summaryrefslogtreecommitdiffstats
path: root/sysdep/unix/main.c
blob: 55477913bc63441a4da1153e7497dd18262fe6b0 (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
/*
 *	BIRD Internet Routing Daemon -- Unix Entry Point
 *
 *	(c) 1998--2000 Martin Mares <mj@ucw.cz>
 *
 *	Can be freely distributed and used under the terms of the GNU GPL.
 */

#undef LOCAL_DEBUG

#define _GNU_SOURCE 1

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>
#include <pwd.h>
#include <grp.h>
#include <sys/stat.h>

#include "nest/bird.h"
#include "lib/lists.h"
#include "lib/resource.h"
#include "lib/socket.h"
#include "lib/event.h"
#include "lib/string.h"
#include "nest/route.h"
#include "nest/protocol.h"
#include "nest/iface.h"
#include "nest/cli.h"
#include "nest/locks.h"
#include "conf/conf.h"
#include "filter/filter.h"

#include "unix.h"
#include "krt.h"

/*
 *	Debugging
 */

#ifdef DEBUGGING
static int debug_flag = 1;
#else
static int debug_flag = 0;
#endif

void
async_dump(void)
{
  debug("INTERNAL STATE DUMP\n\n");

  rdump(&root_pool);
  sk_dump_all();
  tm_dump_all();
  if_dump_all();
  neigh_dump_all();
  rta_dump_all();
  rt_dump_all();
  protos_dump_all();

  debug("\n");
}

/*
 *	Dropping privileges
 */

#ifdef CONFIG_RESTRICTED_PRIVILEGES
#include "lib/syspriv.h"
#else

static inline void
drop_uid(uid_t uid)
{
  die("Cannot change user on this platform");
}

#endif

static inline void
drop_gid(gid_t gid)
{
  if (setgid(gid) < 0)
    die("setgid: %m");
}

/*
 *	Reading the Configuration
 */

#ifdef PATH_IPROUTE_DIR

static inline void
add_num_const(char *name, int val)
{
  struct symbol *s = cf_find_symbol(name);
  s->class = SYM_NUMBER;
  s->def = NULL;
  s->aux = val;
}

/* the code of read_iproute_table() is based on
   rtnl_tab_initialize() from iproute2 package */
static void
read_iproute_table(char *file, char *prefix, int max)
{
  char buf[512], namebuf[512];
  char *name;
  int val;
  FILE *fp;

  strcpy(namebuf, prefix);
  name = namebuf + strlen(prefix);

  fp = fopen(file, "r");
  if (!fp)
    return;

  while (fgets(buf, sizeof(buf), fp))
  {
    char *p = buf;

    while (*p == ' ' || *p == '\t')
      p++;

    if (*p == '#' || *p == '\n' || *p == 0)
      continue;
   
    if (sscanf(p, "0x%x %s\n", &val, name) != 2 &&
	sscanf(p, "0x%x %s #", &val, name) != 2 &&
	sscanf(p, "%d %s\n", &val, name) != 2 &&
	sscanf(p, "%d %s #", &val, name) != 2)
      continue;

    if (val < 0 || val > max)
      continue;

    for(p = name; *p; p++)
      if ((*p < 'a' || *p > 'z') && (*p < '0' || *p > '9') && (*p != '_'))
	*p = '_';

    add_num_const(namebuf, val);
  }

  fclose(fp);
}

#endif // PATH_IPROUTE_DIR


static int conf_fd;
static char *config_name = PATH_CONFIG;

static int
cf_read(byte *dest, unsigned int len)
{
  int l = read(conf_fd, dest, len);
  if (l < 0)
    cf_error("Read error");
  return l;
}

void
sysdep_preconfig(struct config *c)
{
  init_list(&c->logfiles);

#ifdef PATH_IPROUTE_DIR
  // read_iproute_table(PATH_IPROUTE_DIR "/rt_protos", "ipp_", 256);
  read_iproute_table(PATH_IPROUTE_DIR "/rt_realms", "ipr_", 256);
  read_iproute_table(PATH_IPROUTE_DIR "/rt_scopes", "ips_", 256);
  read_iproute_table(PATH_IPROUTE_DIR "/rt_tables", "ipt_", 256);
#endif
}

int
sysdep_commit(struct config *new, struct config *old UNUSED)
{
  log_switch(debug_flag, &new->logfiles, new->syslog_name);
  return 0;
}

static int
unix_read_config(struct config **cp, char *name)
{
  struct config *conf = config_alloc(name);
  int ret;

