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eb64128d8a
freebsd-nq/contrib/bind/named/ns_resp.c
Peter Wemm 0bf958b1eb Clean (trimmed down) import of bind-4.9.6 onto vendor branch. This is 
to buy time to allow v8.1.1 to be done right rather than rushing it.
1997-06-27 07:25:32 +00:00

3163 lines
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#if !defined(lint) && !defined(SABER)
static char sccsid[] = "@(#)ns_resp.c 4.65 (Berkeley) 3/3/91";
static char rcsid[] = "$Id: ns_resp.c,v 8.38 1997/06/01 20:34:34 vixie Exp vixie $";
#endif /* not lint */
/*
* ++Copyright++ 1986, 1988, 1990
* -
* Copyright (c) 1986, 1988, 1990
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* -
* Portions Copyright (c) 1993 by Digital Equipment Corporation.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies, and that
* the name of Digital Equipment Corporation not be used in advertising or
* publicity pertaining to distribution of the document or software without
* specific, written prior permission.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
* SOFTWARE.
* -
* Portions Copyright (c) 1995 by International Business Machines, Inc.
*
* International Business Machines, Inc. (hereinafter called IBM) grants
* permission under its copyrights to use, copy, modify, and distribute this
* Software with or without fee, provided that the above copyright notice and
* all paragraphs of this notice appear in all copies, and that the name of IBM
* not be used in connection with the marketing of any product incorporating
* the Software or modifications thereof, without specific, written prior
* permission.
*
* To the extent it has a right to do so, IBM grants an immunity from suit
* under its patents, if any, for the use, sale or manufacture of products to
* the extent that such products are used for performing Domain Name System
* dynamic updates in TCP/IP networks by means of the Software. No immunity is
* granted for any product per se or for any other function of any product.
*
* THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL,
* DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN
* IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES.
* --Copyright--
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>
#include <syslog.h>
#include <errno.h>
#include <stdio.h>
#include <resolv.h>
#include "named.h"
static u_int8_t norootlogged[MAXCLASS]; /* XXX- should be a bitmap */
static const char skipnameFailedAnswer[] = "skipname failed in answer",
skipnameFailedAuth[] = "skipname failed in authority",
skipnameFailedQuery[] = "skipname failed in query",
outofDataQuery[] = "ran out of data in query",
outofDataAnswer[] = "ran out of data in answer",
notSingleQuery[] = "not exactly one query",
expandFailedQuery[] = "dn_expand failed in query",
expandFailedAnswer[] = "dn_expand failed in answer",
expandFailedAuth[] = "dn_expand failed in authority",
outofDataAuth[] = "ran out of data in authority",
dlenOverrunAnswer[] = "dlen overrun in answer",
dlenOverrunAuth[] = "dlen overrun in authority",
dlenUnderrunAnswer[] = "dlen underrun in answer",
outofDataFinal[] = "out of data in final pass",
outofDataAFinal[] = "out of data after final pass",
badNameFound[] = "found an invalid domain name",
wrongQuestion[] = "answer to wrong question",
danglingCname[] = "dangling CNAME pointer";
struct db_list {
struct db_list *db_next;
struct databuf *db_dp;
};
struct flush_set {
char * fs_name;
int fs_type;
int fs_class;
u_int fs_cred;
struct db_list *fs_list;
struct db_list *fs_last;
};
static void rrsetadd __P((struct flush_set *, char *,
struct databuf *)),
rrsetupdate __P((struct flush_set *, int flags)),
flushrrset __P((struct flush_set *));
static int rrsetcmp __P((char *, struct db_list *)),
check_root __P((void)),
check_ns __P((void)),
rrextract __P((u_char *, int, u_char *,
struct databuf **, char *, int,
char **));
static void add_related_additional __P((char *));
static void free_related_additional __P((void));
static int related_additional __P((char *));
static void maybe_free __P((char **));
#define MAX_RELATED 100
static int num_related = 0;
static char *related[MAX_RELATED];
#ifdef LAME_LOGGING
static char *
learntFrom(qp, server)
struct qinfo *qp;
struct sockaddr_in *server;
{
static char *buf = NULL;
char *a, *ns, *na;
struct databuf *db;
#ifdef STATS
char nsbuf[20];
char abuf[20];
#endif
int i;
if (buf) {
free(buf);
buf = NULL;
}
a = ns = na = "<Not Available>";
for (i = 0; i < (int)qp->q_naddr; i++) {
if (qp->q_addr[i].ns_addr.sin_addr.s_addr ==
server->sin_addr.s_addr) {
db = qp->q_addr[i].ns;
if (db) {
#ifdef STATS
if (db->d_ns) {
strcpy(nsbuf,
inet_ntoa(db->d_ns->addr));
ns = nsbuf;
} else {
ns = zones[db->d_zone].z_origin;
}
#endif
#ifdef NCACHE
if (!db->d_rcode)
#endif
na = (char*)qp->q_addr[i].ns->d_data;
}
#ifdef STATS
db = qp->q_addr[i].nsdata;
if (db) {
if (db->d_ns) {
strcpy(abuf,
inet_ntoa(db->d_ns->addr));
a = abuf;
} else {
a = zones[db->d_zone].z_origin;
}
}
#endif
break;
}
}
if ((a == ns) && (ns == na)) /* all "UNKNOWN" */
return ("");
#ifdef STATS
# define LEARNTFROM " '%s': learnt (A=%s,NS=%s)"
#else
# define LEARNTFROM " '%s'"
#endif
buf = malloc(strlen(a = (*a ? a : "\".\"")) +
strlen(ns = (*ns ? ns : "\".\"")) +
strlen(na = (*na ? na : "\".\"")) +
sizeof(LEARNTFROM));
if (!buf)
return ("");
sprintf(buf, LEARNTFROM, na, a, ns);
return (buf);
}
#endif /*LAME_LOGGING*/
void
ns_resp(msg, msglen)
u_char *msg;
int msglen;
{
register struct qinfo *qp;
register HEADER *hp;
register struct qserv *qs;
register struct databuf *ns, *ns2;
register u_char *cp;
u_char *eom = msg + msglen;
struct flush_set *flushset;
struct sockaddr_in *nsa;
struct databuf *nsp[NSMAX];
int i, c, n, qdcount, ancount, aucount, nscount, arcount, arfirst;
int qtype, qclass, dbflags;
int restart; /* flag for processing cname response */
int validanswer;
int cname, lastwascname, externalcname;
int count, founddata, foundname;
int buflen;
int newmsglen;
char name[MAXDNAME], qname[MAXDNAME], aname[MAXDNAME];
char msgbuf[MAXDNAME];
char *dname, tmpdomain[MAXDNAME];
const char *fname;
const char *formerrmsg = "brain damage";
u_char newmsg[PACKETSZ];
u_char **dpp, *tp;
time_t rtrip;
struct hashbuf *htp;
struct namebuf *np;
struct netinfo *lp;
struct fwdinfo *fwd;
char *tname = NULL;
free_related_additional();
nameserIncr(from_addr.sin_addr, nssRcvdR);
nsp[0] = NULL;
hp = (HEADER *) msg;
if ((qp = qfindid(hp->id)) == NULL ) {
dprintf(1, (ddt, "DUP? dropped (id %d)\n", ntohs(hp->id)));
nameserIncr(from_addr.sin_addr, nssRcvdDupR);
return;
}
dprintf(2, (ddt, "Response (%s %s %s) nsid=%d id=%d\n",
(qp->q_flags & Q_SYSTEM) ?"SYSTEM" :"USER",
(qp->q_flags & Q_PRIMING) ?"PRIMING" :"NORMAL",
(qp->q_flags & Q_ZSERIAL) ?"ZSERIAL" :"-",
ntohs(qp->q_nsid), ntohs(qp->q_id)));
/*
* Here we handle high level formatting problems by parsing the header.
*/
qdcount = ntohs(hp->qdcount);
ancount = ntohs(hp->ancount);
aucount = ntohs(hp->nscount); /* !!! */
arcount = ntohs(hp->arcount);
free_addinfo(); /* sets addcount to zero */
cp = msg + HFIXEDSZ;
dpp = dnptrs;
*dpp++ = msg;
if ((*cp & INDIR_MASK) == 0)
*dpp++ = cp;
*dpp = NULL;
if (qdcount == 1) {
n = dn_expand(msg, eom, cp, qname, sizeof(qname));
if (n <= 0) {
formerrmsg = expandFailedQuery;
goto formerr;
}
cp += n;
GETSHORT(qtype, cp);
GETSHORT(qclass, cp);
if (!ns_nameok(qname, qclass, response_trans,
ns_ownercontext(qtype, response_trans),
qname, from_addr.sin_addr)) {
formerrmsg = badNameFound;
goto formerr;
}
if (cp > eom) {
formerrmsg = outofDataQuery;
goto formerr;
}
if (qp->q_msg && qp->q_msglen &&
!res_nameinquery(qname, qtype, qclass,
qp->q_msg, qp->q_msg + qp->q_msglen)) {
sprintf(msgbuf,
"query section mismatch (%s %s %s)",
qname, p_class(qclass), p_type(qtype));
formerrmsg = msgbuf;
goto formerr;
}
if (strcasecmp(qp->q_name, qname) != 0 ||
qp->q_class != qclass ||
qp->q_type != qtype) {
formerrmsg = wrongQuestion;
goto formerr;
}
} else {
strcpy(qname, qp->q_name);
qclass = qp->q_class;
qtype = qp->q_type;
}
/* cp now points after the query section. */
/*
* Here we handle bad responses from servers.
* Several possibilities come to mind:
* The server is sick and returns SERVFAIL
* The server returns some garbage opcode (it's sick)
* The server can't understand our query and return FORMERR
* In all these cases, we drop the packet, disable retries on
* this server and immediately force a retry.
*/
if ((hp->rcode != NOERROR && hp->rcode != NXDOMAIN)
|| (hp->opcode != QUERY
#ifdef BIND_NOTIFY
&& hp->opcode != NS_NOTIFY_OP
#endif
)) {
dprintf(2, (ddt, "resp: error (ret %d, op %d), dropped\n",
hp->rcode, hp->opcode));
switch (hp->rcode) {
case SERVFAIL:
nameserIncr(from_addr.sin_addr, nssRcvdFail);
break;
case FORMERR:
nameserIncr(from_addr.sin_addr, nssRcvdFErr);
break;
default:
nameserIncr(from_addr.sin_addr, nssRcvdErr);
break;
}
/* mark server as bad */
if (!qp->q_fwd)
for (i = 0; i < (int)qp->q_naddr; i++)
if (qp->q_addr[i].ns_addr.sin_addr.s_addr
== from_addr.sin_addr.s_addr)
qp->q_addr[i].nretry = MAXRETRY;
/*
* XXX: doesn't handle responses sent from the wrong
* interface on a multihomed server.
*/
if (qp->q_fwd ||
qp->q_addr[qp->q_curaddr].ns_addr.sin_addr.s_addr
== from_addr.sin_addr.s_addr)
retry(qp);
return;
}
if (qdcount != 1) {
/* We don't generate or forward these (yet). */
formerrmsg = notSingleQuery;
goto formerr;
}
/*
* Determine if the response came from a forwarder. Packets from
* anyplace not listed as a forwarder or as a server to whom we
* might have forwarded the query will be dropped.
