summaryrefslogtreecommitdiffstats
path: root/usr.sbin/ppp/main.c
blob: b4d5e29517d824370a3e9e6ca950147391be517a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
/*-
 * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
 *          based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
 *                           Internet Initiative Japan, Inc (IIJ)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD$
 */

#include <sys/param.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <sys/un.h>
#include <sys/socket.h>
#include <net/route.h>

#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <termios.h>
#include <unistd.h>
#include <sys/stat.h>

#ifndef NONAT
#ifdef LOCALNAT
#include "alias.h"
#else
#include <alias.h>
#endif
#endif

#include "layer.h"
#include "probe.h"
#include "mbuf.h"
#include "log.h"
#include "defs.h"
#include "id.h"
#include "timer.h"
#include "fsm.h"
#include "lqr.h"
#include "hdlc.h"
#include "lcp.h"
#include "ccp.h"
#include "iplist.h"
#include "throughput.h"
#include "slcompress.h"
#include "ncpaddr.h"
#include "ipcp.h"
#include "filter.h"
#include "descriptor.h"
#include "link.h"
#include "mp.h"
#ifndef NORADIUS
#include "radius.h"
#endif
#include "ipv6cp.h"
#include "ncp.h"
#include "bundle.h"
#include "auth.h"
#include "systems.h"
#include "sig.h"
#include "main.h"
#include "server.h"
#include "prompt.h"
#include "chat.h"
#include "chap.h"
#include "cbcp.h"
#include "datalink.h"
#include "iface.h"

#ifndef O_NONBLOCK
#ifdef O_NDELAY
#define	O_NONBLOCK O_NDELAY
#endif
#endif

static void DoLoop(struct bundle *);
static void TerminalStop(int);

static struct bundle *SignalBundle;
static struct prompt *SignalPrompt;
struct libalias *la;

void
Cleanup()
{
  SignalBundle->CleaningUp = 1;
  bundle_Close(SignalBundle, NULL, CLOSE_STAYDOWN);
}

void
AbortProgram(int excode)
{
  if (SignalBundle)
    server_Close(SignalBundle);
  log_Printf(LogPHASE, "PPP Terminated (%s).\n", ex_desc(excode));
  if (SignalBundle) {
    bundle_Close(SignalBundle, NULL, CLOSE_STAYDOWN);
    bundle_Destroy(SignalBundle);
  }
  log_Close();
  exit(excode);
}

static void
CloseConnection(int signo)
{
  /* NOTE, these are manual, we've done a setsid() */
  sig_signal(SIGINT, SIG_IGN);
  log_Printf(LogPHASE, "Caught signal %d, abort connection(s)\n", signo);
  bundle_Down(SignalBundle, CLOSE_STAYDOWN);
  sig_signal(SIGINT, CloseConnection);
}

static void
CloseSession(int signo)
{
  log_Printf(LogPHASE, "Signal %d, terminate.\n", signo);
  Cleanup();
}

static pid_t BGPid = 0;

static void
KillChild(int signo)
{
  signal(signo, SIG_IGN);
  log_Printf(LogPHASE, "Parent: Signal %d\n", signo);
  kill(BGPid, SIGINT);
}

static void
TerminalCont(int signo __unused)
{
  signal(SIGCONT, SIG_DFL);
  prompt_Continue(SignalPrompt);
}

static void
TerminalStop(int signo __unused)
{
  prompt_Suspend(SignalPrompt);
  signal(SIGCONT, TerminalCont);
  raise(SIGSTOP);
}

static void
BringDownServer(int signo __unused)
{
  /* Drops all child prompts too ! */
  if (server_Close(SignalBundle))
    log_Printf(LogPHASE, "Closed server socket\n");
}

static void
RestartServer(int signo __unused)
{
  /* Drops all child prompts and re-opens the socket */
  server_Reopen(SignalBundle);
}

static void
Usage(void)
{
  fprintf(stderr, "usage: ppp [-auto | -foreground | -background | -direct |"
          " -dedicated | -ddial | -interactive]"
#ifndef NONAT
          " [-nat]"
#endif
          " [-quiet] [-unit N] [system ...]\n");
  exit(EX_START);
}