  *cp = conf;
  conf_fd = open(name, O_RDONLY);
  if (conf_fd < 0)
    return 0;
  cf_read_hook = cf_read;
  ret = config_parse(conf);
  close(conf_fd);
  return ret;
}

static void
read_config(void)
{
  struct config *conf;

  if (!unix_read_config(&conf, config_name))
    {
      if (conf->err_msg)
	die("%s, line %d: %s", config_name, conf->err_lino, conf->err_msg);
      else
	die("Unable to open configuration file %s: %m", config_name);
    }
  config_commit(conf, RECONFIG_HARD);
}

void
async_config(void)
{
  struct config *conf;

  log(L_INFO "Reconfiguration requested by SIGHUP");
  if (!unix_read_config(&conf, config_name))
    {
      if (conf->err_msg)
	log(L_ERR "%s, line %d: %s", config_name, conf->err_lino, conf->err_msg);
      else
	log(L_ERR "Unable to open configuration file %s: %m", config_name);
      config_free(conf);
    }
  else
    config_commit(conf, RECONFIG_HARD);
}

void
cmd_reconfig(char *name, int type)
{
  struct config *conf;

  if (cli_access_restricted())
    return;

  if (!name)
    name = config_name;
  cli_msg(-2, "Reading configuration from %s", name);
  if (!unix_read_config(&conf, name))
    {
      if (conf->err_msg)
	cli_msg(8002, "%s, line %d: %s", name, conf->err_lino, conf->err_msg);
      else
	cli_msg(8002, "%s: %m", name);
      config_free(conf);
    }
  else
    {
      switch (config_commit(conf, type))
	{
	case CONF_DONE:
	  cli_msg(3, "Reconfigured.");
	  break;
	case CONF_PROGRESS:
	  cli_msg(4, "Reconfiguration in progress.");
	  break;
	case CONF_SHUTDOWN:
	  cli_msg(6, "Reconfiguration ignored, shutting down.");
	  break;
	default:
	  cli_msg(5, "Reconfiguration already in progress, queueing new config");
	}
    }
}

/*
 *	Command-Line Interface
 */

static sock *cli_sk;
static char *path_control_socket = PATH_CONTROL_SOCKET;


static void
cli_write(cli *c)
{
  sock *s = c->priv;

  while (c->tx_pos)
    {
      struct cli_out *o = c->tx_pos;

      int len = o->wpos - o->outpos;
      s->tbuf = o->outpos;
      o->outpos = o->wpos;

      if (sk_send(s, len) <= 0)
	return;

      c->tx_pos = o->next;
    }

  /* Everything is written */
  s->tbuf = NULL;
  cli_written(c);
}

void
cli_write_trigger(cli *c)
{
  sock *s = c->priv;

  if (s->tbuf == NULL)
    cli_write(c);
}

static void
cli_tx(sock *s)
{
  cli_write(s->data);
}

int
cli_get_command(cli *c)
{
  sock *s = c->priv;
  byte *t = c->rx_aux ? : s->rbuf;
  byte *tend = s->rpos;
  byte *d = c->rx_pos;
  byte *dend = c->rx_buf + CLI_RX_BUF_SIZE - 2;

  while (t < tend)
    {
      if (*t == '\r')
	t++;
      else if (*t == '\n')
	{
	  t++;
	  c->rx_pos = c->rx_buf;
	  c->rx_aux = t;
	  *d = 0;
	  return (d < dend) ? 1 : -1;
	}
      else if (d < dend)
	*d++ = *t++;
    }
  c->rx_aux = s->rpos = s->rbuf;
  c->rx_pos = d;
  return 0;
}

static int
cli_rx(sock *s, int size UNUSED)
{
  cli_kick(s->data);
  return 0;
}

static void
cli_err(sock *s, int err)
{
  if (config->cli_debug)
    {
      if (err)
	log(L_INFO "CLI connection dropped: %s", strerror(err));
      else
	log(L_INFO "CLI connection closed");
    }
  cli_free(s->data);
}

static int
cli_connect(sock *s, int size UNUSED)
{
  cli *c;

  if (config->cli_debug)
    log(L_INFO "CLI connect");
  s->rx_hook = cli_rx;
  s->tx_hook = cli_tx;
  s->err_hook = cli_err;
  s->data = c = cli_new(s);
  s->pool = c->pool;		/* We need to have all the socket buffers allocated in the cli pool */
  c->rx_pos = c->rx_buf;
  c->rx_aux = NULL;
  rmove(s, c->pool);
  return 1;
}

static void
cli_init_unix(uid_t use_uid, gid_t use_gid)
{
  sock *s;

  cli_init();
  s = cli_sk = sk_new(cli_pool);
  s->type = SK_UNIX_PASSIVE;
  s->rx_hook = cli_connect;
  s->rbsize = 1024;
  sk_open_unix(s, path_control_socket);

  if (use_uid || use_gid)
    if (chown(path_control_socket, use_uid, use_gid) < 0)
      die("chown: %m");

  if (chmod(path_control_socket, 0660) < 0)
    die("chmod: %m");
}

/*
 *	Shutdown
 */

void
cmd_shutdown(void)
{
  if (cli_access_restricted())
    return;

  cli_msg(7, "Shutdown requested");
  order_shutdown();
}

void
async_shutdown(void)
{
  DBG("Shutting down...\n");
  order_shutdown();
}

void
sysdep_shutdown_done(void)
{
  unlink(path_control_socket);
  log_msg(L_FATAL "Shutdown completed");
  exit(0);
}