*/
for (fwd = fwdtab; fwd != (struct fwdinfo *)NULL; fwd = fwd->next) {
if (fwd->fwdaddr.sin_addr.s_addr ==
from_addr.sin_addr.s_addr) {
/* XXX - should put this in STATS somewhere. */
break;
}
}
/*
* XXX: note bad ambiguity here. if one of our forwarders is also
* a delegated server for some domain, then we will not update
* the RTT information on any replies we get from those servers.
* Workaround: disable recursion on authoritative servers so that
* the ambiguity does not arise.
*/
/*
* If we weren't using a forwarder, find the qinfo pointer and update
* the rtt and fact that we have called on this server before.
*/
if (fwd == (struct fwdinfo *)NULL) {
struct timeval *stp;
for (n = 0, qs = qp->q_addr; (u_int)n < qp->q_naddr; n++, qs++)
if (qs->ns_addr.sin_addr.s_addr ==
from_addr.sin_addr.s_addr)
break;
if ((u_int)n >= qp->q_naddr) {
if (!haveComplained((char*)from_addr.sin_addr.s_addr,
"unexpected source")) {
syslog(LOG_INFO,
"Response from unexpected source (%s)",
sin_ntoa(&from_addr));
}
/*
* We don't know who this response came from so it
* gets dropped on the floor.
*/
return;
}
stp = &qs->stime;
/* Handle response from different (untried) interface */
if ((qs->ns != NULL) && (stp->tv_sec == 0)) {
ns = qs->ns;
while (qs > qp->q_addr
&& (qs->stime.tv_sec == 0 || qs->ns != ns))
qs--;
*stp = qs->stime;
/* XXX - sometimes stp still ends up pointing to
* a zero timeval, in spite of the above attempt.
* Why? What should we do about it?
*/
dprintf(1, (ddt,
"Response from unused address %s, assuming %s\n",
sin_ntoa(&from_addr),
sin_ntoa(&qs->ns_addr)));
/* XXX - catch aliases here */
}
/* compute query round trip time */
/* XXX - avoid integer overflow, which is quite likely if stp
* points to a zero timeval (see above).
* rtrip is of type time_t, which we assume is at least
* as big as an int.
*/
if ((tt.tv_sec - stp->tv_sec) > (INT_MAX-999)/1000) {
rtrip = INT_MAX;
} else {
rtrip = ((tt.tv_sec - stp->tv_sec) * 1000 +
(tt.tv_usec - stp->tv_usec) / 1000);
}
dprintf(3, (ddt, "stime %lu/%lu now %lu/%lu rtt %ld\n",
(u_long)stp->tv_sec, (u_long)stp->tv_usec,
(u_long)tt.tv_sec, (u_long)tt.tv_usec,
(long)rtrip));
/* prevent floating point overflow, limit to 1000 sec */
if (rtrip > 1000000) {
rtrip = 1000000;
}
ns = qs->nsdata;
/*
* Don't update nstime if this doesn't look
* like an address databuf now. XXX
*/
if (ns &&
ns->d_type == T_A &&
ns->d_class == qs->ns->d_class) {
u_long t;
if (ns->d_nstime == 0)
t = rtrip;
else
t = ns->d_nstime * ALPHA
+
(1 - ALPHA) * rtrip;
if (t > 65535)
t = 65535;
ns->d_nstime = (u_int16_t)t;
}
/*
* Record the source so that we do not use this NS again.
*/
if (ns && qs->ns && (qp->q_nusedns < NSMAX)) {
qp->q_usedns[qp->q_nusedns++] = qs->ns;
dprintf(2, (ddt, "NS #%d addr %s used, rtt %d\n",
n, sin_ntoa(&qs->ns_addr),
ns->d_nstime));
}
/*
* Penalize those who had earlier chances but failed
* by multiplying round-trip times by BETA (>1).
* Improve nstime for unused addresses by applying GAMMA.
* The GAMMA factor makes unused entries slowly
* improve, so they eventually get tried again.
* GAMMA should be slightly less than 1.
* Watch out for records that may have timed out
* and are no longer the correct type. XXX
*/
for (n = 0, qs = qp->q_addr;
(u_int)n < qp->q_naddr;
n++, qs++) {
u_long t;
ns2 = qs->nsdata;
if ((!ns2) || (ns2 == ns))
continue;
if (ns2->d_type != T_A ||
ns2->d_class != qs->ns->d_class) /* XXX */
continue;
if (qs->stime.tv_sec) {
if (ns2->d_nstime == 0)
t = (rtrip * BETA);
else
t = ns2->d_nstime * BETA
+
(1 - ALPHA) * rtrip;
} else
t = ns2->d_nstime * GAMMA;
if (t > 65535)
t = 65535;
ns2->d_nstime = (u_int16_t)t;
dprintf(2, (ddt, "NS #%d %s rtt now %d\n", n,
sin_ntoa(&qs->ns_addr),
ns2->d_nstime));
}
}
#ifdef BIND_NOTIFY
/* for now, NOTIFY isn't defined for ANCOUNT!=0, AUCOUNT!=0,
* or ADCOUNT!=0. therefore the only real work to be done for
* a NOTIFY-QR is to remove it from the query queue.
*/
if (hp->opcode == NS_NOTIFY_OP) {
qremove(qp);
return;
}
#endif
#ifdef LAME_DELEGATION
/*
* Non-authoritative, no answer, no error, with referral.
*/
if (hp->rcode == NOERROR && !hp->aa && ancount == 0 && aucount > 0
#ifdef BIND_NOTIFY
&& hp->opcode != NS_NOTIFY_OP
#endif
) {
u_char *tp;
int type, class;
#ifdef DEBUG
if (debug > 0)
fp_nquery(msg, msglen, ddt);
#endif
/*
* Since there is no answer section (ancount == 0),
* we must be pointing at the authority section (aucount > 0).
*/
tp = cp;
n = dn_expand(msg, eom, tp, name, sizeof name);
if (n < 0) {
formerrmsg = expandFailedAuth;
goto formerr;
}
tp += n;
GETSHORT(type, tp);
if (tp >= eom) {
formerrmsg = outofDataAuth;
goto formerr;
}
GETSHORT(class, tp);
if (tp >= eom) {
formerrmsg = outofDataAuth;
goto formerr;
}
if (!ns_nameok(name, class, response_trans,
ns_ownercontext(type, response_trans),
name, from_addr.sin_addr)) {
formerrmsg = badNameFound;
goto formerr;
}
/*
* If the answer delegates us either to the same level in
* the hierarchy or closer to the root, we consider this
* server lame. Note that for now we only log the message
* if the T_NS was C_IN, which is technically wrong (NS is
* visible in all classes) but necessary anyway (non-IN
* classes tend to not have good strong delegation graphs).
*/
if (type == T_NS && samedomain(qp->q_domain, name)) {
nameserIncr(from_addr.sin_addr, nssRcvdLDel);
/* mark server as bad */
if (!qp->q_fwd)
for (i = 0; i < (int)qp->q_naddr; i++)
if (qp->q_addr[i].ns_addr.sin_addr.s_addr
== from_addr.sin_addr.s_addr)
qp->q_addr[i].nretry = MAXRETRY;
#ifdef LAME_LOGGING
if (class == C_IN &&
!haveComplained((char*)nhash(sin_ntoa(&from_addr)),
(char*)nhash(qp->q_domain)))
syslog(LAME_LOGGING,
"Lame server on '%s' (in '%s'?): %s%s\n",
qname, qp->q_domain,
sin_ntoa(&from_addr),
learntFrom(qp, &from_addr));
#endif /* LAME_LOGGING */
/* XXX - doesn't handle responses sent from the wrong
* interface on a multihomed server
*/
if (qp->q_fwd ||
qp->q_addr[qp->q_curaddr].ns_addr.sin_addr.s_addr
== from_addr.sin_addr.s_addr)
retry(qp);
return;
}
}
#endif /* LAME_DELEGATION */
if (qp->q_flags & Q_ZSERIAL) {
if (hp->aa && ancount > 0 && hp->rcode == NOERROR &&
qtype == T_SOA && ((qclass == C_IN) || (qclass == C_HS))) {
int n;
u_int16_t type, class, dlen;
u_int32_t serial;
u_char *tp = cp;
n = dn_expand(msg, eom, tp, name, sizeof name);
if (n < 0) {
formerrmsg = expandFailedAnswer;
goto formerr;
}
tp += n; /* name */
GETSHORT(type, tp); /* type */
GETSHORT(class, tp); /* class */
tp += INT32SZ; /* ttl */
GETSHORT(dlen, tp); /* dlen */
if (tp >= eom) {
formerrmsg = outofDataAnswer;
goto formerr;
}
if (!ns_nameok(name, class, response_trans,
ns_ownercontext(type, response_trans),
name, from_addr.sin_addr)) {
formerrmsg = badNameFound;
goto formerr;
}
if (strcasecmp(qname, name) ||
qtype != type ||
qclass != class) {
sprintf(msgbuf,
"qserial answer mismatch (%s %s %s)",
name, p_class(class), p_type(type));
formerrmsg = msgbuf;
goto formerr;
}
if ((u_int)dlen < (5 * INT32SZ)) {
formerrmsg = dlenUnderrunAnswer;
goto formerr;
}
if (0 >= (n = dn_skipname(tp, eom))) {
formerrmsg = skipnameFailedAnswer;
goto formerr;
}
tp += n; /* mname */
if (0 >= (n = dn_skipname(tp, eom))) {
formerrmsg = skipnameFailedAnswer;
goto formerr;
}
tp += n; /* rname */
GETLONG(serial, tp);
qserial_answer(qp, serial);
qremove(qp);
} else {
retry(qp);
}
return;
}
/*
* Add the info received in the response to the data base.
*/
arfirst = ancount + aucount;
c = arfirst + arcount;
/* -ve $ing non-existence of record, must handle non-authoritative
* NOERRORs with c == 0.
*/
if (!hp->aa && hp->rcode == NOERROR && c == 0)
goto return_msg;
#ifdef notdef
/*
* If the request was for a CNAME that doesn't exist,
* but the name is valid, fetch any other data for the name.
* DON'T do this now, as it will requery if data are already
* in the cache (maybe later with negative caching).
*/
if (type == T_CNAME && c == 0 && hp->rcode == NOERROR
&& !(qp->q_flags & Q_SYSTEM)) {
dprintf(4, (ddt, "resp: leaving, no CNAME\n"));
/* Cause us to put it in the cache later */
prime(class, T_ANY, qp);
/* Nothing to store, just give user the answer */
goto return_msg;
}
#endif /* notdef */
if (qp->q_flags & Q_SYSTEM)
dbflags = DB_NOTAUTH | DB_NODATA;
else
dbflags = DB_NOTAUTH | DB_NODATA | DB_NOHINTS;
count = c;
if (qp->q_flags & Q_PRIMING)
dbflags |= DB_PRIMING;
if (hp->tc) {
count -= arcount; /* truncation had to affect this */
if (!arcount) {
count -= aucount; /* guess it got this too */
}
if (!(arcount || aucount)) {
count -= ancount; /* things are pretty grim */
}
/* XXX - should retry this query with TCP */
/*
* XXX - if this response is forwarded to the client
* the truncated section is included. We will not
* validate it, and if it somehow corrupt, we won't
* notice.
*
* XXX - if the answer section is truncated and we got
* this response after being redirected by a CNAME, we
* will not include any part of the final answer in our
* response to the client. This will make the client
* think that there are no RRs of the appropriate type.
