1/* 2 * tty.c - code for handling serial ports in pppd. 3 * 4 * Copyright (C) 2000-2004 Paul Mackerras. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 13 * 2. The name(s) of the authors of this software must not be used to 14 * endorse or promote products derived from this software without 15 * prior written permission. 16 * 17 * 3. Redistributions of any form whatsoever must retain the following 18 * acknowledgment: 19 * "This product includes software developed by Paul Mackerras 20 * <paulus@samba.org>". 21 * 22 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO 23 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 24 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY 25 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 26 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 27 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING 28 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 29 * 30 * Portions derived from main.c, which is: 31 * 32 * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved. 33 * 34 * Redistribution and use in source and binary forms, with or without 35 * modification, are permitted provided that the following conditions 36 * are met: 37 * 38 * 1. Redistributions of source code must retain the above copyright 39 * notice, this list of conditions and the following disclaimer. 40 * 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in 43 * the documentation and/or other materials provided with the 44 * distribution. 45 * 46 * 3. The name "Carnegie Mellon University" must not be used to 47 * endorse or promote products derived from this software without 48 * prior written permission. For permission or any legal 49 * details, please contact 50 * Office of Technology Transfer 51 * Carnegie Mellon University 52 * 5000 Forbes Avenue 53 * Pittsburgh, PA 15213-3890 54 * (412) 268-4387, fax: (412) 268-7395 55 * tech-transfer@andrew.cmu.edu 56 * 57 * 4. Redistributions of any form whatsoever must retain the following 58 * acknowledgment: 59 * "This product includes software developed by Computing Services 60 * at Carnegie Mellon University (http://www.cmu.edu/computing/)." 61 * 62 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO 63 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 64 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE 65 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 66 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 67 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING 68 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 69 */ 70 71#define RCSID "$Id: tty.c,v 1.25 2006/06/04 07:04:57 paulus Exp $" 72 73#include <stdio.h> 74#include <ctype.h> 75#include <stdlib.h> 76#include <string.h> 77#include <unistd.h> 78#include <signal.h> 79#include <errno.h> 80#include <fcntl.h> 81#include <syslog.h> 82#include <netdb.h> 83#include <utmp.h> 84#include <pwd.h> 85#include <setjmp.h> 86#include <sys/param.h> 87#include <sys/types.h> 88#include <sys/wait.h> 89#include <sys/time.h> 90#include <sys/resource.h> 91#include <sys/stat.h> 92#include <sys/socket.h> 93#include <netinet/in.h> 94#include <arpa/inet.h> 95 96#include "pppd.h" 97#include "fsm.h" 98#include "lcp.h" 99 100void tty_process_extra_options __P((void)); 101void tty_check_options __P((void)); 102int connect_tty __P((void)); 103void disconnect_tty __P((void)); 104void tty_close_fds __P((void)); 105void cleanup_tty __P((void)); 106void tty_do_send_config __P((int, u_int32_t, int, int)); 107 108static int setdevname __P((char *, char **, int)); 109static int setspeed __P((char *, char **, int)); 110static int setxonxoff __P((char **)); 111static int setescape __P((char **)); 112static void printescape __P((option_t *, void (*)(void *, char *,...),void *)); 113static void finish_tty __P((void)); 114static int start_charshunt __P((int, int)); 115static void stop_charshunt __P((void *, int)); 116static void charshunt_done __P((void *)); 117static void charshunt __P((int, int, char *)); 118static int record_write __P((FILE *, int code, u_char *buf, int nb, 119 struct timeval *)); 120static int open_socket __P((char *)); 121static void maybe_relock __P((void *, int)); 122 123static int pty_master; /* fd for master side of pty */ 124static int pty_slave; /* fd for slave side of pty */ 125static int