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aff33962 | 1 | /* dnsmasq is Copyright (c) 2000-2015 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 | 24 | static void free_frec(struct frec *f); |
9e4abcb5 | 25 | |
00a5b5d4 SK |
26 | #ifdef HAVE_DNSSEC |
27 | static int tcp_key_recurse(time_t now, int status, struct dns_header *header, size_t n, | |
28 | int class, char *name, char *keyname, struct server *server, int *keycount); | |
97e618a0 SK |
29 | static int do_check_sign(struct frec *forward, int status, time_t now, char *name, char *keyname); |
30 | static int send_check_sign(struct frec *forward, time_t now, struct dns_header *header, size_t plen, | |
31 | char *name, char *keyname); | |
00a5b5d4 SK |
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) |
25cf5e37 | 282 | log_query(F_NOEXTRA | F_DNSSEC | F_IPV4, "retry", (struct all_addr *)&forward->sentto->addr.in.sin_addr, "dnssec"); |
e0c0ad3b SK |
283 | #ifdef HAVE_IPV6 |
284 | else | |
25cf5e37 | 285 | log_query(F_NOEXTRA | F_DNSSEC | F_IPV6, "retry", (struct all_addr *)&forward->sentto->addr.in6.sin6_addr, "dnssec"); |
e0c0ad3b SK |
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 | |
25cf5e37 SK |
392 | /* If a query is retried, use the log_id for the retry when logging the answer. */ |
393 | forward->log_id = daemon->log_id; | |
394 | ||
797a7afb | 395 | if (option_bool(OPT_ADD_MAC)) |
60b68069 | 396 | plen = add_mac(header, plen, ((char *) header) + daemon->packet_buff_sz, &forward->source); |
28866e95 | 397 | |
ed4c0767 SK |
398 | if (option_bool(OPT_CLIENT_SUBNET)) |
399 | { | |
60b68069 | 400 | size_t new = add_source_addr(header, plen, ((char *) header) + daemon->packet_buff_sz, &forward->source); |
ed4c0767 SK |
401 | if (new != plen) |
402 | { | |
403 | plen = new; | |
404 | forward->flags |= FREC_HAS_SUBNET; | |
405 | } | |
406 | } | |
407 | ||
3a237152 SK |
408 | #ifdef HAVE_DNSSEC |
409 | if (option_bool(OPT_DNSSEC_VALID)) | |
0fc2f313 | 410 | { |
613ad15d SK |
411 | size_t new_plen = add_do_bit(header, plen, ((char *) header) + daemon->packet_buff_sz); |
412 | ||
5b3bf921 SK |
413 | /* For debugging, set Checking Disabled, otherwise, have the upstream check too, |
414 | this allows it to select auth servers when one is returning bad data. */ | |
415 | if (option_bool(OPT_DNSSEC_DEBUG)) | |
416 | header->hb4 |= HB4_CD; | |
613ad15d SK |
417 | |
418 | if (new_plen != plen) | |
419 | forward->flags |= FREC_ADDED_PHEADER; | |
420 | ||
421 | plen = new_plen; | |
0fc2f313 | 422 | } |
3a237152 SK |
423 | #endif |
424 | ||
9e4abcb5 SK |
425 | while (1) |
426 | { | |
9e4abcb5 SK |
427 | /* only send to servers dealing with our domain. |
428 | domain may be NULL, in which case server->domain | |
429 | must be NULL also. */ | |
430 | ||
de37951c | 431 | if (type == (start->flags & SERV_TYPE) && |
fd9fa481 | 432 | (type != SERV_HAS_DOMAIN || hostname_isequal(domain, start->domain)) && |
b5ea1cc2 | 433 | !(start->flags & (SERV_LITERAL_ADDRESS | SERV_LOOP))) |
9e4abcb5 | 434 | { |
1a6bca81 SK |
435 | int fd; |
436 | ||
437 | /* find server socket to use, may need to get random one. */ | |
438 | if (start->sfd) | |
439 | fd = start->sfd->fd; | |
440 | else | |
441 | { | |
442 | #ifdef HAVE_IPV6 | |
443 | if (start->addr.sa.sa_family == AF_INET6) | |
444 | { | |
445 | if (!forward->rfd6 && | |
446 | !(forward->rfd6 = allocate_rfd(AF_INET6))) | |
447 | break; | |
3927da46 | 448 | daemon->rfd_save = forward->rfd6; |
1a6bca81 SK |
449 | fd = forward->rfd6->fd; |
450 | } | |
451 | else | |
452 | #endif | |
453 | { | |
454 | if (!forward->rfd4 && | |
455 | !(forward->rfd4 = allocate_rfd(AF_INET))) | |
456 | break; | |
3927da46 | 457 | daemon->rfd_save = forward->rfd4; |
1a6bca81 SK |
458 | fd = forward->rfd4->fd; |
459 | } | |
7de060b0 SK |
460 | |
461 | #ifdef HAVE_CONNTRACK | |
462 | /* Copy connection mark of incoming query to outgoing connection. */ | |
463 | if (option_bool(OPT_CONNTRACK)) | |
464 | { | |
465 | unsigned int mark; | |
797a7afb | 466 | if (get_incoming_mark(&forward->source, &forward->dest, 0, &mark)) |
7de060b0 SK |
467 | setsockopt(fd, SOL_SOCKET, SO_MARK, &mark, sizeof(unsigned int)); |
468 | } | |
469 | #endif | |
1a6bca81 SK |
470 | } |
471 | ||
472 | if (sendto(fd, (char *)header, plen, 0, | |
feba5c1d | 473 | &start->addr.sa, |
fd9fa481 SK |
474 | sa_len(&start->addr)) == -1) |
475 | { | |
476 | if (retry_send()) | |
477 | continue; | |
478 | } | |
479 | else | |
9e4abcb5 | 480 | { |
cdeda28f SK |
481 | /* Keep info in case we want to re-send this packet */ |
482 | daemon->srv_save = start; | |
483 | daemon->packet_len = plen; | |
484 | ||
de37951c | 485 | if (!gotname) |
3be34541 | 486 | strcpy(daemon->namebuff, "query"); |
de37951c | 487 | if (start->addr.sa.sa_family == AF_INET) |
3be34541 | 488 | log_query(F_SERVER | F_IPV4 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 489 | (struct all_addr *)&start->addr.in.sin_addr, NULL); |
de37951c SK |
490 | #ifdef HAVE_IPV6 |
491 | else | |
3be34541 | 492 | log_query(F_SERVER | F_IPV6 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 493 | (struct all_addr *)&start->addr.in6.sin6_addr, NULL); |
de37951c | 494 | #endif |
824af85b | 495 | start->queries++; |
de37951c SK |
496 | forwarded = 1; |
497 | forward->sentto = start; | |
0a852541 | 498 | if (!forward->forwardall) |
de37951c | 499 | break; |
0a852541 | 500 | forward->forwardall++; |
9e4abcb5 SK |
501 | } |
502 | } | |
503 | ||
de37951c | 504 | if (!(start = start->next)) |
3be34541 | 505 | start = daemon->servers; |
9e4abcb5 | 506 | |
de37951c | 507 | if (start == firstsentto) |
9e4abcb5 SK |
508 | break; |
509 | } | |
510 | ||
de37951c | 511 | if (forwarded) |
824af85b | 512 | return 1; |
de37951c | 513 | |
9e4abcb5 SK |
514 | /* could not send on, prepare to return */ |
515 | header->id = htons(forward->orig_id); | |
1a6bca81 | 516 | free_frec(forward); /* cancel */ |
9e4abcb5 SK |
517 | } |
518 | ||
519 | /* could not send on, return empty answer or address if known for whole domain */ | |
b8187c80 SK |
520 | if (udpfd != -1) |
521 | { | |
cdeda28f | 522 | plen = setup_reply(header, plen, addrp, flags, daemon->local_ttl); |
54dd393f | 523 | send_from(udpfd, option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND), (char *)header, plen, udpaddr, dst_addr, dst_iface); |
b8187c80 SK |
524 | } |
525 | ||
824af85b | 526 | return 0; |
9e4abcb5 SK |
527 | } |
528 | ||
ed4c0767 | 529 | static size_t process_reply(struct dns_header *header, time_t now, struct server *server, size_t n, int check_rebind, |
613ad15d | 530 | int no_cache, int cache_secure, int ad_reqd, int do_bit, int added_pheader, int check_subnet, union mysockaddr *query_source) |
feba5c1d | 531 | { |
36717eee | 532 | unsigned char *pheader, *sizep; |
13d86c73 | 533 | char **sets = 0; |
832af0ba | 534 | int munged = 0, is_sign; |
cdeda28f SK |
535 | size_t plen; |
536 | ||
83349b8a | 537 | (void)ad_reqd; |
00a5b5d4 | 538 | (void) do_bit; |
83349b8a | 539 | |
13d86c73 | 540 | #ifdef HAVE_IPSET |
82a14af5 | 541 | if (daemon->ipsets && extract_request(header, n, daemon->namebuff, NULL)) |
13d86c73 | 542 | { |
82a14af5 SK |
543 | /* Similar algorithm to search_servers. */ |
544 | struct ipsets *ipset_pos; | |
545 | unsigned int namelen = strlen(daemon->namebuff); | |
546 | unsigned int matchlen = 0; | |
547 | for (ipset_pos = daemon->ipsets; ipset_pos; ipset_pos = ipset_pos->next) | |
6c0cb858 | 548 | { |
82a14af5 SK |
549 | unsigned int domainlen = strlen(ipset_pos->domain); |
550 | char *matchstart = daemon->namebuff + namelen - domainlen; | |
551 | if (namelen >= domainlen && hostname_isequal(matchstart, ipset_pos->domain) && | |
552 | (domainlen == 0 || namelen == domainlen || *(matchstart - 1) == '.' ) && | |
553 | domainlen >= matchlen) | |
554 | { | |
555 | matchlen = domainlen; | |
556 | sets = ipset_pos->sets; | |
557 | } | |
6c0cb858 | 558 | } |
13d86c73 JD |
559 | } |
560 | #endif | |
561 | ||
feba5c1d | 562 | /* If upstream is advertising a larger UDP packet size |
9009d746 SK |
563 | than we allow, trim it so that we don't get overlarge |
564 | requests for the client. We can't do this for signed packets. */ | |
feba5c1d | 565 | |
ed4c0767 | 566 | if ((pheader = find_pseudoheader(header, n, &plen, &sizep, &is_sign))) |
feba5c1d | 567 | { |
83349b8a SK |
568 | unsigned short udpsz; |
569 | unsigned char *psave = sizep; | |
570 | ||
571 | GETSHORT(udpsz, sizep); | |
572 | ||
573 | if (!is_sign && udpsz > daemon->edns_pktsz) | |
574 | PUTSHORT(daemon->edns_pktsz, psave); | |
feba5c1d | 575 | |
ed4c0767 SK |
576 | if (check_subnet && !check_source(header, plen, pheader, query_source)) |
577 | { | |
578 | my_syslog(LOG_WARNING, _("discarding DNS reply: subnet option mismatch")); | |
579 | return 0; | |
580 | } | |
613ad15d SK |
581 | |
582 | if (added_pheader) | |
583 | { | |
584 | pheader = 0; | |
585 | header->arcount = htons(0); | |
586 | } | |
feba5c1d | 587 | } |
83349b8a | 588 | |
28866e95 | 589 | /* RFC 4035 sect 4.6 para 3 */ |
237724c0 | 590 | if (!is_sign && !option_bool(OPT_DNSSEC_PROXY)) |
795501bc | 591 | header->hb4 &= ~HB4_AD; |
3a237152 | 592 | |
572b41eb | 593 | if (OPCODE(header) != QUERY || (RCODE(header) != NOERROR && RCODE(header) != NXDOMAIN)) |
8938ae05 | 594 | return resize_packet(header, n, pheader, plen); |
0a852541 | 595 | |
feba5c1d | 596 | /* Complain loudly if the upstream server is non-recursive. */ |
572b41eb | 597 | if (!(header->hb4 & HB4_RA) && RCODE(header) == NOERROR && ntohs(header->ancount) == 0 && |
0a852541 | 598 | server && !(server->flags & SERV_WARNED_RECURSIVE)) |
