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824af85b | 1 | /* dnsmasq is Copyright (c) 2000-2007 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 SK |
12 | |
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 | ||
849a8357 | 19 | static struct frec *frec_list = NULL; |
9e4abcb5 | 20 | |
832af0ba | 21 | static struct frec *lookup_frec(unsigned short id, unsigned int crc); |
9e4abcb5 | 22 | static struct frec *lookup_frec_by_sender(unsigned short id, |
fd9fa481 SK |
23 | union mysockaddr *addr, |
24 | unsigned int crc); | |
832af0ba | 25 | static unsigned short get_id(int force, unsigned short force_id, unsigned int crc); |
9e4abcb5 | 26 | |
9e4abcb5 | 27 | |
824af85b | 28 | /* Send a UDP packet with its source address set as "source" |
44a2a316 | 29 | unless nowild is true, when we just send it with the kernel default */ |
cdeda28f | 30 | static void send_from(int fd, int nowild, char *packet, size_t len, |
dfa666f2 SK |
31 | union mysockaddr *to, struct all_addr *source, |
32 | unsigned int iface) | |
9e4abcb5 | 33 | { |
44a2a316 SK |
34 | struct msghdr msg; |
35 | struct iovec iov[1]; | |
44a2a316 SK |
36 | union { |
37 | struct cmsghdr align; /* this ensures alignment */ | |
5e9e0efb | 38 | #if defined(HAVE_LINUX_NETWORK) |
44a2a316 SK |
39 | char control[CMSG_SPACE(sizeof(struct in_pktinfo))]; |
40 | #elif defined(IP_SENDSRCADDR) | |
41 | char control[CMSG_SPACE(sizeof(struct in_addr))]; | |
42 | #endif | |
43 | #ifdef HAVE_IPV6 | |
44 | char control6[CMSG_SPACE(sizeof(struct in6_pktinfo))]; | |
45 | #endif | |
46 | } control_u; | |
feba5c1d | 47 | |
44a2a316 SK |
48 | iov[0].iov_base = packet; |
49 | iov[0].iov_len = len; | |
50 | ||
feba5c1d SK |
51 | msg.msg_control = NULL; |
52 | msg.msg_controllen = 0; | |
44a2a316 SK |
53 | msg.msg_flags = 0; |
54 | msg.msg_name = to; | |
55 | msg.msg_namelen = sa_len(to); | |
56 | msg.msg_iov = iov; | |
57 | msg.msg_iovlen = 1; | |
feba5c1d | 58 | |
26128d27 | 59 | if (!nowild) |
44a2a316 | 60 | { |
26128d27 | 61 | struct cmsghdr *cmptr; |
feba5c1d SK |
62 | msg.msg_control = &control_u; |
63 | msg.msg_controllen = sizeof(control_u); | |
26128d27 SK |
64 | cmptr = CMSG_FIRSTHDR(&msg); |
65 | ||
66 | if (to->sa.sa_family == AF_INET) | |
67 | { | |
5e9e0efb | 68 | #if defined(HAVE_LINUX_NETWORK) |
26128d27 SK |
69 | struct in_pktinfo *pkt = (struct in_pktinfo *)CMSG_DATA(cmptr); |
70 | pkt->ipi_ifindex = 0; | |
71 | pkt->ipi_spec_dst = source->addr.addr4; | |
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) |
26128d27 SK |
76 | struct in_addr *a = (struct in_addr *)CMSG_DATA(cmptr); |
77 | *a = source->addr.addr4; | |
78 | msg.msg_controllen = cmptr->cmsg_len = CMSG_LEN(sizeof(struct in_addr)); | |
79 | cmptr->cmsg_level = IPPROTO_IP; | |
80 | cmptr->cmsg_type = IP_SENDSRCADDR; | |
44a2a316 | 81 | #endif |
26128d27 | 82 | } |
26128d27 | 83 | else |
b8187c80 | 84 | #ifdef HAVE_IPV6 |
26128d27 SK |
85 | { |
86 | struct in6_pktinfo *pkt = (struct in6_pktinfo *)CMSG_DATA(cmptr); | |
87 | pkt->ipi6_ifindex = iface; /* Need iface for IPv6 to handle link-local addrs */ | |
88 | pkt->ipi6_addr = source->addr.addr6; | |
89 | msg.msg_controllen = cmptr->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); | |
90 | cmptr->cmsg_type = IPV6_PKTINFO; | |
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, |
36717eee | 115 | unsigned short qtype, char *qdomain, int *type, char **domain) |
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 SK |
156 | hostname_isequal(matchstart, serv->domain) && |
157 | domainlen >= matchlen && | |
cdeda28f | 158 | (domainlen == 0 || namelen == domainlen || *(serv->domain) == '.' || *(matchstart-1) == '.' )) |
feba5c1d SK |
159 | { |
160 | unsigned short sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6; | |
161 | *type = SERV_HAS_DOMAIN; | |
162 | *domain = serv->domain; | |
163 | matchlen = domainlen; | |
feba5c1d | 164 | if (serv->flags & SERV_NO_ADDR) |
36717eee SK |
165 | flags = F_NXDOMAIN; |
166 | else if (serv->flags & SERV_LITERAL_ADDRESS) | |
feba5c1d | 167 | { |
824af85b | 168 | if (sflag & qtype) |
36717eee | 169 | { |
824af85b | 170 | flags = sflag; |
36717eee SK |
171 | if (serv->addr.sa.sa_family == AF_INET) |
172 | *addrpp = (struct all_addr *)&serv->addr.in.sin_addr; | |
feba5c1d | 173 | #ifdef HAVE_IPV6 |
36717eee SK |
174 | else |
175 | *addrpp = (struct all_addr *)&serv->addr.in6.sin6_addr; | |
feba5c1d | 176 | #endif |
36717eee | 177 | } |
824af85b | 178 | else if (!flags || (flags & F_NXDOMAIN)) |
36717eee | 179 | flags = F_NOERR; |
feba5c1d SK |
180 | } |
181 | } | |
182 | } | |
183 | ||
824af85b SK |
