channel locking: Add locking for channel snapshot creation

Original commit message by mmichelson (asterisk 12 r403311):

"This adds channel locks around calls to create channel snapshots as well
as other functions which operate on a channel and then end up
creating a channel snapshot. Functions that expect the channel to be
locked prior to being called have had their documentation updated to
indicate such."

The above was initially committed and then reverted at r403398.  The problem
was found to be in core_local.c in the publish_local_bridge_message function.
The ast_unreal_lock_all function locks and adds a reference to the returned
channels and while they were being unlocked they were not being unreffed when
no longer needed.  Fixed by unreffing the channels.

Also in bridge.c a lock was obtained on "other->chan", but then an attempt was
made to unlock "other" and not the previously locked channel.  Fixed by
unlocking "other->chan"

(closes issue ASTERISK-22709)
Reported by: John Bigelow
........

Merged revisions 404237 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@404260 f38db490-d61c-443f-a65b-d21fe96a405b

addons/chan_mobile.c

@@ -878,7 +878,6 @@ static struct ast_channel *mbl_new(int state, struct mbl_pvt *pvt, char *cid_num
 	if (pvt->sco_socket != -1) {
 		ast_channel_set_fd(chn, 0, pvt->sco_socket);
 	}
-
 	ast_channel_unlock(chn);
 
 	return chn;

addons/chan_ooh323.c

@@ -2164,8 +2164,8 @@ int onCallEstablished(ooCallData *call)
 			}
 
 			ast_queue_control(c, AST_CONTROL_ANSWER);
-   			ast_channel_unlock(p->owner);
 			ast_publish_channel_state(c);
+			ast_channel_unlock(p->owner);
 		}
 		ast_mutex_unlock(&p->lock);
 

apps/app_agent_pool.c

@@ -1465,7 +1465,9 @@ static void agent_logout(struct agent_pvt *agent)
 		ast_bridge_destroy(caller_bridge, AST_CAUSE_USER_BUSY);
 	}
 
+	ast_channel_lock(logged);
 	send_agent_logoff(logged, agent->username, time_logged_in);
+	ast_channel_unlock(logged);
 	ast_verb(2, "Agent '%s' logged out.  Logged in for %ld seconds.\n",
 		agent->username, time_logged_in);
 	ast_channel_unref(logged);
@@ -2046,7 +2048,9 @@ static int agent_login_exec(struct ast_channel *chan, const char *data)
 	ast_verb(2, "Agent '%s' logged in (format %s/%s)\n", agent->username,
 		ast_getformatname(ast_channel_readformat(chan)),
 		ast_getformatname(ast_channel_writeformat(chan)));
+	ast_channel_lock(chan);
 	send_agent_login(chan, agent->username);
+	ast_channel_unlock(chan);
 
 	agent_run(agent, chan);
 	return -1;

apps/app_confbridge.c

@@ -1379,7 +1379,9 @@ static int alloc_playback_chan(struct confbridge_conference *conference)
 	}
 
 	/* To make sure playback_chan has the same language of that profile */
+	ast_channel_lock(conference->playback_chan);
 	ast_channel_language_set(conference->playback_chan, conference->b_profile.language);
+	ast_channel_unlock(conference->playback_chan);
 
 	ast_debug(1, "Created announcer channel '%s' to conference bridge '%s'\n",
 		ast_channel_name(conference->playback_chan), conference->name);

apps/app_dial.c

@@ -2104,13 +2104,15 @@ static int dial_exec_full(struct ast_channel *chan, const char *data, struct ast
 	struct ast_party_caller caller;
 
 	/* Reset all DIAL variables back to blank, to prevent confusion (in case we don't reset all of them). */
+	ast_channel_lock(chan);
 	ast_channel_stage_snapshot(chan);
 	pbx_builtin_setvar_helper(chan, "DIALSTATUS", "");
 	pbx_builtin_setvar_helper(chan, "DIALEDPEERNUMBER", "");
 	pbx_builtin_setvar_helper(chan, "DIALEDPEERNAME", "");
 	pbx_builtin_setvar_helper(chan, "ANSWEREDTIME", "");
 	pbx_builtin_setvar_helper(chan, "DIALEDTIME", "");
 	ast_channel_stage_snapshot_done(chan);
+	ast_channel_unlock(chan);
 
 	if (ast_strlen_zero(data)) {
 		ast_log(LOG_WARNING, "Dial requires an argument (technology/resource)\n");
@@ -2443,15 +2445,17 @@ static int dial_exec_full(struct ast_channel *chan, const char *data, struct ast
 			continue;
 		}
 