/*
 *	Signals
 */

static void
handle_sighup(int sig UNUSED)
{
  DBG("Caught SIGHUP...\n");
  async_config_flag = 1;
}

static void
handle_sigusr(int sig UNUSED)
{
  DBG("Caught SIGUSR...\n");
  async_dump_flag = 1;
}

static void
handle_sigterm(int sig UNUSED)
{
  DBG("Caught SIGTERM...\n");
  async_shutdown_flag = 1;
}

static void
signal_init(void)
{
  struct sigaction sa;

  bzero(&sa, sizeof(sa));
  sa.sa_handler = handle_sigusr;
  sa.sa_flags = SA_RESTART;
  sigaction(SIGUSR1, &sa, NULL);
  sa.sa_handler = handle_sighup;
  sa.sa_flags = SA_RESTART;
  sigaction(SIGHUP, &sa, NULL);
  sa.sa_handler = handle_sigterm;
  sa.sa_flags = SA_RESTART;
  sigaction(SIGTERM, &sa, NULL);
  signal(SIGPIPE, SIG_IGN);
}

/*
 *	Parsing of command-line arguments
 */

static char *opt_list = "c:dD:ps:u:g:";
static int parse_and_exit;
char *bird_name;
static char *use_user;
static char *use_group;

static void
usage(void)
{
  fprintf(stderr, "Usage: %s [-c <config-file>] [-d] [-D <debug-file>] [-p] [-s <control-socket>] [-u <user>] [-g <group>]\n", bird_name);
  exit(1);
}

static inline char *
get_bird_name(char *s, char *def)
{
  char *t;
  if (!s)
    return def;
  t = strrchr(s, '/');
  if (!t)
    return s;
  if (!t[1])
    return def;
  return t+1;
}

static inline uid_t
get_uid(const char *s)
{
  struct passwd *pw;
  char *endptr;
  long int rv;

  if (!s)
    return 0;

  errno = 0;
  rv = strtol(s, &endptr, 10);

  if (!errno && !*endptr)
    return rv;

  pw = getpwnam(s);
  if (!pw)
    die("Cannot find user '%s'", s);

  return pw->pw_uid;
}

static inline gid_t
get_gid(const char *s)
{
  struct group *gr;
  char *endptr;
  long int rv;

  if (!s)
    return 0;
  
  errno = 0;
  rv = strtol(s, &endptr, 10);

  if (!errno && !*endptr)
    return rv;

  gr = getgrnam(s);
  if (!gr)
    die("Cannot find group '%s'", s);

  return gr->gr_gid;
}

static void
parse_args(int argc, char **argv)
{
  int c;

  bird_name = get_bird_name(argv[0], "bird");
  if (argc == 2)
    {
      if (!strcmp(argv[1], "--version"))
	{
	  fprintf(stderr, "BIRD version " BIRD_VERSION "\n");
	  exit(0);
	}
      if (!strcmp(argv[1], "--help"))
	usage();
    }
  while ((c = getopt(argc, argv, opt_list)) >= 0)
    switch (c)
      {
      case 'c':
	config_name = optarg;
	break;
      case 'd':
	debug_flag |= 1;
	break;
      case 'D':
	log_init_debug(optarg);
	debug_flag |= 2;
	break;
      case 'p':
	parse_and_exit = 1;
	break;
      case 's':
	path_control_socket = optarg;
	break;
      case 'u':
	use_user = optarg;
	break;
      case 'g':
	use_group = optarg;
	break;
      default:
	usage();
      }
  if (optind < argc)
    usage();
}

/*
 *	Hic Est main()
 */

int
main(int argc, char **argv)
{
#ifdef HAVE_LIBDMALLOC
  if (!getenv("DMALLOC_OPTIONS"))
    dmalloc_debug(0x2f03d00);
#endif

  parse_args(argc, argv);
  if (debug_flag == 1)
    log_init_debug("");
  log_switch(debug_flag, NULL, NULL);

  resource_init();
  olock_init();
  io_init();
  rt_init();
  if_init();

  uid_t use_uid = get_uid(use_user);
  gid_t use_gid = get_gid(use_group);

  if (!parse_and_exit)
  {
    test_old_bird(path_control_socket);
    cli_init_unix(use_uid, use_gid);
  }

  if (use_gid)
    drop_gid(use_gid);

  if (use_uid)
    drop_uid(use_uid);

  protos_build();
  proto_build(&proto_unix_kernel);
  proto_build(&proto_unix_iface);

  read_config();

  if (parse_and_exit)
    exit(0);

  if (!debug_flag)
    {
      pid_t pid = fork();
      if (pid < 0)
	die("fork: %m");
      if (pid)
	return 0;
      setsid();
      close(0);
      if (open("/dev/null", O_RDWR) < 0)
	die("Cannot open /dev/null: %m");
      dup2(0, 1);
      dup2(0, 2);
    }

  signal_init();

#ifdef LOCAL_DEBUG
  async_dump_flag = 1;
#endif

  log(L_INFO "Started");
  DBG("Entering I/O loop.\n");

  io_loop();
  bug("I/O loop died");
}