real_ttyfd; /* fd for actual serial port (not pty) */ 126static int ttyfd; /* Serial port file descriptor */ 127static char speed_str[16]; /* Serial port speed as string */ 128 129mode_t tty_mode = (mode_t)-1; /* Original access permissions to tty */ 130int baud_rate; /* Actual bits/second for serial device */ 131char *callback_script; /* script for doing callback */ 132int charshunt_pid; /* Process ID for charshunt */ 133int locked; /* lock() has succeeded */ 134struct stat devstat; /* result of stat() on devnam */ 135 136/* option variables */ 137int crtscts = 0; /* Use hardware flow control */ 138bool modem = 1; /* Use modem control lines */ 139int inspeed = 0; /* Input/Output speed requested */ 140bool lockflag = 0; /* Create lock file to lock the serial dev */ 141char *initializer = NULL; /* Script to initialize physical link */ 142char *connect_script = NULL; /* Script to establish physical link */ 143char *disconnect_script = NULL; /* Script to disestablish physical link */ 144char *welcomer = NULL; /* Script to run after phys link estab. */ 145char *ptycommand = NULL; /* Command to run on other side of pty */ 146bool notty = 0; /* Stdin/out is not a tty */ 147char *record_file = NULL; /* File to record chars sent/received */ 148int max_data_rate; /* max bytes/sec through charshunt */ 149bool sync_serial = 0; /* Device is synchronous serial device */ 150char *pty_socket = NULL; /* Socket to connect to pty */ 151int using_pty = 0; /* we're allocating a pty as the device */ 152 153extern uid_t uid; 154extern int kill_link; 155extern int asked_to_quit; 156extern int got_sigterm; 157 158/* XXX */ 159extern int privopen; /* don't lock, open device as root */ 160 161u_int32_t xmit_accm[8]; /* extended transmit ACCM */ 162 163/* option descriptors */ 164option_t tty_options[] = { 165 /* device name must be first, or change connect_tty() below! */ 166 { "device name", o_wild, (void *) &setdevname, 167 "Serial port device name", 168 OPT_DEVNAM | OPT_PRIVFIX | OPT_NOARG | OPT_A2STRVAL | OPT_STATIC, 169 devnam}, 170 171 { "tty speed", o_wild, (void *) &setspeed, 172 "Baud rate for serial port", 173 OPT_PRIO | OPT_NOARG | OPT_A2STRVAL | OPT_STATIC, speed_str }, 174 175 { "lock", o_bool, &lockflag, 176 "Lock serial device with UUCP-style lock file", OPT_PRIO | 1 }, 177 { "nolock", o_bool, &lockflag, 178 "Don't lock serial device", OPT_PRIOSUB | OPT_PRIV }, 179 180 { "init", o_string, &initializer, 181 "A program to initialize the device", OPT_PRIO | OPT_PRIVFIX }, 182 183 { "connect", o_string, &connect_script, 184 "A program to set up a connection", OPT_PRIO | OPT_PRIVFIX }, 185 186 { "disconnect", o_string, &disconnect_script, 187 "Program to disconnect serial device", OPT_PRIO | OPT_PRIVFIX }, 188 189 { "welcome", o_string, &welcomer, 190 "Script to welcome client", OPT_PRIO | OPT_PRIVFIX }, 191 192 { "pty", o_string, &ptycommand, 193 "Script to run on pseudo-tty master side", 194 OPT_PRIO | OPT_PRIVFIX | OPT_DEVNAM }, 195 196 { "notty", o_bool, ¬ty, 197 "Input/output is not a tty", OPT_DEVNAM | 1 }, 198 199 { "socket", o_string, &pty_socket, 200 "Send and receive over socket, arg is host:port", 201 OPT_PRIO | OPT_DEVNAM }, 202 203 { "record", o_string, &record_file, 204 "Record characters sent/received to file", OPT_PRIO }, 205 206 { "crtscts", o_int, &crtscts, 207 "Set hardware (RTS/CTS) flow control", 208 OPT_PRIO | OPT_NOARG | OPT_VAL(1) }, 209 { "cdtrcts", o_int, &crtscts, 210 "Set alternate hardware (DTR/CTS) flow control", 211 OPT_PRIOSUB | OPT_NOARG | OPT_VAL(2) }, 212 { "nocrtscts", o_int, &crtscts, 213 "Disable hardware flow control", 214 OPT_PRIOSUB | OPT_NOARG | OPT_VAL(-1) }, 215 { "-crtscts", o_int, &crtscts, 216 "Disable hardware flow control", 217 OPT_PRIOSUB | OPT_ALIAS | OPT_NOARG | OPT_VAL(-1) }, 218 { "nocdtrcts", o_int, &crtscts, 219 "Disable hardware flow control", 220 OPT_PRIOSUB | OPT_ALIAS | OPT_NOARG | OPT_VAL(-1) }, 221 { "xonxoff", o_special_noarg, (void *)setxonxoff, 222 "Set software (XON/XOFF) flow control", OPT_PRIOSUB }, 223 224 { "modem", o_bool, &modem, 225 "Use modem control lines", OPT_PRIO | 1 }, 226 { "local", o_bool, &modem, 227 "Don't use modem control lines", OPT_PRIOSUB | 0 }, 228 229 { "sync", o_bool, &sync_serial, 230 "Use synchronous HDLC serial encoding", 1 }, 231 232 { "datarate", o_int, &max_data_rate, 