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 1.4 2003/11/01 17:16:02 drhodus 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 <strings.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 void sighup_handler(); /* SIGHUP handler */ 64 void sigint_handler(); /* SIGINT handler */ 65 void sigterm_handler(); /* SIGTERM handler */ 66 void sigurg_handler(); /* SIGURG handler */ 67 void exit_handler(int ret); /* run exit_cmd iff specified upon exit. */ 68 void setup_line(int cflag); /* configure terminal settings */ 69 void slip_discipline(); /* switch to slip line discipline */ 70 void configure_network(); /* configure slip interface */ 71 void acquire_line(); /* get tty device as controlling terminal */ 72 static void usage(void); 73 74 int fd = -1; 75 char *dev = (char *)0; /* 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() 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 == (char *)0) { 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(); 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 void acquire_line(void) 235 { 236 int ttydisc = TTYDISC; 237 int oflags; 238 FILE *pidfile; 239 240 /* reset to tty discipline */ 241 if (fd >= 0 && ioctl(fd, TIOCSETD, &ttydisc) < 0) { 242 syslog(LOG_ERR, "ioctl(TIOCSETD): %m"); 243 exit_handler(1); 244 } 245 246 (void)close(STDIN_FILENO); /* close FDs before forking. */ 247 (void)close(STDOUT_FILENO); 248 (void)close(STDERR_FILENO); 249 if (fd > 2) 250 (void)close(fd); 251 252 signal(SIGHUP, SIG_IGN); /* ignore HUP signal when parent dies. */ 253 if (daemon(0,0)) { /* fork, setsid, chdir /, and close std*. */ 254 syslog(LOG_ERR, "daemon(0,0): %m"); 255 exit_handler(1); 256 } 257 258 while (getppid () != 1) 259 sleep (1); /* Wait for parent to die. */ 260 261 /* create PID file */ 262 if((pidfile = fopen(pidfilename, "w"))) { 263 fprintf(pidfile, "%ld\n", (long)getpid()); 264 fclose(pidfile); 265 } 266 267 if (signal(SIGHUP,sighup_handler) == SIG_ERR) /* Re-enable HUP signal */ 268 syslog(LOG_NOTICE,"cannot install SIGHUP handler: %m"); 269 270 if (uucp_lock) { 271 /* unlock not needed here, always re-lock with new pid */ 272 int res; 273 if ((res = uu_lock(dvname)) != UU_LOCK_OK) { 274 if (res != UU_LOCK_INUSE) 275 syslog(LOG_ERR, "uu_lock: %s", uu_lockerr(res)); 276 syslog(LOG_ERR, "can't lock %s", dev); 277 exit_handler(1); 278 } 279 locked = 1; 280 } 281 282 if ((fd = open(dev, O_RDWR | O_NONBLOCK, 0)) < 0) { 283 syslog(LOG_ERR, "open(%s) %m", dev); 284 exit_handler(1); 285 } 286 /* Turn off O_NONBLOCK for dumb redialers, if any. */ 287 if ((oflags = fcntl(fd, F_GETFL)) == -1) { 288 syslog(LOG_ERR, "fcntl(F_GETFL) failed: %m"); 289 exit_handler(1); 290 } 291 if (fcntl(fd, F_SETFL, oflags & ~O_NONBLOCK) == -1) { 292 syslog(LOG_ERR, "fcntl(F_SETFL) failed: %m"); 293 exit_handler(1); 294 } 295 (void)dup2(fd, STDIN_FILENO); 296 (void)dup2(fd, STDOUT_FILENO); 297 (void)dup2(fd, STDERR_FILENO); 298 if (fd > 2) 299 (void)close (fd); 300 fd = STDIN_FILENO; 301 302 /* acquire the serial line as a controlling terminal. */ 303 if (ioctl(fd, TIOCSCTTY, 0) < 0) { 304 syslog(LOG_ERR,"ioctl(TIOCSCTTY): %m"); 305 exit_handler(1); 306 } 307 /* Make us the foreground process group associated with the 308 slip line which is our controlling terminal. */ 309 if (tcsetpgrp(fd, getpid()) < 0) 310 syslog(LOG_NOTICE,"tcsetpgrp failed: %m"); 311 } 312 313 /* Set the tty flags and set DTR. */ 314 /* Call as setup_line(CLOCAL) to force clocal assertion. */ 315 void setup_line(int cflag) 316 { 317 tty.c_lflag = tty.c_iflag = tty.c_oflag = 0; 318 tty.c_cflag = CREAD | CS8 | flow_control | modem_control | cflag; 319 cfsetispeed(&tty, speed); 320 cfsetospeed(&tty, speed); 321 /* set the line speed and flow control */ 322 if (tcsetattr(fd, TCSAFLUSH, &tty) < 0) { 323 syslog(LOG_ERR, "tcsetattr(TCSAFLUSH): %m"); 324 exit_handler(1); 325 } 326 /* set data terminal ready */ 327 if (ioctl(fd, TIOCSDTR) < 0) { 328 syslog(LOG_ERR, "ioctl(TIOCSDTR): %m"); 329 exit_handler(1); 330 } 331 } 332 333 /* Put the line in slip discipline. */ 334 void slip_discipline(void) 335 { 336 struct ifreq ifr; 337 int slipdisc = SLIPDISC; 338 int s, tmp_unit = -1; 339 340 /* Switch to slip line discipline. */ 341 if (ioctl(fd, TIOCSETD, &slipdisc) < 0) { 342 syslog(LOG_ERR, "ioctl(TIOCSETD): %m"); 343 exit_handler(1); 344 } 345 346 if (sl_unit >= 0 && ioctl(fd, SLIOCSUNIT, &sl_unit) < 0) { 347 syslog(LOG_ERR, "ioctl(SLIOCSUNIT): %m"); 348 exit_handler(1); 349 } 350 351 /* find out what unit number we were assigned */ 352 if (ioctl(fd, SLIOCGUNIT, (caddr_t)&tmp_unit) < 0) { 353 syslog(LOG_ERR, "ioctl(SLIOCGUNIT): %m"); 354 exit_handler(1); 355 } 356 357 if (tmp_unit < 0) { 358 syslog(LOG_ERR, "bad unit (%d) from ioctl(SLIOCGUNIT)",tmp_unit); 359 exit_handler(1); 360 } 361 362 if (keepal > 0) { 363 signal(SIGURG, sigurg_handler); 364 if (ioctl(fd, SLIOCSKEEPAL, &keepal) < 0) { 365 syslog(LOG_ERR, "ioctl(SLIOCSKEEPAL): %m"); 366 exit_handler(1); 367 } 368 } 369 if (outfill > 0 && ioctl(fd, SLIOCSOUTFILL, &outfill) < 0) { 370 syslog(LOG_ERR, "ioctl(SLIOCSOUTFILL): %m"); 371 exit_handler(1); 372 } 373 374 /* open a socket as the handle to the interface */ 375 s = socket(AF_INET, SOCK_DGRAM, 0); 376 if (s < 0) { 377 syslog(LOG_ERR, "socket: %m"); 378 exit_handler(1); 379 } 380 sprintf(ifr.ifr_name, "sl%d", tmp_unit); 381 382 /* get the flags for the interface */ 383 if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) { 384 syslog(LOG_ERR, "ioctl (SIOCGIFFLAGS): %m"); 385 exit_handler(1); 386 } 387 388 /* Assert any compression or no-icmp flags. */ 389 #define SLMASK (~(IFF_LINK0 | IFF_LINK1 | IFF_LINK2)) 390 ifr.ifr_flags &= SLMASK; 391 ifr.ifr_flags |= slflags; 392 if (ioctl(s, SIOCSIFFLAGS, (caddr_t)&ifr) < 