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316e2730 | 1 | /* dnsmasq is Copyright (c) 2000-2010 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 */ |
cdeda28f | 29 | static void send_from(int fd, int nowild, char *packet, size_t len, |
dfa666f2 SK |
30 | union mysockaddr *to, struct all_addr *source, |
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 SK |
72 | msg.msg_controllen = cmptr->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo)); |
73 | cmptr->cmsg_level = SOL_IP; | |
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; |
26128d27 SK |
91 | cmptr->cmsg_level = IPV6_LEVEL; |
92 | } | |
3d8df260 SK |
93 | #else |
94 | iface = 0; /* eliminate warning */ | |
44a2a316 | 95 | #endif |
26128d27 | 96 | } |
feba5c1d | 97 | |
fd9fa481 SK |
98 | retry: |
99 | if (sendmsg(fd, &msg, 0) == -1) | |
feba5c1d | 100 | { |
fd9fa481 SK |
101 | /* certain Linux kernels seem to object to setting the source address in the IPv6 stack |
102 | by returning EINVAL from sendmsg. In that case, try again without setting the | |
103 | source address, since it will nearly alway be correct anyway. IPv6 stinks. */ | |
104 | if (errno == EINVAL && msg.msg_controllen) | |
105 | { | |
106 | msg.msg_controllen = 0; | |
107 | goto retry; | |
108 | } | |
109 | if (retry_send()) | |
110 | goto retry; | |
feba5c1d | 111 | } |
9e4abcb5 | 112 | } |
44a2a316 | 113 | |
5aabfc78 | 114 | static unsigned short search_servers(time_t now, struct all_addr **addrpp, |
8ef5ada2 | 115 | unsigned short 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; | |
125 | unsigned short flags = 0; | |
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 SK |
130 | { |
131 | unsigned short sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6; | |
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; | |
161 | else if (domainlen >= matchlen) | |
feba5c1d | 162 | { |
8ef5ada2 SK |
163 | unsigned short sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6; |
164 | *type = serv->flags & (SERV_HAS_DOMAIN | SERV_USE_RESOLV | SERV_NO_REBIND); | |
165 | *domain = serv->domain; | |
166 | matchlen = domainlen; | |
167 | if (serv->flags & SERV_NO_ADDR) | |
168 | flags = F_NXDOMAIN; | |
169 | else if (serv->flags & SERV_LITERAL_ADDRESS) | |
36717eee | 170 | { |
8ef5ada2 SK |
171 | if (sflag & qtype) |
172 | { | |
173 | flags = sflag; | |
174 | if (serv->addr.sa.sa_family == AF_INET) | |
175 | *addrpp = (struct all_addr *)&serv->addr.in.sin_addr; | |
feba5c1d | 176 | #ifdef HAVE_IPV6 |
8ef5ada2 SK |
177 | else |
178 | *addrpp = (struct all_addr *)&serv->addr.in6.sin6_addr; | |
feba5c1d | 179 | #endif |
8ef5ada2 SK |
180 | } |
181 | else if (!flags || (flags & F_NXDOMAIN)) | |
182 | flags = F_NOERR; | |
36717eee | 183 | } |
8ef5ada2 SK |
184 | else |
185 | flags = 0; | |
186 | } | |
187 | } | |
feba5c1d | 188 | } |
8ef5ada2 | 189 | |
824af85b SK |
190 | if (flags == 0 && !(qtype & F_BIGNAME) && |
191 | (daemon->options & OPT_NODOTS_LOCAL) && !strchr(qdomain, '.') && namelen != 0) | |
192 | /* don't forward simple names, make exception for NS queries and empty name. */ | |
36717eee | 193 | flags = F_NXDOMAIN; |
8ef5ada2 | 194 | |
5aabfc78 | 195 | if (flags == F_NXDOMAIN && check_for_local_domain(qdomain, now)) |
c1bb8504 | 196 | flags = F_NOERR; |
feba5c1d | 197 | |
824af85b SK |
198 | if (flags) |
199 | { | |
200 | int logflags = 0; | |
201 | ||
202 | if (flags == F_NXDOMAIN || flags == F_NOERR) | |
203 | logflags = F_NEG | qtype; | |
204 | ||
1a6bca81 | 205 | log_query(logflags | flags | F_CONFIG | F_FORWARD, qdomain, *addrpp, NULL); |
824af85b | 206 | } |
8ef5ada2 SK |
207 | else if ((*type) & SERV_USE_RESOLV) |
208 | { | |
209 | *type = 0; /* use normal servers for this domain */ | |
210 | *domain = NULL; | |
211 | } | |
feba5c1d SK |
212 | return flags; |
213 | } | |
44a2a316 | 214 | |
824af85b SK |
215 | static int forward_query(int udpfd, union mysockaddr *udpaddr, |
216 | struct all_addr *dst_addr, unsigned int dst_iface, | |
217 | HEADER *header, size_t plen, time_t now, struct frec *forward) | |
9e4abcb5 | 218 | { |
9e4abcb5 | 219 | char *domain = NULL; |
8ef5ada2 | 220 | int type = 0, norebind = 0; |
9e4abcb5 | 221 | struct all_addr *addrp = NULL; |
cdeda28f | 222 | unsigned int crc = questions_crc(header, plen, daemon->namebuff); |
9e4abcb5 | 223 | unsigned short flags = 0; |
cdeda28f | 224 | unsigned short gotname = extract_request(header, plen, daemon->namebuff, NULL); |
de37951c | 225 | struct server *start = NULL; |
3d8df260 SK |
226 | |
227 | /* may be no servers available. */ | |
228 | if (!daemon->servers) | |
9e4abcb5 | 229 | forward = NULL; |
b8187c80 | 230 | else if (forward || (forward = lookup_frec_by_sender(ntohs(header->id), udpaddr, crc))) |
9e4abcb5 | 231 | { |
de37951c | 232 | /* retry on existing query, send to all available servers */ |
9e4abcb5 | 233 | domain = forward->sentto->domain; |
824af85b | 234 | forward->sentto->failed_queries++; |
