errno = 0;
 /* While ast_waitfor_nandfds tries to help by reducing the timeout by how much was waited,
 * it is unhelpful if it waited less than a millisecond.
 */
 rchan = ast_waitfor_nandfds(&c, 1, &cmdfd, (cmdfd > -1) ? 1 : 0, NULL, &outfd, &ms);

 if (!rchan && outfd < 0 && ms) {
 if (errno == 0 || errno == EINTR)
 continue;
 ast_log(LOG_WARNING, "Wait failed (%s)\n", strerror(errno));
 ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
 return -1;
 } else if (outfd > -1) {
 /* The FD we were watching has something waiting */
 ast_log(LOG_WARNING, "The FD we were waiting for has something waiting. Waitfordigit returning numeric 1\n");
 ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
 return 1;
 } else if (rchan) {
 int res;
 struct ast_frame *f = ast_read(c);

 if (!f) {
 ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);

 return -1;
 }

 switch (f->frametype) {
 case AST_FRAME_DTMF_BEGIN:
 break;
 case AST_FRAME_DTMF_END:
 res = f->subclass.integer;
 if (!breakon || strchr(breakon, res)) {
 ast_frfree(f);
 ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
 return res;
 }
 break;
 case AST_FRAME_CONTROL:
 switch (f->subclass.integer) {
 case AST_CONTROL_HANGUP:
 ast_frfree(f);
 ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
 return -1;
 case AST_CONTROL_STREAM_STOP:
 case AST_CONTROL_STREAM_SUSPEND:
 case AST_CONTROL_STREAM_RESTART:
 case AST_CONTROL_STREAM_REVERSE:
 case AST_CONTROL_STREAM_FORWARD:
 /* Fall-through and treat as if it were a DTMF signal. Items
 * that perform stream control will handle this. */
 res = f->subclass.integer;
 ast_frfree(f);
 ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
 return res;
 case AST_CONTROL_PVT_CAUSE_CODE:
 case AST_CONTROL_RINGING:
 case AST_CONTROL_ANSWER:
 case AST_CONTROL_SRCUPDATE:
 case AST_CONTROL_SRCCHANGE:
 case AST_CONTROL_CONNECTED_LINE:
 case AST_CONTROL_REDIRECTING:
 case AST_CONTROL_UPDATE_RTP_PEER:
 case AST_CONTROL_HOLD:
 case AST_CONTROL_UNHOLD:
 case AST_CONTROL_FLASH:
 case -1:
 /* Unimportant */
 break;
 default:
 ast_log(LOG_WARNING, "Unexpected control subclass '%d'\n", f->subclass.integer);
 break;
 }
 break;
 case AST_FRAME_VOICE:
 /* Write audio if appropriate */
 if (audiofd > -1) {
 if (write(audiofd, f->data.ptr, f->datalen) < 0) {
 ast_log(LOG_WARNING, "write() failed: %s\n", strerror(errno));
 }
 }
 default:
 /* Ignore */
 break;
 }
 ast_frfree(f);
 }
 }

 ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);

 return 0; /* Time is up */
}

enum DtmfDirection {
 DTMF_RECEIVED,
 DTMF_SENT
};

static const char *dtmf_direction_to_string(enum DtmfDirection direction)
{
 switch (direction) {
 case DTMF_RECEIVED:
 return "Received";
 case DTMF_SENT:
 return "Sent";
 }

 return "?";
}

static void send_dtmf_begin_event(struct ast_channel *chan,
 enum DtmfDirection direction, const char digit)
{
 RAII_VAR(struct ast_json *, blob, NULL, ast_json_unref);
 char digit_str[] = { digit, '\0' };

 blob = ast_json_pack("{ s: s, s: s }",
 "digit", digit_str,
 "direction", dtmf_direction_to_string(direction));
 if (!blob) {
 return;
 }

 ast_channel_publish_blob(chan, ast_channel_dtmf_begin_type(), blob);
}

static void send_dtmf_end_event(struct ast_channel *chan,
 enum DtmfDirection direction, const char digit, long duration_ms)
{
 RAII_VAR(struct ast_json *, blob, NULL, ast_json_unref);
 char digit_str[] = { digit, '\0' };

 blob = ast_json_pack("{ s: s, s: s, s: I }",
 "digit", digit_str,
 "direction", dtmf_direction_to_string(direction),
 "duration_ms", (ast_json_int_t)duration_ms);
 if (!blob) {
 return;
 }

 ast_channel_publish_blob(chan, ast_channel_dtmf_end_type(), blob);
}

static void send_flash_event(struct ast_channel *chan)
{
 ast_channel_publish_blob(chan, ast_channel_flash_type(), NULL);
}

static void ast_read_generator_actions(struct ast_channel *chan, struct ast_frame *f)
{
 struct ast_generator *generator;
 void *gendata;
 int res;
 int samples;

 generator = ast_channel_generator(chan);
 if (!generator
 || !generator->generate
 || f->frametype != AST_FRAME_VOICE
 || !ast_channel_generatordata(chan)
 || ast_channel_timingfunc(chan)) {
 return;
 }

 /*
 * We must generate frames in phase locked mode since
 * we have no internal timer available.
 */
 if (ast_format_cmp(f->subclass.format, ast_channel_writeformat(chan)) == AST_FORMAT_CMP_NOT_EQUAL) {
 float factor;
 factor = ((float) ast_format_get_sample_rate(ast_channel_writeformat(chan))) / ((float) ast_format_get_sample_rate(f->subclass.format));
 samples = (int) (((float) f->samples) * factor);
 } else {
 samples = f->samples;
 }

 gendata = ast_channel_generatordata(chan);
 ast_channel_generatordata_set(chan, NULL); /* reset, to let writes go through */

 /*
 * This unlock is here based on two assumptions that hold true at
 * this point in the code. 1) this function is only called from
 * within __ast_read() and 2) all generators call ast_write() in
 * their generate callback.
 *
 * The reason this is added is so that when ast_write is called,
 * the lock that occurs there will not recursively lock the
 * channel. Doing this will allow deadlock avoidance to work in
 * deeper functions.
 */
 ast_channel_unlock(chan);
 res = generator->generate(chan, gendata, f->datalen, samples);
 ast_channel_lock(chan);
 if (generator == ast_channel_generator(chan)) {
 ast_channel_generatordata_set(chan, gendata);
 if (res) {
 ast_debug(1, "Auto-deactivating generator\n");
 ast_deactivate_generator(chan);
 }
 }
}

static inline void queue_dtmf_readq(struct ast_channel *chan, struct ast_frame *f)
{
 struct ast_frame *fr = ast_channel_dtmff(chan);
 ast_log(LOG_WARNING, "Came out of the chan driv\n");

 fr->frametype = AST_FRAME_DTMF_END;
 fr->subclass.integer = f->subclass.integer;
 fr->len = f->len;

 /* The only time this function will be called is for a frame that just came
 * out of the channel driver. So, we want to stick it on the tail of the
 * readq. */

 ast_queue_frame(chan, fr);
}

/*!
 * \brief Determine whether or not we should ignore DTMF in the readq
 */
static inline int should_skip_dtmf(struct ast_channel *chan)
{
 if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_DEFER_DTMF | AST_FLAG_EMULATE_DTMF)) {
 /* We're in the middle of emulating a digit, or DTMF has been
 * explicitly deferred. Skip this digit, then. */
 return 1;
 }

 if (!ast_tvzero(*ast_channel_dtmf_tv(chan)) &&
 ast_tvdiff_ms(ast_tvnow(), *ast_channel_dtmf_tv(chan)) < AST_MIN_DTMF_GAP) {
 /* We're not in the middle of a digit, but it hasn't been long enough
 * since the last digit, so we'll have to skip DTMF for now. */
 return 1;
 }

 return 0;
}

/*!
 * \brief calculates the number of samples to jump forward with in a monitor stream.