0) { 393 syslog(LOG_ERR, "ioctl (SIOCSIFFLAGS): %m"); 394 exit_handler(1); 395 } 396 close(s); 397 } 398 399 /* configure the interface, e.g. by passing the unit number to a script. */ 400 void configure_network(void) 401 { 402 int new_unit; 403 404 /* find out what unit number we were assigned */ 405 if (ioctl(fd, SLIOCGUNIT, (caddr_t)&new_unit) < 0) { 406 syslog(LOG_ERR, "ioctl(SLIOCGUNIT): %m"); 407 exit_handler(1); 408 } 409 /* iff the unit number changes either invoke config_cmd or punt. */ 410 if (config_cmd) { 411 char *s; 412 s = (char*) malloc(strlen(config_cmd) + 32); 413 if (s == NULL) { 414 syslog(LOG_ERR, "malloc failed"); 415 exit(1); 416 } 417 sprintf (s, "%s %d %d", config_cmd, unit, new_unit); 418 syslog(LOG_NOTICE, "configuring %s (sl%d):", dev, unit); 419 syslog(LOG_NOTICE, " '%s'", s); 420 system(s); 421 free (s); 422 unit = new_unit; 423 } else { 424 /* don't compare unit numbers if this is the first time to attach. */ 425 if (unit < 0) 426 unit = new_unit; 427 if (new_unit != unit) { 428 syslog(LOG_ERR, 429 "slip unit changed from sl%d to sl%d, but no -u CMD was specified!", 430 unit, new_unit); 431 exit_handler(1); 432 } 433 syslog(LOG_NOTICE,"sl%d connected to %s at %d baud",unit,dev,speed); 434 } 435 } 436 437 /* sighup_handler() is invoked when carrier drops, eg. before redial. */ 438 void sighup_handler(void) 439 { 440 if(exiting) return; 441 442 if (redial_cmd == NULL) { 443 syslog(LOG_NOTICE,"SIGHUP on %s (sl%d); exiting", dev, unit); 444 exit_handler(1); 445 } 446 again: 447 /* invoke a shell for redial_cmd or punt. */ 448 if (*redial_cmd) { /* Non-empty redial command */ 449 syslog(LOG_NOTICE,"SIGHUP on %s (sl%d); running '%s'", 450 dev, unit, redial_cmd); 451 acquire_line(); /* reopen dead line */ 452 setup_line(CLOCAL); 453 if (locked) { 454 if (uucp_lock) 455 uu_unlock(dvname); /* for redial */ 456 locked = 0; 457 } 458 if (system(redial_cmd)) 459 goto again; 460 if (uucp_lock) { 461 int res; 462 if ((res = uu_lock(dvname)) != UU_LOCK_OK) { 463 if (res != UU_LOCK_INUSE) 464 syslog(LOG_ERR, "uu_lock: %s", uu_lockerr(res)); 465 syslog(LOG_ERR, "can't relock %s after %s, aborting", 466 dev, redial_cmd); 467 exit_handler(1); 468 } 469 locked = 1; 470 } 471 /* Now check again for carrier (dial command is done): */ 472 if (!(modem_control & CLOCAL)) { 473 tty.c_cflag &= ~CLOCAL; 474 if (tcsetattr(fd, TCSAFLUSH, &tty) < 0) { 475 syslog(LOG_ERR, "tcsetattr(TCSAFLUSH): %m"); 476 exit_handler(1); 477 } 478 ioctl(fd, TIOCMGET, &comstate); 479 if (!(comstate & TIOCM_CD)) { /* check for carrier */ 480 /* force a redial if no carrier */ 481 goto again; 482 } 483 } else 484 setup_line(0); 485 } else { /* Empty redial command */ 486 syslog(LOG_NOTICE,"SIGHUP on %s (sl%d); reestablish connection", 487 dev, unit); 488 acquire_line(); /* reopen dead line */ 489 setup_line(0); /* restore ospeed from hangup (B0) */ 490 /* If modem control, just wait for carrier before attaching. 