-/**/
+/*
+ * reply.c
+ * - main handling and parsing routine for received datagrams
+ */
+/*
+ * This file is
+ * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
+ *
+ * It is part of adns, which is
+ * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
+ * Copyright (C) 1999 Tony Finch <dot@dotat.at>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
-#include "internal.h"
+#include <stdlib.h>
-static void cname_recurse(adns_state ads, adns_query qu, adns_queryflags xflags) {
- abort(); /* FIXME */
-}
+#include "internal.h"
void adns__procdgram(adns_state ads, const byte *dgram, int dglen,
- int serv, struct timeval now) {
- int cbyte, rrstart, wantedrrs, rri, foundsoa, foundns;
- int id, f1, f2, qdcount, ancount, nscount, arcount, flg_ra, flg_rd, flg_tc, opcode;
- int rrtype, rrclass, rdlength, rdstart, ownermatched, ownerstart;
+ int serv, int viatcp, struct timeval now) {
+ int cbyte, rrstart, wantedrrs, rri, foundsoa, foundns, cname_here;
+ int id, f1, f2, qdcount, ancount, nscount, arcount;
+ int flg_ra, flg_rd, flg_tc, flg_qr, opcode;
+ int rrtype, rrclass, rdlength, rdstart;
int anstart, nsstart, arstart;
- int currentrrs;
+ int ownermatched, l, nrrs;
+ unsigned long ttl, soattl;
+ const typeinfo *typei;
adns_query qu, nqu;
dns_rcode rcode;
adns_status st;
- vbuf vb;
-#error init and free vb properly
+ vbuf tempvb;
+ byte *newquery, *rrsdata;
+ parseinfo pai;
if (dglen<DNS_HDRSIZE) {
- adns__diag(ads,serv,"received datagram too short for message header (%d)",dglen);
+ adns__diag(ads,serv,0,"received datagram too short for message header (%d)",dglen);
return;
}
+ cbyte= 0;
GET_W(cbyte,id);
GET_B(cbyte,f1);
GET_B(cbyte,f2);
flg_qr= f1&0x80;
opcode= (f1&0x78)>>3;
- flg_tc= f1&0x20;
+ flg_tc= f1&0x02;
flg_rd= f1&0x01;
flg_ra= f2&0x80;
- rcode= (f1&0x0f);
+ rcode= (f2&0x0f);
- if (flg_qr) {
- adns__diag(ads,serv,"server sent us a query, not a response");
+ cname_here= 0;
+
+ if (!flg_qr) {
+ adns__diag(ads,serv,0,"server sent us a query, not a response");
return;
}
if (opcode) {
- adns__diag(ads,serv,"server sent us unknown opcode %d (wanted 0=QUERY)",opcode);
- return;
- }
- if (!qdcount) {
- adns__diag(ads,serv,"server sent reply without quoting our question");
- return;
- } else if (qdcount>1) {
- adns__diag(ads,serv,"server claimed to answer %d questions with one message",
- qdcount);
- return;
- }
- for (qu= ads->timew.head; qu; qu= nqu) {
- nqu= qu->next;
- if (qu->id != id) continue;
- if (dglen < qu->querylen) continue;
- if (memcmp(qu->querymsg+DNS_HDRSIZE,dgram+DNS_HDRSIZE,qu->querylen-DNS_HDRSIZE))
- continue;
- break;
- }
- assert(qu->cnameoff == -1);
- anstart= qu->querylen;
- if (!qu) {
- adns__debug(ads,serv,"reply not found (id=%02x)",id);
+ adns__diag(ads,serv,0,"server sent us unknown opcode %d (wanted 0=QUERY)",opcode);
return;
}
- LIST_UNLINK(ads->timew,qu);
- /* We're definitely going to do something with this query now */
+ qu= 0;
+ /* See if we can find the relevant query, or leave qu=0 otherwise ... */
+
+ if (qdcount == 1) {
+ for (qu= viatcp ? ads->tcpw.head : ads->udpw.head; qu; qu= nqu) {
+ nqu= qu->next;
+ if (qu->id != id) continue;
+ if (dglen < qu->query_dglen) continue;
+ if (memcmp(qu->query_dgram+DNS_HDRSIZE,
+ dgram+DNS_HDRSIZE,
+ qu->query_dglen-DNS_HDRSIZE))
+ continue;
+ if (viatcp) {
+ assert(qu->state == query_tcpw);
+ } else {
+ assert(qu->state == query_tosend);
+ if (!(qu->udpsent & (1<<serv))) continue;
+ }
+ break;
+ }
+ if (qu) {
+ /* We're definitely going to do something with this query now */
+ if (viatcp) LIST_UNLINK(ads->tcpw,qu);
+ else LIST_UNLINK(ads->udpw,qu);
+ }
+ }
+ /* If we're going to ignore the packet, we return as soon as we have
+ * failed the query (if any) and printed the warning message (if
+ * any).