feba5c1d | 599 | { |
3d8df260 | 600 | prettyprint_addr(&server->addr, daemon->namebuff); |
f2621c7f | 601 | my_syslog(LOG_WARNING, _("nameserver %s refused to do a recursive query"), daemon->namebuff); |
28866e95 | 602 | if (!option_bool(OPT_LOG)) |
0a852541 SK |
603 | server->flags |= SERV_WARNED_RECURSIVE; |
604 | } | |
e292e93d | 605 | |
572b41eb | 606 | if (daemon->bogus_addr && RCODE(header) != NXDOMAIN && |
fd9fa481 | 607 | check_for_bogus_wildcard(header, n, daemon->namebuff, daemon->bogus_addr, now)) |
feba5c1d | 608 | { |
fd9fa481 | 609 | munged = 1; |
572b41eb SK |
610 | SET_RCODE(header, NXDOMAIN); |
611 | header->hb3 &= ~HB3_AA; | |
6938f347 | 612 | cache_secure = 0; |
36717eee | 613 | } |
fd9fa481 | 614 | else |
36717eee | 615 | { |
6938f347 SK |
616 | int doctored = 0; |
617 | ||
572b41eb | 618 | if (RCODE(header) == NXDOMAIN && |
fd9fa481 | 619 | extract_request(header, n, daemon->namebuff, NULL) && |
5aabfc78 | 620 | check_for_local_domain(daemon->namebuff, now)) |
36717eee SK |
621 | { |
622 | /* if we forwarded a query for a locally known name (because it was for | |
623 | an unknown type) and the answer is NXDOMAIN, convert that to NODATA, | |
624 | since we know that the domain exists, even if upstream doesn't */ | |
fd9fa481 | 625 | munged = 1; |
572b41eb SK |
626 | header->hb3 |= HB3_AA; |
627 | SET_RCODE(header, NOERROR); | |
6938f347 | 628 | cache_secure = 0; |
feba5c1d | 629 | } |
832af0ba | 630 | |
6938f347 | 631 | if (extract_addresses(header, n, daemon->namebuff, now, sets, is_sign, check_rebind, no_cache, cache_secure, &doctored)) |
824af85b | 632 | { |
8ef5ada2 | 633 | my_syslog(LOG_WARNING, _("possible DNS-rebind attack detected: %s"), daemon->namebuff); |
824af85b | 634 | munged = 1; |
6938f347 | 635 | cache_secure = 0; |
824af85b | 636 | } |
6938f347 SK |
637 | |
638 | if (doctored) | |
639 | cache_secure = 0; | |
feba5c1d | 640 | } |
fd9fa481 | 641 | |
a25720a3 SK |
642 | #ifdef HAVE_DNSSEC |
643 | if (no_cache && !(header->hb4 & HB4_CD)) | |
644 | { | |
7d23a66f | 645 | if (!option_bool(OPT_DNSSEC_DEBUG)) |
a25720a3 SK |
646 | { |
647 | /* Bogus reply, turn into SERVFAIL */ | |
648 | SET_RCODE(header, SERVFAIL); | |
649 | munged = 1; | |
650 | } | |
651 | } | |
6938f347 SK |
652 | |
653 | if (option_bool(OPT_DNSSEC_VALID)) | |
654 | header->hb4 &= ~HB4_AD; | |
655 | ||
83349b8a | 656 | if (!(header->hb4 & HB4_CD) && ad_reqd && cache_secure) |
6938f347 | 657 | header->hb4 |= HB4_AD; |
613ad15d SK |
658 | |
659 | /* If the requestor didn't set the DO bit, don't return DNSSEC info. */ | |
660 | if (!do_bit) | |
661 | n = filter_rrsigs(header, n); | |
a25720a3 SK |
662 | #endif |
663 | ||
fd9fa481 SK |
664 | /* do this after extract_addresses. Ensure NODATA reply and remove |
665 | nameserver info. */ | |
666 | ||
667 | if (munged) | |
668 | { | |
669 | header->ancount = htons(0); | |
670 | header->nscount = htons(0); | |
671 | header->arcount = htons(0); | |
672 | } | |
673 | ||
36717eee SK |
674 | /* the bogus-nxdomain stuff, doctor and NXDOMAIN->NODATA munging can all elide |
675 | sections of the packet. Find the new length here and put back pseudoheader | |
676 | if it was removed. */ | |
677 | return resize_packet(header, n, pheader, plen); | |
feba5c1d SK |
678 | } |
679 | ||
3be34541 | 680 | /* sets new last_server */ |
1a6bca81 | 681 | void reply_query(int fd, int family, time_t now) |
9e4abcb5 SK |
682 | { |
683 | /* packet from peer server, extract data for cache, and send to | |
684 | original requester */ | |
572b41eb | 685 | struct dns_header *header; |
de37951c | 686 | union mysockaddr serveraddr; |
832af0ba | 687 | struct frec *forward; |
de37951c | 688 | socklen_t addrlen = sizeof(serveraddr); |
60b68069 | 689 | ssize_t n = recvfrom(fd, daemon->packet, daemon->packet_buff_sz, 0, &serveraddr.sa, &addrlen); |
cdeda28f | 690 | size_t nn; |
1a6bca81 | 691 | struct server *server; |
8a9be9e4 SK |
692 | void *hash; |
693 | #ifndef HAVE_DNSSEC | |
694 | unsigned int crc; | |
695 | #endif | |
696 | ||
cdeda28f SK |
697 | /* packet buffer overwritten */ |
698 | daemon->srv_save = NULL; | |
832af0ba | 699 | |
de37951c | 700 | /* Determine the address of the server replying so that we can mark that as good */ |
1a6bca81 | 701 | serveraddr.sa.sa_family = family; |
de37951c SK |
702 | #ifdef HAVE_IPV6 |
703 | if (serveraddr.sa.sa_family == AF_INET6) | |
5e9e0efb | 704 | serveraddr.in6.sin6_flowinfo = 0; |
de37951c | 705 | #endif |
9e4abcb5 | 706 | |
490f9075 SK |
707 | header = (struct dns_header *)daemon->packet; |
708 | ||
709 | if (n < (int)sizeof(struct dns_header) || !(header->hb3 & HB3_QR)) | |
710 | return; | |
711 | ||
1a6bca81 SK |
712 | /* spoof check: answer must come from known server, */ |
713 | for (server = daemon->servers; server; server = server->next) | |
714 | if (!(server->flags & (SERV_LITERAL_ADDRESS | SERV_NO_ADDR)) && | |
715 | sockaddr_isequal(&server->addr, &serveraddr)) | |
716 | break; | |
490f9075 SK |
717 | |
718 | if (!server) | |
719 | return; | |
720 | ||
8a9be9e4 SK |
721 | #ifdef HAVE_DNSSEC |
722 | hash = hash_questions(header, n, daemon->namebuff); | |
723 | #else | |
724 | hash = &crc; | |
725 | crc = questions_crc(header, n, daemon->namebuff); | |
726 | #endif | |
fd9fa481 | 727 | |
490f9075 | 728 | if (!(forward = lookup_frec(ntohs(header->id), hash))) |
1a6bca81 | 729 | return; |
490f9075 | 730 | |
25cf5e37 SK |
731 | /* log_query gets called indirectly all over the place, so |
732 | pass these in global variables - sorry. */ | |
733 | daemon->log_display_id = forward->log_id; | |
734 | daemon->log_source_addr = &forward->source; | |
735 | ||
32fc6dbe GH |
736 | if (daemon->ignore_addr && RCODE(header) == NOERROR && |
737 | check_for_ignored_address(header, n, daemon->ignore_addr)) | |
738 | return; | |
739 | ||
2ae195f5 | 740 | if (RCODE(header) == REFUSED && |
28866e95 | 741 | !option_bool(OPT_ORDER) && |
1a6bca81 SK |
742 | forward->forwardall == 0) |
743 | /* for broken servers, attempt to send to another one. */ | |
9e4abcb5 | 744 | { |
1a6bca81 SK |
745 | unsigned char *pheader; |
746 | size_t plen; | |
747 | int is_sign; | |
832af0ba | 748 | |
1a6bca81 SK |
749 | /* recreate query from reply */ |
750 | pheader = find_pseudoheader(header, (size_t)n, &plen, NULL, &is_sign); | |
751 | if (!is_sign) | |
832af0ba | 752 | { |
1a6bca81 SK |
753 | header->ancount = htons(0); |
754 | header->nscount = htons(0); | |
755 | header->arcount = htons(0); | |
756 | if ((nn = resize_packet(header, (size_t)n, pheader, plen))) | |
832af0ba | 757 | { |
572b41eb | 758 | header->hb3 &= ~(HB3_QR | HB3_TC); |
613ad15d | 759 | forward_query(-1, NULL, NULL, 0, header, nn, now, forward, 0, 0); |
1a6bca81 | 760 | return; |
832af0ba | 761 | } |
832af0ba | 762 | } |
1a6bca81 | 763 | } |
3a237152 SK |
764 | |
765 | server = forward->sentto; | |
1a6bca81 SK |
766 | |
767 | if ((forward->sentto->flags & SERV_TYPE) == 0) | |
768 | { | |
51967f98 | 769 | if (RCODE(header) == REFUSED) |
1a6bca81 SK |
770 | server = NULL; |
771 | else | |
b8187c80 | 772 | { |
1a6bca81 SK |
773 | struct server *last_server; |
774 | ||
775 | /* find good server by address if possible, otherwise assume the last one we sent to */ | |
776 | for (last_server = daemon->servers; last_server; last_server = last_server->next) | |
777 | if (!(last_server->flags & (SERV_LITERAL_ADDRESS | SERV_HAS_DOMAIN | SERV_FOR_NODOTS | SERV_NO_ADDR)) && | |
778 | sockaddr_isequal(&last_server->addr, &serveraddr)) | |
779 | { | |
780 | server = last_server; | |
781 | break; | |
782 | } | |
783 | } | |
28866e95 | 784 | if (!option_bool(OPT_ALL_SERVERS)) |
1a6bca81 SK |
785 | daemon->last_server = server; |
786 | } | |
3a237152 | 787 | |
1a6bca81 SK |
788 | /* If the answer is an error, keep the forward record in place in case |
789 | we get a good reply from another server. Kill it when we've | |
790 | had replies from all to avoid filling the forwarding table when | |
791 | everything is broken */ | |
51967f98 | 792 | if (forward->forwardall == 0 || --forward->forwardall == 1 || RCODE(header) != SERVFAIL) |
1a6bca81 | 793 | { |
3a237152 SK |
794 | int check_rebind = 0, no_cache_dnssec = 0, cache_secure = 0; |
795 | ||
796 | if (option_bool(OPT_NO_REBIND)) | |
797 | check_rebind = !(forward->flags & FREC_NOREBIND); | |
798 | ||
799 | /* Don't cache replies where DNSSEC validation was turned off, either | |
800 | the upstream server told us so, or the original query specified it. */ | |
801 | if ((header->hb4 & HB4_CD) || (forward->flags & FREC_CHECKING_DISABLED)) | |
802 | no_cache_dnssec = 1; | |
803 | ||
804 | #ifdef HAVE_DNSSEC | |
51967f98 | 805 | if (server && option_bool(OPT_DNSSEC_VALID) && !(forward->flags & FREC_CHECKING_DISABLED)) |
3a237152 | 806 | { |
9d633048 | 807 | int status; |
0fc2f313 SK |
808 | |
809 | /* We've had a reply already, which we're validating. Ignore this duplicate */ | |
e0c0ad3b | 810 | if (forward->blocking_query) |
0fc2f313 | 811 | return; |
9d633048 | 812 | |
871417d4 SK |
813 | if (header->hb3 & HB3_TC) |
814 | { | |
815 | /* Truncated answer can't be validated. | |
5d3b87a4 SK |
816 | If this is an answer to a DNSSEC-generated query, we still |
817 | need to get the client to retry over TCP, so return | |
818 | an answer with the TC bit set, even if the actual answer fits. | |
819 | */ | |
820 | status = STAT_TRUNCATED; | |
871417d4 SK |
821 | } |
822 | else if (forward->flags & FREC_DNSKEY_QUERY) | |
8d718cbb | 823 | status = dnssec_validate_by_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class); |
c3e0b9b6 | 824 | else if (forward->flags & FREC_DS_QUERY) |
