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c47e3ba4 | 1 | /* dnsmasq is Copyright (c) 2000-2014 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 |
5aabfc78 | 61 | |
824af85b | 62 | #ifdef LOCALEDIR |
b8187c80 SK |
63 | setlocale(LC_ALL, ""); |
64 | bindtextdomain("dnsmasq", LOCALEDIR); | |
65 | textdomain("dnsmasq"); | |
66 | #endif | |
67 | ||
9e4abcb5 SK |
68 | sigact.sa_handler = sig_handler; |
69 | sigact.sa_flags = 0; | |
70 | sigemptyset(&sigact.sa_mask); | |
71 | sigaction(SIGUSR1, &sigact, NULL); | |
5aabfc78 | 72 | sigaction(SIGUSR2, &sigact, NULL); |
9e4abcb5 SK |
73 | sigaction(SIGHUP, &sigact, NULL); |
74 | sigaction(SIGTERM, &sigact, NULL); | |
44a2a316 | 75 | sigaction(SIGALRM, &sigact, NULL); |
feba5c1d SK |
76 | sigaction(SIGCHLD, &sigact, NULL); |
77 | ||
78 | /* ignore SIGPIPE */ | |
79 | sigact.sa_handler = SIG_IGN; | |
80 | sigaction(SIGPIPE, &sigact, NULL); | |
9e4abcb5 | 81 | |
5aabfc78 | 82 | umask(022); /* known umask, create leases and pid files as 0644 */ |
b5ea1cc2 SK |
83 | |
84 | rand_init(); /* Must precede read_opts() */ | |
85 | ||
5aabfc78 | 86 | read_opts(argc, argv, compile_opts); |
c3e0b9b6 | 87 | |
3be34541 | 88 | if (daemon->edns_pktsz < PACKETSZ) |
60b68069 SK |
89 | daemon->edns_pktsz = PACKETSZ; |
90 | #ifdef HAVE_DNSSEC | |
91 | /* Enforce min packet big enough for DNSSEC */ | |
92 | if (option_bool(OPT_DNSSEC_VALID) && daemon->edns_pktsz < EDNS_PKTSZ) | |
93 | daemon->edns_pktsz = EDNS_PKTSZ; | |
94 | #endif | |
3ddacb86 | 95 | |
0a852541 SK |
96 | daemon->packet_buff_sz = daemon->edns_pktsz > DNSMASQ_PACKETSZ ? |
97 | daemon->edns_pktsz : DNSMASQ_PACKETSZ; | |
98 | daemon->packet = safe_malloc(daemon->packet_buff_sz); | |
3ddacb86 | 99 | |
c72daea8 | 100 | daemon->addrbuff = 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 | } |
309331f5 | 148 | #endif |
2b5bae9a | 149 | |
0744ca66 SK |
150 | if (option_bool(OPT_DNSSEC_VALID)) |
151 | { | |
3ddacb86 | 152 | #ifdef HAVE_DNSSEC |
ee415867 | 153 | if (!daemon->ds) |
0744ca66 SK |
154 | die(_("No trust anchors provided for DNSSEC"), NULL, EC_BADCONF); |
155 | ||
156 | if (daemon->cachesize < CACHESIZ) | |
157 | die(_("Cannot reduce cache size from default when DNSSEC enabled"), NULL, EC_BADCONF); | |
158 | #else | |
159 | die(_("DNSSEC not available: set HAVE_DNSSEC in src/config.h"), NULL, EC_BADCONF); | |
3ddacb86 | 160 | #endif |
0744ca66 | 161 | } |
3ddacb86 | 162 | |
832af0ba | 163 | #ifndef HAVE_TFTP |
9b40cbf5 | 164 | if (option_bool(OPT_TFTP)) |
5aabfc78 | 165 | die(_("TFTP server not available: set HAVE_TFTP in src/config.h"), NULL, EC_BADCONF); |
832af0ba SK |
166 | #endif |
167 | ||
7de060b0 SK |
168 | #ifdef HAVE_CONNTRACK |
169 | if (option_bool(OPT_CONNTRACK) && (daemon->query_port != 0 || daemon->osport)) | |
170 | die (_("Cannot use --conntrack AND --query-port"), NULL, EC_BADCONF); | |
171 | #else | |
172 | if (option_bool(OPT_CONNTRACK)) | |
173 | die(_("Conntrack support not available: set HAVE_CONNTRACK in src/config.h"), NULL, EC_BADCONF); | |
174 | #endif | |
175 | ||
824af85b SK |
176 | #ifdef HAVE_SOLARIS_NETWORK |
177 | if (daemon->max_logs != 0) | |
178 | die(_("asychronous logging is not available under Solaris"), NULL, EC_BADCONF); | |
179 | #endif | |
180 | ||
572b41eb SK |
181 | #ifdef __ANDROID__ |
182 | if (daemon->max_logs != 0) | |
183 | die(_("asychronous logging is not available under Android"), NULL, EC_BADCONF); | |
184 | #endif | |
185 | ||
4820dce9 SK |
186 | #ifndef HAVE_AUTH |
187 | if (daemon->authserver) | |
188 | die(_("authoritative DNS not available: set HAVE_AUTH in src/config.h"), NULL, EC_BADCONF); | |
189 | #endif | |
190 | ||
b5ea1cc2 SK |
191 | #ifndef HAVE_LOOP |
192 | if (option_bool(OPT_LOOP_DETECT)) | |
193 | die(_("Loop detection not available: set HAVE_LOOP in src/config.h"), NULL, EC_BADCONF); | |
194 | #endif | |
1a6bca81 | 195 | |
5aabfc78 | 196 | now = dnsmasq_time(); |
4f7b304f | 197 | |
b0ff858e | 198 | /* Create a serial at startup if not configured. */ |
4f7b304f SK |
199 | if (daemon->authinterface && daemon->soa_sn == 0) |
200 | #ifdef HAVE_BROKEN_RTC | |
b0ff858e | 201 | die(_("zone serial must be configured in --auth-soa"), NULL, EC_BADCONF); |
4f7b304f SK |
202 | #else |
203 | daemon->soa_sn = now; | |
204 | #endif | |
5aabfc78 | 205 | |
ff7eea27 SK |
206 | #ifdef HAVE_DHCP6 |
207 | if (daemon->dhcp6) | |
208 | { | |
209 | daemon->doing_ra = option_bool(OPT_RA); | |
1f776932 | 210 | |
ff7eea27 | 211 | for (context = daemon->dhcp6; context; context = context->next) |
1f776932 | 212 | { |
ff7eea27 SK |
213 | if (context->flags & CONTEXT_DHCP) |
214 | daemon->doing_dhcp6 = 1; | |
215 | if (context->flags & CONTEXT_RA) | |
216 | daemon->doing_ra = 1; | |
1ee9be4c | 217 | #if !defined(HAVE_LINUX_NETWORK) && !defined(HAVE_BSD_NETWORK) |
ff7eea27 SK |
218 | if (context->flags & CONTEXT_TEMPLATE) |
219 | die (_("dhcp-range constructor not available on this platform"), NULL, EC_BADCONF); | |
bb86e858 | 220 | #endif |
1f776932 | 221 | } |
ff7eea27 SK |
222 | } |
223 | #endif | |
224 | ||
225 | #ifdef HAVE_DHCP | |
226 | /* Note that order matters here, we must call lease_init before | |
227 | creating any file descriptors which shouldn't be leaked | |
228 | to the lease-script init process. We need to call common_init | |
229 | before lease_init to allocate buffers it uses.*/ | |
230 | if (daemon->dhcp || daemon->doing_dhcp6 || daemon->relay4 || daemon->relay6) | |
231 | { | |
232 | dhcp_common_init(); | |
1f776932 | 233 | if (daemon->dhcp || daemon->doing_dhcp6) |
ff7eea27 SK |
234 | lease_init(now); |
235 | } | |
236 | ||
237 | if (daemon->dhcp || daemon->relay4) | |
238 | dhcp_init(); | |
239 | ||
843c96b4 | 240 | # ifdef HAVE_DHCP6 |
89500e31 | 241 | if (daemon->doing_ra || daemon->doing_dhcp6 || daemon->relay6) |
ff7eea27 SK |
242 | ra_init(now); |
243 | ||
244 | if (daemon->doing_dhcp6 || daemon->relay6) | |
245 | dhcp6_init(); | |
801ca9a7 SK |
246 | # endif |
247 | ||
248 | #endif | |
249 | ||
13d86c73 JD |
250 | #ifdef HAVE_IPSET |
251 | if (daemon->ipsets) | |
252 | ipset_init(); | |
253 | #endif | |
254 | ||
1ee9be4c | 255 | #if defined(HAVE_LINUX_NETWORK) |
801ca9a7 | 256 | netlink_init(); |
1ee9be4c SK |
257 | #elif defined(HAVE_BSD_NETWORK) |
258 | route_init(); | |
801ca9a7 SK |
259 | #endif |
260 | ||
1ee9be4c SK |
261 | if (option_bool(OPT_NOWILD) && option_bool(OPT_CLEVERBIND)) |
262 | die(_("cannot set --bind-interfaces and --bind-dynamic"), NULL, EC_BADCONF); | |
263 | ||
115ac3e4 | 264 | if (!enumerate_interfaces(1) || !enumerate_interfaces(0)) |
5aabfc78 | 265 | die(_("failed to find list of interfaces: %s"), NULL, EC_MISC); |
843c96b4 | 266 | |
54dd393f | 267 | if (option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND)) |
de37951c | 268 | { |
74c95c25 | 269 | create_bound_listeners(1); |
54dd393f SK |
270 | |
271 | if (!option_bool(OPT_CLEVERBIND)) | |
272 | for (if_tmp = daemon->if_names; if_tmp; if_tmp = if_tmp->next) | |
273 | if (if_tmp->name && !if_tmp->used) | |
274 | die(_("unknown interface %s"), if_tmp->name, EC_BADNET); | |
9380ba70 SK |
275 | |
276 | #if defined(HAVE_LINUX_NETWORK) && defined(HAVE_DHCP) | |
277 | /* after enumerate_interfaces() */ | |
3b3f4411 SK |
278 | bound_device = whichdevice(); |
279 | ||
9380ba70 SK |
280 | if (daemon->dhcp) |
281 | { | |
3b3f4411 SK |
282 | if (!daemon->relay4 && bound_device) |
283 | { | |
284 | bindtodevice(bound_device, daemon->dhcpfd); | |
285 | did_bind = 1; | |
286 | } | |
287 | if (daemon->enable_pxe && bound_device) | |
288 | { | |
289 | bindtodevice(bound_device, daemon->pxefd); | |
290 | did_bind = 1; | |
291 | } | |
9380ba70 SK |
292 | } |
293 | #endif | |
294 | ||
295 | #if defined(HAVE_LINUX_NETWORK) && defined(HAVE_DHCP6) | |
3b3f4411 SK |
