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-rw-r--r--src/osmo-bsc/codec_pref.c121
1 files changed, 81 insertions, 40 deletions
diff --git a/src/osmo-bsc/codec_pref.c b/src/osmo-bsc/codec_pref.c
index c998e6007..afecaa3ad 100644
--- a/src/osmo-bsc/codec_pref.c
+++ b/src/osmo-bsc/codec_pref.c
@@ -94,14 +94,18 @@ static enum gsm0808_permitted_speech audio_support_to_gsm88(const struct gsm_aud
* 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)
+static bool test_codec_pref(const struct gsm0808_speech_codec **sc_match,
+ const struct gsm0808_speech_codec_list *scl,
+ const struct gsm0808_channel_type *ct,
+ uint8_t perm_spch)
{
unsigned int i;
bool match = false;
struct gsm0808_speech_codec sc;
int rc;
+ *sc_match = NULL;
+
/* Try to find the given permitted speech value in the
* codec list of the channel type element */
for (i = 0; i < ct->perm_spch_len; i++) {
@@ -129,8 +133,10 @@ static bool test_codec_pref(const struct gsm0808_channel_type *ct,
/* Try to find extrapolated speech codec data in
* the speech codec list */
for (i = 0; i < scl->len; i++) {
- if (sc.type == scl->codec[i].type)
+ if (sc.type == scl->codec[i].type) {
+ *sc_match = &scl->codec[i];
return true;
+ }
}
return false;
@@ -168,40 +174,74 @@ static bool test_codec_support_bts(const struct bts_codec_conf *bts_codec, uint8
return false;
}
+/* Generate the bss supported amr configuration bits (S0-S15) */
+static uint16_t gen_bss_supported_amr_s15_s0(const struct bsc_msc_data *msc, const struct gsm_bts *bts, bool hr)
+{
+ const struct gsm48_multi_rate_conf *amr_cfg_bts;
+ const struct gsm48_multi_rate_conf *amr_cfg_msc;
+ uint16_t amr_s15_s0_bts;
+ uint16_t amr_s15_s0_msc;
+
+ /* Lookup the BTS specific AMR rate configuration. This config is set
+ * via the VTY for each BTS individually. In cases where no configuration
+ * is set we will assume a safe default */
+ if (hr) {
+ amr_cfg_bts = (struct gsm48_multi_rate_conf *)&bts->mr_half.gsm48_ie;
+ amr_s15_s0_bts = gsm0808_sc_cfg_from_gsm48_mr_cfg(amr_cfg_bts, false);
+ } else {
+ amr_cfg_bts = (struct gsm48_multi_rate_conf *)&bts->mr_full.gsm48_ie;
+ amr_s15_s0_bts = gsm0808_sc_cfg_from_gsm48_mr_cfg(amr_cfg_bts, true);
+ }
+
+ /* Lookup the AMR rate configuration that is set for the MSC */
+ amr_cfg_msc = &msc->amr_conf;
+ amr_s15_s0_msc = gsm0808_sc_cfg_from_gsm48_mr_cfg(amr_cfg_msc, true);
+
+ /* Calculate the intersection of the two configurations and update S0-S15
+ * in the codec list. */
+ return amr_s15_s0_bts & amr_s15_s0_msc;
+}
+
/*! Match the codec preferences from local config with a received codec preferences IEs received from the
* MSC and the BTS' codec configuration.
* \param[out] chan_mode GSM 04.08 channel mode.
* \param[out] full_rate true if full-rate.
+ * \param[out] s15_s0 codec configuration bits S15-S0 (AMR)
* \param[in] ct GSM 08.08 channel type received from MSC.
* \param[in] scl GSM 08.08 speech codec list received from MSC (optional).
- * \param[in] audio_support List of allowed codecs as from local config.
- * \param[in] audio_length Number of items in audio_support.
- * \param[in] bts_codec BTS codec configuration.
+ * \param[in] msc associated msc (current codec settings).
+ * \param[in] bts associated bts (current codec settings).
* \returns 0 on success, -1 in case no match was found */
int match_codec_pref(enum gsm48_chan_mode *chan_mode,
bool *full_rate,
+ uint16_t *s15_s0,
const struct gsm0808_channel_type *ct,
const struct gsm0808_speech_codec_list *scl,
- struct gsm_audio_support * const *audio_support,
- int audio_length,
- const struct bts_codec_conf *bts_codec)
+ const struct bsc_msc_data *msc,
+ const struct gsm_bts *bts)
{
unsigned int i;
uint8_t perm_spch;
bool match = false;
+ const struct gsm0808_speech_codec *sc_match = NULL;
+ uint16_t amr_s15_s0_supported;
- for (i = 0; i < audio_length; i++) {
+ /* Note: Normally the MSC should never try to advertise a codec that
+ * we did not advertise as supported before. In order to ensure that
+ * no unsupported codec is accepted, we make sure that the codec is
+ * indeed available with the current BTS and MSC configuration */
+ for (i = 0; i < msc->audio_length; i++) {
/* Pick a permitted speech value from the global codec configuration list */
- perm_spch = audio_support_to_gsm88(audio_support[i]);
+ perm_spch = audio_support_to_gsm88(msc->audio_support[i]);
/* Check this permitted speech value against the BTS specific parameters.
