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Commit | Line | Data |
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61744359 | 1 | /* dnsmasq is Copyright (c) 2000-2013 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; | |
53 | #endif | |
408c368f | 54 | #if defined(HAVE_DHCP) || defined(HAVE_DHCP6) |
1f776932 | 55 | struct dhcp_context *context; |
ff7eea27 | 56 | struct dhcp_relay *relay; |
408c368f | 57 | #endif |
5aabfc78 | 58 | |
824af85b | 59 | #ifdef LOCALEDIR |
b8187c80 SK |
60 | setlocale(LC_ALL, ""); |
61 | bindtextdomain("dnsmasq", LOCALEDIR); | |
62 | textdomain("dnsmasq"); | |
63 | #endif | |
64 | ||
9e4abcb5 SK |
65 | sigact.sa_handler = sig_handler; |
66 | sigact.sa_flags = 0; | |
67 | sigemptyset(&sigact.sa_mask); | |
68 | sigaction(SIGUSR1, &sigact, NULL); | |
5aabfc78 | 69 | sigaction(SIGUSR2, &sigact, NULL); |
9e4abcb5 SK |
70 | sigaction(SIGHUP, &sigact, NULL); |
71 | sigaction(SIGTERM, &sigact, NULL); | |
44a2a316 | 72 | sigaction(SIGALRM, &sigact, NULL); |
feba5c1d SK |
73 | sigaction(SIGCHLD, &sigact, NULL); |
74 | ||
75 | /* ignore SIGPIPE */ | |
76 | sigact.sa_handler = SIG_IGN; | |
77 | sigaction(SIGPIPE, &sigact, NULL); | |
9e4abcb5 | 78 | |
5aabfc78 SK |
79 | umask(022); /* known umask, create leases and pid files as 0644 */ |
80 | ||
81 | read_opts(argc, argv, compile_opts); | |
82 | ||
3be34541 SK |
83 | if (daemon->edns_pktsz < PACKETSZ) |
84 | daemon->edns_pktsz = PACKETSZ; | |
0a852541 SK |
85 | daemon->packet_buff_sz = daemon->edns_pktsz > DNSMASQ_PACKETSZ ? |
86 | daemon->edns_pktsz : DNSMASQ_PACKETSZ; | |
87 | daemon->packet = safe_malloc(daemon->packet_buff_sz); | |
1a6bca81 | 88 | |
c72daea8 SK |
89 | daemon->addrbuff = safe_malloc(ADDRSTRLEN); |
90 | ||
4f7b304f | 91 | |
7622fc06 | 92 | #ifdef HAVE_DHCP |
3be34541 | 93 | if (!daemon->lease_file) |
9e4abcb5 | 94 | { |
52b92f4d | 95 | if (daemon->dhcp || daemon->dhcp6) |
3be34541 | 96 | daemon->lease_file = LEASEFILE; |
9e4abcb5 | 97 | } |
7622fc06 | 98 | #endif |
9e4abcb5 | 99 | |
a2761754 SK |
100 | /* Close any file descriptors we inherited apart from std{in|out|err} |
101 | ||
102 | Ensure that at least stdin, stdout and stderr (fd 0, 1, 2) exist, | |
103 | otherwise file descriptors we create can end up being 0, 1, or 2 | |
104 | and then get accidentally closed later when we make 0, 1, and 2 | |
105 | open to /dev/null. Normally we'll be started with 0, 1 and 2 open, | |
106 | but it's not guaranteed. By opening /dev/null three times, we | |
107 | ensure that we're not using those fds for real stuff. */ | |
5aabfc78 SK |
108 | for (i = 0; i < max_fd; i++) |
109 | if (i != STDOUT_FILENO && i != STDERR_FILENO && i != STDIN_FILENO) | |
110 | close(i); | |
a2761754 SK |
111 | else |
112 | open("/dev/null", O_RDWR); | |
5aabfc78 | 113 | |
801ca9a7 SK |
114 | #ifndef HAVE_LINUX_NETWORK |
115 | # if !(defined(IP_RECVDSTADDR) && defined(IP_RECVIF) && defined(IP_SENDSRCADDR)) | |
28866e95 | 116 | if (!option_bool(OPT_NOWILD)) |
de37951c SK |
117 | { |
118 | bind_fallback = 1; | |
28866e95 | 119 | set_option_bool(OPT_NOWILD); |
de37951c | 120 | } |
801ca9a7 | 121 | # endif |
2b5bae9a SK |
122 | |
123 | /* -- bind-dynamic not supported on !Linux, fall back to --bind-interfaces */ | |
54dd393f | 124 | if (option_bool(OPT_CLEVERBIND)) |
2b5bae9a SK |
125 | { |
126 | bind_fallback = 1; | |
127 | set_option_bool(OPT_NOWILD); | |
236e072c | 128 | reset_option_bool(OPT_CLEVERBIND); |
2b5bae9a | 129 | } |
309331f5 | 130 | #endif |
2b5bae9a | 131 | |
832af0ba | 132 | #ifndef HAVE_TFTP |
9b40cbf5 | 133 | if (option_bool(OPT_TFTP)) |
5aabfc78 | 134 | die(_("TFTP server not available: set HAVE_TFTP in src/config.h"), NULL, EC_BADCONF); |
832af0ba SK |
135 | #endif |
136 | ||
7de060b0 SK |
137 | #ifdef HAVE_CONNTRACK |
138 | if (option_bool(OPT_CONNTRACK) && (daemon->query_port != 0 || daemon->osport)) | |
139 | die (_("Cannot use --conntrack AND --query-port"), NULL, EC_BADCONF); | |
140 | #else | |
141 | if (option_bool(OPT_CONNTRACK)) | |
142 | die(_("Conntrack support not available: set HAVE_CONNTRACK in src/config.h"), NULL, EC_BADCONF); | |
143 | #endif | |
144 | ||
824af85b SK |
145 | #ifdef HAVE_SOLARIS_NETWORK |
146 | if (daemon->max_logs != 0) | |
147 | die(_("asychronous logging is not available under Solaris"), NULL, EC_BADCONF); | |
148 | #endif | |
149 | ||
572b41eb SK |
150 | #ifdef __ANDROID__ |
151 | if (daemon->max_logs != 0) | |
152 | die(_("asychronous logging is not available under Android"), NULL, EC_BADCONF); | |
153 | #endif | |
154 | ||
4820dce9 SK |
155 | #ifndef HAVE_AUTH |
156 | if (daemon->authserver) | |
157 | die(_("authoritative DNS not available: set HAVE_AUTH in src/config.h"), NULL, EC_BADCONF); | |
158 | #endif | |
159 | ||
1a6bca81 SK |
160 | rand_init(); |
161 | ||
5aabfc78 | 162 | now = dnsmasq_time(); |
4f7b304f | 163 | |
b0ff858e | 164 | /* Create a serial at startup if not configured. */ |
4f7b304f SK |
165 | if (daemon->authinterface && daemon->soa_sn == 0) |
166 | #ifdef HAVE_BROKEN_RTC | |
b0ff858e | 167 | die(_("zone serial must be configured in --auth-soa"), NULL, EC_BADCONF); |
4f7b304f SK |
168 | #else |
169 | daemon->soa_sn = now; | |
170 | #endif | |
5aabfc78 | 171 | |
ff7eea27 SK |
172 | #ifdef HAVE_DHCP6 |
173 | if (daemon->dhcp6) | |
174 | { | |
175 | daemon->doing_ra = option_bool(OPT_RA); | |
1f776932 | 176 | |
ff7eea27 | 177 | for (context = daemon->dhcp6; context; context = context->next) |
1f776932 | 178 | { |
ff7eea27 SK |
179 | if (context->flags & CONTEXT_DHCP) |
180 | daemon->doing_dhcp6 = 1; | |
181 | if (context->flags & CONTEXT_RA) | |
182 | daemon->doing_ra = 1; | |
bb86e858 | 183 | #ifndef HAVE_LINUX_NETWORK |
ff7eea27 SK |
184 | if (context->flags & CONTEXT_TEMPLATE) |
185 | die (_("dhcp-range constructor not available on this platform"), NULL, EC_BADCONF); | |
bb86e858 | 186 | #endif |
1f776932 | 187 | } |
ff7eea27 SK |
188 | } |
189 | #endif | |
190 | ||
191 | #ifdef HAVE_DHCP | |
192 | /* Note that order matters here, we must call lease_init before | |
193 | creating any file descriptors which shouldn't be leaked | |
194 | to the lease-script init process. We need to call common_init | |
195 | before lease_init to allocate buffers it uses.*/ | |
196 | if (daemon->dhcp || daemon->doing_dhcp6 || daemon->relay4 || daemon->relay6) | |
197 | { | |
198 | dhcp_common_init(); | |
1f776932 | 199 | if (daemon->dhcp || daemon->doing_dhcp6) |
ff7eea27 SK |
200 | lease_init(now); |
201 | } | |
202 | ||
203 | if (daemon->dhcp || daemon->relay4) | |
204 | dhcp_init(); | |
205 | ||
843c96b4 | 206 | # ifdef HAVE_DHCP6 |
89500e31 | 207 | if (daemon->doing_ra || daemon->doing_dhcp6 || daemon->relay6) |
ff7eea27 SK |
208 | ra_init(now); |
209 | ||
210 | if (daemon->doing_dhcp6 || daemon->relay6) | |
211 | dhcp6_init(); | |
801ca9a7 SK |
212 | # endif |
213 | ||
214 | #endif | |
215 | ||
13d86c73 JD |
216 | #ifdef HAVE_IPSET |
217 | if (daemon->ipsets) | |
218 | ipset_init(); | |
219 | #endif | |
220 | ||
801ca9a7 | 221 | #ifdef HAVE_LINUX_NETWORK |
801ca9a7 | 222 | netlink_init(); |
8445f5d2 | 223 | |
54dd393f SK |
224 | if (option_bool(OPT_NOWILD) && option_bool(OPT_CLEVERBIND)) |
225 | die(_("cannot set --bind-interfaces and --bind-dynamic"), NULL, EC_BADCONF); | |
801ca9a7 SK |
226 | #endif |
227 | ||
115ac3e4 | 228 | if (!enumerate_interfaces(1) || !enumerate_interfaces(0)) |
5aabfc78 | 229 | die(_("failed to find list of interfaces: %s"), NULL, EC_MISC); |
843c96b4 | 230 | |
