osmux: Add negotiation state so race conditions can't disable osmux
Without this commit it is possible that osmux is disabled again on links with
high jitter. This happens when an MGCP response without X-Osmux header is
received before the NAT receives an Osmux dummy frame from the other side.
Ticket: SYS#2628, SYS#2627
Sponsored-by: On-Waves ehf
Change-Id: Id624b0279aee5e2412059a10296ce7896e2d4628
diff --git a/openbsc/include/openbsc/osmux.h b/openbsc/include/openbsc/osmux.h
index 82b8fa3..0b64a7f 100644
--- a/openbsc/include/openbsc/osmux.h
+++ b/openbsc/include/openbsc/osmux.h
@@ -28,6 +28,7 @@
enum osmux_state {
OSMUX_STATE_DISABLED = 0,
+ OSMUX_STATE_NEGOTIATING,
OSMUX_STATE_ACTIVATING,
OSMUX_STATE_ENABLED,
};
diff --git a/openbsc/src/libmgcp/mgcp_protocol.c b/openbsc/src/libmgcp/mgcp_protocol.c
index 1819cea..ff0fc3e 100644
--- a/openbsc/src/libmgcp/mgcp_protocol.c
+++ b/openbsc/src/libmgcp/mgcp_protocol.c
@@ -277,7 +277,7 @@
if (!addr)
addr = mgcp_net_src_addr(endp);
- if (endp->osmux.state == OSMUX_STATE_ACTIVATING)
+ if (endp->osmux.state == OSMUX_STATE_NEGOTIATING)
sprintf(osmux_extension, "\nX-Osmux: %u", endp->osmux.cid);
else
osmux_extension[0] = '\0';
@@ -811,13 +811,13 @@
if (endp->ci == CI_UNUSED)
goto error2;
- /* Annotate Osmux circuit ID and set it to activating state until this
+ /* Annotate Osmux circuit ID and set it to negotiating state until this
* is fully set up from the dummy load.
*/
endp->osmux.state = OSMUX_STATE_DISABLED;
if (osmux_cid >= 0) {
endp->osmux.cid = osmux_cid;
- endp->osmux.state = OSMUX_STATE_ACTIVATING;
+ endp->osmux.state = OSMUX_STATE_NEGOTIATING;
} else if(endp->cfg->osmux == OSMUX_USAGE_ONLY) {
LOGP(DMGCP, LOGL_ERROR,
"Osmux only and no osmux offered on 0x%x\n", ENDPOINT_NUMBER(endp));
diff --git a/openbsc/src/osmo-bsc_nat/bsc_mgcp_utils.c b/openbsc/src/osmo-bsc_nat/bsc_mgcp_utils.c
index 9fd9967..4884786 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_mgcp_utils.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_mgcp_utils.c
@@ -590,7 +590,7 @@
*/
if (mgcp_endp->osmux.allocated_cid >= 0 &&
mgcp_endp->osmux.state != OSMUX_STATE_ENABLED) {
- mgcp_endp->osmux.state = OSMUX_STATE_ACTIVATING;
+ mgcp_endp->osmux.state = OSMUX_STATE_NEGOTIATING;
mgcp_endp->osmux.cid = mgcp_endp->osmux.allocated_cid;
}
@@ -680,6 +680,7 @@
LOGP(DMGCP, LOGL_NOTICE, "bsc accepted to use Osmux (cid=%u)\n",
osmux_cid);
+ endp->osmux.state = OSMUX_STATE_ACTIVATING;
return;
err:
osmux_release_cid(endp);
@@ -747,7 +748,7 @@
return;
}
- if (endp->osmux.state == OSMUX_STATE_ACTIVATING)
+ if (endp->osmux.state == OSMUX_STATE_NEGOTIATING)
bsc_mgcp_osmux_confirm(endp, (const char *) msg->l2h);
/* If we require osmux and it is disabled.. fail */