1 /***
2 This file is part of avahi.
3
4 avahi is free software; you can redistribute it and/or modify it
5 under the terms of the GNU Lesser General Public License as
6 published by the Free Software Foundation; either version 2.1 of the
7 License, or (at your option) any later version.
8
9 avahi is distributed in the hope that it will be useful, but WITHOUT
10 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
12 Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with avahi; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
17 USA.
18 ***/
19
20 #ifdef HAVE_CONFIG_H
21 #include <config.h>
22 #endif
23
24 #include <assert.h>
25 #include <getopt.h>
26 #include <string.h>
27 #include <signal.h>
28 #include <errno.h>
29 #include <string.h>
30 #include <unistd.h>
31 #include <grp.h>
32 #include <pwd.h>
33 #include <sys/stat.h>
34 #include <sys/ioctl.h>
35 #include <stdio.h>
36 #include <fcntl.h>
37 #include <time.h>
38 #include <stdlib.h>
39 #include <sys/time.h>
40 #include <sys/resource.h>
41 #include <sys/socket.h>
42
43 #ifdef HAVE_INOTIFY
44 #include <sys/inotify.h>
45 #endif
46
47 #ifdef HAVE_KQUEUE
48 #include <sys/types.h>
49 #include <sys/event.h>
50 #include <unistd.h>
51 #endif
52
53 #include <libdaemon/dfork.h>
54 #include <libdaemon/dsignal.h>
55 #include <libdaemon/dlog.h>
56 #include <libdaemon/dpid.h>
57
58 #include "avahi-common/avahi-malloc.h"
59 #include <avahi-common/simple-watch.h>
60 #include <avahi-common/error.h>
61 #include <avahi-common/alternative.h>
62 #include <avahi-common/domain.h>
63
64 #include <avahi-core/core.h>
65 #include <avahi-core/publish.h>
66 #include <avahi-core/dns-srv-rr.h>
67 #include <avahi-core/log.h>
68 #include <avahi-core/util.h>
69
70 #ifdef ENABLE_CHROOT
71 #include "chroot.h"
72 #include "caps.h"
73 #endif
74
75 #include "setproctitle.h"
76 #include "main.h"
77 #include "static-services.h"
78 #include "static-hosts.h"
79 #include "ini-file-parser.h"
80 #include "sd-daemon.h"
81
82 #ifdef AVAHI_SOCKET
83 #include "simple-protocol.h"
84 #endif
85
86 #ifdef HAVE_DBUS
87 #include "dbus-protocol.h"
88 #endif
89
90 AvahiServer *avahi_server = NULL;
91 AvahiSimplePoll *simple_poll_api = NULL;
92 static char *argv0 = NULL;
93 int nss_support = 0;
94
95 typedef enum {
96 DAEMON_RUN,
97 DAEMON_KILL,
98 DAEMON_VERSION,
99 DAEMON_HELP,
100 DAEMON_RELOAD,
101 DAEMON_CHECK
102 } DaemonCommand;
103
104 typedef struct {
105 AvahiServerConfig server_config;
106 DaemonCommand command;
107 int daemonize;
108 int use_syslog;
109 char *config_file;
110 #ifdef HAVE_DBUS
111 int enable_dbus;
112 int fail_on_missing_dbus;
113 unsigned n_clients_max;
114 unsigned n_objects_per_client_max;
115 unsigned n_entries_per_entry_group_max;
116 #endif
117 int drop_root;
118 int set_rlimits;
119 #ifdef ENABLE_CHROOT
120 int use_chroot;
121 #endif
122 int modify_proc_title;
123
124 int disable_user_service_publishing;
125 int publish_resolv_conf;
126 char ** publish_dns_servers;
127 int debug;
128
129 int rlimit_as_set, rlimit_core_set, rlimit_data_set, rlimit_fsize_set, rlimit_nofile_set, rlimit_stack_set;
130 rlim_t rlimit_as, rlimit_core, rlimit_data, rlimit_fsize, rlimit_nofile, rlimit_stack;
131
132 #ifdef RLIMIT_NPROC
133 int rlimit_nproc_set;
134 rlim_t rlimit_nproc;
135 #endif
136 } DaemonConfig;
137
138 #define RESOLV_CONF "/etc/resolv.conf"
139 #define BROWSE_DOMAINS_MAX 16
140
141 static AvahiSEntryGroup *dns_servers_entry_group = NULL;
142 static AvahiSEntryGroup *resolv_conf_entry_group = NULL;
143
144 static char **resolv_conf_name_servers = NULL;
145 static char **resolv_conf_search_domains = NULL;
146
147 static DaemonConfig config;
148
has_prefix(const char * s,const char * prefix)149 static int has_prefix(const char *s, const char *prefix) {
150 size_t l;
151
152 l = strlen(prefix);
153
154 return strlen(s) >= l && strncmp(s, prefix, l) == 0;
155 }
156
load_resolv_conf(void)157 static int load_resolv_conf(void) {
158 int ret = -1;
159 FILE *f;
160 int i = 0, j = 0;
161
162 avahi_strfreev(resolv_conf_name_servers);
163 resolv_conf_name_servers = NULL;
164
165 avahi_strfreev(resolv_conf_search_domains);
166 resolv_conf_search_domains = NULL;
167
168 #ifdef ENABLE_CHROOT
169 f = avahi_chroot_helper_get_file(RESOLV_CONF);
170 #else
171 f = fopen(RESOLV_CONF, "r");
172 #endif
173
174 if (!f) {
175 avahi_log_warn("Failed to open "RESOLV_CONF": %s", strerror(errno));
176 goto finish;
177 }
178
179 resolv_conf_name_servers = avahi_new0(char*, AVAHI_WIDE_AREA_SERVERS_MAX+1);
180 resolv_conf_search_domains = avahi_new0(char*, BROWSE_DOMAINS_MAX+1);
181
182 while (!feof(f)) {
183 char ln[128];
184 char *p;
185
186 if (!(fgets(ln, sizeof(ln), f)))
187 break;
188
189 ln[strcspn(ln, "\r\n#")] = 0;
190 p = ln + strspn(ln, "\t ");
191
192 if ((has_prefix(p, "nameserver ") || has_prefix(p, "nameserver\t")) && i < AVAHI_WIDE_AREA_SERVERS_MAX) {
193 p += 10;
194 p += strspn(p, "\t ");
195 p[strcspn(p, "\t ")] = 0;
196 resolv_conf_name_servers[i++] = avahi_strdup(p);
197 }
198
199 if ((has_prefix(p, "search ") || has_prefix(p, "search\t") ||
200 has_prefix(p, "domain ") || has_prefix(p, "domain\t"))) {
201
202 p += 6;
203
204 while (j < BROWSE_DOMAINS_MAX) {
205 size_t k;
206
207 p += strspn(p, "\t ");
208 k = strcspn(p, "\t ");
209
210 if (k > 0) {
211 resolv_conf_search_domains[j++] = avahi_strndup(p, k);
212 p += k;
213 }
214
215 if (!*p)
216 break;
217 }
218 }
219 }
220
221 ret = 0;
222
223 finish:
224
225 if (ret != 0) {
226 avahi_strfreev(resolv_conf_name_servers);
227 resolv_conf_name_servers = NULL;
228
229 avahi_strfreev(resolv_conf_search_domains);
230 resolv_conf_search_domains = NULL;
231 }
232
233 if (f)
234 fclose(f);
235
236 return ret;
237 }
238
add_dns_servers(AvahiServer * s,AvahiSEntryGroup * g,char ** l)239 static AvahiSEntryGroup* add_dns_servers(AvahiServer *s, AvahiSEntryGroup* g, char **l) {
240 char **p;
241
242 assert(s);
243 assert(l);
244
245 if (!g)
246 g = avahi_s_entry_group_new(s, NULL, NULL);
247
248 assert(avahi_s_entry_group_is_empty(g));
249
250 for (p = l; *p; p++) {
251 AvahiAddress a;
252
