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61744359 | 1 | /* dnsmasq is Copyright (c) 2000-2013 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 | { |
de37951c | 255 | /* retry on existing query, send to all available servers */ |
9e4abcb5 | 256 | domain = forward->sentto->domain; |
824af85b | 257 | forward->sentto->failed_queries++; |
28866e95 | 258 | if (!option_bool(OPT_ORDER)) |
de37951c | 259 | { |
0a852541 | 260 | forward->forwardall = 1; |
3be34541 | 261 | daemon->last_server = NULL; |
de37951c | 262 | } |
9e4abcb5 | 263 | type = forward->sentto->flags & SERV_TYPE; |
de37951c | 264 | if (!(start = forward->sentto->next)) |
3be34541 | 265 | start = daemon->servers; /* at end of list, recycle */ |
9e4abcb5 SK |
266 | header->id = htons(forward->new_id); |
267 | } | |
268 | else | |
269 | { | |
270 | if (gotname) | |
8ef5ada2 | 271 | flags = search_servers(now, &addrp, gotname, daemon->namebuff, &type, &domain, &norebind); |
9e4abcb5 | 272 | |
3a237152 | 273 | if (!flags && !(forward = get_new_frec(now, NULL, 0))) |
feba5c1d SK |
274 | /* table full - server failure. */ |
275 | flags = F_NEG; | |
9e4abcb5 SK |
276 | |
277 | if (forward) | |
278 | { | |
0a852541 SK |
279 | forward->source = *udpaddr; |
280 | forward->dest = *dst_addr; | |
281 | forward->iface = dst_iface; | |
0a852541 | 282 | forward->orig_id = ntohs(header->id); |
316e2730 | 283 | forward->new_id = get_id(crc); |
832af0ba | 284 | forward->fd = udpfd; |
0a852541 SK |
285 | forward->crc = crc; |
286 | forward->forwardall = 0; | |
ed4c0767 | 287 | forward->flags = 0; |
28866e95 SK |
288 | if (norebind) |
289 | forward->flags |= FREC_NOREBIND; | |
572b41eb | 290 | if (header->hb4 & HB4_CD) |
28866e95 | 291 | forward->flags |= FREC_CHECKING_DISABLED; |
0a852541 | 292 | |
28866e95 SK |
293 | header->id = htons(forward->new_id); |
294 | ||
8ef5ada2 SK |
295 | /* In strict_order mode, always try servers in the order |
296 | specified in resolv.conf, if a domain is given | |
297 | always try all the available servers, | |
9e4abcb5 SK |
298 | otherwise, use the one last known to work. */ |
299 | ||
8ef5ada2 SK |
300 | if (type == 0) |
301 | { | |
28866e95 | 302 | if (option_bool(OPT_ORDER)) |
8ef5ada2 SK |
303 | start = daemon->servers; |
304 | else if (!(start = daemon->last_server) || | |
305 | daemon->forwardcount++ > FORWARD_TEST || | |
306 | difftime(now, daemon->forwardtime) > FORWARD_TIME) | |
307 | { | |
308 | start = daemon->servers; | |
309 | forward->forwardall = 1; | |
310 | daemon->forwardcount = 0; | |
311 | daemon->forwardtime = now; | |
312 | } | |
313 | } | |
314 | else | |
de37951c | 315 | { |
3be34541 | 316 | start = daemon->servers; |
28866e95 | 317 | if (!option_bool(OPT_ORDER)) |
8ef5ada2 | 318 | forward->forwardall = 1; |
de37951c | 319 | } |
9e4abcb5 SK |
320 | } |
321 | } | |
feba5c1d | 322 | |
9e4abcb5 SK |
323 | /* check for send errors here (no route to host) |
324 | if we fail to send to all nameservers, send back an error | |
325 | packet straight away (helps modem users when offline) */ | |
326 | ||
327 | if (!flags && forward) | |
328 | { | |
de37951c SK |
329 | struct server *firstsentto = start; |
330 | int forwarded = 0; | |
28866e95 | 331 | |
797a7afb GT |
332 | if (option_bool(OPT_ADD_MAC)) |
333 | plen = add_mac(header, plen, ((char *) header) + PACKETSZ, &forward->source); | |
28866e95 | 334 | |
ed4c0767 SK |
335 | if (option_bool(OPT_CLIENT_SUBNET)) |
336 | { | |
337 | size_t new = add_source_addr(header, plen, ((char *) header) + PACKETSZ, &forward->source); | |
338 | if (new != plen) | |
339 | { | |
340 | plen = new; | |
341 | forward->flags |= FREC_HAS_SUBNET; | |
342 | } | |
343 | } | |
344 | ||
3a237152 SK |
345 | #ifdef HAVE_DNSSEC |
346 | if (option_bool(OPT_DNSSEC_VALID)) | |
0fc2f313 SK |
347 | { |
348 | plen = add_do_bit(header, plen, ((char *) header) + PACKETSZ); | |
349 | header->hb4 |= HB4_CD; | |
350 | } | |
3a237152 SK |
351 | #endif |
352 | ||
9e4abcb5 SK |
353 | while (1) |
354 | { | |
9e4abcb5 SK |
355 | /* only send to servers dealing with our domain. |
356 | domain may be NULL, in which case server->domain | |
357 | must be NULL also. */ | |
358 | ||
de37951c | 359 | if (type == (start->flags & SERV_TYPE) && |
fd9fa481 SK |
360 | (type != SERV_HAS_DOMAIN || hostname_isequal(domain, start->domain)) && |
361 | !(start->flags & SERV_LITERAL_ADDRESS)) | |
9e4abcb5 | 362 | { |
1a6bca81 SK |
363 | int fd; |
364 | ||
365 | /* find server socket to use, may need to get random one. */ | |
366 | if (start->sfd) | |
367 | fd = start->sfd->fd; | |
368 | else | |
369 | { | |
370 | #ifdef HAVE_IPV6 | |
371 | if (start->addr.sa.sa_family == AF_INET6) | |
372 | { | |
373 | if (!forward->rfd6 && | |
374 | !(forward->rfd6 = allocate_rfd(AF_INET6))) | |
375 | break; | |
3927da46 | 376 | daemon->rfd_save = forward->rfd6; |
1a6bca81 SK |
377 | fd = forward->rfd6->fd; |
378 | } | |
379 | else | |
380 | #endif | |
381 | { | |
382 | if (!forward->rfd4 && | |
383 | !(forward->rfd4 = allocate_rfd(AF_INET))) | |
384 | break; | |
3927da46 | 385 | daemon->rfd_save = forward->rfd4; |
1a6bca81 SK |
386 | fd = forward->rfd4->fd; |
387 | } | |
7de060b0 SK |
388 | |
389 | #ifdef HAVE_CONNTRACK | |
390 | /* Copy connection mark of incoming query to outgoing connection. */ | |
391 | if (option_bool(OPT_CONNTRACK)) | |
392 | { | |
393 | unsigned int mark; | |
797a7afb | 394 | if (get_incoming_mark(&forward->source, &forward->dest, 0, &mark)) |
7de060b0 SK |
395 | setsockopt(fd, SOL_SOCKET, SO_MARK, &mark, sizeof(unsigned int)); |
396 | } | |
397 | #endif | |
1a6bca81 SK |
398 | } |
399 | ||
400 | if (sendto(fd, (char *)header, plen, 0, | |
feba5c1d | 401 | &start->addr.sa, |
fd9fa481 SK |
402 | sa_len(&start->addr)) == -1) |
403 | { | |
404 | if (retry_send()) | |
405 | continue; | |
406 | } | |
407 | else | |
9e4abcb5 | 408 | { |
cdeda28f SK |
409 | /* Keep info in case we want to re-send this packet */ |
410 | daemon->srv_save = start; | |
411 | daemon->packet_len = plen; | |
412 | ||
de37951c | 413 | if (!gotname) |
3be34541 | 414 | strcpy(daemon->namebuff, "query"); |
de37951c | 415 | if (start->addr.sa.sa_family == AF_INET) |
3be34541 | 416 | log_query(F_SERVER | F_IPV4 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 417 | (struct all_addr *)&start->addr.in.sin_addr, NULL); |
de37951c SK |
418 | #ifdef HAVE_IPV6 |
419 | else | |
3be34541 | 420 | log_query(F_SERVER | F_IPV6 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 421 | (struct all_addr *)&start->addr.in6.sin6_addr, NULL); |
