Merge "res_calendar: Specialized calendars depend on symbols of general calendar."
[asterisk/asterisk.git] / main / channel_internal_api.c
index 35bcb18..d31ce94 100644 (file)
 
 #include "asterisk.h"
 
-ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
-
 #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/data.h"
 #include "asterisk/endpoints.h"
 #include "asterisk/indications.h"
 #include "asterisk/stasis_cache_pattern.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 */
+};
 
 /*!
  * \brief Main Channel structure associated with a channel.
@@ -67,10 +77,6 @@ struct ast_channel {
        void *music_state;                              /*!< Music State*/
        void *generatordata;                            /*!< Current generator data if there is any */
        struct ast_generator *generator;                /*!< Current active data generator */
-/* BUGBUG bridged_channel must be eliminated from ast_channel */
-       struct ast_channel * bridged_channel;                   /*!< Who are we bridged to, if we're bridged.
-                                                        *   Who is proxying for us, if we are proxied (i.e. chan_agent).
-                                                        *   Do not access directly, use ast_bridged_channel(chan) */
        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 */
@@ -90,27 +96,26 @@ struct ast_channel {
        struct ast_tone_zone *zone;                     /*!< Tone zone as set in indications.conf or
                                                         *   in the CHANNEL dialplan function */
        struct ast_channel_monitor *monitor;            /*!< Channel monitoring */
-       struct ast_callid *callid;                      /*!< Bound call identifier pointer */
-#ifdef HAVE_EPOLL
-       struct ast_epoll_data *epfd_data[AST_MAX_FDS];
-#endif
+       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(uniqueid);     /*!< Unique Channel Identifier */
-               AST_STRING_FIELD(linkedid);     /*!< Linked Channel Identifier -- gets propagated by linkage */
                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 */
 
@@ -160,7 +165,7 @@ struct ast_channel {
        unsigned long insmpl;                           /*!< Track the read/written samples for monitor use */
        unsigned long outsmpl;                          /*!< Track the read/written samples for monitor use */
 
-       int fds[AST_MAX_FDS];                           /*!< File descriptors for channel -- Drivers will poll on
+       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
@@ -168,7 +173,7 @@ struct ast_channel {
        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 */
+       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 */
@@ -185,19 +190,16 @@ struct ast_channel {
        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 (after translation) */
-       struct ast_format rawreadformat;         /*!< Raw read format (before translation) */
-       struct ast_format rawwriteformat;        /*!< Raw write format (before translation) */
+       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 */
-#ifdef HAVE_EPOLL
-       int epfd;
-#endif
        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 */
 
-/* BUGBUG the bridge pointer must change to an ast_channel_bridge pointer because it will never change while the channel is in the bridging system whereas the bridge could change. */
        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 */
@@ -206,223 +208,23 @@ struct ast_channel {
        char exten[AST_MAX_EXTENSION];                  /*!< Dialplan: Current extension number */
        char macrocontext[AST_MAX_CONTEXT];             /*!< Macro: Current non-macro context. See app_macro.c */
        char macroexten[AST_MAX_EXTENSION];             /*!< Macro: Current non-macro extension. See app_macro.c */
+       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_cp_single *topics;                /*!< Topic for all channel's events */
-       struct stasis_subscription *forwarder;          /*!< Subscription for event forwarding to all topic */
-       struct stasis_subscription *endpoint_forward;   /*!< Subscription for event forwarding to endpoint's topic */
+       struct stasis_forward *endpoint_forward;        /*!< Subscription for event forwarding to endpoint's topic */
+       struct stasis_forward *endpoint_cache_forward; /*!< Subscription for cache updates 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 */
 };
 
 /*! \brief The monotonically increasing integer counter for channel uniqueids */
 static int uniqueint;
 
