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c47e3ba4 | 1 | /* dnsmasq is Copyright (c) 2000-2014 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 | ||
9e4abcb5 SK |
17 | #include "dnsmasq.h" |
18 | ||
8a9be9e4 | 19 | static struct frec *lookup_frec(unsigned short id, void *hash); |
9e4abcb5 | 20 | static struct frec *lookup_frec_by_sender(unsigned short id, |
fd9fa481 | 21 | union mysockaddr *addr, |
8a9be9e4 SK |
22 | void *hash); |
23 | static unsigned short get_id(void); | |
1a6bca81 SK |
24 | static void free_frec(struct frec *f); |
25 | static struct randfd *allocate_rfd(int family); | |
9e4abcb5 | 26 | |
00a5b5d4 SK |
27 | #ifdef HAVE_DNSSEC |
28 | static int tcp_key_recurse(time_t now, int status, struct dns_header *header, size_t n, | |
29 | int class, char *name, char *keyname, struct server *server, int *keycount); | |
30 | static int do_check_sign(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class); | |
31 | static int send_check_sign(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname); | |
32 | #endif | |
33 | ||
34 | ||
824af85b | 35 | /* Send a UDP packet with its source address set as "source" |
44a2a316 | 36 | unless nowild is true, when we just send it with the kernel default */ |
29689cfa SK |
37 | int send_from(int fd, int nowild, char *packet, size_t len, |
38 | union mysockaddr *to, struct all_addr *source, | |
50303b19 | 39 | unsigned int iface) |
9e4abcb5 | 40 | { |
44a2a316 SK |
41 | struct msghdr msg; |
42 | struct iovec iov[1]; | |
44a2a316 SK |
43 | union { |
44 | struct cmsghdr align; /* this ensures alignment */ | |
5e9e0efb | 45 | #if defined(HAVE_LINUX_NETWORK) |
44a2a316 SK |
46 | char control[CMSG_SPACE(sizeof(struct in_pktinfo))]; |
47 | #elif defined(IP_SENDSRCADDR) | |
48 | char control[CMSG_SPACE(sizeof(struct in_addr))]; | |
49 | #endif | |
50 | #ifdef HAVE_IPV6 | |
51 | char control6[CMSG_SPACE(sizeof(struct in6_pktinfo))]; | |
52 | #endif | |
53 | } control_u; | |
feba5c1d | 54 | |
44a2a316 SK |
55 | iov[0].iov_base = packet; |
56 | iov[0].iov_len = len; | |
57 | ||
feba5c1d SK |
58 | msg.msg_control = NULL; |
59 | msg.msg_controllen = 0; | |
44a2a316 SK |
60 | msg.msg_flags = 0; |
61 | msg.msg_name = to; | |
62 | msg.msg_namelen = sa_len(to); | |
63 | msg.msg_iov = iov; | |
64 | msg.msg_iovlen = 1; | |
feba5c1d | 65 | |
26128d27 | 66 | if (!nowild) |
44a2a316 | 67 | { |
26128d27 | 68 | struct cmsghdr *cmptr; |
feba5c1d SK |
69 | msg.msg_control = &control_u; |
70 | msg.msg_controllen = sizeof(control_u); | |
26128d27 SK |
71 | cmptr = CMSG_FIRSTHDR(&msg); |
72 | ||
73 | if (to->sa.sa_family == AF_INET) | |
74 | { | |
5e9e0efb | 75 | #if defined(HAVE_LINUX_NETWORK) |
8ef5ada2 SK |
76 | struct in_pktinfo p; |
77 | p.ipi_ifindex = 0; | |
78 | p.ipi_spec_dst = source->addr.addr4; | |
79 | memcpy(CMSG_DATA(cmptr), &p, sizeof(p)); | |
26128d27 | 80 | msg.msg_controllen = cmptr->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo)); |
c72daea8 | 81 | cmptr->cmsg_level = IPPROTO_IP; |
26128d27 | 82 | cmptr->cmsg_type = IP_PKTINFO; |
44a2a316 | 83 | #elif defined(IP_SENDSRCADDR) |
8ef5ada2 | 84 | memcpy(CMSG_DATA(cmptr), &(source->addr.addr4), sizeof(source->addr.addr4)); |
26128d27 SK |
85 | msg.msg_controllen = cmptr->cmsg_len = CMSG_LEN(sizeof(struct in_addr)); |
86 | cmptr->cmsg_level = IPPROTO_IP; | |
87 | cmptr->cmsg_type = IP_SENDSRCADDR; | |
44a2a316 | 88 | #endif |
26128d27 | 89 | } |
26128d27 | 90 | else |
b8187c80 | 91 | #ifdef HAVE_IPV6 |
26128d27 | 92 | { |
8ef5ada2 SK |
93 | struct in6_pktinfo p; |
94 | p.ipi6_ifindex = iface; /* Need iface for IPv6 to handle link-local addrs */ | |
95 | p.ipi6_addr = source->addr.addr6; | |
96 | memcpy(CMSG_DATA(cmptr), &p, sizeof(p)); | |
26128d27 | 97 | msg.msg_controllen = cmptr->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); |
316e2730 | 98 | cmptr->cmsg_type = daemon->v6pktinfo; |
c72daea8 | 99 | cmptr->cmsg_level = IPPROTO_IPV6; |
26128d27 | 100 | } |
3d8df260 | 101 | #else |
c72daea8 | 102 | (void)iface; /* eliminate warning */ |
44a2a316 | 103 | #endif |
26128d27 | 104 | } |
feba5c1d | 105 | |
29d28dda | 106 | while (sendmsg(fd, &msg, 0) == -1) |
feba5c1d | 107 | { |
fd9fa481 | 108 | if (retry_send()) |
29d28dda | 109 | continue; |
22d904db | 110 | |
29d28dda SK |
111 | /* If interface is still in DAD, EINVAL results - ignore that. */ |
112 | if (errno == EINVAL) | |
113 | break; | |
29689cfa | 114 | |
29d28dda | 115 | my_syslog(LOG_ERR, _("failed to send packet: %s"), strerror(errno)); |
29689cfa | 116 | return 0; |
feba5c1d | 117 | } |
29d28dda | 118 | |
29689cfa | 119 | return 1; |
9e4abcb5 | 120 | } |
44a2a316 | 121 | |
28866e95 SK |
122 | static unsigned int search_servers(time_t now, struct all_addr **addrpp, |
123 | unsigned int qtype, char *qdomain, int *type, char **domain, int *norebind) | |
feba5c1d SK |
124 | |
125 | { | |
126 | /* If the query ends in the domain in one of our servers, set | |
127 | domain to point to that name. We find the largest match to allow both | |
128 | domain.org and sub.domain.org to exist. */ | |
129 | ||
130 | unsigned int namelen = strlen(qdomain); | |
131 | unsigned int matchlen = 0; | |
132 | struct server *serv; | |
28866e95 | 133 | unsigned int flags = 0; |
feba5c1d | 134 | |
3be34541 | 135 | for (serv = daemon->servers; serv; serv=serv->next) |
feba5c1d | 136 | /* domain matches take priority over NODOTS matches */ |
3d8df260 | 137 | if ((serv->flags & SERV_FOR_NODOTS) && *type != SERV_HAS_DOMAIN && !strchr(qdomain, '.') && namelen != 0) |
feba5c1d | 138 | { |
28866e95 | 139 | unsigned int sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6; |
feba5c1d | 140 | *type = SERV_FOR_NODOTS; |
feba5c1d | 141 | if (serv->flags & SERV_NO_ADDR) |
36717eee SK |
142 | flags = F_NXDOMAIN; |
143 | else if (serv->flags & SERV_LITERAL_ADDRESS) | |
144 | { | |
145 | if (sflag & qtype) | |
146 | { | |
147 | flags = sflag; | |
148 | if (serv->addr.sa.sa_family == AF_INET) | |
149 | *addrpp = (struct all_addr *)&serv->addr.in.sin_addr; | |
feba5c1d | 150 | #ifdef HAVE_IPV6 |
36717eee SK |
151 | else |
152 | *addrpp = (struct all_addr *)&serv->addr.in6.sin6_addr; | |
feba5c1d | 153 | #endif |
36717eee | 154 | } |
824af85b | 155 | else if (!flags || (flags & F_NXDOMAIN)) |
36717eee SK |
156 | flags = F_NOERR; |
157 | } | |
feba5c1d SK |
158 | } |
159 | else if (serv->flags & SERV_HAS_DOMAIN) | |
160 | { | |
161 | unsigned int domainlen = strlen(serv->domain); | |
b8187c80 | 162 | char *matchstart = qdomain + namelen - domainlen; |
feba5c1d | 163 | if (namelen >= domainlen && |
b8187c80 | 164 | hostname_isequal(matchstart, serv->domain) && |
8ef5ada2 | 165 | (domainlen == 0 || namelen == domainlen || *(matchstart-1) == '.' )) |
feba5c1d | 166 | { |
8ef5ada2 SK |
167 | if (serv->flags & SERV_NO_REBIND) |
168 | *norebind = 1; | |
28866e95 | 169 | else |
feba5c1d | 170 | { |
28866e95 SK |
171 | unsigned int sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6; |
172 | /* implement priority rules for --address and --server for same domain. | |
173 | --address wins if the address is for the correct AF | |
174 | --server wins otherwise. */ | |
175 | if (domainlen != 0 && domainlen == matchlen) | |
36717eee | 176 | { |
28866e95 | 177 | if ((serv->flags & SERV_LITERAL_ADDRESS)) |
8ef5ada2 | 178 | { |
28866e95 SK |
179 | if (!(sflag & qtype) && flags == 0) |
180 | continue; | |
181 | } | |
182 | else | |
183 | { | |
184 | if (flags & (F_IPV4 | F_IPV6)) | |
185 | continue; | |
186 | } | |
187 | } | |
188 | ||
189 | if (domainlen >= matchlen) | |
190 | { | |
191 | *type = serv->flags & (SERV_HAS_DOMAIN | SERV_USE_RESOLV | SERV_NO_REBIND); | |
192 | *domain = serv->domain; | |
193 | matchlen = domainlen; | |
194 | if (serv->flags & SERV_NO_ADDR) | |
195 | flags = F_NXDOMAIN; | |
196 | else if (serv->flags & SERV_LITERAL_ADDRESS) | |
197 | { | |
198 | if (sflag & qtype) | |
199 | { | |
200 | flags = sflag; | |
201 | if (serv->addr.sa.sa_family == AF_INET) | |
202 | *addrpp = (struct all_addr *)&serv->addr.in.sin_addr; | |
feba5c1d | 203 | #ifdef HAVE_IPV6 |
28866e95 SK |
204 | else |
205 | *addrpp = (struct all_addr *)&serv->addr.in6.sin6_addr; | |
feba5c1d | 206 | #endif |
28866e95 SK |
207 | } |
208 | else if (!flags || (flags & F_NXDOMAIN)) | |
209 | flags = F_NOERR; | |
8ef5ada2 | 210 | } |
28866e95 SK |
211 | else |
212 | flags = 0; | |
213 | } | |
214 | } | |
8ef5ada2 | 215 | } |
feba5c1d | 216 | } |
8ef5ada2 | 217 | |
7de060b0 | 218 | if (flags == 0 && !(qtype & F_QUERY) && |
28866e95 | 219 | option_bool(OPT_NODOTS_LOCAL) && !strchr(qdomain, '.') && namelen != 0) |
7de060b0 SK |
220 | /* don't forward A or AAAA queries for simple names, except the empty name */ |
221 | flags = F_NOERR; | |
8ef5ada2 | 222 | |
5aabfc78 | 223 | if (flags == F_NXDOMAIN && check_for_local_domain(qdomain, now)) |
c1bb8504 | 224 | flags = F_NOERR; |
feba5c1d | 225 | |
824af85b SK |
226 | if (flags) |
227 | { | |
228 | int logflags = 0; | |
229 | ||
230 | if (flags == F_NXDOMAIN || flags == F_NOERR) | |
231 | logflags = F_NEG | qtype; | |
232 | ||
1a6bca81 | 233 | log_query(logflags | flags | F_CONFIG | F_FORWARD, qdomain, *addrpp, NULL); |
824af85b | 234 | } |
8ef5ada2 SK |
235 | else if ((*type) & SERV_USE_RESOLV) |
236 | { | |
237 | *type = 0; /* use normal servers for this domain */ | |
238 | *domain = NULL; | |
239 | } | |
feba5c1d SK |
240 | return flags; |
241 | } | |
44a2a316 | 242 | |
824af85b SK |
243 | static int forward_query(int udpfd, union mysockaddr *udpaddr, |
244 | struct all_addr *dst_addr, unsigned int dst_iface, | |
83349b8a | 245 | struct dns_header *header, size_t plen, time_t now, |
613ad15d | 246 | struct frec *forward, int ad_reqd, int do_bit) |
9e4abcb5 | 247 | { |
9e4abcb5 | 248 | char *domain = NULL; |
8ef5ada2 | 249 | int type = 0, norebind = 0; |
9e4abcb5 | 250 | struct all_addr *addrp = NULL; |
28866e95 | 251 | unsigned int flags = 0; |
de37951c | 252 | struct server *start = NULL; |
8a9be9e4 SK |
253 | #ifdef HAVE_DNSSEC |
254 | void *hash = hash_questions(header, plen, daemon->namebuff); | |
255 | #else | |
256 | unsigned int crc = questions_crc(header, plen, daemon->namebuff); | |
257 | void *hash = &crc; | |
258 | #endif | |
259 | unsigned int gotname = extract_request(header, plen, daemon->namebuff, NULL); | |
260 | ||
00a5b5d4 SK |
261 | (void)do_bit; |
262 | ||
3d8df260 SK |
263 | /* may be no servers available. */ |
264 | if (!daemon->servers) | |
9e4abcb5 | 265 | forward = NULL; |
8a9be9e4 | 266 | else if (forward || (hash && (forward = lookup_frec_by_sender(ntohs(header->id), udpaddr, hash)))) |
9e4abcb5 | 267 | { |