54dd393f | 231 | if (option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND)) |
de37951c | 232 | { |
74c95c25 | 233 | create_bound_listeners(1); |
54dd393f SK |
234 | |
235 | if (!option_bool(OPT_CLEVERBIND)) | |
236 | for (if_tmp = daemon->if_names; if_tmp; if_tmp = if_tmp->next) | |
237 | if (if_tmp->name && !if_tmp->used) | |
238 | die(_("unknown interface %s"), if_tmp->name, EC_BADNET); | |
9380ba70 SK |
239 | |
240 | #if defined(HAVE_LINUX_NETWORK) && defined(HAVE_DHCP) | |
241 | /* after enumerate_interfaces() */ | |
10ae7b50 | 242 | if (daemon->dhcp) |
9380ba70 | 243 | { |
10ae7b50 SK |
244 | if (!daemon->relay4) |
245 | bindtodevice(daemon->dhcpfd); | |
9380ba70 SK |
246 | if (daemon->enable_pxe) |
247 | bindtodevice(daemon->pxefd); | |
248 | } | |
249 | #endif | |
250 | ||
251 | #if defined(HAVE_LINUX_NETWORK) && defined(HAVE_DHCP6) | |
10ae7b50 | 252 | if (daemon->doing_dhcp6 && !daemon->relay6) |
9380ba70 SK |
253 | bindtodevice(daemon->dhcp6fd); |
254 | #endif | |
de37951c | 255 | } |
28866e95 | 256 | else |
74c95c25 | 257 | create_wildcard_listeners(); |
5d162f20 SK |
258 | |
259 | #ifdef HAVE_DHCP6 | |
260 | /* after enumerate_interfaces() */ | |
ff7eea27 | 261 | if (daemon->doing_dhcp6 || daemon->relay6 || daemon->doing_ra) |
5d162f20 SK |
262 | join_multicast(1); |
263 | #endif | |
de37951c | 264 | |
824af85b SK |
265 | if (daemon->port != 0) |
266 | cache_init(); | |
1a6bca81 | 267 | |
28866e95 | 268 | if (option_bool(OPT_DBUS)) |
3d8df260 SK |
269 | #ifdef HAVE_DBUS |
270 | { | |
271 | char *err; | |
272 | daemon->dbus = NULL; | |
273 | daemon->watches = NULL; | |
5aabfc78 SK |
274 | if ((err = dbus_init())) |
275 | die(_("DBus error: %s"), err, EC_MISC); | |
3d8df260 SK |
276 | } |
277 | #else | |
5aabfc78 | 278 | die(_("DBus not available: set HAVE_DBUS in src/config.h"), NULL, EC_BADCONF); |
3d8df260 SK |
279 | #endif |
280 | ||
824af85b SK |
281 | if (daemon->port != 0) |
282 | pre_allocate_sfds(); | |
1a6bca81 | 283 | |
c72daea8 | 284 | #if defined(HAVE_SCRIPT) |
1a6bca81 | 285 | /* Note getpwnam returns static storage */ |
843c96b4 SK |
286 | if ((daemon->dhcp || daemon->dhcp6) && |
287 | daemon->scriptuser && | |
c72daea8 | 288 | (daemon->lease_change_command || daemon->luascript)) |
1a6bca81 SK |
289 | { |
290 | if ((ent_pw = getpwnam(daemon->scriptuser))) | |
291 | { | |
292 | script_uid = ent_pw->pw_uid; | |
293 | script_gid = ent_pw->pw_gid; | |
294 | } | |
295 | else | |
296 | baduser = daemon->scriptuser; | |
297 | } | |
7622fc06 | 298 | #endif |
9e4abcb5 | 299 | |
1a6bca81 SK |
300 | if (daemon->username && !(ent_pw = getpwnam(daemon->username))) |
301 | baduser = daemon->username; | |
302 | else if (daemon->groupname && !(gp = getgrnam(daemon->groupname))) | |
303 | baduser = daemon->groupname; | |
304 | ||
305 | if (baduser) | |
306 | die(_("unknown user or group: %s"), baduser, EC_BADCONF); | |
307 | ||
308 | /* implement group defaults, "dip" if available, or group associated with uid */ | |
309 | if (!daemon->group_set && !gp) | |
310 | { | |
311 | if (!(gp = getgrnam(CHGRP)) && ent_pw) | |
312 | gp = getgrgid(ent_pw->pw_gid); | |
313 | ||
314 | /* for error message */ | |
315 | if (gp) | |
316 | daemon->groupname = gp->gr_name; | |
317 | } | |
318 | ||
319 | #if defined(HAVE_LINUX_NETWORK) | |
320 | /* determine capability API version here, while we can still | |
321 | call safe_malloc */ | |
322 | if (ent_pw && ent_pw->pw_uid != 0) | |
323 | { | |
1a6bca81 | 324 | int capsize = 1; /* for header version 1 */ |
3927da46 SK |
325 | hdr = safe_malloc(sizeof(*hdr)); |
326 | ||
1a6bca81 SK |
327 | /* find version supported by kernel */ |
328 | memset(hdr, 0, sizeof(*hdr)); | |
329 | capget(hdr, NULL); | |
330 | ||
331 | if (hdr->version != LINUX_CAPABILITY_VERSION_1) | |
332 | { | |
333 | /* if unknown version, use largest supported version (3) */ | |
334 | if (hdr->version != LINUX_CAPABILITY_VERSION_2) | |
335 | hdr->version = LINUX_CAPABILITY_VERSION_3; | |
336 | capsize = 2; | |
337 | } | |
338 | ||
339 | data = safe_malloc(sizeof(*data) * capsize); | |
340 | memset(data, 0, sizeof(*data) * capsize); | |
341 | } | |
342 | #endif | |
343 | ||
5aabfc78 | 344 | /* Use a pipe to carry signals and other events back to the event loop |
1a6bca81 SK |
345 | in a race-free manner and another to carry errors to daemon-invoking process */ |
346 | safe_pipe(pipefd, 1); | |
5e9e0efb SK |
347 | |
348 | piperead = pipefd[0]; | |
349 | pipewrite = pipefd[1]; | |
350 | /* prime the pipe to load stuff first time. */ | |
c72daea8 | 351 | send_event(pipewrite, EVENT_RELOAD, 0, NULL); |
1a6bca81 SK |
352 | |
353 | err_pipe[1] = -1; | |
1697269c | 354 | |
28866e95 | 355 | if (!option_bool(OPT_DEBUG)) |
9e4abcb5 | 356 | { |
9e4abcb5 SK |
357 | /* The following code "daemonizes" the process. |
358 | See Stevens section 12.4 */ | |
1a6bca81 | 359 | |
9e038946 SK |
360 | if (chdir("/") != 0) |
361 | die(_("cannot chdir to filesystem root: %s"), NULL, EC_MISC); | |
362 | ||
1697269c | 363 | #ifndef NO_FORK |
28866e95 | 364 | if (!option_bool(OPT_NO_FORK)) |
3be34541 | 365 | { |
5aabfc78 | 366 | pid_t pid; |
3be34541 | 367 | |
1a6bca81 SK |
368 | /* pipe to carry errors back to original process. |
369 | When startup is complete we close this and the process terminates. */ | |
370 | safe_pipe(err_pipe, 0); | |
371 | ||
7622fc06 SK |
372 | if ((pid = fork()) == -1) |
373 | /* fd == -1 since we've not forked, never returns. */ | |
c72daea8 | 374 | send_event(-1, EVENT_FORK_ERR, errno, NULL); |
9e038946 | 375 | |
5aabfc78 | 376 | if (pid != 0) |
1a6bca81 SK |
377 | { |
378 | struct event_desc ev; | |
c72daea8 SK |
379 | char *msg; |
380 | ||
1a6bca81 SK |
381 | /* close our copy of write-end */ |
382 | close(err_pipe[1]); | |
383 | ||
384 | /* check for errors after the fork */ | |
c72daea8 SK |
385 | if (read_event(err_pipe[0], &ev, &msg)) |
386 | fatal_event(&ev, msg); | |
1a6bca81 SK |
387 | |
388 | _exit(EC_GOOD); | |
389 | } | |
390 | ||
391 | close(err_pipe[0]); | |
392 | ||
393 | /* NO calls to die() from here on. */ | |
3be34541 | 394 | |
5aabfc78 | 395 | setsid(); |
7622fc06 SK |
396 | |
397 | if ((pid = fork()) == -1) | |
c72daea8 | 398 | send_event(err_pipe[1], EVENT_FORK_ERR, errno, NULL); |
7622fc06 SK |
399 | |
400 | if (pid != 0) | |
7cebd20f | 401 | _exit(0); |
3be34541 | 402 | } |
9e4abcb5 | 403 | #endif |
9e038946 | 404 | |
9e4abcb5 | 405 | /* write pidfile _after_ forking ! */ |
1a6bca81 SK |
406 | if (daemon->runfile) |
407 | { | |
79cfefd8 SK |
408 | int fd, err = 0; |
409 | ||
410 | sprintf(daemon->namebuff, "%d\n", (int) getpid()); | |
411 | ||
412 | /* Explanation: Some installations of dnsmasq (eg Debian/Ubuntu) locate the pid-file | |
413 | in a directory which is writable by the non-privileged user that dnsmasq runs as. This | |
414 | allows the daemon to delete the file as part of its shutdown. This is a security hole to the | |
415 | extent that an attacker running as the unprivileged user could replace the pidfile with a | |
416 | symlink, and have the target of that symlink overwritten as root next time dnsmasq starts. | |
417 | ||
418 | The folowing code first deletes any existing file, and then opens it with the O_EXCL flag, | |
419 | ensuring that the open() fails should there be any existing file (because the unlink() failed, | |
420 | or an attacker exploited the race between unlink() and open()). This ensures that no symlink | |
421 | attack can succeed. | |
422 | ||
423 | Any compromise of the non-privileged user still theoretically allows the pid-file to be | |