3be34541 | 235 | if (!(daemon->options & OPT_ORDER)) |
de37951c | 236 | { |
0a852541 | 237 | forward->forwardall = 1; |
3be34541 | 238 | daemon->last_server = NULL; |
de37951c | 239 | } |
9e4abcb5 | 240 | type = forward->sentto->flags & SERV_TYPE; |
de37951c | 241 | if (!(start = forward->sentto->next)) |
3be34541 | 242 | start = daemon->servers; /* at end of list, recycle */ |
9e4abcb5 SK |
243 | header->id = htons(forward->new_id); |
244 | } | |
245 | else | |
246 | { | |
247 | if (gotname) | |
8ef5ada2 | 248 | flags = search_servers(now, &addrp, gotname, daemon->namebuff, &type, &domain, &norebind); |
9e4abcb5 | 249 | |
5aabfc78 | 250 | if (!flags && !(forward = get_new_frec(now, NULL))) |
feba5c1d SK |
251 | /* table full - server failure. */ |
252 | flags = F_NEG; | |
9e4abcb5 SK |
253 | |
254 | if (forward) | |
255 | { | |
0a852541 SK |
256 | forward->source = *udpaddr; |
257 | forward->dest = *dst_addr; | |
258 | forward->iface = dst_iface; | |
0a852541 | 259 | forward->orig_id = ntohs(header->id); |
316e2730 | 260 | forward->new_id = get_id(crc); |
832af0ba | 261 | forward->fd = udpfd; |
0a852541 SK |
262 | forward->crc = crc; |
263 | forward->forwardall = 0; | |
8ef5ada2 | 264 | forward->norebind = norebind; |
0a852541 SK |
265 | header->id = htons(forward->new_id); |
266 | ||
8ef5ada2 SK |
267 | /* In strict_order mode, always try servers in the order |
268 | specified in resolv.conf, if a domain is given | |
269 | always try all the available servers, | |
9e4abcb5 SK |
270 | otherwise, use the one last known to work. */ |
271 | ||
8ef5ada2 SK |
272 | if (type == 0) |
273 | { | |
274 | if (daemon->options & OPT_ORDER) | |
275 | start = daemon->servers; | |
276 | else if (!(start = daemon->last_server) || | |
277 | daemon->forwardcount++ > FORWARD_TEST || | |
278 | difftime(now, daemon->forwardtime) > FORWARD_TIME) | |
279 | { | |
280 | start = daemon->servers; | |
281 | forward->forwardall = 1; | |
282 | daemon->forwardcount = 0; | |
283 | daemon->forwardtime = now; | |
284 | } | |
285 | } | |
286 | else | |
de37951c | 287 | { |
3be34541 | 288 | start = daemon->servers; |
8ef5ada2 SK |
289 | if (!(daemon->options & OPT_ORDER)) |
290 | forward->forwardall = 1; | |
de37951c | 291 | } |
9e4abcb5 SK |
292 | } |
293 | } | |
feba5c1d | 294 | |
9e4abcb5 SK |
295 | /* check for send errors here (no route to host) |
296 | if we fail to send to all nameservers, send back an error | |
297 | packet straight away (helps modem users when offline) */ | |
298 | ||
299 | if (!flags && forward) | |
300 | { | |
de37951c SK |
301 | struct server *firstsentto = start; |
302 | int forwarded = 0; | |
303 | ||
9e4abcb5 SK |
304 | while (1) |
305 | { | |
9e4abcb5 SK |
306 | /* only send to servers dealing with our domain. |
307 | domain may be NULL, in which case server->domain | |
308 | must be NULL also. */ | |
309 | ||
de37951c | 310 | if (type == (start->flags & SERV_TYPE) && |
fd9fa481 SK |
311 | (type != SERV_HAS_DOMAIN || hostname_isequal(domain, start->domain)) && |
312 | !(start->flags & SERV_LITERAL_ADDRESS)) | |
9e4abcb5 | 313 | { |
1a6bca81 SK |
314 | int fd; |
315 | ||
316 | /* find server socket to use, may need to get random one. */ | |
317 | if (start->sfd) | |
318 | fd = start->sfd->fd; | |
319 | else | |
320 | { | |
321 | #ifdef HAVE_IPV6 | |
322 | if (start->addr.sa.sa_family == AF_INET6) | |
323 | { | |
324 | if (!forward->rfd6 && | |
325 | !(forward->rfd6 = allocate_rfd(AF_INET6))) | |
326 | break; | |
3927da46 | 327 | daemon->rfd_save = forward->rfd6; |
1a6bca81 SK |
328 | fd = forward->rfd6->fd; |
329 | } | |
330 | else | |
331 | #endif | |
332 | { | |
333 | if (!forward->rfd4 && | |
334 | !(forward->rfd4 = allocate_rfd(AF_INET))) | |
335 | break; | |
3927da46 | 336 | daemon->rfd_save = forward->rfd4; |
1a6bca81 SK |
337 | fd = forward->rfd4->fd; |
338 | } | |
339 | } | |
340 | ||
341 | if (sendto(fd, (char *)header, plen, 0, | |
feba5c1d | 342 | &start->addr.sa, |
fd9fa481 SK |
343 | sa_len(&start->addr)) == -1) |
344 | { | |
345 | if (retry_send()) | |
346 | continue; | |
347 | } | |
348 | else | |
9e4abcb5 | 349 | { |
cdeda28f SK |
350 | /* Keep info in case we want to re-send this packet */ |
351 | daemon->srv_save = start; | |
352 | daemon->packet_len = plen; | |
353 | ||
de37951c | 354 | if (!gotname) |
3be34541 | 355 | strcpy(daemon->namebuff, "query"); |
de37951c | 356 | if (start->addr.sa.sa_family == AF_INET) |
3be34541 | 357 | log_query(F_SERVER | F_IPV4 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 358 | (struct all_addr *)&start->addr.in.sin_addr, NULL); |
de37951c SK |
359 | #ifdef HAVE_IPV6 |
360 | else | |
3be34541 | 361 | log_query(F_SERVER | F_IPV6 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 362 | (struct all_addr *)&start->addr.in6.sin6_addr, NULL); |
de37951c | 363 | #endif |
824af85b | 364 | start->queries++; |
de37951c SK |
365 | forwarded = 1; |
366 | forward->sentto = start; | |
