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Commit | Line | Data |
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f6b7dc47 | 1 | /* dnsmasq is Copyright (c) 2000 - 2005 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 | |
5 | the Free Software Foundation; version 2 dated June, 1991. | |
6 | ||
7 | This program is distributed in the hope that it will be useful, | |
8 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
9 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
10 | GNU General Public License for more details. | |
11 | */ | |
12 | ||
9e4abcb5 SK |
13 | #include "dnsmasq.h" |
14 | ||
849a8357 | 15 | static struct frec *frec_list = NULL; |
9e4abcb5 | 16 | |
9e4abcb5 SK |
17 | static struct frec *lookup_frec(unsigned short id); |
18 | static struct frec *lookup_frec_by_sender(unsigned short id, | |
fd9fa481 SK |
19 | union mysockaddr *addr, |
20 | unsigned int crc); | |
9e4abcb5 SK |
21 | static unsigned short get_id(void); |
22 | ||
9e4abcb5 | 23 | |
44a2a316 SK |
24 | /* Send a UDP packet with it's source address set as "source" |
25 | unless nowild is true, when we just send it with the kernel default */ | |
cdeda28f | 26 | static void send_from(int fd, int nowild, char *packet, size_t len, |
dfa666f2 SK |
27 | union mysockaddr *to, struct all_addr *source, |
28 | unsigned int iface) | |
9e4abcb5 | 29 | { |
44a2a316 SK |
30 | struct msghdr msg; |
31 | struct iovec iov[1]; | |
44a2a316 SK |
32 | union { |
33 | struct cmsghdr align; /* this ensures alignment */ | |
5e9e0efb | 34 | #if defined(HAVE_LINUX_NETWORK) |
44a2a316 SK |
35 | char control[CMSG_SPACE(sizeof(struct in_pktinfo))]; |
36 | #elif defined(IP_SENDSRCADDR) | |
37 | char control[CMSG_SPACE(sizeof(struct in_addr))]; | |
38 | #endif | |
39 | #ifdef HAVE_IPV6 | |
40 | char control6[CMSG_SPACE(sizeof(struct in6_pktinfo))]; | |
41 | #endif | |
42 | } control_u; | |
feba5c1d | 43 | |
44a2a316 SK |
44 | iov[0].iov_base = packet; |
45 | iov[0].iov_len = len; | |
46 | ||
feba5c1d SK |
47 | msg.msg_control = NULL; |
48 | msg.msg_controllen = 0; | |
44a2a316 SK |
49 | msg.msg_flags = 0; |
50 | msg.msg_name = to; | |
51 | msg.msg_namelen = sa_len(to); | |
52 | msg.msg_iov = iov; | |
53 | msg.msg_iovlen = 1; | |
feba5c1d | 54 | |
26128d27 | 55 | if (!nowild) |
44a2a316 | 56 | { |
26128d27 | 57 | struct cmsghdr *cmptr; |
feba5c1d SK |
58 | msg.msg_control = &control_u; |
59 | msg.msg_controllen = sizeof(control_u); | |
26128d27 SK |
60 | cmptr = CMSG_FIRSTHDR(&msg); |
61 | ||
62 | if (to->sa.sa_family == AF_INET) | |
63 | { | |
5e9e0efb | 64 | #if defined(HAVE_LINUX_NETWORK) |
26128d27 SK |
65 | struct in_pktinfo *pkt = (struct in_pktinfo *)CMSG_DATA(cmptr); |
66 | pkt->ipi_ifindex = 0; | |
67 | pkt->ipi_spec_dst = source->addr.addr4; | |
68 | msg.msg_controllen = cmptr->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo)); | |
69 | cmptr->cmsg_level = SOL_IP; | |
70 | cmptr->cmsg_type = IP_PKTINFO; | |
44a2a316 | 71 | #elif defined(IP_SENDSRCADDR) |
26128d27 SK |
72 | struct in_addr *a = (struct in_addr *)CMSG_DATA(cmptr); |
73 | *a = source->addr.addr4; | |
74 | msg.msg_controllen = cmptr->cmsg_len = CMSG_LEN(sizeof(struct in_addr)); | |
75 | cmptr->cmsg_level = IPPROTO_IP; | |
76 | cmptr->cmsg_type = IP_SENDSRCADDR; | |
44a2a316 | 77 | #endif |
26128d27 | 78 | } |
26128d27 | 79 | else |
b8187c80 | 80 | #ifdef HAVE_IPV6 |
26128d27 SK |
81 | { |
82 | struct in6_pktinfo *pkt = (struct in6_pktinfo *)CMSG_DATA(cmptr); | |
83 | pkt->ipi6_ifindex = iface; /* Need iface for IPv6 to handle link-local addrs */ | |
84 | pkt->ipi6_addr = source->addr.addr6; | |
85 | msg.msg_controllen = cmptr->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); | |
86 | cmptr->cmsg_type = IPV6_PKTINFO; | |
87 | cmptr->cmsg_level = IPV6_LEVEL; | |
88 | } | |
3d8df260 SK |
89 | #else |
90 | iface = 0; /* eliminate warning */ | |
44a2a316 | 91 | #endif |
26128d27 | 92 | } |
feba5c1d | 93 | |
fd9fa481 SK |
94 | retry: |
95 | if (sendmsg(fd, &msg, 0) == -1) | |
feba5c1d | 96 | { |
fd9fa481 SK |
97 | /* certain Linux kernels seem to object to setting the source address in the IPv6 stack |
98 | by returning EINVAL from sendmsg. In that case, try again without setting the | |
99 | source address, since it will nearly alway be correct anyway. IPv6 stinks. */ | |
100 | if (errno == EINVAL && msg.msg_controllen) | |
101 | { | |
102 | msg.msg_controllen = 0; | |
103 | goto retry; | |
104 | } | |
105 | if (retry_send()) | |
106 | goto retry; | |
feba5c1d | 107 | } |
9e4abcb5 | 108 | } |
44a2a316 | 109 | |
36717eee SK |
110 | static unsigned short search_servers(struct daemon *daemon, time_t now, struct all_addr **addrpp, |
111 | unsigned short qtype, char *qdomain, int *type, char **domain) | |
feba5c1d SK |
112 | |
