1 /* dnsmasq is Copyright (c) 2000-2010 Simon Kelley
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
5 the Free Software Foundation; version 2 dated June, 1991, or
6 (at your option) version 3 dated 29 June, 2007.
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.
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/>.
20 #include <asm/unistd.h>
21 _syscall5(int, prctl
, int, a
, int, b
, int, c
, int, d
, int, e
);
23 struct daemon
*daemon
;
25 static char *compile_opts
=
30 #ifndef HAVE_GETOPT_LONG
34 #ifdef HAVE_BROKEN_RTC
52 #if defined(HAVE_DHCP) && !defined(HAVE_SCRIPT)
62 static volatile pid_t pid
= 0;
63 static volatile int pipewrite
;
65 static int set_dns_listeners(time_t now
, fd_set
*set
, int *maxfdp
);
66 static void check_dns_listeners(fd_set
*set
, time_t now
);
67 static void sig_handler(int sig
);
68 static void async_event(int pipe
, time_t now
);
69 static void fatal_event(struct event_desc
*ev
);
71 void tomato_helper(time_t now
); // zzz
72 void flush_lease_file(time_t now
); // zzz
74 int main (int argc
, char **argv
)
76 int bind_fallback
= 0;
78 struct sigaction sigact
;
80 int piperead
, pipefd
[2], err_pipe
[2];
81 struct passwd
*ent_pw
= NULL
;
82 #if defined(HAVE_DHCP) && defined(HAVE_SCRIPT)
86 struct group
*gp
= NULL
;
87 long i
, max_fd
= sysconf(_SC_OPEN_MAX
);
90 #if defined(HAVE_LINUX_NETWORK)
91 cap_user_header_t hdr
= NULL
;
92 cap_user_data_t data
= NULL
;
96 setlocale(LC_ALL
, "");
97 bindtextdomain("dnsmasq", LOCALEDIR
);
98 textdomain("dnsmasq");
101 sigact
.sa_handler
= sig_handler
;
103 sigemptyset(&sigact
.sa_mask
);
104 sigaction(SIGUSR1
, &sigact
, NULL
);
105 sigaction(SIGUSR2
, &sigact
, NULL
);
106 sigaction(SIGHUP
, &sigact
, NULL
);
107 sigaction(SIGTERM
, &sigact
, NULL
);
108 sigaction(SIGALRM
, &sigact
, NULL
);
109 sigaction(SIGCHLD
, &sigact
, NULL
);
112 sigact
.sa_handler
= SIG_IGN
;
113 sigaction(SIGPIPE
, &sigact
, NULL
);
115 umask(022); /* known umask, create leases and pid files as 0644 */
117 read_opts(argc
, argv
, compile_opts
);
119 if (daemon
->edns_pktsz
< PACKETSZ
)
120 daemon
->edns_pktsz
= PACKETSZ
;
121 daemon
->packet_buff_sz
= daemon
->edns_pktsz
> DNSMASQ_PACKETSZ
?
122 daemon
->edns_pktsz
: DNSMASQ_PACKETSZ
;
123 daemon
->packet
= safe_malloc(daemon
->packet_buff_sz
);
126 if (!daemon
->lease_file
)
129 daemon
->lease_file
= LEASEFILE
;
133 /* Close any file descriptors we inherited apart from std{in|out|err} */
134 for (i
= 0; i
< max_fd
; i
++)
135 if (i
!= STDOUT_FILENO
&& i
!= STDERR_FILENO
&& i
!= STDIN_FILENO
)
138 #ifdef HAVE_LINUX_NETWORK
140 #elif !(defined(IP_RECVDSTADDR) && \
141 defined(IP_RECVIF) && \
142 defined(IP_SENDSRCADDR))
143 if (!(daemon
->options
& OPT_NOWILD
))
146 daemon
->options
|= OPT_NOWILD
;
151 if (daemon
->tftp_unlimited
|| daemon
->tftp_interfaces
)
152 die(_("TFTP server not available: set HAVE_TFTP in src/config.h"), NULL
, EC_BADCONF
);
155 #ifdef HAVE_SOLARIS_NETWORK
156 if (daemon
->max_logs
!= 0)
157 die(_("asychronous logging is not available under Solaris"), NULL
, EC_BADCONF
);
162 now
= dnsmasq_time();
167 /* Note that order matters here, we must call lease_init before
168 creating any file descriptors which shouldn't be leaked
169 to the lease-script init process. */
