Neels Hofmeyr | 2188a77 | 2016-05-20 21:59:55 +0200 | [diff] [blame] | 1 | /* mgcp_utils - common functions to setup an MGCP connection |
| 2 | */ |
| 3 | /* (C) 2016 by sysmocom s.f.m.c. GmbH <info@sysmocom.de> |
| 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 Affero General Public License as published by |
| 8 | * the Free Software Foundation; either version 3 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 Affero General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Affero General Public License |
| 17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | #include <osmocom/core/select.h> |
| 22 | #include <osmocom/core/write_queue.h> |
| 23 | #include <osmocom/core/msgb.h> |
| 24 | #include <osmocom/core/logging.h> |
| 25 | |
| 26 | #include <openbsc/mgcpgw_client.h> |
| 27 | #include <openbsc/mgcp.h> |
| 28 | #include <openbsc/mgcp_internal.h> |
| 29 | #include <openbsc/debug.h> |
| 30 | |
| 31 | #include <netinet/in.h> |
| 32 | #include <arpa/inet.h> |
| 33 | |
| 34 | #include <errno.h> |
| 35 | #include <unistd.h> |
| 36 | #include <string.h> |
| 37 | |
| 38 | struct mgcpgw_client { |
| 39 | struct mgcpgw_client_conf actual; |
| 40 | uint32_t remote_addr; |
| 41 | struct osmo_wqueue wq; |
| 42 | mgcp_trans_id_t next_trans_id; |
| 43 | uint16_t next_endpoint; |
| 44 | struct llist_head responses_pending; |
| 45 | }; |
| 46 | |
| 47 | void mgcpgw_client_conf_init(struct mgcpgw_client_conf *conf) |
| 48 | { |
| 49 | /* NULL and -1 default to MGCPGW_CLIENT_*_DEFAULT values */ |
| 50 | *conf = (struct mgcpgw_client_conf){ |
| 51 | .local_addr = NULL, |
| 52 | .local_port = -1, |
| 53 | .remote_addr = NULL, |
| 54 | .remote_port = -1, |
| 55 | }; |
| 56 | } |
| 57 | |
| 58 | unsigned int mgcpgw_client_next_endpoint(struct mgcpgw_client *client) |
| 59 | { |
| 60 | return client->next_endpoint ++; |
| 61 | } |
| 62 | |
| 63 | static void mgcpgw_client_handle_response(struct mgcpgw_client *mgcp, |
| 64 | struct mgcp_response_pending *pending, |
| 65 | struct mgcp_response *response) |
| 66 | { |
| 67 | if (!pending) { |
| 68 | LOGP(DMGCP, LOGL_ERROR, |
| 69 | "Cannot handle NULL response\n"); |
| 70 | return; |
| 71 | } |
| 72 | if (pending->response_cb) |
| 73 | pending->response_cb(response, pending->priv); |
| 74 | else |
| 75 | LOGP(DMGCP, LOGL_INFO, "MGCP response ignored (NULL cb)\n"); |
| 76 | talloc_free(pending); |
| 77 | } |
| 78 | |
| 79 | static int mgcp_response_parse_head(struct mgcp_response *r, struct msgb *msg) |
| 80 | { |
| 81 | int comment_pos; |
| 82 | char *end; |
| 83 | |
| 84 | if (mgcp_msg_terminate_nul(msg)) |
| 85 | goto response_parse_failure; |
| 86 | |
| 87 | r->body = (char *)msg->data; |
| 88 | |
| 89 | if (sscanf(r->body, "%3d %u %n", |
| 90 | &r->head.response_code, &r->head.trans_id, |
| 91 | &comment_pos) != 2) |
| 92 | goto response_parse_failure; |
| 93 | |
| 94 | r->head.comment = r->body + comment_pos; |
| 95 | end = strchr(r->head.comment, '\r'); |
| 96 | if (!end) |
| 97 | goto response_parse_failure; |
