channel_internal_api.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2012, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * 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 Accessor API
 *
 * This file is intended to be the only file that ever accesses the
 * internals of an ast_channel. All other files should use the
 * accessor functions defined here.
 *
 * \author Terry Wilson
 */
 
/*** MODULEINFO
    <support_level>core</support_level>
 ***/
 
#include "asterisk.h"
 
#include <unistd.h>
#include <fcntl.h>
 
#include "asterisk/alertpipe.h"
#include "asterisk/paths.h"
#include "asterisk/channel.h"
#include "asterisk/channel_internal.h"
#include "asterisk/endpoints.h"
#include "asterisk/indications.h"
#include "asterisk/stasis_channels.h"
#include "asterisk/stasis_endpoints.h"
#include "asterisk/stringfields.h"
#include "asterisk/stream.h"
#include "asterisk/test.h"
#include "asterisk/vector.h"
 
/*!
 * \brief Channel UniqueId structure
 * \note channel creation time used for determining LinkedId Propagation
 */
struct ast_channel_id {
    time_t creation_time;               /*!< Creation time */
    int creation_unique;                /*!< sub-second unique value */
    char unique_id[AST_MAX_UNIQUEID];   /*!< Unique Identifier */
    char tenant_id[AST_MAX_TENANT_ID];  /*!< Multi-tenant identifier */
};
 
/*!
 * \brief Main Channel structure associated with a channel.
 *
 * \note When adding fields to this structure, it is important to add the field
 *       'in position' with like-aligned fields, so as to keep the compiler from
 *       having to add padding to align fields. The structure's fields are sorted
 *       in this order: pointers, structures, long, int/enum, short, char. This
 *       is especially important on 64-bit architectures, where mixing 4-byte
 *       and 8-byte fields causes 4 bytes of padding to be added before many
 *       8-byte fields.
 */
struct ast_channel {
    const struct ast_channel_tech *tech;        /*!< Technology (point to channel driver) */
    void *tech_pvt;                 /*!< Private data used by the technology driver */
    void *music_state;              /*!< Music State*/
    void *generatordata;                /*!< Current generator data if there is any */
    struct ast_generator *generator;        /*!< Current active data generator */
    struct ast_channel *masq;           /*!< Channel that will masquerade as us */
    struct ast_channel *masqr;          /*!< Who we are masquerading as */
    const char *blockproc;              /*!< Procedure causing blocking */
    const char *appl;               /*!< Current application */
    const char *data;               /*!< Data passed to current application */
    struct ast_sched_context *sched;                /*!< Schedule context */
    struct ast_filestream *stream;          /*!< Stream itself. */
    struct ast_filestream *vstream;         /*!< Video Stream itself. */
    ast_timing_func_t timingfunc;
    void *timingdata;
    struct ast_pbx *pbx;                /*!< PBX private structure for this channel */
    struct ast_trans_pvt *writetrans;       /*!< Write translation path */
    struct ast_trans_pvt *readtrans;        /*!< Read translation path */
    struct ast_audiohook_list *audiohooks;
    struct ast_framehook_list *framehooks;
    struct ast_cdr *cdr;                /*!< Call Detail Record */
    struct ast_tone_zone *zone;         /*!< Tone zone as set in indications.conf or
                             *   in the CHANNEL dialplan function */
    ast_callid callid;          /*!< Bound call identifier pointer */
    struct ao2_container *dialed_causes;        /*!< Contains tech-specific and Asterisk cause data from dialed channels */
 
    AST_DECLARE_STRING_FIELDS(
        AST_STRING_FIELD(name);         /*!< ASCII unique channel name */
        AST_STRING_FIELD(language);     /*!< Language requested for voice prompts */
        AST_STRING_FIELD(musicclass);   /*!< Default music class */
        AST_STRING_FIELD(latest_musicclass);   /*!< Latest active music class */
        AST_STRING_FIELD(accountcode);  /*!< Account code for billing */
        AST_STRING_FIELD(peeraccount);  /*!< Peer account code for billing */
        AST_STRING_FIELD(userfield);    /*!< Userfield for CEL billing */
        AST_STRING_FIELD(call_forward); /*!< Where to forward to if asked to dial on this interface */
        AST_STRING_FIELD(parkinglot);   /*! Default parking lot, if empty, default parking lot  */
        AST_STRING_FIELD(hangupsource); /*! Who is responsible for hanging up this channel */
        AST_STRING_FIELD(dialcontext);  /*!< Dial: Extension context that we were called from */
    );
 
    struct ast_channel_id uniqueid;     /*!< Unique Channel Identifier - can be specified on creation */
    struct ast_channel_id linkedid;     /*!< Linked Channel Identifier - oldest propagated when bridged */
 
    struct timeval whentohangup; /*!< Non-zero, set to actual time when channel is to be hung up */
    pthread_t blocker;           /*!< If anyone is blocking, this is them */
 
    /*!
     * \brief Dialed/Called information.
     * \note Set on incoming channels to indicate the originally dialed party.
     * \note Dialed Number Identifier (DNID)
     */
    struct ast_party_dialed dialed;
 
    /*!
     * \brief Channel Caller ID information.
     * \note The caller id information is the caller id of this
     * channel when it is used to initiate a call.
     */
    struct ast_party_caller caller;
 
    /*!
     * \brief Channel Connected Line ID information.
     * \note The connected line information identifies the channel
     * connected/bridged to this channel.
     */
    struct ast_party_connected_line connected;
 
    /*!
     * \brief Channel Connected Line ID information that was last indicated.
     */
    struct ast_party_connected_line connected_indicated;
 
    /*! \brief Redirecting/Diversion information */
    struct ast_party_redirecting redirecting;
 
    struct ast_frame dtmff;             /*!< DTMF frame */
    struct varshead varshead;           /*!< A linked list for channel variables. See \ref AstChanVar */
    ast_group_t callgroup;              /*!< Call group for call pickups */
    ast_group_t pickupgroup;            /*!< Pickup group - which calls groups can be picked up? */
    struct ast_namedgroups *named_callgroups;   /*!< Named call group for call pickups */
    struct ast_namedgroups *named_pickupgroups; /*!< Named pickup group - which call groups can be picked up? */
    struct timeval creationtime;            /*!< The time of channel creation */
    struct timeval answertime;              /*!< The time the channel was answered */
    struct ast_readq_list readq;
    struct ast_jb jb;               /*!< The jitterbuffer state */
    struct timeval dtmf_tv;             /*!< The time that an in process digit began, or the last digit ended */
    struct ast_hangup_handler_list hangup_handlers;/*!< Hangup handlers on the channel. */
    struct ast_datastore_list datastores; /*!< Data stores on the channel */
    struct ast_autochan_list autochans; /*!< Autochans on the channel */
    unsigned long insmpl;               /*!< Track the read/written samples for monitor use */
    unsigned long outsmpl;              /*!< Track the read/written samples for monitor use */
 