-/* AST_DATA definitions, which will probably have to be re-thought since the channel will be opaque */
-
-#if 0  /* XXX AstData: ast_callerid no longer exists. (Equivalent code not readily apparent.) */
-#define DATA_EXPORT_CALLERID(MEMBER)                           \
-       MEMBER(ast_callerid, cid_dnid, AST_DATA_STRING)         \
-       MEMBER(ast_callerid, cid_num, AST_DATA_STRING)          \
-       MEMBER(ast_callerid, cid_name, AST_DATA_STRING)         \
-       MEMBER(ast_callerid, cid_ani, AST_DATA_STRING)          \
-       MEMBER(ast_callerid, cid_pres, AST_DATA_INTEGER)        \
-       MEMBER(ast_callerid, cid_ani2, AST_DATA_INTEGER)        \
-       MEMBER(ast_callerid, cid_tag, AST_DATA_STRING)
-
-AST_DATA_STRUCTURE(ast_callerid, DATA_EXPORT_CALLERID);
-#endif
-
-#define DATA_EXPORT_CHANNEL(MEMBER)                                            \
-       MEMBER(ast_channel, blockproc, AST_DATA_STRING)                         \
-       MEMBER(ast_channel, appl, AST_DATA_STRING)                              \
-       MEMBER(ast_channel, data, AST_DATA_STRING)                              \
-       MEMBER(ast_channel, name, AST_DATA_STRING) \
-       MEMBER(ast_channel, language, AST_DATA_STRING)                          \
-       MEMBER(ast_channel, musicclass, AST_DATA_STRING)                        \
-       MEMBER(ast_channel, accountcode, AST_DATA_STRING)                       \
-       MEMBER(ast_channel, peeraccount, AST_DATA_STRING)                       \
-       MEMBER(ast_channel, userfield, AST_DATA_STRING)                         \
-       MEMBER(ast_channel, call_forward, AST_DATA_STRING)                      \
-       MEMBER(ast_channel, uniqueid, AST_DATA_STRING)                          \
-       MEMBER(ast_channel, linkedid, AST_DATA_STRING)                          \
-       MEMBER(ast_channel, parkinglot, AST_DATA_STRING)                        \
-       MEMBER(ast_channel, hangupsource, AST_DATA_STRING)                      \
-       MEMBER(ast_channel, dialcontext, AST_DATA_STRING)                       \
-       MEMBER(ast_channel, rings, AST_DATA_INTEGER)                            \
-       MEMBER(ast_channel, priority, AST_DATA_INTEGER)                         \
-       MEMBER(ast_channel, macropriority, AST_DATA_INTEGER)                    \
-       MEMBER(ast_channel, adsicpe, AST_DATA_INTEGER)                          \
-       MEMBER(ast_channel, fin, AST_DATA_UNSIGNED_INTEGER)                     \
-       MEMBER(ast_channel, fout, AST_DATA_UNSIGNED_INTEGER)                    \
-       MEMBER(ast_channel, emulate_dtmf_duration, AST_DATA_UNSIGNED_INTEGER)   \
-       MEMBER(ast_channel, visible_indication, AST_DATA_INTEGER)               \
-       MEMBER(ast_channel, context, AST_DATA_STRING)                           \
-       MEMBER(ast_channel, exten, AST_DATA_STRING)                             \
-       MEMBER(ast_channel, macrocontext, AST_DATA_STRING)                      \
-       MEMBER(ast_channel, macroexten, AST_DATA_STRING)
-
-AST_DATA_STRUCTURE(ast_channel, DATA_EXPORT_CHANNEL);
-
-static void channel_data_add_flags(struct ast_data *tree,
-       struct ast_channel *chan)
-{
-       ast_data_add_bool(tree, "DEFER_DTMF", ast_test_flag(ast_channel_flags(chan), AST_FLAG_DEFER_DTMF));
-       ast_data_add_bool(tree, "WRITE_INT", ast_test_flag(ast_channel_flags(chan), AST_FLAG_WRITE_INT));
-       ast_data_add_bool(tree, "BLOCKING", ast_test_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING));
-       ast_data_add_bool(tree, "ZOMBIE", ast_test_flag(ast_channel_flags(chan), AST_FLAG_ZOMBIE));
-       ast_data_add_bool(tree, "EXCEPTION", ast_test_flag(ast_channel_flags(chan), AST_FLAG_EXCEPTION));
-       ast_data_add_bool(tree, "MOH", ast_test_flag(ast_channel_flags(chan), AST_FLAG_MOH));
-       ast_data_add_bool(tree, "SPYING", ast_test_flag(ast_channel_flags(chan), AST_FLAG_SPYING));
-       ast_data_add_bool(tree, "IN_AUTOLOOP", ast_test_flag(ast_channel_flags(chan), AST_FLAG_IN_AUTOLOOP));
-       ast_data_add_bool(tree, "OUTGOING", ast_test_flag(ast_channel_flags(chan), AST_FLAG_OUTGOING));
-       ast_data_add_bool(tree, "IN_DTMF", ast_test_flag(ast_channel_flags(chan), AST_FLAG_IN_DTMF));
-       ast_data_add_bool(tree, "EMULATE_DTMF", ast_test_flag(ast_channel_flags(chan), AST_FLAG_EMULATE_DTMF));
-       ast_data_add_bool(tree, "END_DTMF_ONLY", ast_test_flag(ast_channel_flags(chan), AST_FLAG_END_DTMF_ONLY));
-       ast_data_add_bool(tree, "MASQ_NOSTREAM", ast_test_flag(ast_channel_flags(chan), AST_FLAG_MASQ_NOSTREAM));
-       ast_data_add_bool(tree, "BRIDGE_HANGUP_RUN", ast_test_flag(ast_channel_flags(chan), AST_FLAG_BRIDGE_HANGUP_RUN));
-       ast_data_add_bool(tree, "DISABLE_WORKAROUNDS", ast_test_flag(ast_channel_flags(chan), AST_FLAG_DISABLE_WORKAROUNDS));
-       ast_data_add_bool(tree, "DISABLE_DEVSTATE_CACHE", ast_test_flag(ast_channel_flags(chan), AST_FLAG_DISABLE_DEVSTATE_CACHE));
-       ast_data_add_bool(tree, "BRIDGE_DUAL_REDIRECT_WAIT", ast_test_flag(ast_channel_flags(chan), AST_FLAG_BRIDGE_DUAL_REDIRECT_WAIT));
-       ast_data_add_bool(tree, "ORIGINATED", ast_test_flag(ast_channel_flags(chan), AST_FLAG_ORIGINATED));
-       ast_data_add_bool(tree, "DEAD", ast_test_flag(ast_channel_flags(chan), AST_FLAG_DEAD));
-}
-
-int ast_channel_data_add_structure(struct ast_data *tree,
-       struct ast_channel *chan, int add_bridged)
-{
-       struct ast_channel *bc;
-       struct ast_data *data_bridged;
-       struct ast_data *data_cdr;