233 "Maximum data rate in bytes/sec (with pty, notty or record option)", 234 OPT_PRIO }, 235 236 { "escape", o_special, (void *)setescape, 237 "List of character codes to escape on transmission", 238 OPT_A2PRINTER, (void *)printescape }, 239 240 { NULL } 241}; 242 243 244struct channel tty_channel = { 245 tty_options, 246 &tty_process_extra_options, 247 &tty_check_options, 248 &connect_tty, 249 &disconnect_tty, 250 &tty_establish_ppp, 251 &tty_disestablish_ppp, 252 &tty_do_send_config, 253 &tty_recv_config, 254 &cleanup_tty, 255 &tty_close_fds 256}; 257 258/* 259 * setspeed - Set the serial port baud rate. 260 * If doit is 0, the call is to check whether this option is 261 * potentially a speed value. 262 */ 263static int 264setspeed(arg, argv, doit) 265 char *arg; 266 char **argv; 267 int doit; 268{ 269 char *ptr; 270 int spd; 271 272 spd = strtol(arg, &ptr, 0); 273 if (ptr == arg || *ptr != 0 || spd == 0) 274 return 0; 275 if (doit) { 276 inspeed = spd; 277 slprintf(speed_str, sizeof(speed_str), "%d", spd); 278 } 279 return 1; 280} 281 282 283/* 284 * setdevname - Set the device name. 285 * If doit is 0, the call is to check whether this option is 286 * potentially a device name. 287 */ 288static int 289setdevname(cp, argv, doit) 290 char *cp; 291 char **argv; 292 int doit; 293{ 294 struct stat statbuf; 295 char dev[MAXPATHLEN]; 296 297 if (*cp == 0) 298 return 0; 299 300 if (*cp != '/') { 301 strlcpy(dev, "/dev/", sizeof(dev)); 302 strlcat(dev, cp, sizeof(dev)); 303 cp = dev; 304 } 305 306 /* 307 * Check if there is a character device by this name. 308 */ 309 if (stat(cp, &statbuf) < 0) { 310 if (!doit) 311 return errno != ENOENT; 312 option_error("Couldn't stat %s: %m", cp); 313 return 0; 314 } 315 if (!S_ISCHR(statbuf.st_mode)) { 316 if (doit) 317 option_error("%s is not a character device", cp); 318 return 0; 319 } 320 321 if (doit) { 322 strlcpy(devnam, cp, sizeof(devnam)); 323 devstat = statbuf; 324 default_device = 0; 325 } 326 327 return 1; 328} 329 330static int 331setxonxoff(argv) 332 char **argv; 333{ 334 lcp_wantoptions[0].asyncmap |= 0x000A0000; /* escape ^S and ^Q */ 335 lcp_wantoptions[0].neg_asyncmap = 1; 336 337 crtscts = -2; 338 return 1; 339} 340 341/* 342 * setescape - add chars to the set we escape on transmission. 343 */ 344static int 345setescape(argv) 346 char **argv; 347{ 348 int n, ret; 349 char *p, *endp; 350 351 p = *argv; 352 ret = 1; 353 while (*p) { 354 n = strtol(p, &endp, 16); 355 if (p == endp) { 356 option_error("escape parameter contains invalid hex number '%s'", 357 p); 358 return 0; 359 } 360 p = endp; 361 if (n < 0 || n == 0x5E || n > 0xFF) { 362 option_error("can't escape character 0x%x", n); 363 ret = 0; 364 } else 365 xmit_accm[n >> 5] |= 1 << (n & 0x1F); 366 while (*p == ',' || *p == ' ') 367 ++p; 368 } 369 lcp_allowoptions[0].asyncmap = xmit_accm[0]; 370 return ret; 371} 372 373static void 374printescape(opt, printer, arg) 375 option_t *opt; 376 void (*printer) __P((void *, char *, ...)); 377 void *arg; 378{ 379 int n; 380 int first = 1; 381 382 for (n = 0; n < 256; ++n) { 383 if (n == 0x7d) 384 n += 2; /* skip 7d, 7e */ 385 if (xmit_accm[n >> 5] & (1 << (n & 0x1f))) { 386 if (!first) 387 printer(arg, ","); 388 else 389 first = 0; 390 printer(arg, "%x", n); 391 } 392 } 393 if (first) 394 printer(arg, "oops # nothing escaped"); 395} 396 397/* 398 * tty_init - do various tty-related initializations. 399 */ 400void tty_init() 401{ 402 add_notifier(&pidchange, maybe_relock, 0); 403 the_channel = &tty_channel; 404 xmit_accm[3] = 0x60000000; 405} 406 407/* 408 * tty_process_extra_options - work out which tty device we are using 409 * and read its options file. 410 */ 411void tty_process_extra_options() 412{ 413 using_pty = notty || ptycommand != NULL || pty_socket != NULL; 414 if (using_pty) 415 return; 416 if (default_device) { 417 char *p; 418 if (!isatty(0) || (p = ttyname(0)) == NULL) { 419 option_error("no device specified and stdin is not a tty"); 420 exit(EXIT_OPTION_ERROR); 421 } 422 strlcpy(devnam, p, sizeof(devnam)); 423 if (stat(devnam, &devstat) < 0) 424 fatal("Couldn't stat default device %s: %m", devnam); 425 } 426 427 428 /* 429 * Parse the tty options file. 430 * The per-tty options file should not change 431 * ptycommand, pty_socket, notty or devnam. 