struct switches {
  unsigned nat : 1;
  unsigned fg : 1;
  unsigned quiet : 1;
  int mode;
  int unit;
};

static int
ProcessArgs(int argc, char **argv, struct switches *sw)
{
  int optc, newmode, arg;
  char *cp;

  optc = 0;
  memset(sw, '\0', sizeof *sw);
  sw->mode = PHYS_INTERACTIVE;
  sw->unit = -1;

  for (arg = 1; arg < argc && *argv[arg] == '-'; arg++, optc++) {
    cp = argv[arg] + 1;
    newmode = Nam2mode(cp);
    switch (newmode) {
      case PHYS_NONE:
        if (strcmp(cp, "nat") == 0) {
#ifdef NONAT
          log_Printf(LogWARN, "%s ignored: NAT is compiled out\n", argv[arg]);
#else
          sw->nat = 1;
#endif
          optc--;			/* this option isn't exclusive */
        } else if (strcmp(cp, "alias") == 0) {
#ifdef NONAT
          log_Printf(LogWARN, "%s ignored: NAT is compiled out\n", argv[arg]);
          fprintf(stderr, "%s ignored: NAT is compiled out\n", argv[arg]);
#else
          log_Printf(LogWARN, "%s is deprecated\n", argv[arg]);
          fprintf(stderr, "%s is deprecated\n", argv[arg]);
          sw->nat = 1;
#endif
          optc--;			/* this option isn't exclusive */
        } else if (strncmp(cp, "unit", 4) == 0) {
          optc--;			/* this option isn't exclusive */
          if (cp[4] == '\0') {
            optc--;			/* nor is the argument */
            if (++arg == argc) {
              fprintf(stderr, "-unit: Expected unit number\n");
              Usage();
            } else
              sw->unit = atoi(argv[arg]);
          } else
            sw->unit = atoi(cp + 4);
        } else if (strcmp(cp, "quiet") == 0) {
          sw->quiet = 1;
          optc--;			/* this option isn't exclusive */
        } else
          Usage();
        break;

      case PHYS_ALL:
        Usage();
        break;

      default:
        sw->mode = newmode;
        if (newmode == PHYS_FOREGROUND)
          sw->fg = 1;
    }
  }

  if (optc > 1) {
    fprintf(stderr, "You may specify only one mode.\n");
    exit(EX_START);
  }

  if (sw->mode == PHYS_AUTO && arg == argc) {
    fprintf(stderr, "A system must be specified in auto mode.\n");
    exit(EX_START);
  }

  return arg;		/* Don't SetLabel yet ! */
}

static void
CheckLabel(const char *label, struct prompt *prompt, int mode)
{
  const char *err;

  if ((err = system_IsValid(label, prompt, mode)) != NULL) {
    fprintf(stderr, "%s: %s\n", label, err);
    if (mode == PHYS_DIRECT)
      log_Printf(LogWARN, "Label %s rejected -direct connection: %s\n",
                 label, err);
    log_Close();
    exit(1);
  }
}


int
main(int argc, char **argv)
{
  char *name;
  const char *lastlabel;
  int arg, holdfd[3], label;
  unsigned f;
  struct bundle *bundle;
  struct prompt *prompt;
  struct switches sw;

  probe_Init();

  /*
   * We open 3 descriptors to ensure that STDIN_FILENO, STDOUT_FILENO and
   * STDERR_FILENO are always open.  These are closed before DoLoop(),
   * but *after* we've avoided the possibility of erroneously closing
   * an important descriptor with close(STD{IN,OUT,ERR}_FILENO).
   */
  if ((holdfd[0] = open(_PATH_DEVNULL, O_RDWR)) == -1) {
    fprintf(stderr, "Cannot open %s !\n", _PATH_DEVNULL);
    return 2;
  }
  for (f = 1; f < sizeof holdfd / sizeof *holdfd; f++)
    holdfd[f] = dup(holdfd[0]);

  name = strrchr(argv[0], '/');
  log_Open(name ? name + 1 : argv[0]);