-       struct ast_data *data_flags;
-       struct ast_data *data_zones;
-       struct ast_data *enum_node;
-       struct ast_data *data_softhangup;
-#if 0  /* XXX AstData: ast_callerid no longer exists. (Equivalent code not readily apparent.) */
-       struct ast_data *data_callerid;
-       char value_str[100];
-#endif
-
-       if (!tree) {
-               return -1;
-       }
-
-       ast_data_add_structure(ast_channel, tree, chan);
-
-       if (add_bridged) {
-               bc = ast_bridged_channel(chan);
-               if (bc) {
-                       data_bridged = ast_data_add_node(tree, "bridged");
-                       if (!data_bridged) {
-                               return -1;
-                       }
-                       ast_channel_data_add_structure(data_bridged, bc, 0);
-               }
-       }
-
-       ast_data_add_codec(tree, "oldwriteformat", ast_channel_oldwriteformat(chan));
-       ast_data_add_codec(tree, "readformat", ast_channel_readformat(chan));
-       ast_data_add_codec(tree, "writeformat", ast_channel_writeformat(chan));
-       ast_data_add_codec(tree, "rawreadformat", ast_channel_rawreadformat(chan));
-       ast_data_add_codec(tree, "rawwriteformat", ast_channel_rawwriteformat(chan));
-       ast_data_add_codecs(tree, "nativeformats", ast_channel_nativeformats(chan));
-
-       /* state */
-       enum_node = ast_data_add_node(tree, "state");
-       if (!enum_node) {
-               return -1;
-       }
-       ast_data_add_str(enum_node, "text", ast_state2str(ast_channel_state(chan)));
-       ast_data_add_int(enum_node, "value", ast_channel_state(chan));
-
-       /* hangupcause */
-       enum_node = ast_data_add_node(tree, "hangupcause");
-       if (!enum_node) {
-               return -1;
-       }
-       ast_data_add_str(enum_node, "text", ast_cause2str(ast_channel_hangupcause(chan)));
-       ast_data_add_int(enum_node, "value", ast_channel_hangupcause(chan));
-
-       /* amaflags */
-       enum_node = ast_data_add_node(tree, "amaflags");
-       if (!enum_node) {
-               return -1;
-       }
-       ast_data_add_str(enum_node, "text", ast_channel_amaflags2string(ast_channel_amaflags(chan)));
-       ast_data_add_int(enum_node, "value", ast_channel_amaflags(chan));
-
-       /* transfercapability */
-       enum_node = ast_data_add_node(tree, "transfercapability");
-       if (!enum_node) {
-               return -1;
-       }
-       ast_data_add_str(enum_node, "text", ast_transfercapability2str(ast_channel_transfercapability(chan)));
-       ast_data_add_int(enum_node, "value", ast_channel_transfercapability(chan));
-
-       /* _softphangup */
-       data_softhangup = ast_data_add_node(tree, "softhangup");
-       if (!data_softhangup) {
-               return -1;
-       }
-       ast_data_add_bool(data_softhangup, "dev", ast_channel_softhangup_internal_flag(chan) & AST_SOFTHANGUP_DEV);
-       ast_data_add_bool(data_softhangup, "asyncgoto", ast_channel_softhangup_internal_flag(chan) & AST_SOFTHANGUP_ASYNCGOTO);
-       ast_data_add_bool(data_softhangup, "shutdown", ast_channel_softhangup_internal_flag(chan) & AST_SOFTHANGUP_SHUTDOWN);
-       ast_data_add_bool(data_softhangup, "timeout", ast_channel_softhangup_internal_flag(chan) & AST_SOFTHANGUP_TIMEOUT);
-       ast_data_add_bool(data_softhangup, "appunload", ast_channel_softhangup_internal_flag(chan) & AST_SOFTHANGUP_APPUNLOAD);
-       ast_data_add_bool(data_softhangup, "explicit", ast_channel_softhangup_internal_flag(chan) & AST_SOFTHANGUP_EXPLICIT);
-       ast_data_add_bool(data_softhangup, "unbridge", ast_channel_softhangup_internal_flag(chan) & AST_SOFTHANGUP_UNBRIDGE);
-
-       /* channel flags */
-       data_flags = ast_data_add_node(tree, "flags");
-       if (!data_flags) {
-               return -1;
-       }
-       channel_data_add_flags(data_flags, chan);
-
-       ast_data_add_uint(tree, "timetohangup", ast_channel_whentohangup(chan)->tv_sec);
-
-#if 0  /* XXX AstData: ast_callerid no longer exists. (Equivalent code not readily apparent.) */
-       /* callerid */
-       data_callerid = ast_data_add_node(tree, "callerid");
-       if (!data_callerid) {
-               return -1;
-       }
-       ast_data_add_structure(ast_callerid, data_callerid, &(chan->cid));
-       /* insert the callerid ton */
-       enum_node = ast_data_add_node(data_callerid, "cid_ton");
-       if (!enum_node) {
-               return -1;
-       }
-       ast_data_add_int(enum_node, "value", chan->cid.cid_ton);
-       snprintf(value_str, sizeof(value_str), "TON: %s/Plan: %s",
-               party_number_ton2str(chan->cid.cid_ton),
-               party_number_plan2str(chan->cid.cid_ton));
-       ast_data_add_str(enum_node, "text", value_str);
-#endif
-
-       /* tone zone */
-       if (ast_channel_zone(chan)) {
-               data_zones = ast_data_add_node(tree, "zone");
-               if (!data_zones) {
-                       return -1;
-               }
-               ast_tone_zone_data_add_structure(data_zones, ast_channel_zone(chan));
-       }
-
-       /* insert cdr */
-       data_cdr = ast_data_add_node(tree, "cdr");
-       if (!data_cdr) {
-               return -1;
-       }
-
-       return 0;
-}
-
-int ast_channel_data_cmp_structure(const struct ast_data_search *tree,
-       struct ast_channel *chan, const char *structure_name)
-{
-       return ast_data_search_cmp_structure(tree, ast_channel, chan, structure_name);
-}
-
 /* ACCESSORS */
 
