main.c revision 53830 
1/*
2 *			User Process PPP
3 *
4 *	    Written by Toshiharu OHNO (tony-o@iij.ad.jp)
5 *
6 *   Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd.
7 *
8 * Redistribution and use in source and binary forms are permitted
9 * provided that the above copyright notice and this paragraph are
10 * duplicated in all such forms and that any documentation,
11 * advertising materials, and other materials related to such
12 * distribution and use acknowledge that the software was developed
13 * by the Internet Initiative Japan, Inc.  The name of the
14 * IIJ may not be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
18 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
19 *
20 * $FreeBSD: head/usr.sbin/ppp/main.c 53830 1999-11-28 15:50:08Z brian $
21 *
22 *	TODO:
23 */
24
25#include <sys/param.h>
26#include <netinet/in.h>
27#include <netinet/in_systm.h>
28#include <netinet/ip.h>
29#include <sys/un.h>
30
31#include <errno.h>
32#include <fcntl.h>
33#include <paths.h>
34#include <signal.h>
35#include <stdio.h>
36#include <stdlib.h>
37#include <string.h>
38#include <sys/time.h>
39#include <termios.h>
40#include <unistd.h>
41#include <sys/stat.h>
42
43#ifndef NONAT
44#ifdef __FreeBSD__
45#include <alias.h>
46#else
47#include "alias.h"
48#endif
49#endif
50#include "layer.h"
51#include "probe.h"
52#include "mbuf.h"
53#include "log.h"
54#include "defs.h"
55#include "id.h"
56#include "timer.h"
57#include "fsm.h"
58#include "lqr.h"
59#include "hdlc.h"
60#include "lcp.h"
61#include "ccp.h"
62#include "iplist.h"
63#include "throughput.h"
64#include "slcompress.h"
65#include "ipcp.h"
66#include "filter.h"
67#include "descriptor.h"
68#include "link.h"
69#include "mp.h"
70#ifndef NORADIUS
71#include "radius.h"
72#endif
73#include "bundle.h"
74#include "auth.h"
75#include "systems.h"
76#include "sig.h"
77#include "main.h"
78#include "server.h"
79#include "prompt.h"
80#include "chat.h"
81#include "chap.h"
82#include "cbcp.h"
83#include "datalink.h"
84#include "iface.h"
85
86#ifndef O_NONBLOCK
87#ifdef O_NDELAY
88#define	O_NONBLOCK O_NDELAY
89#endif
90#endif
91
92static void DoLoop(struct bundle *);
93static void TerminalStop(int);
94static const char *ex_desc(int);
95
96static struct bundle *SignalBundle;
97static struct prompt *SignalPrompt;
98
99void
100Cleanup(int excode)
101{
102  SignalBundle->CleaningUp = 1;
103  bundle_Close(SignalBundle, NULL, CLOSE_STAYDOWN);
104}
105
106void
107AbortProgram(int excode)
108{
109  server_Close(SignalBundle);
110  log_Printf(LogPHASE, "PPP Terminated (%s).\n", ex_desc(excode));
111  bundle_Close(SignalBundle, NULL, CLOSE_STAYDOWN);
112  bundle_Destroy(SignalBundle);
113  log_Close();
114  exit(excode);
115}
116
117static void
118CloseConnection(int signo)
119{
120  /* NOTE, these are manual, we've done a setsid() */
121  sig_signal(SIGINT, SIG_IGN);
122  log_Printf(LogPHASE, "Caught signal %d, abort connection(s)\n", signo);
123  bundle_Down(SignalBundle, CLOSE_STAYDOWN);
124  sig_signal(SIGINT, CloseConnection);
125}
126
127static void
128CloseSession(int signo)
129{
130  log_Printf(LogPHASE, "Signal %d, terminate.\n", signo);
131  Cleanup(EX_TERM);
132}
133
134static pid_t BGPid = 0;
135
136static void
137KillChild(int signo)
138{
139  signal(signo, SIG_IGN);
140  log_Printf(LogPHASE, "Parent: Signal %d\n", signo);
141  kill(BGPid, SIGINT);
142}
143
144static void
145TerminalCont(int signo)
146{
147  signal(SIGCONT, SIG_DFL);
148  prompt_Continue(SignalPrompt);
149}
150
151static void
152TerminalStop(int signo)
153{
154  prompt_Suspend(SignalPrompt);
155  signal(SIGCONT, TerminalCont);
156  raise(SIGSTOP);
157}
158
159static void
160BringDownServer(int signo)
161{
162  /* Drops all child prompts too ! */
163  server_Close(SignalBundle);
164}
165
166static const char *
167ex_desc(int ex)
168{
169  static char num[12];		/* Used immediately if returned */
170  static const char *desc[] = {