 * \note When using ast_seekstream() with the read and write streams of a monitor,
 * the number of samples to seek forward must be of the same sample rate as the stream
 * or else the jump will not be calculated correctly.
 *
 * \retval number of samples to seek forward after rate conversion.
 */
static inline int calc_monitor_jump(int samples, int sample_rate, int seek_rate)
{
 int diff = sample_rate - seek_rate;

 if (diff > 0) {
 samples = samples / (float) (sample_rate / seek_rate);
 } else if (diff < 0) {
 samples = samples * (float) (seek_rate / sample_rate);
 }

 return samples;
}

static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio, int dropnondefault)
{
 struct ast_frame *f = NULL; /* the return value */
 int prestate;
 int cause = 0;
 struct ast_stream *stream = NULL, *default_stream = NULL;

 /* this function is very long so make sure there is only one return
 * point at the end (there are only two exceptions to this).
 */
 ast_channel_lock(chan);

 /* Stop if we're a zombie or need a soft hangup */
 if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_ZOMBIE) || ast_check_hangup(chan)) {
 if (ast_channel_generator(chan))
 ast_deactivate_generator(chan);

 /*
 * It is possible for chan->_softhangup to be set and there
 * still be control frames that need to be read. Instead of
 * just going to 'done' in the case of ast_check_hangup(), we
 * need to queue the end-of-Q frame so that it can mark the end
 * of the read queue. If there are frames to be read,
 * ast_queue_control() will be called repeatedly, but will only
 * queue the first end-of-Q frame.
 */
 if (ast_channel_softhangup_internal_flag(chan)) {
 ast_log(LOG_WARNING, "GOT HERE\n");
 ast_queue_control(chan, AST_CONTROL_END_OF_Q);
 } else {
 goto done;
 }
 } else {
#ifdef AST_DEVMODE
 /*
 * The ast_waitfor() code records which of the channel's file
 * descriptors reported that data is available. In theory,
 * ast_read() should only be called after ast_waitfor() reports
 * that a channel has data available for reading. However,
 * there still may be some edge cases throughout the code where
 * ast_read() is called improperly. This can potentially cause
 * problems, so if this is a developer build, make a lot of
 * noise if this happens so that it can be addressed.
 *
 * One of the potential problems is blocking on a dead channel.
 */
 if (ast_channel_fdno(chan) == -1) {
 ast_log(LOG_ERROR,
 "ast_read() on chan '%s' called with no recorded file descriptor.\n",
 ast_channel_name(chan));
 }
#endif
 }

 prestate = ast_channel_state(chan);

 if (ast_channel_timingfd(chan) > -1 && ast_channel_fdno(chan) == AST_TIMING_FD) {
 enum ast_timer_event res;
 int trigger_dtmf_emulating = should_trigger_dtmf_emulating(chan);

 ast_clear_flag(ast_channel_flags(chan), AST_FLAG_EXCEPTION);

 res = ast_timer_get_event(ast_channel_timer(chan));

 switch (res) {
 case AST_TIMING_EVENT_EXPIRED:
 if (ast_timer_ack(ast_channel_timer(chan), 1) < 0) {
 ast_log(LOG_ERROR, "Failed to acknoweldge timer in ast_read\n");
 goto done;
 }

 if (ast_channel_timingfunc(chan)) {
 /* save a copy of func/data before unlocking the channel */
 ast_timing_func_t func = ast_channel_timingfunc(chan);
 void *data = ast_channel_timingdata(chan);
 int got_ref = 0;
 if (data && ast_test_flag(ast_channel_flags(chan), AST_FLAG_TIMINGDATA_IS_AO2_OBJ)) {
 ao2_ref(data, 1);
 got_ref = 1;
 }
 ast_channel_fdno_set(chan, -1);
 ast_channel_unlock(chan);
 func(data);
 if (got_ref) {
 ao2_ref(data, -1);
 }

 if (trigger_dtmf_emulating) {
 /*
 * Since we're breaking out of this switch block and not
 * returning, we need to re-lock the channel.
 */
 ast_channel_lock(chan);
 /* generate null frame to trigger dtmf emulating */
 f = &ast_null_frame;
 break;
 }
 } else if (trigger_dtmf_emulating) {
 /* generate null frame to trigger dtmf emualating */
 f = &ast_null_frame;
 break;
 } else {
 ast_timer_set_rate(ast_channel_timer(chan), 0);
 /* generate very last null frame to trigger dtmf emulating */
 f = &ast_null_frame;
 break;
 }

 /* cannot 'goto done' because the channel is already unlocked */
 return &ast_null_frame;

 case AST_TIMING_EVENT_CONTINUOUS:
 if (AST_LIST_EMPTY(ast_channel_readq(chan)) ||
 !AST_LIST_NEXT(AST_LIST_FIRST(ast_channel_readq(chan)), frame_list)) {
 ast_timer_disable_continuous(ast_channel_timer(chan));
 }
 break;
 }

 } else if (ast_channel_fd_isset(chan, AST_GENERATOR_FD) && ast_channel_fdno(chan) == AST_GENERATOR_FD) {
 /* if the AST_GENERATOR_FD is set, call the generator with args
 * set to -1 so it can do whatever it needs to.
 */
 void *tmp = ast_channel_generatordata(chan);
 ast_channel_generatordata_set(chan, NULL); /* reset to let ast_write get through */
 ast_channel_generator(chan)->generate(chan, tmp, -1, -1);
 ast_channel_generatordata_set(chan, tmp);
 f = &ast_null_frame;
 ast_channel_fdno_set(chan, -1);
 goto done;
 } else if (ast_channel_fd_isset(chan, AST_JITTERBUFFER_FD) && ast_channel_fdno(chan) == AST_JITTERBUFFER_FD) {
 ast_clear_flag(ast_channel_flags(chan), AST_FLAG_EXCEPTION);
 }

 /* Read and ignore anything on the alertpipe, but read only
 one sizeof(blah) per frame that we send from it */
 if (ast_channel_internal_alert_read(chan) == AST_ALERT_READ_FATAL) {
 f = &ast_null_frame;
 goto done;
 }

 /* Check for pending read queue */
 if (!AST_LIST_EMPTY(ast_channel_readq(chan))) {
 int skipped_dtmf_frame = 0;
 int skip_dtmf = should_skip_dtmf(chan);

 AST_LIST_TRAVERSE_SAFE_BEGIN(ast_channel_readq(chan), f, frame_list) {
 /* We have to be picky about which frame we pull off of the readq because
 * there are cases where we want to leave DTMF frames on the queue until
 * some later time. */

 if ( (f->frametype == AST_FRAME_DTMF_BEGIN || f->frametype == AST_FRAME_DTMF_END) && skip_dtmf) {
 skipped_dtmf_frame = 1;
 continue;
 }

 AST_LIST_REMOVE_CURRENT(frame_list);
 break;
 }
 AST_LIST_TRAVERSE_SAFE_END;

 if (!f) {
 /* There were no acceptable frames on the readq. */
 f = &ast_null_frame;
 if (!skipped_dtmf_frame) {
 /*
 * Do not trigger alert pipe if only buffered dtmf begin or end frames
 * are left in the readq.
 */
 ast_channel_alert_write(chan);
 } else {
 /*
 * Safely disable continous timer events if only buffered dtmf begin or end
 * frames are left in the readq.
 */
 ast_timer_disable_continuous(ast_channel_timer(chan));
 }
 }

 /* Interpret hangup and end-of-Q frames to return NULL */
 /* XXX why not the same for frames from the channel ? */
 if (f->frametype == AST_FRAME_CONTROL) {
 switch (f->subclass.integer) {
 case AST_CONTROL_HANGUP:
 ast_channel_softhangup_internal_flag_add(chan, AST_SOFTHANGUP_DEV);
 cause = f->data.uint32;
 /* Fall through */
 case AST_CONTROL_END_OF_Q:
 ast_frfree(f);
 f = NULL;
 break;
 default:
 break;
 }
 } else if (f->frametype == AST_FRAME_VOICE || f->frametype == AST_FRAME_VIDEO) {
 if (ast_channel_tech(chan) && ast_channel_tech(chan)->read_stream) {
 stream = ast_stream_topology_get_stream(ast_channel_get_stream_topology(chan), f->stream_num);
 default_stream = ast_channel_get_default_stream(chan, ast_format_get_type(f->subclass.format));
 } else {
 /* Since this channel driver does not support multistream determine the default stream this frame
 * originated from and update the frame to include it.
 */
 stream = default_stream = ast_channel_get_default_stream(chan, ast_format_get_type(f->subclass.format));
 /* In order to allow media to be passed up the underlying media type has to have a format negotiated on
 * the channel itself. In cases where this hasn't happened the channel driver is incorrectly passing up
 * a frame for a format that has not been negotiated. If this occurs just drop the frame as we have no
 * stream that it came from.
 */
 if (!stream) {
 ast_frfree(f);
 f = &ast_null_frame;
 } else {
 f->stream_num = ast_stream_get_position(stream);
 }
 }
 }
 } else {
 if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_EXCEPTION)) {
 if (ast_channel_tech(chan)->exception)
 f = ast_channel_tech(chan)->exception(chan);
 else {
 ast_log(LOG_WARNING, "Exception flag set on '%s', but no exception handler\n", ast_channel_name(chan));
 f = &ast_null_frame;
 }
 /* Clear the exception flag */
 ast_clear_flag(ast_channel_flags(chan), AST_FLAG_EXCEPTION);
 } else if (ast_channel_tech(chan) && ast_channel_tech(chan)->read_stream) {
 f = ast_channel_tech(chan)->read_stream(chan);

