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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); | |
9e4abcb5 SK |
33 | |
34 | int main (int argc, char **argv) | |
35 | { | |
de37951c | 36 | int bind_fallback = 0; |
9009d746 | 37 | time_t now; |
9e4abcb5 | 38 | struct sigaction sigact; |
26128d27 | 39 | struct iname *if_tmp; |
1a6bca81 SK |
40 | int piperead, pipefd[2], err_pipe[2]; |
41 | struct passwd *ent_pw = NULL; | |
c72daea8 | 42 | #if defined(HAVE_SCRIPT) |
1a6bca81 SK |
43 | uid_t script_uid = 0; |
44 | gid_t script_gid = 0; | |
7622fc06 SK |
45 | #endif |
46 | struct group *gp = NULL; | |
5aabfc78 | 47 | long i, max_fd = sysconf(_SC_OPEN_MAX); |
1a6bca81 SK |
48 | char *baduser = NULL; |
49 | int log_err; | |
50 | #if defined(HAVE_LINUX_NETWORK) | |
51 | cap_user_header_t hdr = NULL; | |
52 | cap_user_data_t data = NULL; | |
3b3f4411 SK |
53 | char *bound_device = NULL; |
54 | int did_bind = 0; | |
1a6bca81 | 55 | #endif |
408c368f | 56 | #if defined(HAVE_DHCP) || defined(HAVE_DHCP6) |
1f776932 | 57 | struct dhcp_context *context; |
ff7eea27 | 58 | struct dhcp_relay *relay; |
408c368f | 59 | #endif |
5aabfc78 | 60 | |
824af85b | 61 | #ifdef LOCALEDIR |
b8187c80 SK |
62 | setlocale(LC_ALL, ""); |
63 | bindtextdomain("dnsmasq", LOCALEDIR); | |
64 | textdomain("dnsmasq"); | |
65 | #endif | |
66 | ||
9e4abcb5 SK |
67 | sigact.sa_handler = sig_handler; |
68 | sigact.sa_flags = 0; | |
69 | sigemptyset(&sigact.sa_mask); | |
70 | sigaction(SIGUSR1, &sigact, NULL); | |
5aabfc78 | 71 | sigaction(SIGUSR2, &sigact, NULL); |
9e4abcb5 SK |
72 | sigaction(SIGHUP, &sigact, NULL); |
73 | sigaction(SIGTERM, &sigact, NULL); | |
44a2a316 | 74 | sigaction(SIGALRM, &sigact, NULL); |
feba5c1d SK |
75 | sigaction(SIGCHLD, &sigact, NULL); |
76 | ||
77 | /* ignore SIGPIPE */ | |
78 | sigact.sa_handler = SIG_IGN; | |
79 | sigaction(SIGPIPE, &sigact, NULL); | |
9e4abcb5 | 80 | |
5aabfc78 SK |
81 | umask(022); /* known umask, create leases and pid files as 0644 */ |
82 | ||
83 | read_opts(argc, argv, compile_opts); | |
c3e0b9b6 | 84 | |
3be34541 | 85 | if (daemon->edns_pktsz < PACKETSZ) |
60b68069 SK |
86 | daemon->edns_pktsz = PACKETSZ; |
87 | #ifdef HAVE_DNSSEC | |
88 | /* Enforce min packet big enough for DNSSEC */ | |
89 | if (option_bool(OPT_DNSSEC_VALID) && daemon->edns_pktsz < EDNS_PKTSZ) | |
90 | daemon->edns_pktsz = EDNS_PKTSZ; | |
91 | #endif | |
3ddacb86 | 92 | |
0a852541 SK |
93 | daemon->packet_buff_sz = daemon->edns_pktsz > DNSMASQ_PACKETSZ ? |
94 | daemon->edns_pktsz : DNSMASQ_PACKETSZ; | |
95 | daemon->packet = safe_malloc(daemon->packet_buff_sz); | |
3ddacb86 | 96 | |
c72daea8 | 97 | daemon->addrbuff = safe_malloc(ADDRSTRLEN); |
3ddacb86 SK |
98 | |
99 | #ifdef HAVE_DNSSEC | |
100 | if (option_bool(OPT_DNSSEC_VALID)) | |
101 | daemon->keyname = safe_malloc(MAXDNAME); | |
102 | #endif | |
4f7b304f | 103 | |
7622fc06 | 104 | #ifdef HAVE_DHCP |
3be34541 | 105 | if (!daemon->lease_file) |
9e4abcb5 | 106 | { |
52b92f4d | 107 | if (daemon->dhcp || daemon->dhcp6) |
3be34541 | 108 | daemon->lease_file = LEASEFILE; |
9e4abcb5 | 109 | } |
7622fc06 | 110 | #endif |
9e4abcb5 | 111 | |
a2761754 SK |
112 | /* Close any file descriptors we inherited apart from std{in|out|err} |
113 | ||
114 | Ensure that at least stdin, stdout and stderr (fd 0, 1, 2) exist, | |
115 | otherwise file descriptors we create can end up being 0, 1, or 2 | |
116 | and then get accidentally closed later when we make 0, 1, and 2 | |
117 | open to /dev/null. Normally we'll be started with 0, 1 and 2 open, | |
118 | but it's not guaranteed. By opening /dev/null three times, we | |
119 | ensure that we're not using those fds for real stuff. */ | |
5aabfc78 SK |
120 | for (i = 0; i < max_fd; i++) |
121 | if (i != STDOUT_FILENO && i != STDERR_FILENO && i != STDIN_FILENO) | |
122 | close(i); | |
a2761754 SK |
123 | else |
124 | open("/dev/null", O_RDWR); | |
5aabfc78 | 125 | |
801ca9a7 SK |
126 | #ifndef HAVE_LINUX_NETWORK |
127 | # if !(defined(IP_RECVDSTADDR) && defined(IP_RECVIF) && defined(IP_SENDSRCADDR)) | |
28866e95 | 128 | if (!option_bool(OPT_NOWILD)) |
de37951c SK |
129 | { |
130 | bind_fallback = 1; | |
28866e95 | 131 | set_option_bool(OPT_NOWILD); |
de37951c | 132 | } |
801ca9a7 | 133 | # endif |
2b5bae9a SK |
134 | |
135 | /* -- bind-dynamic not supported on !Linux, fall back to --bind-interfaces */ | |
54dd393f | 136 | if (option_bool(OPT_CLEVERBIND)) |
2b5bae9a SK |
137 | { |
138 | bind_fallback = 1; | |
139 | set_option_bool(OPT_NOWILD); | |
236e072c | 140 | reset_option_bool(OPT_CLEVERBIND); |
2b5bae9a | 141 | } |
309331f5 | 142 | #endif |
2b5bae9a | 143 | |
0744ca66 SK |
144 | if (option_bool(OPT_DNSSEC_VALID)) |
145 | { | |
3ddacb86 | 146 | #ifdef HAVE_DNSSEC |
ee415867 | 147 | if (!daemon->ds) |
0744ca66 SK |
148 | die(_("No trust anchors provided for DNSSEC"), NULL, EC_BADCONF); |
149 | ||
150 | if (daemon->cachesize < CACHESIZ) | |
151 | die(_("Cannot reduce cache size from default when DNSSEC enabled"), NULL, EC_BADCONF); | |
152 | #else | |
153 | die(_("DNSSEC not available: set HAVE_DNSSEC in src/config.h"), NULL, EC_BADCONF); | |
3ddacb86 | 154 | #endif |
0744ca66 | 155 | } |
3ddacb86 | 156 | |
832af0ba | 157 | #ifndef HAVE_TFTP |
9b40cbf5 | 158 | if (option_bool(OPT_TFTP)) |
5aabfc78 | 159 | die(_("TFTP server not available: set HAVE_TFTP in src/config.h"), NULL, EC_BADCONF); |
832af0ba SK |
160 | #endif |
161 | ||
7de060b0 SK |
162 | #ifdef HAVE_CONNTRACK |
163 | if (option_bool(OPT_CONNTRACK) && (daemon->query_port != 0 || daemon->osport)) | |
164 | die (_("Cannot use --conntrack AND --query-port"), NULL, EC_BADCONF); | |
165 | #else | |
166 | if (option_bool(OPT_CONNTRACK)) | |
167 | die(_("Conntrack support not available: set HAVE_CONNTRACK in src/config.h"), NULL, EC_BADCONF); | |
168 | #endif | |
169 | ||
824af85b SK |
170 | #ifdef HAVE_SOLARIS_NETWORK |
171 | if (daemon->max_logs != 0) | |
172 | die(_("asychronous logging is not available under Solaris"), NULL, EC_BADCONF); | |
173 | #endif | |
174 | ||
572b41eb SK |
175 | #ifdef __ANDROID__ |
176 | if (daemon->max_logs != 0) | |
177 | die(_("asychronous logging is not available under Android"), NULL, EC_BADCONF); | |
178 | #endif | |
179 | ||
4820dce9 SK |
180 | #ifndef HAVE_AUTH |
181 | if (daemon->authserver) | |
182 | die(_("authoritative DNS not available: set HAVE_AUTH in src/config.h"), NULL, EC_BADCONF); | |
183 | #endif | |
184 | ||
1a6bca81 SK |
185 | rand_init(); |
186 | ||
5aabfc78 | 187 | now = dnsmasq_time(); |
4f7b304f | 188 | |
b0ff858e | 189 | /* Create a serial at startup if not configured. */ |
4f7b304f SK |
190 | if (daemon->authinterface && daemon->soa_sn == 0) |
191 | #ifdef HAVE_BROKEN_RTC | |
b0ff858e | 192 | die(_("zone serial must be configured in --auth-soa"), NULL, EC_BADCONF); |
4f7b304f SK |
193 | #else |
194 | daemon->soa_sn = now; | |
195 | #endif | |
5aabfc78 | 196 | |
ff7eea27 SK |
197 | #ifdef HAVE_DHCP6 |
198 | if (daemon->dhcp6) | |
199 | { | |
200 | daemon->doing_ra = option_bool(OPT_RA); | |
1f776932 | 201 | |
ff7eea27 | 202 | for (context = daemon->dhcp6; context; context = context->next) |
1f776932 | 203 | { |
ff7eea27 SK |
204 | if (context->flags & CONTEXT_DHCP) |
205 | daemon->doing_dhcp6 = 1; | |
206 | if (context->flags & CONTEXT_RA) | |
207 | daemon->doing_ra = 1; | |
1ee9be4c | 208 | #if !defined(HAVE_LINUX_NETWORK) && !defined(HAVE_BSD_NETWORK) |
ff7eea27 SK |
209 | if (context->flags & CONTEXT_TEMPLATE) |
210 | die (_("dhcp-range constructor not available on this platform"), NULL, EC_BADCONF); | |
bb86e858 | 211 | #endif |
1f776932 | 212 | } |
ff7eea27 SK |
213 | } |
214 | #endif | |
215 | ||
216 | #ifdef HAVE_DHCP | |
217 | /* Note that order matters here, we must call lease_init before | |
218 | creating any file descriptors which shouldn't be leaked | |
219 | to the lease-script init process. We need to call common_init | |
220 | before lease_init to allocate buffers it uses.*/ | |
