summaryrefslogtreecommitdiffstats
path: root/sysdep/unix/io.c
blob: fef1bd7635f408414e57819c6f6e5b57c55bcd1a (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
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
/*
 *	BIRD Internet Routing Daemon -- Unix I/O
 *
 *	(c) 1998--1999 Martin Mares <mj@ucw.cz>
 *
 *	Can be freely distributed and used under the terms of the GNU GPL.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/fcntl.h>
#include <unistd.h>
#include <errno.h>

#ifndef HAVE_STRUCT_IP_MREQN
#include <net/if.h>
#endif

#include "nest/bird.h"
#include "lib/lists.h"
#include "lib/resource.h"
#include "lib/timer.h"
#include "lib/socket.h"
#include "lib/event.h"
#include "nest/iface.h"

#ifdef IPV6
#include <linux/in6.h>			/* FIXMEv6: glibc variant? */
#endif

#include "lib/unix.h"

/*
 *	Random Numbers
 */

u32
random_u32(void)
{
  long int rand_low, rand_high;

  rand_low = random();
  rand_high = random();
  return (rand_low & 0xffff) | ((rand_high & 0xffff) << 16);
}

/*
 *	Timers
 */

#define NEAR_TIMER_LIMIT 4

#ifdef TIME_T_IS_64BIT
#define TIME_INFINITY 0x7fffffffffffffff
#else
#ifdef TIME_T_IS_SIGNED
#define TIME_INFINITY 0x7fffffff
#else
#define TIME_INFINITY 0xffffffff
#endif
#endif

static list near_timers, far_timers;
static bird_clock_t first_far_timer = TIME_INFINITY;

bird_clock_t now;

static void
tm_free(resource *r)
{
  timer *t = (timer *) r;

  tm_stop(t);
}

static void
tm_dump(resource *r)
{
  timer *t = (timer *) r;

  debug("(code %p, data %p, ", t->hook, t->data);
  if (t->randomize)
    debug("rand %d, ", t->randomize);
  if (t->recurrent)
    debug("recur %d, ", t->recurrent);
  if (t->expires)
    debug("expires in %d sec)\n", t->expires - now);
  else
    debug("inactive)\n");
}

static struct resclass tm_class = {
  "Timer",
  sizeof(timer),
  tm_free,
  tm_dump
};

timer *
tm_new(pool *p)
{
  timer *t = ralloc(p, &tm_class);
  t->hook = NULL;
  t->data = NULL;
  t->randomize = 0;
  t->expires = 0;
  return t;
}

static inline void
tm_insert_near(timer *t)
{
  node *n = HEAD(near_timers);

  while (n->next && (SKIP_BACK(timer, n, n)->expires < t->expires))
    n = n->next;
  insert_node(&t->n, n->prev);
}

void
tm_start(timer *t, unsigned after)
{
  bird_clock_t when;

  if (t->randomize)
    after += random() % (t->randomize + 1);
  when = now + after;
  if (t->expires == when)
    return;
  if (t->expires)
    rem_node(&t->n);
  t->expires = when;
  if (after <= NEAR_TIMER_LIMIT)
    tm_insert_near(t);
  else
    {
      if (!first_far_timer || first_far_timer > when)
	first_far_timer = when;
      add_tail(&far_timers, &t->n);
    }
}

void
tm_stop(timer *t)
{
  if (t->expires)
    {
      rem_node(&t->n);
      t->expires = 0;
    }
}

static void
tm_dump_them(char *name, list *l)
{
  node *n;
  timer *t;

  debug("%s timers:\n", name);
  WALK_LIST(n, *l)
    {
      t = SKIP_BACK(timer, n, n);
      debug("%p ", t);
      tm_dump(&t->r);
    }
  debug("\n");
}

void
tm_dump_all(void)
{
  tm_dump_them("Near", &near_timers);
  tm_dump_them("Far", &far_timers);
}

static inline time_t
tm_first_shot(void)
{
  time_t x = first_far_timer;

  if (!EMPTY_LIST(near_timers))
    {
      timer *t = SKIP_BACK(timer, n, HEAD(near_timers));
      if (t->expires < x)
	x = t->expires;
    }
  return x;
}

static void
tm_shot(void)
{
  timer *t;
  node *n, *m;

