ip_netbios_pxy.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* Simple netbios-dgm transparent proxy for in-kernel use.
* For use with the NAT code.
* $Id: ip_netbios_pxy.c,v 2.7 2003/06/25 12:08:21 darrenr Exp $
*/
/*-
* Copyright (c) 2002-2003 Paul J. Ledbetter III
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $Id: ip_netbios_pxy.c,v 2.7 2003/06/25 12:08:21 darrenr Exp $
*/
#define IPF_NETBIOS_PROXY
int ippr_netbios_init __P((void));
void ippr_netbios_fini __P((void));
int ippr_netbios_out __P((fr_info_t *, ap_session_t *, nat_t *));
static frentry_t netbiosfr;
int netbios_proxy_init = 0;
/*
* Initialize local structures.
*/
int ippr_netbios_init()
{
bzero((char *)&netbiosfr, sizeof(netbiosfr));
netbiosfr.fr_ref = 1;
netbiosfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
MUTEX_INIT(&netbiosfr.fr_lock, "NETBIOS proxy rule lock");
netbios_proxy_init = 1;
return 0;
}
void ippr_netbios_fini()
{
if (netbios_proxy_init == 1) {
MUTEX_DESTROY(&netbiosfr.fr_lock);
netbios_proxy_init = 0;
}
}
int ippr_netbios_out(fin, aps, nat)
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
char dgmbuf[6];
int off, dlen;
udphdr_t *udp;
ip_t *ip;
mb_t *m;
aps = aps; /* LINT */
nat = nat; /* LINT */
ip = fin->fin_ip;
m = *(mb_t **)fin->fin_mp;
off = fin->fin_hlen + sizeof(udphdr_t);
dlen = M_LEN(m);
dlen -= off;
/*
* no net bios datagram could possibly be shorter than this
*/
if (dlen < 11)
return 0;
udp = (udphdr_t *)fin->fin_dp;
/*
* move past the
* ip header;
* udp header;
* 4 bytes into the net bios dgm header.
* According to rfc1002, this should be the exact location of
* the source address/port
*/
off += 4;
/* Copy NATed source Address/port*/
dgmbuf[0] = (char)((ip->ip_src.s_addr ) &0xFF);
dgmbuf[1] = (char)((ip->ip_src.s_addr >> 8) &0xFF);
dgmbuf[2] = (char)((ip->ip_src.s_addr >> 16)&0xFF);
dgmbuf[3] = (char)((ip->ip_src.s_addr >> 24)&0xFF);
dgmbuf[4] = (char)((udp->uh_sport )&0xFF);
dgmbuf[5] = (char)((udp->uh_sport >> 8)&0xFF);
/* replace data in packet */
COPYBACK(m, off, sizeof(dgmbuf), dgmbuf);
return 0;
}