0a852541 | 367 | if (!forward->forwardall) |
de37951c | 368 | break; |
0a852541 | 369 | forward->forwardall++; |
9e4abcb5 SK |
370 | } |
371 | } | |
372 | ||
de37951c | 373 | if (!(start = start->next)) |
3be34541 | 374 | start = daemon->servers; |
9e4abcb5 | 375 | |
de37951c | 376 | if (start == firstsentto) |
9e4abcb5 SK |
377 | break; |
378 | } | |
379 | ||
de37951c | 380 | if (forwarded) |
824af85b | 381 | return 1; |
de37951c | 382 | |
9e4abcb5 SK |
383 | /* could not send on, prepare to return */ |
384 | header->id = htons(forward->orig_id); | |
1a6bca81 | 385 | free_frec(forward); /* cancel */ |
9e4abcb5 SK |
386 | } |
387 | ||
388 | /* could not send on, return empty answer or address if known for whole domain */ | |
b8187c80 SK |
389 | if (udpfd != -1) |
390 | { | |
cdeda28f | 391 | plen = setup_reply(header, plen, addrp, flags, daemon->local_ttl); |
b8187c80 SK |
392 | send_from(udpfd, daemon->options & OPT_NOWILD, (char *)header, plen, udpaddr, dst_addr, dst_iface); |
393 | } | |
394 | ||
824af85b | 395 | return 0; |
9e4abcb5 SK |
396 | } |
397 | ||
5aabfc78 | 398 | static size_t process_reply(HEADER *header, time_t now, |
8ef5ada2 | 399 | struct server *server, size_t n, int check_rebind) |
feba5c1d | 400 | { |
36717eee | 401 | unsigned char *pheader, *sizep; |
832af0ba | 402 | int munged = 0, is_sign; |
cdeda28f SK |
403 | size_t plen; |
404 | ||
feba5c1d | 405 | /* If upstream is advertising a larger UDP packet size |
9009d746 SK |
406 | than we allow, trim it so that we don't get overlarge |
407 | requests for the client. We can't do this for signed packets. */ | |
feba5c1d | 408 | |
832af0ba | 409 | if ((pheader = find_pseudoheader(header, n, &plen, &sizep, &is_sign)) && !is_sign) |
feba5c1d SK |
410 | { |
411 | unsigned short udpsz; | |
36717eee | 412 | unsigned char *psave = sizep; |
feba5c1d | 413 | |
36717eee | 414 | GETSHORT(udpsz, sizep); |
3be34541 SK |
415 | if (udpsz > daemon->edns_pktsz) |
416 | PUTSHORT(daemon->edns_pktsz, psave); | |
feba5c1d SK |
417 | } |
418 | ||
1b7ecd11 | 419 | if (header->opcode != QUERY || (header->rcode != NOERROR && header->rcode != NXDOMAIN)) |
0a852541 SK |
420 | return n; |
421 | ||
feba5c1d | 422 | /* Complain loudly if the upstream server is non-recursive. */ |
0a852541 SK |
423 | if (!header->ra && header->rcode == NOERROR && ntohs(header->ancount) == 0 && |
424 | server && !(server->flags & SERV_WARNED_RECURSIVE)) | |
feba5c1d | 425 | { |
3d8df260 | 426 | prettyprint_addr(&server->addr, daemon->namebuff); |
f2621c7f | 427 | my_syslog(LOG_WARNING, _("nameserver %s refused to do a recursive query"), daemon->namebuff); |
0a852541 SK |
428 | if (!(daemon->options & OPT_LOG)) |
429 | server->flags |= SERV_WARNED_RECURSIVE; | |
430 | } | |
431 | ||
fd9fa481 SK |
432 | if (daemon->bogus_addr && header->rcode != NXDOMAIN && |
433 | check_for_bogus_wildcard(header, n, daemon->namebuff, daemon->bogus_addr, now)) | |
feba5c1d | 434 | { |
fd9fa481 SK |
435 | munged = 1; |
436 | header->rcode = NXDOMAIN; | |
437 | header->aa = 0; | |
36717eee | 438 | } |
fd9fa481 | 439 | else |
36717eee | 440 | { |
fd9fa481 SK |
441 | if (header->rcode == NXDOMAIN && |
442 | extract_request(header, n, daemon->namebuff, NULL) && | |
5aabfc78 | 443 | check_for_local_domain(daemon->namebuff, now)) |
36717eee SK |
444 | { |
445 | /* if we forwarded a query for a locally known name (because it was for | |
446 | an unknown type) and the answer is NXDOMAIN, convert that to NODATA, | |
447 | since we know that the domain exists, even if upstream doesn't */ | |
fd9fa481 SK |
448 | munged = 1; |
449 | header->aa = 1; | |
450 | header->rcode = NOERROR; | |
feba5c1d | 451 | } |
832af0ba | 452 | |
8ef5ada2 | 453 | if (extract_addresses(header, n, daemon->namebuff, now, is_sign, check_rebind)) |
824af85b | 454 | { |
8ef5ada2 | 455 | my_syslog(LOG_WARNING, _("possible DNS-rebind attack detected: %s"), daemon->namebuff); |
824af85b SK |
456 | munged = 1; |
457 | } | |
feba5c1d | 458 | } |
fd9fa481 SK |
459 | |
460 | /* do this after extract_addresses. Ensure NODATA reply and remove | |
461 | nameserver info. */ | |
462 | ||
463 | if (munged) | |
464 | { | |
465 | header->ancount = htons(0); | |
466 | header->nscount = htons(0); | |
467 | header->arcount = htons(0); | |
468 | } | |
469 | ||
36717eee SK |
470 | /* the bogus-nxdomain stuff, doctor and NXDOMAIN->NODATA munging can all elide |
471 | sections of the packet. Find the new length here and put back pseudoheader | |
472 | if it was removed. */ | |
473 | return resize_packet(header, n, pheader, plen); | |
feba5c1d SK |
474 | } |
475 | ||
3be34541 | 476 | /* sets new last_server */ |
1a6bca81 | 477 | void reply_query(int fd, int family, time_t now) |
9e4abcb5 SK |
478 | { |
479 | /* packet from peer server, extract data for cache, and send to | |
480 | original requester */ | |
9e4abcb5 | 481 | HEADER *header; |
de37951c | 482 | union mysockaddr serveraddr; |
832af0ba | 483 | struct frec *forward; |