  if (first_far_timer <= now)
    {
      bird_clock_t limit = now + NEAR_TIMER_LIMIT;
      first_far_timer = TIME_INFINITY;
      n = HEAD(far_timers);
      while (m = n->next)
	{
	  t = SKIP_BACK(timer, n, n);
	  if (t->expires <= limit)
	    {
	      rem_node(n);
	      tm_insert_near(t);
	    }
	  else if (t->expires < first_far_timer)
	    first_far_timer = t->expires;
	  n = m;
	}
    }
  while ((n = HEAD(near_timers)) -> next)
    {
      int delay;
      t = SKIP_BACK(timer, n, n);
      if (t->expires > now)
	break;
      rem_node(n);
      delay = t->expires - now;
      t->expires = 0;
      if (t->recurrent)
	{
	  int i = t->recurrent - delay;
	  if (i < 0)
	    i = 0;
	  tm_start(t, i);
	}
      t->hook(t);
    }
}

bird_clock_t
tm_parse_date(char *x)
{
  struct tm tm;
  int n;
  time_t t;

  if (sscanf(x, "%d-%d-%d%n", &tm.tm_mday, &tm.tm_mon, &tm.tm_year, &n) != 3 || x[n])
    return 0;
  tm.tm_mon--;
  tm.tm_year -= 1900;
  tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
  t = mktime(&tm);
  if (t == (time_t) -1)
    return 0;
  return t;
}

void
tm_format_date(char *x, bird_clock_t t)
{
  struct tm *tm;

  tm = localtime(&t);
  sprintf(x, "%02d-%02d-%04d", tm->tm_mday, tm->tm_mon+1, tm->tm_year+1900);
}

/*
 *	Sockets
 */

#ifndef SOL_IP
#define SOL_IP IPPROTO_IP
#endif

static list sock_list;

static void
sk_free(resource *r)
{
  sock *s = (sock *) r;

  if (s->fd >= 0)
    rem_node(&s->n);
}

static void
sk_dump(resource *r)
{
  sock *s = (sock *) r;
  static char *sk_type_names[] = { "TCP<", "TCP>", "TCP", "UDP", "UDP/MC", "IP", "IP/MC", "MAGIC" };

  debug("(%s, ud=%p, sa=%08x, sp=%d, da=%08x, dp=%d, tos=%d, ttl=%d, if=%s)\n",
	sk_type_names[s->type],
	s->data,
	s->saddr,
	s->sport,
	s->daddr,
	s->dport,
	s->tos,
	s->ttl,
	s->iface ? s->iface->name : "none");
}

static struct resclass sk_class = {
  "Socket",
  sizeof(sock),
  sk_free,
  sk_dump
};

sock *
sk_new(pool *p)
{
  sock *s = ralloc(p, &sk_class);
  s->pool = p;
  s->data = NULL;
  s->saddr = s->daddr = IPA_NONE;
  s->sport = s->dport = 0;
  s->tos = s->ttl = -1;
  s->iface = NULL;
  s->rbuf = NULL;
  s->rx_hook = NULL;
  s->rbsize = 0;
  s->tbuf = NULL;
  s->tx_hook = NULL;
  s->tbsize = 0;
  s->err_hook = NULL;
  s->fd = -1;
  return s;
}

#define ERR(x) do { err = x; goto bad; } while(0)

#ifdef IPV6

static inline void
set_inaddr(struct in6_addr *ia, ip_addr a)
{
  ipa_hton(a);
  memcpy(ia, &a, sizeof(a));
}

void
fill_in_sockaddr(sockaddr *sa, ip_addr a, unsigned port)
{
  sa->sin6_family = AF_INET6;
  sa->sin6_port = htons(port);
  sa->sin6_flowinfo = 0;
  set_inaddr(&sa->sin6_addr, a);
}

void
get_sockaddr(sockaddr *sa, ip_addr *a, unsigned *port)
{
  if (sa->sin6_family != AF_INET6)
    bug("get_sockaddr called for wrong address family");
  if (port)
    *port = ntohs(sa->sin6_port);
  memcpy(a, &sa->sin6_addr, sizeof(*a));
  ipa_ntoh(*a);
}

