1 /* 2 * rfcomm_pppd.c 3 */ 4 5 /*- 6 * SPDX-License-Identifier: BSD-2-Clause 7 * 8 * Copyright (c) 2001-2008 Maksim Yevmenkin <m_evmenkin@yahoo.com> 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * $Id: rfcomm_pppd.c,v 1.5 2003/09/07 18:32:11 max Exp $ 33 */ 34 #define L2CAP_SOCKET_CHECKED 35 #include <bluetooth.h> 36 #include <ctype.h> 37 #include <err.h> 38 #include <errno.h> 39 #include <fcntl.h> 40 #include <sdp.h> 41 #include <signal.h> 42 #include <stdarg.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <syslog.h> 47 #include <unistd.h> 48 49 #define RFCOMM_PPPD "rfcomm_pppd" 50 51 int rfcomm_channel_lookup (bdaddr_t const *local, 52 bdaddr_t const *remote, 53 int service, int *channel, int *error); 54 55 static void exec_ppp (int s, char *unit, char *label); 56 static void sighandler (int s); 57 static void usage (void); 58 59 static int done; 60 61 /* Main */ 62 int 63 main(int argc, char *argv[]) 64 { 65 struct sockaddr_rfcomm sock_addr; 66 char *label = NULL, *unit = NULL, *ep = NULL; 67 bdaddr_t addr; 68 int s, channel, detach, server, service, 69 regdun, regsp; 70 pid_t pid; 71 72 memcpy(&addr, NG_HCI_BDADDR_ANY, sizeof(addr)); 73 channel = 0; 74 detach = 1; 75 server = 0; 76 service = 0; 77 regdun = 0; 78 regsp = 0; 79 80 /* Parse command line arguments */ 81 while ((s = getopt(argc, argv, "a:cC:dDhl:sSu:")) != -1) { 82 switch (s) { 83 case 'a': /* BDADDR */ 84 if (!bt_aton(optarg, &addr)) { 85 struct hostent *he = NULL; 86 87 if ((he = bt_gethostbyname(optarg)) == NULL) 88 errx(1, "%s: %s", optarg, hstrerror(h_errno)); 89 90 memcpy(&addr, he->h_addr, sizeof(addr)); 91 } 92 break; 93 94 case 'c': /* client */ 95 server = 0; 96 break; 97 98 case 'C': /* RFCOMM channel */ 99 channel = strtoul(optarg, &ep, 10); 100 if (*ep != '\0') { 101 channel = 0; 102 switch (tolower(optarg[0])) { 103 case 'd': /* DialUp Networking */ 104 service = SDP_SERVICE_CLASS_DIALUP_NETWORKING; 105 break; 106 107 case 'l': /* LAN Access Using PPP */ 108 service = SDP_SERVICE_CLASS_LAN_ACCESS_USING_PPP; 109 break; 110 } 111 } 112 break; 113 114 case 'd': /* do not detach */ 115 detach = 0; 116 break; 117 118 case 'D': /* Register DUN service as well as LAN service */ 119 regdun = 1; 120 break; 121 122 case 'l': /* PPP label */ 123 label = optarg; 124 break; 125 126 case 's': /* server */ 127 server = 1; 128 break; 129 130 case 'S': /* Register SP service as well as LAN service */ 131 regsp = 1; 132 break; 133 134 case 'u': /* PPP -unit option */ 135 strtoul(optarg, &ep, 10); 136 if (*ep != '\0') 137 usage(); 138 /* NOT REACHED */ 139 140 unit = optarg; 141 break; 142 143 case 'h': 144 default: 145 usage(); 146 /* NOT REACHED */ 147 } 148 } 149 150 /* Check if we got everything we wanted */ 151 if (label == NULL) 152 errx(1, "Must specify PPP label"); 153 154 if (!server) { 155 if (memcmp(&addr, NG_HCI_BDADDR_ANY, sizeof(addr)) == 0) 156 errx(1, "Must specify