Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [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> |
| 32 | #include <openbsc/debug.h> |
| 33 | |
| 34 | struct map_entry { |
| 35 | struct llist_head list; |
| 36 | struct gsm_e1_subslot src, dst; |
| 37 | }; |
| 38 | |
| 39 | struct upqueue_entry { |
| 40 | struct llist_head list; |
| 41 | struct gsm_network *net; |
| 42 | struct gsm_e1_subslot src; |
| 43 | u_int32_t callref; |
| 44 | }; |
| 45 | |
| 46 | static LLIST_HEAD(ss_map); |
| 47 | static LLIST_HEAD(ss_upqueue); |
| 48 | |
| 49 | /* map one particular subslot to another subslot */ |
| 50 | int trau_mux_map(const struct gsm_e1_subslot *src, |
| 51 | const struct gsm_e1_subslot *dst) |
| 52 | { |
| 53 | struct map_entry *me = malloc(sizeof(*me)); |
| 54 | if (!me) |
| 55 | return -ENOMEM; |
| 56 | |
| 57 | DEBUGP(DCC, "Setting up TRAU mux map between (e1=%u,ts=%u,ss=%u) " |
| 58 | "and (e1=%u,ts=%u,ss=%u)\n", |
| 59 | src->e1_nr, src->e1_ts, src->e1_ts_ss, |
| 60 | dst->e1_nr, dst->e1_ts, dst->e1_ts_ss); |
| 61 | |
| 62 | /* make sure to get rid of any stale old mappings */ |
| 63 | trau_mux_unmap(src, 0); |
| 64 | trau_mux_unmap(dst, 0); |
| 65 | |
| 66 | memcpy(&me->src, src, sizeof(me->src)); |
| 67 | memcpy(&me->dst, dst, sizeof(me->dst)); |
| 68 | llist_add(&me->list, &ss_map); |
| 69 | |
| 70 | return 0; |
| 71 | } |
| 72 | |
| 73 | int trau_mux_map_lchan(const struct gsm_lchan *src, |
| 74 | const struct gsm_lchan *dst) |
| 75 | { |
| 76 | struct gsm_e1_subslot *src_ss, *dst_ss; |
| 77 | |
| 78 | src_ss = &src->ts->e1_link; |
| 79 | dst_ss = &dst->ts->e1_link; |
| 80 | |
| 81 | return trau_mux_map(src_ss, dst_ss); |
| 82 | } |
| 83 | |
| 84 | |
| 85 | /* unmap one particular subslot from another subslot */ |
| 86 | int trau_mux_unmap(const struct gsm_e1_subslot *ss, u_int32_t callref) |
| 87 | { |
| 88 | struct map_entry *me, *me2; |
| 89 | struct upqueue_entry *ue, *ue2; |
| 90 | |
| 91 | if (ss) |
| 92 | llist_for_each_entry_safe(me, me2, &ss_map, list) { |
| 93 | if (!memcmp(&me->src, ss, sizeof(*ss)) || |
| 94 | !memcmp(&me->dst, ss, sizeof(*ss))) { |
| 95 | llist_del(&me->list); |
| 96 | return 0; |
| 97 | } |
| 98 | } |
| 99 | llist_for_each_entry_safe(ue, ue2, &ss_upqueue, list) { |
| 100 | if (ue->callref == callref) { |
| 101 | llist_del(&ue->list); |
| 102 | return 0; |
| 103 | } |
| 104 | if (ss && !memcmp(&ue->src, ss, sizeof(*ss))) { |
| 105 | llist_del(&ue->list); |
| 106 | return 0; |
| 107 | } |
| 108 | } |
| 109 | return -ENOENT; |
| 110 | } |
| 111 | |
| 112 | /* look-up an enty in the TRAU mux map */ |
| 113 | static struct gsm_e1_subslot * |
| 114 | lookup_trau_mux_map(const struct gsm_e1_subslot *src) |
| 115 | { |
| 116 | struct map_entry *me; |
| 117 | |
| 118 | llist_for_each_entry(me, &ss_map, list) { |
| 119 | if (!memcmp(&me->src, src, sizeof(*src))) |
| 120 | return &me->dst; |
| 121 | if (!memcmp(&me->dst, src, sizeof(*src))) |
| 122 | return &me->src; |
| 123 | } |
| 124 | return NULL; |
| 125 | } |
| 126 | |
| 127 | /* look-up an enty in the TRAU upqueue */ |
| 128 | struct upqueue_entry * |
| 129 | lookup_trau_upqueue(const struct gsm_e1_subslot *src) |
| 130 | { |
| 131 | struct upqueue_entry *ue; |
| 132 | |
| 133 | llist_for_each_entry(ue, &ss_upqueue, list) { |
| 134 | if (!memcmp(&ue->src, src, sizeof(*src))) |
| 135 | return ue; |
| 136 | } |
| 137 | return NULL; |
| 138 | } |
| 139 | |
