1 /* 2 * Copyright (c) 1988 Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Rick Adams. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#) Copyright (c) 1988 Regents of the University of California. All rights reserved. 37 * @(#)slattach.c 4.6 (Berkeley) 6/1/90 38 * $FreeBSD: src/sbin/slattach/slattach.c,v 1.36 1999/08/28 00:14:25 peter Exp $ 39 * $DragonFly: src/sbin/slattach/slattach.c,v 1.6 2005/02/02 07:59:48 cpressey Exp $ 40 */ 41 42 #include <sys/types.h> 43 #include <sys/ioctl.h> 44 #include <sys/socket.h> 45 46 #include <err.h> 47 #include <fcntl.h> 48 #include <libutil.h> 49 #include <paths.h> 50 #include <signal.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <syslog.h> 55 #include <termios.h> 56 #include <unistd.h> 57 58 #include <net/if.h> 59 #include <net/slip.h> 60 61 #define DEFAULT_BAUD 9600 62 63 static void sighup_handler(int); /* SIGHUP handler */ 64 static void sigint_handler(int); /* SIGINT handler */ 65 static void sigterm_handler(int); /* SIGTERM handler */ 66 static void sigurg_handler(int); /* SIGURG handler */ 67 static void exit_handler(int); /* run exit_cmd iff specified upon exit. */ 68 static void setup_line(int); /* configure terminal settings */ 69 static void slip_discipline(void); /* switch to slip line discipline */ 70 static void configure_network(void); /* configure slip interface */ 71 static void acquire_line(void); /* get tty device as controlling terminal */ 72 static void usage(void); 73 74 int fd = -1; 75 char *dev = NULL; /* path name of the tty (e.g. /dev/tty01) */ 76 char *dvname; /* basename of dev */ 77 int locked = 0; /* uucp lock active */ 78 int flow_control = 0; /* non-zero to enable hardware flow control. */ 79 int modem_control = HUPCL; /* !CLOCAL+HUPCL iff we watch carrier. */ 80 int comstate; /* TIOCMGET current state of serial driver */ 81 int redial_on_startup = 0; /* iff non-zero execute redial_cmd on startup */ 82 speed_t speed = DEFAULT_BAUD; /* baud rate of tty */ 83 int slflags = 0; /* compression flags */ 84 int unit = -1; /* slip device unit number */ 85 int foreground = 0; /* act as demon if zero, else don't fork. */ 86 int keepal = 0; /* keepalive timeout */ 87 int outfill = 0; /* outfill timeout */ 88 int sl_unit = -1; /* unit number */ 89 int uucp_lock = 0; /* do uucp locking */ 90 int exiting = 0; /* already running exit_handler */ 91 92 struct termios tty; /* tty configuration/state */ 93 94 char tty_path[32]; /* path name of the tty (e.g. /dev/tty01) */ 95 char pidfilename[40]; /* e.g. /var/run/slattach.tty01.pid */ 96 char *redial_cmd = 0; /* command to exec upon shutdown. */ 97 char *config_cmd = 0; /* command to exec if slip unit changes. */ 98 char *exit_cmd = 0; /* command to exec before exiting. */ 99 100 static void 101 usage(void) 102 { 103 fprintf(stderr, "%s\n%s\n", 104 "usage: slattach [-acfhlnz] [-e command] [-r command] [-s speed] [-u command]", 105 " [-L] [-K timeout] [-O timeout] [-S unit] device"); 106 /* do not exit here */ 107 } 108 109 int 110 main(int argc, char **argv) 111 { 112 int option; 113 114 while ((option = getopt(argc, argv, "ace:fhlnr:s:u:zLK:O:S:")) != -1) { 115 switch (option) { 116 case 'a': 117 slflags |= IFF_LINK2; 118 slflags &= ~IFF_LINK0; 119 break; 120 case 'c': 121 slflags |= IFF_LINK0; 122 slflags &= ~IFF_LINK2; 123 break; 124 case 'e': 125 exit_cmd = (char*) strdup (optarg); 