Holger Hans Peter Freyther | 9e2c5f5 | 2010-06-15 18:44:42 +0800 | [diff] [blame] | 1 | /* BSC Multiplexer/NAT */ |
| 2 | |
| 3 | /* |
| 4 | * (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org> |
| 5 | * (C) 2010 by on-waves.com |
Holger Hans Peter Freyther | 49d8068 | 2010-01-12 21:34:54 +0100 | [diff] [blame] | 6 | * (C) 2009 by Harald Welte <laforge@gnumonks.org> |
Holger Hans Peter Freyther | 9e2c5f5 | 2010-06-15 18:44:42 +0800 | [diff] [blame] | 7 | * All Rights Reserved |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License as published by |
| 11 | * the Free Software Foundation; either version 2 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | * GNU General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License along |
| 20 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 21 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 22 | * |
| 23 | */ |
| 24 | #include <sys/socket.h> |
| 25 | #include <netinet/in.h> |
| 26 | #include <arpa/inet.h> |
| 27 | |
Holger Hans Peter Freyther | 49d8068 | 2010-01-12 21:34:54 +0100 | [diff] [blame] | 28 | #include <errno.h> |
Holger Hans Peter Freyther | 6ace522 | 2010-01-12 21:15:08 +0100 | [diff] [blame] | 29 | #include <signal.h> |
Holger Hans Peter Freyther | 9e2c5f5 | 2010-06-15 18:44:42 +0800 | [diff] [blame] | 30 | #include <stdio.h> |
| 31 | #include <stdlib.h> |
Holger Hans Peter Freyther | 5aa25ae | 2010-01-12 21:36:08 +0100 | [diff] [blame] | 32 | #include <time.h> |
Holger Hans Peter Freyther | 9e2c5f5 | 2010-06-15 18:44:42 +0800 | [diff] [blame] | 33 | #include <unistd.h> |
| 34 | |
| 35 | #define _GNU_SOURCE |
| 36 | #include <getopt.h> |
| 37 | |
| 38 | #include <openbsc/debug.h> |
Holger Hans Peter Freyther | 6ace522 | 2010-01-12 21:15:08 +0100 | [diff] [blame] | 39 | #include <openbsc/msgb.h> |
| 40 | #include <openbsc/bsc_msc.h> |
| 41 | #include <openbsc/ipaccess.h> |
| 42 | #include <openbsc/abis_nm.h> |
| 43 | #include <openbsc/talloc.h> |
Holger Hans Peter Freyther | 24614ad | 2010-01-13 09:28:12 +0100 | [diff] [blame] | 44 | #include <openbsc/linuxlist.h> |
Holger Hans Peter Freyther | 9e2c5f5 | 2010-06-15 18:44:42 +0800 | [diff] [blame] | 45 | |
| 46 | static const char *config_file = "openbsc.cfg"; |
| 47 | static char *msc_address = "127.0.0.1"; |
| 48 | static struct in_addr local_addr; |
Holger Hans Peter Freyther | 6ace522 | 2010-01-12 21:15:08 +0100 | [diff] [blame] | 49 | static struct bsc_fd msc_connection; |
Holger Hans Peter Freyther | 49d8068 | 2010-01-12 21:34:54 +0100 | [diff] [blame] | 50 | static struct bsc_fd bsc_connection; |
Holger Hans Peter Freyther | 6ace522 | 2010-01-12 21:15:08 +0100 | [diff] [blame] | 51 | |
Holger Hans Peter Freyther | 24614ad | 2010-01-13 09:28:12 +0100 | [diff] [blame] | 52 | |
| 53 | /* |
| 54 | * Per BSC data structure |
| 55 | */ |
| 56 | struct bsc_connection { |
| 57 | struct llist_head list_entry; |
| 58 | |
| 59 | /* do we know anything about this BSC? */ |
| 60 | int authenticated; |
| 61 | |
| 62 | /* the fd we use to communicate */ |
| 63 | struct bsc_fd bsc_fd; |
| 64 | }; |
| 65 | |
| 66 | static LLIST_HEAD(bsc_connections); |
| 67 | |
Holger Hans Peter Freyther | 6ace522 | 2010-01-12 21:15:08 +0100 | [diff] [blame] | 68 | /* |
| 69 | * below are stubs we need to link |
| 70 | */ |
