add generic keepalive system and implement it in sofia to send MESSAGE or INFO packets in-dialog at specified interval.

Adds app: enable_keepalive 0|<seconds>
This app can be run in the dialplan or with execute_on_* type variables for B-legs.

Adds sofia param: keepalive-method  : defaults to MESSAGE can also be "INFO"
This param sets which SIP method to use.

src/include/switch_types.h

@@ -1009,6 +1009,7 @@ typedef enum {
 	SWITCH_MESSAGE_INDICATE_BLIND_TRANSFER_RESPONSE,
 	SWITCH_MESSAGE_INDICATE_STUN_ERROR,
 	SWITCH_MESSAGE_INDICATE_MEDIA_RENEG,
+	SWITCH_MESSAGE_INDICATE_KEEPALIVE,
 	SWITCH_MESSAGE_REFER_EVENT,
 	SWITCH_MESSAGE_ANSWER_EVENT,
 	SWITCH_MESSAGE_PROGRESS_EVENT,

src/mod/applications/mod_dptools/mod_dptools.c

@@ -552,6 +552,31 @@ SWITCH_STANDARD_APP(heartbeat_function)
 	if (data) {
 		seconds = atoi(data);
 		if (seconds >= 0) {
+
+			switch_core_session_enable_heartbeat(session, seconds);
+			return;
+		}
+	}
+
+	switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Usage: %s\n", HEARTBEAT_SYNTAX);
+
+}
+
+
+#define KEEPALIVE_SYNTAX "[0|<seconds>]"
+SWITCH_STANDARD_APP(keepalive_function)
+{
+	int seconds = 0;
+
+	if (data) {
+		seconds = atoi(data);
+		if (seconds >= 0) {
+			switch_core_session_message_t msg = { 0 };
+
+			msg.message_id = SWITCH_MESSAGE_INDICATE_KEEPALIVE;
+			msg.numeric_arg = seconds;
+			switch_core_session_receive_message(session, &msg);
+			
 			switch_core_session_enable_heartbeat(session, seconds);
 			return;
 		}
@@ -5777,6 +5802,10 @@ SWITCH_MODULE_LOAD_FUNCTION(mod_dptools_load)
 				   sched_heartbeat_function, SCHED_HEARTBEAT_SYNTAX, SAF_SUPPORT_NOMEDIA);
 	SWITCH_ADD_APP(app_interface, "enable_heartbeat", "Enable Media Heartbeat", "Enable Media Heartbeat",
 				   heartbeat_function, HEARTBEAT_SYNTAX, SAF_SUPPORT_NOMEDIA);
+
+	SWITCH_ADD_APP(app_interface, "enable_keepalive", "Enable Keepalive", "Enable Keepalive",
+				   keepalive_function, KEEPALIVE_SYNTAX, SAF_SUPPORT_NOMEDIA);
+
 	SWITCH_ADD_APP(app_interface, "media_reset", "Reset all bypass/proxy media flags", "Reset all bypass/proxy media flags", media_reset_function, "", SAF_SUPPORT_NOMEDIA);
 	SWITCH_ADD_APP(app_interface, "mkdir", "Create a directory", "Create a directory", mkdir_function, MKDIR_SYNTAX, SAF_SUPPORT_NOMEDIA);
 	SWITCH_ADD_APP(app_interface, "rename", "Rename file", "Rename file", rename_function, RENAME_SYNTAX, SAF_SUPPORT_NOMEDIA | SAF_ZOMBIE_EXEC);

src/mod/endpoints/mod_sofia/mod_sofia.c

@@ -1124,6 +1124,38 @@ static switch_status_t sofia_receive_message(switch_core_session_t *session, swi
 