e0c0ad3b | 268 | #ifdef HAVE_DNSSEC |
dac74312 | 269 | /* If we've already got an answer to this query, but we're awaiting keys for validation, |
e0c0ad3b SK |
270 | there's no point retrying the query, retry the key query instead...... */ |
271 | if (forward->blocking_query) | |
272 | { | |
273 | int fd; | |
274 | ||
275 | while (forward->blocking_query) | |
276 | forward = forward->blocking_query; | |
277 | ||
278 | blockdata_retrieve(forward->stash, forward->stash_len, (void *)header); | |
279 | plen = forward->stash_len; | |
280 | ||
2b29191e | 281 | if (forward->sentto->addr.sa.sa_family == AF_INET) |
e0c0ad3b SK |
282 | log_query(F_DNSSEC | F_IPV4, "retry", (struct all_addr *)&forward->sentto->addr.in.sin_addr, "dnssec"); |
283 | #ifdef HAVE_IPV6 | |
284 | else | |
285 | log_query(F_DNSSEC | F_IPV6, "retry", (struct all_addr *)&forward->sentto->addr.in6.sin6_addr, "dnssec"); | |
286 | #endif | |
287 | ||
288 | if (forward->sentto->sfd) | |
289 | fd = forward->sentto->sfd->fd; | |
290 | else | |
291 | { | |
292 | #ifdef HAVE_IPV6 | |
293 | if (forward->sentto->addr.sa.sa_family == AF_INET6) | |
294 | fd = forward->rfd6->fd; | |
295 | else | |
296 | #endif | |
297 | fd = forward->rfd4->fd; | |
298 | } | |
299 | ||
300 | while (sendto(fd, (char *)header, plen, 0, | |
301 | &forward->sentto->addr.sa, | |
2b29191e | 302 | sa_len(&forward->sentto->addr)) == -1 && retry_send()); |
e0c0ad3b SK |
303 | |
304 | return 1; | |
305 | } | |
306 | #endif | |
307 | ||
de37951c | 308 | /* retry on existing query, send to all available servers */ |
9e4abcb5 | 309 | domain = forward->sentto->domain; |
824af85b | 310 | forward->sentto->failed_queries++; |
28866e95 | 311 | if (!option_bool(OPT_ORDER)) |
de37951c | 312 | { |
0a852541 | 313 | forward->forwardall = 1; |
3be34541 | 314 | daemon->last_server = NULL; |
de37951c | 315 | } |
9e4abcb5 | 316 | type = forward->sentto->flags & SERV_TYPE; |
de37951c | 317 | if (!(start = forward->sentto->next)) |
3be34541 | 318 | start = daemon->servers; /* at end of list, recycle */ |
9e4abcb5 SK |
319 | header->id = htons(forward->new_id); |
320 | } | |
321 | else | |
322 | { | |
323 | if (gotname) | |
8ef5ada2 | 324 | flags = search_servers(now, &addrp, gotname, daemon->namebuff, &type, &domain, &norebind); |
9e4abcb5 | 325 | |
3a237152 | 326 | if (!flags && !(forward = get_new_frec(now, NULL, 0))) |
feba5c1d SK |
327 | /* table full - server failure. */ |
328 | flags = F_NEG; | |
9e4abcb5 SK |
329 | |
330 | if (forward) | |
331 | { | |
0a852541 SK |
332 | forward->source = *udpaddr; |
333 | forward->dest = *dst_addr; | |
334 | forward->iface = dst_iface; | |
0a852541 | 335 | forward->orig_id = ntohs(header->id); |
8a9be9e4 | 336 | forward->new_id = get_id(); |
832af0ba | 337 | forward->fd = udpfd; |
8a9be9e4 | 338 | memcpy(forward->hash, hash, HASH_SIZE); |
0a852541 | 339 | forward->forwardall = 0; |
ed4c0767 | 340 | forward->flags = 0; |
28866e95 SK |
341 | if (norebind) |
342 | forward->flags |= FREC_NOREBIND; | |
572b41eb | 343 | if (header->hb4 & HB4_CD) |
28866e95 | 344 | forward->flags |= FREC_CHECKING_DISABLED; |
83349b8a SK |
345 | if (ad_reqd) |
346 | forward->flags |= FREC_AD_QUESTION; | |
7fa836e1 SK |
347 | #ifdef HAVE_DNSSEC |
348 | forward->work_counter = DNSSEC_WORK; | |
613ad15d SK |
349 | if (do_bit) |
350 | forward->flags |= FREC_DO_QUESTION; | |
7fa836e1 | 351 | #endif |
613ad15d | 352 | |
28866e95 SK |
353 | header->id = htons(forward->new_id); |
354 | ||
8ef5ada2 SK |
355 | /* In strict_order mode, always try servers in the order |
356 | specified in resolv.conf, if a domain is given | |
357 | always try all the available servers, | |
9e4abcb5 SK |
358 | otherwise, use the one last known to work. */ |
359 | ||
8ef5ada2 SK |
360 | if (type == 0) |
361 | { | |
28866e95 | 362 | if (option_bool(OPT_ORDER)) |
8ef5ada2 SK |
363 | start = daemon->servers; |
364 | else if (!(start = daemon->last_server) || | |
365 | daemon->forwardcount++ > FORWARD_TEST || | |
366 | difftime(now, daemon->forwardtime) > FORWARD_TIME) | |
367 | { | |
368 | start = daemon->servers; | |
369 | forward->forwardall = 1; | |
370 | daemon->forwardcount = 0; | |
371 | daemon->forwardtime = now; | |
372 | } | |
373 | } | |
374 | else | |
de37951c | 375 | { |
3be34541 | 376 | start = daemon->servers; |
28866e95 | 377 | if (!option_bool(OPT_ORDER)) |
8ef5ada2 | 378 | forward->forwardall = 1; |
de37951c | 379 | } |
9e4abcb5 SK |
380 | } |
381 | } | |
feba5c1d | 382 | |
9e4abcb5 SK |
383 | /* check for send errors here (no route to host) |
384 | if we fail to send to all nameservers, send back an error | |
385 | packet straight away (helps modem users when offline) */ | |
386 | ||
387 | if (!flags && forward) | |
388 | { | |
de37951c SK |
389 | struct server *firstsentto = start; |
390 | int forwarded = 0; | |
28866e95 | 391 | |
797a7afb | 392 | if (option_bool(OPT_ADD_MAC)) |
60b68069 | 393 | plen = add_mac(header, plen, ((char *) header) + daemon->packet_buff_sz, &forward->source); |
28866e95 | 394 | |
ed4c0767 SK |
395 | if (option_bool(OPT_CLIENT_SUBNET)) |
396 | { | |
60b68069 | 397 | size_t new = add_source_addr(header, plen, ((char *) header) + daemon->packet_buff_sz, &forward->source); |
ed4c0767 SK |
398 | if (new != plen) |
399 | { | |
400 | plen = new; | |
401 | forward->flags |= FREC_HAS_SUBNET; | |
402 | } | |
403 | } | |
404 | ||
3a237152 SK |
405 | #ifdef HAVE_DNSSEC |
406 | if (option_bool(OPT_DNSSEC_VALID)) | |
0fc2f313 | 407 | { |
613ad15d SK |
408 | size_t new_plen = add_do_bit(header, plen, ((char *) header) + daemon->packet_buff_sz); |
409 | ||
5b3bf921 SK |
410 | /* For debugging, set Checking Disabled, otherwise, have the upstream check too, |
411 | this allows it to select auth servers when one is returning bad data. */ | |
412 | if (option_bool(OPT_DNSSEC_DEBUG)) | |
413 | header->hb4 |= HB4_CD; | |
613ad15d SK |
414 | |
415 | if (new_plen != plen) | |
416 | forward->flags |= FREC_ADDED_PHEADER; | |
417 | ||
418 | plen = new_plen; | |
0fc2f313 | 419 | } |
3a237152 SK |
420 | #endif |
421 | ||
9e4abcb5 SK |
422 | while (1) |
423 | { | |
9e4abcb5 SK |
424 | /* only send to servers dealing with our domain. |
425 | domain may be NULL, in which case server->domain | |
426 | must be NULL also. */ | |
427 | ||
de37951c | 428 | if (type == (start->flags & SERV_TYPE) && |
fd9fa481 SK |
429 | (type != SERV_HAS_DOMAIN || hostname_isequal(domain, start->domain)) && |
430 | !(start->flags & SERV_LITERAL_ADDRESS)) | |
9e4abcb5 | 431 | { |
1a6bca81 SK |
432 | int fd; |
433 | ||
434 | /* find server socket to use, may need to get random one. */ | |
435 | if (start->sfd) | |
436 | fd = start->sfd->fd; | |
437 | else | |
438 | { | |
439 | #ifdef HAVE_IPV6 | |
440 | if (start->addr.sa.sa_family == AF_INET6) | |
441 | { | |
442 | if (!forward->rfd6 && | |
443 | !(forward->rfd6 = allocate_rfd(AF_INET6))) | |
444 | break; | |
3927da46 | 445 | daemon->rfd_save = forward->rfd6; |
1a6bca81 SK |
446 | fd = forward->rfd6->fd; |
447 | } | |
448 | else | |
449 | #endif | |
450 | { | |
451 | if (!forward->rfd4 && | |
452 | !(forward->rfd4 = allocate_rfd(AF_INET))) | |
453 | break; | |
3927da46 | 454 | daemon->rfd_save = forward->rfd4; |
1a6bca81 SK |
455 | fd = forward->rfd4->fd; |
456 | } | |
7de060b0 SK |
457 | |
458 | #ifdef HAVE_CONNTRACK | |
459 | /* Copy connection mark of incoming query to outgoing connection. */ | |
460 | if (option_bool(OPT_CONNTRACK)) | |
461 | { | |
462 | unsigned int mark; | |
797a7afb | 463 | if (get_incoming_mark(&forward->source, &forward->dest, 0, &mark)) |
7de060b0 SK |
464 | setsockopt(fd, SOL_SOCKET, SO_MARK, &mark, sizeof(unsigned int)); |
465 | } | |
466 | #endif | |
1a6bca81 SK |
467 | } |
468 | ||
469 | if (sendto(fd, (char *)header, plen, 0, | |
feba5c1d | 470 | &start->addr.sa, |
fd9fa481 SK |
471 | sa_len(&start->addr)) == -1) |
472 | { | |
473 | if (retry_send()) | |
474 | continue; | |
475 | } | |
476 | else | |
9e4abcb5 | 477 | { |
cdeda28f SK |
478 | /* Keep info in case we want to re-send this packet */ |
479 | daemon->srv_save = start; | |
480 | daemon->packet_len = plen; | |
481 | ||
de37951c | 482 | if (!gotname) |
3be34541 | 483 | strcpy(daemon->namebuff, "query"); |
de37951c | 484 | if (start->addr.sa.sa_family == AF_INET) |
3be34541 | 485 | log_query(F_SERVER | F_IPV4 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 486 | (struct all_addr *)&start->addr.in.sin_addr, NULL); |
de37951c SK |
487 | #ifdef HAVE_IPV6 |
488 | else | |
3be34541 | 489 | log_query(F_SERVER | F_IPV6 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 490 | (struct all_addr *)&start->addr.in6.sin6_addr, NULL); |
de37951c | 491 | #endif |
824af85b | 492 | start->queries++; |
de37951c SK |
493 | forwarded = 1; |
494 | forward->sentto = start; | |
0a852541 | 495 | if (!forward->forwardall) |
de37951c | 496 | break; |
0a852541 | 497 | forward->forwardall++; |
9e4abcb5 SK |
498 | } |
499 | } | |
500 | ||
de37951c | 501 | if (!(start = start->next)) |
3be34541 | 502 | start = daemon->servers; |
9e4abcb5 | 503 | |
de37951c | 504 | if (start == firstsentto) |
9e4abcb5 SK |
505 | break; |
506 | } | |
507 | ||
de37951c | 508 | if (forwarded) |
824af85b | 509 | return 1; |
de37951c | 510 | |
9e4abcb5 SK |
511 | /* could not send on, prepare to return */ |
512 | header->id = htons(forward->orig_id); | |
1a6bca81 | 513 | free_frec(forward); /* cancel */ |
9e4abcb5 SK |
514 | } |
515 | ||
516 | /* could not send on, return empty answer or address if known for whole domain */ | |
b8187c80 SK |
517 | if (udpfd != -1) |
518 | { | |
cdeda28f | 519 | plen = setup_reply(header, plen, addrp, flags, daemon->local_ttl); |
54dd393f | 520 | send_from(udpfd, option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND), (char *)header, plen, udpaddr, dst_addr, dst_iface); |
b8187c80 SK |
521 | } |
522 | ||
824af85b | 523 | return 0; |
9e4abcb5 SK |
524 | } |
525 | ||
ed4c0767 | 526 | static size_t process_reply(struct dns_header *header, time_t now, struct server *server, size_t n, int check_rebind, |
613ad15d | 527 | int no_cache, int cache_secure, int ad_reqd, int do_bit, int added_pheader, int check_subnet, union mysockaddr *query_source) |
feba5c1d | 528 | { |
36717eee | 529 | unsigned char *pheader, *sizep; |
13d86c73 | 530 | char **sets = 0; |
832af0ba | 531 | int munged = 0, is_sign; |
cdeda28f SK |
532 | size_t plen; |
533 | ||
83349b8a | 534 | (void)ad_reqd; |
00a5b5d4 | 535 | (void) do_bit; |
83349b8a | 536 | |
13d86c73 JD |
537 | #ifdef HAVE_IPSET |
538 | /* Similar algorithm to search_servers. */ | |
539 | struct ipsets *ipset_pos; | |
