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Commit | Line | Data |
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aff33962 | 1 | /* dnsmasq is Copyright (c) 2000-2015 Simon Kelley |
9e4abcb5 SK |
2 | |
3 | This program is free software; you can redistribute it and/or modify | |
4 | it under the terms of the GNU General Public License as published by | |
824af85b SK |
5 | the Free Software Foundation; version 2 dated June, 1991, or |
6 | (at your option) version 3 dated 29 June, 2007. | |
7 | ||
9e4abcb5 SK |
8 | This program is distributed in the hope that it will be useful, |
9 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | GNU General Public License for more details. | |
824af85b | 12 | |
73a08a24 SK |
13 | You should have received a copy of the GNU General Public License |
14 | along with this program. If not, see <http://www.gnu.org/licenses/>. | |
9e4abcb5 SK |
15 | */ |
16 | ||
c72daea8 SK |
17 | /* Declare static char *compiler_opts in config.h */ |
18 | #define DNSMASQ_COMPILE_OPTS | |
19 | ||
9e4abcb5 SK |
20 | #include "dnsmasq.h" |
21 | ||
5aabfc78 SK |
22 | struct daemon *daemon; |
23 | ||
5aabfc78 SK |
24 | static volatile pid_t pid = 0; |
25 | static volatile int pipewrite; | |
9e4abcb5 | 26 | |
5aabfc78 SK |
27 | static int set_dns_listeners(time_t now, fd_set *set, int *maxfdp); |
28 | static void check_dns_listeners(fd_set *set, time_t now); | |
3be34541 | 29 | static void sig_handler(int sig); |
5aabfc78 | 30 | static void async_event(int pipe, time_t now); |
c72daea8 SK |
31 | static void fatal_event(struct event_desc *ev, char *msg); |
32 | static int read_event(int fd, struct event_desc *evp, char **msg); | |
47a95169 | 33 | static void poll_resolv(int force, int do_reload, time_t now); |
9e4abcb5 SK |
34 | |
35 | int main (int argc, char **argv) | |
36 | { | |
de37951c | 37 | int bind_fallback = 0; |
9009d746 | 38 | time_t now; |
9e4abcb5 | 39 | struct sigaction sigact; |
26128d27 | 40 | struct iname *if_tmp; |
1a6bca81 SK |
41 | int piperead, pipefd[2], err_pipe[2]; |
42 | struct passwd *ent_pw = NULL; | |
c72daea8 | 43 | #if defined(HAVE_SCRIPT) |
1a6bca81 SK |
44 | uid_t script_uid = 0; |
45 | gid_t script_gid = 0; | |
7622fc06 SK |
46 | #endif |
47 | struct group *gp = NULL; | |
5aabfc78 | 48 | long i, max_fd = sysconf(_SC_OPEN_MAX); |
1a6bca81 SK |
49 | char *baduser = NULL; |
50 | int log_err; | |
51 | #if defined(HAVE_LINUX_NETWORK) | |
52 | cap_user_header_t hdr = NULL; | |
53 | cap_user_data_t data = NULL; | |
3b3f4411 SK |
54 | char *bound_device = NULL; |
55 | int did_bind = 0; | |
1a6bca81 | 56 | #endif |
408c368f | 57 | #if defined(HAVE_DHCP) || defined(HAVE_DHCP6) |
1f776932 | 58 | struct dhcp_context *context; |
ff7eea27 | 59 | struct dhcp_relay *relay; |
408c368f | 60 | #endif |
30d0879e ST |
61 | #ifdef HAVE_TFTP |
62 | int tftp_prefix_missing = 0; | |
63 | #endif | |
5aabfc78 | 64 | |
824af85b | 65 | #ifdef LOCALEDIR |
b8187c80 SK |
66 | setlocale(LC_ALL, ""); |
67 | bindtextdomain("dnsmasq", LOCALEDIR); | |
68 | textdomain("dnsmasq"); | |
69 | #endif | |
70 | ||
9e4abcb5 SK |
71 | sigact.sa_handler = sig_handler; |
72 | sigact.sa_flags = 0; | |
73 | sigemptyset(&sigact.sa_mask); | |
74 | sigaction(SIGUSR1, &sigact, NULL); | |
5aabfc78 | 75 | sigaction(SIGUSR2, &sigact, NULL); |
9e4abcb5 SK |
76 | sigaction(SIGHUP, &sigact, NULL); |
77 | sigaction(SIGTERM, &sigact, NULL); | |
44a2a316 | 78 | sigaction(SIGALRM, &sigact, NULL); |
feba5c1d SK |
79 | sigaction(SIGCHLD, &sigact, NULL); |
80 | ||
81 | /* ignore SIGPIPE */ | |
82 | sigact.sa_handler = SIG_IGN; | |
83 | sigaction(SIGPIPE, &sigact, NULL); | |
9e4abcb5 | 84 | |
5aabfc78 | 85 | umask(022); /* known umask, create leases and pid files as 0644 */ |
b5ea1cc2 SK |
86 | |
87 | rand_init(); /* Must precede read_opts() */ | |
88 | ||
5aabfc78 | 89 | read_opts(argc, argv, compile_opts); |
c3e0b9b6 | 90 | |
3be34541 | 91 | if (daemon->edns_pktsz < PACKETSZ) |
60b68069 | 92 | daemon->edns_pktsz = PACKETSZ; |
3ddacb86 | 93 | |
0a852541 SK |
94 | daemon->packet_buff_sz = daemon->edns_pktsz > DNSMASQ_PACKETSZ ? |
95 | daemon->edns_pktsz : DNSMASQ_PACKETSZ; | |
96 | daemon->packet = safe_malloc(daemon->packet_buff_sz); | |
3ddacb86 | 97 | |
c72daea8 | 98 | daemon->addrbuff = safe_malloc(ADDRSTRLEN); |
25cf5e37 SK |
99 | if (option_bool(OPT_EXTRALOG)) |
100 | daemon->addrbuff2 = safe_malloc(ADDRSTRLEN); | |
3ddacb86 SK |
101 | |
102 | #ifdef HAVE_DNSSEC | |
103 | if (option_bool(OPT_DNSSEC_VALID)) | |
5107ace1 SK |
104 | { |
105 | daemon->keyname = safe_malloc(MAXDNAME); | |
106 | daemon->workspacename = safe_malloc(MAXDNAME); | |
107 | } | |
3ddacb86 | 108 | #endif |
4f7b304f | 109 | |
7622fc06 | 110 | #ifdef HAVE_DHCP |
3be34541 | 111 | if (!daemon->lease_file) |
9e4abcb5 | 112 | { |
52b92f4d | 113 | if (daemon->dhcp || daemon->dhcp6) |
3be34541 | 114 | daemon->lease_file = LEASEFILE; |
9e4abcb5 | 115 | } |
7622fc06 | 116 | #endif |
9e4abcb5 | 117 | |
a2761754 SK |
118 | /* Close any file descriptors we inherited apart from std{in|out|err} |
119 | ||
120 | Ensure that at least stdin, stdout and stderr (fd 0, 1, 2) exist, | |
121 | otherwise file descriptors we create can end up being 0, 1, or 2 | |
122 | and then get accidentally closed later when we make 0, 1, and 2 | |
123 | open to /dev/null. Normally we'll be started with 0, 1 and 2 open, | |
124 | but it's not guaranteed. By opening /dev/null three times, we | |
125 | ensure that we're not using those fds for real stuff. */ | |
5aabfc78 SK |
126 | for (i = 0; i < max_fd; i++) |
127 | if (i != STDOUT_FILENO && i != STDERR_FILENO && i != STDIN_FILENO) | |
128 | close(i); | |
a2761754 SK |
129 | else |
130 | open("/dev/null", O_RDWR); | |
5aabfc78 | 131 | |
801ca9a7 SK |
132 | #ifndef HAVE_LINUX_NETWORK |
133 | # if !(defined(IP_RECVDSTADDR) && defined(IP_RECVIF) && defined(IP_SENDSRCADDR)) | |
28866e95 | 134 | if (!option_bool(OPT_NOWILD)) |
de37951c SK |
135 | { |
136 | bind_fallback = 1; | |
28866e95 | 137 | set_option_bool(OPT_NOWILD); |
de37951c | 138 | } |
801ca9a7 | 139 | # endif |
2b5bae9a SK |
140 | |
141 | /* -- bind-dynamic not supported on !Linux, fall back to --bind-interfaces */ | |
54dd393f | 142 | if (option_bool(OPT_CLEVERBIND)) |
2b5bae9a SK |
143 | { |
144 | bind_fallback = 1; | |
145 | set_option_bool(OPT_NOWILD); | |
236e072c | 146 | reset_option_bool(OPT_CLEVERBIND); |
2b5bae9a | 147 | } |
0491805d | 148 | #endif |
5f4dc5c6 | 149 | |
0491805d | 150 | #ifndef HAVE_INOTIFY |
70d1873d SK |
151 | if (daemon->dynamic_dirs) |
152 | die(_("dhcp-hostsdir, dhcp-optsdir and hostsdir are not supported on this platform"), NULL, EC_BADCONF); | |
309331f5 | 153 | #endif |
2b5bae9a | 154 | |
0744ca66 SK |
155 | if (option_bool(OPT_DNSSEC_VALID)) |
156 | { | |
3ddacb86 | 157 | #ifdef HAVE_DNSSEC |
ee415867 | 158 | if (!daemon->ds) |
360f2513 | 159 | die(_("no trust anchors provided for DNSSEC"), NULL, EC_BADCONF); |
0744ca66 SK |
160 | |
161 | if (daemon->cachesize < CACHESIZ) | |
360f2513 | 162 | die(_("cannot reduce cache size from default when DNSSEC enabled"), NULL, EC_BADCONF); |
0744ca66 SK |
163 | #else |
164 | die(_("DNSSEC not available: set HAVE_DNSSEC in src/config.h"), NULL, EC_BADCONF); | |
3ddacb86 | 165 | #endif |
0744ca66 | 166 | } |
3ddacb86 | 167 | |
832af0ba | 168 | #ifndef HAVE_TFTP |
9b40cbf5 | 169 | if (option_bool(OPT_TFTP)) |
5aabfc78 | 170 | die(_("TFTP server not available: set HAVE_TFTP in src/config.h"), NULL, EC_BADCONF); |
832af0ba SK |
171 | #endif |
172 | ||
7de060b0 SK |
173 | #ifdef HAVE_CONNTRACK |
174 | if (option_bool(OPT_CONNTRACK) && (daemon->query_port != 0 || daemon->osport)) | |
360f2513 | 175 | die (_("cannot use --conntrack AND --query-port"), NULL, EC_BADCONF); |
7de060b0 SK |
176 | #else |
177 | if (option_bool(OPT_CONNTRACK)) | |
360f2513 | 178 | die(_("conntrack support not available: set HAVE_CONNTRACK in src/config.h"), NULL, EC_BADCONF); |
7de060b0 SK |
179 | #endif |
180 | ||
824af85b SK |
181 | #ifdef HAVE_SOLARIS_NETWORK |
182 | if (daemon->max_logs != 0) | |
183 | die(_("asychronous logging is not available under Solaris"), NULL, EC_BADCONF); | |
184 | #endif | |
185 | ||
572b41eb SK |
186 | #ifdef __ANDROID__ |
187 | if (daemon->max_logs != 0) | |
188 | die(_("asychronous logging is not available under Android"), NULL, EC_BADCONF); | |
189 | #endif | |
190 | ||
4820dce9 SK |
191 | #ifndef HAVE_AUTH |
192 | if (daemon->authserver) | |
193 | die(_("authoritative DNS not available: set HAVE_AUTH in src/config.h"), NULL, EC_BADCONF); | |
194 | #endif | |
195 | ||
b5ea1cc2 SK |
196 | #ifndef HAVE_LOOP |
197 | if (option_bool(OPT_LOOP_DETECT)) | |
360f2513 | 198 | die(_("loop detection not available: set HAVE_LOOP in src/config.h"), NULL, EC_BADCONF); |
b5ea1cc2 | 199 | #endif |
1a6bca81 | 200 | |
5aabfc78 | 201 | now = dnsmasq_time(); |