 /* This channel driver supports multistream so the stream_num on the frame is valid, the only
 * thing different is that we need to find the default stream so we know whether to invoke the
 * default stream logic or not (such as transcoding).
 */
 if (f && (f->frametype == AST_FRAME_VOICE || f->frametype == AST_FRAME_VIDEO)) {
 stream = ast_stream_topology_get_stream(ast_channel_get_stream_topology(chan), f->stream_num);
 default_stream = ast_channel_get_default_stream(chan, ast_format_get_type(f->subclass.format));
 }
 } else if (ast_channel_tech(chan) && ast_channel_tech(chan)->read) {
 f = ast_channel_tech(chan)->read(chan);

 /* Since this channel driver does not support multistream determine the default stream this frame
 * originated from and update the frame to include it.
 */
 if (f && (f->frametype == AST_FRAME_VOICE || f->frametype == AST_FRAME_VIDEO)) {
 stream = default_stream = ast_channel_get_default_stream(chan, ast_format_get_type(f->subclass.format));
 if (!stream) {
 ast_frfree(f);
 f = &ast_null_frame;
 } else {
 f->stream_num = ast_stream_get_position(stream);
 }
 }
 }
 else
 ast_log(LOG_WARNING, "No read routine on channel %s\n", ast_channel_name(chan));
 }

 if (stream == default_stream) {
 /* Perform the framehook read event here. After the frame enters the framehook list
 * there is no telling what will happen, <insert mad scientist laugh here>!!! */
 f = ast_framehook_list_read_event(ast_channel_framehooks(chan), f);
 }

 /*
 * Reset the recorded file descriptor that triggered this read so that we can
 * easily detect when ast_read() is called without properly using ast_waitfor().
 */
 ast_channel_fdno_set(chan, -1);

 if (f) {
 struct ast_frame *readq_tail = AST_LIST_LAST(ast_channel_readq(chan));
 struct ast_control_read_action_payload *read_action_payload;
 struct ast_party_connected_line connected;
 int hooked = 0;


 /* if the channel driver returned more than one frame, stuff the excess
 into the readq for the next ast_read call
 */
 if (AST_LIST_NEXT(f, frame_list)) {
 ast_queue_frame(chan, AST_LIST_NEXT(f, frame_list));
 ast_frfree(AST_LIST_NEXT(f, frame_list));
 AST_LIST_NEXT(f, frame_list) = NULL;
 }

 if (dropnondefault && stream != default_stream) {
 /* If the frame originates from a non-default stream and the caller can not handle other streams
 * absorb the frame and replace it with a null one instead.
 */
 ast_frfree(f);
 f = &ast_null_frame;
 }

 switch (f->frametype) {
 case AST_FRAME_CONTROL:
 if (f->subclass.integer == AST_CONTROL_ANSWER) {
 if (prestate == AST_STATE_UP && ast_channel_is_bridged(chan)) {
 ast_debug(1, "Dropping duplicate answer!\n");
 ast_frfree(f);
 f = &ast_null_frame;
 } else {
 /*
 * Mark when outgoing channel answered so we can know how
 * long the channel has been up.
 */
 set_channel_answer_time(chan);

 ast_setstate(chan, AST_STATE_UP);
 }
 } else if (f->subclass.integer == AST_CONTROL_READ_ACTION) {
 read_action_payload = f->data.ptr;
 switch (read_action_payload->action) {
 case AST_FRAME_READ_ACTION_CONNECTED_LINE_MACRO:
 ast_party_connected_line_init(&connected);
 ast_party_connected_line_copy(&connected, ast_channel_connected(chan));
 if (ast_connected_line_parse_data(read_action_payload->payload,
 read_action_payload->payload_size, &connected)) {
 ast_party_connected_line_free(&connected);
 break;
 }
 ast_channel_unlock(chan);
 if (ast_channel_connected_line_sub(NULL, chan, &connected, 0) &&
 ast_channel_connected_line_macro(NULL, chan, &connected, 1, 0)) {
 ast_indicate_data(chan, AST_CONTROL_CONNECTED_LINE,
 read_action_payload->payload,
 read_action_payload->payload_size);
 }
 ast_party_connected_line_free(&connected);
 ast_channel_lock(chan);
 break;
 case AST_FRAME_READ_ACTION_SEND_TEXT:
 ast_channel_unlock(chan);
 ast_sendtext(chan, (const char *)read_action_payload->payload);
 ast_channel_lock(chan);
 break;
 case AST_FRAME_READ_ACTION_SEND_TEXT_DATA:
 ast_channel_unlock(chan);
 ast_sendtext_data(chan, (struct ast_msg_data *)read_action_payload->payload);
 ast_channel_lock(chan);
 break;
 }
 ast_frfree(f);
 f = &ast_null_frame;
 } else if (f->subclass.integer == AST_CONTROL_STREAM_TOPOLOGY_REQUEST_CHANGE && dropnondefault) {
 /* The caller of this function is incapable of handling streams so we don't accept the change request
 * and stick to the streams currently on the channel.
 */
 ast_channel_stream_topology_changed(chan, ast_channel_get_stream_topology(chan));
 ast_frfree(f);
 f = &ast_null_frame;
 } else if (f->subclass.integer == AST_CONTROL_STREAM_TOPOLOGY_CHANGED && dropnondefault) {
 /* The caller of this function is incapable of handling streams so we absorb the notification that the
 * stream topology has changed.
 */
 ast_frfree(f);
 f = &ast_null_frame;
 } else if (f->subclass.integer == AST_CONTROL_FLASH) {
 send_flash_event(chan);
 }
 break;
 case AST_FRAME_DTMF_END:
 send_dtmf_end_event(chan, DTMF_RECEIVED, f->subclass.integer, f->len);
 ast_log(LOG_DTMF, "DTMF end '%c' received on %s, duration %ld ms\n", f->subclass.integer, ast_channel_name(chan), f->len);
 /* Queue it up if DTMF is deferred, or if DTMF emulation is forced. */
 if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_DEFER_DTMF) || ast_test_flag(ast_channel_flags(chan), AST_FLAG_EMULATE_DTMF)) {
 queue_dtmf_readq(chan, f);
 ast_frfree(f);
 f = &ast_null_frame;
 } else if (!ast_test_flag(ast_channel_flags(chan), AST_FLAG_IN_DTMF | AST_FLAG_END_DTMF_ONLY)) {
 if (!ast_tvzero(*ast_channel_dtmf_tv(chan)) &&
 ast_tvdiff_ms(ast_tvnow(), *ast_channel_dtmf_tv(chan)) < AST_MIN_DTMF_GAP) {
 /* If it hasn't been long enough, defer this digit */
 queue_dtmf_readq(chan, f);
 ast_frfree(f);
 f = &ast_null_frame;
 } else {
 /* There was no begin, turn this into a begin and send the end later */
 struct timeval tv = ast_tvnow();
 f->frametype = AST_FRAME_DTMF_BEGIN;
 ast_set_flag(ast_channel_flags(chan), AST_FLAG_EMULATE_DTMF);
 ast_channel_dtmf_digit_to_emulate_set(chan, f->subclass.integer);
 ast_channel_dtmf_tv_set(chan, &tv);
 if (f->len) {
 if (f->len > option_dtmfminduration)
 ast_channel_emulate_dtmf_duration_set(chan, f->len);
 else
 ast_channel_emulate_dtmf_duration_set(chan, option_dtmfminduration);
 } else
 ast_channel_emulate_dtmf_duration_set(chan, AST_DEFAULT_EMULATE_DTMF_DURATION);
 ast_log(LOG_DTMF, "DTMF begin emulation of '%c' with duration %u queued on %s\n", f->subclass.integer, ast_channel_emulate_dtmf_duration(chan), ast_channel_name(chan));

