From 218e4b4aa0fc6de842ff820dec8e97d1f083268a Mon Sep 17 00:00:00 2001 From: Neels Hofmeyr Date: Tue, 4 Jul 2017 23:08:44 +0200 Subject: move openbsc/* to repos root This is the first step in creating this repository from the legacy openbsc.git. Like all other Osmocom repositories, keep the autoconf and automake files in the repository root. openbsc.git has been the sole exception, which ends now. Change-Id: I9c6f2a448d9cb1cc088cf1cf6918b69d7e69b4e7 --- src/libtrau/trau_mux.c | 547 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 547 insertions(+) create mode 100644 src/libtrau/trau_mux.c (limited to 'src/libtrau/trau_mux.c') diff --git a/src/libtrau/trau_mux.c b/src/libtrau/trau_mux.c new file mode 100644 index 000000000..b37c7650e --- /dev/null +++ b/src/libtrau/trau_mux.c @@ -0,0 +1,547 @@ +/* Simple TRAU frame reflector to route voice calls */ + +/* (C) 2009 by Harald Welte + * 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 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 . + * + */ + +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* this corresponds to the bit-lengths of the individual codec + * parameters as indicated in Table 1.1 of TS 06.10 */ +static const uint8_t gsm_fr_map[] = { + 6, 6, 5, 5, 4, 4, 3, 3, + 7, 2, 2, 6, 3, 3, 3, 3, + 3, 3, 3, 3, 3, 3, 3, 3, + 3, 7, 2, 2, 6, 3, 3, 3, + 3, 3, 3, 3, 3, 3, 3, 3, + 3, 3, 7, 2, 2, 6, 3, 3, + 3, 3, 3, 3, 3, 3, 3, 3, + 3, 3, 3, 7, 2, 2, 6, 3, + 3, 3, 3, 3, 3, 3, 3, 3, + 3, 3, 3, 3 +}; + + +/* + * EFR TRAU parity + * + * g(x) = x^3 + x^1 + 1 + */ +static const struct osmo_crc8gen_code gsm0860_efr_crc3 = { + .bits = 3, + .poly = 0x3, + .init = 0x0, + .remainder = 0x7, +}; + +/* EFR parity bits */ +static inline void efr_parity_bits_1(ubit_t *check_bits, const ubit_t *d_bits) +{ + memcpy(check_bits + 0 , d_bits + 0, 22); + memcpy(check_bits + 22 , d_bits + 24, 3); + check_bits[25] = d_bits[28]; +} + +static inline void efr_parity_bits_2(ubit_t *check_bits, const ubit_t *d_bits) +{ + memcpy(check_bits + 0 , d_bits + 42, 10); + memcpy(check_bits + 10 , d_bits + 90, 2); +} + +static inline void efr_parity_bits_3(ubit_t *check_bits, const ubit_t *d_bits) +{ + memcpy(check_bits + 0 , d_bits + 98, 5); + check_bits[5] = d_bits[104]; + memcpy(check_bits + 6 , d_bits + 143, 2); +} + +static inline void efr_parity_bits_4(ubit_t *check_bits, const ubit_t *d_bits) +{ + memcpy(check_bits + 0 , d_bits + 151, 10); + memcpy(check_bits + 10 , d_bits + 199, 2); +} + +static inline void efr_parity_bits_5(ubit_t *check_bits, const ubit_t *d_bits) +{ + memcpy(check_bits + 0 , d_bits + 207, 5); + check_bits[5] = d_bits[213]; + memcpy(check_bits + 6 , d_bits + 252, 2); +} + +struct map_entry { + struct llist_head list; + struct gsm_e1_subslot src, dst; +}; + +struct upqueue_entry { + struct llist_head list; + struct gsm_network *net; + struct gsm_e1_subslot src; + uint32_t callref; +}; + +static