a_iface: Check if channel type and speech codec list are successful

Currently we do not check for errors during the generation of
channel type and speech codec list. This might blow an assertion
in gsm0808_create_ass if the generated data is invalid. So
we need to check beforehand.

1 files changed, 17 insertions, 4 deletions

diff --git a/openbsc/src/libmsc/a_iface.c b/openbsc/src/libmsc/a_iface.c
index d64710f84..332880567 100644
--- a/openbsc/src/libmsc/a_iface.c
+++ b/openbsc/src/libmsc/a_iface.c
@@ -203,7 +203,7 @@ static uint8_t convert_Abis_prev_to_A_pref(int radio)
 }
 
 /* Assemble the channel type field */
-static void enc_channel_type(struct gsm0808_channel_type *ct, const struct gsm_mncc_bearer_cap *bc)
+int enc_channel_type(struct gsm0808_channel_type *ct, const struct gsm_mncc_bearer_cap *bc)
 {
 	unsigned int i;
 	uint8_t sv;
@@ -216,7 +216,6 @@ static void enc_channel_type(struct gsm0808_channel_type *ct, const struct gsm_m
 		if (bc->speech_ver[i] == -1)
 			break;
 		sv = convert_Abis_sv_to_A_sv(bc->speech_ver[i]);
-
 		if (sv != 0xFF) {
 			/* Detect if something else than
 			 * GSM HR V1 is supported */
@@ -239,6 +238,11 @@ static void enc_channel_type(struct gsm0808_channel_type *ct, const struct gsm_m
 		ct->ch_rate_type = GSM0808_SPEECH_FULL_BM;
 	else
 		ct->ch_rate_type = convert_Abis_prev_to_A_pref(bc->radio);
+
+	if (count)
+		return 0;
+	else
+		return -EINVAL;
 }
 
 /* Assemble the speech codec field */
@@ -268,15 +272,24 @@ int a_iface_tx_assignment(struct gsm_trans *trans)
 	struct msgb *msg;
 	struct sockaddr_storage rtp_addr;
 	struct sockaddr_in rtp_addr_in;
+	int rc;
 
 	conn = trans->conn;
 	OSMO_ASSERT(conn);
 
 	/* Channel type */
-	enc_channel_type(&ct, &trans->bearer_cap);
+	rc = enc_channel_type(&ct, &trans->bearer_cap);
+	if (rc < 0) {
+		LOGP(DMSC, LOGL_ERROR, "Faild to generate channel type -- assignment not sent!\n");
+		return -EINVAL;
+	}
 
 	/* Speech codec list */
-	enc_speeach_codec_list(&scl, &ct);
+	rc = enc_speeach_codec_list(&scl, &ct);
+	if (rc < 0) {
+		LOGP(DMSC, LOGL_ERROR, "Faild to generate Speech codec list -- assignment not sent!\n");
+		return -EINVAL;
+	}
 
 	/* Package RTP-Address data */
 	memset(&rtp_addr_in, 0, sizeof(rtp_addr_in));