540 | unsigned int namelen = strlen(daemon->namebuff); | |
541 | unsigned int matchlen = 0; | |
542 | for (ipset_pos = daemon->ipsets; ipset_pos; ipset_pos = ipset_pos->next) | |
543 | { | |
544 | unsigned int domainlen = strlen(ipset_pos->domain); | |
545 | char *matchstart = daemon->namebuff + namelen - domainlen; | |
546 | if (namelen >= domainlen && hostname_isequal(matchstart, ipset_pos->domain) && | |
547 | (domainlen == 0 || namelen == domainlen || *(matchstart - 1) == '.' ) && | |
6c0cb858 SK |
548 | domainlen >= matchlen) |
549 | { | |
550 | matchlen = domainlen; | |
551 | sets = ipset_pos->sets; | |
552 | } | |
13d86c73 JD |
553 | } |
554 | #endif | |
555 | ||
feba5c1d | 556 | /* If upstream is advertising a larger UDP packet size |
9009d746 SK |
557 | than we allow, trim it so that we don't get overlarge |
558 | requests for the client. We can't do this for signed packets. */ | |
feba5c1d | 559 | |
ed4c0767 | 560 | if ((pheader = find_pseudoheader(header, n, &plen, &sizep, &is_sign))) |
feba5c1d | 561 | { |
83349b8a SK |
562 | unsigned short udpsz; |
563 | unsigned char *psave = sizep; | |
564 | ||
565 | GETSHORT(udpsz, sizep); | |
566 | ||
567 | if (!is_sign && udpsz > daemon->edns_pktsz) | |
568 | PUTSHORT(daemon->edns_pktsz, psave); | |
feba5c1d | 569 | |
ed4c0767 SK |
570 | if (check_subnet && !check_source(header, plen, pheader, query_source)) |
571 | { | |
572 | my_syslog(LOG_WARNING, _("discarding DNS reply: subnet option mismatch")); | |
573 | return 0; | |
574 | } | |
613ad15d SK |
575 | |
576 | if (added_pheader) | |
577 | { | |
578 | pheader = 0; | |
579 | header->arcount = htons(0); | |
580 | } | |
feba5c1d | 581 | } |
83349b8a | 582 | |
28866e95 | 583 | /* RFC 4035 sect 4.6 para 3 */ |
237724c0 | 584 | if (!is_sign && !option_bool(OPT_DNSSEC_PROXY)) |
795501bc | 585 | header->hb4 &= ~HB4_AD; |
3a237152 | 586 | |
572b41eb | 587 | if (OPCODE(header) != QUERY || (RCODE(header) != NOERROR && RCODE(header) != NXDOMAIN)) |
0a852541 SK |
588 | return n; |
589 | ||
feba5c1d | 590 | /* Complain loudly if the upstream server is non-recursive. */ |
572b41eb | 591 | if (!(header->hb4 & HB4_RA) && RCODE(header) == NOERROR && ntohs(header->ancount) == 0 && |
0a852541 | 592 | server && !(server->flags & SERV_WARNED_RECURSIVE)) |
feba5c1d | 593 | { |
3d8df260 | 594 | prettyprint_addr(&server->addr, daemon->namebuff); |
f2621c7f | 595 | my_syslog(LOG_WARNING, _("nameserver %s refused to do a recursive query"), daemon->namebuff); |
28866e95 | 596 | if (!option_bool(OPT_LOG)) |
0a852541 SK |
597 | server->flags |= SERV_WARNED_RECURSIVE; |
598 | } | |
e292e93d | 599 | |
572b41eb | 600 | if (daemon->bogus_addr && RCODE(header) != NXDOMAIN && |
fd9fa481 | 601 | check_for_bogus_wildcard(header, n, daemon->namebuff, daemon->bogus_addr, now)) |
feba5c1d | 602 | { |
fd9fa481 | 603 | munged = 1; |
572b41eb SK |
604 | SET_RCODE(header, NXDOMAIN); |
605 | header->hb3 &= ~HB3_AA; | |
6938f347 | 606 | cache_secure = 0; |
36717eee | 607 | } |
fd9fa481 | 608 | else |
36717eee | 609 | { |
6938f347 SK |
610 | int doctored = 0; |
611 | ||
572b41eb | 612 | if (RCODE(header) == NXDOMAIN && |
fd9fa481 | 613 | extract_request(header, n, daemon->namebuff, NULL) && |
5aabfc78 | 614 | check_for_local_domain(daemon->namebuff, now)) |
36717eee SK |
615 | { |
616 | /* if we forwarded a query for a locally known name (because it was for | |
617 | an unknown type) and the answer is NXDOMAIN, convert that to NODATA, | |
618 | since we know that the domain exists, even if upstream doesn't */ | |
fd9fa481 | 619 | munged = 1; |
572b41eb SK |
620 | header->hb3 |= HB3_AA; |
621 | SET_RCODE(header, NOERROR); | |
6938f347 | 622 | cache_secure = 0; |
feba5c1d | 623 | } |
832af0ba | 624 | |
6938f347 | 625 | if (extract_addresses(header, n, daemon->namebuff, now, sets, is_sign, check_rebind, no_cache, cache_secure, &doctored)) |
824af85b | 626 | { |
8ef5ada2 | 627 | my_syslog(LOG_WARNING, _("possible DNS-rebind attack detected: %s"), daemon->namebuff); |
824af85b | 628 | munged = 1; |
6938f347 | 629 | cache_secure = 0; |
824af85b | 630 | } |
6938f347 SK |
631 | |
632 | if (doctored) | |
633 | cache_secure = 0; | |
feba5c1d | 634 | } |
fd9fa481 | 635 | |
a25720a3 SK |
636 | #ifdef HAVE_DNSSEC |
637 | if (no_cache && !(header->hb4 & HB4_CD)) | |
638 | { | |
7d23a66f | 639 | if (!option_bool(OPT_DNSSEC_DEBUG)) |
a25720a3 SK |
640 | { |
641 | /* Bogus reply, turn into SERVFAIL */ | |
642 | SET_RCODE(header, SERVFAIL); | |
643 | munged = 1; | |
644 | } | |
645 | } | |
6938f347 SK |
646 | |
647 | if (option_bool(OPT_DNSSEC_VALID)) | |
648 | header->hb4 &= ~HB4_AD; | |
649 | ||
83349b8a | 650 | if (!(header->hb4 & HB4_CD) && ad_reqd && cache_secure) |
6938f347 | 651 | header->hb4 |= HB4_AD; |
613ad15d SK |
652 | |
653 | /* If the requestor didn't set the DO bit, don't return DNSSEC info. */ | |
654 | if (!do_bit) | |
655 | n = filter_rrsigs(header, n); | |
a25720a3 SK |
656 | #endif |
657 | ||
fd9fa481 SK |
658 | /* do this after extract_addresses. Ensure NODATA reply and remove |
659 | nameserver info. */ | |
660 | ||
661 | if (munged) | |
662 | { | |
663 | header->ancount = htons(0); | |
664 | header->nscount = htons(0); | |
665 | header->arcount = htons(0); | |
666 | } | |
667 | ||
36717eee SK |
668 | /* the bogus-nxdomain stuff, doctor and NXDOMAIN->NODATA munging can all elide |
669 | sections of the packet. Find the new length here and put back pseudoheader | |
670 | if it was removed. */ | |
671 | return resize_packet(header, n, pheader, plen); | |
feba5c1d SK |
672 | } |
673 | ||
3be34541 | 674 | /* sets new last_server */ |
1a6bca81 | 675 | void reply_query(int fd, int family, time_t now) |
9e4abcb5 SK |
676 | { |
677 | /* packet from peer server, extract data for cache, and send to | |
678 | original requester */ | |
572b41eb | 679 | struct dns_header *header; |
de37951c | 680 | union mysockaddr serveraddr; |
832af0ba | 681 | struct frec *forward; |
de37951c | 682 | socklen_t addrlen = sizeof(serveraddr); |
60b68069 | 683 | ssize_t n = recvfrom(fd, daemon->packet, daemon->packet_buff_sz, 0, &serveraddr.sa, &addrlen); |
cdeda28f | 684 | size_t nn; |
1a6bca81 | 685 | struct server *server; |
8a9be9e4 SK |
686 | void *hash; |
687 | #ifndef HAVE_DNSSEC | |
688 | unsigned int crc; | |
689 | #endif | |
690 | ||
cdeda28f SK |
691 | /* packet buffer overwritten */ |
692 | daemon->srv_save = NULL; | |
832af0ba | 693 | |
de37951c | 694 | /* Determine the address of the server replying so that we can mark that as good */ |
1a6bca81 | 695 | serveraddr.sa.sa_family = family; |
de37951c SK |
696 | #ifdef HAVE_IPV6 |
697 | if (serveraddr.sa.sa_family == AF_INET6) | |
5e9e0efb | 698 | serveraddr.in6.sin6_flowinfo = 0; |
de37951c | 699 | #endif |
9e4abcb5 | 700 | |
1a6bca81 SK |
701 | /* spoof check: answer must come from known server, */ |
702 | for (server = daemon->servers; server; server = server->next) | |
703 | if (!(server->flags & (SERV_LITERAL_ADDRESS | SERV_NO_ADDR)) && | |
704 | sockaddr_isequal(&server->addr, &serveraddr)) | |
705 | break; | |
706 | ||
572b41eb | 707 | header = (struct dns_header *)daemon->packet; |
8a9be9e4 SK |
708 | |
709 | #ifdef HAVE_DNSSEC | |
710 | hash = hash_questions(header, n, daemon->namebuff); | |
711 | #else | |
712 | hash = &crc; | |
713 | crc = questions_crc(header, n, daemon->namebuff); | |
714 | #endif | |
fd9fa481 | 715 | |
1a6bca81 | 716 | if (!server || |
572b41eb | 717 | n < (int)sizeof(struct dns_header) || !(header->hb3 & HB3_QR) || |
8a9be9e4 | 718 | !(forward = lookup_frec(ntohs(header->id), hash))) |
1a6bca81 | 719 | return; |
3a237152 | 720 | |
572b41eb | 721 | if ((RCODE(header) == SERVFAIL || RCODE(header) == REFUSED) && |
28866e95 | 722 | !option_bool(OPT_ORDER) && |
1a6bca81 SK |
723 | forward->forwardall == 0) |
724 | /* for broken servers, attempt to send to another one. */ | |
9e4abcb5 | 725 | { |
1a6bca81 SK |
726 | unsigned char *pheader; |
727 | size_t plen; | |
728 | int is_sign; | |
832af0ba | 729 | |
1a6bca81 SK |
730 | /* recreate query from reply */ |
731 | pheader = find_pseudoheader(header, (size_t)n, &plen, NULL, &is_sign); | |
732 | if (!is_sign) | |
832af0ba | 733 | { |
1a6bca81 SK |
734 | header->ancount = htons(0); |
735 | header->nscount = htons(0); | |
736 | header->arcount = htons(0); | |
737 | if ((nn = resize_packet(header, (size_t)n, pheader, plen))) | |
832af0ba | 738 | { |
572b41eb | 739 | header->hb3 &= ~(HB3_QR | HB3_TC); |
613ad15d | 740 | forward_query(-1, NULL, NULL, 0, header, nn, now, forward, 0, 0); |
1a6bca81 | 741 | return; |
832af0ba | 742 | } |
832af0ba | 743 | } |
1a6bca81 | 744 | } |
3a237152 SK |
745 | |
746 | server = forward->sentto; | |
1a6bca81 SK |
747 | |
748 | if ((forward->sentto->flags & SERV_TYPE) == 0) | |
749 | { | |
572b41eb | 750 | if (RCODE(header) == SERVFAIL || RCODE(header) == REFUSED) |
1a6bca81 SK |
751 | server = NULL; |
752 | else | |
b8187c80 | 753 | { |
1a6bca81 SK |
754 | struct server *last_server; |
755 | ||
756 | /* find good server by address if possible, otherwise assume the last one we sent to */ | |
757 | for (last_server = daemon->servers; last_server; last_server = last_server->next) | |
758 | if (!(last_server->flags & (SERV_LITERAL_ADDRESS | SERV_HAS_DOMAIN | SERV_FOR_NODOTS | SERV_NO_ADDR)) && | |
759 | sockaddr_isequal(&last_server->addr, &serveraddr)) | |
760 | { | |
761 | server = last_server; | |
762 | break; | |
763 | } | |
764 | } | |
28866e95 | 765 | if (!option_bool(OPT_ALL_SERVERS)) |
1a6bca81 SK |
766 | daemon->last_server = server; |
767 | } | |
3a237152 | 768 | |
1a6bca81 SK |
769 | /* If the answer is an error, keep the forward record in place in case |
770 | we get a good reply from another server. Kill it when we've | |
771 | had replies from all to avoid filling the forwarding table when | |
772 | everything is broken */ | |
773 | if (forward->forwardall == 0 || --forward->forwardall == 1 || | |
572b41eb | 774 | (RCODE(header) != REFUSED && RCODE(header) != SERVFAIL)) |
1a6bca81 | 775 | { |
3a237152 SK |
776 | int check_rebind = 0, no_cache_dnssec = 0, cache_secure = 0; |
777 | ||
778 | if (option_bool(OPT_NO_REBIND)) | |
779 | check_rebind = !(forward->flags & FREC_NOREBIND); | |
780 | ||
781 | /* Don't cache replies where DNSSEC validation was turned off, either | |
782 | the upstream server told us so, or the original query specified it. */ | |
783 | if ((header->hb4 & HB4_CD) || (forward->flags & FREC_CHECKING_DISABLED)) | |
784 | no_cache_dnssec = 1; | |
785 | ||
786 | #ifdef HAVE_DNSSEC | |
787 | if (option_bool(OPT_DNSSEC_VALID) && !(forward->flags & FREC_CHECKING_DISABLED)) | |
788 | { | |