126 break; 127 case 'f': 128 foreground = 1; 129 break; 130 case 'h': 131 flow_control |= CRTSCTS; 132 break; 133 case 'l': 134 modem_control = CLOCAL; /* clear HUPCL too */ 135 break; 136 case 'n': 137 slflags |= IFF_LINK1; 138 break; 139 case 'r': 140 redial_cmd = (char*) strdup (optarg); 141 break; 142 case 's': 143 speed = atoi(optarg); 144 break; 145 case 'u': 146 config_cmd = (char*) strdup (optarg); 147 break; 148 case 'z': 149 redial_on_startup = 1; 150 break; 151 case 'L': 152 uucp_lock = 1; 153 break; 154 case 'K': 155 keepal = atoi(optarg); 156 break; 157 case 'O': 158 outfill = atoi(optarg); 159 break; 160 case 'S': 161 sl_unit = atoi(optarg); 162 break; 163 case '?': 164 default: 165 usage(); 166 exit_handler(1); 167 } 168 } 169 170 if (optind == argc - 1) 171 dev = argv[optind]; 172 173 if (optind < (argc - 1)) 174 warnx("too many args, first='%s'", argv[optind]); 175 if (optind > (argc - 1)) 176 warnx("not enough args"); 177 if (dev == NULL) { 178 usage(); 179 exit_handler(2); 180 } 181 if (strncmp(_PATH_DEV, dev, sizeof(_PATH_DEV) - 1)) { 182 strcpy(tty_path, _PATH_DEV); 183 strcat(tty_path, "/"); 184 strncat(tty_path, dev, 10); 185 dev = tty_path; 186 } 187 dvname = strrchr(dev, '/'); /* always succeeds */ 188 dvname++; /* trailing tty pathname component */ 189 snprintf(pidfilename, sizeof(pidfilename), 190 "%sslattach.%s.pid", _PATH_VARRUN, dvname); 191 printf("%s\n",pidfilename); 192 193 if (!foreground) 194 daemon(0,0); /* fork, setsid, chdir /, and close std*. */ 195 /* daemon() closed stderr, so log errors from here on. */ 196 openlog("slattach",LOG_CONS|LOG_PID,LOG_DAEMON); 197 198 acquire_line(); /* get tty device as controlling terminal */ 199 setup_line(0); /* configure for slip line discipline */ 200 slip_discipline(); /* switch to slip line discipline */ 201 202 /* upon INT log a timestamp and exit. */ 203 if (signal(SIGINT,sigint_handler) == SIG_ERR) 204 syslog(LOG_NOTICE,"cannot install SIGINT handler: %m"); 205 /* upon TERM log a timestamp and exit. */ 206 if (signal(SIGTERM,sigterm_handler) == SIG_ERR) 207 syslog(LOG_NOTICE,"cannot install SIGTERM handler: %m"); 208 /* upon HUP redial and reconnect. */ 209 if (signal(SIGHUP,sighup_handler) == SIG_ERR) 210 syslog(LOG_NOTICE,"cannot install SIGHUP handler: %m"); 211 212 if (redial_on_startup) 213 sighup_handler(0); 214 else if (!(modem_control & CLOCAL)) { 215 if (ioctl(fd, TIOCMGET, &comstate) < 0) 216 syslog(LOG_NOTICE,"cannot get carrier state: %m"); 217 if (!(comstate & TIOCM_CD)) { /* check for carrier */ 218 /* force a redial if no carrier */ 219 kill (getpid(), SIGHUP); 220 } else 221 configure_network(); 222 } else 223 configure_network(); /* configure the network if needed. */ 224 225 for (;;) { 226 sigset_t mask; 227 sigemptyset(&mask); 228 sigsuspend(&mask); 229 } 230 } 231 232 /* Close all FDs, fork, reopen tty port as 0-2, and make it the 233 controlling terminal for our process group. */ 234 static void 235 acquire_line(void) 236 { 237 int ttydisc = TTYDISC; 238 int oflags; 239 FILE *pid_file; 240 241 /* reset to tty discipline */ 242 if (fd >= 0 && ioctl(fd, TIOCSETD, &ttydisc) < 0) { 243 syslog(LOG_ERR, "ioctl(TIOCSETD): %m"); 244 exit_handler(1); 245 } 246 247 close(STDIN_FILENO); /* close FDs before forking. */ 248 close(STDOUT_FILENO); 249 close(STDERR_FILENO); 250 if (fd > 2) 251 close(fd); 252 253 