4f7b304f | 202 | |
b0ff858e | 203 | /* Create a serial at startup if not configured. */ |
4f7b304f SK |
204 | if (daemon->authinterface && daemon->soa_sn == 0) |
205 | #ifdef HAVE_BROKEN_RTC | |
b0ff858e | 206 | die(_("zone serial must be configured in --auth-soa"), NULL, EC_BADCONF); |
4f7b304f SK |
207 | #else |
208 | daemon->soa_sn = now; | |
209 | #endif | |
5aabfc78 | 210 | |
ff7eea27 SK |
211 | #ifdef HAVE_DHCP6 |
212 | if (daemon->dhcp6) | |
213 | { | |
214 | daemon->doing_ra = option_bool(OPT_RA); | |
1f776932 | 215 | |
ff7eea27 | 216 | for (context = daemon->dhcp6; context; context = context->next) |
1f776932 | 217 | { |
ff7eea27 SK |
218 | if (context->flags & CONTEXT_DHCP) |
219 | daemon->doing_dhcp6 = 1; | |
220 | if (context->flags & CONTEXT_RA) | |
221 | daemon->doing_ra = 1; | |
1ee9be4c | 222 | #if !defined(HAVE_LINUX_NETWORK) && !defined(HAVE_BSD_NETWORK) |
ff7eea27 SK |
223 | if (context->flags & CONTEXT_TEMPLATE) |
224 | die (_("dhcp-range constructor not available on this platform"), NULL, EC_BADCONF); | |
bb86e858 | 225 | #endif |
1f776932 | 226 | } |
ff7eea27 SK |
227 | } |
228 | #endif | |
229 | ||
230 | #ifdef HAVE_DHCP | |
231 | /* Note that order matters here, we must call lease_init before | |
232 | creating any file descriptors which shouldn't be leaked | |
233 | to the lease-script init process. We need to call common_init | |
234 | before lease_init to allocate buffers it uses.*/ | |
235 | if (daemon->dhcp || daemon->doing_dhcp6 || daemon->relay4 || daemon->relay6) | |
236 | { | |
237 | dhcp_common_init(); | |
1f776932 | 238 | if (daemon->dhcp || daemon->doing_dhcp6) |
ff7eea27 SK |
239 | lease_init(now); |
240 | } | |
241 | ||
242 | if (daemon->dhcp || daemon->relay4) | |
243 | dhcp_init(); | |
244 | ||
843c96b4 | 245 | # ifdef HAVE_DHCP6 |
89500e31 | 246 | if (daemon->doing_ra || daemon->doing_dhcp6 || daemon->relay6) |
ff7eea27 SK |
247 | ra_init(now); |
248 | ||
249 | if (daemon->doing_dhcp6 || daemon->relay6) | |
250 | dhcp6_init(); | |
801ca9a7 SK |
251 | # endif |
252 | ||
253 | #endif | |
254 | ||
13d86c73 JD |
255 | #ifdef HAVE_IPSET |
256 | if (daemon->ipsets) | |
257 | ipset_init(); | |
258 | #endif | |
259 | ||
1ee9be4c | 260 | #if defined(HAVE_LINUX_NETWORK) |
801ca9a7 | 261 | netlink_init(); |
1ee9be4c SK |
262 | #elif defined(HAVE_BSD_NETWORK) |
263 | route_init(); | |
801ca9a7 SK |
264 | #endif |
265 | ||
1ee9be4c SK |
266 | if (option_bool(OPT_NOWILD) && option_bool(OPT_CLEVERBIND)) |
267 | die(_("cannot set --bind-interfaces and --bind-dynamic"), NULL, EC_BADCONF); | |
268 | ||
115ac3e4 | 269 | if (!enumerate_interfaces(1) || !enumerate_interfaces(0)) |
5aabfc78 | 270 | die(_("failed to find list of interfaces: %s"), NULL, EC_MISC); |
843c96b4 | 271 | |
54dd393f | 272 | if (option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND)) |
de37951c | 273 | { |
74c95c25 | 274 | create_bound_listeners(1); |
54dd393f SK |
275 | |
276 | if (!option_bool(OPT_CLEVERBIND)) | |
277 | for (if_tmp = daemon->if_names; if_tmp; if_tmp = if_tmp->next) | |
278 | if (if_tmp->name && !if_tmp->used) | |
279 | die(_("unknown interface %s"), if_tmp->name, EC_BADNET); | |
9380ba70 SK |
280 | |
281 | #if defined(HAVE_LINUX_NETWORK) && defined(HAVE_DHCP) | |
282 | /* after enumerate_interfaces() */ | |
3b3f4411 SK |
283 | bound_device = whichdevice(); |
284 | ||
9380ba70 SK |
285 | if (daemon->dhcp) |
286 | { | |
3b3f4411 SK |
287 | if (!daemon->relay4 && bound_device) |
288 | { | |
289 | bindtodevice(bound_device, daemon->dhcpfd); | |
290 | did_bind = 1; | |
291 | } | |
292 | if (daemon->enable_pxe && bound_device) | |
293 | { | |
294 | bindtodevice(bound_device, daemon->pxefd); | |
295 | did_bind = 1; | |
296 | } | |
9380ba70 SK |
297 | } |
298 | #endif | |
299 | ||
300 | #if defined(HAVE_LINUX_NETWORK) && defined(HAVE_DHCP6) | |
3b3f4411 SK |
301 | if (daemon->doing_dhcp6 && !daemon->relay6 && bound_device) |
302 | { | |
303 | bindtodevice(bound_device, daemon->dhcp6fd); | |
304 | did_bind = 1; | |
305 | } | |
9380ba70 | 306 | #endif |
de37951c | 307 | } |
28866e95 | 308 | else |
74c95c25 | 309 | create_wildcard_listeners(); |
5d162f20 SK |
310 | |
311 | #ifdef HAVE_DHCP6 | |
312 | /* after enumerate_interfaces() */ | |
ff7eea27 | 313 | if (daemon->doing_dhcp6 || daemon->relay6 || daemon->doing_ra) |
5d162f20 | 314 | join_multicast(1); |
3511a928 SK |
315 | |
316 | /* After netlink_init() and before create_helper() */ | |
317 | lease_make_duid(now); | |
5d162f20 | 318 | #endif |
de37951c | 319 | |
824af85b | 320 | if (daemon->port != 0) |
82e3f45a SK |
321 | { |
322 | cache_init(); | |
193de4ab | 323 | |
82e3f45a SK |
324 | #ifdef HAVE_DNSSEC |
325 | blockdata_init(); | |
326 | #endif | |
5f4dc5c6 | 327 | } |
193de4ab | 328 | |
0491805d | 329 | #ifdef HAVE_INOTIFY |
70d1873d | 330 | if (daemon->port != 0 || daemon->dhcp || daemon->doing_dhcp6) |
5f4dc5c6 SK |
331 | inotify_dnsmasq_init(); |
332 | else | |
333 | daemon->inotifyfd = -1; | |
193de4ab | 334 | #endif |
5f4dc5c6 | 335 | |
28866e95 | 336 | if (option_bool(OPT_DBUS)) |
3d8df260 SK |
337 | #ifdef HAVE_DBUS |
338 | { | |
339 | char *err; | |
340 | daemon->dbus = NULL; | |
341 | daemon->watches = NULL; | |
5aabfc78 SK |
342 | if ((err = dbus_init())) |
343 | die(_("DBus error: %s"), err, EC_MISC); | |
3d8df260 SK |
344 | } |
345 | #else | |
5aabfc78 | 346 | die(_("DBus not available: set HAVE_DBUS in src/config.h"), NULL, EC_BADCONF); |
3d8df260 SK |
347 | #endif |
348 | ||
824af85b SK |
349 | if (daemon->port != 0) |
350 | pre_allocate_sfds(); | |
1a6bca81 | 351 | |
c72daea8 | 352 | #if defined(HAVE_SCRIPT) |
1a6bca81 | 353 | /* Note getpwnam returns static storage */ |
843c96b4 SK |
354 | if ((daemon->dhcp || daemon->dhcp6) && |
355 | daemon->scriptuser && | |
c72daea8 | 356 | (daemon->lease_change_command || daemon->luascript)) |
1a6bca81 SK |
357 | { |
358 | if ((ent_pw = getpwnam(daemon->scriptuser))) | |
359 | { | |
360 | script_uid = ent_pw->pw_uid; | |
361 | script_gid = ent_pw->pw_gid; | |
362 | } | |
363 | else | |
364 | baduser = daemon->scriptuser; | |
365 | } | |
7622fc06 | 366 | #endif |
9e4abcb5 | 367 | |
1a6bca81 SK |
368 | if (daemon->username && !(ent_pw = getpwnam(daemon->username))) |
369 | baduser = daemon->username; | |
370 | else if (daemon->groupname && !(gp = getgrnam(daemon->groupname))) | |
371 | baduser = daemon->groupname; | |
372 | ||
373 | if (baduser) | |
374 | die(_("unknown user or group: %s"), baduser, EC_BADCONF); | |
f6e62e2a | 375 | |
1a6bca81 SK |
376 | /* implement group defaults, "dip" if available, or group associated with uid */ |
377 | if (!daemon->group_set && !gp) | |
378 | { | |
379 | if (!(gp = getgrnam(CHGRP)) && ent_pw) | |
380 | gp = getgrgid(ent_pw->pw_gid); | |
381 | ||
382 | /* for error message */ | |
383 | if (gp) | |
384 | daemon->groupname = gp->gr_name; | |
385 | } | |
386 | ||
387 | #if defined(HAVE_LINUX_NETWORK) | |
388 | /* determine capability API version here, while we can still | |
389 | call safe_malloc */ | |
390 | if (ent_pw && ent_pw->pw_uid != 0) | |
391 | { | |
1a6bca81 | 392 | int capsize = 1; /* for header version 1 */ |
3927da46 SK |
393 | hdr = safe_malloc(sizeof(*hdr)); |
394 | ||
1a6bca81 SK |
395 | /* find version supported by kernel */ |
396 | memset(hdr, 0, sizeof(*hdr)); | |
397 | capget(hdr, NULL); | |
398 | ||
399 | if (hdr->version != LINUX_CAPABILITY_VERSION_1) | |
400 | { | |
401 | /* if unknown version, use largest supported version (3) */ | |
402 | if (hdr->version != LINUX_CAPABILITY_VERSION_2) | |
403 | hdr->version = LINUX_CAPABILITY_VERSION_3; | |
404 | capsize = 2; | |
405 | } | |
406 | ||
407 | data = safe_malloc(sizeof(*data) * capsize); | |
408 | memset(data, 0, sizeof(*data) * capsize); | |
409 | } | |
410 | #endif | |
411 | ||
5aabfc78 | 412 | /* Use a pipe to carry signals and other events back to the event loop |
1a6bca81 SK |
413 | in a race-free manner and another to carry errors to daemon-invoking process */ |
414 | safe_pipe(pipefd, 1); | |
5e9e0efb SK |
415 | |
416 | piperead = pipefd[0]; | |
417 | pipewrite = pipefd[1]; | |
418 | /* prime the pipe to load stuff first time. */ | |
e98bd52e | 419 | send_event(pipewrite, EVENT_INIT, 0, NULL); |
1a6bca81 SK |
420 | |
421 | err_pipe[1] = -1; | |
1697269c | 422 | |
28866e95 | 423 | if (!option_bool(OPT_DEBUG)) |
9e4abcb5 | 424 | { |
9e4abcb5 SK |
425 | /* The following code "daemonizes" the process. |
426 | See Stevens section 12.4 */ | |
1a6bca81 | 427 | |
9e038946 SK |
428 | if (chdir("/") != 0) |
429 | die(_("cannot chdir to filesystem root: %s"), NULL, EC_MISC); | |
430 | ||
1697269c | 431 | #ifndef NO_FORK |
28866e95 | 432 | if (!option_bool(OPT_NO_FORK)) |
3be34541 | 433 | { |
5aabfc78 | 434 | pid_t pid; |
3be34541 | 435 | |
1a6bca81 SK |
436 | /* pipe to carry errors back to original process. |