+ */
switch (rcode) {
case rcode_noerror:
case rcode_nxdomain:
break;
case rcode_formaterror:
adns__warn(ads,serv,qu,"server cannot understand our query (Format Error)");
- adns__query_fail(ads,qu,adns_s_serverfaulty);
+ if (qu) adns__query_fail(qu,adns_s_rcodeformaterror);
return;
case rcode_servfail:
- adns__query_fail(ads,qu,adns_s_servfail);
+ if (qu) adns__query_fail(qu,adns_s_rcodeservfail);
+ else adns__debug(ads,serv,qu,"server failure on unidentifiable query");
return;
case rcode_notimp:
adns__warn(ads,serv,qu,"server claims not to implement our query");
- adns__query_fail(ads,qu,adns_s_notimplemented);
+ if (qu) adns__query_fail(qu,adns_s_rcodenotimplemented);
return;
case rcode_refused:
adns__warn(ads,serv,qu,"server refused our query");
- adns__query_fail(ads,qu,adns_s_refused);
+ if (qu) adns__query_fail(qu,adns_s_rcoderefused);
return;
default:
adns__warn(ads,serv,qu,"server gave unknown response code %d",rcode);
- adns__query_fail(ads,qu,adns_s_reasonunknown);
+ if (qu) adns__query_fail(qu,adns_s_rcodeunknown);
+ return;
+ }
+
+ if (!qu) {
+ if (!qdcount) {
+ adns__diag(ads,serv,0,"server sent reply without quoting our question");
+ } else if (qdcount>1) {
+ adns__diag(ads,serv,0,"server claimed to answer %d questions with one message",
+ qdcount);
+ } else if (ads->iflags & adns_if_debug) {
+ adns__vbuf_init(&tempvb);
+ adns__debug(ads,serv,0,"reply not found, id %02x, query owner %s",
+ id, adns__diag_domain(ads,serv,0,&tempvb,dgram,dglen,DNS_HDRSIZE));
+ adns__vbuf_free(&tempvb);
+ }
return;
}
+ /* We're definitely going to do something with this packet and this query now. */
+
+ anstart= qu->query_dglen;
+ arstart= -1;
+
/* Now, take a look at the answer section, and see if it is complete.
* If it has any CNAMEs we stuff them in the answer.
