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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; | |
3b3f4411 SK |
53 | char *bound_device = NULL; |
54 | int did_bind = 0; | |
1a6bca81 | 55 | #endif |
408c368f | 56 | #if defined(HAVE_DHCP) || defined(HAVE_DHCP6) |
1f776932 | 57 | struct dhcp_context *context; |
ff7eea27 | 58 | struct dhcp_relay *relay; |
408c368f | 59 | #endif |
5aabfc78 | 60 | |
824af85b | 61 | #ifdef LOCALEDIR |
b8187c80 SK |
62 | setlocale(LC_ALL, ""); |
63 | bindtextdomain("dnsmasq", LOCALEDIR); | |
64 | textdomain("dnsmasq"); | |
65 | #endif | |
66 | ||
9e4abcb5 SK |
67 | sigact.sa_handler = sig_handler; |
68 | sigact.sa_flags = 0; | |
69 | sigemptyset(&sigact.sa_mask); | |
70 | sigaction(SIGUSR1, &sigact, NULL); | |
5aabfc78 | 71 | sigaction(SIGUSR2, &sigact, NULL); |
9e4abcb5 SK |
72 | sigaction(SIGHUP, &sigact, NULL); |
73 | sigaction(SIGTERM, &sigact, NULL); | |
44a2a316 | 74 | sigaction(SIGALRM, &sigact, NULL); |
feba5c1d SK |
75 | sigaction(SIGCHLD, &sigact, NULL); |
76 | ||
77 | /* ignore SIGPIPE */ | |
78 | sigact.sa_handler = SIG_IGN; | |
79 | sigaction(SIGPIPE, &sigact, NULL); | |
9e4abcb5 | 80 | |
5aabfc78 SK |
81 | umask(022); /* known umask, create leases and pid files as 0644 */ |
82 | ||
83 | read_opts(argc, argv, compile_opts); | |
84 | ||
3be34541 SK |
85 | if (daemon->edns_pktsz < PACKETSZ) |
86 | daemon->edns_pktsz = PACKETSZ; | |
0a852541 SK |
87 | daemon->packet_buff_sz = daemon->edns_pktsz > DNSMASQ_PACKETSZ ? |
88 | daemon->edns_pktsz : DNSMASQ_PACKETSZ; | |
89 | daemon->packet = safe_malloc(daemon->packet_buff_sz); | |
1a6bca81 | 90 | |
c72daea8 SK |
91 | daemon->addrbuff = safe_malloc(ADDRSTRLEN); |
92 | ||
4f7b304f | 93 | |
7622fc06 | 94 | #ifdef HAVE_DHCP |
3be34541 | 95 | if (!daemon->lease_file) |
9e4abcb5 | 96 | { |
52b92f4d | 97 | if (daemon->dhcp || daemon->dhcp6) |
3be34541 | 98 | daemon->lease_file = LEASEFILE; |
9e4abcb5 | 99 | } |
7622fc06 | 100 | #endif |
9e4abcb5 | 101 | |
a2761754 SK |
102 | /* Close any file descriptors we inherited apart from std{in|out|err} |
103 | ||
104 | Ensure that at least stdin, stdout and stderr (fd 0, 1, 2) exist, | |
105 | otherwise file descriptors we create can end up being 0, 1, or 2 | |
106 | and then get accidentally closed later when we make 0, 1, and 2 | |
107 | open to /dev/null. Normally we'll be started with 0, 1 and 2 open, | |
108 | but it's not guaranteed. By opening /dev/null three times, we | |
109 | ensure that we're not using those fds for real stuff. */ | |
5aabfc78 SK |
110 | for (i = 0; i < max_fd; i++) |
111 | if (i != STDOUT_FILENO && i != STDERR_FILENO && i != STDIN_FILENO) | |
112 | close(i); | |
a2761754 SK |
113 | else |
114 | open("/dev/null", O_RDWR); | |
5aabfc78 | 115 | |
801ca9a7 SK |
116 | #ifndef HAVE_LINUX_NETWORK |
117 | # if !(defined(IP_RECVDSTADDR) && defined(IP_RECVIF) && defined(IP_SENDSRCADDR)) | |
28866e95 | 118 | if (!option_bool(OPT_NOWILD)) |
de37951c SK |
119 | { |
120 | bind_fallback = 1; | |
28866e95 | 121 | set_option_bool(OPT_NOWILD); |
de37951c | 122 | } |
801ca9a7 | 123 | # endif |
2b5bae9a SK |
124 | |
125 | /* -- bind-dynamic not supported on !Linux, fall back to --bind-interfaces */ | |
54dd393f | 126 | if (option_bool(OPT_CLEVERBIND)) |
2b5bae9a SK |
127 | { |
128 | bind_fallback = 1; | |
129 | set_option_bool(OPT_NOWILD); | |
236e072c | 130 | reset_option_bool(OPT_CLEVERBIND); |
2b5bae9a | 131 | } |
309331f5 | 132 | #endif |
2b5bae9a | 133 | |
832af0ba | 134 | #ifndef HAVE_TFTP |
9b40cbf5 | 135 | if (option_bool(OPT_TFTP)) |
5aabfc78 | 136 | die(_("TFTP server not available: set HAVE_TFTP in src/config.h"), NULL, EC_BADCONF); |
832af0ba SK |
137 | #endif |
138 | ||
7de060b0 SK |
139 | #ifdef HAVE_CONNTRACK |
140 | if (option_bool(OPT_CONNTRACK) && (daemon->query_port != 0 || daemon->osport)) | |
141 | die (_("Cannot use --conntrack AND --query-port"), NULL, EC_BADCONF); | |
142 | #else | |
143 | if (option_bool(OPT_CONNTRACK)) | |
144 | die(_("Conntrack support not available: set HAVE_CONNTRACK in src/config.h"), NULL, EC_BADCONF); | |
145 | #endif | |
146 | ||
824af85b SK |
147 | #ifdef HAVE_SOLARIS_NETWORK |
148 | if (daemon->max_logs != 0) | |
149 | die(_("asychronous logging is not available under Solaris"), NULL, EC_BADCONF); | |
150 | #endif | |
151 | ||
572b41eb SK |
152 | #ifdef __ANDROID__ |
153 | if (daemon->max_logs != 0) | |
154 | die(_("asychronous logging is not available under Android"), NULL, EC_BADCONF); | |
155 | #endif | |
156 | ||
4820dce9 SK |
157 | #ifndef HAVE_AUTH |
158 | if (daemon->authserver) | |
159 | die(_("authoritative DNS not available: set HAVE_AUTH in src/config.h"), NULL, EC_BADCONF); | |
160 | #endif | |
161 | ||
1a6bca81 SK |
162 | rand_init(); |
163 | ||
5aabfc78 | 164 | now = dnsmasq_time(); |
4f7b304f | 165 | |
b0ff858e | 166 | /* Create a serial at startup if not configured. */ |
4f7b304f SK |
167 | if (daemon->authinterface && daemon->soa_sn == 0) |
168 | #ifdef HAVE_BROKEN_RTC | |
b0ff858e | 169 | die(_("zone serial must be configured in --auth-soa"), NULL, EC_BADCONF); |
4f7b304f SK |
170 | #else |
171 | daemon->soa_sn = now; | |
172 | #endif | |
5aabfc78 | 173 | |
ff7eea27 SK |
174 | #ifdef HAVE_DHCP6 |
175 | if (daemon->dhcp6) | |
176 | { | |
177 | daemon->doing_ra = option_bool(OPT_RA); | |
1f776932 | 178 | |
ff7eea27 | 179 | for (context = daemon->dhcp6; context; context = context->next) |
1f776932 | 180 | { |
ff7eea27 SK |
181 | if (context->flags & CONTEXT_DHCP) |
182 | daemon->doing_dhcp6 = 1; | |
183 | if (context->flags & CONTEXT_RA) | |
184 | daemon->doing_ra = 1; | |
bb86e858 | 185 | #ifndef HAVE_LINUX_NETWORK |
ff7eea27 SK |
186 | if (context->flags & CONTEXT_TEMPLATE) |
187 | die (_("dhcp-range constructor not available on this platform"), NULL, EC_BADCONF); | |
bb86e858 | 188 | #endif |
1f776932 | 189 | } |
ff7eea27 SK |
190 | } |
191 | #endif | |
192 | ||
193 | #ifdef HAVE_DHCP | |
194 | /* Note that order matters here, we must call lease_init before | |
195 | creating any file descriptors which shouldn't be leaked | |
196 | to the lease-script init process. We need to call common_init | |
197 | before lease_init to allocate buffers it uses.*/ | |
198 | if (daemon->dhcp || daemon->doing_dhcp6 || daemon->relay4 || daemon->relay6) | |
199 | { | |
200 | dhcp_common_init(); | |
1f776932 | 201 | if (daemon->dhcp || daemon->doing_dhcp6) |
ff7eea27 SK |
202 | lease_init(now); |
203 | } | |
204 | ||
205 | if (daemon->dhcp || daemon->relay4) | |
206 | dhcp_init(); | |
207 | ||
843c96b4 | 208 | # ifdef HAVE_DHCP6 |
89500e31 | 209 | if (daemon->doing_ra || daemon->doing_dhcp6 || daemon->relay6) |
ff7eea27 SK |
210 | ra_init(now); |
211 | ||
212 | if (daemon->doing_dhcp6 || daemon->relay6) | |
213 | dhcp6_init(); | |
801ca9a7 SK |
214 | # endif |
215 | ||
216 | #endif | |
217 | ||
13d86c73 JD |
218 | #ifdef HAVE_IPSET |
219 | if (daemon->ipsets) | |
220 | ipset_init(); | |
221 | #endif | |
222 | ||
801ca9a7 | 223 | #ifdef HAVE_LINUX_NETWORK |
801ca9a7 | 224 | netlink_init(); |
8445f5d2 | 225 | |
54dd393f SK |
226 | if (option_bool(OPT_NOWILD) && option_bool(OPT_CLEVERBIND)) |
227 | die(_("cannot set --bind-interfaces and --bind-dynamic"), NULL, EC_BADCONF); | |
801ca9a7 SK |
228 | #endif |
229 | ||
115ac3e4 | 230 | if (!enumerate_interfaces(1) || !enumerate_interfaces(0)) |
5aabfc78 | 231 | die(_("failed to find list of interfaces: %s"), NULL, EC_MISC); |
843c96b4 | 232 | |
54dd393f | 233 | if (option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND)) |
de37951c | 234 | { |
74c95c25 | 235 | create_bound_listeners(1); |