LLIST_HEAD(ss_map); +static LLIST_HEAD(ss_upqueue); + +void *tall_map_ctx, *tall_upq_ctx; + +/* map one particular subslot to another subslot */ +int trau_mux_map(const struct gsm_e1_subslot *src, + const struct gsm_e1_subslot *dst) +{ + struct map_entry *me; + + me = talloc(tall_map_ctx, struct map_entry); + if (!me) { + LOGP(DLMIB, LOGL_FATAL, "Out of memory\n"); + return -ENOMEM; + } + + DEBUGP(DCC, "Setting up TRAU mux map between (e1=%u,ts=%u,ss=%u) " + "and (e1=%u,ts=%u,ss=%u)\n", + src->e1_nr, src->e1_ts, src->e1_ts_ss, + dst->e1_nr, dst->e1_ts, dst->e1_ts_ss); + + /* make sure to get rid of any stale old mappings */ + trau_mux_unmap(src, 0); + trau_mux_unmap(dst, 0); + + memcpy(&me->src, src, sizeof(me->src)); + memcpy(&me->dst, dst, sizeof(me->dst)); + llist_add(&me->list, &ss_map); + + return 0; +} + +int trau_mux_map_lchan(const struct gsm_lchan *src, + const struct gsm_lchan *dst) +{ + struct gsm_e1_subslot *src_ss, *dst_ss; + + src_ss = &src->ts->e1_link; + dst_ss = &dst->ts->e1_link; + + return trau_mux_map(src_ss, dst_ss); +} + + +/* unmap one particular subslot from another subslot */ +int trau_mux_unmap(const struct gsm_e1_subslot *ss, uint32_t callref) +{ + struct map_entry *me, *me2; + struct upqueue_entry *ue, *ue2; + + if (ss) + llist_for_each_entry_safe(me, me2, &ss_map, list) { + if (!memcmp(&me->src, ss, sizeof(*ss)) || + !memcmp(&me->dst, ss, sizeof(*ss))) { + llist_del(&me->list); + return 0; + } + } + llist_for_each_entry_safe(ue, ue2, &ss_upqueue, list) { + if (ue->callref == callref) { + llist_del(&ue->list); + return 0; + } + if (ss && !memcmp(&ue->src, ss, sizeof(*ss))) { + llist_del(&ue->list); + return 0; + } + } + return -ENOENT; +} + +/* look-up an enty in the TRAU mux map */ +static struct gsm_e1_subslot * +lookup_trau_mux_map(const struct gsm_e1_subslot *src) +{ + struct map_entry *me; + + llist_for_each_entry(me, &ss_map, list) { + if (!memcmp(&me->src, src, sizeof(*src))) + return &me->dst; + if (!memcmp(&me->dst, src, sizeof(*src))) + return &me->src; + } + return NULL; +} + +/* look-up an enty in the TRAU upqueue */ +struct upqueue_entry * +lookup_trau_upqueue(const struct gsm_e1_subslot *src) +{ + struct upqueue_entry *ue; + + llist_for_each_entry(ue, &ss_upqueue, list) { + if (!memcmp(&ue->src, src, sizeof(*src))) + return ue; + } + return NULL; +} + +static const uint8_t c_bits_check_fr[] = { 0, 0, 0, 1, 0 }; +static const uint8_t c_bits_check_efr[] = { 1, 1, 0, 1, 0 }; + +struct msgb *trau_decode_fr(uint32_t callref, + const struct decoded_trau_frame *tf) +{ + struct msgb *msg; + struct gsm_data_frame *frame; + unsigned char *data; + int i, j, k, l, o; + + msg = msgb_alloc(sizeof(struct gsm_data_frame) + 33, + "GSM-DATA"); + if (!msg) + return NULL; + + frame = (struct gsm_data_frame *)msg->data; + memset(frame, 0, sizeof(struct gsm_data_frame)); + data = frame->data; + data[0] = 0xd << 