1/*	$NetBSD: ip_netbios_pxy.c,v 1.4 2007/12/11 04:55:02 lukem Exp $	*/
2
3/*
4 * Simple netbios-dgm transparent proxy for in-kernel use.
5 * For use with the NAT code.
6 * Id: ip_netbios_pxy.c,v 2.8.2.1 2005/08/20 13:48:23 darrenr Exp
7 */
8
9/*-
10 * Copyright (c) 2002-2003 Paul J. Ledbetter III
11 * All rights reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 *    notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 *    notice, this list of conditions and the following disclaimer in the
20 *    documentation and/or other materials provided with the distribution.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * Id: ip_netbios_pxy.c,v 2.8.2.1 2005/08/20 13:48:23 darrenr Exp
35 */
36
37#include <sys/cdefs.h>
38__KERNEL_RCSID(1, "$NetBSD: ip_netbios_pxy.c,v 1.4 2007/12/11 04:55:02 lukem Exp $");
39
40#define	IPF_NETBIOS_PROXY
41
42int
43ippr_netbios_init(void);
44void
45ippr_netbios_fini(void);
46int
47ippr_netbios_out(fr_info_t *, ap_session_t *, nat_t *);
48
49static	frentry_t	netbiosfr;
50
51int	netbios_proxy_init = 0;
52
53/*
54 * Initialize local structures.
55 */
56int
57ippr_netbios_init(void)
58{
59	bzero((char *)&netbiosfr, sizeof(netbiosfr));
60	netbiosfr.fr_ref = 1;
61	netbiosfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
62	MUTEX_INIT(&netbiosfr.fr_lock, "NETBIOS proxy rule lock");
63	netbios_proxy_init = 1;
64
65	return 0;
66}
67
68
69void
70ippr_netbios_fini(void)
71{
72	if (netbios_proxy_init == 1) {
73		MUTEX_DESTROY(&netbiosfr.fr_lock);
74		netbios_proxy_init = 0;
75	}
76}
77
78
79int
80ippr_netbios_out(fr_info_t *fin, ap_session_t *aps, nat_t *nat)
81{
82	char dgmbuf[6];
83	int off, dlen;
84	udphdr_t *udp;
85	ip_t *ip;
86	mb_t *m;
87
88	aps = aps;	/* LINT */
89	nat = nat;	/* LINT */
90
91	m = fin->fin_m;
92	dlen = fin->fin_dlen - sizeof(*udp);
93	/*
94	 * no net bios datagram could possibly be shorter than this
95	 */
96	if (dlen < 11)
97		return 0;
98
99	ip = fin->fin_ip;
100	udp = (udphdr_t *)fin->fin_dp;
101	off = (char *)udp - (char *)ip + sizeof(*udp) + fin->fin_ipoff;
102
103	/*
104	 * move past the
105	 *	ip header;
106	 *	udp header;
107	 *	4 bytes into the net bios dgm header.
108	 *  According to rfc1002, this should be the exact location of
109	 *  the source address/port
110	 */
111	off += 4;
112
113	/* Copy NATed source Address/port*/
114	dgmbuf[0] = (char)((ip->ip_src.s_addr     ) &0xFF);
115	dgmbuf[1] = (char)((ip->ip_src.s_addr >> 8) &0xFF);
116	dgmbuf[2] = (char)((ip->ip_src.s_addr >> 16)&0xFF);
117	dgmbuf[3] = (char)((ip->ip_src.s_addr >> 24)&0xFF);
118
119	dgmbuf[4] = (char)((udp->uh_sport     )&0xFF);
120	dgmbuf[5] = (char)((udp->uh_sport >> 8)&0xFF);
121
122	/* replace data in packet */
123	COPYBACK(m, off, sizeof(dgmbuf), dgmbuf);
124
125	return 0;
126}
127