de37951c | 484 | socklen_t addrlen = sizeof(serveraddr); |
1a6bca81 | 485 | ssize_t n = recvfrom(fd, daemon->packet, daemon->edns_pktsz, 0, &serveraddr.sa, &addrlen); |
cdeda28f | 486 | size_t nn; |
1a6bca81 SK |
487 | struct server *server; |
488 | ||
cdeda28f SK |
489 | /* packet buffer overwritten */ |
490 | daemon->srv_save = NULL; | |
832af0ba | 491 | |
de37951c | 492 | /* Determine the address of the server replying so that we can mark that as good */ |
1a6bca81 | 493 | serveraddr.sa.sa_family = family; |
de37951c SK |
494 | #ifdef HAVE_IPV6 |
495 | if (serveraddr.sa.sa_family == AF_INET6) | |
5e9e0efb | 496 | serveraddr.in6.sin6_flowinfo = 0; |
de37951c | 497 | #endif |
9e4abcb5 | 498 | |
1a6bca81 SK |
499 | /* spoof check: answer must come from known server, */ |
500 | for (server = daemon->servers; server; server = server->next) | |
501 | if (!(server->flags & (SERV_LITERAL_ADDRESS | SERV_NO_ADDR)) && | |
502 | sockaddr_isequal(&server->addr, &serveraddr)) | |
503 | break; | |
504 | ||
3be34541 | 505 | header = (HEADER *)daemon->packet; |
fd9fa481 | 506 | |
1a6bca81 SK |
507 | if (!server || |
508 | n < (int)sizeof(HEADER) || !header->qr || | |
509 | !(forward = lookup_frec(ntohs(header->id), questions_crc(header, n, daemon->namebuff)))) | |
510 | return; | |
511 | ||
512 | server = forward->sentto; | |
513 | ||
514 | if ((header->rcode == SERVFAIL || header->rcode == REFUSED) && | |
515 | !(daemon->options & OPT_ORDER) && | |
516 | forward->forwardall == 0) | |
517 | /* for broken servers, attempt to send to another one. */ | |
9e4abcb5 | 518 | { |
1a6bca81 SK |
519 | unsigned char *pheader; |
520 | size_t plen; | |
521 | int is_sign; | |
832af0ba | 522 | |
1a6bca81 SK |
523 | /* recreate query from reply */ |
524 | pheader = find_pseudoheader(header, (size_t)n, &plen, NULL, &is_sign); | |
525 | if (!is_sign) | |
832af0ba | 526 | { |
1a6bca81 SK |
527 | header->ancount = htons(0); |
528 | header->nscount = htons(0); | |
529 | header->arcount = htons(0); | |
530 | if ((nn = resize_packet(header, (size_t)n, pheader, plen))) | |
832af0ba | 531 | { |
1a6bca81 SK |
532 | header->qr = 0; |
533 | header->tc = 0; | |
534 | forward_query(-1, NULL, NULL, 0, header, nn, now, forward); | |
535 | return; | |
832af0ba | 536 | } |
832af0ba | 537 | } |
1a6bca81 SK |
538 | } |
539 | ||
540 | if ((forward->sentto->flags & SERV_TYPE) == 0) | |
541 | { | |
542 | if (header->rcode == SERVFAIL || header->rcode == REFUSED) | |
543 | server = NULL; | |
544 | else | |
b8187c80 | 545 | { |
1a6bca81 SK |
546 | struct server *last_server; |
547 | ||
548 | /* find good server by address if possible, otherwise assume the last one we sent to */ | |
549 | for (last_server = daemon->servers; last_server; last_server = last_server->next) | |
550 | if (!(last_server->flags & (SERV_LITERAL_ADDRESS | SERV_HAS_DOMAIN | SERV_FOR_NODOTS | SERV_NO_ADDR)) && | |
551 | sockaddr_isequal(&last_server->addr, &serveraddr)) | |
552 | { | |
553 | server = last_server; | |
554 | break; | |
555 | } | |
556 | } | |
557 | if (!(daemon->options & OPT_ALL_SERVERS)) | |
558 | daemon->last_server = server; | |
559 | } | |
560 | ||
561 | /* If the answer is an error, keep the forward record in place in case | |
562 | we get a good reply from another server. Kill it when we've | |
563 | had replies from all to avoid filling the forwarding table when | |
564 | everything is broken */ | |
565 | if (forward->forwardall == 0 || --forward->forwardall == 1 || | |
566 | (header->rcode != REFUSED && header->rcode != SERVFAIL)) | |
567 | { | |
8ef5ada2 SK |
568 | int check_rebind = !forward->norebind; |
569 | ||
570 | if (!(daemon->options & OPT_NO_REBIND)) | |
571 | check_rebind = 0; | |
572 | ||
573 | if ((nn = process_reply(header, now, server, (size_t)n, check_rebind))) | |
1a6bca81 SK |
574 | { |
575 | header->id = htons(forward->orig_id); | |
576 | header->ra = 1; /* recursion if available */ | |
577 | send_from(forward->fd, daemon->options & OPT_NOWILD, daemon->packet, nn, | |
578 | &forward->source, &forward->dest, forward->iface); | |
b8187c80 | 579 | } |
1a6bca81 | 580 | free_frec(forward); /* cancel */ |
9e4abcb5 | 581 | } |
9e4abcb5 | 582 | } |
44a2a316 | 583 | |
1a6bca81 | 584 | |
5aabfc78 | 585 | void receive_query(struct listener *listen, time_t now) |
44a2a316 | 586 | { |
3be34541 | 587 | HEADER *header = (HEADER *)daemon->packet; |
44a2a316 | 588 | union mysockaddr source_addr; |
c1bb8504 | 589 | unsigned short type; |
44a2a316 | 590 | struct all_addr dst_addr; |
f6b7dc47 | 591 | struct in_addr netmask, dst_addr_4; |
cdeda28f SK |
592 | size_t m; |
593 | ssize_t n; | |
594 | int if_index = 0; | |
44a2a316 SK |
595 | struct iovec iov[1]; |
596 | struct msghdr msg; | |
597 | struct cmsghdr *cmptr; | |
44a2a316 SK |
598 | union { |
599 | struct cmsghdr align; /* this ensures alignment */ | |
600 | #ifdef HAVE_IPV6 | |
601 | char control6[CMSG_SPACE(sizeof(struct in6_pktinfo))]; | |