184 | if (flags == 0 && !(qtype & F_BIGNAME) && |
185 | (daemon->options & OPT_NODOTS_LOCAL) && !strchr(qdomain, '.') && namelen != 0) | |
186 | /* don't forward simple names, make exception for NS queries and empty name. */ | |
36717eee SK |
187 | flags = F_NXDOMAIN; |
188 | ||
5aabfc78 | 189 | if (flags == F_NXDOMAIN && check_for_local_domain(qdomain, now)) |
c1bb8504 | 190 | flags = F_NOERR; |
feba5c1d | 191 | |
824af85b SK |
192 | if (flags) |
193 | { | |
194 | int logflags = 0; | |
195 | ||
196 | if (flags == F_NXDOMAIN || flags == F_NOERR) | |
197 | logflags = F_NEG | qtype; | |
198 | ||
199 | log_query(logflags | flags | F_CONFIG | F_FORWARD, qdomain, *addrpp, 0, NULL, 0); | |
200 | } | |
feba5c1d SK |
201 | |
202 | return flags; | |
203 | } | |
44a2a316 | 204 | |
824af85b SK |
205 | static int forward_query(int udpfd, union mysockaddr *udpaddr, |
206 | struct all_addr *dst_addr, unsigned int dst_iface, | |
207 | HEADER *header, size_t plen, time_t now, struct frec *forward) | |
9e4abcb5 | 208 | { |
9e4abcb5 | 209 | char *domain = NULL; |
0a852541 | 210 | int type = 0; |
9e4abcb5 | 211 | struct all_addr *addrp = NULL; |
cdeda28f | 212 | unsigned int crc = questions_crc(header, plen, daemon->namebuff); |
9e4abcb5 | 213 | unsigned short flags = 0; |
cdeda28f | 214 | unsigned short gotname = extract_request(header, plen, daemon->namebuff, NULL); |
de37951c | 215 | struct server *start = NULL; |
3d8df260 SK |
216 | |
217 | /* may be no servers available. */ | |
218 | if (!daemon->servers) | |
9e4abcb5 | 219 | forward = NULL; |
b8187c80 | 220 | else if (forward || (forward = lookup_frec_by_sender(ntohs(header->id), udpaddr, crc))) |
9e4abcb5 | 221 | { |
de37951c | 222 | /* retry on existing query, send to all available servers */ |
9e4abcb5 | 223 | domain = forward->sentto->domain; |
824af85b | 224 | forward->sentto->failed_queries++; |
3be34541 | 225 | if (!(daemon->options & OPT_ORDER)) |
de37951c | 226 | { |
0a852541 | 227 | forward->forwardall = 1; |
3be34541 | 228 | daemon->last_server = NULL; |
de37951c | 229 | } |
9e4abcb5 | 230 | type = forward->sentto->flags & SERV_TYPE; |
de37951c | 231 | if (!(start = forward->sentto->next)) |
3be34541 | 232 | start = daemon->servers; /* at end of list, recycle */ |
9e4abcb5 SK |
233 | header->id = htons(forward->new_id); |
234 | } | |
235 | else | |
236 | { | |
237 | if (gotname) | |
5aabfc78 | 238 | flags = search_servers(now, &addrp, gotname, daemon->namebuff, &type, &domain); |
9e4abcb5 | 239 | |
5aabfc78 | 240 | if (!flags && !(forward = get_new_frec(now, NULL))) |
feba5c1d SK |
241 | /* table full - server failure. */ |
242 | flags = F_NEG; | |
9e4abcb5 SK |
243 | |
244 | if (forward) | |
245 | { | |
832af0ba SK |
246 | /* force unchanging id for signed packets */ |
247 | int is_sign; | |
248 | find_pseudoheader(header, plen, NULL, NULL, &is_sign); | |
249 | ||
0a852541 SK |
250 | forward->source = *udpaddr; |
251 | forward->dest = *dst_addr; | |
252 | forward->iface = dst_iface; | |
0a852541 | 253 | forward->orig_id = ntohs(header->id); |
832af0ba SK |
254 | forward->new_id = get_id(is_sign, forward->orig_id, crc); |
255 | forward->fd = udpfd; | |
0a852541 SK |
256 | forward->crc = crc; |
257 | forward->forwardall = 0; | |
258 | header->id = htons(forward->new_id); | |
259 | ||
9e4abcb5 SK |
260 | /* In strict_order mode, or when using domain specific servers |
261 | always try servers in the order specified in resolv.conf, | |
262 | otherwise, use the one last known to work. */ | |
263 | ||
3be34541 SK |
264 | if (type != 0 || (daemon->options & OPT_ORDER)) |
265 | start = daemon->servers; | |
266 | else if (!(start = daemon->last_server)) | |
de37951c | 267 | { |
3be34541 | 268 | start = daemon->servers; |
0a852541 | 269 | forward->forwardall = 1; |
de37951c | 270 | } |
9e4abcb5 SK |
271 | } |
272 | } | |
feba5c1d | 273 | |
9e4abcb5 SK |
274 | /* check for send errors here (no route to host) |
275 | if we fail to send to all nameservers, send back an error | |
276 | packet straight away (helps modem users when offline) */ | |
277 | ||
278 | if (!flags && forward) | |
279 | { | |
de37951c SK |
280 | struct server *firstsentto = start; |
281 | int forwarded = 0; | |
282 | ||
9e4abcb5 SK |
283 | while (1) |
284 | { | |
9e4abcb5 SK |
285 | /* only send to servers dealing with our domain. |
286 | domain may be NULL, in which case server->domain | |
287 | must be NULL also. */ | |
288 | ||
de37951c | 289 | if (type == (start->flags & SERV_TYPE) && |
fd9fa481 SK |
290 | (type != SERV_HAS_DOMAIN || hostname_isequal(domain, start->domain)) && |
291 | !(start->flags & SERV_LITERAL_ADDRESS)) | |
9e4abcb5 | 292 | { |