*/
}
tp = cp;
restart = 0;
validanswer = 0;
nscount = 0;
cname = 0;
lastwascname = 0;
externalcname = 0;
strcpy(aname, qname);
if (count) {
/* allocate 1 extra record for end of set detection */
flushset = (struct flush_set *)
calloc(count+1, sizeof(struct flush_set));
if (!flushset)
panic(-1, "flushset: out of memory");
} else
flushset = NULL;
for (i = 0; i < count; i++) {
struct databuf *dp;
int type;
maybe_free(&tname);
if (cp >= eom) {
formerrmsg = outofDataFinal;
goto formerr;
}
n = rrextract(msg, msglen, cp, &dp, name, sizeof name, &tname);
if (n < 0) {
maybe_free(&tname);
formerrmsg = outofDataFinal;
goto formerr;
}
cp += n;
if (!dp)
continue;
type = dp->d_type;
if (i < ancount) {
/* Answer section. */
if (externalcname || strcasecmp(name, aname) != 0) {
if (!externalcname)
syslog(LOG_DEBUG,
"wrong ans. name (%s != %s)",
name, aname);
else
dprintf(3, (ddt,
"ignoring answer '%s' after external cname\n",
name));
db_free(dp);
continue;
}
if (type == T_CNAME &&
qtype != T_CNAME && qtype != T_ANY) {
strcpy(aname, (char *)dp->d_data);
if (!samedomain(aname, qp->q_domain))
externalcname = 1;
cname = 1;
lastwascname = 1;
} else {
validanswer = 1;
lastwascname = 0;
}
if (tname != NULL) {
add_related_additional(tname);
tname = NULL;
}
dp->d_cred = (hp->aa && !strcasecmp(name, qname))
? DB_C_AUTH
: DB_C_ANSWER;
} else {
/* After answer section. */
if (lastwascname) {
dprintf(3, (ddt,
"last was cname, ignoring auth. and add.\n"));
db_free(dp);
break;
}
if (i < arfirst) {
/* Authority section. */
switch (type) {
case T_NS:
case T_SOA:
if (!samedomain(aname, name)){
syslog(LOG_DEBUG,
"bad referral (%s !< %s)",
aname[0] ? aname : ".",
name[0] ? name : ".");
db_free(dp);
continue;
} else if (!samedomain(name,
qp->q_domain)) {
if (!externalcname)
syslog(LOG_DEBUG,
"bad referral (%s !< %s)",
name[0] ? name : ".",
qp->q_domain[0] ?
qp->q_domain : ".");
db_free(dp);
continue;
}
if (type == T_NS) {
nscount++;
add_related_additional(tname);
tname = NULL;
}
break;
case T_NXT:
case T_SIG:
break;
default:
syslog(LOG_DEBUG,
"invalid RR type '%s' in authority section (name = '%s') from %s",
p_type(type), name,
sin_ntoa(&from_addr));
db_free(dp);
continue;
}
} else {
/* Additional section. */
switch (type) {
case T_A:
case T_AAAA:
if (externalcname ||
!samedomain(name, qp->q_domain)) {
dprintf(3, (ddt,
"ignoring additional info '%s' type %s\n",
name, p_type(type)));
db_free(dp);
continue;
}
if (!related_additional(name)) {
syslog(LOG_DEBUG,
"unrelated additional info '%s' type %s from %s",
name, p_type(type),
sin_ntoa(&from_addr));
db_free(dp);
continue;
}
break;
case T_KEY:
case T_SIG:
break;
default:
syslog(LOG_DEBUG,
"invalid RR type '%s' in additional section (name = '%s') from %s",
p_type(type), name,
sin_ntoa(&from_addr));
db_free(dp);
continue;
}
}
dp->d_cred = (qp->q_flags & Q_PRIMING)
? DB_C_ANSWER
: DB_C_ADDITIONAL;
}
rrsetadd(flushset, name, dp);
}
maybe_free(&tname);
if (flushset) {
rrsetupdate(flushset, dbflags);
for (i = 0; i < count; i++)
if (flushset[i].fs_name)
free(flushset[i].fs_name);
free((char*)flushset);
}
if (lastwascname && !externalcname)
syslog(LOG_DEBUG, "%s (%s)", danglingCname, aname);
if (cp > eom) {
formerrmsg = outofDataAFinal;
goto formerr;
}
if ((qp->q_flags & Q_SYSTEM) && ancount) {
if ((qp->q_flags & Q_PRIMING) && !check_root()) {
/* mark server as bad */
if (!qp->q_fwd)
for (i = 0; i < (int)qp->q_naddr; i++)
if (qp->q_addr[i].ns_addr.sin_addr.s_addr
== from_addr.sin_addr.s_addr)
qp->q_addr[i].nretry = MAXRETRY;
/* XXX - doesn't handle responses sent from
* the wronginterface on a multihomed server
*/
if (qp->q_fwd ||
qp->q_addr[qp->q_curaddr].ns_addr.sin_addr.s_addr
== from_addr.sin_addr.s_addr)
retry(qp);
return;
}
dprintf(3, (ddt, "resp: leaving, SYSQUERY ancount %d\n",
ancount));
#ifdef BIND_NOTIFY
if (qp->q_notifyzone != DB_Z_CACHE) {
struct zoneinfo *zp = &zones[qp->q_notifyzone];
/*
* Clear this first since sysnotify() might set it.
*/
qp->q_notifyzone = DB_Z_CACHE;
sysnotify(zp->z_origin, zp->z_class, T_SOA);
}
#endif
qremove(qp);
return;
}
if (ancount && count && !validanswer)
/*
* Everything passed validation but we didn't get the
* final answer. The response must have contained
* a dangling CNAME. Force a restart of the query.
*
* Don't set restart if count==0, since this means
* the response was truncated in the answer section,
* causing us to set count to 0 which will cause
* validanswer to be 0 as well even though the answer
* section probably contained valid RRs (just not
* a complete set).
* XXX - this works right if we can just forward this
* response to the client, but not if we found a CNAME
* in a prior response and restarted the query.
*/
restart = 1;
/*
* If there are addresses and this is a local query,
* sort them appropriately for the local context.
*/
#ifdef SORT_RESPONSE
if (!restart && ancount > 1 && (lp = local(&qp->q_from)) != NULL)
sort_response(tp, ancount, lp, eom);
#endif
/*
* An answer to a T_ANY query or a successful answer to a
* regular query with no indirection, then just return answer.
*/
if (!restart && ancount && (qtype == T_ANY || !qp->q_cmsglen)) {
dprintf(3, (ddt, "resp: got as much answer as there is\n"));
goto return_msg;
}
/*
* We might want to cache this negative answer.
*/
if (!ancount &&
(!nscount || hp->rcode == NXDOMAIN) &&
(hp->aa || fwd || qclass == C_ANY)) {
/* we have an authoritative NO */
dprintf(3, (ddt, "resp: leaving auth NO\n"));
#ifdef NCACHE
/* answer was NO */
if (hp->aa &&
((hp->rcode == NXDOMAIN) || (hp->rcode == NOERROR))) {
cache_n_resp(msg, msglen);
}
#endif /*NCACHE*/
if (qp->q_cmsglen) {
/* XXX - what about additional CNAMEs in the chain? */
msg = qp->q_cmsg;
msglen = qp->q_cmsglen;
hp = (HEADER *)msg;
}
goto return_msg;
}
/*
* All messages in here need further processing. i.e. they
* are either CNAMEs or we got referred again.
*/
count = 0;
founddata = 0;
foundname = 0;
dname = name;
/*
* Even with VALIDATE, if restart==0 and ancount > 0, we should
* have some valid data because because the data in the answer
* section is owned by the query name and that passes the
* validation test by definition
*
* XXX - the restart stuff doesn't work if any of the answer RRs
* is not cacheable (TTL==0 or unknown RR type), since all of the
* answer must pass through the cache and be re-assembled.
*/
if ((!restart || !cname) && qp->q_cmsglen && ancount) {
dprintf(1, (ddt, "Cname second pass\n"));
newmsglen = MIN(PACKETSZ, qp->q_cmsglen);
bcopy(qp->q_cmsg, newmsg, newmsglen);
} else {
newmsglen = MIN(PACKETSZ, msglen);
bcopy(msg, newmsg, newmsglen);
}
hp = (HEADER *) newmsg;
hp->ancount = htons(0);
hp->nscount = htons(0);
hp->arcount = htons(0);
hp->rcode = NOERROR;
dnptrs[0] = newmsg;
dnptrs[1] = NULL;
cp = newmsg + HFIXEDSZ;
/*
* Keep in mind that none of this code works when QDCOUNT>1.
* cp ends up pointed just past the query section in both cases.
*/
/*
* Arrange for dname to contain the query name. The query
* name can be either the original query name if restart==0
* or the target of the last CNAME if we are following a
* CNAME chain and were referred.
*/
n = dn_expand(newmsg, newmsg + newmsglen, cp, dname,
sizeof name);
if (n < 0) {
dprintf(1, (ddt, "dn_expand failed\n"));
goto servfail;
}
if (!res_dnok(dname)) {
dprintf(1, (ddt, "bad name (%s)\n", dname));
goto servfail;
}
cp += n + QFIXEDSZ;
buflen = sizeof(newmsg) - (cp - newmsg);
cname = 0;
try_again:
dprintf(1, (ddt, "resp: nlookup(%s) qtype=%d\n", dname, qtype));
fname = "";
htp = hashtab; /* lookup relative to root */
np = nlookup(dname, &htp, &fname, 0);
dprintf(1, (ddt, "resp: %s '%s' as '%s' (cname=%d)\n",
np == NULL ? "missed" : "found", dname, fname, cname));
if (np == NULL || fname != dname)
goto fetch_ns;
foundname++;
count = cp - newmsg;
n = finddata(np, qclass, qtype, hp, &dname, &buflen, &count);
if (n == 0)
goto fetch_ns; /* NO data available */
#ifdef NCACHE
if (hp->rcode) {
if (hp->rcode == NOERROR_NODATA)
hp->rcode = NOERROR;
#ifdef RETURNSOA
if (count) {
cp += n;
buflen -= n;
hp->nscount = htons((u_int16_t)count);
}
#endif
goto return_newmsg;
}
#endif
cp += n;
buflen -= n;
hp->ancount = htons(ntohs(hp->ancount) + (u_int16_t)count);
if (fname != dname && qtype != T_CNAME && qtype != T_ANY) {
cname++;
goto try_again;
}
founddata = 1;
dprintf(3, (ddt,
"resp: foundname=%d, count=%d, founddata=%d, cname=%d\n",
foundname, count, founddata, cname));
fetch_ns:
if (hp->tc)
goto return_newmsg;
/*
* Look for name servers to refer to and fill in the authority
* section or record the address for forwarding the query
* (recursion desired).
*/
free_nsp(nsp);
switch (findns(&np, qclass, nsp, &count, 0)) {
case NXDOMAIN: /* shouldn't happen */
dprintf(3, (ddt, "req: leaving (%s, rcode %d)\n",
dname, hp->rcode));
if (!foundname)
hp->rcode = NXDOMAIN;
if (qclass != C_ANY) {
hp->aa = 1;
if (np && (!foundname || !founddata)) {
n = doaddauth(hp, cp, buflen, np, nsp[0]);
cp += n;
buflen -= n;
}
}
goto return_newmsg;
case SERVFAIL:
goto servfail;
}
if (founddata) {
hp = (HEADER *)newmsg;
n = add_data(np, nsp, cp, buflen, &count);
if (n < 0) {
hp->tc = 1;
n = (-n);
}
cp += n;
buflen -= n;
hp->nscount = htons((u_int16_t)count);
goto return_newmsg;
}
/*
* If we get here, we don't have the answer yet and are about
* to iterate to try and get it. First, infinite loop avoidance.