de37951c | 422 | #endif |
824af85b | 423 | start->queries++; |
de37951c SK |
424 | forwarded = 1; |
425 | forward->sentto = start; | |
0a852541 | 426 | if (!forward->forwardall) |
de37951c | 427 | break; |
0a852541 | 428 | forward->forwardall++; |
9e4abcb5 SK |
429 | } |
430 | } | |
431 | ||
de37951c | 432 | if (!(start = start->next)) |
3be34541 | 433 | start = daemon->servers; |
9e4abcb5 | 434 | |
de37951c | 435 | if (start == firstsentto) |
9e4abcb5 SK |
436 | break; |
437 | } | |
438 | ||
de37951c | 439 | if (forwarded) |
824af85b | 440 | return 1; |
de37951c | 441 | |
9e4abcb5 SK |
442 | /* could not send on, prepare to return */ |
443 | header->id = htons(forward->orig_id); | |
1a6bca81 | 444 | free_frec(forward); /* cancel */ |
9e4abcb5 SK |
445 | } |
446 | ||
447 | /* could not send on, return empty answer or address if known for whole domain */ | |
b8187c80 SK |
448 | if (udpfd != -1) |
449 | { | |
cdeda28f | 450 | plen = setup_reply(header, plen, addrp, flags, daemon->local_ttl); |
54dd393f | 451 | send_from(udpfd, option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND), (char *)header, plen, udpaddr, dst_addr, dst_iface); |
b8187c80 SK |
452 | } |
453 | ||
824af85b | 454 | return 0; |
9e4abcb5 SK |
455 | } |
456 | ||
ed4c0767 | 457 | static size_t process_reply(struct dns_header *header, time_t now, struct server *server, size_t n, int check_rebind, |
3a237152 | 458 | int no_cache, int cache_secure, int check_subnet, union mysockaddr *query_source) |
feba5c1d | 459 | { |
36717eee | 460 | unsigned char *pheader, *sizep; |
13d86c73 | 461 | char **sets = 0; |
832af0ba | 462 | int munged = 0, is_sign; |
cdeda28f | 463 | size_t plen; |
3a237152 | 464 | int squash_ad = 0; |
cdeda28f | 465 | |
13d86c73 JD |
466 | #ifdef HAVE_IPSET |
467 | /* Similar algorithm to search_servers. */ | |
468 | struct ipsets *ipset_pos; | |
469 | unsigned int namelen = strlen(daemon->namebuff); | |
470 | unsigned int matchlen = 0; | |
471 | for (ipset_pos = daemon->ipsets; ipset_pos; ipset_pos = ipset_pos->next) | |
472 | { | |
473 | unsigned int domainlen = strlen(ipset_pos->domain); | |
474 | char *matchstart = daemon->namebuff + namelen - domainlen; | |
475 | if (namelen >= domainlen && hostname_isequal(matchstart, ipset_pos->domain) && | |
476 | (domainlen == 0 || namelen == domainlen || *(matchstart - 1) == '.' ) && | |
477 | domainlen >= matchlen) { | |
478 | matchlen = domainlen; | |
479 | sets = ipset_pos->sets; | |
480 | } | |
481 | } | |
482 | #endif | |
483 | ||
feba5c1d | 484 | /* If upstream is advertising a larger UDP packet size |
9009d746 SK |
485 | than we allow, trim it so that we don't get overlarge |
486 | requests for the client. We can't do this for signed packets. */ | |
feba5c1d | 487 | |
ed4c0767 | 488 | if ((pheader = find_pseudoheader(header, n, &plen, &sizep, &is_sign))) |
feba5c1d | 489 | { |
ed4c0767 SK |
490 | if (!is_sign) |
491 | { | |
492 | unsigned short udpsz; | |
493 | unsigned char *psave = sizep; | |
494 | ||
495 | GETSHORT(udpsz, sizep); | |
496 | if (udpsz > daemon->edns_pktsz) | |
497 | PUTSHORT(daemon->edns_pktsz, psave); | |
498 | } | |
feba5c1d | 499 | |
ed4c0767 SK |
500 | if (check_subnet && !check_source(header, plen, pheader, query_source)) |
501 | { | |
502 | my_syslog(LOG_WARNING, _("discarding DNS reply: subnet option mismatch")); | |
503 | return 0; | |
504 | } | |
feba5c1d | 505 | } |
ed4c0767 | 506 | |
28866e95 | 507 | /* RFC 4035 sect 4.6 para 3 */ |
237724c0 | 508 | if (!is_sign && !option_bool(OPT_DNSSEC_PROXY)) |
3a237152 SK |
509 | squash_ad = 1; |
510 | ||
511 | #ifdef HAVE_DNSSEC | |
512 | if (option_bool(OPT_DNSSEC_VALID)) | |
513 | squash_ad = no_cache; | |
28866e95 | 514 | |
3a237152 SK |
515 | if (cache_secure) |
516 | header->hb4 |= HB4_AD; | |
517 | #endif | |
518 | ||
519 | if (squash_ad) | |
520 | header->hb4 &= ~HB4_AD; | |
521 | ||
572b41eb | 522 | if (OPCODE(header) != QUERY || (RCODE(header) != NOERROR && RCODE(header) != NXDOMAIN)) |
0a852541 SK |
523 | return n; |
524 | ||
feba5c1d | 525 | /* Complain loudly if the upstream server is non-recursive. */ |
572b41eb | 526 | if (!(header->hb4 & HB4_RA) && RCODE(header) == NOERROR && ntohs(header->ancount) == 0 && |
0a852541 | 527 | server && !(server->flags & SERV_WARNED_RECURSIVE)) |
feba5c1d | 528 | { |
3d8df260 | 529 | prettyprint_addr(&server->addr, daemon->namebuff); |
f2621c7f | 530 | my_syslog(LOG_WARNING, _("nameserver %s refused to do a recursive query"), daemon->namebuff); |
28866e95 | 531 | if (!option_bool(OPT_LOG)) |
0a852541 SK |
532 | server->flags |= SERV_WARNED_RECURSIVE; |
533 | } | |
e292e93d | 534 | |
572b41eb | 535 | if (daemon->bogus_addr && RCODE(header) != NXDOMAIN && |
fd9fa481 | 536 | check_for_bogus_wildcard(header, n, daemon->namebuff, daemon->bogus_addr, now)) |
feba5c1d | 537 | { |
fd9fa481 | 538 | munged = 1; |
572b41eb SK |
539 | SET_RCODE(header, NXDOMAIN); |
540 | header->hb3 &= ~HB3_AA; | |
36717eee | 541 | } |
fd9fa481 | 542 | else |
36717eee | 543 | { |
572b41eb | 544 | if (RCODE(header) == NXDOMAIN && |
fd9fa481 | 545 | extract_request(header, n, daemon->namebuff, NULL) && |
5aabfc78 | 546 | check_for_local_domain(daemon->namebuff, now)) |
36717eee SK |
547 | { |
548 | /* if we forwarded a query for a locally known name (because it was for | |
549 | an unknown type) and the answer is NXDOMAIN, convert that to NODATA, | |
550 | since we know that the domain exists, even if upstream doesn't */ | |
fd9fa481 | 551 | munged = 1; |
572b41eb SK |
552 | header->hb3 |= HB3_AA; |
553 | SET_RCODE(header, NOERROR); | |
feba5c1d | 554 | } |
832af0ba | 555 | |
0fc2f313 | 556 | if (extract_addresses(header, n, daemon->namebuff, now, sets, is_sign, check_rebind, no_cache, cache_secure)) |
824af85b | 557 | { |
8ef5ada2 | 558 | my_syslog(LOG_WARNING, _("possible DNS-rebind attack detected: %s"), daemon->namebuff); |
824af85b SK |
559 | munged = 1; |
560 | } | |
feba5c1d | 561 | } |
fd9fa481 SK |
562 | |
563 | /* do this after extract_addresses. Ensure NODATA reply and remove | |
564 | nameserver info. */ | |
565 | ||
566 | if (munged) | |
567 | { | |
568 | header->ancount = htons(0); | |
569 | header->nscount = htons(0); | |
570 | header->arcount = htons(0); | |
571 | } | |
572 | ||
36717eee SK |
573 | /* the bogus-nxdomain stuff, doctor and NXDOMAIN->NODATA munging can all elide |
574 | sections of the packet. Find the new length here and put back pseudoheader | |