+		ast_channel_lock(tc);
 		ast_channel_stage_snapshot(tc);
+		ast_channel_unlock(tc);
 
 		ast_channel_get_device_name(tc, device_name, sizeof(device_name));
 		if (!ignore_cc) {
 			ast_cc_extension_monitor_add_dialstring(chan, tmp->interface, device_name);
 		}
-		pbx_builtin_setvar_helper(tc, "DIALEDPEERNUMBER", tmp->number);
 
 		ast_channel_lock_both(tc, chan);
+		pbx_builtin_setvar_helper(tc, "DIALEDPEERNUMBER", tmp->number);
 
 		/* Setup outgoing SDP to match incoming one */
 		if (!AST_LIST_FIRST(&out_chans) && !rest && CAN_EARLY_BRIDGE(peerflags, chan, tc)) {
@@ -2724,8 +2728,10 @@ static int dial_exec_full(struct ast_channel *chan, const char *data, struct ast
 			number = ast_strdupa(number);
 		}
 		ast_channel_unlock(peer);
+		ast_channel_lock(chan);
 		pbx_builtin_setvar_helper(chan, "DIALEDPEERNUMBER", number);
 		ast_channel_stage_snapshot_done(chan);
+		ast_channel_unlock(chan);
 
 		if (!ast_strlen_zero(args.url) && ast_channel_supports_html(peer) ) {
 			ast_debug(1, "app_dial: sendurl=%s.\n", args.url);
@@ -2811,16 +2817,18 @@ static int dial_exec_full(struct ast_channel *chan, const char *data, struct ast
 			/* chan and peer are going into the PBX; as such neither are considered
 			 * outgoing channels any longer */
 			ast_clear_flag(ast_channel_flags(chan), AST_FLAG_OUTGOING);
-			ast_channel_stage_snapshot(peer);
-			ast_clear_flag(ast_channel_flags(peer), AST_FLAG_OUTGOING);
 
 			ast_replace_subargument_delimiter(opt_args[OPT_ARG_GOTO]);
 			ast_parseable_goto(chan, opt_args[OPT_ARG_GOTO]);
 			/* peer goes to the same context and extension as chan, so just copy info from chan*/
+			ast_channel_lock(peer);
+			ast_channel_stage_snapshot(peer);
+			ast_clear_flag(ast_channel_flags(peer), AST_FLAG_OUTGOING);
 			ast_channel_context_set(peer, ast_channel_context(chan));
 			ast_channel_exten_set(peer, ast_channel_exten(chan));
 			ast_channel_priority_set(peer, ast_channel_priority(chan) + 2);
 			ast_channel_stage_snapshot_done(peer);
+			ast_channel_unlock(peer);
 			if (ast_pbx_start(peer)) {
 				ast_autoservice_chan_hangup_peer(chan, peer);
 			}
@@ -2970,7 +2978,9 @@ static int dial_exec_full(struct ast_channel *chan, const char *data, struct ast
 		if (!res) {
 			if (!ast_tvzero(calldurationlimit)) {
 				struct timeval whentohangup = ast_tvadd(ast_tvnow(), calldurationlimit);
+				ast_channel_lock(peer);
 				ast_channel_whentohangup_set(peer, &whentohangup);
+				ast_channel_unlock(peer);
 			}
 			if (!ast_strlen_zero(dtmfcalled)) {
 				ast_verb(3, "Sending DTMF '%s' to the called party.\n", dtmfcalled);

apps/app_disa.c

@@ -381,8 +381,11 @@ static int disa_exec(struct ast_channel *chan, const char *data)
 				ast_set_callerid(chan, ourcidnum, ourcidname, ourcidnum);
 			}
 
-			if (!ast_strlen_zero(acctcode))
+			if (!ast_strlen_zero(acctcode)) {
+				ast_channel_lock(chan);
 				ast_channel_accountcode_set(chan, acctcode);
+				ast_channel_unlock(chan);
+			}
 
 			if (special_noanswer) {
 				ast_clear_flag(&cdr_flags, AST_CDR_FLAG_DISABLE);

apps/app_meetme.c

@@ -1384,7 +1384,9 @@ static void meetme_stasis_generate_msg(struct ast_conference *meetme_conference,
 		}
 	}
 
+	ast_channel_lock(chan);
 	msg = ast_channel_blob_create(chan, message_type, json_object);
+	ast_channel_unlock(chan);
 
 	if (!msg) {
 		return;

apps/app_queue.c

@@ -2040,8 +2040,12 @@ static void queue_publish_multi_channel_blob(struct ast_channel *caller, struct
 	RAII_VAR(struct ast_channel_snapshot *, caller_snapshot, NULL, ao2_cleanup);
 	RAII_VAR(struct ast_channel_snapshot *, agent_snapshot, NULL, ao2_cleanup);
 