fd9fa481 | 293 | if (sendto(start->sfd->fd, (char *)header, plen, 0, |
feba5c1d | 294 | &start->addr.sa, |
fd9fa481 SK |
295 | sa_len(&start->addr)) == -1) |
296 | { | |
297 | if (retry_send()) | |
298 | continue; | |
299 | } | |
300 | else | |
9e4abcb5 | 301 | { |
cdeda28f SK |
302 | /* Keep info in case we want to re-send this packet */ |
303 | daemon->srv_save = start; | |
304 | daemon->packet_len = plen; | |
305 | ||
de37951c | 306 | if (!gotname) |
3be34541 | 307 | strcpy(daemon->namebuff, "query"); |
de37951c | 308 | if (start->addr.sa.sa_family == AF_INET) |
3be34541 | 309 | log_query(F_SERVER | F_IPV4 | F_FORWARD, daemon->namebuff, |
fd9fa481 SK |
310 | (struct all_addr *)&start->addr.in.sin_addr, 0, |
311 | NULL, 0); | |
de37951c SK |
312 | #ifdef HAVE_IPV6 |
313 | else | |
3be34541 | 314 | log_query(F_SERVER | F_IPV6 | F_FORWARD, daemon->namebuff, |
fd9fa481 SK |
315 | (struct all_addr *)&start->addr.in6.sin6_addr, 0, |
316 | NULL, 0); | |
de37951c | 317 | #endif |
824af85b | 318 | start->queries++; |
de37951c SK |
319 | forwarded = 1; |
320 | forward->sentto = start; | |
0a852541 | 321 | if (!forward->forwardall) |
de37951c | 322 | break; |
0a852541 | 323 | forward->forwardall++; |
9e4abcb5 SK |
324 | } |
325 | } | |
326 | ||
de37951c | 327 | if (!(start = start->next)) |
3be34541 | 328 | start = daemon->servers; |
9e4abcb5 | 329 | |
de37951c | 330 | if (start == firstsentto) |
9e4abcb5 SK |
331 | break; |
332 | } | |
333 | ||
de37951c | 334 | if (forwarded) |
824af85b | 335 | return 1; |
de37951c | 336 | |
9e4abcb5 SK |
337 | /* could not send on, prepare to return */ |
338 | header->id = htons(forward->orig_id); | |
832af0ba | 339 | forward->sentto = NULL; /* cancel */ |
9e4abcb5 SK |
340 | } |
341 | ||
342 | /* could not send on, return empty answer or address if known for whole domain */ | |
b8187c80 SK |
343 | if (udpfd != -1) |
344 | { | |
cdeda28f | 345 | plen = setup_reply(header, plen, addrp, flags, daemon->local_ttl); |
b8187c80 SK |
346 | send_from(udpfd, daemon->options & OPT_NOWILD, (char *)header, plen, udpaddr, dst_addr, dst_iface); |
347 | } | |
348 | ||
824af85b | 349 | return 0; |
9e4abcb5 SK |
350 | } |
351 | ||
5aabfc78 | 352 | static size_t process_reply(HEADER *header, time_t now, |
832af0ba | 353 | struct server *server, size_t n) |
feba5c1d | 354 | { |
36717eee | 355 | unsigned char *pheader, *sizep; |
832af0ba | 356 | int munged = 0, is_sign; |
cdeda28f SK |
357 | size_t plen; |
358 | ||
feba5c1d SK |
359 | /* If upstream is advertising a larger UDP packet size |
360 | than we allow, trim it so that we don't get overlarge | |
832af0ba | 361 | requests for the client. We can't do this for signed packets. */ |
feba5c1d | 362 | |
832af0ba | 363 | if ((pheader = find_pseudoheader(header, n, &plen, &sizep, &is_sign)) && !is_sign) |
feba5c1d SK |
364 | { |
365 | unsigned short udpsz; | |
36717eee | 366 | unsigned char *psave = sizep; |
feba5c1d | 367 | |
36717eee | 368 | GETSHORT(udpsz, sizep); |
3be34541 SK |
369 | if (udpsz > daemon->edns_pktsz) |
370 | PUTSHORT(daemon->edns_pktsz, psave); | |
feba5c1d SK |
371 | } |
372 | ||
1b7ecd11 | 373 | if (header->opcode != QUERY || (header->rcode != NOERROR && header->rcode != NXDOMAIN)) |
0a852541 SK |
374 | return n; |
375 | ||
feba5c1d | 376 | /* Complain loudly if the upstream server is non-recursive. */ |
0a852541 SK |
377 | if (!header->ra && header->rcode == NOERROR && ntohs(header->ancount) == 0 && |
378 | server && !(server->flags & SERV_WARNED_RECURSIVE)) | |
feba5c1d | 379 | { |
3d8df260 | 380 | prettyprint_addr(&server->addr, daemon->namebuff); |
f2621c7f | 381 | my_syslog(LOG_WARNING, _("nameserver %s refused to do a recursive query"), daemon->namebuff); |
0a852541 SK |
382 | if (!(daemon->options & OPT_LOG)) |
383 | server->flags |= SERV_WARNED_RECURSIVE; | |
384 | } | |
385 | ||
fd9fa481 SK |
386 | if (daemon->bogus_addr && header->rcode != NXDOMAIN && |
387 | check_for_bogus_wildcard(header, n, daemon->namebuff, daemon->bogus_addr, now)) | |
feba5c1d | 388 | { |
fd9fa481 SK |
389 | munged = 1; |
390 | header->rcode = NXDOMAIN; | |
391 | header->aa = 0; | |
36717eee | 392 | } |
fd9fa481 | 393 | else |
36717eee | 394 | { |
fd9fa481 SK |
395 | if (header->rcode == NXDOMAIN && |
396 | extract_request(header, n, daemon->namebuff, NULL) && | |
5aabfc78 | 397 | check_for_local_domain(daemon->namebuff, now)) |
36717eee SK |
398 | { |
399 | /* if we forwarded a query for a locally known name (because it was for | |
400 | an unknown type) and the answer is NXDOMAIN, convert that to NODATA, | |
401 | since we know that the domain exists, even if upstream doesn't */ | |