437 | When startup is complete we close this and the process terminates. */ | |
438 | safe_pipe(err_pipe, 0); | |
439 | ||
7622fc06 SK |
440 | if ((pid = fork()) == -1) |
441 | /* fd == -1 since we've not forked, never returns. */ | |
c72daea8 | 442 | send_event(-1, EVENT_FORK_ERR, errno, NULL); |
9e038946 | 443 | |
5aabfc78 | 444 | if (pid != 0) |
1a6bca81 SK |
445 | { |
446 | struct event_desc ev; | |
c72daea8 SK |
447 | char *msg; |
448 | ||
1a6bca81 | 449 | /* close our copy of write-end */ |
ff841ebf | 450 | while (retry_send(close(err_pipe[1]))); |
1a6bca81 SK |
451 | |
452 | /* check for errors after the fork */ | |
c72daea8 SK |
453 | if (read_event(err_pipe[0], &ev, &msg)) |
454 | fatal_event(&ev, msg); | |
1a6bca81 SK |
455 | |
456 | _exit(EC_GOOD); | |
457 | } | |
458 | ||
ff841ebf | 459 | while (retry_send(close(err_pipe[0]))); |
1a6bca81 SK |
460 | |
461 | /* NO calls to die() from here on. */ | |
3be34541 | 462 | |
5aabfc78 | 463 | setsid(); |
7622fc06 SK |
464 | |
465 | if ((pid = fork()) == -1) | |
c72daea8 | 466 | send_event(err_pipe[1], EVENT_FORK_ERR, errno, NULL); |
7622fc06 SK |
467 | |
468 | if (pid != 0) | |
7cebd20f | 469 | _exit(0); |
3be34541 | 470 | } |
9e4abcb5 | 471 | #endif |
9e038946 | 472 | |
9e4abcb5 | 473 | /* write pidfile _after_ forking ! */ |
1a6bca81 SK |
474 | if (daemon->runfile) |
475 | { | |
79cfefd8 SK |
476 | int fd, err = 0; |
477 | ||
478 | sprintf(daemon->namebuff, "%d\n", (int) getpid()); | |
479 | ||
480 | /* Explanation: Some installations of dnsmasq (eg Debian/Ubuntu) locate the pid-file | |
481 | in a directory which is writable by the non-privileged user that dnsmasq runs as. This | |
482 | allows the daemon to delete the file as part of its shutdown. This is a security hole to the | |
483 | extent that an attacker running as the unprivileged user could replace the pidfile with a | |
484 | symlink, and have the target of that symlink overwritten as root next time dnsmasq starts. | |
485 | ||
486 | The folowing code first deletes any existing file, and then opens it with the O_EXCL flag, | |
487 | ensuring that the open() fails should there be any existing file (because the unlink() failed, | |
488 | or an attacker exploited the race between unlink() and open()). This ensures that no symlink | |
489 | attack can succeed. | |
490 | ||
491 | Any compromise of the non-privileged user still theoretically allows the pid-file to be | |
492 | replaced whilst dnsmasq is running. The worst that could allow is that the usual | |
493 | "shutdown dnsmasq" shell command could be tricked into stopping any other process. | |
494 | ||
495 | Note that if dnsmasq is started as non-root (eg for testing) it silently ignores | |
496 | failure to write the pid-file. | |
497 | */ | |
498 | ||
499 | unlink(daemon->runfile); | |
1a6bca81 | 500 | |
79cfefd8 | 501 | if ((fd = open(daemon->runfile, O_WRONLY|O_CREAT|O_TRUNC|O_EXCL, S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH)) == -1) |
1a6bca81 | 502 | { |
79cfefd8 SK |
503 | /* only complain if started as root */ |
504 | if (getuid() == 0) | |
505 | err = 1; | |
1a6bca81 | 506 | } |
79cfefd8 SK |
507 | else |
508 | { | |
509 | if (!read_write(fd, (unsigned char *)daemon->namebuff, strlen(daemon->namebuff), 0)) | |
510 | err = 1; | |
ff841ebf SK |
511 | else |
512 | { | |
513 | while (retry_send(close(fd))); | |
514 | if (errno != 0) | |
515 | err = 1; | |
516 | } | |
79cfefd8 SK |
517 | } |
518 | ||
519 | if (err) | |
1a6bca81 | 520 | { |
c72daea8 | 521 | send_event(err_pipe[1], EVENT_PIDFILE, errno, daemon->runfile); |
1a6bca81 SK |
522 | _exit(0); |
523 | } | |
9e4abcb5 | 524 | } |
1697269c SK |
525 | } |
526 | ||
8ef5ada2 SK |
527 | log_err = log_start(ent_pw, err_pipe[1]); |
528 | ||
28866e95 | 529 | if (!option_bool(OPT_DEBUG)) |
8ef5ada2 SK |
530 | { |
531 | /* open stdout etc to /dev/null */ | |
532 | int nullfd = open("/dev/null", O_RDWR); | |
533 | dup2(nullfd, STDOUT_FILENO); | |
534 | dup2(nullfd, STDERR_FILENO); | |
535 | dup2(nullfd, STDIN_FILENO); | |
536 | close(nullfd); | |
537 | } | |
1a6bca81 SK |
538 | |
539 | /* if we are to run scripts, we need to fork a helper before dropping root. */ | |
540 | daemon->helperfd = -1; | |
c72daea8 | 541 | #ifdef HAVE_SCRIPT |
52b92f4d | 542 | if ((daemon->dhcp || daemon->dhcp6) && (daemon->lease_change_command || daemon->luascript)) |
1a6bca81 | 543 | daemon->helperfd = create_helper(pipewrite, err_pipe[1], script_uid, script_gid, max_fd); |
5aabfc78 | 544 | #endif |
5aabfc78 | 545 | |
28866e95 | 546 | if (!option_bool(OPT_DEBUG) && getuid() == 0) |
1697269c | 547 | { |
1a6bca81 SK |
548 | int bad_capabilities = 0; |
549 | gid_t dummy; | |
550 | ||
551 | /* remove all supplimentary groups */ | |
552 | if (gp && | |
553 | (setgroups(0, &dummy) == -1 || | |
554 | setgid(gp->gr_gid) == -1)) | |
9e4abcb5 | 555 | { |
c72daea8 | 556 | send_event(err_pipe[1], EVENT_GROUP_ERR, errno, daemon->groupname); |
1a6bca81 | 557 | _exit(0); |
7cebd20f | 558 | } |
1a6bca81 | 559 | |
7cebd20f | 560 | if (ent_pw && ent_pw->pw_uid != 0) |
1697269c | 561 | { |
74c95c25 | 562 | #if defined(HAVE_LINUX_NETWORK) |
1697269c | 563 | /* On linux, we keep CAP_NETADMIN (for ARP-injection) and |
74c95c25 | 564 | CAP_NET_RAW (for icmp) if we're doing dhcp. If we have yet to bind |
54dd393f SK |
565 | ports because of DAD, or we're doing it dynamically, |
566 | we need CAP_NET_BIND_SERVICE too. */ | |
567 | if (is_dad_listeners() || option_bool(OPT_CLEVERBIND)) | |
74c95c25 SK |
568 | data->effective = data->permitted = data->inheritable = |
569 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | | |
570 | (1 << CAP_SETUID) | (1 << CAP_NET_BIND_SERVICE); | |
571 | else | |
572 | data->effective = data->permitted = data->inheritable = | |
573 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | (1 << CAP_SETUID); | |
5e9e0efb | 574 | |
1697269c | 575 | /* Tell kernel to not clear capabilities when dropping root */ |
572b41eb | 576 | if (capset(hdr, data) == -1 || prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) |
1697269c | 577 | bad_capabilities = errno; |
1a6bca81 | 578 | |
7622fc06 | 579 | #elif defined(HAVE_SOLARIS_NETWORK) |
824af85b SK |
580 | /* http://developers.sun.com/solaris/articles/program_privileges.html */ |
581 | priv_set_t *priv_set; | |
582 | ||
583 | if (!(priv_set = priv_str_to_set("basic", ",", NULL)) || | |
584 | priv_addset(priv_set, PRIV_NET_ICMPACCESS) == -1 || | |
585 | priv_addset(priv_set, PRIV_SYS_NET_CONFIG) == -1) | |
586 | bad_capabilities = errno; | |
587 | ||
588 | if (priv_set && bad_capabilities == 0) | |
589 | { | |
590 | priv_inverse(priv_set); | |
591 | ||
592 | if (setppriv(PRIV_OFF, PRIV_LIMIT, priv_set) == -1) | |
593 | bad_capabilities = errno; | |
594 | } | |
595 | ||
596 | if (priv_set) | |
597 | priv_freeset(priv_set); | |
598 | ||
824af85b SK |
599 | #endif |
600 | ||
1a6bca81 | 601 | if (bad_capabilities != 0) |
1697269c | 602 | { |
c72daea8 | 603 | send_event(err_pipe[1], EVENT_CAP_ERR, bad_capabilities, NULL); |
1a6bca81 SK |
604 | _exit(0); |
605 | } | |
606 | ||
607 | /* finally drop root */ | |
608 | if (setuid(ent_pw->pw_uid) == -1) | |
609 | { | |
c72daea8 | 610 | send_event(err_pipe[1], EVENT_USER_ERR, errno, daemon->username); |
1a6bca81 SK |
611 | _exit(0); |
612 | } | |
613 | ||
1697269c | 614 | #ifdef HAVE_LINUX_NETWORK |
54dd393f | 615 | if (is_dad_listeners() || option_bool(OPT_CLEVERBIND)) |
74c95c25 SK |
616 | data->effective = data->permitted = |
617 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | (1 << CAP_NET_BIND_SERVICE); | |
618 | else | |
619 | data->effective = data->permitted = | |
620 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW); | |
1a6bca81 SK |
621 | data->inheritable = 0; |
622 | ||
623 | /* lose the setuid and setgid capbilities */ | |
624 | if (capset(hdr, data) == -1) | |
625 | { | |
c72daea8 | 626 | send_event(err_pipe[1], EVENT_CAP_ERR, errno, NULL); |
1a6bca81 | 627 | _exit(0); |
1697269c | 628 | } |
1a6bca81 SK |
629 | #endif |
630 | ||
9e4abcb5 SK |
631 | } |
632 | } | |
1697269c | 633 | |
1697269c | 634 | #ifdef HAVE_LINUX_NETWORK |
28b879ac CW |
635 | free(hdr); |
636 | free(data); | |
28866e95 | 637 | if (option_bool(OPT_DEBUG)) |
572b41eb | 638 | prctl(PR_SET_DUMPABLE, 1, 0, 0, 0); |
1697269c | 639 | #endif |
9e4abcb5 | 640 | |
8b3ae2fd | 641 | #ifdef HAVE_TFTP |
30d0879e | 642 | if (option_bool(OPT_TFTP)) |
8b3ae2fd SK |
643 | { |
644 | DIR *dir; | |
645 | struct tftp_prefix *p; | |
646 | ||
647 | if (daemon->tftp_prefix) | |
648 | { | |
649 | if (!((dir = opendir(daemon->tftp_prefix)))) | |
650 | { | |
30d0879e ST |
651 | tftp_prefix_missing = 1; |
652 | if (!option_bool(OPT_TFTP_NO_FAIL)) | |
653 | { | |
654 | send_event(err_pipe[1], EVENT_TFTP_ERR, errno, daemon->tftp_prefix); | |
655 | _exit(0); | |