221 | if (daemon->dhcp || daemon->doing_dhcp6 || daemon->relay4 || daemon->relay6) | |
222 | { | |
223 | dhcp_common_init(); | |
1f776932 | 224 | if (daemon->dhcp || daemon->doing_dhcp6) |
ff7eea27 SK |
225 | lease_init(now); |
226 | } | |
227 | ||
228 | if (daemon->dhcp || daemon->relay4) | |
229 | dhcp_init(); | |
230 | ||
843c96b4 | 231 | # ifdef HAVE_DHCP6 |
89500e31 | 232 | if (daemon->doing_ra || daemon->doing_dhcp6 || daemon->relay6) |
ff7eea27 SK |
233 | ra_init(now); |
234 | ||
235 | if (daemon->doing_dhcp6 || daemon->relay6) | |
236 | dhcp6_init(); | |
801ca9a7 SK |
237 | # endif |
238 | ||
239 | #endif | |
240 | ||
13d86c73 JD |
241 | #ifdef HAVE_IPSET |
242 | if (daemon->ipsets) | |
243 | ipset_init(); | |
244 | #endif | |
245 | ||
1ee9be4c | 246 | #if defined(HAVE_LINUX_NETWORK) |
801ca9a7 | 247 | netlink_init(); |
1ee9be4c SK |
248 | #elif defined(HAVE_BSD_NETWORK) |
249 | route_init(); | |
801ca9a7 SK |
250 | #endif |
251 | ||
1ee9be4c SK |
252 | if (option_bool(OPT_NOWILD) && option_bool(OPT_CLEVERBIND)) |
253 | die(_("cannot set --bind-interfaces and --bind-dynamic"), NULL, EC_BADCONF); | |
254 | ||
115ac3e4 | 255 | if (!enumerate_interfaces(1) || !enumerate_interfaces(0)) |
5aabfc78 | 256 | die(_("failed to find list of interfaces: %s"), NULL, EC_MISC); |
843c96b4 | 257 | |
54dd393f | 258 | if (option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND)) |
de37951c | 259 | { |
74c95c25 | 260 | create_bound_listeners(1); |
54dd393f SK |
261 | |
262 | if (!option_bool(OPT_CLEVERBIND)) | |
263 | for (if_tmp = daemon->if_names; if_tmp; if_tmp = if_tmp->next) | |
264 | if (if_tmp->name && !if_tmp->used) | |
265 | die(_("unknown interface %s"), if_tmp->name, EC_BADNET); | |
9380ba70 SK |
266 | |
267 | #if defined(HAVE_LINUX_NETWORK) && defined(HAVE_DHCP) | |
268 | /* after enumerate_interfaces() */ | |
3b3f4411 SK |
269 | bound_device = whichdevice(); |
270 | ||
9380ba70 SK |
271 | if (daemon->dhcp) |
272 | { | |
3b3f4411 SK |
273 | if (!daemon->relay4 && bound_device) |
274 | { | |
275 | bindtodevice(bound_device, daemon->dhcpfd); | |
276 | did_bind = 1; | |
277 | } | |
278 | if (daemon->enable_pxe && bound_device) | |
279 | { | |
280 | bindtodevice(bound_device, daemon->pxefd); | |
281 | did_bind = 1; | |
282 | } | |
9380ba70 SK |
283 | } |
284 | #endif | |
285 | ||
286 | #if defined(HAVE_LINUX_NETWORK) && defined(HAVE_DHCP6) | |
3b3f4411 SK |
287 | if (daemon->doing_dhcp6 && !daemon->relay6 && bound_device) |
288 | { | |
289 | bindtodevice(bound_device, daemon->dhcp6fd); | |
290 | did_bind = 1; | |
291 | } | |
9380ba70 | 292 | #endif |
de37951c | 293 | } |
28866e95 | 294 | else |
74c95c25 | 295 | create_wildcard_listeners(); |
5d162f20 SK |
296 | |
297 | #ifdef HAVE_DHCP6 | |
298 | /* after enumerate_interfaces() */ | |
ff7eea27 | 299 | if (daemon->doing_dhcp6 || daemon->relay6 || daemon->doing_ra) |
5d162f20 | 300 | join_multicast(1); |
3511a928 SK |
301 | |
302 | /* After netlink_init() and before create_helper() */ | |
303 | lease_make_duid(now); | |
5d162f20 | 304 | #endif |
de37951c | 305 | |
824af85b | 306 | if (daemon->port != 0) |
82e3f45a SK |
307 | { |
308 | cache_init(); | |
309 | #ifdef HAVE_DNSSEC | |
310 | blockdata_init(); | |
311 | #endif | |
312 | } | |
1a6bca81 | 313 | |
28866e95 | 314 | if (option_bool(OPT_DBUS)) |
3d8df260 SK |
315 | #ifdef HAVE_DBUS |
316 | { | |
317 | char *err; | |
318 | daemon->dbus = NULL; | |
319 | daemon->watches = NULL; | |
5aabfc78 SK |
320 | if ((err = dbus_init())) |
321 | die(_("DBus error: %s"), err, EC_MISC); | |
3d8df260 SK |
322 | } |
323 | #else | |
5aabfc78 | 324 | die(_("DBus not available: set HAVE_DBUS in src/config.h"), NULL, EC_BADCONF); |
3d8df260 SK |
325 | #endif |
326 | ||
824af85b SK |
327 | if (daemon->port != 0) |
328 | pre_allocate_sfds(); | |
1a6bca81 | 329 | |
c72daea8 | 330 | #if defined(HAVE_SCRIPT) |
1a6bca81 | 331 | /* Note getpwnam returns static storage */ |
843c96b4 SK |
332 | if ((daemon->dhcp || daemon->dhcp6) && |
333 | daemon->scriptuser && | |
c72daea8 | 334 | (daemon->lease_change_command || daemon->luascript)) |
1a6bca81 SK |
335 | { |
336 | if ((ent_pw = getpwnam(daemon->scriptuser))) | |
337 | { | |
338 | script_uid = ent_pw->pw_uid; | |
339 | script_gid = ent_pw->pw_gid; | |
340 | } | |
341 | else | |
342 | baduser = daemon->scriptuser; | |
343 | } | |
7622fc06 | 344 | #endif |
9e4abcb5 | 345 | |
1a6bca81 SK |
346 | if (daemon->username && !(ent_pw = getpwnam(daemon->username))) |
347 | baduser = daemon->username; | |
348 | else if (daemon->groupname && !(gp = getgrnam(daemon->groupname))) | |
349 | baduser = daemon->groupname; | |
350 | ||
351 | if (baduser) | |
352 | die(_("unknown user or group: %s"), baduser, EC_BADCONF); | |
353 | ||
354 | /* implement group defaults, "dip" if available, or group associated with uid */ | |
355 | if (!daemon->group_set && !gp) | |
356 | { | |
357 | if (!(gp = getgrnam(CHGRP)) && ent_pw) | |
358 | gp = getgrgid(ent_pw->pw_gid); | |
359 | ||
360 | /* for error message */ | |
361 | if (gp) | |
362 | daemon->groupname = gp->gr_name; | |
363 | } | |
364 | ||
365 | #if defined(HAVE_LINUX_NETWORK) | |
366 | /* determine capability API version here, while we can still | |
367 | call safe_malloc */ | |
368 | if (ent_pw && ent_pw->pw_uid != 0) | |
369 | { | |
1a6bca81 | 370 | int capsize = 1; /* for header version 1 */ |
3927da46 SK |
371 | hdr = safe_malloc(sizeof(*hdr)); |
372 | ||
1a6bca81 SK |
373 | /* find version supported by kernel */ |
374 | memset(hdr, 0, sizeof(*hdr)); | |
375 | capget(hdr, NULL); | |
376 | ||
377 | if (hdr->version != LINUX_CAPABILITY_VERSION_1) | |
378 | { | |
379 | /* if unknown version, use largest supported version (3) */ | |
380 | if (hdr->version != LINUX_CAPABILITY_VERSION_2) | |
381 | hdr->version = LINUX_CAPABILITY_VERSION_3; | |
382 | capsize = 2; | |
383 | } | |
384 | ||
385 | data = safe_malloc(sizeof(*data) * capsize); | |
386 | memset(data, 0, sizeof(*data) * capsize); | |
387 | } | |
388 | #endif | |
389 | ||
5aabfc78 | 390 | /* Use a pipe to carry signals and other events back to the event loop |
1a6bca81 SK |
391 | in a race-free manner and another to carry errors to daemon-invoking process */ |
392 | safe_pipe(pipefd, 1); | |
5e9e0efb SK |
393 | |
394 | piperead = pipefd[0]; | |
395 | pipewrite = pipefd[1]; | |
396 | /* prime the pipe to load stuff first time. */ | |
c72daea8 | 397 | send_event(pipewrite, EVENT_RELOAD, 0, NULL); |
1a6bca81 SK |
398 | |
399 | err_pipe[1] = -1; | |
1697269c | 400 | |
28866e95 | 401 | if (!option_bool(OPT_DEBUG)) |
9e4abcb5 | 402 | { |
9e4abcb5 SK |
403 | /* The following code "daemonizes" the process. |
404 | See Stevens section 12.4 */ | |
1a6bca81 | 405 | |
9e038946 SK |
406 | if (chdir("/") != 0) |
407 | die(_("cannot chdir to filesystem root: %s"), NULL, EC_MISC); | |
408 | ||
1697269c | 409 | #ifndef NO_FORK |
28866e95 | 410 | if (!option_bool(OPT_NO_FORK)) |
3be34541 | 411 | { |
5aabfc78 | 412 | pid_t pid; |
3be34541 | 413 | |
1a6bca81 SK |
414 | /* pipe to carry errors back to original process. |
415 | When startup is complete we close this and the process terminates. */ | |
416 | safe_pipe(err_pipe, 0); | |
417 | ||
7622fc06 SK |
418 | if ((pid = fork()) == -1) |
419 | /* fd == -1 since we've not forked, never returns. */ | |
c72daea8 | 420 | send_event(-1, EVENT_FORK_ERR, errno, NULL); |
9e038946 | 421 | |
5aabfc78 | 422 | if (pid != 0) |
1a6bca81 SK |
423 | { |
424 | struct event_desc ev; | |
c72daea8 SK |
425 | char *msg; |
426 | ||
1a6bca81 SK |
427 | /* close our copy of write-end */ |
428 | close(err_pipe[1]); | |
429 | ||
430 | /* check for errors after the fork */ | |
c72daea8 SK |
431 | if (read_event(err_pipe[0], &ev, &msg)) |
432 | fatal_event(&ev, msg); | |
1a6bca81 SK |
433 | |
434 | _exit(EC_GOOD); | |
435 | } | |
436 | ||
437 | close(err_pipe[0]); | |
438 | ||
439 | /* NO calls to die() from here on. */ | |
3be34541 | 440 | |
5aabfc78 | 441 | setsid(); |
7622fc06 SK |