432 * options_for_tty doesn't override options set on the command line, 433 * except for some privileged options. 434 */ 435 if (!options_for_tty()) 436 exit(EXIT_OPTION_ERROR); 437} 438 439/* 440 * tty_check_options - do consistency checks on the options we were given. 441 */ 442void 443tty_check_options() 444{ 445 struct stat statbuf; 446 int fdflags; 447 448 if (demand && notty) { 449 option_error("demand-dialling is incompatible with notty"); 450 exit(EXIT_OPTION_ERROR); 451 } 452 if (demand && connect_script == 0 && ptycommand == NULL 453 && pty_socket == NULL) { 454 option_error("connect script is required for demand-dialling\n"); 455 exit(EXIT_OPTION_ERROR); 456 } 457 /* default holdoff to 0 if no connect script has been given */ 458 if (connect_script == 0 && !holdoff_specified) 459 holdoff = 0; 460 461 if (using_pty) { 462 if (!default_device) { 463 option_error("%s option precludes specifying device name", 464 pty_socket? "socket": notty? "notty": "pty"); 465 exit(EXIT_OPTION_ERROR); 466 } 467 if (ptycommand != NULL && notty) { 468 option_error("pty option is incompatible with notty option"); 469 exit(EXIT_OPTION_ERROR); 470 } 471 if (pty_socket != NULL && (ptycommand != NULL || notty)) { 472 option_error("socket option is incompatible with pty and notty"); 473 exit(EXIT_OPTION_ERROR); 474 } 475 default_device = notty; 476 lockflag = 0; 477 modem = 0; 478 if (notty && log_to_fd <= 1) 479 log_to_fd = -1; 480 } else { 481 /* 482 * If the user has specified a device which is the same as 483 * the one on stdin, pretend they didn't specify any. 484 * If the device is already open read/write on stdin, 485 * we assume we don't need to lock it, and we can open it 486 * as root. 487 */ 488 if (fstat(0, &statbuf) >= 0 && S_ISCHR(statbuf.st_mode) 489 && statbuf.st_rdev == devstat.st_rdev) { 490 default_device = 1; 491 fdflags = fcntl(0, F_GETFL); 492 if (fdflags != -1 && (fdflags & O_ACCMODE) == O_RDWR) 493 privopen = 1; 494 } 495 } 496 if (default_device) 497 nodetach = 1; 498 499 /* 500 * Don't send log messages to the serial port, it tends to 501 * confuse the peer. :-) 502 */ 503 if (log_to_fd >= 0 && fstat(log_to_fd, &statbuf) >= 0 504 && S_ISCHR(statbuf.st_mode) && statbuf.st_rdev == devstat.st_rdev) 505 log_to_fd = -1; 506} 507 508/* 509 * connect_tty - get the serial port ready to start doing PPP. 510 * That is, open the serial port, set its speed and mode, and run 511 * the connector and/or welcomer. 512 */ 513int connect_tty() 514{ 515 char *connector; 516 int fdflags; 517#ifndef __linux__ 518 struct stat statbuf; 519#endif 520 char numbuf[16]; 521 522 /* 523 * Get a pty master/slave pair if the pty, notty, socket, 524 * or record options were specified. 525 */ 526 strlcpy(ppp_devnam, devnam, sizeof(ppp_devnam)); 527 pty_master = -1; 528 pty_slave = -1; 529 real_ttyfd = -1; 530 if (using_pty || record_file != NULL) { 531 if (!get_pty(&pty_master, &pty_slave, ppp_devnam, uid)) { 532 error("Couldn't allocate pseudo-tty"); 533 status = EXIT_FATAL_ERROR; 534 return -1; 535 } 536 set_up_tty(pty_slave, 1); 537 } 538 539 /* 540 * Lock the device if we've been asked to. 541 */ 542 status = EXIT_LOCK_FAILED; 543 if (lockflag && !privopen) { 544 if (lock(devnam) < 0) 545 goto errret; 546 locked = 1; 547 } 548 549 /* 550 * Open the serial device and set it up to be the ppp interface. 551 * First we open it in non-blocking mode so we can set the 552 * various termios flags appropriately. If we aren't dialling 553 * out and we want to use the modem lines, we reopen it later 554 * in order to wait for the carrier detect signal from the modem. 555 */ 556 hungup = 0; 557 got_sigterm = 0; 558 connector = doing_callback? callback_script: connect_script; 559 if (devnam[0] != 0) { 560 for (;;) { 561 /* If the user specified the device name, become the 562 user before opening it. */ 563 int err, prio; 564 565 prio = privopen? OPRIO_ROOT: tty_options[0].priority; 566 if (prio < OPRIO_ROOT && seteuid(uid) == -1) { 567 error("Unable to drop privileges before opening %s: %m\n", 568 devnam); 569 status = EXIT_OPEN_FAILED; 570 goto errret; 571 } 572 real_ttyfd = open(devnam, O_NONBLOCK | O_RDWR, 0); 573 err = errno; 574 if (prio < OPRIO_ROOT && seteuid(0) == -1) 575 fatal("Unable to regain privileges"); 576 if (real_ttyfd >= 0) 577 break; 578 errno = err; 579 if (err != EINTR) { 580 error("Failed to open %s: %m", devnam); 581 status = EXIT_OPEN_FAILED; 582 } 583 if (!persist || err != EINTR) 584 goto errret; 585 } 586 ttyfd = real_ttyfd; 587 if ((fdflags = fcntl(ttyfd, F_GETFL)) == -1 588 || fcntl(ttyfd, F_SETFL, fdflags & ~O_NONBLOCK) < 0) 589 warn("Couldn't reset non-blocking mode on device: %m"); 590 591#ifndef __linux__ 592 /* 593 * Linux 2.4 and above blocks normal writes to the tty 594 * when it is in PPP line discipline, so this isn't needed. 