/* * (C) 2013 by Andreas Eversberg * (C) 2015-2017 by Harald Welte * Contributions by sysmocom - s.f.m.c. GmbH * * All Rights Reserved * * 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 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 . * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* 3GPP TS 45.009, table 3.2.1.3-{1,3}: AMR on Uplink TCH/F. * * +---+---+---+---+---+---+---+---+ * | a | b | c | d | e | f | g | h | Burst 'a' received first * +---+---+---+---+---+---+---+---+ * ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Speech/FACCH frame (bursts 'a' .. 'h') * * TDMA frame number of burst 'h' is always used as the table index. */ static const uint8_t sched_tchf_ul_amr_cmi_map[26] = { [7] = 1, /* TCH/F: a=0 / h=7 */ [16] = 1, /* TCH/F: a=8 / h=16 */ [24] = 1, /* TCH/F: a=17 / h=24 */ }; /*! \brief a single TCH/F burst was received by the PHY, process it */ int rx_tchf_fn(struct l1sched_ts *l1ts, const struct trx_ul_burst_ind *bi) { struct l1sched_chan_state *chan_state = &l1ts->chan_state[bi->chan]; struct gsm_lchan *lchan = chan_state->lchan; sbit_t *burst, **bursts_p = &chan_state->ul_bursts; uint8_t *mask = &chan_state->ul_mask; uint8_t rsl_cmode = chan_state->rsl_cmode; uint8_t tch_mode = chan_state->tch_mode; uint8_t tch_data[128]; /* just to be safe */ enum sched_meas_avg_mode meas_avg_mode = SCHED_MEAS_AVG_M_S8N8; struct l1sched_meas_set meas_avg; int rc, amr = 0; int n_errors = 0; int n_bits_total = 0; bool bfi_flag = false; unsigned int fn_begin; uint16_t ber10k; uint8_t is_sub = 0; uint8_t ft; bool amr_is_cmr; /* If handover RACH detection is turned on, treat this burst as an Access Burst. * Handle NOPE.ind as usually to ensure proper Uplink measurement reporting. */ if (chan_state->ho_rach_detect == 1 && ~bi->flags & TRX_BI_F_NOPE_IND) return rx_rach_fn(l1ts, bi); LOGL1SB(DL1P, LOGL_DEBUG, l1ts, bi, "Received TCH/F, bid=%u\n", bi->bid); /* allocate burst memory, if not already */ if (!*bursts_p) { *bursts_p = talloc_zero_size(l1ts, 928); if (!*bursts_p) return -ENOMEM; } /* shift the buffer by 4 bursts leftwards */ if (bi->bid == 0) { memcpy(*bursts_p, *bursts_p + 464, 464); memset(*bursts_p + 464, 0, 464); *mask = *mask << 4; } /* update mask */ *mask |= (1 << bi->bid); /* store measurements */ trx_sched_meas_push(chan_state, bi); /* copy burst to end of buffer of 8 bursts */ burst = *bursts_p + bi->bid * 116 + 464; if (bi->burst_len > 0) { memcpy(burst, bi->burst + 3, 58); memcpy(burst + 58, bi->burst + 87, 58); } else memset(burst, 0, 116); /* wait until complete set of bursts */ if (bi->bid != 3) return 0; /* fill up the burst buffer so that we have 8 bursts in there */ if (OSMO_UNLIKELY((*mask & 0xff) != 0xff)) { LOGL1SB(DL1P, LOGL_DEBUG, l1ts, bi, "UL burst buffer is not filled up: mask=0x%02x != 0xff\n", *mask); return 0; /* TODO: send BFI */ } /* decode * also shift buffer by 4 bursts for interleaving */ switch (tch_mode) { case GSM48_CMODE_SIGN: case GSM48_CMODE_SPEECH_V1: /* FR */ rc = gsm0503_tch_fr_decode(tch_data, *bursts_p, 1, 0, &n_errors, &n_bits_total); if (rc == GSM_FR_BYTES) /* only for valid *speech* frames */ lchan_set_marker(osmo_fr_check_sid(tch_data, rc), lchan); /* DTXu */ break; case GSM48_CMODE_SPEECH_EFR: /* EFR */ rc = gsm0503_tch_fr_decode(tch_data, *bursts_p, 1, 1, &n_errors, &n_bits_total); break; case GSM48_CMODE_SPEECH_AMR: /* AMR */ /* the first FN 0,8,17 defines that CMI is included in frame, * the first FN 4,13,21 defines that CMR is included in frame. * NOTE: A frame ends 7 FN after start. */ amr_is_cmr = !sched_tchf_ul_amr_cmi_map[bi->fn % 26]; /* The AFS_ONSET frame itself does not result into an RTP frame * since it only contains a recognition pattern that marks the * end of the DTX interval. To mark the end of the DTX interval * in the RTP stream as well, the voice frame after the * AFS_ONSET frame is used. */ if (chan_state->amr_last_dtx == AFS_ONSET) lchan_set_marker(false, lchan); /* we store tch_data + 2 header bytes, the amr variable set to * 2 will allow us to skip the first 2 bytes in case we did * receive an FACCH frame instead of a voice frame (we do not * know this before we actually decode the frame) */ amr = 2; rc = gsm0503_tch_afs_decode_dtx(tch_data + amr, *bursts_p, amr_is_cmr, chan_state->codec, chan_state->codecs, &chan_state->ul_ft, &chan_state->ul_cmr, &n_errors, &n_bits_total, &chan_state->amr_last_dtx); /* Tag all frames that are not regular AMR voice frames as * SUB-Frames */ if (chan_state->amr_last_dtx != AMR_OTHER) { LOGL1SB(DL1P, LOGL_DEBUG, l1ts, bi, "Received AMR DTX frame (rc=%d, BER %d/%d): %s\n", rc, n_errors, n_bits_total, gsm0503_amr_dtx_frame_name(chan_state->amr_last_dtx)); is_sub = 1; } /* The occurrence of the following frames indicates that we * are either at the beginning or in the middle of a talk * spurt. We update the SID status accordingly, but we do * not want the marker to be set, since this must only * happen when the talk spurt is over (see above) */ switch (chan_state->amr_last_dtx) { case AFS_SID_FIRST: case AFS_SID_UPDATE: case AFS_SID_UPDATE_CN: lchan_set_marker(true, lchan); lchan->rtp_tx_marker = false; break; } switch (chan_state->amr_last_dtx) { case AFS_SID_FIRST: case AFS_SID_UPDATE_CN: meas_avg_mode = SCHED_MEAS_AVG_M_S8N4; break; case AFS_SID_UPDATE: case AFS_ONSET: meas_avg_mode = SCHED_MEAS_AVG_M_S4N4; break; } /* only good speech frames get rtp header */ if (rc != GSM_MACBLOCK_LEN && rc >= 4) { if (chan_state->amr_last_dtx == AMR_OTHER) { ft = chan_state->codec[chan_state->ul_ft]; } else { /* SID frames will always get Frame Type Index 8 (AMR_SID) */ ft = AMR_SID; } rc = osmo_amr_rtp_enc(tch_data, chan_state->codec[chan_state->ul_cmr], ft, AMR_GOOD); } break; default: LOGL1SB(DL1P, LOGL_ERROR, l1ts, bi, "TCH mode %u invalid, please fix!