fd9fa481 SK |
402 | munged = 1; |
403 | header->aa = 1; | |
404 | header->rcode = NOERROR; | |
feba5c1d | 405 | } |
832af0ba | 406 | |
824af85b SK |
407 | if (extract_addresses(header, n, daemon->namebuff, now)) |
408 | { | |
409 | my_syslog(LOG_WARNING, _("possible DNS-rebind attack detected")); | |
410 | munged = 1; | |
411 | } | |
feba5c1d | 412 | } |
fd9fa481 SK |
413 | |
414 | /* do this after extract_addresses. Ensure NODATA reply and remove | |
415 | nameserver info. */ | |
416 | ||
417 | if (munged) | |
418 | { | |
419 | header->ancount = htons(0); | |
420 | header->nscount = htons(0); | |
421 | header->arcount = htons(0); | |
422 | } | |
423 | ||
36717eee SK |
424 | /* the bogus-nxdomain stuff, doctor and NXDOMAIN->NODATA munging can all elide |
425 | sections of the packet. Find the new length here and put back pseudoheader | |
426 | if it was removed. */ | |
427 | return resize_packet(header, n, pheader, plen); | |
feba5c1d SK |
428 | } |
429 | ||
3be34541 | 430 | /* sets new last_server */ |
5aabfc78 | 431 | void reply_query(struct serverfd *sfd, time_t now) |
9e4abcb5 SK |
432 | { |
433 | /* packet from peer server, extract data for cache, and send to | |
434 | original requester */ | |
9e4abcb5 | 435 | HEADER *header; |
de37951c | 436 | union mysockaddr serveraddr; |
832af0ba | 437 | struct frec *forward; |
de37951c | 438 | socklen_t addrlen = sizeof(serveraddr); |
cdeda28f SK |
439 | ssize_t n = recvfrom(sfd->fd, daemon->packet, daemon->edns_pktsz, 0, &serveraddr.sa, &addrlen); |
440 | size_t nn; | |
441 | ||
442 | /* packet buffer overwritten */ | |
443 | daemon->srv_save = NULL; | |
832af0ba | 444 | |
de37951c SK |
445 | /* Determine the address of the server replying so that we can mark that as good */ |
446 | serveraddr.sa.sa_family = sfd->source_addr.sa.sa_family; | |
447 | #ifdef HAVE_IPV6 | |
448 | if (serveraddr.sa.sa_family == AF_INET6) | |
5e9e0efb | 449 | serveraddr.in6.sin6_flowinfo = 0; |
de37951c | 450 | #endif |
9e4abcb5 | 451 | |
3be34541 | 452 | header = (HEADER *)daemon->packet; |
fd9fa481 | 453 | |
832af0ba SK |
454 | if (n >= (int)sizeof(HEADER) && header->qr && |
455 | (forward = lookup_frec(ntohs(header->id), questions_crc(header, n, daemon->namebuff)))) | |
9e4abcb5 | 456 | { |
832af0ba SK |
457 | struct server *server = forward->sentto; |
458 | ||
6b01084f SK |
459 | if ((header->rcode == SERVFAIL || header->rcode == REFUSED) && |
460 | !(daemon->options & OPT_ORDER) && | |
461 | forward->forwardall == 0) | |
832af0ba SK |
462 | /* for broken servers, attempt to send to another one. */ |
463 | { | |
464 | unsigned char *pheader; | |
465 | size_t plen; | |
466 | int is_sign; | |
467 | ||
468 | /* recreate query from reply */ | |
469 | pheader = find_pseudoheader(header, (size_t)n, &plen, NULL, &is_sign); | |
470 | if (!is_sign) | |
471 | { | |
472 | header->ancount = htons(0); | |
473 | header->nscount = htons(0); | |
474 | header->arcount = htons(0); | |
475 | if ((nn = resize_packet(header, (size_t)n, pheader, plen))) | |
476 | { | |
477 | header->qr = 0; | |
478 | header->tc = 0; | |
5aabfc78 | 479 | forward_query(-1, NULL, NULL, 0, header, nn, now, forward); |
832af0ba SK |
480 | return; |
481 | } | |
482 | } | |
483 | } | |
484 | ||
485 | if ((forward->sentto->flags & SERV_TYPE) == 0) | |
486 | { | |
487 | if (header->rcode == SERVFAIL || header->rcode == REFUSED) | |
488 | server = NULL; | |
489 | else | |
490 | { | |
491 | struct server *last_server; | |
492 | /* find good server by address if possible, otherwise assume the last one we sent to */ | |
493 | for (last_server = daemon->servers; last_server; last_server = last_server->next) | |
494 | if (!(last_server->flags & (SERV_LITERAL_ADDRESS | SERV_HAS_DOMAIN | SERV_FOR_NODOTS | SERV_NO_ADDR)) && | |
495 | sockaddr_isequal(&last_server->addr, &serveraddr)) | |
496 | { | |
497 | server = last_server; | |
498 | break; | |
499 | } | |
500 | } | |
824af85b SK |
501 | if (!(daemon->options & OPT_ALL_SERVERS)) |
502 | daemon->last_server = server; | |
832af0ba SK |
503 | } |
504 | ||
0a852541 SK |
505 | /* If the answer is an error, keep the forward record in place in case |
506 | we get a good reply from another server. Kill it when we've | |
507 | had replies from all to avoid filling the forwarding table when | |
508 | everything is broken */ | |
509 | if (forward->forwardall == 0 || --forward->forwardall == 1 || | |
510 | (header->rcode != REFUSED && header->rcode != SERVFAIL)) | |
b8187c80 | 511 | { |
5aabfc78 | 512 | if ((nn = process_reply(header, now, server, (size_t)n))) |
b8187c80 SK |
513 | { |
514 | header->id = htons(forward->orig_id); | |
