Use struct sockaddr in several places; distinguish various places where
[adns] / src / reply.c
CommitLineData
e576be50 1/*
2 * reply.c
3 * - main handling and parsing routine for received datagrams
4 */
5/*
6 * This file is part of adns, which is Copyright (C) 1997, 1998 Ian Jackson
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2, or (at your option)
11 * any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software Foundation,
20 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 */
4353a5c4 22
e062dcae 23#include <stdlib.h>
24#include <string.h>
4353a5c4 25
e062dcae 26#include "internal.h"
b9de380c 27
98a3f706 28void adns__procdgram(adns_state ads, const byte *dgram, int dglen,
29 int serv, struct timeval now) {
86e7b8d9 30 int cbyte, rrstart, wantedrrs, rri, foundsoa, foundns, cname_here;
3955725c 31 int id, f1, f2, qdcount, ancount, nscount, arcount;
32 int flg_ra, flg_rd, flg_tc, flg_qr, opcode;
e062dcae 33 int rrtype, rrclass, rdlength, rdstart;
98a3f706 34 int anstart, nsstart, arstart;
e062dcae 35 int ownermatched, l, nrrs, place;
36 const typeinfo *typei;
98a3f706 37 adns_query qu, nqu;
38 dns_rcode rcode;
b9de380c 39 adns_status st;
86e7b8d9 40 vbuf tempvb;
e062dcae 41 byte *newquery, *rrsdata;
ec477b9e 42
98a3f706 43 if (dglen<DNS_HDRSIZE) {
3955725c 44 adns__diag(ads,serv,0,"received datagram too short for message header (%d)",dglen);
ec477b9e 45 return;
46 }
9557e604 47 cbyte= 0;
b9de380c 48 GET_W(cbyte,id);
49 GET_B(cbyte,f1);
50 GET_B(cbyte,f2);
51 GET_W(cbyte,qdcount);
52 GET_W(cbyte,ancount);
53 GET_W(cbyte,nscount);
54 GET_W(cbyte,arcount);
98a3f706 55 assert(cbyte == DNS_HDRSIZE);
ec477b9e 56
31144a72 57 flg_qr= f1&0x80;
58 opcode= (f1&0x78)>>3;
e062dcae 59 flg_tc= f1&0x02;
31144a72 60 flg_rd= f1&0x01;
0ba0614a 61 flg_ra= f2&0x80;
86e7b8d9 62 rcode= (f2&0x0f);
0ba0614a 63
86e7b8d9 64 cname_here= 0;
65
9557e604 66 if (!flg_qr) {
3955725c 67 adns__diag(ads,serv,0,"server sent us a query, not a response");
ec477b9e 68 return;
69 }
31144a72 70 if (opcode) {
3955725c 71 adns__diag(ads,serv,0,"server sent us unknown opcode %d (wanted 0=QUERY)",opcode);
ec477b9e 72 return;
73 }
74 if (!qdcount) {
3955725c 75 adns__diag(ads,serv,0,"server sent reply without quoting our question");
ec477b9e 76 return;
77 } else if (qdcount>1) {
3955725c 78 adns__diag(ads,serv,0,"server claimed to answer %d questions with one message",
ec477b9e 79 qdcount);
80 return;
81 }
98a3f706 82 for (qu= ads->timew.head; qu; qu= nqu) {
ec477b9e 83 nqu= qu->next;
84 if (qu->id != id) continue;
3955725c 85 if (dglen < qu->query_dglen) continue;
86 if (memcmp(qu->query_dgram+DNS_HDRSIZE,
87 dgram+DNS_HDRSIZE,
88 qu->query_dglen-DNS_HDRSIZE))
b9de380c 89 continue;
ec477b9e 90 break;
91 }
92 if (!qu) {
86e7b8d9 93 if (ads->iflags & adns_if_debug) {
94 adns__vbuf_init(&tempvb);
95 adns__debug(ads,serv,0,"reply not found, id %02x, query owner %s",
828d89bd 96 id, adns__diag_domain(ads,serv,0,&tempvb,dgram,dglen,DNS_HDRSIZE));
86e7b8d9 97 adns__vbuf_free(&tempvb);
98 }
ec477b9e 99 return;
100 }
86e7b8d9 101 anstart= qu->query_dglen;
98a3f706 102
103 LIST_UNLINK(ads->timew,qu);