#else

static inline void
set_inaddr(struct in_addr *ia, ip_addr a)
{
  ipa_hton(a);
  memcpy(&ia->s_addr, &a, sizeof(a));
}

void
fill_in_sockaddr(sockaddr *sa, ip_addr a, unsigned port)
{
  sa->sin_family = AF_INET;
  sa->sin_port = htons(port);
  set_inaddr(&sa->sin_addr, a);
}

void
get_sockaddr(sockaddr *sa, ip_addr *a, unsigned *port)
{
  if (sa->sin_family != AF_INET)
    bug("get_sockaddr called for wrong address family");
  if (port)
    *port = ntohs(sa->sin_port);
  memcpy(a, &sa->sin_addr.s_addr, sizeof(*a));
  ipa_ntoh(*a);
}

#endif

static char *
sk_setup(sock *s)
{
  int fd = s->fd;
  int one = 1;
  char *err;

  if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
    ERR("fcntl(O_NONBLOCK)");
#ifdef IPV6
  if (s->ttl >= 0 && s->type != SK_UDP_MC && s->type != SK_IP_MC &&
      setsockopt(fd, SOL_IPV6, IPV6_UNICAST_HOPS, &s->ttl, sizeof(s->ttl)) < 0)
    ERR("IPV6_UNICAST_HOPS");
#else
  if ((s->tos >= 0) && setsockopt(fd, SOL_IP, IP_TOS, &s->tos, sizeof(s->tos)) < 0)
    ERR("IP_TOS");
  if (s->ttl >= 0)
    {
      if (setsockopt(fd, SOL_IP, IP_TTL, &s->ttl, sizeof(s->ttl)) < 0)
	ERR("IP_TTL");
      if (setsockopt(fd, SOL_SOCKET, SO_DONTROUTE, &one, sizeof(one)) < 0)
	ERR("SO_DONTROUTE");
    }
#endif
  /* FIXME: Set send/receive buffers? */
  /* FIXME: Set keepalive for TCP connections? */
  err = NULL;
bad:
  return err;
}

static void
sk_alloc_bufs(sock *s)
{
  if (!s->rbuf && s->rbsize)
    s->rbuf = mb_alloc(s->pool, s->rbsize);
  s->rpos = s->rbuf;
  if (!s->tbuf && s->tbsize)
    s->tbuf = mb_alloc(s->pool, s->tbsize);
  s->tpos = s->ttx = s->tbuf;
}

void
sk_tcp_connected(sock *s)
{
  s->rx_hook(s, 0);
  s->type = SK_TCP;
  sk_alloc_bufs(s);
}

int
sk_open(sock *s)
{
  int fd, e;
  sockaddr sa;
  int zero = 0;
  int one = 1;
  int type = s->type;
  int has_src = ipa_nonzero(s->saddr) || s->sport;
  int has_dest = ipa_nonzero(s->daddr);
  char *err;

  switch (type)
    {
    case SK_TCP_ACTIVE:
    case SK_TCP_PASSIVE:
      fd = socket(BIRD_PF, SOCK_STREAM, IPPROTO_TCP);
      break;
    case SK_UDP:
    case SK_UDP_MC:
      fd = socket(BIRD_PF, SOCK_DGRAM, IPPROTO_UDP);
      break;
    case SK_IP:
    case SK_IP_MC:
      fd = socket(BIRD_PF, SOCK_RAW, s->dport);
      break;
    case SK_MAGIC:
      fd = s->fd;
      break;
    default:
      bug("sk_open() called for invalid sock type %d", type);
    }
  if (fd < 0)
    die("sk_open: socket: %m");
  s->fd = fd;

