TT#72000 add different endpoint detection algorithms

Change-Id: I791dba23450cab31bc5744a6156965afbb8a3b5c

daemon/main.c

@@ -308,6 +308,7 @@ static void options(int *argc, char ***argv) {
 	double max_load = 0;
 	double max_cpu = 0;
 	char *dtmf_udp_ep = NULL;
+	char *endpoint_learning = NULL;
 
 	GOptionEntry e[] = {
 		{ "table",	't', 0, G_OPTION_ARG_INT,	&rtpe_config.kernel_table,		"Kernel table to use",		"INT"		},
@@ -374,6 +375,7 @@ static void options(int *argc, char ***argv) {
 		{ "mysql-user",	0,   0,	G_OPTION_ARG_STRING,	&rtpe_config.mysql_user,"MySQL connection credentials",		"USERNAME"	},
 		{ "mysql-pass",	0,   0,	G_OPTION_ARG_STRING,	&rtpe_config.mysql_pass,"MySQL connection credentials",		"PASSWORD"	},
 		{ "mysql-query",0,   0,	G_OPTION_ARG_STRING,	&rtpe_config.mysql_query,"MySQL select query",			"STRING"	},
+		{ "endpoint-learning",0,0,G_OPTION_ARG_STRING,	&endpoint_learning,	"RTP endpoint learning algorithm",	"delayed|immediate|off|heuristic"	},
 		{ NULL, }
 	};
 
@@ -547,6 +549,21 @@ static void options(int *argc, char ***argv) {
 			die("Too many '%%' placeholders (%u) present in --mysql-query='%s'",
 					count, rtpe_config.mysql_query);
 	}
+
+	enum endpoint_learning el_config = EL_DELAYED;
+	if (endpoint_learning) {
+		if (!strcasecmp(endpoint_learning, "delayed"))
+			el_config = EL_DELAYED;
+		else if (!strcasecmp(endpoint_learning, "immediate"))
+			el_config = EL_IMMEDIATE;
+		else if (!strcasecmp(endpoint_learning, "off"))
+			el_config = EL_OFF;
+		else if (!strcasecmp(endpoint_learning, "heuristic"))
+			el_config = EL_HEURISTIC;
+		else
+			die("Invalid --endpoint-learning option ('%s')", endpoint_learning);
+	}
+	rtpe_config.endpoint_learning = el_config;
 }
 
 void fill_initial_rtpe_cfg(struct rtpengine_config* ini_rtpe_cfg) {
@@ -608,6 +625,7 @@ void fill_initial_rtpe_cfg(struct rtpengine_config* ini_rtpe_cfg) {
 	ini_rtpe_cfg->redis_ep = rtpe_config.redis_ep;
 	ini_rtpe_cfg->redis_write_ep = rtpe_config.redis_write_ep;
 	ini_rtpe_cfg->homer_ep = rtpe_config.homer_ep;
+	ini_rtpe_cfg->endpoint_learning = rtpe_config.endpoint_learning;
 
 	ini_rtpe_cfg->b2b_url = g_strdup(rtpe_config.b2b_url);
 	ini_rtpe_cfg->redis_auth = g_strdup(rtpe_config.redis_auth);

daemon/media_socket.c

@@ -1532,7 +1532,7 @@ static int media_packet_address_check(struct packet_handler_ctx *phc)
 	}
 
 	/* do not pay attention to source addresses of incoming packets for asymmetric streams */
-	if (MEDIA_ISSET(phc->mp.media, ASYMMETRIC))
+	if (MEDIA_ISSET(phc->mp.media, ASYMMETRIC) || rtpe_config.endpoint_learning == EL_OFF)
 		PS_SET(phc->mp.stream, CONFIRMED);
 
 	/* confirm sink for unidirectional streams in order to kernelize */
@@ -1574,22 +1574,55 @@ static int media_packet_address_check(struct packet_handler_ctx *phc)
 		goto out;
 	}
 
