| /* |
| * OsmocomBB <-> SDR connection bridge |
| * TDMA scheduler: handlers for DL / UL bursts on logical channels |
| * |
| * (C) 2017-2020 by Vadim Yanitskiy <axilirator@gmail.com> |
| * |
| * All Rights Reserved |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 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 General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| */ |
| |
| #include <errno.h> |
| #include <string.h> |
| #include <stdint.h> |
| |
| #include <osmocom/core/logging.h> |
| #include <osmocom/core/bits.h> |
| |
| #include <osmocom/gsm/protocol/gsm_04_08.h> |
| #include <osmocom/gsm/gsm_utils.h> |
| |
| #include <osmocom/coding/gsm0503_coding.h> |
| #include <osmocom/codec/codec.h> |
| |
| #include "l1ctl_proto.h" |
| #include "scheduler.h" |
| #include "sched_trx.h" |
| #include "logging.h" |
| #include "trx_if.h" |
| #include "l1ctl.h" |
| |
| int rx_tchf_fn(struct trx_instance *trx, struct trx_ts *ts, |
| struct trx_lchan_state *lchan, uint32_t fn, uint8_t bid, |
| const sbit_t *bits, const struct trx_meas_set *meas) |
| { |
| const struct trx_lchan_desc *lchan_desc; |
| int n_errors = -1, n_bits_total, rc; |
| sbit_t *buffer, *offset; |
| uint8_t l2[128], *mask; |
| size_t l2_len; |
| |
| /* Set up pointers */ |
| lchan_desc = &trx_lchan_desc[lchan->type]; |
| mask = &lchan->rx_burst_mask; |
| buffer = lchan->rx_bursts; |
| |
| LOGP(DSCHD, LOGL_DEBUG, "Traffic received on %s: fn=%u ts=%u bid=%u\n", |
| lchan_desc->name, fn, ts->index, bid); |
| |
| /* Align to the first burst of a block */ |
| if (*mask == 0x00 && bid != 0) |
| return 0; |
| |
| /* Update mask */ |
| *mask |= (1 << bid); |
| |
| /* Store the measurements */ |
| sched_trx_meas_push(lchan, meas); |
| |
| /* Copy burst to end of buffer of 8 bursts */ |
| offset = buffer + bid * 116 + 464; |
| memcpy(offset, bits + 3, 58); |
| memcpy(offset + 58, bits + 87, 58); |
| |
| /* Wait until complete set of bursts */ |
| if (bid != 3) |
| return 0; |
| |
| /* Calculate AVG of the measurements */ |
| sched_trx_meas_avg(lchan, 8); |
| |
| /* Check for complete set of bursts */ |
| if ((*mask & 0xff) != 0xff) { |
| LOGP(DSCHD, LOGL_ERROR, "Received incomplete (%s) traffic frame at " |
| "fn=%u (%u/%u) for %s\n", |
| burst_mask2str(mask, 8), lchan->meas_avg.fn, |
| lchan->meas_avg.fn % ts->mf_layout->period, |
| ts->mf_layout->period, |
| lchan_desc->name); |
| /* NOTE: do not abort here, give it a try. Maybe we're lucky ;) */ |
| |
| } |
| |
| /* Keep the mask updated */ |
| *mask = *mask << 4; |
| |
| switch (lchan->tch_mode) { |
| case GSM48_CMODE_SIGN: |
| case GSM48_CMODE_SPEECH_V1: /* FR */ |
| rc = gsm0503_tch_fr_decode(l2, buffer, |
| 1, 0, &n_errors, &n_bits_total); |
| break; |
| case GSM48_CMODE_SPEECH_EFR: /* EFR */ |
| rc = gsm0503_tch_fr_decode(l2, buffer, |
| 1, 1, &n_errors, &n_bits_total); |
| break; |
| case GSM48_CMODE_SPEECH_AMR: /* AMR */ |
| /** |
| * TODO: AMR requires a dedicated loop, |
| * which will be implemented later... |
| */ |
| LOGP(DSCHD, LOGL_ERROR, "AMR isn't supported yet\n"); |
| return -ENOTSUP; |
| default: |
| LOGP(DSCHD, LOGL_ERROR, "Invalid TCH mode: %u\n", lchan->tch_mode); |
| return -EINVAL; |
| } |
| |
| /* Shift buffer by 4 bursts for interleaving */ |
| memcpy(buffer, buffer + 464, 464); |
| |
| /* Check decoding result */ |
| if (rc < 4) { |
| LOGP(DSCHD, LOGL_ERROR, "Received bad TCH frame ending at " |
| "fn=%u for %s\n", fn, lchan_desc->name); |
| |
| /* Send BFI */ |
| goto bfi; |
| } else if (rc == GSM_MACBLOCK_LEN) { |
| /* FACCH received, forward it to the higher layers */ |
| sched_send_dt_ind(trx, ts, lchan, l2, GSM_MACBLOCK_LEN, |
| n_errors, false, false); |
| |
| /* Send BFI substituting a stolen TCH frame */ |
| n_errors = -1; /* ensure fake measurements */ |
| goto bfi; |
| } else { |
| /* A good TCH frame received */ |
| l2_len = rc; |
| } |
| |
| /* Send a traffic frame to the higher layers */ |
| return sched_send_dt_ind(trx, ts, lchan, l2, l2_len, |
| n_errors, false, true); |
| |
| bfi: |
| /* Didn't try to decode, fake measurements */ |
| if (n_errors < 0) { |