175 if (!enumerate_interfaces())
176 die(_("failed to find list of interfaces: %s"), NULL
, EC_MISC
);
178 if (daemon
->options
& OPT_NOWILD
)
180 daemon
->listeners
= create_bound_listeners();
182 for (if_tmp
= daemon
->if_names
; if_tmp
; if_tmp
= if_tmp
->next
)
183 if (if_tmp
->name
&& !if_tmp
->used
)
184 die(_("unknown interface %s"), if_tmp
->name
, EC_BADNET
);
186 for (if_tmp
= daemon
->if_addrs
; if_tmp
; if_tmp
= if_tmp
->next
)
189 prettyprint_addr(&if_tmp
->addr
, daemon
->namebuff
);
190 die(_("no interface with address %s"), daemon
->namebuff
, EC_BADNET
);
193 else if ((daemon
->port
!= 0 || daemon
->tftp_interfaces
|| daemon
->tftp_unlimited
) &&
194 !(daemon
->listeners
= create_wildcard_listeners()))
195 die(_("failed to create listening socket: %s"), NULL
, EC_BADNET
);
197 if (daemon
->port
!= 0)
200 if (daemon
->options
& OPT_DBUS
)
205 daemon
->watches
= NULL
;
206 if ((err
= dbus_init()))
207 die(_("DBus error: %s"), err
, EC_MISC
);
210 die(_("DBus not available: set HAVE_DBUS in src/config.h"), NULL
, EC_BADCONF
);
213 if (daemon
->port
!= 0)
216 #if defined(HAVE_DHCP) && defined(HAVE_SCRIPT)
217 /* Note getpwnam returns static storage */
218 if (daemon
->dhcp
&& daemon
->lease_change_command
&& daemon
->scriptuser
)
220 if ((ent_pw
= getpwnam(daemon
->scriptuser
)))
222 script_uid
= ent_pw
->pw_uid
;
223 script_gid
= ent_pw
->pw_gid
;
226 baduser
= daemon
->scriptuser
;
230 if (daemon
->username
&& !(ent_pw
= getpwnam(daemon
->username
)))
231 baduser
= daemon
->username
;
232 else if (daemon
->groupname
&& !(gp
= getgrnam(daemon
->groupname
)))
233 baduser
= daemon
->groupname
;
236 die(_("unknown user or group: %s"), baduser
, EC_BADCONF
);
238 /* implement group defaults, "dip" if available, or group associated with uid */
239 if (!daemon
->group_set
&& !gp
)
241 if (!(gp
= getgrnam(CHGRP
)) && ent_pw
)
242 gp
= getgrgid(ent_pw
->pw_gid
);
244 /* for error message */
246 daemon
->groupname
= gp
->gr_name
;
249 #if defined(HAVE_LINUX_NETWORK)
250 /* determine capability API version here, while we can still
252 if (ent_pw
&& ent_pw
->pw_uid
!= 0)
254 int capsize
= 1; /* for header version 1 */
255 hdr
= safe_malloc(sizeof(*hdr
));
257 /* find version supported by kernel */
258 memset(hdr
, 0, sizeof(*hdr
));
261 if (hdr
->version
!= LINUX_CAPABILITY_VERSION_1
)
263 /* if unknown version, use largest supported version (3) */
264 if (hdr
->version
!= LINUX_CAPABILITY_VERSION_2
)
265 hdr
->version
= LINUX_CAPABILITY_VERSION_3
;
269 data
= safe_malloc(sizeof(*data
) * capsize
);
270 memset(data
, 0, sizeof(*data
) * capsize
);
274 /* Use a pipe to carry signals and other events back to the event loop
275 in a race-free manner and another to carry errors to daemon-invoking process */
276 safe_pipe(pipefd
, 1);
278 piperead
= pipefd
[0];
279 pipewrite
= pipefd
[1];
280 /* prime the pipe to load stuff first time. */
281 send_event(pipewrite
, EVENT_RELOAD
, 0);
285 if (!(daemon
->options
& OPT_DEBUG
))
287 /* The following code "daemonizes" the process.
288 See Stevens section 12.4 */
291 die(_("cannot chdir to filesystem root: %s"), NULL
, EC_MISC
);
294 if (!(daemon
->options
& OPT_NO_FORK
))
298 /* pipe to carry errors back to original process.
