Holger Hans Peter Freyther | dccb915 | 2010-06-15 18:49:53 +0800 | [diff] [blame] | 1 | /* |
| 2 | * (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org> |
| 3 | * (C) 2010 by On-Waves |
| 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 <openbsc/bsc_nat.h> |
| 23 | #include <openbsc/gsm_data.h> |
| 24 | #include <openbsc/bssap.h> |
| 25 | #include <openbsc/debug.h> |
Holger Hans Peter Freyther | 1f27839 | 2010-03-31 09:16:56 +0200 | [diff] [blame] | 26 | #include <openbsc/mgcp.h> |
| 27 | #include <openbsc/mgcp_internal.h> |
Holger Hans Peter Freyther | dccb915 | 2010-06-15 18:49:53 +0800 | [diff] [blame] | 28 | |
Holger Hans Peter Freyther | 8ddcc15 | 2010-04-01 08:21:33 +0200 | [diff] [blame^] | 29 | #include <osmocore/talloc.h> |
| 30 | |
Holger Hans Peter Freyther | dccb915 | 2010-06-15 18:49:53 +0800 | [diff] [blame] | 31 | #include <netinet/in.h> |
| 32 | #include <arpa/inet.h> |
| 33 | |
Holger Hans Peter Freyther | 3468be3 | 2010-03-31 13:02:22 +0200 | [diff] [blame] | 34 | #include <errno.h> |
| 35 | #include <unistd.h> |
| 36 | |
Holger Hans Peter Freyther | dccb915 | 2010-06-15 18:49:53 +0800 | [diff] [blame] | 37 | int bsc_mgcp_assign(struct sccp_connections *con, struct msgb *msg) |
| 38 | { |
| 39 | struct tlv_parsed tp; |
| 40 | u_int16_t cic; |
| 41 | u_int8_t timeslot; |
| 42 | u_int8_t multiplex; |
| 43 | |
| 44 | if (!msg->l3h) { |
| 45 | LOGP(DNAT, LOGL_ERROR, "Assignment message should have l3h pointer.\n"); |
| 46 | return -1; |
| 47 | } |
| 48 | |
| 49 | if (msgb_l3len(msg) < 3) { |
| 50 | LOGP(DNAT, LOGL_ERROR, "Assignment message has not enough space for GSM0808.\n"); |
| 51 | return -1; |
| 52 | } |
| 53 | |
| 54 | tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l3h + 3, msgb_l3len(msg) - 3, 0, 0); |
| 55 | if (!TLVP_PRESENT(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE)) { |
| 56 | LOGP(DNAT, LOGL_ERROR, "Circuit identity code not found in assignment message.\n"); |
| 57 | return -1; |
| 58 | } |
| 59 | |
| 60 | cic = ntohs(*(u_int16_t *)TLVP_VAL(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE)); |
| 61 | timeslot = cic & 0x1f; |
| 62 | multiplex = (cic & ~0x1f) >> 5; |
| 63 | |
| 64 | con->msc_timeslot = (32 * multiplex) + timeslot; |
| 65 | con->bsc_timeslot = con->msc_timeslot; |
| 66 | return 0; |
| 67 | } |
| 68 | |
| 69 | void bsc_mgcp_clear(struct sccp_connections *con) |
| 70 | { |
| 71 | con->msc_timeslot = -1; |
| 72 | con->bsc_timeslot = -1; |
| 73 | } |
Holger Hans Peter Freyther | 1f27839 | 2010-03-31 09:16:56 +0200 | [diff] [blame] | 74 | |
Holger Hans Peter Freyther | 8ddcc15 | 2010-04-01 08:21:33 +0200 | [diff] [blame^] | 75 | void bsc_mgcp_free_endpoint(struct bsc_nat *nat, int i) |
| 76 | { |