| lchan->meas_avg = (struct trx_meas_set) { |
| .fn = lchan->meas_avg.fn, |
| .toa256 = 0, |
| .rssi = -110, |
| }; |
| |
| /* No bursts => no errors */ |
| n_errors = 0; |
| } |
| |
| /* BFI is not applicable in signalling mode */ |
| if (lchan->tch_mode == GSM48_CMODE_SIGN) |
| return sched_send_dt_ind(trx, ts, lchan, NULL, 0, |
| n_errors, true, false); |
| |
| /* Bad frame indication */ |
| l2_len = sched_bad_frame_ind(l2, lchan); |
| |
| /* Send a BFI frame to the higher layers */ |
| return sched_send_dt_ind(trx, ts, lchan, l2, l2_len, |
| n_errors, true, true); |
| } |
| |
| int tx_tchf_fn(struct trx_instance *trx, struct trx_ts *ts, |
| struct trx_lchan_state *lchan, uint32_t fn, uint8_t bid) |
| { |
| const struct trx_lchan_desc *lchan_desc; |
| ubit_t burst[GSM_BURST_LEN]; |
| ubit_t *buffer, *offset; |
| const uint8_t *tsc; |
| uint8_t *mask; |
| size_t l2_len; |
| int rc; |
| |
| /* Set up pointers */ |
| lchan_desc = &trx_lchan_desc[lchan->type]; |
| mask = &lchan->tx_burst_mask; |
| buffer = lchan->tx_bursts; |
| |
| /* If we have encoded bursts */ |
| if (*mask) |
| goto send_burst; |
| |
| /* Wait until a first burst in period */ |
| if (bid > 0) |
| return 0; |
| |
| /* Check the current TCH mode */ |
| switch (lchan->tch_mode) { |
| case GSM48_CMODE_SIGN: |
| case GSM48_CMODE_SPEECH_V1: /* FR */ |
| l2_len = GSM_FR_BYTES; |
| break; |
| case GSM48_CMODE_SPEECH_EFR: /* EFR */ |
| l2_len = GSM_EFR_BYTES; |
| break; |
| case GSM48_CMODE_SPEECH_AMR: /* AMR */ |
| /** |
| * TODO: AMR requires a dedicated loop, |
| * which will be implemented later... |
| */ |
| LOGP(DSCHD, LOGL_ERROR, "AMR isn't supported yet, " |
| "dropping frame...\n"); |
| |
| /* Forget this primitive */ |
| sched_prim_drop(lchan); |
| |
| return -ENOTSUP; |
| default: |
| LOGP(DSCHD, LOGL_ERROR, "Invalid TCH mode: %u, " |
| "dropping frame...\n", lchan->tch_mode); |
| |
| /* Forget this primitive */ |
| sched_prim_drop(lchan); |
| |
| return -EINVAL; |
| } |
| |
| /* Determine and check the payload length */ |
| if (lchan->prim->payload_len == GSM_MACBLOCK_LEN) { |
| l2_len = GSM_MACBLOCK_LEN; /* FACCH */ |
| } else if (lchan->prim->payload_len != l2_len) { |
| LOGP(DSCHD, LOGL_ERROR, "Primitive has odd length %zu " |
| "(expected %zu for TCH or %u for FACCH), so dropping...\n", |
| lchan->prim->payload_len, l2_len, GSM_MACBLOCK_LEN); |
| |
| sched_prim_drop(lchan); |
| return -EINVAL; |
| } |
| |
| /* Shift buffer by 4 bursts back for interleaving */ |
| memcpy(buffer, buffer + 464, 464); |
| |
| /* Encode payload */ |
| rc = gsm0503_tch_fr_encode(buffer, lchan->prim->payload, l2_len, 1); |
| if (rc) { |
| LOGP(DSCHD, LOGL_ERROR, "Failed to encode L2 payload (len=%zu): %s\n", |
| lchan->prim->payload_len, osmo_hexdump(lchan->prim->payload, |
| lchan->prim->payload_len)); |
| |
| /* Forget this primitive */ |
| sched_prim_drop(lchan); |
| |
| return -EINVAL; |
| } |
| |
| send_burst: |
| /* Determine which burst should be sent */ |
| offset = buffer + bid * 116; |
| |
| /* Update mask */ |
| *mask |= (1 << bid); |
| |
| /* Choose proper TSC */ |
| tsc = sched_nb_training_bits[trx->tsc]; |
| |
| /* Compose a new burst */ |
| memset(burst, 0, 3); /* TB */ |
| memcpy(burst + 3, offset, 58); /* Payload 1/2 */ |
| memcpy(burst + 61, tsc, 26); /* TSC */ |
| memcpy(burst + 87, offset + 58, 58); /* Payload 2/2 */ |
| memset(burst + 145, 0, 3); /* TB */ |
| |
| LOGP(DSCHD, LOGL_DEBUG, "Transmitting %s fn=%u ts=%u burst=%u\n", |
| lchan_desc->name, fn, ts->index, bid); |
| |
| /* Forward burst to scheduler */ |
| rc = sched_trx_handle_tx_burst(trx, ts, lchan, fn, burst); |
| if (rc) { |
| /* Forget this primitive */ |
| sched_prim_drop(lchan); |
| |
| /* Reset mask */ |
| *mask = 0x00; |
| |
| return rc; |
| } |
| |
| /* If we have sent the last (4/4) burst */ |
| if (*mask == 0x0f) { |
| /* Confirm data / traffic sending */ |
| sched_send_dt_conf(trx, ts, lchan, fn, PRIM_IS_TCH(lchan->prim)); |
| |
| /* Forget processed primitive */ |
| sched_prim_drop(lchan); |
| |
| /* Reset mask */ |
| *mask = 0x00; |
| } |
| |
| return 0; |
| } |