1 /*- 2 * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org> 3 * based on work by Toshiharu OHNO <tony-o@iij.ad.jp> 4 * Internet Initiative Japan, Inc (IIJ) 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #include <sys/param.h> 32 #include <netinet/in.h> 33 #include <netinet/in_systm.h> 34 #include <netinet/ip.h> 35 #include <sys/un.h> 36 #include <sys/socket.h> 37 #include <net/route.h> 38 39 #include <errno.h> 40 #include <fcntl.h> 41 #include <paths.h> 42 #include <signal.h> 43 #include <stdarg.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <sys/time.h> 48 #include <termios.h> 49 #include <unistd.h> 50 #include <sys/stat.h> 51 52 #ifndef NONAT 53 #ifdef LOCALNAT 54 #include "alias.h" 55 #else 56 #include <alias.h> 57 #endif 58 #endif 59 60 #include "layer.h" 61 #include "probe.h" 62 #include "mbuf.h" 63 #include "log.h" 64 #include "defs.h" 65 #include "id.h" 66 #include "timer.h" 67 #include "fsm.h" 68 #include "lqr.h" 69 #include "hdlc.h" 70 #include "lcp.h" 71 #include "ccp.h" 72 #include "iplist.h" 73 #include "throughput.h" 74 #include "slcompress.h" 75 #include "ncpaddr.h" 76 #include "ipcp.h" 77 #include "filter.h" 78 #include "descriptor.h" 79 #include "link.h" 80 #include "mp.h" 81 #ifndef NORADIUS 82 #include "radius.h" 83 #endif 84 #include "ipv6cp.h" 85 #include "ncp.h" 86 #include "bundle.h" 87 #include "auth.h" 88 #include "systems.h" 89 #include "sig.h" 90 #include "main.h" 91 #include "server.h" 92 #include "prompt.h" 93 #include "chat.h" 94 #include "chap.h" 95 #include "cbcp.h" 96 #include "datalink.h" 97 #include "iface.h" 98 99 #ifndef O_NONBLOCK 100 #ifdef O_NDELAY 101 #define O_NONBLOCK O_NDELAY 102 #endif 103 #endif 104 105 static void DoLoop(struct bundle *); 106 static void TerminalStop(int); 107 108 static struct bundle *SignalBundle; 109 static struct prompt *SignalPrompt; 110 struct libalias *la; 111 112 void 113 Cleanup() 114 { 115 SignalBundle->CleaningUp = 1; 116 bundle_Close(SignalBundle, NULL, CLOSE_STAYDOWN); 117 } 118 119 void 120 AbortProgram(int excode) 121 { 122 if (SignalBundle) 123 server_Close(SignalBundle); 124 log_Printf(LogPHASE, "PPP Terminated (%s).\n", ex_desc(excode)); 125 if (SignalBundle) { 126 bundle_Close(SignalBundle, NULL, CLOSE_STAYDOWN); 127 bundle_Destroy(SignalBundle); 128 } 129 log_Close(); 130 exit(excode); 131 } 132 133 static void 134 CloseConnection(int signo) 135 { 136 /* NOTE, these are manual, we've done a setsid() */ 137 sig_signal(SIGINT, SIG_IGN); 138 log_Printf(LogPHASE, "Caught signal %d, abort connection(s)\n", signo); 139 bundle_Down(SignalBundle, CLOSE_STAYDOWN); 140 sig_signal(SIGINT, CloseConnection); 141 } 142 143 static void 144 CloseSession(int signo) 145 { 146 log_Printf(LogPHASE, "Signal %d, terminate.\n", signo); 147 Cleanup(); 148 } 149 150 static pid_t BGPid = 0; 151 152 static void 153 KillChild(int signo) 154 { 155 signal(signo, SIG_IGN); 156 log_Printf(LogPHASE, "Parent: Signal %d\n", signo); 157 kill(BGPid, SIGINT); 158 } 159 160 static void 161 TerminalCont(int signo __unused) 162 { 163 signal(SIGCONT, SIG_DFL); 164 prompt_Continue(SignalPrompt); 165 } 166 167 static void 168 TerminalStop(int signo __unused) 169 { 170 prompt_Suspend(SignalPrompt); 171 signal(SIGCONT, TerminalCont); 172 raise(SIGSTOP); 173 } 174 175 static void 176 BringDownServer(int signo __unused) 177 { 178 /* Drops all child prompts too ! */ 179 if (server_Close(SignalBundle)) 180 log_Printf(LogPHASE, "Closed server socket\n"); 181 } 182 183 static void 184 RestartServer(int signo __unused) 185 { 186 /* Drops all child prompts and re-opens the socket */ 187 server_Reopen(SignalBundle); 188 } 189 190 static void 191 Usage(void) 192 { 193 fprintf(stderr, "usage: ppp [-auto | -foreground | -background | -direct |" 194 " -dedicated | -ddial | -interactive]" 195 #ifndef NONAT 196 " [-nat]" 197 #endif 198 " [-quiet] [-unit N] [system ...]