 /*
 * Start generating 50 fps timer events (null frames) for dtmf emulating
 * independently from any existing incoming voice frames.
 * If channel generator is already activated in regular mode use these
 * timer events to generate null frames.
 */
 if (!ast_channel_generator(chan)) {
 ast_timer_set_rate(ast_channel_timer(chan), 50);
 }
 }
 if (ast_channel_audiohooks(chan)) {
 struct ast_frame *old_frame = f;
 /*!
 * \todo XXX It is possible to write a digit to the audiohook twice
 * if the digit was originally read while the channel was in autoservice. */
 f = ast_audiohook_write_list(chan, ast_channel_audiohooks(chan), AST_AUDIOHOOK_DIRECTION_READ, f);
 if (old_frame != f)
 ast_frfree(old_frame);
 }
 } else {
 struct timeval now = ast_tvnow();
 if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_IN_DTMF)) {
 ast_log(LOG_DTMF, "DTMF end accepted with begin '%c' on %s\n", f->subclass.integer, ast_channel_name(chan));
 ast_clear_flag(ast_channel_flags(chan), AST_FLAG_IN_DTMF);
 if (!f->len)
 f->len = ast_tvdiff_ms(now, *ast_channel_dtmf_tv(chan));

 /* detect tones that were received on
 * the wire with durations shorter than
 * option_dtmfminduration and set f->len
 * to the actual duration of the DTMF
 * frames on the wire. This will cause
 * dtmf emulation to be triggered later
 * on.
 */
 if (ast_tvdiff_ms(now, *ast_channel_dtmf_tv(chan)) < option_dtmfminduration) {
 f->len = ast_tvdiff_ms(now, *ast_channel_dtmf_tv(chan));
 ast_log(LOG_DTMF, "DTMF end '%c' detected to have actual duration %ld on the wire, emulation will be triggered on %s\n", f->subclass.integer, f->len, ast_channel_name(chan));
 }
 } else if (!f->len) {
 ast_log(LOG_DTMF, "DTMF end accepted without begin '%c' on %s\n", f->subclass.integer, ast_channel_name(chan));
 f->len = option_dtmfminduration;
 }
 if (f->len < option_dtmfminduration && !ast_test_flag(ast_channel_flags(chan), AST_FLAG_END_DTMF_ONLY)) {
 ast_log(LOG_DTMF, "DTMF end '%c' has duration %ld but want minimum %u, emulating on %s\n", f->subclass.integer, f->len, option_dtmfminduration, ast_channel_name(chan));
 ast_set_flag(ast_channel_flags(chan), AST_FLAG_EMULATE_DTMF);
 ast_channel_dtmf_digit_to_emulate_set(chan, f->subclass.integer);
 ast_channel_emulate_dtmf_duration_set(chan, option_dtmfminduration - f->len);
 ast_frfree(f);
 f = &ast_null_frame;

 /* Start generating 50 fps timer events (null frames) for dtmf emulating
 * independently from any existing incoming voice frames.
 * If channel generator is already activated in regular mode use these
 * timer events to generate null frames.
 */
 if (!ast_channel_generator(chan)) {
 ast_timer_set_rate(ast_channel_timer(chan), 50);
 }
 } else {
 ast_log(LOG_DTMF, "DTMF end passthrough '%c' on %s\n", f->subclass.integer, ast_channel_name(chan));
 if (f->len < option_dtmfminduration) {
 f->len = option_dtmfminduration;
 }
 ast_channel_dtmf_tv_set(chan, &now);

 /* Start generating 50 fps timer events (null frames) for dtmf emulating
 * independently from any existing incoming voice frames.
 * If channel generator is already activated in regular mode use these
 * timer events to generate null frames.
 */
 if (!ast_channel_generator(chan)) {
 ast_timer_set_rate(ast_channel_timer(chan), 50);
 }
 }
 if (ast_channel_audiohooks(chan)) {
 struct ast_frame *old_frame = f;
 f = ast_audiohook_write_list(chan, ast_channel_audiohooks(chan), AST_AUDIOHOOK_DIRECTION_READ, f);
 if (old_frame != f)
 ast_frfree(old_frame);
 }
 }
 break;
 case AST_FRAME_DTMF_BEGIN:
 send_dtmf_begin_event(chan, DTMF_RECEIVED, f->subclass.integer);
 ast_log(LOG_DTMF, "DTMF begin '%c' received on %s\n", f->subclass.integer, ast_channel_name(chan));
 if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_DEFER_DTMF | AST_FLAG_END_DTMF_ONLY | AST_FLAG_EMULATE_DTMF) ||
 (!ast_tvzero(*ast_channel_dtmf_tv(chan)) &&
 ast_tvdiff_ms(ast_tvnow(), *ast_channel_dtmf_tv(chan)) < AST_MIN_DTMF_GAP) ) {
 ast_log(LOG_DTMF, "DTMF begin ignored '%c' on %s\n", f->subclass.integer, ast_channel_name(chan));
 ast_frfree(f);
 f = &ast_null_frame;
 } else {
 struct timeval now = ast_tvnow();
 ast_set_flag(ast_channel_flags(chan), AST_FLAG_IN_DTMF);
 ast_channel_dtmf_tv_set(chan, &now);
 ast_log(LOG_DTMF, "DTMF begin passthrough '%c' on %s\n", f->subclass.integer, ast_channel_name(chan));
 }
 break;
 case AST_FRAME_NULL:
 /* The EMULATE_DTMF flag must be cleared here as opposed to when the duration
 * is reached , because we want to make sure we pass at least one
 * voice frame through before starting the next digit, to ensure a gap
 * between DTMF digits. */
 if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_EMULATE_DTMF)) {
 struct timeval now = ast_tvnow();
 if (!ast_channel_emulate_dtmf_duration(chan)) {
 ast_clear_flag(ast_channel_flags(chan), AST_FLAG_EMULATE_DTMF);
 ast_channel_dtmf_digit_to_emulate_set(chan, 0);
 } else if (ast_tvdiff_ms(now, *ast_channel_dtmf_tv(chan)) >= ast_channel_emulate_dtmf_duration(chan)) {
 ast_channel_emulate_dtmf_duration_set(chan, 0);
 ast_frfree(f);
 f = ast_channel_dtmff(chan);
 f->frametype = AST_FRAME_DTMF_END;
 f->subclass.integer = ast_channel_dtmf_digit_to_emulate(chan);
 f->len = ast_tvdiff_ms(now, *ast_channel_dtmf_tv(chan));
 ast_channel_dtmf_tv_set(chan, &now);
 ast_clear_flag(ast_channel_flags(chan), AST_FLAG_EMULATE_DTMF);
 ast_channel_dtmf_digit_to_emulate_set(chan, 0);
 ast_log(LOG_DTMF, "DTMF end emulation of '%c' queued on %s\n", f->subclass.integer, ast_channel_name(chan));
 if (ast_channel_audiohooks(chan)) {
 struct ast_frame *old_frame = f;
 f = ast_audiohook_write_list(chan, ast_channel_audiohooks(chan), AST_AUDIOHOOK_DIRECTION_READ, f);
 if (old_frame != f) {
 ast_frfree(old_frame);
 }
 }

 /* Start generating 50 fps timer events (null frames) for dtmf emulating
 * independently from any existing incoming voice frames.
 * If channel generator is already activated in regular mode use these
 * timer events to generate null frames.
 */
 if (!ast_channel_generator(chan)) {
 ast_timer_set_rate(ast_channel_timer(chan), 50);
 }
 }
 }
 break;
 case AST_FRAME_VOICE:
 /* If media was received from a non-default stream don't perform any actions, let it just go through */
 if (stream != default_stream) {
 break;
 }