595 */ 596 /* 597 * Do the equivalent of `mesg n' to stop broadcast messages. 598 */ 599 if (fstat(ttyfd, &statbuf) < 0 600 || fchmod(ttyfd, statbuf.st_mode & ~(S_IWGRP | S_IWOTH)) < 0) { 601 warn("Couldn't restrict write permissions to %s: %m", devnam); 602 } else 603 tty_mode = statbuf.st_mode; 604#endif /* __linux__ */ 605 606 /* 607 * Set line speed, flow control, etc. 608 * If we have a non-null connection or initializer script, 609 * on most systems we set CLOCAL for now so that we can talk 610 * to the modem before carrier comes up. But this has the 611 * side effect that we might miss it if CD drops before we 612 * get to clear CLOCAL below. On systems where we can talk 613 * successfully to the modem with CLOCAL clear and CD down, 614 * we could clear CLOCAL at this point. 615 */ 616 set_up_tty(ttyfd, ((connector != NULL && connector[0] != 0) 617 || initializer != NULL)); 618 } 619 620 /* 621 * If the pty, socket, notty and/or record option was specified, 622 * start up the character shunt now. 623 */ 624 status = EXIT_PTYCMD_FAILED; 625 if (ptycommand != NULL) { 626 if (record_file != NULL) { 627 int ipipe[2], opipe[2], ok; 628 629 if (pipe(ipipe) < 0 || pipe(opipe) < 0) 630 fatal("Couldn't create pipes for record option: %m"); 631 632 /* don't leak these to the ptycommand */ 633 (void) fcntl(ipipe[0], F_SETFD, FD_CLOEXEC); 634 (void) fcntl(opipe[1], F_SETFD, FD_CLOEXEC); 635 636 ok = device_script(ptycommand, opipe[0], ipipe[1], 1) == 0 637 && start_charshunt(ipipe[0], opipe[1]); 638 close(ipipe[0]); 639 close(ipipe[1]); 640 close(opipe[0]); 641 close(opipe[1]); 642 if (!ok) 643 goto errret; 644 } else { 645 if (device_script(ptycommand, pty_master, pty_master, 1) < 0) 646 goto errret; 647 } 648 } else if (pty_socket != NULL) { 649 int fd = open_socket(pty_socket); 650 if (fd < 0) 651 goto errret; 652 if (!start_charshunt(fd, fd)) 653 goto errret; 654 close(fd); 655 } else if (notty) { 656 if (!start_charshunt(0, 1)) 657 goto errret; 658 dup2(fd_devnull, 0); 659 dup2(fd_devnull, 1); 660 if (log_to_fd == 1) 661 log_to_fd = -1; 662 if (log_to_fd != 2) 663 dup2(fd_devnull, 2); 664 } else if (record_file != NULL) { 665 int fd = dup(ttyfd); 666 if (!start_charshunt(fd, fd)) 667 goto errret; 668 } 669 670 if (using_pty || record_file != NULL) { 671 ttyfd = pty_slave; 672 close(pty_master); 673 pty_master = -1; 674 } 675 676 /* run connection script */ 677 if ((connector && connector[0]) || initializer) { 678 if (real_ttyfd != -1) { 679 /* XXX do this if doing_callback == CALLBACK_DIALIN? */ 680 if (!default_device && modem) { 681 setdtr(real_ttyfd, 0); /* in case modem is off hook */ 682 sleep(1); 683 setdtr(real_ttyfd, 1); 684 } 685 } 686 687 if (initializer && initializer[0]) { 688 if (device_script(initializer, ttyfd, ttyfd, 0) < 0) { 689 error("Initializer script failed"); 690 status = EXIT_INIT_FAILED; 691 goto errret; 692 } 693 if (got_sigterm) { 694 disconnect_tty(); 695 goto errret; 696 } 697 info("Serial port initialized."); 698 } 699 700 if (connector && connector[0]) { 701 if (device_script(connector, ttyfd, ttyfd, 0) < 0) { 702 error("Connect script failed"); 703 status = EXIT_CONNECT_FAILED; 704 goto errret; 705 } 706 if (got_sigterm) { 707 disconnect_tty(); 708 goto errret; 709 } 710 info("Serial connection established."); 711 } 712 713 /* set line speed, flow control, etc.; 714 clear CLOCAL if modem option */ 715 if (real_ttyfd != -1) 716 set_up_tty(real_ttyfd, 0); 717 718 if (doing_callback == CALLBACK_DIALIN) 719 connector = NULL; 720 } 721 722 /* reopen tty if necessary to wait for carrier */ 723 if (connector == NULL && modem && devnam[0] != 0) { 724 int i; 725 for (;;) { 726 if ((i = open(devnam, O_RDWR)) >= 0) 727 break; 728 if (errno != EINTR) { 729 error("Failed to reopen %s: %m", devnam); 730 status = EXIT_OPEN_FAILED; 