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Commit | Line | Data |
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59546085 | 1 | /* dnsmasq is Copyright (c) 2000-2012 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 | |
1f776932 | 54 | struct dhcp_context *context; |
5aabfc78 | 55 | |
824af85b | 56 | #ifdef LOCALEDIR |
b8187c80 SK |
57 | setlocale(LC_ALL, ""); |
58 | bindtextdomain("dnsmasq", LOCALEDIR); | |
59 | textdomain("dnsmasq"); | |
60 | #endif | |
61 | ||
9e4abcb5 SK |
62 | sigact.sa_handler = sig_handler; |
63 | sigact.sa_flags = 0; | |
64 | sigemptyset(&sigact.sa_mask); | |
65 | sigaction(SIGUSR1, &sigact, NULL); | |
5aabfc78 | 66 | sigaction(SIGUSR2, &sigact, NULL); |
9e4abcb5 SK |
67 | sigaction(SIGHUP, &sigact, NULL); |
68 | sigaction(SIGTERM, &sigact, NULL); | |
44a2a316 | 69 | sigaction(SIGALRM, &sigact, NULL); |
feba5c1d SK |
70 | sigaction(SIGCHLD, &sigact, NULL); |
71 | ||
72 | /* ignore SIGPIPE */ | |
73 | sigact.sa_handler = SIG_IGN; | |
74 | sigaction(SIGPIPE, &sigact, NULL); | |
9e4abcb5 | 75 | |
5aabfc78 SK |
76 | umask(022); /* known umask, create leases and pid files as 0644 */ |
77 | ||
78 | read_opts(argc, argv, compile_opts); | |
79 | ||
3be34541 SK |
80 | if (daemon->edns_pktsz < PACKETSZ) |
81 | daemon->edns_pktsz = PACKETSZ; | |
0a852541 SK |
82 | daemon->packet_buff_sz = daemon->edns_pktsz > DNSMASQ_PACKETSZ ? |
83 | daemon->edns_pktsz : DNSMASQ_PACKETSZ; | |
84 | daemon->packet = safe_malloc(daemon->packet_buff_sz); | |
1a6bca81 | 85 | |
c72daea8 SK |
86 | daemon->addrbuff = safe_malloc(ADDRSTRLEN); |
87 | ||
4f7b304f | 88 | |
7622fc06 | 89 | #ifdef HAVE_DHCP |
3be34541 | 90 | if (!daemon->lease_file) |
9e4abcb5 | 91 | { |
52b92f4d | 92 | if (daemon->dhcp || daemon->dhcp6) |
3be34541 | 93 | daemon->lease_file = LEASEFILE; |
9e4abcb5 | 94 | } |
7622fc06 | 95 | #endif |
9e4abcb5 | 96 | |
a2761754 SK |
97 | /* Close any file descriptors we inherited apart from std{in|out|err} |
98 | ||
99 | Ensure that at least stdin, stdout and stderr (fd 0, 1, 2) exist, | |
100 | otherwise file descriptors we create can end up being 0, 1, or 2 | |
101 | and then get accidentally closed later when we make 0, 1, and 2 | |
102 | open to /dev/null. Normally we'll be started with 0, 1 and 2 open, | |
103 | but it's not guaranteed. By opening /dev/null three times, we | |
104 | ensure that we're not using those fds for real stuff. */ | |
5aabfc78 SK |
105 | for (i = 0; i < max_fd; i++) |
106 | if (i != STDOUT_FILENO && i != STDERR_FILENO && i != STDIN_FILENO) | |
107 | close(i); | |
a2761754 SK |
108 | else |
109 | open("/dev/null", O_RDWR); | |
5aabfc78 | 110 | |
801ca9a7 SK |
111 | #ifndef HAVE_LINUX_NETWORK |
112 | # if !(defined(IP_RECVDSTADDR) && defined(IP_RECVIF) && defined(IP_SENDSRCADDR)) | |
28866e95 | 113 | if (!option_bool(OPT_NOWILD)) |
de37951c SK |
114 | { |
115 | bind_fallback = 1; | |
28866e95 | 116 | set_option_bool(OPT_NOWILD); |
de37951c | 117 | } |
801ca9a7 | 118 | # endif |
2b5bae9a SK |
119 | |
120 | /* -- bind-dynamic not supported on !Linux, fall back to --bind-interfaces */ | |
54dd393f | 121 | if (option_bool(OPT_CLEVERBIND)) |
2b5bae9a SK |
122 | { |
123 | bind_fallback = 1; | |
124 | set_option_bool(OPT_NOWILD); | |
236e072c | 125 | reset_option_bool(OPT_CLEVERBIND); |
2b5bae9a | 126 | } |
309331f5 | 127 | #endif |
2b5bae9a | 128 | |
832af0ba | 129 | #ifndef HAVE_TFTP |
9b40cbf5 | 130 | if (option_bool(OPT_TFTP)) |
5aabfc78 | 131 | die(_("TFTP server not available: set HAVE_TFTP in src/config.h"), NULL, EC_BADCONF); |
832af0ba SK |
132 | #endif |
133 | ||
7de060b0 SK |
134 | #ifdef HAVE_CONNTRACK |
135 | if (option_bool(OPT_CONNTRACK) && (daemon->query_port != 0 || daemon->osport)) | |
136 | die (_("Cannot use --conntrack AND --query-port"), NULL, EC_BADCONF); | |
137 | #else | |
138 | if (option_bool(OPT_CONNTRACK)) | |
139 | die(_("Conntrack support not available: set HAVE_CONNTRACK in src/config.h"), NULL, EC_BADCONF); | |
140 | #endif | |
141 | ||
824af85b SK |
142 | #ifdef HAVE_SOLARIS_NETWORK |
143 | if (daemon->max_logs != 0) | |
144 | die(_("asychronous logging is not available under Solaris"), NULL, EC_BADCONF); | |
145 | #endif | |
146 | ||
572b41eb SK |
147 | #ifdef __ANDROID__ |
148 | if (daemon->max_logs != 0) | |
149 | die(_("asychronous logging is not available under Android"), NULL, EC_BADCONF); | |
150 | #endif | |
151 | ||
4820dce9 SK |
152 | #ifndef HAVE_AUTH |
153 | if (daemon->authserver) | |
154 | die(_("authoritative DNS not available: set HAVE_AUTH in src/config.h"), NULL, EC_BADCONF); | |
155 | #endif | |
156 | ||
1a6bca81 SK |
157 | rand_init(); |
158 | ||
5aabfc78 | 159 | now = dnsmasq_time(); |
4f7b304f SK |
160 | |
161 | /* Create a serial at startup is not configured. */ | |
162 | if (daemon->authinterface && daemon->soa_sn == 0) | |
163 | #ifdef HAVE_BROKEN_RTC | |
164 | die(_("zone serial must be configured in --auth-soa")); | |
165 | #else | |
166 | daemon->soa_sn = now; | |
167 | #endif | |
5aabfc78 | 168 | |
7622fc06 | 169 | #ifdef HAVE_DHCP |
52b92f4d | 170 | if (daemon->dhcp || daemon->dhcp6) |
1f776932 SK |
171 | { |
172 | ||
173 | # ifdef HAVE_DHCP6 | |
174 | if (daemon->dhcp6) | |
175 | { | |
176 | daemon->doing_ra = option_bool(OPT_RA); | |
177 | ||
178 | for (context = daemon->dhcp6; context; context = context->next) | |
179 | { | |
180 | if (context->flags & CONTEXT_DHCP) | |
181 | daemon->doing_dhcp6 = 1; | |
bb86e858 | 182 | if (context->flags & CONTEXT_RA) |
1f776932 | 183 | daemon->doing_ra = 1; |
bb86e858 SK |
184 | #ifndef HAVE_LINUX_NETWORK |
185 | if (context->flags & CONTEXT_TEMPLATE) | |
9d299494 | 186 | die (_("dhcp-range constructor not available on this platform"), NULL, EC_BADCONF); |
bb86e858 | 187 | #endif |
1f776932 SK |
188 | } |
189 | } | |
190 | # endif | |
191 | ||
5aabfc78 SK |
192 | /* Note that order matters here, we must call lease_init before |
193 | creating any file descriptors which shouldn't be leaked | |
4cb1b320 SK |
194 | to the lease-script init process. We need to call common_init |
195 | before lease_init to allocate buffers it uses.*/ | |
1f776932 SK |
196 | if (daemon->dhcp || daemon->doing_dhcp6) |
197 | { | |
198 | dhcp_common_init(); | |
199 | lease_init(now); | |
200 | } | |
201 | ||
52b92f4d SK |
202 | if (daemon->dhcp) |
203 | dhcp_init(); | |
1f776932 | 204 | |
843c96b4 | 205 | # ifdef HAVE_DHCP6 |
1f776932 SK |
206 | if (daemon->doing_ra) |
207 | ra_init(now); | |
843c96b4 | 208 | |
1f776932 SK |
209 | if (daemon->doing_dhcp6) |
210 | dhcp6_init(); | |
801ca9a7 | 211 | # endif |
1f776932 | 212 | } |
801ca9a7 SK |
213 | |
214 | #endif | |
215 | ||
216 | #ifdef HAVE_LINUX_NETWORK | |
801ca9a7 | 217 | netlink_init(); |
8445f5d2 | 218 | |
54dd393f SK |
219 | if (option_bool(OPT_NOWILD) && option_bool(OPT_CLEVERBIND)) |
220 | die(_("cannot set --bind-interfaces and --bind-dynamic"), NULL, EC_BADCONF); | |
801ca9a7 SK |
221 | #endif |
222 | ||
223 | #ifdef HAVE_DHCP6 | |
224 | /* after netlink_init */ | |
1f776932 | 225 | if (daemon->doing_dhcp6 || daemon->doing_ra) |
843c96b4 | 226 | join_multicast(); |
801ca9a7 | 227 | #endif |
8445f5d2 | 228 | |
5aabfc78 SK |
229 | if (!enumerate_interfaces()) |