4; + /* reassemble d-bits */ + i = 0; /* counts bits */ + j = 4; /* counts output bits */ + k = gsm_fr_map[0]-1; /* current number bit in element */ + l = 0; /* counts element bits */ + o = 0; /* offset input bits */ + while (i < 260) { + data[j/8] |= (tf->d_bits[k+o] << (7-(j%8))); + /* to avoid out-of-bounds access in gsm_fr_map[++l] */ + if (i == 259) + break; + if (--k < 0) { + o += gsm_fr_map[l]; + k = gsm_fr_map[++l]-1; + } + i++; + j++; + } + if (tf->c_bits[11]) /* BFI */ + frame->msg_type = GSM_BAD_FRAME; + else + frame->msg_type = GSM_TCHF_FRAME; + frame->callref = callref; + msgb_put(msg, sizeof(struct gsm_data_frame) + 33); + + return msg; +} + +struct msgb *trau_decode_efr(uint32_t callref, + const struct decoded_trau_frame *tf) +{ + struct msgb *msg; + struct gsm_data_frame *frame; + unsigned char *data; + int i, j, rc; + ubit_t check_bits[26]; + + msg = msgb_alloc(sizeof(struct gsm_data_frame) + 31, + "GSM-DATA"); + if (!msg) + return NULL; + + frame = (struct gsm_data_frame *)msg->data; + memset(frame, 0, sizeof(struct gsm_data_frame)); + frame->msg_type = GSM_TCHF_FRAME_EFR; + frame->callref = callref; + msgb_put(msg, sizeof(struct gsm_data_frame) + 31); + + if (tf->c_bits[11]) /* BFI */ + goto bad_frame; + + data = frame->data; + data[0] = 0xc << 4; + /* reassemble d-bits */ + for (i = 1, j = 4; i < 39; i++, j++) + data[j/8] |= (tf->d_bits[i] << (7-(j%8))); + efr_parity_bits_1(check_bits, tf->d_bits); + rc = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, check_bits, 26, + tf->d_bits + 39); + if (rc) + goto bad_frame; + for (i = 42, j = 42; i < 95; i++, j++) + data[j/8] |= (tf->d_bits[i] << (7-(j%8))); + efr_parity_bits_2(check_bits, tf->d_bits); + rc = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, check_bits, 12, + tf->d_bits + 95); + if (rc) + goto bad_frame; + for (i = 98, j = 95; i < 148; i++, j++) + data[j/8] |= (tf->d_bits[i] << (7-(j%8))); + efr_parity_bits_3(check_bits, tf->d_bits); + rc = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, check_bits, 8, + tf->d_bits + 148); + if (rc) + goto bad_frame; + for (i = 151, j = 145; i < 204; i++, j++) + data[j/8] |= (tf->d_bits[i] << (7-(j%8))); + efr_parity_bits_4(check_bits, tf->d_bits); + rc = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, check_bits, 12, + tf->d_bits + 204); + if (rc) + goto bad_frame; + for (i = 207, j = 198; i < 257; i++, j++) + data[j/8] |= (tf->d_bits[i] << (7-(j%8))); + efr_parity_bits_5(check_bits, tf->d_bits); + rc = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, check_bits, 8, + tf->d_bits + 257); + if (rc) + goto bad_frame; + + return msg; + +bad_frame: + frame->msg_type = GSM_BAD_FRAME; + + return msg; +} + +/* we get called by subchan_demux */ +int trau_mux_input(struct gsm_e1_subslot *src_e1_ss, + const uint8_t *trau_bits, int num_bits) +{ + struct decoded_trau_frame tf; + uint8_t trau_bits_out[TRAU_FRAME_BITS]; + struct gsm_e1_subslot *dst_e1_ss = lookup_trau_mux_map(src_e1_ss); + struct subch_mux *mx; + struct upqueue_entry *ue; + int rc; + + /* decode TRAU, change it to downlink, re-encode */ + rc = decode_trau_frame(&tf, trau_bits); + if (rc) + return rc; + + if (!dst_e1_ss) { + struct msgb *msg = NULL; + /* frame shall be sent to upqueue */ + if (!