9d633048 | 789 | int status; |
0fc2f313 SK |
790 | |
791 | /* We've had a reply already, which we're validating. Ignore this duplicate */ | |
e0c0ad3b | 792 | if (forward->blocking_query) |
0fc2f313 | 793 | return; |
9d633048 | 794 | |
871417d4 SK |
795 | if (header->hb3 & HB3_TC) |
796 | { | |
797 | /* Truncated answer can't be validated. | |
5d3b87a4 SK |
798 | If this is an answer to a DNSSEC-generated query, we still |
799 | need to get the client to retry over TCP, so return | |
800 | an answer with the TC bit set, even if the actual answer fits. | |
801 | */ | |
802 | status = STAT_TRUNCATED; | |
871417d4 SK |
803 | } |
804 | else if (forward->flags & FREC_DNSKEY_QUERY) | |
8d718cbb | 805 | status = dnssec_validate_by_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class); |
c3e0b9b6 | 806 | else if (forward->flags & FREC_DS_QUERY) |
00a5b5d4 SK |
807 | { |
808 | status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class); | |
809 | if (status == STAT_NO_DS) | |
810 | status = STAT_INSECURE; | |
811 | } | |
812 | else if (forward->flags & FREC_CHECK_NOSIGN) | |
813 | status = do_check_sign(now, header, n, daemon->namebuff, daemon->keyname, forward->class); | |
9d633048 | 814 | else |
00a5b5d4 SK |
815 | { |
816 | status = dnssec_validate_reply(now, header, n, daemon->namebuff, daemon->keyname, &forward->class, NULL); | |
817 | if (status == STAT_NO_SIG) | |
818 | { | |
819 | if (option_bool(OPT_DNSSEC_NO_SIGN)) | |
820 | status = send_check_sign(now, header, n, daemon->namebuff, daemon->keyname); | |
821 | else | |
822 | status = STAT_INSECURE; | |
823 | } | |
824 | } | |
3a237152 SK |
825 | /* Can't validate, as we're missing key data. Put this |
826 | answer aside, whilst we get that. */ | |
00a5b5d4 | 827 | if (status == STAT_NEED_DS || status == STAT_NEED_DS_NEG || status == STAT_NEED_KEY) |
3a237152 | 828 | { |
7fa836e1 SK |
829 | struct frec *new, *orig; |
830 | ||
831 | /* Free any saved query */ | |
832 | if (forward->stash) | |
833 | blockdata_free(forward->stash); | |
834 | ||
835 | /* Now save reply pending receipt of key data */ | |
836 | if (!(forward->stash = blockdata_alloc((char *)header, n))) | |
837 | return; | |
838 | forward->stash_len = n; | |
0fc2f313 | 839 | |
7fa836e1 SK |
840 | anotherkey: |
841 | /* Find the original query that started it all.... */ | |
842 | for (orig = forward; orig->dependent; orig = orig->dependent); | |
843 | ||
844 | if (--orig->work_counter == 0 || !(new = get_new_frec(now, NULL, 1))) | |
845 | status = STAT_INSECURE; | |
846 | else | |
3a237152 | 847 | { |
7fa836e1 | 848 | int fd; |
0fc2f313 SK |
849 | struct frec *next = new->next; |
850 | *new = *forward; /* copy everything, then overwrite */ | |
851 | new->next = next; | |
0fc2f313 | 852 | new->blocking_query = NULL; |
f1668d27 SK |
853 | new->rfd4 = NULL; |
854 | #ifdef HAVE_IPV6 | |
855 | new->rfd6 = NULL; | |
856 | #endif | |
00a5b5d4 | 857 | new->flags &= ~(FREC_DNSKEY_QUERY | FREC_DS_QUERY | FREC_CHECK_NOSIGN); |
9d633048 | 858 | |
7fa836e1 SK |
859 | new->dependent = forward; /* to find query awaiting new one. */ |
860 | forward->blocking_query = new; /* for garbage cleaning */ | |
861 | /* validate routines leave name of required record in daemon->keyname */ | |
862 | if (status == STAT_NEED_KEY) | |
863 | { | |
864 | new->flags |= FREC_DNSKEY_QUERY; | |
865 | nn = dnssec_generate_query(header, ((char *) header) + daemon->packet_buff_sz, | |
866 | daemon->keyname, forward->class, T_DNSKEY, &server->addr); | |
867 | } | |
868 | else | |
869 | { | |
00a5b5d4 SK |
870 | if (status == STAT_NEED_DS_NEG) |
871 | new->flags |= FREC_CHECK_NOSIGN; | |
872 | else | |
873 | new->flags |= FREC_DS_QUERY; | |
7fa836e1 SK |
874 | nn = dnssec_generate_query(header,((char *) header) + daemon->packet_buff_sz, |
875 | daemon->keyname, forward->class, T_DS, &server->addr); | |
876 | } | |
877 | if ((hash = hash_questions(header, nn, daemon->namebuff))) | |
878 | memcpy(new->hash, hash, HASH_SIZE); | |
879 | new->new_id = get_id(); | |
880 | header->id = htons(new->new_id); | |
881 | /* Save query for retransmission */ | |
882 | new->stash = blockdata_alloc((char *)header, nn); | |
883 | new->stash_len = nn; | |
884 | ||
885 | /* Don't resend this. */ | |
886 | daemon->srv_save = NULL; | |
e0c0ad3b | 887 | |
7fa836e1 SK |
888 | if (server->sfd) |
889 | fd = server->sfd->fd; | |
e0c0ad3b | 890 | else |
3a237152 | 891 | { |
7fa836e1 SK |
892 | fd = -1; |
893 | #ifdef HAVE_IPV6 | |
894 | if (server->addr.sa.sa_family == AF_INET6) | |
9d633048 | 895 | { |
7fa836e1 SK |
896 | if (new->rfd6 || (new->rfd6 = allocate_rfd(AF_INET6))) |
897 | fd = new->rfd6->fd; | |
9d633048 | 898 | } |
3a237152 | 899 | else |
3a237152 | 900 | #endif |
f1668d27 | 901 | { |
7fa836e1 SK |
902 | if (new->rfd4 || (new->rfd4 = allocate_rfd(AF_INET))) |
903 | fd = new->rfd4->fd; | |
f1668d27 | 904 | } |
3a237152 | 905 | } |
7fa836e1 SK |
906 | |
907 | if (fd != -1) | |
908 | { | |
909 | while (sendto(fd, (char *)header, nn, 0, &server->addr.sa, sa_len(&server->addr)) == -1 && retry_send()); | |
910 | server->queries++; | |
911 | } | |
912 | ||
913 | return; | |
3a237152 | 914 | } |
3a237152 SK |
915 | } |
916 | ||
917 | /* Ok, we reached far enough up the chain-of-trust that we can validate something. | |
918 | Now wind back down, pulling back answers which wouldn't previously validate | |
7fa836e1 SK |
919 | and validate them with the new data. Note that if an answer needs multiple |
920 | keys to validate, we may find another key is needed, in which case we set off | |
921 | down another branch of the tree. Once we get to the original answer | |
922 | (FREC_DNSSEC_QUERY not set) and it validates, return it to the original requestor. */ | |
0744ca66 | 923 | while (forward->dependent) |
3a237152 | 924 | { |
0744ca66 SK |
925 | struct frec *prev = forward->dependent; |
926 | free_frec(forward); | |
927 | forward = prev; | |
928 | forward->blocking_query = NULL; /* already gone */ | |
929 | blockdata_retrieve(forward->stash, forward->stash_len, (void *)header); | |
930 | n = forward->stash_len; | |
931 | ||
932 | if (status == STAT_SECURE) | |
3a237152 | 933 | { |
0744ca66 SK |
934 | if (forward->flags & FREC_DNSKEY_QUERY) |
935 | status = dnssec_validate_by_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class); | |
936 | else if (forward->flags & FREC_DS_QUERY) | |
00a5b5d4 SK |
937 | { |
938 | status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class); | |
939 | if (status == STAT_NO_DS) | |
940 | status = STAT_INSECURE; | |
941 | } | |
942 | else if (forward->flags & FREC_CHECK_NOSIGN) | |
943 | status = do_check_sign(now, header, n, daemon->namebuff, daemon->keyname, forward->class); | |
0744ca66 | 944 | else |
00a5b5d4 SK |
945 | { |
946 | status = dnssec_validate_reply(now, header, n, daemon->namebuff, daemon->keyname, &forward->class, NULL); | |
947 | if (status == STAT_NO_SIG) | |
948 | { | |
949 | if (option_bool(OPT_DNSSEC_NO_SIGN)) | |
950 | status = send_check_sign(now, header, n, daemon->namebuff, daemon->keyname); | |
951 | else | |
952 | status = STAT_INSECURE; | |
953 | } | |
954 | } | |
955 | ||
956 | if (status == STAT_NEED_DS || status == STAT_NEED_DS_NEG || status == STAT_NEED_KEY) | |
7fa836e1 | 957 | goto anotherkey; |
3a237152 SK |
958 | } |
959 | } | |
5d3b87a4 SK |
960 | |
961 | if (status == STAT_TRUNCATED) | |
0744ca66 | 962 | header->hb3 |= HB3_TC; |
5d3b87a4 | 963 | else |
7fa836e1 SK |
964 | { |
965 | char *result; | |
966 | ||
967 | if (forward->work_counter == 0) | |
968 | result = "ABANDONED"; | |
969 | else | |
970 | result = (status == STAT_SECURE ? "SECURE" : (status == STAT_INSECURE ? "INSECURE" : "BOGUS")); | |
971 | ||
972 | log_query(F_KEYTAG | F_SECSTAT, "result", NULL, result); | |
973 | } | |
5d3b87a4 | 974 | |
0fc2f313 | 975 | no_cache_dnssec = 0; |
5d3b87a4 | 976 | |
3a237152 SK |
977 | if (status == STAT_SECURE) |
978 | cache_secure = 1; | |
3a237152 SK |
979 | else if (status == STAT_BOGUS) |
980 | no_cache_dnssec = 1; | |
981 | } | |
83349b8a SK |
982 | #endif |
983 | ||
984 | /* restore CD bit to the value in the query */ | |
985 | if (forward->flags & FREC_CHECKING_DISABLED) | |
986 | header->hb4 |= HB4_CD; | |
987 | else | |
988 | header->hb4 &= ~HB4_CD; | |
8ef5ada2 | 989 | |
3a237152 | 990 | if ((nn = process_reply(header, now, server, (size_t)n, check_rebind, no_cache_dnssec, cache_secure, |
613ad15d SK |
991 | forward->flags & FREC_AD_QUESTION, forward->flags & FREC_DO_QUESTION, |
992 | forward->flags & FREC_ADDED_PHEADER, forward->flags & FREC_HAS_SUBNET, &forward->source))) | |
1a6bca81 SK |
993 | { |
994 | header->id = htons(forward->orig_id); | |
572b41eb | 995 | header->hb4 |= HB4_RA; /* recursion if available */ |
54dd393f | 996 | send_from(forward->fd, option_bool(OPT_NOWILD) || option_bool (OPT_CLEVERBIND), daemon->packet, nn, |
50303b19 | 997 | &forward->source, &forward->dest, forward->iface); |
b8187c80 | 998 | } |
1a6bca81 | 999 | free_frec(forward); /* cancel */ |
9e4abcb5 | 1000 | } |
9e4abcb5 | 1001 | } |
44a2a316 | 1002 | |
1a6bca81 | 1003 | |
5aabfc78 | 1004 | void receive_query(struct listener *listen, time_t now) |
44a2a316 | 1005 | { |
572b41eb | 1006 | struct dns_header *header = (struct dns_header *)daemon->packet; |
44a2a316 | 1007 | union mysockaddr source_addr; |
c1bb8504 | 1008 | unsigned short type; |
44a2a316 | 1009 | struct all_addr dst_addr; |
f6b7dc47 | 1010 | struct in_addr netmask, dst_addr_4; |
cdeda28f SK |
1011 | size_t m; |
1012 | ssize_t n; | |
3b195961 VG |
1013 | int if_index = 0, auth_dns = 0; |
1014 | #ifdef HAVE_AUTH | |
1015 | int local_auth = 0; | |
1016 | #endif | |
44a2a316 SK |
1017 | struct iovec iov[1]; |
1018 | struct msghdr msg; | |
1019 | struct cmsghdr *cmptr; | |
44a2a316 SK |
1020 | union { |
1021 | struct cmsghdr align; /* this ensures alignment */ | |
1022 | #ifdef HAVE_IPV6 | |
1023 | char control6[CMSG_SPACE(sizeof(struct in6_pktinfo))]; | |
1024 | #endif | |
5e9e0efb | 1025 | #if defined(HAVE_LINUX_NETWORK) |
44a2a316 | 1026 | char control[CMSG_SPACE(sizeof(struct in_pktinfo))]; |
824af85b SK |
1027 | #elif defined(IP_RECVDSTADDR) && defined(HAVE_SOLARIS_NETWORK) |
1028 | char control[CMSG_SPACE(sizeof(struct in_addr)) + | |
1029 | CMSG_SPACE(sizeof(unsigned int))]; | |
44a2a316 SK |
1030 | #elif defined(IP_RECVDSTADDR) |
1031 | char control[CMSG_SPACE(sizeof(struct in_addr)) + | |
1032 | CMSG_SPACE(sizeof(struct sockaddr_dl))]; | |
1033 | #endif | |
1034 | } control_u; | |
2329bef5 SK |
1035 | #ifdef HAVE_IPV6 |
1036 | /* Can always get recvd interface for IPv6 */ | |