171    "normal", "start", "sock", "modem", "dial", "dead", "done",
172    "reboot", "errdead", "hangup", "term", "nodial", "nologin"
173  };
174
175  if (ex >= 0 && ex < sizeof desc / sizeof *desc)
176    return desc[ex];
177  snprintf(num, sizeof num, "%d", ex);
178  return num;
179}
180
181static void
182Usage(void)
183{
184  fprintf(stderr,
185	  "Usage: ppp [-auto | -foreground | -background | -direct | -dedicated | -ddial | -interactive]"
186#ifndef NOALIAS
187          " [-nat]"
188#endif
189          " [-quiet] [-unit N] [system ...]\n");
190  exit(EX_START);
191}
192
193struct switches {
194  unsigned nat : 1;
195  unsigned fg : 1;
196  unsigned quiet : 1;
197  int mode;
198  int unit;
199};
200
201static int
202ProcessArgs(int argc, char **argv, struct switches *sw)
203{
204  int optc, newmode, arg;
205  char *cp;
206
207  optc = 0;
208  memset(sw, '\0', sizeof *sw);
209  sw->mode = PHYS_INTERACTIVE;
210  sw->unit = -1;
211
212  for (arg = 1; arg < argc && *argv[arg] == '-'; arg++, optc++) {
213    cp = argv[arg] + 1;
214    newmode = Nam2mode(cp);
215    switch (newmode) {
216      case PHYS_NONE:
217        if (strcmp(cp, "nat") == 0) {
218#ifdef NONAT
219          log_Printf(LogWARN, "%s ignored: NAT is compiled out\n", argv[arg]);
220#else
221          sw->nat = 1;
222#endif
223          optc--;			/* this option isn't exclusive */
224        } else if (strcmp(cp, "alias") == 0) {
225#ifdef NONAT
226          log_Printf(LogWARN, "%s ignored: NAT is compiled out\n", argv[arg]);
227          fprintf(stderr, "%s ignored: NAT is compiled out\n", argv[arg]);
228#else
229          log_Printf(LogWARN, "%s is depricated\n", argv[arg]);
230          fprintf(stderr, "%s is depricated\n", argv[arg]);
231          sw->nat = 1;
232#endif
233          optc--;			/* this option isn't exclusive */
234        } else if (strncmp(cp, "unit", 4) == 0) {
235          optc--;			/* this option isn't exclusive */
236          if (cp[4] == '\0') {
237            optc--;			/* nor is the argument */
238            if (++arg == argc) {
239              fprintf(stderr, "-unit: Expected unit number\n");
240              Usage();
241            } else
242              sw->unit = atoi(argv[arg]);
243          } else
244            sw->unit = atoi(cp + 4);
245        } else if (strcmp(cp, "quiet") == 0) {
246          sw->quiet = 1;
247          optc--;			/* this option isn't exclusive */
248        } else
249          Usage();
250        break;
251
252      case PHYS_ALL:
253        Usage();
254        break;
255
256      default:
257        sw->mode = newmode;
258        if (newmode == PHYS_FOREGROUND)
259          sw->fg = 1;
260    }
261  }
262
263  if (optc > 1) {
264    fprintf(stderr, "You may specify only one mode.\n");
265    exit(EX_START);
266  }
267
268  if (sw->mode == PHYS_AUTO && arg == argc) {
269    fprintf(stderr, "A system must be specified in auto mode.\n");
270    exit(EX_START);
271  }
272
273  return arg;		/* Don't SetLabel yet ! */
274}
275
276static void
277CheckLabel(const char *label, struct prompt *prompt, int mode)
278{
279  const char *err;
280
281  if ((err = system_IsValid(label, prompt, mode)) != NULL) {
282    fprintf(stderr, "%s: %s\n", label, err);
283    if (mode == PHYS_DIRECT)
284      log_Printf(LogWARN, "Label %s rejected -direct connection: %s\n",
285                 label, err);
286    log_Close();
287    exit(1);
288  }
289}
290
291
292int
293main(int argc, char **argv)
294{
295  char *name;
296  const char *lastlabel;
297  int nfds, label, arg;
298  struct bundle *bundle;
299  struct prompt *prompt;
300  struct switches sw;
301
302  nfds = getdtablesize();
303  if (nfds >= FD_SETSIZE)
304    /*
305     * If we've got loads of file descriptors, make sure they're all
306     * closed.  If they aren't, we may end up with a seg fault when our
307     * `fd_set's get too big when select()ing !
