Add new option to configure ICE nomination mode, if libnice is recent…

… enough (meetecho#2541)

* Add new option to configure ICE nomination mode, if libnice is recent enough
* Added support for libnice keepalive-conncheck property

conf/janus.jcfg.sample.in

@@ -239,7 +239,15 @@ media: {
 # configured to do full-trickle (Janus also trickles its candidates to
 # users) rather than the default half-trickle (Janus supports trickle
 # candidates from users, but sends its own within the SDP), and whether
-# it should work in ICE-Lite mode (by default it doesn't). Finally,
+# it should work in ICE-Lite mode (by default it doesn't). If libnice is
+# at least 0.1.15, you can choose which ICE nomination mode to use: valid
+# values are "regular" and "aggressive" (the default depends on the libnice
+# version itself; if we can set it, we set regular nomination). You can
+# also configure whether to use connectivity checks as keep-alives, which
+# might help detecting when a peer is no longer available (notice that
+# current libnice master is breaking connections after 50 seconds when
+# keepalive-conncheck is being used, so if you want to use it, better
+# sticking to 0.1.18 until the issue is addressed upstream). Finally,
 # you can also enable ICE-TCP support (beware that this may lead to problems
 # if you do not enable ICE Lite as well), choose which interfaces should
 # be used for gathering candidates, and enable or disable the
@@ -249,6 +257,8 @@ nat: {
 	#stun_port = 3478
 	nice_debug = false
 	#full_trickle = true
+	#ice_nomination = "regular"
+	#ice_keepalive_conncheck = true
 	#ice_lite = true
 	#ice_tcp = true
 

configure.ac

@@ -402,6 +402,12 @@ AC_CHECK_LIB([nice],
              [AC_MSG_NOTICE([libnice version does not have nice_agent_close_async])]
              )
 
+AC_CHECK_LIB([nice],
+             [nice_agent_new_full],
+             [AC_DEFINE(HAVE_ICE_NOMINATION)],
+             [AC_MSG_NOTICE([libnice version does not have nice_agent_new_full])]
+             )
+
 AC_CHECK_LIB([dl],
              [dlopen],
              [JANUS_MANUAL_LIBS="${JANUS_MANUAL_LIBS} -ldl"],

ice.c

@@ -101,6 +101,41 @@ gboolean janus_ice_is_ipv6_enabled(void) {
 	return janus_ipv6_enabled;
 }
 
+#ifdef HAVE_ICE_NOMINATION
+/* Since libnice 0.1.15, we can configure the ICE nomination mode: it was
+ * always "aggressive" before, we set it to "regular" by default if we can */
+static NiceNominationMode janus_ice_nomination = NICE_NOMINATION_MODE_REGULAR;
+void janus_ice_set_nomination_mode(const char *nomination) {
+	if(nomination == NULL) {
+		JANUS_LOG(LOG_WARN, "Invalid ICE nomination mode, falling back to 'regular'\n");
+	} else if(!strcasecmp(nomination, "regular")) {
+		JANUS_LOG(LOG_INFO, "Configuring Janus to use ICE regular nomination\n");
+		janus_ice_nomination = NICE_NOMINATION_MODE_REGULAR;
+	} else if(!strcasecmp(nomination, "aggressive")) {
+		JANUS_LOG(LOG_INFO, "Configuring Janus to use ICE aggressive nomination\n");
+		janus_ice_nomination = NICE_NOMINATION_MODE_AGGRESSIVE;
+	} else {
+		JANUS_LOG(LOG_WARN, "Unsupported ICE nomination mode '%s', falling back to 'regular'\n", nomination);
+	}
+}
+const char *janus_ice_get_nomination_mode(void) {
+	return (janus_ice_nomination == NICE_NOMINATION_MODE_REGULAR ? "regular" : "aggressive");
+}
+#endif
+
+/* Keepalive via connectivity checks */
+static gboolean janus_ice_keepalive_connckecks = FALSE;
+void janus_ice_set_keepalive_conncheck_enabled(gboolean enabled) {
+	janus_ice_keepalive_connckecks = enabled;
+	if(janus_ice_keepalive_connckecks) {
+		JANUS_LOG(LOG_INFO, "Using connectivity checks as PeerConnection keep-alives\n");
+		JANUS_LOG(LOG_WARN, "Notice that the current libnice master is breaking connections after 50s when keepalive-conncheck enabled. As such, better to stick to 0.1.18 until the issue is addressed upstream\n");
+	}
+}
+gboolean janus_ice_is_keepalive_conncheck_enabled(void) {
+	return janus_ice_keepalive_connckecks;
+}
+
 /* Opaque IDs set by applications are by default only passed to event handlers
  * for correlation purposes, but not sent back to the user or application in
  * the related Janus API responses or events, unless configured otherwise */
@@ -3461,6 +3496,10 @@ int janus_ice_setup_local(janus_ice_handle *handle, int offer, int audio, int vi
 		"main-context", handle->mainctx,
 		"reliable", FALSE,
 		"full-mode", janus_ice_lite_enabled ? FALSE : TRUE,
+#ifdef HAVE_ICE_NOMINATION
+		"nomination-mode", janus_ice_nomination,
+#endif
+		"keepalive-conncheck", janus_ice_keepalive_connckecks ? FALSE : TRUE,
 #ifdef HAVE_LIBNICE_TCP
 		"ice-udp", TRUE,
 		"ice-tcp", janus_ice_tcp_enabled ? TRUE : FALSE,