230 | die(_("failed to find list of interfaces: %s"), NULL, EC_MISC); | |
843c96b4 | 231 | |
54dd393f | 232 | if (option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND)) |
de37951c | 233 | { |
74c95c25 | 234 | create_bound_listeners(1); |
54dd393f SK |
235 | |
236 | if (!option_bool(OPT_CLEVERBIND)) | |
237 | for (if_tmp = daemon->if_names; if_tmp; if_tmp = if_tmp->next) | |
238 | if (if_tmp->name && !if_tmp->used) | |
239 | die(_("unknown interface %s"), if_tmp->name, EC_BADNET); | |
9380ba70 SK |
240 | |
241 | #if defined(HAVE_LINUX_NETWORK) && defined(HAVE_DHCP) | |
242 | /* after enumerate_interfaces() */ | |
243 | if (daemon->dhcp) | |
244 | { | |
245 | bindtodevice(daemon->dhcpfd); | |
246 | if (daemon->enable_pxe) | |
247 | bindtodevice(daemon->pxefd); | |
248 | } | |
249 | #endif | |
250 | ||
251 | #if defined(HAVE_LINUX_NETWORK) && defined(HAVE_DHCP6) | |
252 | if (daemon->dhcp6) | |
253 | bindtodevice(daemon->dhcp6fd); | |
254 | #endif | |
de37951c | 255 | } |
28866e95 | 256 | else |
74c95c25 | 257 | create_wildcard_listeners(); |
de37951c | 258 | |
824af85b SK |
259 | if (daemon->port != 0) |
260 | cache_init(); | |
1a6bca81 | 261 | |
28866e95 | 262 | if (option_bool(OPT_DBUS)) |
3d8df260 SK |
263 | #ifdef HAVE_DBUS |
264 | { | |
265 | char *err; | |
266 | daemon->dbus = NULL; | |
267 | daemon->watches = NULL; | |
5aabfc78 SK |
268 | if ((err = dbus_init())) |
269 | die(_("DBus error: %s"), err, EC_MISC); | |
3d8df260 SK |
270 | } |
271 | #else | |
5aabfc78 | 272 | die(_("DBus not available: set HAVE_DBUS in src/config.h"), NULL, EC_BADCONF); |
3d8df260 SK |
273 | #endif |
274 | ||
824af85b SK |
275 | if (daemon->port != 0) |
276 | pre_allocate_sfds(); | |
1a6bca81 | 277 | |
c72daea8 | 278 | #if defined(HAVE_SCRIPT) |
1a6bca81 | 279 | /* Note getpwnam returns static storage */ |
843c96b4 SK |
280 | if ((daemon->dhcp || daemon->dhcp6) && |
281 | daemon->scriptuser && | |
c72daea8 | 282 | (daemon->lease_change_command || daemon->luascript)) |
1a6bca81 SK |
283 | { |
284 | if ((ent_pw = getpwnam(daemon->scriptuser))) | |
285 | { | |
286 | script_uid = ent_pw->pw_uid; | |
287 | script_gid = ent_pw->pw_gid; | |
288 | } | |
289 | else | |
290 | baduser = daemon->scriptuser; | |
291 | } | |
7622fc06 | 292 | #endif |
9e4abcb5 | 293 | |
1a6bca81 SK |
294 | if (daemon->username && !(ent_pw = getpwnam(daemon->username))) |
295 | baduser = daemon->username; | |
296 | else if (daemon->groupname && !(gp = getgrnam(daemon->groupname))) | |
297 | baduser = daemon->groupname; | |
298 | ||
299 | if (baduser) | |
300 | die(_("unknown user or group: %s"), baduser, EC_BADCONF); | |
301 | ||
302 | /* implement group defaults, "dip" if available, or group associated with uid */ | |
303 | if (!daemon->group_set && !gp) | |
304 | { | |
305 | if (!(gp = getgrnam(CHGRP)) && ent_pw) | |
306 | gp = getgrgid(ent_pw->pw_gid); | |
307 | ||
308 | /* for error message */ | |
309 | if (gp) | |
310 | daemon->groupname = gp->gr_name; | |
311 | } | |
312 | ||
313 | #if defined(HAVE_LINUX_NETWORK) | |
314 | /* determine capability API version here, while we can still | |
315 | call safe_malloc */ | |
316 | if (ent_pw && ent_pw->pw_uid != 0) | |
317 | { | |
1a6bca81 | 318 | int capsize = 1; /* for header version 1 */ |
3927da46 SK |
319 | hdr = safe_malloc(sizeof(*hdr)); |
320 | ||
1a6bca81 SK |
321 | /* find version supported by kernel */ |
322 | memset(hdr, 0, sizeof(*hdr)); | |
323 | capget(hdr, NULL); | |
324 | ||
325 | if (hdr->version != LINUX_CAPABILITY_VERSION_1) | |
326 | { | |
327 | /* if unknown version, use largest supported version (3) */ | |
328 | if (hdr->version != LINUX_CAPABILITY_VERSION_2) | |
329 | hdr->version = LINUX_CAPABILITY_VERSION_3; | |
330 | capsize = 2; | |
331 | } | |
332 | ||
333 | data = safe_malloc(sizeof(*data) * capsize); | |
334 | memset(data, 0, sizeof(*data) * capsize); | |
335 | } | |
336 | #endif | |
337 | ||
5aabfc78 | 338 | /* Use a pipe to carry signals and other events back to the event loop |
1a6bca81 SK |
339 | in a race-free manner and another to carry errors to daemon-invoking process */ |
340 | safe_pipe(pipefd, 1); | |
5e9e0efb SK |
341 | |
342 | piperead = pipefd[0]; | |
343 | pipewrite = pipefd[1]; | |
344 | /* prime the pipe to load stuff first time. */ | |
c72daea8 | 345 | send_event(pipewrite, EVENT_RELOAD, 0, NULL); |
1a6bca81 SK |
346 | |
347 | err_pipe[1] = -1; | |
1697269c | 348 | |
28866e95 | 349 | if (!option_bool(OPT_DEBUG)) |
9e4abcb5 | 350 | { |
9e4abcb5 SK |
351 | /* The following code "daemonizes" the process. |
352 | See Stevens section 12.4 */ | |
1a6bca81 | 353 | |
9e038946 SK |
354 | if (chdir("/") != 0) |
355 | die(_("cannot chdir to filesystem root: %s"), NULL, EC_MISC); | |
356 | ||
1697269c | 357 | #ifndef NO_FORK |
28866e95 | 358 | if (!option_bool(OPT_NO_FORK)) |
3be34541 | 359 | { |
5aabfc78 | 360 | pid_t pid; |
3be34541 | 361 | |
1a6bca81 SK |
362 | /* pipe to carry errors back to original process. |
363 | When startup is complete we close this and the process terminates. */ | |
364 | safe_pipe(err_pipe, 0); | |
365 | ||
7622fc06 SK |
366 | if ((pid = fork()) == -1) |
367 | /* fd == -1 since we've not forked, never returns. */ | |
c72daea8 | 368 | send_event(-1, EVENT_FORK_ERR, errno, NULL); |
9e038946 | 369 | |
5aabfc78 | 370 | if (pid != 0) |
1a6bca81 SK |
371 | { |
372 | struct event_desc ev; | |
c72daea8 SK |
373 | char *msg; |
374 | ||
1a6bca81 SK |
375 | /* close our copy of write-end */ |
376 | close(err_pipe[1]); | |
377 | ||
378 | /* check for errors after the fork */ | |
c72daea8 SK |
379 | if (read_event(err_pipe[0], &ev, &msg)) |
380 | fatal_event(&ev, msg); | |
1a6bca81 SK |
381 | |
382 | _exit(EC_GOOD); | |
383 | } | |
384 | ||
385 | close(err_pipe[0]); | |
386 | ||
387 | /* NO calls to die() from here on. */ | |
3be34541 | 388 | |
5aabfc78 | 389 | setsid(); |
7622fc06 SK |
390 | |
391 | if ((pid = fork()) == -1) | |
c72daea8 | 392 | send_event(err_pipe[1], EVENT_FORK_ERR, errno, NULL); |
7622fc06 SK |
393 | |
394 | if (pid != 0) | |
7cebd20f | 395 | _exit(0); |
3be34541 | 396 | } |
9e4abcb5 | 397 | #endif |
9e038946 | 398 | |
9e4abcb5 | 399 | /* write pidfile _after_ forking ! */ |
1a6bca81 SK |
400 | if (daemon->runfile) |
401 | { | |
79cfefd8 SK |
402 | int fd, err = 0; |
403 | ||
404 | sprintf(daemon->namebuff, "%d\n", (int) getpid()); | |
405 | ||
406 | /* Explanation: Some installations of dnsmasq (eg Debian/Ubuntu) locate the pid-file | |
407 | in a directory which is writable by the non-privileged user that dnsmasq runs as. This | |
408 | allows the daemon to delete the file as part of its shutdown. This is a security hole to the | |
409 | extent that an attacker running as the unprivileged user could replace the pidfile with a | |
410 | symlink, and have the target of that symlink overwritten as root next time dnsmasq starts. | |
411 | ||
412 | The folowing code first deletes any existing file, and then opens it with the O_EXCL flag, | |
413 | ensuring that the open() fails should there be any existing file (because the unlink() failed, | |
414 | or an attacker exploited the race between unlink() and open()). This ensures that no symlink | |