00a5b5d4 SK |
825 | { |
826 | status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class); | |
97e618a0 SK |
827 | if (status == STAT_NO_DS || status == STAT_NO_NS) |
828 | status = STAT_BOGUS; | |
00a5b5d4 SK |
829 | } |
830 | else if (forward->flags & FREC_CHECK_NOSIGN) | |
97e618a0 SK |
831 | { |
832 | status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class); | |
833 | if (status != STAT_NEED_KEY) | |
834 | status = do_check_sign(forward, status, now, daemon->namebuff, daemon->keyname); | |
835 | } | |
9d633048 | 836 | else |
00a5b5d4 | 837 | { |
97e618a0 | 838 | status = dnssec_validate_reply(now, header, n, daemon->namebuff, daemon->keyname, &forward->class, NULL, NULL); |
00a5b5d4 SK |
839 | if (status == STAT_NO_SIG) |
840 | { | |
841 | if (option_bool(OPT_DNSSEC_NO_SIGN)) | |
97e618a0 | 842 | status = send_check_sign(forward, now, header, n, daemon->namebuff, daemon->keyname); |
00a5b5d4 SK |
843 | else |
844 | status = STAT_INSECURE; | |
845 | } | |
846 | } | |
3a237152 SK |
847 | /* Can't validate, as we're missing key data. Put this |
848 | answer aside, whilst we get that. */ | |
00a5b5d4 | 849 | if (status == STAT_NEED_DS || status == STAT_NEED_DS_NEG || status == STAT_NEED_KEY) |
3a237152 | 850 | { |
7fa836e1 SK |
851 | struct frec *new, *orig; |
852 | ||
853 | /* Free any saved query */ | |
854 | if (forward->stash) | |
855 | blockdata_free(forward->stash); | |
856 | ||
857 | /* Now save reply pending receipt of key data */ | |
858 | if (!(forward->stash = blockdata_alloc((char *)header, n))) | |
859 | return; | |
860 | forward->stash_len = n; | |
0fc2f313 | 861 | |
7fa836e1 SK |
862 | anotherkey: |
863 | /* Find the original query that started it all.... */ | |
864 | for (orig = forward; orig->dependent; orig = orig->dependent); | |
865 | ||
866 | if (--orig->work_counter == 0 || !(new = get_new_frec(now, NULL, 1))) | |
867 | status = STAT_INSECURE; | |
868 | else | |
3a237152 | 869 | { |
7fa836e1 | 870 | int fd; |
0fc2f313 SK |
871 | struct frec *next = new->next; |
872 | *new = *forward; /* copy everything, then overwrite */ | |
873 | new->next = next; | |
0fc2f313 | 874 | new->blocking_query = NULL; |
8a8bbad0 | 875 | new->sentto = server; |
f1668d27 | 876 | new->rfd4 = NULL; |
97e618a0 | 877 | new->orig_domain = NULL; |
f1668d27 SK |
878 | #ifdef HAVE_IPV6 |
879 | new->rfd6 = NULL; | |
880 | #endif | |
00a5b5d4 | 881 | new->flags &= ~(FREC_DNSKEY_QUERY | FREC_DS_QUERY | FREC_CHECK_NOSIGN); |
9d633048 | 882 | |
7fa836e1 SK |
883 | new->dependent = forward; /* to find query awaiting new one. */ |
884 | forward->blocking_query = new; /* for garbage cleaning */ | |
885 | /* validate routines leave name of required record in daemon->keyname */ | |
886 | if (status == STAT_NEED_KEY) | |
887 | { | |
888 | new->flags |= FREC_DNSKEY_QUERY; | |
889 | nn = dnssec_generate_query(header, ((char *) header) + daemon->packet_buff_sz, | |
890 | daemon->keyname, forward->class, T_DNSKEY, &server->addr); | |
891 | } | |
892 | else | |
893 | { | |
00a5b5d4 SK |
894 | if (status == STAT_NEED_DS_NEG) |
895 | new->flags |= FREC_CHECK_NOSIGN; | |
896 | else | |
897 | new->flags |= FREC_DS_QUERY; | |
7fa836e1 SK |
898 | nn = dnssec_generate_query(header,((char *) header) + daemon->packet_buff_sz, |
899 | daemon->keyname, forward->class, T_DS, &server->addr); | |
900 | } | |
901 | if ((hash = hash_questions(header, nn, daemon->namebuff))) | |
902 | memcpy(new->hash, hash, HASH_SIZE); | |
903 | new->new_id = get_id(); | |
904 | header->id = htons(new->new_id); | |
905 | /* Save query for retransmission */ | |
97e618a0 SK |
906 | if (!(new->stash = blockdata_alloc((char *)header, nn))) |
907 | return; | |
908 | ||
7fa836e1 SK |
909 | new->stash_len = nn; |
910 | ||
911 | /* Don't resend this. */ | |
912 | daemon->srv_save = NULL; | |
e0c0ad3b | 913 | |
7fa836e1 SK |
914 | if (server->sfd) |
915 | fd = server->sfd->fd; | |
e0c0ad3b | 916 | else |
3a237152 | 917 | { |
7fa836e1 SK |
918 | fd = -1; |
919 | #ifdef HAVE_IPV6 | |
920 | if (server->addr.sa.sa_family == AF_INET6) | |
9d633048 | 921 | { |
7fa836e1 SK |
922 | if (new->rfd6 || (new->rfd6 = allocate_rfd(AF_INET6))) |
923 | fd = new->rfd6->fd; | |
9d633048 | 924 | } |
3a237152 | 925 | else |
3a237152 | 926 | #endif |
f1668d27 | 927 | { |
7fa836e1 SK |
928 | if (new->rfd4 || (new->rfd4 = allocate_rfd(AF_INET))) |
929 | fd = new->rfd4->fd; | |
f1668d27 | 930 | } |
3a237152 | 931 | } |
7fa836e1 SK |
932 | |
933 | if (fd != -1) | |
934 | { | |
935 | while (sendto(fd, (char *)header, nn, 0, &server->addr.sa, sa_len(&server->addr)) == -1 && retry_send()); | |
936 | server->queries++; | |
937 | } | |
938 | ||
939 | return; | |
3a237152 | 940 | } |
3a237152 SK |
941 | } |
942 | ||
943 | /* Ok, we reached far enough up the chain-of-trust that we can validate something. | |
944 | Now wind back down, pulling back answers which wouldn't previously validate | |
7fa836e1 SK |
945 | and validate them with the new data. Note that if an answer needs multiple |
946 | keys to validate, we may find another key is needed, in which case we set off | |
947 | down another branch of the tree. Once we get to the original answer | |
948 | (FREC_DNSSEC_QUERY not set) and it validates, return it to the original requestor. */ | |
0744ca66 | 949 | while (forward->dependent) |
3a237152 | 950 | { |
0744ca66 SK |
951 | struct frec *prev = forward->dependent; |
952 | free_frec(forward); | |
953 | forward = prev; | |
954 | forward->blocking_query = NULL; /* already gone */ | |
955 | blockdata_retrieve(forward->stash, forward->stash_len, (void *)header); | |
956 | n = forward->stash_len; | |
957 | ||
958 | if (status == STAT_SECURE) | |
3a237152 | 959 | { |
0744ca66 SK |
960 | if (forward->flags & FREC_DNSKEY_QUERY) |
961 | status = dnssec_validate_by_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class); | |
962 | else if (forward->flags & FREC_DS_QUERY) | |
00a5b5d4 SK |
963 | { |
964 | status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class); | |
97e618a0 SK |
965 | if (status == STAT_NO_DS || status == STAT_NO_NS) |
966 | status = STAT_BOGUS; | |
00a5b5d4 SK |
967 | } |
968 | else if (forward->flags & FREC_CHECK_NOSIGN) | |
97e618a0 SK |
969 | { |
970 | status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class); | |
971 | if (status != STAT_NEED_KEY) | |
972 | status = do_check_sign(forward, status, now, daemon->namebuff, daemon->keyname); | |
973 | } | |
0744ca66 | 974 | else |
00a5b5d4 | 975 | { |
97e618a0 | 976 | status = dnssec_validate_reply(now, header, n, daemon->namebuff, daemon->keyname, &forward->class, NULL, NULL); |
00a5b5d4 SK |
977 | if (status == STAT_NO_SIG) |
978 | { | |
979 | if (option_bool(OPT_DNSSEC_NO_SIGN)) | |
97e618a0 | 980 | status = send_check_sign(forward, now, header, n, daemon->namebuff, daemon->keyname); |
00a5b5d4 SK |
981 | else |
982 | status = STAT_INSECURE; | |
983 | } | |
984 | } | |
985 | ||
986 | if (status == STAT_NEED_DS || status == STAT_NEED_DS_NEG || status == STAT_NEED_KEY) | |
7fa836e1 | 987 | goto anotherkey; |
3a237152 SK |
988 | } |
989 | } | |
5d3b87a4 SK |
990 | |
991 | if (status == STAT_TRUNCATED) | |
0744ca66 | 992 | header->hb3 |= HB3_TC; |
5d3b87a4 | 993 | else |
7fa836e1 SK |
994 | { |
995 | char *result; | |
996 | ||
997 | if (forward->work_counter == 0) | |
998 | result = "ABANDONED"; | |
999 | else | |
1000 | result = (status == STAT_SECURE ? "SECURE" : (status == STAT_INSECURE ? "INSECURE" : "BOGUS")); | |
1001 | ||
1002 | log_query(F_KEYTAG | F_SECSTAT, "result", NULL, result); | |
1003 | } | |
5d3b87a4 | 1004 | |
0fc2f313 | 1005 | no_cache_dnssec = 0; |
5d3b87a4 | 1006 | |
3a237152 SK |
1007 | if (status == STAT_SECURE) |
1008 | cache_secure = 1; | |
3a237152 SK |
1009 | else if (status == STAT_BOGUS) |
1010 | no_cache_dnssec = 1; | |
1011 | } | |
83349b8a SK |
1012 | #endif |
1013 | ||
1014 | /* restore CD bit to the value in the query */ | |
1015 | if (forward->flags & FREC_CHECKING_DISABLED) | |
1016 | header->hb4 |= HB4_CD; | |
1017 | else | |
1018 | header->hb4 &= ~HB4_CD; | |
8ef5ada2 | 1019 | |
3a237152 | 1020 | if ((nn = process_reply(header, now, server, (size_t)n, check_rebind, no_cache_dnssec, cache_secure, |
613ad15d SK |
1021 | forward->flags & FREC_AD_QUESTION, forward->flags & FREC_DO_QUESTION, |
1022 | forward->flags & FREC_ADDED_PHEADER, forward->flags & FREC_HAS_SUBNET, &forward->source))) | |
1a6bca81 SK |
1023 | { |
1024 | header->id = htons(forward->orig_id); | |
572b41eb | 1025 | header->hb4 |= HB4_RA; /* recursion if available */ |
54dd393f | 1026 | send_from(forward->fd, option_bool(OPT_NOWILD) || option_bool (OPT_CLEVERBIND), daemon->packet, nn, |
50303b19 | 1027 | &forward->source, &forward->dest, forward->iface); |
b8187c80 | 1028 | } |
1a6bca81 | 1029 | free_frec(forward); /* cancel */ |
9e4abcb5 | 1030 | } |
9e4abcb5 | 1031 | } |
44a2a316 | 1032 | |
1a6bca81 | 1033 | |
5aabfc78 | 1034 | void receive_query(struct listener *listen, time_t now) |
44a2a316 | 1035 | { |
572b41eb | 1036 | struct dns_header *header = (struct dns_header *)daemon->packet; |
44a2a316 | 1037 | union mysockaddr source_addr; |
c1bb8504 | 1038 | unsigned short type; |
44a2a316 | 1039 | struct all_addr dst_addr; |
f6b7dc47 | 1040 | struct in_addr netmask, dst_addr_4; |
cdeda28f SK |
1041 | size_t m; |
1042 | ssize_t n; | |
3b195961 VG |
1043 | int if_index = 0, auth_dns = 0; |
1044 | #ifdef HAVE_AUTH | |
1045 | int local_auth = 0; | |
1046 | #endif | |
44a2a316 SK |
1047 | struct iovec iov[1]; |
1048 | struct msghdr msg; | |
1049 | struct cmsghdr *cmptr; | |
44a2a316 SK |