+	const struct endpoint *use_endpoint_confirm = &phc->mp.fsin;
+
+	if (rtpe_config.endpoint_learning == EL_IMMEDIATE)
+		goto confirm_now;
+
+	if (rtpe_config.endpoint_learning == EL_HEURISTIC
+			&& phc->mp.stream->advertised_endpoint.address.family
+			&& phc->mp.stream->advertised_endpoint.port)
+	{
+		// possible endpoints that can be detected in order of preference:
+		// 0: endpoint that matches the address advertised in the SDP
+		// 1: endpoint with the same address but different port
+		// 2: endpoint with the same port but different address
+		// 3: endpoint with both different port and different address
+		unsigned int idx = 0;
+		if (phc->mp.fsin.port != phc->mp.stream->advertised_endpoint.port)
+			idx |= 1;
+		if (memcmp(&phc->mp.fsin.address, &phc->mp.stream->advertised_endpoint.address,
+					sizeof(sockaddr_t)))
+			idx |= 2;
+
+		// fill appropriate slot
+		phc->mp.stream->detected_endpoints[idx] = phc->mp.fsin;
+
+		// now grab the best matched endpoint
+		for (idx = 0; idx < 4; idx++) {
+			use_endpoint_confirm = &phc->mp.stream->detected_endpoints[idx];
+			if (use_endpoint_confirm->address.family)
+				break;
+		}
+	}
+
 	/* wait at least 3 seconds after last signal before committing to a particular
 	 * endpoint address */
 	if (!phc->mp.call->last_signal || rtpe_now.tv_sec <= phc->mp.call->last_signal + 3)
 		goto update_peerinfo;
 
+confirm_now:
 	phc->kernelize = 1;
 	phc->update = 1;
 
-	ilog(LOG_INFO, "Confirmed peer address as %s%s%s", FMT_M(endpoint_print_buf(&phc->mp.fsin)));
+	ilog(LOG_INFO, "Confirmed peer address as %s%s%s", FMT_M(endpoint_print_buf(use_endpoint_confirm)));
 
 	PS_SET(phc->mp.stream, CONFIRMED);
 
 update_peerinfo:
 	mutex_lock(&phc->mp.stream->out_lock);
 	endpoint = phc->mp.stream->endpoint;
-	phc->mp.stream->endpoint = phc->mp.fsin;
+	phc->mp.stream->endpoint = *use_endpoint_confirm;
 	if (memcmp(&endpoint, &phc->mp.stream->endpoint, sizeof(endpoint))) {
 		phc->unkernelize = 1;
 		phc->update = 1;

daemon/rtpengine.pod

@@ -655,6 +655,22 @@ An example configuration might look like this:
 
   mysql-query = select data from voip.files where id = %llu
 
+=item B<--endpoint-learning=>B<delayed>|B<immediate>|B<off>|B<heuristic>
+
+Chooses one of the available algorithms to learn RTP endpoint addresses. The
+legacy setting is B<delayed> which waits 3 seconds before committing to an
+endpoint address, which is then learned from the first incoming RTP packet seen
+after this delay. The setting B<immediate> learns the endpoint address from the
+first incoming packet seen without the 3-second delay. Using B<off> disables
+endpoint learning altogether, likely breaking clients behind NAT. The setting
+B<heuristic> includes the 3-second delay, but source addresses seen from
+incoming RTP packets are ranked according to preference: If a packet with a
+source address and port matching the SDP address is seen, this address is used.
+Otherwise, if a packet with a matching source address (but a different port) is
+seen, that address is used. Otherwise, if a packet with a matching source port
+(but different address) is seen, that address is used. Otherwise, the source
+address of any incoming packet seen is used.
+
 =back
 
 =head1 INTERFACES

include/call.h

@@ -260,6 +260,7 @@ struct packet_stream {
 	struct packet_stream	*rtcp_sibling;	/* LOCK: call->master_lock */
 	const struct streamhandler *handler;	/* LOCK: in_lock */
 	struct endpoint		endpoint;	/* LOCK: out_lock */
+	struct endpoint		detected_endpoints[4];	/* LOCK: out_lock */
 	struct endpoint		advertised_endpoint; /* RO */
 	struct crypto_context	crypto;		/* OUT direction, LOCK: out_lock */
 	struct ssrc_ctx		*ssrc_in,	/* LOCK: in_lock */ // XXX eliminate these

include/main.h

@@ -18,6 +18,14 @@ enum log_format {
 
 	__LF_LAST
 };
+enum endpoint_learning {
+	EL_DELAYED = 0,
+	EL_IMMEDIATE = 1,
+	EL_OFF = 2,
+	EL_HEURISTIC = 3,
+
+	__EL_LAST
+};
 
 struct rtpengine_config {
 	/* everything below protected by config_lock */
@@ -84,6 +92,7 @@ struct rtpengine_config {
 	char			*mysql_pass;
 	char			*mysql_query;
 	endpoint_t		dtmf_udp_ep;
+	enum endpoint_learning	endpoint_learning;
 };