mgcp: Add a call tap feature to forward audio to another forward port
For debugging it is useful to forward (tee) UDP packets to another
system and use gstreamer to inspect the rtp stream. This is untested
code and might contain bugs.... and of course only tap your own calls.
diff --git a/openbsc/src/mgcp/mgcp_network.c b/openbsc/src/mgcp/mgcp_network.c
index 3877112..bbc46f4 100644
--- a/openbsc/src/mgcp/mgcp_network.c
+++ b/openbsc/src/mgcp/mgcp_network.c
@@ -151,6 +151,14 @@
* The below code is for dispatching. We have a dedicated port for
* the data coming from the net and one to discover the BTS.
*/
+static int forward_data(int fd, struct mgcp_rtp_tap *tap, const char *buf, int len)
+{
+ if (!tap->enabled)
+ return 0;
+
+ return sendto(fd, buf, len, 0,
+ (struct sockaddr *)&tap->forward, sizeof(tap->forward));
+}
static int send_to(struct mgcp_endpoint *endp, int dest, int is_rtp,
struct sockaddr_in *addr, char *buf, int rc)
{
@@ -168,6 +176,8 @@
patch_and_count(endp, &endp->bts_state,
endp->net_end.payload_type,
addr, buf, rc);
+ forward_data(endp->net_end.rtp.fd,
+ &endp->taps[MGCP_TAP_NET_OUT], buf, rc);
return udp_send(endp->net_end.rtp.fd, &endp->net_end.addr,
endp->net_end.rtp_port, buf, rc);
} else {
@@ -179,6 +189,8 @@
patch_and_count(endp, &endp->net_state,
endp->bts_end.payload_type,
addr, buf, rc);
+ forward_data(endp->bts_end.rtp.fd,
+ &endp->taps[MGCP_TAP_BTS_OUT], buf, rc);
return udp_send(endp->bts_end.rtp.fd, &endp->bts_end.addr,
endp->bts_end.rtp_port, buf, rc);
} else {
@@ -248,6 +260,8 @@
proto = fd == &endp->net_end.rtp ? PROTO_RTP : PROTO_RTCP;
endp->net_end.packets += 1;
+
+ forward_data(fd->fd, &endp->taps[MGCP_TAP_NET_IN], buf, rc);
return send_to(endp, DEST_BTS, proto == PROTO_RTP, &addr, &buf[0], rc);
}
@@ -310,6 +324,7 @@
/* do this before the loop handling */
endp->bts_end.packets += 1;
+ forward_data(fd->fd, &endp->taps[MGCP_TAP_BTS_IN], buf, rc);
return send_to(endp, DEST_NETWORK, proto == PROTO_RTP, &addr, &buf[0], rc);
}