253 if (!avahi_address_parse(*p, AVAHI_PROTO_UNSPEC, &a))
254 avahi_log_warn("Failed to parse address '%s', ignoring.", *p);
255 else
256 if (avahi_server_add_dns_server_address(s, g, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, 0, NULL, AVAHI_DNS_SERVER_RESOLVE, &a, 53) < 0) {
257 avahi_s_entry_group_free(g);
258 avahi_log_error("Failed to add DNS server address: %s", avahi_strerror(avahi_server_errno(s)));
259 return NULL;
260 }
261 }
262
263 avahi_s_entry_group_commit(g);
264
265 return g;
266 }
267
remove_dns_server_entry_groups(void)268 static void remove_dns_server_entry_groups(void) {
269
270 if (resolv_conf_entry_group)
271 avahi_s_entry_group_reset(resolv_conf_entry_group);
272
273 if (dns_servers_entry_group)
274 avahi_s_entry_group_reset(dns_servers_entry_group);
275 }
276
update_wide_area_servers(void)277 static void update_wide_area_servers(void) {
278 AvahiAddress a[AVAHI_WIDE_AREA_SERVERS_MAX];
279 unsigned n = 0;
280 char **p;
281
282 if (!resolv_conf_name_servers) {
283 avahi_server_set_wide_area_servers(avahi_server, NULL, 0);
284 return;
285 }
286
287 for (p = resolv_conf_name_servers; *p && n < AVAHI_WIDE_AREA_SERVERS_MAX; p++) {
288 if (!avahi_address_parse(*p, AVAHI_PROTO_UNSPEC, &a[n]))
289 avahi_log_warn("Failed to parse address '%s', ignoring.", *p);
290 else
291 n++;
292 }
293
294 avahi_server_set_wide_area_servers(avahi_server, a, n);
295 }
296
filter_duplicate_domains(AvahiStringList * l)297 static AvahiStringList *filter_duplicate_domains(AvahiStringList *l) {
298 AvahiStringList *e, *n, *p;
299
300 if (!l)
301 return l;
302
303 for (p = l, e = l->next; e; e = n) {
304 n = e->next;
305
306 if (avahi_domain_equal((char*) e->text, (char*) l->text)) {
307 p->next = e->next;
308 avahi_free(e);
309 } else
310 p = e;
311 }
312
313 l->next = filter_duplicate_domains(l->next);
314 return l;
315 }
316
update_browse_domains(void)317 static void update_browse_domains(void) {
318 AvahiStringList *l;
319 int n;
320 char **p;
321
322 if (!resolv_conf_search_domains) {
323 avahi_server_set_browse_domains(avahi_server, NULL);
324 return;
325 }
326
327 l = avahi_string_list_copy(config.server_config.browse_domains);
328
329 for (p = resolv_conf_search_domains, n = 0; *p && n < BROWSE_DOMAINS_MAX; p++, n++) {
330 if (!avahi_is_valid_domain_name(*p))
331 avahi_log_warn("'%s' is no valid domain name, ignoring.", *p);
332 else
333 l = avahi_string_list_add(l, *p);
334 }
335
336 l = filter_duplicate_domains(l);
337
338 avahi_server_set_browse_domains(avahi_server, l);
339 avahi_string_list_free(l);
340 }
341
server_callback(AvahiServer * s,AvahiServerState state,void * userdata)342 static void server_callback(AvahiServer *s, AvahiServerState state, void *userdata) {
343 DaemonConfig *c = userdata;
344
345 assert(s);
346 assert(c);
347
348 /* This function is possibly called before the global variable
349 * avahi_server has been set, therefore we do it explicitly */
350
351 avahi_server = s;
352
353 #ifdef HAVE_DBUS
354 if (c->enable_dbus && state != AVAHI_SERVER_INVALID && state != AVAHI_SERVER_FAILURE)
355 dbus_protocol_server_state_changed(state);
356 #endif
357
358 switch (state) {
359 case AVAHI_SERVER_RUNNING:
360 avahi_log_info("Server startup complete. Host name is %s. Local service cookie is %u.", avahi_server_get_host_name_fqdn(s), avahi_server_get_local_service_cookie(s));
361 sd_notifyf(0, "STATUS=Server startup complete. Host name is %s. Local service cookie is %u.", avahi_server_get_host_name_fqdn(s), avahi_server_get_local_service_cookie(s));
362 avahi_set_proc_title(argv0, "%s: running [%s]", argv0, avahi_server_get_host_name_fqdn(s));
363
364 static_service_add_to_server();
365 static_hosts_add_to_server();
366
367 remove_dns_server_entry_groups();
368
369 if (c->publish_resolv_conf && resolv_conf_name_servers && resolv_conf_name_servers[0])
370 resolv_conf_entry_group = add_dns_servers(s, resolv_conf_entry_group, resolv_conf_name_servers);
371
372 if (c->publish_dns_servers && c->publish_dns_servers[0])
373 dns_servers_entry_group = add_dns_servers(s, dns_servers_entry_group, c->publish_dns_servers);
374
375 #ifdef AVAHI_SOCKET
376 simple_protocol_restart_queries();
377 #endif
378 break;
379
380 case AVAHI_SERVER_COLLISION: {
381 char *n;
382
383 static_service_remove_from_server();
384 static_hosts_remove_from_server();
385 remove_dns_server_entry_groups();
386
387 n = avahi_alternative_host_name(avahi_server_get_host_name(s));
388
389 avahi_log_warn("Host name conflict, retrying with %s", n);
390 sd_notifyf(0, "STATUS=Host name conflict, retrying with %s", n);
391 avahi_set_proc_title(argv0, "%s: collision [%s]", argv0, n);
392
393 avahi_server_set_host_name(s, n);
394 avahi_free(n);
395
396 break;
397 }
398
399 case AVAHI_SERVER_FAILURE:
400
401 avahi_log_error("Server error: %s", avahi_strerror(avahi_server_errno(s)));
402 sd_notifyf(0, "STATUS=Server error: %s", avahi_strerror(avahi_server_errno(s)));
403
404 avahi_simple_poll_quit(simple_poll_api);
405 break;
406
407 case AVAHI_SERVER_REGISTERING:
408
409 sd_notifyf(0, "STATUS=Registering host name %s", avahi_server_get_host_name_fqdn(s));
410 avahi_set_proc_title(argv0, "%s: registering [%s]", argv0, avahi_server_get_host_name_fqdn(s));
411
412 static_service_remove_from_server();
413 static_hosts_remove_from_server();
414 remove_dns_server_entry_groups();
415
416 break;
417
418 case AVAHI_SERVER_INVALID:
419 break;
420
421 }
422 }
423
help(FILE * f)424 static void help(FILE *f) {
425 fprintf(f,
426 "%s [options]\n"
427 " -h --help Show this help\n"
428 " -D --daemonize Daemonize after startup (implies -s)\n"
429 " -s --syslog Write log messages to syslog(3) instead of STDERR\n"
430 " -k --kill Kill a running daemon\n"
431 " -r --reload Request a running daemon to reload static services\n"
432 " -c --check Return 0 if a daemon is already running\n"
433 " -V --version Show version\n"
434 " -f --file=FILE Load the specified configuration file instead of\n"
435 " "AVAHI_CONFIG_FILE"\n"
436 " --no-rlimits Don't enforce resource limits\n"
437 " --no-drop-root Don't drop privileges\n"