415 | attack can succeed. | |
416 | ||
417 | Any compromise of the non-privileged user still theoretically allows the pid-file to be | |
418 | replaced whilst dnsmasq is running. The worst that could allow is that the usual | |
419 | "shutdown dnsmasq" shell command could be tricked into stopping any other process. | |
420 | ||
421 | Note that if dnsmasq is started as non-root (eg for testing) it silently ignores | |
422 | failure to write the pid-file. | |
423 | */ | |
424 | ||
425 | unlink(daemon->runfile); | |
1a6bca81 | 426 | |
79cfefd8 | 427 | if ((fd = open(daemon->runfile, O_WRONLY|O_CREAT|O_TRUNC|O_EXCL, S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH)) == -1) |
1a6bca81 | 428 | { |
79cfefd8 SK |
429 | /* only complain if started as root */ |
430 | if (getuid() == 0) | |
431 | err = 1; | |
1a6bca81 | 432 | } |
79cfefd8 SK |
433 | else |
434 | { | |
435 | if (!read_write(fd, (unsigned char *)daemon->namebuff, strlen(daemon->namebuff), 0)) | |
436 | err = 1; | |
437 | ||
438 | while (!err && close(fd) == -1) | |
439 | if (!retry_send()) | |
440 | err = 1; | |
441 | } | |
442 | ||
443 | if (err) | |
1a6bca81 | 444 | { |
c72daea8 | 445 | send_event(err_pipe[1], EVENT_PIDFILE, errno, daemon->runfile); |
1a6bca81 SK |
446 | _exit(0); |
447 | } | |
9e4abcb5 | 448 | } |
1697269c SK |
449 | } |
450 | ||
8ef5ada2 SK |
451 | log_err = log_start(ent_pw, err_pipe[1]); |
452 | ||
28866e95 | 453 | if (!option_bool(OPT_DEBUG)) |
8ef5ada2 SK |
454 | { |
455 | /* open stdout etc to /dev/null */ | |
456 | int nullfd = open("/dev/null", O_RDWR); | |
457 | dup2(nullfd, STDOUT_FILENO); | |
458 | dup2(nullfd, STDERR_FILENO); | |
459 | dup2(nullfd, STDIN_FILENO); | |
460 | close(nullfd); | |
461 | } | |
1a6bca81 SK |
462 | |
463 | /* if we are to run scripts, we need to fork a helper before dropping root. */ | |
464 | daemon->helperfd = -1; | |
c72daea8 | 465 | #ifdef HAVE_SCRIPT |
52b92f4d | 466 | if ((daemon->dhcp || daemon->dhcp6) && (daemon->lease_change_command || daemon->luascript)) |
1a6bca81 | 467 | daemon->helperfd = create_helper(pipewrite, err_pipe[1], script_uid, script_gid, max_fd); |
5aabfc78 | 468 | #endif |
5aabfc78 | 469 | |
28866e95 | 470 | if (!option_bool(OPT_DEBUG) && getuid() == 0) |
1697269c | 471 | { |
1a6bca81 SK |
472 | int bad_capabilities = 0; |
473 | gid_t dummy; | |
474 | ||
475 | /* remove all supplimentary groups */ | |
476 | if (gp && | |
477 | (setgroups(0, &dummy) == -1 || | |
478 | setgid(gp->gr_gid) == -1)) | |
9e4abcb5 | 479 | { |
c72daea8 | 480 | send_event(err_pipe[1], EVENT_GROUP_ERR, errno, daemon->groupname); |
1a6bca81 | 481 | _exit(0); |
7cebd20f | 482 | } |
1a6bca81 | 483 | |
7cebd20f | 484 | if (ent_pw && ent_pw->pw_uid != 0) |
1697269c | 485 | { |
74c95c25 | 486 | #if defined(HAVE_LINUX_NETWORK) |
1697269c | 487 | /* On linux, we keep CAP_NETADMIN (for ARP-injection) and |
74c95c25 | 488 | CAP_NET_RAW (for icmp) if we're doing dhcp. If we have yet to bind |
54dd393f SK |
489 | ports because of DAD, or we're doing it dynamically, |
490 | we need CAP_NET_BIND_SERVICE too. */ | |
491 | if (is_dad_listeners() || option_bool(OPT_CLEVERBIND)) | |
74c95c25 SK |
492 | data->effective = data->permitted = data->inheritable = |
493 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | | |
494 | (1 << CAP_SETUID) | (1 << CAP_NET_BIND_SERVICE); | |
495 | else | |
496 | data->effective = data->permitted = data->inheritable = | |
497 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | (1 << CAP_SETUID); | |
5e9e0efb | 498 | |
1697269c | 499 | /* Tell kernel to not clear capabilities when dropping root */ |
572b41eb | 500 | if (capset(hdr, data) == -1 || prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) |
1697269c | 501 | bad_capabilities = errno; |
1a6bca81 | 502 | |
7622fc06 | 503 | #elif defined(HAVE_SOLARIS_NETWORK) |
824af85b SK |
504 | /* http://developers.sun.com/solaris/articles/program_privileges.html */ |
505 | priv_set_t *priv_set; | |
506 | ||
507 | if (!(priv_set = priv_str_to_set("basic", ",", NULL)) || | |
508 | priv_addset(priv_set, PRIV_NET_ICMPACCESS) == -1 || | |
509 | priv_addset(priv_set, PRIV_SYS_NET_CONFIG) == -1) | |
510 | bad_capabilities = errno; | |
511 | ||
512 | if (priv_set && bad_capabilities == 0) | |
513 | { | |
514 | priv_inverse(priv_set); | |
515 | ||
516 | if (setppriv(PRIV_OFF, PRIV_LIMIT, priv_set) == -1) | |
517 | bad_capabilities = errno; | |
518 | } | |
519 | ||
520 | if (priv_set) | |
521 | priv_freeset(priv_set); | |
522 | ||
824af85b SK |
523 | #endif |
524 | ||
1a6bca81 | 525 | if (bad_capabilities != 0) |
1697269c | 526 | { |
c72daea8 | 527 | send_event(err_pipe[1], EVENT_CAP_ERR, bad_capabilities, NULL); |
1a6bca81 SK |
528 | _exit(0); |
529 | } | |
530 | ||
531 | /* finally drop root */ | |
532 | if (setuid(ent_pw->pw_uid) == -1) | |
533 | { | |
c72daea8 | 534 | send_event(err_pipe[1], EVENT_USER_ERR, errno, daemon->username); |
1a6bca81 SK |
535 | _exit(0); |
536 | } | |
537 | ||
1697269c | 538 | #ifdef HAVE_LINUX_NETWORK |
54dd393f | 539 | if (is_dad_listeners() || option_bool(OPT_CLEVERBIND)) |
74c95c25 SK |
540 | data->effective = data->permitted = |
541 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | (1 << CAP_NET_BIND_SERVICE); | |
542 | else | |
543 | data->effective = data->permitted = | |
544 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW); | |
1a6bca81 SK |
545 | data->inheritable = 0; |
546 | ||
547 | /* lose the setuid and setgid capbilities */ | |
548 | if (capset(hdr, data) == -1) | |
549 | { | |
c72daea8 | 550 | send_event(err_pipe[1], EVENT_CAP_ERR, errno, NULL); |
1a6bca81 | 551 | _exit(0); |
1697269c | 552 | } |
1a6bca81 SK |
553 | #endif |
554 | ||
9e4abcb5 SK |
555 | } |
556 | } | |
1697269c | 557 | |
1697269c | 558 | #ifdef HAVE_LINUX_NETWORK |
28866e95 | 559 | if (option_bool(OPT_DEBUG)) |
572b41eb | 560 | prctl(PR_SET_DUMPABLE, 1, 0, 0, 0); |
1697269c | 561 | #endif |
9e4abcb5 | 562 | |
8b3ae2fd | 563 | #ifdef HAVE_TFTP |
8bc4cece | 564 | if (option_bool(OPT_TFTP)) |
8b3ae2fd SK |
565 | { |
566 | DIR *dir; | |
567 | struct tftp_prefix *p; | |
568 | ||
569 | if (daemon->tftp_prefix) | |
570 | { | |
571 | if (!((dir = opendir(daemon->tftp_prefix)))) | |
572 | { | |
573 | send_event(err_pipe[1], EVENT_TFTP_ERR, errno, daemon->tftp_prefix); | |
574 | _exit(0); | |
575 | } | |
576 | closedir(dir); | |
577 | } | |
578 | ||
579 | for (p = daemon->if_prefix; p; p = p->next) | |
580 | { | |
581 | if (!((dir = opendir(p->prefix)))) | |
582 | { | |
583 | send_event(err_pipe[1], EVENT_TFTP_ERR, errno, p->prefix); | |
584 | _exit(0); | |
585 | } | |
586 | closedir(dir); | |
587 | } | |
588 | } | |
589 | #endif | |
590 | ||
824af85b SK |
591 | if (daemon->port == 0) |
592 | my_syslog(LOG_INFO, _("started, version %s DNS disabled"), VERSION); | |
593 | else if (daemon->cachesize != 0) | |
f2621c7f | 594 | my_syslog(LOG_INFO, _("started, version %s cachesize %d"), VERSION, daemon->cachesize); |
9e4abcb5 | 595 | else |
f2621c7f | 596 | my_syslog(LOG_INFO, _("started, version %s cache disabled"), VERSION); |
1697269c | 597 | |
f2621c7f | 598 | my_syslog(LOG_INFO, _("compile time options: %s"), compile_opts); |
1697269c | 599 | |