| 98 | /* Mark the end of the comment */ |
| 99 | *end = '\0'; |
| 100 | r->body = end + 1; |
| 101 | if (r->body[0] == '\n') |
| 102 | r->body ++; |
| 103 | return 0; |
| 104 | |
| 105 | response_parse_failure: |
| 106 | LOGP(DMGCP, LOGL_ERROR, |
| 107 | "Failed to parse MGCP response header\n"); |
| 108 | return -EINVAL; |
| 109 | } |
| 110 | |
| 111 | /* TODO undup against mgcp_protocol.c:mgcp_check_param() */ |
| 112 | static bool mgcp_line_is_valid(const char *line) |
| 113 | { |
| 114 | const size_t line_len = strlen(line); |
| 115 | if (line[0] == '\0') |
| 116 | return true; |
| 117 | |
| 118 | if (line_len < 2 |
| 119 | || line[1] != '=') { |
| 120 | LOGP(DMGCP, LOGL_ERROR, |
| 121 | "Wrong MGCP option format: '%s'\n", |
| 122 | line); |
| 123 | return false; |
| 124 | } |
| 125 | |
| 126 | return true; |
| 127 | } |
| 128 | |
| 129 | /* Parse a line like "m=audio 16002 RTP/AVP 98" */ |
| 130 | static int mgcp_parse_audio(struct mgcp_response *r, const char *line) |
| 131 | { |
| 132 | if (sscanf(line, "m=audio %hu", |
| 133 | &r->audio_port) != 1) |
| 134 | goto response_parse_failure; |
| 135 | |
| 136 | return 0; |
| 137 | |
| 138 | response_parse_failure: |
| 139 | LOGP(DMGCP, LOGL_ERROR, |
| 140 | "Failed to parse MGCP response header\n"); |
| 141 | return -EINVAL; |
| 142 | } |
| 143 | |
| 144 | int mgcp_response_parse_params(struct mgcp_response *r) |
| 145 | { |
| 146 | char *line; |
| 147 | int rc; |
| 148 | OSMO_ASSERT(r->body); |
| 149 | char *data = strstr(r->body, "\n\n"); |
| 150 | |
| 151 | if (!data) { |
| 152 | LOGP(DMGCP, LOGL_ERROR, |
| 153 | "MGCP response: cannot find start of parameters\n"); |
| 154 | return -EINVAL; |
| 155 | } |
| 156 | |
| 157 | /* Advance to after the \n\n, replace the second \n with \0. That's |
| 158 | * where the parameters start. */ |
| 159 | data ++; |
| 160 | *data = '\0'; |
| 161 | data ++; |
| 162 | |
| 163 | for_each_line(line, data) { |
| 164 | if (!mgcp_line_is_valid(line)) |
| 165 | return -EINVAL; |
| 166 | |
| 167 | switch (line[0]) { |
| 168 | case 'm': |
| 169 | rc = mgcp_parse_audio(r, line); |
| 170 | if (rc) |
| 171 | return rc; |
| 172 | break; |
| 173 | default: |
| 174 | /* skip unhandled parameters */ |
| 175 | break; |
| 176 | } |
| 177 | } |
| 178 | return 0; |
| 179 | } |
| 180 | |
| 181 | static struct mgcp_response_pending *mgcpgw_client_response_pending_get( |
| 182 | struct mgcpgw_client *mgcp, |
| 183 | struct mgcp_response *r) |
| 184 | { |
| 185 | struct mgcp_response_pending *pending; |
| 186 | if (!r) |
| 187 | return NULL; |
| 188 | llist_for_each_entry(pending, &mgcp->responses_pending, entry) { |
| 189 | if (pending->trans_id == r->head.trans_id) { |
| 190 | llist_del(&pending->entry); |
| 191 | return pending; |
| 192 | } |
| 193 | } |
| 194 | return NULL; |
| 195 | } |
| 196 | |
| 197 | /* Feed an MGCP message into the receive processing. |
| 198 | * Parse the head and call any callback registered for the transaction id found |
| 199 | * in the MGCP message. This is normally called directly from the internal |