438 #ifdef ENABLE_CHROOT
439 " --no-chroot Don't chroot()\n"
440 #endif
441 " --no-proc-title Don't modify process title\n"
442 " --debug Increase verbosity\n",
443 argv0);
444 }
445
446
parse_command_line(DaemonConfig * c,int argc,char * argv[])447 static int parse_command_line(DaemonConfig *c, int argc, char *argv[]) {
448 int o;
449
450 enum {
451 OPTION_NO_RLIMITS = 256,
452 OPTION_NO_DROP_ROOT,
453 #ifdef ENABLE_CHROOT
454 OPTION_NO_CHROOT,
455 #endif
456 OPTION_NO_PROC_TITLE,
457 OPTION_DEBUG
458 };
459
460 static const struct option long_options[] = {
461 { "help", no_argument, NULL, 'h' },
462 { "daemonize", no_argument, NULL, 'D' },
463 { "kill", no_argument, NULL, 'k' },
464 { "version", no_argument, NULL, 'V' },
465 { "file", required_argument, NULL, 'f' },
466 { "reload", no_argument, NULL, 'r' },
467 { "check", no_argument, NULL, 'c' },
468 { "syslog", no_argument, NULL, 's' },
469 { "no-rlimits", no_argument, NULL, OPTION_NO_RLIMITS },
470 { "no-drop-root", no_argument, NULL, OPTION_NO_DROP_ROOT },
471 #ifdef ENABLE_CHROOT
472 { "no-chroot", no_argument, NULL, OPTION_NO_CHROOT },
473 #endif
474 { "no-proc-title", no_argument, NULL, OPTION_NO_PROC_TITLE },
475 { "debug", no_argument, NULL, OPTION_DEBUG },
476 { NULL, 0, NULL, 0 }
477 };
478
479 assert(c);
480
481 while ((o = getopt_long(argc, argv, "hDkVf:rcs", long_options, NULL)) >= 0) {
482
483 switch(o) {
484 case 's':
485 c->use_syslog = 1;
486 break;
487 case 'h':
488 c->command = DAEMON_HELP;
489 break;
490 case 'D':
491 c->daemonize = 1;
492 break;
493 case 'k':
494 c->command = DAEMON_KILL;
495 break;
496 case 'V':
497 c->command = DAEMON_VERSION;
498 break;
499 case 'f':
500 avahi_free(c->config_file);
501 c->config_file = avahi_strdup(optarg);
502 break;
503 case 'r':
504 c->command = DAEMON_RELOAD;
505 break;
506 case 'c':
507 c->command = DAEMON_CHECK;
508 break;
509 case OPTION_NO_RLIMITS:
510 c->set_rlimits = 0;
511 break;
512 case OPTION_NO_DROP_ROOT:
513 c->drop_root = 0;
514 break;
515 #ifdef ENABLE_CHROOT
516 case OPTION_NO_CHROOT:
517 c->use_chroot = 0;
518 break;
519 #endif
520 case OPTION_NO_PROC_TITLE:
521 c->modify_proc_title = 0;
522 break;
523 case OPTION_DEBUG:
524 c->debug = 1;
525 break;
526 default:
527 return -1;
528 }
529 }
530
531 if (optind < argc) {
532 fprintf(stderr, "Too many arguments\n");
533 return -1;
534 }
535
536 return 0;
537 }
538
is_yes(const char * s)539 static int is_yes(const char *s) {
540 assert(s);
541
542 return *s == 'y' || *s == 'Y' || *s == '1' || *s == 't' || *s == 'T';
543 }
544
parse_unsigned(const char * s,unsigned * u)545 static int parse_unsigned(const char *s, unsigned *u) {
546 char *e = NULL;
547 unsigned long ul;
548 unsigned k;
549
550 errno = 0;
551 ul = strtoul(s, &e, 0);
552
553 if (!e || *e || errno != 0)
554 return -1;
555
556 k = (unsigned) ul;
557
558 if ((unsigned long) k != ul)
559 return -1;
560
561 *u = k;
562 return 0;
563 }
564
parse_usec(const char * s,AvahiUsec * u)565 static int parse_usec(const char *s, AvahiUsec *u) {
566 char *e = NULL;
567 unsigned long long ull;
568 AvahiUsec k;
569
570 errno = 0;
571 ull = strtoull(s, &e, 0);
572
573 if (!e || *e || errno != 0)
574 return -1;
575
576 k = (AvahiUsec) ull;
577
578 if ((unsigned long long) k != ull)
579 return -1;
580
581 *u = k;
582 return 0;
583 }
584
get_machine_id(void)585 static char *get_machine_id(void) {
586 int fd;
587 char buf[32];
588
589 fd = open("/etc/machine-id", O_RDONLY|O_CLOEXEC|O_NOCTTY);
590 if (fd == -1 && errno == ENOENT)
591 fd = open("/var/lib/dbus/machine-id", O_RDONLY|O_CLOEXEC|O_NOCTTY);
592 if (fd == -1)
593 return NULL;
594
595 /* File is on a filesystem so we never get EINTR or partial reads */
596 if (read(fd, buf, sizeof buf) != sizeof buf) {
597 close(fd);
598 return NULL;
599 }
600 close(fd);
601
602 /* Contents can be lower, upper and even mixed case so normalize */
603 avahi_strdown(buf);
604
605 return avahi_strndup(buf, sizeof buf);
606 }
607
load_config_file(DaemonConfig * c)608 static int load_config_file(DaemonConfig *c) {
609 int r = -1;
610 AvahiIniFile *f;
611 AvahiIniFileGroup *g;
612
613 assert(c);
614
615 if (!(f = avahi_ini_file_load(c->config_file ? c->config_file : AVAHI_CONFIG_FILE)))
616 goto finish;
617
618 for (g = f->groups; g; g = g->groups_next) {
619
620 if (strcasecmp(g->name, "server") == 0) {
621 AvahiIniFilePair *p;
622
623 for (p = g->pairs; p; p = p->pairs_next) {
624
625 if (strcasecmp(p->key, "host-name") == 0) {
626 avahi_free(c->server_config.host_name);
627 c->server_config.host_name = avahi_strdup(p->value);
628 } else if (strcasecmp(p->key, "domain-name") == 0) {
629 avahi_free(c->server_config.domain_name);
630 c->server_config.domain_name = avahi_strdup(p->value);
631 } else if (strcasecmp(p->key, "browse-domains") == 0) {
632 char **e, **t;
633
634 e = avahi_split_csv(p->value);
635
636 for (t = e; *t; t++) {
637 char cleaned[AVAHI_DOMAIN_NAME_MAX];
638
639 if (!avahi_normalize_name(*t, cleaned, sizeof(cleaned))) {
640 avahi_log_error("Invalid domain name \"%s\" for key \"%s\" in group \"%s\"\n", *t, p->key, g->name);
641 avahi_strfreev(e);
642 goto finish;
643 }
644
645 c->server_config.browse_domains = avahi_string_list_add(c->server_config.browse_domains, cleaned);
646 }
647
648 avahi_strfreev(e);
649
650 c->server_config.browse_domains = filter_duplicate_domains(c->server_config.browse_domains);
651 } else if (strcasecmp(p->key, "use-ipv4") == 0)
652 c->server_config.use_ipv4 = is_yes(p->value);
653 else if (strcasecmp(p->key, "use-ipv6") == 0)
654 c->server_config.use_ipv6 = is_yes(p->value);
655 else if (strcasecmp(p->key, "check-response-ttl") == 0)
656 c->server_config.check_response_ttl = is_yes(p->value);
657 else if (strcasecmp(p->key, "allow-point-to-point") == 0)
658 c->server_config.allow_point_to_point = is_yes(p->value);
659 else if (strcasecmp(p->key, "use-iff-running") == 0)
660 c->server_config.use_iff_running = is_yes(p->value);
661 else if (strcasecmp(p->key, "disallow-other-stacks") == 0)
662 c->server_config.disallow_other_stacks = is_yes(p->value);