602 | #endif | |
5e9e0efb | 603 | #if defined(HAVE_LINUX_NETWORK) |
44a2a316 | 604 | char control[CMSG_SPACE(sizeof(struct in_pktinfo))]; |
824af85b SK |
605 | #elif defined(IP_RECVDSTADDR) && defined(HAVE_SOLARIS_NETWORK) |
606 | char control[CMSG_SPACE(sizeof(struct in_addr)) + | |
607 | CMSG_SPACE(sizeof(unsigned int))]; | |
44a2a316 SK |
608 | #elif defined(IP_RECVDSTADDR) |
609 | char control[CMSG_SPACE(sizeof(struct in_addr)) + | |
610 | CMSG_SPACE(sizeof(struct sockaddr_dl))]; | |
611 | #endif | |
612 | } control_u; | |
613 | ||
cdeda28f SK |
614 | /* packet buffer overwritten */ |
615 | daemon->srv_save = NULL; | |
616 | ||
f6b7dc47 SK |
617 | if (listen->family == AF_INET && (daemon->options & OPT_NOWILD)) |
618 | { | |
619 | dst_addr_4 = listen->iface->addr.in.sin_addr; | |
620 | netmask = listen->iface->netmask; | |
621 | } | |
622 | else | |
3d8df260 SK |
623 | { |
624 | dst_addr_4.s_addr = 0; | |
625 | netmask.s_addr = 0; | |
626 | } | |
f6b7dc47 | 627 | |
3be34541 SK |
628 | iov[0].iov_base = daemon->packet; |
629 | iov[0].iov_len = daemon->edns_pktsz; | |
44a2a316 SK |
630 | |
631 | msg.msg_control = control_u.control; | |
632 | msg.msg_controllen = sizeof(control_u); | |
633 | msg.msg_flags = 0; | |
634 | msg.msg_name = &source_addr; | |
635 | msg.msg_namelen = sizeof(source_addr); | |
636 | msg.msg_iov = iov; | |
637 | msg.msg_iovlen = 1; | |
638 | ||
de37951c | 639 | if ((n = recvmsg(listen->fd, &msg, 0)) == -1) |
3be34541 | 640 | return; |
44a2a316 | 641 | |
5e9e0efb SK |
642 | if (n < (int)sizeof(HEADER) || |
643 | (msg.msg_flags & MSG_TRUNC) || | |
644 | header->qr) | |
26128d27 SK |
645 | return; |
646 | ||
44a2a316 SK |
647 | source_addr.sa.sa_family = listen->family; |
648 | #ifdef HAVE_IPV6 | |
649 | if (listen->family == AF_INET6) | |
5e9e0efb | 650 | source_addr.in6.sin6_flowinfo = 0; |
44a2a316 SK |
651 | #endif |
652 | ||
26128d27 SK |
653 | if (!(daemon->options & OPT_NOWILD)) |
654 | { | |
655 | struct ifreq ifr; | |
656 | ||
657 | if (msg.msg_controllen < sizeof(struct cmsghdr)) | |
658 | return; | |
44a2a316 | 659 | |
5e9e0efb | 660 | #if defined(HAVE_LINUX_NETWORK) |
26128d27 SK |
661 | if (listen->family == AF_INET) |
662 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) | |
663 | if (cmptr->cmsg_level == SOL_IP && cmptr->cmsg_type == IP_PKTINFO) | |
664 | { | |
8ef5ada2 SK |
665 | union { |
666 | unsigned char *c; | |
667 | struct in_pktinfo *p; | |
668 | } p; | |
669 | p.c = CMSG_DATA(cmptr); | |
670 | dst_addr_4 = dst_addr.addr.addr4 = p.p->ipi_spec_dst; | |
671 | if_index = p.p->ipi_ifindex; | |
26128d27 SK |
672 | } |
673 | #elif defined(IP_RECVDSTADDR) && defined(IP_RECVIF) | |
674 | if (listen->family == AF_INET) | |
44a2a316 | 675 | { |
26128d27 | 676 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) |
8ef5ada2 SK |
677 | { |
678 | union { | |
679 | unsigned char *c; | |
680 | unsigned int *i; | |
681 | struct in_addr *a; | |
682 | #ifndef HAVE_SOLARIS_NETWORK | |
683 | struct sockaddr_dl *s; | |
684 | #endif | |
685 | } p; | |
686 | p.c = CMSG_DATA(cmptr); | |
687 | if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVDSTADDR) | |
688 | dst_addr_4 = dst_addr.addr.addr4 = *(p.a); | |
689 | else if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVIF) | |
824af85b | 690 | #ifdef HAVE_SOLARIS_NETWORK |
8ef5ada2 | 691 | if_index = *(p.i); |
824af85b | 692 | #else |
8ef5ada2 | 693 | if_index = p.s->sdl_index; |
824af85b | 694 | #endif |
8ef5ada2 | 695 | } |
44a2a316 | 696 | } |
44a2a316 | 697 | #endif |
26128d27 | 698 | |
44a2a316 | 699 | #ifdef HAVE_IPV6 |
26128d27 SK |
700 | if (listen->family == AF_INET6) |
701 | { | |
702 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) | |
316e2730 | 703 | if (cmptr->cmsg_level == IPV6_LEVEL && cmptr->cmsg_type == daemon->v6pktinfo) |
26128d27 | 704 | { |
8ef5ada2 SK |
705 | union { |
706 | unsigned char *c; | |
707 | struct in6_pktinfo *p; | |
708 | } p; | |
709 | p.c = CMSG_DATA(cmptr); | |
710 | ||
711 | dst_addr.addr.addr6 = p.p->ipi6_addr; | |
712 | if_index = p.p->ipi6_ifindex; | |
26128d27 SK |
713 | } |
714 | } | |
44a2a316 | 715 | #endif |
26128d27 SK |
716 | |
717 | /* enforce available interface configuration */ | |
718 | ||
7622fc06 SK |
719 | if (!indextoname(listen->fd, if_index, ifr.ifr_name) || |
720 | !iface_check(listen->family, &dst_addr, ifr.ifr_name, &if_index)) | |
5e9e0efb | 721 | return; |
832af0ba SK |
722 | |
723 | if (listen->family == AF_INET && | |
724 | (daemon->options & OPT_LOCALISE) && | |
725 | ioctl(listen->fd, SIOCGIFNETMASK, &ifr) == -1) | |
726 | return; | |
727 | ||
728 | netmask = ((struct sockaddr_in *) &ifr.ifr_addr)->sin_addr; | |
44a2a316 SK |
729 | } |
730 | ||
cdeda28f | 731 | if (extract_request(header, (size_t)n, daemon->namebuff, &type)) |
44a2a316 | 732 | { |
1a6bca81 SK |
733 | char types[20]; |
734 | ||
735 | querystr(types, type); | |
736 | ||
44a2a316 | 737 | if (listen->family == AF_INET) |
