5 static void cname_recurse(adns_state ads, adns_query qu, adns_queryflags xflags) {
9 void adns__procdgram(adns_state ads, const byte *dgram, int dglen,
10 int serv, struct timeval now) {
11 int cbyte, rrstart, wantedrrs, rri, foundsoa, foundns;
12 int id, f1, f2, qdcount, ancount, nscount, arcount, flg_ra, flg_tc;
13 int rrtype, rrclass, rdlength, rdstart, ownermatched, ownerstart;
14 int anstart, nsstart, arstart;
21 if (dglen<DNS_HDRSIZE) {
22 adns__diag(ads,serv,"received datagram too short for message header (%d)",dglen);
32 assert(cbyte == DNS_HDRSIZE);
38 adns__diag(ads,serv,"server sent us a query, not a response");
42 adns__diag(ads,serv,"server sent us unknown opcode %d (wanted 0=QUERY)",
47 adns__diag(ads,serv,"server sent reply without quoting our question");
49 } else if (qdcount>1) {
50 adns__diag(ads,serv,"server claimed to answer %d questions with one message",
54 for (qu= ads->timew.head; qu; qu= nqu) {
56 if (qu->id != id) continue;
57 if (dglen < qu->querylen) continue;
58 if (memcmp(qu->querymsg+DNS_HDRSIZE,dgram+DNS_HDRSIZE,qu->querylen-DNS_HDRSIZE))
62 assert(qu->cnameoff == -1);
63 anstart= qu->querylen;
65 adns__debug(ads,serv,"reply not found (id=%02x)",id);
69 LIST_UNLINK(ads->timew,qu);
70 /* We're definitely going to do something with this query now */
73 adns__diag(ads,serv,"server thinks we didn't ask for recursive lookup");
74 adns__query_fail(ads,qu,adns_s_serverfaulty);
83 case rcode_formaterror:
84 adns__warn(ads,serv,"server cannot understand our query (Format Error)");
85 adns__query_fail(ads,qu,adns_s_serverfaulty);
88 adns__query_fail(ads,qu,adns_s_servfail);
91 adns__warn(ads,serv,"server claims not to implement our query");
92 adns__query_fail(ads,qu,adns_s_notimplemented);
95 adns__warn(ads,serv,"server refused our query");
96 adns__query_fail(ads,qu,adns_s_refused);
99 adns__warn(ads,serv,"server gave unknown response code %d",rcode);
100 adns__query_fail(ads,qu,adns_s_reasonunknown);
104 /* Now, take a look at the answer section, and see if it is complete.
105 * If it has any CNAMEs we stuff them in the answer.
108 for (rri= 0; rri<ancount; rri++) {
110 if (qu->cnameoff >= 0) {
111 st= adns__findrr(ads,serv, dgram,dglen,&cbyte,
112 &rrtype,&rrclass,&rdlength,&rdstart,
113 dgram,dglen,qu->cnameoff, &ownermatched);
115 st= adns__get_rr_temp(ads,qu,serv, dgram,dglen,&cbyte,
116 &rrtype,&rrclass,&rdlength,&rdstart,
117 qu->querymsg,qu->querylen,DNS_HDRSIZE, &ownermatched);
119 if (st) adns__query_fail(ads,qu,st);
120 if (rrtype == -1) goto x_truncated;
122 if (rrclass != DNS_CLASS_IN) {
123 adns__diag(ads,serv,"ignoring answer RR with wrong class %d (expected IN=%d)",
124 rrclass,DNS_CLASS_IN);
128 if (ads->iflags & adns_if_debug) {
129 st= adns__get_domain_temp(ads,qu,serv, dgram,dglen,&rrstart,dglen, &ownerstart);
131 adns__debug(ads,serv, "ignoring RR with an irrelevant owner"
132 " whose format is bad, code %d",st);
133 else if (ownerstart>=0)
134 adns__debug(ads,serv, "ignoring RR with an irrelevant owner"
135 " \"%s\"", qu->ans.buf+ownerstart);
137 adns__debug(ads,serv,"ignoring RR with an irrelevant truncated owner");
141 if (qu->cnameoff<0 &&
142 (qu->typei->type & adns__rrt_typemask) != adns_r_cname &&
143 rrtype == adns_r_cname) { /* Ignore second and subsequent CNAMEs */
144 st= adns__get_domain_perm(ads,qu,serv, dgram,dglen,
145 &rdstart,rdstart+rdlength,&qu->cnameoff);
146 if (st) { adns__query_fail(ads,qu,st); return; }
147 if (qu->cnameoff==-1) goto x_truncated;
148 /* If we find the answer section truncated after this point we restart
149 * the query at the CNAME; if beforehand then we obviously have to use
150 * TCP. If there is no truncation we can use the whole answer if
151 * it contains the relevant info.