575 | if it was removed. */ | |
576 | return resize_packet(header, n, pheader, plen); | |
feba5c1d SK |
577 | } |
578 | ||
3be34541 | 579 | /* sets new last_server */ |
1a6bca81 | 580 | void reply_query(int fd, int family, time_t now) |
9e4abcb5 SK |
581 | { |
582 | /* packet from peer server, extract data for cache, and send to | |
583 | original requester */ | |
572b41eb | 584 | struct dns_header *header; |
de37951c | 585 | union mysockaddr serveraddr; |
832af0ba | 586 | struct frec *forward; |
de37951c | 587 | socklen_t addrlen = sizeof(serveraddr); |
1a6bca81 | 588 | ssize_t n = recvfrom(fd, daemon->packet, daemon->edns_pktsz, 0, &serveraddr.sa, &addrlen); |
cdeda28f | 589 | size_t nn; |
1a6bca81 SK |
590 | struct server *server; |
591 | ||
cdeda28f SK |
592 | /* packet buffer overwritten */ |
593 | daemon->srv_save = NULL; | |
832af0ba | 594 | |
de37951c | 595 | /* Determine the address of the server replying so that we can mark that as good */ |
1a6bca81 | 596 | serveraddr.sa.sa_family = family; |
de37951c SK |
597 | #ifdef HAVE_IPV6 |
598 | if (serveraddr.sa.sa_family == AF_INET6) | |
5e9e0efb | 599 | serveraddr.in6.sin6_flowinfo = 0; |
de37951c | 600 | #endif |
9e4abcb5 | 601 | |
1a6bca81 SK |
602 | /* spoof check: answer must come from known server, */ |
603 | for (server = daemon->servers; server; server = server->next) | |
604 | if (!(server->flags & (SERV_LITERAL_ADDRESS | SERV_NO_ADDR)) && | |
605 | sockaddr_isequal(&server->addr, &serveraddr)) | |
606 | break; | |
607 | ||
572b41eb | 608 | header = (struct dns_header *)daemon->packet; |
fd9fa481 | 609 | |
1a6bca81 | 610 | if (!server || |
572b41eb | 611 | n < (int)sizeof(struct dns_header) || !(header->hb3 & HB3_QR) || |
1a6bca81 SK |
612 | !(forward = lookup_frec(ntohs(header->id), questions_crc(header, n, daemon->namebuff)))) |
613 | return; | |
3a237152 | 614 | |
572b41eb | 615 | if ((RCODE(header) == SERVFAIL || RCODE(header) == REFUSED) && |
28866e95 | 616 | !option_bool(OPT_ORDER) && |
1a6bca81 SK |
617 | forward->forwardall == 0) |
618 | /* for broken servers, attempt to send to another one. */ | |
9e4abcb5 | 619 | { |
1a6bca81 SK |
620 | unsigned char *pheader; |
621 | size_t plen; | |
622 | int is_sign; | |
832af0ba | 623 | |
1a6bca81 SK |
624 | /* recreate query from reply */ |
625 | pheader = find_pseudoheader(header, (size_t)n, &plen, NULL, &is_sign); | |
626 | if (!is_sign) | |
832af0ba | 627 | { |
1a6bca81 SK |
628 | header->ancount = htons(0); |
629 | header->nscount = htons(0); | |
630 | header->arcount = htons(0); | |
631 | if ((nn = resize_packet(header, (size_t)n, pheader, plen))) | |
832af0ba | 632 | { |
572b41eb | 633 | header->hb3 &= ~(HB3_QR | HB3_TC); |
1a6bca81 SK |
634 | forward_query(-1, NULL, NULL, 0, header, nn, now, forward); |
635 | return; | |
832af0ba | 636 | } |
832af0ba | 637 | } |
1a6bca81 | 638 | } |
3a237152 SK |
639 | |
640 | server = forward->sentto; | |
1a6bca81 SK |
641 | |
642 | if ((forward->sentto->flags & SERV_TYPE) == 0) | |
643 | { | |
572b41eb | 644 | if (RCODE(header) == SERVFAIL || RCODE(header) == REFUSED) |
1a6bca81 SK |
645 | server = NULL; |
646 | else | |
b8187c80 | 647 | { |
1a6bca81 SK |
648 | struct server *last_server; |
649 | ||
650 | /* find good server by address if possible, otherwise assume the last one we sent to */ | |
651 | for (last_server = daemon->servers; last_server; last_server = last_server->next) | |
652 | if (!(last_server->flags & (SERV_LITERAL_ADDRESS | SERV_HAS_DOMAIN | SERV_FOR_NODOTS | SERV_NO_ADDR)) && | |
653 | sockaddr_isequal(&last_server->addr, &serveraddr)) | |
654 | { | |
655 | server = last_server; | |
656 | break; | |
657 | } | |
658 | } | |
28866e95 | 659 | if (!option_bool(OPT_ALL_SERVERS)) |
1a6bca81 SK |
660 | daemon->last_server = server; |
661 | } | |
3a237152 | 662 | |
1a6bca81 SK |
663 | /* If the answer is an error, keep the forward record in place in case |
664 | we get a good reply from another server. Kill it when we've | |
665 | had replies from all to avoid filling the forwarding table when | |
666 | everything is broken */ | |
667 | if (forward->forwardall == 0 || --forward->forwardall == 1 || | |
572b41eb | 668 | (RCODE(header) != REFUSED && RCODE(header) != SERVFAIL)) |
1a6bca81 | 669 | { |
3a237152 SK |
670 | int check_rebind = 0, no_cache_dnssec = 0, cache_secure = 0; |
671 | ||
672 | if (option_bool(OPT_NO_REBIND)) | |
673 | check_rebind = !(forward->flags & FREC_NOREBIND); | |
674 | ||
675 | /* Don't cache replies where DNSSEC validation was turned off, either | |
676 | the upstream server told us so, or the original query specified it. */ | |
677 | if ((header->hb4 & HB4_CD) || (forward->flags & FREC_CHECKING_DISABLED)) | |
678 | no_cache_dnssec = 1; | |
679 | ||
680 | #ifdef HAVE_DNSSEC | |
681 | if (option_bool(OPT_DNSSEC_VALID) && !(forward->flags & FREC_CHECKING_DISABLED)) | |
682 | { | |
9d633048 | 683 | int status; |
0fc2f313 SK |
684 | |
685 | /* We've had a reply already, which we're validating. Ignore this duplicate */ | |
686 | if (forward->stash) | |
687 | return; | |
9d633048 | 688 | |
c3e0b9b6 | 689 | if (forward->flags & FREC_DNSKEY_QUERY) |
0fc2f313 | 690 | status = dnssec_validate_by_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class); |
c3e0b9b6 SK |
691 | else if (forward->flags & FREC_DS_QUERY) |
692 | status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class); | |
9d633048 | 693 | else |
0fc2f313 | 694 | status = dnssec_validate_reply(now, header, n, daemon->namebuff, daemon->keyname, &forward->class); |
3a237152 SK |
695 | |
696 | /* Can't validate, as we're missing key data. Put this | |
697 | answer aside, whilst we get that. */ | |
698 | if (status == STAT_NEED_DS || status == STAT_NEED_KEY) | |
699 | { | |
700 | struct frec *new; | |
0fc2f313 SK |
701 | |
702 | if ((new = get_new_frec(now, NULL, 1))) | |
3a237152 | 703 | { |
0fc2f313 SK |
704 | struct frec *next = new->next; |
705 | *new = *forward; /* copy everything, then overwrite */ | |
706 | new->next = next; | |
707 | new->stash = NULL; | |
708 | new->blocking_query = NULL; | |
709 | new->flags &= ~(FREC_DNSKEY_QUERY | FREC_DS_QUERY); | |
9d633048 | 710 | |
0fc2f313 | 711 | if ((forward->stash = blockdata_alloc((char *)header, n))) |
3a237152 SK |
712 | { |
713 | int fd; | |
9d633048 | 714 | |
0fc2f313 SK |
715 | forward->stash_len = n; |
716 | ||
3a237152 SK |
717 | new->dependent = forward; /* to find query awaiting new one. */ |
718 | forward->blocking_query = new; /* for garbage cleaning */ | |