442 | |
443 | if ((pid = fork()) == -1) | |
c72daea8 | 444 | send_event(err_pipe[1], EVENT_FORK_ERR, errno, NULL); |
7622fc06 SK |
445 | |
446 | if (pid != 0) | |
7cebd20f | 447 | _exit(0); |
3be34541 | 448 | } |
9e4abcb5 | 449 | #endif |
9e038946 | 450 | |
9e4abcb5 | 451 | /* write pidfile _after_ forking ! */ |
1a6bca81 SK |
452 | if (daemon->runfile) |
453 | { | |
79cfefd8 SK |
454 | int fd, err = 0; |
455 | ||
456 | sprintf(daemon->namebuff, "%d\n", (int) getpid()); | |
457 | ||
458 | /* Explanation: Some installations of dnsmasq (eg Debian/Ubuntu) locate the pid-file | |
459 | in a directory which is writable by the non-privileged user that dnsmasq runs as. This | |
460 | allows the daemon to delete the file as part of its shutdown. This is a security hole to the | |
461 | extent that an attacker running as the unprivileged user could replace the pidfile with a | |
462 | symlink, and have the target of that symlink overwritten as root next time dnsmasq starts. | |
463 | ||
464 | The folowing code first deletes any existing file, and then opens it with the O_EXCL flag, | |
465 | ensuring that the open() fails should there be any existing file (because the unlink() failed, | |
466 | or an attacker exploited the race between unlink() and open()). This ensures that no symlink | |
467 | attack can succeed. | |
468 | ||
469 | Any compromise of the non-privileged user still theoretically allows the pid-file to be | |
470 | replaced whilst dnsmasq is running. The worst that could allow is that the usual | |
471 | "shutdown dnsmasq" shell command could be tricked into stopping any other process. | |
472 | ||
473 | Note that if dnsmasq is started as non-root (eg for testing) it silently ignores | |
474 | failure to write the pid-file. | |
475 | */ | |
476 | ||
477 | unlink(daemon->runfile); | |
1a6bca81 | 478 | |
79cfefd8 | 479 | if ((fd = open(daemon->runfile, O_WRONLY|O_CREAT|O_TRUNC|O_EXCL, S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH)) == -1) |
1a6bca81 | 480 | { |
79cfefd8 SK |
481 | /* only complain if started as root */ |
482 | if (getuid() == 0) | |
483 | err = 1; | |
1a6bca81 | 484 | } |
79cfefd8 SK |
485 | else |
486 | { | |
487 | if (!read_write(fd, (unsigned char *)daemon->namebuff, strlen(daemon->namebuff), 0)) | |
488 | err = 1; | |
489 | ||
490 | while (!err && close(fd) == -1) | |
491 | if (!retry_send()) | |
492 | err = 1; | |
493 | } | |
494 | ||
495 | if (err) | |
1a6bca81 | 496 | { |
c72daea8 | 497 | send_event(err_pipe[1], EVENT_PIDFILE, errno, daemon->runfile); |
1a6bca81 SK |
498 | _exit(0); |
499 | } | |
9e4abcb5 | 500 | } |
1697269c SK |
501 | } |
502 | ||
8ef5ada2 SK |
503 | log_err = log_start(ent_pw, err_pipe[1]); |
504 | ||
28866e95 | 505 | if (!option_bool(OPT_DEBUG)) |
8ef5ada2 SK |
506 | { |
507 | /* open stdout etc to /dev/null */ | |
508 | int nullfd = open("/dev/null", O_RDWR); | |
509 | dup2(nullfd, STDOUT_FILENO); | |
510 | dup2(nullfd, STDERR_FILENO); | |
511 | dup2(nullfd, STDIN_FILENO); | |
512 | close(nullfd); | |
513 | } | |
1a6bca81 SK |
514 | |
515 | /* if we are to run scripts, we need to fork a helper before dropping root. */ | |
516 | daemon->helperfd = -1; | |
c72daea8 | 517 | #ifdef HAVE_SCRIPT |
52b92f4d | 518 | if ((daemon->dhcp || daemon->dhcp6) && (daemon->lease_change_command || daemon->luascript)) |
1a6bca81 | 519 | daemon->helperfd = create_helper(pipewrite, err_pipe[1], script_uid, script_gid, max_fd); |
5aabfc78 | 520 | #endif |
5aabfc78 | 521 | |
28866e95 | 522 | if (!option_bool(OPT_DEBUG) && getuid() == 0) |
1697269c | 523 | { |
1a6bca81 SK |
524 | int bad_capabilities = 0; |
525 | gid_t dummy; | |
526 | ||
527 | /* remove all supplimentary groups */ | |
528 | if (gp && | |
529 | (setgroups(0, &dummy) == -1 || | |
530 | setgid(gp->gr_gid) == -1)) | |
9e4abcb5 | 531 | { |
c72daea8 | 532 | send_event(err_pipe[1], EVENT_GROUP_ERR, errno, daemon->groupname); |
1a6bca81 | 533 | _exit(0); |
7cebd20f | 534 | } |
1a6bca81 | 535 | |
7cebd20f | 536 | if (ent_pw && ent_pw->pw_uid != 0) |
1697269c | 537 | { |
74c95c25 | 538 | #if defined(HAVE_LINUX_NETWORK) |
1697269c | 539 | /* On linux, we keep CAP_NETADMIN (for ARP-injection) and |
74c95c25 | 540 | CAP_NET_RAW (for icmp) if we're doing dhcp. If we have yet to bind |
54dd393f SK |
541 | ports because of DAD, or we're doing it dynamically, |
542 | we need CAP_NET_BIND_SERVICE too. */ | |
543 | if (is_dad_listeners() || option_bool(OPT_CLEVERBIND)) | |
74c95c25 SK |
544 | data->effective = data->permitted = data->inheritable = |
545 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | | |
546 | (1 << CAP_SETUID) | (1 << CAP_NET_BIND_SERVICE); | |
547 | else | |
548 | data->effective = data->permitted = data->inheritable = | |
549 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | (1 << CAP_SETUID); | |
5e9e0efb | 550 | |
1697269c | 551 | /* Tell kernel to not clear capabilities when dropping root */ |
572b41eb | 552 | if (capset(hdr, data) == -1 || prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) |
1697269c | 553 | bad_capabilities = errno; |
1a6bca81 | 554 | |
7622fc06 | 555 | #elif defined(HAVE_SOLARIS_NETWORK) |
824af85b SK |
556 | /* http://developers.sun.com/solaris/articles/program_privileges.html */ |
557 | priv_set_t *priv_set; | |
558 | ||
559 | if (!(priv_set = priv_str_to_set("basic", ",", NULL)) || | |
560 | priv_addset(priv_set, PRIV_NET_ICMPACCESS) == -1 || | |
561 | priv_addset(priv_set, PRIV_SYS_NET_CONFIG) == -1) | |
562 | bad_capabilities = errno; | |
563 | ||
564 | if (priv_set && bad_capabilities == 0) | |
565 | { | |
566 | priv_inverse(priv_set); | |
567 | ||
568 | if (setppriv(PRIV_OFF, PRIV_LIMIT, priv_set) == -1) | |
569 | bad_capabilities = errno; | |
570 | } | |
571 | ||
572 | if (priv_set) | |
573 | priv_freeset(priv_set); | |
574 | ||
824af85b SK |
575 | #endif |
576 | ||
1a6bca81 | 577 | if (bad_capabilities != 0) |
1697269c | 578 | { |
c72daea8 | 579 | send_event(err_pipe[1], EVENT_CAP_ERR, bad_capabilities, NULL); |
1a6bca81 SK |
580 | _exit(0); |
581 | } | |
582 | ||
583 | /* finally drop root */ | |
584 | if (setuid(ent_pw->pw_uid) == -1) | |
585 | { | |
c72daea8 | 586 | send_event(err_pipe[1], EVENT_USER_ERR, errno, daemon->username); |
1a6bca81 SK |
587 | _exit(0); |
588 | } | |
589 | ||
1697269c | 590 | #ifdef HAVE_LINUX_NETWORK |
54dd393f | 591 | if (is_dad_listeners() || option_bool(OPT_CLEVERBIND)) |
74c95c25 SK |
592 | data->effective = data->permitted = |
593 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | (1 << CAP_NET_BIND_SERVICE); | |
594 | else | |
595 | data->effective = data->permitted = | |
596 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW); | |
1a6bca81 SK |
597 | data->inheritable = 0; |
598 | ||
599 | /* lose the setuid and setgid capbilities */ | |
600 | if (capset(hdr, data) == -1) | |
601 | { | |
c72daea8 | 602 | send_event(err_pipe[1], EVENT_CAP_ERR, errno, NULL); |
1a6bca81 | 603 | _exit(0); |
1697269c | 604 | } |
1a6bca81 SK |
605 | #endif |
606 | ||
9e4abcb5 SK |
607 | } |
608 | } | |
1697269c | 609 | |
1697269c | 610 | #ifdef HAVE_LINUX_NETWORK |
28866e95 | 611 | if (option_bool(OPT_DEBUG)) |
572b41eb | 612 | prctl(PR_SET_DUMPABLE, 1, 0, 0, 0); |
1697269c | 613 | #endif |
9e4abcb5 | 614 | |
8b3ae2fd | 615 | #ifdef HAVE_TFTP |
8bc4cece | 616 | if (option_bool(OPT_TFTP)) |
8b3ae2fd SK |
617 | { |
618 | DIR *dir; | |
619 | struct tftp_prefix *p; | |
620 | ||
621 | if (daemon->tftp_prefix) | |
622 | { | |
623 | if (!((dir = opendir(daemon->tftp_prefix)))) | |
624 | { | |
625 | send_event(err_pipe[1], EVENT_TFTP_ERR, errno, daemon->tftp_prefix); | |
626 | _exit(0); | |
627 | } | |
628 | closedir(dir); | |
629 | } | |
630 | ||
631 | for (p = daemon->if_prefix; p; p = p->next) | |
632 | { | |
633 | if (!((dir = opendir(p->prefix)))) | |
634 | { | |
635 | send_event(err_pipe[1], EVENT_TFTP_ERR, errno, p->prefix); | |
636 | _exit(0); | |
637 | } | |
638 | closedir(dir); | |
639 | } | |
640 | } | |