3d8df260 | 600 | #ifdef HAVE_DBUS |
28866e95 | 601 | if (option_bool(OPT_DBUS)) |
3d8df260 SK |
602 | { |
603 | if (daemon->dbus) | |
f2621c7f | 604 | my_syslog(LOG_INFO, _("DBus support enabled: connected to system bus")); |
3d8df260 | 605 | else |
f2621c7f | 606 | my_syslog(LOG_INFO, _("DBus support enabled: bus connection pending")); |
3d8df260 SK |
607 | } |
608 | #endif | |
609 | ||
1a6bca81 SK |
610 | if (log_err != 0) |
611 | my_syslog(LOG_WARNING, _("warning: failed to change owner of %s: %s"), | |
612 | daemon->log_file, strerror(log_err)); | |
613 | ||
de37951c | 614 | if (bind_fallback) |
f2621c7f | 615 | my_syslog(LOG_WARNING, _("setting --bind-interfaces option because of OS limitations")); |
de37951c | 616 | |
28866e95 | 617 | if (!option_bool(OPT_NOWILD)) |
26128d27 SK |
618 | for (if_tmp = daemon->if_names; if_tmp; if_tmp = if_tmp->next) |
619 | if (if_tmp->name && !if_tmp->used) | |
f2621c7f | 620 | my_syslog(LOG_WARNING, _("warning: interface %s does not currently exist"), if_tmp->name); |
5e9e0efb | 621 | |
28866e95 | 622 | if (daemon->port != 0 && option_bool(OPT_NO_RESOLV)) |
208b65c5 SK |
623 | { |
624 | if (daemon->resolv_files && !daemon->resolv_files->is_default) | |
f2621c7f | 625 | my_syslog(LOG_WARNING, _("warning: ignoring resolv-file flag because no-resolv is set")); |
208b65c5 | 626 | daemon->resolv_files = NULL; |
1b7ecd11 | 627 | if (!daemon->servers) |
f2621c7f | 628 | my_syslog(LOG_WARNING, _("warning: no upstream servers configured")); |
208b65c5 SK |
629 | } |
630 | ||
f2621c7f SK |
631 | if (daemon->max_logs != 0) |
632 | my_syslog(LOG_INFO, _("asynchronous logging enabled, queue limit is %d messages"), daemon->max_logs); | |
1f776932 | 633 | |
f2621c7f | 634 | |
7622fc06 | 635 | #ifdef HAVE_DHCP |
1f776932 SK |
636 | for (context = daemon->dhcp; context; context = context->next) |
637 | log_context(AF_INET, context); | |
52b92f4d | 638 | |
1f776932 SK |
639 | # ifdef HAVE_DHCP6 |
640 | for (context = daemon->dhcp6; context; context = context->next) | |
641 | log_context(AF_INET6, context); | |
642 | ||
643 | if (daemon->doing_dhcp6 || daemon->doing_ra) | |
644 | dhcp_construct_contexts(now); | |
645 | ||
646 | if (option_bool(OPT_RA)) | |
647 | my_syslog(MS_DHCP | LOG_INFO, _("IPv6 router advertisement enabled")); | |
648 | # endif | |
26128d27 | 649 | |
8445f5d2 SK |
650 | /* after dhcp_contruct_contexts */ |
651 | if (daemon->dhcp || daemon->doing_dhcp6) | |
652 | lease_find_interfaces(now); | |
1f776932 | 653 | #endif |
52b92f4d | 654 | |
832af0ba | 655 | #ifdef HAVE_TFTP |
8bc4cece | 656 | if (option_bool(OPT_TFTP)) |
832af0ba | 657 | { |
832af0ba | 658 | #ifdef FD_SETSIZE |
5aabfc78 | 659 | if (FD_SETSIZE < (unsigned)max_fd) |
832af0ba SK |
660 | max_fd = FD_SETSIZE; |
661 | #endif | |
662 | ||
7622fc06 | 663 | my_syslog(MS_TFTP | LOG_INFO, "TFTP %s%s %s", |
f2621c7f SK |
664 | daemon->tftp_prefix ? _("root is ") : _("enabled"), |
665 | daemon->tftp_prefix ? daemon->tftp_prefix: "", | |
28866e95 | 666 | option_bool(OPT_TFTP_SECURE) ? _("secure mode") : ""); |
f2621c7f | 667 | |
832af0ba | 668 | /* This is a guess, it assumes that for small limits, |
f2621c7f | 669 | disjoint files might be served, but for large limits, |
832af0ba SK |
670 | a single file will be sent to may clients (the file only needs |
671 | one fd). */ | |
672 | ||
673 | max_fd -= 30; /* use other than TFTP */ | |
674 | ||
675 | if (max_fd < 0) | |
676 | max_fd = 5; | |
677 | else if (max_fd < 100) | |
678 | max_fd = max_fd/2; | |
679 | else | |
680 | max_fd = max_fd - 20; | |
824af85b SK |
681 | |
682 | /* if we have to use a limited range of ports, | |
683 | that will limit the number of transfers */ | |
684 | if (daemon->start_tftp_port != 0 && | |
685 | daemon->end_tftp_port - daemon->start_tftp_port + 1 < max_fd) | |
686 | max_fd = daemon->end_tftp_port - daemon->start_tftp_port + 1; | |
832af0ba SK |
687 | |
688 | if (daemon->tftp_max > max_fd) | |
689 | { | |
690 | daemon->tftp_max = max_fd; | |
7622fc06 | 691 | my_syslog(MS_TFTP | LOG_WARNING, |
f2621c7f SK |
692 | _("restricting maximum simultaneous TFTP transfers to %d"), |
693 | daemon->tftp_max); | |
832af0ba SK |
694 | } |
695 | } | |
696 | #endif | |
697 | ||
1a6bca81 SK |
698 | /* finished start-up - release original process */ |
699 | if (err_pipe[1] != -1) | |
700 | close(err_pipe[1]); | |
9e4abcb5 | 701 | |
824af85b SK |
702 | if (daemon->port != 0) |
703 | check_servers(); | |
704 | ||
7cebd20f SK |
705 | pid = getpid(); |
706 | ||
5e9e0efb | 707 | while (1) |
9e4abcb5 | 708 | { |
1697269c | 709 | int maxfd = -1; |
5e9e0efb | 710 | struct timeval t, *tp = NULL; |
3d8df260 | 711 | fd_set rset, wset, eset; |
9e4abcb5 SK |
712 | |
713 | FD_ZERO(&rset); | |
3d8df260 SK |
714 | FD_ZERO(&wset); |
715 | FD_ZERO(&eset); | |
9e4abcb5 | 716 | |
1697269c SK |
717 | /* if we are out of resources, find how long we have to wait |
718 | for some to come free, we'll loop around then and restart | |
719 | listening for queries */ | |
5aabfc78 | 720 | if ((t.tv_sec = set_dns_listeners(now, &rset, &maxfd)) != 0) |
1697269c SK |
721 | { |
722 | t.tv_usec = 0; | |
723 | tp = &t; | |
724 | } | |
725 | ||
832af0ba SK |
726 | /* Whilst polling for the dbus, or doing a tftp transfer, wake every quarter second */ |
727 | if (daemon->tftp_trans || | |
28866e95 | 728 | (option_bool(OPT_DBUS) && !daemon->dbus)) |
5e9e0efb | 729 | { |
1697269c SK |
730 | t.tv_sec = 0; |
731 | t.tv_usec = 250000; | |
5e9e0efb | 732 | tp = &t; |
5e9e0efb | 733 | } |
74c95c25 SK |
734 | /* Wake every second whilst waiting for DAD to complete */ |
735 | else if (is_dad_listeners()) | |
736 | { | |
737 | t.tv_sec = 1; | |
738 | t.tv_usec = 0; | |
739 | tp = &t; | |
740 | } | |
44a2a316 | 741 | |
832af0ba | 742 | #ifdef HAVE_DBUS |
5aabfc78 | 743 | set_dbus_listeners(&maxfd, &rset, &wset, &eset); |
5e9e0efb SK |
744 | #endif |
745 | ||
7622fc06 | 746 | #ifdef HAVE_DHCP |
5e9e0efb SK |
747 | if (daemon->dhcp) |
748 | { | |
749 | FD_SET(daemon->dhcpfd, &rset); | |
1697269c | 750 | bump_maxfd(daemon->dhcpfd, &maxfd); |
316e2730 SK |
751 | if (daemon->pxefd != -1) |
752 | { | |
753 | FD_SET(daemon->pxefd, &rset); | |
754 | bump_maxfd(daemon->pxefd, &maxfd); | |
755 | } | |
5e9e0efb | 756 | } |
7622fc06 | 757 | #endif |
cdeda28f | 758 | |
52b92f4d | 759 | #ifdef HAVE_DHCP6 |
1f776932 | 760 | if (daemon->doing_dhcp6) |
52b92f4d SK |
761 | { |
762 | FD_SET(daemon->dhcp6fd, &rset); | |
c5ad4e79 | 763 | bump_maxfd(daemon->dhcp6fd, &maxfd); |
5d71d834 SK |
764 | } |
765 | ||
1f776932 | 766 | if (daemon->doing_ra) |
5d71d834 SK |
767 | { |
768 | FD_SET(daemon->icmp6fd, &rset); | |
769 | bump_maxfd(daemon->icmp6fd, &maxfd); | |
52b92f4d SK |
770 | } |
771 | #endif | |
772 | ||
5e9e0efb SK |
773 | #ifdef HAVE_LINUX_NETWORK |
774 | FD_SET(daemon->netlinkfd, &rset); | |
1697269c | 775 | bump_maxfd(daemon->netlinkfd, &maxfd); |
3d8df260 | 776 | #endif |
3d8df260 | 777 | |
5e9e0efb | 778 | FD_SET(piperead, &rset); |
1697269c SK |
779 | bump_maxfd(piperead, &maxfd); |
780 | ||
7622fc06 | 781 | #ifdef HAVE_DHCP |
1f15b81d | 782 | # ifdef HAVE_SCRIPT |
5aabfc78 | 783 | while (helper_buf_empty() && do_script_run(now)); |
1697269c | 784 | |