308     */
309    while (--nfds > 2)
310      close(nfds);
311
312  name = strrchr(argv[0], '/');
313  log_Open(name ? name + 1 : argv[0]);
314
315#ifndef NONAT
316  PacketAliasInit();
317#endif
318  label = ProcessArgs(argc, argv, &sw);
319
320  /*
321   * A FreeBSD & OpenBSD hack to dodge a bug in the tty driver that drops
322   * output occasionally.... I must find the real reason some time.  To
323   * display the dodgy behaviour, comment out this bit, make yourself a large
324   * routing table and then run ppp in interactive mode.  The `show route'
325   * command will drop chunks of data !!!
326   */
327  if (sw.mode == PHYS_INTERACTIVE) {
328    close(STDIN_FILENO);
329    if (open(_PATH_TTY, O_RDONLY) != STDIN_FILENO) {
330      fprintf(stderr, "Cannot open %s for input !\n", _PATH_TTY);
331      return 2;
332    }
333  }
334
335  /* Allow output for the moment (except in direct mode) */
336  if (sw.mode == PHYS_DIRECT)
337    prompt = NULL;
338  else
339    SignalPrompt = prompt = prompt_Create(NULL, NULL, PROMPT_STD);
340
341  ID0init();
342  if (ID0realuid() != 0) {
343    char conf[200], *ptr;
344
345    snprintf(conf, sizeof conf, "%s/%s", _PATH_PPP, CONFFILE);
346    do {
347      struct stat sb;
348
349      if (stat(conf, &sb) == 0 && sb.st_mode & S_IWOTH) {
350        log_Printf(LogALERT, "ppp: Access violation: Please protect %s\n",
351                   conf);
352        return -1;
353      }
354      ptr = conf + strlen(conf)-2;
355      while (ptr > conf && *ptr != '/')
356        *ptr-- = '\0';
357    } while (ptr >= conf);
358  }
359
360  if (label < argc)
361    for (arg = label; arg < argc; arg++)
362      CheckLabel(argv[arg], prompt, sw.mode);
363  else
364    CheckLabel("default", prompt, sw.mode);
365
366  if (!sw.quiet)
367    prompt_Printf(prompt, "Working in %s mode\n", mode2Nam(sw.mode));
368
369  if ((bundle = bundle_Create(TUN_PREFIX, sw.mode, sw.unit)) == NULL)
370    return EX_START;
371
372  /* NOTE:  We may now have changed argv[1] via a ``set proctitle'' */
373
374  if (prompt) {
375    prompt->bundle = bundle;	/* couldn't do it earlier */
376    if (!sw.quiet)
377      prompt_Printf(prompt, "Using interface: %s\n", bundle->iface->name);
378  }
379  SignalBundle = bundle;
380  bundle->NatEnabled = sw.nat;
381  if (sw.nat)
382    bundle->cfg.opt |= OPT_IFACEALIAS;
383
384  if (system_Select(bundle, "default", CONFFILE, prompt, NULL) < 0)
385    prompt_Printf(prompt, "Warning: No default entry found in config file.\n");
386
387  sig_signal(SIGHUP, CloseSession);
388  sig_signal(SIGTERM, CloseSession);
389  sig_signal(SIGINT, CloseConnection);
390  sig_signal(SIGQUIT, CloseSession);
391  sig_signal(SIGALRM, SIG_IGN);
392  signal(SIGPIPE, SIG_IGN);
393
394  if (sw.mode == PHYS_INTERACTIVE)
395    sig_signal(SIGTSTP, TerminalStop);
396
397  sig_signal(SIGUSR2, BringDownServer);
398
399  lastlabel = argv[argc - 1];
400  for (arg = label; arg < argc; arg++) {
401    /* In case we use LABEL or ``set enddisc label'' */
402    bundle_SetLabel(bundle, lastlabel);
403    system_Select(bundle, argv[arg], CONFFILE, prompt, NULL);
404  }
405
406  if (label < argc)
407    /* In case the last label did a ``load'' */
408    bundle_SetLabel(bundle, lastlabel);
409
410  if (sw.mode == PHYS_AUTO &&
411      bundle->ncp.ipcp.cfg.peer_range.ipaddr.s_addr == INADDR_ANY) {
412    prompt_Printf(prompt, "You must ``set ifaddr'' with a peer address "
413                  "in auto mode.\n");
414    AbortProgram(EX_START);
