summaryrefslogtreecommitdiffabout
path: root/src/nssync.c
blob: d10ce05c4a7373aabcfa3d25bfe4e0c34bef965e (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
/* This file is part of NSsync 
   Copyright (C) 2011-2017 Sergey Poznyakoff
  
   NSsync is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3, or (at your option)
   any later version.
  
   NSsync is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
  
   You should have received a copy of the GNU General Public License
   along with NSsync.  If not, see <http://www.gnu.org/licenses/>. */

#include "nssync.h"
#include <sys/stat.h>
#include <fcntl.h>
#include "runcap.h"
#include <sys/types.h>
#include <sys/time.h>
#include <signal.h>
#include <syslog.h>

int lint_mode;
int dry_run_mode;
int preprocess_only;
int debug_level;
char *config_file = SYSCONFDIR "/nssync.conf";
char *slave_status_file;
char *pidfile;
int force;
char *tempdir;
char *reload_command = "/usr/sbin/rndc reload";
struct json_value *error_list;
struct json_value *changed_zones;
int check_ns;
int server_mode;
struct grecs_sockaddr *server_addr;
unsigned periodic_timeout = 3600;
unsigned delay_timeout = 30;

int syslog_facility = LOG_DAEMON;
char *syslog_tag;
int foreground;
int syslog_option;

#include "cmdline.h"

void
start_syslog(void)
{
	grecs_log_to_stderr = 0;
	openlog(program_name, LOG_PID, syslog_facility);
}

void
vdiag(int prio, const char *fmt, va_list ap)
{
	if (grecs_log_to_stderr) {
		fprintf(stderr, "%s: ", program_name);
		vfprintf(stderr, fmt, ap);
		fputc('\n', stderr);
	} else {
		vsyslog(prio, fmt, ap);
	}
}

void
verror(const char *fmt, va_list ap)
{
	vdiag(LOG_ERR, fmt, ap);
}

void
error(const char *fmt, ...)
{
	va_list ap;
	va_start(ap, fmt);
	verror(fmt, ap);
	va_end(ap);
}

void
info_printf(const char *fmt, ...)
{
	va_list ap;
	va_start(ap, fmt);
	vdiag(LOG_INFO, fmt, ap);
	va_end(ap);
}

void
debug_printf(const char *fmt, ...)
{
	va_list ap;
	va_start(ap, fmt);
	vdiag(LOG_DEBUG, fmt, ap);
	va_end(ap);
}

void
dlz_error(char const *zone, char const *fmt, ...)
{
	struct json_value *obj;
	char *str = NULL;
	size_t sz = 0;
	va_list ap;

	va_start(ap, fmt);
	grecs_vasprintf(&str, &sz, fmt, ap);
	va_end(ap);
	
	obj = json_new_object();
	json_object_set(obj, "message", json_new_string(str));
	free(str);
	if (zone)
		json_object_set(obj, "zone", json_new_string(zone));
	json_array_append(error_list, obj);
}

void
dlz_success(char const *zone)
{
	json_array_append(changed_zones, json_new_string(zone));
}

/* Create the directory DIR, eventually creating all intermediate directories
   starting from DIR + BASELEN. */
int
create_hierarchy(char *dir, size_t baselen)
{
	int rc;
	struct stat st;
	char *p;
	
	if (stat(dir, &st) == 0) {
		if (!S_ISDIR(st.st_mode)) {
			error("component %s is not a directory", dir);
			return 1;
		}
		return 0;
	} else if (errno != ENOENT) {
		error("cannot stat file %s: %s", dir, strerror(errno));
		return 1;
	}

	p = strrchr(dir, '/');
	if (p) {
		if (p - dir + 1 < baselen) {
			error("base directory %s does not exist", dir);
			return 1;
		}
		*p = 0;
	}

	rc = create_hierarchy(dir, baselen);
	if (rc == 0) {
		if (p)
			*p = '/';
		if (mkdir(dir, 0744)) {
			error("cannot create directory %s: %s",
			      dir, strerror(errno));
			rc = 1;
		}
	}
	return rc;
}

static int
trycreate(const char *file_name)
{
	int rc = 1;
	char *dir_name = grecs_strdup(file_name);
	char *p = strrchr(dir_name, '/');

	if (p) {
		size_t len = strlen(bind_working_dir);
		if (strncmp(dir_name, bind_working_dir, len) == 0) {
			*p = 0;
			rc = create_hierarchy(dir_name, len);
		}
	}
	free(dir_name);
	return rc;
}
	  