113 | { | |
114 | /* If the query ends in the domain in one of our servers, set | |
115 | domain to point to that name. We find the largest match to allow both | |
116 | domain.org and sub.domain.org to exist. */ | |
117 | ||
118 | unsigned int namelen = strlen(qdomain); | |
119 | unsigned int matchlen = 0; | |
120 | struct server *serv; | |
121 | unsigned short flags = 0; | |
122 | ||
3be34541 | 123 | for (serv = daemon->servers; serv; serv=serv->next) |
feba5c1d | 124 | /* domain matches take priority over NODOTS matches */ |
3d8df260 | 125 | if ((serv->flags & SERV_FOR_NODOTS) && *type != SERV_HAS_DOMAIN && !strchr(qdomain, '.') && namelen != 0) |
feba5c1d SK |
126 | { |
127 | unsigned short sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6; | |
128 | *type = SERV_FOR_NODOTS; | |
feba5c1d | 129 | if (serv->flags & SERV_NO_ADDR) |
36717eee SK |
130 | flags = F_NXDOMAIN; |
131 | else if (serv->flags & SERV_LITERAL_ADDRESS) | |
132 | { | |
133 | if (sflag & qtype) | |
134 | { | |
135 | flags = sflag; | |
136 | if (serv->addr.sa.sa_family == AF_INET) | |
137 | *addrpp = (struct all_addr *)&serv->addr.in.sin_addr; | |
feba5c1d | 138 | #ifdef HAVE_IPV6 |
36717eee SK |
139 | else |
140 | *addrpp = (struct all_addr *)&serv->addr.in6.sin6_addr; | |
feba5c1d | 141 | #endif |
36717eee SK |
142 | } |
143 | else if (!flags) | |
144 | flags = F_NOERR; | |
145 | } | |
feba5c1d SK |
146 | } |
147 | else if (serv->flags & SERV_HAS_DOMAIN) | |
148 | { | |
149 | unsigned int domainlen = strlen(serv->domain); | |
b8187c80 | 150 | char *matchstart = qdomain + namelen - domainlen; |
feba5c1d | 151 | if (namelen >= domainlen && |
b8187c80 SK |
152 | hostname_isequal(matchstart, serv->domain) && |
153 | domainlen >= matchlen && | |
cdeda28f | 154 | (domainlen == 0 || namelen == domainlen || *(serv->domain) == '.' || *(matchstart-1) == '.' )) |
feba5c1d SK |
155 | { |
156 | unsigned short sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6; | |
157 | *type = SERV_HAS_DOMAIN; | |
158 | *domain = serv->domain; | |
159 | matchlen = domainlen; | |
feba5c1d | 160 | if (serv->flags & SERV_NO_ADDR) |
36717eee SK |
161 | flags = F_NXDOMAIN; |
162 | else if (serv->flags & SERV_LITERAL_ADDRESS) | |
feba5c1d | 163 | { |
36717eee SK |
164 | if ((sflag | F_QUERY ) & qtype) |
165 | { | |
166 | flags = qtype; | |
167 | if (serv->addr.sa.sa_family == AF_INET) | |
168 | *addrpp = (struct all_addr *)&serv->addr.in.sin_addr; | |
feba5c1d | 169 | #ifdef HAVE_IPV6 |
36717eee SK |
170 | else |
171 | *addrpp = (struct all_addr *)&serv->addr.in6.sin6_addr; | |
feba5c1d | 172 | #endif |
36717eee SK |
173 | } |
174 | else if (!flags) | |
175 | flags = F_NOERR; | |
feba5c1d SK |
176 | } |
177 | } | |
178 | } | |
179 | ||
36717eee | 180 | if (flags & ~(F_NOERR | F_NXDOMAIN)) /* flags set here means a literal found */ |
feba5c1d SK |
181 | { |
182 | if (flags & F_QUERY) | |
fd9fa481 | 183 | log_query(F_CONFIG | F_FORWARD | F_NEG, qdomain, NULL, 0, NULL, 0); |
feba5c1d | 184 | else |
fd9fa481 | 185 | log_query(F_CONFIG | F_FORWARD | flags, qdomain, *addrpp, 0, NULL, 0); |
feba5c1d | 186 | } |
3d8df260 | 187 | else if (qtype && (daemon->options & OPT_NODOTS_LOCAL) && !strchr(qdomain, '.') && namelen != 0) |
36717eee SK |
188 | flags = F_NXDOMAIN; |
189 | ||
f6b7dc47 | 190 | if (flags == F_NXDOMAIN && check_for_local_domain(qdomain, now, daemon)) |
c1bb8504 | 191 | flags = F_NOERR; |
feba5c1d | 192 | |
36717eee | 193 | if (flags == F_NXDOMAIN || flags == F_NOERR) |
fd9fa481 | 194 | log_query(F_CONFIG | F_FORWARD | F_NEG | qtype | (flags & F_NXDOMAIN), qdomain, NULL, 0, NULL, 0); |
feba5c1d SK |
195 | |
196 | return flags; | |
197 | } | |
44a2a316 | 198 | |
9e4abcb5 | 199 | /* returns new last_server */ |
3be34541 SK |
200 | static void forward_query(struct daemon *daemon, int udpfd, union mysockaddr *udpaddr, |
201 | struct all_addr *dst_addr, unsigned int dst_iface, | |
cdeda28f | 202 | HEADER *header, size_t plen, time_t now, struct frec *forward) |
9e4abcb5 | 203 | { |
9e4abcb5 | 204 | char *domain = NULL; |
0a852541 | 205 | int type = 0; |
9e4abcb5 | 206 | struct all_addr *addrp = NULL; |
cdeda28f | 207 | unsigned int crc = questions_crc(header, plen, daemon->namebuff); |
9e4abcb5 | 208 | unsigned short flags = 0; |
cdeda28f | 209 | unsigned short gotname = extract_request(header, plen, daemon->namebuff, NULL); |
de37951c | 210 | struct server *start = NULL; |
3d8df260 SK |
211 | |
212 | /* may be no servers available. */ | |
213 | if (!daemon->servers) | |
9e4abcb5 | 214 | forward = NULL; |
b8187c80 | 215 | else if (forward || (forward = lookup_frec_by_sender(ntohs(header->id), udpaddr, crc))) |
9e4abcb5 | 216 | { |
de37951c | 217 | /* retry on existing query, send to all available servers */ |