299 When startup is complete we close this and the process terminates. */
300 safe_pipe(err_pipe
, 0);
302 if ((pid
= fork()) == -1)
303 /* fd == -1 since we've not forked, never returns. */
304 send_event(-1, EVENT_FORK_ERR
, errno
);
308 struct event_desc ev
;
310 /* close our copy of write-end */
313 /* check for errors after the fork */
314 if (read_write(err_pipe
[0], (unsigned char *)&ev
, sizeof(ev
), 1))
322 /* NO calls to die() from here on. */
326 if ((pid
= fork()) == -1)
327 send_event(err_pipe
[1], EVENT_FORK_ERR
, errno
);
334 /* write pidfile _after_ forking ! */
339 /* only complain if started as root */
340 if ((pidfile
= fopen(daemon
->runfile
, "w")))
342 fprintf(pidfile
, "%d\n", (int) getpid());
345 else if (getuid() == 0)
347 send_event(err_pipe
[1], EVENT_PIDFILE
, errno
);
353 log_err
= log_start(ent_pw
, err_pipe
[1]);
355 if (!(daemon
->options
& OPT_DEBUG
))
357 /* open stdout etc to /dev/null */
358 int nullfd
= open("/dev/null", O_RDWR
);
359 dup2(nullfd
, STDOUT_FILENO
);
360 dup2(nullfd
, STDERR_FILENO
);
361 dup2(nullfd
, STDIN_FILENO
);
365 /* if we are to run scripts, we need to fork a helper before dropping root. */
366 daemon
->helperfd
= -1;
367 #if defined(HAVE_DHCP) && defined(HAVE_SCRIPT)
368 if (daemon
->dhcp
&& daemon
->lease_change_command
)
369 daemon
->helperfd
= create_helper(pipewrite
, err_pipe
[1], script_uid
, script_gid
, max_fd
);
372 if (!(daemon
->options
& OPT_DEBUG
) && getuid() == 0)
374 int bad_capabilities
= 0;
377 /* remove all supplimentary groups */
379 (setgroups(0, &dummy
) == -1 ||
380 setgid(gp
->gr_gid
) == -1))
382 send_event(err_pipe
[1], EVENT_GROUP_ERR
, errno
);
386 if (ent_pw
&& ent_pw
->pw_uid
!= 0)
388 #if defined(HAVE_LINUX_NETWORK)
389 /* On linux, we keep CAP_NETADMIN (for ARP-injection) and
390 CAP_NET_RAW (for icmp) if we're doing dhcp */
391 data
->effective
= data
->permitted
= data
->inheritable
=
392 (1 << CAP_NET_ADMIN
) | (1 << CAP_NET_RAW
) | (1 << CAP_SETUID
);
394 /* Tell kernel to not clear capabilities when dropping root */
395 if (capset(hdr
, data
) == -1 || prctl(PR_SET_KEEPCAPS
, 1, 0, 0, 0) == -1)
396 bad_capabilities
= errno
;
398 #elif defined(HAVE_SOLARIS_NETWORK)
399 /* http://developers.sun.com/solaris/articles/program_privileges.html */
400 priv_set_t
*priv_set
;
402 if (!(priv_set
= priv_str_to_set("basic", ",", NULL
)) ||
403 priv_addset(priv_set
, PRIV_NET_ICMPACCESS
) == -1 ||
404 priv_addset(priv_set
, PRIV_SYS_NET_CONFIG
) == -1)
405 bad_capabilities
= errno
;
407 if (priv_set
&& bad_capabilities
== 0)
409 priv_inverse(priv_set
);
411 if (setppriv(PRIV_OFF
, PRIV_LIMIT
, priv_set
) == -1)
412 bad_capabilities
= errno
;
416 priv_freeset(priv_set
);
420 if (bad_capabilities
!= 0)
422 send_event(err_pipe
[1], EVENT_CAP_ERR
, bad_capabilities
);
426 /* finally drop root */
427 if (setuid(ent_pw
->pw_uid
) == -1)
429 send_event(err_pipe
[1], EVENT_USER_ERR
, errno
);
433 #ifdef HAVE_LINUX_NETWORK
434 data
->effective
= data
->permitted
=
435 (1 << CAP_NET_ADMIN
) | (1 << CAP_NET_RAW
);
436 data
->inheritable
= 0;
438 /* lose the setuid and setgid capbilities */
439 if (capset(hdr
, data
) == -1)
441 send_event(err_pipe
[1], EVENT_CAP_ERR
, errno
);
449 #ifdef HAVE_LINUX_NETWORK
450 if (daemon
->options
& OPT_DEBUG
)
451 prctl(PR_SET_DUMPABLE
, 1, 0, 0, 0);
454 if (daemon
->port
== 0)
455 my_syslog(LOG_INFO
, _("started, version %s DNS disabled"), VERSION
);
456 else if (daemon
->cachesize
!= 0)
457 my_syslog(LOG_INFO
, _("started, version %s cachesize %d"), VERSION
, daemon
->cachesize
);
459 my_syslog(LOG_INFO
, _("started, version %s cache disabled"), VERSION
);
461 my_syslog(LOG_INFO
, _("compile time options: %s"), compile_opts
);
464 if (daemon
->options
& OPT_DBUS
)
467 my_syslog(LOG_INFO
, _("DBus support enabled: connected to system bus"));
469 my_syslog(LOG_INFO
, _("DBus support enabled: bus connection pending"));
474 my_syslog(LOG_WARNING
, _("warning: failed to change owner of %s: %s"),