| 200 | * mgcp_do_read that reads from the socket connected to the MGCP gateway. This |
| 201 | * function is published mainly to be able to feed data from the test suite. |
| 202 | */ |
| 203 | int mgcpgw_client_rx(struct mgcpgw_client *mgcp, struct msgb *msg) |
| 204 | { |
| 205 | struct mgcp_response r = { 0 }; |
| 206 | struct mgcp_response_pending *pending; |
| 207 | int rc; |
| 208 | |
| 209 | rc = mgcp_response_parse_head(&r, msg); |
| 210 | if (rc) { |
| 211 | LOGP(DMGCP, LOGL_ERROR, "Cannot parse MGCP response\n"); |
| 212 | return -1; |
| 213 | } |
| 214 | |
| 215 | pending = mgcpgw_client_response_pending_get(mgcp, &r); |
| 216 | if (!pending) { |
| 217 | LOGP(DMGCP, LOGL_ERROR, |
| 218 | "Cannot find matching MGCP transaction for trans_id %d\n", |
| 219 | r.head.trans_id); |
| 220 | return -1; |
| 221 | } |
| 222 | |
| 223 | mgcpgw_client_handle_response(mgcp, pending, &r); |
| 224 | return 0; |
| 225 | } |
| 226 | |
| 227 | static int mgcp_do_read(struct osmo_fd *fd) |
| 228 | { |
| 229 | struct mgcpgw_client *mgcp = fd->data; |
| 230 | struct msgb *msg; |
| 231 | int ret; |
| 232 | |
| 233 | msg = msgb_alloc_headroom(4096, 128, "mgcp_from_gw"); |
| 234 | if (!msg) { |
| 235 | LOGP(DMGCP, LOGL_ERROR, "Failed to allocate MGCP message.\n"); |
| 236 | return -1; |
| 237 | } |
| 238 | |
| 239 | ret = read(fd->fd, msg->data, 4096 - 128); |
| 240 | if (ret <= 0) { |
| 241 | LOGP(DMGCP, LOGL_ERROR, "Failed to read: %d/%s\n", errno, strerror(errno)); |
| 242 | msgb_free(msg); |
| 243 | return -1; |
| 244 | } else if (ret > 4096 - 128) { |
| 245 | LOGP(DMGCP, LOGL_ERROR, "Too much data: %d\n", ret); |
| 246 | msgb_free(msg); |
| 247 | return -1; |
| 248 | } |
| 249 | |
| 250 | msg->l2h = msgb_put(msg, ret); |
| 251 | ret = mgcpgw_client_rx(mgcp, msg); |
| 252 | talloc_free(msg); |
| 253 | return ret; |
| 254 | } |
| 255 | |
| 256 | static int mgcp_do_write(struct osmo_fd *fd, struct msgb *msg) |
| 257 | { |
| 258 | int ret; |
| 259 | static char strbuf[4096]; |
| 260 | unsigned int l = msg->len < sizeof(strbuf)-1 ? msg->len : sizeof(strbuf)-1; |
| 261 | strncpy(strbuf, (const char*)msg->data, l); |
| 262 | strbuf[l] = '\0'; |
| 263 | DEBUGP(DMGCP, "Tx MGCP msg to MGCP GW: '%s'\n", strbuf); |
| 264 | |
| 265 | LOGP(DMGCP, LOGL_DEBUG, "Sending msg to MGCP GW size: %u\n", msg->len); |
| 266 | |
| 267 | ret = write(fd->fd, msg->data, msg->len); |
| 268 | if (ret != msg->len) |
| 269 | LOGP(DMGCP, LOGL_ERROR, "Failed to forward message to MGCP" |
| 270 | " GW: %s\n", strerror(errno)); |
| 271 | |
| 272 | return ret; |
| 273 | } |
| 274 | |
| 275 | struct mgcpgw_client *mgcpgw_client_init(void *ctx, |
| 276 | struct mgcpgw_client_conf *conf) |
| 277 | { |
| 278 | struct mgcpgw_client *mgcp; |
| 279 | |
| 280 | mgcp = talloc_zero(ctx, struct mgcpgw_client); |
| 281 | |
| 282 | INIT_LLIST_HEAD(&mgcp->responses_pending); |
| 283 | |
| 284 | mgcp->next_trans_id = 1; |
| 285 | mgcp->next_endpoint = 1; |
| 286 | |
| 287 | mgcp->actual.local_addr = conf->local_addr ? conf->local_addr : |
