main.c revision 134789 
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: head/usr.sbin/ppp/main.c 134789 2004-09-05 01:46:52Z brian $
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
105static void DoLoop(struct bundle *);
106static void TerminalStop(int);
107
108static struct bundle *SignalBundle;
109static struct prompt *SignalPrompt;
110
111void
112Cleanup()
113{
114  SignalBundle->CleaningUp = 1;
115  bundle_Close(SignalBundle, NULL, CLOSE_STAYDOWN);
116}
117
118void
119AbortProgram(int excode)
120{
121  if (SignalBundle)
122    server_Close(SignalBundle);
123  log_Printf(LogPHASE, "PPP Terminated (%s).\n", ex_desc(excode));
124  if (SignalBundle) {
125    bundle_Close(SignalBundle, NULL, CLOSE_STAYDOWN);
126    bundle_Destroy(SignalBundle);
127  }
128  log_Close();
129  exit(excode);
130}
131
132static void
133CloseConnection(int signo)
134{
135  /* NOTE, these are manual, we've done a setsid() */
136  sig_signal(SIGINT, SIG_IGN);
137  log_Printf(LogPHASE, "Caught signal %d, abort connection(s)\n", signo);
138  bundle_Down(SignalBundle, CLOSE_STAYDOWN);
139  sig_signal(SIGINT, CloseConnection);
140}
141
142static void
143CloseSession(int signo)
144{
145  log_Printf(LogPHASE, "Signal %d, terminate.\n", signo);
146  Cleanup();
147}
148
149static pid_t BGPid = 0;
150
151static void
152KillChild(int signo)
153{
154  signal(signo, SIG_IGN);
155  log_Printf(LogPHASE, "Parent: Signal %d\n", signo);
156  kill(BGPid, SIGINT);
157}
158
159static void
160TerminalCont(int signo __unused)
161{
162  signal(SIGCONT, SIG_DFL);
163  prompt_Continue(SignalPrompt);
164}
165
166static void
167TerminalStop(int signo __unused)
168{
169  prompt_Suspend(SignalPrompt);
170  signal(SIGCONT, TerminalCont);
171  raise(SIGSTOP);
172}
173
174static void
175BringDownServer(int signo __unused)
176{
177  /* Drops all child prompts too ! */
178  if (server_Close(SignalBundle))
179    log_Printf(LogPHASE, "Closed server socket\n");
180}
181
182static void
183RestartServer(int signo __unused)
184{
185  /* Drops all child prompts and re-opens the socket */
186  server_Reopen(SignalBundle);
187}
188
189static void
190Usage(void)
191{
192  fprintf(stderr, "usage: ppp [-auto | -foreground | -background | -direct |"
193          " -dedicated | -ddial | -interactive]"
194#ifndef NOALIAS
195          " [-nat]"
196#endif
197          " [-quiet] [-unit N] [system ...]\n");
198  exit(EX_START);
199}
200
201struct switches {
202  unsigned nat : 1;
203  unsigned fg : 1;
204  unsigned quiet : 1;
205  int mode;
206  int unit;
207};
208
209static int
210ProcessArgs(int argc, char **argv, struct switches *sw)
211{
212  int optc, newmode, arg;
213  char *cp;
214
215  optc = 0;
216  memset(sw, '\0', sizeof *sw);
217  sw->mode = PHYS_INTERACTIVE;
218  sw->unit = -1;
219
220  for (arg = 1; arg < argc && *argv[arg] == '-'; arg++, optc++) {
221    cp = argv[arg] + 1;
222    newmode = Nam2mode(cp);
223    switch (newmode) {
224      case PHYS_NONE:
225        if (strcmp(cp, "nat") == 0) {
226#ifdef NONAT
227          log_Printf(LogWARN, "%s ignored: NAT is compiled out\n", argv[arg]);
228#else
229          sw->nat = 1;
230#endif
231          optc--;			/* this option isn't exclusive */
232        } else if (strcmp(cp, "alias") == 0) {
233#ifdef NONAT
