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By Popular Request 2.0 (Arsenal Computer).ISO
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amiga_4
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named.lha
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named.c
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C/C++ Source or Header
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1995-03-21
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514 lines
/*
**
** AmiTCP Dumb Nameserver
** ----------------------
** Amiga version hacked & slain by Oliver Wagner (o.wagner@pluribus.wupper.de)
**
** very loosely based on JoranNameserver for AmiTCP 2.x
**
** compile with SAS/C 6.55
**
*/
#include <bsdsocket.h>
#include <syslog.h>
#define BYTE_ORDER BIG_ENDIAN
#include <arpa/nameser.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
// Amiga stuff
#include <proto/dos.h>
#include <dos/stdio.h>
#include <proto/utility.h>
#include <string.h>
#include "rev.h"
char version[] = {á"$VER: AmiTCP-NameServer " VERTAG };
long __oslibversion = 37;
/*
* ++Copyright++ 1985
* -
* 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.
* -
* 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--
*/
/*
* 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.
*/
static dn_expand(const u_char *msg, const u_char *eomorig, const u_char *comp_dn, u_char *exp_dn, int length)
{
u_char *cp, *dn;
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);
}
/*
* 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 int dn_find(u_char *exp_dn, u_char *msg, u_char **dnptrs, u_char **lastdnptr)
{
u_char *dn, *cp, **cpp;
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);
}
/*
* 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.
*/
static dn_comp( const u_char *exp_dn, u_char *comp_dn, int length, u_char **dnptrs, u_char **lastdnptr)
{
u_char *cp, *dn;
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);
}
// -------------------------------------------------------------------------
/*
** Amiga specific stuff
*/
/*
** Format of host entries
*/
#define ENTRYTIMEOUT (3600*24*90) // 90 Days timeout
struct nsdbentry {
time_t read; // When entry was created
ULONG ip;
ULONG hash;
UBYTE name[á244 ];
};
//
// We do some hashing to avoid numerous stricmp()s
//
static ULONG hash( char *name )
{
ULONG val = strlen( name );
while( *name )
val = ( val * 13 ) + ( ToUpper( *name++ ) );
return( val );
}
static ULONG findhost( char *name )
{
BPTR fh = Open( "AmiTCP:db/nameserver.db", MODE_OLDFILE );
ULONG myhash = hash( name );
struct nsdbentry ns;
time_t limit = time( NULL ) - ENTRYTIMEOUT;
int toold = FALSE;
struct hostent *host;
// First, look into table
if( fh )
{
SetVBuf( fh, NULL, BUF_FULL, 16384 );
Flush( fh );
while( FRead( fh, &ns, sizeof( ns ), 1 ) == 1 )
{
// Found!
if( ns.hash == myhash && !stricmp( ns.name, name ) )
{
if( ns.read >= limit )
{
// ok!
Close( fh );
return( ns.ip );
}
// Found, but too old
toold = TRUE;
break;
}
}
}
// We need to do a real lookup
host = gethostbyname( name );
if( !host )
{
if( fh )
Close( fh );
return( ~0 );
}
// Create entry
time( &ns.read );
memcpy( &ns.ip, &host->h_addr_list[á0 ][á0 ], 4 );
ns.hash = myhash;
strncpy( ns.name, name, 243 ); // This really sucks...
ns.name[á243 ]á= 0;
if( !fh )
fh = Open( "AmiTCP:db/nameserver.db", MODE_NEWFILE );
if( fh )
{
Flush( fh );
if( toold )
Seek( fh, -sizeof ns , OFFSET_CURRENT );
else
Seek( fh, 0, OFFSET_END );
Write( fh, &ns, sizeof ns );
Close( fh );
}
return( ns.ip );
}
static void send_err( int s, char *msg, int msglen, struct sockaddr_in *to, LONG tolen, short rcode )
{
HEADER *h;
h = ( HEADER * ) msg + sizeof( HEADER );
h->qr = 1;
h->rcode = rcode;
sendto( s, msg, msglen, 0, ( struct sockaddr * ) to, tolen );
}
void __stdargs __main( char *dummy )
{
int s; /* Datagram socket */
struct sockaddr_in from; /* Address of requestor */
int fromlen; /* Length of his address */
int msglen; /* Length of the message received */
ULONG ip;
UBYTE msg[á512 ], *cp, *eom, dnbuf[á512 ], *lmsg;
HEADER *h;
int n, type, class;
ULONG xxx = 100000;
s = init_inet_daemon();
if( s < 0 )
exit( 20 );
SetProgramName( "NameD" );
openlog( "NameD", LOG_PID | LOG_CONS, LOG_DAEMON );
fromlen = sizeof( from );
/* Main loop */
for(;;)
{
if( CheckSignal( SIGBREAKF_CTRL_C ) )
break;
/* Read a message */
fromlen = sizeof(from);
if( ( msglen = recvfrom( s, msg, sizeof( msg ), 0, (struct sockaddr *)&from, &fromlen ) ) == -1 )
{
syslog( LOG_ERR, "recvfrom() error %ld", Errno() );
continue;
}
h = ( HEADER * ) msg;
if( h->opcode != QUERY )
{
send_err( s, msg, msglen, &from, fromlen, NOTIMP );
continue;
}
cp = msg + sizeof( HEADER );
eom = msg + msglen;
// Only simple requests
if( h->qdcount != 1 || h->ancount || h->nscount || h->arcount )
{
h->qdcount = 0;
h->ancount = 0;
h->nscount = 0;
h->arcount = 0;
send_err( s, msg, msglen, &from, fromlen, FORMERR );
continue;
}
if( ( n = dn_expand( msg, eom, cp, dnbuf, sizeof( dnbuf ) ) ) < 0 )
{
send_err(s,msg,msglen,&from,fromlen,FORMERR);
continue;
}
cp += n;
GETSHORT( type, cp );
GETSHORT( class, cp );
if( cp > eom )
{
send_err( s, msg, msglen, &from, fromlen, FORMERR );
continue;
}
if( type != T_A || class != C_IN )
{
send_err(s,msg,msglen,&from,fromlen,NOTIMP);
continue;
}
// find IP address of host
ip = findhost( dnbuf );
if( ip == ~0 )
{
send_err( s, msg, msglen, &from, fromlen, NXDOMAIN );
continue;
}
lmsg = msg + sizeof( msg );
if( ( n = dn_comp( dnbuf, cp, lmsg - cp, NULL, NULL ) ) < 0 )
{
send_err( s, msg, msglen, &from, fromlen, SERVFAIL );
continue;
}
cp += n;
if( cp + 14 > lmsg )
{
send_err( s, msg, msglen, &from, fromlen, SERVFAIL );
continue;
}
PUTSHORT( type, cp );
PUTSHORT( class, cp );
PUTLONG( xxx, cp );
PUTSHORT( sizeof( LONG ), cp );
PUTLONG( ip, cp );
h->qr = 1;
h->rcode = NOERROR;
h->ancount = 1;
sendto( s, msg, cp - msg, 0, ( struct sockaddr * ) &from, fromlen );
}
}
// EOF