296 | if (daemon->doing_dhcp6 && !daemon->relay6 && bound_device) |
297 | { | |
298 | bindtodevice(bound_device, daemon->dhcp6fd); | |
299 | did_bind = 1; | |
300 | } | |
9380ba70 | 301 | #endif |
de37951c | 302 | } |
28866e95 | 303 | else |
74c95c25 | 304 | create_wildcard_listeners(); |
5d162f20 SK |
305 | |
306 | #ifdef HAVE_DHCP6 | |
307 | /* after enumerate_interfaces() */ | |
ff7eea27 | 308 | if (daemon->doing_dhcp6 || daemon->relay6 || daemon->doing_ra) |
5d162f20 | 309 | join_multicast(1); |
3511a928 SK |
310 | |
311 | /* After netlink_init() and before create_helper() */ | |
312 | lease_make_duid(now); | |
5d162f20 | 313 | #endif |
de37951c | 314 | |
824af85b | 315 | if (daemon->port != 0) |
82e3f45a SK |
316 | { |
317 | cache_init(); | |
318 | #ifdef HAVE_DNSSEC | |
319 | blockdata_init(); | |
320 | #endif | |
321 | } | |
1a6bca81 | 322 | |
28866e95 | 323 | if (option_bool(OPT_DBUS)) |
3d8df260 SK |
324 | #ifdef HAVE_DBUS |
325 | { | |
326 | char *err; | |
327 | daemon->dbus = NULL; | |
328 | daemon->watches = NULL; | |
5aabfc78 SK |
329 | if ((err = dbus_init())) |
330 | die(_("DBus error: %s"), err, EC_MISC); | |
3d8df260 SK |
331 | } |
332 | #else | |
5aabfc78 | 333 | die(_("DBus not available: set HAVE_DBUS in src/config.h"), NULL, EC_BADCONF); |
3d8df260 SK |
334 | #endif |
335 | ||
824af85b SK |
336 | if (daemon->port != 0) |
337 | pre_allocate_sfds(); | |
1a6bca81 | 338 | |
c72daea8 | 339 | #if defined(HAVE_SCRIPT) |
1a6bca81 | 340 | /* Note getpwnam returns static storage */ |
843c96b4 SK |
341 | if ((daemon->dhcp || daemon->dhcp6) && |
342 | daemon->scriptuser && | |
c72daea8 | 343 | (daemon->lease_change_command || daemon->luascript)) |
1a6bca81 SK |
344 | { |
345 | if ((ent_pw = getpwnam(daemon->scriptuser))) | |
346 | { | |
347 | script_uid = ent_pw->pw_uid; | |
348 | script_gid = ent_pw->pw_gid; | |
349 | } | |
350 | else | |
351 | baduser = daemon->scriptuser; | |
352 | } | |
7622fc06 | 353 | #endif |
9e4abcb5 | 354 | |
1a6bca81 SK |
355 | if (daemon->username && !(ent_pw = getpwnam(daemon->username))) |
356 | baduser = daemon->username; | |
357 | else if (daemon->groupname && !(gp = getgrnam(daemon->groupname))) | |
358 | baduser = daemon->groupname; | |
359 | ||
360 | if (baduser) | |
361 | die(_("unknown user or group: %s"), baduser, EC_BADCONF); | |
362 | ||
363 | /* implement group defaults, "dip" if available, or group associated with uid */ | |
364 | if (!daemon->group_set && !gp) | |
365 | { | |
366 | if (!(gp = getgrnam(CHGRP)) && ent_pw) | |
367 | gp = getgrgid(ent_pw->pw_gid); | |
368 | ||
369 | /* for error message */ | |
370 | if (gp) | |
371 | daemon->groupname = gp->gr_name; | |
372 | } | |
373 | ||
374 | #if defined(HAVE_LINUX_NETWORK) | |
375 | /* determine capability API version here, while we can still | |
376 | call safe_malloc */ | |
377 | if (ent_pw && ent_pw->pw_uid != 0) | |
378 | { | |
1a6bca81 | 379 | int capsize = 1; /* for header version 1 */ |
3927da46 SK |
380 | hdr = safe_malloc(sizeof(*hdr)); |
381 | ||
1a6bca81 SK |
382 | /* find version supported by kernel */ |
383 | memset(hdr, 0, sizeof(*hdr)); | |
384 | capget(hdr, NULL); | |
385 | ||
386 | if (hdr->version != LINUX_CAPABILITY_VERSION_1) | |
387 | { | |
388 | /* if unknown version, use largest supported version (3) */ | |
389 | if (hdr->version != LINUX_CAPABILITY_VERSION_2) | |
390 | hdr->version = LINUX_CAPABILITY_VERSION_3; | |
391 | capsize = 2; | |
392 | } | |
393 | ||
394 | data = safe_malloc(sizeof(*data) * capsize); | |
395 | memset(data, 0, sizeof(*data) * capsize); | |
396 | } | |
397 | #endif | |
398 | ||
5aabfc78 | 399 | /* Use a pipe to carry signals and other events back to the event loop |
1a6bca81 SK |
400 | in a race-free manner and another to carry errors to daemon-invoking process */ |
401 | safe_pipe(pipefd, 1); | |
5e9e0efb SK |
402 | |
403 | piperead = pipefd[0]; | |
404 | pipewrite = pipefd[1]; | |
405 | /* prime the pipe to load stuff first time. */ | |
e98bd52e | 406 | send_event(pipewrite, EVENT_INIT, 0, NULL); |
1a6bca81 SK |
407 | |
408 | err_pipe[1] = -1; | |
1697269c | 409 | |
28866e95 | 410 | if (!option_bool(OPT_DEBUG)) |
9e4abcb5 | 411 | { |
9e4abcb5 SK |
412 | /* The following code "daemonizes" the process. |
413 | See Stevens section 12.4 */ | |
1a6bca81 | 414 | |
9e038946 SK |
415 | if (chdir("/") != 0) |
416 | die(_("cannot chdir to filesystem root: %s"), NULL, EC_MISC); | |
417 | ||
1697269c | 418 | #ifndef NO_FORK |
28866e95 | 419 | if (!option_bool(OPT_NO_FORK)) |
3be34541 | 420 | { |
5aabfc78 | 421 | pid_t pid; |
3be34541 | 422 | |
1a6bca81 SK |
423 | /* pipe to carry errors back to original process. |
424 | When startup is complete we close this and the process terminates. */ | |
425 | safe_pipe(err_pipe, 0); | |
426 | ||
7622fc06 SK |
427 | if ((pid = fork()) == -1) |
428 | /* fd == -1 since we've not forked, never returns. */ | |
c72daea8 | 429 | send_event(-1, EVENT_FORK_ERR, errno, NULL); |
9e038946 | 430 | |
5aabfc78 | 431 | if (pid != 0) |
1a6bca81 SK |
432 | { |
433 | struct event_desc ev; | |
c72daea8 SK |
434 | char *msg; |
435 | ||
1a6bca81 SK |
436 | /* close our copy of write-end */ |
437 | close(err_pipe[1]); | |
438 | ||
439 | /* check for errors after the fork */ | |
c72daea8 SK |
440 | if (read_event(err_pipe[0], &ev, &msg)) |
441 | fatal_event(&ev, msg); | |
1a6bca81 SK |
442 | |
443 | _exit(EC_GOOD); | |
444 | } | |
445 | ||
446 | close(err_pipe[0]); | |
447 | ||
448 | /* NO calls to die() from here on. */ | |
3be34541 | 449 | |
5aabfc78 | 450 | setsid(); |
7622fc06 SK |
451 | |
452 | if ((pid = fork()) == -1) | |
c72daea8 | 453 | send_event(err_pipe[1], EVENT_FORK_ERR, errno, NULL); |
7622fc06 SK |
454 | |
455 | if (pid != 0) | |
7cebd20f | 456 | _exit(0); |
3be34541 | 457 | } |
9e4abcb5 | 458 | #endif |
9e038946 | 459 | |
9e4abcb5 | 460 | /* write pidfile _after_ forking ! */ |
1a6bca81 SK |
461 | if (daemon->runfile) |
462 | { | |
79cfefd8 SK |
463 | int fd, err = 0; |
464 | ||
465 | sprintf(daemon->namebuff, "%d\n", (int) getpid()); | |
466 | ||
467 | /* Explanation: Some installations of dnsmasq (eg Debian/Ubuntu) locate the pid-file | |
468 | in a directory which is writable by the non-privileged user that dnsmasq runs as. This | |
469 | allows the daemon to delete the file as part of its shutdown. This is a security hole to the | |
470 | extent that an attacker running as the unprivileged user could replace the pidfile with a | |
471 | symlink, and have the target of that symlink overwritten as root next time dnsmasq starts. | |
472 | ||
473 | The folowing code first deletes any existing file, and then opens it with the O_EXCL flag, | |
474 | ensuring that the open() fails should there be any existing file (because the unlink() failed, | |
475 | or an attacker exploited the race between unlink() and open()). This ensures that no symlink | |
476 | attack can succeed. | |
477 | ||
478 | Any compromise of the non-privileged user still theoretically allows the pid-file to be | |
479 | replaced whilst dnsmasq is running. The worst that could allow is that the usual | |
480 | "shutdown dnsmasq" shell command could be tricked into stopping any other process. | |
481 | ||
482 | Note that if dnsmasq is started as non-root (eg for testing) it silently ignores | |
483 | failure to write the pid-file. | |
484 | */ | |
485 | ||
486 | unlink(daemon->runfile); | |
1a6bca81 | 487 | |
79cfefd8 | 488 | if ((fd = open(daemon->runfile, O_WRONLY|O_CREAT|O_TRUNC|O_EXCL, S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH)) == -1) |
1a6bca81 | 489 | { |
79cfefd8 SK |
490 | /* only complain if started as root */ |
491 | if (getuid() == 0) | |
492 | err = 1; | |
1a6bca81 | 493 | } |
79cfefd8 SK |
494 | else |
495 | { | |
496 | if (!read_write(fd, (unsigned char *)daemon->namebuff, strlen(daemon->namebuff), 0)) | |