104 /* We're definitely going to do something with this query now */
105
b9de380c 106 switch (rcode) {
107 case rcode_noerror:
108 case rcode_nxdomain:
ec477b9e 109 break;
b9de380c 110 case rcode_formaterror:
31144a72 111 adns__warn(ads,serv,qu,"server cannot understand our query (Format Error)");
3955725c 112 adns__query_fail(qu,adns_s_serverfaulty);
ec477b9e 113 return;
98a3f706 114 case rcode_servfail:
3955725c 115 adns__query_fail(qu,adns_s_servfail);
ec477b9e 116 return;
b9de380c 117 case rcode_notimp:
31144a72 118 adns__warn(ads,serv,qu,"server claims not to implement our query");
3955725c 119 adns__query_fail(qu,adns_s_notimplemented);
b9de380c 120 return;
121 case rcode_refused:
31144a72 122 adns__warn(ads,serv,qu,"server refused our query");
3955725c 123 adns__query_fail(qu,adns_s_refused);
b9de380c 124 return;
125 default:
31144a72 126 adns__warn(ads,serv,qu,"server gave unknown response code %d",rcode);
3955725c 127 adns__query_fail(qu,adns_s_reasonunknown);
b9de380c 128 return;
129 }
130
131 /* Now, take a look at the answer section, and see if it is complete.
132 * If it has any CNAMEs we stuff them in the answer.
133 */
134 wantedrrs= 0;
86e7b8d9 135 cbyte= anstart;
b9de380c 136 for (rri= 0; rri<ancount; rri++) {
137 rrstart= cbyte;
3955725c 138 st= adns__findrr(qu,serv, dgram,dglen,&cbyte,
139 &rrtype,&rrclass,&rdlength,&rdstart,
140 &ownermatched);
86e7b8d9 141 if (st) { adns__query_fail(qu,st); return; }
0ba0614a 142 if (rrtype == -1) goto x_truncated;
143
b9de380c 144 if (rrclass != DNS_CLASS_IN) {
31144a72 145 adns__diag(ads,serv,qu,"ignoring answer RR with wrong class %d (expected IN=%d)",
b9de380c 146 rrclass,DNS_CLASS_IN);
147 continue;
148 }
0ba0614a 149 if (!ownermatched) {
98a3f706 150 if (ads->iflags & adns_if_debug) {
31144a72 151 adns__debug(ads,serv,qu,"ignoring RR with an unexpected owner %s",
828d89bd 152 adns__diag_domain(ads,serv,qu, &qu->vb, dgram,dglen,rrstart));
0ba0614a 153 }
b9de380c 154 continue;
155 }
e062dcae 156 if (rrtype == adns_r_cname && /* fixme - implement adns_qf_nocname */
31144a72 157 (qu->typei->type & adns__rrt_typemask) != adns_r_cname) {
3955725c 158 if (!qu->cname_dgram) { /* Ignore second and subsequent CNAMEs */
31144a72 159 qu->cname_begin= rdstart;
31144a72 160 qu->cname_dglen= dglen;
828d89bd 161 st= adns__parse_domain(ads,serv,qu, &qu->vb,
162 qu->flags & adns_qf_quoteok_cname ? pdf_quoteok : 0,
31144a72 163 dgram,dglen, &rdstart,rdstart+rdlength);
3955725c 164 if (!qu->vb.used) goto x_truncated;
165 if (st) { adns__query_fail(qu,st); return; }
166 l= strlen(qu->vb.buf)+1;
167 qu->answer->cname= adns__alloc_interim(qu,l);
e062dcae 168 if (!qu->answer->cname) { adns__query_fail(qu,adns_s_nolocalmem); return; }
169
170 qu->cname_dgram= adns__alloc_mine(qu,dglen);
171 memcpy(qu->cname_dgram,dgram,dglen);
172
3955725c 173 memcpy(qu->answer->cname,qu->vb.buf,l);
86e7b8d9 174 cname_here= 1;
31144a72 175 /* If we find the answer section truncated after this point we restart
176 * the query at the CNAME; if beforehand then we obviously have to use
177 * TCP. If there is no truncation we can use the whole answer if
178 * it contains the relevant info.