424 | replaced whilst dnsmasq is running. The worst that could allow is that the usual | |
425 | "shutdown dnsmasq" shell command could be tricked into stopping any other process. | |
426 | ||
427 | Note that if dnsmasq is started as non-root (eg for testing) it silently ignores | |
428 | failure to write the pid-file. | |
429 | */ | |
430 | ||
431 | unlink(daemon->runfile); | |
1a6bca81 | 432 | |
79cfefd8 | 433 | if ((fd = open(daemon->runfile, O_WRONLY|O_CREAT|O_TRUNC|O_EXCL, S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH)) == -1) |
1a6bca81 | 434 | { |
79cfefd8 SK |
435 | /* only complain if started as root */ |
436 | if (getuid() == 0) | |
437 | err = 1; | |
1a6bca81 | 438 | } |
79cfefd8 SK |
439 | else |
440 | { | |
441 | if (!read_write(fd, (unsigned char *)daemon->namebuff, strlen(daemon->namebuff), 0)) | |
442 | err = 1; | |
443 | ||
444 | while (!err && close(fd) == -1) | |
445 | if (!retry_send()) | |
446 | err = 1; | |
447 | } | |
448 | ||
449 | if (err) | |
1a6bca81 | 450 | { |
c72daea8 | 451 | send_event(err_pipe[1], EVENT_PIDFILE, errno, daemon->runfile); |
1a6bca81 SK |
452 | _exit(0); |
453 | } | |
9e4abcb5 | 454 | } |
1697269c SK |
455 | } |
456 | ||
8ef5ada2 SK |
457 | log_err = log_start(ent_pw, err_pipe[1]); |
458 | ||
28866e95 | 459 | if (!option_bool(OPT_DEBUG)) |
8ef5ada2 SK |
460 | { |
461 | /* open stdout etc to /dev/null */ | |
462 | int nullfd = open("/dev/null", O_RDWR); | |
463 | dup2(nullfd, STDOUT_FILENO); | |
464 | dup2(nullfd, STDERR_FILENO); | |
465 | dup2(nullfd, STDIN_FILENO); | |
466 | close(nullfd); | |
467 | } | |
1a6bca81 SK |
468 | |
469 | /* if we are to run scripts, we need to fork a helper before dropping root. */ | |
470 | daemon->helperfd = -1; | |
c72daea8 | 471 | #ifdef HAVE_SCRIPT |
52b92f4d | 472 | if ((daemon->dhcp || daemon->dhcp6) && (daemon->lease_change_command || daemon->luascript)) |
1a6bca81 | 473 | daemon->helperfd = create_helper(pipewrite, err_pipe[1], script_uid, script_gid, max_fd); |
5aabfc78 | 474 | #endif |
5aabfc78 | 475 | |
28866e95 | 476 | if (!option_bool(OPT_DEBUG) && getuid() == 0) |
1697269c | 477 | { |
1a6bca81 SK |
478 | int bad_capabilities = 0; |
479 | gid_t dummy; | |
480 | ||
481 | /* remove all supplimentary groups */ | |
482 | if (gp && | |
483 | (setgroups(0, &dummy) == -1 || | |
484 | setgid(gp->gr_gid) == -1)) | |
9e4abcb5 | 485 | { |
c72daea8 | 486 | send_event(err_pipe[1], EVENT_GROUP_ERR, errno, daemon->groupname); |
1a6bca81 | 487 | _exit(0); |
7cebd20f | 488 | } |
1a6bca81 | 489 | |
7cebd20f | 490 | if (ent_pw && ent_pw->pw_uid != 0) |
1697269c | 491 | { |
74c95c25 | 492 | #if defined(HAVE_LINUX_NETWORK) |
1697269c | 493 | /* On linux, we keep CAP_NETADMIN (for ARP-injection) and |
74c95c25 | 494 | CAP_NET_RAW (for icmp) if we're doing dhcp. If we have yet to bind |
54dd393f SK |
495 | ports because of DAD, or we're doing it dynamically, |
496 | we need CAP_NET_BIND_SERVICE too. */ | |
497 | if (is_dad_listeners() || option_bool(OPT_CLEVERBIND)) | |
74c95c25 SK |
498 | data->effective = data->permitted = data->inheritable = |
499 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | | |
500 | (1 << CAP_SETUID) | (1 << CAP_NET_BIND_SERVICE); | |
501 | else | |
502 | data->effective = data->permitted = data->inheritable = | |
503 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | (1 << CAP_SETUID); | |
5e9e0efb | 504 | |
1697269c | 505 | /* Tell kernel to not clear capabilities when dropping root */ |
572b41eb | 506 | if (capset(hdr, data) == -1 || prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) |
1697269c | 507 | bad_capabilities = errno; |
1a6bca81 | 508 | |
7622fc06 | 509 | #elif defined(HAVE_SOLARIS_NETWORK) |
824af85b SK |
510 | /* http://developers.sun.com/solaris/articles/program_privileges.html */ |
511 | priv_set_t *priv_set; | |
512 | ||
513 | if (!(priv_set = priv_str_to_set("basic", ",", NULL)) || | |
514 | priv_addset(priv_set, PRIV_NET_ICMPACCESS) == -1 || | |
515 | priv_addset(priv_set, PRIV_SYS_NET_CONFIG) == -1) | |
516 | bad_capabilities = errno; | |
517 | ||
518 | if (priv_set && bad_capabilities == 0) | |
519 | { | |
520 | priv_inverse(priv_set); | |
521 | ||
522 | if (setppriv(PRIV_OFF, PRIV_LIMIT, priv_set) == -1) | |
523 | bad_capabilities = errno; | |
524 | } | |
525 | ||
526 | if (priv_set) | |
527 | priv_freeset(priv_set); | |
528 | ||
824af85b SK |
529 | #endif |
530 | ||
1a6bca81 | 531 | if (bad_capabilities != 0) |
1697269c | 532 | { |
c72daea8 | 533 | send_event(err_pipe[1], EVENT_CAP_ERR, bad_capabilities, NULL); |
1a6bca81 SK |
534 | _exit(0); |
535 | } | |
536 | ||
537 | /* finally drop root */ | |
538 | if (setuid(ent_pw->pw_uid) == -1) | |
539 | { | |
c72daea8 | 540 | send_event(err_pipe[1], EVENT_USER_ERR, errno, daemon->username); |
1a6bca81 SK |
541 | _exit(0); |
542 | } | |
543 | ||
1697269c | 544 | #ifdef HAVE_LINUX_NETWORK |
54dd393f | 545 | if (is_dad_listeners() || option_bool(OPT_CLEVERBIND)) |
74c95c25 SK |
546 | data->effective = data->permitted = |
547 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | (1 << CAP_NET_BIND_SERVICE); | |
548 | else | |
549 | data->effective = data->permitted = | |
550 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW); | |
1a6bca81 SK |
551 | data->inheritable = 0; |
552 | ||
553 | /* lose the setuid and setgid capbilities */ | |
554 | if (capset(hdr, data) == -1) | |
555 | { | |
c72daea8 | 556 | send_event(err_pipe[1], EVENT_CAP_ERR, errno, NULL); |
1a6bca81 | 557 | _exit(0); |
1697269c | 558 | } |
1a6bca81 SK |
559 | #endif |
560 | ||
9e4abcb5 SK |
561 | } |
562 | } | |
1697269c | 563 | |
1697269c | 564 | #ifdef HAVE_LINUX_NETWORK |
28866e95 | 565 | if (option_bool(OPT_DEBUG)) |
572b41eb | 566 | prctl(PR_SET_DUMPABLE, 1, 0, 0, 0); |
1697269c | 567 | #endif |
9e4abcb5 | 568 | |
8b3ae2fd | 569 | #ifdef HAVE_TFTP |
8bc4cece | 570 | if (option_bool(OPT_TFTP)) |
8b3ae2fd SK |
571 | { |
572 | DIR *dir; | |
573 | struct tftp_prefix *p; | |
574 | ||
575 | if (daemon->tftp_prefix) | |
576 | { | |
577 | if (!((dir = opendir(daemon->tftp_prefix)))) | |
578 | { | |
579 | send_event(err_pipe[1], EVENT_TFTP_ERR, errno, daemon->tftp_prefix); | |
580 | _exit(0); | |
581 | } | |
582 | closedir(dir); | |
583 | } | |
584 | ||
585 | for (p = daemon->if_prefix; p; p = p->next) | |
586 | { | |
587 | if (!((dir = opendir(p->prefix)))) | |
588 | { | |
589 | send_event(err_pipe[1], EVENT_TFTP_ERR, errno, p->prefix); | |
590 | _exit(0); | |
591 | } | |
592 | closedir(dir); | |
593 | } | |
594 | } | |
595 | #endif | |
596 | ||
824af85b SK |
597 | if (daemon->port == 0) |
598 | my_syslog(LOG_INFO, _("started, version %s DNS disabled"), VERSION); | |
599 | else if (daemon->cachesize != 0) | |
f2621c7f | 600 | my_syslog(LOG_INFO, _("started, version %s cachesize %d"), VERSION, daemon->cachesize); |
9e4abcb5 | 601 | else |
f2621c7f | 602 | my_syslog(LOG_INFO, _("started, version %s cache disabled"), VERSION); |
1697269c | 603 | |
f2621c7f | 604 | my_syslog(LOG_INFO, _("compile time options: %s"), compile_opts); |
1697269c | 605 | |
3d8df260 | 606 | #ifdef HAVE_DBUS |
28866e95 | 607 | if (option_bool(OPT_DBUS)) |
3d8df260 SK |
608 | { |
609 | if (daemon->dbus) | |
f2621c7f | 610 | my_syslog(LOG_INFO, _("DBus support enabled: connected to system bus")); |
3d8df260 | 611 | else |
f2621c7f | 612 | my_syslog(LOG_INFO, _("DBus support enabled: bus connection pending")); |
3d8df260 SK |
613 | } |
614 | #endif | |
615 | ||
1a6bca81 SK |
616 | if (log_err != 0) |
