main.c revision 81634 
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 81634 2001-08-14 16:05:52Z 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 <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 "ip.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(int excode)
113{
114  SignalBundle->CleaningUp = 1;
115  bundle_Close(SignalBundle, NULL, CLOSE_STAYDOWN);
116}
117
118void
119AbortProgram(int excode)
120{
121  server_Close(SignalBundle);
122  log_Printf(LogPHASE, "PPP Terminated (%s).\n", ex_desc(excode));
123  bundle_Close(SignalBundle, NULL, CLOSE_STAYDOWN);
124  bundle_Destroy(SignalBundle);
125  log_Close();
126  exit(excode);
127}
128
129static void
130CloseConnection(int signo)
131{
132  /* NOTE, these are manual, we've done a setsid() */
133  sig_signal(SIGINT, SIG_IGN);
134  log_Printf(LogPHASE, "Caught signal %d, abort connection(s)\n", signo);
135  bundle_Down(SignalBundle, CLOSE_STAYDOWN);
136  sig_signal(SIGINT, CloseConnection);
137}
138
139static void
140CloseSession(int signo)
141{
142  log_Printf(LogPHASE, "Signal %d, terminate.\n", signo);
143  Cleanup(EX_TERM);
144}
145
146static pid_t BGPid = 0;
147
148static void
149KillChild(int signo)
150{
151  signal(signo, SIG_IGN);
152  log_Printf(LogPHASE, "Parent: Signal %d\n", signo);
153  kill(BGPid, SIGINT);
154}
155
156static void
157TerminalCont(int signo)
158{
159  signal(SIGCONT, SIG_DFL);
160  prompt_Continue(SignalPrompt);
161}
162
163static void
164TerminalStop(int signo)
165{
166  prompt_Suspend(SignalPrompt);
167  signal(SIGCONT, TerminalCont);
168  raise(SIGSTOP);
169}
170
171static void
172BringDownServer(int signo)
173{
174  /* Drops all child prompts too ! */
175  if (server_Close(SignalBundle))
176    log_Printf(LogPHASE, "Closed server socket\n");
177}
178
179static void
180RestartServer(int signo)
181{
182  /* Drops all child prompts and re-opens the socket */
183  server_Reopen(SignalBundle);
184}
185
186static void
187Usage(void)
188{
189  fprintf(stderr, "Usage: ppp [-auto | -foreground | -background | -direct |"
190          " -dedicated | -ddial | -interactive]"
191#ifndef NOALIAS
192          " [-nat]"
193#endif
194          " [-quiet] [-unit N] [system ...]\n");
195  exit(EX_START);
196}
197
198struct switches {
199  unsigned nat : 1;
200  unsigned fg : 1;
201  unsigned quiet : 1;
202  int mode;
203  int unit;
204};
205
206static int
207ProcessArgs(int argc, char **argv, struct switches *sw)
208{
209  int optc, newmode, arg;
210  char *cp;
211
212  optc = 0;
213  memset(sw, '\0', sizeof *sw);
214  sw->mode = PHYS_INTERACTIVE;
215  sw->unit = -1;
216
217  for (arg = 1; arg < argc && *argv[arg] == '-'; arg++, optc++) {
218    cp = argv[arg] + 1;
219    newmode = Nam2mode(cp);
220    switch (newmode) {
221      case PHYS_NONE:
222        if (strcmp(cp, "nat") == 0) {
223#ifdef NONAT
224          log_Printf(LogWARN, "%s ignored: NAT is compiled out\n", argv[arg]);
225#else
226          sw->nat = 1;
227#endif
228          optc--;			/* this option isn't exclusive */
229        } else if (strcmp(cp, "alias") == 0) {
230#ifdef NONAT
231          log_Printf(LogWARN, "%s ignored: NAT is compiled out\n", argv[arg]);