9e4abcb5 | 218 | domain = forward->sentto->domain; |
3be34541 | 219 | if (!(daemon->options & OPT_ORDER)) |
de37951c | 220 | { |
0a852541 | 221 | forward->forwardall = 1; |
3be34541 | 222 | daemon->last_server = NULL; |
de37951c | 223 | } |
9e4abcb5 | 224 | type = forward->sentto->flags & SERV_TYPE; |
de37951c | 225 | if (!(start = forward->sentto->next)) |
3be34541 | 226 | start = daemon->servers; /* at end of list, recycle */ |
9e4abcb5 SK |
227 | header->id = htons(forward->new_id); |
228 | } | |
229 | else | |
230 | { | |
231 | if (gotname) | |
36717eee | 232 | flags = search_servers(daemon, now, &addrp, gotname, daemon->namebuff, &type, &domain); |
9e4abcb5 | 233 | |
1697269c | 234 | if (!flags && !(forward = get_new_frec(daemon, now, NULL))) |
feba5c1d SK |
235 | /* table full - server failure. */ |
236 | flags = F_NEG; | |
9e4abcb5 SK |
237 | |
238 | if (forward) | |
239 | { | |
0a852541 SK |
240 | forward->source = *udpaddr; |
241 | forward->dest = *dst_addr; | |
242 | forward->iface = dst_iface; | |
243 | forward->new_id = get_id(); | |
244 | forward->fd = udpfd; | |
245 | forward->orig_id = ntohs(header->id); | |
246 | forward->crc = crc; | |
247 | forward->forwardall = 0; | |
248 | header->id = htons(forward->new_id); | |
249 | ||
9e4abcb5 SK |
250 | /* In strict_order mode, or when using domain specific servers |
251 | always try servers in the order specified in resolv.conf, | |
252 | otherwise, use the one last known to work. */ | |
253 | ||
3be34541 SK |
254 | if (type != 0 || (daemon->options & OPT_ORDER)) |
255 | start = daemon->servers; | |
256 | else if (!(start = daemon->last_server)) | |
de37951c | 257 | { |
3be34541 | 258 | start = daemon->servers; |
0a852541 | 259 | forward->forwardall = 1; |
de37951c | 260 | } |
9e4abcb5 SK |
261 | } |
262 | } | |
feba5c1d | 263 | |
9e4abcb5 SK |
264 | /* check for send errors here (no route to host) |
265 | if we fail to send to all nameservers, send back an error | |
266 | packet straight away (helps modem users when offline) */ | |
267 | ||
268 | if (!flags && forward) | |
269 | { | |
de37951c SK |
270 | struct server *firstsentto = start; |
271 | int forwarded = 0; | |
272 | ||
9e4abcb5 SK |
273 | while (1) |
274 | { | |
9e4abcb5 SK |
275 | /* only send to servers dealing with our domain. |
276 | domain may be NULL, in which case server->domain | |
277 | must be NULL also. */ | |
278 | ||
de37951c | 279 | if (type == (start->flags & SERV_TYPE) && |
fd9fa481 SK |
280 | (type != SERV_HAS_DOMAIN || hostname_isequal(domain, start->domain)) && |
281 | !(start->flags & SERV_LITERAL_ADDRESS)) | |
9e4abcb5 | 282 | { |
fd9fa481 | 283 | if (sendto(start->sfd->fd, (char *)header, plen, 0, |
feba5c1d | 284 | &start->addr.sa, |
fd9fa481 SK |
285 | sa_len(&start->addr)) == -1) |
286 | { | |
287 | if (retry_send()) | |
288 | continue; | |
289 | } | |
290 | else | |
9e4abcb5 | 291 | { |
cdeda28f SK |
292 | /* Keep info in case we want to re-send this packet */ |
293 | daemon->srv_save = start; | |
294 | daemon->packet_len = plen; | |
295 | ||
de37951c | 296 | if (!gotname) |
3be34541 | 297 | strcpy(daemon->namebuff, "query"); |
de37951c | 298 | if (start->addr.sa.sa_family == AF_INET) |
3be34541 | 299 | log_query(F_SERVER | F_IPV4 | F_FORWARD, daemon->namebuff, |
fd9fa481 SK |
300 | (struct all_addr *)&start->addr.in.sin_addr, 0, |
301 | NULL, 0); | |
de37951c SK |
302 | #ifdef HAVE_IPV6 |
303 | else | |
3be34541 | 304 | log_query(F_SERVER | F_IPV6 | F_FORWARD, daemon->namebuff, |
fd9fa481 SK |
305 | (struct all_addr *)&start->addr.in6.sin6_addr, 0, |
306 | NULL, 0); | |
de37951c SK |
307 | #endif |
308 | forwarded = 1; | |
309 | forward->sentto = start; | |
0a852541 | 310 | if (!forward->forwardall) |
de37951c | 311 | break; |
0a852541 | 312 | forward->forwardall++; |
9e4abcb5 SK |
313 | } |
314 | } | |
315 | ||
de37951c | 316 | if (!(start = start->next)) |
3be34541 | 317 | start = daemon->servers; |
9e4abcb5 | 318 | |
de37951c | 319 | if (start == firstsentto) |
9e4abcb5 SK |
320 | break; |
321 | } | |
322 | ||
de37951c | 323 | if (forwarded) |
3be34541 | 324 | return; |
de37951c | 325 | |
9e4abcb5 SK |
326 | /* could not send on, prepare to return */ |
327 | header->id = htons(forward->orig_id); | |
328 | forward->new_id = 0; /* cancel */ | |
329 | } | |
330 | ||
331 | /* could not send on, return empty answer or address if known for whole domain */ | |
b8187c80 SK |
332 | if (udpfd != -1) |
333 | { | |
cdeda28f | 334 | plen = setup_reply(header, plen, addrp, flags, daemon->local_ttl); |
b8187c80 SK |
335 | send_from(udpfd, daemon->options & OPT_NOWILD, (char *)header, plen, udpaddr, dst_addr, dst_iface); |
336 | } | |
337 | ||
3be34541 | 338 | return; |
9e4abcb5 SK |
339 | } |
340 | ||
cdeda28f | 341 | static size_t process_reply(struct daemon *daemon, HEADER *header, time_t now, |