1037 | int check_dst = !option_bool(OPT_NOWILD) || listen->family == AF_INET6; | |
1038 | #else | |
1039 | int check_dst = !option_bool(OPT_NOWILD); | |
1040 | #endif | |
1041 | ||
cdeda28f SK |
1042 | /* packet buffer overwritten */ |
1043 | daemon->srv_save = NULL; | |
1044 | ||
4f7b304f SK |
1045 | dst_addr_4.s_addr = 0; |
1046 | netmask.s_addr = 0; | |
1047 | ||
7e5664bd | 1048 | if (option_bool(OPT_NOWILD) && listen->iface) |
3d8df260 | 1049 | { |
4f7b304f SK |
1050 | auth_dns = listen->iface->dns_auth; |
1051 | ||
1052 | if (listen->family == AF_INET) | |
1053 | { | |
1054 | dst_addr_4 = listen->iface->addr.in.sin_addr; | |
1055 | netmask = listen->iface->netmask; | |
1056 | } | |
3d8df260 | 1057 | } |
4f7b304f | 1058 | |
3be34541 SK |
1059 | iov[0].iov_base = daemon->packet; |
1060 | iov[0].iov_len = daemon->edns_pktsz; | |
44a2a316 SK |
1061 | |
1062 | msg.msg_control = control_u.control; | |
1063 | msg.msg_controllen = sizeof(control_u); | |
1064 | msg.msg_flags = 0; | |
1065 | msg.msg_name = &source_addr; | |
1066 | msg.msg_namelen = sizeof(source_addr); | |
1067 | msg.msg_iov = iov; | |
1068 | msg.msg_iovlen = 1; | |
1069 | ||
de37951c | 1070 | if ((n = recvmsg(listen->fd, &msg, 0)) == -1) |
3be34541 | 1071 | return; |
44a2a316 | 1072 | |
572b41eb | 1073 | if (n < (int)sizeof(struct dns_header) || |
5e9e0efb | 1074 | (msg.msg_flags & MSG_TRUNC) || |
572b41eb | 1075 | (header->hb3 & HB3_QR)) |
26128d27 SK |
1076 | return; |
1077 | ||
44a2a316 | 1078 | source_addr.sa.sa_family = listen->family; |
2a7a2b84 SK |
1079 | |
1080 | if (listen->family == AF_INET) | |
1081 | { | |
1082 | /* Source-port == 0 is an error, we can't send back to that. | |
1083 | http://www.ietf.org/mail-archive/web/dnsop/current/msg11441.html */ | |
1084 | if (source_addr.in.sin_port == 0) | |
1085 | return; | |
1086 | } | |
44a2a316 | 1087 | #ifdef HAVE_IPV6 |
2a7a2b84 SK |
1088 | else |
1089 | { | |
1090 | /* Source-port == 0 is an error, we can't send back to that. */ | |
1091 | if (source_addr.in6.sin6_port == 0) | |
1092 | return; | |
1093 | source_addr.in6.sin6_flowinfo = 0; | |
1094 | } | |
44a2a316 | 1095 | #endif |
2a7a2b84 | 1096 | |
c8a80487 SK |
1097 | /* We can be configured to only accept queries from at-most-one-hop-away addresses. */ |
1098 | if (option_bool(OPT_LOCAL_SERVICE)) | |
1099 | { | |
1100 | struct addrlist *addr; | |
1101 | #ifdef HAVE_IPV6 | |
1102 | if (listen->family == AF_INET6) | |
1103 | { | |
1104 | for (addr = daemon->interface_addrs; addr; addr = addr->next) | |
1105 | if ((addr->flags & ADDRLIST_IPV6) && | |
1106 | is_same_net6(&addr->addr.addr.addr6, &source_addr.in6.sin6_addr, addr->prefixlen)) | |
1107 | break; | |
1108 | } | |
1109 | else | |
1110 | #endif | |
1111 | { | |
1112 | struct in_addr netmask; | |
1113 | for (addr = daemon->interface_addrs; addr; addr = addr->next) | |
1114 | { | |
1115 | netmask.s_addr = 0xffffffff << (32 - addr->prefixlen); | |
1116 | if (!(addr->flags & ADDRLIST_IPV6) && | |
1117 | is_same_net(addr->addr.addr.addr4, source_addr.in.sin_addr, netmask)) | |
1118 | break; | |
1119 | } | |
1120 | } | |
1121 | if (!addr) | |
1122 | { | |
0c8584ea SK |
1123 | static int warned = 0; |
1124 | if (!warned) | |
1125 | { | |
1126 | my_syslog(LOG_WARNING, _("Ignoring query from non-local network")); | |
1127 | warned = 1; | |
1128 | } | |
c8a80487 SK |
1129 | return; |
1130 | } | |
1131 | } | |
1132 | ||
2329bef5 | 1133 | if (check_dst) |
26128d27 SK |
1134 | { |
1135 | struct ifreq ifr; | |
1136 | ||
1137 | if (msg.msg_controllen < sizeof(struct cmsghdr)) | |
1138 | return; | |
44a2a316 | 1139 | |
5e9e0efb | 1140 | #if defined(HAVE_LINUX_NETWORK) |
26128d27 SK |
1141 | if (listen->family == AF_INET) |
1142 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) | |
c72daea8 | 1143 | if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_PKTINFO) |
26128d27 | 1144 | { |
8ef5ada2 SK |
1145 | union { |
1146 | unsigned char *c; | |
1147 | struct in_pktinfo *p; | |
1148 | } p; | |
1149 | p.c = CMSG_DATA(cmptr); | |
1150 | dst_addr_4 = dst_addr.addr.addr4 = p.p->ipi_spec_dst; | |
1151 | if_index = p.p->ipi_ifindex; | |
26128d27 SK |
1152 | } |
1153 | #elif defined(IP_RECVDSTADDR) && defined(IP_RECVIF) | |
1154 | if (listen->family == AF_INET) | |
44a2a316 | 1155 | { |
26128d27 | 1156 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) |
8ef5ada2 SK |
1157 | { |
1158 | union { | |
1159 | unsigned char *c; | |
1160 | unsigned int *i; | |
1161 | struct in_addr *a; | |
1162 | #ifndef HAVE_SOLARIS_NETWORK | |
1163 | struct sockaddr_dl *s; | |
1164 | #endif | |
1165 | } p; | |
1166 | p.c = CMSG_DATA(cmptr); | |
1167 | if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVDSTADDR) | |
1168 | dst_addr_4 = dst_addr.addr.addr4 = *(p.a); | |
1169 | else if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVIF) | |
824af85b | 1170 | #ifdef HAVE_SOLARIS_NETWORK |
8ef5ada2 | 1171 | if_index = *(p.i); |
824af85b | 1172 | #else |
8ef5ada2 | 1173 | if_index = p.s->sdl_index; |
824af85b | 1174 | #endif |
8ef5ada2 | 1175 | } |
44a2a316 | 1176 | } |
44a2a316 | 1177 | #endif |
26128d27 | 1178 | |
44a2a316 | 1179 | #ifdef HAVE_IPV6 |
26128d27 SK |
1180 | if (listen->family == AF_INET6) |
1181 | { | |
1182 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) | |
c72daea8 | 1183 | if (cmptr->cmsg_level == IPPROTO_IPV6 && cmptr->cmsg_type == daemon->v6pktinfo) |
26128d27 | 1184 | { |
8ef5ada2 SK |
1185 | union { |
1186 | unsigned char *c; | |
1187 | struct in6_pktinfo *p; | |
1188 | } p; | |
1189 | p.c = CMSG_DATA(cmptr); | |
1190 | ||
1191 | dst_addr.addr.addr6 = p.p->ipi6_addr; | |
1192 | if_index = p.p->ipi6_ifindex; | |
26128d27 SK |
1193 | } |
1194 | } | |
44a2a316 | 1195 | #endif |
26128d27 SK |
1196 | |
1197 | /* enforce available interface configuration */ | |
1198 | ||
e25db1f2 | 1199 | if (!indextoname(listen->fd, if_index, ifr.ifr_name)) |
5e9e0efb | 1200 | return; |
832af0ba | 1201 | |
e25db1f2 SK |
1202 | if (!iface_check(listen->family, &dst_addr, ifr.ifr_name, &auth_dns)) |
1203 | { | |
1204 | if (!option_bool(OPT_CLEVERBIND)) | |
115ac3e4 | 1205 | enumerate_interfaces(0); |
3f2873d4 SK |
1206 | if (!loopback_exception(listen->fd, listen->family, &dst_addr, ifr.ifr_name) && |
1207 | !label_exception(if_index, listen->family, &dst_addr)) | |
e25db1f2 SK |
1208 | return; |
1209 | } | |
1210 | ||
552af8b9 SK |
1211 | if (listen->family == AF_INET && option_bool(OPT_LOCALISE)) |
1212 | { | |
1213 | struct irec *iface; | |
1214 | ||
1215 | /* get the netmask of the interface whch has the address we were sent to. | |
1216 | This is no neccessarily the interface we arrived on. */ | |
1217 | ||
1218 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1219 | if (iface->addr.sa.sa_family == AF_INET && | |
1220 | iface->addr.in.sin_addr.s_addr == dst_addr_4.s_addr) | |
1221 | break; | |
1222 | ||
1223 | /* interface may be new */ | |
e25db1f2 | 1224 | if (!iface && !option_bool(OPT_CLEVERBIND)) |
115ac3e4 | 1225 | enumerate_interfaces(0); |
552af8b9 SK |
1226 | |
1227 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1228 | if (iface->addr.sa.sa_family == AF_INET && | |
1229 | iface->addr.in.sin_addr.s_addr == dst_addr_4.s_addr) | |
1230 | break; | |
1231 | ||
1232 | /* If we failed, abandon localisation */ | |
1233 | if (iface) | |
1234 | netmask = iface->netmask; | |
1235 | else | |
1236 | dst_addr_4.s_addr = 0; | |
1237 | } | |
44a2a316 SK |
1238 | } |
1239 | ||
cdeda28f | 1240 | if (extract_request(header, (size_t)n, daemon->namebuff, &type)) |
44a2a316 | 1241 | { |
b485ed97 SK |
1242 | #ifdef HAVE_AUTH |
1243 | struct auth_zone *zone; | |
1244 | #endif | |
610e782a SK |
1245 | char *types = querystr(auth_dns ? "auth" : "query", type); |
1246 | ||
44a2a316 | 1247 | if (listen->family == AF_INET) |
3be34541 | 1248 | log_query(F_QUERY | F_IPV4 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 1249 | (struct all_addr *)&source_addr.in.sin_addr, types); |
44a2a316 SK |
1250 | #ifdef HAVE_IPV6 |
1251 | else | |
3be34541 | 1252 | log_query(F_QUERY | F_IPV6 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 1253 | (struct all_addr *)&source_addr.in6.sin6_addr, types); |
44a2a316 | 1254 | #endif |
44a2a316 | 1255 | |
b485ed97 SK |
1256 | #ifdef HAVE_AUTH |
1257 | /* find queries for zones we're authoritative for, and answer them directly */ | |
6008bdbb SK |
1258 | if (!auth_dns) |
1259 | for (zone = daemon->auth_zones; zone; zone = zone->next) | |
1260 | if (in_zone(zone, daemon->namebuff, NULL)) | |
1261 | { | |
1262 | auth_dns = 1; | |
1263 | local_auth = 1; | |
1264 | break; | |
1265 | } | |
b485ed97 SK |
1266 | #endif |
1267 | } | |
1268 | ||
4820dce9 | 1269 | #ifdef HAVE_AUTH |
4f7b304f | 1270 | if (auth_dns) |
824af85b | 1271 | { |
60b68069 | 1272 | m = answer_auth(header, ((char *) header) + daemon->packet_buff_sz, (size_t)n, now, &source_addr, local_auth); |
4f7b304f | 1273 | if (m >= 1) |
b485ed97 SK |
1274 | { |
1275 | send_from(listen->fd, option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND), | |
1276 | (char *)header, m, &source_addr, &dst_addr, if_index); | |
1277 | daemon->auth_answer++; | |
1278 | } | |
824af85b | 1279 | } |
44a2a316 | 1280 | else |
4820dce9 | 1281 | #endif |
4f7b304f | 1282 | { |
613ad15d | 1283 | int ad_reqd, do_bit; |
60b68069 | 1284 | m = answer_request(header, ((char *) header) + daemon->packet_buff_sz, (size_t)n, |
613ad15d | 1285 | dst_addr_4, netmask, now, &ad_reqd, &do_bit); |
4f7b304f SK |
1286 | |
1287 | if (m >= 1) | |
1288 | { | |
1289 | send_from(listen->fd, option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND), | |
1290 | (char *)header, m, &source_addr, &dst_addr, if_index); | |
1291 | daemon->local_answer++; | |
1292 | } | |
1293 | else if (forward_query(listen->fd, &source_addr, &dst_addr, if_index, | |
613ad15d | 1294 | header, (size_t)n, now, NULL, ad_reqd, do_bit)) |
4f7b304f SK |
1295 | daemon->queries_forwarded++; |
1296 | else | |
1297 | daemon->local_answer++; | |
1298 | } | |
44a2a316 SK |
1299 | } |
1300 | ||
7d7b7b31 | 1301 | #ifdef HAVE_DNSSEC |
00a5b5d4 SK |
1302 | |
1303 | /* UDP: we've got an unsigned answer, return STAT_INSECURE if we can prove there's no DS | |
1304 | and therefore the answer shouldn't be signed, or STAT_BOGUS if it should be, or | |
1305 | STAT_NEED_DS_NEG and keyname if we need to do the query. */ | |
1306 | static int send_check_sign(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname) | |
1307 | { | |
1308 | struct crec *crecp; | |
1309 | char *name_start = name; | |
1310 | int status = dnssec_chase_cname(now, header, plen, name, keyname); | |
1311 | ||
