| /* |
| * (C) 2017-2018 by sysmocom s.f.m.c. GmbH <info@sysmocom.de> |
| * All Rights Reserved |
| * |
| * Author: Philipp Maier |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU Affero General Public License as published by |
| * the Free Software Foundation; either version 3 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU Affero General Public License for more details. |
| * |
| * You should have received a copy of the GNU Affero General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| * |
| */ |
| |
| #include <osmocom/core/msgb.h> |
| #include <osmocom/mgcp_client/mgcp_client_fsm.h> |
| #include <osmocom/netif/rtp.h> |
| #include <osmocom/gsm/protocol/gsm_08_08.h> |
| #include <osmocom/gsm/gsm0808_utils.h> |
| #include <osmocom/bsc/bsc_msc_data.h> |
| #include <osmocom/bsc/codec_pref.h> |
| #include <osmocom/bsc/gsm_data.h> |
| |
| /* Determine whether a permitted speech value is specifies a half rate or full |
| * rate codec */ |
| static int full_rate_from_perm_spch(bool * full_rate, |
| enum gsm0808_permitted_speech perm_spch) |
| { |
| /* Check if the result is a half or full rate codec */ |
| switch (perm_spch) { |
| case GSM0808_PERM_HR1: |
| case GSM0808_PERM_HR2: |
| case GSM0808_PERM_HR3: |
| case GSM0808_PERM_HR4: |
| case GSM0808_PERM_HR6: |
| *full_rate = false; |
| break; |
| |
| case GSM0808_PERM_FR1: |
| case GSM0808_PERM_FR2: |
| case GSM0808_PERM_FR3: |
| case GSM0808_PERM_FR4: |
| case GSM0808_PERM_FR5: |
| *full_rate = true; |
| break; |
| |
| default: |
| LOGP(DMSC, LOGL_ERROR, "Invalid permitted-speech value: %u\n", |
| perm_spch); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| /* Helper function for match_codec_pref(), looks up a matching chan mode for |
| * a given permitted speech value */ |
| static enum gsm48_chan_mode gsm88_to_chan_mode(enum gsm0808_permitted_speech speech) |
| { |
| switch (speech) { |
| case GSM0808_PERM_HR1: |
| case GSM0808_PERM_FR1: |
| return GSM48_CMODE_SPEECH_V1; |
| break; |
| case GSM0808_PERM_FR2: |
| return GSM48_CMODE_SPEECH_EFR; |
| break; |
| case GSM0808_PERM_HR3: |
| case GSM0808_PERM_FR3: |
| return GSM48_CMODE_SPEECH_AMR; |
| break; |
| case GSM0808_PERM_HR2: |
| LOGP(DMSC, LOGL_FATAL, "Speech HR2 was never specified!\n"); |
| /* fall through */ |
| default: |
| LOGP(DMSC, LOGL_FATAL, "Unsupported permitted speech %s selected, " |
| "assuming AMR as channel mode...\n", |
| gsm0808_permitted_speech_name(speech)); |
| return GSM48_CMODE_SPEECH_AMR; |
| } |
| } |
| |
| /* Helper function for match_codec_pref(), looks up a matching permitted speech |
| * value for a given msc audio codec pref */ |
| static enum gsm0808_permitted_speech audio_support_to_gsm88(const struct gsm_audio_support *audio) |
| { |
| if (audio->hr) { |
| switch (audio->ver) { |
| case 1: |
| return GSM0808_PERM_HR1; |
| break; |
| case 2: |
| return GSM0808_PERM_HR2; |
| break; |
| case 3: |
| return GSM0808_PERM_HR3; |
| break; |
| default: |
| LOGP(DMSC, LOGL_ERROR, "Wrong speech mode: hr%d, using hr1 instead\n", audio->ver); |
| return GSM0808_PERM_HR1; |
| } |
| } else { |
| switch (audio->ver) { |
| case 1: |
| return GSM0808_PERM_FR1; |
| break; |
| case 2: |
| return GSM0808_PERM_FR2; |
| break; |
| case 3: |
| return GSM0808_PERM_FR3; |
| break; |
| default: |
| LOGP(DMSC, LOGL_ERROR, "Wrong speech mode: fr%d, using fr1 instead\n", audio->ver); |
| return GSM0808_PERM_FR1; |