 	/* ones that do not need to lock sofia mutex */
 	switch (msg->message_id) {
+	case SWITCH_MESSAGE_INDICATE_KEEPALIVE:
+		{
+			if (msg->numeric_arg) {
+				sofia_set_flag_locked(tech_pvt, TFLAG_KEEPALIVE);
+			} else {
+				sofia_clear_flag_locked(tech_pvt, TFLAG_KEEPALIVE);
+			}
+		}
+		break;
+	case SWITCH_MESSAGE_HEARTBEAT_EVENT:
+		{
+			char pl[160] = "";
+
+			switch_snprintf(pl, sizeof(pl), "KEEP-ALIVE %d\n", ++tech_pvt->keepalive);
+
+			if (sofia_test_flag(tech_pvt, TFLAG_KEEPALIVE)) {
+				if (tech_pvt->profile->keepalive == KA_MESSAGE) {
+					nua_message(tech_pvt->nh,
+								SIPTAG_CONTENT_TYPE_STR("text/plain"),
+								TAG_IF(!zstr(tech_pvt->user_via), SIPTAG_VIA_STR(tech_pvt->user_via)),
+								SIPTAG_PAYLOAD_STR(pl),
+								TAG_END());
+				} else if (tech_pvt->profile->keepalive == KA_INFO) {
+					nua_info(tech_pvt->nh,
+							 SIPTAG_CONTENT_TYPE_STR("text/plain"),
+							 TAG_IF(!zstr(tech_pvt->user_via), SIPTAG_VIA_STR(tech_pvt->user_via)),
+							 SIPTAG_PAYLOAD_STR(pl),
+							 TAG_END());
+				}
+			}
+		}
+		break;
 	case SWITCH_MESSAGE_INDICATE_RECOVERY_REFRESH:
 	case SWITCH_MESSAGE_INDICATE_APPLICATION_EXEC:
 		break;

src/mod/endpoints/mod_sofia/mod_sofia.h

@@ -322,6 +322,7 @@ typedef enum {
 	TFLAG_CAPTURE,
 	TFLAG_REINVITED,
 	TFLAG_PASS_ACK,
+	TFLAG_KEEPALIVE,
 	/* No new flags below this line */
 	TFLAG_MAX
 } TFLAGS;
@@ -534,6 +535,11 @@ typedef enum {
 
 #define MAX_RTPIP 50
 
+typedef enum {
+	KA_MESSAGE,
+	KA_INFO
+} ka_type_t;
+
 struct sofia_profile {
 	int debug;
 	int parse_invite_tel_params;
@@ -706,6 +712,7 @@ struct sofia_profile {
 	int tcp_keepalive;
 	int tcp_pingpong;
 	int tcp_ping2pong;
+	ka_type_t keepalive;
 };
 
 
@@ -772,6 +779,7 @@ struct private_object {
 	int respond_code;
 	char *respond_dest;
 	time_t last_vid_info;
+	uint32_t keepalive;
 };
 
 

src/mod/endpoints/mod_sofia/sofia.c

@@ -4025,6 +4025,14 @@ switch_status_t config_sofia(sofia_config_t reload, char *profile_name)
 						profile->debug = atoi(val);
 					} else if (!strcasecmp(var, "parse-invite-tel-params")) {
 						profile->parse_invite_tel_params = switch_true(val);
+					} else if (!strcasecmp(var, "keepalive-method")) {
+						if (!zstr(val)) {
+							if (!strcasecmp(val, "info")) {
+								profile->keepalive = KA_INFO;
+							} else {
+								profile->keepalive = KA_MESSAGE;								
+							}
+						}
 					} else if (!strcasecmp(var, "shutdown-on-fail")) {
 						profile->shutdown_type = switch_core_strdup(profile->pool, val);
 					} else if (!strcasecmp(var, "sip-trace") && switch_true(val)) {

src/switch_core_io.c

@@ -231,8 +231,9 @@ SWITCH_DECLARE(switch_status_t) switch_core_session_read_frame(switch_core_sessi
 			session->read_frame_count = (session->read_impl.actual_samples_per_second / session->read_impl.samples_per_packet) * session->track_duration;
 
 			msg.message_id = SWITCH_MESSAGE_HEARTBEAT_EVENT;
+			msg.numeric_arg = session->track_duration;
 			switch_core_session_receive_message(session, &msg);
-
+			
 			switch_event_create(&event, SWITCH_EVENT_SESSION_HEARTBEAT);
 			switch_channel_event_set_data(session->channel, event);
 			switch_event_fire(&event);

src/switch_core_session.c

@@ -751,6 +751,7 @@ static const char *message_names[] = {
 	"BLIND_TRANSFER_RESPONSE",
 	"STUN_ERROR",
 	"MEDIA_RENEG",
+	"KEEPALIVE",
 	"ANSWER_EVENT",
 	"PROGRESS_EVENT",
 	"RING_EVENT",
@@ -1506,6 +1507,7 @@ SWITCH_STANDARD_SCHED_FUNC(sch_heartbeat_callback)
 		task->runtime = switch_epoch_time_now(NULL) + session->track_duration;
 
 		msg.message_id = SWITCH_MESSAGE_HEARTBEAT_EVENT;
+		msg.numeric_arg = session->track_duration;
 		switch_core_session_receive_message(session, &msg);
 
 		switch_core_session_rwunlock(session);