| 71 | int nm_state_event(enum nm_evt evt, u_int8_t obj_class, void *obj, |
| 72 | struct gsm_nm_state *old_state, struct gsm_nm_state *new_state) |
| 73 | { |
| 74 | return -1; |
| 75 | } |
| 76 | |
| 77 | void input_event(int event, enum e1inp_sign_type type, struct gsm_bts_trx *trx) |
| 78 | {} |
| 79 | |
| 80 | int gsm0408_rcvmsg(struct msgb *msg, u_int8_t link_id) |
| 81 | { |
| 82 | return -1; |
| 83 | } |
| 84 | |
| 85 | /* |
| 86 | * Below is the handling of messages coming |
| 87 | * from the MSC and need to be forwarded to |
| 88 | * a real BSC. |
| 89 | */ |
| 90 | static void initialize_msc_if_needed() |
| 91 | { |
| 92 | static int init = 0; |
| 93 | init = 1; |
| 94 | |
| 95 | /* do we need to send a GSM 08.08 message here? */ |
| 96 | } |
| 97 | |
| 98 | static void forward_sccp_to_bts(struct msgb *msg) |
| 99 | { |
Holger Hans Peter Freyther | 24614ad | 2010-01-13 09:28:12 +0100 | [diff] [blame] | 100 | struct bsc_connection *bsc; |
| 101 | |
Holger Hans Peter Freyther | 6ace522 | 2010-01-12 21:15:08 +0100 | [diff] [blame] | 102 | /* filter, drop, patch the message? */ |
Holger Hans Peter Freyther | 24614ad | 2010-01-13 09:28:12 +0100 | [diff] [blame] | 103 | |
| 104 | /* currently send this to every BSC connected */ |
| 105 | llist_for_each_entry(bsc, &bsc_connections, list_entry) { |
Holger Hans Peter Freyther | d7fb954 | 2010-01-13 15:22:20 +0100 | [diff] [blame^] | 106 | write(bsc->bsc_fd.fd, msg->data, msg->len); |
Holger Hans Peter Freyther | 24614ad | 2010-01-13 09:28:12 +0100 | [diff] [blame] | 107 | } |
Holger Hans Peter Freyther | 6ace522 | 2010-01-12 21:15:08 +0100 | [diff] [blame] | 108 | } |
| 109 | |
| 110 | static int ipaccess_msc_cb(struct bsc_fd *bfd, unsigned int what) |
| 111 | { |
| 112 | int error; |
| 113 | struct msgb *msg = ipaccess_read_msg(bfd, &error); |
| 114 | struct ipaccess_head *hh; |
| 115 | |
| 116 | if (!msg) { |
| 117 | if (error == 0) { |
| 118 | fprintf(stderr, "The connection to the MSC was lost, exiting\n"); |
| 119 | exit(-2); |
| 120 | } |
| 121 | |
| 122 | fprintf(stderr, "Failed to parse ip access message: %d\n", error); |
| 123 | return -1; |
| 124 | } |
| 125 | |
| 126 | DEBUGP(DMSC, "MSG from MSC: %s proto: %d\n", hexdump(msg->data, msg->len), msg->l2h[0]); |
| 127 | |
| 128 | /* handle base message handling */ |
| 129 | hh = (struct ipaccess_head *) msg->data; |
| 130 | ipaccess_rcvmsg_base(msg, bfd); |
| 131 | |
| 132 | /* initialize the networking. This includes sending a GSM08.08 message */ |
| 133 | if (hh->proto == IPAC_PROTO_IPACCESS && msg->l2h[0] == IPAC_MSGT_ID_ACK) |
| 134 | initialize_msc_if_needed(); |
| 135 | else if (hh->proto == IPAC_PROTO_SCCP) |
| 136 | forward_sccp_to_bts(msg); |
| 137 | |
| 138 | return 0; |
| 139 | } |
Holger Hans Peter Freyther | 9e2c5f5 | 2010-06-15 18:44:42 +0800 | [diff] [blame] | 140 | |
Holger Hans Peter Freyther | 49d8068 | 2010-01-12 21:34:54 +0100 | [diff] [blame] | 141 | /* |
| 142 | * Below is the handling of messages coming |
| 143 | * from the BSC and need to be forwarded to |
| 144 | * a real BSC. |
| 145 | */ |
Holger Hans Peter Freyther | 24614ad | 2010-01-13 09:28:12 +0100 | [diff] [blame] | 146 | |
| 147 | /* |
| 148 | * Remove the connection from the connections list, |
| 149 | * remove it from the patching of SCCP header lists |
