110 lines
2.9 KiB
C
110 lines
2.9 KiB
C
/* Simple TRAU frame reflector to route voice calls */
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/* (C) 2009 by Harald Welte <laforge@gnumonks.org>
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* All Rights Reserved
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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*/
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#include <errno.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/types.h>
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#include <openbsc/gsm_data.h>
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#include <openbsc/trau_frame.h>
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#include <openbsc/trau_mux.h>
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#include <openbsc/subchan_demux.h>
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#include <openbsc/e1_input.h>
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struct map_entry {
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struct llist_head list;
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struct gsm_e1_subslot src, dst;
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};
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static LLIST_HEAD(ss_map);
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/* map one particular subslot to another subslot */
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int trau_mux_map(const struct gsm_e1_subslot *src,
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const struct gsm_e1_subslot *dst)
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{
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struct map_entry *me = malloc(sizeof(*me));
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if (!me)
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return -ENOMEM;
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memcpy(&me->src, src, sizeof(me->src));
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memcpy(&me->dst, dst, sizeof(me->dst));
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llist_add(&me->list, &ss_map);
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return 0;
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}
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/* unmap one particular subslot from another subslot */
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int trau_mux_unmap(const struct gsm_e1_subslot *ss)
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{
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struct map_entry *me, *me2;
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llist_for_each_entry_safe(me, me2, &ss_map, list) {
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if (!memcmp(&me->src, ss, sizeof(*ss)) ||
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!memcmp(&me->dst, ss, sizeof(*ss))) {
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llist_del(&me->list);
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return 0;
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}
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}
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return -ENOENT;
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}
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/* look-up an enty in the TRAU mux map */
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static struct gsm_e1_subslot *
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lookup_trau_mux_map(const struct gsm_e1_subslot *src)
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{
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struct map_entry *me;
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llist_for_each_entry(me, &ss_map, list) {
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if (!memcmp(&me->src, src, sizeof(*src)))
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return &me->dst;
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if (!memcmp(&me->dst, src, sizeof(*src)))
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return &me->src;
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}
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return NULL;
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}
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/* we get called by subchan_demux */
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int trau_mux_input(struct gsm_e1_subslot *src_e1_ss,
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const u_int8_t *trau_bits, int num_bits)
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{
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struct decoded_trau_frame tf;
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u_int8_t trau_bits_out[TRAU_FRAME_BITS];
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struct gsm_e1_subslot *dst_e1_ss = lookup_trau_mux_map(src_e1_ss);
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struct subch_mux *mx;
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if (!dst_e1_ss)
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return -EINVAL;
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mx = e1inp_get_mux(dst_e1_ss->e1_nr, dst_e1_ss->e1_ts);
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if (!mx)
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return -EINVAL;
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/* decode TRAU, change it to downlink, re-encode */
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decode_trau_frame(&tf, trau_bits);
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trau_frame_up2down(&tf);
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encode_trau_frame(trau_bits_out, &tf);
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/* and send it to the muxer */
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return subchan_mux_enqueue(mx, dst_e1_ss->e1_ts_ss, trau_bits_out,
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TRAU_FRAME_BITS);
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}
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