232          fprintf(stderr, "%s ignored: NAT is compiled out\n", argv[arg]);
233#else
234          log_Printf(LogWARN, "%s is deprecated\n", argv[arg]);
235          fprintf(stderr, "%s is deprecated\n", argv[arg]);
236          sw->nat = 1;
237#endif
238          optc--;			/* this option isn't exclusive */
239        } else if (strncmp(cp, "unit", 4) == 0) {
240          optc--;			/* this option isn't exclusive */
241          if (cp[4] == '\0') {
242            optc--;			/* nor is the argument */
243            if (++arg == argc) {
244              fprintf(stderr, "-unit: Expected unit number\n");
245              Usage();
246            } else
247              sw->unit = atoi(argv[arg]);
248          } else
249            sw->unit = atoi(cp + 4);
250        } else if (strcmp(cp, "quiet") == 0) {
251          sw->quiet = 1;
252          optc--;			/* this option isn't exclusive */
253        } else
254          Usage();
255        break;
256
257      case PHYS_ALL:
258        Usage();
259        break;
260
261      default:
262        sw->mode = newmode;
263        if (newmode == PHYS_FOREGROUND)
264          sw->fg = 1;
265    }
266  }
267
268  if (optc > 1) {
269    fprintf(stderr, "You may specify only one mode.\n");
270    exit(EX_START);
271  }
272
273  if (sw->mode == PHYS_AUTO && arg == argc) {
274    fprintf(stderr, "A system must be specified in auto mode.\n");
275    exit(EX_START);
276  }
277
278  return arg;		/* Don't SetLabel yet ! */
279}
280
281static void
282CheckLabel(const char *label, struct prompt *prompt, int mode)
283{
284  const char *err;
285
286  if ((err = system_IsValid(label, prompt, mode)) != NULL) {
287    fprintf(stderr, "%s: %s\n", label, err);
288    if (mode == PHYS_DIRECT)
289      log_Printf(LogWARN, "Label %s rejected -direct connection: %s\n",
290                 label, err);
291    log_Close();
292    exit(1);
293  }
294}
295
296
297int
298main(int argc, char **argv)
299{
300  char *name;
301  const char *lastlabel;
302  int arg, f, holdfd[3], label;
303  struct bundle *bundle;
304  struct prompt *prompt;
305  struct switches sw;
306
307  /*
308   * We open 3 descriptors to ensure that STDIN_FILENO, STDOUT_FILENO and
309   * STDERR_FILENO are always open.  These are closed before DoLoop(),
310   * but *after* we've avoided the possibility of erroneously closing
311   * an important descriptor with close(STD{IN,OUT,ERR}_FILENO).
312   */
313  if ((holdfd[0] = open(_PATH_DEVNULL, O_RDWR)) == -1) {
314    fprintf(stderr, "Cannot open %s !\n", _PATH_DEVNULL);
315    return 2;
316  }
317  for (f = 1; f < sizeof holdfd / sizeof *holdfd; f++)
318    holdfd[f] = dup(holdfd[0]);
319
320  name = strrchr(argv[0], '/');
321  log_Open(name ? name + 1 : argv[0]);
322
323#ifndef NONAT
324  PacketAliasInit();
325#endif
326  label = ProcessArgs(argc, argv, &sw);
327
328  /*
329   * A FreeBSD & OpenBSD hack to dodge a bug in the tty driver that drops
330   * output occasionally.... I must find the real reason some time.  To
331   * display the dodgy behaviour, comment out this bit, make yourself a large
332   * routing table and then run ppp in interactive mode.  The `show route'
333   * command will drop chunks of data !!!
