1 /* dnsmasq is Copyright (c) 2000-2009 Simon Kelley
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
5    the Free Software Foundation; version 2 dated June, 1991, or
6    (at your option) version 3 dated 29 June, 2007.
7 
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.
12 
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/>.
15 */
16 
17 #define COPYRIGHT "Copyright (C) 2000-2009 Simon Kelley"
18 
19 #ifndef NO_LARGEFILE
20 /* Ensure we can use files >2GB (log files may grow this big) */
21 #  define _LARGEFILE_SOURCE 1
22 #  define _FILE_OFFSET_BITS 64
23 #endif
24 
25 /* Get linux C library versions. */
26 #ifdef __linux__
27 #  ifndef __ANDROID__
28 #      define _GNU_SOURCE
29 #  endif
30 #  include <features.h>
31 #endif
32 
33 /* get these before config.h  for IPv6 stuff... */
34 #include <sys/types.h>
35 #include <sys/socket.h>
36 #include <netinet/in.h>
37 
38 #ifdef __APPLE__
39 #  include <nameser.h>
40 #  include <arpa/nameser_compat.h>
41 #else
42 #  ifdef __ANDROID__
43 #    include "nameser.h"
44 #  else
45 #    include <arpa/nameser.h>
46 #  endif
47 #endif
48 
49 /* and this. */
50 #include <getopt.h>
51 
52 #include "config.h"
53 
54 #define gettext_noop(S) (S)
55 #ifndef LOCALEDIR
56 #  define _(S) (S)
57 #else
58 #  include <libintl.h>
59 #  include <locale.h>
60 #  define _(S) gettext(S)
61 #endif
62 
63 #include <arpa/inet.h>
64 #include <sys/stat.h>
65 #include <sys/ioctl.h>
66 #if defined(HAVE_SOLARIS_NETWORK)
67 #include <sys/sockio.h>
68 #endif
69 #include <sys/select.h>
70 #include <sys/wait.h>
71 #include <sys/time.h>
72 #include <sys/un.h>
73 #include <limits.h>
74 #include <net/if.h>
75 #include <unistd.h>
76 #include <stdio.h>
77 #include <string.h>
78 #include <stdlib.h>
79 #include <fcntl.h>
80 #include <ctype.h>
81 #include <signal.h>
82 #include <stddef.h>
83 #include <time.h>
84 #include <errno.h>
85 #include <pwd.h>
86 #include <grp.h>
87 #include <stdarg.h>
88 #if defined(__OpenBSD__) || defined(__NetBSD__) || defined(__sun__) || defined (__sun) || defined (__ANDROID__)
89 #  include <netinet/if_ether.h>
90 #else
91 #  include <net/ethernet.h>
92 #endif
93 #include <net/if_arp.h>
94 #include <netinet/in_systm.h>
95 #include <netinet/ip.h>
96 #include <netinet/ip_icmp.h>
97 #include <sys/uio.h>
98 #include <syslog.h>
99 #include <dirent.h>
100 #ifndef HAVE_LINUX_NETWORK
101 #  include <net/if_dl.h>
102 #endif
103 
104 #if defined(HAVE_LINUX_NETWORK)
105 #include <linux/capability.h>
106 /* There doesn't seem to be a universally-available
107    userpace header for these. */
108 extern int capset(cap_user_header_t header, cap_user_data_t data);
109 extern int capget(cap_user_header_t header, cap_user_data_t data);
110 #define LINUX_CAPABILITY_VERSION_1  0x19980330
111 #define LINUX_CAPABILITY_VERSION_2  0x20071026
112 #define LINUX_CAPABILITY_VERSION_3  0x20080522
113 
114 #include <sys/prctl.h>
115 #elif defined(HAVE_SOLARIS_NETWORK)
116 #include <priv.h>
117 #endif
118 
119 /* daemon is function in the C library.... */
120 #define daemon dnsmasq_daemon
121 
122 /* Async event queue */
123 struct event_desc {
124   int event, data;
125 };
126 
127 #define EVENT_RELOAD    1
128 #define EVENT_DUMP      2
129 #define EVENT_ALARM     3
130 #define EVENT_TERM      4
131 #define EVENT_CHILD     5
132 #define EVENT_REOPEN    6
133 #define EVENT_EXITED    7
134 #define EVENT_KILLED    8
135 #define EVENT_EXEC_ERR  9
136 #define EVENT_PIPE_ERR  10
137 #define EVENT_USER_ERR  11
138 #define EVENT_CAP_ERR   12
139 #define EVENT_PIDFILE   13
140 #define EVENT_HUSER_ERR 14
141 #define EVENT_GROUP_ERR 15
142 #define EVENT_DIE       16
143 #define EVENT_LOG_ERR   17
144 #define EVENT_FORK_ERR  18
145 
146 /* Exit codes. */
147 #define EC_GOOD        0
148 #define EC_BADCONF     1
149 #define EC_BADNET      2
150 #define EC_FILE        3
151 #define EC_NOMEM       4
152 #define EC_MISC        5
153 #define EC_INIT_OFFSET 10
154 
155 /* Min buffer size: we check after adding each record, so there must be
156    memory for the largest packet, and the largest record so the
157    min for DNS is PACKETSZ+MAXDNAME+RRFIXEDSZ which is < 1000.
