350 lines
8.1 KiB
C
350 lines
8.1 KiB
C
/*
|
|
* Copyright (c) 1985 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.
|
|
*/
|
|
|
|
#if defined(LIBC_SCCS) && !defined(lint)
|
|
static char sccsid[] = "@(#)res_comp.c 6.22 (Berkeley) 3/19/91";
|
|
#endif /* LIBC_SCCS and not lint */
|
|
|
|
#include <sys/param.h>
|
|
#include <arpa/nameser.h>
|
|
#include <netinet/in.h>
|
|
#include <resolv.h>
|
|
#include <stdio.h>
|
|
|
|
static dn_find();
|
|
|
|
/*
|
|
* Expand compressed domain name 'comp_dn' to full domain name.
|
|
* 'msg' is a pointer to the begining of the message,
|
|
* 'eomorig' points to the first location after the message,
|
|
* 'exp_dn' is a pointer to a buffer of size 'length' for the result.
|
|
* Return size of compressed name or -1 if there was an error.
|
|
*/
|
|
dn_expand(msg, eomorig, comp_dn, exp_dn, length)
|
|
const u_char *msg, *eomorig, *comp_dn;
|
|
u_char *exp_dn;
|
|
int length;
|
|
{
|
|
register u_char *cp, *dn;
|
|
register int n, c;
|
|
u_char *eom;
|
|
int len = -1, checked = 0;
|
|
|
|
dn = exp_dn;
|
|
cp = (u_char *)comp_dn;
|
|
eom = exp_dn + length;
|
|
/*
|
|
* fetch next label in domain name
|
|
*/
|
|
while (n = *cp++) {
|
|
/*
|
|
* Check for indirection
|
|
*/
|
|
switch (n & INDIR_MASK) {
|
|
case 0:
|
|
if (dn != exp_dn) {
|
|
if (dn >= eom)
|
|
return (-1);
|
|
*dn++ = '.';
|
|
}
|
|
if (dn+n >= eom)
|
|
return (-1);
|
|
checked += n + 1;
|
|
while (--n >= 0) {
|
|
if ((c = *cp++) == '.') {
|
|
if (dn + n + 2 >= eom)
|
|
return (-1);
|
|
*dn++ = '\\';
|
|
}
|
|
*dn++ = c;
|
|
if (cp >= eomorig) /* out of range */
|
|
return(-1);
|
|
}
|
|
break;
|
|
|
|
case INDIR_MASK:
|
|
if (len < 0)
|
|
len = cp - comp_dn + 1;
|
|
cp = (u_char *)msg + (((n & 0x3f) << 8) | (*cp & 0xff));
|
|
if (cp < msg || cp >= eomorig) /* out of range */
|
|
return(-1);
|
|
checked += 2;
|
|
/*
|
|
* Check for loops in the compressed name;
|
|
* if we've looked at the whole message,
|
|
* there must be a loop.
|
|
*/
|
|
if (checked >= eomorig - msg)
|
|
return (-1);
|
|
break;
|
|
|
|
default:
|
|
return (-1); /* flag error */
|
|
}
|
|
}
|
|
*dn = '\0';
|
|
if (len < 0)
|
|
len = cp - comp_dn;
|
|
return (len);
|
|
}
|
|
|
|
/*
|
|
* Compress domain name 'exp_dn' into 'comp_dn'.
|
|
* Return the size of the compressed name or -1.
|
|
* 'length' is the size of the array pointed to by 'comp_dn'.
|
|
* 'dnptrs' is a list of pointers to previous compressed names. dnptrs[0]
|
|
* is a pointer to the beginning of the message. The list ends with NULL.
|
|
* 'lastdnptr' is a pointer to the end of the arrary pointed to
|
|
* by 'dnptrs'. Side effect is to update the list of pointers for
|
|
* labels inserted into the message as we compress the name.
|
|
* If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr'
|
|
* is NULL, we don't update the list.
|
|
*/
|
|
dn_comp(exp_dn, comp_dn, length, dnptrs, lastdnptr)
|
|
const u_char *exp_dn;
|
|
u_char *comp_dn, **dnptrs, **lastdnptr;
|
|
int length;
|
|
{
|
|
register u_char *cp, *dn;
|
|
register int c, l;
|
|
u_char **cpp, **lpp, *sp, *eob;
|
|
u_char *msg;
|
|
|
|
dn = (u_char *)exp_dn;
|
|
cp = comp_dn;
|
|
eob = cp + length;
|
|
if (dnptrs != NULL) {
|
|
if ((msg = *dnptrs++) != NULL) {
|
|
for (cpp = dnptrs; *cpp != NULL; cpp++)
|
|
;
|
|
lpp = cpp; /* end of list to search */
|
|
}
|
|
} else
|
|
msg = NULL;
|
|
for (c = *dn++; c != '\0'; ) {
|
|
/* look to see if we can use pointers */
|
|
if (msg != NULL) {
|
|
if ((l = dn_find(dn-1, msg, dnptrs, lpp)) >= 0) {
|
|
if (cp+1 >= eob)
|
|
return (-1);
|
|
*cp++ = (l >> 8) | INDIR_MASK;
|
|
*cp++ = l % 256;
|
|
return (cp - comp_dn);
|
|
}
|
|
/* not found, save it */
|
|
if (lastdnptr != NULL && cpp < lastdnptr-1) {
|
|
*cpp++ = cp;
|
|
*cpp = NULL;
|
|
}
|
|
}
|
|
sp = cp++; /* save ptr to length byte */
|
|
do {
|
|
if (c == '.') {
|
|
c = *dn++;
|
|
break;
|
|
}
|
|
if (c == '\\') {
|
|
if ((c = *dn++) == '\0')
|
|
break;
|
|
}
|
|
if (cp >= eob) {
|
|
if (msg != NULL)
|
|
*lpp = NULL;
|
|
return (-1);
|
|
}
|
|
*cp++ = c;
|
|
} while ((c = *dn++) != '\0');
|
|
/* catch trailing '.'s but not '..' */
|
|
if ((l = cp - sp - 1) == 0 && c == '\0') {
|
|
cp--;
|
|
break;
|
|
}
|
|
if (l <= 0 || l > MAXLABEL) {
|
|
if (msg != NULL)
|
|
*lpp = NULL;
|
|
return (-1);
|
|
}
|
|
*sp = l;
|
|
}
|
|
if (cp >= eob) {
|
|
if (msg != NULL)
|
|
*lpp = NULL;
|
|
return (-1);
|
|
}
|
|
*cp++ = '\0';
|
|
return (cp - comp_dn);
|
|
}
|
|
|
|
/*
|
|
* Skip over a compressed domain name. Return the size or -1.