*/
wantedrrs= 0;
+ cbyte= anstart;
for (rri= 0; rri<ancount; rri++) {
rrstart= cbyte;
- if (qu->cname_dgram >= 0) {
- st= adns__findrr(ads,serv, dgram,dglen,&cbyte,
- &rrtype,&rrclass,&rdlength,&rdstart,
- qu->cname_dgram,qu->cname_dglen,qu->cname_begin, &ownermatched);
- } else {
- st= adns__findrr(ads,serv, dgram,dglen,&cbyte,
- &rrtype,&rrclass,&rdlength,&rdstart,
- qu->querymsg,qu->querylen,DNS_HDRSIZE, &ownermatched);
- }
- if (st) adns__query_fail(ads,qu,st);
+ st= adns__findrr(qu,serv, dgram,dglen,&cbyte,
+ &rrtype,&rrclass,&ttl, &rdlength,&rdstart,
+ &ownermatched);
+ if (st) { adns__query_fail(qu,st); return; }
if (rrtype == -1) goto x_truncated;
if (rrclass != DNS_CLASS_IN) {
if (!ownermatched) {
if (ads->iflags & adns_if_debug) {
adns__debug(ads,serv,qu,"ignoring RR with an unexpected owner %s",
- adns__diag_domain(ads,serv,&vb,qu->flags,
- dgram,dglen,rrstart,dglen));
+ adns__diag_domain(ads,serv,qu, &qu->vb, dgram,dglen,rrstart));
}
continue;
}
if (rrtype == adns_r_cname &&
(qu->typei->type & adns__rrt_typemask) != adns_r_cname) {
- if (!qu->cname_str) { /* Ignore second and subsequent CNAMEs */
+ if (qu->flags & adns_qf_cname_forbid) {
+ adns__query_fail(qu,adns_s_prohibitedcname);
+ return;
+ } else if (qu->cname_dgram) { /* Ignore second and subsequent CNAME(s) */
+ adns__debug(ads,serv,qu,"allegedly canonical name %s is actually alias for %s",
+ qu->answer->cname,
+ adns__diag_domain(ads,serv,qu, &qu->vb, dgram,dglen,rdstart));
+ adns__query_fail(qu,adns_s_prohibitedcname);
+ return;
+ } else if (wantedrrs) { /* Ignore CNAME(s) after RR(s). */
+ adns__debug(ads,serv,qu,"ignoring CNAME (to %s) coexisting with RR",
+ adns__diag_domain(ads,serv,qu, &qu->vb, dgram,dglen,rdstart));
+ } else {
qu->cname_begin= rdstart;
- qu->cname_dgram= dgram;
qu->cname_dglen= dglen;
- st= adns__parse_domain(ads,serv,&vb,qu->flags,
+ st= adns__parse_domain(ads,serv,qu, &qu->vb,
+ qu->flags & adns_qf_quotefail_cname ? 0 : pdf_quoteok,
dgram,dglen, &rdstart,rdstart+rdlength);
- if (!vb.used) goto x_truncated;
- if (st) { adns__query_fail(ads,qu,st); return; }
- qu->cname_str= adns__vbuf_extractstring(&vb);
+ if (!qu->vb.used) goto x_truncated;
+ if (st) { adns__query_fail(qu,st); return; }
+ l= strlen(qu->vb.buf)+1;
+ qu->answer->cname= adns__alloc_preserved(qu,l);
+ if (!qu->answer->cname) { adns__query_fail(qu,adns_s_nomemory); return; }
+
+ qu->cname_dgram= adns__alloc_mine(qu,dglen);
+ memcpy(qu->cname_dgram,dgram,dglen);
+
+ memcpy(qu->answer->cname,qu->vb.buf,l);
+ cname_here= 1;
+ adns__update_expires(qu,ttl,now);
/* If we find the answer section truncated after this point we restart
* the query at the CNAME; if beforehand then we obviously have to use
* TCP. If there is no truncation we can use the whole answer if
* it contains the relevant info.
*/
- } else {
- adns__debug(ads,serv,qu,"ignoring duplicate CNAME (%s, as well as %s)",
- adns__diag_domain(ads,serv,&vb,qu->flags,
- dgram,dglen, rdstart,rdstart+rdlength),
- qu->cname_str);
}
} else if (rrtype == (qu->typei->type & adns__rrt_typemask)) {
wantedrrs++;
}
}
- /* If we got here then the answer section is intact. */
+ /* We defer handling truncated responses here, in case there was a CNAME
+ * which we could use.
