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Diffstat (limited to 'openbsc/src/osmo-bsc/osmo_bsc_bssap.c')
-rw-r--r--openbsc/src/osmo-bsc/osmo_bsc_bssap.c228
1 files changed, 168 insertions, 60 deletions
diff --git a/openbsc/src/osmo-bsc/osmo_bsc_bssap.c b/openbsc/src/osmo-bsc/osmo_bsc_bssap.c
index e705e708d..7d81a9ece 100644
--- a/openbsc/src/osmo-bsc/osmo_bsc_bssap.c
+++ b/openbsc/src/osmo-bsc/osmo_bsc_bssap.c
@@ -38,7 +38,11 @@
/*
* helpers for the assignment command
*/
-enum gsm0808_permitted_speech audio_support_to_gsm88(struct gsm_audio_support *audio)
+
+/* Helper function for match_codec_pref(), looks up a matching permitted speech
+ * value for a given msc audio codec pref */
+enum gsm0808_permitted_speech audio_support_to_gsm88(struct gsm_audio_support
+ *audio)
{
if (audio->hr) {
switch (audio->ver) {
@@ -52,8 +56,9 @@ enum gsm0808_permitted_speech audio_support_to_gsm88(struct gsm_audio_support *a
return GSM0808_PERM_HR3;
break;
default:
- LOGP(DMSC, LOGL_ERROR, "Wrong speech mode: %d\n", audio->ver);
- return GSM0808_PERM_FR1;
+ LOGP(DMSC, LOGL_ERROR, "Wrong speech mode: %d\n",
+ audio->ver);
+ return GSM0808_PERM_FR1;
}
} else {
switch (audio->ver) {
@@ -67,12 +72,15 @@ enum gsm0808_permitted_speech audio_support_to_gsm88(struct gsm_audio_support *a
return GSM0808_PERM_FR3;
break;
default:
- LOGP(DMSC, LOGL_ERROR, "Wrong speech mode: %d\n", audio->ver);
+ LOGP(DMSC, LOGL_ERROR, "Wrong speech mode: %d\n",
+ audio->ver);
return GSM0808_PERM_HR1;
}
}
}
+/* Helper function for match_codec_pref(), looks up a matching chan mode for
+ * a given permitted speech value */
enum gsm48_chan_mode gsm88_to_chan_mode(enum gsm0808_permitted_speech speech)
{
switch (speech) {
@@ -88,10 +96,98 @@ enum gsm48_chan_mode gsm88_to_chan_mode(enum gsm0808_permitted_speech speech)
case GSM0808_PERM_FR3:
return GSM48_CMODE_SPEECH_AMR;
break;
+ default:
+ LOGP(DMSC, LOGL_FATAL,
+ "Unsupported permitted speech selected, assuming AMR as channel mode...\n");
+ return GSM48_CMODE_SPEECH_AMR;
+ }
+}
+
+/* Helper function for match_codec_pref(), tests if a given audio support
+ * matches one of the permitted speech settings of the channel type element.
+ * The matched permitted speech value is then also compared against the
+ * speech codec list. (optional, only relevant for AoIP) */
+static bool test_codec_pref(const struct gsm0808_channel_type *ct,
+ const struct gsm0808_speech_codec_list *scl,
+ uint8_t perm_spch)
+{
+ unsigned int i;
+ bool match = false;
+ struct gsm0808_speech_codec sc;
+ int rc;
+
+ /* Try to finde the given permitted speech value in the
+ * codec list of the channel type element */
+ for (i = 0; i < ct->perm_spch_len; i++) {
+ if (ct->perm_spch[i] == perm_spch) {
+ match = true;
+ break;
+ }
+ }
+
+ /* If we do not have a speech codec list to test against,
+ * we just exit early (will be always the case in non-AoIP networks) */
+ if (!scl)
+ return match;
+
+ /* If we failed to match until here, there is no
+ * point in testing further */
+ if (match == false)
+ return false;
+
+ /* Extrapolate speech codec data */
+ rc = gsm0808_extrapolate_speech_codec(&sc, perm_spch);
+ if (rc < 0)
+ return false;
+
+ /* Try to find extrapolated speech codec data in
+ * the speech codec list */
+ for (i = 0; i < scl->len; i++) {
+ if (memcmp(&sc, &scl->codec[i], sizeof(sc)) == 0)
+ return true;
+ }
+
+ return false;
+}
+
+/* Helper function for bssmap_handle_assignm_req(), matches the codec
+ * preferences from the MSC with the codec preferences */
+static int match_codec_pref(int *full_rate, enum gsm48_chan_mode *chan_mode,
+ const struct gsm0808_channel_type *ct,
+ const struct gsm0808_speech_codec_list *scl,
+ const struct bsc_msc_data *msc)
+{
+ unsigned int i;
+ uint8_t perm_spch;
+ bool match = false;
+
+ for (i = 0; msc->audio_length; i++) {
+ perm_spch = audio_support_to_gsm88(msc->audio_support[i]);
+ if (test_codec_pref(ct, scl, perm_spch)) {