179 */
180 } else {
181 adns__debug(ads,serv,qu,"ignoring duplicate CNAME (%s, as well as %s)",
828d89bd 182 adns__diag_domain(ads,serv,qu, &qu->vb, dgram,dglen,rdstart),
3955725c 183 qu->answer->cname);
31144a72 184 }
98a3f706 185 } else if (rrtype == (qu->typei->type & adns__rrt_typemask)) {
b9de380c 186 wantedrrs++;
187 } else {
31144a72 188 adns__debug(ads,serv,qu,"ignoring answer RR with irrelevant type %d",rrtype);
b9de380c 189 }
190 }
191
e062dcae 192 /* We defer handling truncated responses here, in case there was a CNAME
193 * which we could use.
194 */
195 if (flg_tc) goto x_truncated;
196
b9de380c 197 nsstart= cbyte;
198
199 if (!wantedrrs) {
200 /* Oops, NODATA or NXDOMAIN or perhaps a referral (which would be a problem) */
201
202 if (rcode == rcode_nxdomain) {
3955725c 203 adns__query_fail(qu,adns_s_nxdomain);
b9de380c 204 return;
205 }
206
207 /* RFC2308: NODATA has _either_ a SOA _or_ _no_ NS records in authority section */
0ba0614a 208 foundsoa= 0; foundns= 0;
b9de380c 209 for (rri= 0; rri<nscount; rri++) {
0ba0614a 210 rrstart= cbyte;
3955725c 211 st= adns__findrr(qu,serv, dgram,dglen,&cbyte,
212 &rrtype,&rrclass,&rdlength,&rdstart, 0);
213 if (st) { adns__query_fail(qu,st); return; }
0ba0614a 214 if (rrtype==-1) goto x_truncated;
215 if (rrclass != DNS_CLASS_IN) {
31144a72 216 adns__diag(ads,serv,qu,
217 "ignoring authority RR with wrong class %d (expected IN=%d)",
0ba0614a 218 rrclass,DNS_CLASS_IN);
219 continue;
220 }
221 if (rrtype == adns_r_soa_raw) { foundsoa= 1; break; }
222 else if (rrtype == adns_r_ns_raw) { foundns= 1; }
b9de380c 223 }
0ba0614a 224
225 if (foundsoa || !foundns) {
226 /* Aha ! A NODATA response, good. */
3955725c 227 adns__query_fail(qu,adns_s_nodata);
0ba0614a 228 return;
229 }
230
231 /* Now what ? No relevant answers, no SOA, and at least some NS's.
232 * Looks like a referral. Just one last chance ... if we came across
31144a72 233 * a CNAME in this datagram then we should probably do our own CNAME
234 * lookup now in the hope that we won't get a referral again.
