/* GSM A-bis TRAU frame synchronization as per TS 48.060 / 48.061 */ /* (C) 2020 by Harald Welte * All Rights Reserved * * SPDX-License-Identifier: GPL-2.0+ * * 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, see . * */ #include #include #include #include #include "ubit_buf.h" #include #define S(x) (1 << (x)) #define MAX_TRAU_BYTES 160 #define MAX_TRAU_SYNC_PATTERN 8 #define PRIMARY_PATTERN 0 #define T_SYNC 1 struct sync_pattern { /* provided by user */ const char *name; /*!< human-readable name */ const uint8_t byte_pattern[MAX_TRAU_BYTES]; /*!< bytes to match against */ const uint8_t byte_mask[MAX_TRAU_BYTES]; /*!< mask applied before matching */ uint8_t byte_len; /*!< length of mask in bytes */ /* generated by code */ ubit_t ubit_pattern[MAX_TRAU_BYTES*8]; /*!< bits to match against */ ubit_t ubit_mask[MAX_TRAU_BYTES*8]; /*!< mask applied before matching */ uint8_t bitcount; /*!< number of high bits in mask */ }; static struct sync_pattern sync_patterns[] = { [OSMO_TRAU_SYNCP_16_FR_EFR] = { /* TS 08.60 Section 4.8.1 */ .name = "FR/EFR", .byte_pattern = { 0x00, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, }, .byte_mask = { 0xff, 0xff, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, }, .byte_len = 40, }, [OSMO_TRAU_SYNCP_8_HR] = { /* TS 08.61 Section 6.8.2.1.1 */ .name = "HR8", .byte_pattern = { 0x00, 0x80, 0x40, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, }, .byte_mask = { 0xff, 0x80, 0xC0, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, }, .byte_len = 20, }, [OSMO_TRAU_SYNCP_8_AMR_LOW] = { /* TS 08.61 Section 6.8.2.1.2 */ /* The frame synchronisation for No_Speech frames and the speech frames of the three lower codec modes */ .name = "AMR8_LOW", .byte_pattern = { 0x00, 0x80, 0x80, 0x40, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, }, .byte_mask = { 0xff, 0x80, 0x80, 0xC0, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, }, .byte_len = 20, }, [OSMO_TRAU_SYNCP_8_AMR_6K7] = { /* The frame synchronisation for the speech frames for codec mode 6,70 kBit/s */ .name = "AMR8_67", .byte_pattern = { 0x00, 0x80, 0x80, 0x80, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, }, .byte_mask = { 0xff, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, }, .byte_len = 20 }, [OSMO_TRAU_SYNCP_8_AMR_7K4] = { /* The frame synchronisation for the speech frames for codec mode 7,40 kBit/s */ .name = "AMR8_74", .byte_pattern = { 0x20, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }, .byte_mask = { 0xe0, 0x80, 0x80, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }, .byte_len = 20, }, [OSMO_TRAU_SYNCP_V110] = { /* See Table 2 of ITU-T V.110 */ .name = "V110", .byte_pattern = { 0x00, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, }, .byte_mask = { 0xff, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, }, .byte_len = 10, }, [OSMO_TRAU_SYNCP_16_ER_CCU] = { .name = "Ericsson CCU 16 kbps", .byte_pattern = { 0x00, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }, .byte_mask = { 0xff, 0xff, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }, .byte_len = 40, }, [OSMO_TRAU_SYNCP_64_ER_CCU] = { .name = "Ericsson CCU 64 kbps", .byte_pattern = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }, .byte_mask = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }, .byte_len = 160, }, [OSMO_TRAU_SYNCP_64_ER_CCU_MCS9] = { .name = "Ericsson CCU 64 kbps MCS9", .byte_pattern = { 0x00, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }, .byte_mask = { 0xff, 0xff, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }, .byte_len = 160, }, [OSMO_TRAU_SYNCP_FA] = { /* See Section 5.2.2.1 of 3GPP TS 43.045 */ .name = "FA", .byte_pattern = { 0x3E, 0x37, 0x50, 0x96, 0xC1, 0xC8, 0xAF, 0x69, }, .byte_mask = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, }, .byte_len = 8, }, }; static void expand_sync_pattern(struct sync_pattern *pat) { osmo_pbit2ubit(pat->ubit_pattern, pat->byte_pattern, pat->byte_len*8); osmo_pbit2ubit(pat->ubit_mask, pat->byte_mask, pat->byte_len*8); } static unsigned int count_one_bits(const ubit_t *in, unsigned int in_bits) { unsigned int i, count = 0; for (i = 0; i < in_bits; i++) { if (in[i]) count++; } return count; } static void sync_pattern_register(struct sync_pattern *p) { expand_sync_pattern(p); p->bitcount = count_one_bits(p->ubit_mask, p->byte_len*8); } #if 0 /*! correlate pattern with unpacked bits from buffer. * \param[in] pattern sync_pattern against which we shall compare * \param[in] bits unpacked bits to compare against pattern * \param[in] num_bits number of unpacked bits * \returns number of bits not matching pattern; -1 if insufficient bits available. */ static int correlate_pattern_ubits(const struct sync_pattern *pattern, const ubit_t *bits, size_t num_bits) { int i, num_wrong = 0; if (num_bits < pattern->byte_len*8) return -1; /* insufficient data */ for (i = 0; i < pattern->byte_len *8; i++) { /* if mask doesn't contain '1', we can skip this octet */ if (!pattern->ubit_mask) continue; if (bits[i] != pattern->ubit_pattern[i]) num_wrong++; } return num_wrong; } #endif struct trau_rx_sync_state { /*! call-back to be called for every TRAU frame (called with * bits=NULL in case of frame sync loss */ frame_out_cb_t out_cb; /*! opaque user data; passed to out_cb */ void *user_data; /*! history of received bits */ ubit_t history[MAX_TRAU_BYTES*8+1]; /* +1 not required, but helps to expose bugs */ /*! index of next-to-be-written ubit in history */ unsigned int history_idx; /*! the pattern(s) we are trying to sync to */ const struct sync_pattern *pattern[MAX_TRAU_SYNC_PATTERN]; /*! number of consecutive frames without sync */ unsigned int num_consecutive_errors; }; /* correlate the history (up to the last received bit) against the pattern */ static int correlate_history_against_pattern(struct trau_rx_sync_state *tss, const struct sync_pattern *pattern) { int i, start, num_wrong = 0; /* compute index of first bit in history array */ start = (ARRAY_SIZE(tss->history) + tss->history_idx - pattern->byte_len*8) % ARRAY_SIZE(tss->history); OSMO_ASSERT(ARRAY_SIZE(tss->history) >= pattern->byte_len*8); for (i = 0; i < pattern->byte_len*8; i++) { unsigned int pos = (start + i) % ARRAY_SIZE(tss->history); /* if mask doesn't contain '1', we can skip this octet */ if (!pattern->ubit_mask[i]) continue; if (tss->history[pos] != pattern->ubit_pattern[i]) num_wrong++; } return num_wrong; } /* correlate the history (up to the last received bit) against multiple patterns */ static int correlate_history_against_patterns(struct trau_rx_sync_state *tss) { size_t pat_index; int num_wrong; int num_wrong_best = MAX_TRAU_BYTES * 8; for (pat_index = PRIMARY_PATTERN; pat_index < MAX_TRAU_SYNC_PATTERN; pat_index++) { const struct sync_pattern *pattern; pattern = tss->pattern[pat_index]; if (!pattern) continue; num_wrong = correlate_history_against_pattern(tss, pattern); /* We cannot achieve a better result than 0 errors */ if (num_wrong == 0) return 0; /* Keep track on the best result */ if (num_wrong < num_wrong_best) num_wrong_best = num_wrong; } return num_wrong_best; } /* add (append) one ubit to the history; wrap as needed */ static void rx_history_add_bit(struct trau_rx_sync_state *tss, ubit_t bit) { tss->history[tss->history_idx] = bit; /* simply wrap around at the end */ tss->history_idx = (tss->history_idx + 1) % ARRAY_SIZE(tss->history); } /* append bits to history. We assume that this does NOT wrap */ static void rx_history_add_bits(struct trau_rx_sync_state *tss, const ubit_t *bits, size_t n_bits) { unsigned int frame_bits_remaining = tss->pattern[PRIMARY_PATTERN]->byte_len*8 - tss->history_idx; OSMO_ASSERT(frame_bits_remaining >= n_bits); memcpy(&tss->history[tss->history_idx], bits, n_bits); tss->history_idx = tss->history_idx + n_bits; } /* align the history, i.e. next received bit is start of frame */ static void rx_history_align(struct trau_rx_sync_state *tss) { ubit_t tmp[sizeof(tss->history)]; size_t history_size = sizeof(tss->history); size_t pattern_bits = tss->pattern[PRIMARY_PATTERN]->byte_len*8; size_t first_bit = (history_size + tss->history_idx - pattern_bits) % history_size; int i; /* we need to shift the last received frame to the start of the history buffer; * do this in two steps: First copy to a local buffer on the stack, using modulo-arithmetic * as index into the history. Second, copy it back to history */ for (i = 0; i < pattern_bits; i++) tmp[i] = tss->history[(first_bit + i) % history_size]; memcpy(tss->history, tmp, history_size); tss->history_idx = 0; } enum trau_sync_state { WAIT_FRAME_ALIGN, FRAME_ALIGNED, /* if at least 3 consecutive frames with each at least one framing error have been received */ FRAME_ALIGNMENT_LOST, }; enum trau_sync_event { TRAUSYNC_E_RESET, /*! a buffer of bits was received (msgb with ubits) */ TRAUSYNC_E_RX_BITS, }; static const struct value_string trau_sync_event_names[] = { { TRAUSYNC_E_RESET, "RESET" }, { TRAUSYNC_E_RX_BITS, "RX_BITS" }, { 0, NULL } }; static void trau_sync_wait_align(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct trau_rx_sync_state *tss = (struct trau_rx_sync_state *) fi->priv; struct ubit_buf *ubb; switch (event) { case TRAUSYNC_E_RX_BITS: ubb = data; /* append every bit individually + check if we have sync */ while (ubb_length(ubb) > 0) { ubit_t bit = ubb_pull_ubit(ubb); int rc; rx_history_add_bit(tss, bit); /* Apply only the primary pattern while waiting for the alignment */ rc = correlate_history_against_pattern(tss, tss->pattern[PRIMARY_PATTERN]); if (!rc) { osmo_fsm_inst_state_chg(fi, FRAME_ALIGNED, 0, 0); /* treat remainder of input bits in correct state */ osmo_fsm_inst_dispatch(fi, TRAUSYNC_E_RX_BITS, ubb); return; } } break; default: OSMO_ASSERT(0); } } static void trau_sync_aligned_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state) { struct trau_rx_sync_state *tss = (struct trau_rx_sync_state *) fi->priv; /* dispatch aligned frame to user */ rx_history_align(tss); tss->out_cb(tss->user_data, tss->history, tss->pattern[PRIMARY_PATTERN]->byte_len*8); } static void trau_sync_aligned(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct trau_rx_sync_state *tss = (struct trau_rx_sync_state *) fi->priv; struct ubit_buf *ubb; int rc; switch (event) { case TRAUSYNC_E_RX_BITS: ubb = data; while (ubb_length(ubb)) { unsigned int frame_bits_remaining = tss->pattern[PRIMARY_PATTERN]->byte_len*8 - tss->history_idx; if (ubb_length(ubb) < frame_bits_remaining) { /* frame not filled by this message; just add data */ rx_history_add_bits(tss, ubb_data(ubb), ubb_length(ubb)); ubb_pull(ubb, ubb_length(ubb)); } else { /* append as many bits as are missing in the current frame */ rx_history_add_bits(tss, ubb_data(ubb), frame_bits_remaining); ubb_pull(ubb, frame_bits_remaining); /* check if we still have frame sync using the primary and all secondary patterns */ rc = correlate_history_against_patterns(tss); if (rc > 0) { tss->num_consecutive_errors++; if (tss->num_consecutive_errors >= 3) { tss->history_idx = 0; /* send NULL frame to user */ tss->out_cb(tss->user_data, NULL, 0); osmo_fsm_inst_state_chg(fi, FRAME_ALIGNMENT_LOST, 1, T_SYNC); osmo_fsm_inst_dispatch(fi, TRAUSYNC_E_RX_BITS, ubb); return; } } else tss->num_consecutive_errors = 0; /* dispatch aligned frame to user */ tss->out_cb(tss->user_data, tss->history, tss->history_idx); tss->history_idx = 0; } } break; default: OSMO_ASSERT(0); } } static void trau_sync_alignment_lost(struct osmo_fsm_inst *fi, uint32_t event, void *data) { /* we try to restore sync for some amount of time before generating an error */ switch (event) { case TRAUSYNC_E_RX_BITS: trau_sync_wait_align(fi, event, data); break; default: OSMO_ASSERT(0); } } static void trau_sync_allstate(struct osmo_fsm_inst *fi, uint32_t event, void *data) { switch (event) { case TRAUSYNC_E_RESET: osmo_fsm_inst_state_chg(fi, WAIT_FRAME_ALIGN, 0, 0); break; default: OSMO_ASSERT(0); } } static int trau_sync_timeout(struct osmo_fsm_inst *fi) { switch (fi->T) { case T_SYNC: /* if Tsync expires before frame synchronization is * again obtained the TRAU initiates sending of the * urgent alarm pattern described in clause 4.10.2. */ osmo_fsm_inst_state_chg(fi, WAIT_FRAME_ALIGN, 0, 0); break; default: OSMO_ASSERT(0); } return 0; } static const struct osmo_fsm_state trau_sync_states[] = { [WAIT_FRAME_ALIGN] = { .name = "WAIT_FRAME_ALIGN", .in_event_mask = S(TRAUSYNC_E_RX_BITS), .out_state_mask = S(FRAME_ALIGNED), .action = trau_sync_wait_align, }, [FRAME_ALIGNED] = { .name = "FRAME_ALIGNED", .in_event_mask = S(TRAUSYNC_E_RX_BITS), .out_state_mask = S(FRAME_ALIGNMENT_LOST) | S(WAIT_FRAME_ALIGN), .action = trau_sync_aligned, .onenter = trau_sync_aligned_onenter, }, [FRAME_ALIGNMENT_LOST] = { .name = "FRAME_ALIGNMENT_LOST", .in_event_mask = S(TRAUSYNC_E_RX_BITS), .out_state_mask = S(WAIT_FRAME_ALIGN) | S(FRAME_ALIGNED), .action = trau_sync_alignment_lost, }, }; static struct osmo_fsm trau_sync_fsm = { .name = "trau_sync", .states = trau_sync_states, .num_states = ARRAY_SIZE(trau_sync_states), .allstate_event_mask = S(TRAUSYNC_E_RESET), .allstate_action = trau_sync_allstate, .timer_cb = trau_sync_timeout, .log_subsys = DLGLOBAL, .event_names = trau_sync_event_names, }; struct osmo_fsm_inst * osmo_trau_sync_alloc(void *ctx, const char *name, frame_out_cb_t frame_out_cb, enum osmo_trau_sync_pat_id pat_id, void *user_data) { struct trau_rx_sync_state *tss; struct osmo_fsm_inst *fi; if (pat_id >= ARRAY_SIZE(sync_patterns)) return NULL; fi = osmo_fsm_inst_alloc(&trau_sync_fsm, ctx, NULL, LOGL_INFO, name); if (!fi) return NULL; tss = talloc_zero(fi, struct trau_rx_sync_state); if (!tss) { osmo_fsm_inst_term(fi, OSMO_FSM_TERM_ERROR, NULL); return NULL; } fi->priv = tss; tss->out_cb = frame_out_cb; tss->user_data = user_data; tss->pattern[PRIMARY_PATTERN] = &sync_patterns[pat_id]; /* An unusued E1 timeslot normally would send an idle signal that * has all bits set to one. In order to prevent false-positive * synchronization on startup we set all history bits to 1, to make * it look like a signal from an unused timeslot. */ memset(tss->history, 1, sizeof(tss->history)); return fi; } void osmo_trau_sync_set_pat(struct osmo_fsm_inst *fi, enum osmo_trau_sync_pat_id pat_id) { struct trau_rx_sync_state *tss = fi->priv; /* Clear the pattern list to get rid of all secondary pattern settings */ memset(tss->pattern, 0, sizeof(tss->pattern)); /* Set the primary pattern and reset the FSM */ tss->pattern[PRIMARY_PATTERN] = &sync_patterns[pat_id]; osmo_fsm_inst_state_chg(fi, FRAME_ALIGNMENT_LOST, 0, 0); } void osmo_trau_sync_set_secondary_pat(struct osmo_fsm_inst *fi, enum osmo_trau_sync_pat_id pat_id, size_t pat_index) { struct trau_rx_sync_state *tss = fi->priv; OSMO_ASSERT(pat_index > PRIMARY_PATTERN); OSMO_ASSERT(pat_index < ARRAY_SIZE(tss->pattern)); /* Make sure that only a pattern of the same size can be set as secondary pattern */ OSMO_ASSERT(tss->pattern[PRIMARY_PATTERN]->byte_len == sync_patterns[pat_id].byte_len); tss->pattern[pat_index] = &sync_patterns[pat_id]; osmo_fsm_inst_state_chg(fi, FRAME_ALIGNMENT_LOST, 0, 0); } void osmo_trau_sync_rx_ubits(struct osmo_fsm_inst *fi, const ubit_t *bits, size_t n_bits) { struct ubit_buf ubb; ubb_init(&ubb, bits, n_bits); osmo_fsm_inst_dispatch(fi, TRAUSYNC_E_RX_BITS, &ubb); } static void __attribute__((constructor)) on_dso_load_sync(void) { int i; for (i = 0; i < ARRAY_SIZE(sync_patterns); i++) sync_pattern_register(&sync_patterns[i]); OSMO_ASSERT(osmo_fsm_register(&trau_sync_fsm) == 0); }