+ match = true;
+ break;
+ }
+ }
+
+ /* Exit without result, in case no match can be deteched */
+ if (!match) {
+ *full_rate = -1;
+ *chan_mode = GSM48_CMODE_SIGN;
+ return -1;
}
- LOGP(DMSC, LOGL_FATAL, "Should not be reached.\n");
- return GSM48_CMODE_SPEECH_AMR;
+ /* Check if the result is a half or full rate codec */
+ if (perm_spch == GSM0808_PERM_HR1 || perm_spch == GSM0808_PERM_HR2
+ || perm_spch == GSM0808_PERM_HR3 || perm_spch == GSM0808_PERM_HR4
+ || perm_spch == GSM0808_PERM_HR6)
+ *full_rate = 0;
+ else
+ *full_rate = 1;
+
+ /* Lookup a channel mode for the selected codec */
+ *chan_mode = gsm88_to_chan_mode(perm_spch);
+
+ return 0;
}
static int bssmap_handle_reset_ack(struct bsc_msc_data *msc,
@@ -308,23 +404,31 @@ static int bssmap_handle_assignm_req(struct osmo_bsc_sccp_con *conn,
struct msgb *resp;
struct bsc_msc_data *msc;
struct tlv_parsed tp;
- uint8_t *data;
uint8_t timeslot = 0;
uint8_t multiplex = 0;
enum gsm48_chan_mode chan_mode = GSM48_CMODE_SIGN;
- int i, supported, port, full_rate = -1;
+ int port, full_rate = -1;
bool aoip = false;
struct sockaddr_storage rtp_addr;
struct sockaddr_in *rtp_addr_in;
+ struct gsm0808_channel_type ct;
+ struct gsm0808_speech_codec_list scl;
+ struct gsm0808_speech_codec_list *scl_ptr = NULL;
int rc;
+ const uint8_t *data;
+ char len;
if (!conn->conn) {
- LOGP(DMSC, LOGL_ERROR, "No lchan/msc_data in cipher mode command.\n");
+ LOGP(DMSC, LOGL_ERROR,
+ "No lchan/msc_data in cipher mode command.\n");
return -1;
}
+ msc = conn->msc;
+
tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h + 1, length - 1, 0, 0);
+ /* Check for channel type element, if its missing, immediately reject */
if (!TLVP_PRESENT(&tp, GSM0808_IE_CHANNEL_TYPE)) {
LOGP(DMSC, LOGL_ERROR, "Mandatory channel type not present.\n");
goto reject;
@@ -333,70 +437,71 @@ static int bssmap_handle_assignm_req(struct osmo_bsc_sccp_con *conn,
/* Detect if a CIC code is present, if so, we use the classic ip.access
* method to calculate the RTP port */
if (TLVP_PRESENT(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE)) {
- conn->cic = osmo_load16be(TLVP_VAL(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE));
+ conn->cic =
+ osmo_load16be(TLVP_VAL
+ (&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE));
timeslot = conn->cic & 0x1f;
multiplex = (conn->cic & ~0x1f) >> 5;
- } else if(TLVP_PRESENT(&tp, GSM0808_IE_AOIP_TRASP_ADDR)) {
+ } else if (TLVP_PRESENT(&tp, GSM0808_IE_AOIP_TRASP_ADDR)) {
/* Decode AoIP transport address element */
- rc = gsm0808_dec_aoip_trasp_addr(&rtp_addr, TLVP_VAL(&tp, GSM0808_IE_AOIP_TRASP_ADDR), TLVP_LEN(&tp, GSM0808_IE_AOIP_TRASP_ADDR));
+ data = TLVP_VAL(&tp, GSM0808_IE_AOIP_TRASP_ADDR);
+ len = TLVP_LEN(&tp, GSM0808_IE_AOIP_TRASP_ADDR);
+ rc = gsm0808_dec_aoip_trasp_addr(&rtp_addr, data, len);
if (rc < 0) {
- LOGP(DMSC, LOGL_ERROR, "Unable to decode aoip transport address.\n");
+ LOGP(DMSC, LOGL_ERROR,
+ "Unable to decode aoip transport address.\n");
goto reject;
}
aoip = true;
} else {
- LOGP(DMSC, LOGL_ERROR, "transport address missing. Audio routing will not work.\n");
+ LOGP(DMSC, LOGL_ERROR,
+ "transport address missing. Audio routing will not work.\n");
goto reject;
}
- /*
- * Currently we only support a limited subset of all
- * possible channel types. The limitation ends by not using
- * multi-slot, limiting the channel coding, speech...
- */
- if (TLVP_LEN(&tp, GSM0808_IE_CHANNEL_TYPE) < 3) {
- LOGP(DMSC, LOGL_ERROR, "ChannelType len !=3 not supported: %d\n",
- TLVP_LEN(&tp, GSM0808_IE_CHANNEL_TYPE));
- goto reject;
- }
+ /* Decode speech codec list (AoIP) */
+ if (aoip) {
+ /* Check for speech codec list element */
+ if (!TLVP_PRESENT(&tp, GSM0808_IE_SPEECH_CODEC_LIST)) {
+ LOGP(DMSC, LOGL_ERROR,
+ "Mandatory speech codec list not present.\n");
+ goto reject;
+ }
- /*
- * Try to figure out if we support the proposed speech codecs. For
- * now we will always pick the full rate codecs.