663 else if (strcasecmp(p->key, "host-name-from-machine-id") == 0) {
664 if (*(p->value) == 'y' || *(p->value) == 'Y') {
665 char *machine_id = get_machine_id();
666 if (machine_id != NULL) {
667 avahi_free(c->server_config.host_name);
668 c->server_config.host_name = machine_id;
669 }
670 }
671 }
672 #ifdef HAVE_DBUS
673 else if (strcasecmp(p->key, "enable-dbus") == 0) {
674
675 if (*(p->value) == 'w' || *(p->value) == 'W') {
676 c->fail_on_missing_dbus = 0;
677 c->enable_dbus = 1;
678 } else if (*(p->value) == 'y' || *(p->value) == 'Y') {
679 c->fail_on_missing_dbus = 1;
680 c->enable_dbus = 1;
681 } else {
682 c->enable_dbus = 0;
683 }
684 }
685 #endif
686 else if (strcasecmp(p->key, "allow-interfaces") == 0) {
687 char **e, **t;
688
689 avahi_string_list_free(c->server_config.allow_interfaces);
690 c->server_config.allow_interfaces = NULL;
691 e = avahi_split_csv(p->value);
692
693 for (t = e; *t; t++)
694 c->server_config.allow_interfaces = avahi_string_list_add(c->server_config.allow_interfaces, *t);
695
696 avahi_strfreev(e);
697 } else if (strcasecmp(p->key, "deny-interfaces") == 0) {
698 char **e, **t;
699
700 avahi_string_list_free(c->server_config.deny_interfaces);
701 c->server_config.deny_interfaces = NULL;
702 e = avahi_split_csv(p->value);
703
704 for (t = e; *t; t++)
705 c->server_config.deny_interfaces = avahi_string_list_add(c->server_config.deny_interfaces, *t);
706
707 avahi_strfreev(e);
708 } else if (strcasecmp(p->key, "ratelimit-interval-usec") == 0) {
709 AvahiUsec k;
710
711 if (parse_usec(p->value, &k) < 0) {
712 avahi_log_error("Invalid ratelimit-interval-usec setting %s", p->value);
713 goto finish;
714 }
715
716 c->server_config.ratelimit_interval = k;
717
718 } else if (strcasecmp(p->key, "ratelimit-burst") == 0) {
719 unsigned k;
720
721 if (parse_unsigned(p->value, &k) < 0) {
722 avahi_log_error("Invalid ratelimit-burst setting %s", p->value);
723 goto finish;
724 }
725
726 c->server_config.ratelimit_burst = k;
727
728 } else if (strcasecmp(p->key, "cache-entries-max") == 0) {
729 unsigned k;
730
731 if (parse_unsigned(p->value, &k) < 0) {
732 avahi_log_error("Invalid cache-entries-max setting %s", p->value);
733 goto finish;
734 }
735
736 c->server_config.n_cache_entries_max = k;
737 #ifdef HAVE_DBUS
738 } else if (strcasecmp(p->key, "clients-max") == 0) {
739 unsigned k;
740
741 if (parse_unsigned(p->value, &k) < 0) {
742 avahi_log_error("Invalid clients-max setting %s", p->value);
743 goto finish;
744 }
745
746 c->n_clients_max = k;
747 } else if (strcasecmp(p->key, "objects-per-client-max") == 0) {
748 unsigned k;
749
750 if (parse_unsigned(p->value, &k) < 0) {
751 avahi_log_error("Invalid objects-per-client-max setting %s", p->value);
752 goto finish;
753 }
754
755 c->n_objects_per_client_max = k;
756 } else if (strcasecmp(p->key, "entries-per-entry-group-max") == 0) {
757 unsigned k;
758
759 if (parse_unsigned(p->value, &k) < 0) {
760 avahi_log_error("Invalid entries-per-entry-group-max setting %s", p->value);
761 goto finish;
762 }
763
764 c->n_entries_per_entry_group_max = k;
765 #endif
766 } else {
767 avahi_log_error("Invalid configuration key \"%s\" in group \"%s\"\n", p->key, g->name);
768 goto finish;
769 }
770 }
771
772 } else if (strcasecmp(g->name, "publish") == 0) {
773 AvahiIniFilePair *p;
774
775 for (p = g->pairs; p; p = p->pairs_next) {
776
777 if (strcasecmp(p->key, "publish-addresses") == 0)
778 c->server_config.publish_addresses = is_yes(p->value);
779 else if (strcasecmp(p->key, "publish-hinfo") == 0)
780 c->server_config.publish_hinfo = is_yes(p->value);
781 else if (strcasecmp(p->key, "publish-workstation") == 0)
782 c->server_config.publish_workstation = is_yes(p->value);
783 else if (strcasecmp(p->key, "publish-domain") == 0)
784 c->server_config.publish_domain = is_yes(p->value);
785 else if (strcasecmp(p->key, "publish-resolv-conf-dns-servers") == 0)
786 c->publish_resolv_conf = is_yes(p->value);
787 else if (strcasecmp(p->key, "disable-publishing") == 0)
788 c->server_config.disable_publishing = is_yes(p->value);
789 else if (strcasecmp(p->key, "disable-user-service-publishing") == 0)
790 c->disable_user_service_publishing = is_yes(p->value);
791 else if (strcasecmp(p->key, "add-service-cookie") == 0)
792 c->server_config.add_service_cookie = is_yes(p->value);
793 else if (strcasecmp(p->key, "publish-dns-servers") == 0) {
794 avahi_strfreev(c->publish_dns_servers);
795 c->publish_dns_servers = avahi_split_csv(p->value);
796 } else if (strcasecmp(p->key, "publish-a-on-ipv6") == 0)
797 c->server_config.publish_a_on_ipv6 = is_yes(p->value);
798 else if (strcasecmp(p->key, "publish-aaaa-on-ipv4") == 0)
799 c->server_config.publish_aaaa_on_ipv4 = is_yes(p->value);
800 else {
801 avahi_log_error("Invalid configuration key \"%s\" in group \"%s\"\n", p->key, g->name);
802 goto finish;
803 }
804 }
805
806 } else if (strcasecmp(g->name, "wide-area") == 0) {
807 AvahiIniFilePair *p;
808
809 for (p = g->pairs; p; p = p->pairs_next) {
810
811 if (strcasecmp(p->key, "enable-wide-area") == 0)
812 c->server_config.enable_wide_area = is_yes(p->value);
813 else {
814 avahi_log_error("Invalid configuration key \"%s\" in group \"%s\"\n", p->key, g->name);
815 goto finish;
816 }
817 }
818
819 } else if (strcasecmp(g->name, "reflector") == 0) {
820 AvahiIniFilePair *p;
821
822 for (p = g->pairs; p; p = p->pairs_next) {
823
824 if (strcasecmp(p->key, "enable-reflector") == 0)
825 c->server_config.enable_reflector = is_yes(p->value);
826 else if (strcasecmp(p->key, "reflect-ipv") == 0)
827 c->server_config.reflect_ipv = is_yes(p->value);
828 else {
829 avahi_log_error("Invalid configuration key \"%s\" in group \"%s\"\n", p->key, g->name);
830 goto finish;
831 }
832 }
833
834 } else if (strcasecmp(g->name, "rlimits") == 0) {
835 AvahiIniFilePair *p;
836
837 for (p = g->pairs; p; p = p->pairs_next) {
838
839 if (strcasecmp(p->key, "rlimit-as") == 0) {
840 c->rlimit_as_set = 1;
841 c->rlimit_as = atoi(p->value);
842 } else if (strcasecmp(p->key, "rlimit-core") == 0) {
843 c->rlimit_core_set = 1;
844 c->rlimit_core = atoi(p->value);