656 | } | |
8b3ae2fd SK |
657 | } |
658 | closedir(dir); | |
659 | } | |
30d0879e | 660 | |
8b3ae2fd SK |
661 | for (p = daemon->if_prefix; p; p = p->next) |
662 | { | |
30d0879e | 663 | p->missing = 0; |
8b3ae2fd | 664 | if (!((dir = opendir(p->prefix)))) |
30d0879e ST |
665 | { |
666 | p->missing = 1; | |
667 | if (!option_bool(OPT_TFTP_NO_FAIL)) | |
668 | { | |
669 | send_event(err_pipe[1], EVENT_TFTP_ERR, errno, p->prefix); | |
670 | _exit(0); | |
671 | } | |
672 | } | |
8b3ae2fd SK |
673 | closedir(dir); |
674 | } | |
675 | } | |
676 | #endif | |
30d0879e | 677 | |
824af85b SK |
678 | if (daemon->port == 0) |
679 | my_syslog(LOG_INFO, _("started, version %s DNS disabled"), VERSION); | |
680 | else if (daemon->cachesize != 0) | |
f2621c7f | 681 | my_syslog(LOG_INFO, _("started, version %s cachesize %d"), VERSION, daemon->cachesize); |
9e4abcb5 | 682 | else |
f2621c7f | 683 | my_syslog(LOG_INFO, _("started, version %s cache disabled"), VERSION); |
1697269c | 684 | |
f2621c7f | 685 | my_syslog(LOG_INFO, _("compile time options: %s"), compile_opts); |
1697269c | 686 | |
3d8df260 | 687 | #ifdef HAVE_DBUS |
28866e95 | 688 | if (option_bool(OPT_DBUS)) |
3d8df260 SK |
689 | { |
690 | if (daemon->dbus) | |
f2621c7f | 691 | my_syslog(LOG_INFO, _("DBus support enabled: connected to system bus")); |
3d8df260 | 692 | else |
f2621c7f | 693 | my_syslog(LOG_INFO, _("DBus support enabled: bus connection pending")); |
3d8df260 SK |
694 | } |
695 | #endif | |
1a9a3489 SK |
696 | |
697 | if (option_bool(OPT_LOCAL_SERVICE)) | |
698 | my_syslog(LOG_INFO, _("DNS service limited to local subnets")); | |
db737466 | 699 | |
1d97ac4f | 700 | #ifdef HAVE_DNSSEC |
db737466 | 701 | if (option_bool(OPT_DNSSEC_VALID)) |
e98bd52e | 702 | { |
360f2513 SK |
703 | int rc; |
704 | ||
705 | /* Delay creating the timestamp file until here, after we've changed user, so that | |
706 | it has the correct owner to allow updating the mtime later. | |
707 | This means we have to report fatal errors via the pipe. */ | |
708 | if ((rc = setup_timestamp()) == -1) | |
709 | { | |
710 | send_event(err_pipe[1], EVENT_TIME_ERR, errno, daemon->timestamp_file); | |
711 | _exit(0); | |
712 | } | |
713 | ||
e98bd52e | 714 | my_syslog(LOG_INFO, _("DNSSEC validation enabled")); |
360f2513 | 715 | |
e98bd52e SK |
716 | if (option_bool(OPT_DNSSEC_TIME)) |
717 | my_syslog(LOG_INFO, _("DNSSEC signature timestamps not checked until first cache reload")); | |
360f2513 SK |
718 | |
719 | if (rc == 1) | |
f6e62e2a | 720 | my_syslog(LOG_INFO, _("DNSSEC signature timestamps not checked until system time valid")); |
e98bd52e | 721 | } |
db737466 | 722 | #endif |
3d8df260 | 723 | |
1a6bca81 SK |
724 | if (log_err != 0) |
725 | my_syslog(LOG_WARNING, _("warning: failed to change owner of %s: %s"), | |
726 | daemon->log_file, strerror(log_err)); | |
db737466 | 727 | |
de37951c | 728 | if (bind_fallback) |
f2621c7f | 729 | my_syslog(LOG_WARNING, _("setting --bind-interfaces option because of OS limitations")); |
dc27e148 | 730 | |
f7029f5c SK |
731 | if (option_bool(OPT_NOWILD)) |
732 | warn_bound_listeners(); | |
733 | ||
734 | warn_int_names(); | |
de37951c | 735 | |
28866e95 | 736 | if (!option_bool(OPT_NOWILD)) |
26128d27 SK |
737 | for (if_tmp = daemon->if_names; if_tmp; if_tmp = if_tmp->next) |
738 | if (if_tmp->name && !if_tmp->used) | |
f2621c7f | 739 | my_syslog(LOG_WARNING, _("warning: interface %s does not currently exist"), if_tmp->name); |
5e9e0efb | 740 | |
28866e95 | 741 | if (daemon->port != 0 && option_bool(OPT_NO_RESOLV)) |
208b65c5 SK |
742 | { |
743 | if (daemon->resolv_files && !daemon->resolv_files->is_default) | |
f2621c7f | 744 | my_syslog(LOG_WARNING, _("warning: ignoring resolv-file flag because no-resolv is set")); |
208b65c5 | 745 | daemon->resolv_files = NULL; |
1b7ecd11 | 746 | if (!daemon->servers) |
f2621c7f | 747 | my_syslog(LOG_WARNING, _("warning: no upstream servers configured")); |
208b65c5 SK |
748 | } |
749 | ||
f2621c7f SK |
750 | if (daemon->max_logs != 0) |
751 | my_syslog(LOG_INFO, _("asynchronous logging enabled, queue limit is %d messages"), daemon->max_logs); | |
1f776932 | 752 | |
f2621c7f | 753 | |
7622fc06 | 754 | #ifdef HAVE_DHCP |
1f776932 SK |
755 | for (context = daemon->dhcp; context; context = context->next) |
756 | log_context(AF_INET, context); | |
52b92f4d | 757 | |
ff7eea27 SK |
758 | for (relay = daemon->relay4; relay; relay = relay->next) |
759 | log_relay(AF_INET, relay); | |
760 | ||
1f776932 SK |
761 | # ifdef HAVE_DHCP6 |
762 | for (context = daemon->dhcp6; context; context = context->next) | |
763 | log_context(AF_INET6, context); | |
764 | ||
ff7eea27 SK |
765 | for (relay = daemon->relay6; relay; relay = relay->next) |
766 | log_relay(AF_INET6, relay); | |
767 | ||
1f776932 SK |
768 | if (daemon->doing_dhcp6 || daemon->doing_ra) |
769 | dhcp_construct_contexts(now); | |
770 | ||
771 | if (option_bool(OPT_RA)) | |
772 | my_syslog(MS_DHCP | LOG_INFO, _("IPv6 router advertisement enabled")); | |
773 | # endif | |
26128d27 | 774 | |
3b3f4411 SK |
775 | # ifdef HAVE_LINUX_NETWORK |
776 | if (did_bind) | |
777 | my_syslog(MS_DHCP | LOG_INFO, _("DHCP, sockets bound exclusively to interface %s"), bound_device); | |
778 | # endif | |
779 | ||
8445f5d2 SK |
780 | /* after dhcp_contruct_contexts */ |
781 | if (daemon->dhcp || daemon->doing_dhcp6) | |
782 | lease_find_interfaces(now); | |
1f776932 | 783 | #endif |
52b92f4d | 784 | |
832af0ba | 785 | #ifdef HAVE_TFTP |
5f4dc5c6 | 786 | if (option_bool(OPT_TFTP)) |
30d0879e ST |
787 | { |
788 | struct tftp_prefix *p; | |
832af0ba | 789 | #ifdef FD_SETSIZE |
5aabfc78 | 790 | if (FD_SETSIZE < (unsigned)max_fd) |
832af0ba SK |
791 | max_fd = FD_SETSIZE; |
792 | #endif | |
793 | ||
7622fc06 | 794 | my_syslog(MS_TFTP | LOG_INFO, "TFTP %s%s %s", |
f2621c7f SK |
795 | daemon->tftp_prefix ? _("root is ") : _("enabled"), |
796 | daemon->tftp_prefix ? daemon->tftp_prefix: "", | |
28866e95 | 797 | option_bool(OPT_TFTP_SECURE) ? _("secure mode") : ""); |
30d0879e ST |
798 | |
799 | if (tftp_prefix_missing) | |
800 | my_syslog(MS_TFTP | LOG_WARNING, _("warning: %s inaccessible"), daemon->tftp_prefix); | |
f2621c7f | 801 | |
30d0879e ST |
802 | for (p = daemon->if_prefix; p; p = p->next) |
803 | if (p->missing) | |
804 | my_syslog(MS_TFTP | LOG_WARNING, _("warning: TFTP directory %s inaccessible"), p->prefix); | |
805 | ||
832af0ba | 806 | /* This is a guess, it assumes that for small limits, |
f2621c7f | 807 | disjoint files might be served, but for large limits, |
832af0ba SK |
808 | a single file will be sent to may clients (the file only needs |
809 | one fd). */ | |
810 | ||
811 | max_fd -= 30; /* use other than TFTP */ | |
812 | ||
813 | if (max_fd < 0) | |
814 | max_fd = 5; | |
815 | else if (max_fd < 100) | |
816 | max_fd = max_fd/2; | |
817 | else | |
818 | max_fd = max_fd - 20; | |
824af85b SK |
819 | |
820 | /* if we have to use a limited range of ports, | |
821 | that will limit the number of transfers */ | |
822 | if (daemon->start_tftp_port != 0 && | |
823 | daemon->end_tftp_port - daemon->start_tftp_port + 1 < max_fd) | |
824 | max_fd = daemon->end_tftp_port - daemon->start_tftp_port + 1; | |
832af0ba SK |
825 | |
826 | if (daemon->tftp_max > max_fd) | |
827 | { | |
828 | daemon->tftp_max = max_fd; | |
7622fc06 | 829 | my_syslog(MS_TFTP | LOG_WARNING, |
f2621c7f SK |
830 | _("restricting maximum simultaneous TFTP transfers to %d"), |
831 | daemon->tftp_max); | |
832af0ba SK |
832 | } |
833 | } | |
834 | #endif | |
835 | ||
1a6bca81 SK |
836 | /* finished start-up - release original process */ |
837 | if (err_pipe[1] != -1) | |
ff841ebf | 838 | while (retry_send(close(err_pipe[1]))); |
9e4abcb5 | 839 | |
824af85b SK |
840 | if (daemon->port != 0) |
841 | check_servers(); | |
842 | ||
7cebd20f SK |
843 | pid = getpid(); |
844 | ||
0491805d | 845 | #ifdef HAVE_INOTIFY |
193de4ab SK |
846 | /* Using inotify, have to select a resolv file at startup */ |
847 | poll_resolv(1, 0, now); | |
848 | #endif | |
849 | ||
5e9e0efb | 850 | while (1) |
9e4abcb5 | 851 | { |
1697269c | 852 | int maxfd = -1; |
5e9e0efb | 853 | struct timeval t, *tp = NULL; |
3d8df260 | 854 | fd_set rset, wset, eset; |
9e4abcb5 SK |
855 | |
856 | FD_ZERO(&rset); | |
3d8df260 SK |
857 | FD_ZERO(&wset); |
858 | FD_ZERO(&eset); | |
9e4abcb5 | 859 | |
1697269c SK |
860 | /* if we are out of resources, find how long we have to wait |
861 | for some to come free, we'll loop around then and restart | |
862 | listening for queries */ | |
5aabfc78 | 863 | if ((t.tv_sec = set_dns_listeners(now, &rset, &maxfd)) != 0) |
1697269c SK |
864 | { |
865 | t.tv_usec = 0; | |
866 | tp = &t; | |
867 | } | |
868 | ||
832af0ba SK |
869 | /* Whilst polling for the dbus, or doing a tftp transfer, wake every quarter second */ |
870 | if (daemon->tftp_trans || | |
