aboutsummaryrefslogtreecommitdiffstats
path: root/src/osmo-bsc
diff options
context:
space:
mode:
Diffstat (limited to 'src/osmo-bsc')
-rw-r--r--src/osmo-bsc/lchan_fsm.c124
1 files changed, 66 insertions, 58 deletions
diff --git a/src/osmo-bsc/lchan_fsm.c b/src/osmo-bsc/lchan_fsm.c
index 39edaff6d..915b62aff 100644
--- a/src/osmo-bsc/lchan_fsm.c
+++ b/src/osmo-bsc/lchan_fsm.c
@@ -36,6 +36,8 @@
#include <osmocom/bsc/assignment_fsm.h>
#include <osmocom/bsc/handover_fsm.h>
#include <osmocom/bsc/bsc_msc_data.h>
+#include <osmocom/bsc/codec_pref.h>
+
static struct osmo_fsm lchan_fsm;
@@ -402,66 +404,71 @@ static void lchan_fsm_unused_onenter(struct osmo_fsm_inst *fi, uint32_t prev_sta
osmo_fsm_inst_dispatch(lchan->ts->fi, TS_EV_LCHAN_UNUSED, lchan);
}
-/*! Configure the multirate setting on this channel. */
-void lchan_mr_config(struct gsm_lchan *lchan, struct gsm48_multi_rate_conf *mr_conf)
+/* Configure the multirate setting on this channel. */
+static int lchan_mr_config(struct gsm_lchan *lchan, const struct gsm48_multi_rate_conf *mr_conf)
{
- struct gsm48_multi_rate_conf *ms_conf, *bts_conf;
bool full_rate = (lchan->type == GSM_LCHAN_TCH_F);
+ struct gsm_bts *bts = lchan->ts->trx->bts;
+ struct bsc_msc_data *msc = lchan->conn->sccp.msc;
+ struct amr_multirate_conf *mr;
+ int rc;
+ int rc_rate;
+ struct gsm48_multi_rate_conf mr_conf_filtered;
+ const struct gsm48_multi_rate_conf *mr_conf_bts;
+
+ /* There are two different active sets, depending on the channel rate,
+ * make sure the appropate one is selected. */
+ if (full_rate)
+ mr = &bts->mr_full;
+ else
+ mr = &bts->mr_half;
+
+ /* The VTY allows to forbid certain codec rates. Unfortunately we can
+ * not articulate all of the prohibitions on through S0-S15 on the A
+ * interface. To ensure that the VTY settings are observed we create
+ * a manipulated copy of the mr_conf that ensures forbidden codec rates
+ * are not used in the multirate configuration IE. */
+ rc_rate = calc_amr_rate_intersection(&mr_conf_filtered, &msc->amr_conf, mr_conf);
+ if (rc_rate < 0) {
+ LOG_LCHAN(lchan, LOGL_ERROR,
+ "can not encode multirate configuration (invalid amr rate setting, MSC)\n");
+ return -EINVAL;
+ }
- /* initialize the data structure */
- lchan->mr_ms_lv[0] = sizeof(*ms_conf);
- lchan->mr_bts_lv[0] = sizeof(*bts_conf);
- ms_conf = (struct gsm48_multi_rate_conf *) &lchan->mr_ms_lv[1];
- bts_conf = (struct gsm48_multi_rate_conf *) &lchan->mr_bts_lv[1];
-
- *ms_conf = *bts_conf = (struct gsm48_multi_rate_conf){
- .ver = 1,
- .icmi = 1,
- .m4_75 = mr_conf->m4_75,
- .m5_15 = mr_conf->m5_15,
- .m5_90 = mr_conf->m5_90,
- .m6_70 = mr_conf->m6_70,
- .m7_40 = mr_conf->m7_40,
- .m7_95 = mr_conf->m7_95,
- .m10_2 = full_rate? mr_conf->m10_2 : 0,
- .m12_2 = full_rate? mr_conf->m12_2 : 0,
- };
-}
+ /* The two last codec rates which are defined for AMR do only work with
+ * full rate channels. We will pinch off those rates für half-rate
+ * channels to ensure they are not included accidently. */
+ if (!full_rate) {
+ if (mr_conf_filtered.m10_2 || mr_conf_filtered.m12_2)
+ LOG_LCHAN(lchan, LOGL_ERROR, "ignoring unsupported amr codec rates\n");
+ mr_conf_filtered.m10_2 = 0;
+ mr_conf_filtered.m12_2 = 0;
+ }
-/* Mask all rates instead of the highest possible */
-static void lchan_mr_config_mask(struct gsm48_multi_rate_conf *mr_conf)
-{
- unsigned int i;
- bool highest_seen = false;
- uint8_t *_mr_conf = (uint8_t *) mr_conf;
-
- /* FIXME: At the moment we can not support multiple codec rates in one
- * struct gsm48_multi_rate_conf, because the struct lacks the fields
- * for Threshold and Hysteresis. Those fields are not needed when only
- * a single codec rate is in place, but as soon as multiple codec
- * rates are used the parameters are mandatory. The layout for the
- * struct would then also be different because each rate needs its
- * own Threshold and Hysteresis value. (See also 3GPP TS 04.08,
- * chapter 10.5.2.21aa MultiRate configuration).
