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/* 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;
};
static LLIST_HEAD(ss_map);
/* 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);
trau_mux_unmap(dst);
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)
{
struct map_entry *me, *me2;
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;
}
}
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;
}
/* 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;
if (!dst_e1_ss)
return -EINVAL;
mx = e1inp_get_mux(dst_e1_ss->e1_nr, dst_e1_ss->e1_ts);
if (!mx)
return -EINVAL;
/* decode TRAU, change it to downlink, re-encode */
rc = decode_trau_frame(&tf, trau_bits);
if (rc)
return rc;
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);
}
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