| 288 | MGCPGW_CLIENT_LOCAL_ADDR_DEFAULT; |
| 289 | mgcp->actual.local_port = conf->local_port >= 0 ? (uint16_t)conf->local_port : |
| 290 | MGCPGW_CLIENT_LOCAL_PORT_DEFAULT; |
| 291 | |
| 292 | mgcp->actual.remote_addr = conf->remote_addr ? conf->remote_addr : |
| 293 | MGCPGW_CLIENT_REMOTE_ADDR_DEFAULT; |
| 294 | mgcp->actual.remote_port = conf->remote_port >= 0 ? (uint16_t)conf->remote_port : |
| 295 | MGCPGW_CLIENT_REMOTE_PORT_DEFAULT; |
| 296 | |
| 297 | return mgcp; |
| 298 | } |
| 299 | |
| 300 | int mgcpgw_client_connect(struct mgcpgw_client *mgcp) |
| 301 | { |
| 302 | int on; |
| 303 | struct sockaddr_in addr; |
| 304 | struct osmo_wqueue *wq; |
| 305 | int rc; |
| 306 | |
| 307 | if (!mgcp) { |
| 308 | LOGP(DMGCP, LOGL_FATAL, "MGCPGW client not initialized properly\n"); |
| 309 | return -EINVAL; |
| 310 | } |
| 311 | |
| 312 | wq = &mgcp->wq; |
| 313 | |
| 314 | wq->bfd.fd = socket(AF_INET, SOCK_DGRAM, 0); |
| 315 | if (wq->bfd.fd < 0) { |
| 316 | LOGP(DMGCP, LOGL_FATAL, "Failed to create UDP socket errno: %d\n", errno); |
| 317 | return -errno; |
| 318 | } |
| 319 | |
| 320 | on = 1; |
| 321 | if (setsockopt(wq->bfd.fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0) { |
| 322 | LOGP(DMGCP, LOGL_FATAL, |
| 323 | "Failed to initialize socket for MGCP GW: %s\n", |
| 324 | strerror(errno)); |
| 325 | rc = -errno; |
| 326 | goto error_close_fd; |
| 327 | } |
| 328 | |
| 329 | /* bind socket */ |
| 330 | memset(&addr, 0, sizeof(addr)); |
| 331 | addr.sin_family = AF_INET; |
| 332 | inet_aton(mgcp->actual.local_addr, &addr.sin_addr); |
| 333 | addr.sin_port = htons(mgcp->actual.local_port); |
| 334 | if (bind(wq->bfd.fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { |
| 335 | LOGP(DMGCP, LOGL_FATAL, |
| 336 | "Failed to bind for MGCP GW to %s %u\n", |
| 337 | mgcp->actual.local_addr, mgcp->actual.local_port); |
| 338 | rc = -errno; |
| 339 | goto error_close_fd; |
| 340 | } |
| 341 | |
| 342 | /* connect to the remote */ |
| 343 | inet_aton(mgcp->actual.remote_addr, &addr.sin_addr); |
| 344 | addr.sin_port = htons(mgcp->actual.remote_port); |
| 345 | if (connect(wq->bfd.fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) { |
| 346 | LOGP(DMGCP, LOGL_FATAL, |
| 347 | "Failed to connect to MGCP GW at %s %u: %s\n", |
| 348 | mgcp->actual.remote_addr, mgcp->actual.remote_port, |
| 349 | strerror(errno)); |
| 350 | rc = -errno; |
| 351 | goto error_close_fd; |
| 352 | } |
| 353 | |
| 354 | mgcp->remote_addr = htonl(addr.sin_addr.s_addr); |
| 355 | |
| 356 | osmo_wqueue_init(wq, 10); |
| 357 | wq->bfd.when = BSC_FD_READ; |
| 358 | wq->bfd.data = mgcp; |
| 359 | wq->read_cb = mgcp_do_read; |
| 360 | wq->write_cb = mgcp_do_write; |
| 361 | |
| 362 | if (osmo_fd_register(&wq->bfd) != 0) { |
| 363 | LOGP(DMGCP, LOGL_FATAL, "Failed to register BFD\n"); |
| 364 | rc = -EIO; |
| 365 | goto error_close_fd; |
| 366 | } |
| 367 | LOGP(DMGCP, LOGL_INFO, "MGCP GW connection: %s:%u -> %s:%u\n", |
| 368 | mgcp->actual.local_addr, mgcp->actual.local_port, |