845 } else if (strcasecmp(p->key, "rlimit-data") == 0) {
846 c->rlimit_data_set = 1;
847 c->rlimit_data = atoi(p->value);
848 } else if (strcasecmp(p->key, "rlimit-fsize") == 0) {
849 c->rlimit_fsize_set = 1;
850 c->rlimit_fsize = atoi(p->value);
851 } else if (strcasecmp(p->key, "rlimit-nofile") == 0) {
852 c->rlimit_nofile_set = 1;
853 c->rlimit_nofile = atoi(p->value);
854 } else if (strcasecmp(p->key, "rlimit-stack") == 0) {
855 c->rlimit_stack_set = 1;
856 c->rlimit_stack = atoi(p->value);
857 } else if (strcasecmp(p->key, "rlimit-nproc") == 0) {
858 #ifdef RLIMIT_NPROC
859 c->rlimit_nproc_set = 1;
860 c->rlimit_nproc = atoi(p->value);
861 #else
862 avahi_log_error("Ignoring configuration key \"%s\" in group \"%s\"\n", p->key, g->name);
863 #endif
864 } else {
865 avahi_log_error("Invalid configuration key \"%s\" in group \"%s\"\n", p->key, g->name);
866 goto finish;
867 }
868
869 }
870
871 } else {
872 avahi_log_error("Invalid configuration file group \"%s\".\n", g->name);
873 goto finish;
874 }
875 }
876
877 r = 0;
878
879 finish:
880
881 if (f)
882 avahi_ini_file_free(f);
883
884 return r;
885 }
886
log_function(AvahiLogLevel level,const char * txt)887 static void log_function(AvahiLogLevel level, const char *txt) {
888
889 static const int log_level_map[] = {
890 LOG_ERR,
891 LOG_WARNING,
892 LOG_NOTICE,
893 LOG_INFO,
894 LOG_DEBUG
895 };
896
897 assert(level < AVAHI_LOG_LEVEL_MAX);
898 assert(txt);
899
900 if (!config.debug && level == AVAHI_LOG_DEBUG)
901 return;
902
903 daemon_log(log_level_map[level], "%s", txt);
904 }
905
dump(const char * text,AVAHI_GCC_UNUSED void * userdata)906 static void dump(const char *text, AVAHI_GCC_UNUSED void* userdata) {
907 avahi_log_info("%s", text);
908 }
909
910 #ifdef HAVE_INOTIFY
911
912 static int inotify_fd = -1;
913
add_inotify_watches(void)914 static void add_inotify_watches(void) {
915 int c = 0;
916 /* We ignore the return values, because one or more of these files
917 * might not exist and we're OK with that. In addition we never
918 * want to remove these watches, hence we keep their ids? */
919
920 #ifdef ENABLE_CHROOT
921 c = config.use_chroot;
922 #endif
923
924 inotify_add_watch(inotify_fd, c ? "/services" : AVAHI_SERVICE_DIR, IN_CLOSE_WRITE|IN_DELETE|IN_DELETE_SELF|IN_MOVED_FROM|IN_MOVED_TO|IN_MOVE_SELF
925 #ifdef IN_ONLYDIR
926 |IN_ONLYDIR
927 #endif
928 );
929
930 #ifdef AVAHI_CONFIG_DIR
931 inotify_add_watch(inotify_fd, c ? "/" : AVAHI_CONFIG_DIR, IN_CLOSE_WRITE|IN_DELETE|IN_DELETE_SELF|IN_MOVED_FROM|IN_MOVED_TO|IN_MOVE_SELF
932 #ifdef IN_ONLYDIR
933 |IN_ONLYDIR
934 #endif
935 );
936 #endif
937
938 }
939
940 #endif
941
942 #ifdef HAVE_KQUEUE
943
944 #define NUM_WATCHES 2
945
946 static int kq = -1;
947 static int kfds[NUM_WATCHES];
948 static int num_kfds = 0;
949
950 static void add_kqueue_watch(const char *dir);
951
add_kqueue_watches(void)952 static void add_kqueue_watches(void) {
953 int c = 0;
954
955 #ifdef ENABLE_CHROOT
956 c = config.use_chroot;
957 #endif
958
959 #ifdef AVAHI_CONFIG_DIR
960 add_kqueue_watch(c ? "/" : AVAHI_CONFIG_DIR);
961 #endif
962
963 add_kqueue_watch(c ? "/services" : AVAHI_SERVICE_DIR);
964 }
965
add_kqueue_watch(const char * dir)966 static void add_kqueue_watch(const char *dir) {
967 int fd;
968 struct kevent ev;
969
970 if (kq < 0)
971 return;
972
973 if (num_kfds >= NUM_WATCHES)
974 return;
975
976 fd = open(dir, O_RDONLY);
977 if (fd < 0)
978 return;
979 EV_SET(&ev, fd, EVFILT_VNODE, EV_ADD | EV_ENABLE | EV_CLEAR,
980 NOTE_DELETE | NOTE_EXTEND | NOTE_WRITE | NOTE_RENAME,
981 0, 0);
982 if (kevent(kq, &ev, 1, NULL, 0, NULL) == -1) {
983 close(fd);
984 return;
985 }
986
987 kfds[num_kfds++] = fd;
988 }
989
990 #endif
991
reload_config(void)992 static void reload_config(void) {
993
994 #ifdef HAVE_INOTIFY
995 /* Refresh in case the config dirs have been removed */
996 add_inotify_watches();
997 #endif
998
999 #ifdef HAVE_KQUEUE
1000 add_kqueue_watches();
1001 #endif
1002
1003 #ifdef ENABLE_CHROOT
1004 static_service_load(config.use_chroot);
1005 static_hosts_load(config.use_chroot);
1006 #else
1007 static_service_load(0);
1008 static_hosts_load(0);
1009 #endif
1010 static_service_add_to_server();
1011 static_hosts_add_to_server();
1012
1013 if (resolv_conf_entry_group)
1014 avahi_s_entry_group_reset(resolv_conf_entry_group);
1015
1016 load_resolv_conf();
1017
1018 update_wide_area_servers();
1019 update_browse_domains();
1020
1021 if (config.publish_resolv_conf && resolv_conf_name_servers && resolv_conf_name_servers[0])
1022 resolv_conf_entry_group = add_dns_servers(avahi_server, resolv_conf_entry_group, resolv_conf_name_servers);
1023 }
1024
1025 #ifdef HAVE_INOTIFY
1026
inotify_callback(AvahiWatch * watch,int fd,AVAHI_GCC_UNUSED AvahiWatchEvent event,AVAHI_GCC_UNUSED void * userdata)1027 static void inotify_callback(AvahiWatch *watch, int fd, AVAHI_GCC_UNUSED AvahiWatchEvent event, AVAHI_GCC_UNUSED void *userdata) {
1028 char* buffer;
1029 int n = 0;
1030
1031 assert(fd == inotify_fd);
1032 assert(watch);
1033
1034 ioctl(inotify_fd, FIONREAD, &n);
1035 if (n <= 0)
1036 n = 128;
1037
1038 buffer = avahi_malloc(n);
1039 if (read(inotify_fd, buffer, n) < 0 ) {
1040 avahi_free(buffer);
1041 avahi_log_error("Failed to read inotify event: %s", avahi_strerror(errno));
1042 return;
1043 }
1044 avahi_free(buffer);
1045
1046 avahi_log_info("Files changed, reloading.");
1047 reload_config();
1048 }
1049
1050 #endif
1051
1052 #ifdef HAVE_KQUEUE
1053
kqueue_callback(AvahiWatch * watch,int fd,AVAHI_GCC_UNUSED AvahiWatchEvent event,AVAHI_GCC_UNUSED void * userdata)1054 static void kqueue_callback(AvahiWatch *watch, int fd, AVAHI_GCC_UNUSED AvahiWatchEvent event, AVAHI_GCC_UNUSED void *userdata) {
1055 struct kevent ev;
1056 struct timespec nullts = { 0, 0 };
1057 int res;
1058
1059 assert(fd == kq);
1060 assert(watch);
1061
1062 res = kevent(kq, NULL, 0, &ev, 1, &nullts);
1063
1064 if (res > 0) {
1065 /* Sleep for a half-second to avoid potential races
1066 * during install/uninstall. */
1067 usleep(500000);
1068 avahi_log_info("Files changed, reloading.");