\n", tch_mode); return -EINVAL; } /* average measurements of the last N (depends on mode) bursts */ trx_sched_meas_avg(chan_state, &meas_avg, meas_avg_mode); /* meas_avg.fn now contains TDMA frame number of the first burst */ fn_begin = meas_avg.fn; if (tch_mode == GSM48_CMODE_SPEECH_AMR) trx_loop_amr_input(chan_state, &meas_avg); /* Check if the frame is bad */ if (rc < 0) { LOGL1SB(DL1P, LOGL_NOTICE, l1ts, bi, "Received bad data (%u/%u)\n", bi->fn % l1ts->mf_period, l1ts->mf_period); bfi_flag = true; } else if (rc < 4) { LOGL1SB(DL1P, LOGL_NOTICE, l1ts, bi, "Received bad data (%u/%u) with invalid codec mode %d\n", bi->fn % l1ts->mf_period, l1ts->mf_period, rc); bfi_flag = true; } if (rc != GSM_MACBLOCK_LEN && lchan->ecu_state) osmo_ecu_frame_in(lchan->ecu_state, bfi_flag, tch_data, rc); ber10k = compute_ber10k(n_bits_total, n_errors); if (bfi_flag) goto bfi; /* FACCH */ if (rc == GSM_MACBLOCK_LEN) { _sched_compose_ph_data_ind(l1ts, fn_begin, bi->chan, tch_data + amr, GSM_MACBLOCK_LEN, meas_avg.rssi, meas_avg.toa256, meas_avg.ci_cb, ber10k, PRES_INFO_UNKNOWN); /* If we are in SPEECH mode we will generate a fake (BFI) TCH * indication as well. This indication is needed by the higher * layers, however we already have reported the measurement * result for the current block together with the FACCH. * To avoid reporting the same measurement result again with * the fake (BFI) TCH indication we set meas_avg.rssi to zero. * Doing so tells l1sap.c to ignore the measurement result. */ meas_avg.rssi = 0; bfi: if (rsl_cmode == RSL_CMOD_SPD_SPEECH) { /* indicate bad frame */ if (lchan->tch.dtx.ul_sid) { /* DTXu: pause in progress. Push empty payload to upper layers */ rc = 0; goto compose_l1sap; } /* If there is an ECU active on this channel, use its output */ if (lchan->ecu_state) { rc = osmo_ecu_frame_out(lchan->ecu_state, tch_data); if (rc >= 0) /* Otherwise we send a BFI */ goto compose_l1sap; } switch (tch_mode) { case GSM48_CMODE_SPEECH_V1: /* FR */ memset(tch_data, 0, GSM_FR_BYTES); tch_data[0] = 0xd0; rc = GSM_FR_BYTES; break; case GSM48_CMODE_SPEECH_EFR: /* EFR */ memset(tch_data, 0, GSM_EFR_BYTES); tch_data[0] = 0xc0; rc = GSM_EFR_BYTES; break; case GSM48_CMODE_SPEECH_AMR: /* AMR */ rc = osmo_amr_rtp_enc(tch_data, chan_state->codec[chan_state->ul_cmr], chan_state->codec[chan_state->ul_ft], AMR_BAD); if (rc < 2) { LOGL1SB(DL1P, LOGL_ERROR, l1ts, bi, "Failed to encode AMR_BAD frame (rc=%d), " "not sending BFI\n", rc); return -EINVAL; } memset(tch_data + 2, 0, rc - 2); break; default: LOGL1SB(DL1P, LOGL_ERROR, l1ts, bi, "TCH mode %u invalid, please fix!