28866e95 | 871 | (option_bool(OPT_DBUS) && !daemon->dbus)) |
5e9e0efb | 872 | { |
1697269c SK |
873 | t.tv_sec = 0; |
874 | t.tv_usec = 250000; | |
5e9e0efb | 875 | tp = &t; |
5e9e0efb | 876 | } |
74c95c25 SK |
877 | /* Wake every second whilst waiting for DAD to complete */ |
878 | else if (is_dad_listeners()) | |
879 | { | |
880 | t.tv_sec = 1; | |
881 | t.tv_usec = 0; | |
882 | tp = &t; | |
883 | } | |
44a2a316 | 884 | |
832af0ba | 885 | #ifdef HAVE_DBUS |
5aabfc78 | 886 | set_dbus_listeners(&maxfd, &rset, &wset, &eset); |
5e9e0efb SK |
887 | #endif |
888 | ||
7622fc06 | 889 | #ifdef HAVE_DHCP |
ff7eea27 | 890 | if (daemon->dhcp || daemon->relay4) |
5e9e0efb SK |
891 | { |
892 | FD_SET(daemon->dhcpfd, &rset); | |
1697269c | 893 | bump_maxfd(daemon->dhcpfd, &maxfd); |
316e2730 SK |
894 | if (daemon->pxefd != -1) |
895 | { | |
896 | FD_SET(daemon->pxefd, &rset); | |
897 | bump_maxfd(daemon->pxefd, &maxfd); | |
898 | } | |
5e9e0efb | 899 | } |
7622fc06 | 900 | #endif |
cdeda28f | 901 | |
52b92f4d | 902 | #ifdef HAVE_DHCP6 |
ff7eea27 | 903 | if (daemon->doing_dhcp6 || daemon->relay6) |
52b92f4d SK |
904 | { |
905 | FD_SET(daemon->dhcp6fd, &rset); | |
c5ad4e79 | 906 | bump_maxfd(daemon->dhcp6fd, &maxfd); |
5d71d834 SK |
907 | } |
908 | ||
1f776932 | 909 | if (daemon->doing_ra) |
5d71d834 SK |
910 | { |
911 | FD_SET(daemon->icmp6fd, &rset); | |
912 | bump_maxfd(daemon->icmp6fd, &maxfd); | |
52b92f4d SK |
913 | } |
914 | #endif | |
0491805d SK |
915 | |
916 | #ifdef HAVE_INOTIFY | |
5f4dc5c6 | 917 | if (daemon->inotifyfd != -1) |
193de4ab SK |
918 | { |
919 | FD_SET(daemon->inotifyfd, &rset); | |
920 | bump_maxfd(daemon->inotifyfd, &maxfd); | |
921 | } | |
0491805d SK |
922 | #endif |
923 | ||
924 | #if defined(HAVE_LINUX_NETWORK) | |
925 | FD_SET(daemon->netlinkfd, &rset); | |
926 | bump_maxfd(daemon->netlinkfd, &maxfd); | |
1ee9be4c SK |
927 | #elif defined(HAVE_BSD_NETWORK) |
928 | FD_SET(daemon->routefd, &rset); | |
929 | bump_maxfd(daemon->routefd, &maxfd); | |
3d8df260 | 930 | #endif |
193de4ab | 931 | |
5e9e0efb | 932 | FD_SET(piperead, &rset); |
1697269c SK |
933 | bump_maxfd(piperead, &maxfd); |
934 | ||
7622fc06 | 935 | #ifdef HAVE_DHCP |
1f15b81d | 936 | # ifdef HAVE_SCRIPT |
5aabfc78 | 937 | while (helper_buf_empty() && do_script_run(now)); |
1697269c | 938 | |
a9530964 SK |
939 | # ifdef HAVE_TFTP |
940 | while (helper_buf_empty() && do_tftp_script_run()); | |
941 | # endif | |
942 | ||
1697269c SK |
943 | if (!helper_buf_empty()) |
944 | { | |
945 | FD_SET(daemon->helperfd, &wset); | |
946 | bump_maxfd(daemon->helperfd, &maxfd); | |
947 | } | |
7622fc06 | 948 | # else |
5aabfc78 SK |
949 | /* need this for other side-effects */ |
950 | while (do_script_run(now)); | |
a9530964 SK |
951 | |
952 | # ifdef HAVE_TFTP | |
953 | while (do_tftp_script_run()); | |
954 | # endif | |
955 | ||
7622fc06 | 956 | # endif |
5aabfc78 | 957 | #endif |
7622fc06 | 958 | |
f2621c7f SK |
959 | /* must do this just before select(), when we know no |
960 | more calls to my_syslog() can occur */ | |
961 | set_log_writer(&wset, &maxfd); | |
962 | ||
5e9e0efb SK |
963 | if (select(maxfd+1, &rset, &wset, &eset, tp) < 0) |
964 | { | |
965 | /* otherwise undefined after error */ | |
966 | FD_ZERO(&rset); FD_ZERO(&wset); FD_ZERO(&eset); | |
967 | } | |
968 | ||
969 | now = dnsmasq_time(); | |
9e4abcb5 | 970 | |
f2621c7f | 971 | check_log_writer(&wset); |
115ac3e4 SK |
972 | |
973 | /* prime. */ | |
974 | enumerate_interfaces(1); | |
975 | ||
74c95c25 SK |
976 | /* Check the interfaces to see if any have exited DAD state |
977 | and if so, bind the address. */ | |
978 | if (is_dad_listeners()) | |
979 | { | |
115ac3e4 | 980 | enumerate_interfaces(0); |
74c95c25 SK |
981 | /* NB, is_dad_listeners() == 1 --> we're binding interfaces */ |
982 | create_bound_listeners(0); | |
dc27e148 | 983 | warn_bound_listeners(); |
74c95c25 | 984 | } |
f2621c7f | 985 | |
1ee9be4c | 986 | #if defined(HAVE_LINUX_NETWORK) |
c52e1897 | 987 | if (FD_ISSET(daemon->netlinkfd, &rset)) |
a0358e5d | 988 | netlink_multicast(); |
1ee9be4c SK |
989 | #elif defined(HAVE_BSD_NETWORK) |
990 | if (FD_ISSET(daemon->routefd, &rset)) | |
a0358e5d | 991 | route_sock(); |
c52e1897 SK |
992 | #endif |
993 | ||
0491805d | 994 | #ifdef HAVE_INOTIFY |
5f4dc5c6 SK |
995 | if (daemon->inotifyfd != -1 && FD_ISSET(daemon->inotifyfd, &rset) && inotify_check(now)) |
996 | { | |
997 | if (daemon->port != 0 && !option_bool(OPT_NO_POLL)) | |
998 | poll_resolv(1, 1, now); | |
999 | } | |
193de4ab | 1000 | #else |
9e4abcb5 | 1001 | /* Check for changes to resolv files once per second max. */ |
3d8df260 | 1002 | /* Don't go silent for long periods if the clock goes backwards. */ |
9009d746 SK |
1003 | if (daemon->last_resolv == 0 || |
1004 | difftime(now, daemon->last_resolv) > 1.0 || | |
1005 | difftime(now, daemon->last_resolv) < -1.0) | |
9e4abcb5 | 1006 | { |
8ef5ada2 SK |
1007 | /* poll_resolv doesn't need to reload first time through, since |
1008 | that's queued anyway. */ | |
33820b7e | 1009 | |
8ef5ada2 SK |
1010 | poll_resolv(0, daemon->last_resolv != 0, now); |
1011 | daemon->last_resolv = now; | |
9e4abcb5 | 1012 | } |
193de4ab SK |
1013 | #endif |
1014 | ||
5e9e0efb | 1015 | if (FD_ISSET(piperead, &rset)) |
5aabfc78 | 1016 | async_event(piperead, now); |
7cebd20f | 1017 | |
3d8df260 SK |
1018 | #ifdef HAVE_DBUS |
1019 | /* if we didn't create a DBus connection, retry now. */ | |
28866e95 | 1020 | if (option_bool(OPT_DBUS) && !daemon->dbus) |
3d8df260 SK |
1021 | { |
1022 | char *err; | |
5aabfc78 | 1023 | if ((err = dbus_init())) |
f2621c7f | 1024 | my_syslog(LOG_WARNING, _("DBus error: %s"), err); |
3d8df260 | 1025 | if (daemon->dbus) |
f2621c7f | 1026 | my_syslog(LOG_INFO, _("connected to system DBus")); |
3d8df260 | 1027 | } |
5aabfc78 | 1028 | check_dbus_listeners(&rset, &wset, &eset); |
3d8df260 | 1029 | #endif |
824af85b | 1030 | |
5aabfc78 | 1031 | check_dns_listeners(&rset, now); |
832af0ba SK |
1032 | |
1033 | #ifdef HAVE_TFTP | |
5aabfc78 | 1034 | check_tftp_listeners(&rset, now); |
832af0ba SK |
1035 | #endif |
1036 | ||
7622fc06 | 1037 | #ifdef HAVE_DHCP |
ff7eea27 | 1038 | if (daemon->dhcp || daemon->relay4) |
316e2730 SK |
1039 | { |
1040 | if (FD_ISSET(daemon->dhcpfd, &rset)) | |
1041 | dhcp_packet(now, 0); | |
1042 | if (daemon->pxefd != -1 && FD_ISSET(daemon->pxefd, &rset)) | |
1043 | dhcp_packet(now, 1); | |
1044 | } | |
1697269c | 1045 | |
52b92f4d | 1046 | #ifdef HAVE_DHCP6 |
ff7eea27 | 1047 | if ((daemon->doing_dhcp6 || daemon->relay6) && FD_ISSET(daemon->dhcp6fd, &rset)) |
18c63eff | 1048 | dhcp6_packet(now); |
c5ad4e79 | 1049 | |
1f776932 SK |
1050 | if (daemon->doing_ra && FD_ISSET(daemon->icmp6fd, &rset)) |
1051 | icmp6_packet(now); | |
52b92f4d SK |
1052 | #endif |
1053 | ||
1f15b81d | 1054 | # ifdef HAVE_SCRIPT |
1697269c | 1055 | if (daemon->helperfd != -1 && FD_ISSET(daemon->helperfd, &wset)) |
5aabfc78 | 1056 | helper_write(); |
7622fc06 | 1057 | # endif |
5aabfc78 SK |
1058 | #endif |
1059 | ||
9e4abcb5 | 1060 | } |
9e4abcb5 SK |
1061 | } |
1062 | ||
3be34541 SK |
1063 | static void sig_handler(int sig) |
1064 | { | |
5e9e0efb | 1065 | if (pid == 0) |
3be34541 | 1066 | { |
1697269c SK |
1067 | /* ignore anything other than TERM during startup |
1068 | and in helper proc. (helper ignore TERM too) */ | |
5e9e0efb | 1069 | if (sig == SIGTERM) |
5aabfc78 | 1070 | exit(EC_MISC); |
3be34541 | 1071 | } |
5aabfc78 | 1072 | else if (pid != getpid()) |
5e9e0efb | 1073 | { |
1697269c | 1074 | /* alarm is used to kill TCP children after a fixed time. */ |
5e9e0efb | 1075 | if (sig == SIGALRM) |
7cebd20f | 1076 | _exit(0); |
3be34541 | 1077 | } |
5aabfc78 SK |
1078 | else |
1079 | { | |
1080 | /* master process */ | |
1081 | int event, errsave = errno; | |
1082 | ||
1083 | if (sig == SIGHUP) | |
1084 | event = EVENT_RELOAD; | |
1085 | else if (sig == SIGCHLD) | |
1086 | event = EVENT_CHILD; | |
1087 | else if (sig == SIGALRM) | |
1088 | event = EVENT_ALARM; | |
1089 | else if (sig == SIGTERM) | |
1090 | event = EVENT_TERM; | |
1091 | else if (sig == SIGUSR1) | |
1092 | event = EVENT_DUMP; | |
1093 | else if (sig == SIGUSR2) | |
1094 | event = EVENT_REOPEN; | |
1095 | else | |
1096 | return; | |
1097 | ||
c72daea8 | 1098 | send_event(pipewrite, event, 0, NULL); |
5aabfc78 SK |
1099 | errno = errsave; |
1100 | } | |
1101 | } | |
1102 | ||
353ae4d2 SK |
1103 | /* now == 0 -> queue immediate callback */ |
1104 | void send_alarm(time_t event, time_t now) | |
741c2952 | 1105 | { |
884a6dfe | 1106 | if (now == 0 || event != 0) |
353ae4d2 | 1107 | { |
884a6dfe SK |
1108 | /* alarm(0) or alarm(-ve) doesn't do what we want.... */ |
1109 | if ((now == 0 || difftime(event, now) <= 0.0)) | |
1110 | send_event(pipewrite, EVENT_ALARM, 0, NULL); | |
1111 | else | |