| } |
| } |
| } |
| |
| /* 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_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++) { |
| 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 || !scl->len) |
| 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_speech_codec_from_chan_type(&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 (sc.type == scl->codec[i].type) { |
| *sc_match = &scl->codec[i]; |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| /* Helper function to check if the given permitted speech value is supported |
| * by the BTS. (vty option bts->codec-support). */ |
| static bool test_codec_support_bts(const struct gsm_bts *bts, uint8_t perm_spch) |
| { |
| struct gsm_bts_trx *trx; |
| const struct bts_codec_conf *bts_codec = &bts->codec; |
| unsigned int i; |
| bool full_rate; |
| int rc; |
| enum gsm_phys_chan_config pchan; |
| bool rate_match = false; |
| |
| /* Check if the BTS provides a physical channel that matches the |
| * bandwidth of the desired codec. */ |
| rc = full_rate_from_perm_spch(&full_rate, perm_spch); |
| if (rc < 0) |
| return false; |
| llist_for_each_entry(trx, &bts->trx_list, list) { |
| for (i = 0; i < TRX_NR_TS; i++) { |
| pchan = trx->ts[i].pchan_from_config; |
| if (pchan == GSM_PCHAN_TCH_F_TCH_H_PDCH) |
| rate_match = true; |
| else if (full_rate && pchan == GSM_PCHAN_TCH_F) |
| rate_match = true; |
| else if (full_rate && pchan == GSM_PCHAN_TCH_F_PDCH) |
| rate_match = true; |
| else if (!full_rate && pchan == GSM_PCHAN_TCH_H) |
| rate_match = true; |
| } |
| } |
| if (!rate_match) |
| return false; |
| |
| /* Check codec support */ |
| switch (perm_spch) { |
| case GSM0808_PERM_FR1: |
| /* GSM-FR is always supported by all BTSs. There is also no way to |
| * selectively disable GSM-RF per BTS via VTY. */ |
| return true; |
| case GSM0808_PERM_FR2: |
| if (bts_codec->efr) |
| return true; |
| break; |
| case GSM0808_PERM_FR3: |
| if (bts_codec->amr) |
| return true; |
| break; |
| case GSM0808_PERM_HR1: |
| if (bts_codec->hr) |
| return true; |
| break; |
| case GSM0808_PERM_HR3: |
| if (bts_codec->amr) |
| return true; |
| break; |
| default: |
| return false; |
| } |
| |
| 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; |
| } |
| |
| /* Special handling for AMR rate configuration bits (S15-S0) */ |
| static int match_amr_s15_s0(struct channel_mode_and_rate *ch_mode_rate, const struct bsc_msc_data *msc, const struct gsm_bts *bts, const struct gsm0808_speech_codec *sc_match, uint8_t perm_spch) |
| { |
| uint16_t amr_s15_s0_supported; |
| |
| /* Normally the MSC should never try to advertise an AMR codec |
| * configuration that we did not previously advertised 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. At the same time we will make sure |
| * that the intersection contains at least one rate setting. */ |
| |
| amr_s15_s0_supported = gen_bss_supported_amr_s15_s0(msc, bts, (perm_spch == GSM0808_PERM_HR3)); |
| |
| /* NOTE: The sc_match pointer points to a speech codec from the speech |
| * codec list that has been communicated with the ASSIGNMENT COMMAND. |
| * However, only AoIP based networks will include a speech codec list |
| * into the ASSIGNMENT COMMAND. For non AoIP based networks, no speech |
| * codec (sc_match) will be available, so we will fully rely on the |
| * local configuration for those cases. */ |
| if (sc_match) |