5e9e0efb | 342 | unsigned int query_crc, struct server *server, size_t n) |
feba5c1d | 343 | { |
36717eee | 344 | unsigned char *pheader, *sizep; |
cdeda28f SK |
345 | int munged = 0; |
346 | size_t plen; | |
347 | ||
feba5c1d SK |
348 | /* If upstream is advertising a larger UDP packet size |
349 | than we allow, trim it so that we don't get overlarge | |
350 | requests for the client. */ | |
351 | ||
36717eee | 352 | if ((pheader = find_pseudoheader(header, n, &plen, &sizep))) |
feba5c1d SK |
353 | { |
354 | unsigned short udpsz; | |
36717eee | 355 | unsigned char *psave = sizep; |
feba5c1d | 356 | |
36717eee | 357 | GETSHORT(udpsz, sizep); |
3be34541 SK |
358 | if (udpsz > daemon->edns_pktsz) |
359 | PUTSHORT(daemon->edns_pktsz, psave); | |
feba5c1d SK |
360 | } |
361 | ||
0a852541 SK |
362 | if (header->opcode != QUERY || (header->rcode != NOERROR && header->rcode != NXDOMAIN)) |
363 | return n; | |
364 | ||
feba5c1d | 365 | /* Complain loudly if the upstream server is non-recursive. */ |
0a852541 SK |
366 | if (!header->ra && header->rcode == NOERROR && ntohs(header->ancount) == 0 && |
367 | server && !(server->flags & SERV_WARNED_RECURSIVE)) | |
feba5c1d | 368 | { |
3d8df260 | 369 | prettyprint_addr(&server->addr, daemon->namebuff); |
b8187c80 | 370 | syslog(LOG_WARNING, _("nameserver %s refused to do a recursive query"), daemon->namebuff); |
0a852541 SK |
371 | if (!(daemon->options & OPT_LOG)) |
372 | server->flags |= SERV_WARNED_RECURSIVE; | |
373 | } | |
374 | ||
fd9fa481 SK |
375 | if (daemon->bogus_addr && header->rcode != NXDOMAIN && |
376 | check_for_bogus_wildcard(header, n, daemon->namebuff, daemon->bogus_addr, now)) | |
feba5c1d | 377 | { |
fd9fa481 SK |
378 | munged = 1; |
379 | header->rcode = NXDOMAIN; | |
380 | header->aa = 0; | |
36717eee | 381 | } |
fd9fa481 | 382 | else |
36717eee | 383 | { |
fd9fa481 SK |
384 | if (header->rcode == NXDOMAIN && |
385 | extract_request(header, n, daemon->namebuff, NULL) && | |
f6b7dc47 | 386 | check_for_local_domain(daemon->namebuff, now, daemon)) |
36717eee SK |
387 | { |
388 | /* if we forwarded a query for a locally known name (because it was for | |
389 | an unknown type) and the answer is NXDOMAIN, convert that to NODATA, | |
390 | since we know that the domain exists, even if upstream doesn't */ | |
fd9fa481 SK |
391 | munged = 1; |
392 | header->aa = 1; | |
393 | header->rcode = NOERROR; | |
feba5c1d | 394 | } |
fd9fa481 | 395 | |
0a852541 SK |
396 | /* If the crc of the question section doesn't match the crc we sent, then |
397 | someone might be attempting to insert bogus values into the cache by | |
398 | sending replies containing questions and bogus answers. */ | |
399 | if (query_crc == questions_crc(header, n, daemon->namebuff)) | |
400 | extract_addresses(header, n, daemon->namebuff, now, daemon); | |
feba5c1d | 401 | } |
fd9fa481 SK |
402 | |
403 | /* do this after extract_addresses. Ensure NODATA reply and remove | |
404 | nameserver info. */ | |
405 | ||
406 | if (munged) | |
407 | { | |
408 | header->ancount = htons(0); | |
409 | header->nscount = htons(0); | |
410 | header->arcount = htons(0); | |
411 | } | |
412 | ||
36717eee SK |
413 | /* the bogus-nxdomain stuff, doctor and NXDOMAIN->NODATA munging can all elide |
414 | sections of the packet. Find the new length here and put back pseudoheader | |
415 | if it was removed. */ | |
416 | return resize_packet(header, n, pheader, plen); | |
feba5c1d SK |
417 | } |
418 | ||
3be34541 SK |
419 | /* sets new last_server */ |
420 | void reply_query(struct serverfd *sfd, struct daemon *daemon, time_t now) | |
9e4abcb5 SK |
421 | { |
422 | /* packet from peer server, extract data for cache, and send to | |
423 | original requester */ | |
424 | struct frec *forward; | |
425 | HEADER *header; | |
de37951c SK |
426 | union mysockaddr serveraddr; |
427 | socklen_t addrlen = sizeof(serveraddr); | |
cdeda28f SK |
428 | ssize_t n = recvfrom(sfd->fd, daemon->packet, daemon->edns_pktsz, 0, &serveraddr.sa, &addrlen); |
429 | size_t nn; | |
430 | ||
431 | /* packet buffer overwritten */ | |
432 | daemon->srv_save = NULL; | |
433 | ||
de37951c SK |
434 | /* Determine the address of the server replying so that we can mark that as good */ |
435 | serveraddr.sa.sa_family = sfd->source_addr.sa.sa_family; | |
436 | #ifdef HAVE_IPV6 | |
437 | if (serveraddr.sa.sa_family == AF_INET6) | |
5e9e0efb | 438 | serveraddr.in6.sin6_flowinfo = 0; |
de37951c | 439 | #endif |
9e4abcb5 | 440 | |
3be34541 | 441 | header = (HEADER *)daemon->packet; |
fd9fa481 SK |
442 | forward = lookup_frec(ntohs(header->id)); |
443 | ||
444 | if (n >= (int)sizeof(HEADER) && header->qr && forward) | |
9e4abcb5 | 445 | { |
0a852541 SK |
446 | struct server *server = forward->sentto; |