334   */
335  if (sw.mode == PHYS_INTERACTIVE) {
336    close(STDIN_FILENO);
337    if (open(_PATH_TTY, O_RDONLY) != STDIN_FILENO) {
338      fprintf(stderr, "Cannot open %s for input !\n", _PATH_TTY);
339      return 2;
340    }
341  }
342
343  /* Allow output for the moment (except in direct mode) */
344  if (sw.mode == PHYS_DIRECT)
345    prompt = NULL;
346  else
347    SignalPrompt = prompt = prompt_Create(NULL, NULL, PROMPT_STD);
348
349  ID0init();
350  if (ID0realuid() != 0) {
351    char conf[200], *ptr;
352
353    snprintf(conf, sizeof conf, "%s/%s", PPP_CONFDIR, CONFFILE);
354    do {
355      struct stat sb;
356
357      if (stat(conf, &sb) == 0 && sb.st_mode & S_IWOTH) {
358        log_Printf(LogALERT, "ppp: Access violation: Please protect %s\n",
359                   conf);
360        return -1;
361      }
362      ptr = conf + strlen(conf)-2;
363      while (ptr > conf && *ptr != '/')
364        *ptr-- = '\0';
365    } while (ptr >= conf);
366  }
367
368  if (label < argc)
369    for (arg = label; arg < argc; arg++)
370      CheckLabel(argv[arg], prompt, sw.mode);
371  else
372    CheckLabel("default", prompt, sw.mode);
373
374  if (!sw.quiet)
375    prompt_Printf(prompt, "Working in %s mode\n", mode2Nam(sw.mode));
376
377  if ((bundle = bundle_Create(TUN_PREFIX, sw.mode, sw.unit)) == NULL)
378    return EX_START;
379
380  /* NOTE:  We may now have changed argv[1] via a ``set proctitle'' */
381
382  if (prompt) {
383    prompt->bundle = bundle;	/* couldn't do it earlier */
384    if (!sw.quiet)
385      prompt_Printf(prompt, "Using interface: %s\n", bundle->iface->name);
386  }
387  SignalBundle = bundle;
388  bundle->NatEnabled = sw.nat;
389  if (sw.nat)
390    bundle->cfg.opt |= OPT_IFACEALIAS;
391
392  if (system_Select(bundle, "default", CONFFILE, prompt, NULL) < 0)
393    prompt_Printf(prompt, "Warning: No default entry found in config file.\n");
394
395  sig_signal(SIGHUP, CloseSession);
396  sig_signal(SIGTERM, CloseSession);
397  sig_signal(SIGINT, CloseConnection);
398  sig_signal(SIGQUIT, CloseSession);
399  sig_signal(SIGALRM, SIG_IGN);
400  signal(SIGPIPE, SIG_IGN);
401
402  if (sw.mode == PHYS_INTERACTIVE)
403    sig_signal(SIGTSTP, TerminalStop);
404
405  sig_signal(SIGUSR1, RestartServer);
406  sig_signal(SIGUSR2, BringDownServer);
407
408  lastlabel = argv[argc - 1];
409  for (arg = label; arg < argc; arg++) {
410    /* In case we use LABEL or ``set enddisc label'' */
411    bundle_SetLabel(bundle, lastlabel);
412    system_Select(bundle, argv[arg], CONFFILE, prompt, NULL);
413  }
414
415  if (label < argc)
416    /* In case the last label did a ``load'' */
417    bundle_SetLabel(bundle, lastlabel);
418
419  if (sw.mode == PHYS_AUTO &&
420      ncprange_family(&bundle->ncp.ipcp.cfg.peer_range) == AF_UNSPEC) {
421    prompt_Printf(prompt, "You must ``set ifaddr'' with a peer address "
422                  "in auto mode.\n");
423    AbortProgram(EX_START);
424  }
425
426  if (sw.mode != PHYS_INTERACTIVE) {
427    if (sw.mode != PHYS_DIRECT) {
428      if (!sw.fg) {
429        int bgpipe[2];
430        pid_t bgpid;
431
432        if (sw.mode == PHYS_BACKGROUND && pipe(bgpipe)) {
433          log_Printf(LogERROR, "pipe: %s\n", strerror(errno));
434	  AbortProgram(EX_SOCK);
435        }
436
437        bgpid = fork();
438        if (bgpid == -1) {
439	  log_Printf(LogERROR, "fork: %s\n", strerror(errno));
440	  AbortProgram(EX_SOCK);
441        }
442
443        if (bgpid) {
444	  char c = EX_NORMAL;
445          int ret;
446
447	  if (sw.mode == PHYS_BACKGROUND) {
448	    close(bgpipe[1]);
449	    BGPid = bgpid;
450            /* If we get a signal, kill the child */
451            signal(SIGHUP, KillChild);
452            signal(SIGTERM, KillChild);
453            signal(SIGINT, KillChild);
454            signal(SIGQUIT, KillChild);
455