497 | err = 1; | |
498 | ||
499 | while (!err && close(fd) == -1) | |
500 | if (!retry_send()) | |
501 | err = 1; | |
502 | } | |
503 | ||
504 | if (err) | |
1a6bca81 | 505 | { |
c72daea8 | 506 | send_event(err_pipe[1], EVENT_PIDFILE, errno, daemon->runfile); |
1a6bca81 SK |
507 | _exit(0); |
508 | } | |
9e4abcb5 | 509 | } |
1697269c SK |
510 | } |
511 | ||
8ef5ada2 SK |
512 | log_err = log_start(ent_pw, err_pipe[1]); |
513 | ||
28866e95 | 514 | if (!option_bool(OPT_DEBUG)) |
8ef5ada2 SK |
515 | { |
516 | /* open stdout etc to /dev/null */ | |
517 | int nullfd = open("/dev/null", O_RDWR); | |
518 | dup2(nullfd, STDOUT_FILENO); | |
519 | dup2(nullfd, STDERR_FILENO); | |
520 | dup2(nullfd, STDIN_FILENO); | |
521 | close(nullfd); | |
522 | } | |
1a6bca81 SK |
523 | |
524 | /* if we are to run scripts, we need to fork a helper before dropping root. */ | |
525 | daemon->helperfd = -1; | |
c72daea8 | 526 | #ifdef HAVE_SCRIPT |
52b92f4d | 527 | if ((daemon->dhcp || daemon->dhcp6) && (daemon->lease_change_command || daemon->luascript)) |
1a6bca81 | 528 | daemon->helperfd = create_helper(pipewrite, err_pipe[1], script_uid, script_gid, max_fd); |
5aabfc78 | 529 | #endif |
5aabfc78 | 530 | |
28866e95 | 531 | if (!option_bool(OPT_DEBUG) && getuid() == 0) |
1697269c | 532 | { |
1a6bca81 SK |
533 | int bad_capabilities = 0; |
534 | gid_t dummy; | |
535 | ||
536 | /* remove all supplimentary groups */ | |
537 | if (gp && | |
538 | (setgroups(0, &dummy) == -1 || | |
539 | setgid(gp->gr_gid) == -1)) | |
9e4abcb5 | 540 | { |
c72daea8 | 541 | send_event(err_pipe[1], EVENT_GROUP_ERR, errno, daemon->groupname); |
1a6bca81 | 542 | _exit(0); |
7cebd20f | 543 | } |
1a6bca81 | 544 | |
7cebd20f | 545 | if (ent_pw && ent_pw->pw_uid != 0) |
1697269c | 546 | { |
74c95c25 | 547 | #if defined(HAVE_LINUX_NETWORK) |
1697269c | 548 | /* On linux, we keep CAP_NETADMIN (for ARP-injection) and |
74c95c25 | 549 | CAP_NET_RAW (for icmp) if we're doing dhcp. If we have yet to bind |
54dd393f SK |
550 | ports because of DAD, or we're doing it dynamically, |
551 | we need CAP_NET_BIND_SERVICE too. */ | |
552 | if (is_dad_listeners() || option_bool(OPT_CLEVERBIND)) | |
74c95c25 SK |
553 | data->effective = data->permitted = data->inheritable = |
554 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | | |
555 | (1 << CAP_SETUID) | (1 << CAP_NET_BIND_SERVICE); | |
556 | else | |
557 | data->effective = data->permitted = data->inheritable = | |
558 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | (1 << CAP_SETUID); | |
5e9e0efb | 559 | |
1697269c | 560 | /* Tell kernel to not clear capabilities when dropping root */ |
572b41eb | 561 | if (capset(hdr, data) == -1 || prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) |
1697269c | 562 | bad_capabilities = errno; |
1a6bca81 | 563 | |
7622fc06 | 564 | #elif defined(HAVE_SOLARIS_NETWORK) |
824af85b SK |
565 | /* http://developers.sun.com/solaris/articles/program_privileges.html */ |
566 | priv_set_t *priv_set; | |
567 | ||
568 | if (!(priv_set = priv_str_to_set("basic", ",", NULL)) || | |
569 | priv_addset(priv_set, PRIV_NET_ICMPACCESS) == -1 || | |
570 | priv_addset(priv_set, PRIV_SYS_NET_CONFIG) == -1) | |
571 | bad_capabilities = errno; | |
572 | ||
573 | if (priv_set && bad_capabilities == 0) | |
574 | { | |
575 | priv_inverse(priv_set); | |
576 | ||
577 | if (setppriv(PRIV_OFF, PRIV_LIMIT, priv_set) == -1) | |
578 | bad_capabilities = errno; | |
579 | } | |
580 | ||
581 | if (priv_set) | |
582 | priv_freeset(priv_set); | |
583 | ||
824af85b SK |
584 | #endif |
585 | ||
1a6bca81 | 586 | if (bad_capabilities != 0) |
1697269c | 587 | { |
c72daea8 | 588 | send_event(err_pipe[1], EVENT_CAP_ERR, bad_capabilities, NULL); |
1a6bca81 SK |
589 | _exit(0); |
590 | } | |
591 | ||
592 | /* finally drop root */ | |
593 | if (setuid(ent_pw->pw_uid) == -1) | |
594 | { | |
c72daea8 | 595 | send_event(err_pipe[1], EVENT_USER_ERR, errno, daemon->username); |
1a6bca81 SK |
596 | _exit(0); |
597 | } | |
598 | ||
1697269c | 599 | #ifdef HAVE_LINUX_NETWORK |
54dd393f | 600 | if (is_dad_listeners() || option_bool(OPT_CLEVERBIND)) |
74c95c25 SK |
601 | data->effective = data->permitted = |
602 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | (1 << CAP_NET_BIND_SERVICE); | |
603 | else | |
604 | data->effective = data->permitted = | |
605 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW); | |
1a6bca81 SK |
606 | data->inheritable = 0; |
607 | ||
608 | /* lose the setuid and setgid capbilities */ | |
609 | if (capset(hdr, data) == -1) | |
610 | { | |
c72daea8 | 611 | send_event(err_pipe[1], EVENT_CAP_ERR, errno, NULL); |
1a6bca81 | 612 | _exit(0); |
1697269c | 613 | } |
1a6bca81 SK |
614 | #endif |
615 | ||
9e4abcb5 SK |
616 | } |
617 | } | |
1697269c | 618 | |
1697269c | 619 | #ifdef HAVE_LINUX_NETWORK |
28866e95 | 620 | if (option_bool(OPT_DEBUG)) |
572b41eb | 621 | prctl(PR_SET_DUMPABLE, 1, 0, 0, 0); |
1697269c | 622 | #endif |
9e4abcb5 | 623 | |
8b3ae2fd | 624 | #ifdef HAVE_TFTP |
8bc4cece | 625 | if (option_bool(OPT_TFTP)) |
8b3ae2fd SK |
626 | { |
627 | DIR *dir; | |
628 | struct tftp_prefix *p; | |
629 | ||
630 | if (daemon->tftp_prefix) | |
631 | { | |
632 | if (!((dir = opendir(daemon->tftp_prefix)))) | |
633 | { | |
634 | send_event(err_pipe[1], EVENT_TFTP_ERR, errno, daemon->tftp_prefix); | |
635 | _exit(0); | |
636 | } | |
637 | closedir(dir); | |
638 | } | |
639 | ||
640 | for (p = daemon->if_prefix; p; p = p->next) | |
641 | { | |
642 | if (!((dir = opendir(p->prefix)))) | |
643 | { | |
644 | send_event(err_pipe[1], EVENT_TFTP_ERR, errno, p->prefix); | |
645 | _exit(0); | |
646 | } | |
647 | closedir(dir); | |
648 | } | |
649 | } | |
650 | #endif | |
651 | ||
824af85b SK |
652 | if (daemon->port == 0) |
653 | my_syslog(LOG_INFO, _("started, version %s DNS disabled"), VERSION); | |
654 | else if (daemon->cachesize != 0) | |
f2621c7f | 655 | my_syslog(LOG_INFO, _("started, version %s cachesize %d"), VERSION, daemon->cachesize); |
9e4abcb5 | 656 | else |
f2621c7f | 657 | my_syslog(LOG_INFO, _("started, version %s cache disabled"), VERSION); |
1697269c | 658 | |
f2621c7f | 659 | my_syslog(LOG_INFO, _("compile time options: %s"), compile_opts); |
1697269c | 660 | |
3d8df260 | 661 | #ifdef HAVE_DBUS |
28866e95 | 662 | if (option_bool(OPT_DBUS)) |
3d8df260 SK |
663 | { |
664 | if (daemon->dbus) | |
f2621c7f | 665 | my_syslog(LOG_INFO, _("DBus support enabled: connected to system bus")); |
3d8df260 | 666 | else |
f2621c7f | 667 | my_syslog(LOG_INFO, _("DBus support enabled: bus connection pending")); |
3d8df260 SK |
668 | } |
669 | #endif | |
1a9a3489 SK |
670 | |
671 | if (option_bool(OPT_LOCAL_SERVICE)) | |
672 | my_syslog(LOG_INFO, _("DNS service limited to local subnets")); | |
db737466 | 673 | |
1d97ac4f | 674 | #ifdef HAVE_DNSSEC |
db737466 | 675 | if (option_bool(OPT_DNSSEC_VALID)) |
e98bd52e SK |
676 | { |
677 | my_syslog(LOG_INFO, _("DNSSEC validation enabled")); | |
678 | if (option_bool(OPT_DNSSEC_TIME)) | |
679 | my_syslog(LOG_INFO, _("DNSSEC signature timestamps not checked until first cache reload")); | |
680 | } | |
db737466 | 681 | #endif |
3d8df260 | 682 | |
1a6bca81 SK |
683 | if (log_err != 0) |
684 | my_syslog(LOG_WARNING, _("warning: failed to change owner of %s: %s"), | |
685 | daemon->log_file, strerror(log_err)); | |
db737466 | 686 | |
de37951c | 687 | if (bind_fallback) |
f2621c7f | 688 | my_syslog(LOG_WARNING, _("setting --bind-interfaces option because of OS limitations")); |
dc27e148 | 689 | |
f7029f5c SK |
690 | if (option_bool(OPT_NOWILD)) |
691 | warn_bound_listeners(); | |
692 | ||
693 | warn_int_names(); | |
de37951c | 694 | |
28866e95 | 695 | if (!option_bool(OPT_NOWILD)) |
26128d27 SK |
696 | for (if_tmp = daemon->if_names; if_tmp; if_tmp = if_tmp->next) |