\n"); 199 exit(EX_START); 200 } 201 202 struct switches { 203 unsigned nat : 1; 204 unsigned fg : 1; 205 unsigned quiet : 1; 206 int mode; 207 int unit; 208 }; 209 210 static int 211 ProcessArgs(int argc, char **argv, struct switches *sw) 212 { 213 int optc, newmode, arg; 214 char *cp; 215 216 optc = 0; 217 memset(sw, '\0', sizeof *sw); 218 sw->mode = PHYS_INTERACTIVE; 219 sw->unit = -1; 220 221 for (arg = 1; arg < argc && *argv[arg] == '-'; arg++, optc++) { 222 cp = argv[arg] + 1; 223 newmode = Nam2mode(cp); 224 switch (newmode) { 225 case PHYS_NONE: 226 if (strcmp(cp, "nat") == 0) { 227 #ifdef NONAT 228 log_Printf(LogWARN, "%s ignored: NAT is compiled out\n", argv[arg]); 229 #else 230 sw->nat = 1; 231 #endif 232 optc--; /* this option isn't exclusive */ 233 } else if (strcmp(cp, "alias") == 0) { 234 #ifdef NONAT 235 log_Printf(LogWARN, "%s ignored: NAT is compiled out\n", argv[arg]); 236 fprintf(stderr, "%s ignored: NAT is compiled out\n", argv[arg]); 237 #else 238 log_Printf(LogWARN, "%s is deprecated\n", argv[arg]); 239 fprintf(stderr, "%s is deprecated\n", argv[arg]); 240 sw->nat = 1; 241 #endif 242 optc--; /* this option isn't exclusive */ 243 } else if (strncmp(cp, "unit", 4) == 0) { 244 optc--; /* this option isn't exclusive */ 245 if (cp[4] == '\0') { 246 optc--; /* nor is the argument */ 247 if (++arg == argc) { 248 fprintf(stderr, "-unit: Expected unit number\n"); 249 Usage(); 250 } else 251 sw->unit = atoi(argv[arg]); 252 } else 253 sw->unit = atoi(cp + 4); 254 } else if (strcmp(cp, "quiet") == 0) { 255 sw->quiet = 1; 256 optc--; /* this option isn't exclusive */ 257 } else 258 Usage(); 259 break; 260 261 case PHYS_ALL: 262 Usage(); 263 break; 264 265 default: 266 sw->mode = newmode; 267 if (newmode == PHYS_FOREGROUND) 268 sw->fg = 1; 269 } 270 } 271 272 if (optc > 1) { 273 fprintf(stderr, "You may specify only one mode.\n"); 274 exit(EX_START); 275 } 276 277 if (sw->mode == PHYS_AUTO && arg == argc) { 278 fprintf(stderr, "A system must be specified in auto mode.\n"); 279 exit(EX_START); 280 } 281 282 return arg; /* Don't SetLabel yet ! */ 283 } 284 285 static void 286 CheckLabel(const char *label, struct prompt *prompt, int mode) 287 { 288 const char *err; 289 290 if ((err = system_IsValid(label, prompt, mode)) != NULL) { 291 fprintf(stderr, "%s: %s\n", label, err); 292 if (mode == PHYS_DIRECT) 293 log_Printf(LogWARN, "Label %s rejected -direct connection: %s\n", 294 label, err); 295 log_Close(); 296 exit(1); 297 } 298 } 299 300 301 int 302 main(int argc, char **argv) 303 { 304 char *name; 305 const char *lastlabel; 306 int arg, holdfd[3], label; 307 unsigned f; 308 struct bundle *bundle; 309 struct prompt *prompt; 310 struct switches sw; 311 312 probe_Init(); 313 314 /* 315 * We open 3 descriptors to ensure that STDIN_FILENO, STDOUT_FILENO and 316 * STDERR_FILENO are always open. These are closed before DoLoop(), 317 * but *after* we've avoided the possibility of erroneously closing 318 * an important descriptor with close(STD{IN,OUT,ERR}_FILENO). 