158    This might be increased is EDNS packet size if greater than the minimum.
159 */
160 #define DNSMASQ_PACKETSZ PACKETSZ+MAXDNAME+RRFIXEDSZ
161 
162 #define OPT_BOGUSPRIV      (1u<<0)
163 #define OPT_FILTER         (1u<<1)
164 #define OPT_LOG            (1u<<2)
165 #define OPT_SELFMX         (1u<<3)
166 #define OPT_NO_HOSTS       (1u<<4)
167 #define OPT_NO_POLL        (1u<<5)
168 #define OPT_DEBUG          (1u<<6)
169 #define OPT_ORDER          (1u<<7)
170 #define OPT_NO_RESOLV      (1u<<8)
171 #define OPT_EXPAND         (1u<<9)
172 #define OPT_LOCALMX        (1u<<10)
173 #define OPT_NO_NEG         (1u<<11)
174 #define OPT_NODOTS_LOCAL   (1u<<12)
175 #define OPT_NOWILD         (1u<<13)
176 #define OPT_ETHERS         (1u<<14)
177 #define OPT_RESOLV_DOMAIN  (1u<<15)
178 #define OPT_NO_FORK        (1u<<16)
179 #define OPT_AUTHORITATIVE  (1u<<17)
180 #define OPT_LOCALISE       (1u<<18)
181 #define OPT_DBUS           (1u<<19)
182 #define OPT_DHCP_FQDN      (1u<<20)
183 #define OPT_NO_PING        (1u<<21)
184 #define OPT_LEASE_RO       (1u<<22)
185 #define OPT_ALL_SERVERS    (1u<<23)
186 #define OPT_RELOAD         (1u<<24)
187 #define OPT_TFTP           (1u<<25)
188 #define OPT_TFTP_SECURE    (1u<<26)
189 #define OPT_TFTP_NOBLOCK   (1u<<27)
190 #define OPT_LOG_OPTS       (1u<<28)
191 #define OPT_TFTP_APREF     (1u<<29)
192 #define OPT_NO_OVERRIDE    (1u<<30)
193 #define OPT_NO_REBIND      (1u<<31)
194 
195 /* extra flags for my_syslog, we use a couple of facilities since they are known
196    not to occupy the same bits as priorities, no matter how syslog.h is set up. */
197 #define MS_TFTP LOG_USER
198 #define MS_DHCP LOG_DAEMON
199 
200 struct all_addr {
201   union {
202     struct in_addr addr4;
203 #ifdef HAVE_IPV6
204     struct in6_addr addr6;
205 #endif
206   } addr;
207 };
208 
209 struct bogus_addr {
210   struct in_addr addr;
211   struct bogus_addr *next;
212 };
213 
214 /* dns doctor param */
215 struct doctor {
216   struct in_addr in, end, out, mask;
217   struct doctor *next;
218 };
219 
220 struct mx_srv_record {
221   char *name, *target;
222   int issrv, srvport, priority, weight;
223   unsigned int offset;
224   struct mx_srv_record *next;
225 };
226 
227 struct naptr {
228   char *name, *replace, *regexp, *services, *flags;
229   unsigned int order, pref;
230   struct naptr *next;
231 };
232 
233 struct txt_record {
234   char *name, *txt;
235   unsigned short class, len;
236   struct txt_record *next;
237 };
238 
239 struct ptr_record {
240   char *name, *ptr;
241   struct ptr_record *next;
242 };
243 
244 struct cname {
245   char *alias, *target;
246   struct cname *next;
247 };
248 
249 struct interface_name {
250   char *name; /* domain name */
251   char *intr; /* interface name */
252   struct interface_name *next;
253 };
254 
255 union bigname {
256   char name[MAXDNAME];
257   union bigname *next; /* freelist */
258 };
259 
260 struct crec {
261   struct crec *next, *prev, *hash_next;
262   time_t ttd; /* time to die */
263   int uid;
264   union {
265     struct all_addr addr;
266     struct {
267       struct crec *cache;
268       int uid;
269     } cname;
270   } addr;
271   unsigned short flags;
272   union {
273     char sname[SMALLDNAME];
274     union bigname *bname;
275     char *namep;
276   } name;
277 };
278 
279 #define F_IMMORTAL  1
280 #define F_CONFIG    2
281 #define F_REVERSE   4
282 #define F_FORWARD   8
283 #define F_DHCP      16
284 #define F_NEG       32
285 #define F_HOSTS     64
286 #define F_IPV4      128