3be34541 | 738 | log_query(F_QUERY | F_IPV4 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 739 | (struct all_addr *)&source_addr.in.sin_addr, types); |
44a2a316 SK |
740 | #ifdef HAVE_IPV6 |
741 | else | |
3be34541 | 742 | log_query(F_QUERY | F_IPV6 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 743 | (struct all_addr *)&source_addr.in6.sin6_addr, types); |
44a2a316 SK |
744 | #endif |
745 | } | |
746 | ||
5aabfc78 | 747 | m = answer_request (header, ((char *) header) + PACKETSZ, (size_t)n, |
f6b7dc47 | 748 | dst_addr_4, netmask, now); |
44a2a316 | 749 | if (m >= 1) |
824af85b SK |
750 | { |
751 | send_from(listen->fd, daemon->options & OPT_NOWILD, (char *)header, | |
752 | m, &source_addr, &dst_addr, if_index); | |
753 | daemon->local_answer++; | |
754 | } | |
755 | else if (forward_query(listen->fd, &source_addr, &dst_addr, if_index, | |
756 | header, (size_t)n, now, NULL)) | |
757 | daemon->queries_forwarded++; | |
44a2a316 | 758 | else |
824af85b | 759 | daemon->local_answer++; |
44a2a316 SK |
760 | } |
761 | ||
feba5c1d SK |
762 | /* The daemon forks before calling this: it should deal with one connection, |
763 | blocking as neccessary, and then return. Note, need to be a bit careful | |
764 | about resources for debug mode, when the fork is suppressed: that's | |
765 | done by the caller. */ | |
5aabfc78 | 766 | unsigned char *tcp_request(int confd, time_t now, |
3d8df260 | 767 | struct in_addr local_addr, struct in_addr netmask) |
feba5c1d | 768 | { |
8ef5ada2 | 769 | int size = 0, norebind = 0; |
cdeda28f | 770 | size_t m; |
c1bb8504 | 771 | unsigned short qtype, gotname; |
feba5c1d SK |
772 | unsigned char c1, c2; |
773 | /* Max TCP packet + slop */ | |
5aabfc78 | 774 | unsigned char *packet = whine_malloc(65536 + MAXDNAME + RRFIXEDSZ); |
feba5c1d | 775 | HEADER *header; |
3be34541 SK |
776 | struct server *last_server; |
777 | ||
feba5c1d SK |
778 | while (1) |
779 | { | |
780 | if (!packet || | |
781 | !read_write(confd, &c1, 1, 1) || !read_write(confd, &c2, 1, 1) || | |
782 | !(size = c1 << 8 | c2) || | |
783 | !read_write(confd, packet, size, 1)) | |
784 | return packet; | |
785 | ||
786 | if (size < (int)sizeof(HEADER)) | |
787 | continue; | |
788 | ||
789 | header = (HEADER *)packet; | |
790 | ||
3be34541 | 791 | if ((gotname = extract_request(header, (unsigned int)size, daemon->namebuff, &qtype))) |
feba5c1d SK |
792 | { |
793 | union mysockaddr peer_addr; | |
794 | socklen_t peer_len = sizeof(union mysockaddr); | |
795 | ||
796 | if (getpeername(confd, (struct sockaddr *)&peer_addr, &peer_len) != -1) | |
797 | { | |
1a6bca81 SK |
798 | char types[20]; |
799 | ||
800 | querystr(types, qtype); | |
801 | ||
feba5c1d | 802 | if (peer_addr.sa.sa_family == AF_INET) |
3be34541 | 803 | log_query(F_QUERY | F_IPV4 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 804 | (struct all_addr *)&peer_addr.in.sin_addr, types); |
feba5c1d SK |
805 | #ifdef HAVE_IPV6 |
806 | else | |
3be34541 | 807 | log_query(F_QUERY | F_IPV6 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 808 | (struct all_addr *)&peer_addr.in6.sin6_addr, types); |
feba5c1d SK |
809 | #endif |
810 | } | |
811 | } | |
812 | ||
813 | /* m > 0 if answered from cache */ | |
5aabfc78 | 814 | m = answer_request(header, ((char *) header) + 65536, (unsigned int)size, |
f6b7dc47 | 815 | local_addr, netmask, now); |
5aabfc78 SK |
816 | |
817 | /* Do this by steam now we're not in the select() loop */ | |
818 | check_log_writer(NULL); | |
feba5c1d SK |
819 | |
820 | if (m == 0) | |
821 | { | |
822 | unsigned short flags = 0; | |
feba5c1d SK |
823 | struct all_addr *addrp = NULL; |
824 | int type = 0; | |
825 | char *domain = NULL; | |
826 | ||
827 | if (gotname) | |
8ef5ada2 | 828 | flags = search_servers(now, &addrp, gotname, daemon->namebuff, &type, &domain, &norebind); |
feba5c1d | 829 | |
3be34541 SK |
830 | if (type != 0 || (daemon->options & OPT_ORDER) || !daemon->last_server) |
831 | last_server = daemon->servers; | |
832 | else | |
833 | last_server = daemon->last_server; | |
feba5c1d SK |
834 | |
835 | if (!flags && last_server) | |
836 | { | |
837 | struct server *firstsendto = NULL; | |
0a852541 SK |
838 | unsigned int crc = questions_crc(header, (unsigned int)size, daemon->namebuff); |
839 | ||
feba5c1d SK |
840 | /* Loop round available servers until we succeed in connecting to one. |
841 | Note that this code subtley ensures that consecutive queries on this connection | |
842 | which can go to the same server, do so. */ | |
843 | while (1) | |
8ef5ada2 | 844 | { |
feba5c1d SK |
845 | if (!firstsendto) |
846 | firstsendto = last_server; | |
847 | else | |
848 | { | |
849 | if (!(last_server = last_server->next)) | |
3be34541 | 850 | last_server = daemon->servers; |
feba5c1d SK |
851 | |
852 | if (last_server == firstsendto) | |
853 | break; | |
854 | } | |
855 | ||
856 | /* server for wrong domain */ | |
857 | if (type != (last_server->flags & SERV_TYPE) || | |