697 | if (if_tmp->name && !if_tmp->used) | |
f2621c7f | 698 | my_syslog(LOG_WARNING, _("warning: interface %s does not currently exist"), if_tmp->name); |
5e9e0efb | 699 | |
28866e95 | 700 | if (daemon->port != 0 && option_bool(OPT_NO_RESOLV)) |
208b65c5 SK |
701 | { |
702 | if (daemon->resolv_files && !daemon->resolv_files->is_default) | |
f2621c7f | 703 | my_syslog(LOG_WARNING, _("warning: ignoring resolv-file flag because no-resolv is set")); |
208b65c5 | 704 | daemon->resolv_files = NULL; |
1b7ecd11 | 705 | if (!daemon->servers) |
f2621c7f | 706 | my_syslog(LOG_WARNING, _("warning: no upstream servers configured")); |
208b65c5 SK |
707 | } |
708 | ||
f2621c7f SK |
709 | if (daemon->max_logs != 0) |
710 | my_syslog(LOG_INFO, _("asynchronous logging enabled, queue limit is %d messages"), daemon->max_logs); | |
1f776932 | 711 | |
f2621c7f | 712 | |
7622fc06 | 713 | #ifdef HAVE_DHCP |
1f776932 SK |
714 | for (context = daemon->dhcp; context; context = context->next) |
715 | log_context(AF_INET, context); | |
52b92f4d | 716 | |
ff7eea27 SK |
717 | for (relay = daemon->relay4; relay; relay = relay->next) |
718 | log_relay(AF_INET, relay); | |
719 | ||
1f776932 SK |
720 | # ifdef HAVE_DHCP6 |
721 | for (context = daemon->dhcp6; context; context = context->next) | |
722 | log_context(AF_INET6, context); | |
723 | ||
ff7eea27 SK |
724 | for (relay = daemon->relay6; relay; relay = relay->next) |
725 | log_relay(AF_INET6, relay); | |
726 | ||
1f776932 SK |
727 | if (daemon->doing_dhcp6 || daemon->doing_ra) |
728 | dhcp_construct_contexts(now); | |
729 | ||
730 | if (option_bool(OPT_RA)) | |
731 | my_syslog(MS_DHCP | LOG_INFO, _("IPv6 router advertisement enabled")); | |
732 | # endif | |
26128d27 | 733 | |
3b3f4411 SK |
734 | # ifdef HAVE_LINUX_NETWORK |
735 | if (did_bind) | |
736 | my_syslog(MS_DHCP | LOG_INFO, _("DHCP, sockets bound exclusively to interface %s"), bound_device); | |
737 | # endif | |
738 | ||
8445f5d2 SK |
739 | /* after dhcp_contruct_contexts */ |
740 | if (daemon->dhcp || daemon->doing_dhcp6) | |
741 | lease_find_interfaces(now); | |
1f776932 | 742 | #endif |
52b92f4d | 743 | |
832af0ba | 744 | #ifdef HAVE_TFTP |
8bc4cece | 745 | if (option_bool(OPT_TFTP)) |
832af0ba | 746 | { |
832af0ba | 747 | #ifdef FD_SETSIZE |
5aabfc78 | 748 | if (FD_SETSIZE < (unsigned)max_fd) |
832af0ba SK |
749 | max_fd = FD_SETSIZE; |
750 | #endif | |
751 | ||
7622fc06 | 752 | my_syslog(MS_TFTP | LOG_INFO, "TFTP %s%s %s", |
f2621c7f SK |
753 | daemon->tftp_prefix ? _("root is ") : _("enabled"), |
754 | daemon->tftp_prefix ? daemon->tftp_prefix: "", | |
28866e95 | 755 | option_bool(OPT_TFTP_SECURE) ? _("secure mode") : ""); |
f2621c7f | 756 | |
832af0ba | 757 | /* This is a guess, it assumes that for small limits, |
f2621c7f | 758 | disjoint files might be served, but for large limits, |
832af0ba SK |
759 | a single file will be sent to may clients (the file only needs |
760 | one fd). */ | |
761 | ||
762 | max_fd -= 30; /* use other than TFTP */ | |
763 | ||
764 | if (max_fd < 0) | |
765 | max_fd = 5; | |
766 | else if (max_fd < 100) | |
767 | max_fd = max_fd/2; | |
768 | else | |
769 | max_fd = max_fd - 20; | |
824af85b SK |
770 | |
771 | /* if we have to use a limited range of ports, | |
772 | that will limit the number of transfers */ | |
773 | if (daemon->start_tftp_port != 0 && | |
774 | daemon->end_tftp_port - daemon->start_tftp_port + 1 < max_fd) | |
775 | max_fd = daemon->end_tftp_port - daemon->start_tftp_port + 1; | |
832af0ba SK |
776 | |
777 | if (daemon->tftp_max > max_fd) | |
778 | { | |
779 | daemon->tftp_max = max_fd; | |
7622fc06 | 780 | my_syslog(MS_TFTP | LOG_WARNING, |
f2621c7f SK |
781 | _("restricting maximum simultaneous TFTP transfers to %d"), |
782 | daemon->tftp_max); | |
832af0ba SK |
783 | } |
784 | } | |
785 | #endif | |
786 | ||
1a6bca81 SK |
787 | /* finished start-up - release original process */ |
788 | if (err_pipe[1] != -1) | |
789 | close(err_pipe[1]); | |
9e4abcb5 | 790 | |
824af85b SK |
791 | if (daemon->port != 0) |
792 | check_servers(); | |
793 | ||
7cebd20f SK |
794 | pid = getpid(); |
795 | ||
5e9e0efb | 796 | while (1) |
9e4abcb5 | 797 | { |
1697269c | 798 | int maxfd = -1; |
5e9e0efb | 799 | struct timeval t, *tp = NULL; |
3d8df260 | 800 | fd_set rset, wset, eset; |
9e4abcb5 SK |
801 | |
802 | FD_ZERO(&rset); | |
3d8df260 SK |
803 | FD_ZERO(&wset); |
804 | FD_ZERO(&eset); | |
9e4abcb5 | 805 | |
1697269c SK |
806 | /* if we are out of resources, find how long we have to wait |
807 | for some to come free, we'll loop around then and restart | |
808 | listening for queries */ | |
5aabfc78 | 809 | if ((t.tv_sec = set_dns_listeners(now, &rset, &maxfd)) != 0) |
1697269c SK |
810 | { |
811 | t.tv_usec = 0; | |
812 | tp = &t; | |
813 | } | |
814 | ||
832af0ba SK |
815 | /* Whilst polling for the dbus, or doing a tftp transfer, wake every quarter second */ |
816 | if (daemon->tftp_trans || | |
28866e95 | 817 | (option_bool(OPT_DBUS) && !daemon->dbus)) |
5e9e0efb | 818 | { |
1697269c SK |
819 | t.tv_sec = 0; |
820 | t.tv_usec = 250000; | |
5e9e0efb | 821 | tp = &t; |
5e9e0efb | 822 | } |
74c95c25 SK |
823 | /* Wake every second whilst waiting for DAD to complete */ |
824 | else if (is_dad_listeners()) | |
825 | { | |
826 | t.tv_sec = 1; | |
827 | t.tv_usec = 0; | |
828 | tp = &t; | |
829 | } | |
44a2a316 | 830 | |
832af0ba | 831 | #ifdef HAVE_DBUS |
5aabfc78 | 832 | set_dbus_listeners(&maxfd, &rset, &wset, &eset); |
5e9e0efb SK |
833 | #endif |
834 | ||
7622fc06 | 835 | #ifdef HAVE_DHCP |
ff7eea27 | 836 | if (daemon->dhcp || daemon->relay4) |
5e9e0efb SK |
837 | { |
838 | FD_SET(daemon->dhcpfd, &rset); | |
1697269c | 839 | bump_maxfd(daemon->dhcpfd, &maxfd); |
316e2730 SK |
840 | if (daemon->pxefd != -1) |
841 | { | |
842 | FD_SET(daemon->pxefd, &rset); | |
843 | bump_maxfd(daemon->pxefd, &maxfd); | |
844 | } | |
5e9e0efb | 845 | } |
7622fc06 | 846 | #endif |
cdeda28f | 847 | |
52b92f4d | 848 | #ifdef HAVE_DHCP6 |
ff7eea27 | 849 | if (daemon->doing_dhcp6 || daemon->relay6) |
52b92f4d SK |
850 | { |
851 | FD_SET(daemon->dhcp6fd, &rset); | |
c5ad4e79 | 852 | bump_maxfd(daemon->dhcp6fd, &maxfd); |
5d71d834 SK |
853 | } |
854 | ||
1f776932 | 855 | if (daemon->doing_ra) |
5d71d834 SK |
856 | { |
857 | FD_SET(daemon->icmp6fd, &rset); | |
858 | bump_maxfd(daemon->icmp6fd, &maxfd); | |
52b92f4d SK |
859 | } |
860 | #endif | |
861 | ||
1ee9be4c | 862 | #if defined(HAVE_LINUX_NETWORK) |
5e9e0efb | 863 | FD_SET(daemon->netlinkfd, &rset); |
1697269c | 864 | bump_maxfd(daemon->netlinkfd, &maxfd); |
1ee9be4c SK |
865 | #elif defined(HAVE_BSD_NETWORK) |
866 | FD_SET(daemon->routefd, &rset); | |
867 | bump_maxfd(daemon->routefd, &maxfd); | |
3d8df260 | 868 | #endif |
1ee9be4c | 869 | |
5e9e0efb | 870 | FD_SET(piperead, &rset); |
1697269c SK |
871 | bump_maxfd(piperead, &maxfd); |
872 | ||
7622fc06 | 873 | #ifdef HAVE_DHCP |
1f15b81d | 874 | # ifdef HAVE_SCRIPT |
5aabfc78 | 875 | while (helper_buf_empty() && do_script_run(now)); |
1697269c | 876 | |
a9530964 SK |
877 | # ifdef HAVE_TFTP |
878 | while (helper_buf_empty() && do_tftp_script_run()); | |
879 | # endif | |
880 | ||
1697269c SK |
881 | if (!helper_buf_empty()) |
882 | { | |
883 | FD_SET(daemon->helperfd, &wset); | |
884 | bump_maxfd(daemon->helperfd, &maxfd); | |
885 | } | |
7622fc06 | 886 | # else |
5aabfc78 SK |
887 | /* need this for other side-effects */ |
888 | while (do_script_run(now)); | |
a9530964 SK |
889 | |
890 | # ifdef HAVE_TFTP | |
891 | while (do_tftp_script_run()); | |
892 | # endif | |
893 | ||
7622fc06 | 894 | # endif |
5aabfc78 | 895 | #endif |
7622fc06 | 896 | |
f2621c7f SK |
897 | /* must do this just before select(), when we know no |
898 | more calls to my_syslog() can occur */ | |
899 | set_log_writer(&wset, &maxfd); | |