 #define DEFINE_STRINGFIELD_SETTERS_FOR(field, publish, assert_on_null) \
@@ -431,13 +233,13 @@ 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); \
-       if (publish) ast_channel_publish_snapshot(chan); \
+       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); \
-       if (publish) ast_channel_publish_snapshot(chan); \
+       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, ...) \
 { \
@@ -450,12 +252,11 @@ void ast_channel_##field##_build(struct ast_channel *chan, const char *fmt, ...)
 DEFINE_STRINGFIELD_SETTERS_FOR(name, 0, 1);
 DEFINE_STRINGFIELD_SETTERS_FOR(language, 1, 0);
 DEFINE_STRINGFIELD_SETTERS_FOR(musicclass, 0, 0);
+DEFINE_STRINGFIELD_SETTERS_FOR(latest_musicclass, 0, 0);
 DEFINE_STRINGFIELD_SETTERS_FOR(accountcode, 1, 0);
 DEFINE_STRINGFIELD_SETTERS_FOR(peeraccount, 1, 0);
 DEFINE_STRINGFIELD_SETTERS_FOR(userfield, 0, 0);
 DEFINE_STRINGFIELD_SETTERS_FOR(call_forward, 0, 0);
-DEFINE_STRINGFIELD_SETTERS_FOR(uniqueid, 0, 1);
-DEFINE_STRINGFIELD_SETTERS_FOR(linkedid, 1, 1);
 DEFINE_STRINGFIELD_SETTERS_FOR(parkinglot, 0, 0);
 DEFINE_STRINGFIELD_SETTERS_FOR(hangupsource, 0, 0);
 DEFINE_STRINGFIELD_SETTERS_FOR(dialcontext, 0, 0);
@@ -468,16 +269,27 @@ DEFINE_STRINGFIELD_SETTERS_FOR(dialcontext, 0, 0);
 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(uniqueid);
-DEFINE_STRINGFIELD_GETTER_FOR(linkedid);
 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_appl(const struct ast_channel *chan)
 {
        return chan->appl;
@@ -576,17 +388,6 @@ void ast_channel_amaflags_set(struct ast_channel *chan, enum ama_flags value)
        chan->amaflags = value;
        ast_channel_publish_snapshot(chan);
 }
-
-#ifdef HAVE_EPOLL
-int ast_channel_epfd(const struct ast_channel *chan)
-{
-       return chan->epfd;
-}
-void ast_channel_epfd_set(struct ast_channel *chan, int value)
-{
-       chan->epfd = value;
-}
-#endif
 int ast_channel_fdno(const struct ast_channel *chan)
 {
        return chan->fdno;
@@ -651,6 +452,14 @@ 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;
@@ -799,10 +608,64 @@ struct ast_format_cap *ast_channel_nativeformats(const struct ast_channel *chan)
 {
        return chan->nativeformats;
 }
-void ast_channel_nativeformats_set(struct ast_channel *chan, struct ast_format_cap *value)
+
+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)
 {
-       chan->nativeformats = value;
+       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) {
+               return;
+       }
+
+       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);
+       }
 }
+
 struct ast_framehook_list *ast_channel_framehooks(const struct ast_channel *chan)
 {
        return chan->framehooks;
@@ -873,8 +736,11 @@ const struct ast_channel_tech *ast_channel_tech(const struct ast_channel *chan)
 }
 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;
-       ast_channel_publish_snapshot(chan);
 }
 enum ast_channel_adsicpe ast_channel_adsicpe(const struct ast_channel *chan)
 {
@@ -888,15 +754,11 @@ enum ast_channel_state ast_channel_state(const struct ast_channel *chan)
 {
        return chan->state;
 }
-struct ast_callid *ast_channel_callid(const struct ast_channel *chan)
+ast_callid ast_channel_callid(const struct ast_channel *chan)
 {
-       if (chan->callid) {
-               ast_callid_ref(chan->callid);
-               return chan->callid;
-       }
-       return NULL;
+       return chan->callid;
 }
-void ast_channel_callid_set(struct ast_channel *chan, struct ast_callid *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];
@@ -905,11 +767,9 @@ void ast_channel_callid_set(struct ast_channel *chan, struct ast_callid *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);
-               /* unbind if already set */
-               ast_callid_unref(chan->callid);
        }
 
