main.c revision 36452 
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 * $Id: main.c,v 1.126 1998/05/27 22:43:31 brian Exp $
21 *
22 *	TODO:
23 */
24
25#include <sys/types.h>
26#include <sys/socket.h>
27#include <netinet/in.h>
28#include <netinet/in_systm.h>
29#include <netinet/ip.h>
30#include <sys/un.h>
31#include <net/if_tun.h>
32
33#include <errno.h>
34#include <fcntl.h>
35#include <paths.h>
36#include <signal.h>
37#include <stdio.h>
38#include <string.h>
39#include <sys/time.h>
40#include <termios.h>
41#include <unistd.h>
42
43#include "mbuf.h"
44#include "log.h"
45#include "defs.h"
46#include "id.h"
47#include "timer.h"
48#include "fsm.h"
49#include "lqr.h"
50#include "hdlc.h"
51#include "lcp.h"
52#include "ccp.h"
53#include "iplist.h"
54#include "throughput.h"
55#include "slcompress.h"
56#include "ipcp.h"
57#include "filter.h"
58#include "descriptor.h"
59#include "link.h"
60#include "mp.h"
61#include "bundle.h"
62#include "loadalias.h"
63#include "auth.h"
64#include "systems.h"
65#include "ip.h"
66#include "sig.h"
67#include "main.h"
68#include "tun.h"
69#include "server.h"
70#include "prompt.h"
71#include "chat.h"
72#include "chap.h"
73#include "datalink.h"
74
75#ifndef O_NONBLOCK
76#ifdef O_NDELAY
77#define	O_NONBLOCK O_NDELAY
78#endif
79#endif
80
81static void DoLoop(struct bundle *);
82static void TerminalStop(int);
83static const char *ex_desc(int);
84
85static struct bundle *SignalBundle;
86static struct prompt *SignalPrompt;
87
88void
89Cleanup(int excode)
90{
91  SignalBundle->CleaningUp = 1;
92  if (bundle_Phase(SignalBundle) != PHASE_DEAD)
93    bundle_Close(SignalBundle, NULL, 1);
94}
95
96void
97AbortProgram(int excode)
98{
99  server_Close(SignalBundle);
100  log_Printf(LogPHASE, "PPP Terminated (%s).\n", ex_desc(excode));
101  bundle_Close(SignalBundle, NULL, 1);
102  bundle_Destroy(SignalBundle);
103  log_Close();
104  exit(excode);
105}
106
107static void
108CloseConnection(int signo)
109{
110  /* NOTE, these are manual, we've done a setsid() */
111  sig_signal(SIGINT, SIG_IGN);
112  log_Printf(LogPHASE, "Caught signal %d, abort connection(s)\n", signo);
113  bundle_Down(SignalBundle);
114  sig_signal(SIGINT, CloseConnection);
115}
116
117static void
118CloseSession(int signo)
119{
120  log_Printf(LogPHASE, "Signal %d, terminate.\n", signo);
121  Cleanup(EX_TERM);
122}
123
124static pid_t BGPid = 0;
125
126static void
127KillChild(int signo)
128{
129  log_Printf(LogPHASE, "Parent: Signal %d\n", signo);
130  kill(BGPid, SIGINT);
131}
132
133static void
134TerminalCont(int signo)
135{
136  signal(SIGCONT, SIG_DFL);
137  prompt_Continue(SignalPrompt);
138}
139
140static void
141TerminalStop(int signo)
142{
143  prompt_Suspend(SignalPrompt);
144  signal(SIGCONT, TerminalCont);
145  raise(SIGSTOP);
146}
147
148static void
149BringDownServer(int signo)
150{
151  /* Drops all child prompts too ! */
152  server_Close(SignalBundle);
153}
154
155static const char *
156ex_desc(int ex)
157{
158  static char num[12];
159  static const char *desc[] = {
160    "normal", "start", "sock", "modem", "dial", "dead", "done",
161    "reboot", "errdead", "hangup", "term", "nodial", "nologin"
162  };
163
164  if (ex >= 0 && ex < sizeof desc / sizeof *desc)
165    return desc[ex];
166  snprintf(num, sizeof num, "%d", ex);
167  return num;
168}
169
170static void
171Usage(void)
172{
173  fprintf(stderr,
174	  "Usage: ppp [-auto | -background | -direct | -dedicated | -ddial ]"
175#ifndef NOALIAS
176          " [ -alias ]"
177#endif
178          " [system]\n");
179  exit(EX_START);
180}
181
182static char *
183ProcessArgs(int argc, char **argv, int *mode)
