* - main handling and parsing routine for received datagrams
*/
/*
- * This file is part of adns, which is Copyright (C) 1997, 1998 Ian Jackson
+ * This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson
*
* 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
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
-#include "internal.h"
+#include <stdlib.h>
-static void cname_recurse(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 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, ownermatched, l;
+ int rrtype, rrclass, rdlength, rdstart;
int anstart, nsstart, arstart;
+ int ownermatched, l, nrrs;
+ unsigned long ttl, soattl;
+ const typeinfo *typei;
adns_query qu, nqu;
dns_rcode rcode;
adns_status st;
+ vbuf tempvb;
+ byte *newquery, *rrsdata;
+ parseinfo pai;
if (dglen<DNS_HDRSIZE) {
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) {
+ cname_here= 0;
+
+ if (!flg_qr) {
adns__diag(ads,serv,0,"server sent us a query, not a response");
return;
}
dgram+DNS_HDRSIZE,
qu->query_dglen-DNS_HDRSIZE))
continue;
+ if (viatcp) {
+ if (qu->state != query_tcpsent) continue;
+ } else {
+ if (qu->state != query_tosend) continue;
+ if (!(qu->udpsent & (1<<serv))) continue;
+ }
break;
}
- anstart= qu->query_dglen;
if (!qu) {
- adns__debug(ads,serv,0,"reply not found (id=%02x)",id);
+ 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;
}
+ anstart= qu->query_dglen;
+ arstart= -1;
LIST_UNLINK(ads->timew,qu);
/* We're definitely going to do something with this query now */
break;
case rcode_formaterror:
adns__warn(ads,serv,qu,"server cannot understand our query (Format Error)");
- adns__query_fail(qu,adns_s_serverfaulty);
+ adns__query_fail(qu,adns_s_rcodeformaterror);
return;
case rcode_servfail:
- adns__query_fail(qu,adns_s_servfail);
+ adns__query_fail(qu,adns_s_rcodeservfail);
return;
case rcode_notimp:
adns__warn(ads,serv,qu,"server claims not to implement our query");
- adns__query_fail(qu,adns_s_notimplemented);
+ adns__query_fail(qu,adns_s_rcodenotimplemented);
return;
case rcode_refused:
adns__warn(ads,serv,qu,"server refused our query");
- adns__query_fail(qu,adns_s_refused);
+ adns__query_fail(qu,adns_s_rcoderefused);
return;
default:
adns__warn(ads,serv,qu,"server gave unknown response code %d",rcode);
- adns__query_fail(qu,adns_s_reasonunknown);
+ adns__query_fail(qu,adns_s_rcodeunknown);
return;
}
* If it has any CNAMEs we stuff them in the answer.
*/
wantedrrs= 0;
+ cbyte= anstart;
for (rri= 0; rri<ancount; rri++) {
rrstart= cbyte;
st= adns__findrr(qu,serv, dgram,dglen,&cbyte,
- &rrtype,&rrclass,&rdlength,&rdstart,
+ &rrtype,&rrclass,&ttl, &rdlength,&rdstart,
&ownermatched);
- if (st) adns__query_fail(qu,st);
+ 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,qu, &qu->vb,qu->flags,
- dgram,dglen,rrstart));
+ 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_dgram) { /* Ignore second and subsequent CNAMEs */
- qu->cname_dgram= adns__alloc_mine(qu,dglen);
- if (!qu->cname_dgram) return;
+ 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_dglen= dglen;
- st= adns__parse_domain(ads,serv,qu, &qu->vb,qu->flags,
+ st= adns__parse_domain(ads,serv,qu, &qu->vb,
+ qu->flags & adns_qf_quoteok_cname ? pdf_quoteok : 0,
dgram,dglen, &rdstart,rdstart+rdlength);
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_interim(qu,l);
- if (!qu->answer->cname) return;
+ 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,qu, &qu->vb,qu->flags,
- dgram,dglen,rdstart),
- qu->answer->cname);
}
} 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_fail(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(qu,serv, dgram,dglen,&cbyte,
- &rrtype,&rrclass,&rdlength,&rdstart, 0);
+ &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) {
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__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(qu,0); return; }
+ if (cname_here) goto x_restartquery;
/* Bloody hell, I thought we asked for recursion ? */
if (flg_rd) {
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(qu,adns_s_serverfaulty);
+ adns__query_fail(qu,adns_s_invalidresponse);
}
return;
}
/* Now, we have some RRs which we wanted. */
qu->answer->rrs.untyped= adns__alloc_interim(qu,qu->typei->rrsz*wantedrrs);
- if (!qu->answer->rrs.untyped) return;
+ if (!qu->answer->rrs.untyped) { adns__query_fail(qu,adns_s_nomemory); return; }
+ typei= qu->typei;
cbyte= anstart;
- arstart= -1;
- for (rri=0; rri<ancount; rri++) {
+ 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,&rdlength,&rdstart,
+ &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(qu->answer->nrrs<wantedrrs);
- st= qu->typei->parse(qu,serv,
- dgram,dglen, rdstart,rdstart+rdlength,
- qu->answer->rrs.bytes+qu->answer->nrrs*qu->typei->rrsz);
+ 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) {
LIST_LINK_TAIL(ads->childw,qu);
return;
}
-
adns__query_done(qu);
return;
x_truncated:
+
if (!flg_tc) {
adns__diag(ads,serv,qu,"server sent datagram which points outside itself");
- adns__query_fail(qu,adns_s_serverfaulty);
+ adns__query_fail(qu,adns_s_invalidresponse);
return;
}
- if (qu->cname_dgram) { cname_recurse(qu,adns_qf_usevc); return; }
- adns__reset_cnameonly(qu);
qu->flags |= adns_qf_usevc;
- adns__query_udp(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_tcpsent) qu->state= query_tosend;
+ adns__reset_preserved(qu);
+ adns__query_send(qu,now);
}
~mdw / adns / blobdiff