287 #define F_IPV6      256
288 #define F_BIGNAME   512
289 #define F_UPSTREAM  1024
290 #define F_SERVER    2048
291 #define F_NXDOMAIN  4096
292 #define F_QUERY     8192
293 #define F_CNAME     16384
294 #define F_NOERR     32768
295 
296 /* struct sockaddr is not large enough to hold any address,
297    and specifically not big enough to hold an IPv6 address.
298    Blech. Roll our own. */
299 union mysockaddr {
300   struct sockaddr sa;
301   struct sockaddr_in in;
302 #if defined(HAVE_IPV6)
303   struct sockaddr_in6 in6;
304 #endif
305 };
306 
307 #define SERV_FROM_RESOLV       1  /* 1 for servers from resolv, 0 for command line. */
308 #define SERV_NO_ADDR           2  /* no server, this domain is local only */
309 #define SERV_LITERAL_ADDRESS   4  /* addr is the answer, not the server */
310 #define SERV_HAS_DOMAIN        8  /* server for one domain only */
311 #define SERV_HAS_SOURCE       16  /* source address defined */
312 #define SERV_FOR_NODOTS       32  /* server for names with no domain part only */
313 #define SERV_WARNED_RECURSIVE 64  /* avoid warning spam */
314 #define SERV_FROM_DBUS       128  /* 1 if source is DBus */
315 #define SERV_MARK            256  /* for mark-and-delete */
316 #define SERV_TYPE    (SERV_HAS_DOMAIN | SERV_FOR_NODOTS)
317 #define SERV_COUNTED         512  /* workspace for log code */
318 
319 struct serverfd {
320   int fd;
321   union mysockaddr source_addr;
322   char interface[IF_NAMESIZE+1];
323   struct serverfd *next;
324   uint32_t mark;
325 };
326 
327 struct randfd {
328   int fd;
329   unsigned short refcount, family;
330 };
331 
332 struct server {
333   union mysockaddr addr, source_addr;
334   char interface[IF_NAMESIZE+1];
335   struct serverfd *sfd;
336   char *domain; /* set if this server only handles a domain. */
337   int flags, tcpfd;
338   unsigned int queries, failed_queries;
339   uint32_t mark;
340   struct server *next;
341 };
342 
343 struct irec {
344   union mysockaddr addr;
345   struct in_addr netmask; /* only valid for IPv4 */
346   int dhcp_ok, mtu;
347   struct irec *next;
348 };
349 
350 struct listener {
351   int fd, tcpfd, tftpfd, family;
352   struct irec *iface; /* only valid for non-wildcard */
353   struct listener *next;
354 };
355 
356 /* interface and address parms from command line. */
357 struct iname {
358   char *name;
359   union mysockaddr addr;
360   int isloop, used;
361   struct iname *next;
362 };
363 
364 /* resolv-file parms from command-line */
365 struct resolvc {
366   struct resolvc *next;
367   int is_default, logged;
368   time_t mtime;
369   char *name;
370 };
371 
372 /* adn-hosts parms from command-line */
373 #define AH_DIR      1
374 #define AH_INACTIVE 2
375 struct hostsfile {
376   struct hostsfile *next;
377   int flags;
378   char *fname;
379   int index; /* matches to cache entries for logging */
380 };
381 
382 struct frec {
383   union mysockaddr source;
384   struct all_addr dest;
385   struct server *sentto; /* NULL means free */
386   struct randfd *rfd4;
387 #ifdef HAVE_IPV6
388   struct randfd *rfd6;
389 #endif
390   unsigned int iface;
391   unsigned short orig_id, new_id;
392   int fd, forwardall;
393   unsigned int crc;
394   time_t time;
395   struct frec *next;
396 };
397 
398 /* actions in the daemon->helper RPC */
399 #define ACTION_DEL           1
400 #define ACTION_OLD_HOSTNAME  2
401 #define ACTION_OLD           3
402 #define ACTION_ADD           4
403 
404 #define DHCP_CHADDR_MAX 16
405 
406 struct dhcp_lease {