54dd393f SK |
236 | |
237 | if (!option_bool(OPT_CLEVERBIND)) | |
238 | for (if_tmp = daemon->if_names; if_tmp; if_tmp = if_tmp->next) | |
239 | if (if_tmp->name && !if_tmp->used) | |
240 | die(_("unknown interface %s"), if_tmp->name, EC_BADNET); | |
9380ba70 SK |
241 | |
242 | #if defined(HAVE_LINUX_NETWORK) && defined(HAVE_DHCP) | |
243 | /* after enumerate_interfaces() */ | |
3b3f4411 SK |
244 | bound_device = whichdevice(); |
245 | ||
10ae7b50 | 246 | if (daemon->dhcp) |
9380ba70 | 247 | { |
3b3f4411 SK |
248 | if (!daemon->relay4 && bound_device) |
249 | { | |
250 | bindtodevice(bound_device, daemon->dhcpfd); | |
251 | did_bind = 1; | |
252 | } | |
253 | if (daemon->enable_pxe && bound_device) | |
254 | { | |
255 | bindtodevice(bound_device, daemon->pxefd); | |
256 | did_bind = 1; | |
257 | } | |
9380ba70 SK |
258 | } |
259 | #endif | |
260 | ||
261 | #if defined(HAVE_LINUX_NETWORK) && defined(HAVE_DHCP6) | |
3b3f4411 SK |
262 | if (daemon->doing_dhcp6 && !daemon->relay6 && bound_device) |
263 | { | |
264 | bindtodevice(bound_device, daemon->dhcp6fd); | |
265 | did_bind = 1; | |
266 | } | |
9380ba70 | 267 | #endif |
de37951c | 268 | } |
28866e95 | 269 | else |
74c95c25 | 270 | create_wildcard_listeners(); |
5d162f20 SK |
271 | |
272 | #ifdef HAVE_DHCP6 | |
273 | /* after enumerate_interfaces() */ | |
ff7eea27 | 274 | if (daemon->doing_dhcp6 || daemon->relay6 || daemon->doing_ra) |
5d162f20 SK |
275 | join_multicast(1); |
276 | #endif | |
de37951c | 277 | |
824af85b SK |
278 | if (daemon->port != 0) |
279 | cache_init(); | |
1a6bca81 | 280 | |
28866e95 | 281 | if (option_bool(OPT_DBUS)) |
3d8df260 SK |
282 | #ifdef HAVE_DBUS |
283 | { | |
284 | char *err; | |
285 | daemon->dbus = NULL; | |
286 | daemon->watches = NULL; | |
5aabfc78 SK |
287 | if ((err = dbus_init())) |
288 | die(_("DBus error: %s"), err, EC_MISC); | |
3d8df260 SK |
289 | } |
290 | #else | |
5aabfc78 | 291 | die(_("DBus not available: set HAVE_DBUS in src/config.h"), NULL, EC_BADCONF); |
3d8df260 SK |
292 | #endif |
293 | ||
824af85b SK |
294 | if (daemon->port != 0) |
295 | pre_allocate_sfds(); | |
1a6bca81 | 296 | |
c72daea8 | 297 | #if defined(HAVE_SCRIPT) |
1a6bca81 | 298 | /* Note getpwnam returns static storage */ |
843c96b4 SK |
299 | if ((daemon->dhcp || daemon->dhcp6) && |
300 | daemon->scriptuser && | |
c72daea8 | 301 | (daemon->lease_change_command || daemon->luascript)) |
1a6bca81 SK |
302 | { |
303 | if ((ent_pw = getpwnam(daemon->scriptuser))) | |
304 | { | |
305 | script_uid = ent_pw->pw_uid; | |
306 | script_gid = ent_pw->pw_gid; | |
307 | } | |
308 | else | |
309 | baduser = daemon->scriptuser; | |
310 | } | |
7622fc06 | 311 | #endif |
9e4abcb5 | 312 | |
1a6bca81 SK |
313 | if (daemon->username && !(ent_pw = getpwnam(daemon->username))) |
314 | baduser = daemon->username; | |
315 | else if (daemon->groupname && !(gp = getgrnam(daemon->groupname))) | |
316 | baduser = daemon->groupname; | |
317 | ||
318 | if (baduser) | |
319 | die(_("unknown user or group: %s"), baduser, EC_BADCONF); | |
320 | ||
321 | /* implement group defaults, "dip" if available, or group associated with uid */ | |
322 | if (!daemon->group_set && !gp) | |
323 | { | |
324 | if (!(gp = getgrnam(CHGRP)) && ent_pw) | |
325 | gp = getgrgid(ent_pw->pw_gid); | |
326 | ||
327 | /* for error message */ | |
328 | if (gp) | |
329 | daemon->groupname = gp->gr_name; | |
330 | } | |
331 | ||
332 | #if defined(HAVE_LINUX_NETWORK) | |
333 | /* determine capability API version here, while we can still | |
334 | call safe_malloc */ | |
335 | if (ent_pw && ent_pw->pw_uid != 0) | |
336 | { | |
1a6bca81 | 337 | int capsize = 1; /* for header version 1 */ |
3927da46 SK |
338 | hdr = safe_malloc(sizeof(*hdr)); |
339 | ||
1a6bca81 SK |
340 | /* find version supported by kernel */ |
341 | memset(hdr, 0, sizeof(*hdr)); | |
342 | capget(hdr, NULL); | |
343 | ||
344 | if (hdr->version != LINUX_CAPABILITY_VERSION_1) | |
345 | { | |
346 | /* if unknown version, use largest supported version (3) */ | |
347 | if (hdr->version != LINUX_CAPABILITY_VERSION_2) | |
348 | hdr->version = LINUX_CAPABILITY_VERSION_3; | |
349 | capsize = 2; | |
350 | } | |
351 | ||
352 | data = safe_malloc(sizeof(*data) * capsize); | |
353 | memset(data, 0, sizeof(*data) * capsize); | |
354 | } | |
355 | #endif | |
356 | ||
5aabfc78 | 357 | /* Use a pipe to carry signals and other events back to the event loop |
1a6bca81 SK |
358 | in a race-free manner and another to carry errors to daemon-invoking process */ |
359 | safe_pipe(pipefd, 1); | |
5e9e0efb SK |
360 | |
361 | piperead = pipefd[0]; | |
362 | pipewrite = pipefd[1]; | |
363 | /* prime the pipe to load stuff first time. */ | |
c72daea8 | 364 | send_event(pipewrite, EVENT_RELOAD, 0, NULL); |
1a6bca81 SK |
365 | |
366 | err_pipe[1] = -1; | |
1697269c | 367 | |
28866e95 | 368 | if (!option_bool(OPT_DEBUG)) |
9e4abcb5 | 369 | { |
9e4abcb5 SK |
370 | /* The following code "daemonizes" the process. |
371 | See Stevens section 12.4 */ | |
1a6bca81 | 372 | |
9e038946 SK |
373 | if (chdir("/") != 0) |
374 | die(_("cannot chdir to filesystem root: %s"), NULL, EC_MISC); | |
375 | ||
1697269c | 376 | #ifndef NO_FORK |
28866e95 | 377 | if (!option_bool(OPT_NO_FORK)) |
3be34541 | 378 | { |
5aabfc78 | 379 | pid_t pid; |
3be34541 | 380 | |
1a6bca81 SK |
381 | /* pipe to carry errors back to original process. |
382 | When startup is complete we close this and the process terminates. */ | |
383 | safe_pipe(err_pipe, 0); | |
384 | ||
7622fc06 SK |
385 | if ((pid = fork()) == -1) |
386 | /* fd == -1 since we've not forked, never returns. */ | |
c72daea8 | 387 | send_event(-1, EVENT_FORK_ERR, errno, NULL); |
9e038946 | 388 | |
5aabfc78 | 389 | if (pid != 0) |
1a6bca81 SK |
390 | { |
391 | struct event_desc ev; | |
c72daea8 SK |
392 | char *msg; |
393 | ||
1a6bca81 SK |
394 | /* close our copy of write-end */ |
395 | close(err_pipe[1]); | |
396 | ||
397 | /* check for errors after the fork */ | |
c72daea8 SK |
398 | if (read_event(err_pipe[0], &ev, &msg)) |
399 | fatal_event(&ev, msg); | |
1a6bca81 SK |
400 | |
401 | _exit(EC_GOOD); | |
402 | } | |
403 | ||
404 | close(err_pipe[0]); | |
405 | ||
406 | /* NO calls to die() from here on. */ | |
3be34541 | 407 | |
5aabfc78 | 408 | setsid(); |
7622fc06 SK |
409 | |
410 | if ((pid = fork()) == -1) | |
c72daea8 | 411 | send_event(err_pipe[1], EVENT_FORK_ERR, errno, NULL); |
7622fc06 SK |
412 | |
413 | if (pid != 0) | |
7cebd20f | 414 | _exit(0); |
3be34541 | 415 | } |
9e4abcb5 | 416 | #endif |
9e038946 | 417 | |
9e4abcb5 | 418 | /* write pidfile _after_ forking ! */ |
1a6bca81 SK |
419 | if (daemon->runfile) |
420 | { | |
79cfefd8 SK |
421 | int fd, err = 0; |
422 | ||
423 | sprintf(daemon->namebuff, "%d\n", (int) getpid()); | |
424 | ||
425 | /* Explanation: Some installations of dnsmasq (eg Debian/Ubuntu) locate the pid-file | |
426 | in a directory which is writable by the non-privileged user that dnsmasq runs as. This | |
427 | allows the daemon to delete the file as part of its shutdown. This is a security hole to the | |
428 | extent that an attacker running as the unprivileged user could replace the pidfile with a | |
429 | symlink, and have the target of that symlink overwritten as root next time dnsmasq starts. | |
430 | ||
431 | The folowing code first deletes any existing file, and then opens it with the O_EXCL flag, | |
432 | ensuring that the open() fails should there be any existing file (because the unlink() failed, | |
433 | or an attacker exploited the race between unlink() and open()). This ensures that no symlink | |
