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freebsd/usr.sbin/named/db_update.c

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#if !defined(lint) && !defined(SABER)
static char sccsid[] = "@(#)db_update.c 4.28 (Berkeley) 3/21/91";
static char rcsid[] = "$Id: db_update.c,v 1.3 1995/08/20 21:18:31 peter Exp $";
#endif /* not lint */
/*
* ++Copyright++ 1986, 1990
* -
* Copyright (c) 1986, 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.
* -
* --Copyright--
*/
#include <stdio.h>
#include <syslog.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <resolv.h>
#include "named.h"
static void fixttl __P((struct databuf *));
static int db_cmp __P((struct databuf *,
struct databuf *));
/* int
* isRefByNS(name, htp)
* recurse through all of `htp' looking for NS RR's that refer to `name'.
* returns:
* nonzero if at least one such NS RR exists
* cautions:
* this is very expensive; probably you only want to use on fcachetab.
*/
static int
isRefByNS(name, htp)
char name[];
struct hashbuf *htp;
{
register struct namebuf *np;
register struct databuf *dp;
for (np = htp->h_tab[0]; np != NULL; np = np->n_next) {
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if ((dp->d_class == C_ANY ||
dp->d_class == C_IN ||
dp->d_class == C_HS) &&
dp->d_type == T_NS &&
#ifdef NCACHE
!dp->d_rcode &&
#endif
!strcasecmp(name, (char *)dp->d_data)) {
return (1);
}
}
if (np->n_hash && isRefByNS(name, np->n_hash))
return (1);
}
return (0);
}
/* int
* findMyZone(struct namebuf *np)
* surf the zone cuts and find this zone the hard way
* return value:
* zone number or DB_Z_CACHE if it's outside a zone
* interesting cases:
* DEC.COM SOA (primary)
* CRL.DEC.COM NS (in primary)
* if you start at CRL.. here, you find the DEC.COM zone
* if you start at NS.CRL.. here, you're in the cache
* DEC.COM SOA (primary)
* CRL.DEC.COM NS (in primary)
* CRL.DEC.COM SOA (secondary)
* CRL.DEC.COM NS (in secondary)
* if you start at CRL.. here, you find the CRL.DEC.COM zone
* if you start at NS.CRL.. here, you're in the CRL.. zone
*/
int
findMyZone(np, class)
struct namebuf *np;
register int class;
{
for (; np; np = np->n_parent) {
register struct databuf *dp;
/* if we encounter an SOA, we're in its zone (which can be
* the cache or an authoritative zone, depending).
*/
for (dp = np->n_data; dp; dp = dp->d_next)
if (match(dp, class, T_SOA))
return (dp->d_zone);
/* if we find an NS at some node without having seen an SOA
* (above), then we're out in the cache somewhere.
*/
for (dp = np->n_data; dp; dp = dp->d_next)
if (match(dp, class, T_NS))
return (DB_Z_CACHE);
}
/* getting all the way to the root without finding an NS or SOA
* probably means that we are in deep dip, but we'll treat it as
* being in the cache. (XXX?)
*/
return (DB_Z_CACHE);
}
#ifdef NO_GLUE
#define ISVALIDGLUE(xdp) ((xdp)->d_type == T_NS || (xdp)->d_type == T_A)
#else
#define ISVALIDGLUE(xdp) (1)
#endif /*NO_GLUE*/
/* int
* db_update(name, odp, newdp, flags, htp)
* update data base node at `name'. `flags' controls the action.
* side effects:
* inverse query tables modified, if we're using them.
* return value:
* OK - success
* NONAME - name doesn't exist
* AUTH - you can't do that
* DATAEXISTS - there's something there and DB_NODATA was specified
* NODATA - there's no data, and (DB_DELETE or DB_MEXIST) was spec'd
*
* Policy: How to add data if one more RR is -ve data
*
* NEND NOERROR_NODATA
* NXD NXDOMAIN
*
* match
* old
* Data NEND NXD
* Data Merge Data Data
* new NEND NEND NEND NEND
* NXD NXD NXD NXD
*
* no match
* old
* Data NEND NXD
* Data Merge Merge Data
* new NEND Merge Merge NEND
* NXD NXD NXD NXD
*
*/
/* XXX: this code calls nlookup, which can create namebuf's. if this code
* has to exit with a fatal error, it should scan from the new np upward
* and for each node which has no children and no data it should remove
* the namebuf. design notes: (1) there's no harm in doing this even if
* success occurred; (2) stopping on the first nonremovable np is optimal;
* the code for removal should be taken out of remove_zone() and made
* general enough for this use, and for remove_zone()'s continued use.