234          log_Printf(LogWARN, "%s ignored: NAT is compiled out\n", argv[arg]);
235          fprintf(stderr, "%s ignored: NAT is compiled out\n", argv[arg]);
236#else
237          log_Printf(LogWARN, "%s is deprecated\n", argv[arg]);
238          fprintf(stderr, "%s is deprecated\n", argv[arg]);
239          sw->nat = 1;
240#endif
241          optc--;			/* this option isn't exclusive */
242        } else if (strncmp(cp, "unit", 4) == 0) {
243          optc--;			/* this option isn't exclusive */
244          if (cp[4] == '\0') {
245            optc--;			/* nor is the argument */
246            if (++arg == argc) {
247              fprintf(stderr, "-unit: Expected unit number\n");
248              Usage();
249            } else
250              sw->unit = atoi(argv[arg]);
251          } else
252            sw->unit = atoi(cp + 4);
253        } else if (strcmp(cp, "quiet") == 0) {
254          sw->quiet = 1;
255          optc--;			/* this option isn't exclusive */
256        } else
257          Usage();
258        break;
259
260      case PHYS_ALL:
261        Usage();
262        break;
263
264      default:
265        sw->mode = newmode;
266        if (newmode == PHYS_FOREGROUND)
267          sw->fg = 1;
268    }
269  }
270
271  if (optc > 1) {
272    fprintf(stderr, "You may specify only one mode.\n");
273    exit(EX_START);
274  }
275
276  if (sw->mode == PHYS_AUTO && arg == argc) {
277    fprintf(stderr, "A system must be specified in auto mode.\n");
278    exit(EX_START);
279  }
280
281  return arg;		/* Don't SetLabel yet ! */
282}
283
284static void
285CheckLabel(const char *label, struct prompt *prompt, int mode)
286{
287  const char *err;
288
289  if ((err = system_IsValid(label, prompt, mode)) != NULL) {
290    fprintf(stderr, "%s: %s\n", label, err);
291    if (mode == PHYS_DIRECT)
292      log_Printf(LogWARN, "Label %s rejected -direct connection: %s\n",
293                 label, err);
294    log_Close();
295    exit(1);
296  }
297}
298
299
300int
301main(int argc, char **argv)
302{
303  char *name;
304  const char *lastlabel;
305  int arg, holdfd[3], label;
306  unsigned f;
307  struct bundle *bundle;
308  struct prompt *prompt;
309  struct switches sw;
310
311  probe_Init();
312
313  /*
314   * We open 3 descriptors to ensure that STDIN_FILENO, STDOUT_FILENO and
315   * STDERR_FILENO are always open.  These are closed before DoLoop(),
316   * but *after* we've avoided the possibility of erroneously closing
317   * an important descriptor with close(STD{IN,OUT,ERR}_FILENO).
318   */
319  if ((holdfd[0] = open(_PATH_DEVNULL, O_RDWR)) == -1) {
320    fprintf(stderr, "Cannot open %s !\n", _PATH_DEVNULL);
321    return 2;
322  }
323  for (f = 1; f < sizeof holdfd / sizeof *holdfd; f++)
324    holdfd[f] = dup(holdfd[0]);
325
326  name = strrchr(argv[0], '/');
327  log_Open(name ? name + 1 : argv[0]);
328
329#ifndef NONAT
330  PacketAliasInit();
331#endif
332  label = ProcessArgs(argc, argv, &sw);
333
334  /*
335   * A FreeBSD & OpenBSD hack to dodge a bug in the tty driver that drops
336   * output occasionally.... I must find the real reason some time.  To
337   * display the dodgy behaviour, comment out this bit, make yourself a large
338   * routing table and then run ppp in interactive mode.  The `show route'
339   * command will drop chunks of data !!!