900 | ||
5e9e0efb SK |
901 | if (select(maxfd+1, &rset, &wset, &eset, tp) < 0) |
902 | { | |
903 | /* otherwise undefined after error */ | |
904 | FD_ZERO(&rset); FD_ZERO(&wset); FD_ZERO(&eset); | |
905 | } | |
906 | ||
907 | now = dnsmasq_time(); | |
9e4abcb5 | 908 | |
f2621c7f | 909 | check_log_writer(&wset); |
115ac3e4 SK |
910 | |
911 | /* prime. */ | |
912 | enumerate_interfaces(1); | |
913 | ||
74c95c25 SK |
914 | /* Check the interfaces to see if any have exited DAD state |
915 | and if so, bind the address. */ | |
916 | if (is_dad_listeners()) | |
917 | { | |
115ac3e4 | 918 | enumerate_interfaces(0); |
74c95c25 SK |
919 | /* NB, is_dad_listeners() == 1 --> we're binding interfaces */ |
920 | create_bound_listeners(0); | |
dc27e148 | 921 | warn_bound_listeners(); |
74c95c25 | 922 | } |
f2621c7f | 923 | |
1ee9be4c | 924 | #if defined(HAVE_LINUX_NETWORK) |
c52e1897 | 925 | if (FD_ISSET(daemon->netlinkfd, &rset)) |
a0358e5d | 926 | netlink_multicast(); |
1ee9be4c SK |
927 | #elif defined(HAVE_BSD_NETWORK) |
928 | if (FD_ISSET(daemon->routefd, &rset)) | |
a0358e5d | 929 | route_sock(); |
c52e1897 SK |
930 | #endif |
931 | ||
9e4abcb5 | 932 | /* Check for changes to resolv files once per second max. */ |
3d8df260 | 933 | /* Don't go silent for long periods if the clock goes backwards. */ |
9009d746 SK |
934 | if (daemon->last_resolv == 0 || |
935 | difftime(now, daemon->last_resolv) > 1.0 || | |
936 | difftime(now, daemon->last_resolv) < -1.0) | |
9e4abcb5 | 937 | { |
8ef5ada2 SK |
938 | /* poll_resolv doesn't need to reload first time through, since |
939 | that's queued anyway. */ | |
33820b7e | 940 | |
8ef5ada2 SK |
941 | poll_resolv(0, daemon->last_resolv != 0, now); |
942 | daemon->last_resolv = now; | |
9e4abcb5 | 943 | } |
5aabfc78 | 944 | |
5e9e0efb | 945 | if (FD_ISSET(piperead, &rset)) |
5aabfc78 | 946 | async_event(piperead, now); |
7cebd20f | 947 | |
3d8df260 SK |
948 | #ifdef HAVE_DBUS |
949 | /* if we didn't create a DBus connection, retry now. */ | |
28866e95 | 950 | if (option_bool(OPT_DBUS) && !daemon->dbus) |
3d8df260 SK |
951 | { |
952 | char *err; | |
5aabfc78 | 953 | if ((err = dbus_init())) |
f2621c7f | 954 | my_syslog(LOG_WARNING, _("DBus error: %s"), err); |
3d8df260 | 955 | if (daemon->dbus) |
f2621c7f | 956 | my_syslog(LOG_INFO, _("connected to system DBus")); |
3d8df260 | 957 | } |
5aabfc78 | 958 | check_dbus_listeners(&rset, &wset, &eset); |
3d8df260 | 959 | #endif |
824af85b | 960 | |
5aabfc78 | 961 | check_dns_listeners(&rset, now); |
832af0ba SK |
962 | |
963 | #ifdef HAVE_TFTP | |
5aabfc78 | 964 | check_tftp_listeners(&rset, now); |
832af0ba SK |
965 | #endif |
966 | ||
7622fc06 | 967 | #ifdef HAVE_DHCP |
ff7eea27 | 968 | if (daemon->dhcp || daemon->relay4) |
316e2730 SK |
969 | { |
970 | if (FD_ISSET(daemon->dhcpfd, &rset)) | |
971 | dhcp_packet(now, 0); | |
972 | if (daemon->pxefd != -1 && FD_ISSET(daemon->pxefd, &rset)) | |
973 | dhcp_packet(now, 1); | |
974 | } | |
1697269c | 975 | |
52b92f4d | 976 | #ifdef HAVE_DHCP6 |
ff7eea27 | 977 | if ((daemon->doing_dhcp6 || daemon->relay6) && FD_ISSET(daemon->dhcp6fd, &rset)) |
18c63eff | 978 | dhcp6_packet(now); |
c5ad4e79 | 979 | |
1f776932 SK |
980 | if (daemon->doing_ra && FD_ISSET(daemon->icmp6fd, &rset)) |
981 | icmp6_packet(now); | |
52b92f4d SK |
982 | #endif |
983 | ||
1f15b81d | 984 | # ifdef HAVE_SCRIPT |
1697269c | 985 | if (daemon->helperfd != -1 && FD_ISSET(daemon->helperfd, &wset)) |
5aabfc78 | 986 | helper_write(); |
7622fc06 | 987 | # endif |
5aabfc78 SK |
988 | #endif |
989 | ||
9e4abcb5 | 990 | } |
9e4abcb5 SK |
991 | } |
992 | ||
3be34541 SK |
993 | static void sig_handler(int sig) |
994 | { | |
5e9e0efb | 995 | if (pid == 0) |
3be34541 | 996 | { |
1697269c SK |
997 | /* ignore anything other than TERM during startup |
998 | and in helper proc. (helper ignore TERM too) */ | |
5e9e0efb | 999 | if (sig == SIGTERM) |
5aabfc78 | 1000 | exit(EC_MISC); |
3be34541 | 1001 | } |
5aabfc78 | 1002 | else if (pid != getpid()) |
5e9e0efb | 1003 | { |
1697269c | 1004 | /* alarm is used to kill TCP children after a fixed time. */ |
5e9e0efb | 1005 | if (sig == SIGALRM) |
7cebd20f | 1006 | _exit(0); |
3be34541 | 1007 | } |
5aabfc78 SK |
1008 | else |
1009 | { | |
1010 | /* master process */ | |
1011 | int event, errsave = errno; | |
1012 | ||
1013 | if (sig == SIGHUP) | |
1014 | event = EVENT_RELOAD; | |
1015 | else if (sig == SIGCHLD) | |
1016 | event = EVENT_CHILD; | |
1017 | else if (sig == SIGALRM) | |
1018 | event = EVENT_ALARM; | |
1019 | else if (sig == SIGTERM) | |
1020 | event = EVENT_TERM; | |
1021 | else if (sig == SIGUSR1) | |
1022 | event = EVENT_DUMP; | |
1023 | else if (sig == SIGUSR2) | |
1024 | event = EVENT_REOPEN; | |
1025 | else | |
1026 | return; | |
1027 | ||
c72daea8 | 1028 | send_event(pipewrite, event, 0, NULL); |
5aabfc78 SK |
1029 | errno = errsave; |
1030 | } | |
1031 | } | |
1032 | ||
353ae4d2 SK |
1033 | /* now == 0 -> queue immediate callback */ |
1034 | void send_alarm(time_t event, time_t now) | |
741c2952 | 1035 | { |
884a6dfe | 1036 | if (now == 0 || event != 0) |
353ae4d2 | 1037 | { |
884a6dfe SK |
1038 | /* alarm(0) or alarm(-ve) doesn't do what we want.... */ |
1039 | if ((now == 0 || difftime(event, now) <= 0.0)) | |
1040 | send_event(pipewrite, EVENT_ALARM, 0, NULL); | |
1041 | else | |
1042 | alarm((unsigned)difftime(event, now)); | |
353ae4d2 | 1043 | } |
741c2952 SK |
1044 | } |
1045 | ||
47a95169 | 1046 | void queue_event(int event) |
a0358e5d | 1047 | { |
47a95169 | 1048 | send_event(pipewrite, event, 0, NULL); |
a0358e5d SK |
1049 | } |
1050 | ||
c72daea8 | 1051 | void send_event(int fd, int event, int data, char *msg) |
5aabfc78 SK |
1052 | { |
1053 | struct event_desc ev; | |
c72daea8 SK |
1054 | struct iovec iov[2]; |
1055 | ||
5aabfc78 SK |
1056 | ev.event = event; |
1057 | ev.data = data; | |
c72daea8 SK |
1058 | ev.msg_sz = msg ? strlen(msg) : 0; |
1059 | ||
1060 | iov[0].iov_base = &ev; | |
1061 | iov[0].iov_len = sizeof(ev); | |
1062 | iov[1].iov_base = msg; | |
1063 | iov[1].iov_len = ev.msg_sz; | |
1a6bca81 SK |
1064 | |
1065 | /* error pipe, debug mode. */ | |
1066 | if (fd == -1) | |
c72daea8 | 1067 | fatal_event(&ev, msg); |
1a6bca81 SK |
1068 | else |
1069 | /* pipe is non-blocking and struct event_desc is smaller than | |
1070 | PIPE_BUF, so this either fails or writes everything */ | |
c72daea8 | 1071 | while (writev(fd, iov, msg ? 2 : 1) == -1 && errno == EINTR); |
5aabfc78 SK |
1072 | } |
1073 | ||
c72daea8 SK |
1074 | /* NOTE: the memory used to return msg is leaked: use msgs in events only |
1075 | to describe fatal errors. */ | |
1076 | static int read_event(int fd, struct event_desc *evp, char **msg) | |
1077 | { | |
1078 | char *buf; | |
1079 | ||
1080 | if (!read_write(fd, (unsigned char *)evp, sizeof(struct event_desc), 1)) | |
1081 | return 0; | |
1082 | ||
1083 | *msg = NULL; | |
1084 | ||
1085 | if (evp->msg_sz != 0 && | |
1086 | (buf = malloc(evp->msg_sz + 1)) && | |
1087 | read_write(fd, (unsigned char *)buf, evp->msg_sz, 1)) | |
1088 | { | |
1089 | buf[evp->msg_sz] = 0; | |
1090 | *msg = buf; | |
1091 | } | |
1092 | ||
1093 | return 1; | |
1094 | } | |
1095 | ||
1096 | static void fatal_event(struct event_desc *ev, char *msg) | |
1a6bca81 SK |
1097 | { |
1098 | errno = ev->data; | |
1099 | ||
1100 | switch (ev->event) | |
1101 | { | |
1102 | case EVENT_DIE: | |
1103 | exit(0); | |
7622fc06 SK |
1104 | |
1105 | case EVENT_FORK_ERR: | |
1106 | die(_("cannot fork into background: %s"), NULL, EC_MISC); | |
1a6bca81 SK |
1107 | |
1108 | case EVENT_PIPE_ERR: | |
1109 | die(_("failed to create helper: %s"), NULL, EC_MISC); | |
1110 | ||
1111 | case EVENT_CAP_ERR: | |
1112 | die(_("setting capabilities failed: %s"), NULL, EC_MISC); | |
1113 | ||
1114 | case EVENT_USER_ERR: | |