 /* The EMULATE_DTMF flag must be cleared here as opposed to when the duration
 * is reached , because we want to make sure we pass at least one
 * voice frame through before starting the next digit, to ensure a gap
 * between DTMF digits. */
 if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_EMULATE_DTMF) && !ast_channel_emulate_dtmf_duration(chan)) {
 ast_log(LOG_WARNING, "!!! t5a\n");
 ast_clear_flag(ast_channel_flags(chan), AST_FLAG_EMULATE_DTMF);
 ast_channel_dtmf_digit_to_emulate_set(chan, 0);
 }

 if (dropaudio || ast_test_flag(ast_channel_flags(chan), AST_FLAG_IN_DTMF)) {
 ast_log(LOG_WARNING, "!!! t5b\n");
 if (dropaudio)
 ast_read_generator_actions(chan, f);
 ast_frfree(f);
 f = &ast_null_frame;
 }

 if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_EMULATE_DTMF) && !ast_test_flag(ast_channel_flags(chan), AST_FLAG_IN_DTMF)) {
 struct timeval now = ast_tvnow();
 ast_log(LOG_WARNING, "!!! t5c\n");
 if (ast_tvdiff_ms(now, *ast_channel_dtmf_tv(chan)) >= ast_channel_emulate_dtmf_duration(chan)) {
 ast_channel_emulate_dtmf_duration_set(chan, 0);
 ast_frfree(f);
 f = ast_channel_dtmff(chan);
 f->frametype = AST_FRAME_DTMF_END;
 f->subclass.integer = ast_channel_dtmf_digit_to_emulate(chan);
 f->len = ast_tvdiff_ms(now, *ast_channel_dtmf_tv(chan));
 ast_channel_dtmf_tv_set(chan, &now);
 if (ast_channel_audiohooks(chan)) {
 struct ast_frame *old_frame = f;
 f = ast_audiohook_write_list(chan, ast_channel_audiohooks(chan), AST_AUDIOHOOK_DIRECTION_READ, f);
 if (old_frame != f)
 ast_frfree(old_frame);
 }
 ast_log(LOG_DTMF, "DTMF end emulation of '%c' queued on %s\n", f->subclass.integer, ast_channel_name(chan));
 } else {
 /* Drop voice frames while we're still in the middle of the digit */
 ast_frfree(f);
 f = &ast_null_frame;
 }
 break;
 }
 if (f->frametype != AST_FRAME_VOICE) {
 ast_log(LOG_WARNING, "!!! t5d\n");
 break;
 }
 if (ast_format_cmp(f->subclass.format, ast_channel_rawreadformat(chan)) != AST_FORMAT_CMP_EQUAL
 && ast_format_cmp(f->subclass.format, ast_channel_readformat(chan)) != AST_FORMAT_CMP_EQUAL) {
 struct ast_format *core_format;

 /*
 * Note: This frame may not be one of the current native
 * formats. We may have gotten it out of the read queue from
 * a previous multi-frame translation, from a framehook
 * injected frame, or the device we're talking to isn't
 * respecting negotiated formats. Regardless we will accept
 * all frames.
 *
 * Update the read translation path to handle the new format
 * that just came in. If the core wants slinear we need to
 * setup a new translation path because the core is usually
 * doing something with the audio itself and may not handle
 * any other format. e.g., Softmix bridge, holding bridge
 * announcer channel, recording, AMD... Otherwise, we'll
 * setup to pass the frame as is to the core. In this case
 * the core doesn't care. The channel is likely in
 * autoservice, safesleep, or the channel is in a bridge.
 * Let the bridge technology deal with format compatibility
 * between the channels in the bridge.
 *
 * Beware of the transcode_via_slin and genericplc options as
 * they force any transcoding to go through slin on a bridge.
 * Unfortunately transcode_via_slin is enabled by default and
 * genericplc is enabled in the codecs.conf.sample file.
 *
 * XXX Only updating translation to slinear frames has some
 * corner cases if slinear is one of the native formats and
 * there are different sample rates involved. We might wind
 * up with conflicting translation paths between channels
 * where the read translation path on this channel reduces
 * the sample rate followed by a write translation path on
 * the peer channel that increases the sample rate.
 */
 core_format = ast_channel_readformat(chan);
 if (!ast_format_cache_is_slinear(core_format)) {
 core_format = f->subclass.format;
 }
 ast_log(LOG_WARNING, "!!! t5f\n");
 if (ast_set_read_format_path(chan, f->subclass.format, core_format)) {
 /* Drop frame. We couldn't make it compatible with the core. */
 ast_frfree(f);
 f = &ast_null_frame;
 break;
 }
 }
 /*
 * Send frame to audiohooks if present, if frametype is linear, to preserve
 * functional compatibility with previous behavior. If not linear, hold off
 * until transcoding is done where we are more likely to have a linear frame
 */
 if (ast_channel_audiohooks(chan) && ast_format_cache_is_slinear(f->subclass.format)) {
 /* Place hooked after declaration */
 struct ast_frame *old_frame = f;
 hooked = 1;
 ast_log(LOG_WARNING, "!!! t5h\n");
 f = ast_audiohook_write_list(chan, ast_channel_audiohooks(chan), AST_AUDIOHOOK_DIRECTION_READ, f);
 if (old_frame != f) {
 ast_frfree(old_frame);
 }
 }

 if (ast_channel_monitor(chan) && ast_channel_monitor(chan)->read_stream) {
 /* XXX what does this do ? */
#ifndef MONITOR_CONSTANT_DELAY
 int jump = ast_channel_outsmpl(chan) - ast_channel_insmpl(chan) - 4 * f->samples;
 if (jump >= 0) {
 jump = calc_monitor_jump((ast_channel_outsmpl(chan) - ast_channel_insmpl(chan)),
 ast_format_get_sample_rate(f->subclass.format),
 ast_format_get_sample_rate(ast_channel_monitor(chan)->read_stream->fmt->format));
 if (ast_seekstream(ast_channel_monitor(chan)->read_stream, jump, SEEK_FORCECUR) == -1) {
 ast_log(LOG_WARNING, "Failed to perform seek in monitoring read stream, synchronization between the files may be broken\n");
 }
 ast_channel_insmpl_set(chan, ast_channel_insmpl(chan) + (ast_channel_outsmpl(chan) - ast_channel_insmpl(chan)) + f->samples);
 } else {
 ast_channel_insmpl_set(chan, ast_channel_insmpl(chan) + f->samples);
 }
#else
 int jump = calc_monitor_jump((ast_channel_outsmpl(chan) - ast_channel_insmpl(chan)),
 ast_format_get_sample_rate(f->subclass.format),
 ast_format_get_sample_rate(ast_channel_monitor(chan)->read_stream->fmt->format));
 if (jump - MONITOR_DELAY >= 0) {
 if (ast_seekstream(ast_channel_monitor(chan)->read_stream, jump - f->samples, SEEK_FORCECUR) == -1) {
 ast_log(LOG_WARNING, "Failed to perform seek in monitoring read stream, synchronization between the files may be broken\n");
 }
 ast_channel_insmpl(chan) += ast_channel_outsmpl(chan) - ast_channel_insmpl(chan);
 } else {
 ast_channel_insmpl(chan) += f->samples;
 }
#endif
 if (ast_channel_monitor(chan)->state == AST_MONITOR_RUNNING) {
 if (ast_writestream(ast_channel_monitor(chan)->read_stream, f) < 0)
 ast_log(LOG_WARNING, "Failed to write data to channel monitor read stream\n");
 }
 ast_log(LOG_WARNING, "!!! t5jj\n");
 }

 if (ast_channel_readtrans(chan)
 && ast_format_cmp(f->subclass.format, ast_channel_rawreadformat(chan)) == AST_FORMAT_CMP_EQUAL) {
 f = ast_translate(ast_channel_readtrans(chan), f, 1);
 if (!f) {
 f = &ast_null_frame;
 }
 }