#ifndef NONAT
  la = LibAliasInit(NULL);
#endif
  label = ProcessArgs(argc, argv, &sw);

  /*
   * A FreeBSD & OpenBSD hack to dodge a bug in the tty driver that drops
   * output occasionally.... I must find the real reason some time.  To
   * display the dodgy behaviour, comment out this bit, make yourself a large
   * routing table and then run ppp in interactive mode.  The `show route'
   * command will drop chunks of data !!!
   */
  if (sw.mode == PHYS_INTERACTIVE) {
    close(STDIN_FILENO);
    if (open(_PATH_TTY, O_RDONLY) != STDIN_FILENO) {
      fprintf(stderr, "Cannot open %s for input !\n", _PATH_TTY);
      return 2;
    }
  }

  /* Allow output for the moment (except in direct mode) */
  if (sw.mode == PHYS_DIRECT)
    prompt = NULL;
  else
    SignalPrompt = prompt = prompt_Create(NULL, NULL, PROMPT_STD);

  ID0init();
  if (ID0realuid() != 0) {
    char conf[200], *ptr;

    snprintf(conf, sizeof conf, "%s/%s", PPP_CONFDIR, CONFFILE);
    do {
      struct stat sb;

      if (stat(conf, &sb) == 0 && sb.st_mode & S_IWOTH) {
        log_Printf(LogALERT, "ppp: Access violation: Please protect %s\n",
                   conf);
        return -1;
      }
      ptr = conf + strlen(conf)-2;
      while (ptr > conf && *ptr != '/')
        *ptr-- = '\0';
    } while (ptr >= conf);
  }

  if (label < argc)
    for (arg = label; arg < argc; arg++)
      CheckLabel(argv[arg], prompt, sw.mode);
  else
    CheckLabel("default", prompt, sw.mode);

  if (!sw.quiet)
    prompt_Printf(prompt, "Working in %s mode\n", mode2Nam(sw.mode));

  if ((bundle = bundle_Create(TUN_PREFIX, sw.mode, sw.unit)) == NULL)
    return EX_START;

  /* NOTE:  We may now have changed argv[1] via a ``set proctitle'' */

  if (prompt) {
    prompt->bundle = bundle;	/* couldn't do it earlier */
    if (!sw.quiet)
      prompt_Printf(prompt, "Using interface: %s\n", bundle->iface->name);
  }
  SignalBundle = bundle;
  bundle->NatEnabled = sw.nat;
  if (sw.nat)
    opt_enable(bundle, OPT_IFACEALIAS);

  if (system_Select(bundle, "default", CONFFILE, prompt, NULL) < 0)
    prompt_Printf(prompt, "Warning: No default entry found in config file.\n");

  sig_signal(SIGHUP, CloseSession);
  sig_signal(SIGTERM, CloseSession);
  sig_signal(SIGINT, CloseConnection);
  sig_signal(SIGQUIT, CloseSession);
  sig_signal(SIGALRM, SIG_IGN);
  signal(SIGPIPE, SIG_IGN);

  if (sw.mode == PHYS_INTERACTIVE)
    sig_signal(SIGTSTP, TerminalStop);

  sig_signal(SIGUSR1, RestartServer);
  sig_signal(SIGUSR2, BringDownServer);

  lastlabel = argv[argc - 1];
  for (arg = label; arg < argc; arg++) {
    /* In case we use LABEL or ``set enddisc label'' */
    bundle_SetLabel(bundle, lastlabel);
    system_Select(bundle, argv[arg], CONFFILE, prompt, NULL);
  }

  if (label < argc)
    /* In case the last label did a ``load'' */
    bundle_SetLabel(bundle, lastlabel);

  if (sw.mode == PHYS_AUTO &&
      ncprange_family(&bundle->ncp.ipcp.cfg.peer_range) == AF_UNSPEC) {
    prompt_Printf(prompt, "You must ``set ifaddr'' with a peer address "
                  "in auto mode.\n");
    AbortProgram(EX_START);
  }