c72daea8 | 1115 | die(_("failed to change user-id to %s: %s"), msg, EC_MISC); |
1a6bca81 SK |
1116 | |
1117 | case EVENT_GROUP_ERR: | |
c72daea8 | 1118 | die(_("failed to change group-id to %s: %s"), msg, EC_MISC); |
1a6bca81 SK |
1119 | |
1120 | case EVENT_PIDFILE: | |
c72daea8 | 1121 | die(_("failed to open pidfile %s: %s"), msg, EC_FILE); |
1a6bca81 SK |
1122 | |
1123 | case EVENT_LOG_ERR: | |
c72daea8 SK |
1124 | die(_("cannot open log %s: %s"), msg, EC_FILE); |
1125 | ||
1126 | case EVENT_LUA_ERR: | |
1127 | die(_("failed to load Lua script: %s"), msg, EC_MISC); | |
8b3ae2fd SK |
1128 | |
1129 | case EVENT_TFTP_ERR: | |
1130 | die(_("TFTP directory %s inaccessible: %s"), msg, EC_FILE); | |
1a6bca81 SK |
1131 | } |
1132 | } | |
1133 | ||
5aabfc78 SK |
1134 | static void async_event(int pipe, time_t now) |
1135 | { | |
1136 | pid_t p; | |
1137 | struct event_desc ev; | |
7b1eae4f | 1138 | int i, check = 0; |
c72daea8 SK |
1139 | char *msg; |
1140 | ||
1141 | /* NOTE: the memory used to return msg is leaked: use msgs in events only | |
1142 | to describe fatal errors. */ | |
1143 | ||
1144 | if (read_event(pipe, &ev, &msg)) | |
5aabfc78 SK |
1145 | switch (ev.event) |
1146 | { | |
1147 | case EVENT_RELOAD: | |
e98bd52e SK |
1148 | #ifdef HAVE_DNSSEC |
1149 | if (option_bool(OPT_DNSSEC_VALID) && option_bool(OPT_DNSSEC_TIME)) | |
1150 | { | |
1151 | my_syslog(LOG_INFO, _("now checking DNSSEC signature timestamps")); | |
1152 | reset_option_bool(OPT_DNSSEC_TIME); | |
1153 | } | |
1154 | #endif | |
1155 | /* fall through */ | |
1156 | ||
1157 | case EVENT_INIT: | |
5aabfc78 | 1158 | clear_cache_and_reload(now); |
e98bd52e | 1159 | |
7b1eae4f | 1160 | if (daemon->port != 0) |
5aabfc78 | 1161 | { |
7b1eae4f SK |
1162 | if (daemon->resolv_files && option_bool(OPT_NO_POLL)) |
1163 | { | |
1164 | reload_servers(daemon->resolv_files->name); | |
1165 | check = 1; | |
1166 | } | |
1167 | ||
1168 | if (daemon->servers_file) | |
1169 | { | |
1170 | read_servers_file(); | |
1171 | check = 1; | |
1172 | } | |
1173 | ||
1174 | if (check) | |
1175 | check_servers(); | |
5aabfc78 | 1176 | } |
7b1eae4f | 1177 | |
7622fc06 | 1178 | #ifdef HAVE_DHCP |
5aabfc78 | 1179 | rerun_scripts(); |
7622fc06 | 1180 | #endif |
5aabfc78 SK |
1181 | break; |
1182 | ||
1183 | case EVENT_DUMP: | |
824af85b SK |
1184 | if (daemon->port != 0) |
1185 | dump_cache(now); | |
5aabfc78 SK |
1186 | break; |
1187 | ||
1188 | case EVENT_ALARM: | |
7622fc06 | 1189 | #ifdef HAVE_DHCP |
1f776932 | 1190 | if (daemon->dhcp || daemon->doing_dhcp6) |
5aabfc78 SK |
1191 | { |
1192 | lease_prune(NULL, now); | |
1193 | lease_update_file(now); | |
1194 | } | |
843c96b4 | 1195 | #ifdef HAVE_DHCP6 |
1f776932 | 1196 | else if (daemon->doing_ra) |
353ae4d2 SK |
1197 | /* Not doing DHCP, so no lease system, manage alarms for ra only */ |
1198 | send_alarm(periodic_ra(now), now); | |
843c96b4 | 1199 | #endif |
7622fc06 | 1200 | #endif |
5aabfc78 SK |
1201 | break; |
1202 | ||
1203 | case EVENT_CHILD: | |
1204 | /* See Stevens 5.10 */ | |
1205 | while ((p = waitpid(-1, NULL, WNOHANG)) != 0) | |
1206 | if (p == -1) | |
1207 | { | |
1208 | if (errno != EINTR) | |
1209 | break; | |
1210 | } | |
1211 | else | |
1212 | for (i = 0 ; i < MAX_PROCS; i++) | |
1213 | if (daemon->tcp_pids[i] == p) | |
1214 | daemon->tcp_pids[i] = 0; | |
1215 | break; | |
1216 | ||
1217 | case EVENT_KILLED: | |
c72daea8 | 1218 | my_syslog(LOG_WARNING, _("script process killed by signal %d"), ev.data); |
5aabfc78 SK |
1219 | break; |
1220 | ||
1221 | case EVENT_EXITED: | |
c72daea8 | 1222 | my_syslog(LOG_WARNING, _("script process exited with status %d"), ev.data); |
5aabfc78 SK |
1223 | break; |
1224 | ||
1225 | case EVENT_EXEC_ERR: | |
9e038946 SK |
1226 | my_syslog(LOG_ERR, _("failed to execute %s: %s"), |
1227 | daemon->lease_change_command, strerror(ev.data)); | |
5aabfc78 SK |
1228 | break; |
1229 | ||
1a6bca81 | 1230 | /* necessary for fatal errors in helper */ |
c72daea8 | 1231 | case EVENT_USER_ERR: |
1a6bca81 | 1232 | case EVENT_DIE: |
c72daea8 SK |
1233 | case EVENT_LUA_ERR: |
1234 | fatal_event(&ev, msg); | |
9e038946 SK |
1235 | break; |
1236 | ||
5aabfc78 SK |
1237 | case EVENT_REOPEN: |
1238 | /* Note: this may leave TCP-handling processes with the old file still open. | |
1239 | Since any such process will die in CHILD_LIFETIME or probably much sooner, | |
1240 | we leave them logging to the old file. */ | |
1241 | if (daemon->log_file != NULL) | |
1242 | log_reopen(daemon->log_file); | |
1243 | break; | |
a0358e5d SK |
1244 | |
1245 | case EVENT_NEWADDR: | |
1246 | newaddress(now); | |
1247 | break; | |
47a95169 SK |
1248 | |
1249 | case EVENT_NEWROUTE: | |
1250 | resend_query(); | |
1251 | /* Force re-reading resolv file right now, for luck. */ | |
1252 | poll_resolv(0, 1, now); | |
1253 | break; | |
1254 | ||
5aabfc78 SK |
1255 | case EVENT_TERM: |
1256 | /* Knock all our children on the head. */ | |
1257 | for (i = 0; i < MAX_PROCS; i++) | |
1258 | if (daemon->tcp_pids[i] != 0) | |
1259 | kill(daemon->tcp_pids[i], SIGALRM); | |
1260 | ||
c72daea8 | 1261 | #if defined(HAVE_SCRIPT) |
5aabfc78 SK |
1262 | /* handle pending lease transitions */ |
1263 | if (daemon->helperfd != -1) | |
1264 | { | |
1265 | /* block in writes until all done */ | |
1266 | if ((i = fcntl(daemon->helperfd, F_GETFL)) != -1) | |
1267 | fcntl(daemon->helperfd, F_SETFL, i & ~O_NONBLOCK); | |
1268 | do { | |
1269 | helper_write(); | |
1270 | } while (!helper_buf_empty() || do_script_run(now)); | |
1271 | close(daemon->helperfd); | |
1272 | } | |
1273 | #endif | |
1274 | ||
1275 | if (daemon->lease_stream) | |
1276 | fclose(daemon->lease_stream); | |
73a08a24 SK |
1277 | |
1278 | if (daemon->runfile) | |
1279 | unlink(daemon->runfile); | |
5aabfc78 SK |
1280 | |
1281 | my_syslog(LOG_INFO, _("exiting on receipt of SIGTERM")); | |
1282 | flush_log(); | |
1283 | exit(EC_GOOD); | |
1284 | } | |
3be34541 SK |
1285 | } |
1286 | ||
47a95169 | 1287 | static void poll_resolv(int force, int do_reload, time_t now) |
5aabfc78 SK |
1288 | { |
1289 | struct resolvc *res, *latest; | |
1290 | struct stat statbuf; | |
1291 | time_t last_change = 0; | |
1292 | /* There may be more than one possible file. | |
1293 | Go through and find the one which changed _last_. | |
1294 | Warn of any which can't be read. */ | |
8ef5ada2 | 1295 | |
28866e95 | 1296 | if (daemon->port == 0 || option_bool(OPT_NO_POLL)) |
8ef5ada2 SK |
1297 | return; |
1298 | ||
5aabfc78 SK |
1299 | for (latest = NULL, res = daemon->resolv_files; res; res = res->next) |
1300 | if (stat(res->name, &statbuf) == -1) | |
1301 | { | |
8ef5ada2 SK |
1302 | if (force) |
1303 | { | |
1304 | res->mtime = 0; | |
1305 | continue; | |
1306 | } | |
1307 | ||
5aabfc78 SK |
1308 | if (!res->logged) |
1309 | my_syslog(LOG_WARNING, _("failed to access %s: %s"), res->name, strerror(errno)); | |
1310 | res->logged = 1; | |
8ef5ada2 SK |
1311 | |
1312 | if (res->mtime != 0) | |
1313 | { | |
1314 | /* existing file evaporated, force selection of the latest | |
1315 | file even if its mtime hasn't changed since we last looked */ | |
1316 | poll_resolv(1, do_reload, now); | |
1317 | return; | |
1318 | } | |
5aabfc78 SK |
1319 | } |
1320 | else | |
1321 | { | |
1322 | res->logged = 0; | |
8ef5ada2 SK |
1323 | if (force || (statbuf.st_mtime != res->mtime)) |
1324 | { | |
1325 | res->mtime = statbuf.st_mtime; | |
5aabfc78 SK |
1326 | if (difftime(statbuf.st_mtime, last_change) > 0.0) |
1327 | { | |
1328 | last_change = statbuf.st_mtime; | |
1329 | latest = res; | |
1330 | } | |
1331 | } | |
1332 | } | |
1333 | ||
1334 | if (latest) | |
1335 | { | |
1336 | static int warned = 0; | |
1337 | if (reload_servers(latest->name)) | |
1338 | { | |
1339 | my_syslog(LOG_INFO, _("reading %s"), latest->name); | |