184{
185  int optc, labelrequired;
186  char *cp;
187
188  optc = labelrequired = 0;
189  *mode = PHYS_MANUAL;
190  while (argc > 0 && **argv == '-') {
191    cp = *argv + 1;
192    if (strcmp(cp, "auto") == 0) {
193      *mode = PHYS_DEMAND;
194      labelrequired = 1;
195    } else if (strcmp(cp, "background") == 0) {
196      *mode = PHYS_1OFF;
197      labelrequired = 1;
198    } else if (strcmp(cp, "direct") == 0)
199      *mode = PHYS_DIRECT;
200    else if (strcmp(cp, "dedicated") == 0)
201      *mode = PHYS_DEDICATED;
202    else if (strcmp(cp, "ddial") == 0) {
203      *mode = PHYS_PERM;
204      labelrequired = 1;
205    } else if (strcmp(cp, "alias") == 0) {
206#ifndef NOALIAS
207      if (alias_Load() != 0)
208#endif
209	log_Printf(LogWARN, "Cannot load alias library\n");
210      optc--;			/* this option isn't exclusive */
211    } else
212      Usage();
213    optc++;
214    argv++;
215    argc--;
216  }
217  if (argc > 1) {
218    fprintf(stderr, "You may specify only one system label.\n");
219    exit(EX_START);
220  }
221
222  if (optc > 1) {
223    fprintf(stderr, "You may specify only one mode.\n");
224    exit(EX_START);
225  }
226
227  if (labelrequired && argc != 1) {
228    fprintf(stderr, "Destination system must be specified in"
229            " auto, background or ddial mode.\n");
230    exit(EX_START);
231  }
232
233  return argc == 1 ? *argv : NULL;	/* Don't SetLabel yet ! */
234}
235
236int
237main(int argc, char **argv)
238{
239  char *name, *label;
240  int nfds, mode;
241  struct bundle *bundle;
242  struct prompt *prompt;
243
244  nfds = getdtablesize();
245  if (nfds >= FD_SETSIZE)
246    /*
247     * If we've got loads of file descriptors, make sure they're all
248     * closed.  If they aren't, we may end up with a seg fault when our
249     * `fd_set's get too big when select()ing !
250     */
251    while (--nfds > 2)
252      close(nfds);
253
254  name = strrchr(argv[0], '/');
255  log_Open(name ? name + 1 : argv[0]);
256
257  argc--;
258  argv++;
259  label = ProcessArgs(argc, argv, &mode);
260
261#ifdef __FreeBSD__
262  /*
263   * A FreeBSD hack to dodge a bug in the tty driver that drops output
264   * occasionally.... I must find the real reason some time.  To display
265   * the dodgy behaviour, comment out this bit, make yourself a large
266   * routing table and then run ppp in interactive mode.  The `show route'
267   * command will drop chunks of data !!!
268   */
269  if (mode == PHYS_MANUAL) {
270    close(STDIN_FILENO);
271    if (open(_PATH_TTY, O_RDONLY) != STDIN_FILENO) {
272      fprintf(stderr, "Cannot open %s for input !\n", _PATH_TTY);
273      return 2;
274    }
275  }
276#endif
277
278  /* Allow output for the moment (except in direct mode) */
279  if (mode == PHYS_DIRECT)
280    prompt = NULL;
281  else {
282    const char *m;
283
284    SignalPrompt = prompt = prompt_Create(NULL, NULL, PROMPT_STD);
285    if (mode == PHYS_PERM)
286      m = "direct dial";
287    else if (mode & PHYS_1OFF)
288      m = "background";
289    else if (mode & PHYS_DEMAND)
290      m = "auto";
291    else if (mode & PHYS_DEDICATED)
292      m = "dedicated";
293    else if (mode & PHYS_MANUAL)
294      m = "interactive";
295    else
296      m = NULL;
297
298    if (m)
299      prompt_Printf(prompt, "Working in %s mode\n", m);
300  }
301
302  ID0init();
303  if (ID0realuid() != 0) {
304    char conf[200], *ptr;
305
306    snprintf(conf, sizeof conf, "%s/%s", _PATH_PPP, CONFFILE);
307    do {
308      if (!access(conf, W_OK)) {
309        log_Printf(LogALERT, "ppp: Access violation: Please protect %s\n", conf);
