* - main handling and parsing routine for received datagrams
*/
/*
- * This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson
+ * This file is part of adns, which is
+ * Copyright (C) 1997-2000,2003,2006,2014-2016 Ian Jackson
+ * Copyright (C) 2014 Mark Wooding
+ * Copyright (C) 1999-2000,2003,2006 Tony Finch
+ * Copyright (C) 1991 Massachusetts Institute of Technology
+ * (See the file INSTALL for full details.)
*
* 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)
+ * the Free Software Foundation; either version 3, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* 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.
+ * along with this program; if not, write to the Free Software Foundation.
*/
#include <stdlib.h>
-#include <string.h>
#include "internal.h"
void adns__procdgram(adns_state ads, const byte *dgram, int dglen,
- int serv, struct timeval now) {
+ 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 anstart, nsstart;
int ownermatched, l, nrrs;
unsigned long ttl, soattl;
const typeinfo *typei;
parseinfo pai;
if (dglen<DNS_HDRSIZE) {
- adns__diag(ads,serv,0,"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;
return;
}
if (opcode) {
- adns__diag(ads,serv,0,"server sent us unknown opcode %d (wanted 0=QUERY)",opcode);
+ adns__diag(ads,serv,0,"server sent us unknown opcode"
+ " %d (wanted 0=QUERY)",opcode);
return;
}
- if (!qdcount) {
- adns__diag(ads,serv,0,"server sent reply without quoting our question");
- return;
- } else if (qdcount>1) {
- adns__diag(ads,serv,0,"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->query_dglen) continue;
- if (memcmp(qu->query_dgram+DNS_HDRSIZE,
- dgram+DNS_HDRSIZE,
- qu->query_dglen-DNS_HDRSIZE))
- continue;
- break;
- }
- if (!qu) {
- 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);
+
+ 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);
}
- return;
}
- anstart= qu->query_dglen;
- arstart= -1;
-
- LIST_UNLINK(ads->timew,qu);
- /* We're definitely going to do something with this query now */
+ /* 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(qu,adns_s_rcodeformaterror);
+ adns__warn(ads,serv,qu,"server cannot understand our query"
+ " (Format Error)");
+ if (qu) adns__query_fail(qu,adns_s_rcodeformaterror);
return;
case rcode_servfail:
- adns__query_fail(qu,adns_s_rcodeservfail);
+ 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(qu,adns_s_rcodenotimplemented);
+ 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(qu,adns_s_rcoderefused);
+ adns__debug(ads,serv,qu,"server refused our query");
+ 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(qu,adns_s_rcodeunknown);
+ 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;
+
/* 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.
*/
if (rrtype == -1) goto x_truncated;
if (rrclass != DNS_CLASS_IN) {
- adns__diag(ads,serv,qu,"ignoring answer RR with wrong class %d (expected IN=%d)",
- rrclass,DNS_CLASS_IN);
+ adns__diag(ads,serv,qu,"ignoring answer RR with wrong class %d"
+ " (expected IN=%d)", rrclass,DNS_CLASS_IN);
continue;
}
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, 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) {
+ (qu->answer->type & adns_rrt_typemask) != adns_r_cname) {
if (qu->flags & adns_qf_cname_forbid) {
adns__query_fail(qu,adns_s_prohibitedcname);
return;
- } else if (!qu->cname_dgram) { /* Ignore second and subsequent CNAMEs */
+ } 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 & adns_qf_quoteok_cname ? pdf_quoteok : 0,
+ qu->flags & adns_qf_quotefail_cname
+ ? 0 : pdf_quoteok,
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_preserved(qu,l);
- if (!qu->answer->cname) { adns__query_fail(qu,adns_s_nomemory); return; }
+ 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);
* 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, dgram,dglen,rdstart),
- qu->answer->cname);
}
- } else if (rrtype == (qu->typei->type & adns__rrt_typemask)) {
+ } else if (rrtype == (qu->answer->type & adns_rrt_typemask)) {
wantedrrs++;
} else {
- adns__debug(ads,serv,qu,"ignoring answer RR with irrelevant type %d",rrtype);
+ adns__debug(ads,serv,qu,"ignoring answer RR"
+ " with irrelevant type %d",rrtype);
}
}
nsstart= cbyte;
if (!wantedrrs) {
- /* Oops, NODATA or NXDOMAIN or perhaps a referral (which would be a problem) */
+ /* Oops, NODATA or NXDOMAIN or perhaps a referral
+ * (which would be a problem) */
- /* RFC2308: NODATA has _either_ a SOA _or_ _no_ NS records in authority section */
+ /* RFC2308: NODATA has _either_ a SOA _or_ _no_ NS records
+ * in authority section */
foundsoa= 0; soattl= 0; foundns= 0;
for (rri= 0; rri<nscount; rri++) {
rrstart= cbyte;
if (rrtype==-1) goto x_truncated;
if (rrclass != DNS_CLASS_IN) {
adns__diag(ads,serv,qu,
- "ignoring authority RR with wrong class %d (expected IN=%d)",
- rrclass,DNS_CLASS_IN);
+ "ignoring authority RR with wrong class %d"
+ " (expected IN=%d)", rrclass,DNS_CLASS_IN);
continue;
}
if (rrtype == adns_r_soa_raw) { foundsoa= 1; soattl= ttl; break; }
/* 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) {
+ if (qu->flags & adns_qf_search && !qu->cname_dgram) {
adns__search_next(ads,qu,now);
} else {
adns__query_fail(qu,adns_s_nxdomain);
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__diag(ads,serv,qu,"server is not willing"
+ " to do recursive lookups for us");
adns__query_fail(qu,adns_s_norecurse);
} else {
- adns__diag(ads,serv,qu,"server claims to do recursion, but gave us a referral");
+ if (!flg_rd)
+ adns__diag(ads,serv,qu,"server thinks"
+ " we didn't ask for recursive lookup");
+ else
+ adns__debug(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. */
- 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; }
+ qu->answer->rrs.untyped= adns__alloc_interim(qu,qu->answer->rrsz*wantedrrs);
+ if (!qu->answer->rrs.untyped) {
+ adns__query_fail(qu,adns_s_nomemory);
+ return;
+ }
typei= qu->typei;
cbyte= anstart;
&ownermatched);
assert(!st); assert(rrtype != -1);
if (rrclass != DNS_CLASS_IN ||
- rrtype != (qu->typei->type & adns__rrt_typemask) ||
+ rrtype != (qu->answer->type & adns_rrt_typemask) ||
!ownermatched)
continue;
adns__update_expires(qu,ttl,now);
- st= typei->parse(&pai, rdstart,rdstart+rdlength, rrsdata+nrrs*typei->rrsz);
+ st= typei->parse(&pai, rdstart,rdstart+rdlength,
+ rrsdata+nrrs*qu->answer->rrsz);
if (st) { adns__query_fail(qu,st); return; }
if (rdstart==-1) goto x_truncated;
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;
}
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);
+ qu->cname_dgram,qu->cname_dglen,qu->cname_begin,
+ qu->answer->type, qu->flags);
if (st) { adns__query_fail(qu,st); return; }
newquery= realloc(qu->query_dgram,qu->vb.used);
memcpy(newquery,qu->vb.buf,qu->vb.used);
}
- if (qu->state == query_tcpsent) qu->state= query_tosend;
+ if (qu->state == query_tcpw) qu->state= query_tosend;
+ qu->retries= 0;
adns__reset_preserved(qu);
adns__query_send(qu,now);
}
~mdw / adns / blobdiff