319 */ 320 if ((holdfd[0] = open(_PATH_DEVNULL, O_RDWR)) == -1) { 321 fprintf(stderr, "Cannot open %s !\n", _PATH_DEVNULL); 322 return 2; 323 } 324 for (f = 1; f < sizeof holdfd / sizeof *holdfd; f++) 325 holdfd[f] = dup(holdfd[0]); 326 327 name = strrchr(argv[0], '/'); 328 log_Open(name ? name + 1 : argv[0]); 329 330 #ifndef NONAT 331 la = LibAliasInit(NULL); 332 #endif 333 label = ProcessArgs(argc, argv, &sw); 334 335 /* 336 * A FreeBSD & OpenBSD hack to dodge a bug in the tty driver that drops 337 * output occasionally.... I must find the real reason some time. To 338 * display the dodgy behaviour, comment out this bit, make yourself a large 339 * routing table and then run ppp in interactive mode. The `show route' 340 * command will drop chunks of data !!! 341 */ 342 if (sw.mode == PHYS_INTERACTIVE) { 343 close(STDIN_FILENO); 344 if (open(_PATH_TTY, O_RDONLY) != STDIN_FILENO) { 345 fprintf(stderr, "Cannot open %s for input !\n", _PATH_TTY); 346 return 2; 347 } 348 } 349 350 /* Allow output for the moment (except in direct mode) */ 351 if (sw.mode == PHYS_DIRECT) 352 prompt = NULL; 353 else 354 SignalPrompt = prompt = prompt_Create(NULL, NULL, PROMPT_STD); 355 356 ID0init(); 357 if (ID0realuid() != 0) { 358 char conf[200], *ptr; 359 360 snprintf(conf, sizeof conf, "%s/%s", PPP_CONFDIR, CONFFILE); 361 do { 362 struct stat sb; 363 364 if (stat(conf, &sb) == 0 && sb.st_mode & S_IWOTH) { 365 log_Printf(LogALERT, "ppp: Access violation: Please protect %s\n", 366 conf); 367 return -1; 368 } 369 ptr = conf + strlen(conf)-2; 370 while (ptr > conf && *ptr != '/') 371 *ptr-- = '\0'; 372 } while (ptr >= conf); 373 } 374 375 if (label < argc) 376 for (arg = label; arg < argc; arg++) 377 CheckLabel(argv[arg], prompt, sw.mode); 378 else 379 CheckLabel("default", prompt, sw.mode); 380 381 if (!sw.quiet) 382 prompt_Printf(prompt, "Working in %s mode\n", mode2Nam(sw.mode)); 383 384 if ((bundle = bundle_Create(TUN_PREFIX, sw.mode, sw.unit)) == NULL) 385 return EX_START; 386 387 /* NOTE: We may now have changed argv[1] via a ``set proctitle'' */ 388 389 if (prompt) { 390 prompt->bundle = bundle; /* couldn't do it earlier */ 391 if (!sw.quiet) 392 prompt_Printf(prompt, "Using interface: %s\n", bundle->iface->name); 393 } 394 SignalBundle = bundle; 395 bundle->NatEnabled = sw.nat; 396 if (sw.nat) 397 opt_enable(bundle, OPT_IFACEALIAS); 398 399 if (system_Select(bundle, "default", CONFFILE, prompt, NULL) < 0) 400 prompt_Printf(prompt, "Warning: No default entry found in config file.\n"); 401 402 sig_signal(SIGHUP, CloseSession); 403 sig_signal(SIGTERM, CloseSession); 404 sig_signal(SIGINT, CloseConnection); 405 sig_signal(SIGQUIT, CloseSession); 406 sig_signal(SIGALRM, SIG_IGN); 407 signal(SIGPIPE, SIG_IGN); 408 409 if (sw.mode == PHYS_INTERACTIVE) 410 sig_signal(SIGTSTP, TerminalStop); 411 412 sig_signal(SIGUSR1, RestartServer); 413 sig_signal(SIGUSR2, BringDownServer); 414 415 lastlabel = argv[argc - 1]; 416 for (arg = label; arg < argc; arg++) { 417 /* In case we use LABEL or ``set enddisc label'' */ 418 bundle_SetLabel(bundle, lastlabel); 419 system_Select(bundle, argv[arg], CONFFILE, prompt, NULL); 420 } 421 422 if (label < argc) 423 /* In case the last label did a ``load'' */ 424 bundle_SetLabel(bundle, lastlabel); 425 426 if (sw.mode == PHYS_AUTO && 427 ncprange_family(&bundle->ncp.ipcp.cfg.peer_range) == AF_UNSPEC) { 428 prompt_Printf(prompt, "You must ``set ifaddr'' with a peer address " 429 "in auto mode.