641 | #endif | |
642 | ||
824af85b SK |
643 | if (daemon->port == 0) |
644 | my_syslog(LOG_INFO, _("started, version %s DNS disabled"), VERSION); | |
645 | else if (daemon->cachesize != 0) | |
f2621c7f | 646 | my_syslog(LOG_INFO, _("started, version %s cachesize %d"), VERSION, daemon->cachesize); |
9e4abcb5 | 647 | else |
f2621c7f | 648 | my_syslog(LOG_INFO, _("started, version %s cache disabled"), VERSION); |
1697269c | 649 | |
f2621c7f | 650 | my_syslog(LOG_INFO, _("compile time options: %s"), compile_opts); |
1697269c | 651 | |
3d8df260 | 652 | #ifdef HAVE_DBUS |
28866e95 | 653 | if (option_bool(OPT_DBUS)) |
3d8df260 SK |
654 | { |
655 | if (daemon->dbus) | |
f2621c7f | 656 | my_syslog(LOG_INFO, _("DBus support enabled: connected to system bus")); |
3d8df260 | 657 | else |
f2621c7f | 658 | my_syslog(LOG_INFO, _("DBus support enabled: bus connection pending")); |
3d8df260 SK |
659 | } |
660 | #endif | |
db737466 | 661 | |
1d97ac4f | 662 | #ifdef HAVE_DNSSEC |
db737466 SK |
663 | if (option_bool(OPT_DNSSEC_VALID)) |
664 | my_syslog(LOG_INFO, _("DNSSEC validation enabled")); | |
665 | #endif | |
3d8df260 | 666 | |
1a6bca81 SK |
667 | if (log_err != 0) |
668 | my_syslog(LOG_WARNING, _("warning: failed to change owner of %s: %s"), | |
669 | daemon->log_file, strerror(log_err)); | |
db737466 | 670 | |
de37951c | 671 | if (bind_fallback) |
f2621c7f | 672 | my_syslog(LOG_WARNING, _("setting --bind-interfaces option because of OS limitations")); |
dc27e148 | 673 | |
f7029f5c SK |
674 | if (option_bool(OPT_NOWILD)) |
675 | warn_bound_listeners(); | |
676 | ||
677 | warn_int_names(); | |
de37951c | 678 | |
28866e95 | 679 | if (!option_bool(OPT_NOWILD)) |
26128d27 SK |
680 | for (if_tmp = daemon->if_names; if_tmp; if_tmp = if_tmp->next) |
681 | if (if_tmp->name && !if_tmp->used) | |
f2621c7f | 682 | my_syslog(LOG_WARNING, _("warning: interface %s does not currently exist"), if_tmp->name); |
5e9e0efb | 683 | |
28866e95 | 684 | if (daemon->port != 0 && option_bool(OPT_NO_RESOLV)) |
208b65c5 SK |
685 | { |
686 | if (daemon->resolv_files && !daemon->resolv_files->is_default) | |
f2621c7f | 687 | my_syslog(LOG_WARNING, _("warning: ignoring resolv-file flag because no-resolv is set")); |
208b65c5 | 688 | daemon->resolv_files = NULL; |
1b7ecd11 | 689 | if (!daemon->servers) |
f2621c7f | 690 | my_syslog(LOG_WARNING, _("warning: no upstream servers configured")); |
208b65c5 SK |
691 | } |
692 | ||
f2621c7f SK |
693 | if (daemon->max_logs != 0) |
694 | my_syslog(LOG_INFO, _("asynchronous logging enabled, queue limit is %d messages"), daemon->max_logs); | |
1f776932 | 695 | |
f2621c7f | 696 | |
7622fc06 | 697 | #ifdef HAVE_DHCP |
1f776932 SK |
698 | for (context = daemon->dhcp; context; context = context->next) |
699 | log_context(AF_INET, context); | |
52b92f4d | 700 | |
ff7eea27 SK |
701 | for (relay = daemon->relay4; relay; relay = relay->next) |
702 | log_relay(AF_INET, relay); | |
703 | ||
1f776932 SK |
704 | # ifdef HAVE_DHCP6 |
705 | for (context = daemon->dhcp6; context; context = context->next) | |
706 | log_context(AF_INET6, context); | |
707 | ||
ff7eea27 SK |
708 | for (relay = daemon->relay6; relay; relay = relay->next) |
709 | log_relay(AF_INET6, relay); | |
710 | ||
1f776932 SK |
711 | if (daemon->doing_dhcp6 || daemon->doing_ra) |
712 | dhcp_construct_contexts(now); | |
713 | ||
714 | if (option_bool(OPT_RA)) | |
715 | my_syslog(MS_DHCP | LOG_INFO, _("IPv6 router advertisement enabled")); | |
716 | # endif | |
26128d27 | 717 | |
3b3f4411 SK |
718 | # ifdef HAVE_LINUX_NETWORK |
719 | if (did_bind) | |
720 | my_syslog(MS_DHCP | LOG_INFO, _("DHCP, sockets bound exclusively to interface %s"), bound_device); | |
721 | # endif | |
722 | ||
8445f5d2 SK |
723 | /* after dhcp_contruct_contexts */ |
724 | if (daemon->dhcp || daemon->doing_dhcp6) | |
725 | lease_find_interfaces(now); | |
1f776932 | 726 | #endif |
52b92f4d | 727 | |
832af0ba | 728 | #ifdef HAVE_TFTP |
8bc4cece | 729 | if (option_bool(OPT_TFTP)) |
832af0ba | 730 | { |
832af0ba | 731 | #ifdef FD_SETSIZE |
5aabfc78 | 732 | if (FD_SETSIZE < (unsigned)max_fd) |
832af0ba SK |
733 | max_fd = FD_SETSIZE; |
734 | #endif | |
735 | ||
7622fc06 | 736 | my_syslog(MS_TFTP | LOG_INFO, "TFTP %s%s %s", |
f2621c7f SK |
737 | daemon->tftp_prefix ? _("root is ") : _("enabled"), |
738 | daemon->tftp_prefix ? daemon->tftp_prefix: "", | |
28866e95 | 739 | option_bool(OPT_TFTP_SECURE) ? _("secure mode") : ""); |
f2621c7f | 740 | |
832af0ba | 741 | /* This is a guess, it assumes that for small limits, |
f2621c7f | 742 | disjoint files might be served, but for large limits, |
832af0ba SK |
743 | a single file will be sent to may clients (the file only needs |
744 | one fd). */ | |
745 | ||
746 | max_fd -= 30; /* use other than TFTP */ | |
747 | ||
748 | if (max_fd < 0) | |
749 | max_fd = 5; | |
750 | else if (max_fd < 100) | |
751 | max_fd = max_fd/2; | |
752 | else | |
753 | max_fd = max_fd - 20; | |
824af85b SK |
754 | |
755 | /* if we have to use a limited range of ports, | |
756 | that will limit the number of transfers */ | |
757 | if (daemon->start_tftp_port != 0 && | |
758 | daemon->end_tftp_port - daemon->start_tftp_port + 1 < max_fd) | |
759 | max_fd = daemon->end_tftp_port - daemon->start_tftp_port + 1; | |
832af0ba SK |
760 | |
761 | if (daemon->tftp_max > max_fd) | |
762 | { | |
763 | daemon->tftp_max = max_fd; | |
7622fc06 | 764 | my_syslog(MS_TFTP | LOG_WARNING, |
f2621c7f SK |
765 | _("restricting maximum simultaneous TFTP transfers to %d"), |
766 | daemon->tftp_max); | |
832af0ba SK |
767 | } |
768 | } | |
769 | #endif | |
770 | ||
1a6bca81 SK |
771 | /* finished start-up - release original process */ |
772 | if (err_pipe[1] != -1) | |
773 | close(err_pipe[1]); | |
9e4abcb5 | 774 | |
824af85b SK |
775 | if (daemon->port != 0) |
776 | check_servers(); | |
777 | ||
7cebd20f SK |
778 | pid = getpid(); |
779 | ||
5e9e0efb | 780 | while (1) |
9e4abcb5 | 781 | { |
1697269c | 782 | int maxfd = -1; |
5e9e0efb | 783 | struct timeval t, *tp = NULL; |
3d8df260 | 784 | fd_set rset, wset, eset; |
9e4abcb5 SK |
785 | |
786 | FD_ZERO(&rset); | |
3d8df260 SK |
787 | FD_ZERO(&wset); |
788 | FD_ZERO(&eset); | |
9e4abcb5 | 789 | |
1697269c SK |
790 | /* if we are out of resources, find how long we have to wait |
791 | for some to come free, we'll loop around then and restart | |
792 | listening for queries */ | |
5aabfc78 | 793 | if ((t.tv_sec = set_dns_listeners(now, &rset, &maxfd)) != 0) |
1697269c SK |
794 | { |
795 | t.tv_usec = 0; | |
796 | tp = &t; | |
797 | } | |
798 | ||
832af0ba SK |
799 | /* Whilst polling for the dbus, or doing a tftp transfer, wake every quarter second */ |
800 | if (daemon->tftp_trans || | |
28866e95 | 801 | (option_bool(OPT_DBUS) && !daemon->dbus)) |
5e9e0efb | 802 | { |
1697269c SK |
803 | t.tv_sec = 0; |
804 | t.tv_usec = 250000; | |
5e9e0efb | 805 | tp = &t; |
5e9e0efb | 806 | } |
74c95c25 SK |
807 | /* Wake every second whilst waiting for DAD to complete */ |
808 | else if (is_dad_listeners()) | |
809 | { | |
810 | t.tv_sec = 1; | |
811 | t.tv_usec = 0; | |
812 | tp = &t; | |
813 | } | |
44a2a316 | 814 | |
832af0ba | 815 | #ifdef HAVE_DBUS |
5aabfc78 | 816 | set_dbus_listeners(&maxfd, &rset, &wset, &eset); |
5e9e0efb SK |
817 | #endif |
818 | ||
7622fc06 | 819 | #ifdef HAVE_DHCP |
ff7eea27 | 820 | if (daemon->dhcp || daemon->relay4) |
5e9e0efb SK |
821 | { |
822 | FD_SET(daemon->dhcpfd, &rset); | |
1697269c | 823 | bump_maxfd(daemon->dhcpfd, &maxfd); |
316e2730 SK |
824 | if (daemon->pxefd != -1) |
825 | { | |
826 | FD_SET(daemon->pxefd, &rset); | |
827 | bump_maxfd(daemon->pxefd, &maxfd); | |
828 | } | |
5e9e0efb | 829 | } |
7622fc06 | 830 | #endif |
cdeda28f | 831 | |
52b92f4d | 832 | #ifdef HAVE_DHCP6 |
ff7eea27 | 833 | if (daemon->doing_dhcp6 || daemon->relay6) |
52b92f4d SK |
834 | { |
835 | FD_SET(daemon->dhcp6fd, &rset); | |
c5ad4e79 | 836 | bump_maxfd(daemon->dhcp6fd, &maxfd); |
5d71d834 SK |
837 | } |
838 | ||
