2.11BSD/src/usr.sbin/named/named/db_update.c
/*
* Copyright (c) 1986 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that this notice is preserved and that due credit is given
* to the University of California at Berkeley. The name of the University
* may not be used to endorse or promote products derived from this
* software without specific prior written permission. This software
* is provided ``as is'' without express or implied warranty.
*/
#ifndef lint
static char sccsid[] = "@(#)db_update.c 4.16 (Berkeley) 2/28/88";
#endif /* not lint */
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <stdio.h>
#include <syslog.h>
#include <arpa/nameser.h>
#include "ns.h"
#include "db.h"
extern struct timeval tt;
extern FILE *ddt;
extern struct zoneinfo zones[];
extern struct sockaddr_in from_addr; /* Source addr of last packet */
extern int needs_prime_cache;
u_long max_cache_ttl = (7*24*60*60); /* ONE_WEEK maximum ttl */
u_long min_cache_ttl = (5*60); /* 5 minute minimum ttl */
/*
* Update data base. Flags control the action.
* Inverse query tables modified.
*/
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 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);
/* Reflect certain updates in hint cache also... */
/* Don't stick data we are authoritative for in hints. */
if (!(flags & DB_NOHINTS) && (odp != NULL) &&
(odp->d_zone <= 0) && !(odp->d_flags & DB_F_HINT) &&
((name[0] == '\0' && odp->d_type == T_NS) ||
(odp->d_type == T_A)))
{
register struct databuf *dp;
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"db_update: hint '%s' %ld\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;
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) &&
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);
}
if ((flags & DB_NODATA) && !db_cmp(dp, odp)) {
/* refresh ttl if cache entry */
if (dp->d_zone == 0) {
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 %ld, +%ld\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 (!(newdp->d_flags & DB_F_HINT))
addinv(np, newdp); /* modify inverse query tables */
/* 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);
}
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;
}
struct invbuf *invtab[INVHASHSZ]; /* Inverse query hash table */
/*
* Add data 'dp' to inverse query tables for name 'np'.
*/
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.
*/
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 (!match(dp, odp->d_class, odp->d_type))
continue;
if (db_cmp(dp, odp))
continue;
while (i < INVBLKSZ-1) {
ip->i_dname[i] = ip->i_dname[i+1];
i++;
}
ip->i_dname[i] = NULL;
return;
}
}
}
}
/*
* Compute hash value from data.
*/
dhash(dp, dlen)
char *dp;
int dlen;
{
register 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 data sections from databufs for equivalence. Must be case
* insensitive for some domain names. We assume that they are the
* same type when they are passed. Return 0 if equivalent, nonzero
* otherwise.
*/
db_cmp(dp1, dp2)
register struct databuf *dp1, *dp2;
{
register char *cp1, *cp2;
int len;
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 ALLOW_T_UNSPEC
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(dp1->d_data, dp2->d_data));
case T_HINFO:
cp1 = dp1->d_data;
cp2 = dp2->d_data;
len = *cp1;
if (strncasecmp(++cp1, ++cp2, len))
return(1);
cp1 += len;
cp2 += len;
len = *cp1;
return(strncasecmp(++cp1, ++cp2, len));
case T_SOA:
case T_MINFO:
if (strcasecmp(dp1->d_data, dp2->d_data))
return(1);
cp1 = dp1->d_data + strlen(dp1->d_data) + 1;
cp2 = dp2->d_data + strlen(dp2->d_data) + 1;
if (dp1->d_type != T_SOA)
return(strcasecmp(cp1, cp2));
if (strcasecmp(cp1, cp2))
return(1);
cp1 += strlen(cp1) + 1;
cp2 += strlen(cp2) + 1;
return(bcmp(cp1, cp2, sizeof(u_long) * 5));
case T_MX:
cp1 = dp1->d_data;
cp2 = dp2->d_data;
if (*cp1++ != *cp2++ || *cp1++ != *cp2++) /* cmp prio */
return(1);
return(strcasecmp(cp1, cp2));
default:
return (1);
}
}