*/
if (qp->q_nqueries++ > MAXQUERIES) {
dprintf(1, (ddt, "resp: MAXQUERIES exceeded (%s %s %s)\n",
dname, p_class(qclass), p_type(qtype)));
syslog(LOG_INFO,
"MAXQUERIES exceeded, possible data loop in resolving (%s)",
dname);
goto servfail;
}
/* Reset the query control structure */
nsfree(qp, "ns_resp");
qp->q_naddr = 0;
qp->q_curaddr = 0;
qp->q_fwd = fwdtab;
getname(np, tmpdomain, sizeof tmpdomain);
if (qp->q_domain != NULL)
free(qp->q_domain);
qp->q_domain = strdup(tmpdomain);
if (qp->q_domain == NULL)
panic(ENOMEM, "ns_resp: strdup failed");
if ((n = nslookup(nsp, qp, dname, "ns_resp")) <= 0) {
if (n < 0) {
dprintf(3, (ddt, "resp: nslookup reports danger\n"));
if (cname) /* a remote CNAME that does not have data */
goto return_newmsg;
goto servfail;
} else {
dprintf(3, (ddt, "resp: no addrs found for NS's\n"));
/*
* Timeout while sysquery looks up the NS addresses.
*
* Hopefully we'll have them when the client asks
* again.
*
* too bad we can't just wait for the sysquery
* response to restart this query (it's too hard).
*
* We could try to crawl back up the tree looking
* for reachable servers, but we may have just
* gotten delegated down here by a response with
* no A RRs for the servers. If we blindly tried
* this strategy, we bang on the same server forever.
*/
goto timeout;
}
}
for (n = 0; (u_int)n < qp->q_naddr; n++)
qp->q_addr[n].stime.tv_sec = 0;
if (!qp->q_fwd)
qp->q_addr[0].stime = tt;
if (cname) {
if (qp->q_cname++ == MAXCNAMES) {
dprintf(3, (ddt,
"resp: leaving, MAXCNAMES exceeded\n"));
goto servfail;
}
dprintf(1, (ddt, "q_cname = %d\n", qp->q_cname));
dprintf(3, (ddt,
"resp: building recursive query; nslookup\n"));
if (!qp->q_cmsg) {
qp->q_cmsg = qp->q_msg;
qp->q_cmsglen = qp->q_msglen;
} else if (qp->q_msg)
(void) free(qp->q_msg);
if ((qp->q_msg = (u_char *)malloc(PACKETSZ)) == NULL) {
syslog(LOG_NOTICE, "resp: malloc error\n");
goto servfail;
}
n = res_mkquery(QUERY, dname, qclass, qtype,
NULL, 0, NULL, qp->q_msg, PACKETSZ);
if (n < 0) {
syslog(LOG_INFO, "resp: res_mkquery(%s) failed",
dname);
goto servfail;
}
if (qp->q_name != NULL)
free(qp->q_name);
qp->q_name = savestr(dname);
qp->q_msglen = n;
hp = (HEADER *) qp->q_msg;
hp->rd = 0;
} else
hp = (HEADER *) qp->q_msg;
hp->id = qp->q_nsid = htons(nsid_next());
if (qp->q_fwd)
hp->rd = 1;
unsched(qp);
schedretry(qp, retrytime(qp));
nsa = Q_NEXTADDR(qp, 0);
dprintf(1, (ddt, "resp: forw -> %s ds=%d nsid=%d id=%d %dms\n",
sin_ntoa(nsa), ds,
ntohs(qp->q_nsid), ntohs(qp->q_id),
(qp->q_addr[0].nsdata != NULL)
? qp->q_addr[0].nsdata->d_nstime
: (-1)));
#ifdef DEBUG
if (debug >= 10)
fp_nquery(qp->q_msg, qp->q_msglen, ddt);
#endif
if (sendto(ds, (char*)qp->q_msg, qp->q_msglen, 0,
(struct sockaddr *)nsa,
sizeof(struct sockaddr_in)) < 0) {
if (!haveComplained((char*)nsa->sin_addr.s_addr, sendtoStr))
syslog(LOG_INFO, "ns_resp: sendto(%s): %m",
sin_ntoa(nsa));
nameserIncr(nsa->sin_addr, nssSendtoErr);
}
hp->rd = 0; /* leave set to 0 for dup detection */
#ifdef XSTATS
nameserIncr(nsa->sin_addr, nssSentFwdR);
#endif
nameserIncr(qp->q_from.sin_addr, nssRcvdFwdR);
dprintf(3, (ddt, "resp: Query sent.\n"));
free_nsp(nsp);
return;
formerr:
if (!haveComplained((char*)from_addr.sin_addr.s_addr,
(char*)nhash(formerrmsg)))
syslog(LOG_INFO, "Malformed response from %s (%s)\n",
sin_ntoa(&from_addr), formerrmsg);
#ifdef XSTATS
nameserIncr(from_addr.sin_addr, nssSentFErr);
#endif
free_nsp(nsp);
return;
return_msg:
nameserIncr(from_addr.sin_addr, nssRcvdFwdR);
#ifdef XSTATS
nameserIncr(qp->q_from.sin_addr, nssSentFwdR);
#endif
/* The "standard" return code */
hp->qr = 1;
hp->id = qp->q_id;
hp->rd = 1;
hp->ra = (NoRecurse == 0);
(void) send_msg(msg, msglen, qp);
qremove(qp);
free_nsp(nsp);
return;
return_newmsg:
nameserIncr(qp->q_from.sin_addr, nssSentAns);
#ifdef XSTATS
if (!hp->aa)
nameserIncr(qp->q_from.sin_addr, nssSentNaAns);
if (hp->rcode == NXDOMAIN)
nameserIncr(qp->q_from.sin_addr, nssSentNXD);
#endif
n = doaddinfo(hp, cp, buflen);
cp += n;
buflen -= n;
hp->qr = 1;
hp->id = qp->q_id;
hp->rd = 1;
hp->ra = (NoRecurse == 0);
(void) send_msg(newmsg, cp - newmsg, qp);
qremove(qp);
free_nsp(nsp);
return;
servfail:
#ifdef XSTATS
nameserIncr(qp->q_from.sin_addr, nssSentFail);
#endif
hp = (HEADER *)(qp->q_cmsglen ? qp->q_cmsg : qp->q_msg);
hp->rcode = SERVFAIL;
hp->qr = 1;
hp->id = qp->q_id;
hp->rd = 1;
hp->ra = (NoRecurse == 0);
(void) send_msg((u_char *)hp, (qp->q_cmsglen ? qp->q_cmsglen : qp->q_msglen),
qp);
timeout:
if (qp->q_stream != QSTREAM_NULL)
sqrm(qp->q_stream);
qremove(qp);
free_nsp(nsp);
return;
}
static int
rrextract(msg, msglen, rrp, dpp, dname, namelen, tnamep)
u_char *msg;
int msglen;
u_char *rrp;
struct databuf **dpp;
char *dname;
int namelen;
char **tnamep;
{
register u_char *cp;
register int n;
int class, type, dlen, n1;
u_int32_t ttl;
u_char *cp1;
u_char data[MAXDNAME*2 + INT32SZ*5];
register HEADER *hp = (HEADER *)msg;
enum context context;
if (tnamep != NULL)
*tnamep = NULL;
*dpp = NULL;
cp = rrp;
if ((n = dn_expand(msg, msg + msglen, cp, dname, namelen)) < 0) {
hp->rcode = FORMERR;
return (-1);
}
cp += n;
GETSHORT(type, cp);
GETSHORT(class, cp);
GETLONG(ttl, cp);
GETSHORT(dlen, cp);
if (!ns_nameok(dname, class, response_trans,
ns_ownercontext(type, response_trans),
dname, from_addr.sin_addr)) {
hp->rcode = FORMERR;
return (-1);
}
dprintf(3, (ddt, "rrextract: dname %s type %d class %d ttl %d\n",
dname, type, class, ttl));
/*
* Convert the resource record data into the internal
* database format.
*
* On entry to the switch:
* CP points to the RDATA section of the wire-format RR.
* DLEN is its length.
* The memory area at DATA is available for processing.
*
* On exit from the switch:
* CP has been incremented past the RR.
* CP1 points to the RDATA section of the database-format RR.
* N contains the length of the RDATA section of the dbase-format RR.
*
* The new data at CP1 for length N will be copied into the database,
* so it need not be in any particular storage location.