\n"); 430 AbortProgram(EX_START); 431 } 432 433 if (sw.mode != PHYS_INTERACTIVE) { 434 if (sw.mode != PHYS_DIRECT) { 435 if (!sw.fg) { 436 int bgpipe[2]; 437 pid_t bgpid; 438 439 if (sw.mode == PHYS_BACKGROUND && pipe(bgpipe)) { 440 log_Printf(LogERROR, "pipe: %s\n", strerror(errno)); 441 AbortProgram(EX_SOCK); 442 } 443 444 bgpid = fork(); 445 if (bgpid == -1) { 446 log_Printf(LogERROR, "fork: %s\n", strerror(errno)); 447 AbortProgram(EX_SOCK); 448 } 449 450 if (bgpid) { 451 char c = EX_NORMAL; 452 int ret; 453 454 if (sw.mode == PHYS_BACKGROUND) { 455 close(bgpipe[1]); 456 BGPid = bgpid; 457 /* If we get a signal, kill the child */ 458 signal(SIGHUP, KillChild); 459 signal(SIGTERM, KillChild); 460 signal(SIGINT, KillChild); 461 signal(SIGQUIT, KillChild); 462 463 /* Wait for our child to close its pipe before we exit */ 464 while ((ret = read(bgpipe[0], &c, 1)) == 1) { 465 switch (c) { 466 case EX_NORMAL: 467 if (!sw.quiet) { 468 prompt_Printf(prompt, "PPP enabled\n"); 469 log_Printf(LogPHASE, "Parent: PPP enabled\n"); 470 } 471 break; 472 case EX_REDIAL: 473 if (!sw.quiet) 474 prompt_Printf(prompt, "Attempting redial\n"); 475 continue; 476 case EX_RECONNECT: 477 if (!sw.quiet) 478 prompt_Printf(prompt, "Attempting reconnect\n"); 479 continue; 480 default: 481 prompt_Printf(prompt, "Child failed (%s)\n", 482 ex_desc((int)c)); 483 log_Printf(LogPHASE, "Parent: Child failed (%s)\n", 484 ex_desc((int) c)); 485 } 486 break; 487 } 488 if (ret != 1) { 489 prompt_Printf(prompt, "Child exit, no status.\n"); 490 log_Printf(LogPHASE, "Parent: Child exit, no status.\n"); 491 } 492 close(bgpipe[0]); 493 } 494 return c; 495 } else if (sw.mode == PHYS_BACKGROUND) { 496 close(bgpipe[0]); 497 bundle->notify.fd = bgpipe[1]; 498 } 499 500 bundle_ChangedPID(bundle); 501 bundle_LockTun(bundle); /* we have a new pid */ 502 } 503 504 /* -auto, -dedicated, -ddial, -foreground & -background */ 505 prompt_Destroy(prompt, 0); 506 close(STDOUT_FILENO); 507 close(STDERR_FILENO); 508 close(STDIN_FILENO); 509 if (!sw.fg) 510 setsid(); 511 } else { 512 /* -direct - STDIN_FILENO gets used by physical_Open */ 513 prompt_TtyInit(NULL); 514 close(STDOUT_FILENO); 515 close(STDERR_FILENO); 516 } 517 } else { 518 /* -interactive */ 519 close(STDERR_FILENO); 520 prompt_TtyInit(prompt); 521 prompt_TtyCommandMode(prompt); 522 prompt_Required(prompt); 523 } 524 525 /* We can get rid of these now */ 526 for (f = 0; f < sizeof holdfd / sizeof *holdfd; f++) 527 close(holdfd[f]); 528 529 log_Printf(LogPHASE, "PPP Started (%s mode).\n", mode2Nam(sw.mode)); 530 DoLoop(bundle); 531 AbortProgram(EX_NORMAL); 532 533 return EX_NORMAL; 534 } 535 536 static void 537 DoLoop(struct bundle *bundle) 538 { 539 fd_set *rfds, *wfds, *efds; 540 int i, nfds, nothing_done; 541 542 if ((rfds = mkfdset()) == NULL) { 543 log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n"); 544 return; 545 } 546 547 if ((wfds = mkfdset()) == NULL) { 548 log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n"); 549 free(rfds); 550 return; 551 } 552 553 if ((efds = mkfdset()) == NULL) { 554 log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n"); 555 free(rfds); 