* vix, 21jul94
*/
int
db_update(name, odp, newdp, flags, htp)
char name[];
struct databuf *odp, *newdp;
int flags;
struct hashbuf *htp;
{
register struct databuf *dp, *pdp;
register struct namebuf *np;
int zn, isHintNS;
const char *fname;
dprintf(3, (ddt, "db_update(%s, 0x%lx, 0x%lx, 0%o, 0x%lx)%s\n",
name, (u_long)odp, (u_long)newdp, flags, (u_long)htp,
(odp && (odp->d_flags&DB_F_HINT)) ? " hint":"" ));
np = nlookup(name, &htp, &fname, newdp != NULL);
if (np == NULL || fname != name)
return (NONAME);
/* don't let nonauthoritative updates write in authority zones */
if (newdp && ((zn = findMyZone(np, newdp->d_class)) != DB_Z_CACHE) &&
#ifdef STUBS
(zones[zn].z_type != Z_STUB) &&
#endif
(flags & DB_NOTAUTH)) {
int foundRR = 0;
/*
* Don't generate the warning if the update
* would have been harmless (identical data).
*/
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if (!db_cmp(dp, newdp)) {
foundRR++;
break;
}
}
if (!foundRR)
dprintf(5, (ddt,
"[%s].%d update? to auth zone \"%s\" (%s)",
inet_ntoa(from_addr.sin_addr),
ntohs(from_addr.sin_port),
zones[zn].z_origin,
name));
return (AUTH);
}
if (newdp && zn && !(flags & DB_NOTAUTH)) {
if (db_getclev(zones[zn].z_origin) > newdp->d_clev) {
dprintf(5,(ddt, "attempted update child zone %s, %s\n",
zones[zn].z_origin, name));
return(AUTH);
}
}
/* some special checks for root NS' A RR's */
isHintNS = isRefByNS(name, fcachetab);
#ifdef DEPRECATED
if (newdp && isHintNS && newdp->d_type == T_A) {
/* upgrade credibility of additional data for rootsrv addrs */
if (newdp->d_cred == DB_C_ADDITIONAL) {
dprintf(3, (ddt,
"upgrading credibility for A RR (%s)\n",
name));
/* XXX: should copy NS RR's, but we really just want
* to prevent deprecation later so this will do.
*/
newdp->d_cred = DB_C_ANSWER;
newdp->d_clev = 0;
}
}
#endif
/* Reflect certain updates in hint cache also... */
/* Don't stick data we are authoritative for in hints. */
if (!(flags & DB_NOHINTS) &&
(flags & DB_PRIMING) &&
(odp != NULL) &&
(htp != fcachetab) &&
(odp->d_zone <= 0) &&
!(odp->d_flags & DB_F_HINT) &&
#ifdef NCACHE
(!newdp || !newdp->d_rcode) &&
#endif
((name[0] == '\0' && odp->d_type == T_NS) ||
(odp->d_type == T_A && isHintNS)
)
)
{
dprintf(3, (ddt, "db_update: hint '%s' %d\n",
name, odp->d_ttl));
dp = savedata(odp->d_class, odp->d_type, odp->d_ttl,
odp->d_data, odp->d_size);
dp->d_zone = DB_Z_CACHE;
dp->d_flags = DB_F_HINT;
dp->d_cred = DB_C_CACHE;
dp->d_clev = 0;
if (db_update(name,
dp, dp,
(flags|DB_NOHINTS),
fcachetab)
!= OK) {
dprintf(3, (ddt, "db_update: hint %lx freed\n",
(u_long)dp));
(void) free((char *)dp);
}
}
if (odp != NULL) {
int foundRR = 0;
pdp = NULL;
for (dp = np->n_data; dp != NULL; ) {
if (!match(dp, odp->d_class, odp->d_type)) {
/* {class,type} doesn't match. these are
* the aggregation cases.