456	    /* Wait for our child to close its pipe before we exit */
457            while ((ret = read(bgpipe[0], &c, 1)) == 1) {
458              switch (c) {
459                case EX_NORMAL:
460                  if (!sw.quiet) {
461	            prompt_Printf(prompt, "PPP enabled\n");
462	            log_Printf(LogPHASE, "Parent: PPP enabled\n");
463                  }
464	          break;
465                case EX_REDIAL:
466                  if (!sw.quiet)
467	            prompt_Printf(prompt, "Attempting redial\n");
468                  continue;
469                case EX_RECONNECT:
470                  if (!sw.quiet)
471	            prompt_Printf(prompt, "Attempting reconnect\n");
472                  continue;
473	        default:
474	          prompt_Printf(prompt, "Child failed (%s)\n",
475                                ex_desc((int)c));
476	          log_Printf(LogPHASE, "Parent: Child failed (%s)\n",
477		             ex_desc((int) c));
478	      }
479	      break;
480            }
481            if (ret != 1) {
482	      prompt_Printf(prompt, "Child exit, no status.\n");
483	      log_Printf(LogPHASE, "Parent: Child exit, no status.\n");
484	    }
485	    close(bgpipe[0]);
486	  }
487	  return c;
488        } else if (sw.mode == PHYS_BACKGROUND) {
489	  close(bgpipe[0]);
490          bundle->notify.fd = bgpipe[1];
491        }
492
493        bundle_ChangedPID(bundle);
494        bundle_LockTun(bundle);	/* we have a new pid */
495      }
496
497      /* -auto, -dedicated, -ddial, -foreground & -background */
498      prompt_Destroy(prompt, 0);
499      close(STDOUT_FILENO);
500      close(STDERR_FILENO);
501      close(STDIN_FILENO);
502      if (!sw.fg)
503        setsid();
504    } else {
505      /* -direct - STDIN_FILENO gets used by physical_Open */
506      prompt_TtyInit(NULL);
507      close(STDOUT_FILENO);
508      close(STDERR_FILENO);
509    }
510  } else {
511    /* -interactive */
512    close(STDERR_FILENO);
513    prompt_TtyInit(prompt);
514    prompt_TtyCommandMode(prompt);
515    prompt_Required(prompt);
516  }
517
518  /* We can get rid of these now */
519  for (f = 0; f < sizeof holdfd / sizeof *holdfd; f++)
520    close(holdfd[f]);
521
522  log_Printf(LogPHASE, "PPP Started (%s mode).\n", mode2Nam(sw.mode));
523  DoLoop(bundle);
524  AbortProgram(EX_NORMAL);
525
526  return EX_NORMAL;
527}
528
529static void
530DoLoop(struct bundle *bundle)
531{
532  fd_set *rfds, *wfds, *efds;
533  int i, nfds, nothing_done;
534  struct probe probe;
535
536  probe_Init(&probe);
537
538  if ((rfds = mkfdset()) == NULL) {
539    log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
540    return;
541  }
542
543  if ((wfds = mkfdset()) == NULL) {
544    log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
545    free(rfds);
546    return;
547  }
548
549  if ((efds = mkfdset()) == NULL) {
550    log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
551    free(rfds);
552    free(wfds);
553    return;
554  }
555
556  for (; !bundle_IsDead(bundle); bundle_CleanDatalinks(bundle)) {
557    nfds = 0;
558    zerofdset(rfds);
559    zerofdset(wfds);
560    zerofdset(efds);
561
562    /* All our datalinks, the tun device and the MP socket */
563    descriptor_UpdateSet(&bundle->desc, rfds, wfds, efds, &nfds);
564
565    /* All our prompts and the diagnostic socket */
566    descriptor_UpdateSet(&server.desc, rfds, NULL, NULL, &nfds);
567
568    bundle_CleanDatalinks(bundle);
569    if (bundle_IsDead(bundle))
570      /* Don't select - we'll be here forever */
571      break;
572
573    /*
574     * It's possible that we've had a signal since we last checked.  If
575     * we don't check again before calling select(), we may end up stuck
576     * after having missed the event.... sig_Handle() tries to be as
577     * quick as possible if nothing is likely to have happened.
