4.4BSD/usr/src/contrib/bind-4.9/named/db_update.c
#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 4.9.1.1 1993/05/02 22:43:03 vixie Rel $";
#endif /* not lint */
/*
* ++Copyright++ 1986, 1990
* -
* Copyright (c) 1986, 1990 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 <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <syslog.h>
#include "../conf/portability.h"
#include "../conf/options.h"
#include "ns.h"
#include "db.h"
extern struct timeval tt;
extern FILE *ddt;
extern struct sockaddr_in from_addr; /* Source addr of last packet */
extern int needs_prime_cache;
extern int match();
void fixttl();
int db_cmp(), dhash();
#ifdef INVQ
void addinv(), rminv();
#endif
int max_cache_ttl = (7*24*60*60); /* ONE_WEEK maximum ttl */
int min_cache_ttl = (5*60); /* 5 minute minimum ttl */
#ifdef CRED
/* 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_type == T_NS) &&
!strcasecmp(name, (char *)dp->d_data)) {
return 1;
}
}
if (np->n_hash && isRefByNS(name, np->n_hash)) {
return 1;
}
}
return 0;
}
#endif /*CRED*/
/* 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
*/
int
db_update(name, odp, newdp, flags, htp)
char name[];
struct databuf *odp, *newdp;
int flags;
struct hashbuf *htp;
{
register struct namebuf *np;
register struct databuf *dp, *pdp;
char *fname;
int foundRR = 0;
#ifdef CRED
int isHintNS = isRefByNS(name, fcachetab);
#endif /*CRED*/
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"db_update(%s, 0x%x, 0x%x, 0%o, 0x%x)%s\n",
name, odp, newdp, flags, htp,
(odp && (odp->d_flags&DB_F_HINT)) ? " hint":"" );
#endif
np = nlookup(name, &htp, &fname, newdp != NULL);
if (np == NULL || fname != name)
return NONAME;
#ifdef CRED
/* some special checks for root NS' A RR's */
if (newdp && isHintNS && newdp->d_type == T_A) {
/* obviously bogus addresses die here */
if (((struct in_addr *)newdp->d_data)->s_addr == 0) {
syslog(LOG_INFO, "bogus (0.0.0.0) root A RR received");
return AUTH;
}
/* upgrade credibility of additional data */
if (newdp->d_cred == DB_C_ADDITIONAL) {
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,
"upgrading credibility for A RR (%s)\n",
name);
#endif
newdp->d_cred = DB_C_ANSWER;
}
}
#endif /*CRED*/
/* Reflect certain updates in hint cache also... */
/* Don't stick data we are authoritative for in hints. */
if (!(flags & DB_NOHINTS) && (odp != NULL) &&
(htp != fcachetab) && /* vix@dec mar92 */
(odp->d_zone <= 0) && !(odp->d_flags & DB_F_HINT) &&
((name[0] == '\0' && odp->d_type == T_NS) ||
(odp->d_type == T_A
#ifdef CRED
&& isHintNS
#endif /*CRED*/
)
)
)
{
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"db_update: hint '%s' %d\n",
name, odp->d_ttl);
#endif
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;
#ifdef CRED
dp->d_cred = DB_C_CACHE;
#endif /*CRED*/
if (db_update(name, dp, dp, (flags|DB_NOHINTS),
fcachetab) != OK) {
#ifdef DEBUG
if (debug > 2)
fprintf(ddt, "db_update: hint %x freed\n", dp);
#endif
(void) free((char *)dp);
}
}
if (odp != NULL) {
pdp = NULL;
for (dp = np->n_data; dp != NULL; ) {
if (!match(dp, odp->d_class, odp->d_type)) {
if ((dp->d_type == T_CNAME ||
odp->d_type == T_CNAME) &&
odp->d_mark == dp->d_mark &&
zones[odp->d_zone].z_type != Z_CACHE) {
syslog(LOG_ERR,
"%s has CNAME and other data (illegal)\n",
name);
#ifdef DEBUG
if (debug)
fprintf(ddt,
"db_update: %s: CNAME and more (%d, %d)\n",
name, odp->d_type, dp->d_type);
#endif
}
goto skip;
}
#ifdef DEBUG
if (debug >= 5)
fprintf(ddt,"db_update: flags = %#x, sizes = %d, %d (%d)\n",
flags, odp->d_size, dp->d_size,
db_cmp(dp, odp));
#endif
if (flags & DB_NOTAUTH && dp->d_zone) {
#ifdef DEBUG
if (debug)
fprintf(ddt,
"%s attempted update to auth zone %d '%s'\n",
inet_ntoa(from_addr.sin_addr),
dp->d_zone, zones[dp->d_zone].z_origin);
#endif
return AUTH;
}
#ifdef CRED
if (newdp) {
#ifdef DEBUG
if (debug > 3)
fprintf(ddt,
"credibility for %s is %d from %s, is %d in cache\n",
name,
newdp->d_cred,
inet_ntoa(from_addr.sin_addr),
dp->d_cred);
#endif
if (newdp->d_cred > dp->d_cred) {
/* better credibility and the old datum
* was not from a zone file. remove
* the old datum.