434 | attack can succeed. | |
435 | ||
436 | Any compromise of the non-privileged user still theoretically allows the pid-file to be | |
437 | replaced whilst dnsmasq is running. The worst that could allow is that the usual | |
438 | "shutdown dnsmasq" shell command could be tricked into stopping any other process. | |
439 | ||
440 | Note that if dnsmasq is started as non-root (eg for testing) it silently ignores | |
441 | failure to write the pid-file. | |
442 | */ | |
443 | ||
444 | unlink(daemon->runfile); | |
1a6bca81 | 445 | |
79cfefd8 | 446 | if ((fd = open(daemon->runfile, O_WRONLY|O_CREAT|O_TRUNC|O_EXCL, S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH)) == -1) |
1a6bca81 | 447 | { |
79cfefd8 SK |
448 | /* only complain if started as root */ |
449 | if (getuid() == 0) | |
450 | err = 1; | |
1a6bca81 | 451 | } |
79cfefd8 SK |
452 | else |
453 | { | |
454 | if (!read_write(fd, (unsigned char *)daemon->namebuff, strlen(daemon->namebuff), 0)) | |
455 | err = 1; | |
456 | ||
457 | while (!err && close(fd) == -1) | |
458 | if (!retry_send()) | |
459 | err = 1; | |
460 | } | |
461 | ||
462 | if (err) | |
1a6bca81 | 463 | { |
c72daea8 | 464 | send_event(err_pipe[1], EVENT_PIDFILE, errno, daemon->runfile); |
1a6bca81 SK |
465 | _exit(0); |
466 | } | |
9e4abcb5 | 467 | } |
1697269c SK |
468 | } |
469 | ||
8ef5ada2 SK |
470 | log_err = log_start(ent_pw, err_pipe[1]); |
471 | ||
28866e95 | 472 | if (!option_bool(OPT_DEBUG)) |
8ef5ada2 SK |
473 | { |
474 | /* open stdout etc to /dev/null */ | |
475 | int nullfd = open("/dev/null", O_RDWR); | |
476 | dup2(nullfd, STDOUT_FILENO); | |
477 | dup2(nullfd, STDERR_FILENO); | |
478 | dup2(nullfd, STDIN_FILENO); | |
479 | close(nullfd); | |
480 | } | |
1a6bca81 SK |
481 | |
482 | /* if we are to run scripts, we need to fork a helper before dropping root. */ | |
483 | daemon->helperfd = -1; | |
c72daea8 | 484 | #ifdef HAVE_SCRIPT |
52b92f4d | 485 | if ((daemon->dhcp || daemon->dhcp6) && (daemon->lease_change_command || daemon->luascript)) |
1a6bca81 | 486 | daemon->helperfd = create_helper(pipewrite, err_pipe[1], script_uid, script_gid, max_fd); |
5aabfc78 | 487 | #endif |
5aabfc78 | 488 | |
28866e95 | 489 | if (!option_bool(OPT_DEBUG) && getuid() == 0) |
1697269c | 490 | { |
1a6bca81 SK |
491 | int bad_capabilities = 0; |
492 | gid_t dummy; | |
493 | ||
494 | /* remove all supplimentary groups */ | |
495 | if (gp && | |
496 | (setgroups(0, &dummy) == -1 || | |
497 | setgid(gp->gr_gid) == -1)) | |
9e4abcb5 | 498 | { |
c72daea8 | 499 | send_event(err_pipe[1], EVENT_GROUP_ERR, errno, daemon->groupname); |
1a6bca81 | 500 | _exit(0); |
7cebd20f | 501 | } |
1a6bca81 | 502 | |
7cebd20f | 503 | if (ent_pw && ent_pw->pw_uid != 0) |
1697269c | 504 | { |
74c95c25 | 505 | #if defined(HAVE_LINUX_NETWORK) |
1697269c | 506 | /* On linux, we keep CAP_NETADMIN (for ARP-injection) and |
74c95c25 | 507 | CAP_NET_RAW (for icmp) if we're doing dhcp. If we have yet to bind |
54dd393f SK |
508 | ports because of DAD, or we're doing it dynamically, |
509 | we need CAP_NET_BIND_SERVICE too. */ | |
510 | if (is_dad_listeners() || option_bool(OPT_CLEVERBIND)) | |
74c95c25 SK |
511 | data->effective = data->permitted = data->inheritable = |
512 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | | |
513 | (1 << CAP_SETUID) | (1 << CAP_NET_BIND_SERVICE); | |
514 | else | |
515 | data->effective = data->permitted = data->inheritable = | |
516 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | (1 << CAP_SETUID); | |
5e9e0efb | 517 | |
1697269c | 518 | /* Tell kernel to not clear capabilities when dropping root */ |
572b41eb | 519 | if (capset(hdr, data) == -1 || prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) |
1697269c | 520 | bad_capabilities = errno; |
1a6bca81 | 521 | |
7622fc06 | 522 | #elif defined(HAVE_SOLARIS_NETWORK) |
824af85b SK |
523 | /* http://developers.sun.com/solaris/articles/program_privileges.html */ |
524 | priv_set_t *priv_set; | |
525 | ||
526 | if (!(priv_set = priv_str_to_set("basic", ",", NULL)) || | |
527 | priv_addset(priv_set, PRIV_NET_ICMPACCESS) == -1 || | |
528 | priv_addset(priv_set, PRIV_SYS_NET_CONFIG) == -1) | |
529 | bad_capabilities = errno; | |
530 | ||
531 | if (priv_set && bad_capabilities == 0) | |
532 | { | |
533 | priv_inverse(priv_set); | |
534 | ||
535 | if (setppriv(PRIV_OFF, PRIV_LIMIT, priv_set) == -1) | |
536 | bad_capabilities = errno; | |
537 | } | |
538 | ||
539 | if (priv_set) | |
540 | priv_freeset(priv_set); | |
541 | ||
824af85b SK |
542 | #endif |
543 | ||
1a6bca81 | 544 | if (bad_capabilities != 0) |
1697269c | 545 | { |
c72daea8 | 546 | send_event(err_pipe[1], EVENT_CAP_ERR, bad_capabilities, NULL); |
1a6bca81 SK |
547 | _exit(0); |
548 | } | |
549 | ||
550 | /* finally drop root */ | |
551 | if (setuid(ent_pw->pw_uid) == -1) | |
552 | { | |
c72daea8 | 553 | send_event(err_pipe[1], EVENT_USER_ERR, errno, daemon->username); |
1a6bca81 SK |
554 | _exit(0); |
555 | } | |
556 | ||
1697269c | 557 | #ifdef HAVE_LINUX_NETWORK |
54dd393f | 558 | if (is_dad_listeners() || option_bool(OPT_CLEVERBIND)) |
74c95c25 SK |
559 | data->effective = data->permitted = |
560 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) | (1 << CAP_NET_BIND_SERVICE); | |
561 | else | |
562 | data->effective = data->permitted = | |
563 | (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW); | |
1a6bca81 SK |
564 | data->inheritable = 0; |
565 | ||
566 | /* lose the setuid and setgid capbilities */ | |
567 | if (capset(hdr, data) == -1) | |
568 | { | |
c72daea8 | 569 | send_event(err_pipe[1], EVENT_CAP_ERR, errno, NULL); |
1a6bca81 | 570 | _exit(0); |
1697269c | 571 | } |
1a6bca81 SK |
572 | #endif |
573 | ||
9e4abcb5 SK |
574 | } |
575 | } | |
1697269c | 576 | |
1697269c | 577 | #ifdef HAVE_LINUX_NETWORK |
28866e95 | 578 | if (option_bool(OPT_DEBUG)) |
572b41eb | 579 | prctl(PR_SET_DUMPABLE, 1, 0, 0, 0); |
1697269c | 580 | #endif |
9e4abcb5 | 581 | |
8b3ae2fd | 582 | #ifdef HAVE_TFTP |
8bc4cece | 583 | if (option_bool(OPT_TFTP)) |
8b3ae2fd SK |
584 | { |
585 | DIR *dir; | |
586 | struct tftp_prefix *p; | |
587 | ||
588 | if (daemon->tftp_prefix) | |
589 | { | |
590 | if (!((dir = opendir(daemon->tftp_prefix)))) | |
591 | { | |
592 | send_event(err_pipe[1], EVENT_TFTP_ERR, errno, daemon->tftp_prefix); | |
593 | _exit(0); | |
594 | } | |
595 | closedir(dir); | |
596 | } | |
597 | ||
598 | for (p = daemon->if_prefix; p; p = p->next) | |
599 | { | |
600 | if (!((dir = opendir(p->prefix)))) | |
601 | { | |
602 | send_event(err_pipe[1], EVENT_TFTP_ERR, errno, p->prefix); | |
603 | _exit(0); | |
604 | } | |
605 | closedir(dir); | |
606 | } | |
607 | } | |
608 | #endif | |
609 | ||
824af85b SK |
610 | if (daemon->port == 0) |
611 | my_syslog(LOG_INFO, _("started, version %s DNS disabled"), VERSION); | |
612 | else if (daemon->cachesize != 0) | |
f2621c7f | 613 | my_syslog(LOG_INFO, _("started, version %s cachesize %d"), VERSION, daemon->cachesize); |
9e4abcb5 | 614 | else |
f2621c7f | 615 | my_syslog(LOG_INFO, _("started, version %s cache disabled"), VERSION); |
1697269c | 616 | |
f2621c7f | 617 | my_syslog(LOG_INFO, _("compile time options: %s"), compile_opts); |
1697269c | 618 | |
3d8df260 | 619 | #ifdef HAVE_DBUS |
28866e95 | 620 | if (option_bool(OPT_DBUS)) |
3d8df260 SK |
621 | { |
622 | if (daemon->dbus) | |
f2621c7f | 623 | my_syslog(LOG_INFO, _("DBus support enabled: connected to system bus")); |
3d8df260 | 624 | else |
f2621c7f | 625 | my_syslog(LOG_INFO, _("DBus support enabled: bus connection pending")); |
3d8df260 SK |
626 | } |
627 | #endif | |
628 | ||