\n", tch_mode); return -EINVAL; } } } if (rsl_cmode != RSL_CMOD_SPD_SPEECH) return 0; /* TCH or BFI */ compose_l1sap: return _sched_compose_tch_ind(l1ts, fn_begin, bi->chan, tch_data, rc, meas_avg.toa256, ber10k, meas_avg.rssi, meas_avg.ci_cb, is_sub); } /* common section for generation of TCH bursts (TCH/H and TCH/F). * FIXME: this function is over-complicated, refactor / get rid of it. */ struct msgb *tch_dl_dequeue(struct l1sched_ts *l1ts, struct trx_dl_burst_req *br) { struct msgb *msg1, *msg2, *msg_tch = NULL, *msg_facch = NULL; struct l1sched_chan_state *chan_state = &l1ts->chan_state[br->chan]; uint8_t rsl_cmode = chan_state->rsl_cmode; uint8_t tch_mode = chan_state->tch_mode; struct osmo_phsap_prim *l1sap; /* get frame and unlink from queue */ msg1 = _sched_dequeue_prim(l1ts, br); msg2 = _sched_dequeue_prim(l1ts, br); if (msg1) { l1sap = msgb_l1sap_prim(msg1); if (l1sap->oph.primitive == PRIM_TCH) { msg_tch = msg1; if (msg2) { l1sap = msgb_l1sap_prim(msg2); if (l1sap->oph.primitive == PRIM_TCH) { LOGL1SB(DL1P, LOGL_FATAL, l1ts, br, "TCH twice, please FIX!\n"); msgb_free(msg2); } else msg_facch = msg2; } } else { msg_facch = msg1; if (msg2) { l1sap = msgb_l1sap_prim(msg2); if (l1sap->oph.primitive != PRIM_TCH) { LOGL1SB(DL1P, LOGL_FATAL, l1ts, br, "FACCH twice, please FIX!\n"); msgb_free(msg2); } else msg_tch = msg2; } } } /* check validity of message */ if (msg_facch && msgb_l2len(msg_facch) != GSM_MACBLOCK_LEN) { LOGL1SB(DL1P, LOGL_FATAL, l1ts, br, "Prim has odd len=%u != %u\n", msgb_l2len(msg_facch), GSM_MACBLOCK_LEN); /* free message */ msgb_free(msg_facch); msg_facch = NULL; } /* prioritize FACCH over speech */ if (msg_facch) { /* Unlike SACCH, FACCH has no dedicated slots on the multiframe layout. * It's multiplexed together with TCH (speech or data) frames basically * by replacing (stealing) them. This is common for both TCH/F and * TCH/H, with the only difference that FACCH/H steals two TCH frames * (not just one) due to a longer interleaving period. */ msgb_free(msg_tch); return msg_facch; } /* check validity of message, get AMR ft and cmr */ if (msg_tch) { int len; uint8_t cmr_codec; int ft, i; enum osmo_amr_type ft_codec; enum osmo_amr_quality bfi; int8_t sti, cmi; bool amr_is_cmr = !dl_amr_fn_is_cmi(br->fn); if (rsl_cmode != RSL_CMOD_SPD_SPEECH) { LOGL1SB(DL1P, LOGL_NOTICE, l1ts, br, "Dropping speech frame, " "because we are not in speech mode\n"); goto free_bad_msg; } switch (tch_mode) { case GSM48_CMODE_SPEECH_V1: /* FR / HR */ if (br->chan != TRXC_TCHF) /* HR */ len = 15; else len = GSM_FR_BYTES; break; case GSM48_CMODE_SPEECH_EFR: /* EFR */ if (br->chan != TRXC_TCHF) goto inval_mode2; len = GSM_EFR_BYTES; break; case GSM48_CMODE_SPEECH_AMR: /* AMR */ len = osmo_amr_rtp_dec(msg_tch->l2h, msgb_l2len(msg_tch), &cmr_codec, &cmi, &ft_codec, &bfi, &sti); if (len < 0) { LOGL1SB(DL1P, LOGL_ERROR, l1ts, br, "Cannot send invalid AMR payload\n"); goto free_bad_msg; } ft = -1; for (i = 0; i < chan_state->codecs; i++) { if (chan_state->codec[i] == ft_codec) ft = i; } if (ft < 0) { LOGL1SB(DL1P, LOGL_ERROR, l1ts, br, "Codec (FT = %d) of RTP frame not in list\n", ft_codec); goto free_bad_msg; } if (amr_is_cmr && chan_state->dl_ft != ft) { LOGL1SB(DL1P, LOGL_NOTICE, l1ts, br, "Codec (FT = %d) " " of RTP cannot be changed now, but in next frame\n", ft_codec); goto free_bad_msg; } chan_state->dl_ft = ft; if (bfi == AMR_BAD) { LOGL1SB(DL1P, LOGL_NOTICE, l1ts, br, "Transmitting 'bad AMR frame'\n"); goto free_bad_msg; } break; default: inval_mode2: LOGL1SB(DL1P, LOGL_ERROR, l1ts, br, "TCH mode invalid, please fix!