main.c revision 190633 
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 177100 2008-03-12 14:34:34Z piso $
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;
110struct libalias *la;
111
112void
113Cleanup()
114{
115  SignalBundle->CleaningUp = 1;
116  bundle_Close(SignalBundle, NULL, CLOSE_STAYDOWN);
117}
118
119void
120AbortProgram(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
133static void
134CloseConnection(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
143static void
144CloseSession(int signo)
145{
146  log_Printf(LogPHASE, "Signal %d, terminate.\n", signo);
147  Cleanup();
148}
149
150static pid_t BGPid = 0;
151
152static void
153KillChild(int signo)
154{
155  signal(signo, SIG_IGN);
156  log_Printf(LogPHASE, "Parent: Signal %d\n", signo);
157  kill(BGPid, SIGINT);
158}
159
160static void
161TerminalCont(int signo __unused)
162{
163  signal(SIGCONT, SIG_DFL);
164  prompt_Continue(SignalPrompt);
165}
166
167static void
168TerminalStop(int signo __unused)
169{
170  prompt_Suspend(SignalPrompt);
171  signal(SIGCONT, TerminalCont);
172  raise(SIGSTOP);
173}
174
175static void
176BringDownServer(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
183static void
184RestartServer(int signo __unused)
185{
186  /* Drops all child prompts and re-opens the socket */
187  server_Reopen(SignalBundle);
188}
189
190static void
191Usage(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
202struct switches {
203  unsigned nat : 1;
204  unsigned fg : 1;
205  unsigned quiet : 1;
206  int mode;
207  int unit;
208};
209
210static int
211ProcessArgs(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
285static void
286CheckLabel(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
301int
302main(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
536static void
537DoLoop(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