1050 | union { |
1051 | struct cmsghdr align; /* this ensures alignment */ | |
1052 | #ifdef HAVE_IPV6 | |
1053 | char control6[CMSG_SPACE(sizeof(struct in6_pktinfo))]; | |
1054 | #endif | |
5e9e0efb | 1055 | #if defined(HAVE_LINUX_NETWORK) |
44a2a316 | 1056 | char control[CMSG_SPACE(sizeof(struct in_pktinfo))]; |
824af85b SK |
1057 | #elif defined(IP_RECVDSTADDR) && defined(HAVE_SOLARIS_NETWORK) |
1058 | char control[CMSG_SPACE(sizeof(struct in_addr)) + | |
1059 | CMSG_SPACE(sizeof(unsigned int))]; | |
44a2a316 SK |
1060 | #elif defined(IP_RECVDSTADDR) |
1061 | char control[CMSG_SPACE(sizeof(struct in_addr)) + | |
1062 | CMSG_SPACE(sizeof(struct sockaddr_dl))]; | |
1063 | #endif | |
1064 | } control_u; | |
2329bef5 SK |
1065 | #ifdef HAVE_IPV6 |
1066 | /* Can always get recvd interface for IPv6 */ | |
1067 | int check_dst = !option_bool(OPT_NOWILD) || listen->family == AF_INET6; | |
1068 | #else | |
1069 | int check_dst = !option_bool(OPT_NOWILD); | |
1070 | #endif | |
1071 | ||
cdeda28f SK |
1072 | /* packet buffer overwritten */ |
1073 | daemon->srv_save = NULL; | |
1074 | ||
98906275 | 1075 | dst_addr_4.s_addr = dst_addr.addr.addr4.s_addr = 0; |
4f7b304f SK |
1076 | netmask.s_addr = 0; |
1077 | ||
7e5664bd | 1078 | if (option_bool(OPT_NOWILD) && listen->iface) |
3d8df260 | 1079 | { |
4f7b304f SK |
1080 | auth_dns = listen->iface->dns_auth; |
1081 | ||
1082 | if (listen->family == AF_INET) | |
1083 | { | |
98906275 | 1084 | dst_addr_4 = dst_addr.addr.addr4 = listen->iface->addr.in.sin_addr; |
4f7b304f SK |
1085 | netmask = listen->iface->netmask; |
1086 | } | |
3d8df260 | 1087 | } |
4f7b304f | 1088 | |
3be34541 SK |
1089 | iov[0].iov_base = daemon->packet; |
1090 | iov[0].iov_len = daemon->edns_pktsz; | |
44a2a316 SK |
1091 | |
1092 | msg.msg_control = control_u.control; | |
1093 | msg.msg_controllen = sizeof(control_u); | |
1094 | msg.msg_flags = 0; | |
1095 | msg.msg_name = &source_addr; | |
1096 | msg.msg_namelen = sizeof(source_addr); | |
1097 | msg.msg_iov = iov; | |
1098 | msg.msg_iovlen = 1; | |
1099 | ||
de37951c | 1100 | if ((n = recvmsg(listen->fd, &msg, 0)) == -1) |
3be34541 | 1101 | return; |
44a2a316 | 1102 | |
572b41eb | 1103 | if (n < (int)sizeof(struct dns_header) || |
5e9e0efb | 1104 | (msg.msg_flags & MSG_TRUNC) || |
572b41eb | 1105 | (header->hb3 & HB3_QR)) |
26128d27 SK |
1106 | return; |
1107 | ||
44a2a316 | 1108 | source_addr.sa.sa_family = listen->family; |
2a7a2b84 SK |
1109 | |
1110 | if (listen->family == AF_INET) | |
1111 | { | |
1112 | /* Source-port == 0 is an error, we can't send back to that. | |
1113 | http://www.ietf.org/mail-archive/web/dnsop/current/msg11441.html */ | |
1114 | if (source_addr.in.sin_port == 0) | |
1115 | return; | |
1116 | } | |
44a2a316 | 1117 | #ifdef HAVE_IPV6 |
2a7a2b84 SK |
1118 | else |
1119 | { | |
1120 | /* Source-port == 0 is an error, we can't send back to that. */ | |
1121 | if (source_addr.in6.sin6_port == 0) | |
1122 | return; | |
1123 | source_addr.in6.sin6_flowinfo = 0; | |
1124 | } | |
44a2a316 | 1125 | #endif |
2a7a2b84 | 1126 | |
c8a80487 SK |
1127 | /* We can be configured to only accept queries from at-most-one-hop-away addresses. */ |
1128 | if (option_bool(OPT_LOCAL_SERVICE)) | |
1129 | { | |
1130 | struct addrlist *addr; | |
1131 | #ifdef HAVE_IPV6 | |
1132 | if (listen->family == AF_INET6) | |
1133 | { | |
1134 | for (addr = daemon->interface_addrs; addr; addr = addr->next) | |
1135 | if ((addr->flags & ADDRLIST_IPV6) && | |
1136 | is_same_net6(&addr->addr.addr.addr6, &source_addr.in6.sin6_addr, addr->prefixlen)) | |
1137 | break; | |
1138 | } | |
1139 | else | |
1140 | #endif | |
1141 | { | |
1142 | struct in_addr netmask; | |
1143 | for (addr = daemon->interface_addrs; addr; addr = addr->next) | |
1144 | { | |
15b1b7e9 | 1145 | netmask.s_addr = htonl(~(in_addr_t)0 << (32 - addr->prefixlen)); |
c8a80487 SK |
1146 | if (!(addr->flags & ADDRLIST_IPV6) && |
1147 | is_same_net(addr->addr.addr.addr4, source_addr.in.sin_addr, netmask)) | |
1148 | break; | |
1149 | } | |
1150 | } | |
1151 | if (!addr) | |
1152 | { | |
0c8584ea SK |
1153 | static int warned = 0; |
1154 | if (!warned) | |
1155 | { | |
1156 | my_syslog(LOG_WARNING, _("Ignoring query from non-local network")); | |
1157 | warned = 1; | |
1158 | } | |
c8a80487 SK |
1159 | return; |
1160 | } | |
1161 | } | |
1162 | ||
2329bef5 | 1163 | if (check_dst) |
26128d27 SK |
1164 | { |
1165 | struct ifreq ifr; | |
1166 | ||
1167 | if (msg.msg_controllen < sizeof(struct cmsghdr)) | |
1168 | return; | |
44a2a316 | 1169 | |
5e9e0efb | 1170 | #if defined(HAVE_LINUX_NETWORK) |
26128d27 SK |
1171 | if (listen->family == AF_INET) |
1172 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) | |
c72daea8 | 1173 | if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_PKTINFO) |
26128d27 | 1174 | { |
8ef5ada2 SK |
1175 | union { |
1176 | unsigned char *c; | |
1177 | struct in_pktinfo *p; | |
1178 | } p; | |
1179 | p.c = CMSG_DATA(cmptr); | |
1180 | dst_addr_4 = dst_addr.addr.addr4 = p.p->ipi_spec_dst; | |
1181 | if_index = p.p->ipi_ifindex; | |
26128d27 SK |
1182 | } |
1183 | #elif defined(IP_RECVDSTADDR) && defined(IP_RECVIF) | |
1184 | if (listen->family == AF_INET) | |
44a2a316 | 1185 | { |
26128d27 | 1186 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) |
8ef5ada2 SK |
1187 | { |
1188 | union { | |
1189 | unsigned char *c; | |
1190 | unsigned int *i; | |
1191 | struct in_addr *a; | |
1192 | #ifndef HAVE_SOLARIS_NETWORK | |
1193 | struct sockaddr_dl *s; | |
1194 | #endif | |
1195 | } p; | |
1196 | p.c = CMSG_DATA(cmptr); | |
1197 | if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVDSTADDR) | |
1198 | dst_addr_4 = dst_addr.addr.addr4 = *(p.a); | |
1199 | else if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVIF) | |
824af85b | 1200 | #ifdef HAVE_SOLARIS_NETWORK |
8ef5ada2 | 1201 | if_index = *(p.i); |
824af85b | 1202 | #else |
8ef5ada2 | 1203 | if_index = p.s->sdl_index; |
824af85b | 1204 | #endif |
8ef5ada2 | 1205 | } |
44a2a316 | 1206 | } |
44a2a316 | 1207 | #endif |
26128d27 | 1208 | |
44a2a316 | 1209 | #ifdef HAVE_IPV6 |
26128d27 SK |
1210 | if (listen->family == AF_INET6) |
1211 | { | |
1212 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) | |
c72daea8 | 1213 | if (cmptr->cmsg_level == IPPROTO_IPV6 && cmptr->cmsg_type == daemon->v6pktinfo) |
26128d27 | 1214 | { |
8ef5ada2 SK |
1215 | union { |
1216 | unsigned char *c; | |
1217 | struct in6_pktinfo *p; | |
1218 | } p; | |
1219 | p.c = CMSG_DATA(cmptr); | |
1220 | ||
1221 | dst_addr.addr.addr6 = p.p->ipi6_addr; | |
1222 | if_index = p.p->ipi6_ifindex; | |
26128d27 SK |
1223 | } |
1224 | } | |
44a2a316 | 1225 | #endif |
26128d27 SK |
1226 | |
1227 | /* enforce available interface configuration */ | |
1228 | ||
e25db1f2 | 1229 | if (!indextoname(listen->fd, if_index, ifr.ifr_name)) |
5e9e0efb | 1230 | return; |
832af0ba | 1231 | |
e25db1f2 SK |
1232 | if (!iface_check(listen->family, &dst_addr, ifr.ifr_name, &auth_dns)) |
1233 | { | |
1234 | if (!option_bool(OPT_CLEVERBIND)) | |
115ac3e4 | 1235 | enumerate_interfaces(0); |
3f2873d4 SK |
1236 | if (!loopback_exception(listen->fd, listen->family, &dst_addr, ifr.ifr_name) && |
1237 | !label_exception(if_index, listen->family, &dst_addr)) | |
e25db1f2 SK |
1238 | return; |
1239 | } | |
1240 | ||
552af8b9 SK |
1241 | if (listen->family == AF_INET && option_bool(OPT_LOCALISE)) |
1242 | { | |
1243 | struct irec *iface; | |
1244 | ||
1245 | /* get the netmask of the interface whch has the address we were sent to. | |
1246 | This is no neccessarily the interface we arrived on. */ | |
1247 | ||
1248 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1249 | if (iface->addr.sa.sa_family == AF_INET && | |
1250 | iface->addr.in.sin_addr.s_addr == dst_addr_4.s_addr) | |
1251 | break; | |
1252 | ||
1253 | /* interface may be new */ | |
e25db1f2 | 1254 | if (!iface && !option_bool(OPT_CLEVERBIND)) |
115ac3e4 | 1255 | enumerate_interfaces(0); |
552af8b9 SK |
1256 | |
1257 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1258 | if (iface->addr.sa.sa_family == AF_INET && | |
1259 | iface->addr.in.sin_addr.s_addr == dst_addr_4.s_addr) | |
1260 | break; | |
1261 | ||
1262 | /* If we failed, abandon localisation */ | |
1263 | if (iface) | |
1264 | netmask = iface->netmask; | |
1265 | else | |
1266 | dst_addr_4.s_addr = 0; | |
1267 | } | |
44a2a316 | 1268 | } |
25cf5e37 SK |
1269 | |
1270 | /* log_query gets called indirectly all over the place, so | |
1271 | pass these in global variables - sorry. */ | |
1272 | daemon->log_display_id = ++daemon->log_id; | |
1273 | daemon->log_source_addr = &source_addr; | |
44a2a316 | 1274 | |
cdeda28f | 1275 | if (extract_request(header, (size_t)n, daemon->namebuff, &type)) |
44a2a316 | 1276 | { |
b485ed97 SK |
1277 | #ifdef HAVE_AUTH |
1278 | struct auth_zone *zone; | |
1279 | #endif | |
610e782a SK |
1280 | char *types = querystr(auth_dns ? "auth" : "query", type); |
1281 | ||
44a2a316 | 1282 | if (listen->family == AF_INET) |
3be34541 | 1283 | log_query(F_QUERY | F_IPV4 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 1284 | (struct all_addr *)&source_addr.in.sin_addr, types); |
44a2a316 SK |
1285 | #ifdef HAVE_IPV6 |
1286 | else | |
3be34541 | 1287 | log_query(F_QUERY | F_IPV6 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 1288 | (struct all_addr *)&source_addr.in6.sin6_addr, types); |
44a2a316 | 1289 | #endif |
44a2a316 | 1290 | |
b485ed97 SK |
1291 | #ifdef HAVE_AUTH |
1292 | /* find queries for zones we're authoritative for, and answer them directly */ | |
6008bdbb SK |
1293 | if (!auth_dns) |