515 | header->ra = 1; /* recursion if available */ | |
cdeda28f | 516 | send_from(forward->fd, daemon->options & OPT_NOWILD, daemon->packet, nn, |
b8187c80 SK |
517 | &forward->source, &forward->dest, forward->iface); |
518 | } | |
832af0ba | 519 | forward->sentto = NULL; /* cancel */ |
b8187c80 | 520 | } |
9e4abcb5 | 521 | } |
9e4abcb5 | 522 | } |
44a2a316 | 523 | |
5aabfc78 | 524 | void receive_query(struct listener *listen, time_t now) |
44a2a316 | 525 | { |
3be34541 | 526 | HEADER *header = (HEADER *)daemon->packet; |
44a2a316 | 527 | union mysockaddr source_addr; |
c1bb8504 | 528 | unsigned short type; |
44a2a316 | 529 | struct all_addr dst_addr; |
f6b7dc47 | 530 | struct in_addr netmask, dst_addr_4; |
cdeda28f SK |
531 | size_t m; |
532 | ssize_t n; | |
533 | int if_index = 0; | |
44a2a316 SK |
534 | struct iovec iov[1]; |
535 | struct msghdr msg; | |
536 | struct cmsghdr *cmptr; | |
44a2a316 SK |
537 | union { |
538 | struct cmsghdr align; /* this ensures alignment */ | |
539 | #ifdef HAVE_IPV6 | |
540 | char control6[CMSG_SPACE(sizeof(struct in6_pktinfo))]; | |
541 | #endif | |
5e9e0efb | 542 | #if defined(HAVE_LINUX_NETWORK) |
44a2a316 | 543 | char control[CMSG_SPACE(sizeof(struct in_pktinfo))]; |
824af85b SK |
544 | #elif defined(IP_RECVDSTADDR) && defined(HAVE_SOLARIS_NETWORK) |
545 | char control[CMSG_SPACE(sizeof(struct in_addr)) + | |
546 | CMSG_SPACE(sizeof(unsigned int))]; | |
44a2a316 SK |
547 | #elif defined(IP_RECVDSTADDR) |
548 | char control[CMSG_SPACE(sizeof(struct in_addr)) + | |
549 | CMSG_SPACE(sizeof(struct sockaddr_dl))]; | |
550 | #endif | |
551 | } control_u; | |
552 | ||
cdeda28f SK |
553 | /* packet buffer overwritten */ |
554 | daemon->srv_save = NULL; | |
555 | ||
f6b7dc47 SK |
556 | if (listen->family == AF_INET && (daemon->options & OPT_NOWILD)) |
557 | { | |
558 | dst_addr_4 = listen->iface->addr.in.sin_addr; | |
559 | netmask = listen->iface->netmask; | |
560 | } | |
561 | else | |
3d8df260 SK |
562 | { |
563 | dst_addr_4.s_addr = 0; | |
564 | netmask.s_addr = 0; | |
565 | } | |
f6b7dc47 | 566 | |
3be34541 SK |
567 | iov[0].iov_base = daemon->packet; |
568 | iov[0].iov_len = daemon->edns_pktsz; | |
44a2a316 SK |
569 | |
570 | msg.msg_control = control_u.control; | |
571 | msg.msg_controllen = sizeof(control_u); | |
572 | msg.msg_flags = 0; | |
573 | msg.msg_name = &source_addr; | |
574 | msg.msg_namelen = sizeof(source_addr); | |
575 | msg.msg_iov = iov; | |
576 | msg.msg_iovlen = 1; | |
577 | ||
de37951c | 578 | if ((n = recvmsg(listen->fd, &msg, 0)) == -1) |
3be34541 | 579 | return; |
44a2a316 | 580 | |
5e9e0efb SK |
581 | if (n < (int)sizeof(HEADER) || |
582 | (msg.msg_flags & MSG_TRUNC) || | |
583 | header->qr) | |
26128d27 SK |
584 | return; |
585 | ||
44a2a316 SK |
586 | source_addr.sa.sa_family = listen->family; |
587 | #ifdef HAVE_IPV6 | |
588 | if (listen->family == AF_INET6) | |
5e9e0efb | 589 | source_addr.in6.sin6_flowinfo = 0; |
44a2a316 SK |
590 | #endif |
591 | ||
26128d27 SK |
592 | if (!(daemon->options & OPT_NOWILD)) |
593 | { | |
594 | struct ifreq ifr; | |
595 | ||
596 | if (msg.msg_controllen < sizeof(struct cmsghdr)) | |
597 | return; | |
44a2a316 | 598 | |
5e9e0efb | 599 | #if defined(HAVE_LINUX_NETWORK) |
26128d27 SK |
600 | if (listen->family == AF_INET) |
601 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) | |
602 | if (cmptr->cmsg_level == SOL_IP && cmptr->cmsg_type == IP_PKTINFO) | |
603 | { | |
f6b7dc47 | 604 | dst_addr_4 = dst_addr.addr.addr4 = ((struct in_pktinfo *)CMSG_DATA(cmptr))->ipi_spec_dst; |
26128d27 SK |
605 | if_index = ((struct in_pktinfo *)CMSG_DATA(cmptr))->ipi_ifindex; |
606 | } | |
607 | #elif defined(IP_RECVDSTADDR) && defined(IP_RECVIF) | |
608 | if (listen->family == AF_INET) | |
44a2a316 | 609 | { |
26128d27 SK |
610 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) |
611 | if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVDSTADDR) | |
f6b7dc47 | 612 | dst_addr_4 = dst_addr.addr.addr4 = *((struct in_addr *)CMSG_DATA(cmptr)); |
26128d27 | 613 | else if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVIF) |
824af85b SK |
614 | #ifdef HAVE_SOLARIS_NETWORK |
615 | if_index = *((unsigned int *)CMSG_DATA(cmptr)); | |
616 | #else | |
26128d27 | 617 | if_index = ((struct sockaddr_dl *)CMSG_DATA(cmptr))->sdl_index; |
824af85b | 618 | #endif |
44a2a316 | 619 | } |
44a2a316 | 620 | #endif |
26128d27 | 621 | |
44a2a316 | 622 | #ifdef HAVE_IPV6 |
26128d27 SK |
623 | if (listen->family == AF_INET6) |
624 | { | |
625 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) | |
626 | if (cmptr->cmsg_level == IPV6_LEVEL && cmptr->cmsg_type == IPV6_PKTINFO) | |