*/
switch (type) {
case T_A:
if (dlen != INT32SZ) {
hp->rcode = FORMERR;
return (-1);
}
/*FALLTHROUGH*/
case T_WKS:
case T_HINFO:
case T_UINFO:
case T_UID:
case T_GID:
case T_TXT:
case T_X25:
case T_ISDN:
case T_NSAP:
case T_AAAA:
case T_LOC:
case T_KEY:
#ifdef ALLOW_T_UNSPEC
case T_UNSPEC:
#endif
cp1 = cp;
n = dlen;
cp += n;
break;
case T_CNAME:
case T_MB:
case T_MG:
case T_MR:
case T_NS:
case T_PTR:
n = dn_expand(msg, msg + msglen, cp,
(char *)data, sizeof data);
if (n < 0) {
hp->rcode = FORMERR;
return (-1);
}
if (!ns_nameok((char *)data, class, response_trans,
type == T_PTR ?ns_ptrcontext(dname) :domain_ctx,
dname, from_addr.sin_addr)) {
hp->rcode = FORMERR;
return (-1);
}
cp += n;
cp1 = data;
n = strlen((char *)data) + 1;
if (tnamep != NULL && (type == T_NS || type == T_MB))
*tnamep = strdup((char *)cp1);
break;
case T_SOA:
context = hostname_ctx;
goto soa_rp_minfo;
case T_RP:
case T_MINFO:
context = mailname_ctx;
/* FALLTHROUGH */
soa_rp_minfo:
n = dn_expand(msg, msg + msglen, cp,
(char *)data, sizeof data);
if (n < 0) {
hp->rcode = FORMERR;
return (-1);
}
if (!ns_nameok((char *)data, class, response_trans, context,
dname, from_addr.sin_addr)) {
hp->rcode = FORMERR;
return (-1);
}
cp += n;
cp1 = data + (n = strlen((char *)data) + 1);
n1 = sizeof(data) - n;
if (type == T_SOA)
n1 -= 5 * INT32SZ;
n = dn_expand(msg, msg + msglen, cp, (char *)cp1, n1);
if (n < 0) {
hp->rcode = FORMERR;
return (-1);
}
if (type == T_RP)
context = domain_ctx;
else
context = mailname_ctx;
if (!ns_nameok((char *)cp1, class, response_trans, context,
dname, from_addr.sin_addr)) {
hp->rcode = FORMERR;
return (-1);
}
cp += n;
cp1 += strlen((char *)cp1) + 1;
if (type == T_SOA) {
bcopy(cp, cp1, n = 5 * INT32SZ);
cp += n;
cp1 += n;
}
n = cp1 - data;
cp1 = data;
break;
case T_NAPTR:
/* Grab weight and port. */
bcopy(cp, data, INT16SZ*2);
cp1 = data + INT16SZ*2;
cp += INT16SZ*2;
/* Flags */
n = *cp++;
*cp1++ = n;
bcopy(cp, cp1, n);
cp += n; cp1 += n;
/* Service */
n = *cp++;
*cp1++ = n;
bcopy(cp, cp1, n);
cp += n; cp1 += n;
/* Regexp */
n = *cp++;
*cp1++ = n;
bcopy(cp, cp1, n);
cp += n; cp1 += n;
/* Replacement */
n = dn_expand(msg, msg + msglen, cp, (char *)cp1,
sizeof data - (cp1 - data));
if (n < 0) {
hp->rcode = FORMERR;
return (-1);
}
if (!ns_nameok((char *)cp1, class, response_trans,
hostname_ctx, dname, from_addr.sin_addr)) {
hp->rcode = FORMERR;
return (-1);
}
cp += n;
/* compute end of data */
cp1 += strlen((char *)cp1) + 1;
/* compute size of data */
n = cp1 - data;
cp1 = data;
break;
case T_MX:
case T_AFSDB:
case T_RT:
case T_SRV:
/* grab preference */
bcopy(cp, data, INT16SZ);
cp1 = data + INT16SZ;
cp += INT16SZ;
if (type == T_SRV) {
/* Grab weight and port. */
bcopy(cp, cp1, INT16SZ*2);
cp1 += INT16SZ*2;
cp += INT16SZ*2;
}
/* get name */
n = dn_expand(msg, msg + msglen, cp, (char *)cp1,
sizeof data - (cp1 - data));
if (n < 0) {
hp->rcode = FORMERR;
return (-1);
}
if (!ns_nameok((char *)cp1, class, response_trans,
hostname_ctx, dname, from_addr.sin_addr)) {
hp->rcode = FORMERR;
return (-1);
}
cp += n;
if (tnamep != NULL)
*tnamep = strdup((char *)cp1);
/* compute end of data */
cp1 += strlen((char *)cp1) + 1;
/* compute size of data */
n = cp1 - data;
cp1 = data;
break;
case T_PX:
/* grab preference */
bcopy(cp, data, INT16SZ);
cp1 = data + INT16SZ;
cp += INT16SZ;
/* get MAP822 name */
n = dn_expand(msg, msg + msglen, cp, (char *)cp1,
sizeof data - INT16SZ);
if (n < 0) {
hp->rcode = FORMERR;
return (-1);
}
if (!ns_nameok((char *)cp1, class, response_trans,
domain_ctx, dname, from_addr.sin_addr)) {
hp->rcode = FORMERR;
return (-1);
}
cp += n;
cp1 += (n = strlen((char *)cp1) + 1);
n1 = sizeof(data) - n;
n = dn_expand(msg, msg + msglen, cp, (char *)cp1, n1);
if (n < 0) {
hp->rcode = FORMERR;
return (-1);
}
if (!ns_nameok((char *)cp1, class, response_trans,
domain_ctx, dname, from_addr.sin_addr)) {
hp->rcode = FORMERR;
return (-1);
}
cp += n;
cp1 += strlen((char *)cp1) + 1;
n = cp1 - data;
cp1 = data;
break;
case T_SIG: {
u_long origTTL, exptime, signtime, timetilexp, now;
/* Check signature time, expiration, and adjust TTL. */
/* This code is similar to that in db_load.c. */
/* Skip coveredType, alg, labels */
cp1 = cp + INT16SZ + 1 + 1;
GETLONG(origTTL, cp1);
GETLONG(exptime, cp1);
GETLONG(signtime, cp1);
now = time(NULL); /* Get current time in GMT/UTC */
/* Don't let bogus name servers increase the signed TTL */
if (ttl > origTTL) {
dprintf(3, (ddt,
"shrinking SIG TTL from %d to origTTL %d\n",
ttl, origTTL));
ttl = origTTL;
}
/* Don't let bogus signers "sign" in the future. */
if (signtime > now) {
dprintf(3, (ddt,
"ignoring SIG: signature date %s is in the future\n",
p_secstodate (signtime)));
return ((cp - rrp) + dlen);
}
/* Ignore received SIG RR's that are already expired. */
if (exptime <= now) {
dprintf(3, (ddt,
"ignoring SIG: expiration %s is in the past\n",
p_secstodate (exptime)));
return ((cp - rrp) + dlen);
}
/* Lop off the TTL at the expiration time. */
timetilexp = exptime - now;
if (timetilexp < ttl) {
dprintf(3, (ddt,
"shrinking expiring %s SIG TTL from %d to %d\n",
p_secstodate (exptime), ttl, timetilexp));
ttl = timetilexp;
}
/* The following code is copied from named-xfer.c. */
cp1 = (u_char *)data;
/* first just copy over the type_covered, algorithm, */
/* labels, orig ttl, two timestamps, and the footprint */
bcopy(cp, cp1, 18);
cp += 18;
cp1 += 18;
/* then the signer's name */
n = dn_expand(msg, msg + msglen, cp,
(char *)cp1, (sizeof data) - 18);
if (n < 0)
return (-1);
cp += n;
cp1 += strlen((char*)cp1)+1;
/* finally, we copy over the variable-length signature.
Its size is the total data length, minus what we copied. */
n = dlen - (18 + n);
if (n > (sizeof data) - (cp1 - (u_char *)data))
return (-1); /* out of room! */
bcopy(cp, cp1, n);
cp += n;
cp1 += n;
/* compute size of data */
n = cp1 - (u_char *)data;
cp1 = (u_char *)data;
break;
}
default:
dprintf(3, (ddt, "unknown type %d\n", type));
return ((cp - rrp) + dlen);
}
if (n > MAXDATA) {
dprintf(1, (ddt,
"update type %d: %d bytes is too much data\n",
type, n));
hp->rcode = FORMERR;
return (-1);
}
ttl += tt.tv_sec;
*dpp = savedata(class, type, ttl, cp1, n);
return (cp - rrp);
}
/*
* Decode the resource record 'rrp' and update the database.
* If savens is non-nil, record pointer for forwarding queries a second time.
*/
int
doupdate(msg, msglen, rrp, zone, savens, flags, cred)
u_char *msg;
int msglen;
u_char *rrp;
int zone;
struct databuf **savens;
int flags;
u_int cred;
{
register u_char *cp;
register int n;
int class, type;
struct databuf *dp;
char dname[MAXDNAME];
dprintf(3, (ddt, "doupdate(zone %d, savens %#lx, flags %#lx)\n",
zone, (u_long)savens, (u_long)flags));
if ((n = rrextract(msg, msglen, rrp, &dp, dname, sizeof(dname), NULL))
== -1)
return (-1);
if (!dp)
return (-1);
type = dp->d_type;
class = dp->d_class;
cp = rrp + n;
#if defined(TRACEROOT) || defined(BOGUSNS)
if ((type == T_NS) && (savens != NULL)) {
char *temp, qname[MAXDNAME];
register int bogus = 0;
int bogusns = 0;
#ifdef BOGUSNS
if (addr_on_netlist(from_addr.sin_addr, boglist)) {
bogusns++;
bogus++;
}
#endif
if (!bogus &&
((temp = strrchr((char *)dp->d_data, '.')) != NULL) &&
!strcasecmp(temp, ".arpa")
)
bogus++;
qname[0] = qname[1] = '\0';
if (dn_expand(msg, msg + msglen, msg + HFIXEDSZ,
qname, sizeof(qname)) < 0)
qname[0] = '?';
else if (qname[0] == '\0')
qname[0] = '.';
if (bogus && ((dname[0] == '\0') && (zone == 0))) {
if (!haveComplained((char*)from_addr.sin_addr.s_addr,
"bogus root NS"))
syslog(LOG_NOTICE,
"bogus root NS %s rcvd from %s on query for \"%s\"",
dp->d_data, sin_ntoa(&from_addr), qname);
db_free(dp);
return (cp - rrp);
}
#ifdef BOGUSNS
if (bogusns) {
if (!haveComplained((char*)from_addr.sin_addr.s_addr,
"bogus nonroot NS"))
syslog(LOG_INFO,
"bogus nonroot NS %s rcvd from %s on query for \"%s\"",
dp->d_data, sin_ntoa(&from_addr), qname);
db_free(dp);
return (cp - rrp);
}
#endif
}
#endif /*TRACEROOT || BOGUSNS*/
dp->d_zone = zone;
dp->d_cred = cred;
dp->d_clev = 0; /* We trust what is on disk more, except root srvrs */
if ((n = db_update(dname, dp, dp, flags, hashtab)) != OK) {
#ifdef DEBUG
if (debug && (n != DATAEXISTS))
fprintf(ddt, "update failed (%d)\n", n);
else if (debug >= 3)
fprintf(ddt, "update failed (DATAEXISTS)\n");
#endif
db_free(dp);
} else if (type == T_NS && savens != NULL)
*savens = dp;
return (cp - rrp);
}
int
send_msg(msg, msglen, qp)
u_char *msg;
int msglen;
struct qinfo *qp;
{
if (qp->q_flags & Q_SYSTEM)
return (1);
#ifdef DEBUG
if (debug) {
fprintf(ddt,"send_msg -> %s (%s %d) id=%d\n",
sin_ntoa(&qp->q_from),
qp->q_stream == QSTREAM_NULL ? "UDP" : "TCP",
qp->q_stream == QSTREAM_NULL ? qp->q_dfd
: qp->q_stream->s_rfd,
ntohs(qp->q_id));
}
if (debug > 4) {
struct qinfo *tqp;
for (tqp = nsqhead; tqp!=QINFO_NULL; tqp = tqp->q_link) {
fprintf(ddt,
"qp %#lx q_id: %d q_nsid: %d q_msglen: %d ",
(u_long)tqp, tqp->q_id,
tqp->q_nsid, tqp->q_msglen);
fprintf(ddt,
"q_naddr: %d q_curaddr: %d\n",
tqp->q_naddr, tqp->q_curaddr);
fprintf(ddt, "q_next: %#lx q_link: %#lx\n",
(u_long)qp->q_next, (u_long)qp->q_link);
}
}
if (debug > 5)
fp_nquery(msg, msglen, ddt);
#endif /* DEBUG */
if (qp->q_stream == QSTREAM_NULL) {
if (sendto(qp->q_dfd, (char*)msg, msglen, 0,
(struct sockaddr *)&qp->q_from,
sizeof(qp->q_from)) < 0) {
if (!haveComplained((char*)qp->q_from.sin_addr.s_addr,
sendtoStr))
#if defined(SPURIOUS_ECONNREFUSED)
if (errno != ECONNREFUSED)
#endif
syslog(LOG_INFO,
"send_msg: sendto(%s): %m",
sin_ntoa(&qp->q_from));
nameserIncr(qp->q_from.sin_addr, nssSendtoErr);
return (1);
}
} else {
(void) writemsg(qp->q_stream->s_rfd, (u_char*)msg, msglen);
sq_done(qp->q_stream);
}
return (0);
}
#ifdef notdef
/* i don't quite understand this but the only ref to it is notdef'd --vix */
prime(class, type, oqp)
int class, type;
register struct qinfo *oqp;
{
char dname[BUFSIZ];
if (oqp->q_msg == NULL)
return;
if (dn_expand((u_char *)oqp->q_msg,
(u_char *)oqp->q_msg + oqp->q_msglen,
(u_char *)oqp->q_msg + HFIXEDSZ, (u_char *)dname,
sizeof(dname)) < 0)
return;
dprintf(2, (ddt, "prime: %s\n", dname));
(void) sysquery(dname, class, type, NULL, 0, QUERY);
}
#endif
void
prime_cache()
{
register struct qinfo *qp;
dprintf(1, (ddt, "prime_cache: priming = %d\n", priming));
if (!priming && fcachetab->h_tab[0] != NULL && !forward_only) {
priming++;
if (!(qp = sysquery("", C_IN, T_NS, NULL, 0, QUERY)))
priming = 0;
else
qp->q_flags |= (Q_SYSTEM | Q_PRIMING);
}
needs_prime_cache = 0;
return;
}
#ifdef BIND_NOTIFY
struct notify *
findNotifyPeer(zp, ina)
const struct zoneinfo *zp;
struct in_addr ina;
{
register struct notify *ap;
for (ap = zp->z_notifylist; ap; ap = ap->next)
if (ap->addr.s_addr == ina.s_addr)
break;
return (ap);
}
/* sysnotify(dname, class, type)
* cause a NOTIFY request to be sysquery()'d to each secondary server
* of the zone that "dname" is within.