310        return -1;
311      }
312      ptr = conf + strlen(conf)-2;
313      while (ptr > conf && *ptr != '/')
314        *ptr-- = '\0';
315    } while (ptr >= conf);
316  }
317
318  if (!system_IsValid(label, prompt, mode)) {
319    fprintf(stderr, "You may not use ppp in this mode with this label\n");
320    if (mode == PHYS_DIRECT) {
321      const char *l;
322      l = label ? label : "default";
323      log_Printf(LogWARN, "Label %s rejected -direct connection\n", l);
324    }
325    log_Close();
326    return 1;
327  }
328
329  if ((bundle = bundle_Create(TUN_PREFIX, mode)) == NULL) {
330    log_Printf(LogWARN, "bundle_Create: %s\n", strerror(errno));
331    return EX_START;
332  }
333  if (prompt) {
334    prompt->bundle = bundle;	/* couldn't do it earlier */
335    prompt_Printf(prompt, "Using interface: %s\n", bundle->ifp.Name);
336  }
337  SignalBundle = bundle;
338
339  if (system_Select(bundle, "default", CONFFILE, prompt) < 0)
340    prompt_Printf(prompt, "Warning: No default entry found in config file.\n");
341
342  sig_signal(SIGHUP, CloseSession);
343  sig_signal(SIGTERM, CloseSession);
344  sig_signal(SIGINT, CloseConnection);
345  sig_signal(SIGQUIT, CloseSession);
346  sig_signal(SIGALRM, SIG_IGN);
347  signal(SIGPIPE, SIG_IGN);
348
349  if (mode == PHYS_MANUAL)
350    sig_signal(SIGTSTP, TerminalStop);
351
352  sig_signal(SIGUSR2, BringDownServer);
353
354  if (label) {
355    /*
356     * Set label both before and after system_Select !
357     * This way, "set enddisc label" works during system_Select, and we
358     * also end up with the correct label if we have embedded load
359     * commands.
360     */
361    bundle_SetLabel(bundle, label);
362    if (system_Select(bundle, label, CONFFILE, prompt) < 0) {
363      prompt_Printf(prompt, "Destination system (%s) not found.\n", label);
364      AbortProgram(EX_START);
365    }
366    bundle_SetLabel(bundle, label);
367    if (mode == PHYS_DEMAND &&
368	bundle->ncp.ipcp.cfg.peer_range.ipaddr.s_addr == INADDR_ANY) {
369      prompt_Printf(prompt, "You must \"set ifaddr\" with a peer address "
370                    "in label %s for auto mode.\n", label);
371      AbortProgram(EX_START);
372    }
373  }
374
375  if (mode != PHYS_MANUAL) {
376    if (mode != PHYS_DIRECT) {
377      int bgpipe[2];
378      pid_t bgpid;
379
380      if (mode == PHYS_1OFF && pipe(bgpipe)) {
381        log_Printf(LogERROR, "pipe: %s\n", strerror(errno));
382	AbortProgram(EX_SOCK);
383      }
384
385      bgpid = fork();
386      if (bgpid == -1) {
387	log_Printf(LogERROR, "fork: %s\n", strerror(errno));
388	AbortProgram(EX_SOCK);
389      }
390
391      if (bgpid) {
392	char c = EX_NORMAL;
393
394	if (mode == PHYS_1OFF) {
395	  close(bgpipe[1]);
396	  BGPid = bgpid;
397          /* If we get a signal, kill the child */
398          signal(SIGHUP, KillChild);
399          signal(SIGTERM, KillChild);
400          signal(SIGINT, KillChild);
401          signal(SIGQUIT, KillChild);
402
403	  /* Wait for our child to close its pipe before we exit */
404	  if (read(bgpipe[0], &c, 1) != 1) {
405	    prompt_Printf(prompt, "Child exit, no status.\n");
406	    log_Printf(LogPHASE, "Parent: Child exit, no status.\n");
407	  } else if (c == EX_NORMAL) {
408	    prompt_Printf(prompt, "PPP enabled.\n");
409	    log_Printf(LogPHASE, "Parent: PPP enabled.\n");
410	  } else {
411	    prompt_Printf(prompt, "Child failed (%s).\n", ex_desc((int) c));
412	    log_Printf(LogPHASE, "Parent: Child failed (%s).\n",
413		      ex_desc((int) c));
414	  }
415	  close(bgpipe[0]);