0fc2f313 | 719 | /* validate routines leave name of required record in daemon->keyname */ |
3a237152 | 720 | if (status == STAT_NEED_KEY) |
9d633048 SK |
721 | { |
722 | new->flags |= FREC_DNSKEY_QUERY; | |
0fc2f313 | 723 | nn = dnssec_generate_query(header, daemon->keyname, forward->class, T_DNSKEY, &server->addr); |
9d633048 | 724 | } |
3a237152 | 725 | else if (status == STAT_NEED_DS) |
9d633048 SK |
726 | { |
727 | new->flags |= FREC_DS_QUERY; | |
0fc2f313 | 728 | nn = dnssec_generate_query(header, daemon->keyname, forward->class, T_DS, &server->addr); |
9d633048 | 729 | } |
3a237152 SK |
730 | new->crc = questions_crc(header, nn, daemon->namebuff); |
731 | new->new_id = get_id(new->crc); | |
c3e0b9b6 | 732 | header->id = htons(new->new_id); |
9d633048 | 733 | |
3a237152 SK |
734 | /* Don't resend this. */ |
735 | daemon->srv_save = NULL; | |
736 | ||
737 | if (server->sfd) | |
738 | fd = server->sfd->fd; | |
739 | else | |
740 | #ifdef HAVE_IPV6 | |
9d633048 SK |
741 | /* Note that we use the same random port for the DNSSEC stuff */ |
742 | if (server->addr.sa.sa_family == AF_INET6) | |
743 | { | |
744 | fd = new->rfd6->fd; | |
745 | new->rfd6->refcount++; | |
746 | } | |
747 | else | |
3a237152 | 748 | #endif |
9d633048 SK |
749 | { |
750 | fd = new->rfd4->fd; | |
751 | new->rfd4->refcount++; | |
752 | } | |
753 | ||
3a237152 | 754 | /* Send DNSSEC query to same server as original query */ |
0fc2f313 SK |
755 | while (sendto(fd, (char *)header, nn, 0, &server->addr.sa, sa_len(&server->addr)) == -1 && retry_send()); |
756 | server->queries++; | |
3a237152 SK |
757 | } |
758 | } | |
0fc2f313 | 759 | |
3a237152 SK |
760 | return; |
761 | } | |
762 | ||
763 | /* Ok, we reached far enough up the chain-of-trust that we can validate something. | |
764 | Now wind back down, pulling back answers which wouldn't previously validate | |
765 | and validate them with the new data. Failure to find needed data here is an internal error. | |
766 | Once we get to the original answer (FREC_DNSSEC_QUERY not set) and it validates, | |
767 | return it to the original requestor. */ | |
0fc2f313 | 768 | if (forward->flags & (FREC_DNSKEY_QUERY | FREC_DS_QUERY)) |
3a237152 | 769 | { |
0fc2f313 | 770 | while (forward->dependent) |
3a237152 | 771 | { |
0fc2f313 | 772 | struct frec *prev; |
c3e0b9b6 | 773 | |
0fc2f313 SK |
774 | if (status == STAT_SECURE) |
775 | { | |
776 | if (forward->flags & FREC_DNSKEY_QUERY) | |
777 | status = dnssec_validate_by_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class); | |
778 | else if (forward->flags & FREC_DS_QUERY) | |
779 | status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class); | |
780 | } | |
781 | ||
782 | prev = forward->dependent; | |
783 | free_frec(forward); | |
784 | forward = prev; | |
785 | forward->blocking_query = NULL; /* already gone */ | |
786 | blockdata_retrieve(forward->stash, forward->stash_len, (void *)header); | |
787 | n = forward->stash_len; | |
788 | } | |
789 | ||
790 | /* All DNSKEY and DS records done and in cache, now finally validate original | |
791 | answer, provided last DNSKEY is OK. */ | |
792 | if (status == STAT_SECURE) | |
793 | status = dnssec_validate_reply(now, header, n, daemon->namebuff, daemon->keyname, &forward->class); | |
794 | ||
795 | if (status == STAT_NEED_DS || status == STAT_NEED_KEY) | |
796 | { | |
797 | my_syslog(LOG_ERR, _("Unexpected missing data for DNSSEC validation")); | |
798 | status = STAT_INSECURE; | |
3a237152 SK |
799 | } |
800 | } | |
0fc2f313 SK |
801 | |
802 | log_query(F_KEYTAG | F_SECSTAT, "result", NULL, | |
803 | status == STAT_SECURE ? "SECURE" : (status == STAT_INSECURE ? "INSECURE" : "BOGUS")); | |
804 | ||
805 | no_cache_dnssec = 0; | |
c3e0b9b6 | 806 | |
3a237152 SK |
807 | if (status == STAT_SECURE) |
808 | cache_secure = 1; | |
809 | /* TODO return SERVFAIL here */ | |
810 | else if (status == STAT_BOGUS) | |
811 | no_cache_dnssec = 1; | |
0fc2f313 SK |
812 | |
813 | /* restore CD bit to the value in the query */ | |
814 | if (forward->flags & FREC_CHECKING_DISABLED) | |
815 | header->hb4 |= HB4_CD; | |
816 | else | |
817 | header->hb4 &= ~HB4_CD; | |
3a237152 SK |
818 | } |
819 | #endif | |
8ef5ada2 | 820 | |
3a237152 | 821 | if ((nn = process_reply(header, now, server, (size_t)n, check_rebind, no_cache_dnssec, cache_secure, |
ed4c0767 | 822 | forward->flags & FREC_HAS_SUBNET, &forward->source))) |
1a6bca81 SK |
823 | { |
824 | header->id = htons(forward->orig_id); | |
572b41eb | 825 | header->hb4 |= HB4_RA; /* recursion if available */ |
54dd393f | 826 | send_from(forward->fd, option_bool(OPT_NOWILD) || option_bool (OPT_CLEVERBIND), daemon->packet, nn, |
50303b19 | 827 | &forward->source, &forward->dest, forward->iface); |
b8187c80 | 828 | } |
1a6bca81 | 829 | free_frec(forward); /* cancel */ |
9e4abcb5 | 830 | } |
9e4abcb5 | 831 | } |
44a2a316 | 832 | |
1a6bca81 | 833 | |
5aabfc78 | 834 | void receive_query(struct listener *listen, time_t now) |
44a2a316 | 835 | { |
572b41eb | 836 | struct dns_header *header = (struct dns_header *)daemon->packet; |
44a2a316 | 837 | union mysockaddr source_addr; |
c1bb8504 | 838 | unsigned short type; |
44a2a316 | 839 | struct all_addr dst_addr; |
f6b7dc47 | 840 | struct in_addr netmask, dst_addr_4; |
cdeda28f SK |
841 | size_t m; |
842 | ssize_t n; | |
3b195961 VG |
843 | int if_index = 0, auth_dns = 0; |
844 | #ifdef HAVE_AUTH | |
845 | int local_auth = 0; | |
846 | #endif | |
44a2a316 SK |
847 | struct iovec iov[1]; |
848 | struct msghdr msg; | |
849 | struct cmsghdr *cmptr; | |
44a2a316 SK |
850 | union { |
851 | struct cmsghdr align; /* this ensures alignment */ | |
852 | #ifdef HAVE_IPV6 | |
853 | char control6[CMSG_SPACE(sizeof(struct in6_pktinfo))]; | |
854 | #endif | |
5e9e0efb | 855 | #if defined(HAVE_LINUX_NETWORK) |
44a2a316 | 856 | char control[CMSG_SPACE(sizeof(struct in_pktinfo))]; |
824af85b SK |
857 | #elif defined(IP_RECVDSTADDR) && defined(HAVE_SOLARIS_NETWORK) |
858 | char control[CMSG_SPACE(sizeof(struct in_addr)) + | |
859 | CMSG_SPACE(sizeof(unsigned int))]; | |
44a2a316 SK |
860 | #elif defined(IP_RECVDSTADDR) |
861 | char control[CMSG_SPACE(sizeof(struct in_addr)) + | |
862 | CMSG_SPACE(sizeof(struct sockaddr_dl))]; | |
863 | #endif | |
864 | } control_u; | |
2329bef5 SK |
865 | #ifdef HAVE_IPV6 |
866 | /* Can always get recvd interface for IPv6 */ | |
867 | int check_dst = !option_bool(OPT_NOWILD) || listen->family == AF_INET6; | |
868 | #else | |