    int blocker_tid;                    /*!< If anyone is blocking, this is their thread id */
    AST_VECTOR(, int) fds;              /*!< File descriptors for channel -- Drivers will poll on
                             *   these file descriptors, so at least one must be non -1.
                             *   See \arg \ref AstFileDesc */
    int softhangup;             /*!< Whether or not we have been hung up...  Do not set this value
                             *   directly, use ast_softhangup() */
    int fdno;                   /*!< Which fd had an event detected on */
    int streamid;                   /*!< For streaming playback, the schedule ID */
    int vstreamid;                  /*!< For streaming video playback, the schedule ID */
    struct ast_format *oldwriteformat;  /*!< Original writer format */
    int timingfd;                   /*!< Timing fd */
    enum ast_channel_state state;           /*!< State of line -- Don't write directly, use ast_setstate() */
    int rings;                  /*!< Number of rings so far */
    int priority;                   /*!< Dialplan: Current extension priority */
    int amaflags;                   /*!< Set BEFORE PBX is started to determine AMA flags */
    enum ast_channel_adsicpe adsicpe;       /*!< Whether or not ADSI is detected on CPE */
    unsigned int fin;               /*!< Frames in counters. The high bit is a debug mask, so
                             *   the counter is only in the remaining bits */
    unsigned int fout;              /*!< Frames out counters. The high bit is a debug mask, so
                             *   the counter is only in the remaining bits */
    int hangupcause;                /*!< Why is the channel hanged up. See causes.h */
    unsigned int finalized:1;       /*!< Whether or not the channel has been successfully allocated */
    struct ast_flags flags;             /*!< channel flags of AST_FLAG_ type */
    int alertpipe[2];
    struct ast_format_cap *nativeformats;         /*!< Kinds of data this channel can natively handle */
    struct ast_format *readformat;            /*!< Requested read format (after translation) */
    struct ast_format *writeformat;           /*!< Requested write format (before translation) */
    struct ast_format *rawreadformat;         /*!< Raw read format (before translation) */
    struct ast_format *rawwriteformat;        /*!< Raw write format (after translation) */
    unsigned int emulate_dtmf_duration;     /*!< Number of ms left to emulate DTMF for */
    int visible_indication;                         /*!< Indication currently playing on the channel */
    int hold_state;                         /*!< Current Hold/Unhold state */
 
    unsigned short transfercapability;      /*!< ISDN Transfer Capability - AST_FLAG_DIGITAL is not enough */
 
    struct ast_bridge *bridge;                      /*!< Bridge this channel is participating in */
    struct ast_bridge_channel *bridge_channel;/*!< The bridge_channel this channel is linked with. */
    struct ast_timer *timer;            /*!< timer object that provided timingfd */
 
    char context[AST_MAX_CONTEXT];          /*!< Dialplan: Current extension context */
    char exten[AST_MAX_EXTENSION];          /*!< Dialplan: Current extension number */
    char lastcontext[AST_MAX_CONTEXT];      /*!< Dialplan: Previous extension context */
    char lastexten[AST_MAX_EXTENSION];      /*!< Dialplan: Previous extension number */
    char unbridged;                         /*!< non-zero if the bridge core needs to re-evaluate the current
                                             bridging technology which is in use by this channel's bridge. */
    char is_t38_active;                     /*!< non-zero if T.38 is active on this channel. */
    char dtmf_digit_to_emulate;         /*!< Digit being emulated */
    char sending_dtmf_digit;            /*!< Digit this channel is currently sending out. (zero if not sending) */
    struct timeval sending_dtmf_tv;     /*!< The time this channel started sending the current digit. (Invalid if sending_dtmf_digit is zero.) */
    struct stasis_topic *topic;     /*!< Topic for this channel */
    struct stasis_forward *channel_forward; /*!< Subscription for event forwarding to all channel topic */
    struct stasis_forward *endpoint_forward;    /*!< Subscription for event forwarding to endpoint's topic */
    struct ast_stream_topology *stream_topology; /*!< Stream topology */
    void *stream_topology_change_source; /*!< Source that initiated a stream topology change */
    struct ast_stream *default_streams[AST_MEDIA_TYPE_END]; /*!< Default streams indexed by media type */
    struct ast_channel_snapshot *snapshot; /*!< The current up to date snapshot of the channel */
    struct ast_flags snapshot_segment_flags; /*!< Flags regarding the segments of the snapshot */
};
 
/*! \brief The monotonically increasing integer counter for channel uniqueids */
static int uniqueint;
 
/* ACCESSORS */
 
#define DEFINE_STRINGFIELD_SETTERS_FOR(field, assert_on_null) \
void ast_channel_##field##_set(struct ast_channel *chan, const char *value) \
{ \
    if ((assert_on_null)) ast_assert(!ast_strlen_zero(value)); \
    if (!strcmp(value, chan->field)) return; \
    ast_string_field_set(chan, field, value); \
} \
  \
void ast_channel_##field##_build_va(struct ast_channel *chan, const char *fmt, va_list ap) \
{ \
    ast_string_field_build_va(chan, field, fmt, ap); \
} \
void ast_channel_##field##_build(struct ast_channel *chan, const char *fmt, ...) \
{ \
    va_list ap; \
    va_start(ap, fmt); \
    ast_channel_##field##_build_va(chan, fmt, ap); \
    va_end(ap); \
}
 
#define DEFINE_STRINGFIELD_SETTERS_AND_INVALIDATE_FOR(field, publish, assert_on_null, invalidate) \
void ast_channel_##field##_set(struct ast_channel *chan, const char *value) \
{ \
    if ((assert_on_null)) ast_assert(!ast_strlen_zero(value)); \
    if (!strcmp(value, chan->field)) return; \
    ast_string_field_set(chan, field, value); \
    ast_channel_snapshot_invalidate_segment(chan, invalidate); \
    if (publish && ast_channel_internal_is_finalized(chan)) ast_channel_publish_snapshot(chan); \
} \
  \
void ast_channel_##field##_build_va(struct ast_channel *chan, const char *fmt, va_list ap) \
{ \
    ast_string_field_build_va(chan, field, fmt, ap); \
    ast_channel_snapshot_invalidate_segment(chan, invalidate); \
    if (publish && ast_channel_internal_is_finalized(chan)) ast_channel_publish_snapshot(chan); \
} \
void ast_channel_##field##_build(struct ast_channel *chan, const char *fmt, ...) \
{ \
    va_list ap; \
    va_start(ap, fmt); \
    ast_channel_##field##_build_va(chan, fmt, ap); \
    va_end(ap); \
}
 
DEFINE_STRINGFIELD_SETTERS_AND_INVALIDATE_FOR(name, 0, 1, AST_CHANNEL_SNAPSHOT_INVALIDATE_BASE);
DEFINE_STRINGFIELD_SETTERS_AND_INVALIDATE_FOR(language, 1, 0, AST_CHANNEL_SNAPSHOT_INVALIDATE_BASE);
DEFINE_STRINGFIELD_SETTERS_FOR(musicclass, 0);
DEFINE_STRINGFIELD_SETTERS_FOR(latest_musicclass, 0);
DEFINE_STRINGFIELD_SETTERS_AND_INVALIDATE_FOR(accountcode, 1, 0, AST_CHANNEL_SNAPSHOT_INVALIDATE_BASE);
DEFINE_STRINGFIELD_SETTERS_AND_INVALIDATE_FOR(peeraccount, 1, 0, AST_CHANNEL_SNAPSHOT_INVALIDATE_PEER);
DEFINE_STRINGFIELD_SETTERS_AND_INVALIDATE_FOR(userfield, 0, 0, AST_CHANNEL_SNAPSHOT_INVALIDATE_BASE);
DEFINE_STRINGFIELD_SETTERS_FOR(call_forward, 0);
DEFINE_STRINGFIELD_SETTERS_FOR(parkinglot, 0);
DEFINE_STRINGFIELD_SETTERS_AND_INVALIDATE_FOR(hangupsource, 0, 0, AST_CHANNEL_SNAPSHOT_INVALIDATE_HANGUP);
DEFINE_STRINGFIELD_SETTERS_FOR(dialcontext, 0);
 
#define DEFINE_STRINGFIELD_GETTER_FOR(field) const char *ast_channel_##field(const struct ast_channel *chan) \
{ \
    return chan->field; \
}
 