407   int clid_len;          /* length of client identifier */
408   unsigned char *clid;   /* clientid */
409   char *hostname, *fqdn; /* name from client-hostname option or config */
410   char *old_hostname;    /* hostname before it moved to another lease */
411   char auth_name;        /* hostname came from config, not from client */
412   char new;              /* newly created */
413   char changed;          /* modified */
414   char aux_changed;      /* CLID or expiry changed */
415   time_t expires;        /* lease expiry */
416 #ifdef HAVE_BROKEN_RTC
417   unsigned int length;
418 #endif
419   int hwaddr_len, hwaddr_type;
420   unsigned char hwaddr[DHCP_CHADDR_MAX];
421   struct in_addr addr, override, giaddr;
422   unsigned char *vendorclass, *userclass, *supplied_hostname;
423   unsigned int vendorclass_len, userclass_len, supplied_hostname_len;
424   int last_interface;
425   struct dhcp_lease *next;
426 };
427 
428 struct dhcp_netid {
429   char *net;
430   struct dhcp_netid *next;
431 };
432 
433 struct dhcp_netid_list {
434   struct dhcp_netid *list;
435   struct dhcp_netid_list *next;
436 };
437 
438 struct hwaddr_config {
439   int hwaddr_len, hwaddr_type;
440   unsigned char hwaddr[DHCP_CHADDR_MAX];
441   unsigned int wildcard_mask;
442   struct hwaddr_config *next;
443 };
444 
445 struct dhcp_config {
446   unsigned int flags;
447   int clid_len;          /* length of client identifier */
448   unsigned char *clid;   /* clientid */
449   char *hostname, *domain;
450   struct dhcp_netid netid;
451   struct in_addr addr;
452   time_t decline_time;
453   unsigned int lease_time;
454   struct hwaddr_config *hwaddr;
455   struct dhcp_config *next;
456 };
457 
458 #define CONFIG_DISABLE           1
459 #define CONFIG_CLID              2
460 #define CONFIG_TIME              8
461 #define CONFIG_NAME             16
462 #define CONFIG_ADDR             32
463 #define CONFIG_NETID            64
464 #define CONFIG_NOCLID          128
465 #define CONFIG_FROM_ETHERS     256    /* entry created by /etc/ethers */
466 #define CONFIG_ADDR_HOSTS      512    /* address added by from /etc/hosts */
467 #define CONFIG_DECLINED       1024    /* address declined by client */
468 #define CONFIG_BANK           2048    /* from dhcp hosts file */
469 
470 struct dhcp_opt {
471   int opt, len, flags;
472   union {
473     int encap;
474     unsigned int wildcard_mask;
475     unsigned char *vendor_class;
476   } u;
477   unsigned char *val;
478   struct dhcp_netid *netid;
479   struct dhcp_opt *next;
480 };
481 
482 #define DHOPT_ADDR               1
483 #define DHOPT_STRING             2
484 #define DHOPT_ENCAPSULATE        4
485 #define DHOPT_ENCAP_MATCH        8
486 #define DHOPT_FORCE             16
487 #define DHOPT_BANK              32
488 #define DHOPT_ENCAP_DONE        64
489 #define DHOPT_MATCH            128
490 #define DHOPT_VENDOR           256
491 #define DHOPT_HEX              512
492 #define DHOPT_VENDOR_MATCH    1024
493 
494 struct dhcp_boot {
495   char *file, *sname;
496   struct in_addr next_server;
497   struct dhcp_netid *netid;
498   struct dhcp_boot *next;
499 };
500 
501 struct pxe_service {
502   unsigned short CSA, type;
503   char *menu, *basename;
504   struct in_addr server;
505   struct dhcp_netid *netid;
506   struct pxe_service *next;
507 };
508 
509 #define MATCH_VENDOR     1
510 #define MATCH_USER       2
511 #define MATCH_CIRCUIT    3
512 #define MATCH_REMOTE     4
513 #define MATCH_SUBSCRIBER 5
514 