556 free(wfds); 557 return; 558 } 559 560 for (; !bundle_IsDead(bundle); bundle_CleanDatalinks(bundle)) { 561 nfds = 0; 562 zerofdset(rfds); 563 zerofdset(wfds); 564 zerofdset(efds); 565 566 /* All our datalinks, the tun device and the MP socket */ 567 descriptor_UpdateSet(&bundle->desc, rfds, wfds, efds, &nfds); 568 569 /* All our prompts and the diagnostic socket */ 570 descriptor_UpdateSet(&server.desc, rfds, NULL, NULL, &nfds); 571 572 bundle_CleanDatalinks(bundle); 573 if (bundle_IsDead(bundle)) 574 /* Don't select - we'll be here forever */ 575 break; 576 577 /* 578 * It's possible that we've had a signal since we last checked. If 579 * we don't check again before calling select(), we may end up stuck 580 * after having missed the event.... sig_Handle() tries to be as 581 * quick as possible if nothing is likely to have happened. 582 * This is only really likely if we block in open(... O_NONBLOCK) 583 * which will happen with a misconfigured device. 584 */ 585 if (sig_Handle()) 586 continue; 587 588 i = select(nfds, rfds, wfds, efds, NULL); 589 590 if (i < 0 && errno != EINTR) { 591 log_Printf(LogERROR, "DoLoop: select(): %s\n", strerror(errno)); 592 if (log_IsKept(LogTIMER)) { 593 struct timeval t; 594 595 for (i = 0; i <= nfds; i++) { 596 if (FD_ISSET(i, rfds)) { 597 log_Printf(LogTIMER, "Read set contains %d\n", i); 598 FD_CLR(i, rfds); 599 t.tv_sec = t.tv_usec = 0; 600 if (select(nfds, rfds, wfds, efds, &t) != -1) { 601 log_Printf(LogTIMER, "The culprit !\n"); 602 break; 603 } 604 } 605 if (FD_ISSET(i, wfds)) { 606 log_Printf(LogTIMER, "Write set contains %d\n", i); 607 FD_CLR(i, wfds); 608 t.tv_sec = t.tv_usec = 0; 609 if (select(nfds, rfds, wfds, efds, &t) != -1) { 610 log_Printf(LogTIMER, "The culprit !\n"); 611 break; 612 } 613 } 614 if (FD_ISSET(i, efds)) { 615 log_Printf(LogTIMER, "Error set contains %d\n", i); 616 FD_CLR(i, efds); 617 t.tv_sec = t.tv_usec = 0; 618 if (select(nfds, rfds, wfds, efds, &t) != -1) { 619 log_Printf(LogTIMER, "The culprit !\n"); 620 break; 621 } 622 } 623 } 624 } 625 break; 626 } 627 628 log_Printf(LogTIMER, "Select returns %d\n", i); 629 630 sig_Handle(); 631 632 if (i <= 0) 633 continue; 634 635 for (i = 0; i <= nfds; i++) 636 if (FD_ISSET(i, efds)) { 637 log_Printf(LogPHASE, "Exception detected on descriptor %d\n", i); 638 /* We deal gracefully with link descriptor exceptions */ 639 if (!bundle_Exception(bundle, i)) { 640 log_Printf(LogERROR, "Exception cannot be handled !\n"); 641 break; 642 } 643 } 644 645 if (i <= nfds) 646 break; 647 648 nothing_done = 1; 649 650 if (descriptor_IsSet(&server.desc, rfds)) { 651 descriptor_Read(&server.desc, bundle, rfds); 652 nothing_done = 0; 653 } 654 655 if (descriptor_IsSet(&bundle->desc, rfds)) { 656 descriptor_Read(&bundle->desc, bundle, rfds); 657 nothing_done = 0; 658 } 659 660 if (descriptor_IsSet(&bundle->desc, wfds)) 661 if (descriptor_Write(&bundle->desc, bundle, wfds) <= 0 && nothing_done) { 662 /* 663 * This is disastrous. The OS has told us that something is 664 * writable, and all our write()s have failed. Rather than 665 * going back immediately to do our UpdateSet()s and select(), 666 * we sleep for a bit to avoid gobbling up all cpu time. 667 */ 668 struct timeval t; 669 670 t.tv_sec = 0; 671 t.tv_usec = 100000; 672 select(0, NULL, NULL, NULL, &t); 673 } 674 } 675 676 log_Printf(LogDEBUG, "DoLoop done.\n"); 677 } 678