153 } else if (rrtype == (qu->typei->type & adns__rrt_typemask)) {
156 adns__debug(ads,serv,"ignoring answer RR with irrelevant type %d",rrtype);
160 /* If we got here then the answer section is intact. */
164 /* Oops, NODATA or NXDOMAIN or perhaps a referral (which would be a problem) */
166 if (rcode == rcode_nxdomain) {
167 adns__query_finish(ads,qu,adns_s_nxdomain);
171 /* RFC2308: NODATA has _either_ a SOA _or_ _no_ NS records in authority section */
172 foundsoa= 0; foundns= 0;
173 for (rri= 0; rri<nscount; rri++) {
175 st= adns__get_rr_temp(ads,qu,serv, dgram,dglen,&cbyte,
176 &rrtype,&rrclass, &rdlength,&rdstart, 0,0,0,0);
177 if (st) { adns__query_fail(ads,qu,st); return; }
178 if (rrtype==-1) goto x_truncated;
179 if (rrclass != DNS_CLASS_IN) {
180 adns__diag(ads,serv,"ignoring authority RR with wrong class %d (expected IN=%d)",
181 rrclass,DNS_CLASS_IN);
184 if (rrtype == adns_r_soa_raw) { foundsoa= 1; break; }
185 else if (rrtype == adns_r_ns_raw) { foundns= 1; }
188 if (foundsoa || !foundns) {
189 /* Aha ! A NODATA response, good. */
190 adns__query_finish(ads,qu,adns_s_nodata);
194 /* Now what ? No relevant answers, no SOA, and at least some NS's.
195 * Looks like a referral. Just one last chance ... if we came across
196 * a CNAME then perhaps we should do our own CNAME lookup.
198 if (qu->cnameoff != -1) { cname_recurse(ads,qu,0); return; }
200 /* Bloody hell, I thought we asked for recursion ? */
202 adns__diag(ads,serv,"server is not willing to do recursive lookups for us");
203 adns__query_fail(ads,qu,adns_s_norecurse);
206 adns__diag(ads,serv,"server claims to do recursion, but gave us a referral");
207 adns__query_fail(ads,qu,adns_s_serverfaulty);
211 /* Now, we have some RRs which we wanted. */
213 qu->rrsoff= adns__vbuf_malloc(&qu->ans,qu->typei->rrsz*wantedrrs);
214 if (qu->rrsoff == -1) adns__query_fail(ads,qu,adns_s_nolocalmem);
219 for (rri=0; rri<ancount; rri++) {
220 st= adns__get_rr_temp(ads,qu,serv, dgram,dglen,&cbyte,
221 &rrtype,&rrclass, &rdlength,&rdstart, 0,0,0,0);
222 assert(!st); assert(rrtype != -1);
223 if (rrclass != DNS_CLASS_IN ||
224 rrtype != (qu->typei->type & adns__rrt_typemask))
226 assert(currentrrs<wantedrrs);
227 st= qu->typei->get_fn(ads,qu,serv, dgram,dglen, &rdstart,rdstart+rdlength,
228 nsstart,arcount,&arstart, qu->rrsoff,¤trrs);
229 if (st) { adns__query_fail(ads,qu,st); return; }
230 if (currentrrs==-1) goto x_truncated;
233 /* This may have generated some child queries ... */
234 if (qu->children.head) {
235 qu->state= query_child;
236 LIST_LINK_TAIL(ads->childw,qu);
240 adns__query_finish(ads,qu,adns_s_ok);
245 adns__diag(ads,serv,"server sent datagram which points outside itself");
246 adns__query_fail(ads,qu,adns_s_serverfaulty);
249 if (qu->cnameoff != -1) { cname_recurse(ads,qu,adns_qf_usevc); return; }
252 ans= (adns_answer*)qu->ans.buf;
254 qu->ans.used= sizeof(adns_answer);
255 qu->flags |= adns_qf_usevc;
256 adns__query_udp(ads,qu,now);