Added option to ignore mDNS candidates

conf/janus.jcfg.sample.in

@@ -231,6 +231,14 @@ nat: {
 	#ice_lite = true
 	#ice_tcp = true
 
+	# By default Janus tries to resolve mDNS (.local) candidates: since
+	# this is currently done synchronously and might keep the API busy,
+	# especially in case mDNS resolution takes a long time to timeout,
+	# you can choose to drop all .local candidates instead, which is
+	# helpful in case you know clients will never be in the same private
+	# network as the one the Janus instance is running from.
+	#ignore_mdns = true
+
 	# In case you're deploying Janus on a server which is configured with
 	# a 1:1 NAT (e.g., Amazon EC2), you might want to also specify the public
 	# address of the machine using the setting below. This will result in

ice.c

@@ -89,6 +89,12 @@ gboolean janus_ice_is_full_trickle_enabled(void) {
 	return janus_full_trickle_enabled;
 }
 
+/* mDNS resolution support */
+static gboolean janus_mdns_enabled;
+gboolean janus_ice_is_mdns_enabled(void) {
+	return janus_mdns_enabled;
+}
+
 /* IPv6 support (still mostly WIP) */
 static gboolean janus_ipv6_enabled;
 gboolean janus_ice_is_ipv6_enabled(void) {
@@ -784,10 +790,12 @@ void janus_ice_trickle_destroy(janus_ice_trickle *trickle) {
 
 
 /* libnice initialization */
-void janus_ice_init(gboolean ice_lite, gboolean ice_tcp, gboolean full_trickle, gboolean ipv6, uint16_t rtp_min_port, uint16_t rtp_max_port) {
+void janus_ice_init(gboolean ice_lite, gboolean ice_tcp, gboolean full_trickle, gboolean ignore_mdns,
+		gboolean ipv6, uint16_t rtp_min_port, uint16_t rtp_max_port) {
 	janus_ice_lite_enabled = ice_lite;
 	janus_ice_tcp_enabled = ice_tcp;
 	janus_full_trickle_enabled = full_trickle;
+	janus_mdns_enabled = !ignore_mdns;
 	janus_ipv6_enabled = ipv6;
 	JANUS_LOG(LOG_INFO, "Initializing ICE stuff (%s mode, ICE-TCP candidates %s, %s-trickle, IPv6 support %s)\n",
 		janus_ice_lite_enabled ? "Lite" : "Full",
@@ -822,6 +830,8 @@ void janus_ice_init(gboolean ice_lite, gboolean ice_tcp, gboolean full_trickle,
 		JANUS_LOG(LOG_INFO, "ICE port range: %"SCNu16"-%"SCNu16"\n", rtp_range_min, rtp_range_max);
 #endif
 	}
+	if(!janus_mdns_enabled)
+		JANUS_LOG(LOG_WARN, "mDNS resolution disabled, .local candidates will be ignored\n");
 
 	/* We keep track of plugin sessions to avoid problems */
 	plugin_sessions = g_hash_table_new_full(NULL, NULL, NULL, (GDestroyNotify)janus_plugin_session_dereference);

ice.h

@@ -35,10 +35,12 @@
  * @param[in] ice_lite Whether the ICE Lite mode should be enabled or not
  * @param[in] ice_tcp Whether ICE-TCP support should be enabled or not (only libnice >= 0.1.8, currently broken)
  * @param[in] full_trickle Whether full-trickle must be used (instead of half-trickle)
+ * @param[in] ignore_mdns Whether mDNS candidates should be ignored, instead of resolved
  * @param[in] ipv6 Whether IPv6 candidates must be negotiated or not
  * @param[in] rtp_min_port Minimum port to use for RTP/RTCP, if a range is to be used
  * @param[in] rtp_max_port Maximum port to use for RTP/RTCP, if a range is to be used */
-void janus_ice_init(gboolean ice_lite, gboolean ice_tcp, gboolean full_trickle, gboolean ipv6, uint16_t rtp_min_port, uint16_t rtp_max_port);
+void janus_ice_init(gboolean ice_lite, gboolean ice_tcp, gboolean full_trickle, gboolean ignore_mdns,
+	gboolean ipv6, uint16_t rtp_min_port, uint16_t rtp_max_port);
 /*! \brief ICE stuff de-initialization */
 void janus_ice_deinit(void);
 /*! \brief Method to check whether a STUN server is reachable
@@ -119,6 +121,9 @@ gboolean janus_ice_is_ice_tcp_enabled(void);
 /*! \brief Method to check whether full-trickle support is enabled or not
  * @returns true if full-trickle support is enabled, false otherwise */
 gboolean janus_ice_is_full_trickle_enabled(void);
+/*! \brief Method to check whether mDNS resolution is enabled or not
+ * @returns true if mDNS resolution is enabled, false otherwise */
+gboolean janus_ice_is_mdns_enabled(void);
 /*! \brief Method to check whether IPv6 candidates are enabled/supported or not (still WIP)
  * @returns true if IPv6 candidates are enabled/supported, false otherwise */
 gboolean janus_ice_is_ipv6_enabled(void);