| ch_mode_rate->s15_s0 = sc_match->cfg & amr_s15_s0_supported; |
| else |
| ch_mode_rate->s15_s0 = amr_s15_s0_supported; |
| |
| /* Prefer "Config-NB-Code = 1" (S1) over all other AMR rates settings. |
| * When S1 is set, the active set will automatically include 12.2k, 7.4k, |
| * 5.9k, 4.75k, in case of HR 12,2k is left out. */ |
| if (ch_mode_rate->s15_s0 & GSM0808_SC_CFG_AMR_4_75_5_90_7_40_12_20) { |
| ch_mode_rate->s15_s0 &= 0xff00; |
| ch_mode_rate->s15_s0 |= GSM0808_SC_CFG_AMR_4_75_5_90_7_40_12_20; |
| } |
| |
| /* Make sure at least one rate is set. */ |
| if ((ch_mode_rate->s15_s0 & 0x00ff) == 0x0000) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| /*! Match the codec preferences from local config with a received codec preferences IEs received from the |
| * MSC and the BTS' codec configuration. |
| * \param[out] ch_mode_rate resulting codec and rate information |
| * \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] msc associated msc (current codec settings). |
| * \param[in] bts associated bts (current codec settings). |
| * \param[in] pref selected rate preference (full, half or none). |
| * \returns 0 on success, -1 in case no match was found */ |
| int match_codec_pref(struct channel_mode_and_rate *ch_mode_rate, |
| const struct gsm0808_channel_type *ct, |
| const struct gsm0808_speech_codec_list *scl, |
| const struct bsc_msc_data *msc, |
| const struct gsm_bts *bts, enum rate_pref rate_pref) |
| { |
| unsigned int i; |
| uint8_t perm_spch; |
| bool full_rate; |
| bool match = false; |
| const struct gsm0808_speech_codec *sc_match = NULL; |
| int rc; |
| |
| /* 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(msc->audio_support[i]); |
| |
| /* Determine if the result is a half or full rate codec */ |
| rc = full_rate_from_perm_spch(&full_rate, perm_spch); |
| if (rc < 0) |
| return -EINVAL; |
| ch_mode_rate->chan_rate = full_rate ? CH_RATE_FULL : CH_RATE_HALF; |
| |
| /* If we have a preference for FR or HR in our request, we |
| * discard the potential match */ |
| if (rate_pref == RATE_PREF_HR && ch_mode_rate->chan_rate == CH_RATE_FULL) |
| continue; |
| if (rate_pref == RATE_PREF_FR && ch_mode_rate->chan_rate == CH_RATE_HALF) |
| continue; |
| |
| /* 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, 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(&sc_match, scl, ct, perm_spch)) { |
| continue; |
| } |
| |
| /* Special handling for AMR */ |
| if (perm_spch == GSM0808_PERM_HR3 || perm_spch == GSM0808_PERM_FR3) { |
| rc = match_amr_s15_s0(ch_mode_rate, msc, bts, sc_match, perm_spch); |
| if (rc < 0) { |
| ch_mode_rate->s15_s0 = 0; |
| continue; |
| } |
| } else |
| ch_mode_rate->s15_s0 = 0; |
| |
| match = true; |
| break; |
| } |
| |
| /* Exit without result, in case no match can be deteched */ |
| if (!match) { |
| ch_mode_rate->chan_mode = GSM48_CMODE_SIGN; |
| ch_mode_rate->chan_rate = CH_RATE_SDCCH; |
| ch_mode_rate->s15_s0 = 0; |
| return -1; |
| } |
| |
| /* Lookup a channel mode for the selected codec */ |
| ch_mode_rate->chan_mode = gsm88_to_chan_mode(perm_spch); |
| |
| return 0; |
| } |
| |
| /*! Determine the BSS supported speech codec list that is sent to the MSC with |
| * the COMPLETE LAYER 3 INFORMATION message. |
| * \param[out] scl GSM 08.08 speech codec list with BSS supported codecs. |
| * \param[in] msc associated msc (current codec settings). |
| * \param[in] bts associated bts (current codec settings). */ |