| 369 | mgcp->actual.remote_addr, mgcp->actual.remote_port); |
| 370 | |
| 371 | return 0; |
| 372 | error_close_fd: |
| 373 | close(wq->bfd.fd); |
| 374 | wq->bfd.fd = -1; |
| 375 | return rc; |
| 376 | } |
| 377 | |
| 378 | const char *mgcpgw_client_remote_addr_str(struct mgcpgw_client *mgcp) |
| 379 | { |
| 380 | return mgcp->actual.remote_addr; |
| 381 | } |
| 382 | |
| 383 | uint16_t mgcpgw_client_remote_port(struct mgcpgw_client *mgcp) |
| 384 | { |
| 385 | return mgcp->actual.remote_port; |
| 386 | } |
| 387 | |
| 388 | /* Return the MGCP GW binary IPv4 address in network byte order. */ |
| 389 | uint32_t mgcpgw_client_remote_addr_n(struct mgcpgw_client *mgcp) |
| 390 | { |
| 391 | return mgcp->remote_addr; |
| 392 | } |
| 393 | |
| 394 | struct mgcp_response_pending * mgcpgw_client_pending_add( |
| 395 | struct mgcpgw_client *mgcp, |
| 396 | mgcp_trans_id_t trans_id, |
| 397 | mgcp_response_cb_t response_cb, |
| 398 | void *priv) |
| 399 | { |
| 400 | struct mgcp_response_pending *pending; |
| 401 | |
| 402 | pending = talloc_zero(mgcp, struct mgcp_response_pending); |
| 403 | pending->trans_id = trans_id; |
| 404 | pending->response_cb = response_cb; |
| 405 | pending->priv = priv; |
| 406 | llist_add_tail(&pending->entry, &mgcp->responses_pending); |
| 407 | |
| 408 | return pending; |
| 409 | } |
| 410 | |
| 411 | /* Send the MGCP message in msg to the MGCP GW and handle a response with |
| 412 | * response_cb. NOTE: the response_cb still needs to call |
| 413 | * mgcp_response_parse_params(response) to get the parsed parameters -- to |
| 414 | * potentially save some CPU cycles, only the head line has been parsed when |
| 415 | * the response_cb is invoked. */ |
| 416 | int mgcpgw_client_tx(struct mgcpgw_client *mgcp, struct msgb *msg, |
| 417 | mgcp_response_cb_t response_cb, void *priv) |
| 418 | { |
| 419 | struct mgcp_response_pending *pending; |
| 420 | mgcp_trans_id_t trans_id; |
| 421 | int rc; |
| 422 | |
| 423 | trans_id = msg->cb[MSGB_CB_MGCP_TRANS_ID]; |
| 424 | if (!trans_id) { |
| 425 | LOGP(DMGCP, LOGL_ERROR, |
| 426 | "Unset transaction id in mgcp send request\n"); |
| 427 | talloc_free(msg); |
| 428 | return -EINVAL; |
| 429 | } |
| 430 | |
| 431 | pending = mgcpgw_client_pending_add(mgcp, trans_id, response_cb, priv); |
| 432 | |
| 433 | if (msgb_l2len(msg) > 4096) { |
| 434 | LOGP(DMGCP, LOGL_ERROR, |
| 435 | "Cannot send, MGCP message too large: %u\n", |
| 436 | msgb_l2len(msg)); |
| 437 | msgb_free(msg); |
| 438 | rc = -EINVAL; |
| 439 | goto mgcp_tx_error; |
| 440 | } |
| 441 | |
| 442 | rc = osmo_wqueue_enqueue(&mgcp->wq, msg); |
| 443 | if (rc) { |
| 444 | LOGP(DMGCP, LOGL_FATAL, "Could not queue message to MGCP GW\n"); |
| 445 | msgb_free(msg); |
| 446 | goto mgcp_tx_error; |
| 447 | } else |
| 448 | LOGP(DMGCP, LOGL_INFO, "Queued %u bytes for MGCP GW\n", |
| 449 | msgb_l2len(msg)); |
| 450 | return 0; |
| 451 | |
| 452 | mgcp_tx_error: |
| 453 | /* Pass NULL to response cb to indicate an error */ |
