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authorPhilipp Maier <pmaier@sysmocom.de>2017-04-20 18:40:37 +0200
committerNeels Hofmeyr <nhofmeyr@sysmocom.de>2017-06-17 17:38:15 +0200
commit57d0b25ddff5fde4a22314fa13071e50d444a5c5 (patch)
tree79c12bbd5f29c4ad0697a8d1b8bc73d0fe5f33ee
parent7cadf1111c1a29bb7524f23e79491a6c1fd12f64 (diff)
libmsc: make pitfall in gsm0408_dispatch() more obvious
The function gsm0408_dispatch() accepts a message buffer pointer and accesses the l3h pointer. Even in a properly allocated message buffer, this may lead into a segfault if the user forgets to set the l3h pointer. This commit adds assertions to popup a more expressive error message.
-rw-r--r--openbsc/src/libmsc/gsm_04_08.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/openbsc/src/libmsc/gsm_04_08.c b/openbsc/src/libmsc/gsm_04_08.c
index 219e89692..a380b033e 100644
--- a/openbsc/src/libmsc/gsm_04_08.c
+++ b/openbsc/src/libmsc/gsm_04_08.c
@@ -3582,13 +3582,17 @@ void cm_service_request_concludes(struct gsm_subscriber_connection *conn,
/* Main entry point for GSM 04.08/44.008 Layer 3 data (e.g. from the BSC). */
int gsm0408_dispatch(struct gsm_subscriber_connection *conn, struct msgb *msg)
{
- struct gsm48_hdr *gh = msgb_l3(msg);
- uint8_t pdisc = gsm48_hdr_pdisc(gh);
+ struct gsm48_hdr *gh;
+ uint8_t pdisc;
int rc = 0;
+ OSMO_ASSERT(msg->l3h)
OSMO_ASSERT(conn);
OSMO_ASSERT(msg);
+ gh = msgb_l3(msg);
+ pdisc = gsm48_hdr_pdisc(gh);
+
LOGP(DRLL, LOGL_DEBUG, "Dispatching 04.08 message %s (0x%x:0x%x)\n",
gsm48_pdisc_msgtype_name(pdisc, gsm48_hdr_msg_type(gh)),
pdisc, gsm48_hdr_msg_type(gh));