447 | ||
b8187c80 SK |
448 | if ((header->rcode == SERVFAIL || header->rcode == REFUSED) && forward->forwardall == 0) |
449 | /* for broken servers, attempt to send to another one. */ | |
450 | { | |
451 | unsigned char *pheader; | |
cdeda28f SK |
452 | size_t plen; |
453 | ||
b8187c80 | 454 | /* recreate query from reply */ |
cdeda28f | 455 | pheader = find_pseudoheader(header, (size_t)n, &plen, NULL); |
b8187c80 SK |
456 | header->ancount = htons(0); |
457 | header->nscount = htons(0); | |
458 | header->arcount = htons(0); | |
cdeda28f | 459 | if ((nn = resize_packet(header, (size_t)n, pheader, plen))) |
b8187c80 | 460 | { |
b8187c80 SK |
461 | header->qr = 0; |
462 | header->tc = 0; | |
463 | forward_query(daemon, -1, NULL, NULL, 0, header, nn, now, forward); | |
464 | return; | |
465 | } | |
466 | } | |
467 | ||
0a852541 SK |
468 | if ((forward->sentto->flags & SERV_TYPE) == 0) |
469 | { | |
470 | if (header->rcode == SERVFAIL || header->rcode == REFUSED) | |
471 | server = NULL; | |
472 | else | |
b8187c80 SK |
473 | { |
474 | struct server *last_server; | |
475 | /* find good server by address if possible, otherwise assume the last one we sent to */ | |
476 | for (last_server = daemon->servers; last_server; last_server = last_server->next) | |
477 | if (!(last_server->flags & (SERV_LITERAL_ADDRESS | SERV_HAS_DOMAIN | SERV_FOR_NODOTS | SERV_NO_ADDR)) && | |
478 | sockaddr_isequal(&last_server->addr, &serveraddr)) | |
479 | { | |
480 | server = last_server; | |
481 | break; | |
482 | } | |
483 | } | |
0a852541 SK |
484 | daemon->last_server = server; |
485 | } | |
b8187c80 | 486 | |
0a852541 SK |
487 | /* If the answer is an error, keep the forward record in place in case |
488 | we get a good reply from another server. Kill it when we've | |
489 | had replies from all to avoid filling the forwarding table when | |
490 | everything is broken */ | |
491 | if (forward->forwardall == 0 || --forward->forwardall == 1 || | |
492 | (header->rcode != REFUSED && header->rcode != SERVFAIL)) | |
b8187c80 | 493 | { |
cdeda28f | 494 | if ((nn = process_reply(daemon, header, now, forward->crc, server, (size_t)n))) |
b8187c80 SK |
495 | { |
496 | header->id = htons(forward->orig_id); | |
497 | header->ra = 1; /* recursion if available */ | |
cdeda28f | 498 | send_from(forward->fd, daemon->options & OPT_NOWILD, daemon->packet, nn, |
b8187c80 SK |
499 | &forward->source, &forward->dest, forward->iface); |
500 | } | |
501 | forward->new_id = 0; /* cancel */ | |
502 | } | |
9e4abcb5 | 503 | } |
9e4abcb5 | 504 | } |
44a2a316 | 505 | |
3be34541 | 506 | void receive_query(struct listener *listen, struct daemon *daemon, time_t now) |
44a2a316 | 507 | { |
3be34541 | 508 | HEADER *header = (HEADER *)daemon->packet; |
44a2a316 | 509 | union mysockaddr source_addr; |
c1bb8504 | 510 | unsigned short type; |
44a2a316 | 511 | struct all_addr dst_addr; |
f6b7dc47 | 512 | struct in_addr netmask, dst_addr_4; |
cdeda28f SK |
513 | size_t m; |
514 | ssize_t n; | |
515 | int if_index = 0; | |
44a2a316 SK |
516 | struct iovec iov[1]; |
517 | struct msghdr msg; | |
518 | struct cmsghdr *cmptr; | |
44a2a316 SK |
519 | union { |
520 | struct cmsghdr align; /* this ensures alignment */ | |
521 | #ifdef HAVE_IPV6 | |
522 | char control6[CMSG_SPACE(sizeof(struct in6_pktinfo))]; | |
523 | #endif | |
5e9e0efb | 524 | #if defined(HAVE_LINUX_NETWORK) |
44a2a316 SK |
525 | char control[CMSG_SPACE(sizeof(struct in_pktinfo))]; |
526 | #elif defined(IP_RECVDSTADDR) | |
527 | char control[CMSG_SPACE(sizeof(struct in_addr)) + | |
528 | CMSG_SPACE(sizeof(struct sockaddr_dl))]; | |
529 | #endif | |
530 | } control_u; | |
531 | ||
cdeda28f SK |
532 | /* packet buffer overwritten */ |
533 | daemon->srv_save = NULL; | |
534 | ||
f6b7dc47 SK |
535 | if (listen->family == AF_INET && (daemon->options & OPT_NOWILD)) |
536 | { | |
537 | dst_addr_4 = listen->iface->addr.in.sin_addr; | |
538 | netmask = listen->iface->netmask; | |
539 | } | |
540 | else | |
3d8df260 SK |
541 | { |
542 | dst_addr_4.s_addr = 0; | |
543 | netmask.s_addr = 0; | |
544 | } | |
f6b7dc47 | 545 | |
3be34541 SK |
546 | iov[0].iov_base = daemon->packet; |
547 | iov[0].iov_len = daemon->edns_pktsz; | |
44a2a316 SK |
548 | |
549 | msg.msg_control = control_u.control; | |
550 | msg.msg_controllen = sizeof(control_u); | |
551 | msg.msg_flags = 0; | |
552 | msg.msg_name = &source_addr; | |
553 | msg.msg_namelen = sizeof(source_addr); | |
554 | msg.msg_iov = iov; | |
555 | msg.msg_iovlen = 1; | |
556 | ||
de37951c | 557 | if ((n = recvmsg(listen->fd, &msg, 0)) == -1) |
3be34541 | 558 | return; |
44a2a316 | 559 | |
5e9e0efb SK |
560 | if (n < (int)sizeof(HEADER) || |
561 | (msg.msg_flags & MSG_TRUNC) || | |
562 | header->qr) | |
26128d27 SK |