475 daemon
->log_file
, strerror(log_err
));
478 my_syslog(LOG_WARNING
, _("setting --bind-interfaces option because of OS limitations"));
480 if (!(daemon
->options
& OPT_NOWILD
))
481 for (if_tmp
= daemon
->if_names
; if_tmp
; if_tmp
= if_tmp
->next
)
482 if (if_tmp
->name
&& !if_tmp
->used
)
483 my_syslog(LOG_WARNING
, _("warning: interface %s does not currently exist"), if_tmp
->name
);
485 if (daemon
->port
!= 0 && (daemon
->options
& OPT_NO_RESOLV
))
487 if (daemon
->resolv_files
&& !daemon
->resolv_files
->is_default
)
488 my_syslog(LOG_WARNING
, _("warning: ignoring resolv-file flag because no-resolv is set"));
489 daemon
->resolv_files
= NULL
;
490 if (!daemon
->servers
)
491 my_syslog(LOG_WARNING
, _("warning: no upstream servers configured"));
494 if (daemon
->max_logs
!= 0)
495 my_syslog(LOG_INFO
, _("asynchronous logging enabled, queue limit is %d messages"), daemon
->max_logs
);
500 struct dhcp_context
*dhcp_tmp
;
502 for (dhcp_tmp
= daemon
->dhcp
; dhcp_tmp
; dhcp_tmp
= dhcp_tmp
->next
)
504 prettyprint_time(daemon
->dhcp_buff2
, dhcp_tmp
->lease_time
);
505 strcpy(daemon
->dhcp_buff
, inet_ntoa(dhcp_tmp
->start
));
506 my_syslog(MS_DHCP
| LOG_INFO
,
507 (dhcp_tmp
->flags
& CONTEXT_STATIC
) ?
508 _("DHCP, static leases only on %.0s%s, lease time %s") :
509 (dhcp_tmp
->flags
& CONTEXT_PROXY
) ?
510 _("DHCP, proxy on subnet %.0s%s%.0s") :
511 _("DHCP, IP range %s -- %s, lease time %s"),
512 daemon
->dhcp_buff
, inet_ntoa(dhcp_tmp
->end
), daemon
->dhcp_buff2
);
518 if (daemon
->tftp_unlimited
|| daemon
->tftp_interfaces
)
521 if (FD_SETSIZE
< (unsigned)max_fd
)
525 my_syslog(MS_TFTP
| LOG_INFO
, "TFTP %s%s %s",
526 daemon
->tftp_prefix
? _("root is ") : _("enabled"),
527 daemon
->tftp_prefix
? daemon
->tftp_prefix
: "",
528 daemon
->options
& OPT_TFTP_SECURE
? _("secure mode") : "");
530 /* This is a guess, it assumes that for small limits,
531 disjoint files might be served, but for large limits,
532 a single file will be sent to may clients (the file only needs
535 max_fd
-= 30; /* use other than TFTP */
539 else if (max_fd
< 100)
542 max_fd
= max_fd
- 20;
544 /* if we have to use a limited range of ports,
545 that will limit the number of transfers */
546 if (daemon
->start_tftp_port
!= 0 &&
547 daemon
->end_tftp_port
- daemon
->start_tftp_port
+ 1 < max_fd
)
548 max_fd
= daemon
->end_tftp_port
- daemon
->start_tftp_port
+ 1;
550 if (daemon
->tftp_max
> max_fd
)
552 daemon
->tftp_max
= max_fd
;
553 my_syslog(MS_TFTP
| LOG_WARNING
,
554 _("restricting maximum simultaneous TFTP transfers to %d"),
560 /* finished start-up - release original process */
561 if (err_pipe
[1] != -1)
564 if (daemon
->port
!= 0)
572 struct timeval t
, *tp
= NULL
;
573 fd_set rset
, wset
, eset
;
579 /* if we are out of resources, find how long we have to wait
580 for some to come free, we'll loop around then and restart
581 listening for queries */
582 if ((t
.tv_sec
= set_dns_listeners(now
, &rset
, &maxfd
)) != 0)
588 /* Whilst polling for the dbus, or doing a tftp transfer, wake every quarter second */
589 if (daemon
->tftp_trans
||
590 ((daemon
->options
& OPT_DBUS
) && !daemon
->dbus
))
598 set_dbus_listeners(&maxfd
, &rset
, &wset
, &eset
);
604 FD_SET(daemon
->dhcpfd
, &rset
);
605 bump_maxfd(daemon
->dhcpfd
, &maxfd
);
606 if (daemon
->pxefd
!= -1)
608 FD_SET(daemon
->pxefd
, &rset
);
609 bump_maxfd(daemon
->pxefd
, &maxfd
);
614 #ifdef HAVE_LINUX_NETWORK
615 FD_SET(daemon
->netlinkfd
, &rset
);
616 bump_maxfd(daemon
->netlinkfd
, &maxfd
);
619 FD_SET(piperead
, &rset
);
620 bump_maxfd(piperead
, &maxfd
);
624 while (helper_buf_empty() && do_script_run(now
));
626 if (!helper_buf_empty())
628 FD_SET(daemon
->helperfd
, &wset
);
629 bump_maxfd(daemon
->helperfd
, &maxfd
);
632 /* need this for other side-effects */
633 while (do_script_run(now
));
637 /* must do this just before select(), when we know no
638 more calls to my_syslog() can occur */
639 set_log_writer(&wset
