make belle-sip channel to enter retry state when a REGISTER transaction gets a...

make belle-sip channel to enter retry state when a REGISTER transaction gets a 500 Server Internal Error

src/channel.c

@@ -849,8 +849,9 @@ static void channel_connect_next(belle_sip_channel_t *obj){
 }
 
 static void belle_sip_channel_handle_error(belle_sip_channel_t *obj){
-	if (obj->state!=BELLE_SIP_CHANNEL_READY){
-		/* Previous connection attempts were failed (channel could not get ready).*/
+	if (obj->state!=BELLE_SIP_CHANNEL_READY || obj->soft_error){
+		/* Previous connection attempts were failed (channel could not get ready) OR soft error reported*/
+		obj->soft_error = FALSE;
 		/* See if you can retry on an alternate ip address.*/
 		if (obj->current_peer && obj->current_peer->ai_next){ /*obj->current_peer may be null in case of dns error*/
 			obj->current_peer=obj->current_peer->ai_next;
@@ -880,6 +881,12 @@ int belle_sip_channel_notify_timeout(belle_sip_channel_t *obj){
 	return FALSE;
 }
 
+void belle_sip_channel_notify_server_error(belle_sip_channel_t *obj){
+	belle_sip_message("channel[%p]: this server is encountering internal errors, moving to error state to eventually connect to another IP.", obj);
+	obj->soft_error = TRUE;
+	channel_set_state(obj,BELLE_SIP_CHANNEL_ERROR);
+}
+
 void channel_set_state(belle_sip_channel_t *obj, belle_sip_channel_state_t state) {
 	belle_sip_message("channel %p: state %s",obj,belle_sip_channel_state_to_string(state));
 

src/channel.h

@@ -120,6 +120,7 @@ struct belle_sip_channel{
 	unsigned char has_name; /*set when the name of the peer is known, which is not the case of inboud connections*/
 	unsigned char about_to_be_closed;
 	unsigned char srv_overrides_port; /*set when this channel was connected to destination port provided by SRV resolution*/
+	unsigned char soft_error; /*set when this channel enters ERROR state because of error detected in upper layer */
 };
 
 #define BELLE_SIP_CHANNEL(obj)		BELLE_SIP_CAST(obj,belle_sip_channel_t)
@@ -193,6 +194,9 @@ void belle_sip_channel_force_close(belle_sip_channel_t *obj);
  Returns TRUE if the channel enters error state, 0 otherwise (channel is given a second chance) */
 int belle_sip_channel_notify_timeout(belle_sip_channel_t *obj);
 
+/*Used by transaction layer to report a server having internal errors, so that we can retry with another IP (in case of DNS SRV)*/
+void belle_sip_channel_notify_server_error(belle_sip_channel_t *obj);
+
 BELLE_SIP_END_DECLS
 
 

src/transaction.c

@@ -457,8 +457,13 @@ void belle_sip_client_transaction_notify_response(belle_sip_client_transaction_t
 	event.response=(belle_sip_response_t*)resp;
 	BELLE_SIP_PROVIDER_INVOKE_LISTENERS_FOR_TRANSACTION(((belle_sip_transaction_t*)t),process_response_event,&event);
 	/*check that 200Ok for INVITEs have been acknowledged by listener*/
-	if (dialog && strcmp(method,"INVITE")==0)
+	if (dialog && strcmp(method,"INVITE")==0){
 		belle_sip_dialog_check_ack_sent(dialog);
+	}
+	/*report a server having internal errors for REGISTER to the channel, in order to go to a fallback IP*/
+	if (status_code == 500 && strcmp(method,"REGISTER") == 0){
+		belle_sip_channel_notify_server_error(base->channel);
+	}
 }