a9530964 SK |
785 | # ifdef HAVE_TFTP |
786 | while (helper_buf_empty() && do_tftp_script_run()); | |
787 | # endif | |
788 | ||
1697269c SK |
789 | if (!helper_buf_empty()) |
790 | { | |
791 | FD_SET(daemon->helperfd, &wset); | |
792 | bump_maxfd(daemon->helperfd, &maxfd); | |
793 | } | |
7622fc06 | 794 | # else |
5aabfc78 SK |
795 | /* need this for other side-effects */ |
796 | while (do_script_run(now)); | |
a9530964 SK |
797 | |
798 | # ifdef HAVE_TFTP | |
799 | while (do_tftp_script_run()); | |
800 | # endif | |
801 | ||
7622fc06 | 802 | # endif |
5aabfc78 | 803 | #endif |
7622fc06 | 804 | |
f2621c7f SK |
805 | /* must do this just before select(), when we know no |
806 | more calls to my_syslog() can occur */ | |
807 | set_log_writer(&wset, &maxfd); | |
808 | ||
5e9e0efb SK |
809 | if (select(maxfd+1, &rset, &wset, &eset, tp) < 0) |
810 | { | |
811 | /* otherwise undefined after error */ | |
812 | FD_ZERO(&rset); FD_ZERO(&wset); FD_ZERO(&eset); | |
813 | } | |
814 | ||
815 | now = dnsmasq_time(); | |
9e4abcb5 | 816 | |
f2621c7f | 817 | check_log_writer(&wset); |
74c95c25 SK |
818 | |
819 | /* Check the interfaces to see if any have exited DAD state | |
820 | and if so, bind the address. */ | |
821 | if (is_dad_listeners()) | |
822 | { | |
823 | enumerate_interfaces(); | |
824 | /* NB, is_dad_listeners() == 1 --> we're binding interfaces */ | |
825 | create_bound_listeners(0); | |
826 | } | |
f2621c7f | 827 | |
c52e1897 SK |
828 | #ifdef HAVE_LINUX_NETWORK |
829 | if (FD_ISSET(daemon->netlinkfd, &rset)) | |
1f776932 | 830 | netlink_multicast(now); |
c52e1897 SK |
831 | #endif |
832 | ||
9e4abcb5 | 833 | /* Check for changes to resolv files once per second max. */ |
3d8df260 | 834 | /* Don't go silent for long periods if the clock goes backwards. */ |
9009d746 SK |
835 | if (daemon->last_resolv == 0 || |
836 | difftime(now, daemon->last_resolv) > 1.0 || | |
837 | difftime(now, daemon->last_resolv) < -1.0) | |
9e4abcb5 | 838 | { |
8ef5ada2 SK |
839 | /* poll_resolv doesn't need to reload first time through, since |
840 | that's queued anyway. */ | |
33820b7e | 841 | |
8ef5ada2 SK |
842 | poll_resolv(0, daemon->last_resolv != 0, now); |
843 | daemon->last_resolv = now; | |
9e4abcb5 | 844 | } |
5aabfc78 | 845 | |
5e9e0efb | 846 | if (FD_ISSET(piperead, &rset)) |
5aabfc78 | 847 | async_event(piperead, now); |
7cebd20f | 848 | |
3d8df260 SK |
849 | #ifdef HAVE_DBUS |
850 | /* if we didn't create a DBus connection, retry now. */ | |
28866e95 | 851 | if (option_bool(OPT_DBUS) && !daemon->dbus) |
3d8df260 SK |
852 | { |
853 | char *err; | |
5aabfc78 | 854 | if ((err = dbus_init())) |
f2621c7f | 855 | my_syslog(LOG_WARNING, _("DBus error: %s"), err); |
3d8df260 | 856 | if (daemon->dbus) |
f2621c7f | 857 | my_syslog(LOG_INFO, _("connected to system DBus")); |
3d8df260 | 858 | } |
5aabfc78 | 859 | check_dbus_listeners(&rset, &wset, &eset); |
3d8df260 | 860 | #endif |
824af85b | 861 | |
5aabfc78 | 862 | check_dns_listeners(&rset, now); |
832af0ba SK |
863 | |
864 | #ifdef HAVE_TFTP | |
5aabfc78 | 865 | check_tftp_listeners(&rset, now); |
832af0ba SK |
866 | #endif |
867 | ||
7622fc06 | 868 | #ifdef HAVE_DHCP |
316e2730 SK |
869 | if (daemon->dhcp) |
870 | { | |
871 | if (FD_ISSET(daemon->dhcpfd, &rset)) | |
872 | dhcp_packet(now, 0); | |
873 | if (daemon->pxefd != -1 && FD_ISSET(daemon->pxefd, &rset)) | |
874 | dhcp_packet(now, 1); | |
875 | } | |
1697269c | 876 | |
52b92f4d | 877 | #ifdef HAVE_DHCP6 |
1f776932 | 878 | if (daemon->doing_dhcp6 && FD_ISSET(daemon->dhcp6fd, &rset)) |
18c63eff | 879 | dhcp6_packet(now); |
c5ad4e79 | 880 | |
1f776932 SK |
881 | if (daemon->doing_ra && FD_ISSET(daemon->icmp6fd, &rset)) |
882 | icmp6_packet(now); | |
52b92f4d SK |
883 | #endif |
884 | ||
1f15b81d | 885 | # ifdef HAVE_SCRIPT |
1697269c | 886 | if (daemon->helperfd != -1 && FD_ISSET(daemon->helperfd, &wset)) |
5aabfc78 | 887 | helper_write(); |
7622fc06 | 888 | # endif |
5aabfc78 SK |
889 | #endif |
890 | ||
9e4abcb5 | 891 | } |
9e4abcb5 SK |
892 | } |
893 | ||
3be34541 SK |
894 | static void sig_handler(int sig) |
895 | { | |
5e9e0efb | 896 | if (pid == 0) |
3be34541 | 897 | { |
1697269c SK |
898 | /* ignore anything other than TERM during startup |
899 | and in helper proc. (helper ignore TERM too) */ | |
5e9e0efb | 900 | if (sig == SIGTERM) |
5aabfc78 | 901 | exit(EC_MISC); |
3be34541 | 902 | } |
5aabfc78 | 903 | else if (pid != getpid()) |
5e9e0efb | 904 | { |
1697269c | 905 | /* alarm is used to kill TCP children after a fixed time. */ |
5e9e0efb | 906 | if (sig == SIGALRM) |
7cebd20f | 907 | _exit(0); |
3be34541 | 908 | } |
5aabfc78 SK |
909 | else |
910 | { | |
911 | /* master process */ | |
912 | int event, errsave = errno; | |
913 | ||
914 | if (sig == SIGHUP) | |
915 | event = EVENT_RELOAD; | |
916 | else if (sig == SIGCHLD) | |
917 | event = EVENT_CHILD; | |
918 | else if (sig == SIGALRM) | |
919 | event = EVENT_ALARM; | |
920 | else if (sig == SIGTERM) | |
921 | event = EVENT_TERM; | |
922 | else if (sig == SIGUSR1) | |
923 | event = EVENT_DUMP; | |
924 | else if (sig == SIGUSR2) | |
925 | event = EVENT_REOPEN; | |
926 | else | |
927 | return; | |
928 | ||
c72daea8 | 929 | send_event(pipewrite, event, 0, NULL); |
5aabfc78 SK |
930 | errno = errsave; |
931 | } | |
932 | } | |
933 | ||
353ae4d2 SK |
934 | /* now == 0 -> queue immediate callback */ |
935 | void send_alarm(time_t event, time_t now) | |
741c2952 | 936 | { |
884a6dfe | 937 | if (now == 0 || event != 0) |
353ae4d2 | 938 | { |
884a6dfe SK |
939 | /* alarm(0) or alarm(-ve) doesn't do what we want.... */ |
940 | if ((now == 0 || difftime(event, now) <= 0.0)) | |
941 | send_event(pipewrite, EVENT_ALARM, 0, NULL); | |
942 | else | |
943 | alarm((unsigned)difftime(event, now)); | |
353ae4d2 | 944 | } |
741c2952 SK |
945 | } |
946 | ||
c72daea8 | 947 | void send_event(int fd, int event, int data, char *msg) |
5aabfc78 SK |
948 | { |
949 | struct event_desc ev; | |
c72daea8 SK |
950 | struct iovec iov[2]; |
951 | ||
5aabfc78 SK |
952 | ev.event = event; |
953 | ev.data = data; | |
c72daea8 SK |
954 | ev.msg_sz = msg ? strlen(msg) : 0; |
955 | ||
956 | iov[0].iov_base = &ev; | |
957 | iov[0].iov_len = sizeof(ev); | |
958 | iov[1].iov_base = msg; | |
959 | iov[1].iov_len = ev.msg_sz; | |
1a6bca81 SK |
960 | |
961 | /* error pipe, debug mode. */ | |
962 | if (fd == -1) | |
c72daea8 | 963 | fatal_event(&ev, msg); |
1a6bca81 SK |
964 | else |
965 | /* pipe is non-blocking and struct event_desc is smaller than | |
966 | PIPE_BUF, so this either fails or writes everything */ | |
c72daea8 | 967 | while (writev(fd, iov, msg ? 2 : 1) == -1 && errno == EINTR); |
5aabfc78 SK |
968 | } |
969 | ||
c72daea8 SK |
970 | /* NOTE: the memory used to return msg is leaked: use msgs in events only |
971 | to describe fatal errors. */ | |
972 | static int read_event(int fd, struct event_desc *evp, char **msg) | |
973 | { | |
974 | char *buf; | |
975 | ||
976 | if (!read_write(fd, (unsigned char *)evp, sizeof(struct event_desc), 1)) | |
977 | return 0; | |
978 | ||
979 | *msg = NULL; | |
980 | ||
981 | if (evp->msg_sz != 0 && | |
982 | (buf = malloc(evp->msg_sz + 1)) && | |