0ba0614a 235 */
e062dcae 236 if (cname_here) goto x_restartquery;
0ba0614a 237
238 /* Bloody hell, I thought we asked for recursion ? */
31144a72 239 if (flg_rd) {
240 adns__diag(ads,serv,qu,"server thinks we didn't ask for recursive lookup");
241 }
0ba0614a 242 if (!flg_ra) {
31144a72 243 adns__diag(ads,serv,qu,"server is not willing to do recursive lookups for us");
3955725c 244 adns__query_fail(qu,adns_s_norecurse);
31144a72 245 } else {
246 adns__diag(ads,serv,qu,"server claims to do recursion, but gave us a referral");
3955725c 247 adns__query_fail(qu,adns_s_serverfaulty);
0ba0614a 248 }
b9de380c 249 return;
250 }
251
0ba0614a 252 /* Now, we have some RRs which we wanted. */
b9de380c 253
3955725c 254 qu->answer->rrs.untyped= adns__alloc_interim(qu,qu->typei->rrsz*wantedrrs);
e062dcae 255 if (!qu->answer->rrs.untyped) { adns__query_fail(qu,adns_s_nolocalmem); return; }
98a3f706 256
e062dcae 257 typei= qu->typei;
98a3f706 258 cbyte= anstart;
98a3f706 259 arstart= -1;
e062dcae 260 rrsdata= qu->answer->rrs.bytes;
261
262 if (typei->diff_needswap) {
263 if (!adns__vbuf_ensure(&qu->vb,typei->rrsz)) {
264 adns__query_fail(qu,adns_s_nolocalmem);
265 return;
266 }
267 }
268 nrrs= 0;
269
98a3f706 270 for (rri=0; rri<ancount; rri++) {
3955725c 271 st= adns__findrr(qu,serv, dgram,dglen,&cbyte,
272 &rrtype,&rrclass,&rdlength,&rdstart,
273 &ownermatched);
98a3f706 274 assert(!st); assert(rrtype != -1);
275 if (rrclass != DNS_CLASS_IN ||
31144a72 276 rrtype != (qu->typei->type & adns__rrt_typemask) ||
277 !ownermatched)
98a3f706 278 continue;
e062dcae 279 st= typei->parse(qu,serv, dgram,dglen, rdstart,rdstart+rdlength,
280 rrsdata+nrrs*typei->rrsz);
3955725c 281 if (st) { adns__query_fail(qu,st); return; }
31144a72 282 if (rdstart==-1) goto x_truncated;
e062dcae 283
284 if (typei->diff_needswap) {
285 for (place= nrrs;
286 place>0 && typei->diff_needswap(rrsdata+(place-1)*typei->rrsz,
287 rrsdata+nrrs*typei->rrsz);
288 place--);
289 if (place != nrrs) {
290 memcpy(qu->vb.buf,rrsdata+nrrs*typei->rrsz,typei->rrsz);
291 memmove(rrsdata+(place+1)*typei->rrsz,
292 rrsdata+place*typei->rrsz,
293 (nrrs-place)*typei->rrsz);
294 memcpy(rrsdata+place*typei->rrsz,qu->vb.buf,typei->rrsz);
295 }
296 }
297 nrrs++;
98a3f706 298 }
e062dcae 299 assert(nrrs==wantedrrs);
300 qu->answer->nrrs= nrrs;
b9de380c 301
98a3f706 302 /* This may have generated some child queries ... */
303 if (qu->children.head) {
304 qu->state= query_child;
305 LIST_LINK_TAIL(ads->childw,qu);
306 return;
b9de380c 307 }
ec477b9e 308
3955725c 309 adns__query_done(qu);
98a3f706 310 return;
0ba0614a 311
e576be50 312 x_truncated:
e062dcae 313
98a3f706 314 if (!flg_tc) {
31144a72 315 adns__diag(ads,serv,qu,"server sent datagram which points outside itself");
3955725c 316 adns__query_fail(qu,adns_s_serverfaulty);
98a3f706 317 return;
318 }
98a3f706 319 qu->flags |= adns_qf_usevc;
e062dcae 320
321 x_restartquery:
322
323 if (qu->cname_dgram) {
324 st= adns__mkquery_frdgram(qu->ads,&qu->vb,&qu->id,
325 qu->cname_dgram, qu->cname_dglen, qu->cname_begin,
326 qu->typei->type, qu->flags);
327 if (st) { adns__query_fail(qu,st); return; }
328
329 newquery= realloc(qu->query_dgram,qu->vb.used);
330 if (!newquery) { adns__query_fail(qu,adns_s_nolocalmem); return; }
331
332 qu->query_dgram= newquery;
333 qu->query_dglen= qu->vb.used;
334 memcpy(newquery,qu->vb.buf,qu->vb.used);
335 }
336
337 adns__reset_cnameonly(qu);
3955725c 338 adns__query_udp(qu,now);
98a3f706 339}