731 } 732 if (!persist || errno != EINTR || hungup || got_sigterm) 733 goto errret; 734 } 735 close(i); 736 } 737 738 slprintf(numbuf, sizeof(numbuf), "%d", baud_rate); 739 script_setenv("SPEED", numbuf, 0); 740 741 /* run welcome script, if any */ 742 if (welcomer && welcomer[0]) { 743 if (device_script(welcomer, ttyfd, ttyfd, 0) < 0) 744 warn("Welcome script failed"); 745 } 746 747 /* 748 * If we are initiating this connection, wait for a short 749 * time for something from the peer. This can avoid bouncing 750 * our packets off his tty before he has it set up. 751 */ 752 if (connector != NULL || ptycommand != NULL || pty_socket != NULL) 753 listen_time = connect_delay; 754 755 return ttyfd; 756 757 errret: 758 if (pty_master >= 0) { 759 close(pty_master); 760 pty_master = -1; 761 } 762 ttyfd = -1; 763 if (got_sigterm) 764 asked_to_quit = 1; 765 return -1; 766} 767 768 769void disconnect_tty() 770{ 771 if (disconnect_script == NULL || hungup) 772 return; 773 if (real_ttyfd >= 0) 774 set_up_tty(real_ttyfd, 1); 775 if (device_script(disconnect_script, ttyfd, ttyfd, 0) < 0) { 776 warn("disconnect script failed"); 777 } else { 778 info("Serial link disconnected."); 779 } 780 stop_charshunt(NULL, 0); 781} 782 783void tty_close_fds() 784{ 785 if (pty_slave >= 0) 786 close(pty_slave); 787 if (real_ttyfd >= 0) { 788 close(real_ttyfd); 789 real_ttyfd = -1; 790 } 791 /* N.B. ttyfd will == either pty_slave or real_ttyfd */ 792} 793 794void cleanup_tty() 795{ 796 if (real_ttyfd >= 0) 797 finish_tty(); 798 tty_close_fds(); 799 if (locked) { 800 unlock(); 801 locked = 0; 802 } 803} 804 805/* 806 * tty_do_send_config - set transmit-side PPP configuration. 807 * We set the extended transmit ACCM here as well. 808 */ 809void 810tty_do_send_config(mtu, accm, pcomp, accomp) 811 int mtu; 812 u_int32_t accm; 813 int pcomp, accomp; 814{ 815 tty_set_xaccm(xmit_accm); 816 tty_send_config(mtu, accm, pcomp, accomp); 817} 818 819/* 820 * finish_tty - restore the terminal device to its original settings 821 */ 822static void 823finish_tty() 824{ 825 /* drop dtr to hang up */ 826 if (!default_device && modem) { 827 setdtr(real_ttyfd, 0); 828 /* 829 * This sleep is in case the serial port has CLOCAL set by default, 830 * and consequently will reassert DTR when we close the device. 831 */ 832 sleep(1); 833 } 834 835 restore_tty(real_ttyfd); 836 837#ifndef __linux__ 838 if (tty_mode != (mode_t) -1) { 839 if (fchmod(real_ttyfd, tty_mode) != 0) 840 error("Couldn't restore tty permissions"); 841 } 842#endif /* __linux__ */ 843 844 close(real_ttyfd); 845 real_ttyfd = -1; 846} 847 848/* 849 * maybe_relock - our PID has changed, maybe update the lock file. 850 */ 851static void 852maybe_relock(arg, pid) 853 void *arg; 854 int pid; 855{ 856 if (locked) 857 relock(pid); 858} 859 860/* 861 * open_socket - establish a stream socket connection to the nominated 862 * host and port. 863 */ 864static int 865open_socket(dest) 866 char *dest; 867{ 868 char *sep, *endp = NULL; 869 int sock, port = -1; 870 u_int32_t host; 871 struct hostent *hent; 872 struct sockaddr_in sad; 873 874 /* parse host:port and resolve host to an IP address */ 875 sep = strchr(dest, ':'); 876 if (sep != NULL) 877 port = strtol(sep+1, &endp, 10); 878 if (port < 0 || endp == sep+1 || sep == dest) { 879 error("Can't parse host:port for socket destination"); 880 return -1; 881 } 882 *sep = 0; 883 host = inet_addr(dest); 884 if (host == (u_int32_t) -1) { 885 hent = gethostbyname(dest); 886 if (hent == NULL) { 887 error("%s: unknown host in socket option", dest); 888 *sep = ':'; 889 return -1; 890 } 891 host = *(u_int32_t *)(hent->h_addr_list[0]); 892 } 893 *sep = ':'; 894 895 /* get a socket and connect it to the other end */ 896 sock = socket(PF_INET, SOCK_STREAM, 0); 897 if (sock < 0) { 898 error("Can't create socket: %m"); 899 return -1; 900 } 901 memset(&sad, 0, sizeof(sad)); 902 sad.sin_family = AF_INET; 903 sad.sin_port = htons(port); 904 sad.sin_addr.s_addr = host; 905 if (connect(sock, (struct sockaddr *)&sad, sizeof(sad)) < 0) { 906 error("Can't connect to %s: %m", dest); 907 close(sock); 908 return -1; 909 } 910 911 return sock; 912} 913 914 915/* 916 * start_charshunt - create a child process to run the character shunt. 