869 | int check_dst = !option_bool(OPT_NOWILD); | |
870 | #endif | |
871 | ||
cdeda28f SK |
872 | /* packet buffer overwritten */ |
873 | daemon->srv_save = NULL; | |
874 | ||
4f7b304f SK |
875 | dst_addr_4.s_addr = 0; |
876 | netmask.s_addr = 0; | |
877 | ||
7e5664bd | 878 | if (option_bool(OPT_NOWILD) && listen->iface) |
3d8df260 | 879 | { |
4f7b304f SK |
880 | auth_dns = listen->iface->dns_auth; |
881 | ||
882 | if (listen->family == AF_INET) | |
883 | { | |
884 | dst_addr_4 = listen->iface->addr.in.sin_addr; | |
885 | netmask = listen->iface->netmask; | |
886 | } | |
3d8df260 | 887 | } |
4f7b304f | 888 | |
3be34541 SK |
889 | iov[0].iov_base = daemon->packet; |
890 | iov[0].iov_len = daemon->edns_pktsz; | |
44a2a316 SK |
891 | |
892 | msg.msg_control = control_u.control; | |
893 | msg.msg_controllen = sizeof(control_u); | |
894 | msg.msg_flags = 0; | |
895 | msg.msg_name = &source_addr; | |
896 | msg.msg_namelen = sizeof(source_addr); | |
897 | msg.msg_iov = iov; | |
898 | msg.msg_iovlen = 1; | |
899 | ||
de37951c | 900 | if ((n = recvmsg(listen->fd, &msg, 0)) == -1) |
3be34541 | 901 | return; |
44a2a316 | 902 | |
572b41eb | 903 | if (n < (int)sizeof(struct dns_header) || |
5e9e0efb | 904 | (msg.msg_flags & MSG_TRUNC) || |
572b41eb | 905 | (header->hb3 & HB3_QR)) |
26128d27 SK |
906 | return; |
907 | ||
44a2a316 SK |
908 | source_addr.sa.sa_family = listen->family; |
909 | #ifdef HAVE_IPV6 | |
910 | if (listen->family == AF_INET6) | |
5e9e0efb | 911 | source_addr.in6.sin6_flowinfo = 0; |
44a2a316 | 912 | #endif |
28866e95 | 913 | |
2329bef5 | 914 | if (check_dst) |
26128d27 SK |
915 | { |
916 | struct ifreq ifr; | |
917 | ||
918 | if (msg.msg_controllen < sizeof(struct cmsghdr)) | |
919 | return; | |
44a2a316 | 920 | |
5e9e0efb | 921 | #if defined(HAVE_LINUX_NETWORK) |
26128d27 SK |
922 | if (listen->family == AF_INET) |
923 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) | |
c72daea8 | 924 | if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_PKTINFO) |
26128d27 | 925 | { |
8ef5ada2 SK |
926 | union { |
927 | unsigned char *c; | |
928 | struct in_pktinfo *p; | |
929 | } p; | |
930 | p.c = CMSG_DATA(cmptr); | |
931 | dst_addr_4 = dst_addr.addr.addr4 = p.p->ipi_spec_dst; | |
932 | if_index = p.p->ipi_ifindex; | |
26128d27 SK |
933 | } |
934 | #elif defined(IP_RECVDSTADDR) && defined(IP_RECVIF) | |
935 | if (listen->family == AF_INET) | |
44a2a316 | 936 | { |
26128d27 | 937 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) |
8ef5ada2 SK |
938 | { |
939 | union { | |
940 | unsigned char *c; | |
941 | unsigned int *i; | |
942 | struct in_addr *a; | |
943 | #ifndef HAVE_SOLARIS_NETWORK | |
944 | struct sockaddr_dl *s; | |
945 | #endif | |
946 | } p; | |
947 | p.c = CMSG_DATA(cmptr); | |
948 | if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVDSTADDR) | |
949 | dst_addr_4 = dst_addr.addr.addr4 = *(p.a); | |
950 | else if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVIF) | |
824af85b | 951 | #ifdef HAVE_SOLARIS_NETWORK |
8ef5ada2 | 952 | if_index = *(p.i); |
824af85b | 953 | #else |
8ef5ada2 | 954 | if_index = p.s->sdl_index; |
824af85b | 955 | #endif |
8ef5ada2 | 956 | } |
44a2a316 | 957 | } |
44a2a316 | 958 | #endif |
26128d27 | 959 | |
44a2a316 | 960 | #ifdef HAVE_IPV6 |
26128d27 SK |
961 | if (listen->family == AF_INET6) |
962 | { | |
963 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) | |
c72daea8 | 964 | if (cmptr->cmsg_level == IPPROTO_IPV6 && cmptr->cmsg_type == daemon->v6pktinfo) |
26128d27 | 965 | { |
8ef5ada2 SK |
966 | union { |
967 | unsigned char *c; | |
968 | struct in6_pktinfo *p; | |
969 | } p; | |
970 | p.c = CMSG_DATA(cmptr); | |
971 | ||
972 | dst_addr.addr.addr6 = p.p->ipi6_addr; | |
973 | if_index = p.p->ipi6_ifindex; | |
26128d27 SK |
974 | } |
975 | } | |
44a2a316 | 976 | #endif |
26128d27 SK |
977 | |
978 | /* enforce available interface configuration */ | |
979 | ||
e25db1f2 | 980 | if (!indextoname(listen->fd, if_index, ifr.ifr_name)) |
5e9e0efb | 981 | return; |
832af0ba | 982 | |
e25db1f2 SK |
983 | if (!iface_check(listen->family, &dst_addr, ifr.ifr_name, &auth_dns)) |
984 | { | |
985 | if (!option_bool(OPT_CLEVERBIND)) | |
115ac3e4 | 986 | enumerate_interfaces(0); |
3f2873d4 SK |
987 | if (!loopback_exception(listen->fd, listen->family, &dst_addr, ifr.ifr_name) && |
988 | !label_exception(if_index, listen->family, &dst_addr)) | |
e25db1f2 SK |
989 | return; |
990 | } | |
991 | ||
552af8b9 SK |
992 | if (listen->family == AF_INET && option_bool(OPT_LOCALISE)) |
993 | { | |
994 | struct irec *iface; | |
995 | ||
996 | /* get the netmask of the interface whch has the address we were sent to. | |
997 | This is no neccessarily the interface we arrived on. */ | |
998 | ||
999 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1000 | if (iface->addr.sa.sa_family == AF_INET && | |
1001 | iface->addr.in.sin_addr.s_addr == dst_addr_4.s_addr) | |
1002 | break; | |
1003 | ||
1004 | /* interface may be new */ | |
e25db1f2 | 1005 | if (!iface && !option_bool(OPT_CLEVERBIND)) |
115ac3e4 | 1006 | enumerate_interfaces(0); |
552af8b9 SK |
1007 | |
1008 | for (iface = daemon->interfaces; iface; iface = iface->next) | |
1009 | if (iface->addr.sa.sa_family == AF_INET && | |
1010 | iface->addr.in.sin_addr.s_addr == dst_addr_4.s_addr) | |
1011 | break; | |
1012 | ||
1013 | /* If we failed, abandon localisation */ | |
1014 | if (iface) | |
1015 | netmask = iface->netmask; | |
1016 | else | |
1017 | dst_addr_4.s_addr = 0; | |
1018 | } | |
44a2a316 SK |
1019 | } |
1020 | ||
cdeda28f | 1021 | if (extract_request(header, (size_t)n, daemon->namebuff, &type)) |
44a2a316 | 1022 | { |
1a6bca81 | 1023 | char types[20]; |
b485ed97 SK |
1024 | #ifdef HAVE_AUTH |
1025 | struct auth_zone *zone; | |
1026 | #endif | |
1a6bca81 | 1027 | |
4f7b304f | 1028 | querystr(auth_dns ? "auth" : "query", types, type); |
1a6bca81 | 1029 | |
44a2a316 | 1030 | if (listen->family == AF_INET) |
3be34541 | 1031 | log_query(F_QUERY | F_IPV4 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 1032 | (struct all_addr *)&source_addr.in.sin_addr, types); |
44a2a316 SK |
1033 | #ifdef HAVE_IPV6 |
1034 | else | |
3be34541 | 1035 | log_query(F_QUERY | F_IPV6 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 1036 | (struct all_addr *)&source_addr.in6.sin6_addr, types); |
44a2a316 | 1037 | #endif |
44a2a316 | 1038 | |
b485ed97 SK |
1039 | #ifdef HAVE_AUTH |
1040 | /* find queries for zones we're authoritative for, and answer them directly */ | |