-       chan->callid = ast_callid_ref(callid);
+       chan->callid = callid;
 
        ast_test_suite_event_notify("CallIDChange",
                "State: CallIDChange\r\n"
@@ -919,32 +779,51 @@ void ast_channel_callid_set(struct ast_channel *chan, struct ast_callid *callid)
                ast_channel_name(chan),
                call_identifier_to,
                call_identifier_from);
-
-       ast_channel_publish_snapshot(chan);
 }
+
 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;
+       return chan->oldwriteformat;
 }
 struct ast_format *ast_channel_rawreadformat(struct ast_channel *chan)
 {
-       return &chan->rawreadformat;
+       return chan->rawreadformat;
 }
 struct ast_format *ast_channel_rawwriteformat(struct ast_channel *chan)
 {
-       return &chan->rawwriteformat;
+       return chan->rawwriteformat;
 }
 struct ast_format *ast_channel_readformat(struct ast_channel *chan)
 {
-       return &chan->readformat;
+       return chan->readformat;
 }
 struct ast_format *ast_channel_writeformat(struct ast_channel *chan)
 {
-       return &chan->writeformat;
+       return chan->writeformat;
 }
 struct ast_hangup_handler_list *ast_channel_hangup_handlers(struct ast_channel *chan)
 {
@@ -1049,7 +928,6 @@ void ast_channel_dtmf_tv_set(struct ast_channel *chan, struct timeval *value)
 void ast_channel_whentohangup_set(struct ast_channel *chan, struct timeval *value)
 {
        chan->whentohangup = *value;
-       ast_channel_publish_snapshot(chan);
 }
 void ast_channel_varshead_set(struct ast_channel *chan, struct varshead *value)
 {
@@ -1092,11 +970,63 @@ void ast_channel_softhangup_internal_flag_clear(struct ast_channel *chan, int va
        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)
 {
-       if (chan->callid) {
-               chan->callid = ast_callid_unref(chan->callid);
-       }
+       chan->callid = 0;
 }
 