*/
void
sysnotify(dname, class, type)
const char *dname;
int class, type;
{
char *soaname, *zname;
const char *fname;
register struct databuf *dp;
struct in_addr nss[NSMAX];
int nns, na, zn, nsc;
struct hashbuf *htp;
struct zoneinfo *zp;
struct notify *ap;
struct namebuf *np;
htp = hashtab;
np = nlookup(dname, &htp, &fname, 0);
if (!np)
panic(-1, "sysnotify: can't find name");
zn = findMyZone(np, class);
if (zn == DB_Z_CACHE)
panic(-1, "sysnotify: not auth zone");
zp = &zones[zn];
if (zp->z_type != Z_PRIMARY && zp->z_type != Z_SECONDARY)
panic(-1, "sysnotify: not pri/sec");
zname = zp->z_origin;
/*
**DBG** syslog(LOG_INFO, "sysnotify: found \"%s\" in \"%s\" (%s)",
**DBG** dname, zname, zoneTypeString(zp));
*/
nns = na = 0;
/*
* Send to recent AXFR peers.
*/
for (ap = zp->z_notifylist; ap; ap = ap->next) {
if (tt.tv_sec - ap->last >= zp->z_refresh) {
/* XXX - probably should do GC here. */
continue;
}
nss[0] = ap->addr;
nsc = 1;
nns++;
na++;
sysquery(dname, class, T_SOA, nss, nsc, NS_NOTIFY_OP);
}
if (zp->z_type != Z_PRIMARY)
goto done;
/*
* Master.
*/
htp = hashtab;
np = nlookup(zname, &htp, &fname, 0);
if (!np)
panic(-1, "sysnotify: found name but not zone");
soaname = NULL;
for (dp = np->n_data; dp; dp = dp->d_next) {
if (!dp->d_zone || !match(dp, class, T_SOA))
continue;
if (soaname) {
syslog(LOG_NOTICE, "multiple SOA's for zone \"%s\"?",
zname);
return;
}
soaname = (char *) dp->d_data;
}
if (!soaname) {
syslog(LOG_NOTICE, "no SOA found for zone \"%s\"", zname);
return;
}
for (dp = np->n_data; dp; dp = dp->d_next) {
register struct databuf *adp;
struct namebuf *anp;
if (!dp->d_zone || !match(dp, class, T_NS))
continue;
/* NS RDATA is server name. */
if (strcasecmp((char*)dp->d_data, soaname) == 0)
continue;
htp = hashtab;
anp = nlookup((char*)dp->d_data, &htp, &fname, 0);
if (!anp) {
syslog(LOG_INFO, "sysnotify: can't nlookup(%s)?",
(char*)dp->d_data);
continue;
}
nsc = 0;
for (adp = anp->n_data; adp; adp = adp->d_next) {
struct in_addr ina;
if (!match(adp, class, T_A))
continue;
ina = data_inaddr(adp->d_data);
/* Don't send to things we handled above. */
ap = findNotifyPeer(zp, ina);
if (ap && tt.tv_sec - ap->last < zp->z_refresh)
goto nextns;
if (nsc < NSMAX)
nss[nsc++] = ina;
} /*next A*/
if (nsc == 0) {
struct qinfo *qp;
qp = sysquery((char*)dp->d_data, /*NS name*/
class, /*XXX: C_IN?*/
T_A, 0, 0, QUERY);
if (qp)
qp->q_notifyzone = zn;
continue;
}
(void) sysquery(dname, class, T_SOA, nss, nsc, NS_NOTIFY_OP);
nns++;
na += nsc;
nextns:;
} /*next NS*/
done:
if (nns || na) {
char tmp[MAXDNAME];
/* Many syslog()'s only take 5 args. */
sprintf(tmp, "%s %s %s", dname, p_class(class), p_type(type));
syslog(LOG_INFO, "Sent NOTIFY for \"%s\" (%s); %d NS, %d A",
tmp, zname, nns, na);
}
}
#endif /*BIND_NOTIFY*/
struct qinfo *
sysquery(dname, class, type, nss, nsc, opcode)
const char *dname;
int class, type;
struct in_addr *nss;
int nsc, opcode;
{
register struct qinfo *qp, *oqp;
register HEADER *hp;
char tmpdomain[MAXDNAME];
struct namebuf *np;
struct databuf *nsp[NSMAX];
struct hashbuf *htp;
struct sockaddr_in *nsa;
const char *fname;
int n, count;
nsp[0] = NULL;
dprintf(3, (ddt, "sysquery(%s, %d, %d, %#lx, %d)\n",
dname, class, type, (u_long)nss, nsc));
qp = qnew(dname, class, type);
if (nss && nsc) {
np = NULL;
} else {
htp = hashtab;
if (priming && dname[0] == '\0') {
np = NULL;
} else if ((np = nlookup(dname, &htp, &fname, 1)) == NULL) {
syslog(LOG_INFO, "sysquery: nlookup error on %s?",
dname);
err1:
qfree(qp);
return (NULL);
}
n = findns(&np, class, nsp, &count, 0);
switch (n) {
case NXDOMAIN:
case SERVFAIL:
syslog(LOG_DEBUG, "sysquery: findns error (%s) on %s?",
n == NXDOMAIN ? "NXDOMAIN" : "SERVFAIL", dname);
err2:
free_nsp(nsp);
goto err1;
}
}
/* build new qinfo struct */
qp->q_cmsg = qp->q_msg = NULL;
qp->q_dfd = ds;
if (nss && nsc)
qp->q_fwd = NULL;
else
qp->q_fwd = fwdtab;
qp->q_expire = tt.tv_sec + RETRY_TIMEOUT*2;
qp->q_flags |= Q_SYSTEM;
getname(np, tmpdomain, sizeof tmpdomain);
if (qp->q_domain != NULL)
free(qp->q_domain);
qp->q_domain = strdup(tmpdomain);
if (qp->q_domain == NULL)
panic(ENOMEM, "ns_resp: strdup failed");
if ((qp->q_msg = (u_char *)malloc(PACKETSZ)) == NULL) {
syslog(LOG_NOTICE, "sysquery: malloc failed");
goto err2;
}
n = res_mkquery(opcode, dname, class,
type, NULL, 0, NULL,
qp->q_msg, PACKETSZ);
if (n < 0) {
syslog(LOG_INFO, "sysquery: res_mkquery(%s) failed", dname);
goto err2;
}
qp->q_msglen = n;
hp = (HEADER *) qp->q_msg;
hp->id = qp->q_nsid = htons(nsid_next());
hp->rd = (qp->q_fwd ? 1 : 0);
/* First check for an already pending query for this data */
for (oqp = nsqhead; oqp != QINFO_NULL; oqp = oqp->q_link) {
if ((oqp != qp)
&& (oqp->q_msglen == qp->q_msglen)
&& bcmp((char *)oqp->q_msg+2,
qp->q_msg+2,
qp->q_msglen-2) == 0
) {
#ifdef BIND_NOTIFY
/* XXX - need fancier test to suppress duplicate
* NOTIFYs to the same server (compare nss?)
*/
if (opcode != NS_NOTIFY_OP)
#endif /*BIND_NOTIFY*/
{
dprintf(3, (ddt, "sysquery: duplicate\n"));
goto err2;
}
}
}
if (nss && nsc) {
int i;
struct qserv *qs;
for (i = 0, qs = qp->q_addr;
i < nsc;
i++, qs++) {
qs->ns_addr.sin_family = AF_INET;
qs->ns_addr.sin_addr = nss[i];
qs->ns_addr.sin_port = ns_port;
qs->ns = NULL;
qs->nsdata = NULL;
qs->stime = tt;
qs->nretry = 0;
}
qp->q_naddr = nsc;
} else {
fetch_a:
count = nslookup(nsp, qp, dname, "sysquery");
if (count <= 0) {
if (count < 0) {
syslog(LOG_INFO,
"sysquery: nslookup reports danger (%s)",
dname);
goto err2;
} else if (np && NAME(*np)[0] == '\0') {
syslog(LOG_WARNING,
"sysquery: no addrs found for root NS (%s)",
dname);
if (class == C_IN && !priming)
needs_prime_cache = 1;
goto err2;
}
if (np) {
free_nsp(nsp);
nsp[0] = NULL;
np = np_parent(np);
n = findns(&np, class, nsp, &count, 0);
switch (n) {
case NXDOMAIN: /*FALLTHROUGH*/
case SERVFAIL:
syslog(LOG_DEBUG,
"sysquery: findns error (%d) on %s?",
n, dname);
goto err2;
}
goto fetch_a;
}
goto err2;
}
}
schedretry(qp, retrytime(qp));
if (qp->q_fwd == NULL)
qp->q_addr[0].stime = tt; /* XXX - why not every? */
nsa = Q_NEXTADDR(qp, 0);
dprintf(1, (ddt,
"sysquery: send -> %s dfd=%d nsid=%d id=%d retry=%ld\n",
sin_ntoa(nsa), qp->q_dfd,
ntohs(qp->q_nsid), ntohs(qp->q_id),
(long)qp->q_time));
#ifdef DEBUG
if (debug >= 10)
fp_nquery(qp->q_msg, qp->q_msglen, ddt);
#endif
if (sendto(qp->q_dfd, (char*)qp->q_msg, qp->q_msglen, 0,
(struct sockaddr *)nsa,
sizeof(struct sockaddr_in)) < 0) {
if (!haveComplained((char*)nsa->sin_addr.s_addr, sendtoStr))
syslog(LOG_INFO, "sysquery: sendto(%s): %m",
sin_ntoa(nsa));
nameserIncr(nsa->sin_addr, nssSendtoErr);
}
nameserIncr(nsa->sin_addr, nssSentSysQ);
free_nsp(nsp);
return (qp);
}
/*
* Check the list of root servers after receiving a response
* to a query for the root servers.