int
copy_file(const char *file_name, FILE *infile, const char *dst_file)
{
	int out_fd;
	struct stat st;
	int rc;
	char *buf;
	size_t bufsize;
	size_t fsize;

	if (dry_run_mode)
		return 0;
	
	if (fstat(fileno(infile), &st)) {
		error("cannot stat source file %s: %s",
		      file_name, strerror(errno));
		return 1;
	}

	out_fd = open(dst_file, O_WRONLY|O_TRUNC|O_CREAT, 0640);
	if (out_fd == -1) {
		if (errno == ENOENT) {
			if (trycreate(dst_file))
				return 1;
			out_fd = open(dst_file, O_WRONLY|O_TRUNC|O_CREAT,
				      0640);
		}
		if (out_fd == -1) {
			error("cannot create destination file %s: %s",
			      dst_file, strerror(errno));
			return 1;
		}
	}

	buf = NULL;
	fsize = st.st_size;

	for (bufsize = fsize; bufsize > 0 && (buf = malloc (bufsize)) == NULL;
	     bufsize /= 2)
		;
	if (bufsize == 0)
		grecs_alloc_die ();

	rc = 0;
	fseeko(infile, 0, SEEK_SET);
	while (fsize > 0) {
		size_t rest;
		size_t rdbytes;
		
		rest = fsize > bufsize ? bufsize : fsize;
		rdbytes = fread(buf, 1, rest, infile);
		if (rdbytes == -1) {
			error("unexpected error reading %s: %s",
			      file_name, strerror(errno));
			rc = 1;
			break;
		}
		rest = write(out_fd, buf, rdbytes);
		if (rest == -1)	{
			error("unexpected error writing to %s: %s",
			      dst_file, strerror(errno));
			rc = 1;
			break;
		} else if (rest != rdbytes) {
			error("short write on %s", dst_file);
			rc = 1;
		}
		fsize -= rdbytes;
	}
	free(buf);

	close(out_fd);
	if (rc)
		unlink(dst_file);

	return rc;
}

/* Move FILE to DST_FILE. If they reside on different devices, use copy_file
   + unlink. */
int
move_file(const char *file, const char *dst_file)
{
	int rc = 0;

	rc = rename(file, dst_file);
	if (rc && errno == ENOENT) {
		if (trycreate(dst_file))
			return 1;
		rc = rename(file, dst_file);
	}
	if (rc) {
		if (errno == EXDEV) {
			FILE *fp = fopen(file, "r");
			if (!fp) {
				error("cannot open %s for reading: %s",
				      file, strerror(errno));
				return 1;
			}
			rc = copy_file (file, fp, dst_file);
			fclose(fp);
			if (rc) {
				error("cannot copy %s to %s: %s",
				      file, dst_file, strerror(errno));
				rc = 1;
			} else if (unlink(file)) {
				error("cannot unlink %s: %s",
				      file, strerror(errno));
			}
		} else {
			error("cannot move %s to %s: %s",
			      file, dst_file, strerror(errno));
			rc = 1;
		}
	}
	return rc;
}


/* Return 0 if files are the same, 1 if they differ and -1 if in trouble
 */
static int
filecmp(FILE *fp1, FILE *fp2)
{
	int c1, c2;
	while (1) {
		c1 = fgetc(fp1);
		c2 = fgetc(fp2);
		if (c1 == c2) {
			if (c1 == EOF)
				break;
			continue;
		}
		return 1;
	}
	return 0;
}

int
compare(const char *file1, const char *file2)
{
	int rc;
	FILE *fp1, *fp2;
	struct stat st1, st2;
	
	if (access(file2, F_OK) && errno == ENOENT) {
		debug(2,("destination file %s does not exist", file2));
		return 1;
	}

	if (stat(file1, &st1) == 0 && stat(file2, &st2) == 0) {
		if (st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino)
			return 0;
		else if (st1.st_size != st2.st_size)
			return 1;
	}
	
	fp1 = fopen(file1, "r");
	if (!fp1) {
		error("can't open file \"%s\": %s", file1, strerror(errno));
		return -1;
	}
	
	fp2 = fopen(file2, "r");
	if (!fp2) {
		error("can't open file \"%s\": %s", file2, strerror(errno));
		return -1;
	}

	rc = filecmp(fp1, fp2);

	fclose(fp1);
	fclose(fp2);

	return rc;
}


static void
synchronize(struct nssync *sp)
{
	mode_t um;
	size_t size = 0;
	
	debug(1, ("processing %s", sp->tag));
	if (grecs_asprintf(&sp->temp_file_name, &size,
			   "%s/%s.tmp", tempdir, sp->tag))
		grecs_alloc_die();
	
	um = umask(077);
	sp->fp = fopen(sp->temp_file_name, "w+");
	umask(um);
	if (!sp->fp) {
		error("cannot open %s: %s", sp->temp_file_name,
		      strerror(errno));
		return;
	}
	format_zones(sp);
	if (!dry_run_mode)
		unlink(sp->temp_file_name);