1294 | for (zone = daemon->auth_zones; zone; zone = zone->next) | |
1295 | if (in_zone(zone, daemon->namebuff, NULL)) | |
1296 | { | |
1297 | auth_dns = 1; | |
1298 | local_auth = 1; | |
1299 | break; | |
1300 | } | |
b485ed97 | 1301 | #endif |
b5ea1cc2 SK |
1302 | |
1303 | #ifdef HAVE_LOOP | |
1304 | /* Check for forwarding loop */ | |
1305 | if (detect_loop(daemon->namebuff, type)) | |
1306 | return; | |
1307 | #endif | |
b485ed97 SK |
1308 | } |
1309 | ||
4820dce9 | 1310 | #ifdef HAVE_AUTH |
4f7b304f | 1311 | if (auth_dns) |
824af85b | 1312 | { |
60b68069 | 1313 | m = answer_auth(header, ((char *) header) + daemon->packet_buff_sz, (size_t)n, now, &source_addr, local_auth); |
4f7b304f | 1314 | if (m >= 1) |
b485ed97 SK |
1315 | { |
1316 | send_from(listen->fd, option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND), | |
1317 | (char *)header, m, &source_addr, &dst_addr, if_index); | |
1318 | daemon->auth_answer++; | |
1319 | } | |
824af85b | 1320 | } |
44a2a316 | 1321 | else |
4820dce9 | 1322 | #endif |
4f7b304f | 1323 | { |
613ad15d | 1324 | int ad_reqd, do_bit; |
60b68069 | 1325 | m = answer_request(header, ((char *) header) + daemon->packet_buff_sz, (size_t)n, |
613ad15d | 1326 | dst_addr_4, netmask, now, &ad_reqd, &do_bit); |
4f7b304f SK |
1327 | |
1328 | if (m >= 1) | |
1329 | { | |
1330 | send_from(listen->fd, option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND), | |
1331 | (char *)header, m, &source_addr, &dst_addr, if_index); | |
1332 | daemon->local_answer++; | |
1333 | } | |
1334 | else if (forward_query(listen->fd, &source_addr, &dst_addr, if_index, | |
613ad15d | 1335 | header, (size_t)n, now, NULL, ad_reqd, do_bit)) |
4f7b304f SK |
1336 | daemon->queries_forwarded++; |
1337 | else | |
1338 | daemon->local_answer++; | |
1339 | } | |
44a2a316 SK |
1340 | } |
1341 | ||
7d7b7b31 | 1342 | #ifdef HAVE_DNSSEC |
00a5b5d4 SK |
1343 | |
1344 | /* UDP: we've got an unsigned answer, return STAT_INSECURE if we can prove there's no DS | |
1345 | and therefore the answer shouldn't be signed, or STAT_BOGUS if it should be, or | |
1346 | STAT_NEED_DS_NEG and keyname if we need to do the query. */ | |
97e618a0 SK |
1347 | static int send_check_sign(struct frec *forward, time_t now, struct dns_header *header, size_t plen, |
1348 | char *name, char *keyname) | |
00a5b5d4 | 1349 | { |
00a5b5d4 SK |
1350 | int status = dnssec_chase_cname(now, header, plen, name, keyname); |
1351 | ||
1352 | if (status != STAT_INSECURE) | |
1353 | return status; | |
1354 | ||
97e618a0 SK |
1355 | /* Store the domain we're trying to check. */ |
1356 | forward->name_start = strlen(name); | |
1357 | forward->name_len = forward->name_start + 1; | |
1358 | if (!(forward->orig_domain = blockdata_alloc(name, forward->name_len))) | |
1359 | return STAT_BOGUS; | |
1360 | ||
1361 | return do_check_sign(forward, 0, now, name, keyname); | |
1362 | } | |
1363 | ||
1364 | /* We either have a a reply (header non-NULL, or we need to start by looking in the cache */ | |
1365 | static int do_check_sign(struct frec *forward, int status, time_t now, char *name, char *keyname) | |
1366 | { | |
1367 | /* get domain we're checking back from blockdata store, it's stored on the original query. */ | |
1368 | while (forward->dependent) | |
1369 | forward = forward->dependent; | |
1370 | ||
1371 | blockdata_retrieve(forward->orig_domain, forward->name_len, name); | |
1372 | ||
00a5b5d4 SK |
1373 | while (1) |
1374 | { | |
97e618a0 SK |
1375 | char *p; |
1376 | ||
1377 | if (status == 0) | |
00a5b5d4 | 1378 | { |
97e618a0 SK |
1379 | struct crec *crecp; |
1380 | ||
1381 | /* Haven't received answer, see if in cache */ | |
1382 | if (!(crecp = cache_find_by_name(NULL, &name[forward->name_start], now, F_DS))) | |
1383 | { | |
1384 | /* put name of DS record we're missing into keyname */ | |
1385 | strcpy(keyname, &name[forward->name_start]); | |
1386 | /* and wait for reply to arrive */ | |
1387 | return STAT_NEED_DS_NEG; | |
1388 | } | |
1389 | ||
1390 | /* F_DNSSECOK misused in DS cache records to non-existance of NS record */ | |
1391 | if (!(crecp->flags & F_NEG)) | |
1392 | status = STAT_SECURE; | |
1393 | else if (crecp->flags & F_DNSSECOK) | |
1394 | status = STAT_NO_DS; | |
1395 | else | |
1396 | status = STAT_NO_NS; | |
00a5b5d4 | 1397 | } |
97e618a0 SK |
1398 | |
1399 | /* Have entered non-signed part of DNS tree. */ | |
1400 | if (status == STAT_NO_DS) | |
1401 | return STAT_INSECURE; | |
00a5b5d4 | 1402 | |
97e618a0 | 1403 | if (status == STAT_BOGUS) |
4e1fe444 SK |
1404 | return STAT_BOGUS; |
1405 | ||
97e618a0 SK |
1406 | /* There's a proven DS record, or we're within a zone, where there doesn't need |
1407 | to be a DS record. Add a name and try again. | |
1408 | If we've already tried the whole name, then fail */ | |
00a5b5d4 | 1409 | |
97e618a0 SK |
1410 | if (forward->name_start == 0) |
1411 | return STAT_BOGUS; | |
4872aa74 | 1412 | |
97e618a0 SK |
1413 | for (p = &name[forward->name_start-2]; (*p != '.') && (p != name); p--); |
1414 | ||
1415 | if (p != name) | |
1416 | p++; | |
1417 | ||
1418 | forward->name_start = p - name; | |
1419 | status = 0; /* force to cache when we iterate. */ | |
00a5b5d4 | 1420 | } |
00a5b5d4 SK |
1421 | } |
1422 | ||
1423 | /* Move toward the root, until we find a signed non-existance of a DS, in which case | |
1424 | an unsigned answer is OK, or we find a signed DS, in which case there should be | |
1425 | a signature, and the answer is BOGUS */ | |
1426 | static int tcp_check_for_unsigned_zone(time_t now, struct dns_header *header, size_t plen, int class, char *name, | |
1427 | char *keyname, struct server *server, int *keycount) | |
1428 | { | |
1429 | size_t m; | |
1430 | unsigned char *packet, *payload; | |
1431 | u16 *length; | |
97e618a0 SK |
1432 | int status, name_len; |
1433 | struct blockdata *block; | |
1434 | ||
1435 | char *name_start; | |
00a5b5d4 SK |
1436 | |
1437 | /* Get first insecure entry in CNAME chain */ | |
1438 | status = tcp_key_recurse(now, STAT_CHASE_CNAME, header, plen, class, name, keyname, server, keycount); | |
1439 | if (status == STAT_BOGUS) | |
1440 | return STAT_BOGUS; | |
1441 | ||
1442 | if (!(packet = whine_malloc(65536 + MAXDNAME + RRFIXEDSZ + sizeof(u16)))) | |
1443 | return STAT_BOGUS; | |
1444 | ||
1445 | payload = &packet[2]; | |
1446 | header = (struct dns_header *)payload; | |
1447 | length = (u16 *)packet; | |
97e618a0 SK |
1448 | |
1449 | /* Stash the name away, since the buffer will be trashed when we recurse */ | |
1450 | name_len = strlen(name) + 1; | |
1451 | name_start = name + name_len - 1; | |
00a5b5d4 | 1452 | |
97e618a0 SK |
1453 | if (!(block = blockdata_alloc(name, name_len))) |
1454 | { | |
1455 | free(packet); | |
1456 | return STAT_BOGUS; | |
1457 | } | |
1458 | ||
00a5b5d4 SK |
1459 | while (1) |
1460 | { | |
00a5b5d4 | 1461 | unsigned char c1, c2; |
97e618a0 SK |
1462 | struct crec *crecp; |
1463 | ||
00a5b5d4 | 1464 | if (--(*keycount) == 0) |
fc2833f1 TH |
1465 | { |
1466 | free(packet); | |
97e618a0 | 1467 | blockdata_free(block); |
fc2833f1 TH |
1468 | return STAT_BOGUS; |
1469 | } | |
00a5b5d4 | 1470 | |
424c4a8a | 1471 | while ((crecp = cache_find_by_name(NULL, name_start, now, F_DS))) |
97e618a0 SK |
1472 | { |
1473 | if ((crecp->flags & F_NEG) && (crecp->flags & F_DNSSECOK)) | |
1474 | { | |
1475 | /* Found a secure denial of DS - delegation is indeed insecure */ | |
1476 | free(packet); | |
1477 | blockdata_free(block); | |
1478 | return STAT_INSECURE; | |
1479 | } | |
1480 | ||
1481 | /* Here, either there's a secure DS, or no NS and no DS, and therefore no delegation. | |
1482 | Add another label and continue. */ | |
1483 | ||
1484 | if (name_start == name) | |
1485 | { | |
1486 | free(packet); | |
1487 | blockdata_free(block); | |
1488 | return STAT_BOGUS; /* run out of labels */ | |
1489 | } | |
1490 | ||
1491 | name_start -= 2; | |
1492 | while (*name_start != '.' && name_start != name) | |
1493 | name_start--; | |
1494 | if (name_start != name) | |
1495 | name_start++; | |
4e1fe444 | 1496 | } |
97e618a0 SK |
1497 | |
1498 | /* Can't find it in the cache, have to send a query */ | |
4e1fe444 | 1499 | |
00a5b5d4 SK |
1500 | m = dnssec_generate_query(header, ((char *) header) + 65536, name_start, class, T_DS, &server->addr); |
1501 | ||
97e618a0 | 1502 | *length = htons(m); |
b37f8b99 | 1503 | |
97e618a0 SK |
1504 | if (read_write(server->tcpfd, packet, m + sizeof(u16), 0) && |
1505 | read_write(server->tcpfd, &c1, 1, 1) && | |
1506 | read_write(server->tcpfd, &c2, 1, 1) && | |
1507 | read_write(server->tcpfd, payload, (c1 << 8) | c2, 1)) | |
1508 | { | |
1509 | m = (c1 << 8) | c2; | |
00a5b5d4 | 1510 | |
97e618a0 SK |
1511 | /* Note this trashes all three name workspaces */ |
1512 | status = tcp_key_recurse(now, STAT_NEED_DS_NEG, header, m, class, name, keyname, server, keycount); | |
1513 | ||
1514 | if (status == STAT_NO_DS) | |
00a5b5d4 | 1515 | { |
97e618a0 SK |
1516 | /* Found a secure denial of DS - delegation is indeed insecure */ |
1517 | free(packet); | |
1518 | blockdata_free(block); | |
1519 | return STAT_INSECURE; | |
1520 | } | |
1521 | ||
1522 | if (status == STAT_BOGUS) | |
1523 | { | |
1524 | free(packet); | |
1525 | blockdata_free(block); | |
1526 | return STAT_BOGUS; | |
1527 | } | |
1528 | ||
1529 | /* Here, either there's a secure DS, or no NS and no DS, and therefore no delegation. | |
1530 | Add another label and continue. */ | |
1531 | ||
1532 | /* Get name we're checking back. */ | |
1533 | blockdata_retrieve(block, name_len, name); | |
1534 | ||
1535 | if (name_start == name) | |
1536 | { | |
