diff options
Diffstat (limited to 'openbsc/src/trau_mux.c')
| -rw-r--r-- | openbsc/src/trau_mux.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/openbsc/src/trau_mux.c b/openbsc/src/trau_mux.c new file mode 100644 index 000000000..96f858992 --- /dev/null +++ b/openbsc/src/trau_mux.c @@ -0,0 +1,212 @@ +/* Simple TRAU frame reflector to route voice calls */ + +/* (C) 2009 by Harald Welte <laforge@gnumonks.org> + * 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 <stdlib.h> +#include <string.h> +#include <sys/types.h> + +#include <openbsc/gsm_data.h> +#include <openbsc/trau_frame.h> +#include <openbsc/trau_mux.h> +#include <openbsc/subchan_demux.h> +#include <openbsc/e1_input.h> +#include <openbsc/debug.h> + +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; + u_int32_t callref; +}; + +static LLIST_HEAD(ss_map); +static LLIST_HEAD(ss_upqueue); + +/* 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 = malloc(sizeof(*me)); + if (!me) + 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, u_int32_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; +} + +/* we get called by subchan_demux */ +int trau_mux_input(struct gsm_e1_subslot *src_e1_ss, + const u_int8_t *trau_bits, int num_bits) +{ + struct decoded_trau_frame tf; + u_int8_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; + 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) + return -EINVAL; + + 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); +} + +/* add receiver instance for lchan and callref */ +int trau_recv_lchan(struct gsm_lchan *lchan, u_int32_t callref) +{ + struct gsm_e1_subslot *src_ss; + struct upqueue_entry *ue = malloc(sizeof(*ue)); + + 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; +} + +int trau_send_lchan(struct gsm_lchan *lchan, struct decoded_trau_frame *tf) +{ + u_int8_t trau_bits_out[TRAU_FRAME_BITS]; + struct gsm_e1_subslot *dst_e1_ss = &lchan->ts->e1_link; + struct subch_mux *mx; + + mx = e1inp_get_mux(dst_e1_ss->e1_nr, dst_e1_ss->e1_ts); + if (!mx) + 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); +} |