  if (err = sk_setup(s))
    goto bad;
  switch (type)
    {
    case SK_UDP:
    case SK_IP:
      if (s->iface)			/* It's a broadcast socket */
#ifdef IPV6
	bug("IPv6 has no broadcasts");
#else
	if (setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &one, sizeof(one)) < 0)
	  ERR("SO_BROADCAST");
#endif
      break;
    case SK_UDP_MC:
    case SK_IP_MC:
      {
#ifdef IPV6
	/* Fortunately, IPv6 socket interface is recent enough and therefore standardized */
	ASSERT(s->iface && s->iface->addr);
	if (has_dest)
	  {
	    int t = s->iface->index;
	    if (setsockopt(fd, SOL_IPV6, IPV6_MULTICAST_HOPS, &s->ttl, sizeof(s->ttl)) < 0)
	      ERR("IPV6_MULTICAST_HOPS");
	    if (setsockopt(fd, SOL_IPV6, IPV6_MULTICAST_LOOP, &zero, sizeof(zero)) < 0)
	      ERR("IPV6_MULTICAST_LOOP");
	    if (setsockopt(fd, SOL_IPV6, IPV6_MULTICAST_IF, &t, sizeof(t)) < 0)
	      ERR("IPV6_MULTICAST_IF");
	  }
	if (has_src)
	  {
	    struct ipv6_mreq mreq;
	    set_inaddr(&mreq.ipv6mr_multiaddr, s->daddr);
	    mreq.ipv6mr_ifindex = s->iface->index;
	    if (setsockopt(fd, SOL_IPV6, IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0)
	      ERR("IPV6_ADD_MEMBERSHIP");
	  }
#else
	/* With IPv4 there are zillions of different socket interface variants. Ugh. */
#ifdef HAVE_STRUCT_IP_MREQN
	struct ip_mreqn mreq;
#define mreq_add mreq
	ASSERT(s->iface && s->iface->addr);
	mreq.imr_ifindex = s->iface->index;
	set_inaddr(&mreq.imr_address, s->iface->addr->ip);
#else
	struct in_addr mreq;
	struct ip_mreq mreq_add;
	ASSERT(s->iface && s->iface->addr);
	set_inaddr(&mreq, s->iface->addr->ip);
#ifdef SO_BINDTODEVICE
	{
	  struct ifreq ifr;
	  strcpy(ifr.ifr_name, s->iface->name);
	  if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) < 0)
	    ERR("SO_BINDTODEVICE");
	  mreq_add.imr_interface.s_addr = INADDR_ANY;
	}
#else
#error Multicasts not supported on PtP devices		/* FIXME: Solve it somehow? */
	mreq_add.imr_interface = mreq;
#endif
#endif
	set_inaddr(&mreq_add.imr_multiaddr, s->daddr);
	if (has_dest)
	  {
	    if (
#ifdef IP_DEFAULT_MULTICAST_TTL
		s->ttl != IP_DEFAULT_MULTICAST_TTL &&
#endif
		setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &s->ttl, sizeof(s->ttl)) < 0)
	      ERR("IP_MULTICAST_TTL");
	    if (
#ifdef IP_DEFAULT_MULTICAST_LOOP
		IP_DEFAULT_MULTICAST_LOOP &&
#endif
		setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &zero, sizeof(zero)) < 0)
	      ERR("IP_MULTICAST_LOOP");
	    /* This defines where should we send _outgoing_ multicasts */
	    if (setsockopt(fd, SOL_IP, IP_MULTICAST_IF, &mreq, sizeof(mreq)) < 0)
	      ERR("IP_MULTICAST_IF");
	}
      /* And this one sets interface for _receiving_ multicasts from */
      if (has_src && setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP, &mreq_add, sizeof(mreq_add)) < 0)
	ERR("IP_ADD_MEMBERSHIP");
#endif
      break;
      }
    }
  if (has_src)
    {
      int port;

      if (type == SK_IP || type == SK_IP_MC)
	port = 0;
      else
	{
	  port = s->sport;
	  if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0)
	    ERR("SO_REUSEADDR");
	}
      fill_in_sockaddr(&sa, s->saddr, port);
      if (bind(fd, (struct sockaddr *) &sa, sizeof(sa)) < 0)
	ERR("bind");
    }
  fill_in_sockaddr(&sa, s->daddr, s->dport);
  switch (type)
    {
    case SK_TCP_ACTIVE:
      if (connect(fd, (struct sockaddr *) &sa, sizeof(sa)) >= 0)
	sk_tcp_connected(s);
      else if (errno != EINTR && errno != EAGAIN)
	ERR("connect");
      break;
    case SK_TCP_PASSIVE:
      if (listen(fd, 8))
	ERR("listen");
      break;
    case SK_MAGIC:
      break;
    default:
#ifdef IPV6
#ifdef IPV6_MTU_DISCOVER
      {
	int dont = IPV6_PMTUDISC_DONT;
	if (setsockopt(fd, SOL_IPV6, IPV6_MTU_DISCOVER, &dont, sizeof(dont)) < 0)
	  ERR("IPV6_MTU_DISCOVER");
      }
#endif
#else
#ifdef IP_PMTUDISC
      {
	int dont = IP_PMTUDISC_DONT;
	if (setsockopt(fd, SOL_IP, IP_PMTUDISC, &dont, sizeof(dont)) < 0)
	  ERR("IP_PMTUDISC");
      }
#endif
#endif
    }