server BD_ADDR"); 157 158 /* Check channel, if was not set then obtain it via SDP */ 159 if (channel == 0 && service != 0) 160 if (rfcomm_channel_lookup(NULL, &addr, service, 161 &channel, &s) != 0) 162 errc(1, s, "Could not obtain RFCOMM channel"); 163 } 164 165 if (channel <= 0 || channel > 30) 166 errx(1, "Invalid RFCOMM channel number %d", channel); 167 168 openlog(RFCOMM_PPPD, LOG_PID | LOG_PERROR | LOG_NDELAY, LOG_USER); 169 170 if (detach && daemon(0, 0) < 0) { 171 syslog(LOG_ERR, "Could not daemon(0, 0). %s (%d)", 172 strerror(errno), errno); 173 exit(1); 174 } 175 176 s = socket(PF_BLUETOOTH, SOCK_STREAM, BLUETOOTH_PROTO_RFCOMM); 177 if (s < 0) { 178 syslog(LOG_ERR, "Could not create socket. %s (%d)", 179 strerror(errno), errno); 180 exit(1); 181 } 182 183 if (server) { 184 struct sigaction sa; 185 void *ss = NULL; 186 sdp_lan_profile_t lan; 187 188 /* Install signal handler */ 189 memset(&sa, 0, sizeof(sa)); 190 sa.sa_handler = sighandler; 191 192 if (sigaction(SIGTERM, &sa, NULL) < 0) { 193 syslog(LOG_ERR, "Could not sigaction(SIGTERM). %s (%d)", 194 strerror(errno), errno); 195 exit(1); 196 } 197 198 if (sigaction(SIGHUP, &sa, NULL) < 0) { 199 syslog(LOG_ERR, "Could not sigaction(SIGHUP). %s (%d)", 200 strerror(errno), errno); 201 exit(1); 202 } 203 204 if (sigaction(SIGINT, &sa, NULL) < 0) { 205 syslog(LOG_ERR, "Could not sigaction(SIGINT). %s (%d)", 206 strerror(errno), errno); 207 exit(1); 208 } 209 210 sa.sa_handler = SIG_IGN; 211 sa.sa_flags = SA_NOCLDWAIT; 212 213 if (sigaction(SIGCHLD, &sa, NULL) < 0) { 214 syslog(LOG_ERR, "Could not sigaction(SIGCHLD). %s (%d)", 215 strerror(errno), errno); 216 exit(1); 217 } 218 219 /* bind socket and listen for incoming connections */ 220 sock_addr.rfcomm_len = sizeof(sock_addr); 221 sock_addr.rfcomm_family = AF_BLUETOOTH; 222 memcpy(&sock_addr.rfcomm_bdaddr, &addr, 223 sizeof(sock_addr.rfcomm_bdaddr)); 224 sock_addr.rfcomm_channel = channel; 225 226 if (bind(s, (struct sockaddr *) &sock_addr, 227 sizeof(sock_addr)) < 0) { 228 syslog(LOG_ERR, "Could not bind socket. %s (%d)", 229 strerror(errno), errno); 230 exit(1); 231 } 232 233 if (listen(s, 10) < 0) { 234 syslog(LOG_ERR, "Could not listen on socket. %s (%d)", 235 strerror(errno), errno); 236 exit(1); 237 } 238 239 ss = sdp_open_local(NULL); 240 if (ss == NULL) { 241 syslog(LOG_ERR, "Unable to create local SDP session"); 242 exit(1); 243 } 244 245 if (sdp_error(ss) != 0) { 246 syslog(LOG_ERR, "Unable to open local SDP session. " \ 247 "%s (%d)", strerror(sdp_error(ss)), 248 sdp_error(ss)); 249 exit(1); 250 } 251 252 memset(&lan, 0, sizeof(lan)); 253 lan.server_channel = channel; 254 255 if (sdp_register_service(ss, 256 SDP_SERVICE_CLASS_LAN_ACCESS_USING_PPP, 257 &addr, (void *) &lan, sizeof(lan), NULL) != 0) { 258 syslog(LOG_ERR, "Unable to register LAN service with " \ 259 "local SDP daemon. %s (%d)", 260 strerror(sdp_error(ss)), sdp_error(ss)); 261 