	/* Cleanup */
	free(sp->temp_file_name);
	sp->temp_file_name = NULL;
}

int
check_slave_status(void)
{
	FILE *fp;
	char *saved_file = NULL;
	char *saved_off;
	char *buf = NULL;
	size_t size = 0;
	char *sql_file, *sql_off;

	if (!slave_status_file)
		return 0;
	
        if (sql_get_slave_status(&sql_file, &sql_off)) {
                unlink(slave_status_file);
                return 0;
        }

	fp = fopen(slave_status_file, "r");
	if (fp) {
		if (grecs_getline(&buf, &size, fp) > 0) {
			buf[strlen(buf)-1] = 0;
			saved_file = buf;
			saved_off = strchr(saved_file, ' ');
			if (saved_off)
				*saved_off++ = 0;
		}
		fclose(fp);
	}

	if (!force && saved_file && saved_off &&
		 strcmp(sql_file, saved_file) == 0 &&
		 strcmp(sql_off, saved_off) == 0) {
		debug(1, ("slave status hasn't changed: nothing to do"));
		return 1;
	}
	fp = fopen(slave_status_file, "w");
	if (fp) {
		fprintf(fp, "%s %s\n", sql_file, sql_off);
		fclose(fp);
	}
	free(sql_file);
	free(sql_off);
	return 0;
}

void
remove_pidfile()
{
	if (pidfile && unlink(pidfile))
		error("cannot unlink pidfile `%s': %s",
		      pidfile, strerror(errno));
}

void
create_pidfile(void)
{
	FILE *fp;

	if (!pidfile)
		return;
	
	fp = fopen(pidfile, "w");
	if (!fp) {
		error("cannot create pidfile `%s': %s",
		      pidfile, strerror(errno));
		exit(EX_TEMPFAIL);
	}
	fprintf(fp, "%lu", (unsigned long) getpid());
	fclose(fp);
}

/* Check whether pidfile NAME exists and if so, whether its PID is still
   active. Exit if it is. */
void
check_pidfile()
{
	unsigned long pid;
	FILE *fp;

	if (!pidfile)
		return;
	
	fp = fopen(pidfile, "r");
	
	if (fp) {
		if (fscanf(fp, "%lu", &pid) != 1) {
			error("cannot get pid from pidfile `%s'", pidfile);
		} else {
			if (kill(pid, 0) == 0) {
				error("%s appears to run with pid %lu. "
				      "If it does not, remove `%s' and retry.",
				      program_name, pid, pidfile);
				exit(EX_TEMPFAIL);
			}
		}
		
		fclose(fp);
		if (unlink(pidfile)) {
			error("cannot unlink pidfile `%s': %s",
			      pidfile, strerror(errno));
			exit(EX_NOPERM);
		}
	} else if (errno != ENOENT) {
		error("cannot open pidfile `%s': %s",
		      pidfile, strerror(errno));
		exit(EX_TEMPFAIL);
	}
}

struct linemon_closure
{
	char const *prefix;
};

static void
linemon(const char *ptr, size_t len, void *data)
{
	struct linemon_closure *clos = data;
	if (ptr[len-1] != '\n')
		error("[%s]: %*.*s\\",
		      clos->prefix, (int)len, (int)len, ptr);
	else
		error("[%s]: %*.*s",
		      clos->prefix, (int)(len - 1), (int)(len - 1), ptr);
}

int
dns_reload(void)
{
	int c;
	struct runcap rc;
	char *argv[4];
	struct linemon_closure closure[2];
	
	debug(1,("about to run %s", reload_command));
	if (dry_run_mode)
		return 0;

	argv[0] = "/bin/sh";
	argv[1] = "-c";
	argv[2] = reload_command;
	argv[3] = NULL;
	