415  }
416
417  if (sw.mode != PHYS_INTERACTIVE) {
418    if (sw.mode != PHYS_DIRECT) {
419      if (!sw.fg) {
420        int bgpipe[2];
421        pid_t bgpid;
422
423        if (sw.mode == PHYS_BACKGROUND && pipe(bgpipe)) {
424          log_Printf(LogERROR, "pipe: %s\n", strerror(errno));
425	  AbortProgram(EX_SOCK);
426        }
427
428        bgpid = fork();
429        if (bgpid == -1) {
430	  log_Printf(LogERROR, "fork: %s\n", strerror(errno));
431	  AbortProgram(EX_SOCK);
432        }
433
434        if (bgpid) {
435	  char c = EX_NORMAL;
436
437	  if (sw.mode == PHYS_BACKGROUND) {
438	    close(bgpipe[1]);
439	    BGPid = bgpid;
440            /* If we get a signal, kill the child */
441            signal(SIGHUP, KillChild);
442            signal(SIGTERM, KillChild);
443            signal(SIGINT, KillChild);
444            signal(SIGQUIT, KillChild);
445
446	    /* Wait for our child to close its pipe before we exit */
447	    if (read(bgpipe[0], &c, 1) != 1) {
448	      prompt_Printf(prompt, "Child exit, no status.\n");
449	      log_Printf(LogPHASE, "Parent: Child exit, no status.\n");
450	    } else if (c == EX_NORMAL) {
451	      prompt_Printf(prompt, "PPP enabled.\n");
452	      log_Printf(LogPHASE, "Parent: PPP enabled.\n");
453	    } else {
454	      prompt_Printf(prompt, "Child failed (%s).\n", ex_desc((int) c));
455	      log_Printf(LogPHASE, "Parent: Child failed (%s).\n",
456		         ex_desc((int) c));
457	    }
458	    close(bgpipe[0]);
459	  }
460	  return c;
461        } else if (sw.mode == PHYS_BACKGROUND) {
462	  close(bgpipe[0]);
463          bundle->notify.fd = bgpipe[1];
464        }
465
466        bundle_LockTun(bundle);	/* we have a new pid */
467      }
468
469      /* -auto, -dedicated, -ddial, -foreground & -background */
470      prompt_Destroy(prompt, 0);
471      close(STDOUT_FILENO);
472      close(STDERR_FILENO);
473      close(STDIN_FILENO);
474      if (!sw.fg)
475        setsid();
476    } else {
477      /* -direct - STDIN_FILENO gets used by physical_Open */
478      prompt_TtyInit(NULL);
479      close(STDOUT_FILENO);
480      close(STDERR_FILENO);
481    }
482  } else {
483    /* -interactive */
484    close(STDERR_FILENO);
485    prompt_TtyInit(prompt);
486    prompt_TtyCommandMode(prompt);
487    prompt_Required(prompt);
488  }
489
490  log_Printf(LogPHASE, "PPP Started (%s mode).\n", mode2Nam(sw.mode));
491  DoLoop(bundle);
492  AbortProgram(EX_NORMAL);
493
494  return EX_NORMAL;
495}
496
497static void
498DoLoop(struct bundle *bundle)
499{
500  fd_set rfds, wfds, efds;
501  int i, nfds, nothing_done;
502  struct probe probe;
503
504  probe_Init(&probe);
505
506  for (; !bundle_IsDead(bundle); bundle_CleanDatalinks(bundle)) {
507    nfds = 0;
508    FD_ZERO(&rfds);
509    FD_ZERO(&wfds);
510    FD_ZERO(&efds);
511
512    /* All our datalinks, the tun device and the MP socket */
513    descriptor_UpdateSet(&bundle->desc, &rfds, &wfds, &efds, &nfds);
514
515    /* All our prompts and the diagnostic socket */
516    descriptor_UpdateSet(&server.desc, &rfds, NULL, NULL, &nfds);
517
518    if (bundle_IsDead(bundle))
519      /* Don't select - we'll be here forever */
520      break;
521
522    /*
523     * It's possible that we've had a signal since we last checked.  If
524     * we don't check again before calling select(), we may end up stuck
525     * after having missed the event.... sig_Handle() tries to be as
526     * quick as possible if nothing is likely to have happened.