917 */ 918static int 919start_charshunt(ifd, ofd) 920 int ifd, ofd; 921{ 922 int cpid; 923 924 cpid = safe_fork(ifd, ofd, (log_to_fd >= 0? log_to_fd: 2)); 925 if (cpid == -1) { 926 error("Can't fork process for character shunt: %m"); 927 return 0; 928 } 929 if (cpid == 0) { 930 /* child */ 931 reopen_log(); 932 if (!nodetach) 933 log_to_fd = -1; 934 else if (log_to_fd >= 0) 935 log_to_fd = 2; 936 setgid(getgid()); 937 setuid(uid); 938 if (getuid() != uid) 939 fatal("setuid failed"); 940 charshunt(0, 1, record_file); 941 exit(0); 942 } 943 charshunt_pid = cpid; 944 record_child(cpid, "pppd (charshunt)", charshunt_done, NULL); 945 return 1; 946} 947 948static void 949charshunt_done(arg) 950 void *arg; 951{ 952 charshunt_pid = 0; 953} 954 955static void 956stop_charshunt(arg, sig) 957 void *arg; 958 int sig; 959{ 960 if (charshunt_pid) 961 kill(charshunt_pid, (sig == SIGINT? sig: SIGTERM)); 962} 963 964/* 965 * charshunt - the character shunt, which passes characters between 966 * the pty master side and the serial port (or stdin/stdout). 967 * This runs as the user (not as root). 968 * (We assume ofd >= ifd which is true the way this gets called. :-). 969 */ 970static void 971charshunt(ifd, ofd, record_file) 972 int ifd, ofd; 973 char *record_file; 974{ 975 int n, nfds; 976 fd_set ready, writey; 977 u_char *ibufp, *obufp; 978 int nibuf, nobuf; 979 int flags; 980 int pty_readable, stdin_readable; 981 struct timeval lasttime; 982 FILE *recordf = NULL; 983 int ilevel, olevel, max_level; 984 struct timeval levelt, tout, *top; 985 extern u_char inpacket_buf[]; 986 987 /* 988 * Reset signal handlers. 989 */ 990 signal(SIGHUP, SIG_IGN); /* Hangup */ 991 signal(SIGINT, SIG_DFL); /* Interrupt */ 992 signal(SIGTERM, SIG_DFL); /* Terminate */ 993 signal(SIGCHLD, SIG_DFL); 994 signal(SIGUSR1, SIG_DFL); 995 signal(SIGUSR2, SIG_DFL); 996 signal(SIGABRT, SIG_DFL); 997 signal(SIGALRM, SIG_DFL); 998 signal(SIGFPE, SIG_DFL); 999 signal(SIGILL, SIG_DFL); 1000 signal(SIGPIPE, SIG_DFL); 1001 signal(SIGQUIT, SIG_DFL); 1002 signal(SIGSEGV, SIG_DFL); 1003#ifdef SIGBUS 1004 signal(SIGBUS, SIG_DFL); 1005#endif 1006#ifdef SIGEMT 1007 signal(SIGEMT, SIG_DFL); 1008#endif 1009#ifdef SIGPOLL 1010 signal(SIGPOLL, SIG_DFL); 1011#endif 1012#ifdef SIGPROF 1013 signal(SIGPROF, SIG_DFL); 1014#endif 1015#ifdef SIGSYS 1016 signal(SIGSYS, SIG_DFL); 1017#endif 1018#ifdef SIGTRAP 1019 signal(SIGTRAP, SIG_DFL); 1020#endif 1021#ifdef SIGVTALRM 1022 signal(SIGVTALRM, SIG_DFL); 1023#endif 1024#ifdef SIGXCPU 1025 signal(SIGXCPU, SIG_DFL); 1026#endif 1027#ifdef SIGXFSZ 1028 signal(SIGXFSZ, SIG_DFL); 1029#endif 1030 1031 /* 1032 * Check that the fds won't overrun the fd_sets 1033 */ 1034 if (ifd >= FD_SETSIZE || ofd >= FD_SETSIZE || pty_master >= FD_SETSIZE) 1035 fatal("internal error: file descriptor too large (%d, %d, %d)", 1036 ifd, ofd, pty_master); 1037 1038 /* 1039 * Open the record file if required. 1040 */ 1041 if (record_file != NULL) { 1042 recordf = fopen(record_file, "a"); 1043 if (recordf == NULL) 1044 error("Couldn't create record file %s: %m", record_file); 1045 } 1046 1047 /* set all the fds to non-blocking mode */ 1048 flags = fcntl(pty_master, F_GETFL); 1049 if (flags == -1 1050 || fcntl(pty_master, F_SETFL, flags | O_NONBLOCK) == -1) 1051 warn("couldn't set pty master to nonblock: %m"); 1052 flags = fcntl(ifd, F_GETFL); 1053 if (flags == -1 1054 || fcntl(ifd, F_SETFL, flags | O_NONBLOCK) == -1) 1055 warn("couldn't set %s to nonblock: %m", (ifd==0? "stdin": "tty")); 1056 if (ofd != ifd) { 1057 flags = fcntl(ofd, F_GETFL); 1058 if (flags == -1 1059 || fcntl(ofd, F_SETFL, flags | O_NONBLOCK) == -1) 1060 warn("couldn't set stdout to nonblock: %m"); 1061 } 1062 1063 nibuf = nobuf = 0; 1064 ibufp = obufp = NULL; 1065 pty_readable = stdin_readable = 1; 1066 1067 ilevel = olevel = 0; 1068 gettimeofday(&levelt, NULL); 1069 if (max_data_rate) { 1070 max_level = max_data_rate / 10; 1071 if (max_level < 100) 1072 max_level = 100; 1073 } else 1074 max_level = PPP_MRU + PPP_HDRLEN + 1; 1075 1076 nfds = (ofd > pty_master? ofd: pty_master) + 1; 1077 if (recordf != NULL) { 1078 gettimeofday(&lasttime, NULL); 1079 putc(7, recordf); /* put start marker */ 1080 putc(lasttime.tv_sec >> 24, recordf); 1081 putc(lasttime.tv_sec >> 16, recordf); 1082 putc(lasttime.tv_sec >> 8, recordf); 1083 putc(lasttime.tv_sec, recordf); 1084 lasttime.tv_usec = 0; 1085 } 1086 1087 