627 | { | |
628 | dst_addr.addr.addr6 = ((struct in6_pktinfo *)CMSG_DATA(cmptr))->ipi6_addr; | |
629 | if_index =((struct in6_pktinfo *)CMSG_DATA(cmptr))->ipi6_ifindex; | |
630 | } | |
631 | } | |
44a2a316 | 632 | #endif |
26128d27 SK |
633 | |
634 | /* enforce available interface configuration */ | |
635 | ||
8a911ccc | 636 | if (if_index == 0) |
3be34541 | 637 | return; |
44a2a316 | 638 | |
8a911ccc | 639 | #ifdef SIOCGIFNAME |
832af0ba SK |
640 | ifr.ifr_ifindex = if_index; |
641 | if (ioctl(listen->fd, SIOCGIFNAME, &ifr) == -1) | |
642 | return; | |
8a911ccc | 643 | #else |
832af0ba SK |
644 | if (!if_indextoname(if_index, ifr.ifr_name)) |
645 | return; | |
8a911ccc | 646 | #endif |
832af0ba | 647 | |
5aabfc78 | 648 | if (!iface_check(listen->family, &dst_addr, &ifr, &if_index)) |
5e9e0efb | 649 | return; |
832af0ba SK |
650 | |
651 | if (listen->family == AF_INET && | |
652 | (daemon->options & OPT_LOCALISE) && | |
653 | ioctl(listen->fd, SIOCGIFNETMASK, &ifr) == -1) | |
654 | return; | |
655 | ||
656 | netmask = ((struct sockaddr_in *) &ifr.ifr_addr)->sin_addr; | |
44a2a316 SK |
657 | } |
658 | ||
cdeda28f | 659 | if (extract_request(header, (size_t)n, daemon->namebuff, &type)) |
44a2a316 SK |
660 | { |
661 | if (listen->family == AF_INET) | |
3be34541 | 662 | log_query(F_QUERY | F_IPV4 | F_FORWARD, daemon->namebuff, |
fd9fa481 | 663 | (struct all_addr *)&source_addr.in.sin_addr, type, NULL, 0); |
44a2a316 SK |
664 | #ifdef HAVE_IPV6 |
665 | else | |
3be34541 | 666 | log_query(F_QUERY | F_IPV6 | F_FORWARD, daemon->namebuff, |
fd9fa481 | 667 | (struct all_addr *)&source_addr.in6.sin6_addr, type, NULL, 0); |
44a2a316 SK |
668 | #endif |
669 | } | |
670 | ||
5aabfc78 | 671 | m = answer_request (header, ((char *) header) + PACKETSZ, (size_t)n, |
f6b7dc47 | 672 | dst_addr_4, netmask, now); |
44a2a316 | 673 | if (m >= 1) |
824af85b SK |
674 | { |
675 | send_from(listen->fd, daemon->options & OPT_NOWILD, (char *)header, | |
676 | m, &source_addr, &dst_addr, if_index); | |
677 | daemon->local_answer++; | |
678 | } | |
679 | else if (forward_query(listen->fd, &source_addr, &dst_addr, if_index, | |
680 | header, (size_t)n, now, NULL)) | |
681 | daemon->queries_forwarded++; | |
44a2a316 | 682 | else |
824af85b | 683 | daemon->local_answer++; |
44a2a316 SK |
684 | } |
685 | ||
feba5c1d SK |
686 | /* The daemon forks before calling this: it should deal with one connection, |
687 | blocking as neccessary, and then return. Note, need to be a bit careful | |
688 | about resources for debug mode, when the fork is suppressed: that's | |
689 | done by the caller. */ | |
5aabfc78 | 690 | unsigned char *tcp_request(int confd, time_t now, |
3d8df260 | 691 | struct in_addr local_addr, struct in_addr netmask) |
feba5c1d | 692 | { |
cdeda28f SK |
693 | int size = 0; |
694 | size_t m; | |
c1bb8504 | 695 | unsigned short qtype, gotname; |
feba5c1d SK |
696 | unsigned char c1, c2; |
697 | /* Max TCP packet + slop */ | |
5aabfc78 | 698 | unsigned char *packet = whine_malloc(65536 + MAXDNAME + RRFIXEDSZ); |
feba5c1d | 699 | HEADER *header; |
3be34541 SK |
700 | struct server *last_server; |
701 | ||
feba5c1d SK |
702 | while (1) |
703 | { | |
704 | if (!packet || | |
705 | !read_write(confd, &c1, 1, 1) || !read_write(confd, &c2, 1, 1) || | |
706 | !(size = c1 << 8 | c2) || | |
707 | !read_write(confd, packet, size, 1)) | |
708 | return packet; | |
709 | ||
710 | if (size < (int)sizeof(HEADER)) | |
711 | continue; | |
712 | ||
713 | header = (HEADER *)packet; | |
714 | ||
3be34541 | 715 | if ((gotname = extract_request(header, (unsigned int)size, daemon->namebuff, &qtype))) |
feba5c1d SK |
716 | { |
717 | union mysockaddr peer_addr; | |
718 | socklen_t peer_len = sizeof(union mysockaddr); | |
719 | ||
720 | if (getpeername(confd, (struct sockaddr *)&peer_addr, &peer_len) != -1) | |
721 | { | |
722 | if (peer_addr.sa.sa_family == AF_INET) | |
3be34541 | 723 | log_query(F_QUERY | F_IPV4 | F_FORWARD, daemon->namebuff, |
fd9fa481 | 724 | (struct all_addr *)&peer_addr.in.sin_addr, qtype, NULL, 0); |
feba5c1d SK |
725 | #ifdef HAVE_IPV6 |
726 | else | |
3be34541 | 727 | log_query(F_QUERY | F_IPV6 | F_FORWARD, daemon->namebuff, |
fd9fa481 | 728 | (struct all_addr *)&peer_addr.in6.sin6_addr, qtype, NULL, 0); |
feba5c1d SK |
729 | #endif |
730 | } | |
731 | } | |
732 | ||
733 | /* m > 0 if answered from cache */ | |
5aabfc78 | 734 | m = answer_request(header, ((char *) header) + 65536, (unsigned int)size, |
f6b7dc47 | 735 | local_addr, netmask, now); |
5aabfc78 SK |
736 | |
737 | /* Do this by steam now we're not in the select() loop */ | |
738 | check_log_writer(NULL); | |