515 /* vendorclass, userclass, remote-id or cicuit-id */
516 struct dhcp_vendor {
517   int len, match_type, option;
518   char *data;
519   struct dhcp_netid netid;
520   struct dhcp_vendor *next;
521 };
522 
523 struct dhcp_mac {
524   unsigned int mask;
525   int hwaddr_len, hwaddr_type;
526   unsigned char hwaddr[DHCP_CHADDR_MAX];
527   struct dhcp_netid netid;
528   struct dhcp_mac *next;
529 };
530 
531 struct dhcp_bridge {
532   char iface[IF_NAMESIZE];
533   struct dhcp_bridge *alias, *next;
534 };
535 
536 struct cond_domain {
537   char *domain;
538   struct in_addr start, end;
539   struct cond_domain *next;
540 };
541 
542 struct dhcp_context {
543   unsigned int lease_time, addr_epoch;
544   struct in_addr netmask, broadcast;
545   struct in_addr local, router;
546   struct in_addr start, end; /* range of available addresses */
547   int flags;
548   struct dhcp_netid netid, *filter;
549   struct dhcp_context *next, *current;
550 };
551 
552 #define CONTEXT_STATIC    1
553 #define CONTEXT_NETMASK   2
554 #define CONTEXT_BRDCAST   4
555 #define CONTEXT_PROXY     8
556 
557 
558 typedef unsigned char u8;
559 typedef unsigned short u16;
560 typedef unsigned int u32;
561 
562 
563 struct dhcp_packet {
564   u8 op, htype, hlen, hops;
565   u32 xid;
566   u16 secs, flags;
567   struct in_addr ciaddr, yiaddr, siaddr, giaddr;
568   u8 chaddr[DHCP_CHADDR_MAX], sname[64], file[128];
569   u8 options[312];
570 };
571 
572 struct ping_result {
573   struct in_addr addr;
574   time_t time;
575   struct ping_result *next;
576 };
577 
578 struct tftp_file {
579   int refcount, fd;
580   off_t size;
581   dev_t dev;
582   ino_t inode;
583   char filename[];
584 };
585 
586 struct tftp_transfer {
587   int sockfd;
588   time_t timeout;
589   int backoff;
590   unsigned int block, blocksize, expansion;
591   off_t offset;
592   struct sockaddr_in peer;
593   char opt_blocksize, opt_transize, netascii, carrylf;
594   struct tftp_file *file;
595   struct tftp_transfer *next;
596 };
597 
598 extern struct daemon {
599   /* datastuctures representing the command-line and
600      config file arguments. All set (including defaults)
601      in option.c */
602 
603   unsigned int options;
604   struct resolvc default_resolv, *resolv_files;
605   time_t last_resolv;
606   struct mx_srv_record *mxnames;
607   struct naptr *naptr;
608   struct txt_record *txt;
609   struct ptr_record *ptr;
610   struct cname *cnames;
611   struct interface_name *int_names;
612   char *mxtarget;
613   char *lease_file;
614   char *username, *groupname, *scriptuser;
615   int group_set, osport;
616   char *domain_suffix;
617   struct cond_domain *cond_domain;
618   char *runfile;
619   char *lease_change_command;
620   struct iname *if_names, *if_addrs, *if_except, *dhcp_except;
621   struct bogus_addr *bogus_addr;
622   struct server *servers;
623   int log_fac; /* log facility */
624   char *log_file; /* optional log file */
625   int max_logs;  /* queue limit */
626   int cachesize, ftabsize;
627   int port, query_port, min_port;
628   unsigned long local_ttl, neg_ttl;
629   struct hostsfile *addn_hosts;
630   struct dhcp_context *dhcp;
631   struct dhcp_config *dhcp_conf;
632   struct dhcp_opt *dhcp_opts, *dhcp_match;
633   struct dhcp_vendor *dhcp_vendors;
634   struct dhcp_mac *dhcp_macs;
635   struct dhcp_boot *boot_config;
636   struct pxe_service *pxe_services;
637   int enable_pxe;
638   struct dhcp_netid_list *dhcp_ignore, *dhcp_ignore_names, *force_broadcast, *bootp_dynamic;