6008bdbb SK |
1041 | if (!auth_dns) |
1042 | for (zone = daemon->auth_zones; zone; zone = zone->next) | |
1043 | if (in_zone(zone, daemon->namebuff, NULL)) | |
1044 | { | |
1045 | auth_dns = 1; | |
1046 | local_auth = 1; | |
1047 | break; | |
1048 | } | |
b485ed97 SK |
1049 | #endif |
1050 | } | |
1051 | ||
4820dce9 | 1052 | #ifdef HAVE_AUTH |
4f7b304f | 1053 | if (auth_dns) |
824af85b | 1054 | { |
19b16891 | 1055 | m = answer_auth(header, ((char *) header) + PACKETSZ, (size_t)n, now, &source_addr, local_auth); |
4f7b304f | 1056 | if (m >= 1) |
b485ed97 SK |
1057 | { |
1058 | send_from(listen->fd, option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND), | |
1059 | (char *)header, m, &source_addr, &dst_addr, if_index); | |
1060 | daemon->auth_answer++; | |
1061 | } | |
824af85b | 1062 | } |
44a2a316 | 1063 | else |
4820dce9 | 1064 | #endif |
4f7b304f SK |
1065 | { |
1066 | m = answer_request(header, ((char *) header) + PACKETSZ, (size_t)n, | |
1067 | dst_addr_4, netmask, now); | |
1068 | ||
1069 | if (m >= 1) | |
1070 | { | |
1071 | send_from(listen->fd, option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND), | |
1072 | (char *)header, m, &source_addr, &dst_addr, if_index); | |
1073 | daemon->local_answer++; | |
1074 | } | |
1075 | else if (forward_query(listen->fd, &source_addr, &dst_addr, if_index, | |
1076 | header, (size_t)n, now, NULL)) | |
1077 | daemon->queries_forwarded++; | |
1078 | else | |
1079 | daemon->local_answer++; | |
1080 | } | |
44a2a316 SK |
1081 | } |
1082 | ||
feba5c1d SK |
1083 | /* The daemon forks before calling this: it should deal with one connection, |
1084 | blocking as neccessary, and then return. Note, need to be a bit careful | |
1085 | about resources for debug mode, when the fork is suppressed: that's | |
1086 | done by the caller. */ | |
5aabfc78 | 1087 | unsigned char *tcp_request(int confd, time_t now, |
4f7b304f | 1088 | union mysockaddr *local_addr, struct in_addr netmask, int auth_dns) |
feba5c1d | 1089 | { |
28866e95 SK |
1090 | size_t size = 0; |
1091 | int norebind = 0; | |
3b195961 | 1092 | #ifdef HAVE_AUTH |
19b16891 | 1093 | int local_auth = 0; |
3b195961 | 1094 | #endif |
ed4c0767 | 1095 | int checking_disabled, check_subnet; |
cdeda28f | 1096 | size_t m; |
ee86ce68 SK |
1097 | unsigned short qtype; |
1098 | unsigned int gotname; | |
feba5c1d | 1099 | unsigned char c1, c2; |
4b5ea12e SK |
1100 | /* Max TCP packet + slop + size */ |
1101 | unsigned char *packet = whine_malloc(65536 + MAXDNAME + RRFIXEDSZ + sizeof(u16)); | |
1102 | unsigned char *payload = &packet[2]; | |
1103 | /* largest field in header is 16-bits, so this is still sufficiently aligned */ | |
1104 | struct dns_header *header = (struct dns_header *)payload; | |
1105 | u16 *length = (u16 *)packet; | |
3be34541 | 1106 | struct server *last_server; |
7de060b0 SK |
1107 | struct in_addr dst_addr_4; |
1108 | union mysockaddr peer_addr; | |
1109 | socklen_t peer_len = sizeof(union mysockaddr); | |
3be34541 | 1110 | |
7de060b0 SK |
1111 | if (getpeername(confd, (struct sockaddr *)&peer_addr, &peer_len) == -1) |
1112 | return packet; | |
1113 | ||
feba5c1d SK |
1114 | while (1) |
1115 | { | |
1116 | if (!packet || | |
1117 | !read_write(confd, &c1, 1, 1) || !read_write(confd, &c2, 1, 1) || | |
1118 | !(size = c1 << 8 | c2) || | |
4b5ea12e | 1119 | !read_write(confd, payload, size, 1)) |
feba5c1d SK |
1120 | return packet; |
1121 | ||
572b41eb | 1122 | if (size < (int)sizeof(struct dns_header)) |
feba5c1d SK |
1123 | continue; |
1124 | ||
ed4c0767 SK |
1125 | check_subnet = 0; |
1126 | ||
28866e95 | 1127 | /* save state of "cd" flag in query */ |
572b41eb | 1128 | checking_disabled = header->hb4 & HB4_CD; |
28866e95 SK |
1129 | |
1130 | /* RFC 4035: sect 4.6 para 2 */ | |
572b41eb | 1131 | header->hb4 &= ~HB4_AD; |
feba5c1d | 1132 | |
3be34541 | 1133 | if ((gotname = extract_request(header, (unsigned int)size, daemon->namebuff, &qtype))) |
feba5c1d | 1134 | { |
7de060b0 | 1135 | char types[20]; |
b485ed97 SK |
1136 | #ifdef HAVE_AUTH |
1137 | struct auth_zone *zone; | |
1138 | #endif | |
4f7b304f | 1139 | querystr(auth_dns ? "auth" : "query", types, qtype); |
7de060b0 SK |
1140 | |
1141 | if (peer_addr.sa.sa_family == AF_INET) | |
1142 | log_query(F_QUERY | F_IPV4 | F_FORWARD, daemon->namebuff, | |
1143 | (struct all_addr *)&peer_addr.in.sin_addr, types); | |
feba5c1d | 1144 | #ifdef HAVE_IPV6 |
7de060b0 SK |
1145 | else |
1146 | log_query(F_QUERY | F_IPV6 | F_FORWARD, daemon->namebuff, | |
1147 | (struct all_addr *)&peer_addr.in6.sin6_addr, types); | |
feba5c1d | 1148 | #endif |
b485ed97 SK |
1149 | |
1150 | #ifdef HAVE_AUTH | |
1151 | /* find queries for zones we're authoritative for, and answer them directly */ | |
6008bdbb SK |
1152 | if (!auth_dns) |
1153 | for (zone = daemon->auth_zones; zone; zone = zone->next) | |
1154 | if (in_zone(zone, daemon->namebuff, NULL)) | |
1155 | { | |
1156 | auth_dns = 1; | |
1157 | local_auth = 1; | |
1158 | break; | |
1159 | } | |
b485ed97 | 1160 | #endif |
feba5c1d SK |
1161 | } |
1162 | ||
7de060b0 SK |
1163 | if (local_addr->sa.sa_family == AF_INET) |
1164 | dst_addr_4 = local_addr->in.sin_addr; | |
1165 | else | |
1166 | dst_addr_4.s_addr = 0; | |
1167 | ||
4820dce9 | 1168 | #ifdef HAVE_AUTH |
4f7b304f | 1169 | if (auth_dns) |
19b16891 | 1170 | m = answer_auth(header, ((char *) header) + 65536, (size_t)size, now, &peer_addr, local_auth); |
4f7b304f | 1171 | else |
4820dce9 | 1172 | #endif |
feba5c1d | 1173 | { |
4f7b304f SK |
1174 | /* m > 0 if answered from cache */ |
1175 | m = answer_request(header, ((char *) header) + 65536, (size_t)size, | |
1176 | dst_addr_4, netmask, now); | |
feba5c1d | 1177 | |
4f7b304f SK |
1178 | /* Do this by steam now we're not in the select() loop */ |
1179 | check_log_writer(NULL); | |
1180 | ||
1181 | if (m == 0) | |
feba5c1d | 1182 | { |
4f7b304f SK |
1183 | unsigned int flags = 0; |
1184 | struct all_addr *addrp = NULL; | |
1185 | int type = 0; | |
1186 | char *domain = NULL; | |
feba5c1d | 1187 | |
4f7b304f SK |
1188 | if (option_bool(OPT_ADD_MAC)) |
1189 | size = add_mac(header, size, ((char *) header) + 65536, &peer_addr); | |
ed4c0767 SK |
1190 | |
1191 | if (option_bool(OPT_CLIENT_SUBNET)) | |
1192 | { | |
1193 | size_t new = add_source_addr(header, size, ((char *) header) + 65536, &peer_addr); | |
1194 | if (size != new) | |
1195 | { | |
1196 | size = new; | |
1197 | check_subnet = 1; | |
1198 | } | |
1199 | } | |
1200 | ||
4f7b304f SK |