1537 | free(packet); | |
1538 | blockdata_free(block); | |
1539 | return STAT_BOGUS; /* run out of labels */ | |
00a5b5d4 | 1540 | } |
97e618a0 SK |
1541 | |
1542 | name_start -= 2; | |
1543 | while (*name_start != '.' && name_start != name) | |
1544 | name_start--; | |
1545 | if (name_start != name) | |
1546 | name_start++; | |
1547 | } | |
1548 | else | |
1549 | { | |
1550 | /* IO failure */ | |
1551 | free(packet); | |
1552 | blockdata_free(block); | |
1553 | return STAT_BOGUS; /* run out of labels */ | |
00a5b5d4 | 1554 | } |
00a5b5d4 SK |
1555 | } |
1556 | } | |
1557 | ||
7fa836e1 SK |
1558 | static int tcp_key_recurse(time_t now, int status, struct dns_header *header, size_t n, |
1559 | int class, char *name, char *keyname, struct server *server, int *keycount) | |
7d7b7b31 SK |
1560 | { |
1561 | /* Recurse up the key heirarchy */ | |
7d7b7b31 | 1562 | int new_status; |
7d7b7b31 | 1563 | |
7fa836e1 SK |
1564 | /* limit the amount of work we do, to avoid cycling forever on loops in the DNS */ |
1565 | if (--(*keycount) == 0) | |
1566 | return STAT_INSECURE; | |
7d7b7b31 | 1567 | |
7fa836e1 SK |
1568 | if (status == STAT_NEED_KEY) |
1569 | new_status = dnssec_validate_by_ds(now, header, n, name, keyname, class); | |
00a5b5d4 SK |
1570 | else if (status == STAT_NEED_DS || status == STAT_NEED_DS_NEG) |
1571 | { | |
1572 | new_status = dnssec_validate_ds(now, header, n, name, keyname, class); | |
97e618a0 SK |
1573 | if (status == STAT_NEED_DS && (new_status == STAT_NO_DS || new_status == STAT_NO_NS)) |
1574 | new_status = STAT_BOGUS; | |
00a5b5d4 SK |
1575 | } |
1576 | else if (status == STAT_CHASE_CNAME) | |
1577 | new_status = dnssec_chase_cname(now, header, n, name, keyname); | |
1578 | else | |
1579 | { | |
97e618a0 | 1580 | new_status = dnssec_validate_reply(now, header, n, name, keyname, &class, NULL, NULL); |
00a5b5d4 SK |
1581 | |
1582 | if (new_status == STAT_NO_SIG) | |
1583 | { | |
1584 | if (option_bool(OPT_DNSSEC_NO_SIGN)) | |
1585 | new_status = tcp_check_for_unsigned_zone(now, header, n, class, name, keyname, server, keycount); | |
1586 | else | |
1587 | new_status = STAT_INSECURE; | |
1588 | } | |
1589 | } | |
1590 | ||
7fa836e1 SK |
1591 | /* Can't validate because we need a key/DS whose name now in keyname. |
1592 | Make query for same, and recurse to validate */ | |
1593 | if (new_status == STAT_NEED_DS || new_status == STAT_NEED_KEY) | |
7d7b7b31 | 1594 | { |
7fa836e1 SK |
1595 | size_t m; |
1596 | unsigned char *packet = whine_malloc(65536 + MAXDNAME + RRFIXEDSZ + sizeof(u16)); | |
1597 | unsigned char *payload = &packet[2]; | |
1598 | struct dns_header *new_header = (struct dns_header *)payload; | |
1599 | u16 *length = (u16 *)packet; | |
1600 | unsigned char c1, c2; | |
1601 | ||
1602 | if (!packet) | |
1603 | return STAT_INSECURE; | |
1604 | ||
1605 | another_tcp_key: | |
1606 | m = dnssec_generate_query(new_header, ((char *) new_header) + 65536, keyname, class, | |
1607 | new_status == STAT_NEED_KEY ? T_DNSKEY : T_DS, &server->addr); | |
7d7b7b31 | 1608 | |
7fa836e1 | 1609 | *length = htons(m); |
7d7b7b31 | 1610 | |
7fa836e1 SK |
1611 | if (!read_write(server->tcpfd, packet, m + sizeof(u16), 0) || |
1612 | !read_write(server->tcpfd, &c1, 1, 1) || | |
1613 | !read_write(server->tcpfd, &c2, 1, 1) || | |
1614 | !read_write(server->tcpfd, payload, (c1 << 8) | c2, 1)) | |
1615 | new_status = STAT_INSECURE; | |
1616 | else | |
7d7b7b31 | 1617 | { |
7fa836e1 SK |
1618 | m = (c1 << 8) | c2; |
1619 | ||
00a5b5d4 SK |
1620 | new_status = tcp_key_recurse(now, new_status, new_header, m, class, name, keyname, server, keycount); |
1621 | ||
1622 | if (new_status == STAT_SECURE) | |
7d7b7b31 | 1623 | { |
7fa836e1 SK |
1624 | /* Reached a validated record, now try again at this level. |
1625 | Note that we may get ANOTHER NEED_* if an answer needs more than one key. | |
1626 | If so, go round again. */ | |
7d7b7b31 | 1627 | |
7fa836e1 SK |
1628 | if (status == STAT_NEED_KEY) |
1629 | new_status = dnssec_validate_by_ds(now, header, n, name, keyname, class); | |
00a5b5d4 SK |
1630 | else if (status == STAT_NEED_DS || status == STAT_NEED_DS_NEG) |
1631 | { | |
1632 | new_status = dnssec_validate_ds(now, header, n, name, keyname, class); | |
97e618a0 SK |
1633 | if (status == STAT_NEED_DS && (new_status == STAT_NO_DS || new_status == STAT_NO_NS)) |
1634 | new_status = STAT_BOGUS; /* Validated no DS */ | |
00a5b5d4 SK |
1635 | } |
1636 | else if (status == STAT_CHASE_CNAME) | |
1637 | new_status = dnssec_chase_cname(now, header, n, name, keyname); | |
1638 | else | |
1639 | { | |
97e618a0 | 1640 | new_status = dnssec_validate_reply(now, header, n, name, keyname, &class, NULL, NULL); |
00a5b5d4 SK |
1641 | |
1642 | if (new_status == STAT_NO_SIG) | |
1643 | { | |
1644 | if (option_bool(OPT_DNSSEC_NO_SIGN)) | |
1645 | new_status = tcp_check_for_unsigned_zone(now, header, n, class, name, keyname, server, keycount); | |
1646 | else | |
1647 | new_status = STAT_INSECURE; | |
1648 | } | |
1649 | } | |
1650 | ||
7d7b7b31 | 1651 | if (new_status == STAT_NEED_DS || new_status == STAT_NEED_KEY) |
7fa836e1 | 1652 | goto another_tcp_key; |
7d7b7b31 SK |
1653 | } |
1654 | } | |
7d7b7b31 | 1655 | |
7fa836e1 SK |
1656 | free(packet); |
1657 | } | |
7d7b7b31 SK |
1658 | return new_status; |
1659 | } | |
1660 | #endif | |
1661 | ||
1662 | ||
feba5c1d SK |
1663 | /* The daemon forks before calling this: it should deal with one connection, |
1664 | blocking as neccessary, and then return. Note, need to be a bit careful | |
1665 | about resources for debug mode, when the fork is suppressed: that's | |
1666 | done by the caller. */ | |
5aabfc78 | 1667 | unsigned char *tcp_request(int confd, time_t now, |
4f7b304f | 1668 | union mysockaddr *local_addr, struct in_addr netmask, int auth_dns) |
feba5c1d | 1669 | { |
28866e95 SK |
1670 | size_t size = 0; |
1671 | int norebind = 0; | |
3b195961 | 1672 | #ifdef HAVE_AUTH |
19b16891 | 1673 | int local_auth = 0; |
3b195961 | 1674 | #endif |
613ad15d SK |
1675 | int checking_disabled, ad_question, do_bit, added_pheader = 0; |
1676 | int check_subnet, no_cache_dnssec = 0, cache_secure = 0; | |
cdeda28f | 1677 | size_t m; |
ee86ce68 SK |
1678 | unsigned short qtype; |
1679 | unsigned int gotname; | |
feba5c1d | 1680 | unsigned char c1, c2; |
4b5ea12e SK |
1681 | /* Max TCP packet + slop + size */ |
1682 | unsigned char *packet = whine_malloc(65536 + MAXDNAME + RRFIXEDSZ + sizeof(u16)); | |
1683 | unsigned char *payload = &packet[2]; | |
1684 | /* largest field in header is 16-bits, so this is still sufficiently aligned */ | |
1685 | struct dns_header *header = (struct dns_header *)payload; | |
1686 | u16 *length = (u16 *)packet; | |
3be34541 | 1687 | struct server *last_server; |
7de060b0 SK |
1688 | struct in_addr dst_addr_4; |
1689 | union mysockaddr peer_addr; | |
1690 | socklen_t peer_len = sizeof(union mysockaddr); | |
25cf5e37 SK |
1691 | int query_count = 0; |
1692 | ||
7de060b0 SK |
1693 | if (getpeername(confd, (struct sockaddr *)&peer_addr, &peer_len) == -1) |
1694 | return packet; | |
c8a80487 SK |
1695 | |
1696 | /* We can be configured to only accept queries from at-most-one-hop-away addresses. */ | |
1697 | if (option_bool(OPT_LOCAL_SERVICE)) | |
1698 | { | |
1699 | struct addrlist *addr; | |
1700 | #ifdef HAVE_IPV6 | |
1701 | if (peer_addr.sa.sa_family == AF_INET6) | |
1702 | { | |
1703 | for (addr = daemon->interface_addrs; addr; addr = addr->next) | |
1704 | if ((addr->flags & ADDRLIST_IPV6) && | |
1705 | is_same_net6(&addr->addr.addr.addr6, &peer_addr.in6.sin6_addr, addr->prefixlen)) | |
1706 | break; | |
1707 | } | |
1708 | else | |
1709 | #endif | |
1710 | { | |
1711 | struct in_addr netmask; | |
1712 | for (addr = daemon->interface_addrs; addr; addr = addr->next) | |
1713 | { | |
15b1b7e9 | 1714 | netmask.s_addr = htonl(~(in_addr_t)0 << (32 - addr->prefixlen)); |
c8a80487 SK |
1715 | if (!(addr->flags & ADDRLIST_IPV6) && |
1716 | is_same_net(addr->addr.addr.addr4, peer_addr.in.sin_addr, netmask)) | |
1717 | break; | |
1718 | } | |
1719 | } | |
1720 | if (!addr) | |
1721 | { | |
1722 | my_syslog(LOG_WARNING, _("Ignoring query from non-local network")); | |
1723 | return packet; | |
1724 | } | |
1725 | } | |
7de060b0 | 1726 | |
feba5c1d SK |
1727 | while (1) |
1728 | { | |
25cf5e37 SK |
1729 | if (query_count == TCP_MAX_QUERIES || |
1730 | !packet || | |
feba5c1d SK |
1731 | !read_write(confd, &c1, 1, 1) || !read_write(confd, &c2, 1, 1) || |
1732 | !(size = c1 << 8 | c2) || | |
4b5ea12e | 1733 | !read_write(confd, payload, size, 1)) |
feba5c1d SK |
1734 | return packet; |
1735 | ||
572b41eb | 1736 | if (size < (int)sizeof(struct dns_header)) |
feba5c1d SK |
1737 | continue; |
1738 | ||
25cf5e37 SK |
1739 | query_count++; |
1740 | ||
1741 | /* log_query gets called indirectly all over the place, so | |
1742 | pass these in global variables - sorry. */ | |
1743 | daemon->log_display_id = ++daemon->log_id; | |
1744 | daemon->log_source_addr = &peer_addr; | |
1745 | ||
ed4c0767 SK |
1746 | check_subnet = 0; |
1747 | ||
28866e95 | 1748 | /* save state of "cd" flag in query */ |
7d7b7b31 SK |
1749 | if ((checking_disabled = header->hb4 & HB4_CD)) |
1750 | no_cache_dnssec = 1; | |
28866e95 | 1751 | |
3be34541 | 1752 | if ((gotname = extract_request(header, (unsigned int)size, daemon->namebuff, &qtype))) |
feba5c1d | 1753 | { |
b485ed97 SK |
1754 | #ifdef HAVE_AUTH |
1755 | struct auth_zone *zone; | |
1756 | #endif | |
610e782a | 1757 | char *types = querystr(auth_dns ? "auth" : "query", qtype); |
7de060b0 SK |
1758 | |
1759 | if (peer_addr.sa.sa_family == AF_INET) | |