 /* Second chance at hooking a linear frame, also the last chance */
 if (ast_channel_audiohooks(chan) && !hooked) {
 struct ast_frame *old_frame = f;
 f = ast_audiohook_write_list(chan, ast_channel_audiohooks(chan), AST_AUDIOHOOK_DIRECTION_READ, f);
 if (old_frame != f) {
 ast_frfree(old_frame);
 }
 }

 /*
 * It is possible for the translation process on the channel to have
 * produced multiple frames from the single input frame we passed it; if
 * this happens, queue the additional frames *before* the frames we may
 * have queued earlier. if the readq was empty, put them at the head of
 * the queue, and if it was not, put them just after the frame that was
 * at the end of the queue.
 */
 if (AST_LIST_NEXT(f, frame_list)) {
 struct ast_frame *cur, *multi_frame = AST_LIST_NEXT(f, frame_list);
 ast_log(LOG_WARNING, "!!! t5k\n");
 /* Mark these frames as being re-queued */
 for (cur = multi_frame; cur; cur = AST_LIST_NEXT(cur, frame_list)) {
 ast_set_flag(cur, AST_FRFLAG_REQUEUED);
 }

 if (!readq_tail) {
 ast_queue_frame_head(chan, multi_frame);
 } else {
 __ast_queue_frame(chan, multi_frame, 0, readq_tail);
 }
 ast_frfree(multi_frame);
 AST_LIST_NEXT(f, frame_list) = NULL;
 }

 /*
 * Run generator sitting on the line if timing device not available
 * and synchronous generation of outgoing frames is necessary
 */
 ast_read_generator_actions(chan, f);
 break;
 case AST_FRAME_RTCP:
 /* Incoming RTCP feedback needs to get to the translator for
 * outgoing media, which means we treat it as an ast_write */
 if (ast_channel_writetrans(chan)) {
 ast_translate(ast_channel_writetrans(chan), f, 0);
 }
 break;
 default:
 /* Just pass it on! */
 break;
 }
 } else {
 /* Make sure we always return NULL in the future */
 if (!ast_channel_softhangup_internal_flag(chan)) {
 ast_channel_softhangup_internal_flag_add(chan, AST_SOFTHANGUP_DEV);
 }
 if (cause)
 ast_channel_hangupcause_set(chan, cause);
 if (ast_channel_generator(chan))
 ast_deactivate_generator(chan);
 /* We no longer End the CDR here */
 }

 /* High bit prints debugging */
 if (ast_channel_fin(chan) & DEBUGCHAN_FLAG)
 ast_frame_dump(ast_channel_name(chan), f, "<<");
 ast_channel_fin_set(chan, FRAMECOUNT_INC(ast_channel_fin(chan)));

done:
 if (ast_channel_music_state(chan) && ast_channel_generator(chan) && ast_channel_generator(chan)->digit && f && f->frametype == AST_FRAME_DTMF_END) {
 ast_channel_generator(chan)->digit(chan, f->subclass.integer);
 }

 if (ast_channel_audiohooks(chan) && ast_audiohook_write_list_empty(ast_channel_audiohooks(chan))) {
 /* The list gets recreated if audiohooks are added again later */
 ast_audiohook_detach_list(ast_channel_audiohooks(chan));
 ast_channel_audiohooks_set(chan, NULL);
 }
 ast_channel_unlock(chan);
 return f;
}

struct ast_frame *ast_read(struct ast_channel *chan)
{
 return __ast_read(chan, 0, 1);
}

struct ast_frame *ast_read_stream(struct ast_channel *chan)
{
 return __ast_read(chan, 0, 0);
}

struct ast_frame *ast_read_noaudio(struct ast_channel *chan)
{
 return __ast_read(chan, 1, 1);
}

struct ast_frame *ast_read_stream_noaudio(struct ast_channel *chan)
{
 return __ast_read(chan, 1, 0);
}

int ast_indicate(struct ast_channel *chan, int condition)
{
 return ast_indicate_data(chan, condition, NULL, 0);
}

static int attribute_const is_visible_indication(enum ast_control_frame_type condition)
{
 /* Don't include a default case here so that we get compiler warnings
 * when a new type is added. */

 switch (condition) {
 case AST_CONTROL_PROGRESS:
 case AST_CONTROL_PROCEEDING:
 case AST_CONTROL_VIDUPDATE:
 case AST_CONTROL_SRCUPDATE:
 case AST_CONTROL_SRCCHANGE:
 case AST_CONTROL_RADIO_KEY:
 case AST_CONTROL_RADIO_UNKEY:
 case AST_CONTROL_OPTION:
 case AST_CONTROL_WINK:
 case AST_CONTROL_FLASH:
 case AST_CONTROL_OFFHOOK:
 case AST_CONTROL_TAKEOFFHOOK:
 case AST_CONTROL_ANSWER:
 case AST_CONTROL_HANGUP:
 case AST_CONTROL_CONNECTED_LINE:
 case AST_CONTROL_REDIRECTING:
 case AST_CONTROL_TRANSFER:
 case AST_CONTROL_T38_PARAMETERS:
 case _XXX_AST_CONTROL_T38:
 case AST_CONTROL_CC:
 case AST_CONTROL_READ_ACTION:
 case AST_CONTROL_AOC:
 case AST_CONTROL_END_OF_Q:
 case AST_CONTROL_MCID:
 case AST_CONTROL_UPDATE_RTP_PEER:
 case AST_CONTROL_PVT_CAUSE_CODE:
 case AST_CONTROL_MASQUERADE_NOTIFY:
 case AST_CONTROL_STREAM_TOPOLOGY_REQUEST_CHANGE:
 case AST_CONTROL_STREAM_TOPOLOGY_CHANGED:
 case AST_CONTROL_STREAM_TOPOLOGY_SOURCE_CHANGED:
 case AST_CONTROL_STREAM_STOP:
 case AST_CONTROL_STREAM_SUSPEND:
 case AST_CONTROL_STREAM_REVERSE:
 case AST_CONTROL_STREAM_FORWARD:
 case AST_CONTROL_STREAM_RESTART:
 case AST_CONTROL_RECORD_CANCEL:
 case AST_CONTROL_RECORD_STOP:
 case AST_CONTROL_RECORD_SUSPEND:
 case AST_CONTROL_RECORD_MUTE:
 break;

 case AST_CONTROL_INCOMPLETE:
 case AST_CONTROL_CONGESTION:
 case AST_CONTROL_BUSY:
 case AST_CONTROL_RINGING:
 case AST_CONTROL_RING:
 case AST_CONTROL_HOLD:
 /* You can hear these */
 return 1;

 case AST_CONTROL_UNHOLD:
 /* This is a special case. You stop hearing this. */
 break;
 }

 return 0;
}

void ast_channel_hangupcause_hash_set(struct ast_channel *chan, const struct ast_control_pvt_cause_code *cause_code, int datalen)
{
 char causevar[256];

 if (ast_channel_dialed_causes_add(chan, cause_code, datalen)) {
 ast_log(LOG_WARNING, "Unable to store hangup cause for %s on %s\n", cause_code->chan_name, ast_channel_name(chan));
 }

 if (cause_code->emulate_sip_cause) {
 snprintf(causevar, sizeof(causevar), "HASH(SIP_CAUSE,%s)", cause_code->chan_name);
 ast_func_write(chan, causevar, cause_code->code);
 }
}

enum ama_flags ast_channel_string2amaflag(const char *flag)
{
 if (!strcasecmp(flag, "default"))
 return DEFAULT_AMA_FLAGS;
 if (!strcasecmp(flag, "omit"))
 return AST_AMA_OMIT;
 if (!strcasecmp(flag, "billing"))
 return AST_AMA_BILLING;
 if (!strcasecmp(flag, "documentation"))
 return AST_AMA_DOCUMENTATION;
 return AST_AMA_NONE;
}

const char *ast_channel_amaflags2string(enum ama_flags flag)
{
 switch (flag) {
 case AST_AMA_OMIT:
 return "OMIT";
 case AST_AMA_BILLING:
 return "BILLING";
 case AST_AMA_DOCUMENTATION:
 return "DOCUMENTATION";
 default:
 return "Unknown";
 }
}