DEFINE_STRINGFIELD_GETTER_FOR(name);
DEFINE_STRINGFIELD_GETTER_FOR(language);
DEFINE_STRINGFIELD_GETTER_FOR(musicclass);
DEFINE_STRINGFIELD_GETTER_FOR(latest_musicclass);
DEFINE_STRINGFIELD_GETTER_FOR(accountcode);
DEFINE_STRINGFIELD_GETTER_FOR(peeraccount);
DEFINE_STRINGFIELD_GETTER_FOR(userfield);
DEFINE_STRINGFIELD_GETTER_FOR(call_forward);
DEFINE_STRINGFIELD_GETTER_FOR(parkinglot);
DEFINE_STRINGFIELD_GETTER_FOR(hangupsource);
DEFINE_STRINGFIELD_GETTER_FOR(dialcontext);
 
const char *ast_channel_uniqueid(const struct ast_channel *chan)
{
    ast_assert(chan->uniqueid.unique_id[0] != '\0');
    return chan->uniqueid.unique_id;
}
 
const char *ast_channel_linkedid(const struct ast_channel *chan)
{
    ast_assert(chan->linkedid.unique_id[0] != '\0');
    return chan->linkedid.unique_id;
}
 
const char *ast_channel_tenantid(const struct ast_channel *chan)
{
    /* It's ok for tenantid to be empty, so no need to assert */
    return chan->linkedid.tenant_id;
}
 
void ast_channel_tenantid_set(struct ast_channel *chan, const char *value)
{
    if (ast_strlen_zero(value)) {
        return;
    }
    ast_copy_string(chan->linkedid.tenant_id, value, sizeof(chan->linkedid.tenant_id));
    ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_BASE);
}
 
const char *ast_channel_appl(const struct ast_channel *chan)
{
    return chan->appl;
}
void ast_channel_appl_set(struct ast_channel *chan, const char *value)
{
    chan->appl = value;
    ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_DIALPLAN);
}
const char *ast_channel_blockproc(const struct ast_channel *chan)
{
    return chan->blockproc;
}
void ast_channel_blockproc_set(struct ast_channel *chan, const char *value)
{
    chan->blockproc = value;
}
const char *ast_channel_data(const struct ast_channel *chan)
{
    return chan->data;
}
void ast_channel_data_set(struct ast_channel *chan, const char *value)
{
    chan->data = value;
    ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_DIALPLAN);
}
 
const char *ast_channel_context(const struct ast_channel *chan)
{
    return chan->context;
}
const char *ast_channel_lastcontext(const struct ast_channel *chan)
{
    return chan->lastcontext;
}
void ast_channel_context_set(struct ast_channel *chan, const char *value)
{
    if (!*chan->lastcontext || strcmp(value, chan->context)) {
        /* only copy to last context when it changes, unless it's empty to begin with */
        ast_copy_string(chan->lastcontext, chan->context, sizeof(chan->lastcontext));
    }
    ast_copy_string(chan->context, value, sizeof(chan->context));
    ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_DIALPLAN);
}
const char *ast_channel_exten(const struct ast_channel *chan)
{
    return chan->exten;
}
const char *ast_channel_lastexten(const struct ast_channel *chan)
{
    return chan->lastexten;
}
void ast_channel_exten_set(struct ast_channel *chan, const char *value)
{
    if (!*chan->lastexten || strcmp(value, chan->exten)) {
        /* only copy to last exten when it changes, unless it's empty to begin with */
        ast_copy_string(chan->lastexten, chan->exten, sizeof(chan->lastexten));
    }
    ast_copy_string(chan->exten, value, sizeof(chan->exten));
    ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_DIALPLAN);
}
 
char ast_channel_dtmf_digit_to_emulate(const struct ast_channel *chan)
{
    return chan->dtmf_digit_to_emulate;
}
void ast_channel_dtmf_digit_to_emulate_set(struct ast_channel *chan, char value)
{
    chan->dtmf_digit_to_emulate = value;
}
 
char ast_channel_sending_dtmf_digit(const struct ast_channel *chan)
{
    return chan->sending_dtmf_digit;
}
void ast_channel_sending_dtmf_digit_set(struct ast_channel *chan, char value)
{
    chan->sending_dtmf_digit = value;
}
 
struct timeval ast_channel_sending_dtmf_tv(const struct ast_channel *chan)
{
    return chan->sending_dtmf_tv;
}
void ast_channel_sending_dtmf_tv_set(struct ast_channel *chan, struct timeval value)
{
    chan->sending_dtmf_tv = value;
}
 
enum ama_flags ast_channel_amaflags(const struct ast_channel *chan)
{
    return chan->amaflags;
}
 
void ast_channel_amaflags_set(struct ast_channel *chan, enum ama_flags value)
{
    if (chan->amaflags == value) {
        return;
    }
    chan->amaflags = value;
    ast_channel_publish_snapshot(chan);
}
int ast_channel_fdno(const struct ast_channel *chan)
{
    return chan->fdno;
}
void ast_channel_fdno_set(struct ast_channel *chan, int value)
{
    chan->fdno = value;
}
int ast_channel_hangupcause(const struct ast_channel *chan)
{
    return chan->hangupcause;
}
void ast_channel_hangupcause_set(struct ast_channel *chan, int value)
{
    chan->hangupcause = value;
    ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_HANGUP);
}
int ast_channel_priority(const struct ast_channel *chan)
{
    return chan->priority;
}
void ast_channel_priority_set(struct ast_channel *chan, int value)
{
    chan->priority = value;
    ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_DIALPLAN);
}
int ast_channel_rings(const struct ast_channel *chan)
{
    return chan->rings;
}
void ast_channel_rings_set(struct ast_channel *chan, int value)
{
    chan->rings = value;
}
int ast_channel_streamid(const struct ast_channel *chan)
{
    return chan->streamid;
}
void ast_channel_streamid_set(struct ast_channel *chan, int value)
{
    chan->streamid = value;
}
int ast_channel_timingfd(const struct ast_channel *chan)
{
    return chan->timingfd;
}
void ast_channel_timingfd_set(struct ast_channel *chan, int value)
{
    chan->timingfd = value;
}
int ast_channel_visible_indication(const struct ast_channel *chan)
{
    return chan->visible_indication;
}
void ast_channel_visible_indication_set(struct ast_channel *chan, int value)
{
    chan->visible_indication = value;
}
int ast_channel_hold_state(const struct ast_channel *chan)
{
    return chan->hold_state;
}
void ast_channel_hold_state_set(struct ast_channel *chan, int value)
{
    chan->hold_state = value;
}
int ast_channel_vstreamid(const struct ast_channel *chan)
{
    return chan->vstreamid;
}
void ast_channel_vstreamid_set(struct ast_channel *chan, int value)
{
    chan->vstreamid = value;
}
unsigned short ast_channel_transfercapability(const struct ast_channel *chan)
{
    return chan->transfercapability;
}
void ast_channel_transfercapability_set(struct ast_channel *chan, unsigned short value)
{
    chan->transfercapability = value;
}
unsigned int ast_channel_emulate_dtmf_duration(const struct ast_channel *chan)
{
    return chan->emulate_dtmf_duration;
}
void ast_channel_emulate_dtmf_duration_set(struct ast_channel *chan, unsigned int value)
{
    chan->emulate_dtmf_duration = value;
}
unsigned int ast_channel_fin(const struct ast_channel *chan)
{
    return chan->fin;
}
void ast_channel_fin_set(struct ast_channel *chan, unsigned int value)
{
    chan->fin = value;
}
unsigned int ast_channel_fout(const struct ast_channel *chan)
{
    return chan->fout;
}
void ast_channel_fout_set(struct ast_channel *chan, unsigned int value)
{
    chan->fout = value;
}
unsigned long ast_channel_insmpl(const struct ast_channel *chan)
{
    return chan->insmpl;
}
void ast_channel_insmpl_set(struct ast_channel *chan, unsigned long value)
{
    chan->insmpl = value;
}
unsigned long ast_channel_outsmpl(const struct ast_channel *chan)
{
    return chan->outsmpl;
}
void ast_channel_outsmpl_set(struct ast_channel *chan, unsigned long value)
{
    chan->outsmpl = value;
}
void *ast_channel_generatordata(const struct ast_channel *chan)
{
    return chan->generatordata;
}
void ast_channel_generatordata_set(struct ast_channel *chan, void *value)
{
    chan->generatordata = value;
}
void *ast_channel_music_state(const struct ast_channel *chan)
{
    return chan->music_state;
}
void ast_channel_music_state_set(struct ast_channel *chan, void *value)
{
    chan->music_state = value;
}
void *ast_channel_tech_pvt(const struct ast_channel *chan)
{
    return chan->tech_pvt;
}
void ast_channel_tech_pvt_set(struct ast_channel *chan, void *value)
{
    chan->tech_pvt = value;
    if (value != NULL) {
        ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_BASE);
    }
}
void *ast_channel_timingdata(const struct ast_channel *chan)
{
    return chan->timingdata;
}
void ast_channel_timingdata_set(struct ast_channel *chan, void *value)
{
    chan->timingdata = value;
}
struct ast_audiohook_list *ast_channel_audiohooks(const struct ast_channel *chan)
{
    return chan->audiohooks;
}
void ast_channel_audiohooks_set(struct ast_channel *chan, struct ast_audiohook_list *value)
{
    chan->audiohooks = value;
}
struct ast_cdr *ast_channel_cdr(const struct ast_channel *chan)
{
    return chan->cdr;
}
void ast_channel_cdr_set(struct ast_channel *chan, struct ast_cdr *value)
{
    chan->cdr = value;
}
struct ast_channel *ast_channel_masq(const struct ast_channel *chan)
{
    return chan->masq;
}
void ast_channel_masq_set(struct ast_channel *chan, struct ast_channel *value)
{
    chan->masq = value;
}
struct ast_channel *ast_channel_masqr(const struct ast_channel *chan)
{
    return chan->masqr;
}
void ast_channel_masqr_set(struct ast_channel *chan, struct ast_channel *value)
{
    chan->masqr = value;
}
struct ast_filestream *ast_channel_stream(const struct ast_channel *chan)
{
    return chan->stream;
}
void ast_channel_stream_set(struct ast_channel *chan, struct ast_filestream *value)
{
    chan->stream = value;
}
struct ast_filestream *ast_channel_vstream(const struct ast_channel *chan)
{
    return chan->vstream;
}
void ast_channel_vstream_set(struct ast_channel *chan, struct ast_filestream *value)
{
    chan->vstream = value;
}
struct ast_format_cap *ast_channel_nativeformats(const struct ast_channel *chan)
{
    return chan->nativeformats;
}
 
