channel.c

	ast_free(doomed->number.str);
	doomed->number.str = NULL;
	ast_party_subaddress_free(&doomed->subaddress);
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	dest->code = src->code;
}

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


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

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

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

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

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

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

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

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

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

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

	ast_pbx_hangup_handler_destroy(chan);

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

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

		ast_channel_lock(chan);
		ast_channel_publish_snapshot(chan);
		ast_channel_unlock(chan);
		publish_cache_clear(chan);
	}

	ast_channel_lock(chan);

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

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

	ast_channel_unlock(chan);

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

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

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

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

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

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

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

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

	/* Close pipes if appropriate */
	ast_channel_internal_alertpipe_close(chan);
	if (ast_channel_timer(chan)) {
		ast_timer_close(ast_channel_timer(chan));
		ast_channel_timer_set(chan, NULL);
	}
#ifdef HAVE_EPOLL
	for (i = 0; i < AST_MAX_FDS; i++) {
		if (ast_channel_internal_epfd_data(chan, i)) {
			ast_free(ast_channel_internal_epfd_data(chan, i));
		}
	}
	close(ast_channel_epfd(chan));
#endif
	while ((f = AST_LIST_REMOVE_HEAD(ast_channel_readq(chan), frame_list)))
		ast_frfree(f);

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

	ast_app_group_discard(chan);

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

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

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

	ast_channel_internal_cleanup(chan);

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

	ast_channel_nativeformats_set(chan, NULL);
	if (callid) {
		ast_callid_unref(callid);
	}

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

	ast_atomic_fetchadd_int(&chancount, -1);
}

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

	ast_pbx_hangup_handler_destroy(chan);

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

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

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

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

	ast_channel_internal_cleanup(chan);
}

struct ast_datastore *ast_channel_datastore_alloc(const struct ast_datastore_info *info, const char *uid)
{
	return ast_datastore_alloc(info, uid);
}

int ast_channel_datastore_free(struct ast_datastore *datastore)
{
	return ast_datastore_free(datastore);
}

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

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

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

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

	return res;
}

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

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

	if (info == NULL)
		return NULL;

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

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

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

	return datastore;
}

/*! Set the file descriptor on the channel */
void ast_channel_set_fd(struct ast_channel *chan, int which, int fd)
{
#ifdef HAVE_EPOLL
	struct epoll_event ev;
	struct ast_epoll_data *aed = NULL;

	if (ast_channel_fd_isset(chan, which)) {
		epoll_ctl(ast_channel_epfd(chan), EPOLL_CTL_DEL, ast_channel_fd(chan, which), &ev);
		aed = ast_channel_internal_epfd_data(chan, which);
	}

	/* If this new fd is valid, add it to the epoll */
	if (fd > -1) {
		if (!aed && (!(aed = ast_calloc(1, sizeof(*aed)))))
			return;

		ast_channel_internal_epfd_data_set(chan, which, aed);
		aed->chan = chan;
		aed->which = which;

		ev.events = EPOLLIN | EPOLLPRI | EPOLLERR | EPOLLHUP;
		ev.data.ptr = aed;
		epoll_ctl(ast_channel_epfd(chan), EPOLL_CTL_ADD, fd, &ev);
	} else if (aed) {
		/* We don't have to keep around this epoll data structure now */
		ast_free(aed);
		ast_channel_epfd_data_set(chan, which, NULL);
	}
#endif
	ast_channel_internal_fd_set(chan, which, fd);
	return;
}

/*! Add a channel to an optimized waitfor */
void ast_poll_channel_add(struct ast_channel *chan0, struct ast_channel *chan1)
{
#ifdef HAVE_EPOLL
	struct epoll_event ev;
	int i = 0;

	if (ast_channel_epfd(chan0) == -1)
		return;