1f776932 | 839 | if (daemon->doing_ra) |
5d71d834 SK |
840 | { |
841 | FD_SET(daemon->icmp6fd, &rset); | |
842 | bump_maxfd(daemon->icmp6fd, &maxfd); | |
52b92f4d SK |
843 | } |
844 | #endif | |
845 | ||
1ee9be4c | 846 | #if defined(HAVE_LINUX_NETWORK) |
5e9e0efb | 847 | FD_SET(daemon->netlinkfd, &rset); |
1697269c | 848 | bump_maxfd(daemon->netlinkfd, &maxfd); |
1ee9be4c SK |
849 | #elif defined(HAVE_BSD_NETWORK) |
850 | FD_SET(daemon->routefd, &rset); | |
851 | bump_maxfd(daemon->routefd, &maxfd); | |
3d8df260 | 852 | #endif |
1ee9be4c | 853 | |
5e9e0efb | 854 | FD_SET(piperead, &rset); |
1697269c SK |
855 | bump_maxfd(piperead, &maxfd); |
856 | ||
7622fc06 | 857 | #ifdef HAVE_DHCP |
1f15b81d | 858 | # ifdef HAVE_SCRIPT |
5aabfc78 | 859 | while (helper_buf_empty() && do_script_run(now)); |
1697269c | 860 | |
a9530964 SK |
861 | # ifdef HAVE_TFTP |
862 | while (helper_buf_empty() && do_tftp_script_run()); | |
863 | # endif | |
864 | ||
1697269c SK |
865 | if (!helper_buf_empty()) |
866 | { | |
867 | FD_SET(daemon->helperfd, &wset); | |
868 | bump_maxfd(daemon->helperfd, &maxfd); | |
869 | } | |
7622fc06 | 870 | # else |
5aabfc78 SK |
871 | /* need this for other side-effects */ |
872 | while (do_script_run(now)); | |
a9530964 SK |
873 | |
874 | # ifdef HAVE_TFTP | |
875 | while (do_tftp_script_run()); | |
876 | # endif | |
877 | ||
7622fc06 | 878 | # endif |
5aabfc78 | 879 | #endif |
7622fc06 | 880 | |
f2621c7f SK |
881 | /* must do this just before select(), when we know no |
882 | more calls to my_syslog() can occur */ | |
883 | set_log_writer(&wset, &maxfd); | |
884 | ||
5e9e0efb SK |
885 | if (select(maxfd+1, &rset, &wset, &eset, tp) < 0) |
886 | { | |
887 | /* otherwise undefined after error */ | |
888 | FD_ZERO(&rset); FD_ZERO(&wset); FD_ZERO(&eset); | |
889 | } | |
890 | ||
891 | now = dnsmasq_time(); | |
9e4abcb5 | 892 | |
f2621c7f | 893 | check_log_writer(&wset); |
115ac3e4 SK |
894 | |
895 | /* prime. */ | |
896 | enumerate_interfaces(1); | |
897 | ||
74c95c25 SK |
898 | /* Check the interfaces to see if any have exited DAD state |
899 | and if so, bind the address. */ | |
900 | if (is_dad_listeners()) | |
901 | { | |
115ac3e4 | 902 | enumerate_interfaces(0); |
74c95c25 SK |
903 | /* NB, is_dad_listeners() == 1 --> we're binding interfaces */ |
904 | create_bound_listeners(0); | |
dc27e148 | 905 | warn_bound_listeners(); |
74c95c25 | 906 | } |
f2621c7f | 907 | |
1ee9be4c | 908 | #if defined(HAVE_LINUX_NETWORK) |
c52e1897 | 909 | if (FD_ISSET(daemon->netlinkfd, &rset)) |
1f776932 | 910 | netlink_multicast(now); |
1ee9be4c SK |
911 | #elif defined(HAVE_BSD_NETWORK) |
912 | if (FD_ISSET(daemon->routefd, &rset)) | |
913 | route_sock(now); | |
c52e1897 SK |
914 | #endif |
915 | ||
9e4abcb5 | 916 | /* Check for changes to resolv files once per second max. */ |
3d8df260 | 917 | /* Don't go silent for long periods if the clock goes backwards. */ |
9009d746 SK |
918 | if (daemon->last_resolv == 0 || |
919 | difftime(now, daemon->last_resolv) > 1.0 || | |
920 | difftime(now, daemon->last_resolv) < -1.0) | |
9e4abcb5 | 921 | { |
8ef5ada2 SK |
922 | /* poll_resolv doesn't need to reload first time through, since |
923 | that's queued anyway. */ | |
33820b7e | 924 | |
8ef5ada2 SK |
925 | poll_resolv(0, daemon->last_resolv != 0, now); |
926 | daemon->last_resolv = now; | |
9e4abcb5 | 927 | } |
5aabfc78 | 928 | |
5e9e0efb | 929 | if (FD_ISSET(piperead, &rset)) |
5aabfc78 | 930 | async_event(piperead, now); |
7cebd20f | 931 | |
3d8df260 SK |
932 | #ifdef HAVE_DBUS |
933 | /* if we didn't create a DBus connection, retry now. */ | |
28866e95 | 934 | if (option_bool(OPT_DBUS) && !daemon->dbus) |
3d8df260 SK |
935 | { |
936 | char *err; | |
5aabfc78 | 937 | if ((err = dbus_init())) |
f2621c7f | 938 | my_syslog(LOG_WARNING, _("DBus error: %s"), err); |
3d8df260 | 939 | if (daemon->dbus) |
f2621c7f | 940 | my_syslog(LOG_INFO, _("connected to system DBus")); |
3d8df260 | 941 | } |
5aabfc78 | 942 | check_dbus_listeners(&rset, &wset, &eset); |
3d8df260 | 943 | #endif |
824af85b | 944 | |
5aabfc78 | 945 | check_dns_listeners(&rset, now); |
832af0ba SK |
946 | |
947 | #ifdef HAVE_TFTP | |
5aabfc78 | 948 | check_tftp_listeners(&rset, now); |
832af0ba SK |
949 | #endif |
950 | ||
7622fc06 | 951 | #ifdef HAVE_DHCP |
ff7eea27 | 952 | if (daemon->dhcp || daemon->relay4) |
316e2730 SK |
953 | { |
954 | if (FD_ISSET(daemon->dhcpfd, &rset)) | |
955 | dhcp_packet(now, 0); | |
956 | if (daemon->pxefd != -1 && FD_ISSET(daemon->pxefd, &rset)) | |
957 | dhcp_packet(now, 1); | |
958 | } | |
1697269c | 959 | |
52b92f4d | 960 | #ifdef HAVE_DHCP6 |
ff7eea27 | 961 | if ((daemon->doing_dhcp6 || daemon->relay6) && FD_ISSET(daemon->dhcp6fd, &rset)) |
18c63eff | 962 | dhcp6_packet(now); |
c5ad4e79 | 963 | |
1f776932 SK |
964 | if (daemon->doing_ra && FD_ISSET(daemon->icmp6fd, &rset)) |
965 | icmp6_packet(now); | |
52b92f4d SK |
966 | #endif |
967 | ||
1f15b81d | 968 | # ifdef HAVE_SCRIPT |
1697269c | 969 | if (daemon->helperfd != -1 && FD_ISSET(daemon->helperfd, &wset)) |
5aabfc78 | 970 | helper_write(); |
7622fc06 | 971 | # endif |
5aabfc78 SK |
972 | #endif |
973 | ||
9e4abcb5 | 974 | } |
9e4abcb5 SK |
975 | } |
976 | ||
3be34541 SK |
977 | static void sig_handler(int sig) |
978 | { | |
5e9e0efb | 979 | if (pid == 0) |
3be34541 | 980 | { |
1697269c SK |
981 | /* ignore anything other than TERM during startup |
982 | and in helper proc. (helper ignore TERM too) */ | |
5e9e0efb | 983 | if (sig == SIGTERM) |
5aabfc78 | 984 | exit(EC_MISC); |
3be34541 | 985 | } |
5aabfc78 | 986 | else if (pid != getpid()) |
5e9e0efb | 987 | { |
1697269c | 988 | /* alarm is used to kill TCP children after a fixed time. */ |
5e9e0efb | 989 | if (sig == SIGALRM) |
7cebd20f | 990 | _exit(0); |
3be34541 | 991 | } |
5aabfc78 SK |
992 | else |
993 | { | |
994 | /* master process */ | |
995 | int event, errsave = errno; | |
996 | ||
997 | if (sig == SIGHUP) | |
998 | event = EVENT_RELOAD; | |
999 | else if (sig == SIGCHLD) | |
1000 | event = EVENT_CHILD; | |
1001 | else if (sig == SIGALRM) | |
1002 | event = EVENT_ALARM; | |
1003 | else if (sig == SIGTERM) | |
1004 | event = EVENT_TERM; | |
1005 | else if (sig == SIGUSR1) | |
1006 | event = EVENT_DUMP; | |
1007 | else if (sig == SIGUSR2) | |
1008 | event = EVENT_REOPEN; | |
1009 | else | |
1010 | return; | |
1011 | ||
c72daea8 | 1012 | send_event(pipewrite, event, 0, NULL); |
5aabfc78 SK |
1013 | errno = errsave; |
1014 | } | |
1015 | } | |
1016 | ||
353ae4d2 SK |
1017 | /* now == 0 -> queue immediate callback */ |
1018 | void send_alarm(time_t event, time_t now) | |
741c2952 | 1019 | { |
884a6dfe | 1020 | if (now == 0 || event != 0) |
353ae4d2 | 1021 | { |
884a6dfe SK |
1022 | /* alarm(0) or alarm(-ve) doesn't do what we want.... */ |
1023 | if ((now == 0 || difftime(event, now) <= 0.0)) | |
1024 | send_event(pipewrite, EVENT_ALARM, 0, NULL); | |
1025 | else | |
1026 | alarm((unsigned)difftime(event, now)); | |
353ae4d2 | 1027 | } |
741c2952 SK |
1028 | } |
1029 | ||
c72daea8 | 1030 | void send_event(int fd, int event, int data, char *msg) |
5aabfc78 SK |
1031 | { |
1032 | struct event_desc ev; | |
c72daea8 SK |
1033 | struct iovec iov[2]; |
1034 | ||
5aabfc78 SK |
1035 | ev.event = event; |
1036 | ev.data = data; | |
c72daea8 SK |
1037 | ev.msg_sz = msg ? strlen(msg) : 0; |
1038 | ||
1039 | iov[0].iov_base = &ev; | |
1040 | iov[0].iov_len = sizeof(ev); | |
1041 | iov[1].iov_base = msg; | |
1042 | iov[1].iov_len = ev.msg_sz; | |
1a6bca81 SK |
1043 | |
1044 | /* error pipe, debug mode. */ | |
1045 | if (fd == -1) | |
c72daea8 | 1046 | fatal_event(&ev, msg); |
1a6bca81 SK |
1047 | else |
1048 | /* pipe is non-blocking and struct event_desc is smaller than | |
1049 | PIPE_BUF, so this either fails or writes everything */ | |
c72daea8 | 1050 | while (writev(fd, iov, msg ? 2 : 1) == -1 && errno == EINTR); |
5aabfc78 SK |
1051 | } |
1052 | ||
c72daea8 SK |
1053 | /* NOTE: the memory used to return msg is leaked: use msgs in events only |