(ue = lookup_trau_upqueue(src_e1_ss))) + return -EINVAL; + if (!ue->callref) + return -EINVAL; + if (!memcmp(tf.c_bits, c_bits_check_fr, 5)) + msg = trau_decode_fr(ue->callref, &tf); + else if (!memcmp(tf.c_bits, c_bits_check_efr, 5)) + msg = trau_decode_efr(ue->callref, &tf); + else { + DEBUGPC(DLMUX, "illegal trau (C1-C5) %s\n", + osmo_hexdump(tf.c_bits, 5)); + DEBUGPC(DLMUX, "test trau (C1-C5) %s\n", + osmo_hexdump(c_bits_check_efr, 5)); + return -EINVAL; + } + if (!msg) + return -ENOMEM; + trau_tx_to_mncc(ue->net, msg); + + return 0; + } + + mx = e1inp_get_mux(dst_e1_ss->e1_nr, dst_e1_ss->e1_ts); + if (!mx) + return -EINVAL; + + trau_frame_up2down(&tf); + encode_trau_frame(trau_bits_out, &tf); + + /* and send it to the muxer */ + return subchan_mux_enqueue(mx, dst_e1_ss->e1_ts_ss, trau_bits_out, + TRAU_FRAME_BITS); +} + +/* callback when a TRAU frame was received */ +int subch_cb(struct subch_demux *dmx, int ch, uint8_t *data, int len, + void *_priv) +{ + struct e1inp_ts *e1i_ts = _priv; + struct gsm_e1_subslot src_ss; + + src_ss.e1_nr = e1i_ts->line->num; + src_ss.e1_ts = e1i_ts->num; + src_ss.e1_ts_ss = ch; + + return trau_mux_input(&src_ss, data, len); +} + +/* add receiver instance for lchan and callref */ +int trau_recv_lchan(struct gsm_lchan *lchan, uint32_t callref) +{ + struct gsm_e1_subslot *src_ss; + struct upqueue_entry *ue; + + ue = talloc(tall_upq_ctx, struct upqueue_entry); + if (!ue) + return -ENOMEM; + + src_ss = &lchan->ts->e1_link; + + DEBUGP(DCC, "Setting up TRAU receiver (e1=%u,ts=%u,ss=%u) " + "and (callref 0x%x)\n", + src_ss->e1_nr, src_ss->e1_ts, src_ss->e1_ts_ss, + callref); + + /* make sure to get rid of any stale old mappings */ + trau_mux_unmap(src_ss, callref); + + memcpy(&ue->src, src_ss, sizeof(ue->src)); + ue->net = lchan->ts->trx->bts->network; + ue->callref = callref; + llist_add(&ue->list, &ss_upqueue); + + return 0; +} + +void trau_encode_fr(struct decoded_trau_frame *tf, + const unsigned char *data) +{ + int i, j, k, l, o; + + /* set c-bits and t-bits */ + tf->c_bits[0] = 1; + tf->c_bits[1] = 1; + tf->c_bits[2] = 1; + tf->c_bits[3] = 0; + tf->c_bits[4] = 0; + memset(&tf->c_bits[5], 0, 6); + memset(&tf->c_bits[11], 1, 10); + memset(&tf->t_bits[0], 1, 4); + /* reassemble d-bits */ + i = 0; /* counts bits */ + j = 4; /* counts input bits */ + k = gsm_fr_map[0]-1; /* current number bit in element */ + l = 0; /* counts element bits */ + o = 0; /* offset output bits */ + while (i < 260) { + tf->d_bits[k+o] = (data[j/8] >> (7-(j%8))) & 1; + /* to avoid out-of-bounds access