1340 | warned = 0; | |
1341 | check_servers(); | |
28866e95 | 1342 | if (option_bool(OPT_RELOAD) && do_reload) |
8ef5ada2 | 1343 | clear_cache_and_reload(now); |
5aabfc78 SK |
1344 | } |
1345 | else | |
1346 | { | |
1347 | latest->mtime = 0; | |
1348 | if (!warned) | |
1349 | { | |
1350 | my_syslog(LOG_WARNING, _("no servers found in %s, will retry"), latest->name); | |
1351 | warned = 1; | |
1352 | } | |
1353 | } | |
1354 | } | |
1355 | } | |
3d8df260 | 1356 | |
5aabfc78 | 1357 | void clear_cache_and_reload(time_t now) |
3d8df260 | 1358 | { |
408c368f VG |
1359 | (void)now; |
1360 | ||
824af85b | 1361 | if (daemon->port != 0) |
7622fc06 | 1362 | cache_reload(); |
824af85b | 1363 | |
7622fc06 | 1364 | #ifdef HAVE_DHCP |
1f776932 | 1365 | if (daemon->dhcp || daemon->doing_dhcp6) |
3d8df260 | 1366 | { |
28866e95 | 1367 | if (option_bool(OPT_ETHERS)) |
5aabfc78 | 1368 | dhcp_read_ethers(); |
824af85b | 1369 | reread_dhcp(); |
3d8df260 | 1370 | dhcp_update_configs(daemon->dhcp_conf); |
5aabfc78 SK |
1371 | lease_update_from_configs(); |
1372 | lease_update_file(now); | |
353ae4d2 | 1373 | lease_update_dns(1); |
3d8df260 | 1374 | } |
843c96b4 | 1375 | #ifdef HAVE_DHCP6 |
1f776932 | 1376 | else if (daemon->doing_ra) |
2021c662 SK |
1377 | /* Not doing DHCP, so no lease system, manage |
1378 | alarms for ra only */ | |
1379 | send_alarm(periodic_ra(now), now); | |
843c96b4 | 1380 | #endif |
7622fc06 | 1381 | #endif |
3d8df260 SK |
1382 | } |
1383 | ||
5aabfc78 | 1384 | static int set_dns_listeners(time_t now, fd_set *set, int *maxfdp) |
3be34541 SK |
1385 | { |
1386 | struct serverfd *serverfdp; | |
1387 | struct listener *listener; | |
824af85b | 1388 | int wait = 0, i; |
832af0ba SK |
1389 | |
1390 | #ifdef HAVE_TFTP | |
1391 | int tftp = 0; | |
1392 | struct tftp_transfer *transfer; | |
1393 | for (transfer = daemon->tftp_trans; transfer; transfer = transfer->next) | |
1394 | { | |
1395 | tftp++; | |
1396 | FD_SET(transfer->sockfd, set); | |
1397 | bump_maxfd(transfer->sockfd, maxfdp); | |
1398 | } | |
1399 | #endif | |
1400 | ||
1697269c | 1401 | /* will we be able to get memory? */ |
824af85b | 1402 | if (daemon->port != 0) |
3a237152 | 1403 | get_new_frec(now, &wait, 0); |
1697269c | 1404 | |
3be34541 SK |
1405 | for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next) |
1406 | { | |
1407 | FD_SET(serverfdp->fd, set); | |
1697269c | 1408 | bump_maxfd(serverfdp->fd, maxfdp); |
3be34541 | 1409 | } |
1a6bca81 SK |
1410 | |
1411 | if (daemon->port != 0 && !daemon->osport) | |
1412 | for (i = 0; i < RANDOM_SOCKS; i++) | |
1413 | if (daemon->randomsocks[i].refcount != 0) | |
1414 | { | |
1415 | FD_SET(daemon->randomsocks[i].fd, set); | |
1416 | bump_maxfd(daemon->randomsocks[i].fd, maxfdp); | |
1417 | } | |
1418 | ||
3be34541 SK |
1419 | for (listener = daemon->listeners; listener; listener = listener->next) |
1420 | { | |
1697269c | 1421 | /* only listen for queries if we have resources */ |
824af85b | 1422 | if (listener->fd != -1 && wait == 0) |
1697269c SK |
1423 | { |
1424 | FD_SET(listener->fd, set); | |
1425 | bump_maxfd(listener->fd, maxfdp); | |
1426 | } | |
1427 | ||
1428 | /* death of a child goes through the select loop, so | |
1429 | we don't need to explicitly arrange to wake up here */ | |
824af85b SK |
1430 | if (listener->tcpfd != -1) |
1431 | for (i = 0; i < MAX_PROCS; i++) | |
1432 | if (daemon->tcp_pids[i] == 0) | |
1433 | { | |
1434 | FD_SET(listener->tcpfd, set); | |
1435 | bump_maxfd(listener->tcpfd, maxfdp); | |
1436 | break; | |
1437 | } | |
9e4abcb5 | 1438 | |
832af0ba SK |
1439 | #ifdef HAVE_TFTP |
1440 | if (tftp <= daemon->tftp_max && listener->tftpfd != -1) | |
1441 | { | |
1442 | FD_SET(listener->tftpfd, set); | |
1443 | bump_maxfd(listener->tftpfd, maxfdp); | |
1444 | } | |
1445 | #endif | |
1446 | ||
1447 | } | |
1448 | ||
1697269c | 1449 | return wait; |
3be34541 | 1450 | } |
9e4abcb5 | 1451 | |
5aabfc78 | 1452 | static void check_dns_listeners(fd_set *set, time_t now) |
3be34541 SK |
1453 | { |
1454 | struct serverfd *serverfdp; | |
1a6bca81 SK |
1455 | struct listener *listener; |
1456 | int i; | |
1457 | ||
832af0ba SK |
1458 | for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next) |
1459 | if (FD_ISSET(serverfdp->fd, set)) | |
1a6bca81 SK |
1460 | reply_query(serverfdp->fd, serverfdp->source_addr.sa.sa_family, now); |
1461 | ||
1462 | if (daemon->port != 0 && !daemon->osport) | |
1463 | for (i = 0; i < RANDOM_SOCKS; i++) | |
1464 | if (daemon->randomsocks[i].refcount != 0 && | |
1465 | FD_ISSET(daemon->randomsocks[i].fd, set)) | |
1466 | reply_query(daemon->randomsocks[i].fd, daemon->randomsocks[i].family, now); | |
832af0ba SK |
1467 | |
1468 | for (listener = daemon->listeners; listener; listener = listener->next) | |
1469 | { | |
824af85b | 1470 | if (listener->fd != -1 && FD_ISSET(listener->fd, set)) |
5aabfc78 | 1471 | receive_query(listener, now); |
1a6bca81 | 1472 | |
832af0ba SK |
1473 | #ifdef HAVE_TFTP |
1474 | if (listener->tftpfd != -1 && FD_ISSET(listener->tftpfd, set)) | |
5aabfc78 | 1475 | tftp_request(listener, now); |
832af0ba | 1476 | #endif |
3be34541 | 1477 | |
824af85b | 1478 | if (listener->tcpfd != -1 && FD_ISSET(listener->tcpfd, set)) |
832af0ba | 1479 | { |
22ce550e | 1480 | int confd, client_ok = 1; |
832af0ba SK |
1481 | struct irec *iface = NULL; |
1482 | pid_t p; | |
52d4abf2 SK |
1483 | union mysockaddr tcp_addr; |
1484 | socklen_t tcp_len = sizeof(union mysockaddr); | |
1485 | ||
1486 | while ((confd = accept(listener->tcpfd, NULL, NULL)) == -1 && errno == EINTR); | |
832af0ba | 1487 | |
46b06656 | 1488 | if (confd == -1) |
832af0ba | 1489 | continue; |
76dd75de | 1490 | |
46b06656 SK |
1491 | if (getsockname(confd, (struct sockaddr *)&tcp_addr, &tcp_len) == -1) |
1492 | { | |
1493 | close(confd); | |
1494 | continue; | |
1495 | } | |
76dd75de SK |
1496 | |
1497 | /* Make sure that the interface list is up-to-date. | |
1498 | ||
1499 | We do this here as we may need the results below, and | |
1500 | the DNS code needs them for --interface-name stuff. | |
1501 | ||
1502 | Multiple calls to enumerate_interfaces() per select loop are | |
1503 | inhibited, so calls to it in the child process (which doesn't select()) | |
1504 | have no effect. This avoids two processes reading from the same | |
1505 | netlink fd and screwing the pooch entirely. | |
1506 | */ | |
e25db1f2 | 1507 | |
76dd75de SK |
1508 | enumerate_interfaces(0); |
1509 | ||
1510 | if (option_bool(OPT_NOWILD)) | |
1511 | iface = listener->iface; /* May be NULL */ | |
1512 | else | |
1513 | { | |
1514 | int if_index; | |
1515 | char intr_name[IF_NAMESIZE]; | |
1516 | ||
1517 | /* if we can find the arrival interface, check it's one that's allowed */ | |
1518 | if ((if_index = tcp_interface(confd, tcp_addr.sa.sa_family)) != 0 && | |
1519 | indextoname(listener->tcpfd, if_index, intr_name)) | |
1520 | { | |
1521 | struct all_addr addr; | |
1522 | addr.addr.addr4 = tcp_addr.in.sin_addr; | |
e25db1f2 | 1523 | #ifdef HAVE_IPV6 |
76dd75de SK |
1524 | if (tcp_addr.sa.sa_family == AF_INET6) |
1525 | addr.addr.addr6 = tcp_addr.in6.sin6_addr; | |
e25db1f2 | 1526 | #endif |
76dd75de SK |
1527 | |
1528 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1529 | if (iface->index == if_index) | |
1530 | break; | |
1531 | ||
1532 | if (!iface && !loopback_exception(listener->tcpfd, tcp_addr.sa.sa_family, &addr, intr_name)) | |
1533 | client_ok = 0; | |
1534 | } | |
1535 | ||
1536 | if (option_bool(OPT_CLEVERBIND)) | |
1537 | iface = listener->iface; /* May be NULL */ | |
1538 | else | |
1539 | { | |
1540 | /* Check for allowed interfaces when binding the wildcard address: | |
1541 | we do this by looking for an interface with the same address as | |
1542 | the local address of the TCP connection, then looking to see if that's | |