+ */
+ if (flg_tc) goto x_truncated;
+
nsstart= cbyte;
if (!wantedrrs) {
/* Oops, NODATA or NXDOMAIN or perhaps a referral (which would be a problem) */
-
- if (rcode == rcode_nxdomain) {
- adns__query_finish(ads,qu,adns_s_nxdomain);
- return;
- }
/* RFC2308: NODATA has _either_ a SOA _or_ _no_ NS records in authority section */
- foundsoa= 0; foundns= 0;
+ foundsoa= 0; soattl= 0; foundns= 0;
for (rri= 0; rri<nscount; rri++) {
rrstart= cbyte;
- st= adns__findrr(ads,serv, dgram,dglen,&cbyte,
- &rrtype,&rrclass,&rdlength,&rdstart,
- 0,0,0,0);
- if (st) { adns__query_fail(ads,qu,st); return; }
+ st= adns__findrr(qu,serv, dgram,dglen,&cbyte,
+ &rrtype,&rrclass,&ttl, &rdlength,&rdstart, 0);
+ if (st) { adns__query_fail(qu,st); return; }
if (rrtype==-1) goto x_truncated;
if (rrclass != DNS_CLASS_IN) {
adns__diag(ads,serv,qu,
rrclass,DNS_CLASS_IN);
continue;
}
- if (rrtype == adns_r_soa_raw) { foundsoa= 1; break; }
+ if (rrtype == adns_r_soa_raw) { foundsoa= 1; soattl= ttl; break; }
else if (rrtype == adns_r_ns_raw) { foundns= 1; }
}
+
+ if (rcode == rcode_nxdomain) {
+ /* We still wanted to look for the SOA so we could find the TTL. */
+ adns__update_expires(qu,soattl,now);
+
+ if (qu->flags & adns_qf_search) {
+ adns__search_next(ads,qu,now);
+ } else {
+ adns__query_fail(qu,adns_s_nxdomain);
+ }
+ return;
+ }
if (foundsoa || !foundns) {
/* Aha ! A NODATA response, good. */
- adns__query_finish(ads,qu,adns_s_nodata);
+ adns__update_expires(qu,soattl,now);
+ adns__query_fail(qu,adns_s_nodata);
return;
}
* a CNAME in this datagram then we should probably do our own CNAME
* lookup now in the hope that we won't get a referral again.
*/
- if (qu->cname_dgram == dgram) { cname_recurse(ads,qu,0); return; }
+ if (cname_here) goto x_restartquery;
/* Bloody hell, I thought we asked for recursion ? */
- if (flg_rd) {
- adns__diag(ads,serv,qu,"server thinks we didn't ask for recursive lookup");
- }
if (!flg_ra) {
adns__diag(ads,serv,qu,"server is not willing to do recursive lookups for us");
- adns__query_fail(ads,qu,adns_s_norecurse);
+ adns__query_fail(qu,adns_s_norecurse);
} else {
- adns__diag(ads,serv,qu,"server claims to do recursion, but gave us a referral");
- adns__query_fail(ads,qu,adns_s_serverfaulty);
+ if (!flg_rd)
+ adns__diag(ads,serv,qu,"server thinks we didn't ask for recursive lookup");
+ else
+ adns__diag(ads,serv,qu,"server claims to do recursion, but gave us a referral");
+ adns__query_fail(qu,adns_s_invalidresponse);
}
return;
}
/* Now, we have some RRs which we wanted. */
- if (!adns__vbuf_ensure(&qu->ansbuf,qu->typei->rrsz*wantedrrs)) {
- adns__query_fail(ads,qu,adns_s_nolocalmem);
- return;
- }
+ qu->answer->rrs.untyped= adns__alloc_interim(qu,qu->typei->rrsz*wantedrrs);
+ if (!qu->answer->rrs.untyped) { adns__query_fail(qu,adns_s_nomemory); return; }