1112 | alarm((unsigned)difftime(event, now)); | |
353ae4d2 | 1113 | } |
741c2952 SK |
1114 | } |
1115 | ||
47a95169 | 1116 | void queue_event(int event) |
a0358e5d | 1117 | { |
47a95169 | 1118 | send_event(pipewrite, event, 0, NULL); |
a0358e5d SK |
1119 | } |
1120 | ||
c72daea8 | 1121 | void send_event(int fd, int event, int data, char *msg) |
5aabfc78 SK |
1122 | { |
1123 | struct event_desc ev; | |
c72daea8 SK |
1124 | struct iovec iov[2]; |
1125 | ||
5aabfc78 SK |
1126 | ev.event = event; |
1127 | ev.data = data; | |
c72daea8 SK |
1128 | ev.msg_sz = msg ? strlen(msg) : 0; |
1129 | ||
1130 | iov[0].iov_base = &ev; | |
1131 | iov[0].iov_len = sizeof(ev); | |
1132 | iov[1].iov_base = msg; | |
1133 | iov[1].iov_len = ev.msg_sz; | |
1a6bca81 SK |
1134 | |
1135 | /* error pipe, debug mode. */ | |
1136 | if (fd == -1) | |
c72daea8 | 1137 | fatal_event(&ev, msg); |
1a6bca81 SK |
1138 | else |
1139 | /* pipe is non-blocking and struct event_desc is smaller than | |
1140 | PIPE_BUF, so this either fails or writes everything */ | |
c72daea8 | 1141 | while (writev(fd, iov, msg ? 2 : 1) == -1 && errno == EINTR); |
5aabfc78 SK |
1142 | } |
1143 | ||
c72daea8 SK |
1144 | /* NOTE: the memory used to return msg is leaked: use msgs in events only |
1145 | to describe fatal errors. */ | |
1146 | static int read_event(int fd, struct event_desc *evp, char **msg) | |
1147 | { | |
1148 | char *buf; | |
1149 | ||
1150 | if (!read_write(fd, (unsigned char *)evp, sizeof(struct event_desc), 1)) | |
1151 | return 0; | |
1152 | ||
1153 | *msg = NULL; | |
1154 | ||
1155 | if (evp->msg_sz != 0 && | |
1156 | (buf = malloc(evp->msg_sz + 1)) && | |
1157 | read_write(fd, (unsigned char *)buf, evp->msg_sz, 1)) | |
1158 | { | |
1159 | buf[evp->msg_sz] = 0; | |
1160 | *msg = buf; | |
1161 | } | |
1162 | ||
1163 | return 1; | |
1164 | } | |
1165 | ||
1166 | static void fatal_event(struct event_desc *ev, char *msg) | |
1a6bca81 SK |
1167 | { |
1168 | errno = ev->data; | |
1169 | ||
1170 | switch (ev->event) | |
1171 | { | |
1172 | case EVENT_DIE: | |
1173 | exit(0); | |
7622fc06 SK |
1174 | |
1175 | case EVENT_FORK_ERR: | |
1176 | die(_("cannot fork into background: %s"), NULL, EC_MISC); | |
1a6bca81 SK |
1177 | |
1178 | case EVENT_PIPE_ERR: | |
1179 | die(_("failed to create helper: %s"), NULL, EC_MISC); | |
1180 | ||
1181 | case EVENT_CAP_ERR: | |
1182 | die(_("setting capabilities failed: %s"), NULL, EC_MISC); | |
1183 | ||
1184 | case EVENT_USER_ERR: | |
c72daea8 | 1185 | die(_("failed to change user-id to %s: %s"), msg, EC_MISC); |
1a6bca81 SK |
1186 | |
1187 | case EVENT_GROUP_ERR: | |
c72daea8 | 1188 | die(_("failed to change group-id to %s: %s"), msg, EC_MISC); |
1a6bca81 SK |
1189 | |
1190 | case EVENT_PIDFILE: | |
c72daea8 | 1191 | die(_("failed to open pidfile %s: %s"), msg, EC_FILE); |
1a6bca81 SK |
1192 | |
1193 | case EVENT_LOG_ERR: | |
c72daea8 SK |
1194 | die(_("cannot open log %s: %s"), msg, EC_FILE); |
1195 | ||
1196 | case EVENT_LUA_ERR: | |
1197 | die(_("failed to load Lua script: %s"), msg, EC_MISC); | |
8b3ae2fd SK |
1198 | |
1199 | case EVENT_TFTP_ERR: | |
1200 | die(_("TFTP directory %s inaccessible: %s"), msg, EC_FILE); | |
360f2513 SK |
1201 | |
1202 | case EVENT_TIME_ERR: | |
1203 | die(_("cannot create timestamp file %s: %s" ), msg, EC_BADCONF); | |
1a6bca81 SK |
1204 | } |
1205 | } | |
1206 | ||
5aabfc78 SK |
1207 | static void async_event(int pipe, time_t now) |
1208 | { | |
1209 | pid_t p; | |
1210 | struct event_desc ev; | |
7b1eae4f | 1211 | int i, check = 0; |
c72daea8 SK |
1212 | char *msg; |
1213 | ||
1214 | /* NOTE: the memory used to return msg is leaked: use msgs in events only | |
1215 | to describe fatal errors. */ | |
1216 | ||
1217 | if (read_event(pipe, &ev, &msg)) | |
5aabfc78 SK |
1218 | switch (ev.event) |
1219 | { | |
1220 | case EVENT_RELOAD: | |
e98bd52e SK |
1221 | #ifdef HAVE_DNSSEC |
1222 | if (option_bool(OPT_DNSSEC_VALID) && option_bool(OPT_DNSSEC_TIME)) | |
1223 | { | |
1224 | my_syslog(LOG_INFO, _("now checking DNSSEC signature timestamps")); | |
1225 | reset_option_bool(OPT_DNSSEC_TIME); | |
1226 | } | |
1227 | #endif | |
1228 | /* fall through */ | |
1229 | ||
1230 | case EVENT_INIT: | |
5aabfc78 | 1231 | clear_cache_and_reload(now); |
e98bd52e | 1232 | |
7b1eae4f | 1233 | if (daemon->port != 0) |
5aabfc78 | 1234 | { |
7b1eae4f SK |
1235 | if (daemon->resolv_files && option_bool(OPT_NO_POLL)) |
1236 | { | |
1237 | reload_servers(daemon->resolv_files->name); | |
1238 | check = 1; | |
1239 | } | |
1240 | ||
1241 | if (daemon->servers_file) | |
1242 | { | |
1243 | read_servers_file(); | |
1244 | check = 1; | |
1245 | } | |
1246 | ||
1247 | if (check) | |
1248 | check_servers(); | |
5aabfc78 | 1249 | } |
7b1eae4f | 1250 | |
7622fc06 | 1251 | #ifdef HAVE_DHCP |
5aabfc78 | 1252 | rerun_scripts(); |
7622fc06 | 1253 | #endif |
5aabfc78 SK |
1254 | break; |
1255 | ||
1256 | case EVENT_DUMP: | |
824af85b SK |
1257 | if (daemon->port != 0) |
1258 | dump_cache(now); | |
5aabfc78 SK |
1259 | break; |
1260 | ||
1261 | case EVENT_ALARM: | |
7622fc06 | 1262 | #ifdef HAVE_DHCP |
1f776932 | 1263 | if (daemon->dhcp || daemon->doing_dhcp6) |
5aabfc78 SK |
1264 | { |
1265 | lease_prune(NULL, now); | |
1266 | lease_update_file(now); | |
1267 | } | |
843c96b4 | 1268 | #ifdef HAVE_DHCP6 |
1f776932 | 1269 | else if (daemon->doing_ra) |
353ae4d2 SK |
1270 | /* Not doing DHCP, so no lease system, manage alarms for ra only */ |
1271 | send_alarm(periodic_ra(now), now); | |
843c96b4 | 1272 | #endif |
7622fc06 | 1273 | #endif |
5aabfc78 SK |
1274 | break; |
1275 | ||
1276 | case EVENT_CHILD: | |
1277 | /* See Stevens 5.10 */ | |
1278 | while ((p = waitpid(-1, NULL, WNOHANG)) != 0) | |
1279 | if (p == -1) | |
1280 | { | |
1281 | if (errno != EINTR) | |
1282 | break; | |
1283 | } | |
1284 | else | |
1285 | for (i = 0 ; i < MAX_PROCS; i++) | |
1286 | if (daemon->tcp_pids[i] == p) | |
1287 | daemon->tcp_pids[i] = 0; | |
1288 | break; | |
1289 | ||
1290 | case EVENT_KILLED: | |
c72daea8 | 1291 | my_syslog(LOG_WARNING, _("script process killed by signal %d"), ev.data); |
5aabfc78 SK |
1292 | break; |
1293 | ||
1294 | case EVENT_EXITED: | |
c72daea8 | 1295 | my_syslog(LOG_WARNING, _("script process exited with status %d"), ev.data); |
5aabfc78 SK |
1296 | break; |
1297 | ||
1298 | case EVENT_EXEC_ERR: | |
9e038946 SK |
1299 | my_syslog(LOG_ERR, _("failed to execute %s: %s"), |
1300 | daemon->lease_change_command, strerror(ev.data)); | |
5aabfc78 SK |
1301 | break; |
1302 | ||
1a6bca81 | 1303 | /* necessary for fatal errors in helper */ |
c72daea8 | 1304 | case EVENT_USER_ERR: |
1a6bca81 | 1305 | case EVENT_DIE: |
c72daea8 SK |
1306 | case EVENT_LUA_ERR: |
1307 | fatal_event(&ev, msg); | |
9e038946 SK |
1308 | break; |
1309 | ||
5aabfc78 SK |
1310 | case EVENT_REOPEN: |
1311 | /* Note: this may leave TCP-handling processes with the old file still open. | |
1312 | Since any such process will die in CHILD_LIFETIME or probably much sooner, | |
1313 | we leave them logging to the old file. */ | |
1314 | if (daemon->log_file != NULL) | |
1315 | log_reopen(daemon->log_file); | |
1316 | break; | |
a0358e5d SK |
1317 | |
1318 | case EVENT_NEWADDR: | |
1319 | newaddress(now); | |
1320 | break; | |
47a95169 SK |
1321 | |
1322 | case EVENT_NEWROUTE: | |
1323 | resend_query(); | |
1324 | /* Force re-reading resolv file right now, for luck. */ | |
1325 | poll_resolv(0, 1, now); | |
1326 | break; | |
1327 | ||
5aabfc78 SK |
1328 | case EVENT_TERM: |
1329 | /* Knock all our children on the head. */ | |
1330 | for (i = 0; i < MAX_PROCS; i++) | |
1331 | if (daemon->tcp_pids[i] != 0) | |
1332 | kill(daemon->tcp_pids[i], SIGALRM); | |
1333 | ||
c72daea8 | 1334 | #if defined(HAVE_SCRIPT) |
5aabfc78 SK |
1335 | /* handle pending lease transitions */ |
1336 | if (daemon->helperfd != -1) | |
1337 | { | |
1338 | /* block in writes until all done */ | |
1339 | if ((i = fcntl(daemon->helperfd, F_GETFL)) != -1) | |
1340 | fcntl(daemon->helperfd, F_SETFL, i & ~O_NONBLOCK); | |
1341 | do { | |
1342 | helper_write(); | |
1343 | } while (!helper_buf_empty() || do_script_run(now)); | |
ff841ebf | 1344 | while (retry_send(close(daemon->helperfd))); |
5aabfc78 SK |
1345 | } |
1346 | #endif | |
1347 | ||
1348 | if (daemon->lease_stream) | |
1349 | fclose(daemon->lease_stream); | |
73a08a24 SK |
1350 | |
1351 | if (daemon->runfile) | |
1352 | unlink(daemon->runfile); | |
5aabfc78 SK |
1353 | |
1354 | my_syslog(LOG_INFO, _("exiting on receipt of SIGTERM")); | |
1355 | flush_log(); | |
1356 | exit(EC_GOOD); | |
1357 | } | |
3be34541 SK |
1358 | } |
1359 | ||
47a95169 | 1360 | static void poll_resolv(int force, int do_reload, time_t now) |
5aabfc78 SK |
1361 | { |
1362 | struct resolvc *res, *latest; | |
1363 | struct stat statbuf; | |
1364 | time_t last_change = 0; | |
1365 | /* There may be more than one possible file. | |