*/
static int
check_root()
{
register struct databuf *dp, *pdp;
register struct namebuf *np;
int count = 0;
priming = 0;
for (np = hashtab->h_tab[0]; np != NULL; np = np->n_next)
if (NAME(*np)[0] == '\0')
break;
if (np == NULL) {
syslog(LOG_NOTICE, "check_root: Can't find root!\n");
return (0);
}
for (dp = np->n_data; dp != NULL; dp = dp->d_next)
if (dp->d_type == T_NS)
count++;
dprintf(1, (ddt, "%d root servers\n", count));
if (count < MINROOTS) {
syslog(LOG_NOTICE,
"check_root: %d root servers after query to root server < min",
count);
return (0);
}
pdp = NULL;
dp = np->n_data;
while (dp != NULL) {
if (dp->d_type == T_NS && dp->d_zone == 0 &&
dp->d_ttl < tt.tv_sec) {
dprintf(1, (ddt, "deleting old root server '%s'\n",
dp->d_data));
dp = rm_datum(dp, np, pdp);
/* SHOULD DELETE FROM HINTS ALSO */
continue;
}
pdp = dp;
dp = dp->d_next;
}
if (check_ns())
return (1);
else {
priming = 1;
return (0);
}
}
/*
* Check the root to make sure that for each NS record we have a A RR
*/
static int
check_ns()
{
register struct databuf *dp, *tdp;
register struct namebuf *np, *tnp;
struct hashbuf *htp;
char *dname;
int found_arr;
const char *fname;
time_t curtime;
int servers = 0, rrsets = 0;
dprintf(2, (ddt, "check_ns()\n"));
curtime = (u_int32_t) tt.tv_sec;
for (np = hashtab->h_tab[0]; np != NULL; np = np->n_next) {
if (NAME(*np)[0] != '\0')
continue;
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
int cnames = 0;
#ifdef NCACHE
if (dp->d_rcode)
continue;
#endif
if (dp->d_type != T_NS)
continue;
servers++;
/* look for A records */
dname = (caddr_t) dp->d_data;
htp = hashtab;
tnp = nlookup(dname, &htp, &fname, 0);
if (tnp == NULL || fname != dname) {
dprintf(3, (ddt,
"check_ns: %s: not found %s %#lx\n",
dname, fname, (u_long)tnp));
sysquery(dname, dp->d_class, T_A, NULL,
0, QUERY);
continue;
}
/* look for name server addresses */
found_arr = 0;
delete_stale(tnp);
for (tdp = tnp->n_data;
tdp != NULL;
tdp = tdp->d_next) {
#ifdef NCACHE
if (tdp->d_rcode)
continue;
#endif
if (tdp->d_type == T_CNAME)
cnames++;
if (tdp->d_type != T_A ||
tdp->d_class != dp->d_class)
continue;
if ((tdp->d_zone == 0) &&
(tdp->d_ttl < curtime)) {
dprintf(3, (ddt,
"check_ns: stale entry '%s'\n",
NAME(*tnp)));
found_arr = 0;
break;
}
found_arr++;
}
if (found_arr)
rrsets++;
else if (cnames > 0)
syslog(LOG_INFO, "Root NS %s -> CNAME %s",
NAME(*np), NAME(*tnp));
else
sysquery(dname, dp->d_class, T_A, NULL,
0, QUERY);
}
}
dprintf(2, (ddt, "check_ns: %d %d\n", servers, rrsets));
return ((servers<=2)?(rrsets==servers):((rrsets*2)>=servers));
}
/* int findns(npp, class, nsp, countp, flag)
* Find NS's or an SOA
* npp, class:
* dname whose most enclosing NS is wanted
* nsp, countp:
* result array and count; array will also be NULL terminated
* flag:
* boolean: we're being called from ADDAUTH, bypass authority checks
* return value:
* NXDOMAIN: we are authoritative for this {dname,class}
* *countp is bogus, but nsp[] has a single SOA returned in it.
* SERVFAIL: we are auth but zone isn't loaded; or, no root servers found
* *countp and nsp[] are bogus.
* OK: we are not authoritative, and here are the NS records we found.
* *countp and nsp[] return NS records of interest.
*/
int
findns(npp, class, nsp, countp, flag)
register struct namebuf **npp;
int class;
struct databuf **nsp;
int *countp;
int flag;
{
register struct namebuf *np = *npp;
register struct databuf *dp;
register struct databuf **nspp;
struct hashbuf *htp;
nsp[0] = NULL;
if (priming && (np == NULL || NAME(*np)[0] == '\0'))
htp = fcachetab;
else
htp = hashtab;
try_again:
if (htp == fcachetab && class == C_IN && !priming)
needs_prime_cache = 1;
if (np == NULL) {
/* find the root */
for (np = htp->h_tab[0]; np != NULL; np = np->n_next)
if (NAME(*np)[0] == '\0')
break;
}
while (np != NULL) {
dprintf(5, (ddt, "findns: np %#lx '%s'\n",
(u_long)np, NAME(*np)));
/* Look first for SOA records. */
#ifdef ADDAUTH
if (!flag)
#endif
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if (dp->d_zone != 0 &&
#ifdef PURGE_ZONE
((zones[dp->d_zone].z_type == Z_PRIMARY) ||
(zones[dp->d_zone].z_type == Z_SECONDARY)) &&
#endif
match(dp, class, T_SOA)) {
dprintf(3, (ddt, "findns: SOA found\n"));
if (zones[dp->d_zone].z_flags & Z_AUTH) {
*npp = np;
nsp[0] = dp;
nsp[1] = NULL;
dp->d_rcnt++;
return (NXDOMAIN);
} else {
/* XXX: zone isn't loaded but we're
* primary or secondary for it.
* should we fwd this?
*/
return (SERVFAIL);
}
}
}
/* If no SOA records, look for NS records. */
nspp = &nsp[0];
*nspp = NULL;
delete_stale(np);
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if (!match(dp, class, T_NS))
continue;
#ifdef NCACHE
if (dp->d_rcode)
continue;
#endif
/*
* Don't use records that may become invalid to
* reference later when we do the rtt computation.
* Never delete our safety-belt information!
*
* XXX: this is horribly bogus.
*/
if ((dp->d_zone == 0) &&
(dp->d_ttl < tt.tv_sec) &&
!(dp->d_flags & DB_F_HINT)) {
dprintf(1, (ddt, "findns: stale entry '%s'\n",
NAME(*np)));
/*
* We may have already added NS databufs
* and are going to throw them away. Fix
* fix reference counts. We don't need
* free() them here as we just got them
* from the cache.
*/
while (nspp > &nsp[0])
(*--nspp)->d_rcnt--;
nsp[0] = NULL;
goto try_parent;
}
if (nspp < &nsp[NSMAX-1]) {
*nspp++ = dp;
dp->d_rcnt++;
}
}
*countp = nspp - nsp;
if (*countp > 0) {
dprintf(3, (ddt, "findns: %d NS's added for '%s'\n",
*countp, NAME(*np)));
*nspp = NULL;
*npp = np;
return (OK); /* Success, got some NS's */
}
try_parent:
np = np_parent(np);
}
if (htp == hashtab) {
htp = fcachetab;
goto try_again;
}
dprintf(1, (ddt, "findns: No root nameservers for class %s?\n",
p_class(class)));
if ((unsigned)class < MAXCLASS && norootlogged[class] == 0) {
norootlogged[class] = 1;
syslog(LOG_INFO, "No root nameservers for class %s\n",
p_class(class));
}
return (SERVFAIL);
}
/*
* Extract RR's from the given node that match class and type.
* Return number of bytes added to response.
* If no matching data is found, then 0 is returned.
*/
int
finddata(np, class, type, hp, dnamep, lenp, countp)
struct namebuf *np;
int class, type;
register HEADER *hp;
char **dnamep;
int *lenp, *countp;
{
register struct databuf *dp;
register char *cp;
int buflen, n, count = 0;
delete_stale(np);
#ifdef ROUND_ROBIN
if (type != T_ANY && type != T_PTR) {
/* cycle order of RRs, for a load balancing effect... */
register struct databuf **dpp;
for (dpp = &np->n_data; dp = *dpp; dpp = &dp->d_next) {
if (dp->d_next && wanted(dp, class, type)) {
register struct databuf *lp;
*dpp = lp = dp->d_next;
dp->d_next = NULL;
for (dpp = &lp->d_next;
*dpp;
dpp = &lp->d_next)
lp = *dpp;
*dpp = dp;
break;
}
}
}
#endif /*ROUND_ROBIN*/
buflen = *lenp;
#ifdef DEBUG
if (buflen > PACKETSZ)
dprintf(1, (ddt, "finddata(): buflen=%d\n", buflen));
#endif
cp = ((char *)hp) + *countp;
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if (!wanted(dp, class, type)) {
#ifndef NCACHE /*if no negative caching then cname => nothing else*/
if (type == T_CNAME && class == dp->d_class) {
/* any data means no CNAME exists */
*countp = 0;
return 0;
}
#endif /*NCACHE*/
continue;
}
if (dp->d_cred == DB_C_ADDITIONAL) {
#ifdef NOADDITIONAL
continue;
#else
/* we want to expire additional data very
* quickly. current strategy is to cut 5%
* off each time it is accessed. this makes
* stale(dp) true earlier when this datum is
* used often.
*/
dp->d_ttl = tt.tv_sec
+
0.95 * (int) (dp->d_ttl - tt.tv_sec);
#endif
}
#ifdef NCACHE
/* -ve $ing stuff, anant@isi.edu
* if we have a -ve $ed record, change the rcode on the
* header to reflect that
*/
if (dp->d_rcode == NOERROR_NODATA) {
if (count != 0) {
/*
* This should not happen, yet it does...
*/
syslog(LOG_INFO,
"NODATA & data for \"%s\" type %d class %d",
*dnamep, type, class);
continue;
}
if (type == T_ANY)
continue;
hp->rcode = NOERROR_NODATA;
if (dp->d_size == 0) { /* !RETURNSOA */
*countp = 0;
return 1; /* XXX - we have to report success */
}
}
if (dp->d_rcode == NXDOMAIN) {
if (count != 0) {
/*
* This should not happen, yet it might...
*/
syslog(LOG_INFO,
"NXDOMAIN & data for \"%s\" type %d class %d",
*dnamep, type, class);
continue;
}
hp->rcode = NXDOMAIN;
if (dp->d_size == 0) { /* !RETURNSOA */
*countp = 0;
return 1; /* XXX - we have to report success */
}
}
#endif /*NCACHE*/
/* Don't put anything but key or sig RR's in response to
requests for key or sig */
if (((type == T_SIG) || (type == T_KEY)) &&
(!((dp->d_type == T_SIG) || (dp->d_type == T_KEY))) )
continue;
if ((n = make_rr(*dnamep, dp, (u_char *)cp, buflen, 1)) < 0) {
hp->tc = 1;
*countp = count;
return (*lenp - buflen);
}
cp += n;
buflen -= n;
count++;
#ifdef notdef
/* this isn't right for glue records, aa is set in ns_req */
if (dp->d_zone &&
(zones[dp->d_zone].z_flags & Z_AUTH) &&
class != C_ANY)
hp->aa = 1; /* XXX */
#endif
if (dp->d_type == T_CNAME) {
/* don't alias if querying for key, sig, nxt, or any */
if ((type != T_KEY) &&
(type != T_SIG) &&
(type != T_NXT) &&
(type != T_ANY)) { /* or T_NS? */
*dnamep = (caddr_t) dp->d_data;
if (dp->d_zone != DB_Z_CACHE &&
(zones[dp->d_zone].z_flags & Z_AUTH) &&
class != C_ANY) /* XXX */
hp->aa = 1; /* XXX */
}
break;
}
}
/*
* Cache invalidate the other RR's of same type
* if some have timed out
*/
dprintf(3, (ddt, "finddata: added %d class %d type %d RRs\n",
count, class, type));
*countp = count;
return (*lenp - buflen);
}
/*
* Do we want this data record based on the class and type?