  sk_alloc_bufs(s);
  add_tail(&sock_list, &s->n);
  return 0;

bad:
  log(L_ERR "sk_open: %s: %m", err);
  close(fd);
  s->fd = -1;
  return -1;
}

static int
sk_maybe_write(sock *s)
{
  int e;

  switch (s->type)
    {
    case SK_TCP:
    case SK_MAGIC:
      while (s->ttx != s->tpos)
	{
	  e = write(s->fd, s->ttx, s->tpos - s->ttx);
	  if (e < 0)
	    {
	      if (errno != EINTR && errno != EAGAIN)
		{
		  log(L_ERR "write: %m");
		  s->err_hook(s, errno);
		  return -1;
		}
	      return 0;
	    }
	  s->ttx += e;
	}
      s->ttx = s->tpos = s->tbuf;
      return 1;
    case SK_UDP:
    case SK_UDP_MC:
    case SK_IP:
    case SK_IP_MC:
      {
	sockaddr sa;

	if (s->tbuf == s->tpos)
	  return 1;
	fill_in_sockaddr(&sa, s->faddr, s->fport);
	e = sendto(s->fd, s->tbuf, s->tpos - s->tbuf, 0, (struct sockaddr *) &sa, sizeof(sa));
	if (e < 0)
	  {
	    if (errno != EINTR && errno != EAGAIN)
	      {
		log(L_ERR "sendto: %m");
		s->err_hook(s, errno);
		return -1;
	      }
	    return 0;
	  }
	s->tpos = s->tbuf;
	return 1;
      }
    default:
      bug("sk_maybe_write: unknown socket type %d", s->type);
    }
}

int
sk_send(sock *s, unsigned len)
{
  s->faddr = s->daddr;
  s->fport = s->dport;
  s->ttx = s->tbuf;
  s->tpos = s->tbuf + len;
  return sk_maybe_write(s);
}

int
sk_send_to(sock *s, unsigned len, ip_addr addr, unsigned port)
{
  s->faddr = addr;
  s->fport = port;
  s->ttx = s->tbuf;
  s->tpos = s->tbuf + len;
  return sk_maybe_write(s);
}

static int
sk_read(sock *s)
{
  switch (s->type)
    {
    case SK_TCP_ACTIVE:
      {
	sockaddr sa;
	fill_in_sockaddr(&sa, s->daddr, s->dport);
	if (connect(s->fd, (struct sockaddr *) &sa, sizeof(sa)) >= 0)
	  sk_tcp_connected(s);
	else if (errno != EINTR && errno != EAGAIN)
	  {
	    log(L_ERR "connect: %m");
	    s->err_hook(s, errno);
	  }
	return 0;
      }
    case SK_TCP_PASSIVE:
      {
	sockaddr sa;
	int al = sizeof(sa);
	int fd = accept(s->fd, (struct sockaddr *) &sa, &al);
	if (fd >= 0)
	  {
	    sock *t = sk_new(s->pool);
	    char *err;
	    t->type = SK_TCP;
	    t->fd = fd;
	    add_tail(&sock_list, &t->n);
	    s->rx_hook(t, 0);
	    if (err = sk_setup(t))
	      {
		log(L_ERR "Incoming connection: %s: %m", err);
		s->err_hook(s, errno);
		return 0;
	      }
	    sk_alloc_bufs(t);
	    return 1;
	  }
	else if (errno != EINTR && errno != EAGAIN)
	  {
	    log(L_ERR "accept: %m");
	    s->err_hook(s, errno);
	  }
	return 0;
      }
    case SK_TCP:
      {
	int c = read(s->fd, s->rpos, s->rbuf + s->rbsize - s->rpos);