| 150 | * as well. Maybe in the future even close connection.. |
| 151 | */ |
| 152 | static void remove_bsc_connection(struct bsc_connection *connection) |
| 153 | { |
Holger Hans Peter Freyther | 7625506 | 2010-01-13 09:51:23 +0100 | [diff] [blame] | 154 | bsc_unregister_fd(&connection->bsc_fd); |
Holger Hans Peter Freyther | 24614ad | 2010-01-13 09:28:12 +0100 | [diff] [blame] | 155 | llist_del(&connection->list_entry); |
| 156 | talloc_free(connection); |
| 157 | } |
| 158 | |
| 159 | static int forward_sccp_to_msc(struct msgb *msg) |
| 160 | { |
| 161 | /* FIXME: We need to filter out certain messages */ |
| 162 | |
| 163 | /* send the non-filtered but maybe modified msg */ |
Holger Hans Peter Freyther | d7fb954 | 2010-01-13 15:22:20 +0100 | [diff] [blame^] | 164 | return write(msc_connection.fd, msg->data, msg->len); |
Holger Hans Peter Freyther | 24614ad | 2010-01-13 09:28:12 +0100 | [diff] [blame] | 165 | } |
| 166 | |
| 167 | static int ipaccess_bsc_cb(struct bsc_fd *bfd, unsigned int what) |
| 168 | { |
| 169 | int error; |
| 170 | struct msgb *msg = ipaccess_read_msg(bfd, &error); |
| 171 | struct ipaccess_head *hh; |
| 172 | |
| 173 | if (!msg) { |
| 174 | if (error == 0) { |
| 175 | fprintf(stderr, "The connection to the BSC was lost. Cleaning it\n"); |
| 176 | remove_bsc_connection((struct bsc_connection *) bfd->data); |
| 177 | } |
| 178 | |
| 179 | fprintf(stderr, "Failed to parse ip access message: %d\n", error); |
| 180 | return -1; |
| 181 | } |
| 182 | |
| 183 | DEBUGP(DMSC, "MSG from BSC: %s proto: %d\n", hexdump(msg->data, msg->len), msg->l2h[0]); |
| 184 | |
| 185 | /* handle base message handling */ |
| 186 | hh = (struct ipaccess_head *) msg->data; |
| 187 | |
| 188 | /* Handle messages from the BSC */ |
| 189 | /* FIXME: Currently no PONG is sent to the BSC */ |
| 190 | /* FIXME: Currently no ID ACK is sent to the BSC */ |
| 191 | if (hh->proto == IPAC_PROTO_SCCP) |
| 192 | forward_sccp_to_msc(msg); |
| 193 | |
| 194 | return 0; |
| 195 | } |
| 196 | |
Holger Hans Peter Freyther | 49d8068 | 2010-01-12 21:34:54 +0100 | [diff] [blame] | 197 | static int ipaccess_listen_bsc_cb(struct bsc_fd *bfd, unsigned int what) |
| 198 | { |
Holger Hans Peter Freyther | 24614ad | 2010-01-13 09:28:12 +0100 | [diff] [blame] | 199 | struct bsc_connection *bsc; |
Holger Hans Peter Freyther | 49d8068 | 2010-01-12 21:34:54 +0100 | [diff] [blame] | 200 | int ret; |
| 201 | struct sockaddr_in sa; |
| 202 | socklen_t sa_len = sizeof(sa); |
| 203 | |
| 204 | if (!(what & BSC_FD_READ)) |
| 205 | return 0; |
| 206 | |
| 207 | ret = accept(bfd->fd, (struct sockaddr *) &sa, &sa_len); |
| 208 | if (ret < 0) { |
| 209 | perror("accept"); |
| 210 | return ret; |
| 211 | } |
| 212 | |
| 213 | /* todo... do something with the connection */ |
Holger Hans Peter Freyther | da86c0a | 2010-01-12 21:35:32 +0100 | [diff] [blame] | 214 | /* todo... use GNUtls to see if we want to trust this as a BTS */ |
Holger Hans Peter Freyther | 49d8068 | 2010-01-12 21:34:54 +0100 | [diff] [blame] | 215 | |
Holger Hans Peter Freyther | 24614ad | 2010-01-13 09:28:12 +0100 | [diff] [blame] | 216 | /* |
| 217 | * |
| 218 | */ |
| 219 | bsc = talloc_zero(tall_bsc_ctx, struct bsc_connection); |
| 220 | if (!bsc) { |