491 If no modem control, just fall through immediately. */ 492 if (!(modem_control & CLOCAL)) { 493 int carrier = 0; 494 495 syslog(LOG_NOTICE, "waiting for carrier on %s (sl%d)", 496 dev, unit); 497 /* Now wait for carrier before attaching line. */ 498 /* We must poll since CLOCAL prevents signal. */ 499 while (! carrier) { 500 sleep(2); 501 ioctl(fd, TIOCMGET, &comstate); 502 if (comstate & TIOCM_CD) 503 carrier = 1; 504 } 505 syslog(LOG_NOTICE, "carrier now present on %s (sl%d)", 506 dev, unit); 507 } 508 } 509 slip_discipline(); 510 configure_network(); 511 } 512 /* Signal handler for SIGINT. We just log and exit. */ 513 void sigint_handler(void) 514 { 515 if(exiting) return; 516 syslog(LOG_NOTICE,"SIGINT on %s (sl%d); exiting",dev,unit); 517 exit_handler(0); 518 } 519 /* Signal handler for SIGURG. */ 520 void sigurg_handler(void) 521 { 522 int ttydisc = TTYDISC; 523 524 signal(SIGURG, SIG_IGN); 525 if(exiting) return; 526 syslog(LOG_NOTICE,"SIGURG on %s (sl%d); hangup",dev,unit); 527 if (ioctl(fd, TIOCSETD, &ttydisc) < 0) { 528 syslog(LOG_ERR, "ioctl(TIOCSETD): %m"); 529 exit_handler(1); 530 } 531 cfsetospeed(&tty, B0); 532 if (tcsetattr(fd, TCSANOW, &tty) < 0) { 533 syslog(LOG_ERR, "tcsetattr(TCSANOW): %m"); 534 exit_handler(1); 535 } 536 /* Need to go to sighup handler in any case */ 537 if (modem_control & CLOCAL) 538 kill (getpid(), SIGHUP); 539 540 } 541 /* Signal handler for SIGTERM. We just log and exit. */ 542 void sigterm_handler(void) 543 { 544 if(exiting) return; 545 syslog(LOG_NOTICE,"SIGTERM on %s (sl%d); exiting",dev,unit); 546 exit_handler(0); 547 } 548 /* Run config_cmd if specified before exiting. */ 549 void exit_handler(int ret) 550 { 551 if(exiting) return; 552 exiting = 1; 553 /* 554 * First close the slip line in case exit_cmd wants it (like to hang 555 * up a modem or something). 556 */ 557 if (fd != -1) 558 close(fd); 559 if (uucp_lock && locked) 560 uu_unlock(dvname); 561 562 /* Remove the PID file */ 563 (void)unlink(pidfilename); 564 565 if (config_cmd) { 566 char *s; 567 s = (char*) malloc(strlen(config_cmd) + 32); 568 if (s == NULL) { 569 syslog(LOG_ERR, "malloc failed"); 570 exit(1); 571 } 572 sprintf (s, "%s %d -1", config_cmd, unit); 573 syslog(LOG_NOTICE, "deconfiguring %s (sl%d):", dev, unit); 574 syslog(LOG_NOTICE, " '%s'", s); 575 system(s); 576 free (s); 577 } 578 /* invoke a shell for exit_cmd. */ 579 if (exit_cmd) { 580 syslog(LOG_NOTICE,"exiting after running %s", exit_cmd); 581 system(exit_cmd); 582 } 583 exit(ret); 584 } 585 586 /* local variables: */ 587 /* c-indent-level: 8 */ 588 /* c-argdecl-indent: 0 */ 589 /* c-label-offset: -8 */ 590 /* c-continued-statement-offset: 8 */ 591 /* c-brace-offset: 0 */ 592 /* comment-column: 32 */ 593 /* end: */ 594