TT#14008 add `pierce-NAT` flag

Change-Id: I1ec9b0ba152939cb6dc079e0047040da862945dc

README.md

@@ -842,6 +842,13 @@ Optionally included keys are:
 
 		Enabled full debug logging for this call, regardless of global log level settings.
 
+	- `pierce NAT`
+
+		Sends empty UDP packets to the remote RTP peer as soon as an
+		endpoint address is available from a received SDP, for as long
+		as no incoming packets have been received. Useful to create an
+		initial NAT mapping. Not needed when ICE is in use.
+
 * `generate RTCP`
 
 	Contains a string, either `on` or `off`. If enabled for a call,

daemon/call.c

@@ -1004,7 +1004,7 @@ static int __num_media_streams(struct call_media *media, unsigned int num_ports)
 }
 
 static void __fill_stream(struct packet_stream *ps, const struct endpoint *epp, unsigned int port_off,
-		const struct stream_params *sp)
+		const struct stream_params *sp, const struct sdp_ng_flags *flags)
 {
 	struct endpoint ep;
 	struct call_media *media = ps->media;
@@ -1035,6 +1035,9 @@ static void __fill_stream(struct packet_stream *ps, const struct endpoint *epp,
 	ilog(LOG_DEBUG, "set FILLED flag for stream %s%s:%d%s",
 			FMT_M(sockaddr_print_buf(&ps->endpoint.address), ps->endpoint.port));
 	PS_SET(ps, FILLED);
+
+	if (flags && flags->pierce_nat)
+		PS_SET(ps, PIERCE_NAT);
 }
 
 /* called with call locked in R or W, but ps not locked */
@@ -1070,6 +1073,16 @@ enum call_stream_state call_stream_state_machine(struct packet_stream *ps) {
 		mutex_unlock(&ps->in_lock);
 	}
 
+	if (PS_ISSET(ps, PIERCE_NAT) && PS_ISSET(ps, FILLED) && !PS_ISSET(ps, CONFIRMED)) {
+		for (GList *l = ps->sfds.head; l; l = l->next) {
+			static const str fake_rtp = STR_CONST_INIT("\x80\x7f\xff\xff\x00\x00\x00\x00"
+					"\x00\x00\x00\x00");
+			struct stream_fd *sfd = l->data;
+			socket_sendto(&sfd->socket, fake_rtp.s, fake_rtp.len, &ps->endpoint);
+		}
+		ret = CSS_PIERCE_NAT;
+	}
+
 	return ret;
 }
 
@@ -1188,7 +1201,7 @@ static int __init_streams(struct call_media *A, struct call_media *B, const stru
 		__rtp_stats_update(a->rtp_stats, A->codecs_recv);
 
 		if (sp) {
-			__fill_stream(a, &sp->rtp_endpoint, port_off, sp);
+			__fill_stream(a, &sp->rtp_endpoint, port_off, sp, flags);
 			bf_copy_same(&a->ps_flags, &sp->sp_flags,
 					SHARED_FLAG_STRICT_SOURCE | SHARED_FLAG_MEDIA_HANDOVER);
 		}
@@ -1244,11 +1257,11 @@ static int __init_streams(struct call_media *A, struct call_media *B, const stru
 
 		if (sp) {
 			if (!SP_ISSET(sp, IMPLICIT_RTCP)) {
-				__fill_stream(a, &sp->rtcp_endpoint, port_off, sp);
+				__fill_stream(a, &sp->rtcp_endpoint, port_off, sp, flags);
 				PS_CLEAR(a, IMPLICIT_RTCP);
 			}
 			else {
-				__fill_stream(a, &sp->rtp_endpoint, port_off + 1, sp);
+				__fill_stream(a, &sp->rtp_endpoint, port_off + 1, sp, flags);
 				PS_SET(a, IMPLICIT_RTCP);
 			}
 			bf_copy_same(&a->ps_flags, &sp->sp_flags,

daemon/call_interfaces.c

@@ -888,6 +888,9 @@ static void call_ng_flags_flags(struct sdp_ng_flags *out, str *s, void *dummy) {
 		case CSH_LOOKUP("no-jitter-buffer"):
 			out->disable_jb = 1;
 			break;
+		case CSH_LOOKUP("pierce-NAT"):
+			out->pierce_nat = 1;
+			break;
 		default:
 			// handle values aliases from other dictionaries
 			if (call_ng_flags_prefix(out, s, "SDES-no-", call_ng_flags_str_ht, &out->sdes_no))

include/call.h

@@ -62,6 +62,7 @@ enum call_stream_state {
 	CSS_SHUTDOWN,
 	CSS_ICE,
 	CSS_DTLS,
+	CSS_PIERCE_NAT,
 	CSS_RUNNING,
 };
 
@@ -132,6 +133,7 @@ enum call_stream_state {
 #define PS_FLAG_MEDIA_HANDOVER			SHARED_FLAG_MEDIA_HANDOVER
 #define PS_FLAG_ICE				SHARED_FLAG_ICE
 #define PS_FLAG_ZERO_ADDR			0x04000000
+#define PS_FLAG_PIERCE_NAT			0x08000000
 
 /* struct call_media */
 #define MEDIA_FLAG_INITIALIZED			0x00010000

include/call_interfaces.h

@@ -138,7 +138,8 @@ struct sdp_ng_flags {
 	             drop_traffic_stop:1,
 	             passthrough_on:1,
 	             passthrough_off:1,
-	             disable_jb:1;
+	             disable_jb:1,
+		     pierce_nat:1;
 };
 
 

utils/rtpengine-ng-client

@@ -90,6 +90,7 @@ GetOptions(
 	'single-codec'			=> \$options{'single codec'},
 	'reorder-codecs'		=> \$options{'reorder codecs'},
 	'media-echo=s'			=> \$options{'media echo'},
+	'pierce-NAT'			=> \$options{'pierce NAT'},
 ) or die;
 
 my $cmd = shift(@ARGV) or die;
@@ -102,7 +103,7 @@ for my $x (split(/,/, 'from-tag,to-tag,call-id,transport protocol,media address,
 for my $x (split(/,/, 'TOS,delete-delay')) {
 	defined($options{$x}) and $packet{$x} = $options{$x};
 }
-for my $x (split(/,/, 'trust address,symmetric,asymmetric,unidirectional,force,strict source,media handover,sip source address,reset,port latching,no rtcp attribute,full rtcp attribute,loop protect,record call,always transcode,all,pad crypto,generate mid,fragment,original sendrecv,symmetric codecs,asymmetric codecs,inject DTMF,generate RTCP,single codec,reorder codecs')) {
+for my $x (split(/,/, 'trust address,symmetric,asymmetric,unidirectional,force,strict source,media handover,sip source address,reset,port latching,no rtcp attribute,full rtcp attribute,loop protect,record call,always transcode,all,pad crypto,generate mid,fragment,original sendrecv,symmetric codecs,asymmetric codecs,inject DTMF,generate RTCP,single codec,reorder codecs,pierce NAT')) {
 	defined($options{$x}) and push(@{$packet{flags}}, $x);
 }
 for my $x (split(/,/, 'origin,session connection,sdp version,username,session-name,zero-address')) {