1312 | if (status != STAT_INSECURE) | |
1313 | return status; | |
1314 | ||
1315 | while (1) | |
1316 | { | |
1317 | crecp = cache_find_by_name(NULL, name_start, now, F_DS); | |
1318 | ||
1319 | if (crecp && (crecp->flags & F_DNSSECOK)) | |
1320 | return (crecp->flags & F_NEG) ? STAT_INSECURE : STAT_BOGUS; | |
1321 | ||
1322 | if (crecp && (crecp->flags & F_NEG) && (name_start = strchr(name_start, '.'))) | |
1323 | { | |
1324 | name_start++; /* chop a label off and try again */ | |
1325 | continue; | |
1326 | } | |
1327 | ||
1328 | strcpy(keyname, name_start); | |
1329 | return STAT_NEED_DS_NEG; | |
1330 | } | |
1331 | } | |
1332 | ||
1333 | /* Got answer to DS query from send_check_sign, check for proven non-existence, or make the next DS query to try. */ | |
1334 | static int do_check_sign(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class) | |
1335 | ||
1336 | { | |
1337 | char *name_start; | |
1338 | unsigned char *p; | |
1339 | int status = dnssec_validate_ds(now, header, plen, name, keyname, class); | |
1340 | ||
1341 | if (status != STAT_INSECURE) | |
1342 | { | |
1343 | if (status == STAT_NO_DS) | |
1344 | status = STAT_INSECURE; | |
1345 | return status; | |
1346 | } | |
1347 | ||
1348 | p = (unsigned char *)(header+1); | |
1349 | ||
1350 | if (extract_name(header, plen, &p, name, 1, 4) && | |
1351 | (name_start = strchr(name, '.'))) | |
1352 | { | |
1353 | name_start++; /* chop a label off and try again */ | |
1354 | strcpy(keyname, name_start); | |
1355 | return STAT_NEED_DS_NEG; | |
1356 | } | |
1357 | ||
1358 | return STAT_BOGUS; | |
1359 | } | |
1360 | ||
1361 | /* Move toward the root, until we find a signed non-existance of a DS, in which case | |
1362 | an unsigned answer is OK, or we find a signed DS, in which case there should be | |
1363 | a signature, and the answer is BOGUS */ | |
1364 | static int tcp_check_for_unsigned_zone(time_t now, struct dns_header *header, size_t plen, int class, char *name, | |
1365 | char *keyname, struct server *server, int *keycount) | |
1366 | { | |
1367 | size_t m; | |
1368 | unsigned char *packet, *payload; | |
1369 | u16 *length; | |
1370 | unsigned char *p = (unsigned char *)(header+1); | |
1371 | int status; | |
1372 | char *name_start = name; | |
1373 | ||
1374 | /* Get first insecure entry in CNAME chain */ | |
1375 | status = tcp_key_recurse(now, STAT_CHASE_CNAME, header, plen, class, name, keyname, server, keycount); | |
1376 | if (status == STAT_BOGUS) | |
1377 | return STAT_BOGUS; | |
1378 | ||
1379 | if (!(packet = whine_malloc(65536 + MAXDNAME + RRFIXEDSZ + sizeof(u16)))) | |
1380 | return STAT_BOGUS; | |
1381 | ||
1382 | payload = &packet[2]; | |
1383 | header = (struct dns_header *)payload; | |
1384 | length = (u16 *)packet; | |
1385 | ||
1386 | while (1) | |
1387 | { | |
1388 | unsigned char *newhash, hash[HASH_SIZE]; | |
1389 | unsigned char c1, c2; | |
1390 | struct crec *crecp = cache_find_by_name(NULL, name_start, now, F_DS); | |
1391 | ||
1392 | if (--(*keycount) == 0) | |
1393 | return STAT_BOGUS; | |
1394 | ||
1395 | if (crecp && (crecp->flags & F_DNSSECOK)) | |
1396 | { | |
1397 | free(packet); | |
1398 | return (crecp->flags & F_NEG) ? STAT_INSECURE : STAT_BOGUS; | |
1399 | } | |
1400 | ||
1401 | /* If we have cached insecurely that a DS doesn't exist, | |
1402 | ise that is a hit for where to start looking for the secure one */ | |
1403 | if (crecp && (crecp->flags & F_NEG) && (name_start = strchr(name_start, '.'))) | |
1404 | { | |
1405 | name_start++; /* chop a label off and try again */ | |
1406 | continue; | |
1407 | } | |
1408 | ||
1409 | m = dnssec_generate_query(header, ((char *) header) + 65536, name_start, class, T_DS, &server->addr); | |
1410 | ||
1411 | /* We rely on the question section coming back unchanged, ensure it is with the hash. */ | |
1412 | if ((newhash = hash_questions(header, (unsigned int)m, name))) | |
1413 | memcpy(hash, newhash, HASH_SIZE); | |
1414 | ||
1415 | *length = htons(m); | |
1416 | ||
1417 | if (read_write(server->tcpfd, packet, m + sizeof(u16), 0) && | |
1418 | read_write(server->tcpfd, &c1, 1, 1) && | |
1419 | read_write(server->tcpfd, &c2, 1, 1) && | |
1420 | read_write(server->tcpfd, payload, (c1 << 8) | c2, 1)) | |
1421 | { | |
1422 | m = (c1 << 8) | c2; | |
1423 | ||
1424 | newhash = hash_questions(header, (unsigned int)m, name); | |
1425 | if (newhash && memcmp(hash, newhash, HASH_SIZE) == 0) | |
1426 | { | |
1427 | /* Note this trashes all three name workspaces */ | |
1428 | status = tcp_key_recurse(now, STAT_NEED_DS_NEG, header, m, class, name, keyname, server, keycount); | |
1429 | ||
1430 | /* We've found a DS which proves the bit of the DNS where the | |
1431 | original query is, is unsigned, so the answer is OK, | |
1432 | if unvalidated. */ | |
1433 | if (status == STAT_NO_DS) | |
1434 | { | |
1435 | free(packet); | |
1436 | return STAT_INSECURE; | |
1437 | } | |
1438 | ||
1439 | /* No DS, not got to DNSSEC-land yet, go up. */ | |
1440 | if (status == STAT_INSECURE) | |
1441 | { | |
1442 | p = (unsigned char *)(header+1); | |
1443 | ||
1444 | if (extract_name(header, plen, &p, name, 1, 4) && | |
1445 | (name_start = strchr(name, '.'))) | |
1446 | { | |
1447 | name_start++; /* chop a label off and try again */ | |
1448 | continue; | |
1449 | } | |
1450 | } | |
1451 | } | |
1452 | } | |
1453 | ||
1454 | free(packet); | |
1455 | ||
1456 | return STAT_BOGUS; | |
1457 | } | |
1458 | } | |
1459 | ||
7fa836e1 SK |
1460 | static int tcp_key_recurse(time_t now, int status, struct dns_header *header, size_t n, |
1461 | int class, char *name, char *keyname, struct server *server, int *keycount) | |
7d7b7b31 SK |
1462 | { |
1463 | /* Recurse up the key heirarchy */ | |
7d7b7b31 | 1464 | int new_status; |
7d7b7b31 | 1465 | |
7fa836e1 SK |
1466 | /* limit the amount of work we do, to avoid cycling forever on loops in the DNS */ |
1467 | if (--(*keycount) == 0) | |
1468 | return STAT_INSECURE; | |
7d7b7b31 | 1469 | |
7fa836e1 SK |
1470 | if (status == STAT_NEED_KEY) |
1471 | new_status = dnssec_validate_by_ds(now, header, n, name, keyname, class); | |
00a5b5d4 SK |
1472 | else if (status == STAT_NEED_DS || status == STAT_NEED_DS_NEG) |
1473 | { | |
1474 | new_status = dnssec_validate_ds(now, header, n, name, keyname, class); | |
1475 | if (status == STAT_NEED_DS && new_status == STAT_NO_DS) | |
1476 | new_status = STAT_INSECURE; | |
1477 | } | |
1478 | else if (status == STAT_CHASE_CNAME) | |
1479 | new_status = dnssec_chase_cname(now, header, n, name, keyname); | |
1480 | else | |
1481 | { | |
1482 | new_status = dnssec_validate_reply(now, header, n, name, keyname, &class, NULL); | |
1483 | ||
1484 | if (new_status == STAT_NO_SIG) | |
1485 | { | |
1486 | if (option_bool(OPT_DNSSEC_NO_SIGN)) | |
1487 | new_status = tcp_check_for_unsigned_zone(now, header, n, class, name, keyname, server, keycount); | |
1488 | else | |
1489 | new_status = STAT_INSECURE; | |
1490 | } | |
1491 | } | |
1492 | ||
7fa836e1 SK |
1493 | /* Can't validate because we need a key/DS whose name now in keyname. |
1494 | Make query for same, and recurse to validate */ | |
1495 | if (new_status == STAT_NEED_DS || new_status == STAT_NEED_KEY) | |
7d7b7b31 | 1496 | { |
7fa836e1 SK |
1497 | size_t m; |
1498 | unsigned char *packet = whine_malloc(65536 + MAXDNAME + RRFIXEDSZ + sizeof(u16)); | |
1499 | unsigned char *payload = &packet[2]; | |
1500 | struct dns_header *new_header = (struct dns_header *)payload; | |
1501 | u16 *length = (u16 *)packet; | |
1502 | unsigned char c1, c2; | |
1503 | ||
1504 | if (!packet) | |
1505 | return STAT_INSECURE; | |
1506 | ||
1507 | another_tcp_key: | |
1508 | m = dnssec_generate_query(new_header, ((char *) new_header) + 65536, keyname, class, | |
1509 | new_status == STAT_NEED_KEY ? T_DNSKEY : T_DS, &server->addr); | |
7d7b7b31 | 1510 | |
7fa836e1 | 1511 | *length = htons(m); |
7d7b7b31 | 1512 | |
7fa836e1 SK |
1513 | if (!read_write(server->tcpfd, packet, m + sizeof(u16), 0) || |
1514 | !read_write(server->tcpfd, &c1, 1, 1) || | |
1515 | !read_write(server->tcpfd, &c2, 1, 1) || | |
1516 | !read_write(server->tcpfd, payload, (c1 << 8) | c2, 1)) | |
1517 | new_status = STAT_INSECURE; | |
1518 | else | |
7d7b7b31 | 1519 | { |
7fa836e1 SK |
1520 | m = (c1 << 8) | c2; |
1521 | ||
00a5b5d4 SK |
1522 | new_status = tcp_key_recurse(now, new_status, new_header, m, class, name, keyname, server, keycount); |
1523 | ||
1524 | if (new_status == STAT_SECURE) | |
7d7b7b31 | 1525 | { |
7fa836e1 SK |
1526 | /* Reached a validated record, now try again at this level. |
1527 | Note that we may get ANOTHER NEED_* if an answer needs more than one key. | |
1528 | If so, go round again. */ | |
7d7b7b31 | 1529 | |
7fa836e1 SK |
1530 | if (status == STAT_NEED_KEY) |
1531 | new_status = dnssec_validate_by_ds(now, header, n, name, keyname, class); | |
00a5b5d4 SK |
1532 | else if (status == STAT_NEED_DS || status == STAT_NEED_DS_NEG) |
1533 | { | |
1534 | new_status = dnssec_validate_ds(now, header, n, name, keyname, class); | |
1535 | if (status == STAT_NEED_DS && new_status == STAT_NO_DS) | |
1536 | new_status = STAT_INSECURE; /* Validated no DS */ | |
1537 | } | |
1538 | else if (status == STAT_CHASE_CNAME) | |
1539 | new_status = dnssec_chase_cname(now, header, n, name, keyname); | |
1540 | else | |
1541 | { | |
1542 | new_status = dnssec_validate_reply(now, header, n, name, keyname, &class, NULL); | |
1543 | ||
1544 | if (new_status == STAT_NO_SIG) | |
1545 | { | |
1546 | if (option_bool(OPT_DNSSEC_NO_SIGN)) | |
1547 | new_status = tcp_check_for_unsigned_zone(now, header, n, class, name, keyname, server, keycount); | |
1548 | else | |
1549 | new_status = STAT_INSECURE; | |
1550 | } | |
1551 | } | |
1552 | ||
7d7b7b31 | 1553 | if (new_status == STAT_NEED_DS || new_status == STAT_NEED_KEY) |
7fa836e1 | 1554 | goto another_tcp_key; |
7d7b7b31 SK |
1555 | } |
1556 | } | |
7d7b7b31 | 1557 | |
7fa836e1 SK |
1558 | free(packet); |
1559 | } | |
7d7b7b31 SK |
1560 | return new_status; |
1561 | } | |
1562 | #endif | |
1563 | ||
1564 | ||
feba5c1d SK |
1565 | /* The daemon forks before calling this: it should deal with one connection, |
1566 | blocking as neccessary, and then return. Note, need to be a bit careful | |
1567 | about resources for debug mode, when the fork is suppressed: that's | |
1568 | done by the caller. */ | |
5aabfc78 | 1569 | unsigned char *tcp_request(int confd, time_t now, |
4f7b304f | 1570 | union mysockaddr *local_addr, struct in_addr netmask, int auth_dns) |
feba5c1d | 1571 | { |
28866e95 SK |
1572 | size_t size = 0; |
1573 | int norebind = 0; | |
3b195961 | 1574 | #ifdef HAVE_AUTH |