static void channel_set_default_streams(struct ast_channel *chan)
{
    enum ast_media_type type;
 
    ast_assert(chan != NULL);
 
    for (type = AST_MEDIA_TYPE_UNKNOWN; type < AST_MEDIA_TYPE_END; type++) {
        if (chan->stream_topology) {
            chan->default_streams[type] =
                ast_stream_topology_get_first_stream_by_type(chan->stream_topology, type);
        } else {
            chan->default_streams[type] = NULL;
        }
    }
}
 
void ast_channel_internal_set_stream_topology(struct ast_channel *chan,
    struct ast_stream_topology *topology)
{
    ast_stream_topology_free(chan->stream_topology);
    chan->stream_topology = topology;
    channel_set_default_streams(chan);
}
 
void ast_channel_internal_set_stream_topology_change_source(
    struct ast_channel *chan, void *change_source)
{
    chan->stream_topology_change_source = change_source;
}
 
void *ast_channel_get_stream_topology_change_source(struct ast_channel *chan)
{
    return chan->stream_topology_change_source;
}
 
void ast_channel_nativeformats_set(struct ast_channel *chan,
    struct ast_format_cap *value)
{
    SCOPE_ENTER(2, "%s: %sFormats: %s\n", S_OR(ast_channel_name(chan), "<initializing>"),
        S_COR(ast_channel_is_multistream(chan), "Multistream", ""),
        ast_str_tmp(128, ast_format_cap_get_names(value, &STR_TMP)));
 
    ast_assert(chan != NULL);
 
    ao2_replace(chan->nativeformats, value);
 
    /* If chan->stream_topology is NULL, the channel is being destroyed
     * and topology is destroyed.
     */
    if (!chan->stream_topology) {
        SCOPE_EXIT_RTN("Channel is being initialized or destroyed\n");
    }
 
    if (!ast_channel_is_multistream(chan) || !value) {
        struct ast_stream_topology *new_topology;
 
        new_topology = ast_stream_topology_create_from_format_cap(value);
        ast_channel_internal_set_stream_topology(chan, new_topology);
        SCOPE_EXIT_RTN("New %stopology set\n", value ? "" : "empty ");
    }
    SCOPE_EXIT_RTN("Set native formats but not topology\n");
}
 
struct ast_framehook_list *ast_channel_framehooks(const struct ast_channel *chan)
{
    return chan->framehooks;
}
void ast_channel_framehooks_set(struct ast_channel *chan, struct ast_framehook_list *value)
{
    chan->framehooks = value;
}
struct ast_generator *ast_channel_generator(const struct ast_channel *chan)
{
    return chan->generator;
}
void ast_channel_generator_set(struct ast_channel *chan, struct ast_generator *value)
{
    chan->generator = value;
}
struct ast_pbx *ast_channel_pbx(const struct ast_channel *chan)
{
    return chan->pbx;
}
void ast_channel_pbx_set(struct ast_channel *chan, struct ast_pbx *value)
{
    chan->pbx = value;
}
struct ast_sched_context *ast_channel_sched(const struct ast_channel *chan)
{
    return chan->sched;
}
void ast_channel_sched_set(struct ast_channel *chan, struct ast_sched_context *value)
{
    chan->sched = value;
}
struct ast_timer *ast_channel_timer(const struct ast_channel *chan)
{
    return chan->timer;
}
void ast_channel_timer_set(struct ast_channel *chan, struct ast_timer *value)
{
    chan->timer = value;
}
struct ast_tone_zone *ast_channel_zone(const struct ast_channel *chan)
{
    return chan->zone;
}
void ast_channel_zone_set(struct ast_channel *chan, struct ast_tone_zone *value)
{
    chan->zone = value;
}
struct ast_trans_pvt *ast_channel_readtrans(const struct ast_channel *chan)
{
    return chan->readtrans;
}
void ast_channel_readtrans_set(struct ast_channel *chan, struct ast_trans_pvt *value)
{
    chan->readtrans = value;
}
struct ast_trans_pvt *ast_channel_writetrans(const struct ast_channel *chan)
{
    return chan->writetrans;
}
void ast_channel_writetrans_set(struct ast_channel *chan, struct ast_trans_pvt *value)
{
    chan->writetrans = value;
}
const struct ast_channel_tech *ast_channel_tech(const struct ast_channel *chan)
{
    return chan->tech;
}
void ast_channel_tech_set(struct ast_channel *chan, const struct ast_channel_tech *value)
{
    if (value->read_stream || value->write_stream) {
        ast_assert(value->read_stream && value->write_stream);
    }
 