*/
if ((dp->d_type == T_CNAME ||
odp->d_type == T_CNAME) &&
odp->d_class == dp->d_class &&
odp->d_mark == dp->d_mark &&
#ifdef NCACHE
/* neither the odp nor the new dp are
* negatively cached records...
*/
!dp->d_rcode &&
!odp->d_rcode &&
#endif /*NCACHE*/
zones[odp->d_zone].z_type != Z_CACHE) {
syslog(LOG_INFO,
"%s has CNAME and other data (illegal)\n",
name);
goto skip;
}
if (!newdp || newdp->d_class != dp->d_class)
goto skip;
/* if the new data is authorative
* remove any data for this domain with
* the same class that isn't as credable
*/
if (newdp->d_cred == DB_C_ZONE &&
newdp->d_cred > dp->d_cred)
/* better credibility and the old datum
* was not from a zone file. remove
* the old datum.
*/
goto delete;
#if 0 /* caught by findMyZone() now. */
/* if we have authoritative data for a
* node, don't add in other data.
*/
if (dp->d_cred == DB_C_ZONE &&
newdp->d_cred < dp->d_cred)
return (AUTH);
#endif
/* if the new data is authoritative but
* but isn't as credible, reject it.
*/
if (newdp->d_cred == DB_C_ZONE &&
dp->d_cred == DB_C_ZONE) {
/* Both records are from a zone file.
* If their credibility levels differ,
* we're dealing with a zone cut. The
* record with lower clev is from the
* upper zone's file and is therefore
* glue.
*/
if (newdp->d_clev < dp->d_clev) {
if (!ISVALIDGLUE(newdp)) {
syslog(LOG_INFO,
"domain %s %s record in zone %s should be in zone %s, ignored",
name, p_type(newdp->d_type),
zones[newdp->d_zone].z_origin,
zones[dp->d_zone].z_origin);
}
return (AUTH);
}
if (newdp->d_clev > dp->d_clev) {
if (!ISVALIDGLUE(dp)) {
syslog(LOG_INFO,
"domain %s %s record in zone %s should be in zone %s, deleted",
name, p_type(dp->d_type),
zones[dp->d_zone].z_origin,
zones[newdp->d_zone].z_origin);
}
goto delete;
}
}
#ifdef NCACHE
/* process NXDOMAIN */
/* policy */
if (newdp->d_rcode == NXDOMAIN) {
if (dp->d_cred < DB_C_AUTH)
goto delete;
else
return (DATAEXISTS);
}
if (dp->d_rcode == NXDOMAIN)
goto delete;
/* process NOERROR_NODATA */
/* NO PROCESSING REQUIRED */
#endif /*NCACHE*/
goto skip;
} /*if {class,type} did not match*/
/* {type,class} did match. this is the replace case.
*/
dprintf(5, (ddt,
"db_update: flags = %#x, sizes = %d, %d (cmp %d)\n",
flags, odp->d_size, dp->d_size,
db_cmp(dp, odp)));
if (newdp) {
dprintf(4, (ddt,
"credibility for %s is %d(%d) from [%s].%d, is %d(%d) in cache\n",
*name? name : ".",
newdp->d_cred,
newdp->d_clev,
inet_ntoa(from_addr.sin_addr),
ntohs(from_addr.sin_port),
dp->d_cred,
dp->d_clev));
if (newdp->d_cred > dp->d_cred) {
/* better credibility.
* remove the old datum.
*/
goto delete;
}
if (newdp->d_cred < dp->d_cred) {
/* credibility is worse. ignore it. */
return (AUTH);
}
if (newdp->d_cred == DB_C_ZONE &&
dp->d_cred == DB_C_ZONE ) {
/* Both records are from a zone file.
* If their credibility levels differ,
* we're dealing with a zone cut. The
* record with lower clev is from the
* upper zone's file and is therefore
* glue.
*/
/* XXX - Tricky situation here is you
* have 2 zones a.b.c and sub.a.b.c
* being served by the same server.