1760 | log_query(F_QUERY | F_IPV4 | F_FORWARD, daemon->namebuff, | |
1761 | (struct all_addr *)&peer_addr.in.sin_addr, types); | |
feba5c1d | 1762 | #ifdef HAVE_IPV6 |
7de060b0 SK |
1763 | else |
1764 | log_query(F_QUERY | F_IPV6 | F_FORWARD, daemon->namebuff, | |
1765 | (struct all_addr *)&peer_addr.in6.sin6_addr, types); | |
feba5c1d | 1766 | #endif |
b485ed97 SK |
1767 | |
1768 | #ifdef HAVE_AUTH | |
1769 | /* find queries for zones we're authoritative for, and answer them directly */ | |
6008bdbb SK |
1770 | if (!auth_dns) |
1771 | for (zone = daemon->auth_zones; zone; zone = zone->next) | |
1772 | if (in_zone(zone, daemon->namebuff, NULL)) | |
1773 | { | |
1774 | auth_dns = 1; | |
1775 | local_auth = 1; | |
1776 | break; | |
1777 | } | |
b485ed97 | 1778 | #endif |
feba5c1d SK |
1779 | } |
1780 | ||
7de060b0 SK |
1781 | if (local_addr->sa.sa_family == AF_INET) |
1782 | dst_addr_4 = local_addr->in.sin_addr; | |
1783 | else | |
1784 | dst_addr_4.s_addr = 0; | |
1785 | ||
4820dce9 | 1786 | #ifdef HAVE_AUTH |
4f7b304f | 1787 | if (auth_dns) |
19b16891 | 1788 | m = answer_auth(header, ((char *) header) + 65536, (size_t)size, now, &peer_addr, local_auth); |
4f7b304f | 1789 | else |
4820dce9 | 1790 | #endif |
feba5c1d | 1791 | { |
4f7b304f SK |
1792 | /* m > 0 if answered from cache */ |
1793 | m = answer_request(header, ((char *) header) + 65536, (size_t)size, | |
613ad15d | 1794 | dst_addr_4, netmask, now, &ad_question, &do_bit); |
feba5c1d | 1795 | |
4f7b304f SK |
1796 | /* Do this by steam now we're not in the select() loop */ |
1797 | check_log_writer(NULL); | |
1798 | ||
1799 | if (m == 0) | |
feba5c1d | 1800 | { |
4f7b304f SK |
1801 | unsigned int flags = 0; |
1802 | struct all_addr *addrp = NULL; | |
1803 | int type = 0; | |
1804 | char *domain = NULL; | |
feba5c1d | 1805 | |
4f7b304f SK |
1806 | if (option_bool(OPT_ADD_MAC)) |
1807 | size = add_mac(header, size, ((char *) header) + 65536, &peer_addr); | |
ed4c0767 SK |
1808 | |
1809 | if (option_bool(OPT_CLIENT_SUBNET)) | |
1810 | { | |
1811 | size_t new = add_source_addr(header, size, ((char *) header) + 65536, &peer_addr); | |
1812 | if (size != new) | |
1813 | { | |
1814 | size = new; | |
1815 | check_subnet = 1; | |
1816 | } | |
1817 | } | |
1818 | ||
4f7b304f SK |
1819 | if (gotname) |
1820 | flags = search_servers(now, &addrp, gotname, daemon->namebuff, &type, &domain, &norebind); | |
1821 | ||
1822 | if (type != 0 || option_bool(OPT_ORDER) || !daemon->last_server) | |
1823 | last_server = daemon->servers; | |
1824 | else | |
1825 | last_server = daemon->last_server; | |
1826 | ||
1827 | if (!flags && last_server) | |
1828 | { | |
1829 | struct server *firstsendto = NULL; | |
8a9be9e4 | 1830 | #ifdef HAVE_DNSSEC |
703c7ff4 | 1831 | unsigned char *newhash, hash[HASH_SIZE]; |
63758384 | 1832 | if ((newhash = hash_questions(header, (unsigned int)size, daemon->namebuff))) |
8a9be9e4 | 1833 | memcpy(hash, newhash, HASH_SIZE); |
b37f8b99 TH |
1834 | else |
1835 | memset(hash, 0, HASH_SIZE); | |
8a9be9e4 | 1836 | #else |
4f7b304f | 1837 | unsigned int crc = questions_crc(header, (unsigned int)size, daemon->namebuff); |
8a9be9e4 | 1838 | #endif |
4f7b304f SK |
1839 | /* Loop round available servers until we succeed in connecting to one. |
1840 | Note that this code subtley ensures that consecutive queries on this connection | |
1841 | which can go to the same server, do so. */ | |
1842 | while (1) | |
feba5c1d | 1843 | { |
4f7b304f SK |
1844 | if (!firstsendto) |
1845 | firstsendto = last_server; | |
1846 | else | |
1847 | { | |
1848 | if (!(last_server = last_server->next)) | |
1849 | last_server = daemon->servers; | |
1850 | ||
1851 | if (last_server == firstsendto) | |
1852 | break; | |
1853 | } | |
1854 | ||
1855 | /* server for wrong domain */ | |
1856 | if (type != (last_server->flags & SERV_TYPE) || | |
b5ea1cc2 SK |
1857 | (type == SERV_HAS_DOMAIN && !hostname_isequal(domain, last_server->domain)) || |
1858 | (last_server->flags & (SERV_LITERAL_ADDRESS | SERV_LOOP))) | |
7de060b0 SK |
1859 | continue; |
1860 | ||
4f7b304f | 1861 | if (last_server->tcpfd == -1) |
7de060b0 | 1862 | { |
4f7b304f SK |
1863 | if ((last_server->tcpfd = socket(last_server->addr.sa.sa_family, SOCK_STREAM, 0)) == -1) |
1864 | continue; | |
1865 | ||
e9828b6f KV |
1866 | #ifdef HAVE_CONNTRACK |
1867 | /* Copy connection mark of incoming query to outgoing connection. */ | |
1868 | if (option_bool(OPT_CONNTRACK)) | |
1869 | { | |
1870 | unsigned int mark; | |
1871 | struct all_addr local; | |
1872 | #ifdef HAVE_IPV6 | |
1873 | if (local_addr->sa.sa_family == AF_INET6) | |
1874 | local.addr.addr6 = local_addr->in6.sin6_addr; | |
1875 | else | |
1876 | #endif | |
1877 | local.addr.addr4 = local_addr->in.sin_addr; | |
1878 | ||
1879 | if (get_incoming_mark(&peer_addr, &local, 1, &mark)) | |
1880 | setsockopt(last_server->tcpfd, SOL_SOCKET, SO_MARK, &mark, sizeof(unsigned int)); | |
1881 | } | |
1882 | #endif | |
1883 | ||
4f7b304f SK |
1884 | if ((!local_bind(last_server->tcpfd, &last_server->source_addr, last_server->interface, 1) || |
1885 | connect(last_server->tcpfd, &last_server->addr.sa, sa_len(&last_server->addr)) == -1)) | |
1886 | { | |
1887 | close(last_server->tcpfd); | |
1888 | last_server->tcpfd = -1; | |
1889 | continue; | |
1890 | } | |
1891 | ||
7d7b7b31 SK |
1892 | #ifdef HAVE_DNSSEC |
1893 | if (option_bool(OPT_DNSSEC_VALID)) | |
1894 | { | |
613ad15d SK |
1895 | size_t new_size = add_do_bit(header, size, ((char *) header) + 65536); |
1896 | ||
2ecd9bd5 SK |
1897 | /* For debugging, set Checking Disabled, otherwise, have the upstream check too, |
1898 | this allows it to select auth servers when one is returning bad data. */ | |
1899 | if (option_bool(OPT_DNSSEC_DEBUG)) | |
1900 | header->hb4 |= HB4_CD; | |
613ad15d SK |
1901 | |
1902 | if (size != new_size) | |
1903 | added_pheader = 1; | |
1904 | ||
1905 | size = new_size; | |
7d7b7b31 SK |
1906 | } |
1907 | #endif | |
4f7b304f SK |
1908 | } |
1909 | ||
4b5ea12e | 1910 | *length = htons(size); |
1fc02680 SK |
1911 | |
1912 | /* get query name again for logging - may have been overwritten */ | |
1913 | if (!(gotname = extract_request(header, (unsigned int)size, daemon->namebuff, &qtype))) | |
1914 | strcpy(daemon->namebuff, "query"); | |
4f7b304f | 1915 | |
4b5ea12e | 1916 | if (!read_write(last_server->tcpfd, packet, size + sizeof(u16), 0) || |
4f7b304f | 1917 | !read_write(last_server->tcpfd, &c1, 1, 1) || |
7d7b7b31 SK |
1918 | !read_write(last_server->tcpfd, &c2, 1, 1) || |
1919 | !read_write(last_server->tcpfd, payload, (c1 << 8) | c2, 1)) | |
4f7b304f SK |
1920 | { |
1921 | close(last_server->tcpfd); | |
1922 | last_server->tcpfd = -1; | |
1923 | continue; | |
1924 | } | |
1925 | ||
1926 | m = (c1 << 8) | c2; | |
4f7b304f | 1927 | |
4f7b304f SK |
1928 | if (last_server->addr.sa.sa_family == AF_INET) |
1929 | log_query(F_SERVER | F_IPV4 | F_FORWARD, daemon->namebuff, | |
1930 | (struct all_addr *)&last_server->addr.in.sin_addr, NULL); | |
feba5c1d | 1931 | #ifdef HAVE_IPV6 |
4f7b304f SK |
1932 | else |
1933 | log_query(F_SERVER | F_IPV6 | F_FORWARD, daemon->namebuff, | |
1934 | (struct all_addr *)&last_server->addr.in6.sin6_addr, NULL); | |
feba5c1d | 1935 | #endif |
7d7b7b31 SK |
1936 | |
1937 | #ifdef HAVE_DNSSEC | |
1938 | if (option_bool(OPT_DNSSEC_VALID) && !checking_disabled) | |
1939 | { | |
7fa836e1 SK |
1940 | int keycount = DNSSEC_WORK; /* Limit to number of DNSSEC questions, to catch loops and avoid filling cache. */ |
1941 | int status = tcp_key_recurse(now, STAT_TRUNCATED, header, m, 0, daemon->namebuff, daemon->keyname, last_server, &keycount); | |
1942 | char *result; | |
1943 | ||
1944 | if (keycount == 0) | |
1945 | result = "ABANDONED"; | |
1946 | else | |
1947 | result = (status == STAT_SECURE ? "SECURE" : (status == STAT_INSECURE ? "INSECURE" : "BOGUS")); | |
7d7b7b31 | 1948 | |
7fa836e1 | 1949 | log_query(F_KEYTAG | F_SECSTAT, "result", NULL, result); |
7d7b7b31 | 1950 | |
7d7b7b31 SK |
1951 | if (status == STAT_BOGUS) |
1952 | no_cache_dnssec = 1; | |
7fa836e1 | 1953 | |
7d7b7b31 SK |
1954 | if (status == STAT_SECURE) |
1955 | cache_secure = 1; | |
1956 | } | |
1957 | #endif | |
1958 | ||
1959 | /* restore CD bit to the value in the query */ | |
1960 | if (checking_disabled) | |
1961 | header->hb4 |= HB4_CD; | |
1962 | else | |
1963 | header->hb4 &= ~HB4_CD; | |
4f7b304f SK |
1964 | |
1965 | /* There's no point in updating the cache, since this process will exit and | |
1966 | lose the information after a few queries. We make this call for the alias and | |
1967 | bogus-nxdomain side-effects. */ | |
1968 | /* If the crc of the question section doesn't match the crc we sent, then | |
1969 | someone might be attempting to insert bogus values into the cache by | |
1970 | sending replies containing questions and bogus answers. */ | |
8a9be9e4 SK |
1971 | #ifdef HAVE_DNSSEC |
1972 | newhash = hash_questions(header, (unsigned int)m, daemon->namebuff); | |
1973 | if (!newhash || memcmp(hash, newhash, HASH_SIZE) != 0) | |
703c7ff4 SK |
1974 | { |
1975 | m = 0; | |
1976 | break; | |
1977 | } | |
8a9be9e4 SK |
1978 | #else |
1979 | if (crc != questions_crc(header, (unsigned int)m, daemon->namebuff)) | |
703c7ff4 SK |
1980 | { |
1981 | m = 0; | |
1982 | break; | |
1983 | } | |
8a9be9e4 SK |
1984 | #endif |
1985 | ||
1986 | m = process_reply(header, now, last_server, (unsigned int)m, | |
1987 | option_bool(OPT_NO_REBIND) && !norebind, no_cache_dnssec, | |
613ad15d | 1988 | cache_secure, ad_question, do_bit, added_pheader, check_subnet, &peer_addr); |
4f7b304f SK |