| void gen_bss_supported_codec_list(struct gsm0808_speech_codec_list *scl, |
| const struct bsc_msc_data *msc, const struct gsm_bts *bts) |
| { |
| uint8_t perm_spch; |
| unsigned int i; |
| int rc; |
| |
| memset(scl, 0, sizeof(*scl)); |
| |
| 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(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, perm_spch)) |
| continue; |
| |
| /* Write item into codec list */ |
| rc = gsm0808_speech_codec_from_chan_type(&scl->codec[scl->len], perm_spch); |
| if (rc != 0) |
| continue; |
| |
| /* 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) |
| scl->codec[scl->len].cfg = gen_bss_supported_amr_s15_s0(msc, bts, msc->audio_support[i]->hr); |
| |
| scl->len++; |
| } |
| } |
| |
| /*! Calculate the intersection of the rate configuration of two multirate configuration |
| * IE structures. The result c will be a copy of a, but the rate configuration bits |
| * will be the intersection of the rate configuration bits in a and b. |
| * \param[out] c user provided memory to store the result. |
| * \param[in] a multi rate configuration a. |
| * \param[in] b multi rate configuration b. |
| * \returns 0 on success, -1 when the result contains an empty set of modes. */ |
| int calc_amr_rate_intersection(struct gsm48_multi_rate_conf *c, |
| const struct gsm48_multi_rate_conf *b, |
| const struct gsm48_multi_rate_conf *a) |
| { |
| struct gsm48_multi_rate_conf res; |
| uint8_t *_a = (uint8_t *) a; |
| uint8_t *_b = (uint8_t *) b; |
| uint8_t *_res = (uint8_t *) & res; |
| |
| memcpy(&res, a, sizeof(res)); |
| |
| _res[1] = _a[1] & _b[1]; |
| |
| if (_res[1] == 0x00) |
| return -1; |
| |
| if (c) |
| memcpy(c, &res, sizeof(*c)); |
| |
| return 0; |
| } |
| |
| /*! Visit the codec settings for the MSC and for each BTS in order to make sure |
| * that the configuration does not contain any combinations that lead into a |
| * mutually exclusive codec configuration (empty intersection). |
| * \param[in] mscs list head of the msc list. |
| * \returns 0 on success, -1 in case an invalid setting is found. */ |
| int check_codec_pref(struct llist_head *mscs) |
| { |
| struct bsc_msc_data *msc; |
| struct gsm_bts *bts; |
| struct gsm0808_speech_codec_list scl; |
| int rc = 0; |
| int rc_rate; |
| const struct gsm48_multi_rate_conf *bts_gsm48_ie; |
| |
| llist_for_each_entry(msc, mscs, entry) { |
| llist_for_each_entry(bts, &msc->network->bts_list, list) { |
| gen_bss_supported_codec_list(&scl, msc, bts); |
| if (scl.len <= 0) { |
| LOGP(DMSC, LOGL_FATAL, |
| "codec-support/trx config of BTS %u does not intersect with codec-list of MSC %u\n", |
| bts->nr, msc->nr); |
| rc = -1; |
| } |
| |
| bts_gsm48_ie = (struct gsm48_multi_rate_conf *)&bts->mr_full.gsm48_ie; |
| rc_rate = calc_amr_rate_intersection(NULL, &msc->amr_conf, bts_gsm48_ie); |
| if (rc_rate < 0) { |
| LOGP(DMSC, LOGL_FATAL, |
| "network amr tch-f mode config of BTS %u does not intersect with amr-config of MSC %u\n", |
| bts->nr, msc->nr); |
| rc = -1; |
| } |
| |
| bts_gsm48_ie = (struct gsm48_multi_rate_conf *)&bts->mr_half.gsm48_ie; |
| rc_rate = calc_amr_rate_intersection(NULL, &msc->amr_conf, bts_gsm48_ie); |
| if (rc_rate < 0) { |
| LOGP(DMSC, LOGL_FATAL, |
| "network amr tch-h mode config of BTS %u does not intersect with amr-config of MSC %u\n", |
| bts->nr, msc->nr); |
| rc = -1; |
| } |
| } |
| } |
| |
| return rc; |
| } |