  if (sw.mode != PHYS_INTERACTIVE) {
    if (sw.mode != PHYS_DIRECT) {
      if (!sw.fg) {
        int bgpipe[2];
        pid_t bgpid;

        if (sw.mode == PHYS_BACKGROUND && pipe(bgpipe)) {
          log_Printf(LogERROR, "pipe: %s\n", strerror(errno));
	  AbortProgram(EX_SOCK);
        }

        bgpid = fork();
        if (bgpid == -1) {
	  log_Printf(LogERROR, "fork: %s\n", strerror(errno));
	  AbortProgram(EX_SOCK);
        }

        if (bgpid) {
	  char c = EX_NORMAL;
          int ret;

	  if (sw.mode == PHYS_BACKGROUND) {
	    close(bgpipe[1]);
	    BGPid = bgpid;
            /* If we get a signal, kill the child */
            signal(SIGHUP, KillChild);
            signal(SIGTERM, KillChild);
            signal(SIGINT, KillChild);
            signal(SIGQUIT, KillChild);

	    /* Wait for our child to close its pipe before we exit */
            while ((ret = read(bgpipe[0], &c, 1)) == 1) {
              switch (c) {
                case EX_NORMAL:
                  if (!sw.quiet) {
	            prompt_Printf(prompt, "PPP enabled\n");
	            log_Printf(LogPHASE, "Parent: PPP enabled\n");
                  }
	          break;
                case EX_REDIAL:
                  if (!sw.quiet)
	            prompt_Printf(prompt, "Attempting redial\n");
                  continue;
                case EX_RECONNECT:
                  if (!sw.quiet)
	            prompt_Printf(prompt, "Attempting reconnect\n");
                  continue;
	        default:
	          prompt_Printf(prompt, "Child failed (%s)\n",
                                ex_desc((int)c));
	          log_Printf(LogPHASE, "Parent: Child failed (%s)\n",
		             ex_desc((int) c));
	      }
	      break;
            }
            if (ret != 1) {
	      prompt_Printf(prompt, "Child exit, no status.\n");
	      log_Printf(LogPHASE, "Parent: Child exit, no status.\n");
	    }
	    close(bgpipe[0]);
	  }
	  return c;
        } else if (sw.mode == PHYS_BACKGROUND) {
	  close(bgpipe[0]);
          bundle->notify.fd = bgpipe[1];
        }

        bundle_ChangedPID(bundle);
        bundle_LockTun(bundle);	/* we have a new pid */
      }

      /* -auto, -dedicated, -ddial, -foreground & -background */
      prompt_Destroy(prompt, 0);
      close(STDOUT_FILENO);
      close(STDERR_FILENO);
      close(STDIN_FILENO);
      if (!sw.fg)
        setsid();
    } else {
      /* -direct - STDIN_FILENO gets used by physical_Open */
      prompt_TtyInit(NULL);
      close(STDOUT_FILENO);
      close(STDERR_FILENO);
    }
  } else {
    /* -interactive */
    close(STDERR_FILENO);
    prompt_TtyInit(prompt);
    prompt_TtyCommandMode(prompt);
    prompt_Required(prompt);
  }

  /* We can get rid of these now */
  for (f = 0; f < sizeof holdfd / sizeof *holdfd; f++)
    close(holdfd[f]);

  log_Printf(LogPHASE, "PPP Started (%s mode).\n", mode2Nam(sw.mode));
  DoLoop(bundle);
  AbortProgram(EX_NORMAL);

  return EX_NORMAL;
}

static void
DoLoop(struct bundle *bundle)
{
  fd_set *rfds, *wfds, *efds;
  int i, nfds, nothing_done;

  if ((rfds = mkfdset()) == NULL) {
    log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
    return;
  }

  if ((wfds = mkfdset()) == NULL) {
    log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
    free(rfds);
    return;
  }

  if ((efds = mkfdset()) == NULL) {
    log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
    free(rfds);
    free(wfds);
    return;
  }

  for (; !bundle_IsDead(bundle); bundle_CleanDatalinks(bundle)) {
    nfds = 0;
    zerofdset(rfds);
    zerofdset(wfds);
    zerofdset(efds);