while (nibuf != 0 || nobuf != 0 || pty_readable || stdin_readable) { 1088 top = 0; 1089 tout.tv_sec = 0; 1090 tout.tv_usec = 10000; 1091 FD_ZERO(&ready); 1092 FD_ZERO(&writey); 1093 if (nibuf != 0) { 1094 if (ilevel >= max_level) 1095 top = &tout; 1096 else 1097 FD_SET(pty_master, &writey); 1098 } else if (stdin_readable) 1099 FD_SET(ifd, &ready); 1100 if (nobuf != 0) { 1101 if (olevel >= max_level) 1102 top = &tout; 1103 else 1104 FD_SET(ofd, &writey); 1105 } else if (pty_readable) 1106 FD_SET(pty_master, &ready); 1107 if (select(nfds, &ready, &writey, NULL, top) < 0) { 1108 if (errno != EINTR) 1109 fatal("select"); 1110 continue; 1111 } 1112 if (max_data_rate) { 1113 double dt; 1114 int nbt; 1115 struct timeval now; 1116 1117 gettimeofday(&now, NULL); 1118 dt = (now.tv_sec - levelt.tv_sec 1119 + (now.tv_usec - levelt.tv_usec) / 1e6); 1120 nbt = (int)(dt * max_data_rate); 1121 ilevel = (nbt < 0 || nbt > ilevel)? 0: ilevel - nbt; 1122 olevel = (nbt < 0 || nbt > olevel)? 0: olevel - nbt; 1123 levelt = now; 1124 } else 1125 ilevel = olevel = 0; 1126 if (FD_ISSET(ifd, &ready)) { 1127 ibufp = inpacket_buf; 1128 nibuf = read(ifd, ibufp, PPP_MRU + PPP_HDRLEN); 1129 if (nibuf < 0 && errno == EIO) 1130 nibuf = 0; 1131 if (nibuf < 0) { 1132 if (!(errno == EINTR || errno == EAGAIN)) { 1133 error("Error reading standard input: %m"); 1134 break; 1135 } 1136 nibuf = 0; 1137 } else if (nibuf == 0) { 1138 /* end of file from stdin */ 1139 stdin_readable = 0; 1140 if (recordf) 1141 if (!record_write(recordf, 4, NULL, 0, &lasttime)) 1142 recordf = NULL; 1143 } else { 1144 FD_SET(pty_master, &writey); 1145 if (recordf) 1146 if (!record_write(recordf, 2, ibufp, nibuf, &lasttime)) 1147 recordf = NULL; 1148 } 1149 } 1150 if (FD_ISSET(pty_master, &ready)) { 1151 obufp = outpacket_buf; 1152 nobuf = read(pty_master, obufp, PPP_MRU + PPP_HDRLEN); 1153 if (nobuf < 0 && errno == EIO) 1154 nobuf = 0; 1155 if (nobuf < 0) { 1156 if (!(errno == EINTR || errno == EAGAIN)) { 1157 error("Error reading pseudo-tty master: %m"); 1158 break; 1159 } 1160 nobuf = 0; 1161 } else if (nobuf == 0) { 1162 /* end of file from the pty - slave side has closed */ 1163 pty_readable = 0; 1164 stdin_readable = 0; /* pty is not writable now */ 1165 nibuf = 0; 1166 close(ofd); 1167 if (recordf) 1168 if (!record_write(recordf, 3, NULL, 0, &lasttime)) 1169 recordf = NULL; 1170 } else { 1171 FD_SET(ofd, &writey); 1172 if (recordf) 1173 if (!record_write(recordf, 1, obufp, nobuf, &lasttime)) 1174 recordf = NULL; 1175 } 1176 } else if (!stdin_readable) 1177 pty_readable = 0; 1178 if (FD_ISSET(ofd, &writey)) { 1179 n = nobuf; 1180 if (olevel + n > max_level) 1181 n = max_level - olevel; 1182 n = write(ofd, obufp, n); 1183 if (n < 0) { 1184 if (errno == EIO) { 1185 pty_readable = 0; 1186 nobuf = 0; 1187 } else if (errno != EAGAIN && errno != EINTR) { 1188 error("Error writing standard output: %m"); 1189 break; 1190 } 1191 } else { 1192 obufp += n; 1193 nobuf -= n; 1194 olevel += n; 1195 } 1196 } 1197 if (FD_ISSET(pty_master, &writey)) { 1198 n = nibuf; 1199 if (ilevel + n > max_level) 1200 n = max_level - ilevel; 1201 n = write(pty_master, ibufp, n); 1202 if (n < 0) { 1203 if (errno == EIO) { 1204 stdin_readable = 0; 1205 nibuf = 0; 1206 } else if (errno != EAGAIN && errno != EINTR) { 1207 error("Error writing pseudo-tty master: %m"); 1208 break; 1209 } 1210 } else { 1211 ibufp += n; 1212 nibuf -= n; 1213 ilevel += n; 1214 } 1215 } 1216 } 1217 exit(0); 1218} 1219 1220static int 1221record_write(f, code, buf, nb, tp) 1222 FILE *f; 1223 int code; 1224 u_char *buf; 1225 int nb; 1226 struct timeval *tp; 1227{ 1228 struct timeval now; 1229 int diff; 1230 1231 gettimeofday(&now, NULL); 1232 now.tv_usec /= 100000; /* actually 1/10 s, not usec now */ 1233 diff = (now.tv_sec - tp->tv_sec) * 10 + (now.tv_usec - tp->tv_usec); 1234 if (diff > 0) { 1235 if (diff > 255) { 1236 putc(5, f); 1237 putc(diff >> 24, f); 1238 putc(diff >> 16, f); 1239 putc(diff >> 8, f); 1240 putc(diff, f); 1241 } else { 1242 putc(6, f); 1243 putc(diff, f); 1244 } 1245 *tp = now; 1246 } 1247 putc(code, f); 1248 if (buf != NULL) { 1249 putc(nb >> 8, f); 1250 putc(nb, f); 1251 fwrite(buf, nb, 1, f); 1252 } 1253 fflush(f); 1254 if (ferror(f)) { 1255 error("Error writing record file: %m"); 1256 return 0; 1257 } 1258 return 1; 1259} 1260