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