 /* Typedef accessors */
@@ -1107,7 +1037,6 @@ ast_group_t ast_channel_callgroup(const struct ast_channel *chan)
 void ast_channel_callgroup_set(struct ast_channel *chan, ast_group_t value)
 {
        chan->callgroup = value;
-       ast_channel_publish_snapshot(chan);
 }
 ast_group_t ast_channel_pickupgroup(const struct ast_channel *chan)
 {
@@ -1116,7 +1045,6 @@ ast_group_t ast_channel_pickupgroup(const struct ast_channel *chan)
 void ast_channel_pickupgroup_set(struct ast_channel *chan, ast_group_t value)
 {
        chan->pickupgroup = value;
-       ast_channel_publish_snapshot(chan);
 }
 struct ast_namedgroups *ast_channel_named_callgroups(const struct ast_channel *chan)
 {
@@ -1140,132 +1068,106 @@ void ast_channel_named_pickupgroups_set(struct ast_channel *chan, struct ast_nam
 /* Alertpipe functions */
 int ast_channel_alert_write(struct ast_channel *chan)
 {
-       char blah = 0x7F;
-       return ast_channel_alert_writable(chan) && write(chan->alertpipe[1], &blah, sizeof(blah)) != sizeof(blah);
+       return ast_alertpipe_write(chan->alertpipe);
 }
 
-ast_alert_status_t ast_channel_internal_alert_read(struct ast_channel *chan)
+ast_alert_status_t ast_channel_internal_alert_flush(struct ast_channel *chan)
 {
-       int flags;
-       char blah;
-
-       if (!ast_channel_internal_alert_readable(chan)) {
-               return AST_ALERT_NOT_READABLE;
-       }
-
-       flags = fcntl(chan->alertpipe[0], F_GETFL);
-       /* For some odd reason, the alertpipe occasionally loses nonblocking status,
-        * which immediately causes a deadlock scenario.  Detect and prevent this. */
-       if ((flags & O_NONBLOCK) == 0) {
-               ast_log(LOG_ERROR, "Alertpipe on channel %s lost O_NONBLOCK?!!\n", ast_channel_name(chan));
-               if (fcntl(chan->alertpipe[0], F_SETFL, flags | O_NONBLOCK) < 0) {
-                       ast_log(LOG_WARNING, "Unable to set alertpipe nonblocking! (%d: %s)\n", errno, strerror(errno));
-                       return AST_ALERT_READ_FATAL;
-               }
-       }
-       if (read(chan->alertpipe[0], &blah, sizeof(blah)) < 0) {
-               if (errno != EINTR && errno != EAGAIN) {
-                       ast_log(LOG_WARNING, "read() failed: %s\n", strerror(errno));
-                       return AST_ALERT_READ_FAIL;
-               }
-       }
+       return ast_alertpipe_flush(chan->alertpipe);
+}
 
-       return AST_ALERT_READ_SUCCESS;
+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 chan->alertpipe[1] > -1;
+       return ast_alertpipe_writable(chan->alertpipe);
 }
 
 int ast_channel_internal_alert_readable(struct ast_channel *chan)
 {
-       return chan->alertpipe[0] > -1;
+       return ast_alertpipe_readable(chan->alertpipe);
 }
 
 void ast_channel_internal_alertpipe_clear(struct ast_channel *chan)
 {
-       chan->alertpipe[0] = chan->alertpipe[1] = -1;
+       ast_alertpipe_clear(chan->alertpipe);
 }
 