563 | return; |
564 | ||
44a2a316 SK |
565 | source_addr.sa.sa_family = listen->family; |
566 | #ifdef HAVE_IPV6 | |
567 | if (listen->family == AF_INET6) | |
5e9e0efb | 568 | source_addr.in6.sin6_flowinfo = 0; |
44a2a316 SK |
569 | #endif |
570 | ||
26128d27 SK |
571 | if (!(daemon->options & OPT_NOWILD)) |
572 | { | |
573 | struct ifreq ifr; | |
574 | ||
575 | if (msg.msg_controllen < sizeof(struct cmsghdr)) | |
576 | return; | |
44a2a316 | 577 | |
5e9e0efb | 578 | #if defined(HAVE_LINUX_NETWORK) |
26128d27 SK |
579 | if (listen->family == AF_INET) |
580 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) | |
581 | if (cmptr->cmsg_level == SOL_IP && cmptr->cmsg_type == IP_PKTINFO) | |
582 | { | |
f6b7dc47 | 583 | dst_addr_4 = dst_addr.addr.addr4 = ((struct in_pktinfo *)CMSG_DATA(cmptr))->ipi_spec_dst; |
26128d27 SK |
584 | if_index = ((struct in_pktinfo *)CMSG_DATA(cmptr))->ipi_ifindex; |
585 | } | |
586 | #elif defined(IP_RECVDSTADDR) && defined(IP_RECVIF) | |
587 | if (listen->family == AF_INET) | |
44a2a316 | 588 | { |
26128d27 SK |
589 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) |
590 | if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVDSTADDR) | |
f6b7dc47 | 591 | dst_addr_4 = dst_addr.addr.addr4 = *((struct in_addr *)CMSG_DATA(cmptr)); |
26128d27 SK |
592 | else if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVIF) |
593 | if_index = ((struct sockaddr_dl *)CMSG_DATA(cmptr))->sdl_index; | |
44a2a316 | 594 | } |
44a2a316 | 595 | #endif |
26128d27 | 596 | |
44a2a316 | 597 | #ifdef HAVE_IPV6 |
26128d27 SK |
598 | if (listen->family == AF_INET6) |
599 | { | |
600 | for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr)) | |
601 | if (cmptr->cmsg_level == IPV6_LEVEL && cmptr->cmsg_type == IPV6_PKTINFO) | |
602 | { | |
603 | dst_addr.addr.addr6 = ((struct in6_pktinfo *)CMSG_DATA(cmptr))->ipi6_addr; | |
604 | if_index =((struct in6_pktinfo *)CMSG_DATA(cmptr))->ipi6_ifindex; | |
605 | } | |
606 | } | |
44a2a316 | 607 | #endif |
26128d27 SK |
608 | |
609 | /* enforce available interface configuration */ | |
610 | ||
8a911ccc | 611 | if (if_index == 0) |
3be34541 | 612 | return; |
44a2a316 | 613 | |
f6b7dc47 | 614 | if (daemon->if_except || daemon->if_names || (daemon->options & OPT_LOCALISE)) |
8a911ccc SK |
615 | { |
616 | #ifdef SIOCGIFNAME | |
617 | ifr.ifr_ifindex = if_index; | |
618 | if (ioctl(listen->fd, SIOCGIFNAME, &ifr) == -1) | |
3be34541 | 619 | return; |
8a911ccc SK |
620 | #else |
621 | if (!if_indextoname(if_index, ifr.ifr_name)) | |
3be34541 | 622 | return; |
8a911ccc | 623 | #endif |
f6b7dc47 SK |
624 | |
625 | if (listen->family == AF_INET && | |
626 | (daemon->options & OPT_LOCALISE) && | |
627 | ioctl(listen->fd, SIOCGIFNETMASK, &ifr) == -1) | |
628 | return; | |
629 | ||
630 | netmask = ((struct sockaddr_in *) &ifr.ifr_addr)->sin_addr; | |
8a911ccc SK |
631 | } |
632 | ||
5e9e0efb SK |
633 | if (!iface_check(daemon, listen->family, &dst_addr, ifr.ifr_name)) |
634 | return; | |
44a2a316 SK |
635 | } |
636 | ||
cdeda28f | 637 | if (extract_request(header, (size_t)n, daemon->namebuff, &type)) |
44a2a316 SK |
638 | { |
639 | if (listen->family == AF_INET) | |
3be34541 | 640 | log_query(F_QUERY | F_IPV4 | F_FORWARD, daemon->namebuff, |
fd9fa481 | 641 | (struct all_addr *)&source_addr.in.sin_addr, type, NULL, 0); |
44a2a316 SK |
642 | #ifdef HAVE_IPV6 |
643 | else | |
3be34541 | 644 | log_query(F_QUERY | F_IPV6 | F_FORWARD, daemon->namebuff, |
fd9fa481 | 645 | (struct all_addr *)&source_addr.in6.sin6_addr, type, NULL, 0); |
44a2a316 SK |
646 | #endif |
647 | } | |
648 | ||
cdeda28f | 649 | m = answer_request (header, ((char *) header) + PACKETSZ, (size_t)n, daemon, |
f6b7dc47 | 650 | dst_addr_4, netmask, now); |
44a2a316 | 651 | if (m >= 1) |
3be34541 | 652 | send_from(listen->fd, daemon->options & OPT_NOWILD, (char *)header, m, &source_addr, &dst_addr, if_index); |
44a2a316 | 653 | else |
3be34541 | 654 | forward_query(daemon, listen->fd, &source_addr, &dst_addr, if_index, |
cdeda28f | 655 | header, (size_t)n, now, NULL); |
44a2a316 SK |
656 | } |
657 | ||
feba5c1d SK |
658 | /* The daemon forks before calling this: it should deal with one connection, |
659 | blocking as neccessary, and then return. Note, need to be a bit careful | |
660 | about resources for debug mode, when the fork is suppressed: that's | |
661 | done by the caller. */ | |
3d8df260 SK |
662 | unsigned char *tcp_request(struct daemon *daemon, int confd, time_t now, |
663 | struct in_addr local_addr, struct in_addr netmask) | |
feba5c1d | 664 | { |
cdeda28f SK |
665 | int size = 0; |
666 | size_t m; | |
c1bb8504 | 667 | unsigned short qtype, gotname; |
feba5c1d SK |
668 | unsigned char c1, c2; |
669 | /* Max TCP packet + slop */ | |