- *
- * Since we are unable to signal multiple codec rates properly, we just
- * remove all codec rates from the active set, except the highest
- * possible. Doing so we lack the functionality to switch towards the
- * other, lower codec rates that were offered by the MSC, but it is
- * still guaranteed that a rate is selected that is supported by all
- * entities.
- *
- * To fix this problem, we should implement a proper encoder for
- * struct gsm48_multi_rate_conf, in libosmocore and use it here.
- * struct amr_mode already seems to have members for threshold and
- * hysteresis we can use. */
-
- for (i = 7; i > 0; i--) {
- if (_mr_conf[1] & (1 << i) && highest_seen == false) {
- highest_seen = true;
- } else if (highest_seen)
- _mr_conf[1] &= ~(1 << i);
+ /* Ensure that the resulting filtered conf is coherent with the
+ * configuration that is set for the BTS and the specified rate */
+ mr_conf_bts = (struct gsm48_multi_rate_conf *)mr->gsm48_ie;
+ rc_rate = calc_amr_rate_intersection(&mr_conf_filtered, mr_conf_bts, &mr_conf_filtered);
+ if (rc_rate < 0) {
+ LOG_LCHAN(lchan, LOGL_ERROR,
+ "can not encode multirate configuration (invalid amr rate setting, BTS)\n");
+ return -EINVAL;
}
+
+ /* Proceed with the generation of the multirate configuration IE
+ * (MS and BTS) */
+ rc = gsm48_multirate_config(lchan->mr_ms_lv, &mr_conf_filtered, mr->ms_mode, mr->num_modes);
+ if (rc != 0) {
+ LOG_LCHAN(lchan, LOGL_ERROR, "can not encode multirate configuration (MS)\n");
+ return -EINVAL;
+ }
+ rc = gsm48_multirate_config(lchan->mr_bts_lv, &mr_conf_filtered, mr->bts_mode, mr->num_modes);
+ if (rc != 0) {
+ LOG_LCHAN(lchan, LOGL_ERROR, "can not encode multirate configuration (BTS)\n");
+ return -EINVAL;
+ }
+
+ return 0;
}
static void lchan_fsm_unused(struct osmo_fsm_inst *fi, uint32_t event, void *data)
@@ -511,9 +518,10 @@ static void lchan_fsm_unused(struct osmo_fsm_inst *fi, uint32_t event, void *dat
if (info->chan_mode == GSM48_CMODE_SPEECH_AMR) {
gsm48_mr_cfg_from_gsm0808_sc_cfg(&mr_conf, info->s15_s0);
- /* FIXME: See above. */
- lchan_mr_config_mask(&mr_conf);
- lchan_mr_config(lchan, &mr_conf);
+ if (lchan_mr_config(lchan, &mr_conf) < 0) {
+ lchan_fail("Can not generate multirate configuration IE\n");
+ return;
+ }
}
switch (info->chan_mode) {