/*!
 * \internal
 * \brief Preprocess connected line update.
 * \since 12.0.0
 *
 * \param chan channel to change the indication
 * \param data pointer to payload data
 * \param datalen size of payload data
 *
 * \note This function assumes chan is locked.
 *
 * \retval 0 keep going.
 * \retval -1 quit now.
 */
static int indicate_connected_line(struct ast_channel *chan, const void *data, size_t datalen)
{
 struct ast_party_connected_line *chan_connected = ast_channel_connected(chan);
 struct ast_party_connected_line *chan_indicated = ast_channel_connected_indicated(chan);
 struct ast_party_connected_line connected;
 unsigned char current[1024];
 unsigned char proposed[1024];
 int current_size;
 int proposed_size;
 int res;

 ast_party_connected_line_set_init(&connected, chan_connected);
 res = ast_connected_line_parse_data(data, datalen, &connected);
 if (!res) {
 ast_channel_set_connected_line(chan, &connected, NULL);
 }
 ast_party_connected_line_free(&connected);
 if (res) {
 return -1;
 }

 current_size = ast_connected_line_build_data(current, sizeof(current),
 chan_indicated, NULL);
 proposed_size = ast_connected_line_build_data(proposed, sizeof(proposed),
 chan_connected, NULL);
 if (current_size == -1 || proposed_size == -1) {
 return -1;
 }

 if (current_size == proposed_size && !memcmp(current, proposed, current_size)) {
 ast_debug(1, "%s: Dropping redundant connected line update \"%s\" <%s>.\n",
 ast_channel_name(chan),
 S_COR(chan_connected->id.name.valid, chan_connected->id.name.str, ""),
 S_COR(chan_connected->id.number.valid, chan_connected->id.number.str, ""));
 return -1;
 }

 ast_party_connected_line_copy(chan_indicated, chan_connected);
 return 0;
}

/*!
 * \internal
 * \brief Preprocess redirecting update.
 * \since 12.0.0
 *
 * \param chan channel to change the indication
 * \param data pointer to payload data
 * \param datalen size of payload data
 *
 * \note This function assumes chan is locked.
 *
 * \retval 0 keep going.
 * \retval -1 quit now.
 */
static int indicate_redirecting(struct ast_channel *chan, const void *data, size_t datalen)
{
 struct ast_party_redirecting redirecting;
 int res;

 ast_party_redirecting_set_init(&redirecting, ast_channel_redirecting(chan));
 res = ast_redirecting_parse_data(data, datalen, &redirecting);
 if (!res) {
 ast_channel_set_redirecting(chan, &redirecting, NULL);
 }
 ast_party_redirecting_free(&redirecting);
 return res ? -1 : 0;
}

static int indicate_data_internal(struct ast_channel *chan, int _condition, const void *data, size_t datalen)
{
 /* By using an enum, we'll get compiler warnings for values not handled
 * in switch statements. */
 enum ast_control_frame_type condition = _condition;
 struct ast_tone_zone_sound *ts = NULL;
 const struct ast_control_t38_parameters *t38_parameters;
 int res;

 switch (condition) {
 case AST_CONTROL_CONNECTED_LINE:
 if (indicate_connected_line(chan, data, datalen)) {
 res = 0;
 return res;
 }
 break;
 case AST_CONTROL_REDIRECTING:
 if (indicate_redirecting(chan, data, datalen)) {
 res = 0;
 return res;
 }
 break;
 case AST_CONTROL_HOLD:
 case AST_CONTROL_UNHOLD:
 ast_channel_hold_state_set(chan, _condition);
 break;
 case AST_CONTROL_T38_PARAMETERS:
 t38_parameters = data;
 switch (t38_parameters->request_response) {
 case AST_T38_REQUEST_NEGOTIATE:
 case AST_T38_NEGOTIATED:
 ast_channel_set_is_t38_active_nolock(chan, 1);
 break;
 case AST_T38_REQUEST_TERMINATE:
 case AST_T38_TERMINATED:
 case AST_T38_REFUSED:
 ast_channel_set_is_t38_active_nolock(chan, 0);
 break;
 default:
 break;
 }
 break;
 default:
 break;
 }

 if (is_visible_indication(condition)) {
 /* A new visible indication is requested. */
 ast_channel_visible_indication_set(chan, _condition);
 } else if (condition == AST_CONTROL_UNHOLD || _condition < 0) {
 /* Visible indication is cleared/stopped. */
 ast_channel_visible_indication_set(chan, 0);
 }

 if (ast_channel_tech(chan)->indicate) {
 /* See if the channel driver can handle this condition. */
 res = ast_channel_tech(chan)->indicate(chan, _condition, data, datalen);
 } else {
 res = -1;
 }

 if (!res) {
 /* The channel driver successfully handled this indication */
 res = 0;
 return res;
 }

 /* The channel driver does not support this indication, let's fake
 * it by doing our own tone generation if applicable. */

 /*!\note If we compare the enumeration type, which does not have any
 * negative constants, the compiler may optimize this code away.
 * Therefore, we must perform an integer comparison here. */
 if (_condition < 0) {
 /* Stop any tones that are playing */
 ast_playtones_stop(chan);
 res = 0;
 return res;
 }

 /* Handle conditions that we have tones for. */
 switch (condition) {
 case _XXX_AST_CONTROL_T38:
 /* deprecated T.38 control frame */
 res = -1;
 return res;
 case AST_CONTROL_T38_PARAMETERS:
 /* there is no way to provide 'default' behavior for these
 * control frames, so we need to return failure, but there
 * is also no value in the log message below being emitted
 * since failure to handle these frames is not an 'error'
 * so just return right now. in addition, we want to return
 * whatever value the channel driver returned, in case it
 * has some meaning.*/
 return res;
 case AST_CONTROL_RINGING:
 ts = ast_get_indication_tone(ast_channel_zone(chan), "ring");
 /* It is common practice for channel drivers to return -1 if trying
 * to indicate ringing on a channel which is up. The idea is to let the
 * core generate the ringing inband. However, we don't want the
 * warning message about not being able to handle the specific indication
 * to print nor do we want ast_indicate_data to return an "error" for this
 * condition
 */
 if (ast_channel_state(chan) == AST_STATE_UP) {
 res = 0;
 }
 break;
 case AST_CONTROL_BUSY:
 ts = ast_get_indication_tone(ast_channel_zone(chan), "busy");
 break;
 case AST_CONTROL_INCOMPLETE:
 case AST_CONTROL_CONGESTION:
 ts = ast_get_indication_tone(ast_channel_zone(chan), "congestion");
 break;
 case AST_CONTROL_PVT_CAUSE_CODE:
 ast_channel_hangupcause_hash_set(chan, data, datalen);
 res = 0;
 break;
 case AST_CONTROL_PROGRESS:
 case AST_CONTROL_PROCEEDING:
 case AST_CONTROL_VIDUPDATE:
 case AST_CONTROL_SRCUPDATE:
 case AST_CONTROL_SRCCHANGE:
 case AST_CONTROL_RADIO_KEY:
 case AST_CONTROL_RADIO_UNKEY:
 case AST_CONTROL_OPTION:
 case AST_CONTROL_WINK:
 case AST_CONTROL_FLASH:
 case AST_CONTROL_OFFHOOK:
 case AST_CONTROL_TAKEOFFHOOK:
 case AST_CONTROL_ANSWER:
 case AST_CONTROL_HANGUP:
 case AST_CONTROL_RING:
 case AST_CONTROL_HOLD:
 case AST_CONTROL_UNHOLD:
 case AST_CONTROL_TRANSFER:
 case AST_CONTROL_CONNECTED_LINE:
 case AST_CONTROL_REDIRECTING:
 case AST_CONTROL_CC:
 case AST_CONTROL_READ_ACTION:
 case AST_CONTROL_AOC:
 case AST_CONTROL_END_OF_Q:
 case AST_CONTROL_MCID:
 case AST_CONTROL_MASQUERADE_NOTIFY:
 case AST_CONTROL_UPDATE_RTP_PEER:
 case AST_CONTROL_STREAM_TOPOLOGY_REQUEST_CHANGE:
 case AST_CONTROL_STREAM_TOPOLOGY_CHANGED:
 case AST_CONTROL_STREAM_TOPOLOGY_SOURCE_CHANGED:
 case AST_CONTROL_STREAM_STOP:
 case AST_CONTROL_STREAM_SUSPEND:
 case AST_CONTROL_STREAM_REVERSE:
 case AST_CONTROL_STREAM_FORWARD:
 case AST_CONTROL_STREAM_RESTART:
 case AST_CONTROL_RECORD_CANCEL:
 case AST_CONTROL_RECORD_STOP:
 case AST_CONTROL_RECORD_SUSPEND:
 case AST_CONTROL_RECORD_MUTE:
 /* Nothing left to do for these. */
 res = 0;
 break;
 }