340   */
341  if (sw.mode == PHYS_INTERACTIVE) {
342    close(STDIN_FILENO);
343    if (open(_PATH_TTY, O_RDONLY) != STDIN_FILENO) {
344      fprintf(stderr, "Cannot open %s for input !\n", _PATH_TTY);
345      return 2;
346    }
347  }
348
349  /* Allow output for the moment (except in direct mode) */
350  if (sw.mode == PHYS_DIRECT)
351    prompt = NULL;
352  else
353    SignalPrompt = prompt = prompt_Create(NULL, NULL, PROMPT_STD);
354
355  ID0init();
356  if (ID0realuid() != 0) {
357    char conf[200], *ptr;
358
359    snprintf(conf, sizeof conf, "%s/%s", PPP_CONFDIR, CONFFILE);
360    do {
361      struct stat sb;
362
363      if (stat(conf, &sb) == 0 && sb.st_mode & S_IWOTH) {
364        log_Printf(LogALERT, "ppp: Access violation: Please protect %s\n",
365                   conf);
366        return -1;
367      }
368      ptr = conf + strlen(conf)-2;
369      while (ptr > conf && *ptr != '/')
370        *ptr-- = '\0';
371    } while (ptr >= conf);
372  }
373
374  if (label < argc)
375    for (arg = label; arg < argc; arg++)
376      CheckLabel(argv[arg], prompt, sw.mode);
377  else
378    CheckLabel("default", prompt, sw.mode);
379
380  if (!sw.quiet)
381    prompt_Printf(prompt, "Working in %s mode\n", mode2Nam(sw.mode));
382
383  if ((bundle = bundle_Create(TUN_PREFIX, sw.mode, sw.unit)) == NULL)
384    return EX_START;
385
386  /* NOTE:  We may now have changed argv[1] via a ``set proctitle'' */
387
388  if (prompt) {
389    prompt->bundle = bundle;	/* couldn't do it earlier */
390    if (!sw.quiet)
391      prompt_Printf(prompt, "Using interface: %s\n", bundle->iface->name);
392  }
393  SignalBundle = bundle;
394  bundle->NatEnabled = sw.nat;
395  if (sw.nat)
396    bundle->cfg.opt |= OPT_IFACEALIAS;
397
398  if (system_Select(bundle, "default", CONFFILE, prompt, NULL) < 0)
399    prompt_Printf(prompt, "Warning: No default entry found in config file.\n");
400
401  sig_signal(SIGHUP, CloseSession);
402  sig_signal(SIGTERM, CloseSession);
403  sig_signal(SIGINT, CloseConnection);
404  sig_signal(SIGQUIT, CloseSession);
405  sig_signal(SIGALRM, SIG_IGN);
406  signal(SIGPIPE, SIG_IGN);
407
408  if (sw.mode == PHYS_INTERACTIVE)
409    sig_signal(SIGTSTP, TerminalStop);
410
411  sig_signal(SIGUSR1, RestartServer);
412  sig_signal(SIGUSR2, BringDownServer);
413
414  lastlabel = argv[argc - 1];
415  for (arg = label; arg < argc; arg++) {
416    /* In case we use LABEL or ``set enddisc label'' */
417    bundle_SetLabel(bundle, lastlabel);
418    system_Select(bundle, argv[arg], CONFFILE, prompt, NULL);
419  }
420
421  if (label < argc)
422    /* In case the last label did a ``load'' */
423    bundle_SetLabel(bundle, lastlabel);
424
425  if (sw.mode == PHYS_AUTO &&
426      ncprange_family(&bundle->ncp.ipcp.cfg.peer_range) == AF_UNSPEC) {
427    prompt_Printf(prompt, "You must ``set ifaddr'' with a peer address "
428                  "in auto mode.\n");
429    AbortProgram(EX_START);
430  }
431
432  if (sw.mode != PHYS_INTERACTIVE) {
433    if (sw.mode != PHYS_DIRECT) {
434      if (!sw.fg) {
435        int bgpipe[2];
436        pid_t bgpid;
437
438        if (sw.mode == PHYS_BACKGROUND && pipe(bgpipe)) {
439          log_Printf(LogERROR, "pipe: %s\n", strerror(errno));
440	  AbortProgram(EX_SOCK);
441        }
442
443        bgpid = fork();
444        if (bgpid == -1) {
445	  log_Printf(LogERROR, "fork: %s\n", strerror(errno));
446	  AbortProgram(EX_SOCK);
447        }
448
449        if (bgpid) {
450	  char c = EX_NORMAL;
451          int ret;
452
453	  if (sw.mode == PHYS_BACKGROUND) {
454	    close(bgpipe[1]);
455	    BGPid = bgpid;
456            /* If we get a signal, kill the child */
457            signal(SIGHUP, KillChild);
458            signal(SIGTERM, KillChild);
459            signal(SIGINT, KillChild);
460            signal(SIGQUIT, KillChild);