    chan->tech = value;
}
enum ast_channel_adsicpe ast_channel_adsicpe(const struct ast_channel *chan)
{
    return chan->adsicpe;
}
void ast_channel_adsicpe_set(struct ast_channel *chan, enum ast_channel_adsicpe value)
{
    chan->adsicpe = value;
}
enum ast_channel_state ast_channel_state(const struct ast_channel *chan)
{
    return chan->state;
}
ast_callid ast_channel_callid(const struct ast_channel *chan)
{
    return chan->callid;
}
void ast_channel_callid_set(struct ast_channel *chan, ast_callid callid)
{
    char call_identifier_from[AST_CALLID_BUFFER_LENGTH];
    char call_identifier_to[AST_CALLID_BUFFER_LENGTH];
    call_identifier_from[0] = '\0';
    ast_callid_strnprint(call_identifier_to, sizeof(call_identifier_to), callid);
    if (chan->callid) {
        ast_callid_strnprint(call_identifier_from, sizeof(call_identifier_from), chan->callid);
        ast_debug(3, "Channel Call ID changing from %s to %s\n", call_identifier_from, call_identifier_to);
    }
 
    chan->callid = callid;
 
    ast_test_suite_event_notify("CallIDChange",
        "State: CallIDChange\r\n"
        "Channel: %s\r\n"
        "CallID: %s\r\n"
        "PriorCallID: %s",
        ast_channel_name(chan),
        call_identifier_to,
        call_identifier_from);
}
 
void ast_channel_state_set(struct ast_channel *chan, enum ast_channel_state value)
{
    chan->state = value;
}
void ast_channel_set_oldwriteformat(struct ast_channel *chan, struct ast_format *format)
{
    ao2_replace(chan->oldwriteformat, format);
}
void ast_channel_set_rawreadformat(struct ast_channel *chan, struct ast_format *format)
{
    ao2_replace(chan->rawreadformat, format);
}
void ast_channel_set_rawwriteformat(struct ast_channel *chan, struct ast_format *format)
{
    ao2_replace(chan->rawwriteformat, format);
}
void ast_channel_set_readformat(struct ast_channel *chan, struct ast_format *format)
{
    ao2_replace(chan->readformat, format);
}
void ast_channel_set_writeformat(struct ast_channel *chan, struct ast_format *format)
{
    ao2_replace(chan->writeformat, format);
}
struct ast_format *ast_channel_oldwriteformat(struct ast_channel *chan)
{
    return chan->oldwriteformat;
}
struct ast_format *ast_channel_rawreadformat(struct ast_channel *chan)
{
    return chan->rawreadformat;
}
struct ast_format *ast_channel_rawwriteformat(struct ast_channel *chan)
{
    return chan->rawwriteformat;
}
struct ast_format *ast_channel_readformat(struct ast_channel *chan)
{
    return chan->readformat;
}
struct ast_format *ast_channel_writeformat(struct ast_channel *chan)
{
    return chan->writeformat;
}
struct ast_hangup_handler_list *ast_channel_hangup_handlers(struct ast_channel *chan)
{
    return &chan->hangup_handlers;
}
struct ast_datastore_list *ast_channel_datastores(struct ast_channel *chan)
{
    return &chan->datastores;
}
struct ast_autochan_list *ast_channel_autochans(struct ast_channel *chan)
{
    return &chan->autochans;
}
struct ast_readq_list *ast_channel_readq(struct ast_channel *chan)
{
    return &chan->readq;
}
struct ast_frame *ast_channel_dtmff(struct ast_channel *chan)
{
    return &chan->dtmff;
}
struct ast_jb *ast_channel_jb(struct ast_channel *chan)
{
    return &chan->jb;
}
struct ast_party_caller *ast_channel_caller(struct ast_channel *chan)
{
    return &chan->caller;
}
struct ast_party_connected_line *ast_channel_connected(struct ast_channel *chan)
{
    return &chan->connected;
}
struct ast_party_connected_line *ast_channel_connected_indicated(struct ast_channel *chan)
{
    return &chan->connected_indicated;
}
struct ast_party_id ast_channel_connected_effective_id(struct ast_channel *chan)
{
    return ast_party_id_merge(&chan->connected.id, &chan->connected.priv);
}
struct ast_party_dialed *ast_channel_dialed(struct ast_channel *chan)
{
    return &chan->dialed;
}
struct ast_party_redirecting *ast_channel_redirecting(struct ast_channel *chan)
{
    return &chan->redirecting;
}
struct ast_party_id ast_channel_redirecting_effective_orig(struct ast_channel *chan)
{
    return ast_party_id_merge(&chan->redirecting.orig, &chan->redirecting.priv_orig);
}
struct ast_party_id ast_channel_redirecting_effective_from(struct ast_channel *chan)
{
    return ast_party_id_merge(&chan->redirecting.from, &chan->redirecting.priv_from);
}
struct ast_party_id ast_channel_redirecting_effective_to(struct ast_channel *chan)
{
    return ast_party_id_merge(&chan->redirecting.to, &chan->redirecting.priv_to);
}
struct timeval *ast_channel_dtmf_tv(struct ast_channel *chan)
{
    return &chan->dtmf_tv;
}
struct timeval *ast_channel_whentohangup(struct ast_channel *chan)
{
    return &chan->whentohangup;
}
struct varshead *ast_channel_varshead(struct ast_channel *chan)
{
    return &chan->varshead;
}
void ast_channel_dtmff_set(struct ast_channel *chan, struct ast_frame *value)
{
    chan->dtmff = *value;
}
void ast_channel_jb_set(struct ast_channel *chan, struct ast_jb *value)
{
    chan->jb = *value;
}
void ast_channel_caller_set(struct ast_channel *chan, struct ast_party_caller *value)
{
    chan->caller = *value;
    ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_CALLER);
}
void ast_channel_connected_set(struct ast_channel *chan, struct ast_party_connected_line *value)
{
    chan->connected = *value;
    ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_CONNECTED);
}
void ast_channel_dialed_set(struct ast_channel *chan, struct ast_party_dialed *value)
{
    chan->dialed = *value;
    ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_CALLER);
}
void ast_channel_redirecting_set(struct ast_channel *chan, struct ast_party_redirecting *value)
{
    chan->redirecting = *value;
    ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_CALLER);
}
void ast_channel_dtmf_tv_set(struct ast_channel *chan, struct timeval *value)
{
    chan->dtmf_tv = *value;
}
void ast_channel_whentohangup_set(struct ast_channel *chan, struct timeval *value)
{
    chan->whentohangup = *value;
}
void ast_channel_varshead_set(struct ast_channel *chan, struct varshead *value)
{
    chan->varshead = *value;
}
struct timeval ast_channel_creationtime(struct ast_channel *chan)
{
    return chan->creationtime;
}
void ast_channel_creationtime_set(struct ast_channel *chan, struct timeval *value)
{
    chan->creationtime = *value;
    ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_BASE);
}
 
struct timeval ast_channel_answertime(struct ast_channel *chan)
{
    return chan->answertime;
}
 
void ast_channel_answertime_set(struct ast_channel *chan, struct timeval *value)
{
    chan->answertime = *value;
}
 