1069 reload_config();
1070 } else {
1071 avahi_log_error("Failed to read kqueue event: %s", avahi_strerror(errno));
1072 }
1073 }
1074
1075 #endif
1076
signal_callback(AvahiWatch * watch,AVAHI_GCC_UNUSED int fd,AVAHI_GCC_UNUSED AvahiWatchEvent event,AVAHI_GCC_UNUSED void * userdata)1077 static void signal_callback(AvahiWatch *watch, AVAHI_GCC_UNUSED int fd, AVAHI_GCC_UNUSED AvahiWatchEvent event, AVAHI_GCC_UNUSED void *userdata) {
1078 int sig;
1079 const AvahiPoll *poll_api;
1080
1081 assert(watch);
1082 assert(simple_poll_api);
1083
1084 poll_api = avahi_simple_poll_get(simple_poll_api);
1085
1086 if ((sig = daemon_signal_next()) <= 0) {
1087 avahi_log_error("daemon_signal_next() failed");
1088 poll_api->watch_free(watch);
1089 return;
1090 }
1091
1092 switch (sig) {
1093 case SIGINT:
1094 case SIGTERM:
1095 avahi_log_info(
1096 "Got %s, quitting.",
1097 sig == SIGINT ? "SIGINT" : "SIGTERM");
1098 avahi_simple_poll_quit(simple_poll_api);
1099 break;
1100
1101 case SIGHUP:
1102 avahi_log_info("Got SIGHUP, reloading.");
1103
1104 reload_config();
1105 break;
1106
1107 case SIGUSR1:
1108 avahi_log_info("Got SIGUSR1, dumping record data.");
1109 avahi_server_dump(avahi_server, dump, NULL);
1110 break;
1111
1112 default:
1113 avahi_log_warn("Got spurious signal, ignoring.");
1114 break;
1115 }
1116 }
1117
1118 /* Imported from ../avahi-client/nss-check.c */
1119 int avahi_nss_support(void);
1120
ignore_signal(int sig)1121 static void ignore_signal(int sig) {
1122 struct sigaction sa;
1123
1124 memset(&sa, 0, sizeof(sa));
1125 sa.sa_handler = SIG_IGN;
1126 sa.sa_flags = SA_RESTART;
1127
1128 sigaction(sig, &sa, NULL);
1129 }
1130
run_server(DaemonConfig * c)1131 static int run_server(DaemonConfig *c) {
1132 int r = -1;
1133 int error;
1134 const AvahiPoll *poll_api = NULL;
1135 AvahiWatch *sig_watch = NULL;
1136 int retval_is_sent = 0;
1137 #ifdef HAVE_INOTIFY
1138 AvahiWatch *inotify_watch = NULL;
1139 #endif
1140 #ifdef HAVE_KQUEUE
1141 int i;
1142 AvahiWatch *kqueue_watch = NULL;
1143 #endif
1144
1145 assert(c);
1146
1147 ignore_signal(SIGPIPE);
1148
1149 if (!(nss_support = avahi_nss_support()))
1150 avahi_log_warn("WARNING: No NSS support for mDNS detected, consider installing nss-mdns!");
1151
1152 if (!(simple_poll_api = avahi_simple_poll_new())) {
1153 avahi_log_error("Failed to create main loop object.");
1154 goto finish;
1155 }
1156
1157 poll_api = avahi_simple_poll_get(simple_poll_api);
1158
1159 if (daemon_signal_init(SIGINT, SIGHUP, SIGTERM, SIGUSR1, 0) < 0) {
1160 avahi_log_error("Could not register signal handlers (%s).", strerror(errno));
1161 goto finish;
1162 }
1163
1164 if (!(sig_watch = poll_api->watch_new(poll_api, daemon_signal_fd(), AVAHI_WATCH_IN, signal_callback, simple_poll_api))) {
1165 avahi_log_error( "Failed to create signal watcher");
1166 goto finish;
1167 }
1168
1169 #ifdef AVAHI_SOCKET
1170 if (simple_protocol_setup(poll_api) < 0)
1171 goto finish;
1172 #endif
1173
1174 #ifdef HAVE_DBUS
1175 if (c->enable_dbus) {
1176 if (dbus_protocol_setup(poll_api,
1177 config.disable_user_service_publishing,
1178 config.n_clients_max,
1179 config.n_objects_per_client_max,
1180 config.n_entries_per_entry_group_max,
1181 !c->fail_on_missing_dbus
1182 #ifdef ENABLE_CHROOT
1183 && !config.use_chroot
1184 #endif
1185 ) < 0) {
1186
1187 avahi_log_warn("WARNING: Failed to contact D-Bus daemon.");
1188
1189 if (c->fail_on_missing_dbus)
1190 goto finish;
1191 }
1192 }
1193 #endif
1194
1195 #ifdef ENABLE_CHROOT
1196
1197 if (config.drop_root && config.use_chroot) {
1198 if (chroot(AVAHI_CONFIG_DIR) < 0) {
1199 avahi_log_error("Failed to chroot(): %s", strerror(errno));
1200 goto finish;
1201 }
1202
1203 avahi_log_info("Successfully called chroot().");
1204 chdir("/");
1205
1206 if (avahi_caps_drop_all() < 0) {
1207 avahi_log_error("Failed to drop capabilities.");
1208 goto finish;
1209 }
1210 avahi_log_info("Successfully dropped remaining capabilities.");
1211 }
1212
1213 #endif
1214
1215 #ifdef HAVE_INOTIFY
1216 if ((inotify_fd = inotify_init()) < 0)
1217 avahi_log_warn( "Failed to initialize inotify: %s", strerror(errno));
1218 else {
1219 add_inotify_watches();
1220
1221 if (!(inotify_watch = poll_api->watch_new(poll_api, inotify_fd, AVAHI_WATCH_IN, inotify_callback, NULL))) {
1222 avahi_log_error( "Failed to create inotify watcher");
1223 goto finish;
1224 }
1225 }
1226 #endif
1227
1228 #ifdef HAVE_KQUEUE
1229 if ((kq = kqueue()) < 0)
1230 avahi_log_warn( "Failed to initialize kqueue: %s", strerror(errno));
1231 else {
1232 add_kqueue_watches();
1233
1234 if (!(kqueue_watch = poll_api->watch_new(poll_api, kq, AVAHI_WATCH_IN, kqueue_callback, NULL))) {
1235 avahi_log_error( "Failed to create kqueue watcher");
1236 goto finish;
1237 }
1238 }
1239 #endif
1240
1241 load_resolv_conf();
1242 #ifdef ENABLE_CHROOT
1243 static_service_load(config.use_chroot);
1244 static_hosts_load(config.use_chroot);
1245 #else
1246 static_service_load(0);
1247 static_hosts_load(0);
1248 #endif
1249
1250 if (!(avahi_server = avahi_server_new(poll_api, &c->server_config, server_callback, c, &error))) {
1251 avahi_log_error("Failed to create server: %s", avahi_strerror(error));
1252 goto finish;
1253 }
1254
1255 update_wide_area_servers();
1256 update_browse_domains();
1257
1258 if (c->daemonize) {
1259 daemon_retval_send(0);
1260 retval_is_sent = 1;
1261 }
1262
1263 for (;;) {
1264 if ((r = avahi_simple_poll_iterate(simple_poll_api, -1)) < 0) {
1265
1266 /* We handle signals through an FD, so let's continue */
1267 if (errno == EINTR)
1268 continue;
1269
1270 avahi_log_error("poll(): %s", strerror(errno));
1271 goto finish;
1272 } else if (r > 0)
1273 /* Quit */
1274 break;
1275 }
1276
1277 r = 0;
1278
1279 finish:
1280
1281 static_service_remove_from_server();
1282 static_service_free_all();
1283
1284 static_hosts_remove_from_server();
1285 static_hosts_free_all();
1286
1287 remove_dns_server_entry_groups();
1288
1289 #ifdef AVAHI_SOCKET
1290 simple_protocol_shutdown();
1291 #endif
1292
1293 #ifdef HAVE_DBUS
1294 if (c->enable_dbus)
1295 dbus_protocol_shutdown();
1296 #endif