| 77 | if (nat->bsc_endpoints[i].transaction_id) { |
| 78 | talloc_free(nat->bsc_endpoints[i].transaction_id); |
| 79 | nat->bsc_endpoints[i].transaction_id = NULL; |
| 80 | } |
| 81 | |
| 82 | nat->bsc_endpoints[i].bsc = NULL; |
| 83 | mgcp_free_endp(&nat->mgcp_cfg->endpoints[i]); |
| 84 | } |
| 85 | |
Holger Hans Peter Freyther | 1f27839 | 2010-03-31 09:16:56 +0200 | [diff] [blame] | 86 | void bsc_mgcp_free_endpoints(struct bsc_nat *nat) |
| 87 | { |
| 88 | int i; |
| 89 | |
| 90 | for (i = 1; i < nat->mgcp_cfg->number_endpoints; ++i) |
Holger Hans Peter Freyther | 8ddcc15 | 2010-04-01 08:21:33 +0200 | [diff] [blame^] | 91 | bsc_mgcp_free_endpoint(nat, i); |
Holger Hans Peter Freyther | 1f27839 | 2010-03-31 09:16:56 +0200 | [diff] [blame] | 92 | } |
Holger Hans Peter Freyther | 3468be3 | 2010-03-31 13:02:22 +0200 | [diff] [blame] | 93 | |
Holger Hans Peter Freyther | 8917998 | 2010-04-01 03:55:27 +0200 | [diff] [blame] | 94 | struct bsc_connection *bsc_mgcp_find_con(struct bsc_nat *nat, int endpoint) |
| 95 | { |
| 96 | struct sccp_connections *sccp; |
| 97 | |
| 98 | llist_for_each_entry(sccp, &nat->sccp_connections, list_entry) { |
| 99 | if (sccp->msc_timeslot == -1) |
| 100 | continue; |
| 101 | if (mgcp_timeslot_to_endpoint(0, sccp->msc_timeslot) != endpoint) |
| 102 | continue; |
| 103 | |
| 104 | return sccp->bsc; |
| 105 | } |
| 106 | |
| 107 | LOGP(DMGCP, LOGL_ERROR, "Failed to find the connection.\n"); |
| 108 | return NULL; |
| 109 | } |
| 110 | |
Holger Hans Peter Freyther | 8ddcc15 | 2010-04-01 08:21:33 +0200 | [diff] [blame^] | 111 | int bsc_mgcp_policy_cb(struct mgcp_config *cfg, int endpoint, int state, const char *transaction_id) |
| 112 | { |
| 113 | struct bsc_nat *nat; |
| 114 | struct bsc_endpoint *bsc_endp; |
| 115 | struct bsc_connection *bsc_con; |
| 116 | struct mgcp_endpoint *mgcp_endp; |
| 117 | struct msgb *bsc_msg; |
| 118 | |
| 119 | nat = cfg->data; |
| 120 | bsc_endp = &nat->bsc_endpoints[endpoint]; |
| 121 | mgcp_endp = &nat->mgcp_cfg->endpoints[endpoint]; |
| 122 | |
| 123 | bsc_con = bsc_mgcp_find_con(nat, endpoint); |
| 124 | |
| 125 | if (!bsc_con) { |
| 126 | LOGP(DMGCP, LOGL_ERROR, "Did not find BSC for a new connection on 0x%x for %d\n", endpoint, state); |
| 127 | |
| 128 | switch (state) { |
| 129 | case MGCP_ENDP_CRCX: |
| 130 | return MGCP_POLICY_REJECT; |
| 131 | break; |
| 132 | case MGCP_ENDP_DLCX: |
| 133 | return MGCP_POLICY_CONT; |
| 134 | break; |
| 135 | case MGCP_ENDP_MDCX: |
| 136 | return MGCP_POLICY_CONT; |
| 137 | break; |
| 138 | default: |
| 139 | LOGP(DMGCP, LOGL_FATAL, "Unhandled state: %d\n", state); |
| 140 | return MGCP_POLICY_CONT; |
| 141 | break; |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | if (bsc_endp->transaction_id) { |