617 | my_syslog(LOG_WARNING, _("warning: failed to change owner of %s: %s"), | |
618 | daemon->log_file, strerror(log_err)); | |
619 | ||
de37951c | 620 | if (bind_fallback) |
f2621c7f | 621 | my_syslog(LOG_WARNING, _("setting --bind-interfaces option because of OS limitations")); |
de37951c | 622 | |
28866e95 | 623 | if (!option_bool(OPT_NOWILD)) |
26128d27 SK |
624 | for (if_tmp = daemon->if_names; if_tmp; if_tmp = if_tmp->next) |
625 | if (if_tmp->name && !if_tmp->used) | |
f2621c7f | 626 | my_syslog(LOG_WARNING, _("warning: interface %s does not currently exist"), if_tmp->name); |
5e9e0efb | 627 | |
28866e95 | 628 | if (daemon->port != 0 && option_bool(OPT_NO_RESOLV)) |
208b65c5 SK |
629 | { |
630 | if (daemon->resolv_files && !daemon->resolv_files->is_default) | |
f2621c7f | 631 | my_syslog(LOG_WARNING, _("warning: ignoring resolv-file flag because no-resolv is set")); |
208b65c5 | 632 | daemon->resolv_files = NULL; |
1b7ecd11 | 633 | if (!daemon->servers) |
f2621c7f | 634 | my_syslog(LOG_WARNING, _("warning: no upstream servers configured")); |
208b65c5 SK |
635 | } |
636 | ||
f2621c7f SK |
637 | if (daemon->max_logs != 0) |
638 | my_syslog(LOG_INFO, _("asynchronous logging enabled, queue limit is %d messages"), daemon->max_logs); | |
1f776932 | 639 | |
f2621c7f | 640 | |
7622fc06 | 641 | #ifdef HAVE_DHCP |
1f776932 SK |
642 | for (context = daemon->dhcp; context; context = context->next) |
643 | log_context(AF_INET, context); | |
52b92f4d | 644 | |
ff7eea27 SK |
645 | for (relay = daemon->relay4; relay; relay = relay->next) |
646 | log_relay(AF_INET, relay); | |
647 | ||
1f776932 SK |
648 | # ifdef HAVE_DHCP6 |
649 | for (context = daemon->dhcp6; context; context = context->next) | |
650 | log_context(AF_INET6, context); | |
651 | ||
ff7eea27 SK |
652 | for (relay = daemon->relay6; relay; relay = relay->next) |
653 | log_relay(AF_INET6, relay); | |
654 | ||
1f776932 SK |
655 | if (daemon->doing_dhcp6 || daemon->doing_ra) |
656 | dhcp_construct_contexts(now); | |
657 | ||
658 | if (option_bool(OPT_RA)) | |
659 | my_syslog(MS_DHCP | LOG_INFO, _("IPv6 router advertisement enabled")); | |
660 | # endif | |
26128d27 | 661 | |
8445f5d2 SK |
662 | /* after dhcp_contruct_contexts */ |
663 | if (daemon->dhcp || daemon->doing_dhcp6) | |
664 | lease_find_interfaces(now); | |
1f776932 | 665 | #endif |
52b92f4d | 666 | |
832af0ba | 667 | #ifdef HAVE_TFTP |
8bc4cece | 668 | if (option_bool(OPT_TFTP)) |
832af0ba | 669 | { |
832af0ba | 670 | #ifdef FD_SETSIZE |
5aabfc78 | 671 | if (FD_SETSIZE < (unsigned)max_fd) |
832af0ba SK |
672 | max_fd = FD_SETSIZE; |
673 | #endif | |
674 | ||
7622fc06 | 675 | my_syslog(MS_TFTP | LOG_INFO, "TFTP %s%s %s", |
f2621c7f SK |
676 | daemon->tftp_prefix ? _("root is ") : _("enabled"), |
677 | daemon->tftp_prefix ? daemon->tftp_prefix: "", | |
28866e95 | 678 | option_bool(OPT_TFTP_SECURE) ? _("secure mode") : ""); |
f2621c7f | 679 | |
832af0ba | 680 | /* This is a guess, it assumes that for small limits, |
f2621c7f | 681 | disjoint files might be served, but for large limits, |
832af0ba SK |
682 | a single file will be sent to may clients (the file only needs |
683 | one fd). */ | |
684 | ||
685 | max_fd -= 30; /* use other than TFTP */ | |
686 | ||
687 | if (max_fd < 0) | |
688 | max_fd = 5; | |
689 | else if (max_fd < 100) | |
690 | max_fd = max_fd/2; | |
691 | else | |
692 | max_fd = max_fd - 20; | |
824af85b SK |
693 | |
694 | /* if we have to use a limited range of ports, | |
695 | that will limit the number of transfers */ | |
696 | if (daemon->start_tftp_port != 0 && | |
697 | daemon->end_tftp_port - daemon->start_tftp_port + 1 < max_fd) | |
698 | max_fd = daemon->end_tftp_port - daemon->start_tftp_port + 1; | |
832af0ba SK |
699 | |
700 | if (daemon->tftp_max > max_fd) | |
701 | { | |
702 | daemon->tftp_max = max_fd; | |
7622fc06 | 703 | my_syslog(MS_TFTP | LOG_WARNING, |
f2621c7f SK |
704 | _("restricting maximum simultaneous TFTP transfers to %d"), |
705 | daemon->tftp_max); | |
832af0ba SK |
706 | } |
707 | } | |
708 | #endif | |
709 | ||
1a6bca81 SK |
710 | /* finished start-up - release original process */ |
711 | if (err_pipe[1] != -1) | |
712 | close(err_pipe[1]); | |
9e4abcb5 | 713 | |
824af85b SK |
714 | if (daemon->port != 0) |
715 | check_servers(); | |
716 | ||
7cebd20f SK |
717 | pid = getpid(); |
718 | ||
5e9e0efb | 719 | while (1) |
9e4abcb5 | 720 | { |
1697269c | 721 | int maxfd = -1; |
5e9e0efb | 722 | struct timeval t, *tp = NULL; |
3d8df260 | 723 | fd_set rset, wset, eset; |
9e4abcb5 SK |
724 | |
725 | FD_ZERO(&rset); | |
3d8df260 SK |
726 | FD_ZERO(&wset); |
727 | FD_ZERO(&eset); | |
9e4abcb5 | 728 | |
1697269c SK |
729 | /* if we are out of resources, find how long we have to wait |
730 | for some to come free, we'll loop around then and restart | |
731 | listening for queries */ | |
5aabfc78 | 732 | if ((t.tv_sec = set_dns_listeners(now, &rset, &maxfd)) != 0) |
1697269c SK |
733 | { |
734 | t.tv_usec = 0; | |
735 | tp = &t; | |
736 | } | |
737 | ||
832af0ba SK |
738 | /* Whilst polling for the dbus, or doing a tftp transfer, wake every quarter second */ |
739 | if (daemon->tftp_trans || | |
28866e95 | 740 | (option_bool(OPT_DBUS) && !daemon->dbus)) |
5e9e0efb | 741 | { |
1697269c SK |
742 | t.tv_sec = 0; |
743 | t.tv_usec = 250000; | |
5e9e0efb | 744 | tp = &t; |
5e9e0efb | 745 | } |
74c95c25 SK |
746 | /* Wake every second whilst waiting for DAD to complete */ |
747 | else if (is_dad_listeners()) | |
748 | { | |
749 | t.tv_sec = 1; | |
750 | t.tv_usec = 0; | |
751 | tp = &t; | |
752 | } | |
44a2a316 | 753 | |
832af0ba | 754 | #ifdef HAVE_DBUS |
5aabfc78 | 755 | set_dbus_listeners(&maxfd, &rset, &wset, &eset); |
5e9e0efb SK |
756 | #endif |
757 | ||
7622fc06 | 758 | #ifdef HAVE_DHCP |
ff7eea27 | 759 | if (daemon->dhcp || daemon->relay4) |
5e9e0efb SK |
760 | { |
761 | FD_SET(daemon->dhcpfd, &rset); | |
1697269c | 762 | bump_maxfd(daemon->dhcpfd, &maxfd); |
316e2730 SK |
763 | if (daemon->pxefd != -1) |
764 | { | |
765 | FD_SET(daemon->pxefd, &rset); | |
766 | bump_maxfd(daemon->pxefd, &maxfd); | |
767 | } | |
5e9e0efb | 768 | } |
7622fc06 | 769 | #endif |
cdeda28f | 770 | |
52b92f4d | 771 | #ifdef HAVE_DHCP6 |
ff7eea27 | 772 | if (daemon->doing_dhcp6 || daemon->relay6) |
52b92f4d SK |
773 | { |
774 | FD_SET(daemon->dhcp6fd, &rset); | |
c5ad4e79 | 775 | bump_maxfd(daemon->dhcp6fd, &maxfd); |
5d71d834 SK |
776 | } |
777 | ||
1f776932 | 778 | if (daemon->doing_ra) |
5d71d834 SK |
779 | { |
780 | FD_SET(daemon->icmp6fd, &rset); | |
781 | bump_maxfd(daemon->icmp6fd, &maxfd); | |
52b92f4d SK |
782 | } |
783 | #endif | |
784 | ||
5e9e0efb SK |
785 | #ifdef HAVE_LINUX_NETWORK |
786 | FD_SET(daemon->netlinkfd, &rset); | |
1697269c | 787 | bump_maxfd(daemon->netlinkfd, &maxfd); |
3d8df260 | 788 | #endif |
3d8df260 | 789 | |
5e9e0efb | 790 | FD_SET(piperead, &rset); |
1697269c SK |
791 | bump_maxfd(piperead, &maxfd); |
792 | ||
7622fc06 | 793 | #ifdef HAVE_DHCP |
1f15b81d | 794 | # ifdef HAVE_SCRIPT |
5aabfc78 | 795 | while (helper_buf_empty() && do_script_run(now)); |
1697269c | 796 | |
a9530964 SK |
797 | # ifdef HAVE_TFTP |
798 | while (helper_buf_empty() && do_tftp_script_run()); | |
799 | # endif | |
800 | ||
1697269c SK |
801 | if (!helper_buf_empty()) |
802 | { | |
803 | FD_SET(daemon->helperfd, &wset); | |
804 | bump_maxfd(daemon->helperfd, &maxfd); | |
805 | } | |
7622fc06 | 806 | # else |
5aabfc78 SK |
807 | /* need this for other side-effects */ |
808 | while (do_script_run(now)); | |
a9530964 SK |