1297
1298 if (avahi_server) {
1299 avahi_server_free(avahi_server);
1300 avahi_server = NULL;
1301 }
1302
1303 daemon_signal_done();
1304
1305 if (sig_watch)
1306 poll_api->watch_free(sig_watch);
1307
1308 #ifdef HAVE_INOTIFY
1309 if (inotify_watch)
1310 poll_api->watch_free(inotify_watch);
1311 if (inotify_fd >= 0)
1312 close(inotify_fd);
1313 #endif
1314
1315 #ifdef HAVE_KQUEUE
1316 if (kqueue_watch)
1317 poll_api->watch_free(kqueue_watch);
1318 if (kq >= 0)
1319 close(kq);
1320 for (i = 0; i < num_kfds; i++) {
1321 if (kfds[i] >= 0)
1322 close(kfds[i]);
1323 }
1324 #endif
1325
1326 if (simple_poll_api) {
1327 avahi_simple_poll_free(simple_poll_api);
1328 simple_poll_api = NULL;
1329 }
1330
1331 if (!retval_is_sent && c->daemonize)
1332 daemon_retval_send(1);
1333
1334 return r;
1335 }
1336
1337 #define set_env(key, value) putenv(avahi_strdup_printf("%s=%s", (key), (value)))
1338
drop_root(void)1339 static int drop_root(void) {
1340 struct passwd *pw;
1341 struct group * gr;
1342 int r;
1343
1344 if (!(pw = getpwnam(AVAHI_USER))) {
1345 avahi_log_error( "Failed to find user '"AVAHI_USER"'.");
1346 return -1;
1347 }
1348
1349 if (!(gr = getgrnam(AVAHI_GROUP))) {
1350 avahi_log_error( "Failed to find group '"AVAHI_GROUP"'.");
1351 return -1;
1352 }
1353
1354 avahi_log_info("Found user '"AVAHI_USER"' (UID %lu) and group '"AVAHI_GROUP"' (GID %lu).", (unsigned long) pw->pw_uid, (unsigned long) gr->gr_gid);
1355
1356 if (initgroups(AVAHI_USER, gr->gr_gid) != 0) {
1357 avahi_log_error("Failed to change group list: %s", strerror(errno));
1358 return -1;
1359 }
1360
1361 #if defined(HAVE_SETRESGID)
1362 r = setresgid(gr->gr_gid, gr->gr_gid, gr->gr_gid);
1363 #elif defined(HAVE_SETEGID)
1364 if ((r = setgid(gr->gr_gid)) >= 0)
1365 r = setegid(gr->gr_gid);
1366 #elif defined(HAVE_SETREGID)
1367 r = setregid(gr->gr_gid, gr->gr_gid);
1368 #else
1369 #error "No API to drop privileges"
1370 #endif
1371
1372 if (r < 0) {
1373 avahi_log_error("Failed to change GID: %s", strerror(errno));
1374 return -1;
1375 }
1376
1377 #if defined(HAVE_SETRESUID)
1378 r = setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid);
1379 #elif defined(HAVE_SETEUID)
1380 if ((r = setuid(pw->pw_uid)) >= 0)
1381 r = seteuid(pw->pw_uid);
1382 #elif defined(HAVE_SETREUID)
1383 r = setreuid(pw->pw_uid, pw->pw_uid);
1384 #else
1385 #error "No API to drop privileges"
1386 #endif
1387
1388 if (r < 0) {
1389 avahi_log_error("Failed to change UID: %s", strerror(errno));
1390 return -1;
1391 }
1392
1393 set_env("USER", pw->pw_name);
1394 set_env("LOGNAME", pw->pw_name);
1395 set_env("HOME", pw->pw_dir);
1396
1397 avahi_log_info("Successfully dropped root privileges.");
1398
1399 return 0;
1400 }
1401
pid_file_proc(void)1402 static const char* pid_file_proc(void) {
1403 #ifdef AVAHI_DAEMON_RUNTIME_DIR
1404 return AVAHI_DAEMON_RUNTIME_DIR"/pid";
1405 #else
1406 return NULL;
1407 #endif
1408 }
1409
1410 #ifdef AVAHI_DAEMON_RUNTIME_DIR
make_runtime_dir(void)1411 static int make_runtime_dir(void) {
1412 int r = -1;
1413 mode_t u;
1414 int reset_umask = 0;
1415 struct passwd *pw;
1416 struct group * gr;
1417 struct stat st;
1418
1419 #ifndef __BIONIC__
1420 if (!(pw = getpwnam(AVAHI_USER))) {
1421 avahi_log_error( "Failed to find user '"AVAHI_USER"'.");
1422 goto fail;
1423 }
1424
1425 if (!(gr = getgrnam(AVAHI_GROUP))) {
1426 avahi_log_error( "Failed to find group '"AVAHI_GROUP"'.");
1427 goto fail;
1428 }
1429 #endif
1430
1431 u = umask(0000);
1432 reset_umask = 1;
1433
1434 if (mkdir(AVAHI_DAEMON_RUNTIME_DIR, 0755) < 0 && errno != EEXIST) {
1435 avahi_log_error("mkdir(\""AVAHI_DAEMON_RUNTIME_DIR"\"): %s", strerror(errno));
1436 goto fail;
1437 }
1438 #ifndef __BIONIC__
1439 chown(AVAHI_DAEMON_RUNTIME_DIR, pw->pw_uid, gr->gr_gid);
1440
1441 if (stat(AVAHI_DAEMON_RUNTIME_DIR, &st) < 0) {
1442 avahi_log_error("stat(): %s\n", strerror(errno));
1443 goto fail;
1444 }
1445
1446 if (!S_ISDIR(st.st_mode) || st.st_uid != pw->pw_uid || st.st_gid != gr->gr_gid) {
1447 avahi_log_error("Failed to create runtime directory "AVAHI_DAEMON_RUNTIME_DIR".");
1448 goto fail;
1449 }
1450 #endif
1451 r = 0;
1452
1453 fail:
1454 if (reset_umask)
1455 umask(u);
1456 return r;
1457 }
1458 #endif
1459
set_one_rlimit(int resource,rlim_t limit,const char * name)1460 static void set_one_rlimit(int resource, rlim_t limit, const char *name) {
1461 struct rlimit rl;
1462 rl.rlim_cur = rl.rlim_max = limit;
1463
1464 if (setrlimit(resource, &rl) < 0)
1465 avahi_log_warn("setrlimit(%s, {%u, %u}) failed: %s", name, (unsigned) limit, (unsigned) limit, strerror(errno));
1466 }
1467
enforce_rlimits(void)1468 static void enforce_rlimits(void) {
1469 #ifdef RLIMIT_AS
1470 if (config.rlimit_as_set)
1471 set_one_rlimit(RLIMIT_AS, config.rlimit_as, "RLIMIT_AS");
1472 #endif
1473 if (config.rlimit_core_set)
1474 set_one_rlimit(RLIMIT_CORE, config.rlimit_core, "RLIMIT_CORE");
1475 if (config.rlimit_data_set)
1476 set_one_rlimit(RLIMIT_DATA, config.rlimit_data, "RLIMIT_DATA");
1477 if (config.rlimit_fsize_set)
1478 set_one_rlimit(RLIMIT_FSIZE, config.rlimit_fsize, "RLIMIT_FSIZE");
1479 if (config.rlimit_nofile_set)
1480 set_one_rlimit(RLIMIT_NOFILE, config.rlimit_nofile, "RLIMIT_NOFILE");
1481 if (config.rlimit_stack_set)
1482 set_one_rlimit(RLIMIT_STACK, config.rlimit_stack, "RLIMIT_STACK");
1483 #ifdef RLIMIT_NPROC
1484 if (config.rlimit_nproc_set)
1485 set_one_rlimit(RLIMIT_NPROC, config.rlimit_nproc, "RLIMIT_NPROC");
1486 #endif
1487
1488 /* the sysctl() call from iface-pfroute.c needs locked memory on FreeBSD */
1489 #if defined(RLIMIT_MEMLOCK) && !defined(__FreeBSD__) && !defined(__FreeBSD_kernel__)
1490 /* We don't need locked memory */
1491 set_one_rlimit(RLIMIT_MEMLOCK, 0, "RLIMIT_MEMLOCK");
1492 #endif
1493 }
1494
1495 #define RANDOM_DEVICE "/dev/urandom"
1496
init_rand_seed(void)1497 static void init_rand_seed(void) {
1498 int fd;
1499 unsigned seed = 0;
1500
1501 /* Try to initialize seed from /dev/urandom, to make it a little
1502 * less predictable, and to make sure that multiple machines
1503 * booted at the same time choose different random seeds. */
