In hold/retrieve/reinvite, add check that other_leg exists

We should always check that the other leg did not somehow
dissapear before accessing it.

Change-Id: I947aab6c0cc5019929bde1c7012e1a8c3d3472a5

2 files changed, 31 insertions, 0 deletions

diff --git a/src/mncc.c b/src/mncc.c
index 739f50b..f5a44d5 100644
--- a/src/mncc.c
+++ b/src/mncc.c
@@ -703,6 +703,12 @@ static void check_hold_ind(struct mncc_connection *conn, const char *buf, int rc
 	LOGP(DMNCC, LOGL_DEBUG,
 		"leg(%u) is requesting hold.\n", leg->callref);
 	other_leg = call_leg_other(&leg->base);
+	if (!other_leg) {
+		LOGP(DMNCC, LOGL_ERROR, "leg(%u) other leg gone!\n",
+			leg->callref);
+		mncc_send(leg->conn, MNCC_HOLD_REJ, leg->callref);
+		return;
+	}
 	other_leg->hold_call(other_leg);
 	mncc_send(leg->conn, MNCC_HOLD_CNF, leg->callref);
 	leg->state = MNCC_CC_HOLD;
@@ -721,6 +727,14 @@ static void check_retrieve_ind(struct mncc_connection *conn, const char *buf, in
 	LOGP(DMNCC, LOGL_DEBUG,
 		"leg(%u) is requesting unhold.\n", leg->callref);
 	other_leg = call_leg_other(&leg->base);
+	if (!other_leg) {
+		/* The SIP leg went away while we were holding! */
+		LOGP(DMNCC, LOGL_ERROR, "leg(%u) other leg gone!\n",
+			leg->callref);
+		mncc_send(leg->conn, MNCC_RETRIEVE_CNF, leg->callref);
+		mncc_call_leg_release(&leg->base);
+		return;
+	}
 	other_leg->retrieve_call(other_leg);
 	mncc_send(leg->conn, MNCC_RETRIEVE_CNF, leg->callref);
 	/* In case of call waiting/swap, At this point we need to tell the MSC to send
diff --git a/src/sip.c b/src/sip.c
index 103eb33..2b28b4e 100644
--- a/src/sip.c
+++ b/src/sip.c
@@ -193,6 +193,13 @@ static void sip_handle_reinvite(struct sip_call_leg *leg, nua_handle_t *nh, cons
 	LOGP(DSIP, LOGL_INFO, "re-INVITE for call %s\n", sip->sip_call_id->i_id);
 
 	struct call_leg *other = call_leg_other(&leg->base);
+
+	if (!other) {
+		LOGP(DMNCC, LOGL_ERROR, "leg(%p) other leg gone!\n", leg);
+		sip_release_call(&leg->base);
+		return;
+	}
+
 	if (!sdp_get_sdp_mode(sip, &mode)) {
 		/* re-INVITE with no SDP.
 		 * We should respond with SDP reflecting current session
@@ -540,6 +547,11 @@ static void sip_hold_call(struct call_leg *_leg)
 	OSMO_ASSERT(_leg->type == CALL_TYPE_SIP);
 	leg = (struct sip_call_leg *) _leg;
 	other_leg = call_leg_other(&leg->base);
+	if (!other_leg) {
+		LOGP(DMNCC, LOGL_ERROR, "leg(%p) other leg gone!\n", leg);
+		sip_release_call(&leg->base);
+		return;
+	}
 	char *sdp = sdp_create_file(leg, other_leg, sdp_sendonly);
 	nua_invite(leg->nua_handle,
 		    NUTAG_MEDIA_ENABLE(0),
@@ -557,6 +569,11 @@ static void sip_retrieve_call(struct call_leg *_leg)
 	OSMO_ASSERT(_leg->type == CALL_TYPE_SIP);
 	leg = (struct sip_call_leg *) _leg;
 	other_leg = call_leg_other(&leg->base);
+	if (!other_leg) {
+		LOGP(DMNCC, LOGL_ERROR, "leg(%p) other leg gone!\n", leg);
+		sip_release_call(&leg->base);
+		return;
+	}
 	char *sdp = sdp_create_file(leg, other_leg, sdp_sendrecv);
 	nua_invite(leg->nua_handle,
 		    NUTAG_MEDIA_ENABLE(0),