    /* All our datalinks, the tun device and the MP socket */
    descriptor_UpdateSet(&bundle->desc, rfds, wfds, efds, &nfds);

    /* All our prompts and the diagnostic socket */
    descriptor_UpdateSet(&server.desc, rfds, NULL, NULL, &nfds);

    bundle_CleanDatalinks(bundle);
    if (bundle_IsDead(bundle))
      /* Don't select - we'll be here forever */
      break;

    /*
     * It's possible that we've had a signal since we last checked.  If
     * we don't check again before calling select(), we may end up stuck
     * after having missed the event.... sig_Handle() tries to be as
     * quick as possible if nothing is likely to have happened.
     * This is only really likely if we block in open(... O_NONBLOCK)
     * which will happen with a misconfigured device.
     */
    if (sig_Handle())
      continue;

    i = select(nfds, rfds, wfds, efds, NULL);

    if (i < 0 && errno != EINTR) {
      log_Printf(LogERROR, "DoLoop: select(): %s\n", strerror(errno));
      if (log_IsKept(LogTIMER)) {
        struct timeval t;

        for (i = 0; i <= nfds; i++) {
          if (FD_ISSET(i, rfds)) {
            log_Printf(LogTIMER, "Read set contains %d\n", i);
            FD_CLR(i, rfds);
            t.tv_sec = t.tv_usec = 0;
            if (select(nfds, rfds, wfds, efds, &t) != -1) {
              log_Printf(LogTIMER, "The culprit !\n");
              break;
            }
          }
          if (FD_ISSET(i, wfds)) {
            log_Printf(LogTIMER, "Write set contains %d\n", i);
            FD_CLR(i, wfds);
            t.tv_sec = t.tv_usec = 0;
            if (select(nfds, rfds, wfds, efds, &t) != -1) {
              log_Printf(LogTIMER, "The culprit !\n");
              break;
            }
          }
          if (FD_ISSET(i, efds)) {
            log_Printf(LogTIMER, "Error set contains %d\n", i);
            FD_CLR(i, efds);
            t.tv_sec = t.tv_usec = 0;
            if (select(nfds, rfds, wfds, efds, &t) != -1) {
              log_Printf(LogTIMER, "The culprit !\n");
              break;
            }
          }
        }
      }
      break;
    }

    log_Printf(LogTIMER, "Select returns %d\n", i);

    sig_Handle();

    if (i <= 0)
      continue;

    for (i = 0; i <= nfds; i++)
      if (FD_ISSET(i, efds)) {
        log_Printf(LogPHASE, "Exception detected on descriptor %d\n", i);
        /* We deal gracefully with link descriptor exceptions */
        if (!bundle_Exception(bundle, i)) {
          log_Printf(LogERROR, "Exception cannot be handled !\n");
          break;
        }
      }

    if (i <= nfds)
      break;

    nothing_done = 1;

    if (descriptor_IsSet(&server.desc, rfds)) {
      descriptor_Read(&server.desc, bundle, rfds);
      nothing_done = 0;
    }

    if (descriptor_IsSet(&bundle->desc, rfds)) {
      descriptor_Read(&bundle->desc, bundle, rfds);
      nothing_done = 0;
    }

    if (descriptor_IsSet(&bundle->desc, wfds))
      if (descriptor_Write(&bundle->desc, bundle, wfds) <= 0 && nothing_done) {
        /*
         * This is disastrous.  The OS has told us that something is
         * writable, and all our write()s have failed.  Rather than
         * going back immediately to do our UpdateSet()s and select(),
         * we sleep for a bit to avoid gobbling up all cpu time.
         */
        struct timeval t;

        t.tv_sec = 0;
        t.tv_usec = 100000;
        select(0, NULL, NULL, NULL, &t);
      }
  }

  log_Printf(LogDEBUG, "DoLoop done.\n");
}
OpenPOWER on IntegriCloud