416	}
417	return c;
418      } else if (mode == PHYS_1OFF) {
419	close(bgpipe[0]);
420        bundle->notify.fd = bgpipe[1];
421      }
422
423      /* -auto, -dedicated, -ddial & -background */
424      prompt_Destroy(prompt, 0);
425      close(STDOUT_FILENO);
426      close(STDERR_FILENO);
427      close(STDIN_FILENO);
428      setsid();
429    } else {
430      /* -direct: STDIN_FILENO gets used by modem_Open */
431      prompt_TtyInit(NULL);
432      close(STDOUT_FILENO);
433      close(STDERR_FILENO);
434    }
435  } else {
436    /* Interactive mode */
437    close(STDERR_FILENO);
438    prompt_TtyInit(prompt);
439    prompt_TtyCommandMode(prompt);
440    prompt_Required(prompt);
441  }
442
443  log_Printf(LogPHASE, "PPP Started (%s mode).\n", mode2Nam(mode));
444  DoLoop(bundle);
445  AbortProgram(EX_NORMAL);
446
447  return EX_NORMAL;
448}
449
450static void
451DoLoop(struct bundle *bundle)
452{
453  fd_set rfds, wfds, efds;
454  int i, nfds;
455
456  do {
457    nfds = 0;
458    FD_ZERO(&rfds);
459    FD_ZERO(&wfds);
460    FD_ZERO(&efds);
461
462    /* All our datalinks, the tun device and the MP socket */
463    descriptor_UpdateSet(&bundle->desc, &rfds, &wfds, &efds, &nfds);
464
465    /* All our prompts and the diagnostic socket */
466    descriptor_UpdateSet(&server.desc, &rfds, NULL, NULL, &nfds);
467
468    if (bundle_IsDead(bundle))
469      /* Don't select - we'll be here forever */
470      break;
471
472    i = select(nfds, &rfds, &wfds, &efds, NULL);
473
474    if (i < 0 && errno != EINTR) {
475      log_Printf(LogERROR, "DoLoop: select(): %s\n", strerror(errno));
476      if (log_IsKept(LogTIMER)) {
477        struct timeval t;
478
479        for (i = 0; i <= nfds; i++) {
480          if (FD_ISSET(i, &rfds)) {
481            log_Printf(LogTIMER, "Read set contains %d\n", i);
482            FD_CLR(i, &rfds);
483            t.tv_sec = t.tv_usec = 0;
484            if (select(nfds, &rfds, &wfds, &efds, &t) != -1) {
485              log_Printf(LogTIMER, "The culprit !\n");
486              break;
487            }
488          }
489          if (FD_ISSET(i, &wfds)) {
490            log_Printf(LogTIMER, "Write set contains %d\n", i);
491            FD_CLR(i, &wfds);
492            t.tv_sec = t.tv_usec = 0;
493            if (select(nfds, &rfds, &wfds, &efds, &t) != -1) {
494              log_Printf(LogTIMER, "The culprit !\n");
495              break;
496            }
497          }
498          if (FD_ISSET(i, &efds)) {
499            log_Printf(LogTIMER, "Error set contains %d\n", i);
500            FD_CLR(i, &efds);
501            t.tv_sec = t.tv_usec = 0;
502            if (select(nfds, &rfds, &wfds, &efds, &t) != -1) {
503              log_Printf(LogTIMER, "The culprit !\n");
504              break;
505            }
506          }
507        }
508      }
509      break;
510    }
511
512    sig_Handle();
513
514    if (i <= 0)
515      continue;
516
517    for (i = 0; i <= nfds; i++)
518      if (FD_ISSET(i, &efds)) {
519        log_Printf(LogALERT, "Exception detected on descriptor %d\n", i);
520        break;
521      }
522
523    if (i <= nfds)
524      break;
525
526    if (descriptor_IsSet(&server.desc, &rfds))
527      descriptor_Read(&server.desc, bundle, &rfds);
528
529    if (descriptor_IsSet(&bundle->desc, &wfds))
530      descriptor_Write(&bundle->desc, bundle, &wfds);
531
532    if (descriptor_IsSet(&bundle->desc, &rfds))
533      descriptor_Read(&bundle->desc, bundle, &rfds);
534
535  } while (bundle_CleanDatalinks(bundle), !bundle_IsDead(bundle));
536
537  log_Printf(LogDEBUG, "DoLoop done.\n");
538}
539