	/* Iterate through the file descriptors on chan1, adding them to chan0 */
	for (i = 0; i < AST_MAX_FDS; i++) {
		if (!ast_channel_fd_isset(chan1, i)) {
			continue;
		}
		ev.events = EPOLLIN | EPOLLPRI | EPOLLERR | EPOLLHUP;
		ev.data.ptr = ast_channel_internal_epfd_data(chan1, i);
		epoll_ctl(ast_channel_epfd(chan0), EPOLL_CTL_ADD, ast_channel_fd(chan1, i), &ev);
	}

#endif
	return;
}

/*! Delete a channel from an optimized waitfor */
void ast_poll_channel_del(struct ast_channel *chan0, struct ast_channel *chan1)
{
#ifdef HAVE_EPOLL
	struct epoll_event ev;
	int i = 0;

	if (ast_channel_epfd(chan0) == -1)
		return;

	for (i = 0; i < AST_MAX_FDS; i++) {
		if (!ast_channel_fd_isset(chan1, i)) {
			continue;
		}
		epoll_ctl(ast_channel_epfd(chan0), EPOLL_CTL_DEL, ast_channel_fd(chan1, i), &ev);
	}

#endif
	return;
}

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

	ast_channel_softhangup_internal_flag_clear(chan, flag);

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

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

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

	ast_channel_unlock(chan);
}

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

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

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

	return res;
}

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

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

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

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

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

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

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

	ast_framehook_list_destroy(chan);
}

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

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

	ast_autoservice_stop(chan);

	ast_channel_lock(chan);

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

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

	ast_channel_unlock(chan);

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

	destroy_hooks(chan);

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

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

	if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING)) {
		ast_log(LOG_WARNING, "Hard hangup called by thread %ld on %s, while fd "
			"is blocked by thread %ld in procedure %s!  Expect a failure\n",
			(long) pthread_self(), ast_channel_name(chan), (long)ast_channel_blocker(chan), ast_channel_blockproc(chan));
		ast_assert(ast_test_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING) == 0);
	}

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

	ast_channel_unlock(chan);

	ast_cc_offer(chan);

	ast_channel_unref(chan);
}

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

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

int ast_raw_answer(struct ast_channel *chan)
{
	int res = 0;

	ast_channel_lock(chan);

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

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

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

	ast_channel_unlock(chan);

	switch (ast_channel_state(chan)) {
	case AST_STATE_RINGING:
	case AST_STATE_RING:
		ast_channel_lock(chan);
		if (ast_channel_tech(chan)->answer) {
			res = ast_channel_tech(chan)->answer(chan);
		}
		ast_setstate(chan, AST_STATE_UP);
		ast_channel_unlock(chan);
		break;
	case AST_STATE_UP:
		break;
	default:
		break;
	}

	ast_indicate(chan, -1);

	return res;
}

int __ast_answer(struct ast_channel *chan, unsigned int delay)
{
	int res = 0;
	enum ast_channel_state old_state;

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

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

			AST_LIST_HEAD_INIT_NOLOCK(&frames);

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

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

				AST_LIST_INSERT_HEAD(&frames, new_frame, frame_list);

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

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

				if (done) {
					break;
				}
			}

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

	return res;
}

int ast_answer(struct ast_channel *chan)
{
	return __ast_answer(chan, 0);
}

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

int ast_channel_get_duration(struct ast_channel *chan)
{
	ast_assert(NULL != chan);

	if (ast_tvzero(ast_channel_creationtime(chan))) {
		return 0;
	}
	return (ast_tvdiff_ms(ast_tvnow(), ast_channel_creationtime(chan)) / 1000);
}

int ast_channel_get_up_time(struct ast_channel *chan)
{
	ast_assert(NULL != chan);

	if (ast_tvzero(ast_channel_answertime(chan))) {
		return 0;
	}
	return (ast_tvdiff_ms(ast_tvnow(), ast_channel_answertime(chan)) / 1000);
}

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

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

void ast_deactivate_generator(struct ast_channel *chan)
{
	ast_channel_lock(chan);
	deactivate_generator_nolock(chan);
	ast_channel_unlock(chan);
}

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

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

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