1366 | Go through and find the one which changed _last_. | |
1367 | Warn of any which can't be read. */ | |
8ef5ada2 | 1368 | |
28866e95 | 1369 | if (daemon->port == 0 || option_bool(OPT_NO_POLL)) |
8ef5ada2 SK |
1370 | return; |
1371 | ||
5aabfc78 SK |
1372 | for (latest = NULL, res = daemon->resolv_files; res; res = res->next) |
1373 | if (stat(res->name, &statbuf) == -1) | |
1374 | { | |
8ef5ada2 SK |
1375 | if (force) |
1376 | { | |
1377 | res->mtime = 0; | |
1378 | continue; | |
1379 | } | |
1380 | ||
5aabfc78 SK |
1381 | if (!res->logged) |
1382 | my_syslog(LOG_WARNING, _("failed to access %s: %s"), res->name, strerror(errno)); | |
1383 | res->logged = 1; | |
8ef5ada2 SK |
1384 | |
1385 | if (res->mtime != 0) | |
1386 | { | |
1387 | /* existing file evaporated, force selection of the latest | |
1388 | file even if its mtime hasn't changed since we last looked */ | |
1389 | poll_resolv(1, do_reload, now); | |
1390 | return; | |
1391 | } | |
5aabfc78 SK |
1392 | } |
1393 | else | |
1394 | { | |
1395 | res->logged = 0; | |
8ef5ada2 SK |
1396 | if (force || (statbuf.st_mtime != res->mtime)) |
1397 | { | |
1398 | res->mtime = statbuf.st_mtime; | |
5aabfc78 SK |
1399 | if (difftime(statbuf.st_mtime, last_change) > 0.0) |
1400 | { | |
1401 | last_change = statbuf.st_mtime; | |
1402 | latest = res; | |
1403 | } | |
1404 | } | |
1405 | } | |
1406 | ||
1407 | if (latest) | |
1408 | { | |
1409 | static int warned = 0; | |
1410 | if (reload_servers(latest->name)) | |
1411 | { | |
1412 | my_syslog(LOG_INFO, _("reading %s"), latest->name); | |
1413 | warned = 0; | |
1414 | check_servers(); | |
28866e95 | 1415 | if (option_bool(OPT_RELOAD) && do_reload) |
8ef5ada2 | 1416 | clear_cache_and_reload(now); |
5aabfc78 SK |
1417 | } |
1418 | else | |
1419 | { | |
1420 | latest->mtime = 0; | |
1421 | if (!warned) | |
1422 | { | |
1423 | my_syslog(LOG_WARNING, _("no servers found in %s, will retry"), latest->name); | |
1424 | warned = 1; | |
1425 | } | |
1426 | } | |
1427 | } | |
1428 | } | |
3d8df260 | 1429 | |
5aabfc78 | 1430 | void clear_cache_and_reload(time_t now) |
3d8df260 | 1431 | { |
408c368f VG |
1432 | (void)now; |
1433 | ||
824af85b | 1434 | if (daemon->port != 0) |
7622fc06 | 1435 | cache_reload(); |
824af85b | 1436 | |
7622fc06 | 1437 | #ifdef HAVE_DHCP |
1f776932 | 1438 | if (daemon->dhcp || daemon->doing_dhcp6) |
3d8df260 | 1439 | { |
28866e95 | 1440 | if (option_bool(OPT_ETHERS)) |
5aabfc78 | 1441 | dhcp_read_ethers(); |
824af85b | 1442 | reread_dhcp(); |
0491805d | 1443 | #ifdef HAVE_INOTIFY |
70d1873d | 1444 | set_dynamic_inotify(AH_DHCP_HST | AH_DHCP_OPT, 0, NULL, 0); |
5f4dc5c6 | 1445 | #endif |
3d8df260 | 1446 | dhcp_update_configs(daemon->dhcp_conf); |
5aabfc78 SK |
1447 | lease_update_from_configs(); |
1448 | lease_update_file(now); | |
353ae4d2 | 1449 | lease_update_dns(1); |
3d8df260 | 1450 | } |
843c96b4 | 1451 | #ifdef HAVE_DHCP6 |
1f776932 | 1452 | else if (daemon->doing_ra) |
2021c662 SK |
1453 | /* Not doing DHCP, so no lease system, manage |
1454 | alarms for ra only */ | |
1455 | send_alarm(periodic_ra(now), now); | |
843c96b4 | 1456 | #endif |
7622fc06 | 1457 | #endif |
3d8df260 SK |
1458 | } |
1459 | ||
5aabfc78 | 1460 | static int set_dns_listeners(time_t now, fd_set *set, int *maxfdp) |
3be34541 SK |
1461 | { |
1462 | struct serverfd *serverfdp; | |
1463 | struct listener *listener; | |
824af85b | 1464 | int wait = 0, i; |
832af0ba SK |
1465 | |
1466 | #ifdef HAVE_TFTP | |
1467 | int tftp = 0; | |
1468 | struct tftp_transfer *transfer; | |
1469 | for (transfer = daemon->tftp_trans; transfer; transfer = transfer->next) | |
1470 | { | |
1471 | tftp++; | |
1472 | FD_SET(transfer->sockfd, set); | |
1473 | bump_maxfd(transfer->sockfd, maxfdp); | |
1474 | } | |
1475 | #endif | |
1476 | ||
1697269c | 1477 | /* will we be able to get memory? */ |
824af85b | 1478 | if (daemon->port != 0) |
3a237152 | 1479 | get_new_frec(now, &wait, 0); |
1697269c | 1480 | |
3be34541 SK |
1481 | for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next) |
1482 | { | |
1483 | FD_SET(serverfdp->fd, set); | |
1697269c | 1484 | bump_maxfd(serverfdp->fd, maxfdp); |
3be34541 | 1485 | } |
1a6bca81 SK |
1486 | |
1487 | if (daemon->port != 0 && !daemon->osport) | |
1488 | for (i = 0; i < RANDOM_SOCKS; i++) | |
1489 | if (daemon->randomsocks[i].refcount != 0) | |
1490 | { | |
1491 | FD_SET(daemon->randomsocks[i].fd, set); | |
1492 | bump_maxfd(daemon->randomsocks[i].fd, maxfdp); | |
1493 | } | |
1494 | ||
3be34541 SK |
1495 | for (listener = daemon->listeners; listener; listener = listener->next) |
1496 | { | |
1697269c | 1497 | /* only listen for queries if we have resources */ |
824af85b | 1498 | if (listener->fd != -1 && wait == 0) |
1697269c SK |
1499 | { |
1500 | FD_SET(listener->fd, set); | |
1501 | bump_maxfd(listener->fd, maxfdp); | |
1502 | } | |
1503 | ||
1504 | /* death of a child goes through the select loop, so | |
1505 | we don't need to explicitly arrange to wake up here */ | |
824af85b SK |
1506 | if (listener->tcpfd != -1) |
1507 | for (i = 0; i < MAX_PROCS; i++) | |
1508 | if (daemon->tcp_pids[i] == 0) | |
1509 | { | |
1510 | FD_SET(listener->tcpfd, set); | |
1511 | bump_maxfd(listener->tcpfd, maxfdp); | |
1512 | break; | |
1513 | } | |
9e4abcb5 | 1514 | |
832af0ba SK |
1515 | #ifdef HAVE_TFTP |
1516 | if (tftp <= daemon->tftp_max && listener->tftpfd != -1) | |
1517 | { | |
1518 | FD_SET(listener->tftpfd, set); | |
1519 | bump_maxfd(listener->tftpfd, maxfdp); | |
1520 | } | |
1521 | #endif | |
1522 | ||
1523 | } | |
1524 | ||
1697269c | 1525 | return wait; |
3be34541 | 1526 | } |
9e4abcb5 | 1527 | |
5aabfc78 | 1528 | static void check_dns_listeners(fd_set *set, time_t now) |
3be34541 SK |
1529 | { |
1530 | struct serverfd *serverfdp; | |
1a6bca81 SK |
1531 | struct listener *listener; |
1532 | int i; | |
1533 | ||
832af0ba SK |
1534 | for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next) |
1535 | if (FD_ISSET(serverfdp->fd, set)) | |
1a6bca81 SK |
1536 | reply_query(serverfdp->fd, serverfdp->source_addr.sa.sa_family, now); |
1537 | ||
1538 | if (daemon->port != 0 && !daemon->osport) | |
1539 | for (i = 0; i < RANDOM_SOCKS; i++) | |
1540 | if (daemon->randomsocks[i].refcount != 0 && | |
1541 | FD_ISSET(daemon->randomsocks[i].fd, set)) | |
1542 | reply_query(daemon->randomsocks[i].fd, daemon->randomsocks[i].family, now); | |
832af0ba SK |
1543 | |
1544 | for (listener = daemon->listeners; listener; listener = listener->next) | |
1545 | { | |
824af85b | 1546 | if (listener->fd != -1 && FD_ISSET(listener->fd, set)) |
5aabfc78 | 1547 | receive_query(listener, now); |
1a6bca81 | 1548 | |
832af0ba SK |
1549 | #ifdef HAVE_TFTP |
1550 | if (listener->tftpfd != -1 && FD_ISSET(listener->tftpfd, set)) | |
5aabfc78 | 1551 | tftp_request(listener, now); |
832af0ba | 1552 | #endif |
3be34541 | 1553 | |
824af85b | 1554 | if (listener->tcpfd != -1 && FD_ISSET(listener->tcpfd, set)) |
832af0ba | 1555 | { |
22ce550e | 1556 | int confd, client_ok = 1; |
832af0ba SK |
1557 | struct irec *iface = NULL; |
1558 | pid_t p; | |
52d4abf2 SK |
1559 | union mysockaddr tcp_addr; |
1560 | socklen_t tcp_len = sizeof(union mysockaddr); | |
1561 | ||
1562 | while ((confd = accept(listener->tcpfd, NULL, NULL)) == -1 && errno == EINTR); | |
832af0ba | 1563 | |
46b06656 | 1564 | if (confd == -1) |
832af0ba | 1565 | continue; |
76dd75de | 1566 | |
46b06656 SK |
1567 | if (getsockname(confd, (struct sockaddr *)&tcp_addr, &tcp_len) == -1) |
1568 | { | |
ff841ebf | 1569 | while (retry_send(close(confd))); |
46b06656 SK |
1570 | continue; |
1571 | } | |
76dd75de SK |
1572 | |
1573 | /* Make sure that the interface list is up-to-date. | |
1574 | ||
1575 | We do this here as we may need the results below, and | |
1576 | the DNS code needs them for --interface-name stuff. | |
1577 | ||
1578 | Multiple calls to enumerate_interfaces() per select loop are | |
1579 | inhibited, so calls to it in the child process (which doesn't select()) | |
1580 | have no effect. This avoids two processes reading from the same | |
1581 | netlink fd and screwing the pooch entirely. | |
1582 | */ | |
e25db1f2 | 1583 | |
76dd75de SK |
1584 | enumerate_interfaces(0); |
1585 | ||
1586 | if (option_bool(OPT_NOWILD)) | |
1587 | iface = listener->iface; /* May be NULL */ | |
1588 | else | |
1589 | { | |
1590 | int if_index; | |
1591 | char intr_name[IF_NAMESIZE]; | |
1592 | ||
1593 | /* if we can find the arrival interface, check it's one that's allowed */ | |
1594 | if ((if_index = tcp_interface(confd, tcp_addr.sa.sa_family)) != 0 && | |
1595 | indextoname(listener->tcpfd, if_index, intr_name)) | |
1596 | { | |
1597 | struct all_addr addr; | |
1598 | addr.addr.addr4 = tcp_addr.in.sin_addr; | |
e25db1f2 | 1599 | #ifdef HAVE_IPV6 |
76dd75de SK |
1600 | if (tcp_addr.sa.sa_family == AF_INET6) |