	closure[0].prefix = "STDOUT";
	rc.rc_cap[RUNCAP_STDOUT].sc_linemon = linemon;
	rc.rc_cap[RUNCAP_STDOUT].sc_monarg = &closure[0];
	closure[1].prefix = "STDERR";	
	rc.rc_cap[RUNCAP_STDERR].sc_linemon = linemon;
	rc.rc_cap[RUNCAP_STDERR].sc_monarg = &closure[1];

	rc.rc_timeout = 10; /* FIXME */
	rc.rc_argv = argv;

	c = runcap(&rc,
		   RCF_STDOUT_LINEMON | RCF_STDERR_LINEMON | RCF_TIMEOUT);

	if (c) {
		error("can't run \"%s\": %s", reload_command, strerror(errno));
	} else if (WIFEXITED(rc.rc_status)) {
		int status = WEXITSTATUS(rc.rc_status);
		if (status) {
			error("command \"%s\" returned %d",
			      reload_command, status);
			c = 1;
		}
	} else if (WIFSIGNALED(rc.rc_status)) {
		error("command \"%s\" terminated on signal %d",
		      reload_command, WTERMSIG(rc.rc_status));
		c = 1;
	} else if (WIFSTOPPED(rc.rc_status)) {
		error("command \"%s\" got stopped", reload_command);
		c = 1;
	} else {
		error("command \"%s\" terminated with unrecognized status %d",
		      reload_command, rc.rc_status);
		c = 1;
	}
	runcap_free(&rc);
	return c;
}


int
nssync(struct json_value **ret_json)
{
	struct grecs_list_entry *ep;
	int res = 1;

	changed_zones = json_new_array();
	error_list = json_new_array();
	
 	if (check_slave_status())
		res = 0;
	else {
		sql_connect();
		
		for (ep = synclist->head; ep; ep = ep->next)
			synchronize(ep->data);

		if (json_array_size(error_list) == 0) {
			for (ep = synclist->head; ep; ep = ep->next)
				flush_zone_list(ep->data);

			filetab_clear();
			
			if (json_array_size(error_list) == 0) {
				if (json_array_size(changed_zones) > 0) {
					res = dns_reload();
					if (res)
						dlz_error(NULL,
							  "reload failed");
				} else
					res = 0;
			}
		}
	}
	
	if (ret_json) {
		struct timeval tv;
		struct timezone tz;
		struct json_value *json;

		json = json_new_object();
		json_object_set(json, "success", json_new_bool(!res));
		if (json_array_size(changed_zones) > 0)
			json_object_set(json, "zones", changed_zones);
		if (json_array_size(error_list) > 0)
			json_object_set(json, "errors", error_list);
		gettimeofday(&tv, &tz);
		tv.tv_sec += tz.tz_minuteswest * 60; 
		json_object_set(json, "timestamp", json_new_number(tv.tv_sec));
		*ret_json = json;
	} else {
		json_value_free(error_list);
		json_value_free(changed_zones);
	}
	
	error_list = NULL;
	changed_zones = NULL;

	return res;
}

/* Signal handing */
void
sigfatal(int sig)
{
	remove_pidfile();
	_exit(0);
}

void
sigign(int sig)
{
}

void
set_signal(int sig, void (*sighandler)(int))
{
	struct sigaction act;
	act.sa_handler = sighandler;
	sigemptyset(&act.sa_mask);
	act.sa_flags = SA_RESTART;
	sigaction(sig, &act, NULL);
}

void
set_signals(int *sigv, void (*sighandler)(int))
{
	int i;

	for (i = 0; sigv[i]; i++)
		set_signal(sigv[i], sighandler);
}

int fatal_signals[] = {
	SIGHUP,
	SIGINT,
	SIGQUIT,
	SIGTERM,
	0
};

int
single_run(void)
{
	if (syslog_option)
		start_syslog();
	runas();
	debug(1,("start up"));
	create_pidfile();
	if (nssync(NULL)) {
		error("exiting due to errors");
		return EX_UNAVAILABLE;
	}
	return 0;
}

int
main(int argc, char **argv)
{
	int rc;
	config_init();
	parse_options(argc, argv);
        if (preprocess_only)
		exit(grecs_preproc_run(config_file, grecs_preprocessor) ?
		     EX_CONFIG : 0);
	config_parse();

	check_pidfile();

	if (check_ns)
		get_host_addresses();
	
	if (server_mode) {
		set_signals(fatal_signals, sigign);
		rc = nssync_server();
	} else {
		set_signals(fatal_signals, sigfatal);
		rc = single_run();
	}
	debug(1,("shut down"));
	remove_pidfile();
	return rc;
}

Return to:

Send suggestions and report system problems to the System administrator.