, &maxfd
);
641 if (select(maxfd
+1, &rset
, &wset
, &eset
, tp
) < 0)
643 /* otherwise undefined after error */
644 FD_ZERO(&rset
); FD_ZERO(&wset
); FD_ZERO(&eset
);
647 now
= dnsmasq_time();
649 check_log_writer(&wset
);
651 #ifdef HAVE_LINUX_NETWORK
652 if (FD_ISSET(daemon
->netlinkfd
, &rset
))
656 /* Check for changes to resolv files once per second max. */
657 /* Don't go silent for long periods if the clock goes backwards. */
658 if (daemon
->last_resolv
== 0 ||
659 difftime(now
, daemon
->last_resolv
) > 1.0 ||
660 difftime(now
, daemon
->last_resolv
) < -1.0)
662 /* poll_resolv doesn't need to reload first time through, since
663 that's queued anyway. */
665 poll_resolv(0, daemon
->last_resolv
!= 0, now
);
666 daemon
->last_resolv
= now
;
669 if (FD_ISSET(piperead
, &rset
))
670 async_event(piperead
, now
);
673 /* if we didn't create a DBus connection, retry now. */
674 if ((daemon
->options
& OPT_DBUS
) && !daemon
->dbus
)
677 if ((err
= dbus_init()))
678 my_syslog(LOG_WARNING
, _("DBus error: %s"), err
);
680 my_syslog(LOG_INFO
, _("connected to system DBus"));
682 check_dbus_listeners(&rset
, &wset
, &eset
);
685 check_dns_listeners(&rset
, now
);
688 check_tftp_listeners(&rset
, now
);
694 if (FD_ISSET(daemon
->dhcpfd
, &rset
))
696 if (daemon
->pxefd
!= -1 && FD_ISSET(daemon
->pxefd
, &rset
))
701 if (daemon
->helperfd
!= -1 && FD_ISSET(daemon
->helperfd
, &wset
))
709 static void sig_handler(int sig
)
713 /* ignore anything other than TERM during startup
714 and in helper proc. (helper ignore TERM too) */
718 else if (pid
!= getpid())
720 /* alarm is used to kill TCP children after a fixed time. */
727 int event
, errsave
= errno
;
730 event
= EVENT_RELOAD
;
731 else if (sig
== SIGCHLD
)
733 else if (sig
== SIGALRM
)
735 else if (sig
== SIGTERM
)
737 else if (sig
== SIGUSR1
)
739 else if (sig
== SIGUSR2
)
740 event
= EVENT_REOPEN
;
744 send_event(pipewrite
, event
, 0);
749 void send_event(int fd
, int event
, int data
)
751 struct event_desc ev
;
756 /* error pipe, debug mode. */
760 /* pipe is non-blocking and struct event_desc is smaller than
761 PIPE_BUF, so this either fails or writes everything */
762 while (write(fd
, &ev
, sizeof(ev
)) == -1 && errno
== EINTR
);
765 static void fatal_event(struct event_desc
*ev
)
775 die(_("cannot fork into background: %s"), NULL
, EC_MISC
);
778 die(_("failed to create helper: %s"), NULL
, EC_MISC
);
781 die(_("setting capabilities failed: %s"), NULL
, EC_MISC
);
784 case EVENT_HUSER_ERR
:
785 die(_("failed to change user-id to %s: %s"),
786 ev
->event
== EVENT_USER_ERR
? daemon
->username
: daemon
->scriptuser
,
789 case EVENT_GROUP_ERR
:
790 die(_("failed to change group-id to %s: %s"), daemon
->groupname
, EC_MISC
);
793 die(_("failed to open pidfile %s: %s"), daemon
->runfile
, EC_FILE
);
796 die(_("cannot open %s: %s"), daemon
->log_file
? daemon
->log_file
: "log", EC_FILE
);
800 static void async_event(int pipe
, time_t now
)
803 struct event_desc ev
;
806 if (read_write(pipe
, (unsigned char *)&ev
, sizeof(ev
), 1))
810 clear_cache_and_reload(now
);
811 if (daemon
->port
!= 0 && daemon
->resolv_files
&& (daemon
->options
& OPT_NO_POLL
))
813 reload_servers(daemon
->resolv_files
->name
);
822 if (daemon
->port
!= 0)
830 lease_prune(NULL
, now
);
831 lease_update_file(now
);
837 /* See Stevens 5.10 */
838 while ((p
= waitpid(-1, NULL
, WNOHANG
)) != 0)
845 for (i
= 0 ; i
< MAX_PROCS
; i
++)
846 if (daemon
->tcp_pids
[i
] == p
)
847 daemon
->tcp_pids
[i
] = 0;
851 my_syslog(LOG_WARNING
, _("child process killed by signal %d"), ev
.data
);
855 my_syslog(LOG_WARNING
, _("child process exited with status %d"), ev
.data
);
859 my_syslog(LOG_ERR
, _("failed to execute %s: %s"),
860 daemon
->lease_change_command
, strerror(ev
.data
));
863 /* necessary for fatal errors in helper */
864 case EVENT_HUSER_ERR
:
870 tomato_helper(now
); // zzz
872 /* Note: this may leave TCP-handling processes with the old file still open.