809 | |
810 | # ifdef HAVE_TFTP | |
811 | while (do_tftp_script_run()); | |
812 | # endif | |
813 | ||
7622fc06 | 814 | # endif |
5aabfc78 | 815 | #endif |
7622fc06 | 816 | |
f2621c7f SK |
817 | /* must do this just before select(), when we know no |
818 | more calls to my_syslog() can occur */ | |
819 | set_log_writer(&wset, &maxfd); | |
820 | ||
5e9e0efb SK |
821 | if (select(maxfd+1, &rset, &wset, &eset, tp) < 0) |
822 | { | |
823 | /* otherwise undefined after error */ | |
824 | FD_ZERO(&rset); FD_ZERO(&wset); FD_ZERO(&eset); | |
825 | } | |
826 | ||
827 | now = dnsmasq_time(); | |
9e4abcb5 | 828 | |
f2621c7f | 829 | check_log_writer(&wset); |
115ac3e4 SK |
830 | |
831 | /* prime. */ | |
832 | enumerate_interfaces(1); | |
833 | ||
74c95c25 SK |
834 | /* Check the interfaces to see if any have exited DAD state |
835 | and if so, bind the address. */ | |
836 | if (is_dad_listeners()) | |
837 | { | |
115ac3e4 | 838 | enumerate_interfaces(0); |
74c95c25 SK |
839 | /* NB, is_dad_listeners() == 1 --> we're binding interfaces */ |
840 | create_bound_listeners(0); | |
841 | } | |
f2621c7f | 842 | |
c52e1897 SK |
843 | #ifdef HAVE_LINUX_NETWORK |
844 | if (FD_ISSET(daemon->netlinkfd, &rset)) | |
1f776932 | 845 | netlink_multicast(now); |
c52e1897 SK |
846 | #endif |
847 | ||
9e4abcb5 | 848 | /* Check for changes to resolv files once per second max. */ |
3d8df260 | 849 | /* Don't go silent for long periods if the clock goes backwards. */ |
9009d746 SK |
850 | if (daemon->last_resolv == 0 || |
851 | difftime(now, daemon->last_resolv) > 1.0 || | |
852 | difftime(now, daemon->last_resolv) < -1.0) | |
9e4abcb5 | 853 | { |
8ef5ada2 SK |
854 | /* poll_resolv doesn't need to reload first time through, since |
855 | that's queued anyway. */ | |
33820b7e | 856 | |
8ef5ada2 SK |
857 | poll_resolv(0, daemon->last_resolv != 0, now); |
858 | daemon->last_resolv = now; | |
9e4abcb5 | 859 | } |
5aabfc78 | 860 | |
5e9e0efb | 861 | if (FD_ISSET(piperead, &rset)) |
5aabfc78 | 862 | async_event(piperead, now); |
7cebd20f | 863 | |
3d8df260 SK |
864 | #ifdef HAVE_DBUS |
865 | /* if we didn't create a DBus connection, retry now. */ | |
28866e95 | 866 | if (option_bool(OPT_DBUS) && !daemon->dbus) |
3d8df260 SK |
867 | { |
868 | char *err; | |
5aabfc78 | 869 | if ((err = dbus_init())) |
f2621c7f | 870 | my_syslog(LOG_WARNING, _("DBus error: %s"), err); |
3d8df260 | 871 | if (daemon->dbus) |
f2621c7f | 872 | my_syslog(LOG_INFO, _("connected to system DBus")); |
3d8df260 | 873 | } |
5aabfc78 | 874 | check_dbus_listeners(&rset, &wset, &eset); |
3d8df260 | 875 | #endif |
824af85b | 876 | |
5aabfc78 | 877 | check_dns_listeners(&rset, now); |
832af0ba SK |
878 | |
879 | #ifdef HAVE_TFTP | |
5aabfc78 | 880 | check_tftp_listeners(&rset, now); |
832af0ba SK |
881 | #endif |
882 | ||
7622fc06 | 883 | #ifdef HAVE_DHCP |
ff7eea27 | 884 | if (daemon->dhcp || daemon->relay4) |
316e2730 SK |
885 | { |
886 | if (FD_ISSET(daemon->dhcpfd, &rset)) | |
887 | dhcp_packet(now, 0); | |
888 | if (daemon->pxefd != -1 && FD_ISSET(daemon->pxefd, &rset)) | |
889 | dhcp_packet(now, 1); | |
890 | } | |
1697269c | 891 | |
52b92f4d | 892 | #ifdef HAVE_DHCP6 |
ff7eea27 | 893 | if ((daemon->doing_dhcp6 || daemon->relay6) && FD_ISSET(daemon->dhcp6fd, &rset)) |
18c63eff | 894 | dhcp6_packet(now); |
c5ad4e79 | 895 | |
1f776932 SK |
896 | if (daemon->doing_ra && FD_ISSET(daemon->icmp6fd, &rset)) |
897 | icmp6_packet(now); | |
52b92f4d SK |
898 | #endif |
899 | ||
1f15b81d | 900 | # ifdef HAVE_SCRIPT |
1697269c | 901 | if (daemon->helperfd != -1 && FD_ISSET(daemon->helperfd, &wset)) |
5aabfc78 | 902 | helper_write(); |
7622fc06 | 903 | # endif |
5aabfc78 SK |
904 | #endif |
905 | ||
9e4abcb5 | 906 | } |
9e4abcb5 SK |
907 | } |
908 | ||
3be34541 SK |
909 | static void sig_handler(int sig) |
910 | { | |
5e9e0efb | 911 | if (pid == 0) |
3be34541 | 912 | { |
1697269c SK |
913 | /* ignore anything other than TERM during startup |
914 | and in helper proc. (helper ignore TERM too) */ | |
5e9e0efb | 915 | if (sig == SIGTERM) |
5aabfc78 | 916 | exit(EC_MISC); |
3be34541 | 917 | } |
5aabfc78 | 918 | else if (pid != getpid()) |
5e9e0efb | 919 | { |
1697269c | 920 | /* alarm is used to kill TCP children after a fixed time. */ |
5e9e0efb | 921 | if (sig == SIGALRM) |
7cebd20f | 922 | _exit(0); |
3be34541 | 923 | } |
5aabfc78 SK |
924 | else |
925 | { | |
926 | /* master process */ | |
927 | int event, errsave = errno; | |
928 | ||
929 | if (sig == SIGHUP) | |
930 | event = EVENT_RELOAD; | |
931 | else if (sig == SIGCHLD) | |
932 | event = EVENT_CHILD; | |
933 | else if (sig == SIGALRM) | |
934 | event = EVENT_ALARM; | |
935 | else if (sig == SIGTERM) | |
936 | event = EVENT_TERM; | |
937 | else if (sig == SIGUSR1) | |
938 | event = EVENT_DUMP; | |
939 | else if (sig == SIGUSR2) | |
940 | event = EVENT_REOPEN; | |
941 | else | |
942 | return; | |
943 | ||
c72daea8 | 944 | send_event(pipewrite, event, 0, NULL); |
5aabfc78 SK |
945 | errno = errsave; |
946 | } | |
947 | } | |
948 | ||
353ae4d2 SK |
949 | /* now == 0 -> queue immediate callback */ |
950 | void send_alarm(time_t event, time_t now) | |
741c2952 | 951 | { |
884a6dfe | 952 | if (now == 0 || event != 0) |
353ae4d2 | 953 | { |
884a6dfe SK |
954 | /* alarm(0) or alarm(-ve) doesn't do what we want.... */ |
955 | if ((now == 0 || difftime(event, now) <= 0.0)) | |
956 | send_event(pipewrite, EVENT_ALARM, 0, NULL); | |
957 | else | |
958 | alarm((unsigned)difftime(event, now)); | |
353ae4d2 | 959 | } |
741c2952 SK |
960 | } |
961 | ||
c72daea8 | 962 | void send_event(int fd, int event, int data, char *msg) |
5aabfc78 SK |
963 | { |
964 | struct event_desc ev; | |
c72daea8 SK |
965 | struct iovec iov[2]; |
966 | ||
5aabfc78 SK |
967 | ev.event = event; |
968 | ev.data = data; | |
c72daea8 SK |
969 | ev.msg_sz = msg ? strlen(msg) : 0; |
970 | ||
971 | iov[0].iov_base = &ev; | |
972 | iov[0].iov_len = sizeof(ev); | |
973 | iov[1].iov_base = msg; | |
974 | iov[1].iov_len = ev.msg_sz; | |
1a6bca81 SK |
975 | |
976 | /* error pipe, debug mode. */ | |
977 | if (fd == -1) | |
c72daea8 | 978 | fatal_event(&ev, msg); |
1a6bca81 SK |
979 | else |
980 | /* pipe is non-blocking and struct event_desc is smaller than | |
981 | PIPE_BUF, so this either fails or writes everything */ | |
c72daea8 | 982 | while (writev(fd, iov, msg ? 2 : 1) == -1 && errno == EINTR); |
5aabfc78 SK |
983 | } |
984 | ||
c72daea8 SK |
985 | /* NOTE: the memory used to return msg is leaked: use msgs in events only |
986 | to describe fatal errors. */ | |
987 | static int read_event(int fd, struct event_desc *evp, char **msg) | |
988 | { | |
989 | char *buf; | |
990 | ||
991 | if (!read_write(fd, (unsigned char *)evp, sizeof(struct event_desc), 1)) | |
992 | return 0; | |
993 | ||
994 | *msg = NULL; | |
995 | ||
996 | if (evp->msg_sz != 0 && | |
997 | (buf = malloc(evp->msg_sz + 1)) && | |
998 | read_write(fd, (unsigned char *)buf, evp->msg_sz, 1)) | |
999 | { | |
1000 | buf[evp->msg_sz] = 0; | |
1001 | *msg = buf; | |
1002 | } | |
1003 | ||
1004 | return 1; | |
1005 | } | |
1006 | ||
1007 | static void fatal_event(struct event_desc *ev, char *msg) | |
1a6bca81 SK |
1008 | { |
1009 | errno = ev->data; | |
1010 | ||
1011 | switch (ev->event) | |
1012 | { | |
1013 | case EVENT_DIE: | |
1014 | exit(0); | |
7622fc06 SK |
1015 | |
1016 | case EVENT_FORK_ERR: | |
1017 | die(_("cannot fork into background: %s"), NULL, EC_MISC); | |
1a6bca81 SK |
1018 | |
1019 | case EVENT_PIPE_ERR: | |
1020 | die(_("failed to create helper: %s"), NULL, EC_MISC); | |