feba5c1d SK |
739 | |
740 | if (m == 0) | |
741 | { | |
742 | unsigned short flags = 0; | |
feba5c1d SK |
743 | struct all_addr *addrp = NULL; |
744 | int type = 0; | |
745 | char *domain = NULL; | |
746 | ||
747 | if (gotname) | |
5aabfc78 | 748 | flags = search_servers(now, &addrp, gotname, daemon->namebuff, &type, &domain); |
feba5c1d | 749 | |
3be34541 SK |
750 | if (type != 0 || (daemon->options & OPT_ORDER) || !daemon->last_server) |
751 | last_server = daemon->servers; | |
752 | else | |
753 | last_server = daemon->last_server; | |
feba5c1d SK |
754 | |
755 | if (!flags && last_server) | |
756 | { | |
757 | struct server *firstsendto = NULL; | |
0a852541 SK |
758 | unsigned int crc = questions_crc(header, (unsigned int)size, daemon->namebuff); |
759 | ||
feba5c1d SK |
760 | /* Loop round available servers until we succeed in connecting to one. |
761 | Note that this code subtley ensures that consecutive queries on this connection | |
762 | which can go to the same server, do so. */ | |
763 | while (1) | |
764 | { | |
765 | if (!firstsendto) | |
766 | firstsendto = last_server; | |
767 | else | |
768 | { | |
769 | if (!(last_server = last_server->next)) | |
3be34541 | 770 | last_server = daemon->servers; |
feba5c1d SK |
771 | |
772 | if (last_server == firstsendto) | |
773 | break; | |
774 | } | |
775 | ||
776 | /* server for wrong domain */ | |
777 | if (type != (last_server->flags & SERV_TYPE) || | |
778 | (type == SERV_HAS_DOMAIN && !hostname_isequal(domain, last_server->domain))) | |
779 | continue; | |
780 | ||
781 | if ((last_server->tcpfd == -1) && | |
782 | (last_server->tcpfd = socket(last_server->addr.sa.sa_family, SOCK_STREAM, 0)) != -1 && | |
824af85b SK |
783 | (!local_bind(last_server->tcpfd, &last_server->source_addr, last_server->interface, 1) || |
784 | connect(last_server->tcpfd, &last_server->addr.sa, sa_len(&last_server->addr)) == -1)) | |
feba5c1d SK |
785 | { |
786 | close(last_server->tcpfd); | |
787 | last_server->tcpfd = -1; | |
788 | } | |
789 | ||
790 | if (last_server->tcpfd == -1) | |
791 | continue; | |
824af85b | 792 | |
feba5c1d SK |
793 | c1 = size >> 8; |
794 | c2 = size; | |
795 | ||
796 | if (!read_write(last_server->tcpfd, &c1, 1, 0) || | |
797 | !read_write(last_server->tcpfd, &c2, 1, 0) || | |
798 | !read_write(last_server->tcpfd, packet, size, 0) || | |
799 | !read_write(last_server->tcpfd, &c1, 1, 1) || | |
800 | !read_write(last_server->tcpfd, &c2, 1, 1)) | |
801 | { | |
802 | close(last_server->tcpfd); | |
803 | last_server->tcpfd = -1; | |
804 | continue; | |
805 | } | |
824af85b | 806 | |
feba5c1d SK |
807 | m = (c1 << 8) | c2; |
808 | if (!read_write(last_server->tcpfd, packet, m, 1)) | |
809 | return packet; | |
810 | ||
811 | if (!gotname) | |
3be34541 | 812 | strcpy(daemon->namebuff, "query"); |
feba5c1d | 813 | if (last_server->addr.sa.sa_family == AF_INET) |
3be34541 | 814 | log_query(F_SERVER | F_IPV4 | F_FORWARD, daemon->namebuff, |
fd9fa481 | 815 | (struct all_addr *)&last_server->addr.in.sin_addr, 0, NULL, 0); |
feba5c1d SK |
816 | #ifdef HAVE_IPV6 |
817 | else | |
3be34541 | 818 | log_query(F_SERVER | F_IPV6 | F_FORWARD, daemon->namebuff, |
fd9fa481 | 819 | (struct all_addr *)&last_server->addr.in6.sin6_addr, 0, NULL, 0); |
feba5c1d SK |
820 | #endif |
821 | ||
822 | /* There's no point in updating the cache, since this process will exit and | |
832af0ba | 823 | lose the information after a few queries. We make this call for the alias and |
feba5c1d | 824 | bogus-nxdomain side-effects. */ |
832af0ba SK |
825 | /* If the crc of the question section doesn't match the crc we sent, then |
826 | someone might be attempting to insert bogus values into the cache by | |
827 | sending replies containing questions and bogus answers. */ | |
828 | if (crc == questions_crc(header, (unsigned int)m, daemon->namebuff)) | |
5aabfc78 | 829 | m = process_reply(header, now, last_server, (unsigned int)m); |
feba5c1d SK |
830 | |
831 | break; | |
832 | } | |
833 | } | |
834 | ||
835 | /* In case of local answer or no connections made. */ | |
836 | if (m == 0) | |
3be34541 | 837 | m = setup_reply(header, (unsigned int)size, addrp, flags, daemon->local_ttl); |
feba5c1d | 838 | } |
5aabfc78 SK |
839 | |
840 | check_log_writer(NULL); | |
feba5c1d SK |
841 | |
842 | c1 = m>>8; | |
843 | c2 = m; | |
844 | if (!read_write(confd, &c1, 1, 0) || | |
845 | !read_write(confd, &c2, 1, 0) || | |
846 | !read_write(confd, packet, m, 0)) | |
847 | return packet; | |
848 | } | |
849 | } | |
850 | ||
1697269c | 851 | static struct frec *allocate_frec(time_t now) |
9e4abcb5 | 852 | { |
1697269c SK |
853 | struct frec *f; |