1054 | to describe fatal errors. */ | |
1055 | static int read_event(int fd, struct event_desc *evp, char **msg) | |
1056 | { | |
1057 | char *buf; | |
1058 | ||
1059 | if (!read_write(fd, (unsigned char *)evp, sizeof(struct event_desc), 1)) | |
1060 | return 0; | |
1061 | ||
1062 | *msg = NULL; | |
1063 | ||
1064 | if (evp->msg_sz != 0 && | |
1065 | (buf = malloc(evp->msg_sz + 1)) && | |
1066 | read_write(fd, (unsigned char *)buf, evp->msg_sz, 1)) | |
1067 | { | |
1068 | buf[evp->msg_sz] = 0; | |
1069 | *msg = buf; | |
1070 | } | |
1071 | ||
1072 | return 1; | |
1073 | } | |
1074 | ||
1075 | static void fatal_event(struct event_desc *ev, char *msg) | |
1a6bca81 SK |
1076 | { |
1077 | errno = ev->data; | |
1078 | ||
1079 | switch (ev->event) | |
1080 | { | |
1081 | case EVENT_DIE: | |
1082 | exit(0); | |
7622fc06 SK |
1083 | |
1084 | case EVENT_FORK_ERR: | |
1085 | die(_("cannot fork into background: %s"), NULL, EC_MISC); | |
1a6bca81 SK |
1086 | |
1087 | case EVENT_PIPE_ERR: | |
1088 | die(_("failed to create helper: %s"), NULL, EC_MISC); | |
1089 | ||
1090 | case EVENT_CAP_ERR: | |
1091 | die(_("setting capabilities failed: %s"), NULL, EC_MISC); | |
1092 | ||
1093 | case EVENT_USER_ERR: | |
c72daea8 | 1094 | die(_("failed to change user-id to %s: %s"), msg, EC_MISC); |
1a6bca81 SK |
1095 | |
1096 | case EVENT_GROUP_ERR: | |
c72daea8 | 1097 | die(_("failed to change group-id to %s: %s"), msg, EC_MISC); |
1a6bca81 SK |
1098 | |
1099 | case EVENT_PIDFILE: | |
c72daea8 | 1100 | die(_("failed to open pidfile %s: %s"), msg, EC_FILE); |
1a6bca81 SK |
1101 | |
1102 | case EVENT_LOG_ERR: | |
c72daea8 SK |
1103 | die(_("cannot open log %s: %s"), msg, EC_FILE); |
1104 | ||
1105 | case EVENT_LUA_ERR: | |
1106 | die(_("failed to load Lua script: %s"), msg, EC_MISC); | |
8b3ae2fd SK |
1107 | |
1108 | case EVENT_TFTP_ERR: | |
1109 | die(_("TFTP directory %s inaccessible: %s"), msg, EC_FILE); | |
1a6bca81 SK |
1110 | } |
1111 | } | |
1112 | ||
5aabfc78 SK |
1113 | static void async_event(int pipe, time_t now) |
1114 | { | |
1115 | pid_t p; | |
1116 | struct event_desc ev; | |
7b1eae4f | 1117 | int i, check = 0; |
c72daea8 SK |
1118 | char *msg; |
1119 | ||
1120 | /* NOTE: the memory used to return msg is leaked: use msgs in events only | |
1121 | to describe fatal errors. */ | |
1122 | ||
1123 | if (read_event(pipe, &ev, &msg)) | |
5aabfc78 SK |
1124 | switch (ev.event) |
1125 | { | |
1126 | case EVENT_RELOAD: | |
1127 | clear_cache_and_reload(now); | |
7b1eae4f SK |
1128 | |
1129 | if (daemon->port != 0) | |
5aabfc78 | 1130 | { |
7b1eae4f SK |
1131 | if (daemon->resolv_files && option_bool(OPT_NO_POLL)) |
1132 | { | |
1133 | reload_servers(daemon->resolv_files->name); | |
1134 | check = 1; | |
1135 | } | |
1136 | ||
1137 | if (daemon->servers_file) | |
1138 | { | |
1139 | read_servers_file(); | |
1140 | check = 1; | |
1141 | } | |
1142 | ||
1143 | if (check) | |
1144 | check_servers(); | |
5aabfc78 | 1145 | } |
7b1eae4f | 1146 | |
7622fc06 | 1147 | #ifdef HAVE_DHCP |
5aabfc78 | 1148 | rerun_scripts(); |
7622fc06 | 1149 | #endif |
5aabfc78 SK |
1150 | break; |
1151 | ||
1152 | case EVENT_DUMP: | |
824af85b SK |
1153 | if (daemon->port != 0) |
1154 | dump_cache(now); | |
5aabfc78 SK |
1155 | break; |
1156 | ||
1157 | case EVENT_ALARM: | |
7622fc06 | 1158 | #ifdef HAVE_DHCP |
1f776932 | 1159 | if (daemon->dhcp || daemon->doing_dhcp6) |
5aabfc78 SK |
1160 | { |
1161 | lease_prune(NULL, now); | |
1162 | lease_update_file(now); | |
1163 | } | |
843c96b4 | 1164 | #ifdef HAVE_DHCP6 |
1f776932 | 1165 | else if (daemon->doing_ra) |
353ae4d2 SK |
1166 | /* Not doing DHCP, so no lease system, manage alarms for ra only */ |
1167 | send_alarm(periodic_ra(now), now); | |
843c96b4 | 1168 | #endif |
7622fc06 | 1169 | #endif |
5aabfc78 SK |
1170 | break; |
1171 | ||
1172 | case EVENT_CHILD: | |
1173 | /* See Stevens 5.10 */ | |
1174 | while ((p = waitpid(-1, NULL, WNOHANG)) != 0) | |
1175 | if (p == -1) | |
1176 | { | |
1177 | if (errno != EINTR) | |
1178 | break; | |
1179 | } | |
1180 | else | |
1181 | for (i = 0 ; i < MAX_PROCS; i++) | |
1182 | if (daemon->tcp_pids[i] == p) | |
1183 | daemon->tcp_pids[i] = 0; | |
1184 | break; | |
1185 | ||
1186 | case EVENT_KILLED: | |
c72daea8 | 1187 | my_syslog(LOG_WARNING, _("script process killed by signal %d"), ev.data); |
5aabfc78 SK |
1188 | break; |
1189 | ||
1190 | case EVENT_EXITED: | |
c72daea8 | 1191 | my_syslog(LOG_WARNING, _("script process exited with status %d"), ev.data); |
5aabfc78 SK |
1192 | break; |
1193 | ||
1194 | case EVENT_EXEC_ERR: | |
9e038946 SK |
1195 | my_syslog(LOG_ERR, _("failed to execute %s: %s"), |
1196 | daemon->lease_change_command, strerror(ev.data)); | |
5aabfc78 SK |
1197 | break; |
1198 | ||
1a6bca81 | 1199 | /* necessary for fatal errors in helper */ |
c72daea8 | 1200 | case EVENT_USER_ERR: |
1a6bca81 | 1201 | case EVENT_DIE: |
c72daea8 SK |
1202 | case EVENT_LUA_ERR: |
1203 | fatal_event(&ev, msg); | |
9e038946 SK |
1204 | break; |
1205 | ||
5aabfc78 SK |
1206 | case EVENT_REOPEN: |
1207 | /* Note: this may leave TCP-handling processes with the old file still open. | |
1208 | Since any such process will die in CHILD_LIFETIME or probably much sooner, | |
1209 | we leave them logging to the old file. */ | |
1210 | if (daemon->log_file != NULL) | |
1211 | log_reopen(daemon->log_file); | |
1212 | break; | |
1213 | ||
1214 | case EVENT_TERM: | |
1215 | /* Knock all our children on the head. */ | |
1216 | for (i = 0; i < MAX_PROCS; i++) | |
1217 | if (daemon->tcp_pids[i] != 0) | |
1218 | kill(daemon->tcp_pids[i], SIGALRM); | |
1219 | ||
c72daea8 | 1220 | #if defined(HAVE_SCRIPT) |
5aabfc78 SK |
1221 | /* handle pending lease transitions */ |
1222 | if (daemon->helperfd != -1) | |
1223 | { | |
1224 | /* block in writes until all done */ | |
1225 | if ((i = fcntl(daemon->helperfd, F_GETFL)) != -1) | |
1226 | fcntl(daemon->helperfd, F_SETFL, i & ~O_NONBLOCK); | |
1227 | do { | |
1228 | helper_write(); | |
1229 | } while (!helper_buf_empty() || do_script_run(now)); | |
1230 | close(daemon->helperfd); | |
1231 | } | |
1232 | #endif | |
1233 | ||
1234 | if (daemon->lease_stream) | |
1235 | fclose(daemon->lease_stream); | |
73a08a24 SK |
1236 | |
1237 | if (daemon->runfile) | |
1238 | unlink(daemon->runfile); | |
5aabfc78 SK |
1239 | |
1240 | my_syslog(LOG_INFO, _("exiting on receipt of SIGTERM")); | |
1241 | flush_log(); | |
1242 | exit(EC_GOOD); | |
1243 | } | |
3be34541 SK |
1244 | } |
1245 | ||
8ef5ada2 | 1246 | void poll_resolv(int force, int do_reload, time_t now) |
5aabfc78 SK |
1247 | { |
1248 | struct resolvc *res, *latest; | |
1249 | struct stat statbuf; | |
1250 | time_t last_change = 0; | |
1251 | /* There may be more than one possible file. | |
1252 | Go through and find the one which changed _last_. | |
1253 | Warn of any which can't be read. */ | |
8ef5ada2 | 1254 | |
28866e95 | 1255 | if (daemon->port == 0 || option_bool(OPT_NO_POLL)) |
8ef5ada2 SK |
1256 | return; |
1257 | ||
5aabfc78 SK |
1258 | for (latest = NULL, res = daemon->resolv_files; res; res = res->next) |
1259 | if (stat(res->name, &statbuf) == -1) | |
1260 | { | |
8ef5ada2 SK |
1261 | if (force) |
1262 | { | |
1263 | res->mtime = 0; | |
1264 | continue; | |
1265 | } | |
1266 | ||
5aabfc78 SK |
1267 | if (!res->logged) |
1268 | my_syslog(LOG_WARNING, _("failed to access %s: %s"), res->name, strerror(errno)); | |
1269 | res->logged = 1; | |
8ef5ada2 SK |
1270 | |
1271 | if (res->mtime != 0) | |
1272 | { | |
1273 | /* existing file evaporated, force selection of the latest | |
1274 | file even if its mtime hasn't changed since we last looked */ | |
1275 | poll_resolv(1, do_reload, now); | |
1276 | return; | |
1277 | } | |
5aabfc78 SK |
1278 | } |
1279 | else | |
1280 | { | |
1281 | res->logged = 0; | |
8ef5ada2 SK |
1282 | if (force || (statbuf.st_mtime != res->mtime)) |
1283 | { | |
1284 | res->mtime = statbuf.st_mtime; | |
5aabfc78 SK |