signal(SIGHUP, SIG_IGN); /* ignore HUP signal when parent dies. */ 254 if (daemon(0,0)) { /* fork, setsid, chdir /, and close std*. */ 255 syslog(LOG_ERR, "daemon(0,0): %m"); 256 exit_handler(1); 257 } 258 259 while (getppid () != 1) 260 sleep (1); /* Wait for parent to die. */ 261 262 /* create PID file */ 263 if((pid_file = fopen(pidfilename, "w"))) { 264 fprintf(pid_file, "%ld\n", (long)getpid()); 265 fclose(pid_file); 266 } 267 268 if (signal(SIGHUP,sighup_handler) == SIG_ERR) /* Re-enable HUP signal */ 269 syslog(LOG_NOTICE,"cannot install SIGHUP handler: %m"); 270 271 if (uucp_lock) { 272 /* unlock not needed here, always re-lock with new pid */ 273 int res; 274 if ((res = uu_lock(dvname)) != UU_LOCK_OK) { 275 if (res != UU_LOCK_INUSE) 276 syslog(LOG_ERR, "uu_lock: %s", uu_lockerr(res)); 277 syslog(LOG_ERR, "can't lock %s", dev); 278 exit_handler(1); 279 } 280 locked = 1; 281 } 282 283 if ((fd = open(dev, O_RDWR | O_NONBLOCK, 0)) < 0) { 284 syslog(LOG_ERR, "open(%s) %m", dev); 285 exit_handler(1); 286 } 287 /* Turn off O_NONBLOCK for dumb redialers, if any. */ 288 if ((oflags = fcntl(fd, F_GETFL)) == -1) { 289 syslog(LOG_ERR, "fcntl(F_GETFL) failed: %m"); 290 exit_handler(1); 291 } 292 if (fcntl(fd, F_SETFL, oflags & ~O_NONBLOCK) == -1) { 293 syslog(LOG_ERR, "fcntl(F_SETFL) failed: %m"); 294 exit_handler(1); 295 } 296 dup2(fd, STDIN_FILENO); 297 dup2(fd, STDOUT_FILENO); 298 dup2(fd, STDERR_FILENO); 299 if (fd > 2) 300 close (fd); 301 fd = STDIN_FILENO; 302 303 /* acquire the serial line as a controlling terminal. */ 304 if (ioctl(fd, TIOCSCTTY, 0) < 0) { 305 syslog(LOG_ERR,"ioctl(TIOCSCTTY): %m"); 306 exit_handler(1); 307 } 308 /* Make us the foreground process group associated with the 309 slip line which is our controlling terminal. */ 310 if (tcsetpgrp(fd, getpid()) < 0) 311 syslog(LOG_NOTICE,"tcsetpgrp failed: %m"); 312 } 313 314 /* Set the tty flags and set DTR. */ 315 /* Call as setup_line(CLOCAL) to force clocal assertion. */ 316 static void 317 setup_line(int cflag) 318 { 319 tty.c_lflag = tty.c_iflag = tty.c_oflag = 0; 320 tty.c_cflag = CREAD | CS8 | flow_control | modem_control | cflag; 321 cfsetispeed(&tty, speed); 322 cfsetospeed(&tty, speed); 323 /* set the line speed and flow control */ 324 if (tcsetattr(fd, TCSAFLUSH, &tty) < 0) { 325 syslog(LOG_ERR, "tcsetattr(TCSAFLUSH): %m"); 326 exit_handler(1); 327 } 328 /* set data terminal ready */ 329 if (ioctl(fd, TIOCSDTR) < 0) { 330 syslog(LOG_ERR, "ioctl(TIOCSDTR): %m"); 331 exit_handler(1); 332 } 333 } 334 335 /* Put the line in slip discipline. */ 336 static void 337 slip_discipline(void) 338 { 339 struct ifreq ifr; 340 int slipdisc = SLIPDISC; 341 int s, tmp_unit = -1; 342 343 /* Switch to slip line discipline. */ 344 if (ioctl(fd, TIOCSETD, &slipdisc) < 0) { 345 syslog(LOG_ERR, "ioctl(TIOCSETD): %m"); 346 exit_handler(1); 347 } 348 349 if (sl_unit >= 0 && ioctl(fd, SLIOCSUNIT, &sl_unit) < 0) { 350 syslog(LOG_ERR, "ioctl(SLIOCSUNIT): %m"); 351 exit_handler(1); 352 } 353 354 /* find out what unit number we were assigned */ 355 if (ioctl(fd, SLIOCGUNIT, (caddr_t)&tmp_unit) < 0) { 356 syslog(LOG_ERR, "ioctl(SLIOCGUNIT): %m"); 357 exit_handler(1); 358 } 359 360 if (tmp_unit < 0) { 361 syslog(LOG_ERR, "bad unit (%d) from ioctl(SLIOCGUNIT)",tmp_unit); 362 exit_handler(1); 363 } 364 365 if (keepal > 0) { 366 signal(SIGURG, sigurg_handler); 