BSSMAP: decode Codec List (BSS Supported)

Actually decode the Codec List (BSS Supported) in BSSMAP, in both the Complete
Layer 3 Information and the Assignment Complete messages.

An upcoming patch improves codec negotiation and requires the BSS supported
codecs, which are so far ignored (which is/was a pity as osmo-bsc goes at great
lengths to compose those IEs).

Change-Id: I66c735c79e982388f06b5de783aa584c9d13569e

include/osmocom/msc/ran_msg.h

@@ -192,6 +192,7 @@ struct ran_msg {
 	union {
 		struct {
 			const struct gsm0808_cell_id *cell_id;
+			const struct gsm0808_speech_codec_list *codec_list_bss_supported;
 			struct msgb *msg;
 		} compl_l3;
 		struct msgb *dtap;
@@ -226,6 +227,7 @@ struct ran_msg {
 			struct osmo_sockaddr_str remote_rtp;
 			bool codec_present;
 			enum mgcp_codecs codec;
+			const struct gsm0808_speech_codec_list *codec_list_bss_supported;
 			bool osmux_present;
 			uint8_t osmux_cid;
 		} assignment_complete;

src/libmsc/ran_msg_a.c

@@ -52,6 +52,8 @@ static int ran_a_decode_l3_compl(struct ran_dec *ran_dec, struct msgb *msg, stru
 	struct gsm0808_cell_id cell_id;
 	struct tlv_p_entry *ie_cell_id = TLVP_GET(tp, GSM0808_IE_CELL_IDENTIFIER);
 	struct tlv_p_entry *ie_l3_info = TLVP_GET(tp, GSM0808_IE_LAYER_3_INFORMATION);
+	struct tlv_p_entry *ie_codec_list_bss_supported = TLVP_GET(tp, GSM0808_IE_SPEECH_CODEC_LIST);
+	struct gsm0808_speech_codec_list codec_list_bss_supported;
 	struct ran_msg ran_dec_msg = {
 		.msg_type = RAN_MSG_COMPL_L3,
 		.msg_name = "BSSMAP Complete Layer 3 Information",
@@ -114,6 +116,19 @@ static int ran_a_decode_l3_compl(struct ran_dec *ran_dec, struct msgb *msg, stru
 		return -ENODATA;
 	}
 
+	/* Decode Codec List (BSS Supported) */
+	if (ie_codec_list_bss_supported) {
+		rc = gsm0808_dec_speech_codec_list(&codec_list_bss_supported,
+						   ie_codec_list_bss_supported->val, ie_codec_list_bss_supported->len);
+		if (rc < 0) {
+			LOG_RAN_A_DEC_MSG(LOGL_ERROR,
+					  "Complete Layer 3 Information: unable to decode IE Codec List (BSS Supported)"
+					  " (rc=%d), continuing anyway\n", rc);
+			/* This IE is not critical, do not abort with error. */
+		} else
+			ran_dec_msg.compl_l3.codec_list_bss_supported = &codec_list_bss_supported;
+	}
+
 	return ran_decoded(ran_dec, &ran_dec_msg);
 }
 
@@ -261,10 +276,12 @@ static int ran_a_decode_assignment_complete(struct ran_dec *ran_dec, struct msgb
 {
 	struct tlv_p_entry *ie_aoip_transp_addr = TLVP_GET(tp, GSM0808_IE_AOIP_TRASP_ADDR);
 	struct tlv_p_entry *ie_speech_codec = TLVP_GET(tp, GSM0808_IE_SPEECH_CODEC);
+	struct tlv_p_entry *ie_codec_list_bss_supported = TLVP_GET(tp, GSM0808_IE_SPEECH_CODEC_LIST);
 	struct tlv_p_entry *ie_osmux_cid = TLVP_GET(tp, GSM0808_IE_OSMO_OSMUX_CID);
 	struct sockaddr_storage rtp_addr;
 	struct sockaddr_in *rtp_addr_in;
 	struct gsm0808_speech_codec sc;
+	struct gsm0808_speech_codec_list codec_list_bss_supported;
 	int rc;
 	struct ran_msg ran_dec_msg = {
 		.msg_type = RAN_MSG_ASSIGNMENT_COMPLETE,
@@ -314,6 +331,19 @@ static int ran_a_decode_assignment_complete(struct ran_dec *ran_dec, struct msgb
 		ran_dec_msg.assignment_complete.codec = ran_a_mgcp_codec_from_sc(&sc);
 	}
 
+	if (ie_codec_list_bss_supported) {
+		/* Decode Codec List (BSS Supported) */
+		rc = gsm0808_dec_speech_codec_list(&codec_list_bss_supported,
+						   ie_codec_list_bss_supported->val, ie_codec_list_bss_supported->len);
+		if (rc < 0) {
+			LOG_RAN_A_DEC_MSG(LOGL_ERROR,
+					  "Assignment Complete: unable to decode IE Codec List (BSS Supported)"
+					  " (rc=%d), continuing anyway\n", rc);
+			/* This IE is not critical, do not abort with error. */
+		} else
+			ran_dec_msg.assignment_complete.codec_list_bss_supported = &codec_list_bss_supported;
+	}
+
 	return ran_decoded(ran_dec, &ran_dec_msg);
 }