1021 | ||
1022 | case EVENT_CAP_ERR: | |
1023 | die(_("setting capabilities failed: %s"), NULL, EC_MISC); | |
1024 | ||
1025 | case EVENT_USER_ERR: | |
c72daea8 | 1026 | die(_("failed to change user-id to %s: %s"), msg, EC_MISC); |
1a6bca81 SK |
1027 | |
1028 | case EVENT_GROUP_ERR: | |
c72daea8 | 1029 | die(_("failed to change group-id to %s: %s"), msg, EC_MISC); |
1a6bca81 SK |
1030 | |
1031 | case EVENT_PIDFILE: | |
c72daea8 | 1032 | die(_("failed to open pidfile %s: %s"), msg, EC_FILE); |
1a6bca81 SK |
1033 | |
1034 | case EVENT_LOG_ERR: | |
c72daea8 SK |
1035 | die(_("cannot open log %s: %s"), msg, EC_FILE); |
1036 | ||
1037 | case EVENT_LUA_ERR: | |
1038 | die(_("failed to load Lua script: %s"), msg, EC_MISC); | |
8b3ae2fd SK |
1039 | |
1040 | case EVENT_TFTP_ERR: | |
1041 | die(_("TFTP directory %s inaccessible: %s"), msg, EC_FILE); | |
1a6bca81 SK |
1042 | } |
1043 | } | |
1044 | ||
5aabfc78 SK |
1045 | static void async_event(int pipe, time_t now) |
1046 | { | |
1047 | pid_t p; | |
1048 | struct event_desc ev; | |
1049 | int i; | |
c72daea8 SK |
1050 | char *msg; |
1051 | ||
1052 | /* NOTE: the memory used to return msg is leaked: use msgs in events only | |
1053 | to describe fatal errors. */ | |
1054 | ||
1055 | if (read_event(pipe, &ev, &msg)) | |
5aabfc78 SK |
1056 | switch (ev.event) |
1057 | { | |
1058 | case EVENT_RELOAD: | |
1059 | clear_cache_and_reload(now); | |
28866e95 | 1060 | if (daemon->port != 0 && daemon->resolv_files && option_bool(OPT_NO_POLL)) |
5aabfc78 SK |
1061 | { |
1062 | reload_servers(daemon->resolv_files->name); | |
1063 | check_servers(); | |
1064 | } | |
7622fc06 | 1065 | #ifdef HAVE_DHCP |
5aabfc78 | 1066 | rerun_scripts(); |
7622fc06 | 1067 | #endif |
5aabfc78 SK |
1068 | break; |
1069 | ||
1070 | case EVENT_DUMP: | |
824af85b SK |
1071 | if (daemon->port != 0) |
1072 | dump_cache(now); | |
5aabfc78 SK |
1073 | break; |
1074 | ||
1075 | case EVENT_ALARM: | |
7622fc06 | 1076 | #ifdef HAVE_DHCP |
1f776932 | 1077 | if (daemon->dhcp || daemon->doing_dhcp6) |
5aabfc78 SK |
1078 | { |
1079 | lease_prune(NULL, now); | |
1080 | lease_update_file(now); | |
1081 | } | |
843c96b4 | 1082 | #ifdef HAVE_DHCP6 |
1f776932 | 1083 | else if (daemon->doing_ra) |
353ae4d2 SK |
1084 | /* Not doing DHCP, so no lease system, manage alarms for ra only */ |
1085 | send_alarm(periodic_ra(now), now); | |
843c96b4 | 1086 | #endif |
7622fc06 | 1087 | #endif |
5aabfc78 SK |
1088 | break; |
1089 | ||
1090 | case EVENT_CHILD: | |
1091 | /* See Stevens 5.10 */ | |
1092 | while ((p = waitpid(-1, NULL, WNOHANG)) != 0) | |
1093 | if (p == -1) | |
1094 | { | |
1095 | if (errno != EINTR) | |
1096 | break; | |
1097 | } | |
1098 | else | |
1099 | for (i = 0 ; i < MAX_PROCS; i++) | |
1100 | if (daemon->tcp_pids[i] == p) | |
1101 | daemon->tcp_pids[i] = 0; | |
1102 | break; | |
1103 | ||
1104 | case EVENT_KILLED: | |
c72daea8 | 1105 | my_syslog(LOG_WARNING, _("script process killed by signal %d"), ev.data); |
5aabfc78 SK |
1106 | break; |
1107 | ||
1108 | case EVENT_EXITED: | |
c72daea8 | 1109 | my_syslog(LOG_WARNING, _("script process exited with status %d"), ev.data); |
5aabfc78 SK |
1110 | break; |
1111 | ||
1112 | case EVENT_EXEC_ERR: | |
9e038946 SK |
1113 | my_syslog(LOG_ERR, _("failed to execute %s: %s"), |
1114 | daemon->lease_change_command, strerror(ev.data)); | |
5aabfc78 SK |
1115 | break; |
1116 | ||
1a6bca81 | 1117 | /* necessary for fatal errors in helper */ |
c72daea8 | 1118 | case EVENT_USER_ERR: |
1a6bca81 | 1119 | case EVENT_DIE: |
c72daea8 SK |
1120 | case EVENT_LUA_ERR: |
1121 | fatal_event(&ev, msg); | |
9e038946 SK |
1122 | break; |
1123 | ||
5aabfc78 SK |
1124 | case EVENT_REOPEN: |
1125 | /* Note: this may leave TCP-handling processes with the old file still open. | |
1126 | Since any such process will die in CHILD_LIFETIME or probably much sooner, | |
1127 | we leave them logging to the old file. */ | |
1128 | if (daemon->log_file != NULL) | |
1129 | log_reopen(daemon->log_file); | |
1130 | break; | |
1131 | ||
1132 | case EVENT_TERM: | |
1133 | /* Knock all our children on the head. */ | |
1134 | for (i = 0; i < MAX_PROCS; i++) | |
1135 | if (daemon->tcp_pids[i] != 0) | |
1136 | kill(daemon->tcp_pids[i], SIGALRM); | |
1137 | ||
c72daea8 | 1138 | #if defined(HAVE_SCRIPT) |
5aabfc78 SK |
1139 | /* handle pending lease transitions */ |
1140 | if (daemon->helperfd != -1) | |
1141 | { | |
1142 | /* block in writes until all done */ | |
1143 | if ((i = fcntl(daemon->helperfd, F_GETFL)) != -1) | |
1144 | fcntl(daemon->helperfd, F_SETFL, i & ~O_NONBLOCK); | |
1145 | do { | |
1146 | helper_write(); | |
1147 | } while (!helper_buf_empty() || do_script_run(now)); | |
1148 | close(daemon->helperfd); | |
1149 | } | |
1150 | #endif | |
1151 | ||
1152 | if (daemon->lease_stream) | |
1153 | fclose(daemon->lease_stream); | |
73a08a24 SK |
1154 | |
1155 | if (daemon->runfile) | |
1156 | unlink(daemon->runfile); | |
5aabfc78 SK |
1157 | |
1158 | my_syslog(LOG_INFO, _("exiting on receipt of SIGTERM")); | |
1159 | flush_log(); | |
1160 | exit(EC_GOOD); | |
1161 | } | |
3be34541 SK |
1162 | } |
1163 | ||
8ef5ada2 | 1164 | void poll_resolv(int force, int do_reload, time_t now) |
5aabfc78 SK |
1165 | { |
1166 | struct resolvc *res, *latest; | |
1167 | struct stat statbuf; | |
1168 | time_t last_change = 0; | |
1169 | /* There may be more than one possible file. | |
1170 | Go through and find the one which changed _last_. | |
1171 | Warn of any which can't be read. */ | |
8ef5ada2 | 1172 | |
28866e95 | 1173 | if (daemon->port == 0 || option_bool(OPT_NO_POLL)) |
8ef5ada2 SK |
1174 | return; |
1175 | ||
5aabfc78 SK |
1176 | for (latest = NULL, res = daemon->resolv_files; res; res = res->next) |
1177 | if (stat(res->name, &statbuf) == -1) | |
1178 | { | |
8ef5ada2 SK |
1179 | if (force) |
1180 | { | |
1181 | res->mtime = 0; | |
1182 | continue; | |
1183 | } | |
1184 | ||
5aabfc78 SK |
1185 | if (!res->logged) |
1186 | my_syslog(LOG_WARNING, _("failed to access %s: %s"), res->name, strerror(errno)); | |
1187 | res->logged = 1; | |
8ef5ada2 SK |
1188 | |
1189 | if (res->mtime != 0) | |
1190 | { | |
1191 | /* existing file evaporated, force selection of the latest | |
1192 | file even if its mtime hasn't changed since we last looked */ | |
1193 | poll_resolv(1, do_reload, now); | |
1194 | return; | |
1195 | } | |
5aabfc78 SK |
1196 | } |
1197 | else | |
1198 | { | |
1199 | res->logged = 0; | |
8ef5ada2 SK |
1200 | if (force || (statbuf.st_mtime != res->mtime)) |
1201 | { | |
1202 | res->mtime = statbuf.st_mtime; | |
5aabfc78 SK |
1203 | if (difftime(statbuf.st_mtime, last_change) > 0.0) |
1204 | { | |
1205 | last_change = statbuf.st_mtime; | |
1206 | latest = res; | |
1207 | } | |
1208 | } | |
1209 | } | |
1210 | ||
1211 | if (latest) | |
1212 | { | |
1213 | static int warned = 0; | |
1214 | if (reload_servers(latest->name)) | |
1215 | { | |
1216 | my_syslog(LOG_INFO, _("reading %s"), latest->name); | |
1217 | warned = 0; | |
1218 | check_servers(); | |
28866e95 | 1219 | if (option_bool(OPT_RELOAD) && do_reload) |
8ef5ada2 | 1220 | clear_cache_and_reload(now); |
5aabfc78 SK |
1221 | } |
1222 | else | |
1223 | { | |
1224 | latest->mtime = 0; | |
1225 | if (!warned) | |
1226 | { | |
1227 | my_syslog(LOG_WARNING, _("no servers found in %s, will retry"), latest->name); | |
1228 | warned = 1; | |
1229 | } | |
1230 | } | |
1231 | } | |
1232 | } | |
3d8df260 | 1233 | |
5aabfc78 | 1234 | void clear_cache_and_reload(time_t now) |
