Harald Welte | 1fa60c8 | 2009-02-09 18:13:26 +0000 | [diff] [blame] | 1 | /* Simple TRAU frame reflector to route voice calls */ |
| 2 | |
| 3 | /* (C) 2009 by Harald Welte <laforge@gnumonks.org> |
| 4 | * All Rights Reserved |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License along |
| 17 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 18 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 19 | * |
| 20 | */ |
| 21 | |
| 22 | #include <errno.h> |
| 23 | #include <stdlib.h> |
| 24 | #include <string.h> |
| 25 | #include <sys/types.h> |
| 26 | |
| 27 | #include <openbsc/gsm_data.h> |
| 28 | #include <openbsc/trau_frame.h> |
| 29 | #include <openbsc/trau_mux.h> |
| 30 | #include <openbsc/subchan_demux.h> |
| 31 | #include <openbsc/e1_input.h> |
Harald Welte | 41e1668 | 2009-02-18 03:34:55 +0000 | [diff] [blame] | 32 | #include <openbsc/debug.h> |
Harald Welte | 1fa60c8 | 2009-02-09 18:13:26 +0000 | [diff] [blame] | 33 | |
| 34 | struct map_entry { |
| 35 | struct llist_head list; |
| 36 | struct gsm_e1_subslot src, dst; |
| 37 | }; |
| 38 | |
| 39 | static LLIST_HEAD(ss_map); |
| 40 | |
| 41 | /* map one particular subslot to another subslot */ |
| 42 | int trau_mux_map(const struct gsm_e1_subslot *src, |
| 43 | const struct gsm_e1_subslot *dst) |
| 44 | { |
| 45 | struct map_entry *me = malloc(sizeof(*me)); |
| 46 | if (!me) |
| 47 | return -ENOMEM; |
| 48 | |
Harald Welte | dbd2ea8 | 2009-02-19 17:07:01 +0000 | [diff] [blame] | 49 | DEBUGP(DCC, "Setting up TRAU mux map between (e1=%u,ts=%u,ss=%u) " |
| 50 | "and (e1=%u,ts=%u,ss=%u)\n", |
| 51 | src->e1_nr, src->e1_ts, src->e1_ts_ss, |
| 52 | dst->e1_nr, dst->e1_ts, dst->e1_ts_ss); |
| 53 | |
Harald Welte | 26aa6a1 | 2009-02-19 15:14:23 +0000 | [diff] [blame] | 54 | /* make sure to get rid of any stale old mappings */ |
| 55 | trau_mux_unmap(src); |
| 56 | trau_mux_unmap(dst); |
| 57 | |
Harald Welte | 1fa60c8 | 2009-02-09 18:13:26 +0000 | [diff] [blame] | 58 | memcpy(&me->src, src, sizeof(me->src)); |
| 59 | memcpy(&me->dst, dst, sizeof(me->dst)); |
| 60 | llist_add(&me->list, &ss_map); |
| 61 | |
| 62 | return 0; |
| 63 | } |
| 64 | |
Harald Welte | 26aa6a1 | 2009-02-19 15:14:23 +0000 | [diff] [blame] | 65 | int trau_mux_map_lchan(const struct gsm_lchan *src, |
| 66 | const struct gsm_lchan *dst) |
| 67 | { |
| 68 | struct gsm_e1_subslot *src_ss, *dst_ss; |
| 69 | |
| 70 | src_ss = &src->ts->e1_link; |
| 71 | dst_ss = &dst->ts->e1_link; |
| 72 | |
| 73 | return trau_mux_map(src_ss, dst_ss); |
| 74 | } |
| 75 | |
| 76 | |
Harald Welte | 1fa60c8 | 2009-02-09 18:13:26 +0000 | [diff] [blame] | 77 | /* unmap one particular subslot from another subslot */ |
| 78 | int trau_mux_unmap(const struct gsm_e1_subslot *ss) |
| 79 | { |
| 80 | struct map_entry *me, *me2; |
| 81 | |
| 82 | llist_for_each_entry_safe(me, me2, &ss_map, list) { |
| 83 | if (!memcmp(&me->src, ss, sizeof(*ss)) || |
| 84 | !memcmp(&me->dst, ss, sizeof(*ss))) { |
| 85 | llist_del(&me->list); |
| 86 | return 0; |
| 87 | } |
| 88 | } |
| 89 | return -ENOENT; |
| 90 | } |
| 91 | |
| 92 | /* look-up an enty in the TRAU mux map */ |
| 93 | static struct gsm_e1_subslot * |
| 94 | lookup_trau_mux_map(const struct gsm_e1_subslot *src) |
| 95 | { |
| 96 | struct map_entry *me; |
| 97 | |
| 98 | llist_for_each_entry(me, &ss_map, list) { |
| 99 | if (!memcmp(&me->src, src, sizeof(*src))) |
| 100 | return &me->dst; |
| 101 | if (!memcmp(&me->dst, src, sizeof(*src))) |
| 102 | return &me->src; |
| 103 | } |
| 104 | return NULL; |
| 105 | } |
| 106 | |
| 107 | /* we get called by subchan_demux */ |
| 108 | int trau_mux_input(struct gsm_e1_subslot *src_e1_ss, |
| 109 | const u_int8_t *trau_bits, int num_bits) |
| 110 | { |
| 111 | struct decoded_trau_frame tf; |
| 112 | u_int8_t trau_bits_out[TRAU_FRAME_BITS]; |
| 113 | struct gsm_e1_subslot *dst_e1_ss = lookup_trau_mux_map(src_e1_ss); |
| 114 | struct subch_mux *mx; |
Harald Welte | 41e1668 | 2009-02-18 03:34:55 +0000 | [diff] [blame] | 115 | int rc; |
Harald Welte | 1fa60c8 | 2009-02-09 18:13:26 +0000 | [diff] [blame] | 116 | |
| 117 | if (!dst_e1_ss) |
| 118 | return -EINVAL; |
| 119 | |
| 120 | mx = e1inp_get_mux(dst_e1_ss->e1_nr, dst_e1_ss->e1_ts); |
| 121 | if (!mx) |
| 122 | return -EINVAL; |
| 123 | |
| 124 | /* decode TRAU, change it to downlink, re-encode */ |
Harald Welte | 41e1668 | 2009-02-18 03:34:55 +0000 | [diff] [blame] | 125 | rc = decode_trau_frame(&tf, trau_bits); |
| 126 | if (rc) |
| 127 | return rc; |
| 128 | |
Harald Welte | 1fa60c8 | 2009-02-09 18:13:26 +0000 | [diff] [blame] | 129 | trau_frame_up2down(&tf); |
| 130 | encode_trau_frame(trau_bits_out, &tf); |
| 131 | |
| 132 | /* and send it to the muxer */ |
| 133 | return subchan_mux_enqueue(mx, dst_e1_ss->e1_ts_ss, trau_bits_out, |
| 134 | TRAU_FRAME_BITS); |
| 135 | } |