/* Evil softhangup accessors */
int ast_channel_softhangup_internal_flag(struct ast_channel *chan)
{
    return chan->softhangup;
}
void ast_channel_softhangup_internal_flag_set(struct ast_channel *chan, int value)
{
    chan->softhangup = value;
}
void ast_channel_softhangup_internal_flag_add(struct ast_channel *chan, int value)
{
    chan->softhangup |= value;
}
void ast_channel_softhangup_internal_flag_clear(struct ast_channel *chan, int value)
{
    chan ->softhangup &= ~value;
}
 
int ast_channel_unbridged_nolock(struct ast_channel *chan)
{
    return chan->unbridged;
}
 
int ast_channel_unbridged(struct ast_channel *chan)
{
    int res;
    ast_channel_lock(chan);
    res = ast_channel_unbridged_nolock(chan);
    ast_channel_unlock(chan);
    return res;
}
 
void ast_channel_set_unbridged_nolock(struct ast_channel *chan, int value)
{
    chan->unbridged = !!value;
    ast_queue_frame(chan, &ast_null_frame);
}
 
void ast_channel_set_unbridged(struct ast_channel *chan, int value)
{
    ast_channel_lock(chan);
    ast_channel_set_unbridged_nolock(chan, value);
    ast_channel_unlock(chan);
}
 
int ast_channel_is_t38_active_nolock(struct ast_channel *chan)
{
    return chan->is_t38_active;
}
 
int ast_channel_is_t38_active(struct ast_channel *chan)
{
    int res;
 
    ast_channel_lock(chan);
    res = ast_channel_is_t38_active_nolock(chan);
    ast_channel_unlock(chan);
    return res;
}
 
void ast_channel_set_is_t38_active_nolock(struct ast_channel *chan, int is_t38_active)
{
    chan->is_t38_active = !!is_t38_active;
}
 
void ast_channel_set_is_t38_active(struct ast_channel *chan, int is_t38_active)
{
    ast_channel_lock(chan);
    ast_channel_set_is_t38_active_nolock(chan, is_t38_active);
    ast_channel_unlock(chan);
}
 
void ast_channel_callid_cleanup(struct ast_channel *chan)
{
    chan->callid = 0;
}
 
/* Typedef accessors */
ast_group_t ast_channel_callgroup(const struct ast_channel *chan)
{
    return chan->callgroup;
}
void ast_channel_callgroup_set(struct ast_channel *chan, ast_group_t value)
{
    chan->callgroup = value;
}
ast_group_t ast_channel_pickupgroup(const struct ast_channel *chan)
{
    return chan->pickupgroup;
}
void ast_channel_pickupgroup_set(struct ast_channel *chan, ast_group_t value)
{
    chan->pickupgroup = value;
}
struct ast_namedgroups *ast_channel_named_callgroups(const struct ast_channel *chan)
{
    return chan->named_callgroups;
}
void ast_channel_named_callgroups_set(struct ast_channel *chan, struct ast_namedgroups *value)
{
    ast_unref_namedgroups(chan->named_callgroups);
    chan->named_callgroups = ast_ref_namedgroups(value);
}
struct ast_namedgroups *ast_channel_named_pickupgroups(const struct ast_channel *chan)
{
    return chan->named_pickupgroups;
}
void ast_channel_named_pickupgroups_set(struct ast_channel *chan, struct ast_namedgroups *value)
{
    ast_unref_namedgroups(chan->named_pickupgroups);
    chan->named_pickupgroups = ast_ref_namedgroups(value);
}
 
/* Alertpipe functions */
int ast_channel_alert_write(struct ast_channel *chan)
{
    return ast_alertpipe_write(chan->alertpipe);
}
 
ast_alert_status_t ast_channel_internal_alert_flush(struct ast_channel *chan)
{
    return ast_alertpipe_flush(chan->alertpipe);
}
 
ast_alert_status_t ast_channel_internal_alert_read(struct ast_channel *chan)
{
    return ast_alertpipe_read(chan->alertpipe);
}
 
int ast_channel_alert_writable(struct ast_channel *chan)
{
    return ast_alertpipe_writable(chan->alertpipe);
}
 
int ast_channel_internal_alert_readable(struct ast_channel *chan)
{
    return ast_alertpipe_readable(chan->alertpipe);
}
 
void ast_channel_internal_alertpipe_clear(struct ast_channel *chan)
{
    ast_alertpipe_clear(chan->alertpipe);
}
 
void ast_channel_internal_alertpipe_close(struct ast_channel *chan)
{
    ast_alertpipe_close(chan->alertpipe);
}
 
int ast_channel_internal_alertpipe_init(struct ast_channel *chan)
{
    return ast_alertpipe_init(chan->alertpipe);
}
 
int ast_channel_internal_alert_readfd(struct ast_channel *chan)
{
    return ast_alertpipe_readfd(chan->alertpipe);
}
 
void ast_channel_internal_alertpipe_swap(struct ast_channel *chan1, struct ast_channel *chan2)
{
    ast_alertpipe_swap(chan1->alertpipe, chan2->alertpipe);
}
 
/* file descriptor array accessors */
void ast_channel_internal_fd_set(struct ast_channel *chan, int which, int value)
{
    int pos;
 
    /* This ensures that if the vector has to grow with unused positions they will be
     * initialized to -1.
     */
    for (pos = AST_VECTOR_SIZE(&chan->fds); pos < which; pos++) {
        AST_VECTOR_REPLACE(&chan->fds, pos, -1);
    }
 
    AST_VECTOR_REPLACE(&chan->fds, which, value);
}
void ast_channel_internal_fd_clear(struct ast_channel *chan, int which)
{
    if (which >= AST_VECTOR_SIZE(&chan->fds)) {
        return;
    }
 
    AST_VECTOR_REPLACE(&chan->fds, which, -1);
}
void ast_channel_internal_fd_clear_all(struct ast_channel *chan)
{
    AST_VECTOR_RESET(&chan->fds, AST_VECTOR_ELEM_CLEANUP_NOOP);
}
int ast_channel_fd(const struct ast_channel *chan, int which)
{
    return (which >= AST_VECTOR_SIZE(&chan->fds)) ? -1 : AST_VECTOR_GET(&chan->fds, which);
}
int ast_channel_fd_isset(const struct ast_channel *chan, int which)
{
    return ast_channel_fd(chan, which) > -1;
}
 
int ast_channel_fd_count(const struct ast_channel *chan)
{
    return AST_VECTOR_SIZE(&chan->fds);
}
 
int ast_channel_fd_add(struct ast_channel *chan, int value)
{
    int pos = AST_EXTENDED_FDS;
 
    while (ast_channel_fd_isset(chan, pos)) {
        pos += 1;
    }
 
    AST_VECTOR_REPLACE(&chan->fds, pos, value);
 
    return pos;
}
 
pthread_t ast_channel_blocker(const struct ast_channel *chan)
{
    return chan->blocker;
}
void ast_channel_blocker_set(struct ast_channel *chan, pthread_t value)
{
    chan->blocker = value;
}
 
int ast_channel_blocker_tid(const struct ast_channel *chan)
{
    return chan->blocker_tid;
}
void ast_channel_blocker_tid_set(struct ast_channel *chan, int value)
{
    chan->blocker_tid = value;
}
 
ast_timing_func_t ast_channel_timingfunc(const struct ast_channel *chan)
{
    return chan->timingfunc;
}
void ast_channel_timingfunc_set(struct ast_channel *chan, ast_timing_func_t value)
{
    chan->timingfunc = value;
}
 
struct ast_bridge *ast_channel_internal_bridge(const struct ast_channel *chan)
{
    return chan->bridge;
}
void ast_channel_internal_bridge_set(struct ast_channel *chan, struct ast_bridge *value)
{
    chan->bridge = value;
    ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_BRIDGE);
    ast_channel_publish_snapshot(chan);
}
 
struct ast_bridge_channel *ast_channel_internal_bridge_channel(const struct ast_channel *chan)
{
    return chan->bridge_channel;
}
void ast_channel_internal_bridge_channel_set(struct ast_channel *chan, struct ast_bridge_channel *value)
{
    chan->bridge_channel = value;
}
 