1989 | |
1990 | break; | |
1991 | } | |
feba5c1d | 1992 | } |
4f7b304f SK |
1993 | |
1994 | /* In case of local answer or no connections made. */ | |
1995 | if (m == 0) | |
1996 | m = setup_reply(header, (unsigned int)size, addrp, flags, daemon->local_ttl); | |
feba5c1d | 1997 | } |
feba5c1d | 1998 | } |
4f7b304f | 1999 | |
5aabfc78 | 2000 | check_log_writer(NULL); |
feba5c1d | 2001 | |
4b5ea12e SK |
2002 | *length = htons(m); |
2003 | ||
2004 | if (m == 0 || !read_write(confd, packet, m + sizeof(u16), 0)) | |
feba5c1d SK |
2005 | return packet; |
2006 | } | |
2007 | } | |
2008 | ||
1697269c | 2009 | static struct frec *allocate_frec(time_t now) |
9e4abcb5 | 2010 | { |
1697269c SK |
2011 | struct frec *f; |
2012 | ||
5aabfc78 | 2013 | if ((f = (struct frec *)whine_malloc(sizeof(struct frec)))) |
9e4abcb5 | 2014 | { |
1a6bca81 | 2015 | f->next = daemon->frec_list; |
1697269c | 2016 | f->time = now; |
832af0ba | 2017 | f->sentto = NULL; |
1a6bca81 | 2018 | f->rfd4 = NULL; |
28866e95 | 2019 | f->flags = 0; |
1a6bca81 SK |
2020 | #ifdef HAVE_IPV6 |
2021 | f->rfd6 = NULL; | |
3a237152 SK |
2022 | #endif |
2023 | #ifdef HAVE_DNSSEC | |
97bc798b | 2024 | f->dependent = NULL; |
3a237152 | 2025 | f->blocking_query = NULL; |
4619d946 | 2026 | f->stash = NULL; |
97e618a0 | 2027 | f->orig_domain = NULL; |
1a6bca81 SK |
2028 | #endif |
2029 | daemon->frec_list = f; | |
1697269c | 2030 | } |
9e4abcb5 | 2031 | |
1697269c SK |
2032 | return f; |
2033 | } | |
9e4abcb5 | 2034 | |
b5ea1cc2 | 2035 | struct randfd *allocate_rfd(int family) |
1a6bca81 SK |
2036 | { |
2037 | static int finger = 0; | |
2038 | int i; | |
2039 | ||
2040 | /* limit the number of sockets we have open to avoid starvation of | |
2041 | (eg) TFTP. Once we have a reasonable number, randomness should be OK */ | |
2042 | ||
2043 | for (i = 0; i < RANDOM_SOCKS; i++) | |
9009d746 | 2044 | if (daemon->randomsocks[i].refcount == 0) |
1a6bca81 | 2045 | { |
9009d746 SK |
2046 | if ((daemon->randomsocks[i].fd = random_sock(family)) == -1) |
2047 | break; | |
2048 | ||
1a6bca81 SK |
2049 | daemon->randomsocks[i].refcount = 1; |
2050 | daemon->randomsocks[i].family = family; | |
2051 | return &daemon->randomsocks[i]; | |
2052 | } | |
2053 | ||
9009d746 | 2054 | /* No free ones or cannot get new socket, grab an existing one */ |
1a6bca81 SK |
2055 | for (i = 0; i < RANDOM_SOCKS; i++) |
2056 | { | |
2057 | int j = (i+finger) % RANDOM_SOCKS; | |
9009d746 SK |
2058 | if (daemon->randomsocks[j].refcount != 0 && |
2059 | daemon->randomsocks[j].family == family && | |
2060 | daemon->randomsocks[j].refcount != 0xffff) | |
1a6bca81 SK |
2061 | { |
2062 | finger = j; | |
2063 | daemon->randomsocks[j].refcount++; | |
2064 | return &daemon->randomsocks[j]; | |
2065 | } | |
2066 | } | |
2067 | ||
2068 | return NULL; /* doom */ | |
2069 | } | |
b5ea1cc2 SK |
2070 | |
2071 | void free_rfd(struct randfd *rfd) | |
2072 | { | |
2073 | if (rfd && --(rfd->refcount) == 0) | |
2074 | close(rfd->fd); | |
2075 | } | |
2076 | ||
1a6bca81 SK |
2077 | static void free_frec(struct frec *f) |
2078 | { | |
b5ea1cc2 | 2079 | free_rfd(f->rfd4); |
1a6bca81 SK |
2080 | f->rfd4 = NULL; |
2081 | f->sentto = NULL; | |
28866e95 | 2082 | f->flags = 0; |
1a6bca81 SK |
2083 | |
2084 | #ifdef HAVE_IPV6 | |
b5ea1cc2 | 2085 | free_rfd(f->rfd6); |
1a6bca81 SK |
2086 | f->rfd6 = NULL; |
2087 | #endif | |
3a237152 SK |
2088 | |
2089 | #ifdef HAVE_DNSSEC | |
2090 | if (f->stash) | |
0fc2f313 SK |
2091 | { |
2092 | blockdata_free(f->stash); | |
2093 | f->stash = NULL; | |
2094 | } | |
3a237152 | 2095 | |
97e618a0 SK |
2096 | if (f->orig_domain) |
2097 | { | |
2098 | blockdata_free(f->orig_domain); | |
2099 | f->orig_domain = NULL; | |
2100 | } | |
2101 | ||
3a237152 SK |
2102 | /* Anything we're waiting on is pointless now, too */ |
2103 | if (f->blocking_query) | |
2104 | free_frec(f->blocking_query); | |
2105 | f->blocking_query = NULL; | |
39048ad1 | 2106 | f->dependent = NULL; |
3a237152 | 2107 | #endif |
1a6bca81 SK |
2108 | } |
2109 | ||
1697269c SK |
2110 | /* if wait==NULL return a free or older than TIMEOUT record. |
2111 | else return *wait zero if one available, or *wait is delay to | |
1a6bca81 | 2112 | when the oldest in-use record will expire. Impose an absolute |
3a237152 SK |
2113 | limit of 4*TIMEOUT before we wipe things (for random sockets). |
2114 | If force is set, always return a result, even if we have | |
2115 | to allocate above the limit. */ | |
2116 | struct frec *get_new_frec(time_t now, int *wait, int force) | |
1697269c | 2117 | { |
1a6bca81 | 2118 | struct frec *f, *oldest, *target; |
1697269c SK |
2119 | int count; |
2120 | ||
2121 | if (wait) | |
2122 | *wait = 0; | |
2123 | ||
1a6bca81 | 2124 | for (f = daemon->frec_list, oldest = NULL, target = NULL, count = 0; f; f = f->next, count++) |
832af0ba | 2125 | if (!f->sentto) |
1a6bca81 SK |
2126 | target = f; |
2127 | else | |
1697269c | 2128 | { |
1a6bca81 SK |
2129 | if (difftime(now, f->time) >= 4*TIMEOUT) |
2130 | { | |
2131 | free_frec(f); | |
2132 | target = f; | |
2133 | } | |
2134 | ||
2135 | if (!oldest || difftime(f->time, oldest->time) <= 0) | |
2136 | oldest = f; | |
1697269c | 2137 | } |
1a6bca81 SK |
2138 | |
2139 | if (target) | |
2140 | { | |
2141 | target->time = now; | |
2142 | return target; | |
2143 | } | |
9e4abcb5 SK |
2144 | |
2145 | /* can't find empty one, use oldest if there is one | |
2146 | and it's older than timeout */ | |
1697269c | 2147 | if (oldest && ((int)difftime(now, oldest->time)) >= TIMEOUT) |
9e4abcb5 | 2148 | { |
1697269c SK |
2149 | /* keep stuff for twice timeout if we can by allocating a new |
2150 | record instead */ | |
2151 | if (difftime(now, oldest->time) < 2*TIMEOUT && | |
2152 | count <= daemon->ftabsize && | |
2153 | (f = allocate_frec(now))) | |
2154 | return f; | |
2155 | ||
2156 | if (!wait) | |
2157 | { | |
1a6bca81 | 2158 | free_frec(oldest); |
1697269c SK |
2159 | oldest->time = now; |
2160 | } | |
9e4abcb5 SK |
2161 | return oldest; |
2162 | } | |
2163 | ||
1697269c | 2164 | /* none available, calculate time 'till oldest record expires */ |
3a237152 | 2165 | if (!force && count > daemon->ftabsize) |
1697269c | 2166 | { |
0da5e897 MSB |
2167 | static time_t last_log = 0; |
2168 | ||
1697269c SK |
2169 | if (oldest && wait) |
2170 | *wait = oldest->time + (time_t)TIMEOUT - now; | |
0da5e897 MSB |
2171 | |
2172 | if ((int)difftime(now, last_log) > 5) | |
2173 | { | |
2174 | last_log = now; | |
2175 | my_syslog(LOG_WARNING, _("Maximum number of concurrent DNS queries reached (max: %d)"), daemon->ftabsize); | |
2176 | } | |
2177 | ||
9e4abcb5 SK |
2178 | return NULL; |
2179 | } | |
1697269c SK |
2180 | |
2181 | if (!(f = allocate_frec(now)) && wait) | |
2182 | /* wait one second on malloc failure */ | |
2183 | *wait = 1; | |
9e4abcb5 | 2184 | |
9e4abcb5 SK |
2185 | return f; /* OK if malloc fails and this is NULL */ |
2186 | } | |
2187 | ||
832af0ba | 2188 | /* crc is all-ones if not known. */ |
8a9be9e4 | 2189 | static struct frec *lookup_frec(unsigned short id, void *hash) |
9e4abcb5 SK |
2190 | { |
2191 | struct frec *f; | |
2192 | ||
1a6bca81 | 2193 | for(f = daemon->frec_list; f; f = f->next) |
832af0ba | 2194 | if (f->sentto && f->new_id == id && |
8a9be9e4 | 2195 | (!hash || memcmp(hash, f->hash, HASH_SIZE) == 0)) |
9e4abcb5 SK |
2196 | return f; |
2197 | ||
2198 | return NULL; | |
2199 | } | |
2200 | ||
2201 | static struct frec *lookup_frec_by_sender(unsigned short id, | |
fd9fa481 | 2202 | union mysockaddr *addr, |
8a9be9e4 | 2203 | void *hash) |
9e4abcb5 | 2204 | { |
feba5c1d SK |
2205 | struct frec *f; |
2206 | ||
1a6bca81 | 2207 | for(f = daemon->frec_list; f; f = f->next) |
832af0ba | 2208 | if (f->sentto && |
9e4abcb5 | 2209 | f->orig_id == id && |
8a9be9e4 | 2210 | memcmp(hash, f->hash, HASH_SIZE) == 0 && |
9e4abcb5 SK |
2211 | sockaddr_isequal(&f->source, addr)) |
2212 | return f; | |
2213 | ||
2214 | return NULL; | |
2215 | } | |
47a95169 SK |
2216 | |
2217 | /* Send query packet again, if we can. */ | |
2218 | void resend_query() | |
2219 | { | |
2220 | if (daemon->srv_save) | |
2221 | { | |
2222 | int fd; | |
2223 | ||
2224 | if (daemon->srv_save->sfd) | |
2225 | fd = daemon->srv_save->sfd->fd; | |
2226 | else if (daemon->rfd_save && daemon->rfd_save->refcount != 0) | |
2227 | fd = daemon->rfd_save->fd; | |
2228 | else | |
2229 | return; | |
2230 | ||
2231 | while(sendto(fd, daemon->packet, daemon->packet_len, 0, | |
2232 | &daemon->srv_save->addr.sa, sa_len(&daemon->srv_save->addr)) == -1 && retry_send()); | |
2233 | } | |
2234 | } | |
9e4abcb5 | 2235 | |
849a8357 | 2236 | /* A server record is going away, remove references to it */ |
5aabfc78 | 2237 | void server_gone(struct server *server) |
849a8357 SK |
2238 | { |
2239 | struct frec *f; | |
2240 | ||
1a6bca81 | 2241 | for (f = daemon->frec_list; f; f = f->next) |
832af0ba | 2242 | if (f->sentto && f->sentto == server) |
1a6bca81 | 2243 | free_frec(f); |
849a8357 SK |
2244 | |
2245 | if (daemon->last_server == server) | |
2246 | daemon->last_server = NULL; | |
2247 | ||
2248 | if (daemon->srv_save == server) | |
2249 | daemon->srv_save = NULL; | |
2250 | } | |
9e4abcb5 | 2251 | |
316e2730 | 2252 | /* return unique random ids. */ |
8a9be9e4 | 2253 | static unsigned short get_id(void) |
9e4abcb5 SK |
2254 | { |
2255 | unsigned short ret = 0; | |
832af0ba | 2256 | |
316e2730 | 2257 | do |
832af0ba | 2258 | ret = rand16(); |
8a9be9e4 | 2259 | while (lookup_frec(ret, NULL)); |
832af0ba | 2260 | |
9e4abcb5 SK |
2261 | return ret; |
2262 | } | |
2263 | ||
2264 | ||
2265 | ||
2266 | ||
2267 |