3d8df260 | 670 | unsigned char *packet = malloc(65536 + MAXDNAME + RRFIXEDSZ); |
feba5c1d | 671 | HEADER *header; |
3be34541 SK |
672 | struct server *last_server; |
673 | ||
feba5c1d SK |
674 | while (1) |
675 | { | |
676 | if (!packet || | |
677 | !read_write(confd, &c1, 1, 1) || !read_write(confd, &c2, 1, 1) || | |
678 | !(size = c1 << 8 | c2) || | |
679 | !read_write(confd, packet, size, 1)) | |
680 | return packet; | |
681 | ||
682 | if (size < (int)sizeof(HEADER)) | |
683 | continue; | |
684 | ||
685 | header = (HEADER *)packet; | |
686 | ||
3be34541 | 687 | if ((gotname = extract_request(header, (unsigned int)size, daemon->namebuff, &qtype))) |
feba5c1d SK |
688 | { |
689 | union mysockaddr peer_addr; | |
690 | socklen_t peer_len = sizeof(union mysockaddr); | |
691 | ||
692 | if (getpeername(confd, (struct sockaddr *)&peer_addr, &peer_len) != -1) | |
693 | { | |
694 | if (peer_addr.sa.sa_family == AF_INET) | |
3be34541 | 695 | log_query(F_QUERY | F_IPV4 | F_FORWARD, daemon->namebuff, |
fd9fa481 | 696 | (struct all_addr *)&peer_addr.in.sin_addr, qtype, NULL, 0); |
feba5c1d SK |
697 | #ifdef HAVE_IPV6 |
698 | else | |
3be34541 | 699 | log_query(F_QUERY | F_IPV6 | F_FORWARD, daemon->namebuff, |
fd9fa481 | 700 | (struct all_addr *)&peer_addr.in6.sin6_addr, qtype, NULL, 0); |
feba5c1d SK |
701 | #endif |
702 | } | |
703 | } | |
704 | ||
705 | /* m > 0 if answered from cache */ | |
f6b7dc47 SK |
706 | m = answer_request(header, ((char *) header) + 65536, (unsigned int)size, daemon, |
707 | local_addr, netmask, now); | |
feba5c1d SK |
708 | |
709 | if (m == 0) | |
710 | { | |
711 | unsigned short flags = 0; | |
feba5c1d SK |
712 | struct all_addr *addrp = NULL; |
713 | int type = 0; | |
714 | char *domain = NULL; | |
715 | ||
716 | if (gotname) | |
36717eee | 717 | flags = search_servers(daemon, now, &addrp, gotname, daemon->namebuff, &type, &domain); |
feba5c1d | 718 | |
3be34541 SK |
719 | if (type != 0 || (daemon->options & OPT_ORDER) || !daemon->last_server) |
720 | last_server = daemon->servers; | |
721 | else | |
722 | last_server = daemon->last_server; | |
feba5c1d SK |
723 | |
724 | if (!flags && last_server) | |
725 | { | |
726 | struct server *firstsendto = NULL; | |
0a852541 SK |
727 | unsigned int crc = questions_crc(header, (unsigned int)size, daemon->namebuff); |
728 | ||
feba5c1d SK |
729 | /* Loop round available servers until we succeed in connecting to one. |
730 | Note that this code subtley ensures that consecutive queries on this connection | |
731 | which can go to the same server, do so. */ | |
732 | while (1) | |
733 | { | |
734 | if (!firstsendto) | |
735 | firstsendto = last_server; | |
736 | else | |
737 | { | |
738 | if (!(last_server = last_server->next)) | |
3be34541 | 739 | last_server = daemon->servers; |
feba5c1d SK |
740 | |
741 | if (last_server == firstsendto) | |
742 | break; | |
743 | } | |
744 | ||
745 | /* server for wrong domain */ | |
746 | if (type != (last_server->flags & SERV_TYPE) || | |
747 | (type == SERV_HAS_DOMAIN && !hostname_isequal(domain, last_server->domain))) | |
748 | continue; | |
749 | ||
750 | if ((last_server->tcpfd == -1) && | |
751 | (last_server->tcpfd = socket(last_server->addr.sa.sa_family, SOCK_STREAM, 0)) != -1 && | |
752 | connect(last_server->tcpfd, &last_server->addr.sa, sa_len(&last_server->addr)) == -1) | |
753 | { | |
754 | close(last_server->tcpfd); | |
755 | last_server->tcpfd = -1; | |
756 | } | |
757 | ||
758 | if (last_server->tcpfd == -1) | |
759 | continue; | |
760 | ||
761 | c1 = size >> 8; | |
762 | c2 = size; | |
763 | ||
764 | if (!read_write(last_server->tcpfd, &c1, 1, 0) || | |
765 | !read_write(last_server->tcpfd, &c2, 1, 0) || | |
766 | !read_write(last_server->tcpfd, packet, size, 0) || | |
767 | !read_write(last_server->tcpfd, &c1, 1, 1) || | |
768 | !read_write(last_server->tcpfd, &c2, 1, 1)) | |
769 | { | |
770 | close(last_server->tcpfd); | |
771 | last_server->tcpfd = -1; | |
772 | continue; | |
773 | } | |
774 | ||
775 | m = (c1 << 8) | c2; | |
776 | if (!read_write(last_server->tcpfd, packet, m, 1)) | |
777 | return packet; | |
778 | ||
779 | if (!gotname) | |
3be34541 | 780 | strcpy(daemon->namebuff, "query"); |
feba5c1d | 781 | if (last_server->addr.sa.sa_family == AF_INET) |
3be34541 | 782 | log_query(F_SERVER | F_IPV4 | F_FORWARD, daemon->namebuff, |
fd9fa481 | 783 | (struct all_addr *)&last_server->addr.in.sin_addr, 0, NULL, 0); |
feba5c1d SK |
784 | #ifdef HAVE_IPV6 |
785 | else | |
3be34541 | 786 | log_query(F_SERVER | F_IPV6 | F_FORWARD, daemon->namebuff, |
fd9fa481 | 787 | (struct all_addr *)&last_server->addr.in6.sin6_addr, 0, NULL, 0); |
feba5c1d SK |
788 | #endif |
789 | ||
790 | /* There's no point in updating the cache, since this process will exit and | |