+	ast_channel_lock(caller);
 	caller_snapshot = ast_channel_snapshot_create(caller);
+	ast_channel_unlock(caller);
+	ast_channel_lock(agent);
 	agent_snapshot = ast_channel_snapshot_create(agent);
+	ast_channel_unlock(agent);
 
 	if (!caller_snapshot || !agent_snapshot) {
 		return;
@@ -3452,7 +3456,9 @@ static int join_queue(char *queuename, struct queue_ent *qe, enum queue_result *
 				     "Queue", q->name,
 				     "Position", qe->pos,
 				     "Count", q->count);
+		ast_channel_lock(qe->chan);
 		ast_channel_publish_blob(qe->chan, queue_caller_join_type(), blob);
+		ast_channel_unlock(qe->chan);
 		ast_debug(1, "Queue '%s' Join, Channel '%s', Position '%d'\n", q->name, ast_channel_name(qe->chan), qe->pos );
 	}
 	ao2_unlock(q);
@@ -3731,7 +3737,9 @@ static void leave_queue(struct queue_ent *qe)
 					     "Queue", q->name,
 					     "Position", qe->pos,
 					     "Count", q->count);
+			ast_channel_lock(qe->chan);
 			ast_channel_publish_blob(qe->chan, queue_caller_leave_type(), blob);
+			ast_channel_unlock(qe->chan);
 			ast_debug(1, "Queue '%s' Leave, Channel '%s'\n", q->name, ast_channel_name(qe->chan));
 			/* Take us out of the queue */
 			if (prev) {
@@ -4329,10 +4337,13 @@ static void record_abandoned(struct queue_ent *qe)
 			     "Position", qe->pos,
 			     "OriginalPosition", qe->opos,
 			     "HoldTime", (int)(time(NULL) - qe->start));
-	ast_channel_publish_blob(qe->chan, queue_caller_abandon_type(), blob);
 
 	qe->parent->callsabandoned++;
 	ao2_unlock(qe->parent);
+
+	ast_channel_lock(qe->chan);
+	ast_channel_publish_blob(qe->chan, queue_caller_abandon_type(), blob);
+	ast_channel_unlock(qe->chan);
 }
 
 /*! \brief RNA == Ring No Answer. Common code that is executed when we try a queue member and they don't answer. */

apps/app_userevent.c

@@ -114,7 +114,9 @@ static int userevent_exec(struct ast_channel *chan, const char *data)
 		}
 	}
 
+	ast_channel_lock(chan);
 	ast_channel_publish_blob(chan, ast_channel_user_event_type(), blob);
+	ast_channel_unlock(chan);
 	return 0;
 }
 

apps/app_voicemail.c

@@ -10958,8 +10958,11 @@ static int vm_execmain(struct ast_channel *chan, const char *data)
 #endif
 
 	/* Set language from config to override channel language */
-	if (!ast_strlen_zero(vmu->language))
+	if (!ast_strlen_zero(vmu->language)) {
+		ast_channel_lock(chan);
 		ast_channel_language_set(chan, vmu->language);
+		ast_channel_unlock(chan);
+	}
 
 	/* Retrieve urgent, old and new message counts */
 	ast_debug(1, "Before open_mailbox\n");

channels/chan_alsa.c

@@ -601,7 +601,6 @@ static struct ast_channel *alsa_new(struct chan_alsa_pvt *p, int state, const ch
 	ast_jb_configure(tmp, &global_jbconf);
 
 	ast_channel_stage_snapshot_done(tmp);
-
 	ast_channel_unlock(tmp);
 
 	if (state != AST_STATE_DOWN) {

channels/chan_console.c

@@ -444,7 +444,6 @@ static struct ast_channel *console_new(struct console_pvt *pvt, const char *ext,
 	ast_jb_configure(chan, &global_jbconf);
 
 	ast_channel_stage_snapshot_done(chan);
-
 	ast_channel_unlock(chan);
 
 	if (state != AST_STATE_DOWN) {

channels/chan_dahdi.c

@@ -1667,7 +1667,9 @@ static void publish_dahdichannel(struct ast_channel *chan, int span, const char
 		return;
 	}
 
+	ast_channel_lock(chan);
 	ast_channel_publish_blob(chan, dahdichannel_type(), blob);
+	ast_channel_unlock(chan);
 }
 
 /*!
@@ -9616,6 +9618,7 @@ static void *analog_ss_thread(void *data)
 						getforward = 0;
 					} else {
 						res = tone_zone_play_tone(p->subs[idx].dfd, -1);
+						ast_channel_lock(chan);
 						ast_channel_exten_set(chan, exten);
 						if (!ast_strlen_zero(p->cid_num)) {
 							if (!p->hidecallerid)
@@ -9628,6 +9631,7 @@ static void *analog_ss_thread(void *data)
 								ast_set_callerid(chan, NULL, p->cid_name, NULL);
 						}
 						ast_setstate(chan, AST_STATE_RING);
+						ast_channel_unlock(chan);
 						dahdi_ec_enable(p);
 						res = ast_pbx_run(chan);
 						if (res) {
@@ -10391,8 +10395,10 @@ static void *analog_ss_thread(void *data)
 
 		my_handle_notify_message(chan, p, flags, -1);
 