19b16891 | 1575 | int local_auth = 0; |
3b195961 | 1576 | #endif |
613ad15d SK |
1577 | int checking_disabled, ad_question, do_bit, added_pheader = 0; |
1578 | int check_subnet, no_cache_dnssec = 0, cache_secure = 0; | |
cdeda28f | 1579 | size_t m; |
ee86ce68 SK |
1580 | unsigned short qtype; |
1581 | unsigned int gotname; | |
feba5c1d | 1582 | unsigned char c1, c2; |
4b5ea12e SK |
1583 | /* Max TCP packet + slop + size */ |
1584 | unsigned char *packet = whine_malloc(65536 + MAXDNAME + RRFIXEDSZ + sizeof(u16)); | |
1585 | unsigned char *payload = &packet[2]; | |
1586 | /* largest field in header is 16-bits, so this is still sufficiently aligned */ | |
1587 | struct dns_header *header = (struct dns_header *)payload; | |
1588 | u16 *length = (u16 *)packet; | |
3be34541 | 1589 | struct server *last_server; |
7de060b0 SK |
1590 | struct in_addr dst_addr_4; |
1591 | union mysockaddr peer_addr; | |
1592 | socklen_t peer_len = sizeof(union mysockaddr); | |
3be34541 | 1593 | |
7de060b0 SK |
1594 | if (getpeername(confd, (struct sockaddr *)&peer_addr, &peer_len) == -1) |
1595 | return packet; | |
c8a80487 SK |
1596 | |
1597 | /* We can be configured to only accept queries from at-most-one-hop-away addresses. */ | |
1598 | if (option_bool(OPT_LOCAL_SERVICE)) | |
1599 | { | |
1600 | struct addrlist *addr; | |
1601 | #ifdef HAVE_IPV6 | |
1602 | if (peer_addr.sa.sa_family == AF_INET6) | |
1603 | { | |
1604 | for (addr = daemon->interface_addrs; addr; addr = addr->next) | |
1605 | if ((addr->flags & ADDRLIST_IPV6) && | |
1606 | is_same_net6(&addr->addr.addr.addr6, &peer_addr.in6.sin6_addr, addr->prefixlen)) | |
1607 | break; | |
1608 | } | |
1609 | else | |
1610 | #endif | |
1611 | { | |
1612 | struct in_addr netmask; | |
1613 | for (addr = daemon->interface_addrs; addr; addr = addr->next) | |
1614 | { | |
1615 | netmask.s_addr = 0xffffffff << (32 - addr->prefixlen); | |
1616 | if (!(addr->flags & ADDRLIST_IPV6) && | |
1617 | is_same_net(addr->addr.addr.addr4, peer_addr.in.sin_addr, netmask)) | |
1618 | break; | |
1619 | } | |
1620 | } | |
1621 | if (!addr) | |
1622 | { | |
1623 | my_syslog(LOG_WARNING, _("Ignoring query from non-local network")); | |
1624 | return packet; | |
1625 | } | |
1626 | } | |
7de060b0 | 1627 | |
feba5c1d SK |
1628 | while (1) |
1629 | { | |
1630 | if (!packet || | |
1631 | !read_write(confd, &c1, 1, 1) || !read_write(confd, &c2, 1, 1) || | |
1632 | !(size = c1 << 8 | c2) || | |
4b5ea12e | 1633 | !read_write(confd, payload, size, 1)) |
feba5c1d SK |
1634 | return packet; |
1635 | ||
572b41eb | 1636 | if (size < (int)sizeof(struct dns_header)) |
feba5c1d SK |
1637 | continue; |
1638 | ||
ed4c0767 SK |
1639 | check_subnet = 0; |
1640 | ||
28866e95 | 1641 | /* save state of "cd" flag in query */ |
7d7b7b31 SK |
1642 | if ((checking_disabled = header->hb4 & HB4_CD)) |
1643 | no_cache_dnssec = 1; | |
28866e95 | 1644 | |
3be34541 | 1645 | if ((gotname = extract_request(header, (unsigned int)size, daemon->namebuff, &qtype))) |
feba5c1d | 1646 | { |
b485ed97 SK |
1647 | #ifdef HAVE_AUTH |
1648 | struct auth_zone *zone; | |
1649 | #endif | |
610e782a | 1650 | char *types = querystr(auth_dns ? "auth" : "query", qtype); |
7de060b0 SK |
1651 | |
1652 | if (peer_addr.sa.sa_family == AF_INET) | |
1653 | log_query(F_QUERY | F_IPV4 | F_FORWARD, daemon->namebuff, | |
1654 | (struct all_addr *)&peer_addr.in.sin_addr, types); | |
feba5c1d | 1655 | #ifdef HAVE_IPV6 |
7de060b0 SK |
1656 | else |
1657 | log_query(F_QUERY | F_IPV6 | F_FORWARD, daemon->namebuff, | |
1658 | (struct all_addr *)&peer_addr.in6.sin6_addr, types); | |
feba5c1d | 1659 | #endif |
b485ed97 SK |
1660 | |
1661 | #ifdef HAVE_AUTH | |
1662 | /* find queries for zones we're authoritative for, and answer them directly */ | |
6008bdbb SK |
1663 | if (!auth_dns) |
1664 | for (zone = daemon->auth_zones; zone; zone = zone->next) | |
1665 | if (in_zone(zone, daemon->namebuff, NULL)) | |
1666 | { | |
1667 | auth_dns = 1; | |
1668 | local_auth = 1; | |
1669 | break; | |
1670 | } | |
b485ed97 | 1671 | #endif |
feba5c1d SK |
1672 | } |
1673 | ||
7de060b0 SK |
1674 | if (local_addr->sa.sa_family == AF_INET) |
1675 | dst_addr_4 = local_addr->in.sin_addr; | |
1676 | else | |
1677 | dst_addr_4.s_addr = 0; | |
1678 | ||
4820dce9 | 1679 | #ifdef HAVE_AUTH |
4f7b304f | 1680 | if (auth_dns) |
19b16891 | 1681 | m = answer_auth(header, ((char *) header) + 65536, (size_t)size, now, &peer_addr, local_auth); |
4f7b304f | 1682 | else |
4820dce9 | 1683 | #endif |
feba5c1d | 1684 | { |
4f7b304f SK |
1685 | /* m > 0 if answered from cache */ |
1686 | m = answer_request(header, ((char *) header) + 65536, (size_t)size, | |
613ad15d | 1687 | dst_addr_4, netmask, now, &ad_question, &do_bit); |
feba5c1d | 1688 | |
4f7b304f SK |
1689 | /* Do this by steam now we're not in the select() loop */ |
1690 | check_log_writer(NULL); | |
1691 | ||
1692 | if (m == 0) | |
feba5c1d | 1693 | { |
4f7b304f SK |
1694 | unsigned int flags = 0; |
1695 | struct all_addr *addrp = NULL; | |
1696 | int type = 0; | |
1697 | char *domain = NULL; | |
feba5c1d | 1698 | |
4f7b304f SK |
1699 | if (option_bool(OPT_ADD_MAC)) |
1700 | size = add_mac(header, size, ((char *) header) + 65536, &peer_addr); | |
ed4c0767 SK |
1701 | |
1702 | if (option_bool(OPT_CLIENT_SUBNET)) | |
1703 | { | |
1704 | size_t new = add_source_addr(header, size, ((char *) header) + 65536, &peer_addr); | |
1705 | if (size != new) | |
1706 | { | |
1707 | size = new; | |
1708 | check_subnet = 1; | |
1709 | } | |
1710 | } | |
1711 | ||
4f7b304f SK |
1712 | if (gotname) |
1713 | flags = search_servers(now, &addrp, gotname, daemon->namebuff, &type, &domain, &norebind); | |
1714 | ||
1715 | if (type != 0 || option_bool(OPT_ORDER) || !daemon->last_server) | |
1716 | last_server = daemon->servers; | |
1717 | else | |
1718 | last_server = daemon->last_server; | |
1719 | ||
1720 | if (!flags && last_server) | |
1721 | { | |
1722 | struct server *firstsendto = NULL; | |
8a9be9e4 | 1723 | #ifdef HAVE_DNSSEC |
703c7ff4 | 1724 | unsigned char *newhash, hash[HASH_SIZE]; |
8a9be9e4 SK |
1725 | if ((newhash = hash_questions(header, (unsigned int)size, daemon->keyname))) |
1726 | memcpy(hash, newhash, HASH_SIZE); | |
1727 | #else | |
4f7b304f | 1728 | unsigned int crc = questions_crc(header, (unsigned int)size, daemon->namebuff); |
8a9be9e4 | 1729 | #endif |
4f7b304f SK |
1730 | /* Loop round available servers until we succeed in connecting to one. |
1731 | Note that this code subtley ensures that consecutive queries on this connection | |
1732 | which can go to the same server, do so. */ | |
1733 | while (1) | |
feba5c1d | 1734 | { |
4f7b304f SK |
1735 | if (!firstsendto) |
1736 | firstsendto = last_server; | |
1737 | else | |
1738 | { | |
1739 | if (!(last_server = last_server->next)) | |
1740 | last_server = daemon->servers; | |
1741 | ||
1742 | if (last_server == firstsendto) | |
1743 | break; | |
1744 | } | |
1745 | ||
1746 | /* server for wrong domain */ | |
1747 | if (type != (last_server->flags & SERV_TYPE) || | |
1748 | (type == SERV_HAS_DOMAIN && !hostname_isequal(domain, last_server->domain))) | |
7de060b0 SK |
1749 | continue; |
1750 | ||
4f7b304f | 1751 | if (last_server->tcpfd == -1) |
7de060b0 | 1752 | { |
4f7b304f SK |
1753 | if ((last_server->tcpfd = socket(last_server->addr.sa.sa_family, SOCK_STREAM, 0)) == -1) |
1754 | continue; | |
1755 | ||
1756 | if ((!local_bind(last_server->tcpfd, &last_server->source_addr, last_server->interface, 1) || | |
1757 | connect(last_server->tcpfd, &last_server->addr.sa, sa_len(&last_server->addr)) == -1)) | |
1758 | { | |
1759 | close(last_server->tcpfd); | |
1760 | last_server->tcpfd = -1; | |
1761 | continue; | |
1762 | } | |
1763 | ||
7d7b7b31 SK |
1764 | #ifdef HAVE_DNSSEC |
1765 | if (option_bool(OPT_DNSSEC_VALID)) | |
1766 | { | |
613ad15d SK |
1767 | size_t new_size = add_do_bit(header, size, ((char *) header) + 65536); |
1768 | ||
2ecd9bd5 SK |
1769 | /* For debugging, set Checking Disabled, otherwise, have the upstream check too, |
1770 | this allows it to select auth servers when one is returning bad data. */ | |
1771 | if (option_bool(OPT_DNSSEC_DEBUG)) | |
1772 | header->hb4 |= HB4_CD; | |
613ad15d SK |
1773 | |
1774 | if (size != new_size) | |
1775 | added_pheader = 1; | |
1776 | ||
1777 | size = new_size; | |
7d7b7b31 SK |
1778 | } |
1779 | #endif | |
1780 | ||
7de060b0 | 1781 | #ifdef HAVE_CONNTRACK |
4f7b304f SK |
1782 | /* Copy connection mark of incoming query to outgoing connection. */ |
1783 | if (option_bool(OPT_CONNTRACK)) | |
1784 | { | |
1785 | unsigned int mark; | |
1786 | struct all_addr local; | |
7de060b0 | 1787 | #ifdef HAVE_IPV6 |
4f7b304f SK |
1788 | if (local_addr->sa.sa_family == AF_INET6) |
1789 | local.addr.addr6 = local_addr->in6.sin6_addr; | |
1790 | else | |
7de060b0 | 1791 | #endif |
4f7b304f SK |
1792 | local.addr.addr4 = local_addr->in.sin_addr; |
1793 | ||
1794 | if (get_incoming_mark(&peer_addr, &local, 1, &mark)) | |
1795 | setsockopt(last_server->tcpfd, SOL_SOCKET, SO_MARK, &mark, sizeof(unsigned int)); | |
1796 | } | |
7de060b0 | 1797 | #endif |
4f7b304f SK |
1798 | } |
1799 | ||
4b5ea12e | 1800 | *length = htons(size); |
4f7b304f | 1801 | |
4b5ea12e | 1802 | if (!read_write(last_server->tcpfd, packet, size + sizeof(u16), 0) || |
4f7b304f | 1803 | !read_write(last_server->tcpfd, &c1, 1, 1) || |
7d7b7b31 SK |
1804 | !read_write(last_server->tcpfd, &c2, 1, 1) || |
1805 | !read_write(last_server->tcpfd, payload, (c1 << 8) | c2, 1)) | |
4f7b304f SK |
1806 | { |
1807 | close(last_server->tcpfd); | |
1808 | last_server->tcpfd = -1; | |
1809 | continue; | |
1810 | } | |
1811 | ||
1812 | m = (c1 << 8) | c2; | |
4f7b304f SK |
1813 | |
1814 | if (!gotname) | |
1815 | strcpy(daemon->namebuff, "query"); | |
1816 | if (last_server->addr.sa.sa_family == AF_INET) | |
1817 | log_query(F_SERVER | F_IPV4 | F_FORWARD, daemon->namebuff, | |
1818 | (struct all_addr *)&last_server->addr.in.sin_addr, NULL); | |
feba5c1d | 1819 | #ifdef HAVE_IPV6 |
4f7b304f SK |
1820 | else |
1821 | log_query(F_SERVER | F_IPV6 | F_FORWARD, daemon->namebuff, | |
1822 | (struct all_addr *)&last_server->addr.in6.sin6_addr, NULL); | |
feba5c1d | 1823 | #endif |
7d7b7b31 SK |
1824 | |
1825 | #ifdef HAVE_DNSSEC | |
1826 | if (option_bool(OPT_DNSSEC_VALID) && !checking_disabled) | |
1827 | { | |
7fa836e1 SK |
1828 | int keycount = DNSSEC_WORK; /* Limit to number of DNSSEC questions, to catch loops and avoid filling cache. */ |
1829 | int status = tcp_key_recurse(now, STAT_TRUNCATED, header, m, 0, daemon->namebuff, daemon->keyname, last_server, &keycount); | |