|
|
*/
|
|
__dn_skipname(comp_dn, eom)
|
|
const u_char *comp_dn, *eom;
|
|
{
|
|
register u_char *cp;
|
|
register int n;
|
|
|
|
cp = (u_char *)comp_dn;
|
|
while (cp < eom && (n = *cp++)) {
|
|
/*
|
|
* check for indirection
|
|
*/
|
|
switch (n & INDIR_MASK) {
|
|
case 0: /* normal case, n == len */
|
|
cp += n;
|
|
continue;
|
|
default: /* illegal type */
|
|
return (-1);
|
|
case INDIR_MASK: /* indirection */
|
|
cp++;
|
|
}
|
|
break;
|
|
}
|
|
return (cp - comp_dn);
|
|
}
|
|
|
|
/*
|
|
* Search for expanded name from a list of previously compressed names.
|
|
* Return the offset from msg if found or -1.
|
|
* dnptrs is the pointer to the first name on the list,
|
|
* not the pointer to the start of the message.
|
|
*/
|
|
static
|
|
dn_find(exp_dn, msg, dnptrs, lastdnptr)
|
|
u_char *exp_dn, *msg;
|
|
u_char **dnptrs, **lastdnptr;
|
|
{
|
|
register u_char *dn, *cp, **cpp;
|
|
register int n;
|
|
u_char *sp;
|
|
|
|
for (cpp = dnptrs; cpp < lastdnptr; cpp++) {
|
|
dn = exp_dn;
|
|
sp = cp = *cpp;
|
|
while (n = *cp++) {
|
|
/*
|
|
* check for indirection
|
|
*/
|
|
switch (n & INDIR_MASK) {
|
|
case 0: /* normal case, n == len */
|
|
while (--n >= 0) {
|
|
if (*dn == '.')
|
|
goto next;
|
|
if (*dn == '\\')
|
|
dn++;
|
|
if (*dn++ != *cp++)
|
|
goto next;
|
|
}
|
|
if ((n = *dn++) == '\0' && *cp == '\0')
|
|
return (sp - msg);
|
|
if (n == '.')
|
|
continue;
|
|
goto next;
|
|
|
|
default: /* illegal type */
|
|
return (-1);
|
|
|
|
case INDIR_MASK: /* indirection */
|
|
cp = msg + (((n & 0x3f) << 8) | *cp);
|
|
}
|
|
}
|
|
if (*dn == '\0')
|
|
return (sp - msg);
|
|
next: ;
|
|
}
|
|
return (-1);
|
|
}
|
|
|
|
/*
|
|
* Routines to insert/extract short/long's. Must account for byte
|
|
* order and non-alignment problems. This code at least has the
|
|
* advantage of being portable.
|
|
*
|
|
* used by sendmail.
|
|
*/
|
|
|
|
u_short
|
|
_getshort(msgp)
|
|
u_char *msgp;
|
|
{
|
|
register u_char *p = (u_char *) msgp;
|
|
#ifdef vax
|
|
/*
|
|
* vax compiler doesn't put shorts in registers
|
|
*/
|
|
register u_long u;
|
|
#else
|
|
register u_short u;
|
|
#endif
|
|
|
|
u = *p++ << 8;
|
|
return ((u_short)(u | *p));
|
|
}
|
|
|
|
u_long
|
|
_getlong(msgp)
|
|
u_char *msgp;
|
|
{
|
|
register u_char *p = (u_char *) msgp;
|
|
register u_long u;
|
|
|
|
u = *p++; u <<= 8;
|
|
u |= *p++; u <<= 8;
|
|
u |= *p++; u <<= 8;
|
|
return (u | *p);
|
|
}
|
|
|
|
void
|
|
#ifdef __STDC__
|
|
__putshort(register u_short s, register u_char *msgp)
|
|
#else
|
|
__putshort(s, msgp)
|
|
register u_short s;
|
|
register u_char *msgp;
|
|
#endif
|
|
{
|
|
msgp[1] = s;
|
|
msgp[0] = s >> 8;
|
|
}
|
|
|
|
void
|
|
__putlong(l, msgp)
|
|
register u_long l;
|
|
register u_char *msgp;
|
|
{
|
|
msgp[3] = l;
|
|
msgp[2] = (l >>= 8);
|
|
msgp[1] = (l >>= 8);
|
|
msgp[0] = l >> 8;
|
|
}
|