873 Since any such process will die in CHILD_LIFETIME or probably much sooner,
874 we leave them logging to the old file. */
875 if (daemon
->log_file
!= NULL
)
876 log_reopen(daemon
->log_file
);
880 /* Knock all our children on the head. */
881 for (i
= 0; i
< MAX_PROCS
; i
++)
882 if (daemon
->tcp_pids
[i
] != 0)
883 kill(daemon
->tcp_pids
[i
], SIGALRM
);
885 #if defined(HAVE_DHCP) && defined(HAVE_SCRIPT)
886 /* handle pending lease transitions */
887 if (daemon
->helperfd
!= -1)
889 /* block in writes until all done */
890 if ((i
= fcntl(daemon
->helperfd
, F_GETFL
)) != -1)
891 fcntl(daemon
->helperfd
, F_SETFL
, i
& ~O_NONBLOCK
);
894 } while (!helper_buf_empty() || do_script_run(now
));
895 close(daemon
->helperfd
);
899 flush_lease_file(now
); // zzz
901 if (daemon
->lease_stream
)
902 fclose(daemon
->lease_stream
);
905 unlink(daemon
->runfile
);
907 my_syslog(LOG_INFO
, _("exiting on receipt of SIGTERM"));
913 void poll_resolv(int force
, int do_reload
, time_t now
)
915 struct resolvc
*res
, *latest
;
917 time_t last_change
= 0;
918 /* There may be more than one possible file.
919 Go through and find the one which changed _last_.
920 Warn of any which can't be read. */
922 if (daemon
->port
== 0 || (daemon
->options
& OPT_NO_POLL
))
925 for (latest
= NULL
, res
= daemon
->resolv_files
; res
; res
= res
->next
)
926 if (stat(res
->name
, &statbuf
) == -1)
935 my_syslog(LOG_WARNING
, _("failed to access %s: %s"), res
->name
, strerror(errno
));
940 /* existing file evaporated, force selection of the latest
941 file even if its mtime hasn't changed since we last looked */
942 poll_resolv(1, do_reload
, now
);
949 if (force
|| (statbuf
.st_mtime
!= res
->mtime
))
951 res
->mtime
= statbuf
.st_mtime
;
952 if (difftime(statbuf
.st_mtime
, last_change
) > 0.0)
954 last_change
= statbuf
.st_mtime
;
956 break; // zzz - (~0 time?)