* (We always return found unexpired SIG RR's that cover the wanted rrtype.)
*/
int
wanted(dp, class, type)
struct databuf *dp;
int class, type;
{
u_char *cp;
u_int16_t coveredType;
time_t expiration;
dprintf(3, (ddt, "wanted(%#lx, %d, %d) [%s %s]\n",
(u_long)dp, class, type,
p_class(dp->d_class), p_type(dp->d_type)));
if (dp->d_class != class && class != C_ANY)
return (0);
/* Must check SIG for expiration below, other matches return OK here. */
if (type == dp->d_type && (type != T_SIG))
return (1);
#ifdef NCACHE
/*-ve $ing stuff, for a T_ANY query, we do not want to return
* -ve $ed RRs.
*/
if (type == T_ANY && dp->d_rcode == NOERROR_NODATA)
return (0);
#endif
/* First, look at the type of RR. */
switch (dp->d_type) {
/* Cases to deal with:
T_ANY search, return all unexpired SIGs.
T_SIG search, return all unexpired SIGs.
T_<foo> search, return all unexp SIG <FOO>s.
*/
case T_SIG:
cp = dp->d_data;
GETSHORT(coveredType,cp);
cp += INT16SZ + INT32SZ; /* skip alg, labels, & orig TTL */
GETLONG(expiration,cp);
if (type == T_ANY || type == T_SIG || type == coveredType) {
if (expiration > time(0))
return (1); /* Unexpired matching SIG */
}
return (0); /* We don't return this SIG. */
case T_ANY:
return (1);
case T_CNAME:
#ifdef NCACHE
if (dp->d_rcode != NOERROR_NODATA)
#endif
return (1);
#ifdef NCACHE
else
break;
#endif
}
/* OK, now look at the type of query. */
switch (type) {
case T_ANY:
return (1);
case T_MAILB:
switch (dp->d_type) {
case T_MR:
case T_MB:
case T_MG:
case T_MINFO:
return (1);
}
break;
case T_AXFR:
/* T_AXFR needs an authoritative SOA */
if (dp->d_type == T_SOA && dp->d_zone != 0
&& (zones[dp->d_zone].z_flags & Z_AUTH))
return (1);
break;
}
return (0);
}
/*
* Add RR entries from dpp array to a query/response.
* Return the number of bytes added or negative the amount
* added if truncation occured. Typically you are
* adding NS records to a response.
*/
int
add_data(np, dpp, cp, buflen, countp)
struct namebuf *np;
struct databuf **dpp;
register u_char *cp;
int buflen, *countp;
{
register struct databuf *dp;
char dname[MAXDNAME];
register int n, bytes;
bytes = *countp = 0;
getname(np, dname, sizeof(dname));
for (dp = *dpp++; dp != NULL; dp = *dpp++) {
if (stale(dp))
continue; /* ignore old cache entry */
#ifdef NCACHE
if (dp->d_rcode)
continue;
#endif
if ((n = make_rr(dname, dp, cp, buflen, 1)) < 0)
return (-bytes); /* Truncation */
cp += n;
buflen -= n;
bytes += n;
(*countp)++;
}
return (bytes);
}
static void
rrsetadd(flushset, name, dp)
struct flush_set *flushset;
char *name;
struct databuf *dp;
{
struct flush_set *fs = flushset;
struct db_list *dbl;
while (fs->fs_name && (
strcasecmp(fs->fs_name,name) ||
(fs->fs_class != dp->d_class) ||
(fs->fs_type != dp->d_type) ||
(fs->fs_cred != dp->d_cred))) {
fs++;
}
if (!fs->fs_name) {
fs->fs_name = strdup(name);
if (!fs->fs_name)
panic(-1, "rrsetadd: out of memory");
fs->fs_class = dp->d_class;
fs->fs_type = dp->d_type;
fs->fs_cred = dp->d_cred;
fs->fs_list = NULL;
fs->fs_last = NULL;
}
dbl = (struct db_list *)malloc(sizeof(struct db_list));
if (!dbl)
panic(-1, "rrsetadd: out of memory");
dbl->db_next = NULL;
dbl->db_dp = dp;
if (fs->fs_last == NULL)
fs->fs_list = dbl;
else
fs->fs_last->db_next = dbl;
fs->fs_last = dbl;
}
static int
ttlcheck(name,dbl,update)
char *name;
struct db_list *dbl;
int update;
{
int type = dbl->db_dp->d_type;
int class = dbl->db_dp->d_class;
struct hashbuf *htp = hashtab;
const char *fname;
register struct namebuf *np;
struct db_list *dbp = dbl;
struct databuf *dp;
u_int32_t ttl;
int first;
np = nlookup(name, &htp, &fname, 0);
if (np == NULL || fname != name || ns_wildcard(NAME(*np))) {
return(1);
}
/* check that all the ttl's we have are the same, if not return 1 */
first = 1;
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if (!match(dp, class, type))
continue;
if (first) {
/* we can't update zone data so return early */
if (dp->d_zone != 0)
return(0);
ttl = dp->d_ttl;
first = 0;
} else if (ttl != dp->d_ttl) {
return(1);
}
}
/* there are no records of this type in the cache */
if (first)
return(1);
/*
* the ttls of all records we have in the cache are the same
* if the ttls differ in the new set we don't want it.
*/
/* check that all the ttl's we have are the same, if not return 0 */
first = 1;
while (dbp) {
if (first) {
ttl = dbp->db_dp->d_ttl;
first = 0;
} else if (ttl != dbp->db_dp->d_ttl) {
return(0);
}
dbp = dbp->db_next;
}
/* update ttl if required */
if (update) {
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if (!match(dp, class, type))
continue;
if (dp->d_ttl > ttl)
break;
dp->d_ttl = ttl;
fixttl(dp);
}
}
return(1);
}
static int
rrsetcmp(name, dbl)
char *name;
struct db_list *dbl;
{
int type = dbl->db_dp->d_type;
int class = dbl->db_dp->d_class;
struct hashbuf *htp = hashtab;
const char *fname;
register struct namebuf *np;
struct db_list *dbp = dbl;
struct databuf *dp;
int exists = 0;
np = nlookup(name, &htp, &fname, 0);
if (np == NULL || fname != name || ns_wildcard(NAME(*np))) {
dprintf(1, (ddt, "rrsetcmp: name not in database\n"));
return(-1);
}
/* check that all entries in dbl are in the cache */
while (dbp) {
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if (match(dp, class, type))
exists++;
if (!db_cmp(dp, dbp->db_dp)
#ifdef NOADDITIONAL
&& ((dp->d_cred == dbp->db_dp->d_cred) ||
(dp->d_cred != DB_C_ADDITIONAL))
#endif
)
break;
}
if (!dp) {
dprintf(1, (ddt, "rrsetcmp: %srecord%s in database\n",
exists ? "" : "no ", exists ? " not" : "s"));
return(exists? 1 : -1);
}
dbp = dbp->db_next;
}
/* Check that all cache entries are in the list. */
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if (!match(dp, class, type))
continue;
#ifdef NCACHE
if (dp->d_rcode)
return(1);
#endif
dbp = dbl;
while (dbp) {
if (!db_cmp(dp, dbp->db_dp))
break;
dbp = dbp->db_next;
}
if (!dbp) {
dprintf(1, (ddt, "rrsetcmp: record not in rrset\n"));
return(1);
}
}
dprintf(1, (ddt, "rrsetcmp: rrsets matched\n"));
return(0);
}
static void
rrsetupdate(flushset, flags)
struct flush_set * flushset;
int flags;
{
struct flush_set *fs = flushset;
struct db_list *dbp, *odbp;
int n;
while (fs->fs_name) {
dprintf(1,(ddt, "rrsetupdate: %s\n",
fs->fs_name[0] ? fs->fs_name : "."));
if ((n = rrsetcmp(fs->fs_name, fs->fs_list)) &&
ttlcheck(fs->fs_name, fs->fs_list, 0)) {
if (n > 0)
flushrrset(fs);
dbp = fs->fs_list;
while (dbp) {
n = db_update(fs->fs_name, dbp->db_dp,
dbp->db_dp, flags, hashtab);
dprintf(1,(ddt, "rrsetupdate: %s %d\n",
fs->fs_name[0] ? fs->fs_name : ".", n));
if (n != OK)
db_free(dbp->db_dp);
odbp = dbp;
dbp = dbp->db_next;
free((char *)odbp);
}
} else {
if (n == 0)
(void)ttlcheck(fs->fs_name, fs->fs_list, 1);
dbp = fs->fs_list;
while (dbp) {
db_free(dbp->db_dp);
odbp = dbp;
dbp = dbp->db_next;
free((char *)odbp);
}
}
fs->fs_list = NULL;
fs++;
}
}
static void
flushrrset(fs)
struct flush_set * fs;
{
struct databuf *dp;
int n;
dprintf(1, (ddt, "flushrrset(%s, %s, %s, %d)\n",
fs->fs_name[0]?fs->fs_name:".", p_type(fs->fs_type),
p_class(fs->fs_class), fs->fs_cred));
dp = savedata(fs->fs_class, fs->fs_type, 0, NULL, 0);
dp->d_zone = 0;
dp->d_cred = fs->fs_cred;
dp->d_clev = 0;
do {
n = db_update(fs->fs_name, dp, NULL, DB_DELETE, hashtab);
dprintf(1, (ddt, "flushrrset: %d\n", n));
} while (n == OK);
db_free(dp);
}
/*
* This is best thought of as a "cache invalidate" function.
* It is called whenever a piece of data is determined to have
* become invalid either through a timeout or a validation
* failure. It is better to have no information, than to
* have partial information you pass off as complete.
*/
void
delete_all(np, class, type)
register struct namebuf *np;
int class, type;
{
register struct databuf *dp, *pdp;
dprintf(3, (ddt, "delete_all(%#lx:\"%s\" %s %s)\n",
(u_long)np, NAME(*np), p_class(class), p_type(type)));
pdp = NULL;
dp = np->n_data;
while (dp != NULL) {
if ((dp->d_zone == 0) && !(dp->d_flags & DB_F_HINT)
&& match(dp, class, type)) {
dp = rm_datum(dp, np, pdp);
continue;
}
pdp = dp;
dp = dp->d_next;
}
}
/* delete_stale(np)
* for all RRs associated with this name, check for staleness (& delete)
* arguments:
* np = pointer to namebuf to be cleaned.
* returns:
* void.
* side effects:
* delete_all() can be called, freeing memory and relinking chains.
*/
void
delete_stale(np)
struct namebuf *np;
{
struct databuf *dp;
again:
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if ((dp->d_zone == 0) && stale(dp)) {
delete_all(np, dp->d_class, dp->d_type);
goto again;
}
}
}
static void
add_related_additional(name)
char *name;
{
int i;
if (num_related >= MAX_RELATED - 1)
return;
for (i = 0; i < num_related; i++)
if (strcasecmp(name, related[i]) == 0)
return;
related[num_related++] = name;
}
static void
free_related_additional() {
int i;
for (i = 0; i < num_related; i++)
free(related[i]);
num_related = 0;
}
static int
related_additional(name)
char *name;
{
int i;
for (i = 0; i < num_related; i++)
if (strcasecmp(name, related[i]) == 0)
return (1);
return (0);
}
static void
maybe_free(tname)
char **tname;
{
if (tname == NULL || *tname == NULL)
return;
free(*tname);
*tname = NULL;
}
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