854 | ||
5aabfc78 | 855 | if ((f = (struct frec *)whine_malloc(sizeof(struct frec)))) |
9e4abcb5 | 856 | { |
1697269c SK |
857 | f->next = frec_list; |
858 | f->time = now; | |
832af0ba | 859 | f->sentto = NULL; |
1697269c SK |
860 | frec_list = f; |
861 | } | |
9e4abcb5 | 862 | |
1697269c SK |
863 | return f; |
864 | } | |
9e4abcb5 | 865 | |
1697269c SK |
866 | /* if wait==NULL return a free or older than TIMEOUT record. |
867 | else return *wait zero if one available, or *wait is delay to | |
868 | when the oldest in-use record will expire. */ | |
5aabfc78 | 869 | struct frec *get_new_frec(time_t now, int *wait) |
1697269c SK |
870 | { |
871 | struct frec *f, *oldest; | |
872 | int count; | |
873 | ||
874 | if (wait) | |
875 | *wait = 0; | |
876 | ||
877 | for (f = frec_list, oldest = NULL, count = 0; f; f = f->next, count++) | |
832af0ba | 878 | if (!f->sentto) |
1697269c SK |
879 | { |
880 | f->time = now; | |
881 | return f; | |
882 | } | |
883 | else if (!oldest || difftime(f->time, oldest->time) <= 0) | |
884 | oldest = f; | |
9e4abcb5 SK |
885 | |
886 | /* can't find empty one, use oldest if there is one | |
887 | and it's older than timeout */ | |
1697269c | 888 | if (oldest && ((int)difftime(now, oldest->time)) >= TIMEOUT) |
9e4abcb5 | 889 | { |
1697269c SK |
890 | /* keep stuff for twice timeout if we can by allocating a new |
891 | record instead */ | |
892 | if (difftime(now, oldest->time) < 2*TIMEOUT && | |
893 | count <= daemon->ftabsize && | |
894 | (f = allocate_frec(now))) | |
895 | return f; | |
896 | ||
897 | if (!wait) | |
898 | { | |
832af0ba | 899 | oldest->sentto = 0; |
1697269c SK |
900 | oldest->time = now; |
901 | } | |
9e4abcb5 SK |
902 | return oldest; |
903 | } | |
904 | ||
1697269c | 905 | /* none available, calculate time 'till oldest record expires */ |
208b65c5 | 906 | if (count > daemon->ftabsize) |
1697269c SK |
907 | { |
908 | if (oldest && wait) | |
909 | *wait = oldest->time + (time_t)TIMEOUT - now; | |
9e4abcb5 SK |
910 | return NULL; |
911 | } | |
1697269c SK |
912 | |
913 | if (!(f = allocate_frec(now)) && wait) | |
914 | /* wait one second on malloc failure */ | |
915 | *wait = 1; | |
9e4abcb5 | 916 | |
9e4abcb5 SK |
917 | return f; /* OK if malloc fails and this is NULL */ |
918 | } | |
919 | ||
832af0ba SK |
920 | /* crc is all-ones if not known. */ |
921 | static struct frec *lookup_frec(unsigned short id, unsigned int crc) | |
9e4abcb5 SK |
922 | { |
923 | struct frec *f; | |
924 | ||
925 | for(f = frec_list; f; f = f->next) | |
832af0ba SK |
926 | if (f->sentto && f->new_id == id && |
927 | (f->crc == crc || crc == 0xffffffff)) | |
9e4abcb5 SK |
928 | return f; |
929 | ||
930 | return NULL; | |
931 | } | |
932 | ||
933 | static struct frec *lookup_frec_by_sender(unsigned short id, | |
fd9fa481 SK |
934 | union mysockaddr *addr, |
935 | unsigned int crc) | |
9e4abcb5 | 936 | { |
feba5c1d SK |
937 | struct frec *f; |
938 | ||
9e4abcb5 | 939 | for(f = frec_list; f; f = f->next) |
832af0ba | 940 | if (f->sentto && |
9e4abcb5 | 941 | f->orig_id == id && |
fd9fa481 | 942 | f->crc == crc && |
9e4abcb5 SK |
943 | sockaddr_isequal(&f->source, addr)) |
944 | return f; | |
945 | ||
946 | return NULL; | |
947 | } | |
948 | ||
849a8357 | 949 | /* A server record is going away, remove references to it */ |
5aabfc78 | 950 | void server_gone(struct server *server) |
849a8357 SK |
951 | { |
952 | struct frec *f; | |
953 | ||
954 | for (f = frec_list; f; f = f->next) | |
832af0ba SK |
955 | if (f->sentto && f->sentto == server) |
956 | f->sentto = NULL; | |
849a8357 SK |
957 | |
958 | if (daemon->last_server == server) | |
959 | daemon->last_server = NULL; | |
960 | ||
961 | if (daemon->srv_save == server) | |
962 | daemon->srv_save = NULL; | |
963 | } | |
9e4abcb5 | 964 | |
832af0ba SK |
965 | /* return unique random ids. |
966 | For signed packets we can't change the ID without breaking the | |
967 | signing, so we keep the same one. In this case force is set, and this | |
968 | routine degenerates into killing any conflicting forward record. */ | |
969 | static unsigned short get_id(int force, unsigned short force_id, unsigned int crc) | |
9e4abcb5 SK |
970 | { |
971 | unsigned short ret = 0; | |
832af0ba SK |
972 | |
973 | if (force) | |
9e4abcb5 | 974 | { |
832af0ba SK |
975 | struct frec *f = lookup_frec(force_id, crc); |
976 | if (f) | |
977 | f->sentto = NULL; /* free */ | |
978 | ret = force_id; | |
9e4abcb5 | 979 | } |
832af0ba SK |
980 | else do |
981 | ret = rand16(); | |
982 | while (lookup_frec(ret, crc)); | |
983 | ||
9e4abcb5 SK |
984 | return ret; |
985 | } | |
986 | ||
987 | ||
988 | ||
989 | ||
990 |