1a6bca81 SK |
629 | if (log_err != 0) |
630 | my_syslog(LOG_WARNING, _("warning: failed to change owner of %s: %s"), | |
631 | daemon->log_file, strerror(log_err)); | |
632 | ||
de37951c | 633 | if (bind_fallback) |
f2621c7f | 634 | my_syslog(LOG_WARNING, _("setting --bind-interfaces option because of OS limitations")); |
dc27e148 SK |
635 | |
636 | warn_bound_listeners(); | |
de37951c | 637 | |
28866e95 | 638 | if (!option_bool(OPT_NOWILD)) |
26128d27 SK |
639 | for (if_tmp = daemon->if_names; if_tmp; if_tmp = if_tmp->next) |
640 | if (if_tmp->name && !if_tmp->used) | |
f2621c7f | 641 | my_syslog(LOG_WARNING, _("warning: interface %s does not currently exist"), if_tmp->name); |
5e9e0efb | 642 | |
28866e95 | 643 | if (daemon->port != 0 && option_bool(OPT_NO_RESOLV)) |
208b65c5 SK |
644 | { |
645 | if (daemon->resolv_files && !daemon->resolv_files->is_default) | |
f2621c7f | 646 | my_syslog(LOG_WARNING, _("warning: ignoring resolv-file flag because no-resolv is set")); |
208b65c5 | 647 | daemon->resolv_files = NULL; |
1b7ecd11 | 648 | if (!daemon->servers) |
f2621c7f | 649 | my_syslog(LOG_WARNING, _("warning: no upstream servers configured")); |
208b65c5 SK |
650 | } |
651 | ||
f2621c7f SK |
652 | if (daemon->max_logs != 0) |
653 | my_syslog(LOG_INFO, _("asynchronous logging enabled, queue limit is %d messages"), daemon->max_logs); | |
1f776932 | 654 | |
f2621c7f | 655 | |
7622fc06 | 656 | #ifdef HAVE_DHCP |
1f776932 SK |
657 | for (context = daemon->dhcp; context; context = context->next) |
658 | log_context(AF_INET, context); | |
52b92f4d | 659 | |
ff7eea27 SK |
660 | for (relay = daemon->relay4; relay; relay = relay->next) |
661 | log_relay(AF_INET, relay); | |
662 | ||
1f776932 SK |
663 | # ifdef HAVE_DHCP6 |
664 | for (context = daemon->dhcp6; context; context = context->next) | |
665 | log_context(AF_INET6, context); | |
666 | ||
ff7eea27 SK |
667 | for (relay = daemon->relay6; relay; relay = relay->next) |
668 | log_relay(AF_INET6, relay); | |
669 | ||
1f776932 SK |
670 | if (daemon->doing_dhcp6 || daemon->doing_ra) |
671 | dhcp_construct_contexts(now); | |
672 | ||
673 | if (option_bool(OPT_RA)) | |
674 | my_syslog(MS_DHCP | LOG_INFO, _("IPv6 router advertisement enabled")); | |
675 | # endif | |
26128d27 | 676 | |
3b3f4411 SK |
677 | # ifdef HAVE_LINUX_NETWORK |
678 | if (did_bind) | |
679 | my_syslog(MS_DHCP | LOG_INFO, _("DHCP, sockets bound exclusively to interface %s"), bound_device); | |
680 | # endif | |
681 | ||
8445f5d2 SK |
682 | /* after dhcp_contruct_contexts */ |
683 | if (daemon->dhcp || daemon->doing_dhcp6) | |
684 | lease_find_interfaces(now); | |
1f776932 | 685 | #endif |
52b92f4d | 686 | |
832af0ba | 687 | #ifdef HAVE_TFTP |
8bc4cece | 688 | if (option_bool(OPT_TFTP)) |
832af0ba | 689 | { |
832af0ba | 690 | #ifdef FD_SETSIZE |
5aabfc78 | 691 | if (FD_SETSIZE < (unsigned)max_fd) |
832af0ba SK |
692 | max_fd = FD_SETSIZE; |
693 | #endif | |
694 | ||
7622fc06 | 695 | my_syslog(MS_TFTP | LOG_INFO, "TFTP %s%s %s", |
f2621c7f SK |
696 | daemon->tftp_prefix ? _("root is ") : _("enabled"), |
697 | daemon->tftp_prefix ? daemon->tftp_prefix: "", | |
28866e95 | 698 | option_bool(OPT_TFTP_SECURE) ? _("secure mode") : ""); |
f2621c7f | 699 | |
832af0ba | 700 | /* This is a guess, it assumes that for small limits, |
f2621c7f | 701 | disjoint files might be served, but for large limits, |
832af0ba SK |
702 | a single file will be sent to may clients (the file only needs |
703 | one fd). */ | |
704 | ||
705 | max_fd -= 30; /* use other than TFTP */ | |
706 | ||
707 | if (max_fd < 0) | |
708 | max_fd = 5; | |
709 | else if (max_fd < 100) | |
710 | max_fd = max_fd/2; | |
711 | else | |
712 | max_fd = max_fd - 20; | |
824af85b SK |
713 | |
714 | /* if we have to use a limited range of ports, | |
715 | that will limit the number of transfers */ | |
716 | if (daemon->start_tftp_port != 0 && | |
717 | daemon->end_tftp_port - daemon->start_tftp_port + 1 < max_fd) | |
718 | max_fd = daemon->end_tftp_port - daemon->start_tftp_port + 1; | |
832af0ba SK |
719 | |
720 | if (daemon->tftp_max > max_fd) | |
721 | { | |
722 | daemon->tftp_max = max_fd; | |
7622fc06 | 723 | my_syslog(MS_TFTP | LOG_WARNING, |
f2621c7f SK |
724 | _("restricting maximum simultaneous TFTP transfers to %d"), |
725 | daemon->tftp_max); | |
832af0ba SK |
726 | } |
727 | } | |
728 | #endif | |
729 | ||
1a6bca81 SK |
730 | /* finished start-up - release original process */ |
731 | if (err_pipe[1] != -1) | |
732 | close(err_pipe[1]); | |
9e4abcb5 | 733 | |
824af85b SK |
734 | if (daemon->port != 0) |
735 | check_servers(); | |
736 | ||
7cebd20f SK |
737 | pid = getpid(); |
738 | ||
5e9e0efb | 739 | while (1) |
9e4abcb5 | 740 | { |
1697269c | 741 | int maxfd = -1; |
5e9e0efb | 742 | struct timeval t, *tp = NULL; |
3d8df260 | 743 | fd_set rset, wset, eset; |
9e4abcb5 SK |
744 | |
745 | FD_ZERO(&rset); | |
3d8df260 SK |
746 | FD_ZERO(&wset); |
747 | FD_ZERO(&eset); | |
9e4abcb5 | 748 | |
1697269c SK |
749 | /* if we are out of resources, find how long we have to wait |
750 | for some to come free, we'll loop around then and restart | |
751 | listening for queries */ | |
5aabfc78 | 752 | if ((t.tv_sec = set_dns_listeners(now, &rset, &maxfd)) != 0) |
1697269c SK |
753 | { |
754 | t.tv_usec = 0; | |
755 | tp = &t; | |
756 | } | |
757 | ||
832af0ba SK |
758 | /* Whilst polling for the dbus, or doing a tftp transfer, wake every quarter second */ |
759 | if (daemon->tftp_trans || | |
28866e95 | 760 | (option_bool(OPT_DBUS) && !daemon->dbus)) |
5e9e0efb | 761 | { |
1697269c SK |
762 | t.tv_sec = 0; |
763 | t.tv_usec = 250000; | |
5e9e0efb | 764 | tp = &t; |
5e9e0efb | 765 | } |
74c95c25 SK |
766 | /* Wake every second whilst waiting for DAD to complete */ |
767 | else if (is_dad_listeners()) | |
768 | { | |
769 | t.tv_sec = 1; | |
770 | t.tv_usec = 0; | |
771 | tp = &t; | |
772 | } | |
44a2a316 | 773 | |
832af0ba | 774 | #ifdef HAVE_DBUS |
5aabfc78 | 775 | set_dbus_listeners(&maxfd, &rset, &wset, &eset); |
5e9e0efb SK |
776 | #endif |
777 | ||
7622fc06 | 778 | #ifdef HAVE_DHCP |
ff7eea27 | 779 | if (daemon->dhcp || daemon->relay4) |
5e9e0efb SK |
780 | { |
781 | FD_SET(daemon->dhcpfd, &rset); | |
1697269c | 782 | bump_maxfd(daemon->dhcpfd, &maxfd); |
316e2730 SK |
783 | if (daemon->pxefd != -1) |
784 | { | |
785 | FD_SET(daemon->pxefd, &rset); | |
786 | bump_maxfd(daemon->pxefd, &maxfd); | |
787 | } | |
5e9e0efb | 788 | } |
7622fc06 | 789 | #endif |
cdeda28f | 790 | |
52b92f4d | 791 | #ifdef HAVE_DHCP6 |
ff7eea27 | 792 | if (daemon->doing_dhcp6 || daemon->relay6) |
52b92f4d SK |
793 | { |
794 | FD_SET(daemon->dhcp6fd, &rset); | |
c5ad4e79 | 795 | bump_maxfd(daemon->dhcp6fd, &maxfd); |
5d71d834 SK |
796 | } |
797 | ||
1f776932 | 798 | if (daemon->doing_ra) |
5d71d834 SK |
799 | { |
800 | FD_SET(daemon->icmp6fd, &rset); | |
801 | bump_maxfd(daemon->icmp6fd, &maxfd); | |
52b92f4d SK |
802 | } |
803 | #endif | |
804 | ||
5e9e0efb SK |
805 | #ifdef HAVE_LINUX_NETWORK |
806 | FD_SET(daemon->netlinkfd, &rset); | |
1697269c | 807 | bump_maxfd(daemon->netlinkfd, &maxfd); |
3d8df260 | 808 | #endif |
3d8df260 | 809 | |
5e9e0efb | 810 | FD_SET(piperead, &rset); |
1697269c SK |
811 | bump_maxfd(piperead, &maxfd); |
812 | ||
7622fc06 | 813 | #ifdef HAVE_DHCP |
1f15b81d | 814 | # ifdef HAVE_SCRIPT |
5aabfc78 | 815 | while (helper_buf_empty() && do_script_run(now)); |
1697269c | 816 | |
a9530964 SK |
817 | # ifdef HAVE_TFTP |
818 | while (helper_buf_empty() && do_tftp_script_run()); | |
819 | # endif | |
820 | ||
1697269c SK |
821 | if (!helper_buf_empty()) |
822 | { | |