* named will send NS records for
* sub.a.b.c during zone transfer of
* a.b.c zone. If we're secondary for
* both zones, and we reload zone
* a.b.c, we'll get the NS records
* (and possibly A records to go with
* them?) for sub.a.b.c as part of the
* a.b.c zone transfer. But we've
* already got a more credible record
* from the sub.a.b.c zone. So we want
* to ignore the new record, but we
* shouldn't syslog because there's
* nothing the user can do to prevent
* the situation. Perhaps we should
* only complain when we are primary?
*/
if (newdp->d_clev < dp->d_clev) {
if (!ISVALIDGLUE(newdp)) {
syslog(LOG_INFO,
"domain %s %s record in zone %s should be in zone %s, ignored",
name, p_type(newdp->d_type),
zones[newdp->d_zone].z_origin,
zones[dp->d_zone].z_origin);
}
return (AUTH);
}
if (newdp->d_clev > dp->d_clev) {
if (!ISVALIDGLUE(dp)) {
syslog(LOG_INFO,
"domain %s %s record in zone %s should be in zone %s, deleted",
name, p_type(dp->d_type),
zones[dp->d_zone].z_origin,
zones[newdp->d_zone].z_origin);
}
goto delete;
}
}
/* credibility is the same.
* let it aggregate in the normal way.
*/
#ifdef NCACHE
/*
* if the new or old RR is -ve, delete old.
*/
if (dp->d_rcode || newdp->d_rcode) {
/* XXX: how can a zone rr be neg? */
if (dp->d_cred != DB_C_ZONE)
goto delete;
else
return (DATAEXISTS);
}
#endif
/*
* Some RR types should not be aggregated.
*/
if (dp->d_type == T_SOA)
goto delete;
if (dp->d_type == T_WKS &&
!bcmp(dp->d_data, newdp->d_data,
INT32SZ + sizeof(u_char)))
goto delete;
}
if ((flags & DB_NODATA) && !db_cmp(dp, odp)) {
/* refresh ttl if cache entry */
if (dp->d_zone == 0) {
if (odp->d_zone != 0) { /* XXX */
/* changing cache->auth */
dp->d_zone = odp->d_zone;
dp->d_ttl = odp->d_ttl;
dprintf(4, (ddt,
"db_update: cache entry now in auth zone\n"
));
return (DATAEXISTS);
}
fixttl(odp);
if (odp->d_ttl > dp->d_ttl)
dp->d_ttl = odp->d_ttl;
dprintf(3, (ddt,
"db_update: new ttl %ld +%d\n",
(u_long)dp->d_ttl,
dp->d_ttl - tt.tv_sec));
}
return (DATAEXISTS);
}
/*
* If the old databuf has some data, check that the
* data matches that in the new databuf (so UPDATED
* will delete only the matching RR)
*/
if (odp->d_size > 0)
if (db_cmp(dp, odp))
goto skip;
foundRR = 1;
if (flags & DB_DELETE) {
delete: dp = rm_datum(dp, np, pdp);
} else {
skip: pdp = dp;
dp = dp->d_next;
}
}
if (!foundRR) {
if (flags & DB_DELETE)
return (NODATA);
if (flags & DB_MEXIST)
return (NODATA);
}
}
if (newdp == NULL)
return (OK);
/* XXX: empty nodes bypass credibility checks above; should check
* response source address here if flags&NOTAUTH.
*/
fixttl(newdp);
dprintf(3, (ddt, "db_update: adding%s %lx\n",
(newdp->d_flags&DB_F_HINT) ? " hint":"", (u_long)newdp));
#ifdef INVQ
if (!(newdp->d_flags & DB_F_HINT))
addinv(np, newdp); /* modify inverse query tables */
#endif
#ifdef STATS
if (!newdp->d_zone && !(newdp->d_flags & DB_F_HINT))
newdp->d_ns = nameserFind(from_addr.sin_addr, NS_F_INSERT);
#endif
/* Add to end of list, generally preserving order */
newdp->d_next = NULL;
if ((dp = np->n_data) == NULL) {
#ifdef DATUMREFCNT
newdp->d_rcnt = 1;
#endif
np->n_data = newdp;
return (OK);
}
while (dp->d_next != NULL) {
if ((flags & DB_NODATA) && !db_cmp(dp, newdp))
return (DATAEXISTS);
dp = dp->d_next;
}
if ((flags & DB_NODATA) && !db_cmp(dp, newdp))
return (DATAEXISTS);
#ifdef DATUMREFCNT
newdp->d_rcnt = 1;
#endif
dp->d_next = newdp;
return (OK);
}
static void
fixttl(dp)
register struct databuf *dp;
{
if (dp->d_zone == 0 && !(dp->d_flags & DB_F_HINT)) {
if (dp->d_ttl <= tt.tv_sec)
return;
else if (dp->d_ttl < tt.tv_sec+min_cache_ttl)
dp->d_ttl = tt.tv_sec+min_cache_ttl;
else if (dp->d_ttl > tt.tv_sec+max_cache_ttl)
dp->d_ttl = tt.tv_sec+max_cache_ttl;
}
return;
}
/*
* Compare type, class and data from databufs for equivalence.