+		ast_channel_lock(chan);
 		ast_setstate(chan, AST_STATE_RING);
 		ast_channel_rings_set(chan, 1);
+		ast_channel_unlock(chan);
 		p->ringt = p->ringt_base;
 		res = ast_pbx_run(chan);
 		if (res) {

channels/chan_gtalk.c

@@ -1226,7 +1226,6 @@ static struct ast_channel *gtalk_new(struct gtalk *client, struct gtalk_pvt *i,
 		ast_jb_configure(tmp, &global_jbconf);
 
 	ast_channel_stage_snapshot_done(tmp);
-
 	ast_channel_unlock(tmp);
 
 	if (state != AST_STATE_DOWN && ast_pbx_start(tmp)) {
@@ -1421,7 +1420,9 @@ static int gtalk_newcall(struct gtalk *client, ikspak *pak)
 	ast_format_cap_joint_copy(p->cap, p->peercap, p->jointcap);
 	ast_mutex_unlock(&p->lock);
 
+	ast_channel_lock(chan);
 	ast_setstate(chan, AST_STATE_RING);
+	ast_channel_unlock(chan);
 	if (ast_format_cap_is_empty(p->jointcap)) {
 		ast_log(LOG_WARNING, "Capabilities don't match : us - %s, peer - %s, combined - %s \n", ast_getformatname_multiple(s1, BUFSIZ, p->cap),
 			ast_getformatname_multiple(s2, BUFSIZ, p->peercap),

channels/chan_iax2.c

@@ -5804,7 +5804,6 @@ static struct ast_channel *ast_iax2_new(int callno, int state, iax2_format capab
 	}
 
 	ast_channel_stage_snapshot_done(tmp);
-
 	ast_channel_unlock(tmp);
 
 	if (state != AST_STATE_DOWN) {
@@ -12237,7 +12236,9 @@ static struct ast_channel *iax2_request(const char *type, struct ast_format_cap
 	if (c) {
 		struct ast_format_cap *joint;
 		if (callid) {
+			ast_channel_lock(c);
 			ast_channel_callid_set(c, callid);
+			ast_channel_unlock(c);
 		}
 
 		/* Choose a format we can live with */

channels/chan_jingle.c

@@ -941,7 +941,6 @@ static struct ast_channel *jingle_new(struct jingle *client, struct jingle_pvt *
 		ast_jb_configure(tmp, &global_jbconf);
 
 	ast_channel_stage_snapshot_done(tmp);
-
 	ast_channel_unlock(tmp);
 
 	if (state != AST_STATE_DOWN && ast_pbx_start(tmp)) {
@@ -1117,7 +1116,9 @@ static int jingle_newcall(struct jingle *client, ikspak *pak)
 	}
 
 	ast_mutex_unlock(&p->lock);
+	ast_channel_lock(chan);
 	ast_setstate(chan, AST_STATE_RING);
+	ast_channel_unlock(chan);
 	res = ast_pbx_start(chan);
 
 	switch (res) {

channels/chan_mgcp.c

@@ -1570,7 +1570,6 @@ static struct ast_channel *mgcp_new(struct mgcp_subchannel *sub, int state, cons
 		}
 
 		ast_channel_stage_snapshot_done(tmp);
-
 		ast_channel_unlock(tmp);
 
 		if (state != AST_STATE_DOWN) {
@@ -3048,6 +3047,7 @@ static void *mgcp_ss(void *data)
 				} else {
 					/*res = tone_zone_play_tone(p->subs[index].zfd, -1);*/
 					ast_indicate(chan, -1);
+					ast_channel_lock(chan);
 					ast_channel_exten_set(chan, p->dtmf_buf);
 					ast_channel_dialed(chan)->number.str = ast_strdup(p->dtmf_buf);
 					memset(p->dtmf_buf, 0, sizeof(p->dtmf_buf));
@@ -3056,6 +3056,7 @@ static void *mgcp_ss(void *data)
 						p->hidecallerid ? "" : p->cid_name,
 						ast_channel_caller(chan)->ani.number.valid ? NULL : p->cid_num);
 					ast_setstate(chan, AST_STATE_RING);
+					ast_channel_unlock(chan);
 					if (p->dtmfmode & MGCP_DTMF_HYBRID) {
 						p->dtmfmode |= MGCP_DTMF_INBAND;
 						ast_indicate(chan, -1);