578     * This is only really likely if we block in open(... O_NONBLOCK)
579     * which will happen with a misconfigured device.
580     */
581    if (sig_Handle())
582      continue;
583
584    i = select(nfds, rfds, wfds, efds, NULL);
585
586    if (i < 0 && errno != EINTR) {
587      log_Printf(LogERROR, "DoLoop: select(): %s\n", strerror(errno));
588      if (log_IsKept(LogTIMER)) {
589        struct timeval t;
590
591        for (i = 0; i <= nfds; i++) {
592          if (FD_ISSET(i, rfds)) {
593            log_Printf(LogTIMER, "Read set contains %d\n", i);
594            FD_CLR(i, rfds);
595            t.tv_sec = t.tv_usec = 0;
596            if (select(nfds, rfds, wfds, efds, &t) != -1) {
597              log_Printf(LogTIMER, "The culprit !\n");
598              break;
599            }
600          }
601          if (FD_ISSET(i, wfds)) {
602            log_Printf(LogTIMER, "Write set contains %d\n", i);
603            FD_CLR(i, wfds);
604            t.tv_sec = t.tv_usec = 0;
605            if (select(nfds, rfds, wfds, efds, &t) != -1) {
606              log_Printf(LogTIMER, "The culprit !\n");
607              break;
608            }
609          }
610          if (FD_ISSET(i, efds)) {
611            log_Printf(LogTIMER, "Error set contains %d\n", i);
612            FD_CLR(i, efds);
613            t.tv_sec = t.tv_usec = 0;
614            if (select(nfds, rfds, wfds, efds, &t) != -1) {
615              log_Printf(LogTIMER, "The culprit !\n");
616              break;
617            }
618          }
619        }
620      }
621      break;
622    }
623
624    log_Printf(LogTIMER, "Select returns %d\n", i);
625
626    sig_Handle();
627
628    if (i <= 0)
629      continue;
630
631    for (i = 0; i <= nfds; i++)
632      if (FD_ISSET(i, efds)) {
633        log_Printf(LogPHASE, "Exception detected on descriptor %d\n", i);
634        /* We deal gracefully with link descriptor exceptions */
635        if (!bundle_Exception(bundle, i)) {
636          log_Printf(LogERROR, "Exception cannot be handled !\n");
637          break;
638        }
639      }
640
641    if (i <= nfds)
642      break;
643
644    nothing_done = 1;
645
646    if (descriptor_IsSet(&server.desc, rfds)) {
647      descriptor_Read(&server.desc, bundle, rfds);
648      nothing_done = 0;
649    }
650
651    if (descriptor_IsSet(&bundle->desc, rfds)) {
652      descriptor_Read(&bundle->desc, bundle, rfds);
653      nothing_done = 0;
654    }
655
656    if (descriptor_IsSet(&bundle->desc, wfds))
657      if (!descriptor_Write(&bundle->desc, bundle, wfds) && nothing_done) {
658        /*
659         * This is disasterous.  The OS has told us that something is
660         * writable, and all our write()s have failed.  Rather than
661         * going back immediately to do our UpdateSet()s and select(),
662         * we sleep for a bit to avoid gobbling up all cpu time.
663         */
664        struct timeval t;
665
666        t.tv_sec = 0;
667        t.tv_usec = 100000;
668        select(0, NULL, NULL, NULL, &t);
669      }
670  }
671
672  log_Printf(LogDEBUG, "DoLoop done.\n");
673}
674