* Must be case insensitive for some domain names.
* Return 0 if equivalent, nonzero otherwise.
*/
static int
db_cmp(dp1, dp2)
register struct databuf *dp1, *dp2;
{
register u_char *cp1, *cp2;
int len, len2;
if (dp1->d_type != dp2->d_type || dp1->d_class != dp2->d_class)
return (1);
if (dp1->d_size != dp2->d_size)
return (1);
if (dp1->d_mark != dp2->d_mark)
return (1); /* old and new RR's are distinct */
#ifdef NCACHE
if (dp1->d_rcode && dp2->d_rcode)
return ((dp1->d_rcode == dp1->d_rcode)?0:1);
if (dp1->d_rcode || dp2->d_rcode)
return (1);
#endif
switch (dp1->d_type) {
case T_A:
case T_UID:
case T_GID:
case T_WKS:
case T_NULL:
case T_NSAP:
case T_LOC:
#ifdef ALLOW_T_UNSPEC
case T_UNSPEC:
#endif
return (bcmp(dp1->d_data, dp2->d_data, dp1->d_size));
case T_NS:
case T_CNAME:
case T_PTR:
case T_MB:
case T_MG:
case T_MR:
case T_UINFO:
return (strcasecmp((char *)dp1->d_data, (char *)dp2->d_data));
case T_HINFO:
case T_ISDN:
cp1 = dp1->d_data;
cp2 = dp2->d_data;
len = *cp1;
len2 = *cp2;
if (len != len2)
return (1);
if (strncasecmp((char *)++cp1, (char *)++cp2, len))
return (1);
cp1 += len;
cp2 += len;
len = *cp1;
len2 = *cp2;
if (len != len2)
return (1);
return (strncasecmp((char *)++cp1, (char *)++cp2, len));
case T_SOA:
case T_MINFO:
case T_RP:
if (strcasecmp((char *)dp1->d_data, (char *)dp2->d_data))
return (1);
cp1 = dp1->d_data + strlen((char *)dp1->d_data) + 1;
cp2 = dp2->d_data + strlen((char *)dp2->d_data) + 1;
if (dp1->d_type != T_SOA)
return (strcasecmp((char *)cp1, (char *)cp2));
if (strcasecmp((char *)cp1, (char *)cp2))
return (1);
cp1 += strlen((char *)cp1) + 1;
cp2 += strlen((char *)cp2) + 1;
return (bcmp(cp1, cp2, INT32SZ * 5));
case T_MX:
case T_AFSDB:
case T_RT:
cp1 = dp1->d_data;
cp2 = dp2->d_data;
if (*cp1++ != *cp2++ || *cp1++ != *cp2++) /* cmp prio */
return (1);
return (strcasecmp((char *)cp1, (char *)cp2));
case T_PX:
cp1 = dp1->d_data;
cp2 = dp2->d_data;
if (*cp1++ != *cp2++ || *cp1++ != *cp2++) /* cmp prio */
return (1);
if (strcasecmp((char *)cp1, (char *)cp2))
return (1);
cp1 += strlen((char *)cp1) + 1;
cp2 += strlen((char *)cp2) + 1;
return (strcasecmp((char *)cp1, (char *)cp2));
case T_TXT:
case T_X25:
if (dp1->d_size != dp2->d_size)
return (1);
return (bcmp(dp1->d_data, dp2->d_data, dp1->d_size));
default:
return (1);
}
}
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