1201 | if (gotname) |
1202 | flags = search_servers(now, &addrp, gotname, daemon->namebuff, &type, &domain, &norebind); | |
1203 | ||
1204 | if (type != 0 || option_bool(OPT_ORDER) || !daemon->last_server) | |
1205 | last_server = daemon->servers; | |
1206 | else | |
1207 | last_server = daemon->last_server; | |
1208 | ||
1209 | if (!flags && last_server) | |
1210 | { | |
1211 | struct server *firstsendto = NULL; | |
1212 | unsigned int crc = questions_crc(header, (unsigned int)size, daemon->namebuff); | |
1213 | ||
1214 | /* Loop round available servers until we succeed in connecting to one. | |
1215 | Note that this code subtley ensures that consecutive queries on this connection | |
1216 | which can go to the same server, do so. */ | |
1217 | while (1) | |
feba5c1d | 1218 | { |
4f7b304f SK |
1219 | if (!firstsendto) |
1220 | firstsendto = last_server; | |
1221 | else | |
1222 | { | |
1223 | if (!(last_server = last_server->next)) | |
1224 | last_server = daemon->servers; | |
1225 | ||
1226 | if (last_server == firstsendto) | |
1227 | break; | |
1228 | } | |
1229 | ||
1230 | /* server for wrong domain */ | |
1231 | if (type != (last_server->flags & SERV_TYPE) || | |
1232 | (type == SERV_HAS_DOMAIN && !hostname_isequal(domain, last_server->domain))) | |
7de060b0 SK |
1233 | continue; |
1234 | ||
4f7b304f | 1235 | if (last_server->tcpfd == -1) |
7de060b0 | 1236 | { |
4f7b304f SK |
1237 | if ((last_server->tcpfd = socket(last_server->addr.sa.sa_family, SOCK_STREAM, 0)) == -1) |
1238 | continue; | |
1239 | ||
1240 | if ((!local_bind(last_server->tcpfd, &last_server->source_addr, last_server->interface, 1) || | |
1241 | connect(last_server->tcpfd, &last_server->addr.sa, sa_len(&last_server->addr)) == -1)) | |
1242 | { | |
1243 | close(last_server->tcpfd); | |
1244 | last_server->tcpfd = -1; | |
1245 | continue; | |
1246 | } | |
1247 | ||
7de060b0 | 1248 | #ifdef HAVE_CONNTRACK |
4f7b304f SK |
1249 | /* Copy connection mark of incoming query to outgoing connection. */ |
1250 | if (option_bool(OPT_CONNTRACK)) | |
1251 | { | |
1252 | unsigned int mark; | |
1253 | struct all_addr local; | |
7de060b0 | 1254 | #ifdef HAVE_IPV6 |
4f7b304f SK |
1255 | if (local_addr->sa.sa_family == AF_INET6) |
1256 | local.addr.addr6 = local_addr->in6.sin6_addr; | |
1257 | else | |
7de060b0 | 1258 | #endif |
4f7b304f SK |
1259 | local.addr.addr4 = local_addr->in.sin_addr; |
1260 | ||
1261 | if (get_incoming_mark(&peer_addr, &local, 1, &mark)) | |
1262 | setsockopt(last_server->tcpfd, SOL_SOCKET, SO_MARK, &mark, sizeof(unsigned int)); | |
1263 | } | |
7de060b0 | 1264 | #endif |
4f7b304f SK |
1265 | } |
1266 | ||
4b5ea12e | 1267 | *length = htons(size); |
4f7b304f | 1268 | |
4b5ea12e | 1269 | if (!read_write(last_server->tcpfd, packet, size + sizeof(u16), 0) || |
4f7b304f SK |
1270 | !read_write(last_server->tcpfd, &c1, 1, 1) || |
1271 | !read_write(last_server->tcpfd, &c2, 1, 1)) | |
1272 | { | |
1273 | close(last_server->tcpfd); | |
1274 | last_server->tcpfd = -1; | |
1275 | continue; | |
1276 | } | |
1277 | ||
1278 | m = (c1 << 8) | c2; | |
4b5ea12e | 1279 | if (!read_write(last_server->tcpfd, payload, m, 1)) |
4f7b304f SK |
1280 | return packet; |
1281 | ||
1282 | if (!gotname) | |
1283 | strcpy(daemon->namebuff, "query"); | |
1284 | if (last_server->addr.sa.sa_family == AF_INET) | |
1285 | log_query(F_SERVER | F_IPV4 | F_FORWARD, daemon->namebuff, | |
1286 | (struct all_addr *)&last_server->addr.in.sin_addr, NULL); | |
feba5c1d | 1287 | #ifdef HAVE_IPV6 |
4f7b304f SK |
1288 | else |
1289 | log_query(F_SERVER | F_IPV6 | F_FORWARD, daemon->namebuff, | |
1290 | (struct all_addr *)&last_server->addr.in6.sin6_addr, NULL); | |
feba5c1d | 1291 | #endif |
4f7b304f SK |
1292 | |
1293 | /* There's no point in updating the cache, since this process will exit and | |
1294 | lose the information after a few queries. We make this call for the alias and | |
1295 | bogus-nxdomain side-effects. */ | |
1296 | /* If the crc of the question section doesn't match the crc we sent, then | |
1297 | someone might be attempting to insert bogus values into the cache by | |
1298 | sending replies containing questions and bogus answers. */ | |
1299 | if (crc == questions_crc(header, (unsigned int)m, daemon->namebuff)) | |
1300 | m = process_reply(header, now, last_server, (unsigned int)m, | |
ed4c0767 | 1301 | option_bool(OPT_NO_REBIND) && !norebind, checking_disabled, |
3a237152 | 1302 | 0, check_subnet, &peer_addr); /* TODO - cache secure */ |
4f7b304f SK |
1303 | |
1304 | break; | |
1305 | } | |
feba5c1d | 1306 | } |
4f7b304f SK |
1307 | |
1308 | /* In case of local answer or no connections made. */ | |
1309 | if (m == 0) | |
1310 | m = setup_reply(header, (unsigned int)size, addrp, flags, daemon->local_ttl); | |
feba5c1d | 1311 | } |
feba5c1d | 1312 | } |
4f7b304f | 1313 | |
5aabfc78 | 1314 | check_log_writer(NULL); |
feba5c1d | 1315 | |
4b5ea12e SK |
1316 | *length = htons(m); |
1317 | ||
1318 | if (m == 0 || !read_write(confd, packet, m + sizeof(u16), 0)) | |
feba5c1d SK |
1319 | return packet; |
1320 | } | |
1321 | } | |
1322 | ||
1697269c | 1323 | static struct frec *allocate_frec(time_t now) |
9e4abcb5 | 1324 | { |
1697269c SK |
1325 | struct frec *f; |
1326 | ||
5aabfc78 | 1327 | if ((f = (struct frec *)whine_malloc(sizeof(struct frec)))) |
9e4abcb5 | 1328 | { |
1a6bca81 | 1329 | f->next = daemon->frec_list; |
1697269c | 1330 | f->time = now; |
832af0ba | 1331 | f->sentto = NULL; |
1a6bca81 | 1332 | f->rfd4 = NULL; |
28866e95 | 1333 | f->flags = 0; |
1a6bca81 SK |
1334 | #ifdef HAVE_IPV6 |
1335 | f->rfd6 = NULL; | |
3a237152 SK |
1336 | #endif |
1337 | #ifdef HAVE_DNSSEC | |
1338 | f->blocking_query = NULL; | |
1a6bca81 SK |
1339 | #endif |
1340 | daemon->frec_list = f; | |
1697269c | 1341 | } |
9e4abcb5 | 1342 | |
1697269c SK |
1343 | return f; |
1344 | } | |
9e4abcb5 | 1345 | |
1a6bca81 SK |
1346 | static struct randfd *allocate_rfd(int family) |
1347 | { | |
1348 | static int finger = 0; | |
1349 | int i; | |
1350 | ||
1351 | /* limit the number of sockets we have open to avoid starvation of | |
1352 | (eg) TFTP. Once we have a reasonable number, randomness should be OK */ | |
1353 | ||
1354 | for (i = 0; i < RANDOM_SOCKS; i++) | |
9009d746 | 1355 | if (daemon->randomsocks[i].refcount == 0) |
1a6bca81 | 1356 | { |
9009d746 SK |
1357 | if ((daemon->randomsocks[i].fd = random_sock(family)) == -1) |
1358 | break; | |
1359 | ||
1a6bca81 SK |
1360 | daemon->randomsocks[i].refcount = 1; |