983 | read_write(fd, (unsigned char *)buf, evp->msg_sz, 1)) | |
984 | { | |
985 | buf[evp->msg_sz] = 0; | |
986 | *msg = buf; | |
987 | } | |
988 | ||
989 | return 1; | |
990 | } | |
991 | ||
992 | static void fatal_event(struct event_desc *ev, char *msg) | |
1a6bca81 SK |
993 | { |
994 | errno = ev->data; | |
995 | ||
996 | switch (ev->event) | |
997 | { | |
998 | case EVENT_DIE: | |
999 | exit(0); | |
7622fc06 SK |
1000 | |
1001 | case EVENT_FORK_ERR: | |
1002 | die(_("cannot fork into background: %s"), NULL, EC_MISC); | |
1a6bca81 SK |
1003 | |
1004 | case EVENT_PIPE_ERR: | |
1005 | die(_("failed to create helper: %s"), NULL, EC_MISC); | |
1006 | ||
1007 | case EVENT_CAP_ERR: | |
1008 | die(_("setting capabilities failed: %s"), NULL, EC_MISC); | |
1009 | ||
1010 | case EVENT_USER_ERR: | |
c72daea8 | 1011 | die(_("failed to change user-id to %s: %s"), msg, EC_MISC); |
1a6bca81 SK |
1012 | |
1013 | case EVENT_GROUP_ERR: | |
c72daea8 | 1014 | die(_("failed to change group-id to %s: %s"), msg, EC_MISC); |
1a6bca81 SK |
1015 | |
1016 | case EVENT_PIDFILE: | |
c72daea8 | 1017 | die(_("failed to open pidfile %s: %s"), msg, EC_FILE); |
1a6bca81 SK |
1018 | |
1019 | case EVENT_LOG_ERR: | |
c72daea8 SK |
1020 | die(_("cannot open log %s: %s"), msg, EC_FILE); |
1021 | ||
1022 | case EVENT_LUA_ERR: | |
1023 | die(_("failed to load Lua script: %s"), msg, EC_MISC); | |
8b3ae2fd SK |
1024 | |
1025 | case EVENT_TFTP_ERR: | |
1026 | die(_("TFTP directory %s inaccessible: %s"), msg, EC_FILE); | |
1a6bca81 SK |
1027 | } |
1028 | } | |
1029 | ||
5aabfc78 SK |
1030 | static void async_event(int pipe, time_t now) |
1031 | { | |
1032 | pid_t p; | |
1033 | struct event_desc ev; | |
1034 | int i; | |
c72daea8 SK |
1035 | char *msg; |
1036 | ||
1037 | /* NOTE: the memory used to return msg is leaked: use msgs in events only | |
1038 | to describe fatal errors. */ | |
1039 | ||
1040 | if (read_event(pipe, &ev, &msg)) | |
5aabfc78 SK |
1041 | switch (ev.event) |
1042 | { | |
1043 | case EVENT_RELOAD: | |
1044 | clear_cache_and_reload(now); | |
28866e95 | 1045 | if (daemon->port != 0 && daemon->resolv_files && option_bool(OPT_NO_POLL)) |
5aabfc78 SK |
1046 | { |
1047 | reload_servers(daemon->resolv_files->name); | |
1048 | check_servers(); | |
1049 | } | |
7622fc06 | 1050 | #ifdef HAVE_DHCP |
5aabfc78 | 1051 | rerun_scripts(); |
7622fc06 | 1052 | #endif |
5aabfc78 SK |
1053 | break; |
1054 | ||
1055 | case EVENT_DUMP: | |
824af85b SK |
1056 | if (daemon->port != 0) |
1057 | dump_cache(now); | |
5aabfc78 SK |
1058 | break; |
1059 | ||
1060 | case EVENT_ALARM: | |
7622fc06 | 1061 | #ifdef HAVE_DHCP |
1f776932 | 1062 | if (daemon->dhcp || daemon->doing_dhcp6) |
5aabfc78 SK |
1063 | { |
1064 | lease_prune(NULL, now); | |
1065 | lease_update_file(now); | |
1066 | } | |
843c96b4 | 1067 | #ifdef HAVE_DHCP6 |
1f776932 | 1068 | else if (daemon->doing_ra) |
353ae4d2 SK |
1069 | /* Not doing DHCP, so no lease system, manage alarms for ra only */ |
1070 | send_alarm(periodic_ra(now), now); | |
843c96b4 | 1071 | #endif |
7622fc06 | 1072 | #endif |
5aabfc78 SK |
1073 | break; |
1074 | ||
1075 | case EVENT_CHILD: | |
1076 | /* See Stevens 5.10 */ | |
1077 | while ((p = waitpid(-1, NULL, WNOHANG)) != 0) | |
1078 | if (p == -1) | |
1079 | { | |
1080 | if (errno != EINTR) | |
1081 | break; | |
1082 | } | |
1083 | else | |
1084 | for (i = 0 ; i < MAX_PROCS; i++) | |
1085 | if (daemon->tcp_pids[i] == p) | |
1086 | daemon->tcp_pids[i] = 0; | |
1087 | break; | |
1088 | ||
1089 | case EVENT_KILLED: | |
c72daea8 | 1090 | my_syslog(LOG_WARNING, _("script process killed by signal %d"), ev.data); |
5aabfc78 SK |
1091 | break; |
1092 | ||
1093 | case EVENT_EXITED: | |
c72daea8 | 1094 | my_syslog(LOG_WARNING, _("script process exited with status %d"), ev.data); |
5aabfc78 SK |
1095 | break; |
1096 | ||
1097 | case EVENT_EXEC_ERR: | |
9e038946 SK |
1098 | my_syslog(LOG_ERR, _("failed to execute %s: %s"), |
1099 | daemon->lease_change_command, strerror(ev.data)); | |
5aabfc78 SK |
1100 | break; |
1101 | ||
1a6bca81 | 1102 | /* necessary for fatal errors in helper */ |
c72daea8 | 1103 | case EVENT_USER_ERR: |
1a6bca81 | 1104 | case EVENT_DIE: |
c72daea8 SK |
1105 | case EVENT_LUA_ERR: |
1106 | fatal_event(&ev, msg); | |
9e038946 SK |
1107 | break; |
1108 | ||
5aabfc78 SK |
1109 | case EVENT_REOPEN: |
1110 | /* Note: this may leave TCP-handling processes with the old file still open. | |
1111 | Since any such process will die in CHILD_LIFETIME or probably much sooner, | |
1112 | we leave them logging to the old file. */ | |
1113 | if (daemon->log_file != NULL) | |
1114 | log_reopen(daemon->log_file); | |
1115 | break; | |
1116 | ||
1117 | case EVENT_TERM: | |
1118 | /* Knock all our children on the head. */ | |
1119 | for (i = 0; i < MAX_PROCS; i++) | |
1120 | if (daemon->tcp_pids[i] != 0) | |
1121 | kill(daemon->tcp_pids[i], SIGALRM); | |
1122 | ||
c72daea8 | 1123 | #if defined(HAVE_SCRIPT) |
5aabfc78 SK |
1124 | /* handle pending lease transitions */ |
1125 | if (daemon->helperfd != -1) | |
1126 | { | |
1127 | /* block in writes until all done */ | |
1128 | if ((i = fcntl(daemon->helperfd, F_GETFL)) != -1) | |
1129 | fcntl(daemon->helperfd, F_SETFL, i & ~O_NONBLOCK); | |
1130 | do { | |
1131 | helper_write(); | |
1132 | } while (!helper_buf_empty() || do_script_run(now)); | |
1133 | close(daemon->helperfd); | |
1134 | } | |
1135 | #endif | |
1136 | ||
1137 | if (daemon->lease_stream) | |
1138 | fclose(daemon->lease_stream); | |
73a08a24 SK |
1139 | |
1140 | if (daemon->runfile) | |
1141 | unlink(daemon->runfile); | |
5aabfc78 SK |
1142 | |
1143 | my_syslog(LOG_INFO, _("exiting on receipt of SIGTERM")); | |
1144 | flush_log(); | |
1145 | exit(EC_GOOD); | |
1146 | } | |
3be34541 SK |
1147 | } |
1148 | ||
8ef5ada2 | 1149 | void poll_resolv(int force, int do_reload, time_t now) |
5aabfc78 SK |
1150 | { |
1151 | struct resolvc *res, *latest; | |
1152 | struct stat statbuf; | |
1153 | time_t last_change = 0; | |
1154 | /* There may be more than one possible file. | |
1155 | Go through and find the one which changed _last_. | |
1156 | Warn of any which can't be read. */ | |
8ef5ada2 | 1157 | |
28866e95 | 1158 | if (daemon->port == 0 || option_bool(OPT_NO_POLL)) |
8ef5ada2 SK |
1159 | return; |
1160 | ||
5aabfc78 SK |
1161 | for (latest = NULL, res = daemon->resolv_files; res; res = res->next) |
1162 | if (stat(res->name, &statbuf) == -1) | |
1163 | { | |
8ef5ada2 SK |
1164 | if (force) |
1165 | { | |
1166 | res->mtime = 0; | |
1167 | continue; | |
1168 | } | |
1169 | ||
5aabfc78 SK |
1170 | if (!res->logged) |
1171 | my_syslog(LOG_WARNING, _("failed to access %s: %s"), res->name, strerror(errno)); | |
1172 | res->logged = 1; | |
8ef5ada2 SK |
1173 | |
1174 | if (res->mtime != 0) | |
1175 | { | |
1176 | /* existing file evaporated, force selection of the latest | |
1177 | file even if its mtime hasn't changed since we last looked */ | |
1178 | poll_resolv(1, do_reload, now); | |
1179 | return; | |
1180 | } | |
5aabfc78 SK |
1181 | } |
1182 | else | |
1183 | { | |
1184 | res->logged = 0; | |
8ef5ada2 SK |
1185 | if (force || (statbuf.st_mtime != res->mtime)) |
1186 | { | |
1187 | res->mtime = statbuf.st_mtime; | |
5aabfc78 SK |