963 static int warned
= 0;
964 if (reload_servers(latest
->name
))
966 my_syslog(LOG_INFO
, _("reading %s"), latest
->name
);
969 if ((daemon
->options
& OPT_RELOAD
) && do_reload
)
970 clear_cache_and_reload(now
);
977 my_syslog(LOG_WARNING
, _("no servers found in %s, will retry"), latest
->name
);
984 void clear_cache_and_reload(time_t now
)
986 if (daemon
->port
!= 0)
992 if (daemon
->options
& OPT_ETHERS
)
995 dhcp_update_configs(daemon
->dhcp_conf
);
997 lease_update_from_configs();
998 lease_update_file(now
);
1004 static int set_dns_listeners(time_t now
, fd_set
*set
, int *maxfdp
)
1006 struct serverfd
*serverfdp
;
1007 struct listener
*listener
;
1012 struct tftp_transfer
*transfer
;
1013 for (transfer
= daemon
->tftp_trans
; transfer
; transfer
= transfer
->next
)
1016 FD_SET(transfer
->sockfd
, set
);
1017 bump_maxfd(transfer
->sockfd
, maxfdp
);
1021 /* will we be able to get memory? */
1022 if (daemon
->port
!= 0)
1023 get_new_frec(now
, &wait
);
1025 for (serverfdp
= daemon
->sfds
; serverfdp
; serverfdp
= serverfdp
->next
)
1027 FD_SET(serverfdp
->fd
, set
);
1028 bump_maxfd(serverfdp
->fd
, maxfdp
);
1031 if (daemon
->port
!= 0 && !daemon
->osport
)
1032 for (i
= 0; i
< RANDOM_SOCKS
; i
++)
1033 if (daemon
->randomsocks
[i
].refcount
!= 0)
1035 FD_SET(daemon
->randomsocks
[i
].fd
, set
);
1036 bump_maxfd(daemon
->randomsocks
[i
].fd
, maxfdp
);
1039 for (listener
= daemon
->listeners
; listener
; listener
= listener
->next
)
1041 /* only listen for queries if we have resources */
1042 if (listener
->fd
!= -1 && wait
== 0)
1044 FD_SET(listener
->fd
, set
);
1045 bump_maxfd(listener
->fd
, maxfdp
);
1048 /* death of a child goes through the select loop, so
1049 we don't need to explicitly arrange to wake up here */
1050 if (listener
->tcpfd
!= -1)
1051 for (i
= 0; i
< MAX_PROCS
; i
++)
1052 if (daemon
->tcp_pids
[i
] == 0)
1054 FD_SET(listener
->tcpfd
, set
);
1055 bump_maxfd(listener
->tcpfd
, maxfdp
);
1060 if (tftp
<= daemon
->tftp_max
&& listener
->tftpfd
!= -1)
1062 FD_SET(listener
->tftpfd
, set
);
1063 bump_maxfd(listener
->tftpfd
, maxfdp
);
1072 static void check_dns_listeners(fd_set
*set
, time_t now
)
1074 struct serverfd
*serverfdp
;
1075 struct listener
*listener
;
1078 for (serverfdp
= daemon
->sfds
; serverfdp
; serverfdp
= serverfdp
->next
)
1079 if (FD_ISSET(serverfdp
->fd
, set
))
1080 reply_query(serverfdp
->fd
, serverfdp
->source_addr
.sa
.sa_family
, now
);
1082 if (daemon
->port
!= 0 && !daemon
->osport
)
1083 for (i
= 0; i
< RANDOM_SOCKS
; i
++)
1084 if (daemon
->randomsocks
[i
].refcount
!= 0 &&
1085 FD_ISSET(daemon
->randomsocks
[i
].fd
, set
))
1086 reply_query(daemon
->randomsocks
[i
].fd
, daemon
->randomsocks
[i
].family
, now
);
1088 for (listener
= daemon
->listeners
; listener
; listener
= listener
->next
)
1090 if (listener
->fd
!= -1 && FD_ISSET(listener
->fd
, set
))
1091 receive_query(listener
, now
);
1094 if (listener
->tftpfd
!= -1 && FD_ISSET(listener
->tftpfd
, set
))
1095 tftp_request(listener
, now
);
1098 if (listener
->tcpfd
!= -1 && FD_ISSET(listener
->tcpfd
, set
))
1101 struct irec
*iface
= NULL
;
1104 while((confd
= accept(listener
->tcpfd
, NULL
, NULL
)) == -1 && errno
== EINTR
);
1109 if (daemon
->options
& OPT_NOWILD
)
1110 iface
= listener
->iface
;
1113 union mysockaddr tcp_addr
;
1114 socklen_t tcp_len
= sizeof(union mysockaddr
);
1115 /* Check for allowed interfaces when binding the wildcard address:
1116 we do this by looking for an interface with the same address as
1117 the local address of the TCP connection, then looking to see if that's
1118 an allowed interface. As a side effect, we get the netmask of the
1119 interface too, for localisation. */
1121 /* interface may be new since startup */
1122 if (enumerate_interfaces() &&
1123 getsockname(confd
, (struct sockaddr
*)&tcp_addr
, &tcp_len
) != -1)
1124 for (iface
= daemon
->interfaces
; iface
; iface
= iface
->next
)
1125 if (sockaddr_isequal(&iface
->addr
, &tcp_addr
))
1131 shutdown(confd
, SHUT_RDWR
);
1135 else if (!(daemon
->options
& OPT_DEBUG
) && (p
= fork()) != 0)
1140 for (i
= 0; i
< MAX_PROCS
; i
++)
1141 if (daemon
->tcp_pids
[i
] == 0)
1143 daemon
->tcp_pids
[i
] = p
;
1152 unsigned char *buff
;
1155 struct in_addr dst_addr_4
;
1157 dst_addr_4
.s_addr
= 0;
1160 /* Arrange for SIGALARM after CHILD_LIFETIME seconds to
1161 terminate the process. */
1162 if (!(daemon
->options
& OPT_DEBUG
))
1163 alarm(CHILD_LIFETIME
);
1166 /* start with no upstream connections. */
1167 for (s
= daemon
->servers
; s
; s
= s
->next
)
1170 /* The connected socket inherits non-blocking
1171 attribute from the listening socket.