823 | FD_SET(daemon->helperfd, &wset); | |
824 | bump_maxfd(daemon->helperfd, &maxfd); | |
825 | } | |
7622fc06 | 826 | # else |
5aabfc78 SK |
827 | /* need this for other side-effects */ |
828 | while (do_script_run(now)); | |
a9530964 SK |
829 | |
830 | # ifdef HAVE_TFTP | |
831 | while (do_tftp_script_run()); | |
832 | # endif | |
833 | ||
7622fc06 | 834 | # endif |
5aabfc78 | 835 | #endif |
7622fc06 | 836 | |
f2621c7f SK |
837 | /* must do this just before select(), when we know no |
838 | more calls to my_syslog() can occur */ | |
839 | set_log_writer(&wset, &maxfd); | |
840 | ||
5e9e0efb SK |
841 | if (select(maxfd+1, &rset, &wset, &eset, tp) < 0) |
842 | { | |
843 | /* otherwise undefined after error */ | |
844 | FD_ZERO(&rset); FD_ZERO(&wset); FD_ZERO(&eset); | |
845 | } | |
846 | ||
847 | now = dnsmasq_time(); | |
9e4abcb5 | 848 | |
f2621c7f | 849 | check_log_writer(&wset); |
115ac3e4 SK |
850 | |
851 | /* prime. */ | |
852 | enumerate_interfaces(1); | |
853 | ||
74c95c25 SK |
854 | /* Check the interfaces to see if any have exited DAD state |
855 | and if so, bind the address. */ | |
856 | if (is_dad_listeners()) | |
857 | { | |
115ac3e4 | 858 | enumerate_interfaces(0); |
74c95c25 SK |
859 | /* NB, is_dad_listeners() == 1 --> we're binding interfaces */ |
860 | create_bound_listeners(0); | |
dc27e148 | 861 | warn_bound_listeners(); |
74c95c25 | 862 | } |
f2621c7f | 863 | |
c52e1897 SK |
864 | #ifdef HAVE_LINUX_NETWORK |
865 | if (FD_ISSET(daemon->netlinkfd, &rset)) | |
1f776932 | 866 | netlink_multicast(now); |
c52e1897 SK |
867 | #endif |
868 | ||
9e4abcb5 | 869 | /* Check for changes to resolv files once per second max. */ |
3d8df260 | 870 | /* Don't go silent for long periods if the clock goes backwards. */ |
9009d746 SK |
871 | if (daemon->last_resolv == 0 || |
872 | difftime(now, daemon->last_resolv) > 1.0 || | |
873 | difftime(now, daemon->last_resolv) < -1.0) | |
9e4abcb5 | 874 | { |
8ef5ada2 SK |
875 | /* poll_resolv doesn't need to reload first time through, since |
876 | that's queued anyway. */ | |
33820b7e | 877 | |
8ef5ada2 SK |
878 | poll_resolv(0, daemon->last_resolv != 0, now); |
879 | daemon->last_resolv = now; | |
9e4abcb5 | 880 | } |
5aabfc78 | 881 | |
5e9e0efb | 882 | if (FD_ISSET(piperead, &rset)) |
5aabfc78 | 883 | async_event(piperead, now); |
7cebd20f | 884 | |
3d8df260 SK |
885 | #ifdef HAVE_DBUS |
886 | /* if we didn't create a DBus connection, retry now. */ | |
28866e95 | 887 | if (option_bool(OPT_DBUS) && !daemon->dbus) |
3d8df260 SK |
888 | { |
889 | char *err; | |
5aabfc78 | 890 | if ((err = dbus_init())) |
f2621c7f | 891 | my_syslog(LOG_WARNING, _("DBus error: %s"), err); |
3d8df260 | 892 | if (daemon->dbus) |
f2621c7f | 893 | my_syslog(LOG_INFO, _("connected to system DBus")); |
3d8df260 | 894 | } |
5aabfc78 | 895 | check_dbus_listeners(&rset, &wset, &eset); |
3d8df260 | 896 | #endif |
824af85b | 897 | |
5aabfc78 | 898 | check_dns_listeners(&rset, now); |
832af0ba SK |
899 | |
900 | #ifdef HAVE_TFTP | |
5aabfc78 | 901 | check_tftp_listeners(&rset, now); |
832af0ba SK |
902 | #endif |
903 | ||
7622fc06 | 904 | #ifdef HAVE_DHCP |
ff7eea27 | 905 | if (daemon->dhcp || daemon->relay4) |
316e2730 SK |
906 | { |
907 | if (FD_ISSET(daemon->dhcpfd, &rset)) | |
908 | dhcp_packet(now, 0); | |
909 | if (daemon->pxefd != -1 && FD_ISSET(daemon->pxefd, &rset)) | |
910 | dhcp_packet(now, 1); | |
911 | } | |
1697269c | 912 | |
52b92f4d | 913 | #ifdef HAVE_DHCP6 |
ff7eea27 | 914 | if ((daemon->doing_dhcp6 || daemon->relay6) && FD_ISSET(daemon->dhcp6fd, &rset)) |
18c63eff | 915 | dhcp6_packet(now); |
c5ad4e79 | 916 | |
1f776932 SK |
917 | if (daemon->doing_ra && FD_ISSET(daemon->icmp6fd, &rset)) |
918 | icmp6_packet(now); | |
52b92f4d SK |
919 | #endif |
920 | ||
1f15b81d | 921 | # ifdef HAVE_SCRIPT |
1697269c | 922 | if (daemon->helperfd != -1 && FD_ISSET(daemon->helperfd, &wset)) |
5aabfc78 | 923 | helper_write(); |
7622fc06 | 924 | # endif |
5aabfc78 SK |
925 | #endif |
926 | ||
9e4abcb5 | 927 | } |
9e4abcb5 SK |
928 | } |
929 | ||
3be34541 SK |
930 | static void sig_handler(int sig) |
931 | { | |
5e9e0efb | 932 | if (pid == 0) |
3be34541 | 933 | { |
1697269c SK |
934 | /* ignore anything other than TERM during startup |
935 | and in helper proc. (helper ignore TERM too) */ | |
5e9e0efb | 936 | if (sig == SIGTERM) |
5aabfc78 | 937 | exit(EC_MISC); |
3be34541 | 938 | } |
5aabfc78 | 939 | else if (pid != getpid()) |
5e9e0efb | 940 | { |
1697269c | 941 | /* alarm is used to kill TCP children after a fixed time. */ |
5e9e0efb | 942 | if (sig == SIGALRM) |
7cebd20f | 943 | _exit(0); |
3be34541 | 944 | } |
5aabfc78 SK |
945 | else |
946 | { | |
947 | /* master process */ | |
948 | int event, errsave = errno; | |
949 | ||
950 | if (sig == SIGHUP) | |
951 | event = EVENT_RELOAD; | |
952 | else if (sig == SIGCHLD) | |
953 | event = EVENT_CHILD; | |
954 | else if (sig == SIGALRM) | |
955 | event = EVENT_ALARM; | |
956 | else if (sig == SIGTERM) | |
957 | event = EVENT_TERM; | |
958 | else if (sig == SIGUSR1) | |
959 | event = EVENT_DUMP; | |
960 | else if (sig == SIGUSR2) | |
961 | event = EVENT_REOPEN; | |
962 | else | |
963 | return; | |
964 | ||
c72daea8 | 965 | send_event(pipewrite, event, 0, NULL); |
5aabfc78 SK |
966 | errno = errsave; |
967 | } | |
968 | } | |
969 | ||
353ae4d2 SK |
970 | /* now == 0 -> queue immediate callback */ |
971 | void send_alarm(time_t event, time_t now) | |
741c2952 | 972 | { |
884a6dfe | 973 | if (now == 0 || event != 0) |
353ae4d2 | 974 | { |
884a6dfe SK |
975 | /* alarm(0) or alarm(-ve) doesn't do what we want.... */ |
976 | if ((now == 0 || difftime(event, now) <= 0.0)) | |
977 | send_event(pipewrite, EVENT_ALARM, 0, NULL); | |
978 | else | |
979 | alarm((unsigned)difftime(event, now)); | |
353ae4d2 | 980 | } |
741c2952 SK |
981 | } |
982 | ||
c72daea8 | 983 | void send_event(int fd, int event, int data, char *msg) |
5aabfc78 SK |
984 | { |
985 | struct event_desc ev; | |
c72daea8 SK |
986 | struct iovec iov[2]; |
987 | ||
5aabfc78 SK |
988 | ev.event = event; |
989 | ev.data = data; | |
c72daea8 SK |
990 | ev.msg_sz = msg ? strlen(msg) : 0; |
991 | ||
992 | iov[0].iov_base = &ev; | |
993 | iov[0].iov_len = sizeof(ev); | |
994 | iov[1].iov_base = msg; | |
995 | iov[1].iov_len = ev.msg_sz; | |
1a6bca81 SK |
996 | |
997 | /* error pipe, debug mode. */ | |
998 | if (fd == -1) | |
c72daea8 | 999 | fatal_event(&ev, msg); |
1a6bca81 SK |
1000 | else |
1001 | /* pipe is non-blocking and struct event_desc is smaller than | |
1002 | PIPE_BUF, so this either fails or writes everything */ | |
c72daea8 | 1003 | while (writev(fd, iov, msg ? 2 : 1) == -1 && errno == EINTR); |
5aabfc78 SK |
1004 | } |
1005 | ||
c72daea8 SK |
1006 | /* NOTE: the memory used to return msg is leaked: use msgs in events only |
1007 | to describe fatal errors. */ | |
1008 | static int read_event(int fd, struct event_desc *evp, char **msg) | |
1009 | { | |
1010 | char *buf; | |
1011 | ||
1012 | if (!read_write(fd, (unsigned char *)evp, sizeof(struct event_desc), 1)) | |
1013 | return 0; | |
1014 | ||
1015 | *msg = NULL; | |
1016 | ||
1017 | if (evp->msg_sz != 0 && | |
1018 | (buf = malloc(evp->msg_sz + 1)) && | |
1019 | read_write(fd, (unsigned char *)buf, evp->msg_sz, 1)) | |
1020 | { | |
1021 | buf[evp->msg_sz] = 0; | |
1022 | *msg = buf; | |
1023 | } | |
1024 | ||
1025 | return 1; | |
1026 | } | |
1027 | ||
1028 | static void fatal_event(struct event_desc *ev, char *msg) | |
1a6bca81 SK |
1029 | { |
1030 | errno = ev->data; | |
1031 | ||
1032 | switch (ev->event) | |
1033 | { | |
1034 | case EVENT_DIE: | |
1035 | exit(0); | |