1543 | an allowed interface. As a side effect, we get the netmask of the | |
1544 | interface too, for localisation. */ | |
1545 | ||
1546 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1547 | if (sockaddr_isequal(&iface->addr, &tcp_addr)) | |
1548 | break; | |
1549 | ||
1550 | if (!iface) | |
1551 | client_ok = 0; | |
1552 | } | |
1553 | } | |
1554 | ||
22ce550e | 1555 | if (!client_ok) |
832af0ba SK |
1556 | { |
1557 | shutdown(confd, SHUT_RDWR); | |
1558 | close(confd); | |
1559 | } | |
59353a6b | 1560 | #ifndef NO_FORK |
28866e95 | 1561 | else if (!option_bool(OPT_DEBUG) && (p = fork()) != 0) |
832af0ba SK |
1562 | { |
1563 | if (p != -1) | |
1564 | { | |
1565 | int i; | |
1566 | for (i = 0; i < MAX_PROCS; i++) | |
1567 | if (daemon->tcp_pids[i] == 0) | |
1568 | { | |
1569 | daemon->tcp_pids[i] = p; | |
1570 | break; | |
1571 | } | |
1572 | } | |
1573 | close(confd); | |
1574 | } | |
1575 | #endif | |
1576 | else | |
1577 | { | |
1578 | unsigned char *buff; | |
1579 | struct server *s; | |
1580 | int flags; | |
52d4abf2 | 1581 | struct in_addr netmask; |
4f7b304f | 1582 | int auth_dns; |
52d4abf2 SK |
1583 | |
1584 | if (iface) | |
4f7b304f SK |
1585 | { |
1586 | netmask = iface->netmask; | |
1587 | auth_dns = iface->dns_auth; | |
1588 | } | |
52d4abf2 | 1589 | else |
4f7b304f SK |
1590 | { |
1591 | netmask.s_addr = 0; | |
1592 | auth_dns = 0; | |
1593 | } | |
52d4abf2 | 1594 | |
8ef5ada2 SK |
1595 | #ifndef NO_FORK |
1596 | /* Arrange for SIGALARM after CHILD_LIFETIME seconds to | |
1597 | terminate the process. */ | |
28866e95 | 1598 | if (!option_bool(OPT_DEBUG)) |
832af0ba | 1599 | alarm(CHILD_LIFETIME); |
8ef5ada2 SK |
1600 | #endif |
1601 | ||
832af0ba SK |
1602 | /* start with no upstream connections. */ |
1603 | for (s = daemon->servers; s; s = s->next) | |
7cebd20f | 1604 | s->tcpfd = -1; |
832af0ba SK |
1605 | |
1606 | /* The connected socket inherits non-blocking | |
1607 | attribute from the listening socket. | |
1608 | Reset that here. */ | |
1609 | if ((flags = fcntl(confd, F_GETFL, 0)) != -1) | |
1610 | fcntl(confd, F_SETFL, flags & ~O_NONBLOCK); | |
1611 | ||
4f7b304f | 1612 | buff = tcp_request(confd, now, &tcp_addr, netmask, auth_dns); |
7cebd20f | 1613 | |
832af0ba SK |
1614 | shutdown(confd, SHUT_RDWR); |
1615 | close(confd); | |
1616 | ||
1617 | if (buff) | |
1618 | free(buff); | |
1619 | ||
1620 | for (s = daemon->servers; s; s = s->next) | |
1621 | if (s->tcpfd != -1) | |
1622 | { | |
1623 | shutdown(s->tcpfd, SHUT_RDWR); | |
1624 | close(s->tcpfd); | |
1625 | } | |
7cebd20f | 1626 | #ifndef NO_FORK |
28866e95 | 1627 | if (!option_bool(OPT_DEBUG)) |
5aabfc78 SK |
1628 | { |
1629 | flush_log(); | |
1630 | _exit(0); | |
1631 | } | |
59353a6b | 1632 | #endif |
832af0ba SK |
1633 | } |
1634 | } | |
1635 | } | |
3be34541 SK |
1636 | } |
1637 | ||
7622fc06 | 1638 | #ifdef HAVE_DHCP |
5e9e0efb SK |
1639 | int make_icmp_sock(void) |
1640 | { | |
7cebd20f | 1641 | int fd; |
5e9e0efb SK |
1642 | int zeroopt = 0; |
1643 | ||
1644 | if ((fd = socket (AF_INET, SOCK_RAW, IPPROTO_ICMP)) != -1) | |
1645 | { | |
7cebd20f | 1646 | if (!fix_fd(fd) || |
5e9e0efb SK |
1647 | setsockopt(fd, SOL_SOCKET, SO_DONTROUTE, &zeroopt, sizeof(zeroopt)) == -1) |
1648 | { | |
1649 | close(fd); | |
1650 | fd = -1; | |
1651 | } | |
1652 | } | |
1653 | ||
1654 | return fd; | |
1655 | } | |
1656 | ||
5aabfc78 | 1657 | int icmp_ping(struct in_addr addr) |
3be34541 | 1658 | { |
5e9e0efb | 1659 | /* Try and get an ICMP echo from a machine. */ |
3be34541 SK |
1660 | |
1661 | /* Note that whilst in the three second wait, we check for | |
832af0ba | 1662 | (and service) events on the DNS and TFTP sockets, (so doing that |
3be34541 SK |
1663 | better not use any resources our caller has in use...) |
1664 | but we remain deaf to signals or further DHCP packets. */ | |
1665 | ||
5e9e0efb | 1666 | int fd; |
3be34541 SK |
1667 | struct sockaddr_in saddr; |
1668 | struct { | |
1669 | struct ip ip; | |
1670 | struct icmp icmp; | |
1671 | } packet; | |
1672 | unsigned short id = rand16(); | |
1673 | unsigned int i, j; | |
5e9e0efb | 1674 | int gotreply = 0; |
3be34541 | 1675 | time_t start, now; |
5e9e0efb | 1676 | |
824af85b | 1677 | #if defined(HAVE_LINUX_NETWORK) || defined (HAVE_SOLARIS_NETWORK) |
5e9e0efb SK |
1678 | if ((fd = make_icmp_sock()) == -1) |
1679 | return 0; | |
1680 | #else | |
1681 | int opt = 2000; | |
1682 | fd = daemon->dhcp_icmp_fd; | |
1683 | setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)); | |
1684 | #endif | |
1685 | ||
3be34541 SK |
1686 | saddr.sin_family = AF_INET; |
1687 | saddr.sin_port = 0; | |
1688 | saddr.sin_addr = addr; | |
1689 | #ifdef HAVE_SOCKADDR_SA_LEN | |
1690 | saddr.sin_len = sizeof(struct sockaddr_in); | |
1691 | #endif | |
1692 | ||
1693 | memset(&packet.icmp, 0, sizeof(packet.icmp)); | |
1694 | packet.icmp.icmp_type = ICMP_ECHO; | |
1695 | packet.icmp.icmp_id = id; | |
1696 | for (j = 0, i = 0; i < sizeof(struct icmp) / 2; i++) | |
1697 | j += ((u16 *)&packet.icmp)[i]; | |
1698 | while (j>>16) | |
1699 | j = (j & 0xffff) + (j >> 16); | |
1700 | packet.icmp.icmp_cksum = (j == 0xffff) ? j : ~j; | |
1701 | ||
5e9e0efb | 1702 | while (sendto(fd, (char *)&packet.icmp, sizeof(struct icmp), 0, |
fd9fa481 SK |
1703 | (struct sockaddr *)&saddr, sizeof(saddr)) == -1 && |
1704 | retry_send()); | |
1705 | ||
5e9e0efb SK |
1706 | for (now = start = dnsmasq_time(); |
1707 | difftime(now, start) < (float)PING_WAIT;) | |
fd9fa481 SK |
1708 | { |
1709 | struct timeval tv; | |
f2621c7f | 1710 | fd_set rset, wset; |
fd9fa481 | 1711 | struct sockaddr_in faddr; |
1697269c | 1712 | int maxfd = fd; |
3d8df260 | 1713 | socklen_t len = sizeof(faddr); |
fd9fa481 SK |
1714 | |
1715 | tv.tv_usec = 250000; | |
1716 | tv.tv_sec = 0; | |
1717 | ||
1718 | FD_ZERO(&rset); | |
f2621c7f | 1719 | FD_ZERO(&wset); |
5e9e0efb | 1720 | FD_SET(fd, &rset); |
5aabfc78 | 1721 | set_dns_listeners(now, &rset, &maxfd); |
f2621c7f | 1722 | set_log_writer(&wset, &maxfd); |
c5ad4e79 SK |
1723 | |
1724 | #ifdef HAVE_DHCP6 | |
1f776932 | 1725 | if (daemon->doing_ra) |
c5ad4e79 SK |
1726 | { |
1727 | FD_SET(daemon->icmp6fd, &rset); | |
1728 | bump_maxfd(daemon->icmp6fd, &maxfd); | |
1729 | } | |
1730 | #endif | |
1731 | ||
f2621c7f SK |
1732 | if (select(maxfd+1, &rset, &wset, NULL, &tv) < 0) |
1733 | { | |
1734 | FD_ZERO(&rset); | |
1735 | FD_ZERO(&wset); | |
1736 | } | |
1737 | ||
5e9e0efb | 1738 | now = dnsmasq_time(); |
f2621c7f SK |
1739 | |
1740 | check_log_writer(&wset); | |
5aabfc78 | 1741 | check_dns_listeners(&rset, now); |
832af0ba | 1742 | |
c5ad4e79 | 1743 | #ifdef HAVE_DHCP6 |
1f776932 SK |
1744 | if (daemon->doing_ra && FD_ISSET(daemon->icmp6fd, &rset)) |
1745 | icmp6_packet(now); | |
c5ad4e79 SK |
1746 | #endif |
1747 | ||
832af0ba | 1748 | #ifdef HAVE_TFTP |
5aabfc78 | 1749 | check_tftp_listeners(&rset, now); |
832af0ba SK |
1750 | #endif |
1751 | ||
5e9e0efb SK |
1752 | if (FD_ISSET(fd, &rset) && |
1753 | recvfrom(fd, &packet, sizeof(packet), 0, | |
fd9fa481 SK |
1754 | (struct sockaddr *)&faddr, &len) == sizeof(packet) && |
1755 | saddr.sin_addr.s_addr == faddr.sin_addr.s_addr && | |
1756 | packet.icmp.icmp_type == ICMP_ECHOREPLY && | |
1757 | packet.icmp.icmp_seq == 0 && | |
1758 | packet.icmp.icmp_id == id) | |
1759 | { | |
1760 | gotreply = 1; | |
1761 | break; | |
1762 | } | |
1763 | } | |
1764 | ||
824af85b | 1765 | #if defined(HAVE_LINUX_NETWORK) || defined(HAVE_SOLARIS_NETWORK) |
5e9e0efb SK |
1766 | close(fd); |
1767 | #else | |
3be34541 | 1768 | opt = 1; |
5e9e0efb SK |
1769 | setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)); |
1770 | #endif | |
1771 | ||
3be34541 SK |
1772 | return gotreply; |
1773 | } | |
7622fc06 | 1774 | #endif |
0a852541 SK |
1775 | |
1776 |