791 | lose the information after one query. We make this call for the alias and | |
792 | bogus-nxdomain side-effects. */ | |
0a852541 | 793 | m = process_reply(daemon, header, now, crc, last_server, (unsigned int)m); |
feba5c1d SK |
794 | |
795 | break; | |
796 | } | |
797 | } | |
798 | ||
799 | /* In case of local answer or no connections made. */ | |
800 | if (m == 0) | |
3be34541 | 801 | m = setup_reply(header, (unsigned int)size, addrp, flags, daemon->local_ttl); |
feba5c1d SK |
802 | } |
803 | ||
804 | c1 = m>>8; | |
805 | c2 = m; | |
806 | if (!read_write(confd, &c1, 1, 0) || | |
807 | !read_write(confd, &c2, 1, 0) || | |
808 | !read_write(confd, packet, m, 0)) | |
809 | return packet; | |
810 | } | |
811 | } | |
812 | ||
1697269c | 813 | static struct frec *allocate_frec(time_t now) |
9e4abcb5 | 814 | { |
1697269c SK |
815 | struct frec *f; |
816 | ||
817 | if ((f = (struct frec *)malloc(sizeof(struct frec)))) | |
9e4abcb5 | 818 | { |
1697269c SK |
819 | f->next = frec_list; |
820 | f->time = now; | |
821 | f->new_id = 0; | |
822 | frec_list = f; | |
823 | } | |
9e4abcb5 | 824 | |
1697269c SK |
825 | return f; |
826 | } | |
9e4abcb5 | 827 | |
1697269c SK |
828 | /* if wait==NULL return a free or older than TIMEOUT record. |
829 | else return *wait zero if one available, or *wait is delay to | |
830 | when the oldest in-use record will expire. */ | |
831 | struct frec *get_new_frec(struct daemon *daemon, time_t now, int *wait) | |
832 | { | |
833 | struct frec *f, *oldest; | |
834 | int count; | |
835 | ||
836 | if (wait) | |
837 | *wait = 0; | |
838 | ||
839 | for (f = frec_list, oldest = NULL, count = 0; f; f = f->next, count++) | |
840 | if (f->new_id == 0) | |
841 | { | |
842 | f->time = now; | |
843 | return f; | |
844 | } | |
845 | else if (!oldest || difftime(f->time, oldest->time) <= 0) | |
846 | oldest = f; | |
9e4abcb5 SK |
847 | |
848 | /* can't find empty one, use oldest if there is one | |
849 | and it's older than timeout */ | |
1697269c | 850 | if (oldest && ((int)difftime(now, oldest->time)) >= TIMEOUT) |
9e4abcb5 | 851 | { |
1697269c SK |
852 | /* keep stuff for twice timeout if we can by allocating a new |
853 | record instead */ | |
854 | if (difftime(now, oldest->time) < 2*TIMEOUT && | |
855 | count <= daemon->ftabsize && | |
856 | (f = allocate_frec(now))) | |
857 | return f; | |
858 | ||
859 | if (!wait) | |
860 | { | |
861 | oldest->new_id = 0; | |
862 | oldest->time = now; | |
863 | } | |
9e4abcb5 SK |
864 | return oldest; |
865 | } | |
866 | ||
1697269c | 867 | /* none available, calculate time 'till oldest record expires */ |
208b65c5 | 868 | if (count > daemon->ftabsize) |
1697269c SK |
869 | { |
870 | if (oldest && wait) | |
871 | *wait = oldest->time + (time_t)TIMEOUT - now; | |
9e4abcb5 SK |
872 | return NULL; |
873 | } | |
1697269c SK |
874 | |
875 | if (!(f = allocate_frec(now)) && wait) | |
876 | /* wait one second on malloc failure */ | |
877 | *wait = 1; | |
9e4abcb5 | 878 | |
9e4abcb5 SK |
879 | return f; /* OK if malloc fails and this is NULL */ |
880 | } | |
881 | ||
882 | static struct frec *lookup_frec(unsigned short id) | |
883 | { | |
884 | struct frec *f; | |
885 | ||
886 | for(f = frec_list; f; f = f->next) | |
887 | if (f->new_id == id) | |
888 | return f; | |
889 | ||
890 | return NULL; | |
891 | } | |
892 | ||
893 | static struct frec *lookup_frec_by_sender(unsigned short id, | |
fd9fa481 SK |
894 | union mysockaddr *addr, |
895 | unsigned int crc) | |
9e4abcb5 | 896 | { |
feba5c1d SK |
897 | struct frec *f; |
898 | ||
9e4abcb5 SK |
899 | for(f = frec_list; f; f = f->next) |
900 | if (f->new_id && | |
901 | f->orig_id == id && | |
fd9fa481 | 902 | f->crc == crc && |
9e4abcb5 SK |
903 | sockaddr_isequal(&f->source, addr)) |
904 | return f; | |
905 | ||
906 | return NULL; | |
907 | } | |
908 | ||
849a8357 SK |
909 | /* A server record is going away, remove references to it */ |
910 | void server_gone(struct daemon *daemon, struct server *server) | |
911 | { | |
912 | struct frec *f; | |
913 | ||
914 | for (f = frec_list; f; f = f->next) | |
915 | if (f->new_id != 0 && f->sentto == server) | |
916 | f->new_id = 0; | |
917 | ||
918 | if (daemon->last_server == server) | |
919 | daemon->last_server = NULL; | |
920 | ||
921 | if (daemon->srv_save == server) | |
922 | daemon->srv_save = NULL; | |
923 | } | |
9e4abcb5 SK |
924 | |
925 | /* return unique random ids between 1 and 65535 */ | |
926 | static unsigned short get_id(void) | |
927 | { | |
928 | unsigned short ret = 0; | |
929 | ||
930 | while (ret == 0) | |
931 | { | |
932 | ret = rand16(); | |
933 | ||
934 | /* scrap ids already in use */ | |
935 | if ((ret != 0) && lookup_frec(ret)) | |
936 | ret = 0; | |
937 | } | |
938 | ||
939 | return ret; | |
940 | } | |
941 | ||
942 | ||
943 | ||
944 | ||
945 |