ice.h

@@ -129,6 +129,22 @@ gboolean janus_ice_is_mdns_enabled(void);
 /*! \brief Method to check whether IPv6 candidates are enabled/supported or not
  * @returns true if IPv6 candidates are enabled/supported, false otherwise */
 gboolean janus_ice_is_ipv6_enabled(void);
+#ifdef HAVE_ICE_NOMINATION
+/*! \brief Method to configure the ICE nomination mode (regular or aggressive)
+ * @param[in] nomination The ICE nomination mode (regular or aggressive) */
+void janus_ice_set_nomination_mode(const char *nomination);
+/*! \brief Method to return a string description of the configured ICE nomination mode
+ * @returns "regular" or "aggressive" */
+const char *janus_ice_get_nomination_mode(void);
+#endif
+/*! \brief Method to enable/disable connectivity checks as keepalives for PeerConnections.
+ * \note The main rationale behind this setting is provided in the libnice documentation:
+ * https://libnice.freedesktop.org/libnice/NiceAgent.html#NiceAgent--keepalive-conncheck
+ * @param[in] enabled Whether the functionality should be enabled or disabled */
+void janus_ice_set_keepalive_conncheck_enabled(gboolean enabled);
+/*! \brief Method to check whether connectivity checks will be used as keepalives
+ * @returns true if enabled, false (default) otherwise */
+gboolean janus_ice_is_keepalive_conncheck_enabled(void);
 /*! \brief Method to modify the min NACK value (i.e., the minimum time window of packets per handle to store for retransmissions)
  * @param[in] mnq The new min NACK value */
 void janus_set_min_nack_queue(uint16_t mnq);
@@ -140,7 +156,7 @@ uint16_t janus_get_min_nack_queue(void);
  * keyframe, as any missing packet won't be needed since the keyframe will allow the
  * media recipient to still restore a complete image anyway. Since this optimization
  * seems to cause some issues in some edge cases, it's disabled by default.
- * @param[in] optimize Whether the opzimization should be enabled or disabled */
+ * @param[in] optimize Whether the optimization should be enabled or disabled */
 void janus_set_nack_optimizations_enabled(gboolean optimize);
 /*! \brief Method to check whether NACK optimizations on outgoing keyframes are enabled or not
  * @returns optimize if optimizations are enabled, false otherwise */

janus.c

@@ -346,6 +346,10 @@ static json_t *janus_info(const char *transaction) {
 	json_object_set_new(info, "ipv6", janus_ice_is_ipv6_enabled() ? json_true() : json_false());
 	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());
+#ifdef HAVE_ICE_NOMINATION
+	json_object_set_new(info, "ice-nomination", json_string(janus_ice_get_nomination_mode()));
+#endif
+	json_object_set_new(info, "ice-keepalive-conncheck", janus_ice_is_keepalive_conncheck_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()));
@@ -4787,6 +4791,17 @@ gint main(int argc, char *argv[])
 			JANUS_LOG(LOG_ERR, "Invalid STUN address %s:%u. STUN will be disabled\n", stun_server, stun_port);
 		}
 	}
+	item = janus_config_get(config, config_nat, janus_config_type_item, "ice_nomination");
+	if(item && item->value) {
+#ifndef HAVE_ICE_NOMINATION
+		JANUS_LOG(LOG_WARN, "This version of libnice doesn't support setting the ICE nomination mode, ignoring '%s'\n", item->value);
+#else
+		janus_ice_set_nomination_mode(item->value);
+#endif
+	}
+	item = janus_config_get(config, config_nat, janus_config_type_item, "ice_keepalive_conncheck");
+	if(item && item->value)
+		janus_ice_set_keepalive_conncheck_enabled(janus_is_true(item->value));
 	if(janus_ice_set_turn_server(turn_server, turn_port, turn_type, turn_user, turn_pwd) < 0) {
 		if(!ignore_unreachable_ice_server) {
 			JANUS_LOG(LOG_FATAL, "Invalid TURN address %s:%u\n", turn_server, turn_port);