| 146 | LOGP(DMGCP, LOGL_ERROR, "One transaction with id '%s' on 0x%x\n", |
| 147 | bsc_endp->transaction_id, endpoint); |
| 148 | talloc_free(bsc_endp->transaction_id); |
| 149 | } |
| 150 | |
| 151 | bsc_endp->transaction_id = talloc_strdup(bsc_endp, transaction_id); |
| 152 | bsc_endp->bsc = bsc_con; |
| 153 | |
| 154 | /* we need to update some bits */ |
| 155 | if (state == MGCP_ENDP_CRCX) { |
| 156 | struct sockaddr_in sock; |
| 157 | socklen_t len = sizeof(sock); |
| 158 | if (getpeername(nat->mgcp_queue.bfd.fd, (struct sockaddr *) &sock, &len) != 0) { |
| 159 | LOGP(DMGCP, LOGL_ERROR, "Can not get the peername...\n"); |
| 160 | } else { |
| 161 | mgcp_endp->bts = sock.sin_addr; |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | /* we need to generate a new and patched message */ |
| 166 | bsc_msg = bsc_mgcp_rewrite(nat->mgcp_msg, nat->mgcp_cfg->source_addr, mgcp_endp->rtp_port); |
| 167 | if (!bsc_msg) { |
| 168 | LOGP(DMGCP, LOGL_ERROR, "Failed to patch the msg.\n"); |
| 169 | return MGCP_POLICY_CONT; |
| 170 | } |
| 171 | |
| 172 | bsc_write_mgcp_msg(bsc_con, bsc_msg); |
| 173 | return MGCP_POLICY_DEFER; |
| 174 | } |
| 175 | |
Holger Hans Peter Freyther | acd6420 | 2010-04-01 06:48:52 +0200 | [diff] [blame] | 176 | /* we need to replace some strings... */ |
| 177 | struct msgb *bsc_mgcp_rewrite(struct msgb *input, const char *ip, int port) |
| 178 | { |
| 179 | static const char *ip_str = "c=IN IP4 "; |
| 180 | static const char *aud_str = "m=audio "; |
| 181 | |
| 182 | char buf[128]; |
| 183 | char *running, *token; |
| 184 | struct msgb *output; |
| 185 | |
| 186 | if (msgb_l2len(input) > 4096 - 128) { |
| 187 | LOGP(DMGCP, LOGL_ERROR, "Input is too long.\n"); |
| 188 | return NULL; |
| 189 | } |
| 190 | |
| 191 | output = msgb_alloc_headroom(4096, 128, "MGCP rewritten"); |
| 192 | if (!output) { |
| 193 | LOGP(DMGCP, LOGL_ERROR, "Failed to allocate new MGCP msg.\n"); |
| 194 | return NULL; |
| 195 | } |
| 196 | |
| 197 | running = (char *) input->l2h; |
| 198 | output->l2h = output->data; |
| 199 | for (token = strsep(&running, "\n"); token; token = strsep(&running, "\n")) { |
| 200 | int len = strlen(token); |
| 201 | |
| 202 | /* ignore completely empty lines for now */ |
| 203 | if (len == 0) |
| 204 | continue; |
| 205 | |
| 206 | if (strncmp(ip_str, token, (sizeof ip_str) - 1) == 0) { |
| 207 | output->l3h = msgb_put(output, strlen(ip_str)); |
| 208 | memcpy(output->l3h, ip_str, strlen(ip_str)); |
| 209 | output->l3h = msgb_put(output, strlen(ip)); |
| 210 | memcpy(output->l3h, ip, strlen(ip)); |
| 211 | output->l3h = msgb_put(output, 2); |
| 212 | output->l3h[0] = '\r'; |
| 213 | output->l3h[1] = '\n'; |
| 214 | } else if (strncmp(aud_str, token, (sizeof aud_str) - 1) == 0) { |