exit(1); 262 } 263 264 /* 265 * Register DUN (Dial-Up Networking) service on the same 266 * RFCOMM channel if requested. There is really no good reason 267 * to not to support this. AT-command exchange can be faked 268 * with chat script in ppp.conf 269 */ 270 271 if (regdun) { 272 sdp_dun_profile_t dun; 273 274 memset(&dun, 0, sizeof(dun)); 275 dun.server_channel = channel; 276 277 if (sdp_register_service(ss, 278 SDP_SERVICE_CLASS_DIALUP_NETWORKING, 279 &addr, (void *) &dun, sizeof(dun), 280 NULL) != 0) { 281 syslog(LOG_ERR, "Unable to register DUN " \ 282 "service with local SDP daemon. " \ 283 "%s (%d)", strerror(sdp_error(ss)), 284 sdp_error(ss)); 285 exit(1); 286 } 287 } 288 289 /* 290 * Register SP (Serial Port) service on the same RFCOMM channel 291 * if requested. It appears that some cell phones are using so 292 * called "callback mechanism". In this scenario user is trying 293 * to connect his cell phone to the Internet, and, user's host 294 * computer is acting as the gateway server. It seems that it 295 * is not possible to tell the phone to just connect and start 296 * using the LAN service. Instead the user's host computer must 297 * "jump start" the phone by connecting to the phone's SP 298 * service. What happens next is the phone kills the existing 299 * connection and opens another connection back to the user's 300 * host computer. The phone really wants to use LAN service, 301 * but for whatever reason it looks for SP service on the 302 * user's host computer. This brain damaged behavior was 303 * reported for Nokia 6600 and Sony/Ericsson P900. Both phones 304 * are Symbian-based phones. Perhaps this is a Symbian problem? 305 */ 306 307 if (regsp) { 308 sdp_sp_profile_t sp; 309 310 memset(&sp, 0, sizeof(sp)); 311 sp.server_channel = channel; 312 313 if (sdp_register_service(ss, 314 SDP_SERVICE_CLASS_SERIAL_PORT, 315 &addr, (void *) &sp, sizeof(sp), 316 NULL) != 0) { 317 syslog(LOG_ERR, "Unable to register SP " \ 318 "service with local SDP daemon. " \ 319 "%s (%d)", strerror(sdp_error(ss)), 320 sdp_error(ss)); 321 exit(1); 322 } 323 } 324 325 for (done = 0; !done; ) { 326 socklen_t len = sizeof(sock_addr); 327 int s1 = accept(s, (struct sockaddr *) &sock_addr, &len); 328 329 if (s1 < 0) { 330 syslog(LOG_ERR, "Could not accept connection " \ 331 "on socket. %s (%d)", strerror(errno), 332 errno); 333 exit(1); 334 } 335 336 pid = fork(); 337 if (pid == (pid_t) -1) { 338 syslog(LOG_ERR, "Could not fork(). %s (%d)", 339 strerror(errno), errno); 340 exit(1); 341 } 342 343 if (pid == 0) { 344 sdp_close(ss); 345 close(s); 346 347 /* Reset signal handler */ 348 memset(&sa, 0, sizeof(sa)); 349 sa.sa_handler = SIG_DFL; 350 351 sigaction(SIGTERM, &sa, NULL); 352 sigaction(SIGHUP, &sa, NULL); 353 sigaction(SIGINT, &sa, NULL); 354 sigaction(SIGCHLD, &sa, NULL); 355 356 /* Become daemon */ 357 daemon(0, 0); 358 359 /* 360 * XXX Make sure user does not