janus.c

@@ -296,6 +296,7 @@ static json_t *janus_info(const char *transaction) {
 	json_object_set_new(info, "ice-lite", janus_ice_is_ice_lite_enabled() ? json_true() : json_false());
 	json_object_set_new(info, "ice-tcp", janus_ice_is_ice_tcp_enabled() ? json_true() : json_false());
 	json_object_set_new(info, "full-trickle", janus_ice_is_full_trickle_enabled() ? json_true() : json_false());
+	json_object_set_new(info, "mdns-enabled", janus_ice_is_mdns_enabled() ? json_true() : json_false());
 	json_object_set_new(info, "min-nack-queue", json_integer(janus_get_min_nack_queue()));
 	json_object_set_new(info, "twcc-period", json_integer(janus_get_twcc_period()));
 	if(janus_ice_get_stun_server() != NULL) {
@@ -4438,7 +4439,8 @@ gint main(int argc, char *argv[])
 #endif
 	const char *nat_1_1_mapping = NULL;
 	uint16_t rtp_min_port = 0, rtp_max_port = 0;
-	gboolean ice_lite = FALSE, ice_tcp = FALSE, full_trickle = FALSE, ipv6 = FALSE, ignore_unreachable_ice_server = FALSE;
+	gboolean ice_lite = FALSE, ice_tcp = FALSE, full_trickle = FALSE, ipv6 = FALSE,
+		ignore_mdns = FALSE, ignore_unreachable_ice_server = FALSE;
 	item = janus_config_get(config, config_media, janus_config_type_item, "ipv6");
 	ipv6 = (item && item->value) ? janus_is_true(item->value) : FALSE;
 	item = janus_config_get(config, config_media, janus_config_type_item, "rtp_port_range");
@@ -4485,6 +4487,9 @@ gint main(int argc, char *argv[])
 		JANUS_LOG(LOG_WARN, "Invalid STUN port: %s (disabling STUN)\n", item->value);
 		stun_server = NULL;
 	}
+	/* Check if we should drop mDNS candidates */
+	item = janus_config_get(config, config_nat, janus_config_type_item, "ignore_mdns");
+	ignore_mdns = (item && item->value) ? janus_is_true(item->value) : FALSE;
 	/* Any 1:1 NAT mapping to take into account? */
 	item = janus_config_get(config, config_nat, janus_config_type_item, "nat_1_1_mapping");
 	if(item && item->value) {
@@ -4532,7 +4537,7 @@ gint main(int argc, char *argv[])
 	if(item && item->value)
 		janus_ice_set_static_event_loops(atoi(item->value));
 	/* Initialize the ICE stack now */
-	janus_ice_init(ice_lite, ice_tcp, full_trickle, ipv6, rtp_min_port, rtp_max_port);
+	janus_ice_init(ice_lite, ice_tcp, full_trickle, ignore_mdns, ipv6, rtp_min_port, rtp_max_port);
 	if(janus_ice_set_stun_server(stun_server, stun_port) < 0) {
 		if(!ignore_unreachable_ice_server) {
 			JANUS_LOG(LOG_FATAL, "Invalid STUN address %s:%u\n", stun_server, stun_port);

sdp.c

@@ -666,7 +666,12 @@ int janus_sdp_parse_candidate(void *ice_stream, const char *candidate, int trick
 	if(res >= 7) {
 		if(strstr(rip, ".local")) {
 			/* The IP is actually an mDNS address, try to resolve it
-			 * https://tools.ietf.org/html/draft-ietf-rtcweb-mdns-ice-candidates-00 */
+			 * https://tools.ietf.org/html/draft-ietf-rtcweb-mdns-ice-candidates-04 */
+			if(!janus_ice_is_mdns_enabled()) {
+				/* ...unless mDNS resolution is disabled, in which case ignore this candidate */
+				JANUS_LOG(LOG_VERB, "[%"SCNu64"] mDNS candidate ignored\n", handle->handle_id);
+				return 0;
+			}
 			struct addrinfo *info = NULL;
 			janus_network_address addr;
 			janus_network_address_string_buffer addr_buf;
@@ -798,13 +803,11 @@ int janus_sdp_parse_candidate(void *ice_stream, const char *candidate, int trick
 					added = nice_address_set_from_string(&c->base_addr, rrelip);
 					if(added)
 						nice_address_set_port(&c->base_addr, rrelport);
-
 				} else if(c->type == NICE_CANDIDATE_TYPE_RELAYED) {
 					/* FIXME Do we really need the base address for TURN? */
 					added = nice_address_set_from_string(&c->base_addr, rrelip);
 					if(added)
 						nice_address_set_port(&c->base_addr, rrelport);
-
 				}
 				if(!added) {
 					JANUS_LOG(LOG_WARN, "[%"SCNu64"]    Invalid base address '%s', skipping %s candidate (%s)\n",