7622fc06 SK |
1036 | |
1037 | case EVENT_FORK_ERR: | |
1038 | die(_("cannot fork into background: %s"), NULL, EC_MISC); | |
1a6bca81 SK |
1039 | |
1040 | case EVENT_PIPE_ERR: | |
1041 | die(_("failed to create helper: %s"), NULL, EC_MISC); | |
1042 | ||
1043 | case EVENT_CAP_ERR: | |
1044 | die(_("setting capabilities failed: %s"), NULL, EC_MISC); | |
1045 | ||
1046 | case EVENT_USER_ERR: | |
c72daea8 | 1047 | die(_("failed to change user-id to %s: %s"), msg, EC_MISC); |
1a6bca81 SK |
1048 | |
1049 | case EVENT_GROUP_ERR: | |
c72daea8 | 1050 | die(_("failed to change group-id to %s: %s"), msg, EC_MISC); |
1a6bca81 SK |
1051 | |
1052 | case EVENT_PIDFILE: | |
c72daea8 | 1053 | die(_("failed to open pidfile %s: %s"), msg, EC_FILE); |
1a6bca81 SK |
1054 | |
1055 | case EVENT_LOG_ERR: | |
c72daea8 SK |
1056 | die(_("cannot open log %s: %s"), msg, EC_FILE); |
1057 | ||
1058 | case EVENT_LUA_ERR: | |
1059 | die(_("failed to load Lua script: %s"), msg, EC_MISC); | |
8b3ae2fd SK |
1060 | |
1061 | case EVENT_TFTP_ERR: | |
1062 | die(_("TFTP directory %s inaccessible: %s"), msg, EC_FILE); | |
1a6bca81 SK |
1063 | } |
1064 | } | |
1065 | ||
5aabfc78 SK |
1066 | static void async_event(int pipe, time_t now) |
1067 | { | |
1068 | pid_t p; | |
1069 | struct event_desc ev; | |
1070 | int i; | |
c72daea8 SK |
1071 | char *msg; |
1072 | ||
1073 | /* NOTE: the memory used to return msg is leaked: use msgs in events only | |
1074 | to describe fatal errors. */ | |
1075 | ||
1076 | if (read_event(pipe, &ev, &msg)) | |
5aabfc78 SK |
1077 | switch (ev.event) |
1078 | { | |
1079 | case EVENT_RELOAD: | |
1080 | clear_cache_and_reload(now); | |
28866e95 | 1081 | if (daemon->port != 0 && daemon->resolv_files && option_bool(OPT_NO_POLL)) |
5aabfc78 SK |
1082 | { |
1083 | reload_servers(daemon->resolv_files->name); | |
1084 | check_servers(); | |
1085 | } | |
7622fc06 | 1086 | #ifdef HAVE_DHCP |
5aabfc78 | 1087 | rerun_scripts(); |
7622fc06 | 1088 | #endif |
5aabfc78 SK |
1089 | break; |
1090 | ||
1091 | case EVENT_DUMP: | |
824af85b SK |
1092 | if (daemon->port != 0) |
1093 | dump_cache(now); | |
5aabfc78 SK |
1094 | break; |
1095 | ||
1096 | case EVENT_ALARM: | |
7622fc06 | 1097 | #ifdef HAVE_DHCP |
1f776932 | 1098 | if (daemon->dhcp || daemon->doing_dhcp6) |
5aabfc78 SK |
1099 | { |
1100 | lease_prune(NULL, now); | |
1101 | lease_update_file(now); | |
1102 | } | |
843c96b4 | 1103 | #ifdef HAVE_DHCP6 |
1f776932 | 1104 | else if (daemon->doing_ra) |
353ae4d2 SK |
1105 | /* Not doing DHCP, so no lease system, manage alarms for ra only */ |
1106 | send_alarm(periodic_ra(now), now); | |
843c96b4 | 1107 | #endif |
7622fc06 | 1108 | #endif |
5aabfc78 SK |
1109 | break; |
1110 | ||
1111 | case EVENT_CHILD: | |
1112 | /* See Stevens 5.10 */ | |
1113 | while ((p = waitpid(-1, NULL, WNOHANG)) != 0) | |
1114 | if (p == -1) | |
1115 | { | |
1116 | if (errno != EINTR) | |
1117 | break; | |
1118 | } | |
1119 | else | |
1120 | for (i = 0 ; i < MAX_PROCS; i++) | |
1121 | if (daemon->tcp_pids[i] == p) | |
1122 | daemon->tcp_pids[i] = 0; | |
1123 | break; | |
1124 | ||
1125 | case EVENT_KILLED: | |
c72daea8 | 1126 | my_syslog(LOG_WARNING, _("script process killed by signal %d"), ev.data); |
5aabfc78 SK |
1127 | break; |
1128 | ||
1129 | case EVENT_EXITED: | |
c72daea8 | 1130 | my_syslog(LOG_WARNING, _("script process exited with status %d"), ev.data); |
5aabfc78 SK |
1131 | break; |
1132 | ||
1133 | case EVENT_EXEC_ERR: | |
9e038946 SK |
1134 | my_syslog(LOG_ERR, _("failed to execute %s: %s"), |
1135 | daemon->lease_change_command, strerror(ev.data)); | |
5aabfc78 SK |
1136 | break; |
1137 | ||
1a6bca81 | 1138 | /* necessary for fatal errors in helper */ |
c72daea8 | 1139 | case EVENT_USER_ERR: |
1a6bca81 | 1140 | case EVENT_DIE: |
c72daea8 SK |
1141 | case EVENT_LUA_ERR: |
1142 | fatal_event(&ev, msg); | |
9e038946 SK |
1143 | break; |
1144 | ||
5aabfc78 SK |
1145 | case EVENT_REOPEN: |
1146 | /* Note: this may leave TCP-handling processes with the old file still open. | |
1147 | Since any such process will die in CHILD_LIFETIME or probably much sooner, | |
1148 | we leave them logging to the old file. */ | |
1149 | if (daemon->log_file != NULL) | |
1150 | log_reopen(daemon->log_file); | |
1151 | break; | |
1152 | ||
1153 | case EVENT_TERM: | |
1154 | /* Knock all our children on the head. */ | |
1155 | for (i = 0; i < MAX_PROCS; i++) | |
1156 | if (daemon->tcp_pids[i] != 0) | |
1157 | kill(daemon->tcp_pids[i], SIGALRM); | |
1158 | ||
c72daea8 | 1159 | #if defined(HAVE_SCRIPT) |
5aabfc78 SK |
1160 | /* handle pending lease transitions */ |
1161 | if (daemon->helperfd != -1) | |
1162 | { | |
1163 | /* block in writes until all done */ | |
1164 | if ((i = fcntl(daemon->helperfd, F_GETFL)) != -1) | |
1165 | fcntl(daemon->helperfd, F_SETFL, i & ~O_NONBLOCK); | |
1166 | do { | |
1167 | helper_write(); | |
1168 | } while (!helper_buf_empty() || do_script_run(now)); | |
1169 | close(daemon->helperfd); | |
1170 | } | |
1171 | #endif | |
1172 | ||
1173 | if (daemon->lease_stream) | |
1174 | fclose(daemon->lease_stream); | |
73a08a24 SK |
1175 | |
1176 | if (daemon->runfile) | |
1177 | unlink(daemon->runfile); | |
5aabfc78 SK |
1178 | |
1179 | my_syslog(LOG_INFO, _("exiting on receipt of SIGTERM")); | |
1180 | flush_log(); | |
1181 | exit(EC_GOOD); | |
1182 | } | |
3be34541 SK |
1183 | } |
1184 | ||
8ef5ada2 | 1185 | void poll_resolv(int force, int do_reload, time_t now) |
5aabfc78 SK |
1186 | { |
1187 | struct resolvc *res, *latest; | |
1188 | struct stat statbuf; | |
1189 | time_t last_change = 0; | |
1190 | /* There may be more than one possible file. | |
1191 | Go through and find the one which changed _last_. | |
1192 | Warn of any which can't be read. */ | |
8ef5ada2 | 1193 | |
28866e95 | 1194 | if (daemon->port == 0 || option_bool(OPT_NO_POLL)) |
8ef5ada2 SK |
1195 | return; |
1196 | ||
5aabfc78 SK |
1197 | for (latest = NULL, res = daemon->resolv_files; res; res = res->next) |
1198 | if (stat(res->name, &statbuf) == -1) | |
1199 | { | |
8ef5ada2 SK |
1200 | if (force) |
1201 | { | |
1202 | res->mtime = 0; | |
1203 | continue; | |
1204 | } | |
1205 | ||
5aabfc78 SK |
1206 | if (!res->logged) |
1207 | my_syslog(LOG_WARNING, _("failed to access %s: %s"), res->name, strerror(errno)); | |
1208 | res->logged = 1; | |
8ef5ada2 SK |
1209 | |
1210 | if (res->mtime != 0) | |
1211 | { | |
1212 | /* existing file evaporated, force selection of the latest | |
1213 | file even if its mtime hasn't changed since we last looked */ | |
1214 | poll_resolv(1, do_reload, now); | |
1215 | return; | |
1216 | } | |
5aabfc78 SK |
1217 | } |
1218 | else | |
1219 | { | |
1220 | res->logged = 0; | |
8ef5ada2 SK |
1221 | if (force || (statbuf.st_mtime != res->mtime)) |
1222 | { | |
1223 | res->mtime = statbuf.st_mtime; | |
5aabfc78 SK |
1224 | if (difftime(statbuf.st_mtime, last_change) > 0.0) |
1225 | { | |
1226 | last_change = statbuf.st_mtime; | |
1227 | latest = res; | |
1228 | } | |
1229 | } | |
1230 | } | |
1231 | ||
1232 | if (latest) | |
1233 | { | |
1234 | static int warned = 0; | |
1235 | if (reload_servers(latest->name)) | |
1236 | { | |
1237 | my_syslog(LOG_INFO, _("reading %s"), latest->name); | |
1238 | warned = 0; | |
1239 | check_servers(); | |
28866e95 | 1240 | if (option_bool(OPT_RELOAD) && do_reload) |
8ef5ada2 | 1241 | clear_cache_and_reload(now); |
5aabfc78 SK |
1242 | } |
1243 | else | |
1244 | { | |
1245 | latest->mtime = 0; | |
1246 | if (!warned) | |
1247 | { | |
1248 | my_syslog(LOG_WARNING, _("no servers found in %s, will retry"), latest->name); | |
1249 | warned = 1; | |
