Merge "res_pjsip: Add rtp_keepalive endpoint option."

5 files changed, 63 insertions, 1 deletions

diff --git a/res/res_pjsip.c b/res/res_pjsip.c
index 6d7e4f739..fefbff446 100644
--- a/res/res_pjsip.c
+++ b/res/res_pjsip.c
@@ -790,6 +790,14 @@
 						have this accountcode set on it.
 					</para></description>
 				</configOption>
+				<configOption name="rtp_keepalive">
+					<synopsis>Number of seconds between RTP comfort noise keepalive packets.</synopsis>
+					<description><para>
+						At the specified interval, Asterisk will send an RTP comfort noise frame. This may
+						be useful for situations where Asterisk is behind a NAT or firewall and must keep
+						a hole open in order to allow for media to arrive at Asterisk.
+					</para></description>
+				</configOption>
 			</configObject>
 			<configObject name="auth">
 				<synopsis>Authentication type</synopsis>
diff --git a/res/res_pjsip/pjsip_configuration.c b/res/res_pjsip/pjsip_configuration.c
index e2e5e06b9..31933e352 100644
--- a/res/res_pjsip/pjsip_configuration.c
+++ b/res/res_pjsip/pjsip_configuration.c
@@ -1880,6 +1880,7 @@ int ast_res_pjsip_initialize_configuration(void)
 	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "use_avpf", "no", OPT_BOOL_T, 1, FLDSET(struct ast_sip_endpoint, media.rtp.use_avpf));
 	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "force_avp", "no", OPT_BOOL_T, 1, FLDSET(struct ast_sip_endpoint, media.rtp.force_avp));
 	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "media_use_received_transport", "no", OPT_BOOL_T, 1, FLDSET(struct ast_sip_endpoint, media.rtp.use_received_transport));
+	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "rtp_keepalive", "0", OPT_UINT_T, 0, FLDSET(struct ast_sip_endpoint, media.rtp.keepalive));
 	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "one_touch_recording", "no", OPT_BOOL_T, 1, FLDSET(struct ast_sip_endpoint, info.recording.enabled));
 	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "inband_progress", "no", OPT_BOOL_T, 1, FLDSET(struct ast_sip_endpoint, inband_progress));
 	ast_sorcery_object_field_register_custom(sip_sorcery, "endpoint", "call_group", "", group_handler, callgroup_to_str, NULL, 0, 0);
diff --git a/res/res_pjsip_sdp_rtp.c b/res/res_pjsip_sdp_rtp.c
index 22c4529d9..e8654a91f 100644
--- a/res/res_pjsip_sdp_rtp.c
+++ b/res/res_pjsip_sdp_rtp.c
@@ -107,6 +107,39 @@ static void format_cap_only_type(struct ast_format_cap *caps, enum ast_media_typ
 	}
 }
 
+static int send_keepalive(const void *data)
+{
+	struct ast_sip_session_media *session_media = (struct ast_sip_session_media *) data;
+	struct ast_rtp_instance *rtp = session_media->rtp;
+	int keepalive;
+	time_t interval;
+	int send_keepalive;
+
+	if (!rtp) {
+		return 0;
+	}
+
+	keepalive = ast_rtp_instance_get_keepalive(rtp);
+
+	if (!ast_sockaddr_isnull(&session_media->direct_media_addr)) {
+		ast_debug(3, "Not sending RTP keepalive on RTP instance %p since direct media is in use\n", rtp);
+		return keepalive * 1000;
+	}
+
+	interval = time(NULL) - ast_rtp_instance_get_last_tx(rtp);
+	send_keepalive = interval >= keepalive;
+
+	ast_debug(3, "It has been %d seconds since RTP was last sent on instance %p. %sending keepalive\n",
+			(int) interval, rtp, send_keepalive ? "S" : "Not s");
+
+	if (send_keepalive) {
+		ast_rtp_instance_sendcng(rtp, 0);
+		return keepalive * 1000;
+	}
+
+	return (keepalive - interval) * 1000;
+}
+
 /*! \brief Internal function which creates an RTP instance */
 static int create_rtp(struct ast_sip_session *session, struct ast_sip_session_media *session_media, unsigned int ipv6)
 {
@@ -1228,6 +1261,17 @@ static int apply_negotiated_sdp_stream(struct ast_sip_session *session, struct a
 	/* This purposely resets the encryption to the configured in case it gets added later */
 	session_media->encryption = session->endpoint->media.rtp.encryption;
 
+	if (session->endpoint->media.rtp.keepalive > 0 &&
+			stream_to_media_type(session_media->stream_type) == AST_MEDIA_TYPE_AUDIO) {
+		ast_rtp_instance_set_keepalive(session_media->rtp, session->endpoint->media.rtp.keepalive);
+		/* Schedule the initial keepalive early in case this is being used to punch holes through
+		 * a NAT. This way there won't be an awkward delay before media starts flowing in some
+		 * scenarios.
+		 */
+		session_media->keepalive_sched_id = ast_sched_add_variable(sched, 500, send_keepalive,
+			session_media, 1);
+	}
+
 	return 1;
 }
 
@@ -1257,6 +1301,9 @@ static void change_outgoing_sdp_stream_media_address(pjsip_tx_data *tdata, struc
 static void stream_destroy(struct ast_sip_session_media *session_media)
 {
 	if (session_media->rtp) {
+		if (session_media->keepalive_sched_id != -1) {
+			AST_SCHED_DEL(sched, session_media->keepalive_sched_id);
+		}
 		ast_rtp_instance_stop(session_media->rtp);
 		ast_rtp_instance_destroy(session_media->rtp);
 	}
diff --git a/res/res_pjsip_session.c b/res/res_pjsip_session.c
index ce5237717..eff8bbb12 100644
--- a/res/res_pjsip_session.c
+++ b/res/res_pjsip_session.c
@@ -1220,6 +1220,7 @@ static int add_session_media(void *obj, void *arg, int flags)
 		return CMP_STOP;
 	}
 	session_media->encryption = session->endpoint->media.rtp.encryption;
+	session_media->keepalive_sched_id = -1;
 	/* Safe use of strcpy */
 	strcpy(session_media->stream_type, handler_list->stream_type);
 	ao2_link(session->media, session_media);
diff --git a/res/res_rtp_asterisk.c b/res/res_rtp_asterisk.c
index 0a68a2db7..53e9b29c2 100644
--- a/res/res_rtp_asterisk.c
+++ b/res/res_rtp_asterisk.c
@@ -2166,6 +2166,7 @@ static int __rtp_sendto(struct ast_rtp_instance *instance, void *buf, size_t siz
 	void *temp = buf;
 	struct ast_rtp *rtp = ast_rtp_instance_get_data(instance);
 	struct ast_srtp *srtp = ast_rtp_instance_get_srtp(instance);
+	int res;
 
 	*ice = 0;
 
@@ -2184,7 +2185,11 @@ static int __rtp_sendto(struct ast_rtp_instance *instance, void *buf, size_t siz
 	}
 #endif
 
-	return ast_sendto(rtcp ? rtp->rtcp->s : rtp->s, temp, len, flags, sa);
+	res = ast_sendto(rtcp ? rtp->rtcp->s : rtp->s, temp, len, flags, sa);
+	if (res > 0) {
+		ast_rtp_instance_set_last_tx(instance, time(NULL));
+	}
+	return res;
 }
 
 static int rtcp_sendto(struct ast_rtp_instance *instance, void *buf, size_t size, int flags, struct ast_sockaddr *sa, int *ice)