- */
+ /* Decode Speech Codec list */
+ data = TLVP_VAL(&tp, GSM0808_IE_SPEECH_CODEC_LIST);
+ len = TLVP_LEN(&tp, GSM0808_IE_SPEECH_CODEC_LIST);
+ rc = gsm0808_dec_speech_codec_list(&scl, data, len);
+ if (rc < 0) {
+ LOGP(DMSC, LOGL_ERROR,
+ "Unable to decode speech codec list\n");
+ goto reject;
+ }
+ scl_ptr = &scl;
+ }
- data = (uint8_t *) TLVP_VAL(&tp, GSM0808_IE_CHANNEL_TYPE);
- if ((data[0] & 0xf) != 0x1) {
- LOGP(DMSC, LOGL_ERROR, "ChannelType != speech: %d\n", data[0]);
+ /* Decode Channel Type element */
+ data = TLVP_VAL(&tp, GSM0808_IE_CHANNEL_TYPE);
+ len = TLVP_LEN(&tp, GSM0808_IE_CHANNEL_TYPE);
+ rc = gsm0808_dec_channel_type(&ct, data, len);
+ if (rc < 0) {
+ LOGP(DMSC, LOGL_ERROR, "unable to decode channel type.\n");
goto reject;
}
- /*
- * go through the list of preferred codecs of our gsm network
- * and try to find it among the permitted codecs. If we found
- * it we will send chan_mode to the right mode and break the
- * inner loop. The outer loop will exit due chan_mode having
- * the correct value.
- */
- full_rate = 0;
- msc = conn->msc;
- for (supported = 0;
- chan_mode == GSM48_CMODE_SIGN && supported < msc->audio_length;
- ++supported) {
-
- int perm_val = audio_support_to_gsm88(msc->audio_support[supported]);
- for (i = 2; i < TLVP_LEN(&tp, GSM0808_IE_CHANNEL_TYPE); ++i) {
- if ((data[i] & 0x7f) == perm_val) {
- chan_mode = gsm88_to_chan_mode(perm_val);
- full_rate = (data[i] & 0x4) == 0;
- break;
- } else if ((data[i] & 0x80) == 0x00) {
- break;
- }
- }
+ /* Currently we only support a limited subset of all
+ * possible channel types. The limitation ends by not using
+ * multi-slot, limiting the channel coding to speech */
+ if (ct.ch_indctr != GSM0808_CHAN_SPEECH) {
+ LOGP(DMSC, LOGL_ERROR,
+ "Unsupported channel type, currently only speech is supported!\n");
+ goto reject;
}
- if (chan_mode == GSM48_CMODE_SIGN) {
+ /* Match codec information from the assignment command against the
+ * local preferences of the BSC */
+ rc = match_codec_pref(&full_rate, &chan_mode, &ct, scl_ptr, msc);
+ if (rc < 0) {
LOGP(DMSC, LOGL_ERROR, "No supported audio type found.\n");
goto reject;
}
@@ -409,14 +514,15 @@ static int bssmap_handle_assignm_req(struct osmo_bsc_sccp_con *conn,
} else {
/* use address / port supplied with the AoIP
* transport address element */
- if(rtp_addr.ss_family == AF_INET)
- {
+ if (rtp_addr.ss_family == AF_INET) {
rtp_addr_in = (struct sockaddr_in *)&rtp_addr;
conn->rtp_port = osmo_ntohs(rtp_addr_in->sin_port);
- memcpy(&conn->rtp_ip, &rtp_addr_in->sin_addr.s_addr, IP_V4_ADDR_LEN);
+ memcpy(&conn->rtp_ip, &rtp_addr_in->sin_addr.s_addr,
+ IP_V4_ADDR_LEN);
conn->rtp_ip = osmo_ntohl(conn->rtp_ip);
} else {
- LOGP(DMSC, LOGL_ERROR, "Unsopported addressing scheme. (supports only IPV4)\n");
+ LOGP(DMSC, LOGL_ERROR,
+ "Unsopported addressing scheme. (supports only IPV4)\n");
goto reject;
}
}
@@ -424,7 +530,9 @@ static int bssmap_handle_assignm_req(struct osmo_bsc_sccp_con *conn,
return gsm0808_assign_req(conn->conn, chan_mode, full_rate);
reject:
- resp = gsm0808_create_assignment_failure(GSM0808_CAUSE_NO_RADIO_RESOURCE_AVAILABLE, NULL);
+ resp =
+ gsm0808_create_assignment_failure
+ (GSM0808_CAUSE_NO_RADIO_RESOURCE_AVAILABLE, NULL);
if (!resp) {
LOGP(DMSC, LOGL_ERROR, "Channel allocation failure.\n");
return -1;
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-24 20:42:58 +0000