 if (ts) {
 /* We have a tone to play, yay. */
 ast_debug(1, "Driver for channel '%s' does not support indication %u, emulating it\n", ast_channel_name(chan), condition);
 res = ast_playtones_start(chan, 0, ts->data, 1);
 if (!res) {
 ast_test_suite_event_notify("RINGING_INBAND",
 "Channel: %s\r\n",
 ast_channel_name(chan));
 }
 ts = ast_tone_zone_sound_unref(ts);
 }

 if (res) {
 /* not handled */
 ast_log(LOG_WARNING, "Unable to handle indication %u for '%s'\n", condition, ast_channel_name(chan));
 }

 return res;
}

int ast_indicate_data(struct ast_channel *chan, int _condition, const void *data, size_t datalen)
{
 int res;
 /* this frame is used by framehooks. if it is set, we must free it at the end of this function */
 struct ast_frame *awesome_frame = NULL;

 ast_channel_lock(chan);

 /* Don't bother if the channel is about to go away, anyway. */
 if ((ast_test_flag(ast_channel_flags(chan), AST_FLAG_ZOMBIE)
 || (ast_check_hangup(chan) && !ast_channel_is_leaving_bridge(chan)))
 && _condition != AST_CONTROL_MASQUERADE_NOTIFY) {
 res = -1;
 goto indicate_cleanup;
 }

 if (!ast_framehook_list_is_empty(ast_channel_framehooks(chan))) {
 /* Do framehooks now, do it, go, go now */
 struct ast_frame frame = {
 .frametype = AST_FRAME_CONTROL,
 .subclass.integer = _condition,
 .data.ptr = (void *) data, /* this cast from const is only okay because we do the ast_frdup below */
 .datalen = datalen
 };

 /* we have now committed to freeing this frame */
 awesome_frame = ast_frdup(&frame);

 /* who knows what we will get back! the anticipation is killing me. */
 awesome_frame = ast_framehook_list_write_event(ast_channel_framehooks(chan),
 awesome_frame);
 if (!awesome_frame
 || awesome_frame->frametype != AST_FRAME_CONTROL) {
 res = 0;
 goto indicate_cleanup;
 }

 _condition = awesome_frame->subclass.integer;
 data = awesome_frame->data.ptr;
 datalen = awesome_frame->datalen;
 }

 res = indicate_data_internal(chan, _condition, data, datalen);

indicate_cleanup:
 ast_channel_unlock(chan);
 if (awesome_frame) {
 ast_frfree(awesome_frame);
 }

 return res;
}

int ast_recvchar(struct ast_channel *chan, int timeout)
{
 int c;
 char *buf = ast_recvtext(chan, timeout);
 if (buf == NULL)
 return -1; /* error or timeout */
 c = *(unsigned char *)buf;
 ast_free(buf);
 return c;
}

char *ast_recvtext(struct ast_channel *chan, int timeout)
{
 int res;
 char *buf = NULL;
 struct timeval start = ast_tvnow();
 int ms;

 while ((ms = ast_remaining_ms(start, timeout))) {
 struct ast_frame *f;

 if (ast_check_hangup(chan)) {
 break;
 }
 res = ast_waitfor(chan, ms);
 if (res <= 0) {/* timeout or error */
 break;
 }
 f = ast_read(chan);
 if (f == NULL) {
 break; /* no frame */
 }
 if (f->frametype == AST_FRAME_CONTROL && f->subclass.integer == AST_CONTROL_HANGUP) {
 ast_frfree(f);
 break;
 } else if (f->frametype == AST_FRAME_TEXT) { /* what we want */
 buf = ast_strndup((char *) f->data.ptr, f->datalen); /* dup and break */
 ast_frfree(f);
 break;
 }
 ast_frfree(f);
 }
 return buf;
}

int ast_sendtext_data(struct ast_channel *chan, struct ast_msg_data *msg)
{
 int res = 0;
 const char *body = ast_msg_data_get_attribute(msg, AST_MSG_DATA_ATTR_BODY);
 const char *content_type = ast_msg_data_get_attribute(msg, AST_MSG_DATA_ATTR_CONTENT_TYPE);

 ast_channel_lock(chan);
 /* Stop if we're a zombie or need a soft hangup */
 if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_ZOMBIE) || ast_check_hangup(chan)) {
 ast_channel_unlock(chan);
 return -1;
 }

 CHECK_BLOCKING(chan);
 if (ast_channel_tech(chan)->write_text
 && (ast_strlen_zero(content_type) || ast_begins_with(content_type, "text/"))
 && (ast_format_cap_has_type(ast_channel_nativeformats(chan), AST_MEDIA_TYPE_TEXT))) {
 struct ast_frame f;
 /* T.140 payload does not include the null byte terminator */
 size_t body_len = strlen(body);

 /* Process as T.140 text (moved here from ast_sendtext() */
 memset(&f, 0, sizeof(f));
 f.src = "DIALPLAN";
 f.subclass.format = ast_format_t140;
 f.frametype = AST_FRAME_TEXT;
 f.datalen = body_len;
 f.mallocd = AST_MALLOCD_DATA;
 f.data.ptr = ast_strdup(body);
 if (f.data.ptr) {
 res = ast_channel_tech(chan)->write_text(chan, &f);
 } else {
 res = -1;
 }
 ast_frfree(&f);
 } else if ((ast_channel_tech(chan)->properties & AST_CHAN_TP_SEND_TEXT_DATA)
 && ast_channel_tech(chan)->send_text_data) {
 /* Send enhanced message to a channel driver that supports it */
 ast_debug(1, "Sending TEXT_DATA from '%s' to %s:%s %s\n",
 ast_msg_data_get_attribute(msg, AST_MSG_DATA_ATTR_FROM),
 ast_msg_data_get_attribute(msg, AST_MSG_DATA_ATTR_TO),
 ast_channel_name(chan), body);
 res = ast_channel_tech(chan)->send_text_data(chan, msg);
 } else if (ast_channel_tech(chan)->send_text
 && (ast_strlen_zero(content_type) || ast_begins_with(content_type, "text/"))) {
 /* Send the body of an enhanced message to a channel driver that supports only a char str */
 ast_debug(1, "Sending TEXT to %s: %s\n", ast_channel_name(chan), body);
 res = ast_channel_tech(chan)->send_text(chan, body);
 } else {
 ast_debug(1, "Channel technology does not support sending content type '%s' on channel '%s'\n",
 S_OR(content_type, "text/plain"), ast_channel_name(chan));
 res = -1;
 }
 ast_clear_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING);
 ast_channel_unlock(chan);
 return res;
}

int ast_sendtext(struct ast_channel *chan, const char *text)
{
 struct ast_msg_data *msg;
 int rc;
 struct ast_msg_data_attribute attrs[] =
 {
 {
 .type = AST_MSG_DATA_ATTR_BODY,
 .value = (char *)text,
 }
 };

 if (ast_strlen_zero(text)) {
 return 0;
 }

 msg = ast_msg_data_alloc(AST_MSG_DATA_SOURCE_TYPE_UNKNOWN, attrs, ARRAY_LEN(attrs));
 if (!msg) {
 return -1;
 }
 rc = ast_sendtext_data(chan, msg);
 ast_free(msg);

 return rc;
}

int ast_senddigit_mf_begin(struct ast_channel *chan, char digit)
{
 static const char * const mf_tones[] = {
 "1300+1500", /* 0 */
 "700+900", /* 1 */
 "700+1100", /* 2 */
 "900+1100", /* 3 */
 "700+1300", /* 4 */
 "900+1300", /* 5 */
 "1100+1300", /* 6 */
 "700+1500", /* 7 */
 "900+1500", /* 8 */
 "1100+1500", /* 9 */