527     * This is only really likely if we block in open(... O_NONBLOCK)
528     * which will happen with a misconfigured device.
529     */
530    if (sig_Handle())
531      continue;
532
533    i = select(nfds, &rfds, &wfds, &efds, NULL);
534
535    if (i < 0 && errno != EINTR) {
536      log_Printf(LogERROR, "DoLoop: select(): %s\n", strerror(errno));
537      if (log_IsKept(LogTIMER)) {
538        struct timeval t;
539
540        for (i = 0; i <= nfds; i++) {
541          if (FD_ISSET(i, &rfds)) {
542            log_Printf(LogTIMER, "Read set contains %d\n", i);
543            FD_CLR(i, &rfds);
544            t.tv_sec = t.tv_usec = 0;
545            if (select(nfds, &rfds, &wfds, &efds, &t) != -1) {
546              log_Printf(LogTIMER, "The culprit !\n");
547              break;
548            }
549          }
550          if (FD_ISSET(i, &wfds)) {
551            log_Printf(LogTIMER, "Write set contains %d\n", i);
552            FD_CLR(i, &wfds);
553            t.tv_sec = t.tv_usec = 0;
554            if (select(nfds, &rfds, &wfds, &efds, &t) != -1) {
555              log_Printf(LogTIMER, "The culprit !\n");
556              break;
557            }
558          }
559          if (FD_ISSET(i, &efds)) {
560            log_Printf(LogTIMER, "Error set contains %d\n", i);
561            FD_CLR(i, &efds);
562            t.tv_sec = t.tv_usec = 0;
563            if (select(nfds, &rfds, &wfds, &efds, &t) != -1) {
564              log_Printf(LogTIMER, "The culprit !\n");
565              break;
566            }
567          }
568        }
569      }
570      break;
571    }
572
573    log_Printf(LogTIMER, "Select returns %d\n", i);
574
575    sig_Handle();
576
577    if (i <= 0)
578      continue;
579
580    for (i = 0; i <= nfds; i++)
581      if (FD_ISSET(i, &efds)) {
582        log_Printf(LogPHASE, "Exception detected on descriptor %d\n", i);
583        /* We deal gracefully with link descriptor exceptions */
584        if (!bundle_Exception(bundle, i)) {
585          log_Printf(LogERROR, "Exception cannot be handled !\n");
586          break;
587        }
588      }
589
590    if (i <= nfds)
591      break;
592
593    nothing_done = 1;
594
595    if (descriptor_IsSet(&server.desc, &rfds)) {
596      descriptor_Read(&server.desc, bundle, &rfds);
597      nothing_done = 0;
598    }
599
600    if (descriptor_IsSet(&bundle->desc, &rfds)) {
601      descriptor_Read(&bundle->desc, bundle, &rfds);
602      nothing_done = 0;
603    }
604
605    if (descriptor_IsSet(&bundle->desc, &wfds))
606      if (!descriptor_Write(&bundle->desc, bundle, &wfds) && nothing_done) {
607        /*
608         * This is disasterous.  The OS has told us that something is
609         * writable, and all our write()s have failed.  Rather than
610         * going back immediately to do our UpdateSet()s and select(),
611         * we sleep for a bit to avoid gobbling up all cpu time.
612         */
613        struct timeval t;
614
615        t.tv_sec = 0;
616        t.tv_usec = 100000;
617        select(0, NULL, NULL, NULL, &t);
618      }
619  }
620
621  log_Printf(LogDEBUG, "DoLoop done.\n");
622}
623