1601 | addr.addr.addr6 = tcp_addr.in6.sin6_addr; | |
e25db1f2 | 1602 | #endif |
76dd75de SK |
1603 | |
1604 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1605 | if (iface->index == if_index) | |
1606 | break; | |
1607 | ||
1608 | if (!iface && !loopback_exception(listener->tcpfd, tcp_addr.sa.sa_family, &addr, intr_name)) | |
1609 | client_ok = 0; | |
1610 | } | |
1611 | ||
1612 | if (option_bool(OPT_CLEVERBIND)) | |
1613 | iface = listener->iface; /* May be NULL */ | |
1614 | else | |
1615 | { | |
1616 | /* Check for allowed interfaces when binding the wildcard address: | |
1617 | we do this by looking for an interface with the same address as | |
1618 | the local address of the TCP connection, then looking to see if that's | |
1619 | an allowed interface. As a side effect, we get the netmask of the | |
1620 | interface too, for localisation. */ | |
1621 | ||
1622 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1623 | if (sockaddr_isequal(&iface->addr, &tcp_addr)) | |
1624 | break; | |
1625 | ||
1626 | if (!iface) | |
1627 | client_ok = 0; | |
1628 | } | |
1629 | } | |
1630 | ||
22ce550e | 1631 | if (!client_ok) |
832af0ba SK |
1632 | { |
1633 | shutdown(confd, SHUT_RDWR); | |
ff841ebf | 1634 | while (retry_send(close(confd))); |
832af0ba | 1635 | } |
59353a6b | 1636 | #ifndef NO_FORK |
28866e95 | 1637 | else if (!option_bool(OPT_DEBUG) && (p = fork()) != 0) |
832af0ba SK |
1638 | { |
1639 | if (p != -1) | |
1640 | { | |
1641 | int i; | |
1642 | for (i = 0; i < MAX_PROCS; i++) | |
1643 | if (daemon->tcp_pids[i] == 0) | |
1644 | { | |
1645 | daemon->tcp_pids[i] = p; | |
1646 | break; | |
1647 | } | |
1648 | } | |
ff841ebf | 1649 | while (retry_send(close(confd))); |
25cf5e37 SK |
1650 | |
1651 | /* The child can use up to TCP_MAX_QUERIES ids, so skip that many. */ | |
1652 | daemon->log_id += TCP_MAX_QUERIES; | |
832af0ba SK |
1653 | } |
1654 | #endif | |
1655 | else | |
1656 | { | |
1657 | unsigned char *buff; | |
1658 | struct server *s; | |
1659 | int flags; | |
52d4abf2 | 1660 | struct in_addr netmask; |
4f7b304f | 1661 | int auth_dns; |
52d4abf2 SK |
1662 | |
1663 | if (iface) | |
4f7b304f SK |
1664 | { |
1665 | netmask = iface->netmask; | |
1666 | auth_dns = iface->dns_auth; | |
1667 | } | |
52d4abf2 | 1668 | else |
4f7b304f SK |
1669 | { |
1670 | netmask.s_addr = 0; | |
1671 | auth_dns = 0; | |
1672 | } | |
52d4abf2 | 1673 | |
8ef5ada2 SK |
1674 | #ifndef NO_FORK |
1675 | /* Arrange for SIGALARM after CHILD_LIFETIME seconds to | |
1676 | terminate the process. */ | |
28866e95 | 1677 | if (!option_bool(OPT_DEBUG)) |
832af0ba | 1678 | alarm(CHILD_LIFETIME); |
8ef5ada2 SK |
1679 | #endif |
1680 | ||
832af0ba SK |
1681 | /* start with no upstream connections. */ |
1682 | for (s = daemon->servers; s; s = s->next) | |
7cebd20f | 1683 | s->tcpfd = -1; |
832af0ba SK |
1684 | |
1685 | /* The connected socket inherits non-blocking | |
1686 | attribute from the listening socket. | |
1687 | Reset that here. */ | |
1688 | if ((flags = fcntl(confd, F_GETFL, 0)) != -1) | |
1689 | fcntl(confd, F_SETFL, flags & ~O_NONBLOCK); | |
1690 | ||
4f7b304f | 1691 | buff = tcp_request(confd, now, &tcp_addr, netmask, auth_dns); |
7cebd20f | 1692 | |
832af0ba | 1693 | shutdown(confd, SHUT_RDWR); |
ff841ebf | 1694 | while (retry_send(close(confd))); |
832af0ba SK |
1695 | |
1696 | if (buff) | |
1697 | free(buff); | |
1698 | ||
1699 | for (s = daemon->servers; s; s = s->next) | |
1700 | if (s->tcpfd != -1) | |
1701 | { | |
1702 | shutdown(s->tcpfd, SHUT_RDWR); | |
ff841ebf | 1703 | while (retry_send(close(s->tcpfd))); |
832af0ba | 1704 | } |
7cebd20f | 1705 | #ifndef NO_FORK |
28866e95 | 1706 | if (!option_bool(OPT_DEBUG)) |
5aabfc78 SK |
1707 | { |
1708 | flush_log(); | |
1709 | _exit(0); | |
1710 | } | |
59353a6b | 1711 | #endif |
832af0ba SK |
1712 | } |
1713 | } | |
1714 | } | |
3be34541 SK |
1715 | } |
1716 | ||
7622fc06 | 1717 | #ifdef HAVE_DHCP |
5e9e0efb SK |
1718 | int make_icmp_sock(void) |
1719 | { | |
7cebd20f | 1720 | int fd; |
5e9e0efb SK |
1721 | int zeroopt = 0; |
1722 | ||
1723 | if ((fd = socket (AF_INET, SOCK_RAW, IPPROTO_ICMP)) != -1) | |
1724 | { | |
7cebd20f | 1725 | if (!fix_fd(fd) || |
5e9e0efb SK |
1726 | setsockopt(fd, SOL_SOCKET, SO_DONTROUTE, &zeroopt, sizeof(zeroopt)) == -1) |
1727 | { | |
1728 | close(fd); | |
1729 | fd = -1; | |
1730 | } | |
1731 | } | |
1732 | ||
1733 | return fd; | |
1734 | } | |
1735 | ||
5aabfc78 | 1736 | int icmp_ping(struct in_addr addr) |
3be34541 | 1737 | { |
5e9e0efb | 1738 | /* Try and get an ICMP echo from a machine. */ |
3be34541 SK |
1739 | |
1740 | /* Note that whilst in the three second wait, we check for | |
832af0ba | 1741 | (and service) events on the DNS and TFTP sockets, (so doing that |
3be34541 SK |
1742 | better not use any resources our caller has in use...) |
1743 | but we remain deaf to signals or further DHCP packets. */ | |
1744 | ||
5e9e0efb | 1745 | int fd; |
3be34541 SK |
1746 | struct sockaddr_in saddr; |
1747 | struct { | |
1748 | struct ip ip; | |
1749 | struct icmp icmp; | |
1750 | } packet; | |
1751 | unsigned short id = rand16(); | |
1752 | unsigned int i, j; | |
5e9e0efb | 1753 | int gotreply = 0; |
3be34541 | 1754 | time_t start, now; |
5e9e0efb | 1755 | |
824af85b | 1756 | #if defined(HAVE_LINUX_NETWORK) || defined (HAVE_SOLARIS_NETWORK) |
5e9e0efb SK |
1757 | if ((fd = make_icmp_sock()) == -1) |
1758 | return 0; | |
1759 | #else | |
1760 | int opt = 2000; | |
1761 | fd = daemon->dhcp_icmp_fd; | |
1762 | setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)); | |
1763 | #endif | |
1764 | ||
3be34541 SK |
1765 | saddr.sin_family = AF_INET; |
1766 | saddr.sin_port = 0; | |
1767 | saddr.sin_addr = addr; | |
1768 | #ifdef HAVE_SOCKADDR_SA_LEN | |
1769 | saddr.sin_len = sizeof(struct sockaddr_in); | |
1770 | #endif | |
1771 | ||
1772 | memset(&packet.icmp, 0, sizeof(packet.icmp)); | |
1773 | packet.icmp.icmp_type = ICMP_ECHO; | |
1774 | packet.icmp.icmp_id = id; | |
1775 | for (j = 0, i = 0; i < sizeof(struct icmp) / 2; i++) | |
1776 | j += ((u16 *)&packet.icmp)[i]; | |
1777 | while (j>>16) | |
1778 | j = (j & 0xffff) + (j >> 16); | |
1779 | packet.icmp.icmp_cksum = (j == 0xffff) ? j : ~j; | |
1780 | ||
ff841ebf SK |
1781 | while (retry_send(sendto(fd, (char *)&packet.icmp, sizeof(struct icmp), 0, |
1782 | (struct sockaddr *)&saddr, sizeof(saddr)))); | |
fd9fa481 | 1783 | |
5e9e0efb SK |
1784 | for (now = start = dnsmasq_time(); |
1785 | difftime(now, start) < (float)PING_WAIT;) | |
fd9fa481 SK |
1786 | { |
1787 | struct timeval tv; | |
f2621c7f | 1788 | fd_set rset, wset; |
fd9fa481 | 1789 | struct sockaddr_in faddr; |
1697269c | 1790 | int maxfd = fd; |
3d8df260 | 1791 | socklen_t len = sizeof(faddr); |
fd9fa481 SK |
1792 | |
1793 | tv.tv_usec = 250000; | |
1794 | tv.tv_sec = 0; | |
1795 | ||
1796 | FD_ZERO(&rset); | |
f2621c7f | 1797 | FD_ZERO(&wset); |
5e9e0efb | 1798 | FD_SET(fd, &rset); |
5aabfc78 | 1799 | set_dns_listeners(now, &rset, &maxfd); |
f2621c7f | 1800 | set_log_writer(&wset, &maxfd); |
c5ad4e79 SK |
1801 | |
1802 | #ifdef HAVE_DHCP6 | |
1f776932 | 1803 | if (daemon->doing_ra) |
c5ad4e79 SK |
1804 | { |
1805 | FD_SET(daemon->icmp6fd, &rset); | |
1806 | bump_maxfd(daemon->icmp6fd, &maxfd); | |
1807 | } | |
1808 | #endif | |
1809 | ||
f2621c7f SK |
1810 | if (select(maxfd+1, &rset, &wset, NULL, &tv) < 0) |
1811 | { | |
1812 | FD_ZERO(&rset); | |
1813 | FD_ZERO(&wset); | |
1814 | } | |
1815 | ||
5e9e0efb | 1816 | now = dnsmasq_time(); |
f2621c7f SK |
1817 | |
1818 | check_log_writer(&wset); | |
5aabfc78 | 1819 | check_dns_listeners(&rset, now); |
832af0ba | 1820 | |
c5ad4e79 | 1821 | #ifdef HAVE_DHCP6 |
1f776932 SK |
1822 | if (daemon->doing_ra && FD_ISSET(daemon->icmp6fd, &rset)) |
1823 | icmp6_packet(now); | |
c5ad4e79 SK |
1824 | #endif |
1825 | ||
832af0ba | 1826 | #ifdef HAVE_TFTP |
5aabfc78 | 1827 | check_tftp_listeners(&rset, now); |
832af0ba SK |
1828 | #endif |
1829 | ||
5e9e0efb SK |
1830 | if (FD_ISSET(fd, &rset) && |
1831 | recvfrom(fd, &packet, sizeof(packet), 0, | |
fd9fa481 SK |
1832 | (struct sockaddr *)&faddr, &len) == sizeof(packet) && |
1833 | saddr.sin_addr.s_addr == faddr.sin_addr.s_addr && | |
1834 | packet.icmp.icmp_type == ICMP_ECHOREPLY && | |
1835 | packet.icmp.icmp_seq == 0 && | |
1836 | packet.icmp.icmp_id == id) | |
1837 | { | |
1838 | gotreply = 1; | |
1839 | break; | |
1840 | } | |
1841 | } | |
1842 | ||
824af85b | 1843 | #if defined(HAVE_LINUX_NETWORK) || defined(HAVE_SOLARIS_NETWORK) |
ff841ebf | 1844 | while (retry_send(close(fd))); |
5e9e0efb | 1845 | #else |
3be34541 | 1846 | opt = 1; |
5e9e0efb SK |
1847 | setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)); |
1848 | #endif | |
1849 | ||
3be34541 SK |
1850 | return gotreply; |
1851 | } | |
7622fc06 | 1852 | #endif |
0a852541 SK |
1853 | |
1854 |