1188 | if (difftime(statbuf.st_mtime, last_change) > 0.0) |
1189 | { | |
1190 | last_change = statbuf.st_mtime; | |
1191 | latest = res; | |
1192 | } | |
1193 | } | |
1194 | } | |
1195 | ||
1196 | if (latest) | |
1197 | { | |
1198 | static int warned = 0; | |
1199 | if (reload_servers(latest->name)) | |
1200 | { | |
1201 | my_syslog(LOG_INFO, _("reading %s"), latest->name); | |
1202 | warned = 0; | |
1203 | check_servers(); | |
28866e95 | 1204 | if (option_bool(OPT_RELOAD) && do_reload) |
8ef5ada2 | 1205 | clear_cache_and_reload(now); |
5aabfc78 SK |
1206 | } |
1207 | else | |
1208 | { | |
1209 | latest->mtime = 0; | |
1210 | if (!warned) | |
1211 | { | |
1212 | my_syslog(LOG_WARNING, _("no servers found in %s, will retry"), latest->name); | |
1213 | warned = 1; | |
1214 | } | |
1215 | } | |
1216 | } | |
1217 | } | |
3d8df260 | 1218 | |
5aabfc78 | 1219 | void clear_cache_and_reload(time_t now) |
3d8df260 | 1220 | { |
824af85b | 1221 | if (daemon->port != 0) |
7622fc06 | 1222 | cache_reload(); |
824af85b | 1223 | |
7622fc06 | 1224 | #ifdef HAVE_DHCP |
1f776932 | 1225 | if (daemon->dhcp || daemon->doing_dhcp6) |
3d8df260 | 1226 | { |
28866e95 | 1227 | if (option_bool(OPT_ETHERS)) |
5aabfc78 | 1228 | dhcp_read_ethers(); |
824af85b | 1229 | reread_dhcp(); |
3d8df260 | 1230 | dhcp_update_configs(daemon->dhcp_conf); |
5aabfc78 SK |
1231 | lease_update_from_configs(); |
1232 | lease_update_file(now); | |
353ae4d2 | 1233 | lease_update_dns(1); |
3d8df260 | 1234 | } |
843c96b4 | 1235 | #ifdef HAVE_DHCP6 |
1f776932 | 1236 | else if (daemon->doing_ra) |
2021c662 SK |
1237 | /* Not doing DHCP, so no lease system, manage |
1238 | alarms for ra only */ | |
1239 | send_alarm(periodic_ra(now), now); | |
843c96b4 | 1240 | #endif |
7622fc06 | 1241 | #endif |
3d8df260 SK |
1242 | } |
1243 | ||
5aabfc78 | 1244 | static int set_dns_listeners(time_t now, fd_set *set, int *maxfdp) |
3be34541 SK |
1245 | { |
1246 | struct serverfd *serverfdp; | |
1247 | struct listener *listener; | |
824af85b | 1248 | int wait = 0, i; |
832af0ba SK |
1249 | |
1250 | #ifdef HAVE_TFTP | |
1251 | int tftp = 0; | |
1252 | struct tftp_transfer *transfer; | |
1253 | for (transfer = daemon->tftp_trans; transfer; transfer = transfer->next) | |
1254 | { | |
1255 | tftp++; | |
1256 | FD_SET(transfer->sockfd, set); | |
1257 | bump_maxfd(transfer->sockfd, maxfdp); | |
1258 | } | |
1259 | #endif | |
1260 | ||
1697269c | 1261 | /* will we be able to get memory? */ |
824af85b SK |
1262 | if (daemon->port != 0) |
1263 | get_new_frec(now, &wait); | |
1697269c | 1264 | |
3be34541 SK |
1265 | for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next) |
1266 | { | |
1267 | FD_SET(serverfdp->fd, set); | |
1697269c | 1268 | bump_maxfd(serverfdp->fd, maxfdp); |
3be34541 | 1269 | } |
1a6bca81 SK |
1270 | |
1271 | if (daemon->port != 0 && !daemon->osport) | |
1272 | for (i = 0; i < RANDOM_SOCKS; i++) | |
1273 | if (daemon->randomsocks[i].refcount != 0) | |
1274 | { | |
1275 | FD_SET(daemon->randomsocks[i].fd, set); | |
1276 | bump_maxfd(daemon->randomsocks[i].fd, maxfdp); | |
1277 | } | |
1278 | ||
3be34541 SK |
1279 | for (listener = daemon->listeners; listener; listener = listener->next) |
1280 | { | |
1697269c | 1281 | /* only listen for queries if we have resources */ |
824af85b | 1282 | if (listener->fd != -1 && wait == 0) |
1697269c SK |
1283 | { |
1284 | FD_SET(listener->fd, set); | |
1285 | bump_maxfd(listener->fd, maxfdp); | |
1286 | } | |
1287 | ||
1288 | /* death of a child goes through the select loop, so | |
1289 | we don't need to explicitly arrange to wake up here */ | |
824af85b SK |
1290 | if (listener->tcpfd != -1) |
1291 | for (i = 0; i < MAX_PROCS; i++) | |
1292 | if (daemon->tcp_pids[i] == 0) | |
1293 | { | |
1294 | FD_SET(listener->tcpfd, set); | |
1295 | bump_maxfd(listener->tcpfd, maxfdp); | |
1296 | break; | |
1297 | } | |
9e4abcb5 | 1298 | |
832af0ba SK |
1299 | #ifdef HAVE_TFTP |
1300 | if (tftp <= daemon->tftp_max && listener->tftpfd != -1) | |
1301 | { | |
1302 | FD_SET(listener->tftpfd, set); | |
1303 | bump_maxfd(listener->tftpfd, maxfdp); | |
1304 | } | |
1305 | #endif | |
1306 | ||
1307 | } | |
1308 | ||
1697269c | 1309 | return wait; |
3be34541 | 1310 | } |
9e4abcb5 | 1311 | |
5aabfc78 | 1312 | static void check_dns_listeners(fd_set *set, time_t now) |
3be34541 SK |
1313 | { |
1314 | struct serverfd *serverfdp; | |
1a6bca81 SK |
1315 | struct listener *listener; |
1316 | int i; | |
1317 | ||
832af0ba SK |
1318 | for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next) |
1319 | if (FD_ISSET(serverfdp->fd, set)) | |
1a6bca81 SK |
1320 | reply_query(serverfdp->fd, serverfdp->source_addr.sa.sa_family, now); |
1321 | ||
1322 | if (daemon->port != 0 && !daemon->osport) | |
1323 | for (i = 0; i < RANDOM_SOCKS; i++) | |
1324 | if (daemon->randomsocks[i].refcount != 0 && | |
1325 | FD_ISSET(daemon->randomsocks[i].fd, set)) | |
1326 | reply_query(daemon->randomsocks[i].fd, daemon->randomsocks[i].family, now); | |
832af0ba SK |
1327 | |
1328 | for (listener = daemon->listeners; listener; listener = listener->next) | |
1329 | { | |
824af85b | 1330 | if (listener->fd != -1 && FD_ISSET(listener->fd, set)) |
5aabfc78 | 1331 | receive_query(listener, now); |
1a6bca81 | 1332 | |
832af0ba SK |
1333 | #ifdef HAVE_TFTP |
1334 | if (listener->tftpfd != -1 && FD_ISSET(listener->tftpfd, set)) | |
5aabfc78 | 1335 | tftp_request(listener, now); |
832af0ba | 1336 | #endif |
3be34541 | 1337 | |
824af85b | 1338 | if (listener->tcpfd != -1 && FD_ISSET(listener->tcpfd, set)) |
832af0ba SK |
1339 | { |
1340 | int confd; | |
1341 | struct irec *iface = NULL; | |
1342 | pid_t p; | |
52d4abf2 SK |
1343 | union mysockaddr tcp_addr; |
1344 | socklen_t tcp_len = sizeof(union mysockaddr); | |
1345 | ||
1346 | while ((confd = accept(listener->tcpfd, NULL, NULL)) == -1 && errno == EINTR); | |
832af0ba | 1347 | |
52d4abf2 SK |
1348 | if (confd == -1 || |
1349 | getsockname(confd, (struct sockaddr *)&tcp_addr, &tcp_len) == -1) | |
832af0ba SK |
1350 | continue; |
1351 | ||
54dd393f | 1352 | if (option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND)) |
52d4abf2 | 1353 | iface = listener->iface; /* May be NULL */ |
832af0ba SK |
1354 | else |
1355 | { | |
832af0ba SK |
1356 | /* Check for allowed interfaces when binding the wildcard address: |
1357 | we do this by looking for an interface with the same address as | |
1358 | the local address of the TCP connection, then looking to see if that's | |
1359 | an allowed interface. As a side effect, we get the netmask of the | |
1360 | interface too, for localisation. */ | |
3be34541 | 1361 | |
832af0ba | 1362 | /* interface may be new since startup */ |
52d4abf2 | 1363 | if (enumerate_interfaces()) |
832af0ba SK |
1364 | for (iface = daemon->interfaces; iface; iface = iface->next) |
1365 | if (sockaddr_isequal(&iface->addr, &tcp_addr)) | |
1366 | break; | |
1367 | } | |
1368 | ||
54dd393f | 1369 | if (!iface && !(option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND))) |
832af0ba SK |
1370 | { |
1371 | shutdown(confd, SHUT_RDWR); | |
1372 | close(confd); | |
1373 | } | |
59353a6b | 1374 | #ifndef NO_FORK |