* if the BTS does not support the codec, try the next one */
- if (!test_codec_support_bts(bts_codec, perm_spch))
+ if (!test_codec_support_bts(&bts->codec, perm_spch))
continue;
/* Match the permitted speech value against the codec lists that were
* advertised by the MS and the MSC */
- if (test_codec_pref(ct, scl, perm_spch)) {
+ if (test_codec_pref(&sc_match, scl, ct, perm_spch)) {
match = true;
break;
}
@@ -211,6 +251,7 @@ int match_codec_pref(enum gsm48_chan_mode *chan_mode,
if (!match) {
*full_rate = false;
*chan_mode = GSM48_CMODE_SIGN;
+ *s15_s0 = 0;
return -1;
}
@@ -240,6 +281,31 @@ int match_codec_pref(enum gsm48_chan_mode *chan_mode,
/* Lookup a channel mode for the selected codec */
*chan_mode = gsm88_to_chan_mode(perm_spch);
+ /* Special handling for AMR */
+ if (perm_spch == GSM0808_PERM_HR3 || perm_spch == GSM0808_PERM_FR3) {
+ /* Normally the MSC should never try to advertise an AMR codec
+ * configuration that we did not previously advertise as
+ * supported. However, to ensure that no unsupported AMR codec
+ * configuration enters the further processing steps we again
+ * lookup what we support and generate an intersection. All
+ * further processing is then done with this intersection
+ * result */
+ amr_s15_s0_supported = gen_bss_supported_amr_s15_s0(msc, bts, (perm_spch == GSM0808_PERM_HR3));
+ if (sc_match)
+ *s15_s0 = sc_match->cfg & amr_s15_s0_supported;
+ else
+ *s15_s0 = amr_s15_s0_supported;
+
+ /* NOTE: The function test_codec_pref() will populate the
+ * sc_match pointer from the searched speech codec list. For
+ * AoIP based networks, no speech codec list will be present
+ * and therefore no sc_match will be populated. For those
+ * cases only the local configuration will influence s15_s0.
+ * However s15_s0 is always populated with a meaningful value,
+ * regardless if AoIP is in use or not. */
+ } else
+ *s15_s0 = 0;
+
return 0;
}
@@ -254,11 +320,6 @@ void gen_bss_supported_codec_list(struct gsm0808_speech_codec_list *scl,
uint8_t perm_spch;
unsigned int i;
int rc;
- uint16_t amr_s15_s0_bts;
- uint16_t amr_s15_s0_msc;
- uint16_t amr_s15_s0;
- const struct gsm48_multi_rate_conf *amr_cfg_bts;
- const struct gsm48_multi_rate_conf *amr_cfg_msc;
memset(scl, 0, sizeof(*scl));
@@ -280,28 +341,8 @@ void gen_bss_supported_codec_list(struct gsm0808_speech_codec_list *scl,
/* AMR (HR/FR version 3) is the only codec that requires a codec
* configuration (S0-S15). Determine the current configuration and update
* the cfg flag. */
- if (msc->audio_support[i]->ver == 3) {
-
- /* First lookup the BTS specific AMR rate configuration. Thsi config
- * is set via the VTY for each BTS individually. In cases where no
- * configuration is set we will assume a safe default */
- if (msc->audio_support[i]->hr) {
- amr_cfg_bts = (struct gsm48_multi_rate_conf *)&bts->mr_half.gsm48_ie;
- amr_s15_s0_bts = gsm0808_sc_cfg_from_gsm48_mr_cfg(amr_cfg_bts, false);
- } else {
- amr_cfg_bts = (struct gsm48_multi_rate_conf *)&bts->mr_full.gsm48_ie;
- amr_s15_s0_bts = gsm0808_sc_cfg_from_gsm48_mr_cfg(amr_cfg_bts, true);
- }
-
- /* At next, lookup the AMR rate configuration that is set for the MSC */
- amr_cfg_msc = &msc->amr_conf;
- amr_s15_s0_msc = gsm0808_sc_cfg_from_gsm48_mr_cfg(amr_cfg_msc, true);
-
- /* Calculate the intersection of the two configurations and update S0-S15
- * in the codec list. */
- amr_s15_s0 = amr_s15_s0_bts & amr_s15_s0_msc;
- scl->codec[scl->len].cfg = amr_s15_s0;
- }
+ if (msc->audio_support[i]->ver == 3)
+ scl->codec[scl->len].cfg = gen_bss_supported_amr_s15_s0(msc, bts, msc->audio_support[i]->hr);
scl->len++;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-12 12:11:10 +0000