1250 | } | |
1251 | } | |
1252 | } | |
1253 | } | |
3d8df260 | 1254 | |
5aabfc78 | 1255 | void clear_cache_and_reload(time_t now) |
3d8df260 | 1256 | { |
408c368f VG |
1257 | (void)now; |
1258 | ||
824af85b | 1259 | if (daemon->port != 0) |
7622fc06 | 1260 | cache_reload(); |
824af85b | 1261 | |
7622fc06 | 1262 | #ifdef HAVE_DHCP |
1f776932 | 1263 | if (daemon->dhcp || daemon->doing_dhcp6) |
3d8df260 | 1264 | { |
28866e95 | 1265 | if (option_bool(OPT_ETHERS)) |
5aabfc78 | 1266 | dhcp_read_ethers(); |
824af85b | 1267 | reread_dhcp(); |
3d8df260 | 1268 | dhcp_update_configs(daemon->dhcp_conf); |
5aabfc78 SK |
1269 | lease_update_from_configs(); |
1270 | lease_update_file(now); | |
353ae4d2 | 1271 | lease_update_dns(1); |
3d8df260 | 1272 | } |
843c96b4 | 1273 | #ifdef HAVE_DHCP6 |
1f776932 | 1274 | else if (daemon->doing_ra) |
2021c662 SK |
1275 | /* Not doing DHCP, so no lease system, manage |
1276 | alarms for ra only */ | |
1277 | send_alarm(periodic_ra(now), now); | |
843c96b4 | 1278 | #endif |
7622fc06 | 1279 | #endif |
3d8df260 SK |
1280 | } |
1281 | ||
5aabfc78 | 1282 | static int set_dns_listeners(time_t now, fd_set *set, int *maxfdp) |
3be34541 SK |
1283 | { |
1284 | struct serverfd *serverfdp; | |
1285 | struct listener *listener; | |
824af85b | 1286 | int wait = 0, i; |
832af0ba SK |
1287 | |
1288 | #ifdef HAVE_TFTP | |
1289 | int tftp = 0; | |
1290 | struct tftp_transfer *transfer; | |
1291 | for (transfer = daemon->tftp_trans; transfer; transfer = transfer->next) | |
1292 | { | |
1293 | tftp++; | |
1294 | FD_SET(transfer->sockfd, set); | |
1295 | bump_maxfd(transfer->sockfd, maxfdp); | |
1296 | } | |
1297 | #endif | |
1298 | ||
1697269c | 1299 | /* will we be able to get memory? */ |
824af85b SK |
1300 | if (daemon->port != 0) |
1301 | get_new_frec(now, &wait); | |
1697269c | 1302 | |
3be34541 SK |
1303 | for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next) |
1304 | { | |
1305 | FD_SET(serverfdp->fd, set); | |
1697269c | 1306 | bump_maxfd(serverfdp->fd, maxfdp); |
3be34541 | 1307 | } |
1a6bca81 SK |
1308 | |
1309 | if (daemon->port != 0 && !daemon->osport) | |
1310 | for (i = 0; i < RANDOM_SOCKS; i++) | |
1311 | if (daemon->randomsocks[i].refcount != 0) | |
1312 | { | |
1313 | FD_SET(daemon->randomsocks[i].fd, set); | |
1314 | bump_maxfd(daemon->randomsocks[i].fd, maxfdp); | |
1315 | } | |
1316 | ||
3be34541 SK |
1317 | for (listener = daemon->listeners; listener; listener = listener->next) |
1318 | { | |
1697269c | 1319 | /* only listen for queries if we have resources */ |
824af85b | 1320 | if (listener->fd != -1 && wait == 0) |
1697269c SK |
1321 | { |
1322 | FD_SET(listener->fd, set); | |
1323 | bump_maxfd(listener->fd, maxfdp); | |
1324 | } | |
1325 | ||
1326 | /* death of a child goes through the select loop, so | |
1327 | we don't need to explicitly arrange to wake up here */ | |
824af85b SK |
1328 | if (listener->tcpfd != -1) |
1329 | for (i = 0; i < MAX_PROCS; i++) | |
1330 | if (daemon->tcp_pids[i] == 0) | |
1331 | { | |
1332 | FD_SET(listener->tcpfd, set); | |
1333 | bump_maxfd(listener->tcpfd, maxfdp); | |
1334 | break; | |
1335 | } | |
9e4abcb5 | 1336 | |
832af0ba SK |
1337 | #ifdef HAVE_TFTP |
1338 | if (tftp <= daemon->tftp_max && listener->tftpfd != -1) | |
1339 | { | |
1340 | FD_SET(listener->tftpfd, set); | |
1341 | bump_maxfd(listener->tftpfd, maxfdp); | |
1342 | } | |
1343 | #endif | |
1344 | ||
1345 | } | |
1346 | ||
1697269c | 1347 | return wait; |
3be34541 | 1348 | } |
9e4abcb5 | 1349 | |
5aabfc78 | 1350 | static void check_dns_listeners(fd_set *set, time_t now) |
3be34541 SK |
1351 | { |
1352 | struct serverfd *serverfdp; | |
1a6bca81 SK |
1353 | struct listener *listener; |
1354 | int i; | |
1355 | ||
832af0ba SK |
1356 | for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next) |
1357 | if (FD_ISSET(serverfdp->fd, set)) | |
1a6bca81 SK |
1358 | reply_query(serverfdp->fd, serverfdp->source_addr.sa.sa_family, now); |
1359 | ||
1360 | if (daemon->port != 0 && !daemon->osport) | |
1361 | for (i = 0; i < RANDOM_SOCKS; i++) | |
1362 | if (daemon->randomsocks[i].refcount != 0 && | |
1363 | FD_ISSET(daemon->randomsocks[i].fd, set)) | |
1364 | reply_query(daemon->randomsocks[i].fd, daemon->randomsocks[i].family, now); | |
832af0ba SK |
1365 | |
1366 | for (listener = daemon->listeners; listener; listener = listener->next) | |
1367 | { | |
824af85b | 1368 | if (listener->fd != -1 && FD_ISSET(listener->fd, set)) |
5aabfc78 | 1369 | receive_query(listener, now); |
1a6bca81 | 1370 | |
832af0ba SK |
1371 | #ifdef HAVE_TFTP |
1372 | if (listener->tftpfd != -1 && FD_ISSET(listener->tftpfd, set)) | |
5aabfc78 | 1373 | tftp_request(listener, now); |
832af0ba | 1374 | #endif |
3be34541 | 1375 | |
824af85b | 1376 | if (listener->tcpfd != -1 && FD_ISSET(listener->tcpfd, set)) |
832af0ba | 1377 | { |
22ce550e | 1378 | int confd, client_ok = 1; |
832af0ba SK |
1379 | struct irec *iface = NULL; |
1380 | pid_t p; | |
52d4abf2 SK |
1381 | union mysockaddr tcp_addr; |
1382 | socklen_t tcp_len = sizeof(union mysockaddr); | |
1383 | ||
1384 | while ((confd = accept(listener->tcpfd, NULL, NULL)) == -1 && errno == EINTR); | |
832af0ba | 1385 | |
46b06656 | 1386 | if (confd == -1) |
832af0ba | 1387 | continue; |
76dd75de | 1388 | |
46b06656 SK |
1389 | if (getsockname(confd, (struct sockaddr *)&tcp_addr, &tcp_len) == -1) |
1390 | { | |
1391 | close(confd); | |
1392 | continue; | |
1393 | } | |
76dd75de SK |
1394 | |
1395 | /* Make sure that the interface list is up-to-date. | |
1396 | ||
1397 | We do this here as we may need the results below, and | |
1398 | the DNS code needs them for --interface-name stuff. | |
1399 | ||
1400 | Multiple calls to enumerate_interfaces() per select loop are | |
1401 | inhibited, so calls to it in the child process (which doesn't select()) | |
1402 | have no effect. This avoids two processes reading from the same | |
1403 | netlink fd and screwing the pooch entirely. | |
1404 | */ | |
e25db1f2 | 1405 | |
76dd75de SK |
1406 | enumerate_interfaces(0); |
1407 | ||
1408 | if (option_bool(OPT_NOWILD)) | |
1409 | iface = listener->iface; /* May be NULL */ | |
1410 | else | |
1411 | { | |
1412 | int if_index; | |
1413 | char intr_name[IF_NAMESIZE]; | |
1414 | ||
1415 | /* if we can find the arrival interface, check it's one that's allowed */ | |
1416 | if ((if_index = tcp_interface(confd, tcp_addr.sa.sa_family)) != 0 && | |
1417 | indextoname(listener->tcpfd, if_index, intr_name)) | |
1418 | { | |
1419 | struct all_addr addr; | |
1420 | addr.addr.addr4 = tcp_addr.in.sin_addr; | |
e25db1f2 | 1421 | #ifdef HAVE_IPV6 |
76dd75de SK |
1422 | if (tcp_addr.sa.sa_family == AF_INET6) |
1423 | addr.addr.addr6 = tcp_addr.in6.sin6_addr; | |
e25db1f2 | 1424 | #endif |
76dd75de SK |
1425 | |
1426 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1427 | if (iface->index == if_index) | |
1428 | break; | |
1429 | ||
1430 | if (!iface && !loopback_exception(listener->tcpfd, tcp_addr.sa.sa_family, &addr, intr_name)) | |
1431 | client_ok = 0; | |
1432 | } | |
1433 | ||
1434 | if (option_bool(OPT_CLEVERBIND)) | |
1435 | iface = listener->iface; /* May be NULL */ | |
1436 | else | |
1437 | { | |
1438 | /* Check for allowed interfaces when binding the wildcard address: | |
1439 | we do this by looking for an interface with the same address as | |
1440 | the local address of the TCP connection, then looking to see if that's | |
1441 | an allowed interface. As a side effect, we get the netmask of the | |
1442 | interface too, for localisation. */ | |
1443 | ||