+ typei= qu->typei;
cbyte= anstart;
- currentrrs= 0;
- arstart= -1;
- qu->ansbuf.used= 0;
- for (rri=0; rri<ancount; rri++) {
- if (qu->cname_dgram >= 0) {
- st= adns__findrr(ads,serv, dgram,dglen,&cbyte,
- &rrtype,&rrclass,&rdlength,&rdstart,
- qu->cname_dgram,qu->cname_dglen,qu->cname_begin, &ownermatched);
- } else {
- st= adns__findrr(ads,serv, dgram,dglen,&cbyte,
- &rrtype,&rrclass,&rdlength,&rdstart,
- qu->querymsg,qu->querylen,DNS_HDRSIZE, &ownermatched);
- }
+ rrsdata= qu->answer->rrs.bytes;
+
+ pai.ads= qu->ads;
+ pai.qu= qu;
+ pai.serv= serv;
+ pai.dgram= dgram;
+ pai.dglen= dglen;
+ pai.nsstart= nsstart;
+ pai.nscount= nscount;
+ pai.arcount= arcount;
+ pai.now= now;
+
+ for (rri=0, nrrs=0; rri<ancount; rri++) {
+ st= adns__findrr(qu,serv, dgram,dglen,&cbyte,
+ &rrtype,&rrclass,&ttl, &rdlength,&rdstart,
+ &ownermatched);
assert(!st); assert(rrtype != -1);
if (rrclass != DNS_CLASS_IN ||
rrtype != (qu->typei->type & adns__rrt_typemask) ||
!ownermatched)
continue;
- assert(currentrrs<wantedrrs);
- qu->ansbuf.used += quj->typei->rrsz;
- st= qu->typei->parse(ads,qu,serv,&vb,
- dgram,dglen, &rdstart,rdstart+rdlength,
- (void*)(qu->ansbuf.buf+qu->ansbuf.used));
- if (st) { adns__query_fail(ads,qu,st); return; }
+ adns__update_expires(qu,ttl,now);
+ st= typei->parse(&pai, rdstart,rdstart+rdlength, rrsdata+nrrs*typei->rrsz);
+ if (st) { adns__query_fail(qu,st); return; }
if (rdstart==-1) goto x_truncated;
+ nrrs++;
}
+ assert(nrrs==wantedrrs);
+ qu->answer->nrrs= nrrs;
/* This may have generated some child queries ... */
if (qu->children.head) {
- qu->state= query_child;
+ qu->state= query_childw;
LIST_LINK_TAIL(ads->childw,qu);
return;
}
-
- adns__query_finish(ads,qu,adns_s_ok);
+ adns__query_done(qu);
return;
-x_truncated:
+ x_truncated:
+
if (!flg_tc) {
adns__diag(ads,serv,qu,"server sent datagram which points outside itself");
- adns__query_fail(ads,qu,adns_s_serverfaulty);
+ adns__query_fail(qu,adns_s_invalidresponse);
return;
}
- if (qu->cname_dgram) { cname_recurse(ads,qu,adns_qf_usevc); return; }
- ans= (adns_answer*)qu->ans.buf;
- ans->nrrs= 0;
- qu->ans.used= sizeof(adns_answer);
qu->flags |= adns_qf_usevc;
- adns__query_udp(ads,qu,now);
+
+ x_restartquery:
+ if (qu->cname_dgram) {
+ st= adns__mkquery_frdgram(qu->ads,&qu->vb,&qu->id,
+ qu->cname_dgram, qu->cname_dglen, qu->cname_begin,
+ qu->typei->type, qu->flags);
+ if (st) { adns__query_fail(qu,st); return; }
+
+ newquery= realloc(qu->query_dgram,qu->vb.used);
+ if (!newquery) { adns__query_fail(qu,adns_s_nomemory); return; }
+
+ qu->query_dgram= newquery;
+ qu->query_dglen= qu->vb.used;
+ memcpy(newquery,qu->vb.buf,qu->vb.used);
+ }
+
+ if (qu->state == query_tcpw) qu->state= query_tosend;
+ qu->retries= 0;
+ adns__reset_preserved(qu);
+ adns__query_send(qu,now);
}
~mdw / adns / blobdiff