639   char *dhcp_hosts_file, *dhcp_opts_file;
640   int dhcp_max, tftp_max;
641   int dhcp_server_port, dhcp_client_port;
642   int start_tftp_port, end_tftp_port;
643   unsigned int min_leasetime;
644   struct doctor *doctors;
645   unsigned short edns_pktsz;
646   char *tftp_prefix;
647 
648   /* globally used stuff for DNS */
649   char *packet; /* packet buffer */
650   int packet_buff_sz; /* size of above */
651   char *namebuff; /* MAXDNAME size buffer */
652   unsigned int local_answer, queries_forwarded;
653   struct frec *frec_list;
654   struct serverfd *sfds;
655   struct irec *interfaces;
656   struct listener *listeners;
657   struct server *last_server;
658   time_t forwardtime;
659   int forwardcount;
660   struct server *srv_save; /* Used for resend on DoD */
661   size_t packet_len;       /*      "        "        */
662   struct randfd *rfd_save; /*      "        "        */
663   pid_t tcp_pids[MAX_PROCS];
664   struct randfd randomsocks[RANDOM_SOCKS];
665 
666   /* DHCP state */
667   int dhcpfd, helperfd;
668 #if defined(HAVE_LINUX_NETWORK)
669   int netlinkfd;
670 #elif defined(HAVE_BSD_NETWORK)
671   int dhcp_raw_fd, dhcp_icmp_fd;
672 #endif
673   struct iovec dhcp_packet;
674   char *dhcp_buff, *dhcp_buff2;
675   struct ping_result *ping_results;
676   FILE *lease_stream;
677   struct dhcp_bridge *bridges;
678 
679   /* DBus stuff */
680   /* void * here to avoid depending on dbus headers outside dbus.c */
681   void *dbus;
682 #ifdef HAVE_DBUS
683   struct watch *watches;
684 #endif
685 
686   /* TFTP stuff */
687   struct tftp_transfer *tftp_trans;
688 
689 } *daemon;
690 
691 /* cache.c */
692 void cache_init(void);
693 void log_query(unsigned short flags, char *name, struct all_addr *addr, char *arg);
694 char *record_source(int index);
695 void querystr(char *str, unsigned short type);
696 struct crec *cache_find_by_addr(struct crec *crecp,
697 				struct all_addr *addr, time_t now,
698 				unsigned short prot);
699 struct crec *cache_find_by_name(struct crec *crecp,
700 				char *name, time_t now, unsigned short  prot);
701 void cache_end_insert(void);
702 void cache_start_insert(void);
703 struct crec *cache_insert(char *name, struct all_addr *addr,
704 			  time_t now, unsigned long ttl, unsigned short flags);
705 void cache_reload(void);
706 void cache_add_dhcp_entry(char *host_name, struct in_addr *host_address, time_t ttd);
707 void cache_unhash_dhcp(void);
708 void dump_cache(time_t now);
709 char *cache_get_name(struct crec *crecp);
710 char *get_domain(struct in_addr addr);
711 
712 /* rfc1035.c */
713 unsigned short extract_request(HEADER *header, size_t qlen,
714 			       char *name, unsigned short *typep);
715 size_t setup_reply(HEADER *header, size_t  qlen,
716 		   struct all_addr *addrp, unsigned short flags,
717 		   unsigned long local_ttl);
718 int extract_addresses(HEADER *header, size_t qlen, char *namebuff, time_t now);
719 size_t answer_request(HEADER *header, char *limit, size_t qlen,
720 		   struct in_addr local_addr, struct in_addr local_netmask, time_t now);
721 int check_for_bogus_wildcard(HEADER *header, size_t qlen, char *name,
722 			     struct bogus_addr *addr, time_t now);
723 unsigned char *find_pseudoheader(HEADER *header, size_t plen,
724 				 size_t *len, unsigned char **p, int *is_sign);
725 int check_for_local_domain(char *name, time_t now);
726 unsigned int questions_crc(HEADER *header, size_t plen, char *buff);
727 size_t resize_packet(HEADER *header, size_t plen,
728 		  unsigned char *pheader, size_t hlen);
