* - 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
+ * 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
*/
#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;
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);
+ 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__warn(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);
+ 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;
+ 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.
*/
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; }
* 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)) {
wantedrrs++;
/* 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;
}
qu->flags |= adns_qf_usevc;
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,
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_udp(qu,now);
+ adns__query_send(qu,now);
}
~ianmdlvl / adns.git / blobdiff