GSMTAP now creates a locally bound receive socket

[Gianni Tedesco]

On Sun, 2011-05-22 at 21:45 +0200, Harald Welte wrote:
> Hi!
> 
> libosmocore >= 0.3.1 and the current osmocom-bb code will now generate
> not only the sending GSMTAP UDP socket, but also a locally-bound receive
> socket. 
> 
> This avoids the manual start of "nc -l -u -p 4729 >/dev/null" or
> iptables rules to drop the UDP packets.
> 
> The local receive socket is only created if the GSMTAP IP address is a
> locally configured address on any of your network interfaces.  So
> sending it to 127.0.0.1 should work well.
> 
> Don't be surprised if you happen to see GSMTAP over IPv6, I'm now using
> getaddrinfo() and related functions, i.e. "loopback" may now resolve to
> ::1 instead of 127.0.0.1
> 
> Regards,
> 	Harald

Could these changes be related to the sudden crashes I am having since
enabling test sim in mobile (with no -i specified) ?

Following patch fixes it.

diff --git a/src/shared/libosmocore/src/gsmtap_util.c b/src/shared/libosmocore/src/gsmtap_util.c
index 5c68b6a..2de4beb 100644
--- a/src/shared/libosmocore/src/gsmtap_util.c
+++ b/src/shared/libosmocore/src/gsmtap_util.c
@@ -148,6 +148,11 @@ int gsmtap_source_add_sink_fd(int gsmtap_fd)
 
 int gsmtap_sendmsg(struct gsmtap_inst *gti, struct msgb *msg)
 {
+	if ( NULL == gti ) {
+		msgb_free(msg);
+		return 0;
+	}
+
 	if (gti->ofd_wq_mode)
 		return osmo_wqueue_enqueue(&gti->wq, msg);
 	else {