shoot himself 361 * in the foot. Do not pass unit option to the 362 * PPP when operating in the server mode. 363 */ 364 365 exec_ppp(s1, NULL, label); 366 } else 367 close(s1); 368 } 369 } else { 370 sock_addr.rfcomm_len = sizeof(sock_addr); 371 sock_addr.rfcomm_family = AF_BLUETOOTH; 372 memcpy(&sock_addr.rfcomm_bdaddr, NG_HCI_BDADDR_ANY, 373 sizeof(sock_addr.rfcomm_bdaddr)); 374 sock_addr.rfcomm_channel = 0; 375 376 if (bind(s, (struct sockaddr *) &sock_addr, 377 sizeof(sock_addr)) < 0) { 378 syslog(LOG_ERR, "Could not bind socket. %s (%d)", 379 strerror(errno), errno); 380 exit(1); 381 } 382 383 memcpy(&sock_addr.rfcomm_bdaddr, &addr, 384 sizeof(sock_addr.rfcomm_bdaddr)); 385 sock_addr.rfcomm_channel = channel; 386 387 if (connect(s, (struct sockaddr *) &sock_addr, 388 sizeof(sock_addr)) < 0) { 389 syslog(LOG_ERR, "Could not connect socket. %s (%d)", 390 strerror(errno), errno); 391 exit(1); 392 } 393 394 exec_ppp(s, unit, label); 395 } 396 397 exit(0); 398 } /* main */ 399 400 /* 401 * Redirects stdin/stdout to s, stderr to /dev/null and exec 402 * 'ppp -direct -quiet [-unit N] label'. Never returns. 403 */ 404 405 static void 406 exec_ppp(int s, char *unit, char *label) 407 { 408 char ppp[] = "/usr/sbin/ppp"; 409 char *ppp_args[] = { ppp, "-direct", "-quiet", 410 NULL, NULL, NULL, NULL }; 411 412 close(0); 413 if (dup(s) < 0) { 414 syslog(LOG_ERR, "Could not dup(0). %s (%d)", 415 strerror(errno), errno); 416 exit(1); 417 } 418 419 close(1); 420 if (dup(s) < 0) { 421 syslog(LOG_ERR, "Could not dup(1). %s (%d)", 422 strerror(errno), errno); 423 exit(1); 424 } 425 426 close(2); 427 open("/dev/null", O_RDWR); 428 429 if (unit != NULL) { 430 ppp_args[3] = "-unit"; 431 ppp_args[4] = unit; 432 ppp_args[5] = label; 433 } else 434 ppp_args[3] = label; 435 436 if (execv(ppp, ppp_args) < 0) { 437 syslog(LOG_ERR, "Could not exec(%s -direct -quiet%s%s %s). " \ 438 "%s (%d)", ppp, (unit != NULL)? " -unit " : "", 439 (unit != NULL)? unit : "", label, 440 strerror(errno), errno); 441 exit(1); 442 } 443 } /* run_ppp */ 444 445 /* Signal handler */ 446 static void 447 sighandler(int s) 448 { 449 done = 1; 450 } /* sighandler */ 451 452 /* Display usage and exit */ 453 static void 454 usage(void) 455 { 456 fprintf(stdout, 457 "Usage: %s options\n" \ 458 "Where options are:\n" \ 459 "\t-a address Address to listen on or connect to (required for client)\n" \ 460 "\t-c Act as a clinet (default)\n" \ 461 "\t-C channel RFCOMM channel to listen on or connect to (required)\n" \ 462 "\t-d Run in foreground\n" \ 463 "\t-D Register Dial-Up Networking service (server mode only)\n" \ 464 "\t-l label Use PPP label (required)\n" \ 465 "\t-s Act as a server\n" \ 466 "\t-S Register Serial Port service (server mode only)\n" \ 467 "\t-u N Tell PPP to operate on /dev/tunN (client mode only)\n" \ 468 "\t-h Display this message\n", RFCOMM_PPPD); 469 470 exit(255); 471 } /* usage */ 472 473