729 
730 /* util.c */
731 void rand_init(void);
732 unsigned short rand16(void);
733 int legal_hostname(char *c);
734 char *canonicalise(char *s, int *nomem);
735 unsigned char *do_rfc1035_name(unsigned char *p, char *sval);
736 void *safe_malloc(size_t size);
737 void safe_pipe(int *fd, int read_noblock);
738 void *whine_malloc(size_t size);
739 int sa_len(union mysockaddr *addr);
740 int sockaddr_isequal(union mysockaddr *s1, union mysockaddr *s2);
741 int hostname_isequal(char *a, char *b);
742 time_t dnsmasq_time(void);
743 int is_same_net(struct in_addr a, struct in_addr b, struct in_addr mask);
744 int retry_send(void);
745 int parse_addr(int family, const char *addrstr, union mysockaddr *addr);
746 void prettyprint_time(char *buf, unsigned int t);
747 int prettyprint_addr(const union mysockaddr *addr, char *buf);
748 int parse_hex(char *in, unsigned char *out, int maxlen,
749 	      unsigned int *wildcard_mask, int *mac_type);
750 int memcmp_masked(unsigned char *a, unsigned char *b, int len,
751 		  unsigned int mask);
752 int expand_buf(struct iovec *iov, size_t size);
753 char *print_mac(char *buff, unsigned char *mac, int len);
754 void bump_maxfd(int fd, int *max);
755 int read_write(int fd, unsigned char *packet, int size, int rw);
756 
757 /* log.c */
758 void die(char *message, char *arg1, int exit_code);
759 int log_start(struct passwd *ent_pw, int errfd);
760 int log_reopen(char *log_file);
761 void my_syslog(int priority, const char *format, ...);
762 void set_log_writer(fd_set *set, int *maxfdp);
763 void check_log_writer(fd_set *set);
764 void flush_log(void);
765 
766 /* option.c */
767 void read_opts (int argc, char **argv, char *compile_opts);
768 char *option_string(unsigned char opt, int *is_ip, int *is_name);
769 void reread_dhcp(void);
770 
771 /* forward.c */
772 void reply_query(int fd, int family, time_t now);
773 void receive_query(struct listener *listen, time_t now);
774 unsigned char *tcp_request(int confd, time_t now,
775 			   struct in_addr local_addr, struct in_addr netmask);
776 void server_gone(struct server *server);
777 struct frec *get_new_frec(time_t now, int *wait);
778 
779 /* network.c */
780 int indextoname(int fd, int index, char *name);
781 int local_bind(int fd, union mysockaddr *addr, char *intname, uint32_t mark, int is_tcp);
782 int random_sock(int family);
783 void pre_allocate_sfds(void);
784 int reload_servers(char *fname);
785 #if defined(__ANDROID__) && !defined(__BRILLO__)
786 int set_servers(const char *servers);
787 void set_interfaces(const char *interfaces);
788 #endif
789 void check_servers(void);
790 int enumerate_interfaces();
791 struct listener *create_wildcard_listeners(void);
792 struct listener *create_bound_listeners(void);
793 int iface_check(int family, struct all_addr *addr, char *name, int *indexp);
794 int fix_fd(int fd);
795 struct in_addr get_ifaddr(char *intr);
796 
797 /* dhcp.c */
798 #ifdef HAVE_DHCP
799 void dhcp_init(void);
800 void dhcp_packet(time_t now);
801 struct dhcp_context *address_available(struct dhcp_context *context,
802 				       struct in_addr addr,
803 				       struct dhcp_netid *netids);
804 struct dhcp_context *narrow_context(struct dhcp_context *context,
805 				    struct in_addr taddr,
806 				    struct dhcp_netid *netids);
807 int match_netid(struct dhcp_netid *check, struct dhcp_netid *pool, int negonly);int address_allocate(struct dhcp_context *context,
808 		     struct in_addr *addrp, unsigned char *hwaddr, int hw_len,