1444 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1445 | if (sockaddr_isequal(&iface->addr, &tcp_addr)) | |
1446 | break; | |
1447 | ||
1448 | if (!iface) | |
1449 | client_ok = 0; | |
1450 | } | |
1451 | } | |
1452 | ||
22ce550e | 1453 | if (!client_ok) |
832af0ba SK |
1454 | { |
1455 | shutdown(confd, SHUT_RDWR); | |
1456 | close(confd); | |
1457 | } | |
59353a6b | 1458 | #ifndef NO_FORK |
28866e95 | 1459 | else if (!option_bool(OPT_DEBUG) && (p = fork()) != 0) |
832af0ba SK |
1460 | { |
1461 | if (p != -1) | |
1462 | { | |
1463 | int i; | |
1464 | for (i = 0; i < MAX_PROCS; i++) | |
1465 | if (daemon->tcp_pids[i] == 0) | |
1466 | { | |
1467 | daemon->tcp_pids[i] = p; | |
1468 | break; | |
1469 | } | |
1470 | } | |
1471 | close(confd); | |
1472 | } | |
1473 | #endif | |
1474 | else | |
1475 | { | |
1476 | unsigned char *buff; | |
1477 | struct server *s; | |
1478 | int flags; | |
52d4abf2 | 1479 | struct in_addr netmask; |
4f7b304f | 1480 | int auth_dns; |
52d4abf2 SK |
1481 | |
1482 | if (iface) | |
4f7b304f SK |
1483 | { |
1484 | netmask = iface->netmask; | |
1485 | auth_dns = iface->dns_auth; | |
1486 | } | |
52d4abf2 | 1487 | else |
4f7b304f SK |
1488 | { |
1489 | netmask.s_addr = 0; | |
1490 | auth_dns = 0; | |
1491 | } | |
52d4abf2 | 1492 | |
8ef5ada2 SK |
1493 | #ifndef NO_FORK |
1494 | /* Arrange for SIGALARM after CHILD_LIFETIME seconds to | |
1495 | terminate the process. */ | |
28866e95 | 1496 | if (!option_bool(OPT_DEBUG)) |
832af0ba | 1497 | alarm(CHILD_LIFETIME); |
8ef5ada2 SK |
1498 | #endif |
1499 | ||
832af0ba SK |
1500 | /* start with no upstream connections. */ |
1501 | for (s = daemon->servers; s; s = s->next) | |
7cebd20f | 1502 | s->tcpfd = -1; |
832af0ba SK |
1503 | |
1504 | /* The connected socket inherits non-blocking | |
1505 | attribute from the listening socket. | |
1506 | Reset that here. */ | |
1507 | if ((flags = fcntl(confd, F_GETFL, 0)) != -1) | |
1508 | fcntl(confd, F_SETFL, flags & ~O_NONBLOCK); | |
1509 | ||
4f7b304f | 1510 | buff = tcp_request(confd, now, &tcp_addr, netmask, auth_dns); |
7cebd20f | 1511 | |
832af0ba SK |
1512 | shutdown(confd, SHUT_RDWR); |
1513 | close(confd); | |
1514 | ||
1515 | if (buff) | |
1516 | free(buff); | |
1517 | ||
1518 | for (s = daemon->servers; s; s = s->next) | |
1519 | if (s->tcpfd != -1) | |
1520 | { | |
1521 | shutdown(s->tcpfd, SHUT_RDWR); | |
1522 | close(s->tcpfd); | |
1523 | } | |
7cebd20f | 1524 | #ifndef NO_FORK |
28866e95 | 1525 | if (!option_bool(OPT_DEBUG)) |
5aabfc78 SK |
1526 | { |
1527 | flush_log(); | |
1528 | _exit(0); | |
1529 | } | |
59353a6b | 1530 | #endif |
832af0ba SK |
1531 | } |
1532 | } | |
1533 | } | |
3be34541 SK |
1534 | } |
1535 | ||
7622fc06 | 1536 | #ifdef HAVE_DHCP |
5e9e0efb SK |
1537 | int make_icmp_sock(void) |
1538 | { | |
7cebd20f | 1539 | int fd; |
5e9e0efb SK |
1540 | int zeroopt = 0; |
1541 | ||
1542 | if ((fd = socket (AF_INET, SOCK_RAW, IPPROTO_ICMP)) != -1) | |
1543 | { | |
7cebd20f | 1544 | if (!fix_fd(fd) || |
5e9e0efb SK |
1545 | setsockopt(fd, SOL_SOCKET, SO_DONTROUTE, &zeroopt, sizeof(zeroopt)) == -1) |
1546 | { | |
1547 | close(fd); | |
1548 | fd = -1; | |
1549 | } | |
1550 | } | |
1551 | ||
1552 | return fd; | |
1553 | } | |
1554 | ||
5aabfc78 | 1555 | int icmp_ping(struct in_addr addr) |
3be34541 | 1556 | { |
5e9e0efb | 1557 | /* Try and get an ICMP echo from a machine. */ |
3be34541 SK |
1558 | |
1559 | /* Note that whilst in the three second wait, we check for | |
832af0ba | 1560 | (and service) events on the DNS and TFTP sockets, (so doing that |
3be34541 SK |
1561 | better not use any resources our caller has in use...) |
1562 | but we remain deaf to signals or further DHCP packets. */ | |
1563 | ||
5e9e0efb | 1564 | int fd; |
3be34541 SK |
1565 | struct sockaddr_in saddr; |
1566 | struct { | |
1567 | struct ip ip; | |
1568 | struct icmp icmp; | |
1569 | } packet; | |
1570 | unsigned short id = rand16(); | |
1571 | unsigned int i, j; | |
5e9e0efb | 1572 | int gotreply = 0; |
3be34541 | 1573 | time_t start, now; |
5e9e0efb | 1574 | |
824af85b | 1575 | #if defined(HAVE_LINUX_NETWORK) || defined (HAVE_SOLARIS_NETWORK) |
5e9e0efb SK |
1576 | if ((fd = make_icmp_sock()) == -1) |
1577 | return 0; | |
1578 | #else | |
1579 | int opt = 2000; | |
1580 | fd = daemon->dhcp_icmp_fd; | |
1581 | setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)); | |
1582 | #endif | |
1583 | ||
3be34541 SK |
1584 | saddr.sin_family = AF_INET; |
1585 | saddr.sin_port = 0; | |
1586 | saddr.sin_addr = addr; | |
1587 | #ifdef HAVE_SOCKADDR_SA_LEN | |
1588 | saddr.sin_len = sizeof(struct sockaddr_in); | |
1589 | #endif | |
1590 | ||
1591 | memset(&packet.icmp, 0, sizeof(packet.icmp)); | |
1592 | packet.icmp.icmp_type = ICMP_ECHO; | |
1593 | packet.icmp.icmp_id = id; | |
1594 | for (j = 0, i = 0; i < sizeof(struct icmp) / 2; i++) | |
1595 | j += ((u16 *)&packet.icmp)[i]; | |
1596 | while (j>>16) | |
1597 | j = (j & 0xffff) + (j >> 16); | |
1598 | packet.icmp.icmp_cksum = (j == 0xffff) ? j : ~j; | |
1599 | ||
5e9e0efb | 1600 | while (sendto(fd, (char *)&packet.icmp, sizeof(struct icmp), 0, |
fd9fa481 SK |
1601 | (struct sockaddr *)&saddr, sizeof(saddr)) == -1 && |
1602 | retry_send()); | |
1603 | ||
5e9e0efb SK |
1604 | for (now = start = dnsmasq_time(); |
1605 | difftime(now, start) < (float)PING_WAIT;) | |
fd9fa481 SK |
1606 | { |
1607 | struct timeval tv; | |
f2621c7f | 1608 | fd_set rset, wset; |
fd9fa481 | 1609 | struct sockaddr_in faddr; |
1697269c | 1610 | int maxfd = fd; |
3d8df260 | 1611 | socklen_t len = sizeof(faddr); |
fd9fa481 SK |
1612 | |
1613 | tv.tv_usec = 250000; | |
1614 | tv.tv_sec = 0; | |
1615 | ||
1616 | FD_ZERO(&rset); | |
f2621c7f | 1617 | FD_ZERO(&wset); |
5e9e0efb | 1618 | FD_SET(fd, &rset); |
5aabfc78 | 1619 | set_dns_listeners(now, &rset, &maxfd); |
f2621c7f | 1620 | set_log_writer(&wset, &maxfd); |
c5ad4e79 SK |
1621 | |
1622 | #ifdef HAVE_DHCP6 | |
1f776932 | 1623 | if (daemon->doing_ra) |
c5ad4e79 SK |
1624 | { |
1625 | FD_SET(daemon->icmp6fd, &rset); | |
1626 | bump_maxfd(daemon->icmp6fd, &maxfd); | |
1627 | } | |
1628 | #endif | |
1629 | ||
f2621c7f SK |
1630 | if (select(maxfd+1, &rset, &wset, NULL, &tv) < 0) |
1631 | { | |
1632 | FD_ZERO(&rset); | |
1633 | FD_ZERO(&wset); | |
1634 | } | |
1635 | ||
5e9e0efb | 1636 | now = dnsmasq_time(); |
f2621c7f SK |
1637 | |
1638 | check_log_writer(&wset); | |
5aabfc78 | 1639 | check_dns_listeners(&rset, now); |
832af0ba | 1640 | |
c5ad4e79 | 1641 | #ifdef HAVE_DHCP6 |
1f776932 SK |
1642 | if (daemon->doing_ra && FD_ISSET(daemon->icmp6fd, &rset)) |
1643 | icmp6_packet(now); | |
c5ad4e79 SK |
1644 | #endif |
1645 | ||
832af0ba | 1646 | #ifdef HAVE_TFTP |
5aabfc78 | 1647 | check_tftp_listeners(&rset, now); |
832af0ba SK |
1648 | #endif |
1649 | ||
5e9e0efb SK |
1650 | if (FD_ISSET(fd, &rset) && |
1651 | recvfrom(fd, &packet, sizeof(packet), 0, | |
fd9fa481 SK |
1652 | (struct sockaddr *)&faddr, &len) == sizeof(packet) && |
1653 | saddr.sin_addr.s_addr == faddr.sin_addr.s_addr && | |
1654 | packet.icmp.icmp_type == ICMP_ECHOREPLY && | |
1655 | packet.icmp.icmp_seq == 0 && | |
1656 | packet.icmp.icmp_id == id) | |
1657 | { | |
1658 | gotreply = 1; | |
1659 | break; | |
1660 | } | |
1661 | } | |
1662 | ||
824af85b | 1663 | #if defined(HAVE_LINUX_NETWORK) || defined(HAVE_SOLARIS_NETWORK) |
5e9e0efb SK |
1664 | close(fd); |
1665 | #else | |
3be34541 | 1666 | opt = 1; |
5e9e0efb SK |
1667 | setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)); |
1668 | #endif | |
1669 | ||
3be34541 SK |
1670 | return gotreply; |
1671 | } | |
7622fc06 | 1672 | #endif |
0a852541 SK |
1673 | |
1674 |