3d8df260 | 1235 | { |
408c368f VG |
1236 | (void)now; |
1237 | ||
824af85b | 1238 | if (daemon->port != 0) |
7622fc06 | 1239 | cache_reload(); |
824af85b | 1240 | |
7622fc06 | 1241 | #ifdef HAVE_DHCP |
1f776932 | 1242 | if (daemon->dhcp || daemon->doing_dhcp6) |
3d8df260 | 1243 | { |
28866e95 | 1244 | if (option_bool(OPT_ETHERS)) |
5aabfc78 | 1245 | dhcp_read_ethers(); |
824af85b | 1246 | reread_dhcp(); |
3d8df260 | 1247 | dhcp_update_configs(daemon->dhcp_conf); |
5aabfc78 SK |
1248 | lease_update_from_configs(); |
1249 | lease_update_file(now); | |
353ae4d2 | 1250 | lease_update_dns(1); |
3d8df260 | 1251 | } |
843c96b4 | 1252 | #ifdef HAVE_DHCP6 |
1f776932 | 1253 | else if (daemon->doing_ra) |
2021c662 SK |
1254 | /* Not doing DHCP, so no lease system, manage |
1255 | alarms for ra only */ | |
1256 | send_alarm(periodic_ra(now), now); | |
843c96b4 | 1257 | #endif |
7622fc06 | 1258 | #endif |
3d8df260 SK |
1259 | } |
1260 | ||
5aabfc78 | 1261 | static int set_dns_listeners(time_t now, fd_set *set, int *maxfdp) |
3be34541 SK |
1262 | { |
1263 | struct serverfd *serverfdp; | |
1264 | struct listener *listener; | |
824af85b | 1265 | int wait = 0, i; |
832af0ba SK |
1266 | |
1267 | #ifdef HAVE_TFTP | |
1268 | int tftp = 0; | |
1269 | struct tftp_transfer *transfer; | |
1270 | for (transfer = daemon->tftp_trans; transfer; transfer = transfer->next) | |
1271 | { | |
1272 | tftp++; | |
1273 | FD_SET(transfer->sockfd, set); | |
1274 | bump_maxfd(transfer->sockfd, maxfdp); | |
1275 | } | |
1276 | #endif | |
1277 | ||
1697269c | 1278 | /* will we be able to get memory? */ |
824af85b SK |
1279 | if (daemon->port != 0) |
1280 | get_new_frec(now, &wait); | |
1697269c | 1281 | |
3be34541 SK |
1282 | for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next) |
1283 | { | |
1284 | FD_SET(serverfdp->fd, set); | |
1697269c | 1285 | bump_maxfd(serverfdp->fd, maxfdp); |
3be34541 | 1286 | } |
1a6bca81 SK |
1287 | |
1288 | if (daemon->port != 0 && !daemon->osport) | |
1289 | for (i = 0; i < RANDOM_SOCKS; i++) | |
1290 | if (daemon->randomsocks[i].refcount != 0) | |
1291 | { | |
1292 | FD_SET(daemon->randomsocks[i].fd, set); | |
1293 | bump_maxfd(daemon->randomsocks[i].fd, maxfdp); | |
1294 | } | |
1295 | ||
3be34541 SK |
1296 | for (listener = daemon->listeners; listener; listener = listener->next) |
1297 | { | |
1697269c | 1298 | /* only listen for queries if we have resources */ |
824af85b | 1299 | if (listener->fd != -1 && wait == 0) |
1697269c SK |
1300 | { |
1301 | FD_SET(listener->fd, set); | |
1302 | bump_maxfd(listener->fd, maxfdp); | |
1303 | } | |
1304 | ||
1305 | /* death of a child goes through the select loop, so | |
1306 | we don't need to explicitly arrange to wake up here */ | |
824af85b SK |
1307 | if (listener->tcpfd != -1) |
1308 | for (i = 0; i < MAX_PROCS; i++) | |
1309 | if (daemon->tcp_pids[i] == 0) | |
1310 | { | |
1311 | FD_SET(listener->tcpfd, set); | |
1312 | bump_maxfd(listener->tcpfd, maxfdp); | |
1313 | break; | |
1314 | } | |
9e4abcb5 | 1315 | |
832af0ba SK |
1316 | #ifdef HAVE_TFTP |
1317 | if (tftp <= daemon->tftp_max && listener->tftpfd != -1) | |
1318 | { | |
1319 | FD_SET(listener->tftpfd, set); | |
1320 | bump_maxfd(listener->tftpfd, maxfdp); | |
1321 | } | |
1322 | #endif | |
1323 | ||
1324 | } | |
1325 | ||
1697269c | 1326 | return wait; |
3be34541 | 1327 | } |
9e4abcb5 | 1328 | |
5aabfc78 | 1329 | static void check_dns_listeners(fd_set *set, time_t now) |
3be34541 SK |
1330 | { |
1331 | struct serverfd *serverfdp; | |
1a6bca81 SK |
1332 | struct listener *listener; |
1333 | int i; | |
1334 | ||
832af0ba SK |
1335 | for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next) |
1336 | if (FD_ISSET(serverfdp->fd, set)) | |
1a6bca81 SK |
1337 | reply_query(serverfdp->fd, serverfdp->source_addr.sa.sa_family, now); |
1338 | ||
1339 | if (daemon->port != 0 && !daemon->osport) | |
1340 | for (i = 0; i < RANDOM_SOCKS; i++) | |
1341 | if (daemon->randomsocks[i].refcount != 0 && | |
1342 | FD_ISSET(daemon->randomsocks[i].fd, set)) | |
1343 | reply_query(daemon->randomsocks[i].fd, daemon->randomsocks[i].family, now); | |
832af0ba SK |
1344 | |
1345 | for (listener = daemon->listeners; listener; listener = listener->next) | |
1346 | { | |
824af85b | 1347 | if (listener->fd != -1 && FD_ISSET(listener->fd, set)) |
5aabfc78 | 1348 | receive_query(listener, now); |
1a6bca81 | 1349 | |
832af0ba SK |
1350 | #ifdef HAVE_TFTP |
1351 | if (listener->tftpfd != -1 && FD_ISSET(listener->tftpfd, set)) | |
5aabfc78 | 1352 | tftp_request(listener, now); |
832af0ba | 1353 | #endif |
3be34541 | 1354 | |
824af85b | 1355 | if (listener->tcpfd != -1 && FD_ISSET(listener->tcpfd, set)) |
832af0ba | 1356 | { |
22ce550e | 1357 | int confd, client_ok = 1; |
832af0ba SK |
1358 | struct irec *iface = NULL; |
1359 | pid_t p; | |
52d4abf2 SK |
1360 | union mysockaddr tcp_addr; |
1361 | socklen_t tcp_len = sizeof(union mysockaddr); | |
1362 | ||
1363 | while ((confd = accept(listener->tcpfd, NULL, NULL)) == -1 && errno == EINTR); | |
832af0ba | 1364 | |
46b06656 | 1365 | if (confd == -1) |
832af0ba | 1366 | continue; |
76dd75de | 1367 | |
46b06656 SK |
1368 | if (getsockname(confd, (struct sockaddr *)&tcp_addr, &tcp_len) == -1) |
1369 | { | |
1370 | close(confd); | |
1371 | continue; | |
1372 | } | |
76dd75de SK |
1373 | |
1374 | /* Make sure that the interface list is up-to-date. | |
1375 | ||
1376 | We do this here as we may need the results below, and | |
1377 | the DNS code needs them for --interface-name stuff. | |
1378 | ||
1379 | Multiple calls to enumerate_interfaces() per select loop are | |
1380 | inhibited, so calls to it in the child process (which doesn't select()) | |
1381 | have no effect. This avoids two processes reading from the same | |
1382 | netlink fd and screwing the pooch entirely. | |
1383 | */ | |
e25db1f2 | 1384 | |
76dd75de SK |
1385 | enumerate_interfaces(0); |
1386 | ||
1387 | if (option_bool(OPT_NOWILD)) | |
1388 | iface = listener->iface; /* May be NULL */ | |
1389 | else | |
1390 | { | |
1391 | int if_index; | |
1392 | char intr_name[IF_NAMESIZE]; | |
1393 | ||
1394 | /* if we can find the arrival interface, check it's one that's allowed */ | |
1395 | if ((if_index = tcp_interface(confd, tcp_addr.sa.sa_family)) != 0 && | |
1396 | indextoname(listener->tcpfd, if_index, intr_name)) | |
1397 | { | |
1398 | struct all_addr addr; | |
1399 | addr.addr.addr4 = tcp_addr.in.sin_addr; | |
e25db1f2 | 1400 | #ifdef HAVE_IPV6 |
76dd75de SK |
1401 | if (tcp_addr.sa.sa_family == AF_INET6) |
1402 | addr.addr.addr6 = tcp_addr.in6.sin6_addr; | |
e25db1f2 | 1403 | #endif |
76dd75de SK |
1404 | |
1405 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1406 | if (iface->index == if_index) | |
1407 | break; | |
1408 | ||
1409 | if (!iface && !loopback_exception(listener->tcpfd, tcp_addr.sa.sa_family, &addr, intr_name)) | |
1410 | client_ok = 0; | |
1411 | } | |
1412 | ||
1413 | if (option_bool(OPT_CLEVERBIND)) | |
1414 | iface = listener->iface; /* May be NULL */ | |
1415 | else | |
1416 | { | |
1417 | /* Check for allowed interfaces when binding the wildcard address: | |
1418 | we do this by looking for an interface with the same address as | |
1419 | the local address of the TCP connection, then looking to see if that's | |
1420 | an allowed interface. As a side effect, we get the netmask of the | |
1421 | interface too, for localisation. */ | |
1422 | ||
1423 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1424 | if (sockaddr_isequal(&iface->addr, &tcp_addr)) | |
