add X-Osmo-IGN MGCP header to ignore CallID
The format is
CRCX ...
C: ...
M: ...
X-Osmo-IGN: C
So far the only ignorable element is C, i.e. the CallID. Any other items may be
added in the future.
(I initially intended to also add '@' to ignore the endpoint name's domain
part, but in the osmo-mgw code base the domain part is verified long before any
additional headers are even parsed, so sparing that refactoring for now.)
The intention is that osmo-bsc will issue "X-Osmo-IGN: C" for all SCCPlite
calls, because we are unable to retrieve the CallID that the MSC sends to
osmo-mgw for the network side of the endpoint.
Testing with a specific SCCPlite MSC, I actually observe that all CallIDs are
1, even for concurrent calls. So, an alternative hacky solution would have been
to always pass CallID == 1 for SCCPlite connections from osmo-bsc.
Related: I257ad574d8060fef19afce9798bd8a5a7f8c99fe (osmo-bsc)
Change-Id: Id7ae275ffde8ea9389270cfe3db087ee8db00b51
diff --git a/src/libosmo-mgcp/mgcp_msg.c b/src/libosmo-mgcp/mgcp_msg.c
index a5bef7b..a7c8b47 100644
--- a/src/libosmo-mgcp/mgcp_msg.c
+++ b/src/libosmo-mgcp/mgcp_msg.c
@@ -407,6 +407,11 @@
if (!endp)
return -1;
+
+ /* Accept any CallID for "X-Osmo-IGN: C" */
+ if (endp->x_osmo_ign & MGCP_X_OSMO_IGN_CALLID)
+ return 0;
+
if (!callid)
return -1;
if (!endp->callid)