| 140 | /* we get called by subchan_demux */ |
| 141 | int trau_mux_input(struct gsm_e1_subslot *src_e1_ss, |
| 142 | const u_int8_t *trau_bits, int num_bits) |
| 143 | { |
| 144 | struct decoded_trau_frame tf; |
| 145 | u_int8_t trau_bits_out[TRAU_FRAME_BITS]; |
| 146 | struct gsm_e1_subslot *dst_e1_ss = lookup_trau_mux_map(src_e1_ss); |
| 147 | struct subch_mux *mx; |
Harald Welte | 0374084 | 2009-06-10 23:11:52 +0800 | [diff] [blame] | 148 | struct upqueue_entry *ue; |
| 149 | struct msgb *msg; |
| 150 | struct gsm_trau_frame *frame; |
Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 151 | int rc; |
| 152 | |
| 153 | /* decode TRAU, change it to downlink, re-encode */ |
| 154 | rc = decode_trau_frame(&tf, trau_bits); |
| 155 | if (rc) |
| 156 | return rc; |
| 157 | |
Harald Welte | 0374084 | 2009-06-10 23:11:52 +0800 | [diff] [blame] | 158 | if (!dst_e1_ss) { |
| 159 | /* frame shall be sent to upqueue */ |
| 160 | if (!(ue = lookup_trau_upqueue(src_e1_ss))) |
| 161 | return -EINVAL; |
| 162 | if (!ue->callref) |
| 163 | return -EINVAL; |
| 164 | msg = msgb_alloc(sizeof(struct gsm_trau_frame) + sizeof(tf)); |
| 165 | if (!msg) |
| 166 | return -ENOMEM; |
| 167 | frame = (struct gsm_trau_frame *)msg->data; |
| 168 | frame->msg_type = GSM_TRAU_FRAME; |
| 169 | frame->callref = ue->callref; |
| 170 | memcpy(frame->data, &tf, sizeof(tf)); |
| 171 | msgb_enqueue(&ue->net->upqueue, msg); |
| 172 | |
| 173 | return 0; |
| 174 | } |
Harald Welte | 59b0468 | 2009-06-10 05:40:52 +0800 | [diff] [blame] | 175 | |
| 176 | mx = e1inp_get_mux(dst_e1_ss->e1_nr, dst_e1_ss->e1_ts); |
| 177 | if (!mx) |
| 178 | return -EINVAL; |
| 179 | |
| 180 | trau_frame_up2down(&tf); |
| 181 | encode_trau_frame(trau_bits_out, &tf); |
| 182 | |
| 183 | /* and send it to the muxer */ |
| 184 | return subchan_mux_enqueue(mx, dst_e1_ss->e1_ts_ss, trau_bits_out, |
| 185 | TRAU_FRAME_BITS); |
| 186 | } |
| 187 | |
| 188 | /* add receiver instance for lchan and callref */ |
| 189 | int trau_recv_lchan(struct gsm_lchan *lchan, u_int32_t callref) |
| 190 | { |
| 191 | struct gsm_e1_subslot *src_ss; |
| 192 | struct upqueue_entry *ue = malloc(sizeof(*ue)); |
| 193 | |
| 194 | if (!ue) |
| 195 | return -ENOMEM; |
| 196 | |
| 197 | src_ss = &lchan->ts->e1_link; |
| 198 | |
| 199 | DEBUGP(DCC, "Setting up TRAU receiver (e1=%u,ts=%u,ss=%u) " |
| 200 | "and (callref 0x%x)\n", |
| 201 | src_ss->e1_nr, src_ss->e1_ts, src_ss->e1_ts_ss, |
| 202 | callref); |
| 203 | |
| 204 | /* make sure to get rid of any stale old mappings */ |
| 205 | trau_mux_unmap(src_ss, callref); |
| 206 | |
| 207 | memcpy(&ue->src, src_ss, sizeof(ue->src)); |
| 208 | ue->net = lchan->ts->trx->bts->network; |
| 209 | ue->callref = callref; |
| 210 | llist_add(&ue->list, &ss_upqueue); |
| 211 | |
| 212 | return 0; |
| 213 | } |
| 214 | |
| 215 | int trau_send_lchan(struct gsm_lchan *lchan, struct decoded_trau_frame *tf) |
| 216 | { |
| 217 | u_int8_t trau_bits_out[TRAU_FRAME_BITS]; |
| 218 | struct gsm_e1_subslot *dst_e1_ss = &lchan->ts->e1_link; |
| 219 | struct subch_mux *mx; |
| 220 | |
| 221 | mx = e1inp_get_mux(dst_e1_ss->e1_nr, dst_e1_ss->e1_ts); |
| 222 | if (!mx) |
| 223 | return -EINVAL; |
| 224 | |
| 225 | encode_trau_frame(trau_bits_out, tf); |
| 226 | |
| 227 | /* and send it to the muxer */ |
| 228 | return subchan_mux_enqueue(mx, dst_e1_ss->e1_ts_ss, trau_bits_out, |
| 229 | TRAU_FRAME_BITS); |
| 230 | } |