| 221 | DEBUGP(DMSC, "Failed to allocate BSC struct.\n"); |
| 222 | close(ret); |
| 223 | return -1; |
| 224 | } |
| 225 | |
| 226 | bsc->bsc_fd.data = bsc; |
| 227 | bsc->bsc_fd.fd = ret; |
| 228 | bsc->bsc_fd.cb = ipaccess_bsc_cb; |
Holger Hans Peter Freyther | c7641c9 | 2010-01-13 09:52:29 +0100 | [diff] [blame] | 229 | bsc->bsc_fd.when = BSC_FD_READ; |
Holger Hans Peter Freyther | 24614ad | 2010-01-13 09:28:12 +0100 | [diff] [blame] | 230 | if (bsc_register_fd(&bsc->bsc_fd) < 0) { |
| 231 | DEBUGP(DMSC, "Failed to register BSC fd.\n"); |
| 232 | close(ret); |
| 233 | talloc_free(bsc); |
| 234 | return -2; |
| 235 | } |
| 236 | |
| 237 | DEBUGP(DMSC, "Registered new BSC\n"); |
| 238 | llist_add(&bsc->list_entry, &bsc_connections); |
| 239 | ipaccess_send_id_ack(ret); |
Holger Hans Peter Freyther | 49d8068 | 2010-01-12 21:34:54 +0100 | [diff] [blame] | 240 | return 0; |
| 241 | } |
| 242 | |
| 243 | static int listen_for_bsc(struct bsc_fd *bfd, struct in_addr *in_addr, int port) |
| 244 | { |
| 245 | struct sockaddr_in addr; |
| 246 | int ret, on = 1; |
| 247 | |
| 248 | bfd->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); |
| 249 | bfd->cb = ipaccess_listen_bsc_cb; |
| 250 | bfd->when = BSC_FD_READ; |
| 251 | |
| 252 | memset(&addr, 0, sizeof(addr)); |
| 253 | addr.sin_family = AF_INET; |
| 254 | addr.sin_port = htons(port); |
| 255 | addr.sin_addr.s_addr = in_addr->s_addr; |
| 256 | |
| 257 | setsockopt(bfd->fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); |
| 258 | |
| 259 | ret = bind(bfd->fd, (struct sockaddr *) &addr, sizeof(addr)); |
| 260 | if (ret < 0) { |
| 261 | fprintf(stderr, "Could not bind the BSC socket %s\n", |
| 262 | strerror(errno)); |
| 263 | return -EIO; |
| 264 | } |
| 265 | |
| 266 | ret = listen(bfd->fd, 1); |
| 267 | if (ret < 0) { |
| 268 | perror("listen"); |
| 269 | return ret; |
| 270 | } |
| 271 | |
| 272 | ret = bsc_register_fd(bfd); |
| 273 | if (ret < 0) { |
| 274 | perror("register_listen_fd"); |
| 275 | return ret; |
| 276 | } |
| 277 | return 0; |
| 278 | } |
| 279 | |
Holger Hans Peter Freyther | 9e2c5f5 | 2010-06-15 18:44:42 +0800 | [diff] [blame] | 280 | static void print_usage() |
| 281 | { |
| 282 | printf("Usage: bsc_nat\n"); |
| 283 | } |
| 284 | |
| 285 | static void print_help() |
| 286 | { |
| 287 | printf(" Some useful help...\n"); |
| 288 | printf(" -h --help this text\n"); |
| 289 | printf(" -d option --debug=DRLL:DCC:DMM:DRR:DRSL:DNM enable debugging\n"); |
| 290 | printf(" -s --disable-color\n"); |
| 291 | printf(" -c --config-file filename The config file to use.\n"); |
| 292 | printf(" -m --msc=IP. The address of the MSC.\n"); |
Holger Hans Peter Freyther | 49d8068 | 2010-01-12 21:34:54 +0100 | [diff] [blame] | 293 | printf(" -l --local=IP. The local address of this BSC.\n"); |
Holger Hans Peter Freyther | 9e2c5f5 | 2010-06-15 18:44:42 +0800 | [diff] [blame] | 294 | } |
| 295 | |
| 296 | static void handle_options(int argc, char** argv) |
| 297 | { |
| 298 | while (1) { |
| 299 | int option_index = 0, c; |
| 300 | static struct option long_options[] = { |
| 301 | {"help", 0, 0, 'h'}, |
| 302 | {"debug", 1, 0, 'd'}, |
| 303 | {"config-file", 1, 0, 'c'}, |
| 304 | {"disable-color", 0, 0, 's'}, |
| 305 | {"timestamp", 0, 0, 'T'}, |
| 306 | {"msc", 1, 0, 'm'}, |
| 307 | {"local", 1, 0, 'l'}, |