1285 | if (difftime(statbuf.st_mtime, last_change) > 0.0) |
1286 | { | |
1287 | last_change = statbuf.st_mtime; | |
1288 | latest = res; | |
1289 | } | |
1290 | } | |
1291 | } | |
1292 | ||
1293 | if (latest) | |
1294 | { | |
1295 | static int warned = 0; | |
1296 | if (reload_servers(latest->name)) | |
1297 | { | |
1298 | my_syslog(LOG_INFO, _("reading %s"), latest->name); | |
1299 | warned = 0; | |
1300 | check_servers(); | |
28866e95 | 1301 | if (option_bool(OPT_RELOAD) && do_reload) |
8ef5ada2 | 1302 | clear_cache_and_reload(now); |
5aabfc78 SK |
1303 | } |
1304 | else | |
1305 | { | |
1306 | latest->mtime = 0; | |
1307 | if (!warned) | |
1308 | { | |
1309 | my_syslog(LOG_WARNING, _("no servers found in %s, will retry"), latest->name); | |
1310 | warned = 1; | |
1311 | } | |
1312 | } | |
1313 | } | |
1314 | } | |
3d8df260 | 1315 | |
5aabfc78 | 1316 | void clear_cache_and_reload(time_t now) |
3d8df260 | 1317 | { |
408c368f VG |
1318 | (void)now; |
1319 | ||
824af85b | 1320 | if (daemon->port != 0) |
7622fc06 | 1321 | cache_reload(); |
824af85b | 1322 | |
7622fc06 | 1323 | #ifdef HAVE_DHCP |
1f776932 | 1324 | if (daemon->dhcp || daemon->doing_dhcp6) |
3d8df260 | 1325 | { |
28866e95 | 1326 | if (option_bool(OPT_ETHERS)) |
5aabfc78 | 1327 | dhcp_read_ethers(); |
824af85b | 1328 | reread_dhcp(); |
3d8df260 | 1329 | dhcp_update_configs(daemon->dhcp_conf); |
5aabfc78 SK |
1330 | lease_update_from_configs(); |
1331 | lease_update_file(now); | |
353ae4d2 | 1332 | lease_update_dns(1); |
3d8df260 | 1333 | } |
843c96b4 | 1334 | #ifdef HAVE_DHCP6 |
1f776932 | 1335 | else if (daemon->doing_ra) |
2021c662 SK |
1336 | /* Not doing DHCP, so no lease system, manage |
1337 | alarms for ra only */ | |
1338 | send_alarm(periodic_ra(now), now); | |
843c96b4 | 1339 | #endif |
7622fc06 | 1340 | #endif |
3d8df260 SK |
1341 | } |
1342 | ||
5aabfc78 | 1343 | static int set_dns_listeners(time_t now, fd_set *set, int *maxfdp) |
3be34541 SK |
1344 | { |
1345 | struct serverfd *serverfdp; | |
1346 | struct listener *listener; | |
824af85b | 1347 | int wait = 0, i; |
832af0ba SK |
1348 | |
1349 | #ifdef HAVE_TFTP | |
1350 | int tftp = 0; | |
1351 | struct tftp_transfer *transfer; | |
1352 | for (transfer = daemon->tftp_trans; transfer; transfer = transfer->next) | |
1353 | { | |
1354 | tftp++; | |
1355 | FD_SET(transfer->sockfd, set); | |
1356 | bump_maxfd(transfer->sockfd, maxfdp); | |
1357 | } | |
1358 | #endif | |
1359 | ||
1697269c | 1360 | /* will we be able to get memory? */ |
824af85b | 1361 | if (daemon->port != 0) |
3a237152 | 1362 | get_new_frec(now, &wait, 0); |
1697269c | 1363 | |
3be34541 SK |
1364 | for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next) |
1365 | { | |
1366 | FD_SET(serverfdp->fd, set); | |
1697269c | 1367 | bump_maxfd(serverfdp->fd, maxfdp); |
3be34541 | 1368 | } |
1a6bca81 SK |
1369 | |
1370 | if (daemon->port != 0 && !daemon->osport) | |
1371 | for (i = 0; i < RANDOM_SOCKS; i++) | |
1372 | if (daemon->randomsocks[i].refcount != 0) | |
1373 | { | |
1374 | FD_SET(daemon->randomsocks[i].fd, set); | |
1375 | bump_maxfd(daemon->randomsocks[i].fd, maxfdp); | |
1376 | } | |
1377 | ||
3be34541 SK |
1378 | for (listener = daemon->listeners; listener; listener = listener->next) |
1379 | { | |
1697269c | 1380 | /* only listen for queries if we have resources */ |
824af85b | 1381 | if (listener->fd != -1 && wait == 0) |
1697269c SK |
1382 | { |
1383 | FD_SET(listener->fd, set); | |
1384 | bump_maxfd(listener->fd, maxfdp); | |
1385 | } | |
1386 | ||
1387 | /* death of a child goes through the select loop, so | |
1388 | we don't need to explicitly arrange to wake up here */ | |
824af85b SK |
1389 | if (listener->tcpfd != -1) |
1390 | for (i = 0; i < MAX_PROCS; i++) | |
1391 | if (daemon->tcp_pids[i] == 0) | |
1392 | { | |
1393 | FD_SET(listener->tcpfd, set); | |
1394 | bump_maxfd(listener->tcpfd, maxfdp); | |
1395 | break; | |
1396 | } | |
9e4abcb5 | 1397 | |
832af0ba SK |
1398 | #ifdef HAVE_TFTP |
1399 | if (tftp <= daemon->tftp_max && listener->tftpfd != -1) | |
1400 | { | |
1401 | FD_SET(listener->tftpfd, set); | |
1402 | bump_maxfd(listener->tftpfd, maxfdp); | |
1403 | } | |
1404 | #endif | |
1405 | ||
1406 | } | |
1407 | ||
1697269c | 1408 | return wait; |
3be34541 | 1409 | } |
9e4abcb5 | 1410 | |
5aabfc78 | 1411 | static void check_dns_listeners(fd_set *set, time_t now) |
3be34541 SK |
1412 | { |
1413 | struct serverfd *serverfdp; | |
1a6bca81 SK |
1414 | struct listener *listener; |
1415 | int i; | |
1416 | ||
832af0ba SK |
1417 | for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next) |
1418 | if (FD_ISSET(serverfdp->fd, set)) | |
1a6bca81 SK |
1419 | reply_query(serverfdp->fd, serverfdp->source_addr.sa.sa_family, now); |
1420 | ||
1421 | if (daemon->port != 0 && !daemon->osport) | |
1422 | for (i = 0; i < RANDOM_SOCKS; i++) | |
1423 | if (daemon->randomsocks[i].refcount != 0 && | |
1424 | FD_ISSET(daemon->randomsocks[i].fd, set)) | |
1425 | reply_query(daemon->randomsocks[i].fd, daemon->randomsocks[i].family, now); | |
832af0ba SK |
1426 | |
1427 | for (listener = daemon->listeners; listener; listener = listener->next) | |
1428 | { | |
824af85b | 1429 | if (listener->fd != -1 && FD_ISSET(listener->fd, set)) |
5aabfc78 | 1430 | receive_query(listener, now); |
1a6bca81 | 1431 | |
832af0ba SK |
1432 | #ifdef HAVE_TFTP |
1433 | if (listener->tftpfd != -1 && FD_ISSET(listener->tftpfd, set)) | |
5aabfc78 | 1434 | tftp_request(listener, now); |
832af0ba | 1435 | #endif |
3be34541 | 1436 | |
824af85b | 1437 | if (listener->tcpfd != -1 && FD_ISSET(listener->tcpfd, set)) |
832af0ba | 1438 | { |
22ce550e | 1439 | int confd, client_ok = 1; |
832af0ba SK |
1440 | struct irec *iface = NULL; |
1441 | pid_t p; | |
52d4abf2 SK |
1442 | union mysockaddr tcp_addr; |
1443 | socklen_t tcp_len = sizeof(union mysockaddr); | |
1444 | ||
1445 | while ((confd = accept(listener->tcpfd, NULL, NULL)) == -1 && errno == EINTR); | |
832af0ba | 1446 | |
46b06656 | 1447 | if (confd == -1) |
832af0ba | 1448 | continue; |
76dd75de | 1449 | |
46b06656 SK |
1450 | if (getsockname(confd, (struct sockaddr *)&tcp_addr, &tcp_len) == -1) |
1451 | { | |
1452 | close(confd); | |
1453 | continue; | |
1454 | } | |
76dd75de SK |
1455 | |
1456 | /* Make sure that the interface list is up-to-date. | |
1457 | ||
1458 | We do this here as we may need the results below, and | |
1459 | the DNS code needs them for --interface-name stuff. | |
1460 | ||
1461 | Multiple calls to enumerate_interfaces() per select loop are | |
1462 | inhibited, so calls to it in the child process (which doesn't select()) | |
1463 | have no effect. This avoids two processes reading from the same | |
1464 | netlink fd and screwing the pooch entirely. | |
1465 | */ | |
e25db1f2 | 1466 | |
76dd75de SK |
1467 | enumerate_interfaces(0); |
1468 | ||
1469 | if (option_bool(OPT_NOWILD)) | |
1470 | iface = listener->iface; /* May be NULL */ | |
1471 | else | |
1472 | { | |
1473 | int if_index; | |
1474 | char intr_name[IF_NAMESIZE]; | |
1475 | ||
1476 | /* if we can find the arrival interface, check it's one that's allowed */ | |
1477 | if ((if_index = tcp_interface(confd, tcp_addr.sa.sa_family)) != 0 && | |
1478 | indextoname(listener->tcpfd, if_index, intr_name)) | |
1479 | { | |
1480 | struct all_addr addr; | |
1481 | addr.addr.addr4 = tcp_addr.in.sin_addr; | |
e25db1f2 | 1482 | #ifdef HAVE_IPV6 |
76dd75de SK |
1483 | if (tcp_addr.sa.sa_family == AF_INET6) |
1484 | addr.addr.addr6 = tcp_addr.in6.sin6_addr; | |
e25db1f2 | 1485 | #endif |
76dd75de SK |
1486 | |
1487 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1488 | if (iface->index == if_index) | |
1489 | break; | |
1490 | ||
1491 | if (!iface && !loopback_exception(listener->tcpfd, tcp_addr.sa.sa_family, &addr, intr_name)) | |
1492 | client_ok = 0; | |
1493 | } | |
1494 | ||
1495 | if (option_bool(OPT_CLEVERBIND)) | |
1496 | iface = listener->iface; /* May be NULL */ | |
1497 | else | |
1498 | { | |
