[PATCH 1/4] gprs: Fix and check BVCI in BSSGP STATUS messages

This is merely a historical archive of years 2008-2021, before the migration to mailman3.

A maintained and still updated list archive can be found at https://lists.osmocom.org/hyperkitty/list/OpenBSC@lists.osmocom.org/.

Jacob Erlbeck jerlbeck at sysmocom.de
Tue Sep 23 11:28:21 UTC 2014


Currently the BVCI is not set in all invocations to bssgp_tx_status()
when the cause is UNKNOWN_BVCI.

This patch adds the argument where it is missing.

It also adds a check for compliance (GSM 08.18, 10.4.14.1) to
bssgp_tx_status() to emit errors when the following requirement is
not fulfilled: The BVCI must be included if (and only if) the cause
is either "BVCI blocked" or "BVCI unknown".

Sponsored-by: On-Waves ehf
---
 src/gb/gprs_bssgp.c      |  2 +-
 src/gb/gprs_bssgp_util.c | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/gb/gprs_bssgp.c b/src/gb/gprs_bssgp.c
index 5ef1887..b8c6c74 100644
--- a/src/gb/gprs_bssgp.c
+++ b/src/gb/gprs_bssgp.c
@@ -998,7 +998,7 @@ int bssgp_rcvmsg(struct msgb *msg)
 		LOGP(DBSSGP, LOGL_NOTICE, "NSEI=%u/BVCI=%u Rejecting PDU "
 			"type %u for unknown BVCI\n", msgb_nsei(msg), ns_bvci,
 			pdu_type);
-		return bssgp_tx_status(BSSGP_CAUSE_UNKNOWN_BVCI, NULL, msg);
+		return bssgp_tx_status(BSSGP_CAUSE_UNKNOWN_BVCI, &ns_bvci, msg);
 	}
 
 	if (bctx) {
diff --git a/src/gb/gprs_bssgp_util.c b/src/gb/gprs_bssgp_util.c
index ae4647e..261e0b0 100644
--- a/src/gb/gprs_bssgp_util.c
+++ b/src/gb/gprs_bssgp_util.c
@@ -99,6 +99,20 @@ int bssgp_tx_status(uint8_t cause, uint16_t *bvci, struct msgb *orig_msg)
 	struct bssgp_normal_hdr *bgph =
 			(struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph));
 
+	/* GSM 08.18, 10.4.14.1: The BVCI must be included if (and only if) the
+	   cause is either "BVCI blocked" or "BVCI unknown" */
+	if (cause == BSSGP_CAUSE_UNKNOWN_BVCI || cause == BSSGP_CAUSE_BVCI_BLOCKED) {
+		if (bvci == NULL)
+			LOGP(DBSSGP, LOGL_ERROR, "BSSGP Tx STATUS, cause=%s: "
+			     "missing conditional BVCI\n",
+			     bssgp_cause_str(cause));
+	} else {
+		if (bvci != NULL)
+			LOGP(DBSSGP, LOGL_ERROR, "BSSGP Tx STATUS, cause=%s: "
+			     "unexpected conditional BVCI\n",
+			     bssgp_cause_str(cause));
+	}
+
 	LOGP(DBSSGP, LOGL_NOTICE, "BSSGP BVCI=%u Tx STATUS, cause=%s\n",
 		bvci ? *bvci : 0, bssgp_cause_str(cause));
 	msgb_nsei(msg) = msgb_nsei(orig_msg);
-- 
1.9.1





More information about the OpenBSC mailing list