| 454 | mgcpgw_client_handle_response(mgcp, pending, NULL); |
| 455 | return -1; |
| 456 | } |
| 457 | |
| 458 | static struct msgb *mgcp_msg_from_buf(mgcp_trans_id_t trans_id, |
| 459 | const char *buf, int len) |
| 460 | { |
| 461 | struct msgb *msg; |
| 462 | |
| 463 | if (len > (4096 - 128)) { |
| 464 | LOGP(DMGCP, LOGL_ERROR, "Cannot send to MGCP GW:" |
| 465 | " message too large: %d\n", len); |
| 466 | return NULL; |
| 467 | } |
| 468 | |
| 469 | msg = msgb_alloc_headroom(4096, 128, "MGCP tx"); |
| 470 | OSMO_ASSERT(msg); |
| 471 | |
| 472 | char *dst = (char*)msgb_put(msg, len); |
| 473 | memcpy(dst, buf, len); |
| 474 | msg->l2h = msg->data; |
| 475 | msg->cb[MSGB_CB_MGCP_TRANS_ID] = trans_id; |
| 476 | |
| 477 | return msg; |
| 478 | } |
| 479 | |
| 480 | static struct msgb *mgcp_msg_from_str(mgcp_trans_id_t trans_id, |
| 481 | const char *fmt, ...) |
| 482 | { |
| 483 | static char compose[4096 - 128]; |
| 484 | va_list ap; |
| 485 | int len; |
| 486 | OSMO_ASSERT(fmt); |
| 487 | |
| 488 | va_start(ap, fmt); |
| 489 | len = vsnprintf(compose, sizeof(compose), fmt, ap); |
| 490 | va_end(ap); |
| 491 | if (len >= sizeof(compose)) { |
| 492 | LOGP(DMGCP, LOGL_ERROR, |
| 493 | "Message too large: trans_id=%u len=%d\n", |
| 494 | trans_id, len); |
| 495 | return NULL; |
| 496 | } |
| 497 | if (len < 1) { |
| 498 | LOGP(DMGCP, LOGL_ERROR, |
| 499 | "Failed to compose message: trans_id=%u len=%d\n", |
| 500 | trans_id, len); |
| 501 | return NULL; |
| 502 | } |
| 503 | return mgcp_msg_from_buf(trans_id, compose, len); |
| 504 | } |
| 505 | |
| 506 | static mgcp_trans_id_t mgcpgw_client_next_trans_id(struct mgcpgw_client *mgcp) |
| 507 | { |
| 508 | /* avoid zero trans_id to distinguish from unset trans_id */ |
| 509 | if (!mgcp->next_trans_id) |
| 510 | mgcp->next_trans_id ++; |
| 511 | return mgcp->next_trans_id ++; |
| 512 | } |
| 513 | |
| 514 | struct msgb *mgcp_msg_crcx(struct mgcpgw_client *mgcp, |
| 515 | uint16_t rtp_endpoint, unsigned int call_id, |
| 516 | enum mgcp_connection_mode mode) |
| 517 | { |
| 518 | mgcp_trans_id_t trans_id = mgcpgw_client_next_trans_id(mgcp); |
| 519 | return mgcp_msg_from_str(trans_id, |
| 520 | "CRCX %u %x@mgw MGCP 1.0\r\n" |
| 521 | "C: %x\r\n" |
| 522 | "L: p:20, a:AMR, nt:IN\r\n" |
| 523 | "M: %s\r\n" |
| 524 | , |
| 525 | trans_id, |
| 526 | rtp_endpoint, |
| 527 | call_id, |
| 528 | mgcp_cmode_name(mode)); |
| 529 | } |
| 530 | |
| 531 | struct msgb *mgcp_msg_mdcx(struct mgcpgw_client *mgcp, |
| 532 | uint16_t rtp_endpoint, const char *rtp_conn_addr, |
| 533 | uint16_t rtp_port, enum mgcp_connection_mode mode) |
| 534 | |
| 535 | { |
| 536 | mgcp_trans_id_t trans_id = mgcpgw_client_next_trans_id(mgcp); |
| 537 | return mgcp_msg_from_str(trans_id, |
| 538 | "MDCX %u %x@mgw MGCP 1.0\r\n" |
| 539 | "M: %s\r\n" |
| 540 | "\r\n" |
| 541 | "c=IN IP4 %s\r\n" |
| 542 | "m=audio %u RTP/AVP 255\r\n" |
| 543 | , |
| 544 | trans_id, |
| 545 | rtp_endpoint, |
| 546 | mgcp_cmode_name(mode), |
| 547 | rtp_conn_addr, |
| 548 | rtp_port); |
| 549 | } |