1504 if ((fd = open(RANDOM_DEVICE, O_RDONLY)) >= 0) {
1505 read(fd, &seed, sizeof(seed));
1506 close(fd);
1507 }
1508
1509 /* If the initialization failed by some reason, we add the time to the seed*/
1510 seed ^= (unsigned) time(NULL);
1511
1512 srand(seed);
1513 }
1514
1515 #ifdef BUILD_AS_ANDROID_SERVICE
avahi_main(int argc,char * argv[])1516 int avahi_main(int argc, char *argv[]) {
1517 #else
1518 int main(int argc, char *argv[]) {
1519 #endif
1520 int r = 255;
1521 int wrote_pid_file = 0;
1522
1523 avahi_set_log_function(log_function);
1524
1525 init_rand_seed();
1526
1527 avahi_server_config_init(&config.server_config);
1528 config.command = DAEMON_RUN;
1529 config.daemonize = 0;
1530 config.config_file = NULL;
1531 #ifdef HAVE_DBUS
1532 config.enable_dbus = 1;
1533 config.fail_on_missing_dbus = 1;
1534 config.n_clients_max = 0;
1535 config.n_objects_per_client_max = 0;
1536 config.n_entries_per_entry_group_max = 0;
1537 #endif
1538
1539 config.drop_root = 1;
1540 config.set_rlimits = 1;
1541 #ifdef ENABLE_CHROOT
1542 config.use_chroot = 1;
1543 #endif
1544 config.modify_proc_title = 1;
1545
1546 config.disable_user_service_publishing = 0;
1547 config.publish_dns_servers = NULL;
1548 config.publish_resolv_conf = 0;
1549 config.use_syslog = 0;
1550 config.debug = 0;
1551 config.rlimit_as_set = 0;
1552 config.rlimit_core_set = 0;
1553 config.rlimit_data_set = 0;
1554 config.rlimit_fsize_set = 0;
1555 config.rlimit_nofile_set = 0;
1556 config.rlimit_stack_set = 0;
1557 #ifdef RLIMIT_NPROC
1558 config.rlimit_nproc_set = 0;
1559 #endif
1560
1561 if ((argv0 = strrchr(argv[0], '/')))
1562 argv0 = avahi_strdup(argv0 + 1);
1563 else
1564 argv0 = avahi_strdup(argv[0]);
1565
1566 daemon_pid_file_ident = (const char *) argv0;
1567 daemon_log_ident = (char*) argv0;
1568 daemon_pid_file_proc = pid_file_proc;
1569
1570 if (parse_command_line(&config, argc, argv) < 0)
1571 goto finish;
1572
1573 if (config.modify_proc_title)
1574 avahi_init_proc_title(argc, argv);
1575
1576 #ifdef ENABLE_CHROOT
1577 config.use_chroot = config.use_chroot && config.drop_root;
1578 #endif
1579
1580 if (config.command == DAEMON_HELP) {
1581 help(stdout);
1582 r = 0;
1583 } else if (config.command == DAEMON_VERSION) {
1584 printf("%s "PACKAGE_VERSION"\n", argv0);
1585 r = 0;
1586 } else if (config.command == DAEMON_KILL) {
1587 if (daemon_pid_file_kill_wait(SIGTERM, 5) < 0) {
1588 avahi_log_warn("Failed to kill daemon: %s", strerror(errno));
1589 goto finish;
1590 }
1591
1592 r = 0;
1593
1594 } else if (config.command == DAEMON_RELOAD) {
1595 if (daemon_pid_file_kill(SIGHUP) < 0) {
1596 avahi_log_warn("Failed to kill daemon: %s", strerror(errno));
1597 goto finish;
1598 }
1599
1600 r = 0;
1601
1602 } else if (config.command == DAEMON_CHECK)
1603 r = (daemon_pid_file_is_running() >= 0) ? 0 : 1;
1604 else if (config.command == DAEMON_RUN) {
1605 pid_t pid;
1606
1607 if (getuid() != 0 && config.drop_root) {
1608 avahi_log_error("This program is intended to be run as root.");
1609 goto finish;
1610 }
1611
1612 if ((pid = daemon_pid_file_is_running()) >= 0) {
1613 avahi_log_error("Daemon already running on PID %u", pid);
1614 goto finish;
1615 }
1616
1617 if (load_config_file(&config) < 0)
1618 goto finish;
1619
1620 if (config.daemonize) {
1621 daemon_retval_init();
1622
1623 if ((pid = daemon_fork()) < 0)
1624 goto finish;
1625 else if (pid != 0) {
1626 int ret;
1627 /** Parent **/
1628
1629 if ((ret = daemon_retval_wait(20)) < 0) {
1630 avahi_log_error("Could not receive return value from daemon process.");
1631 goto finish;
1632 }
1633
1634 r = ret;
1635 goto finish;
1636 }
1637
1638 /* Child */
1639 }
1640
1641 if (config.use_syslog || config.daemonize)
1642 daemon_log_use = DAEMON_LOG_SYSLOG;
1643
1644 #ifndef BUILD_AS_ANDROID_SERVICE
1645 if (sd_listen_fds(0) <= 0)
1646 if (daemon_close_all(-1) < 0)
1647 avahi_log_warn("Failed to close all remaining file descriptors: %s", strerror(errno));
1648
1649 daemon_reset_sigs(-1);
1650 daemon_unblock_sigs(-1);
1651 #endif
1652
1653 #ifdef AVAHI_DAEMON_RUNTIME_DIR
1654 if (make_runtime_dir() < 0)
1655 goto finish;
1656 #endif
1657
1658 if (config.drop_root) {
1659 #ifdef ENABLE_CHROOT
1660 if (config.use_chroot)
1661 if (avahi_caps_reduce() < 0)
1662 goto finish;
1663 #endif
1664
1665 if (drop_root() < 0)
1666 goto finish;
1667
1668 #ifdef ENABLE_CHROOT
1669 if (config.use_chroot)
1670 if (avahi_caps_reduce2() < 0)
1671 goto finish;
1672 #endif
1673 }
1674
1675 if (daemon_pid_file_create() < 0) {
1676 if (config.daemonize)
1677 daemon_retval_send(1);
1678
1679 if (pid_file_proc() != NULL) {
1680 avahi_log_error("Failed to create PID file: %s",
1681 strerror(errno));
1682 goto finish;
1683 }
1684 } else
1685 wrote_pid_file = 1;
1686
1687 if (config.set_rlimits)
1688 enforce_rlimits();
1689
1690 chdir("/");
1691
1692 #ifdef ENABLE_CHROOT
1693 if (config.drop_root && config.use_chroot)
1694 if (avahi_chroot_helper_start(argv0) < 0) {
1695 avahi_log_error("failed to start chroot() helper daemon.");
1696 goto finish;
1697 }
1698 #endif
1699 avahi_log_info("%s "PACKAGE_VERSION" starting up.", argv0);
1700 sd_notifyf(0, "STATUS=%s "PACKAGE_VERSION" starting up.", argv0);
1701 avahi_set_proc_title(argv0, "%s: starting up", argv0);
1702
1703 if (run_server(&config) == 0)
1704 r = 0;
1705
1706 avahi_log_info("%s "PACKAGE_VERSION" exiting.", argv0);
1707 sd_notifyf(0, "STATUS=%s "PACKAGE_VERSION" exiting.", argv0);
1708 }
1709
1710 finish:
1711
1712 if (config.daemonize)
1713 daemon_retval_done();
1714
1715 avahi_server_config_free(&config.server_config);
1716 avahi_free(config.config_file);
1717 avahi_strfreev(config.publish_dns_servers);
1718 avahi_strfreev(resolv_conf_name_servers);
1719 avahi_strfreev(resolv_conf_search_domains);
1720
1721 if (wrote_pid_file) {
1722 #ifdef ENABLE_CHROOT
1723 avahi_chroot_helper_unlink(pid_file_proc());
1724 #else
1725 daemon_pid_file_remove();
1726 #endif
1727 }
1728
1729 #ifdef ENABLE_CHROOT
1730 avahi_chroot_helper_shutdown();
1731 #endif
1732
1733 avahi_free(argv0);
1734
1735 return r;
1736 }
1737