struct ast_flags *ast_channel_flags(struct ast_channel *chan)
{
    return &chan->flags;
}
 
static int collect_names_cb(void *obj, void *arg, int flags)
{
    struct ast_control_pvt_cause_code *cause_code = obj;
    struct ast_str **str = arg;
 
    ast_str_append(str, 0, "%s%s", (ast_str_strlen(*str) ? "," : ""), cause_code->chan_name);
 
    return 0;
}
 
struct ast_str *ast_channel_dialed_causes_channels(const struct ast_channel *chan)
{
    struct ast_str *chanlist = ast_str_create(128);
 
    if (!chanlist) {
        return NULL;
    }
 
    ao2_callback(chan->dialed_causes, 0, collect_names_cb, &chanlist);
 
    return chanlist;
}
 
struct ast_control_pvt_cause_code *ast_channel_dialed_causes_find(const struct ast_channel *chan, const char *chan_name)
{
    return ao2_find(chan->dialed_causes, chan_name, OBJ_KEY);
}
 
int ast_channel_dialed_causes_add(const struct ast_channel *chan, const struct ast_control_pvt_cause_code *cause_code, int datalen)
{
    struct ast_control_pvt_cause_code *ao2_cause_code;
    ao2_find(chan->dialed_causes, cause_code->chan_name, OBJ_KEY | OBJ_UNLINK | OBJ_NODATA);
    ao2_cause_code = ao2_alloc(datalen, NULL);
 
    if (ao2_cause_code) {
        memcpy(ao2_cause_code, cause_code, datalen);
        ao2_link(chan->dialed_causes, ao2_cause_code);
        ao2_ref(ao2_cause_code, -1);
        return 0;
    } else {
        return -1;
    }
}
 
void ast_channel_dialed_causes_clear(const struct ast_channel *chan)
{
    ao2_callback(chan->dialed_causes, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL, NULL);
}
 
/*! \brief Hash function for pvt cause code frames */
static int pvt_cause_hash_fn(const void *vpc, const int flags)
{
    const struct ast_control_pvt_cause_code *pc = vpc;
    return ast_str_hash(ast_tech_to_upper(ast_strdupa(pc->chan_name)));
}
 
/*! \brief Comparison function for pvt cause code frames */
static int pvt_cause_cmp_fn(void *obj, void *vstr, int flags)
{
    struct ast_control_pvt_cause_code *pc = obj;
    char *str = ast_tech_to_upper(ast_strdupa(vstr));
    char *pc_str = ast_tech_to_upper(ast_strdupa(pc->chan_name));
    return !strcmp(pc_str, str) ? CMP_MATCH | CMP_STOP : 0;
}
 
#define DIALED_CAUSES_BUCKETS 37
 
struct ast_channel *__ast_channel_internal_alloc_with_initializers(void (*destructor)(void *obj), const struct ast_assigned_ids *assignedids,
    const struct ast_channel *requestor, const struct ast_channel_initializers *initializers, const char *file, int line, const char *function)
{
    struct ast_channel *tmp;
 
    tmp = __ao2_alloc(sizeof(*tmp), destructor,
        AO2_ALLOC_OPT_LOCK_MUTEX, "", file, line, function);
 
    if (!tmp) {
        return NULL;
    }
 
    if ((ast_string_field_init(tmp, 128))) {
        return ast_channel_unref(tmp);
    }
 
    tmp->dialed_causes = ao2_container_alloc_hash(AO2_ALLOC_OPT_LOCK_MUTEX, 0,
        DIALED_CAUSES_BUCKETS, pvt_cause_hash_fn, NULL, pvt_cause_cmp_fn);
    if (!tmp->dialed_causes) {
        return ast_channel_unref(tmp);
    }
 
    /* Check initializers validity here for early abort. Unfortunately, we can't do much here because
     * tenant ID is part of linked ID, which would overwrite it further down. */
    if (initializers) {
        if (initializers->version == 0) {
            ast_log(LOG_ERROR, "Channel initializers must have a non-zero version.\n");
            return ast_channel_unref(tmp);
        } else if (initializers->version != AST_CHANNEL_INITIALIZERS_VERSION) {
            ast_log(LOG_ERROR, "ABI mismatch for ast_channel_initializers. "
                "Please ensure all modules were compiled for "
                "this version of Asterisk.\n");
            return ast_channel_unref(tmp);
        }
    }
 
    /* set the creation time in the uniqueid */
    tmp->uniqueid.creation_time = time(NULL);
    tmp->uniqueid.creation_unique = ast_atomic_fetchadd_int(&uniqueint, 1);
 
    /* use provided id or default to historical {system-}time.# format */
    if (assignedids && !ast_strlen_zero(assignedids->uniqueid)) {
        ast_copy_string(tmp->uniqueid.unique_id, assignedids->uniqueid, sizeof(tmp->uniqueid.unique_id));
    } else if (ast_strlen_zero(ast_config_AST_SYSTEM_NAME)) {
        snprintf(tmp->uniqueid.unique_id, sizeof(tmp->uniqueid.unique_id), "%li.%d",
            (long)(tmp->uniqueid.creation_time),
            tmp->uniqueid.creation_unique);
    } else {
        snprintf(tmp->uniqueid.unique_id, sizeof(tmp->uniqueid.unique_id), "%s-%li.%d",
            ast_config_AST_SYSTEM_NAME,
            (long)(tmp->uniqueid.creation_time),
            tmp->uniqueid.creation_unique);
    }
 
    /* copy linked id from parent channel if known */
    if (requestor) {
        tmp->linkedid = requestor->linkedid;
    } else {
        tmp->linkedid = tmp->uniqueid;
    }
 
    /* Things like tenant ID need to be set here, otherwise they would be overwritten by
     * things like inheriting linked ID above. */
    if (initializers) {
        ast_copy_string(tmp->linkedid.tenant_id, initializers->tenantid, sizeof(tmp->linkedid.tenant_id));
    }
 
    AST_VECTOR_INIT(&tmp->fds, AST_MAX_FDS);
 
    /* Force all channel snapshot segments to be created on first use, so we don't have to check if
     * an old snapshot exists.
     */
    ast_set_flag(&tmp->snapshot_segment_flags, AST_FLAGS_ALL);
 
    return tmp;
}
 
struct ast_channel *__ast_channel_internal_alloc(void (*destructor)(void *obj), const struct ast_assigned_ids *assignedids,
    const struct ast_channel *requestor, const char *file, int line, const char *function)
{
    return __ast_channel_internal_alloc_with_initializers(destructor, assignedids, requestor, NULL, file, line, function);
}
 
struct ast_channel *ast_channel_internal_oldest_linkedid(struct ast_channel *a, struct ast_channel *b)
{
    ast_assert(a->linkedid.creation_time != 0);
    ast_assert(b->linkedid.creation_time != 0);
 
    if (a->linkedid.creation_time < b->linkedid.creation_time) {
        return a;
    }
    if (b->linkedid.creation_time < a->linkedid.creation_time) {
        return b;
    }
    if (a->linkedid.creation_unique < b->linkedid.creation_unique) {
        return a;
    }
    return b;
}
 
void ast_channel_internal_copy_linkedid(struct ast_channel *dest, struct ast_channel *source)
{
    if (dest->linkedid.creation_time == source->linkedid.creation_time
        && dest->linkedid.creation_unique == source->linkedid.creation_unique
        && !strcmp(dest->linkedid.unique_id, source->linkedid.unique_id)) {
        return;
    }
    dest->linkedid = source->linkedid;
    ast_channel_snapshot_invalidate_segment(dest, AST_CHANNEL_SNAPSHOT_INVALIDATE_PEER);
    ast_channel_publish_snapshot(dest);
}
 
void ast_channel_internal_swap_uniqueid_and_linkedid(struct ast_channel *a, struct ast_channel *b)
{
    struct ast_channel_id temp;
 