367 if (ioctl(fd, SLIOCSKEEPAL, &keepal) < 0) { 368 syslog(LOG_ERR, "ioctl(SLIOCSKEEPAL): %m"); 369 exit_handler(1); 370 } 371 } 372 if (outfill > 0 && ioctl(fd, SLIOCSOUTFILL, &outfill) < 0) { 373 syslog(LOG_ERR, "ioctl(SLIOCSOUTFILL): %m"); 374 exit_handler(1); 375 } 376 377 /* open a socket as the handle to the interface */ 378 s = socket(AF_INET, SOCK_DGRAM, 0); 379 if (s < 0) { 380 syslog(LOG_ERR, "socket: %m"); 381 exit_handler(1); 382 } 383 sprintf(ifr.ifr_name, "sl%d", tmp_unit); 384 385 /* get the flags for the interface */ 386 if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) { 387 syslog(LOG_ERR, "ioctl (SIOCGIFFLAGS): %m"); 388 exit_handler(1); 389 } 390 391 /* Assert any compression or no-icmp flags. */ 392 #define SLMASK (~(IFF_LINK0 | IFF_LINK1 | IFF_LINK2)) 393 ifr.ifr_flags &= SLMASK; 394 ifr.ifr_flags |= slflags; 395 if (ioctl(s, SIOCSIFFLAGS, (caddr_t)&ifr) < 0) { 396 syslog(LOG_ERR, "ioctl (SIOCSIFFLAGS): %m"); 397 exit_handler(1); 398 } 399 close(s); 400 } 401 402 /* configure the interface, e.g. by passing the unit number to a script. */ 403 static void 404 configure_network(void) 405 { 406 int new_unit; 407 408 /* find out what unit number we were assigned */ 409 if (ioctl(fd, SLIOCGUNIT, (caddr_t)&new_unit) < 0) { 410 syslog(LOG_ERR, "ioctl(SLIOCGUNIT): %m"); 411 exit_handler(1); 412 } 413 /* iff the unit number changes either invoke config_cmd or punt. */ 414 if (config_cmd) { 415 char *s; 416 s = (char*) malloc(strlen(config_cmd) + 32); 417 if (s == NULL) { 418 syslog(LOG_ERR, "malloc failed"); 419 exit(1); 420 } 421 sprintf (s, "%s %d %d", config_cmd, unit, new_unit); 422 syslog(LOG_NOTICE, "configuring %s (sl%d):", dev, unit); 423 syslog(LOG_NOTICE, " '%s'", s); 424 system(s); 425 free (s); 426 unit = new_unit; 427 } else { 428 /* don't compare unit numbers if this is the first time to attach. */ 429 if (unit < 0) 430 unit = new_unit; 431 if (new_unit != unit) { 432 syslog(LOG_ERR, 433 "slip unit changed from sl%d to sl%d, but no -u CMD was specified!", 434 unit, new_unit); 435 exit_handler(1); 436 } 437 syslog(LOG_NOTICE,"sl%d connected to %s at %d baud",unit,dev,speed); 438 } 439 } 440 441 /* sighup_handler() is invoked when carrier drops, eg. before redial. */ 442 static void 443 sighup_handler(int signo __unused) 444 { 445 if(exiting) return; 446 447 if (redial_cmd == NULL) { 448 syslog(LOG_NOTICE,"SIGHUP on %s (sl%d); exiting", dev, unit); 449 exit_handler(1); 450 } 451 again: 452 /* invoke a shell for redial_cmd or punt. */ 453 if (*redial_cmd) { /* Non-empty redial command */ 454 syslog(LOG_NOTICE,"SIGHUP on %s (sl%d); running '%s'", 455 dev, unit, redial_cmd); 456 acquire_line(); /* reopen dead line */ 457 setup_line(CLOCAL); 458 if (locked) { 459 if (uucp_lock) 460 uu_unlock(dvname); /* for redial */ 461 locked = 0; 462 } 463 if (system(redial_cmd)) 464 goto again; 465 if (uucp_lock) { 466 int res; 467 if ((res = uu_lock(dvname)) != UU_LOCK_OK) { 468 if (res != UU_LOCK_INUSE) 469 syslog(LOG_ERR, "uu_lock: %s", uu_lockerr(res)); 470 syslog(LOG_ERR, "can't relock %s after %s, aborting", 471 dev, redial_cmd); 472 exit_handler(1); 473 } 474 locked = 1; 475 } 476 /* Now check again for carrier (dial command is done): */ 477 if (!(modem_control & CLOCAL)) { 478 tty.c_cflag &= ~CLOCAL; 479 if (tcsetattr(fd, TCSAFLUSH, &tty) < 0) { 480 syslog(LOG_ERR, "tcsetattr(TCSAFLUSH): %m"); 481 exit_handler(1); 482 } 483 ioctl(fd, TIOCMGET, &comstate); 484 if (!