809 		     struct dhcp_netid *netids, time_t now);
810 int config_has_mac(struct dhcp_config *config, unsigned char *hwaddr, int len, int type);
811 struct dhcp_config *find_config(struct dhcp_config *configs,
812 				struct dhcp_context *context,
813 				unsigned char *clid, int clid_len,
814 				unsigned char *hwaddr, int hw_len,
815 				int hw_type, char *hostname);
816 void dhcp_update_configs(struct dhcp_config *configs);
817 void dhcp_read_ethers(void);
818 void check_dhcp_hosts(int fatal);
819 struct dhcp_config *config_find_by_address(struct dhcp_config *configs, struct in_addr addr);
820 char *strip_hostname(char *hostname);
821 char *host_from_dns(struct in_addr addr);
822 char *get_domain(struct in_addr addr);
823 #endif
824 
825 /* lease.c */
826 #ifdef HAVE_DHCP
827 void lease_update_file(time_t now);
828 void lease_update_dns();
829 void lease_init(time_t now);
830 struct dhcp_lease *lease_allocate(struct in_addr addr);
831 void lease_set_hwaddr(struct dhcp_lease *lease, unsigned char *hwaddr,
832 		      unsigned char *clid, int hw_len, int hw_type, int clid_len);
833 void lease_set_hostname(struct dhcp_lease *lease, char *name, int auth);
834 void lease_set_expires(struct dhcp_lease *lease, unsigned int len, time_t now);
835 void lease_set_interface(struct dhcp_lease *lease, int interface);
836 struct dhcp_lease *lease_find_by_client(unsigned char *hwaddr, int hw_len, int hw_type,
837 					unsigned char *clid, int clid_len);
838 struct dhcp_lease *lease_find_by_addr(struct in_addr addr);
839 void lease_prune(struct dhcp_lease *target, time_t now);
840 void lease_update_from_configs(void);
841 int do_script_run(time_t now);
842 void rerun_scripts(void);
843 #endif
844 
845 /* rfc2131.c */
846 #ifdef HAVE_DHCP
847 size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
848 		  size_t sz, time_t now, int unicast_dest, int *is_inform);
849 unsigned char *extended_hwaddr(int hwtype, int hwlen, unsigned char *hwaddr,
850 			       int clid_len, unsigned char *clid, int *len_out);
851 #endif
852 
853 /* dnsmasq.c */
854 #ifdef HAVE_DHCP
855 int make_icmp_sock(void);
856 int icmp_ping(struct in_addr addr);
857 #endif
858 void send_event(int fd, int event, int data);
859 void clear_cache_and_reload(time_t now);
860 
861 /* netlink.c */
862 #ifdef HAVE_LINUX_NETWORK
863 void netlink_init(void);
864 void netlink_multicast(void);
865 #endif
866 
867 /* bpf.c */
868 #ifdef HAVE_BSD_NETWORK
869 void init_bpf(void);
870 void send_via_bpf(struct dhcp_packet *mess, size_t len,
871 		  struct in_addr iface_addr, struct ifreq *ifr);
872 #endif
873 
874 /* bpf.c or netlink.c */
875 int iface_enumerate(void *parm, int (*ipv4_callback)(), int (*ipv6_callback)());
876 
877 /* dbus.c */
878 #ifdef HAVE_DBUS
879 char *dbus_init(void);
880 void check_dbus_listeners(fd_set *rset, fd_set *wset, fd_set *eset);
881 void set_dbus_listeners(int *maxfdp, fd_set *rset, fd_set *wset, fd_set *eset);
882 void emit_dbus_signal(int action, struct dhcp_lease *lease, char *hostname);
883 #endif
884 
885 /* helper.c */
886 #if defined(HAVE_DHCP) && !defined(NO_FORK)
887 int create_helper(int event_fd, int err_fd, uid_t uid, gid_t gid, long max_fd);
888 void helper_write(void);
889 void queue_script(int action, struct dhcp_lease *lease,
890 		  char *hostname, time_t now);
891 int helper_buf_empty(void);
892 #endif
893 
894 /* tftp.c */
895 #ifdef HAVE_TFTP
896 void tftp_request(struct listener *listen, time_t now);
897 void check_tftp_listeners(fd_set *rset, time_t now);
898 #endif
899