28866e95 | 1375 | else if (!option_bool(OPT_DEBUG) && (p = fork()) != 0) |
832af0ba SK |
1376 | { |
1377 | if (p != -1) | |
1378 | { | |
1379 | int i; | |
1380 | for (i = 0; i < MAX_PROCS; i++) | |
1381 | if (daemon->tcp_pids[i] == 0) | |
1382 | { | |
1383 | daemon->tcp_pids[i] = p; | |
1384 | break; | |
1385 | } | |
1386 | } | |
1387 | close(confd); | |
1388 | } | |
1389 | #endif | |
1390 | else | |
1391 | { | |
1392 | unsigned char *buff; | |
1393 | struct server *s; | |
1394 | int flags; | |
52d4abf2 | 1395 | struct in_addr netmask; |
4f7b304f | 1396 | int auth_dns; |
52d4abf2 SK |
1397 | |
1398 | if (iface) | |
4f7b304f SK |
1399 | { |
1400 | netmask = iface->netmask; | |
1401 | auth_dns = iface->dns_auth; | |
1402 | } | |
52d4abf2 | 1403 | else |
4f7b304f SK |
1404 | { |
1405 | netmask.s_addr = 0; | |
1406 | auth_dns = 0; | |
1407 | } | |
52d4abf2 | 1408 | |
8ef5ada2 SK |
1409 | #ifndef NO_FORK |
1410 | /* Arrange for SIGALARM after CHILD_LIFETIME seconds to | |
1411 | terminate the process. */ | |
28866e95 | 1412 | if (!option_bool(OPT_DEBUG)) |
832af0ba | 1413 | alarm(CHILD_LIFETIME); |
8ef5ada2 SK |
1414 | #endif |
1415 | ||
832af0ba SK |
1416 | /* start with no upstream connections. */ |
1417 | for (s = daemon->servers; s; s = s->next) | |
7cebd20f | 1418 | s->tcpfd = -1; |
832af0ba SK |
1419 | |
1420 | /* The connected socket inherits non-blocking | |
1421 | attribute from the listening socket. | |
1422 | Reset that here. */ | |
1423 | if ((flags = fcntl(confd, F_GETFL, 0)) != -1) | |
1424 | fcntl(confd, F_SETFL, flags & ~O_NONBLOCK); | |
1425 | ||
4f7b304f | 1426 | buff = tcp_request(confd, now, &tcp_addr, netmask, auth_dns); |
7cebd20f | 1427 | |
832af0ba SK |
1428 | shutdown(confd, SHUT_RDWR); |
1429 | close(confd); | |
1430 | ||
1431 | if (buff) | |
1432 | free(buff); | |
1433 | ||
1434 | for (s = daemon->servers; s; s = s->next) | |
1435 | if (s->tcpfd != -1) | |
1436 | { | |
1437 | shutdown(s->tcpfd, SHUT_RDWR); | |
1438 | close(s->tcpfd); | |
1439 | } | |
7cebd20f | 1440 | #ifndef NO_FORK |
28866e95 | 1441 | if (!option_bool(OPT_DEBUG)) |
5aabfc78 SK |
1442 | { |
1443 | flush_log(); | |
1444 | _exit(0); | |
1445 | } | |
59353a6b | 1446 | #endif |
832af0ba SK |
1447 | } |
1448 | } | |
1449 | } | |
3be34541 SK |
1450 | } |
1451 | ||
7622fc06 | 1452 | #ifdef HAVE_DHCP |
5e9e0efb SK |
1453 | int make_icmp_sock(void) |
1454 | { | |
7cebd20f | 1455 | int fd; |
5e9e0efb SK |
1456 | int zeroopt = 0; |
1457 | ||
1458 | if ((fd = socket (AF_INET, SOCK_RAW, IPPROTO_ICMP)) != -1) | |
1459 | { | |
7cebd20f | 1460 | if (!fix_fd(fd) || |
5e9e0efb SK |
1461 | setsockopt(fd, SOL_SOCKET, SO_DONTROUTE, &zeroopt, sizeof(zeroopt)) == -1) |
1462 | { | |
1463 | close(fd); | |
1464 | fd = -1; | |
1465 | } | |
1466 | } | |
1467 | ||
1468 | return fd; | |
1469 | } | |
1470 | ||
5aabfc78 | 1471 | int icmp_ping(struct in_addr addr) |
3be34541 | 1472 | { |
5e9e0efb | 1473 | /* Try and get an ICMP echo from a machine. */ |
3be34541 SK |
1474 | |
1475 | /* Note that whilst in the three second wait, we check for | |
832af0ba | 1476 | (and service) events on the DNS and TFTP sockets, (so doing that |
3be34541 SK |
1477 | better not use any resources our caller has in use...) |
1478 | but we remain deaf to signals or further DHCP packets. */ | |
1479 | ||
5e9e0efb | 1480 | int fd; |
3be34541 SK |
1481 | struct sockaddr_in saddr; |
1482 | struct { | |
1483 | struct ip ip; | |
1484 | struct icmp icmp; | |
1485 | } packet; | |
1486 | unsigned short id = rand16(); | |
1487 | unsigned int i, j; | |
5e9e0efb | 1488 | int gotreply = 0; |
3be34541 | 1489 | time_t start, now; |
5e9e0efb | 1490 | |
824af85b | 1491 | #if defined(HAVE_LINUX_NETWORK) || defined (HAVE_SOLARIS_NETWORK) |
5e9e0efb SK |
1492 | if ((fd = make_icmp_sock()) == -1) |
1493 | return 0; | |
1494 | #else | |
1495 | int opt = 2000; | |
1496 | fd = daemon->dhcp_icmp_fd; | |
1497 | setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)); | |
1498 | #endif | |
1499 | ||
3be34541 SK |
1500 | saddr.sin_family = AF_INET; |
1501 | saddr.sin_port = 0; | |
1502 | saddr.sin_addr = addr; | |
1503 | #ifdef HAVE_SOCKADDR_SA_LEN | |
1504 | saddr.sin_len = sizeof(struct sockaddr_in); | |
1505 | #endif | |
1506 | ||
1507 | memset(&packet.icmp, 0, sizeof(packet.icmp)); | |
1508 | packet.icmp.icmp_type = ICMP_ECHO; | |
1509 | packet.icmp.icmp_id = id; | |
1510 | for (j = 0, i = 0; i < sizeof(struct icmp) / 2; i++) | |
1511 | j += ((u16 *)&packet.icmp)[i]; | |
1512 | while (j>>16) | |
1513 | j = (j & 0xffff) + (j >> 16); | |
1514 | packet.icmp.icmp_cksum = (j == 0xffff) ? j : ~j; | |
1515 | ||
5e9e0efb | 1516 | while (sendto(fd, (char *)&packet.icmp, sizeof(struct icmp), 0, |
fd9fa481 SK |
1517 | (struct sockaddr *)&saddr, sizeof(saddr)) == -1 && |
1518 | retry_send()); | |
1519 | ||
5e9e0efb SK |
1520 | for (now = start = dnsmasq_time(); |
1521 | difftime(now, start) < (float)PING_WAIT;) | |
fd9fa481 SK |
1522 | { |
1523 | struct timeval tv; | |
f2621c7f | 1524 | fd_set rset, wset; |
fd9fa481 | 1525 | struct sockaddr_in faddr; |
1697269c | 1526 | int maxfd = fd; |
3d8df260 | 1527 | socklen_t len = sizeof(faddr); |
fd9fa481 SK |
1528 | |
1529 | tv.tv_usec = 250000; | |
1530 | tv.tv_sec = 0; | |
1531 | ||
1532 | FD_ZERO(&rset); | |
f2621c7f | 1533 | FD_ZERO(&wset); |
5e9e0efb | 1534 | FD_SET(fd, &rset); |
5aabfc78 | 1535 | set_dns_listeners(now, &rset, &maxfd); |
f2621c7f | 1536 | set_log_writer(&wset, &maxfd); |
c5ad4e79 SK |
1537 | |
1538 | #ifdef HAVE_DHCP6 | |
1f776932 | 1539 | if (daemon->doing_ra) |
c5ad4e79 SK |
1540 | { |
1541 | FD_SET(daemon->icmp6fd, &rset); | |
1542 | bump_maxfd(daemon->icmp6fd, &maxfd); | |
1543 | } | |
1544 | #endif | |
1545 | ||
f2621c7f SK |
1546 | if (select(maxfd+1, &rset, &wset, NULL, &tv) < 0) |
1547 | { | |
1548 | FD_ZERO(&rset); | |
1549 | FD_ZERO(&wset); | |
1550 | } | |
1551 | ||
5e9e0efb | 1552 | now = dnsmasq_time(); |
f2621c7f SK |
1553 | |
1554 | check_log_writer(&wset); | |
5aabfc78 | 1555 | check_dns_listeners(&rset, now); |
832af0ba | 1556 | |
c5ad4e79 | 1557 | #ifdef HAVE_DHCP6 |
1f776932 SK |
1558 | if (daemon->doing_ra && FD_ISSET(daemon->icmp6fd, &rset)) |
1559 | icmp6_packet(now); | |
c5ad4e79 SK |
1560 | #endif |
1561 | ||
832af0ba | 1562 | #ifdef HAVE_TFTP |
5aabfc78 | 1563 | check_tftp_listeners(&rset, now); |
832af0ba SK |
1564 | #endif |
1565 | ||
5e9e0efb SK |
1566 | if (FD_ISSET(fd, &rset) && |
1567 | recvfrom(fd, &packet, sizeof(packet), 0, | |
fd9fa481 SK |
1568 | (struct sockaddr *)&faddr, &len) == sizeof(packet) && |
1569 | saddr.sin_addr.s_addr == faddr.sin_addr.s_addr && | |
1570 | packet.icmp.icmp_type == ICMP_ECHOREPLY && | |
1571 | packet.icmp.icmp_seq == 0 && | |
1572 | packet.icmp.icmp_id == id) | |
1573 | { | |
1574 | gotreply = 1; | |
1575 | break; | |
1576 | } | |
1577 | } | |
1578 | ||
824af85b | 1579 | #if defined(HAVE_LINUX_NETWORK) || defined(HAVE_SOLARIS_NETWORK) |
5e9e0efb SK |
1580 | close(fd); |
1581 | #else | |
3be34541 | 1582 | opt = 1; |
5e9e0efb SK |
1583 | setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)); |
1584 | #endif | |
1585 | ||
3be34541 SK |
1586 | return gotreply; |
1587 | } | |
7622fc06 | 1588 | #endif |
0a852541 SK |
1589 | |
1590 |