Add support to see whether NAT was detected (yay symmetric RTP) and also add a check in chan_sip so that if NAT has been detected and the reinvite behind nat option has been turned off, then just do partial bridge. (issue #8655 reported by mnicholson)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@50466 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -16656,7 +16656,9 @@ static enum ast_rtp_get_result sip_get_rtp_peer(struct ast_channel *chan, struct
 
 	*rtp = p->rtp;
 
-	if (ast_test_flag(&p->flags[0], SIP_CAN_REINVITE))
+	if (ast_rtp_getnat(*rtp) && !ast_test_flag(&p->flags[0], SIP_CAN_REINVITE_NAT))
+		res = AST_RTP_TRY_PARTIAL;
+	else if (ast_test_flag(&p->flags[0], SIP_CAN_REINVITE))
 		res = AST_RTP_TRY_NATIVE;
 	else if (ast_test_flag(&global_jbconf, AST_JB_FORCED))
 		res = AST_RTP_GET_FAILED;

include/asterisk/rtp.h

@@ -180,6 +180,8 @@ char *ast_rtp_lookup_mime_multiple(char *buf, size_t size, const int capability,
 
 void ast_rtp_setnat(struct ast_rtp *rtp, int nat);
 
+int ast_rtp_getnat(struct ast_rtp *rtp);
+
 /*! \brief Indicate whether this RTP session is carrying DTMF or not */
 void ast_rtp_setdtmf(struct ast_rtp *rtp, int dtmf);
 

main/rtp.c

@@ -591,6 +591,11 @@ void ast_rtp_setnat(struct ast_rtp *rtp, int nat)
 	rtp->nat = nat;
 }
 
+int ast_rtp_getnat(struct ast_rtp *rtp)
+{
+	return ast_test_flag(rtp, FLAG_NAT_ACTIVE);
+}
+
 void ast_rtp_setdtmf(struct ast_rtp *rtp, int dtmf)
 {
 	ast_set2_flag(rtp, dtmf ? 1 : 0, FLAG_HAS_DTMF);