    /* This operation is used as part of masquerading and so does not invalidate the peer
     * segment. This is due to the masquerade process invalidating all segments.
     */
 
    temp = a->uniqueid;
    a->uniqueid = b->uniqueid;
    b->uniqueid = temp;
 
    temp = a->linkedid;
    a->linkedid = b->linkedid;
    b->linkedid = temp;
}
 
void ast_channel_internal_swap_topics(struct ast_channel *a, struct ast_channel *b)
{
    struct stasis_topic *topic;
    struct stasis_forward *forward;
 
    topic = a->topic;
    a->topic = b->topic;
    b->topic = topic;
 
    forward = a->channel_forward;
    a->channel_forward = b->channel_forward;
    b->channel_forward = forward;
}
 
void ast_channel_internal_swap_endpoint_forward(struct ast_channel *a, struct ast_channel *b)
{
    struct stasis_forward *temp;
 
    temp = a->endpoint_forward;
    a->endpoint_forward = b->endpoint_forward;
    b->endpoint_forward = temp;
}
 
void ast_channel_internal_swap_snapshots(struct ast_channel *a, struct ast_channel *b)
{
    struct ast_channel_snapshot *snapshot;
 
    snapshot = a->snapshot;
    a->snapshot = b->snapshot;
    b->snapshot = snapshot;
}
 
void ast_channel_internal_set_fake_ids(struct ast_channel *chan, const char *uniqueid, const char *linkedid)
{
    ast_copy_string(chan->uniqueid.unique_id, uniqueid, sizeof(chan->uniqueid.unique_id));
    ast_copy_string(chan->linkedid.unique_id, linkedid, sizeof(chan->linkedid.unique_id));
}
 
void ast_channel_internal_cleanup(struct ast_channel *chan)
{
    if (chan->dialed_causes) {
        ao2_t_ref(chan->dialed_causes, -1,
            "done with dialed causes since the channel is going away");
        chan->dialed_causes = NULL;
    }
 
    ast_string_field_free_memory(chan);
 
    chan->channel_forward = stasis_forward_cancel(chan->channel_forward);
    chan->endpoint_forward = stasis_forward_cancel(chan->endpoint_forward);
 
    ao2_cleanup(chan->topic);
    chan->topic = NULL;
 
    ast_channel_internal_set_stream_topology(chan, NULL);
 
    AST_VECTOR_FREE(&chan->fds);
}
 
void ast_channel_internal_finalize(struct ast_channel *chan)
{
    chan->finalized = 1;
}
 
int ast_channel_internal_is_finalized(struct ast_channel *chan)
{
    return chan->finalized;
}
 
struct stasis_topic *ast_channel_topic(struct ast_channel *chan)
{
    if (!chan) {
        return ast_channel_topic_all();
    }
 
    return chan->topic;
}
 
int ast_channel_forward_endpoint(struct ast_channel *chan,
    struct ast_endpoint *endpoint)
{
    ast_assert(chan != NULL);
    ast_assert(endpoint != NULL);
 
    chan->endpoint_forward =
        stasis_forward_all(ast_channel_topic(chan),
            ast_endpoint_topic(endpoint));
    if (!chan->endpoint_forward) {
        return -1;
    }
 
    return 0;
}
 
int ast_channel_internal_setup_topics(struct ast_channel *chan)
{
    char *topic_name;
    int ret;
    ast_assert(chan->topic == NULL);
 
    if (ast_strlen_zero(chan->uniqueid.unique_id)) {
        static int dummy_id;
        ret = ast_asprintf(&topic_name, "channel:dummy-%d", ast_atomic_fetchadd_int(&dummy_id, +1));
    } else {
        ret = ast_asprintf(&topic_name, "channel:%s", chan->uniqueid.unique_id);
    }
 
    if (ret < 0) {
        return -1;
    }
 
    chan->topic = stasis_topic_create(topic_name);
    ast_free(topic_name);
    if (!chan->topic) {
        return -1;
    }
 
    chan->channel_forward = stasis_forward_all(ast_channel_topic(chan),
        ast_channel_topic_all());
    if (!chan->channel_forward) {
        ao2_ref(chan->topic, -1);
        chan->topic = NULL;
        return -1;
    }
 
    return 0;
}
 
AST_THREADSTORAGE(channel_errno);
 
void ast_channel_internal_errno_set(enum ast_channel_error error)
{
    enum ast_channel_error *error_code = ast_threadstorage_get(&channel_errno, sizeof(*error_code));
    if (!error_code) {
        return;
    }
 
    *error_code = error;
}
 
enum ast_channel_error ast_channel_internal_errno(void)
{
    enum ast_channel_error *error_code = ast_threadstorage_get(&channel_errno, sizeof(*error_code));
    if (!error_code) {
        return AST_CHANNEL_ERROR_UNKNOWN;
    }
 
    return *error_code;
}
 
struct ast_stream_topology *ast_channel_get_stream_topology(
    const struct ast_channel *chan)
{
    ast_assert(chan != NULL);
 
    return chan->stream_topology;
}
 
struct ast_stream_topology *ast_channel_set_stream_topology(struct ast_channel *chan,
    struct ast_stream_topology *topology)
{
    struct ast_stream_topology *new_topology;
    SCOPE_ENTER(1, "%s: %s\n", ast_channel_name(chan),
        ast_str_tmp(256, ast_stream_topology_to_str(topology, &STR_TMP)));
 
    ast_assert(chan != NULL);
 
    /* A non-MULTISTREAM channel can't manipulate topology directly */
    ast_assert(ast_channel_is_multistream(chan));
 
    /* Unless the channel is being destroyed, we always want a topology on
     * it even if its empty.
     */
    if (!topology) {
        new_topology = ast_stream_topology_alloc();
    } else {
        new_topology = topology;
    }
 
    if (new_topology) {
        ast_channel_internal_set_stream_topology(chan, new_topology);
    }
 
    SCOPE_EXIT_RTN_VALUE(new_topology, "Used %s topology\n", topology ? "provided" : "empty");
}
 
struct ast_stream *ast_channel_get_default_stream(struct ast_channel *chan,
    enum ast_media_type type)
{
    ast_assert(chan != NULL);
    ast_assert(type < AST_MEDIA_TYPE_END);
 
    return chan->default_streams[type];
}
 
void ast_channel_internal_swap_stream_topology(struct ast_channel *chan1,
    struct ast_channel *chan2)
{
    struct ast_stream_topology *tmp_topology;
 
    ast_assert(chan1 != NULL && chan2 != NULL);
 
    tmp_topology = chan1->stream_topology;
    chan1->stream_topology = chan2->stream_topology;
    chan2->stream_topology = tmp_topology;
 
    channel_set_default_streams(chan1);
    channel_set_default_streams(chan2);
}
 
int ast_channel_is_multistream(struct ast_channel *chan)
{
    return (chan && chan->tech && chan->tech->read_stream && chan->tech->write_stream);
}
 
struct ast_channel_snapshot *ast_channel_snapshot(const struct ast_channel *chan)
{
    return chan->snapshot;
}
 
void ast_channel_snapshot_set(struct ast_channel *chan, struct ast_channel_snapshot *snapshot)
{
    ao2_cleanup(chan->snapshot);
    chan->snapshot = ao2_bump(snapshot);
}
 
struct ast_flags *ast_channel_snapshot_segment_flags(struct ast_channel *chan)
{
    return &chan->snapshot_segment_flags;
}