 void ast_channel_internal_alertpipe_close(struct ast_channel *chan)
 {
-       if (ast_channel_internal_alert_readable(chan)) {
-               close(chan->alertpipe[0]);
-       }
-       if (ast_channel_alert_writable(chan)) {
-               close(chan->alertpipe[1]);
-       }
+       ast_alertpipe_close(chan->alertpipe);
 }
 
 int ast_channel_internal_alertpipe_init(struct ast_channel *chan)
 {
-       if (pipe(chan->alertpipe)) {
-               ast_log(LOG_WARNING, "Channel allocation failed: Can't create alert pipe! Try increasing max file descriptors with ulimit -n\n");
-               return -1;
-       } else {
-               int flags = fcntl(chan->alertpipe[0], F_GETFL);
-               if (fcntl(chan->alertpipe[0], F_SETFL, flags | O_NONBLOCK) < 0) {
-                       ast_log(LOG_WARNING, "Channel allocation failed: Unable to set alertpipe nonblocking! (%d: %s)\n", errno, strerror(errno));
-                       return -1;
-               }
-               flags = fcntl(chan->alertpipe[1], F_GETFL);
-               if (fcntl(chan->alertpipe[1], F_SETFL, flags | O_NONBLOCK) < 0) {
-                       ast_log(LOG_WARNING, "Channel allocation failed: Unable to set alertpipe nonblocking! (%d: %s)\n", errno, strerror(errno));
-                       return -1;
-               }
-       }
-       return 0;
+       return ast_alertpipe_init(chan->alertpipe);
 }
 
 int ast_channel_internal_alert_readfd(struct ast_channel *chan)
 {
-       return chan->alertpipe[0];
+       return ast_alertpipe_readfd(chan->alertpipe);
 }
 
 void ast_channel_internal_alertpipe_swap(struct ast_channel *chan1, struct ast_channel *chan2)
 {
-       int i;
-       for (i = 0; i < ARRAY_LEN(chan1->alertpipe); i++) {
-               SWAP(chan1->alertpipe[i], chan2->alertpipe[i]);
-       }
+       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)
 {
-       chan->fds[which] = 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)
 {
-       ast_channel_internal_fd_set(chan, which, -1);
+       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)
 {
-       int i;
-       for (i = 0; i < AST_MAX_FDS; i++) {
-               ast_channel_internal_fd_clear(chan, i);
-       }
+       AST_VECTOR_RESET(&chan->fds, AST_VECTOR_ELEM_CLEANUP_NOOP);
 }
 int ast_channel_fd(const struct ast_channel *chan, int which)
 {
-       return chan->fds[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;
 }
 
-#ifdef HAVE_EPOLL
-struct ast_epoll_data *ast_channel_internal_epfd_data(const struct ast_channel *chan, int which)
+int ast_channel_fd_count(const struct ast_channel *chan)
 {
-       return chan->epfd_data[which];
+       return AST_VECTOR_SIZE(&chan->fds);
 }
-void ast_channel_internal_epfd_data_set(struct ast_channel *chan, int which , struct ast_epoll_data *value)
+
+int ast_channel_fd_add(struct ast_channel *chan, int value)
 {
-       chan->epfd_data[which] = value;
+       int pos = AST_EXTENDED_FDS;
+
+       while (ast_channel_fd_isset(chan, pos)) {
+               pos += 1;
+       }
+
+       AST_VECTOR_REPLACE(&chan->fds, pos, value);
+
+       return pos;
 }
-#endif
 
 pthread_t ast_channel_blocker(const struct ast_channel *chan)
 {
@@ -1304,15 +1206,6 @@ void ast_channel_internal_bridge_channel_set(struct ast_channel *chan, struct as
        chan->bridge_channel = value;
 }
 
-struct ast_channel *ast_channel_internal_bridged_channel(const struct ast_channel *chan)
-{
-       return chan->bridged_channel;
-}
-void ast_channel_internal_bridged_channel_set(struct ast_channel *chan, struct ast_channel *value)
-{
-       chan->bridged_channel = value;
-}
-
 struct ast_flags *ast_channel_flags(struct ast_channel *chan)
 {
        return &chan->flags;
@@ -1384,18 +1277,16 @@ static int pvt_cause_cmp_fn(void *obj, void *vstr, int flags)
 