*/
dp = rm_datum(dp, np, pdp);
continue;
}
if (newdp->d_cred < dp->d_cred) {
/* credibility is worse. ignore it. */
return AUTH;
}
/* credibility is the same.
* let it aggregate in the normal way.
*/
}
#endif /*CRED*/
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;
#ifdef DEBUG /* vix@dec mar92 */
if (debug > 3)
fprintf(ddt,
"db_update: cache entry now in auth zone\n");
#endif
return DATAEXISTS;
}
fixttl(odp);
if (odp->d_ttl > dp->d_ttl)
dp->d_ttl = odp->d_ttl;
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"db_update: new ttl %d, +%d\n",
dp->d_ttl, dp->d_ttl - tt.tv_sec);
#endif
}
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)
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;
fixttl(newdp);
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"db_update: adding%s %x\n",
(newdp->d_flags&DB_F_HINT) ? " hint":"", newdp);
#endif
#if INVQ
if (!(newdp->d_flags & DB_F_HINT))
addinv(np, newdp); /* modify inverse query tables */
#endif
/* Add to end of list, generally preserving order */
newdp->d_next = NULL;
if ((dp = np->n_data) == NULL) {
np->n_data = newdp;
return OK;
}
/* XXX: need to check for duplicate WKS records and flag error */
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;
dp->d_next = newdp;
return OK;
}
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;
}
#if INVQ
struct invbuf *invtab[INVHASHSZ]; /* Inverse query hash table */
/*
* Add data 'dp' to inverse query tables for name 'np'.
*/
void
addinv(np, dp)
struct namebuf *np;
struct databuf *dp;
{
register struct invbuf *ip;
register int hval, i;
switch (dp->d_type) {
case T_A:
case T_UID:
case T_GID:
break;
default:
return;
}
hval = dhash(dp->d_data, dp->d_size);
for (ip = invtab[hval]; ip != NULL; ip = ip->i_next)
for (i = 0; i < INVBLKSZ; i++)
if (ip->i_dname[i] == NULL) {
ip->i_dname[i] = np;
return;
}
ip = saveinv();
ip->i_next = invtab[hval];
invtab[hval] = ip;
ip->i_dname[0] = np;
}
/*
* Remove data 'odp' from inverse query table.
*/
void
rminv(odp)
struct databuf *odp;
{
register struct invbuf *ip;
register struct databuf *dp;
struct namebuf *np;
register int i;
for (ip = invtab[dhash(odp->d_data, odp->d_size)]; ip != NULL;
ip = ip->i_next) {
for (i = 0; i < INVBLKSZ; i++) {
if ((np = ip->i_dname[i]) == NULL)
break;
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if (dp != odp)
continue;
while (i < INVBLKSZ-1) {
ip->i_dname[i] = ip->i_dname[i+1];
i++;
}
ip->i_dname[i] = NULL;
return;
}
}
}
}
#endif /*INVQ*/
/*
* Compute hash value from data.
*/
int
dhash(dp, dlen)
u_char *dp;
int dlen;
{
register u_char *cp;
register unsigned hval;
register int n;
n = dlen;
if (n > 8)
n = 8;
hval = 0;
for (cp = dp; --n >= 0; ) {
hval <<= 1;
hval += *cp++;
}
return (hval % INVHASHSZ);
}
/*
* Compare type, class and data from databufs for equivalence.
* Must be case insensitive for some domain names.
* Return 0 if equivalent, nonzero otherwise.
*/
int
db_cmp(dp1, dp2)
register struct databuf *dp1, *dp2;
{
register u_char *cp1, *cp2;
int len;
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 */
switch (dp1->d_type) {
case T_A:
case T_UID:
case T_GID:
case T_WKS:
case T_NULL:
#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:
cp1 = dp1->d_data;
cp2 = dp2->d_data;
len = *cp1;
if (strncasecmp((char *)++cp1, (char *)++cp2, len))
return 1;
cp1 += len;
cp2 += len;
len = *cp1;
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, sizeof(u_int32_t) * 5);
case T_MX:
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_TXT:
if (dp1->d_size != dp2->d_size)
return 1;
return bcmp(dp1->d_data, dp2->d_data, dp1->d_size);
default:
return (1);
}
}