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