| 215 | int payload; |
| 216 | if (sscanf(token, "m=audio %*d RTP/AVP %d", &payload) != 1) { |
| 217 | LOGP(DMGCP, LOGL_ERROR, "Could not parsed audio line.\n"); |
| 218 | msgb_free(output); |
| 219 | return NULL; |
| 220 | } |
| 221 | |
| 222 | snprintf(buf, sizeof(buf)-1, "m=audio %d RTP/AVP %d\r\n", port, payload); |
| 223 | buf[sizeof(buf)-1] = '\0'; |
| 224 | |
| 225 | output->l3h = msgb_put(output, strlen(buf)); |
| 226 | memcpy(output->l3h, buf, strlen(buf)); |
| 227 | } else { |
| 228 | output->l3h = msgb_put(output, len + 1); |
| 229 | memcpy(output->l3h, token, len); |
| 230 | output->l3h[len] = '\n'; |
| 231 | } |
| 232 | } |
| 233 | |
| 234 | return output; |
| 235 | } |
| 236 | |
Holger Hans Peter Freyther | 3468be3 | 2010-03-31 13:02:22 +0200 | [diff] [blame] | 237 | static int mgcp_do_read(struct bsc_fd *fd) |
| 238 | { |
| 239 | struct bsc_nat *nat; |
| 240 | struct msgb *msg, *resp; |
| 241 | int rc; |
| 242 | |
| 243 | msg = msgb_alloc(4096, "MGCP GW Read"); |
| 244 | if (!msg) { |
| 245 | LOGP(DMGCP, LOGL_ERROR, "Failed to create buffer.\n"); |
| 246 | return -1; |
| 247 | } |
| 248 | |
| 249 | |
| 250 | rc = read(fd->fd, msg->data, msg->data_len); |
| 251 | if (rc <= 0) { |
| 252 | LOGP(DMGCP, LOGL_ERROR, "Failed to read errno: %d\n", errno); |
| 253 | msgb_free(msg); |
| 254 | return -1; |
| 255 | } |
| 256 | |
| 257 | nat = fd->data; |
Holger Hans Peter Freyther | 8ddcc15 | 2010-04-01 08:21:33 +0200 | [diff] [blame^] | 258 | nat->mgcp_msg = msg; |
Holger Hans Peter Freyther | 3468be3 | 2010-03-31 13:02:22 +0200 | [diff] [blame] | 259 | msg->l2h = msgb_put(msg, rc); |
| 260 | resp = mgcp_handle_message(nat->mgcp_cfg, msg); |
| 261 | msgb_free(msg); |
Holger Hans Peter Freyther | 8ddcc15 | 2010-04-01 08:21:33 +0200 | [diff] [blame^] | 262 | nat->mgcp_msg = NULL; |
Holger Hans Peter Freyther | 3468be3 | 2010-03-31 13:02:22 +0200 | [diff] [blame] | 263 | |
| 264 | /* we do have a direct answer... e.g. AUEP */ |
| 265 | if (resp) { |
| 266 | if (write_queue_enqueue(&nat->mgcp_queue, resp) != 0) { |
| 267 | LOGP(DMGCP, LOGL_ERROR, "Failed to enqueue msg.\n"); |
| 268 | msgb_free(resp); |
| 269 | } |
| 270 | } |
| 271 | |
| 272 | return 0; |
| 273 | } |
| 274 | |
| 275 | static int mgcp_do_write(struct bsc_fd *bfd, struct msgb *msg) |
| 276 | { |
| 277 | int rc; |
| 278 | |
| 279 | rc = write(bfd->fd, msg->data, msg->len); |
| 280 | |
| 281 | if (rc != msg->len) { |
| 282 | LOGP(DMGCP, LOGL_ERROR, "Failed to write msg to MGCP CallAgent.\n"); |
| 283 | return -1; |
| 284 | } |
| 285 | |
| 286 | return rc; |
| 287 | } |
| 288 | |
| 289 | int bsc_mgcp_init(struct bsc_nat *nat) |
| 290 | { |
| 291 | int on; |
| 292 | struct sockaddr_in addr; |
| 293 | |
| 294 | if (!nat->mgcp_cfg->call_agent_addr) { |