858 | (type == SERV_HAS_DOMAIN && !hostname_isequal(domain, last_server->domain))) | |
859 | continue; | |
860 | ||
861 | if ((last_server->tcpfd == -1) && | |
862 | (last_server->tcpfd = socket(last_server->addr.sa.sa_family, SOCK_STREAM, 0)) != -1 && | |
824af85b SK |
863 | (!local_bind(last_server->tcpfd, &last_server->source_addr, last_server->interface, 1) || |
864 | connect(last_server->tcpfd, &last_server->addr.sa, sa_len(&last_server->addr)) == -1)) | |
feba5c1d SK |
865 | { |
866 | close(last_server->tcpfd); | |
867 | last_server->tcpfd = -1; | |
868 | } | |
869 | ||
870 | if (last_server->tcpfd == -1) | |
871 | continue; | |
824af85b | 872 | |
feba5c1d SK |
873 | c1 = size >> 8; |
874 | c2 = size; | |
875 | ||
876 | if (!read_write(last_server->tcpfd, &c1, 1, 0) || | |
877 | !read_write(last_server->tcpfd, &c2, 1, 0) || | |
878 | !read_write(last_server->tcpfd, packet, size, 0) || | |
879 | !read_write(last_server->tcpfd, &c1, 1, 1) || | |
880 | !read_write(last_server->tcpfd, &c2, 1, 1)) | |
881 | { | |
882 | close(last_server->tcpfd); | |
883 | last_server->tcpfd = -1; | |
884 | continue; | |
885 | } | |
824af85b | 886 | |
feba5c1d SK |
887 | m = (c1 << 8) | c2; |
888 | if (!read_write(last_server->tcpfd, packet, m, 1)) | |
889 | return packet; | |
890 | ||
891 | if (!gotname) | |
3be34541 | 892 | strcpy(daemon->namebuff, "query"); |
feba5c1d | 893 | if (last_server->addr.sa.sa_family == AF_INET) |
3be34541 | 894 | log_query(F_SERVER | F_IPV4 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 895 | (struct all_addr *)&last_server->addr.in.sin_addr, NULL); |
feba5c1d SK |
896 | #ifdef HAVE_IPV6 |
897 | else | |
3be34541 | 898 | log_query(F_SERVER | F_IPV6 | F_FORWARD, daemon->namebuff, |
1a6bca81 | 899 | (struct all_addr *)&last_server->addr.in6.sin6_addr, NULL); |
feba5c1d SK |
900 | #endif |
901 | ||
902 | /* There's no point in updating the cache, since this process will exit and | |
832af0ba | 903 | lose the information after a few queries. We make this call for the alias and |
feba5c1d | 904 | bogus-nxdomain side-effects. */ |
832af0ba SK |
905 | /* If the crc of the question section doesn't match the crc we sent, then |
906 | someone might be attempting to insert bogus values into the cache by | |
907 | sending replies containing questions and bogus answers. */ | |
908 | if (crc == questions_crc(header, (unsigned int)m, daemon->namebuff)) | |
8ef5ada2 | 909 | m = process_reply(header, now, last_server, (unsigned int)m, (daemon->options & OPT_NO_REBIND) && !norebind ); |
feba5c1d SK |
910 | |
911 | break; | |
912 | } | |
913 | } | |
914 | ||
915 | /* In case of local answer or no connections made. */ | |
916 | if (m == 0) | |
3be34541 | 917 | m = setup_reply(header, (unsigned int)size, addrp, flags, daemon->local_ttl); |
feba5c1d | 918 | } |
5aabfc78 SK |
919 | |
920 | check_log_writer(NULL); | |
feba5c1d SK |
921 | |
922 | c1 = m>>8; | |
923 | c2 = m; | |
924 | if (!read_write(confd, &c1, 1, 0) || | |
925 | !read_write(confd, &c2, 1, 0) || | |
926 | !read_write(confd, packet, m, 0)) | |
927 | return packet; | |
928 | } | |
929 | } | |
930 | ||
1697269c | 931 | static struct frec *allocate_frec(time_t now) |
9e4abcb5 | 932 | { |
1697269c SK |
933 | struct frec *f; |
934 | ||
5aabfc78 | 935 | if ((f = (struct frec *)whine_malloc(sizeof(struct frec)))) |
9e4abcb5 | 936 | { |
1a6bca81 | 937 | f->next = daemon->frec_list; |
1697269c | 938 | f->time = now; |
832af0ba | 939 | f->sentto = NULL; |
1a6bca81 SK |
940 | f->rfd4 = NULL; |
941 | #ifdef HAVE_IPV6 | |
942 | f->rfd6 = NULL; | |
943 | #endif | |
944 | daemon->frec_list = f; | |
1697269c | 945 | } |
9e4abcb5 | 946 | |
1697269c SK |
947 | return f; |
948 | } | |
9e4abcb5 | 949 | |
1a6bca81 SK |
950 | static struct randfd *allocate_rfd(int family) |
951 | { | |
952 | static int finger = 0; | |
953 | int i; | |
954 | ||
955 | /* limit the number of sockets we have open to avoid starvation of | |
956 | (eg) TFTP. Once we have a reasonable number, randomness should be OK */ | |
957 | ||
958 | for (i = 0; i < RANDOM_SOCKS; i++) | |
9009d746 | 959 | if (daemon->randomsocks[i].refcount == 0) |
1a6bca81 | 960 | { |
9009d746 SK |
961 | if ((daemon->randomsocks[i].fd = random_sock(family)) == -1) |
962 | break; | |
963 | ||
1a6bca81 SK |
964 | daemon->randomsocks[i].refcount = 1; |
965 | daemon->randomsocks[i].family = family; | |
966 | return &daemon->randomsocks[i]; | |
967 | } | |
968 | ||
9009d746 | 969 | /* No free ones or cannot get new socket, grab an existing one */ |
1a6bca81 SK |
970 | for (i = 0; i < RANDOM_SOCKS; i++) |
971 | { | |
972 | int j = (i+finger) % RANDOM_SOCKS; | |
9009d746 SK |
973 | if (daemon->randomsocks[j].refcount != 0 && |
974 | daemon->randomsocks[j].family == family && | |
975 | daemon->randomsocks[j].refcount != 0xffff) | |
1a6bca81 SK |
976 | { |
977 | finger = j; | |
978 | daemon->randomsocks[j].refcount++; | |