1361 | daemon->randomsocks[i].family = family; | |
1362 | return &daemon->randomsocks[i]; | |
1363 | } | |
1364 | ||
9009d746 | 1365 | /* No free ones or cannot get new socket, grab an existing one */ |
1a6bca81 SK |
1366 | for (i = 0; i < RANDOM_SOCKS; i++) |
1367 | { | |
1368 | int j = (i+finger) % RANDOM_SOCKS; | |
9009d746 SK |
1369 | if (daemon->randomsocks[j].refcount != 0 && |
1370 | daemon->randomsocks[j].family == family && | |
1371 | daemon->randomsocks[j].refcount != 0xffff) | |
1a6bca81 SK |
1372 | { |
1373 | finger = j; | |
1374 | daemon->randomsocks[j].refcount++; | |
1375 | return &daemon->randomsocks[j]; | |
1376 | } | |
1377 | } | |
1378 | ||
1379 | return NULL; /* doom */ | |
1380 | } | |
1a6bca81 SK |
1381 | static void free_frec(struct frec *f) |
1382 | { | |
1383 | if (f->rfd4 && --(f->rfd4->refcount) == 0) | |
1384 | close(f->rfd4->fd); | |
1385 | ||
1386 | f->rfd4 = NULL; | |
1387 | f->sentto = NULL; | |
28866e95 | 1388 | f->flags = 0; |
1a6bca81 SK |
1389 | |
1390 | #ifdef HAVE_IPV6 | |
1391 | if (f->rfd6 && --(f->rfd6->refcount) == 0) | |
1392 | close(f->rfd6->fd); | |
1393 | ||
1394 | f->rfd6 = NULL; | |
1395 | #endif | |
3a237152 SK |
1396 | |
1397 | #ifdef HAVE_DNSSEC | |
1398 | if (f->stash) | |
0fc2f313 SK |
1399 | { |
1400 | blockdata_free(f->stash); | |
1401 | f->stash = NULL; | |
1402 | } | |
3a237152 SK |
1403 | |
1404 | /* Anything we're waiting on is pointless now, too */ | |
1405 | if (f->blocking_query) | |
1406 | free_frec(f->blocking_query); | |
1407 | f->blocking_query = NULL; | |
1408 | ||
1409 | #endif | |
1a6bca81 SK |
1410 | } |
1411 | ||
1697269c SK |
1412 | /* if wait==NULL return a free or older than TIMEOUT record. |
1413 | else return *wait zero if one available, or *wait is delay to | |
1a6bca81 | 1414 | when the oldest in-use record will expire. Impose an absolute |
3a237152 SK |
1415 | limit of 4*TIMEOUT before we wipe things (for random sockets). |
1416 | If force is set, always return a result, even if we have | |
1417 | to allocate above the limit. */ | |
1418 | struct frec *get_new_frec(time_t now, int *wait, int force) | |
1697269c | 1419 | { |
1a6bca81 | 1420 | struct frec *f, *oldest, *target; |
1697269c SK |
1421 | int count; |
1422 | ||
1423 | if (wait) | |
1424 | *wait = 0; | |
1425 | ||
1a6bca81 | 1426 | for (f = daemon->frec_list, oldest = NULL, target = NULL, count = 0; f; f = f->next, count++) |
832af0ba | 1427 | if (!f->sentto) |
1a6bca81 SK |
1428 | target = f; |
1429 | else | |
1697269c | 1430 | { |
1a6bca81 SK |
1431 | if (difftime(now, f->time) >= 4*TIMEOUT) |
1432 | { | |
1433 | free_frec(f); | |
1434 | target = f; | |
1435 | } | |
1436 | ||
1437 | if (!oldest || difftime(f->time, oldest->time) <= 0) | |
1438 | oldest = f; | |
1697269c | 1439 | } |
1a6bca81 SK |
1440 | |
1441 | if (target) | |
1442 | { | |
1443 | target->time = now; | |
1444 | return target; | |
1445 | } | |
9e4abcb5 SK |
1446 | |
1447 | /* can't find empty one, use oldest if there is one | |
1448 | and it's older than timeout */ | |
1697269c | 1449 | if (oldest && ((int)difftime(now, oldest->time)) >= TIMEOUT) |
9e4abcb5 | 1450 | { |
1697269c SK |
1451 | /* keep stuff for twice timeout if we can by allocating a new |
1452 | record instead */ | |
1453 | if (difftime(now, oldest->time) < 2*TIMEOUT && | |
1454 | count <= daemon->ftabsize && | |
1455 | (f = allocate_frec(now))) | |
1456 | return f; | |
1457 | ||
1458 | if (!wait) | |
1459 | { | |
1a6bca81 | 1460 | free_frec(oldest); |
1697269c SK |
1461 | oldest->time = now; |
1462 | } | |
9e4abcb5 SK |
1463 | return oldest; |
1464 | } | |
1465 | ||
1697269c | 1466 | /* none available, calculate time 'till oldest record expires */ |
3a237152 | 1467 | if (!force && count > daemon->ftabsize) |
1697269c | 1468 | { |
0da5e897 MSB |
1469 | static time_t last_log = 0; |
1470 | ||
1697269c SK |
1471 | if (oldest && wait) |
1472 | *wait = oldest->time + (time_t)TIMEOUT - now; | |
0da5e897 MSB |
1473 | |
1474 | if ((int)difftime(now, last_log) > 5) | |
1475 | { | |
1476 | last_log = now; | |
1477 | my_syslog(LOG_WARNING, _("Maximum number of concurrent DNS queries reached (max: %d)"), daemon->ftabsize); | |
1478 | } | |
1479 | ||
9e4abcb5 SK |
1480 | return NULL; |
1481 | } | |
1697269c SK |
1482 | |
1483 | if (!(f = allocate_frec(now)) && wait) | |
1484 | /* wait one second on malloc failure */ | |
1485 | *wait = 1; | |
9e4abcb5 | 1486 | |
9e4abcb5 SK |
1487 | return f; /* OK if malloc fails and this is NULL */ |
1488 | } | |
1489 | ||
832af0ba SK |
1490 | /* crc is all-ones if not known. */ |
1491 | static struct frec *lookup_frec(unsigned short id, unsigned int crc) | |
9e4abcb5 SK |
1492 | { |
1493 | struct frec *f; | |
1494 | ||
1a6bca81 | 1495 | for(f = daemon->frec_list; f; f = f->next) |
832af0ba SK |
1496 | if (f->sentto && f->new_id == id && |
1497 | (f->crc == crc || crc == 0xffffffff)) | |
9e4abcb5 SK |
1498 | return f; |
1499 | ||
1500 | return NULL; | |
1501 | } | |
1502 | ||
1503 | static struct frec *lookup_frec_by_sender(unsigned short id, | |
fd9fa481 SK |
1504 | union mysockaddr *addr, |
1505 | unsigned int crc) | |
9e4abcb5 | 1506 | { |
feba5c1d SK |
1507 | struct frec *f; |
1508 | ||
1a6bca81 | 1509 | for(f = daemon->frec_list; f; f = f->next) |
832af0ba | 1510 | if (f->sentto && |
9e4abcb5 | 1511 | f->orig_id == id && |
fd9fa481 | 1512 | f->crc == crc && |
9e4abcb5 SK |
1513 | sockaddr_isequal(&f->source, addr)) |
1514 | return f; | |
1515 | ||
1516 | return NULL; | |
1517 | } | |
1518 | ||
849a8357 | 1519 | /* A server record is going away, remove references to it */ |
5aabfc78 | 1520 | void server_gone(struct server *server) |
849a8357 SK |
1521 | { |
1522 | struct frec *f; | |
1523 | ||
1a6bca81 | 1524 | for (f = daemon->frec_list; f; f = f->next) |
832af0ba | 1525 | if (f->sentto && f->sentto == server) |
1a6bca81 | 1526 | free_frec(f); |
849a8357 SK |
1527 | |
1528 | if (daemon->last_server == server) | |
1529 | daemon->last_server = NULL; | |
1530 | ||
1531 | if (daemon->srv_save == server) | |
1532 | daemon->srv_save = NULL; | |
1533 | } | |
9e4abcb5 | 1534 | |
316e2730 SK |
1535 | /* return unique random ids. */ |
1536 | static unsigned short get_id(unsigned int crc) | |
9e4abcb5 SK |
1537 | { |
1538 | unsigned short ret = 0; | |
832af0ba | 1539 | |
316e2730 | 1540 | do |
832af0ba SK |
1541 | ret = rand16(); |
1542 | while (lookup_frec(ret, crc)); | |
1543 | ||
9e4abcb5 SK |
1544 | return ret; |
1545 | } | |
1546 | ||
1547 | ||
1548 | ||
1549 | ||
1550 |