| 295 | LOGP(DMGCP, LOGL_ERROR, "The BSC nat requires the call agent ip to be set.\n"); |
| 296 | return -1; |
| 297 | } |
| 298 | |
Holger Hans Peter Freyther | 8ddcc15 | 2010-04-01 08:21:33 +0200 | [diff] [blame^] | 299 | if (nat->mgcp_cfg->bts_ip) { |
| 300 | LOGP(DMGCP, LOGL_ERROR, "Do not set the BTS ip for the nat.\n"); |
| 301 | return -1; |
| 302 | } |
| 303 | |
Holger Hans Peter Freyther | 3468be3 | 2010-03-31 13:02:22 +0200 | [diff] [blame] | 304 | nat->mgcp_queue.bfd.fd = socket(AF_INET, SOCK_DGRAM, 0); |
| 305 | if (nat->mgcp_queue.bfd.fd < 0) { |
| 306 | LOGP(DMGCP, LOGL_ERROR, "Failed to create MGCP socket. errno: %d\n", errno); |
| 307 | return -1; |
| 308 | } |
| 309 | |
| 310 | on = 1; |
| 311 | setsockopt(nat->mgcp_queue.bfd.fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); |
| 312 | |
| 313 | addr.sin_family = AF_INET; |
| 314 | addr.sin_port = htons(nat->mgcp_cfg->source_port); |
| 315 | inet_aton(nat->mgcp_cfg->source_addr, &addr.sin_addr); |
| 316 | |
| 317 | if (bind(nat->mgcp_queue.bfd.fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { |
| 318 | LOGP(DMGCP, LOGL_ERROR, "Failed to bind. errno: %d\n", errno); |
| 319 | close(nat->mgcp_queue.bfd.fd); |
| 320 | nat->mgcp_queue.bfd.fd = -1; |
| 321 | return -1; |
| 322 | } |
| 323 | |
| 324 | addr.sin_port = htons(2727); |
| 325 | inet_aton(nat->mgcp_cfg->call_agent_addr, &addr.sin_addr); |
| 326 | if (connect(nat->mgcp_queue.bfd.fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { |
| 327 | LOGP(DMGCP, LOGL_ERROR, "Failed to connect to: '%s'. errno: %d\n", |
| 328 | nat->mgcp_cfg->call_agent_addr, errno); |
| 329 | close(nat->mgcp_queue.bfd.fd); |
| 330 | nat->mgcp_queue.bfd.fd = -1; |
| 331 | return -1; |
| 332 | } |
| 333 | |
| 334 | write_queue_init(&nat->mgcp_queue, 10); |
| 335 | nat->mgcp_queue.bfd.when = BSC_FD_READ; |
| 336 | nat->mgcp_queue.bfd.data = nat; |
| 337 | nat->mgcp_queue.read_cb = mgcp_do_read; |
| 338 | nat->mgcp_queue.write_cb = mgcp_do_write; |
| 339 | |
| 340 | if (bsc_register_fd(&nat->mgcp_queue.bfd) != 0) { |
| 341 | LOGP(DMGCP, LOGL_ERROR, "Failed to register MGCP fd.\n"); |
| 342 | close(nat->mgcp_queue.bfd.fd); |
| 343 | nat->mgcp_queue.bfd.fd = -1; |
| 344 | return -1; |
| 345 | } |
| 346 | |
Holger Hans Peter Freyther | 8ddcc15 | 2010-04-01 08:21:33 +0200 | [diff] [blame^] | 347 | /* some more MGCP config handling */ |
| 348 | nat->mgcp_cfg->data = nat; |
| 349 | nat->mgcp_cfg->policy_cb = bsc_mgcp_policy_cb; |
| 350 | nat->bsc_endpoints = talloc_zero_array(nat, |
| 351 | struct bsc_endpoint, |
| 352 | nat->mgcp_cfg->number_endpoints + 1); |
| 353 | |
Holger Hans Peter Freyther | 3468be3 | 2010-03-31 13:02:22 +0200 | [diff] [blame] | 354 | return 0; |
| 355 | } |