in gsm_fr_map[++l] */ + if (i == 259) + break; + if (--k < 0) { + o += gsm_fr_map[l]; + k = gsm_fr_map[++l]-1; + } + i++; + j++; + } +} + +void trau_encode_efr(struct decoded_trau_frame *tf, + const unsigned char *data) +{ + int i, j; + ubit_t check_bits[26]; + + /* set c-bits and t-bits */ + tf->c_bits[0] = 1; + tf->c_bits[1] = 1; + tf->c_bits[2] = 0; + tf->c_bits[3] = 1; + tf->c_bits[4] = 0; + memset(&tf->c_bits[5], 0, 6); + memset(&tf->c_bits[11], 1, 10); + memset(&tf->t_bits[0], 1, 4); + /* reassemble d-bits */ + tf->d_bits[0] = 1; + for (i = 1, j = 4; i < 39; i++, j++) + tf->d_bits[i] = (data[j/8] >> (7-(j%8))) & 1; + efr_parity_bits_1(check_bits, tf->d_bits); + osmo_crc8gen_set_bits(&gsm0860_efr_crc3, check_bits, 26, + tf->d_bits + 39); + for (i = 42, j = 42; i < 95; i++, j++) + tf->d_bits[i] = (data[j/8] >> (7-(j%8))) & 1; + efr_parity_bits_2(check_bits, tf->d_bits); + osmo_crc8gen_set_bits(&gsm0860_efr_crc3, check_bits, 12, + tf->d_bits + 95); + for (i = 98, j = 95; i < 148; i++, j++) + tf->d_bits[i] = (data[j/8] >> (7-(j%8))) & 1; + efr_parity_bits_3(check_bits, tf->d_bits); + osmo_crc8gen_set_bits(&gsm0860_efr_crc3, check_bits, 8, + tf->d_bits + 148); + for (i = 151, j = 145; i < 204; i++, j++) + tf->d_bits[i] = (data[j/8] >> (7-(j%8))) & 1; + efr_parity_bits_4(check_bits, tf->d_bits); + osmo_crc8gen_set_bits(&gsm0860_efr_crc3, check_bits, 12, + tf->d_bits + 204); + for (i = 207, j = 198; i < 257; i++, j++) + tf->d_bits[i] = (data[j/8] >> (7-(j%8))) & 1; + efr_parity_bits_5(check_bits, tf->d_bits); + osmo_crc8gen_set_bits(&gsm0860_efr_crc3, check_bits, 8, + tf->d_bits + 257); +} + +int trau_send_frame(struct gsm_lchan *lchan, struct gsm_data_frame *frame) +{ + uint8_t trau_bits_out[TRAU_FRAME_BITS]; + struct gsm_e1_subslot *dst_e1_ss = &lchan->ts->e1_link; + struct subch_mux *mx; + struct decoded_trau_frame tf; + + mx = e1inp_get_mux(dst_e1_ss->e1_nr, dst_e1_ss->e1_ts); + if (!mx) + return -EINVAL; + + switch (frame->msg_type) { + case GSM_TCHF_FRAME: + trau_encode_fr(&tf, frame->data); + break; + case GSM_TCHF_FRAME_EFR: + trau_encode_efr(&tf, frame->data); + break; + default: + DEBUGPC(DLMUX, "unsupported message type %d\n", + frame->msg_type); + return -EINVAL; + } + + encode_trau_frame(trau_bits_out, &tf); + + /* and send it to the muxer */ + return subchan_mux_enqueue(mx, dst_e1_ss->e1_ts_ss, trau_bits_out, + TRAU_FRAME_BITS); +} + +/* switch trau muxer to new lchan */ +int switch_trau_mux(struct gsm_lchan *old_lchan, struct gsm_lchan *new_lchan) +{ + struct gsm_network *net = old_lchan->ts->trx->bts->network; + struct gsm_trans *trans; + + /* look up transaction with TCH frame receive enabled */ + llist_for_each_entry(trans, &net->trans_list, entry) { + if (trans->conn && trans->conn->lchan == old_lchan && trans->tch_recv) { + /* switch */ + trau_recv_lchan(new_lchan, trans->callref); + } + } + + return 0; +} -- cgit v1.2.3