1499 | /* Check for allowed interfaces when binding the wildcard address: | |
1500 | we do this by looking for an interface with the same address as | |
1501 | the local address of the TCP connection, then looking to see if that's | |
1502 | an allowed interface. As a side effect, we get the netmask of the | |
1503 | interface too, for localisation. */ | |
1504 | ||
1505 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1506 | if (sockaddr_isequal(&iface->addr, &tcp_addr)) | |
1507 | break; | |
1508 | ||
1509 | if (!iface) | |
1510 | client_ok = 0; | |
1511 | } | |
1512 | } | |
1513 | ||
22ce550e | 1514 | if (!client_ok) |
832af0ba SK |
1515 | { |
1516 | shutdown(confd, SHUT_RDWR); | |
1517 | close(confd); | |
1518 | } | |
59353a6b | 1519 | #ifndef NO_FORK |
28866e95 | 1520 | else if (!option_bool(OPT_DEBUG) && (p = fork()) != 0) |
832af0ba SK |
1521 | { |
1522 | if (p != -1) | |
1523 | { | |
1524 | int i; | |
1525 | for (i = 0; i < MAX_PROCS; i++) | |
1526 | if (daemon->tcp_pids[i] == 0) | |
1527 | { | |
1528 | daemon->tcp_pids[i] = p; | |
1529 | break; | |
1530 | } | |
1531 | } | |
1532 | close(confd); | |
1533 | } | |
1534 | #endif | |
1535 | else | |
1536 | { | |
1537 | unsigned char *buff; | |
1538 | struct server *s; | |
1539 | int flags; | |
52d4abf2 | 1540 | struct in_addr netmask; |
4f7b304f | 1541 | int auth_dns; |
52d4abf2 SK |
1542 | |
1543 | if (iface) | |
4f7b304f SK |
1544 | { |
1545 | netmask = iface->netmask; | |
1546 | auth_dns = iface->dns_auth; | |
1547 | } | |
52d4abf2 | 1548 | else |
4f7b304f SK |
1549 | { |
1550 | netmask.s_addr = 0; | |
1551 | auth_dns = 0; | |
1552 | } | |
52d4abf2 | 1553 | |
8ef5ada2 SK |
1554 | #ifndef NO_FORK |
1555 | /* Arrange for SIGALARM after CHILD_LIFETIME seconds to | |
1556 | terminate the process. */ | |
28866e95 | 1557 | if (!option_bool(OPT_DEBUG)) |
832af0ba | 1558 | alarm(CHILD_LIFETIME); |
8ef5ada2 SK |
1559 | #endif |
1560 | ||
832af0ba SK |
1561 | /* start with no upstream connections. */ |
1562 | for (s = daemon->servers; s; s = s->next) | |
7cebd20f | 1563 | s->tcpfd = -1; |
832af0ba SK |
1564 | |
1565 | /* The connected socket inherits non-blocking | |
1566 | attribute from the listening socket. | |
1567 | Reset that here. */ | |
1568 | if ((flags = fcntl(confd, F_GETFL, 0)) != -1) | |
1569 | fcntl(confd, F_SETFL, flags & ~O_NONBLOCK); | |
1570 | ||
4f7b304f | 1571 | buff = tcp_request(confd, now, &tcp_addr, netmask, auth_dns); |
7cebd20f | 1572 | |
832af0ba SK |
1573 | shutdown(confd, SHUT_RDWR); |
1574 | close(confd); | |
1575 | ||
1576 | if (buff) | |
1577 | free(buff); | |
1578 | ||
1579 | for (s = daemon->servers; s; s = s->next) | |
1580 | if (s->tcpfd != -1) | |
1581 | { | |
1582 | shutdown(s->tcpfd, SHUT_RDWR); | |
1583 | close(s->tcpfd); | |
1584 | } | |
7cebd20f | 1585 | #ifndef NO_FORK |
28866e95 | 1586 | if (!option_bool(OPT_DEBUG)) |
5aabfc78 SK |
1587 | { |
1588 | flush_log(); | |
1589 | _exit(0); | |
1590 | } | |
59353a6b | 1591 | #endif |
832af0ba SK |
1592 | } |
1593 | } | |
1594 | } | |
3be34541 SK |
1595 | } |
1596 | ||
7622fc06 | 1597 | #ifdef HAVE_DHCP |
5e9e0efb SK |
1598 | int make_icmp_sock(void) |
1599 | { | |
7cebd20f | 1600 | int fd; |
5e9e0efb SK |
1601 | int zeroopt = 0; |
1602 | ||
1603 | if ((fd = socket (AF_INET, SOCK_RAW, IPPROTO_ICMP)) != -1) | |
1604 | { | |
7cebd20f | 1605 | if (!fix_fd(fd) || |
5e9e0efb SK |
1606 | setsockopt(fd, SOL_SOCKET, SO_DONTROUTE, &zeroopt, sizeof(zeroopt)) == -1) |
1607 | { | |
1608 | close(fd); | |
1609 | fd = -1; | |
1610 | } | |
1611 | } | |
1612 | ||
1613 | return fd; | |
1614 | } | |
1615 | ||
5aabfc78 | 1616 | int icmp_ping(struct in_addr addr) |
3be34541 | 1617 | { |
5e9e0efb | 1618 | /* Try and get an ICMP echo from a machine. */ |
3be34541 SK |
1619 | |
1620 | /* Note that whilst in the three second wait, we check for | |
832af0ba | 1621 | (and service) events on the DNS and TFTP sockets, (so doing that |
3be34541 SK |
1622 | better not use any resources our caller has in use...) |
1623 | but we remain deaf to signals or further DHCP packets. */ | |
1624 | ||
5e9e0efb | 1625 | int fd; |
3be34541 SK |
1626 | struct sockaddr_in saddr; |
1627 | struct { | |
1628 | struct ip ip; | |
1629 | struct icmp icmp; | |
1630 | } packet; | |
1631 | unsigned short id = rand16(); | |
1632 | unsigned int i, j; | |
5e9e0efb | 1633 | int gotreply = 0; |
3be34541 | 1634 | time_t start, now; |
5e9e0efb | 1635 | |
824af85b | 1636 | #if defined(HAVE_LINUX_NETWORK) || defined (HAVE_SOLARIS_NETWORK) |
5e9e0efb SK |
1637 | if ((fd = make_icmp_sock()) == -1) |
1638 | return 0; | |
1639 | #else | |
1640 | int opt = 2000; | |
1641 | fd = daemon->dhcp_icmp_fd; | |
1642 | setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)); | |
1643 | #endif | |
1644 | ||
3be34541 SK |
1645 | saddr.sin_family = AF_INET; |
1646 | saddr.sin_port = 0; | |
1647 | saddr.sin_addr = addr; | |
1648 | #ifdef HAVE_SOCKADDR_SA_LEN | |
1649 | saddr.sin_len = sizeof(struct sockaddr_in); | |
1650 | #endif | |
1651 | ||
1652 | memset(&packet.icmp, 0, sizeof(packet.icmp)); | |
1653 | packet.icmp.icmp_type = ICMP_ECHO; | |
1654 | packet.icmp.icmp_id = id; | |
1655 | for (j = 0, i = 0; i < sizeof(struct icmp) / 2; i++) | |
1656 | j += ((u16 *)&packet.icmp)[i]; | |
1657 | while (j>>16) | |
1658 | j = (j & 0xffff) + (j >> 16); | |
1659 | packet.icmp.icmp_cksum = (j == 0xffff) ? j : ~j; | |
1660 | ||
5e9e0efb | 1661 | while (sendto(fd, (char *)&packet.icmp, sizeof(struct icmp), 0, |
fd9fa481 SK |
1662 | (struct sockaddr *)&saddr, sizeof(saddr)) == -1 && |
1663 | retry_send()); | |
1664 | ||
5e9e0efb SK |
1665 | for (now = start = dnsmasq_time(); |
1666 | difftime(now, start) < (float)PING_WAIT;) | |
fd9fa481 SK |
1667 | { |
1668 | struct timeval tv; | |
f2621c7f | 1669 | fd_set rset, wset; |
fd9fa481 | 1670 | struct sockaddr_in faddr; |
1697269c | 1671 | int maxfd = fd; |
3d8df260 | 1672 | socklen_t len = sizeof(faddr); |
fd9fa481 SK |
1673 | |
1674 | tv.tv_usec = 250000; | |
1675 | tv.tv_sec = 0; | |
1676 | ||
1677 | FD_ZERO(&rset); | |
f2621c7f | 1678 | FD_ZERO(&wset); |
5e9e0efb | 1679 | FD_SET(fd, &rset); |
5aabfc78 | 1680 | set_dns_listeners(now, &rset, &maxfd); |
f2621c7f | 1681 | set_log_writer(&wset, &maxfd); |
c5ad4e79 SK |
1682 | |
1683 | #ifdef HAVE_DHCP6 | |
1f776932 | 1684 | if (daemon->doing_ra) |
c5ad4e79 SK |
1685 | { |
1686 | FD_SET(daemon->icmp6fd, &rset); | |
1687 | bump_maxfd(daemon->icmp6fd, &maxfd); | |
1688 | } | |
1689 | #endif | |
1690 | ||
f2621c7f SK |
1691 | if (select(maxfd+1, &rset, &wset, NULL, &tv) < 0) |
1692 | { | |
1693 | FD_ZERO(&rset); | |
1694 | FD_ZERO(&wset); | |
1695 | } | |
1696 | ||
5e9e0efb | 1697 | now = dnsmasq_time(); |
f2621c7f SK |
1698 | |
1699 | check_log_writer(&wset); | |
5aabfc78 | 1700 | check_dns_listeners(&rset, now); |
832af0ba | 1701 | |
c5ad4e79 | 1702 | #ifdef HAVE_DHCP6 |
1f776932 SK |
1703 | if (daemon->doing_ra && FD_ISSET(daemon->icmp6fd, &rset)) |
1704 | icmp6_packet(now); | |
c5ad4e79 SK |
1705 | #endif |
1706 | ||
832af0ba | 1707 | #ifdef HAVE_TFTP |
5aabfc78 | 1708 | check_tftp_listeners(&rset, now); |
832af0ba SK |
1709 | #endif |
1710 | ||
5e9e0efb SK |
1711 | if (FD_ISSET(fd, &rset) && |
1712 | recvfrom(fd, &packet, sizeof(packet), 0, | |
fd9fa481 SK |
1713 | (struct sockaddr *)&faddr, &len) == sizeof(packet) && |
1714 | saddr.sin_addr.s_addr == faddr.sin_addr.s_addr && | |
1715 | packet.icmp.icmp_type == ICMP_ECHOREPLY && | |
1716 | packet.icmp.icmp_seq == 0 && | |
1717 | packet.icmp.icmp_id == id) | |
1718 | { | |
1719 | gotreply = 1; | |
1720 | break; | |
1721 | } | |
1722 | } | |
1723 | ||
824af85b | 1724 | #if defined(HAVE_LINUX_NETWORK) || defined(HAVE_SOLARIS_NETWORK) |
5e9e0efb SK |
1725 | close(fd); |
1726 | #else | |
3be34541 | 1727 | opt = 1; |
5e9e0efb SK |
1728 | setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)); |
1729 | #endif | |
1730 | ||
3be34541 SK |
1731 | return gotreply; |
1732 | } | |
7622fc06 | 1733 | #endif |
0a852541 SK |
1734 | |
1735 |