1830 | char *result; | |
1831 | ||
1832 | if (keycount == 0) | |
1833 | result = "ABANDONED"; | |
1834 | else | |
1835 | result = (status == STAT_SECURE ? "SECURE" : (status == STAT_INSECURE ? "INSECURE" : "BOGUS")); | |
7d7b7b31 | 1836 | |
7fa836e1 | 1837 | log_query(F_KEYTAG | F_SECSTAT, "result", NULL, result); |
7d7b7b31 | 1838 | |
7d7b7b31 SK |
1839 | if (status == STAT_BOGUS) |
1840 | no_cache_dnssec = 1; | |
7fa836e1 | 1841 | |
7d7b7b31 SK |
1842 | if (status == STAT_SECURE) |
1843 | cache_secure = 1; | |
1844 | } | |
1845 | #endif | |
1846 | ||
1847 | /* restore CD bit to the value in the query */ | |
1848 | if (checking_disabled) | |
1849 | header->hb4 |= HB4_CD; | |
1850 | else | |
1851 | header->hb4 &= ~HB4_CD; | |
4f7b304f SK |
1852 | |
1853 | /* There's no point in updating the cache, since this process will exit and | |
1854 | lose the information after a few queries. We make this call for the alias and | |
1855 | bogus-nxdomain side-effects. */ | |
1856 | /* If the crc of the question section doesn't match the crc we sent, then | |
1857 | someone might be attempting to insert bogus values into the cache by | |
1858 | sending replies containing questions and bogus answers. */ | |
8a9be9e4 SK |
1859 | #ifdef HAVE_DNSSEC |
1860 | newhash = hash_questions(header, (unsigned int)m, daemon->namebuff); | |
1861 | if (!newhash || memcmp(hash, newhash, HASH_SIZE) != 0) | |
703c7ff4 SK |
1862 | { |
1863 | m = 0; | |
1864 | break; | |
1865 | } | |
8a9be9e4 SK |
1866 | #else |
1867 | if (crc != questions_crc(header, (unsigned int)m, daemon->namebuff)) | |
703c7ff4 SK |
1868 | { |
1869 | m = 0; | |
1870 | break; | |
1871 | } | |
8a9be9e4 SK |
1872 | #endif |
1873 | ||
1874 | m = process_reply(header, now, last_server, (unsigned int)m, | |
1875 | option_bool(OPT_NO_REBIND) && !norebind, no_cache_dnssec, | |
613ad15d | 1876 | cache_secure, ad_question, do_bit, added_pheader, check_subnet, &peer_addr); |
4f7b304f SK |
1877 | |
1878 | break; | |
1879 | } | |
feba5c1d | 1880 | } |
4f7b304f SK |
1881 | |
1882 | /* In case of local answer or no connections made. */ | |
1883 | if (m == 0) | |
1884 | m = setup_reply(header, (unsigned int)size, addrp, flags, daemon->local_ttl); | |
feba5c1d | 1885 | } |
feba5c1d | 1886 | } |
4f7b304f | 1887 | |
5aabfc78 | 1888 | check_log_writer(NULL); |
feba5c1d | 1889 | |
4b5ea12e SK |
1890 | *length = htons(m); |
1891 | ||
1892 | if (m == 0 || !read_write(confd, packet, m + sizeof(u16), 0)) | |
feba5c1d SK |
1893 | return packet; |
1894 | } | |
1895 | } | |
1896 | ||
1697269c | 1897 | static struct frec *allocate_frec(time_t now) |
9e4abcb5 | 1898 | { |
1697269c SK |
1899 | struct frec *f; |
1900 | ||
5aabfc78 | 1901 | if ((f = (struct frec *)whine_malloc(sizeof(struct frec)))) |
9e4abcb5 | 1902 | { |
1a6bca81 | 1903 | f->next = daemon->frec_list; |
1697269c | 1904 | f->time = now; |
832af0ba | 1905 | f->sentto = NULL; |
1a6bca81 | 1906 | f->rfd4 = NULL; |
28866e95 | 1907 | f->flags = 0; |
1a6bca81 SK |
1908 | #ifdef HAVE_IPV6 |
1909 | f->rfd6 = NULL; | |
3a237152 SK |
1910 | #endif |
1911 | #ifdef HAVE_DNSSEC | |
97bc798b | 1912 | f->dependent = NULL; |
3a237152 | 1913 | f->blocking_query = NULL; |
4619d946 | 1914 | f->stash = NULL; |
1a6bca81 SK |
1915 | #endif |
1916 | daemon->frec_list = f; | |
1697269c | 1917 | } |
9e4abcb5 | 1918 | |
1697269c SK |
1919 | return f; |
1920 | } | |
9e4abcb5 | 1921 | |
1a6bca81 SK |
1922 | static struct randfd *allocate_rfd(int family) |
1923 | { | |
1924 | static int finger = 0; | |
1925 | int i; | |
1926 | ||
1927 | /* limit the number of sockets we have open to avoid starvation of | |
1928 | (eg) TFTP. Once we have a reasonable number, randomness should be OK */ | |
1929 | ||
1930 | for (i = 0; i < RANDOM_SOCKS; i++) | |
9009d746 | 1931 | if (daemon->randomsocks[i].refcount == 0) |
1a6bca81 | 1932 | { |
9009d746 SK |
1933 | if ((daemon->randomsocks[i].fd = random_sock(family)) == -1) |
1934 | break; | |
1935 | ||
1a6bca81 SK |
1936 | daemon->randomsocks[i].refcount = 1; |
1937 | daemon->randomsocks[i].family = family; | |
1938 | return &daemon->randomsocks[i]; | |
1939 | } | |
1940 | ||
9009d746 | 1941 | /* No free ones or cannot get new socket, grab an existing one */ |
1a6bca81 SK |
1942 | for (i = 0; i < RANDOM_SOCKS; i++) |
1943 | { | |
1944 | int j = (i+finger) % RANDOM_SOCKS; | |
9009d746 SK |
1945 | if (daemon->randomsocks[j].refcount != 0 && |
1946 | daemon->randomsocks[j].family == family && | |
1947 | daemon->randomsocks[j].refcount != 0xffff) | |
1a6bca81 SK |
1948 | { |
1949 | finger = j; | |
1950 | daemon->randomsocks[j].refcount++; | |
1951 | return &daemon->randomsocks[j]; | |
1952 | } | |
1953 | } | |
1954 | ||
1955 | return NULL; /* doom */ | |
1956 | } | |
1a6bca81 SK |
1957 | static void free_frec(struct frec *f) |
1958 | { | |
1959 | if (f->rfd4 && --(f->rfd4->refcount) == 0) | |
1960 | close(f->rfd4->fd); | |
1961 | ||
1962 | f->rfd4 = NULL; | |
1963 | f->sentto = NULL; | |
28866e95 | 1964 | f->flags = 0; |
1a6bca81 SK |
1965 | |
1966 | #ifdef HAVE_IPV6 | |
1967 | if (f->rfd6 && --(f->rfd6->refcount) == 0) | |
1968 | close(f->rfd6->fd); | |
1969 | ||
1970 | f->rfd6 = NULL; | |
1971 | #endif | |
3a237152 SK |
1972 | |
1973 | #ifdef HAVE_DNSSEC | |
1974 | if (f->stash) | |
0fc2f313 SK |
1975 | { |
1976 | blockdata_free(f->stash); | |
1977 | f->stash = NULL; | |
1978 | } | |
3a237152 SK |
1979 | |
1980 | /* Anything we're waiting on is pointless now, too */ | |
1981 | if (f->blocking_query) | |
1982 | free_frec(f->blocking_query); | |
1983 | f->blocking_query = NULL; | |
39048ad1 | 1984 | f->dependent = NULL; |
3a237152 | 1985 | #endif |
1a6bca81 SK |
1986 | } |
1987 | ||
1697269c SK |
1988 | /* if wait==NULL return a free or older than TIMEOUT record. |
1989 | else return *wait zero if one available, or *wait is delay to | |
1a6bca81 | 1990 | when the oldest in-use record will expire. Impose an absolute |
3a237152 SK |
1991 | limit of 4*TIMEOUT before we wipe things (for random sockets). |
1992 | If force is set, always return a result, even if we have | |
1993 | to allocate above the limit. */ | |
1994 | struct frec *get_new_frec(time_t now, int *wait, int force) | |
1697269c | 1995 | { |
1a6bca81 | 1996 | struct frec *f, *oldest, *target; |
1697269c SK |
1997 | int count; |
1998 | ||
1999 | if (wait) | |
2000 | *wait = 0; | |
2001 | ||
1a6bca81 | 2002 | for (f = daemon->frec_list, oldest = NULL, target = NULL, count = 0; f; f = f->next, count++) |
832af0ba | 2003 | if (!f->sentto) |
1a6bca81 SK |
2004 | target = f; |
2005 | else | |
1697269c | 2006 | { |
1a6bca81 SK |
2007 | if (difftime(now, f->time) >= 4*TIMEOUT) |
2008 | { | |
2009 | free_frec(f); | |
2010 | target = f; | |
2011 | } | |
2012 | ||
2013 | if (!oldest || difftime(f->time, oldest->time) <= 0) | |
2014 | oldest = f; | |
1697269c | 2015 | } |
1a6bca81 SK |
2016 | |
2017 | if (target) | |
2018 | { | |
2019 | target->time = now; | |
2020 | return target; | |
2021 | } | |
9e4abcb5 SK |
2022 | |
2023 | /* can't find empty one, use oldest if there is one | |
2024 | and it's older than timeout */ | |
1697269c | 2025 | if (oldest && ((int)difftime(now, oldest->time)) >= TIMEOUT) |
9e4abcb5 | 2026 | { |
1697269c SK |
2027 | /* keep stuff for twice timeout if we can by allocating a new |
2028 | record instead */ | |
2029 | if (difftime(now, oldest->time) < 2*TIMEOUT && | |
2030 | count <= daemon->ftabsize && | |
2031 | (f = allocate_frec(now))) | |
2032 | return f; | |
2033 | ||
2034 | if (!wait) | |
2035 | { | |
1a6bca81 | 2036 | free_frec(oldest); |
1697269c SK |
2037 | oldest->time = now; |
2038 | } | |
9e4abcb5 SK |
2039 | return oldest; |
2040 | } | |
2041 | ||
1697269c | 2042 | /* none available, calculate time 'till oldest record expires */ |
3a237152 | 2043 | if (!force && count > daemon->ftabsize) |
1697269c | 2044 | { |
0da5e897 MSB |
2045 | static time_t last_log = 0; |
2046 | ||
1697269c SK |
2047 | if (oldest && wait) |
2048 | *wait = oldest->time + (time_t)TIMEOUT - now; | |
0da5e897 MSB |
2049 | |
2050 | if ((int)difftime(now, last_log) > 5) | |
2051 | { | |
2052 | last_log = now; | |
2053 | my_syslog(LOG_WARNING, _("Maximum number of concurrent DNS queries reached (max: %d)"), daemon->ftabsize); | |
2054 | } | |
2055 | ||
9e4abcb5 SK |
2056 | return NULL; |
2057 | } | |
1697269c SK |
2058 | |
2059 | if (!(f = allocate_frec(now)) && wait) | |
2060 | /* wait one second on malloc failure */ | |
2061 | *wait = 1; | |
9e4abcb5 | 2062 | |
9e4abcb5 SK |
2063 | return f; /* OK if malloc fails and this is NULL */ |
2064 | } | |
2065 | ||
832af0ba | 2066 | /* crc is all-ones if not known. */ |
8a9be9e4 | 2067 | static struct frec *lookup_frec(unsigned short id, void *hash) |
9e4abcb5 SK |
2068 | { |
2069 | struct frec *f; | |
2070 | ||
1a6bca81 | 2071 | for(f = daemon->frec_list; f; f = f->next) |
832af0ba | 2072 | if (f->sentto && f->new_id == id && |
8a9be9e4 | 2073 | (!hash || memcmp(hash, f->hash, HASH_SIZE) == 0)) |
9e4abcb5 SK |
2074 | return f; |
2075 | ||
2076 | return NULL; | |
2077 | } | |
2078 | ||
2079 | static struct frec *lookup_frec_by_sender(unsigned short id, | |
fd9fa481 | 2080 | union mysockaddr *addr, |
8a9be9e4 | 2081 | void *hash) |
9e4abcb5 | 2082 | { |
feba5c1d SK |
2083 | struct frec *f; |
2084 | ||
1a6bca81 | 2085 | for(f = daemon->frec_list; f; f = f->next) |
832af0ba | 2086 | if (f->sentto && |
9e4abcb5 | 2087 | f->orig_id == id && |
8a9be9e4 | 2088 | memcmp(hash, f->hash, HASH_SIZE) == 0 && |
9e4abcb5 SK |
2089 | sockaddr_isequal(&f->source, addr)) |
2090 | return f; | |
2091 | ||
2092 | return NULL; | |
2093 | } | |
2094 | ||
849a8357 | 2095 | /* A server record is going away, remove references to it */ |
5aabfc78 | 2096 | void server_gone(struct server *server) |
849a8357 SK |
2097 | { |
2098 | struct frec *f; | |
2099 | ||
1a6bca81 | 2100 | for (f = daemon->frec_list; f; f = f->next) |
832af0ba | 2101 | if (f->sentto && f->sentto == server) |
1a6bca81 | 2102 | free_frec(f); |
849a8357 SK |
2103 | |
2104 | if (daemon->last_server == server) | |
2105 | daemon->last_server = NULL; | |
2106 | ||
2107 | if (daemon->srv_save == server) | |
2108 | daemon->srv_save = NULL; | |
2109 | } | |
9e4abcb5 | 2110 | |
316e2730 | 2111 | /* return unique random ids. */ |
8a9be9e4 | 2112 | static unsigned short get_id(void) |
9e4abcb5 SK |
2113 | { |
2114 | unsigned short ret = 0; | |
832af0ba | 2115 | |
316e2730 | 2116 | do |
832af0ba | 2117 | ret = rand16(); |
8a9be9e4 | 2118 | while (lookup_frec(ret, NULL)); |
832af0ba | 2119 | |
9e4abcb5 SK |
2120 | return ret; |
2121 | } | |
2122 | ||
2123 | ||
2124 | ||
2125 | ||
2126 |