461
462	    /* Wait for our child to close its pipe before we exit */
463            while ((ret = read(bgpipe[0], &c, 1)) == 1) {
464              switch (c) {
465                case EX_NORMAL:
466                  if (!sw.quiet) {
467	            prompt_Printf(prompt, "PPP enabled\n");
468	            log_Printf(LogPHASE, "Parent: PPP enabled\n");
469                  }
470	          break;
471                case EX_REDIAL:
472                  if (!sw.quiet)
473	            prompt_Printf(prompt, "Attempting redial\n");
474                  continue;
475                case EX_RECONNECT:
476                  if (!sw.quiet)
477	            prompt_Printf(prompt, "Attempting reconnect\n");
478                  continue;
479	        default:
480	          prompt_Printf(prompt, "Child failed (%s)\n",
481                                ex_desc((int)c));
482	          log_Printf(LogPHASE, "Parent: Child failed (%s)\n",
483		             ex_desc((int) c));
484	      }
485	      break;
486            }
487            if (ret != 1) {
488	      prompt_Printf(prompt, "Child exit, no status.\n");
489	      log_Printf(LogPHASE, "Parent: Child exit, no status.\n");
490	    }
491	    close(bgpipe[0]);
492	  }
493	  return c;
494        } else if (sw.mode == PHYS_BACKGROUND) {
495	  close(bgpipe[0]);
496          bundle->notify.fd = bgpipe[1];
497        }
498
499        bundle_ChangedPID(bundle);
500        bundle_LockTun(bundle);	/* we have a new pid */
501      }
502
503      /* -auto, -dedicated, -ddial, -foreground & -background */
504      prompt_Destroy(prompt, 0);
505      close(STDOUT_FILENO);
506      close(STDERR_FILENO);
507      close(STDIN_FILENO);
508      if (!sw.fg)
509        setsid();
510    } else {
511      /* -direct - STDIN_FILENO gets used by physical_Open */
512      prompt_TtyInit(NULL);
513      close(STDOUT_FILENO);
514      close(STDERR_FILENO);
515    }
516  } else {
517    /* -interactive */
518    close(STDERR_FILENO);
519    prompt_TtyInit(prompt);
520    prompt_TtyCommandMode(prompt);
521    prompt_Required(prompt);
522  }
523
524  /* We can get rid of these now */
525  for (f = 0; f < sizeof holdfd / sizeof *holdfd; f++)
526    close(holdfd[f]);
527
528  log_Printf(LogPHASE, "PPP Started (%s mode).\n", mode2Nam(sw.mode));
529  DoLoop(bundle);
530  AbortProgram(EX_NORMAL);
531
532  return EX_NORMAL;
533}
534
535static void
536DoLoop(struct bundle *bundle)
537{
538  fd_set *rfds, *wfds, *efds;
539  int i, nfds, nothing_done;
540
541  if ((rfds = mkfdset()) == NULL) {
542    log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
543    return;
544  }
545
546  if ((wfds = mkfdset()) == NULL) {
547    log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
548    free(rfds);
549    return;
550  }
551
552  if ((efds = mkfdset()) == NULL) {
553    log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
554    free(rfds);
555    free(wfds);
556    return;
557  }
558
559  for (; !bundle_IsDead(bundle); bundle_CleanDatalinks(bundle)) {
560    nfds = 0;
561    zerofdset(rfds);
562    zerofdset(wfds);
563    zerofdset(efds);
564
565    /* All our datalinks, the tun device and the MP socket */
566    descriptor_UpdateSet(&bundle->desc, rfds, wfds, efds, &nfds);
567
568    /* All our prompts and the diagnostic socket */
569    descriptor_UpdateSet(&server.desc, rfds, NULL, NULL, &nfds);
570
571    bundle_CleanDatalinks(bundle);
572    if (bundle_IsDead(bundle))
573      /* Don't select - we'll be here forever */
574      break;
575
576    /*
577     * It's possible that we've had a signal since we last checked.  If
578     * we don't check again before calling select(), we may end up stuck
579     * after having missed the event.... sig_Handle() tries to be as
580     * quick as possible if nothing is likely to have happened.
