| /* |
| * 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/gsm_utils.h> |
| #include <osmocom/gsm/protocol/gsm_04_08.h> |
| #include <osmocom/coding/gsm0503_coding.h> |
| |
| #include "l1ctl_proto.h" |
| #include "scheduler.h" |
| #include "sched_trx.h" |
| #include "logging.h" |
| #include "trx_if.h" |
| #include "l1ctl.h" |
| |
| __attribute__((xray_always_instrument)) __attribute__((noinline)) |
| static int gsm0503_xcch_decode_xray(uint8_t *l2_data, const sbit_t *bursts, |
| int *n_errors, int *n_bits_total) { |
| return gsm0503_xcch_decode(l2_data, bursts, n_errors, n_bits_total); |
| } |
| |
| __attribute__((xray_always_instrument)) __attribute__((noinline)) int rx_data_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; |
| uint8_t l2[GSM_MACBLOCK_LEN], *mask; |
| int n_errors, n_bits_total, rc; |
| sbit_t *buffer, *offset; |
| |
| /* Set up pointers */ |
| lchan_desc = &trx_lchan_desc[lchan->type]; |
| mask = &lchan->rx_burst_mask; |
| buffer = lchan->rx_bursts; |
| |
| LOGP(DSCHD, LOGL_DEBUG, "Data 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 buffer of 4 bursts */ |
| offset = buffer + bid * 116; |
| 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, 4); |
| |
| /* Check for complete set of bursts */ |
| if ((*mask & 0xf) != 0xf) { |
| LOGP(DSCHD, LOGL_ERROR, "Received incomplete (%s) data frame at " |
| "fn=%u (%u/%u) for %s\n", |
| burst_mask2str(mask, 4), lchan->meas_avg.fn, |
| lchan->meas_avg.fn % ts->mf_layout->period, |
| ts->mf_layout->period, |
| lchan_desc->name); |
| /* NOTE: xCCH has an insane amount of redundancy for error |
| * correction, so even just 2 valid bursts might be enough |
| * to reconstruct some L2 frames. This is why we do not |
| * abort here. */ |
| } |
| |
| /* Keep the mask updated */ |
| *mask = *mask << 4; |
| |
| /* Attempt to decode */ |
| rc = gsm0503_xcch_decode_xray(l2, buffer, &n_errors, &n_bits_total); |
| if (rc) { |
| LOGP(DSCHD, LOGL_ERROR, "Received bad data frame with %d errors at fn=%u " |
| "(%u/%u) for %s\n", n_errors, lchan->meas_avg.fn, |
| lchan->meas_avg.fn % ts->mf_layout->period, |
| ts->mf_layout->period, |
| lchan_desc->name); |
| |
| /** |
| * We should anyway send dummy frame for |
| * proper measurement reporting... |
| */ |
| return sched_send_dt_ind(trx, ts, lchan, NULL, 0, |
| n_errors, true, false); |
| } |
| |
| /* Send a L2 frame to the higher layers */ |
| return sched_send_dt_ind(trx, ts, lchan, l2, GSM_MACBLOCK_LEN, |
| n_errors, false, false); |
| } |
| |
| int tx_data_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; |
| int rc; |
| |
| /* Set up pointers */ |
| lchan_desc = &trx_lchan_desc[lchan->type]; |
| mask = &lchan->tx_burst_mask; |
| buffer = lchan->tx_bursts; |
| |
| if (bid > 0) { |
| /* If we have encoded bursts */ |
| if (*mask) |
| goto send_burst; |
| else |
| return 0; |
| } |
| |
| /* Check the prim payload length */ |
| if (lchan->prim->payload_len != GSM_MACBLOCK_LEN) { |
| LOGP(DSCHD, LOGL_ERROR, "Primitive has odd length %zu (expected %u), " |
| "so dropping...\n", lchan->prim->payload_len, GSM_MACBLOCK_LEN); |
| |
| sched_prim_drop(lchan); |
| return -EINVAL; |
| } |
| |
| /* Encode payload */ |
| rc = gsm0503_xcch_encode(buffer, lchan->prim->payload); |
| 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) == 0x0f) { |
| /* Confirm data sending */ |
| sched_send_dt_conf(trx, ts, lchan, fn, false); |
| |
| /* Forget processed primitive */ |
| sched_prim_drop(lchan); |
| |
| /* Reset mask */ |
| *mask = 0x00; |
| } |
| |
| return 0; |
| } |