 #define DIALED_CAUSES_BUCKETS 37
 
-struct ast_channel *__ast_channel_internal_alloc(void (*destructor)(void *obj), const char *linkedid, const char *file, int line, const char *function)
+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)
 {
        struct ast_channel *tmp;
-#if defined(REF_DEBUG)
-       tmp = __ao2_alloc_debug(sizeof(*tmp), destructor,
-               AO2_ALLOC_OPT_LOCK_MUTEX, "", file, line, function, 1);
-#elif defined(__AST_DEBUG_MALLOC)
-       tmp = __ao2_alloc_debug(sizeof(*tmp), destructor,
-               AO2_ALLOC_OPT_LOCK_MUTEX, "", file, line, function, 0);
-#else
-       tmp = ao2_alloc(sizeof(*tmp), destructor);
-#endif
+
+       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);
@@ -1405,23 +1296,92 @@ struct ast_channel *__ast_channel_internal_alloc(void (*destructor)(void *obj),
                return ast_channel_unref(tmp);
        }
 
-       if (ast_strlen_zero(ast_config_AST_SYSTEM_NAME)) {
-               ast_channel_uniqueid_build(tmp, "%li.%d", (long)time(NULL),
-                       ast_atomic_fetchadd_int(&uniqueint, 1));
+       /* 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 {
-               ast_channel_uniqueid_build(tmp, "%s-%li.%d", ast_config_AST_SYSTEM_NAME,
-                       (long)time(NULL), ast_atomic_fetchadd_int(&uniqueint, 1));
+               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);
        }
 
-       if (!ast_strlen_zero(linkedid)) {
-               ast_string_field_set(tmp, linkedid, linkedid);
+       /* copy linked id from parent channel if known */
+       if (requestor) {
+               tmp->linkedid = requestor->linkedid;
        } else {
-               ast_string_field_set(tmp, linkedid, tmp->uniqueid);
+               tmp->linkedid = tmp->uniqueid;
        }
 
+       AST_VECTOR_INIT(&tmp->fds, AST_MAX_FDS);
+
        return tmp;
 }
 
+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_publish_snapshot(dest);
+}
+
+void ast_channel_internal_swap_uniqueid_and_linkedid(struct ast_channel *a, struct ast_channel *b)
+{
+       struct ast_channel_id temp;
+
+       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_cp_single *temp;
+
+       temp = a->topics;
+       a->topics = b->topics;
+       b->topics = temp;
+}
+
+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) {
@@ -1432,11 +1392,15 @@ void ast_channel_internal_cleanup(struct ast_channel *chan)
 
        ast_string_field_free_memory(chan);
 
-       chan->forwarder = stasis_unsubscribe(chan->forwarder);
-       chan->endpoint_forward = stasis_unsubscribe(chan->endpoint_forward);
+       chan->endpoint_forward = stasis_forward_cancel(chan->endpoint_forward);
+       chan->endpoint_cache_forward = stasis_forward_cancel(chan->endpoint_cache_forward);
 
        stasis_cp_single_unsubscribe(chan->topics);
        chan->topics = NULL;
+
+       ast_channel_internal_set_stream_topology(chan, NULL);
+
+       AST_VECTOR_FREE(&chan->fds);
 }
 
 void ast_channel_internal_finalize(struct ast_channel *chan)
@@ -1476,8 +1440,14 @@ int ast_channel_forward_endpoint(struct ast_channel *chan,
        chan->endpoint_forward =
                stasis_forward_all(ast_channel_topic(chan),
                        ast_endpoint_topic(endpoint));
+       if (!chan->endpoint_forward) {
+               return -1;
+       }
 
-       if (chan->endpoint_forward == NULL) {
+       chan->endpoint_cache_forward = stasis_forward_all(ast_channel_topic_cached(chan),
+               ast_endpoint_topic(endpoint));
+       if (!chan->endpoint_cache_forward) {
+               chan->endpoint_forward = stasis_forward_cancel(chan->endpoint_forward);
                return -1;
        }
 
@@ -1486,7 +1456,7 @@ int ast_channel_forward_endpoint(struct ast_channel *chan,
 
 int ast_channel_internal_setup_topics(struct ast_channel *chan)
 {
-       const char *topic_name = chan->uniqueid;
+       const char *topic_name = chan->uniqueid.unique_id;
        ast_assert(chan->topics == NULL);
 
        if (ast_strlen_zero(topic_name)) {
@@ -1495,10 +1465,94 @@ int ast_channel_internal_setup_topics(struct ast_channel *chan)
 
        chan->topics = stasis_cp_single_create(
                ast_channel_cache_all(), topic_name);
-
        if (!chan->topics) {
                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;
+
+       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);
+       }
+
+       return new_topology;
+}
+
+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->tech && chan->tech->read_stream && chan->tech->write_stream);
+}