	if (c < 0)
	  {
	    if (errno != EINTR && errno != EAGAIN)
	      {
		log(L_ERR "read: %m");
		s->err_hook(s, errno);
	      }
	  }
	else if (!c)
	  s->err_hook(s, 0);
	else
	  {
	    s->rpos += c;
	    if (s->rx_hook(s, s->rpos - s->rbuf))
	      s->rpos = s->rbuf;
	    return 1;
	  }
	return 0;
      }
    case SK_MAGIC:
      return s->rx_hook(s, 0);
    default:
      {
	sockaddr sa;
	int al = sizeof(sa);
	int e = recvfrom(s->fd, s->rbuf, s->rbsize, 0, (struct sockaddr *) &sa, &al);

	if (e < 0)
	  {
	    if (errno != EINTR && errno != EAGAIN)
	      {
		log(L_ERR "recvfrom: %m");
		s->err_hook(s, errno);
	      }
	    return 0;
	  }
	s->rpos = s->rbuf + e;
	get_sockaddr(&sa, &s->faddr, &s->fport);
	s->rx_hook(s, e);
	return 1;
      }
    }
}

static void
sk_write(sock *s)
{
  while (s->ttx != s->tbuf && sk_maybe_write(s) > 0)
    s->tx_hook(s);
}

void
sk_dump_all(void)
{
  node *n;
  sock *s;

  debug("Open sockets:\n");
  WALK_LIST(n, sock_list)
    {
      s = SKIP_BACK(sock, n, n);
      debug("%p ", s);
      sk_dump(&s->r);
    }
  debug("\n");
}

#undef ERR

/*
 *	Main I/O Loop
 */

volatile int async_config_flag;		/* Asynchronous reconfiguration/dump scheduled */
volatile int async_dump_flag;

void
io_init(void)
{
  init_list(&near_timers);
  init_list(&far_timers);
  init_list(&sock_list);
  init_list(&global_event_list);
  krt_io_init();
  now = time(NULL);
  srandom((int) now);
}

void
io_loop(void)
{
  fd_set rd, wr;
  struct timeval timo;
  time_t tout;
  int hi;
  sock *s;
  node *n;

  /* FIXME: Use poll() if available */

  FD_ZERO(&rd);
  FD_ZERO(&wr);
  for(;;)
    {
      ev_run_list(&global_event_list);
      now = time(NULL);
      tout = tm_first_shot();
      if (tout <= now)
	{
	  tm_shot();
	  continue;
	}
      else
	{
	  timo.tv_sec = tout - now;
	  timo.tv_usec = 0;
	}

      hi = 0;
      WALK_LIST(n, sock_list)
	{
	  s = SKIP_BACK(sock, n, n);
	  if (s->rx_hook)
	    {
	      FD_SET(s->fd, &rd);
	      if (s->fd > hi)
		hi = s->fd;
	    }
	  if (s->tx_hook && s->ttx != s->tpos)
	    {
	      FD_SET(s->fd, &wr);
	      if (s->fd > hi)
		hi = s->fd;
	    }
	}

      /*
       * Yes, this is racy. But even if the signal comes before this test
       * and entering select(), it gets caught on the next timer tick.
       */

      if (async_config_flag)
	{
	  async_config();
	  async_config_flag = 0;
	  continue;
	}
      if (async_dump_flag)
	{
	  async_dump();
	  async_dump_flag = 0;
	  continue;
	}
      if (async_shutdown_flag)
	{
	  async_shutdown();
	  async_shutdown_flag = 0;
	  continue;
	}

      /* And finally enter select() to find active sockets */

      hi = select(hi+1, &rd, &wr, NULL, &timo);
      if (hi < 0)
	{
	  if (errno == EINTR || errno == EAGAIN)
	    continue;
	  die("select: %m");
	}
      if (hi)
	{
	  WALK_LIST(n, sock_list)
	    {
	      s = SKIP_BACK(sock, n, n);
	      if (FD_ISSET(s->fd, &rd))
		{
		  FD_CLR(s->fd, &rd);
		  while (sk_read(s))
		    ;
		}
	      if (FD_ISSET(s->fd, &wr))
		{
		  FD_CLR(s->fd, &wr);
		  sk_write(s);
		}
	    }
	}
    }
}