(comstate & TIOCM_CD)) { /* check for carrier */ 485 /* force a redial if no carrier */ 486 goto again; 487 } 488 } else 489 setup_line(0); 490 } else { /* Empty redial command */ 491 syslog(LOG_NOTICE,"SIGHUP on %s (sl%d); reestablish connection", 492 dev, unit); 493 acquire_line(); /* reopen dead line */ 494 setup_line(0); /* restore ospeed from hangup (B0) */ 495 /* If modem control, just wait for carrier before attaching. 496 If no modem control, just fall through immediately. */ 497 if (!(modem_control & CLOCAL)) { 498 int carrier = 0; 499 500 syslog(LOG_NOTICE, "waiting for carrier on %s (sl%d)", 501 dev, unit); 502 /* Now wait for carrier before attaching line. */ 503 /* We must poll since CLOCAL prevents signal. */ 504 while (! carrier) { 505 sleep(2); 506 ioctl(fd, TIOCMGET, &comstate); 507 if (comstate & TIOCM_CD) 508 carrier = 1; 509 } 510 syslog(LOG_NOTICE, "carrier now present on %s (sl%d)", 511 dev, unit); 512 } 513 } 514 slip_discipline(); 515 configure_network(); 516 } 517 518 /* Signal handler for SIGINT. We just log and exit. */ 519 static void 520 sigint_handler(int signo __unused) 521 { 522 if(exiting) return; 523 syslog(LOG_NOTICE,"SIGINT on %s (sl%d); exiting",dev,unit); 524 exit_handler(0); 525 } 526 527 /* Signal handler for SIGURG. */ 528 static void 529 sigurg_handler(int signo __unused) 530 { 531 int ttydisc = TTYDISC; 532 533 signal(SIGURG, SIG_IGN); 534 if(exiting) return; 535 syslog(LOG_NOTICE,"SIGURG on %s (sl%d); hangup",dev,unit); 536 if (ioctl(fd, TIOCSETD, &ttydisc) < 0) { 537 syslog(LOG_ERR, "ioctl(TIOCSETD): %m"); 538 exit_handler(1); 539 } 540 cfsetospeed(&tty, B0); 541 if (tcsetattr(fd, TCSANOW, &tty) < 0) { 542 syslog(LOG_ERR, "tcsetattr(TCSANOW): %m"); 543 exit_handler(1); 544 } 545 /* Need to go to sighup handler in any case */ 546 if (modem_control & CLOCAL) 547 kill (getpid(), SIGHUP); 548 549 } 550 551 /* Signal handler for SIGTERM. We just log and exit. */ 552 static void 553 sigterm_handler(int signo __unused) 554 { 555 if(exiting) return; 556 syslog(LOG_NOTICE,"SIGTERM on %s (sl%d); exiting",dev,unit); 557 exit_handler(0); 558 } 559 560 /* Run config_cmd if specified before exiting. */ 561 static void 562 exit_handler(int ret) 563 { 564 if(exiting) return; 565 exiting = 1; 566 /* 567 * First close the slip line in case exit_cmd wants it (like to hang 568 * up a modem or something). 569 */ 570 if (fd != -1) 571 close(fd); 572 if (uucp_lock && locked) 573 uu_unlock(dvname); 574 575 /* Remove the PID file */ 576 unlink(pidfilename); 577 578 if (config_cmd) { 579 char *s; 580 s = (char*) malloc(strlen(config_cmd) + 32); 581 if (s == NULL) { 582 syslog(LOG_ERR, "malloc failed"); 583 exit(1); 584 } 585 sprintf (s, "%s %d -1", config_cmd, unit); 586 syslog(LOG_NOTICE, "deconfiguring %s (sl%d):", dev, unit); 587 syslog(LOG_NOTICE, " '%s'", s); 588 system(s); 589 free (s); 590 } 591 /* invoke a shell for exit_cmd. */ 592 if (exit_cmd) { 593 syslog(LOG_NOTICE,"exiting after running %s", exit_cmd); 594 system(exit_cmd); 595 } 596 exit(ret); 597 } 598 599 /* local variables: */ 600 /* c-indent-level: 8 */ 601 /* c-argdecl-indent: 0 */ 602 /* c-label-offset: -8 */ 603 /* c-continued-statement-offset: 8 */ 604 /* c-brace-offset: 0 */ 605 /* comment-column: 32 */ 606 /* end: */ 607