1425 | break; | |
1426 | ||
1427 | if (!iface) | |
1428 | client_ok = 0; | |
1429 | } | |
1430 | } | |
1431 | ||
22ce550e | 1432 | if (!client_ok) |
832af0ba SK |
1433 | { |
1434 | shutdown(confd, SHUT_RDWR); | |
1435 | close(confd); | |
1436 | } | |
59353a6b | 1437 | #ifndef NO_FORK |
28866e95 | 1438 | else if (!option_bool(OPT_DEBUG) && (p = fork()) != 0) |
832af0ba SK |
1439 | { |
1440 | if (p != -1) | |
1441 | { | |
1442 | int i; | |
1443 | for (i = 0; i < MAX_PROCS; i++) | |
1444 | if (daemon->tcp_pids[i] == 0) | |
1445 | { | |
1446 | daemon->tcp_pids[i] = p; | |
1447 | break; | |
1448 | } | |
1449 | } | |
1450 | close(confd); | |
1451 | } | |
1452 | #endif | |
1453 | else | |
1454 | { | |
1455 | unsigned char *buff; | |
1456 | struct server *s; | |
1457 | int flags; | |
52d4abf2 | 1458 | struct in_addr netmask; |
4f7b304f | 1459 | int auth_dns; |
52d4abf2 SK |
1460 | |
1461 | if (iface) | |
4f7b304f SK |
1462 | { |
1463 | netmask = iface->netmask; | |
1464 | auth_dns = iface->dns_auth; | |
1465 | } | |
52d4abf2 | 1466 | else |
4f7b304f SK |
1467 | { |
1468 | netmask.s_addr = 0; | |
1469 | auth_dns = 0; | |
1470 | } | |
52d4abf2 | 1471 | |
8ef5ada2 SK |
1472 | #ifndef NO_FORK |
1473 | /* Arrange for SIGALARM after CHILD_LIFETIME seconds to | |
1474 | terminate the process. */ | |
28866e95 | 1475 | if (!option_bool(OPT_DEBUG)) |
832af0ba | 1476 | alarm(CHILD_LIFETIME); |
8ef5ada2 SK |
1477 | #endif |
1478 | ||
832af0ba SK |
1479 | /* start with no upstream connections. */ |
1480 | for (s = daemon->servers; s; s = s->next) | |
7cebd20f | 1481 | s->tcpfd = -1; |
832af0ba SK |
1482 | |
1483 | /* The connected socket inherits non-blocking | |
1484 | attribute from the listening socket. | |
1485 | Reset that here. */ | |
1486 | if ((flags = fcntl(confd, F_GETFL, 0)) != -1) | |
1487 | fcntl(confd, F_SETFL, flags & ~O_NONBLOCK); | |
1488 | ||
4f7b304f | 1489 | buff = tcp_request(confd, now, &tcp_addr, netmask, auth_dns); |
7cebd20f | 1490 | |
832af0ba SK |
1491 | shutdown(confd, SHUT_RDWR); |
1492 | close(confd); | |
1493 | ||
1494 | if (buff) | |
1495 | free(buff); | |
1496 | ||
1497 | for (s = daemon->servers; s; s = s->next) | |
1498 | if (s->tcpfd != -1) | |
1499 | { | |
1500 | shutdown(s->tcpfd, SHUT_RDWR); | |
1501 | close(s->tcpfd); | |
1502 | } | |
7cebd20f | 1503 | #ifndef NO_FORK |
28866e95 | 1504 | if (!option_bool(OPT_DEBUG)) |
5aabfc78 SK |
1505 | { |
1506 | flush_log(); | |
1507 | _exit(0); | |
1508 | } | |
59353a6b | 1509 | #endif |
832af0ba SK |
1510 | } |
1511 | } | |
1512 | } | |
3be34541 SK |
1513 | } |
1514 | ||
7622fc06 | 1515 | #ifdef HAVE_DHCP |
5e9e0efb SK |
1516 | int make_icmp_sock(void) |
1517 | { | |
7cebd20f | 1518 | int fd; |
5e9e0efb SK |
1519 | int zeroopt = 0; |
1520 | ||
1521 | if ((fd = socket (AF_INET, SOCK_RAW, IPPROTO_ICMP)) != -1) | |
1522 | { | |
7cebd20f | 1523 | if (!fix_fd(fd) || |
5e9e0efb SK |
1524 | setsockopt(fd, SOL_SOCKET, SO_DONTROUTE, &zeroopt, sizeof(zeroopt)) == -1) |
1525 | { | |
1526 | close(fd); | |
1527 | fd = -1; | |
1528 | } | |
1529 | } | |
1530 | ||
1531 | return fd; | |
1532 | } | |
1533 | ||
5aabfc78 | 1534 | int icmp_ping(struct in_addr addr) |
3be34541 | 1535 | { |
5e9e0efb | 1536 | /* Try and get an ICMP echo from a machine. */ |
3be34541 SK |
1537 | |
1538 | /* Note that whilst in the three second wait, we check for | |
832af0ba | 1539 | (and service) events on the DNS and TFTP sockets, (so doing that |
3be34541 SK |
1540 | better not use any resources our caller has in use...) |
1541 | but we remain deaf to signals or further DHCP packets. */ | |
1542 | ||
5e9e0efb | 1543 | int fd; |
3be34541 SK |
1544 | struct sockaddr_in saddr; |
1545 | struct { | |
1546 | struct ip ip; | |
1547 | struct icmp icmp; | |
1548 | } packet; | |
1549 | unsigned short id = rand16(); | |
1550 | unsigned int i, j; | |
5e9e0efb | 1551 | int gotreply = 0; |
3be34541 | 1552 | time_t start, now; |
5e9e0efb | 1553 | |
824af85b | 1554 | #if defined(HAVE_LINUX_NETWORK) || defined (HAVE_SOLARIS_NETWORK) |
5e9e0efb SK |
1555 | if ((fd = make_icmp_sock()) == -1) |
1556 | return 0; | |
1557 | #else | |
1558 | int opt = 2000; | |
1559 | fd = daemon->dhcp_icmp_fd; | |
1560 | setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)); | |
1561 | #endif | |
1562 | ||
3be34541 SK |
1563 | saddr.sin_family = AF_INET; |
1564 | saddr.sin_port = 0; | |
1565 | saddr.sin_addr = addr; | |
1566 | #ifdef HAVE_SOCKADDR_SA_LEN | |
1567 | saddr.sin_len = sizeof(struct sockaddr_in); | |
1568 | #endif | |
1569 | ||
1570 | memset(&packet.icmp, 0, sizeof(packet.icmp)); | |
1571 | packet.icmp.icmp_type = ICMP_ECHO; | |
1572 | packet.icmp.icmp_id = id; | |
1573 | for (j = 0, i = 0; i < sizeof(struct icmp) / 2; i++) | |
1574 | j += ((u16 *)&packet.icmp)[i]; | |
1575 | while (j>>16) | |
1576 | j = (j & 0xffff) + (j >> 16); | |
1577 | packet.icmp.icmp_cksum = (j == 0xffff) ? j : ~j; | |
1578 | ||
5e9e0efb | 1579 | while (sendto(fd, (char *)&packet.icmp, sizeof(struct icmp), 0, |
fd9fa481 SK |
1580 | (struct sockaddr *)&saddr, sizeof(saddr)) == -1 && |
1581 | retry_send()); | |
1582 | ||
5e9e0efb SK |
1583 | for (now = start = dnsmasq_time(); |
1584 | difftime(now, start) < (float)PING_WAIT;) | |
fd9fa481 SK |
1585 | { |
1586 | struct timeval tv; | |
f2621c7f | 1587 | fd_set rset, wset; |
fd9fa481 | 1588 | struct sockaddr_in faddr; |
1697269c | 1589 | int maxfd = fd; |
3d8df260 | 1590 | socklen_t len = sizeof(faddr); |
fd9fa481 SK |
1591 | |
1592 | tv.tv_usec = 250000; | |
1593 | tv.tv_sec = 0; | |
1594 | ||
1595 | FD_ZERO(&rset); | |
f2621c7f | 1596 | FD_ZERO(&wset); |
5e9e0efb | 1597 | FD_SET(fd, &rset); |
5aabfc78 | 1598 | set_dns_listeners(now, &rset, &maxfd); |
f2621c7f | 1599 | set_log_writer(&wset, &maxfd); |
c5ad4e79 SK |
1600 | |
1601 | #ifdef HAVE_DHCP6 | |
1f776932 | 1602 | if (daemon->doing_ra) |
c5ad4e79 SK |
1603 | { |
1604 | FD_SET(daemon->icmp6fd, &rset); | |
1605 | bump_maxfd(daemon->icmp6fd, &maxfd); | |
1606 | } | |
1607 | #endif | |
1608 | ||
f2621c7f SK |
1609 | if (select(maxfd+1, &rset, &wset, NULL, &tv) < 0) |
1610 | { | |
1611 | FD_ZERO(&rset); | |
1612 | FD_ZERO(&wset); | |
1613 | } | |
1614 | ||
5e9e0efb | 1615 | now = dnsmasq_time(); |
f2621c7f SK |
1616 | |
1617 | check_log_writer(&wset); | |
5aabfc78 | 1618 | check_dns_listeners(&rset, now); |
832af0ba | 1619 | |
c5ad4e79 | 1620 | #ifdef HAVE_DHCP6 |
1f776932 SK |
1621 | if (daemon->doing_ra && FD_ISSET(daemon->icmp6fd, &rset)) |
1622 | icmp6_packet(now); | |
c5ad4e79 SK |
1623 | #endif |
1624 | ||
832af0ba | 1625 | #ifdef HAVE_TFTP |
5aabfc78 | 1626 | check_tftp_listeners(&rset, now); |
832af0ba SK |
1627 | #endif |
1628 | ||
5e9e0efb SK |
1629 | if (FD_ISSET(fd, &rset) && |
1630 | recvfrom(fd, &packet, sizeof(packet), 0, | |
fd9fa481 SK |
1631 | (struct sockaddr *)&faddr, &len) == sizeof(packet) && |
1632 | saddr.sin_addr.s_addr == faddr.sin_addr.s_addr && | |
1633 | packet.icmp.icmp_type == ICMP_ECHOREPLY && | |
1634 | packet.icmp.icmp_seq == 0 && | |
1635 | packet.icmp.icmp_id == id) | |
1636 | { | |
1637 | gotreply = 1; | |
1638 | break; | |
1639 | } | |
1640 | } | |
1641 | ||
824af85b | 1642 | #if defined(HAVE_LINUX_NETWORK) || defined(HAVE_SOLARIS_NETWORK) |
5e9e0efb SK |
1643 | close(fd); |
1644 | #else | |
3be34541 | 1645 | opt = 1; |
5e9e0efb SK |
1646 | setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)); |
1647 | #endif | |
1648 | ||
3be34541 SK |
1649 | return gotreply; |
1650 | } | |
7622fc06 | 1651 | #endif |
0a852541 SK |
1652 | |
1653 |