1173 if ((flags
= fcntl(confd
, F_GETFL
, 0)) != -1)
1174 fcntl(confd
, F_SETFL
, flags
& ~O_NONBLOCK
);
1176 if (listener
->family
== AF_INET
)
1177 dst_addr_4
= iface
->addr
.in
.sin_addr
;
1179 buff
= tcp_request(confd
, now
, dst_addr_4
, iface
->netmask
);
1181 shutdown(confd
, SHUT_RDWR
);
1187 for (s
= daemon
->servers
; s
; s
= s
->next
)
1190 shutdown(s
->tcpfd
, SHUT_RDWR
);
1194 if (!(daemon
->options
& OPT_DEBUG
))
1206 int make_icmp_sock(void)
1211 if ((fd
= socket (AF_INET
, SOCK_RAW
, IPPROTO_ICMP
)) != -1)
1214 setsockopt(fd
, SOL_SOCKET
, SO_DONTROUTE
, &zeroopt
, sizeof(zeroopt
)) == -1)
1224 int icmp_ping(struct in_addr addr
)
1226 /* Try and get an ICMP echo from a machine. */
1228 /* Note that whilst in the three second wait, we check for
1229 (and service) events on the DNS and TFTP sockets, (so doing that
1230 better not use any resources our caller has in use...)
1231 but we remain deaf to signals or further DHCP packets. */
1234 struct sockaddr_in saddr
;
1239 unsigned short id
= rand16();
1244 #if defined(HAVE_LINUX_NETWORK) || defined (HAVE_SOLARIS_NETWORK)
1245 if ((fd
= make_icmp_sock()) == -1)
1249 fd
= daemon
->dhcp_icmp_fd
;
1250 setsockopt(fd
, SOL_SOCKET
, SO_RCVBUF
, &opt
, sizeof(opt
));
1253 saddr
.sin_family
= AF_INET
;
1255 saddr
.sin_addr
= addr
;
1256 #ifdef HAVE_SOCKADDR_SA_LEN
1257 saddr
.sin_len
= sizeof(struct sockaddr_in
);
1260 memset(&packet
.icmp
, 0, sizeof(packet
.icmp
));
1261 packet
.icmp
.icmp_type
= ICMP_ECHO
;
1262 packet
.icmp
.icmp_id
= id
;
1263 for (j
= 0, i
= 0; i
< sizeof(struct icmp
) / 2; i
++)
1264 j
+= ((u16
*)&packet
.icmp
)[i
];
1266 j
= (j
& 0xffff) + (j
>> 16);
1267 packet
.icmp
.icmp_cksum
= (j
== 0xffff) ? j
: ~j
;
1269 while (sendto(fd
, (char *)&packet
.icmp
, sizeof(struct icmp
), 0,
1270 (struct sockaddr
*)&saddr
, sizeof(saddr
)) == -1 &&
1273 for (now
= start
= dnsmasq_time();
1274 difftime(now
, start
) < (float)PING_WAIT
;)
1278 struct sockaddr_in faddr
;
1280 socklen_t len
= sizeof(faddr
);
1282 tv
.tv_usec
= 250000;
1288 set_dns_listeners(now
, &rset
, &maxfd
);
1289 set_log_writer(&wset
, &maxfd
);
1291 if (select(maxfd
+1, &rset
, &wset
, NULL
, &tv
) < 0)
1297 now
= dnsmasq_time();
1299 check_log_writer(&wset
);
1300 check_dns_listeners(&rset
, now
);
1303 check_tftp_listeners(&rset
, now
);
1306 if (FD_ISSET(fd
, &rset
) &&
1307 recvfrom(fd
, &packet
, sizeof(packet
), 0,
1308 (struct sockaddr
*)&faddr
, &len
) == sizeof(packet
) &&
1309 saddr
.sin_addr
.s_addr
== faddr
.sin_addr
.s_addr
&&
1310 packet
.icmp
.icmp_type
== ICMP_ECHOREPLY
&&
1311 packet
.icmp
.icmp_seq
== 0 &&
1312 packet
.icmp
.icmp_id
== id
)
1319 #if defined(HAVE_LINUX_NETWORK) || defined(HAVE_SOLARIS_NETWORK)
1323 setsockopt(fd
, SOL_SOCKET
, SO_RCVBUF
, &opt
, sizeof(opt
));