581     * This is only really likely if we block in open(... O_NONBLOCK)
582     * which will happen with a misconfigured device.
583     */
584    if (sig_Handle())
585      continue;
586
587    i = select(nfds, rfds, wfds, efds, NULL);
588
589    if (i < 0 && errno != EINTR) {
590      log_Printf(LogERROR, "DoLoop: select(): %s\n", strerror(errno));
591      if (log_IsKept(LogTIMER)) {
592        struct timeval t;
593
594        for (i = 0; i <= nfds; i++) {
595          if (FD_ISSET(i, rfds)) {
596            log_Printf(LogTIMER, "Read set contains %d\n", i);
597            FD_CLR(i, rfds);
598            t.tv_sec = t.tv_usec = 0;
599            if (select(nfds, rfds, wfds, efds, &t) != -1) {
600              log_Printf(LogTIMER, "The culprit !\n");
601              break;
602            }
603          }
604          if (FD_ISSET(i, wfds)) {
605            log_Printf(LogTIMER, "Write set contains %d\n", i);
606            FD_CLR(i, wfds);
607            t.tv_sec = t.tv_usec = 0;
608            if (select(nfds, rfds, wfds, efds, &t) != -1) {
609              log_Printf(LogTIMER, "The culprit !\n");
610              break;
611            }
612          }
613          if (FD_ISSET(i, efds)) {
614            log_Printf(LogTIMER, "Error set contains %d\n", i);
615            FD_CLR(i, efds);
616            t.tv_sec = t.tv_usec = 0;
617            if (select(nfds, rfds, wfds, efds, &t) != -1) {
618              log_Printf(LogTIMER, "The culprit !\n");
619              break;
620            }
621          }
622        }
623      }
624      break;
625    }
626
627    log_Printf(LogTIMER, "Select returns %d\n", i);
628
629    sig_Handle();
630
631    if (i <= 0)
632      continue;
633
634    for (i = 0; i <= nfds; i++)
635      if (FD_ISSET(i, efds)) {
636        log_Printf(LogPHASE, "Exception detected on descriptor %d\n", i);
637        /* We deal gracefully with link descriptor exceptions */
638        if (!bundle_Exception(bundle, i)) {
639          log_Printf(LogERROR, "Exception cannot be handled !\n");
640          break;
641        }
642      }
643
644    if (i <= nfds)
645      break;
646
647    nothing_done = 1;
648
649    if (descriptor_IsSet(&server.desc, rfds)) {
650      descriptor_Read(&server.desc, bundle, rfds);
651      nothing_done = 0;
652    }
653
654    if (descriptor_IsSet(&bundle->desc, rfds)) {
655      descriptor_Read(&bundle->desc, bundle, rfds);
656      nothing_done = 0;
657    }
658
659    if (descriptor_IsSet(&bundle->desc, wfds))
660      if (descriptor_Write(&bundle->desc, bundle, wfds) <= 0 && nothing_done) {
661        /*
662         * This is disastrous.  The OS has told us that something is
663         * writable, and all our write()s have failed.  Rather than
664         * going back immediately to do our UpdateSet()s and select(),
665         * we sleep for a bit to avoid gobbling up all cpu time.
666         */
667        struct timeval t;
668
669        t.tv_sec = 0;
670        t.tv_usec = 100000;
671        select(0, NULL, NULL, NULL, &t);
672      }
673  }
674
675  log_Printf(LogDEBUG, "DoLoop done.\n");
676}
677