\n"); goto free_bad_msg; } if (msgb_l2len(msg_tch) != len) { LOGL1SB(DL1P, LOGL_ERROR, l1ts, br, "Cannot send payload with " "invalid length! (expecting %d, received %d)\n", len, msgb_l2len(msg_tch)); free_bad_msg: /* free message */ msgb_free(msg_tch); msg_tch = NULL; } } return msg_tch; } /* obtain a to-be-transmitted TCH/F (Full Traffic Channel) burst */ int tx_tchf_fn(struct l1sched_ts *l1ts, struct trx_dl_burst_req *br) { struct l1sched_chan_state *chan_state = &l1ts->chan_state[br->chan]; uint8_t tch_mode = chan_state->tch_mode; ubit_t *burst, **bursts_p = &chan_state->dl_bursts; struct msgb *msg; /* send burst, if we already got a frame */ if (br->bid > 0) { if (!*bursts_p) return -ENODEV; goto send_burst; } /* BURST BYPASS */ /* allocate burst memory, if not already, * otherwise shift buffer by 4 bursts for interleaving */ if (!*bursts_p) { *bursts_p = talloc_zero_size(l1ts, 928); if (!*bursts_p) return -ENOMEM; } else { memcpy(*bursts_p, *bursts_p + 464, 464); memset(*bursts_p + 464, 0, 464); } /* dequeue a message to be transmitted */ msg = tch_dl_dequeue(l1ts, br); /* no message at all, send a dummy L2 frame on FACCH */ if (msg == NULL) { static const uint8_t dummy[GSM_MACBLOCK_LEN] = { 0x03, 0x03, 0x01, /* TODO: use randomized padding */ 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, }; LOGL1SB(DL1P, LOGL_DEBUG, l1ts, br, "No TCH or FACCH prim for transmit.\n"); gsm0503_tch_fr_encode(*bursts_p, dummy, sizeof(dummy), 1); chan_state->dl_facch_bursts = 8; goto send_burst; } /* populate the buffer with bursts */ if (msgb_l2len(msg) == GSM_MACBLOCK_LEN) { gsm0503_tch_fr_encode(*bursts_p, msg->l2h, msgb_l2len(msg), 1); chan_state->dl_facch_bursts = 8; } else if (tch_mode == GSM48_CMODE_SPEECH_AMR) /* the first FN 4,13,21 defines that CMI is included in frame, * the first FN 0,8,17 defines that CMR is included in frame. */ gsm0503_tch_afs_encode(*bursts_p, msg->l2h + 2, msgb_l2len(msg) - 2, !dl_amr_fn_is_cmi(br->fn), chan_state->codec, chan_state->codecs, chan_state->dl_ft, chan_state->dl_cmr); else gsm0503_tch_fr_encode(*bursts_p, msg->l2h, msgb_l2len(msg), 1); /* free message */ msgb_free(msg); send_burst: /* compose burst */ burst = *bursts_p + br->bid * 116; memcpy(br->burst + 3, burst, 58); memcpy(br->burst + 61, TRX_GMSK_NB_TSC(br), 26); memcpy(br->burst + 87, burst + 58, 58); br->burst_len = GSM_BURST_LEN; if (chan_state->dl_facch_bursts > 0) { chan_state->dl_facch_bursts--; br->flags |= TRX_BR_F_FACCH; } LOGL1SB(DL1P, LOGL_DEBUG, l1ts, br, "Transmitting burst=%u.\n", br->bid); return 0; }