979 | return &daemon->randomsocks[j]; | |
980 | } | |
981 | } | |
982 | ||
983 | return NULL; /* doom */ | |
984 | } | |
985 | ||
986 | static void free_frec(struct frec *f) | |
987 | { | |
988 | if (f->rfd4 && --(f->rfd4->refcount) == 0) | |
989 | close(f->rfd4->fd); | |
990 | ||
991 | f->rfd4 = NULL; | |
992 | f->sentto = NULL; | |
993 | ||
994 | #ifdef HAVE_IPV6 | |
995 | if (f->rfd6 && --(f->rfd6->refcount) == 0) | |
996 | close(f->rfd6->fd); | |
997 | ||
998 | f->rfd6 = NULL; | |
999 | #endif | |
1000 | } | |
1001 | ||
1697269c SK |
1002 | /* if wait==NULL return a free or older than TIMEOUT record. |
1003 | else return *wait zero if one available, or *wait is delay to | |
1a6bca81 SK |
1004 | when the oldest in-use record will expire. Impose an absolute |
1005 | limit of 4*TIMEOUT before we wipe things (for random sockets) */ | |
5aabfc78 | 1006 | struct frec *get_new_frec(time_t now, int *wait) |
1697269c | 1007 | { |
1a6bca81 | 1008 | struct frec *f, *oldest, *target; |
1697269c SK |
1009 | int count; |
1010 | ||
1011 | if (wait) | |
1012 | *wait = 0; | |
1013 | ||
1a6bca81 | 1014 | for (f = daemon->frec_list, oldest = NULL, target = NULL, count = 0; f; f = f->next, count++) |
832af0ba | 1015 | if (!f->sentto) |
1a6bca81 SK |
1016 | target = f; |
1017 | else | |
1697269c | 1018 | { |
1a6bca81 SK |
1019 | if (difftime(now, f->time) >= 4*TIMEOUT) |
1020 | { | |
1021 | free_frec(f); | |
1022 | target = f; | |
1023 | } | |
1024 | ||
1025 | if (!oldest || difftime(f->time, oldest->time) <= 0) | |
1026 | oldest = f; | |
1697269c | 1027 | } |
1a6bca81 SK |
1028 | |
1029 | if (target) | |
1030 | { | |
1031 | target->time = now; | |
1032 | return target; | |
1033 | } | |
9e4abcb5 SK |
1034 | |
1035 | /* can't find empty one, use oldest if there is one | |
1036 | and it's older than timeout */ | |
1697269c | 1037 | if (oldest && ((int)difftime(now, oldest->time)) >= TIMEOUT) |
9e4abcb5 | 1038 | { |
1697269c SK |
1039 | /* keep stuff for twice timeout if we can by allocating a new |
1040 | record instead */ | |
1041 | if (difftime(now, oldest->time) < 2*TIMEOUT && | |
1042 | count <= daemon->ftabsize && | |
1043 | (f = allocate_frec(now))) | |
1044 | return f; | |
1045 | ||
1046 | if (!wait) | |
1047 | { | |
1a6bca81 | 1048 | free_frec(oldest); |
1697269c SK |
1049 | oldest->time = now; |
1050 | } | |
9e4abcb5 SK |
1051 | return oldest; |
1052 | } | |
1053 | ||
1697269c | 1054 | /* none available, calculate time 'till oldest record expires */ |
208b65c5 | 1055 | if (count > daemon->ftabsize) |
1697269c SK |
1056 | { |
1057 | if (oldest && wait) | |
1058 | *wait = oldest->time + (time_t)TIMEOUT - now; | |
9e4abcb5 SK |
1059 | return NULL; |
1060 | } | |
1697269c SK |
1061 | |
1062 | if (!(f = allocate_frec(now)) && wait) | |
1063 | /* wait one second on malloc failure */ | |
1064 | *wait = 1; | |
9e4abcb5 | 1065 | |
9e4abcb5 SK |
1066 | return f; /* OK if malloc fails and this is NULL */ |
1067 | } | |
1068 | ||
832af0ba SK |
1069 | /* crc is all-ones if not known. */ |
1070 | static struct frec *lookup_frec(unsigned short id, unsigned int crc) | |
9e4abcb5 SK |
1071 | { |
1072 | struct frec *f; | |
1073 | ||
1a6bca81 | 1074 | for(f = daemon->frec_list; f; f = f->next) |
832af0ba SK |
1075 | if (f->sentto && f->new_id == id && |
1076 | (f->crc == crc || crc == 0xffffffff)) | |
9e4abcb5 SK |
1077 | return f; |
1078 | ||
1079 | return NULL; | |
1080 | } | |
1081 | ||
1082 | static struct frec *lookup_frec_by_sender(unsigned short id, | |
fd9fa481 SK |
1083 | union mysockaddr *addr, |
1084 | unsigned int crc) | |
9e4abcb5 | 1085 | { |
feba5c1d SK |
1086 | struct frec *f; |
1087 | ||
1a6bca81 | 1088 | for(f = daemon->frec_list; f; f = f->next) |
832af0ba | 1089 | if (f->sentto && |
9e4abcb5 | 1090 | f->orig_id == id && |
fd9fa481 | 1091 | f->crc == crc && |
9e4abcb5 SK |
1092 | sockaddr_isequal(&f->source, addr)) |
1093 | return f; | |
1094 | ||
1095 | return NULL; | |
1096 | } | |
1097 | ||
849a8357 | 1098 | /* A server record is going away, remove references to it */ |
5aabfc78 | 1099 | void server_gone(struct server *server) |
849a8357 SK |
1100 | { |
1101 | struct frec *f; | |
1102 | ||
1a6bca81 | 1103 | for (f = daemon->frec_list; f; f = f->next) |
832af0ba | 1104 | if (f->sentto && f->sentto == server) |
1a6bca81 | 1105 | free_frec(f); |
849a8357 SK |
1106 | |
1107 | if (daemon->last_server == server) | |
1108 | daemon->last_server = NULL; | |
1109 | ||
1110 | if (daemon->srv_save == server) | |
1111 | daemon->srv_save = NULL; | |
1112 | } | |
9e4abcb5 | 1113 | |
316e2730 SK |
1114 | /* return unique random ids. */ |
1115 | static unsigned short get_id(unsigned int crc) | |
9e4abcb5 SK |
1116 | { |
1117 | unsigned short ret = 0; | |
832af0ba | 1118 | |
316e2730 | 1119 | do |
832af0ba SK |
1120 | ret = rand16(); |
1121 | while (lookup_frec(ret, crc)); | |
1122 | ||
9e4abcb5 SK |
1123 | return ret; |
1124 | } | |
1125 | ||
1126 | ||
1127 | ||
1128 | ||
1129 |