| 308 | {0, 0, 0, 0} |
| 309 | }; |
| 310 | |
| 311 | c = getopt_long(argc, argv, "hd:sTPc:m:l:", |
| 312 | long_options, &option_index); |
| 313 | if (c == -1) |
| 314 | break; |
| 315 | |
| 316 | switch (c) { |
| 317 | case 'h': |
| 318 | print_usage(); |
| 319 | print_help(); |
| 320 | exit(0); |
| 321 | case 's': |
| 322 | debug_use_color(0); |
| 323 | break; |
| 324 | case 'd': |
| 325 | debug_parse_category_mask(optarg); |
| 326 | break; |
| 327 | case 'c': |
| 328 | config_file = strdup(optarg); |
| 329 | break; |
| 330 | case 'T': |
| 331 | debug_timestamp(1); |
| 332 | break; |
| 333 | case 'm': |
| 334 | msc_address = strdup(optarg); |
| 335 | break; |
| 336 | case 'l': |
| 337 | inet_aton(optarg, &local_addr); |
| 338 | break; |
| 339 | default: |
| 340 | /* ignore */ |
| 341 | break; |
| 342 | } |
| 343 | } |
| 344 | } |
| 345 | |
Holger Hans Peter Freyther | 6ace522 | 2010-01-12 21:15:08 +0100 | [diff] [blame] | 346 | static void signal_handler(int signal) |
| 347 | { |
| 348 | fprintf(stdout, "signal %u received\n", signal); |
| 349 | |
| 350 | switch (signal) { |
| 351 | case SIGABRT: |
| 352 | /* in case of abort, we want to obtain a talloc report |
| 353 | * and then return to the caller, who will abort the process */ |
| 354 | case SIGUSR1: |
| 355 | talloc_report_full(tall_bsc_ctx, stderr); |
| 356 | break; |
| 357 | default: |
| 358 | break; |
| 359 | } |
| 360 | } |
| 361 | |
Holger Hans Peter Freyther | 9e2c5f5 | 2010-06-15 18:44:42 +0800 | [diff] [blame] | 362 | int main(int argc, char** argv) |
| 363 | { |
Holger Hans Peter Freyther | 6ace522 | 2010-01-12 21:15:08 +0100 | [diff] [blame] | 364 | int rc; |
| 365 | |
Holger Hans Peter Freyther | 9e2c5f5 | 2010-06-15 18:44:42 +0800 | [diff] [blame] | 366 | /* parse options */ |
Holger Hans Peter Freyther | 49d8068 | 2010-01-12 21:34:54 +0100 | [diff] [blame] | 367 | local_addr.s_addr = INADDR_ANY; |
Holger Hans Peter Freyther | 9e2c5f5 | 2010-06-15 18:44:42 +0800 | [diff] [blame] | 368 | handle_options(argc, argv); |
| 369 | |
| 370 | /* seed the PRNG */ |
| 371 | srand(time(NULL)); |
| 372 | |
Holger Hans Peter Freyther | 49d8068 | 2010-01-12 21:34:54 +0100 | [diff] [blame] | 373 | /* connect to the MSC */ |
Holger Hans Peter Freyther | 6ace522 | 2010-01-12 21:15:08 +0100 | [diff] [blame] | 374 | msc_connection.cb = ipaccess_msc_cb; |
| 375 | rc = connect_to_msc(&msc_connection, msc_address, 5000); |
| 376 | if (rc < 0) { |
| 377 | fprintf(stderr, "Opening the MSC connection failed.\n"); |
| 378 | exit(1); |
| 379 | } |
| 380 | |
Holger Hans Peter Freyther | 49d8068 | 2010-01-12 21:34:54 +0100 | [diff] [blame] | 381 | /* wait for the BSC */ |
| 382 | if (listen_for_bsc(&bsc_connection, &local_addr, 5000) < 0) { |
| 383 | fprintf(stderr, "Failed to listen for BSC.\n"); |
| 384 | exit(1); |
| 385 | } |
| 386 | |
Holger Hans Peter Freyther | 6ace522 | 2010-01-12 21:15:08 +0100 | [diff] [blame] | 387 | signal(SIGINT, &signal_handler); |
| 388 | signal(SIGABRT, &signal_handler); |
| 389 | signal(SIGUSR1, &signal_handler); |
| 390 | signal(SIGPIPE, SIG_IGN); |
| 391 | |
| 392 | while (1) { |
| 393 | bsc_select_main(0); |
| 394 | } |
| 395 | |
Holger Hans Peter Freyther | 9e2c5f5 | 2010-06-15 18:44:42 +0800 | [diff] [blame] | 396 | return 0; |
| 397 | } |