1 /* $NetBSD: ip_netbios_pxy.c,v 1.5 2004/03/28 09:00:57 martti 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 2003/12/01 02:52:16 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 2003/12/01 02:52:16 darrenr Exp
35 */
36
37 __KERNEL_RCSID(1, "$NetBSD: ip_netbios_pxy.c,v 1.5 2004/03/28 09:00:57 martti Exp $");
38
39 #define IPF_NETBIOS_PROXY
40
41 int ippr_netbios_init __P((void));
42 void ippr_netbios_fini __P((void));
43 int ippr_netbios_out __P((fr_info_t *, ap_session_t *, nat_t *));
44
45 static frentry_t netbiosfr;
46
47 int netbios_proxy_init = 0;
48
49 /*
50 * Initialize local structures.
51 */
52 int ippr_netbios_init()
53 {
54 bzero((char *)&netbiosfr, sizeof(netbiosfr));
55 netbiosfr.fr_ref = 1;
56 netbiosfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
57 MUTEX_INIT(&netbiosfr.fr_lock, "NETBIOS proxy rule lock");
58 netbios_proxy_init = 1;
59
60 return 0;
61 }
62
63
64 void ippr_netbios_fini()
65 {
66 if (netbios_proxy_init == 1) {
67 MUTEX_DESTROY(&netbiosfr.fr_lock);
68 netbios_proxy_init = 0;
69 }
70 }
71
72
73 int ippr_netbios_out(fin, aps, nat)
74 fr_info_t *fin;
75 ap_session_t *aps;
76 nat_t *nat;
77 {
78 char dgmbuf[6];
79 int off, dlen;
80 udphdr_t *udp;
81 ip_t *ip;
82 mb_t *m;
83
84 aps = aps; /* LINT */
85 nat = nat; /* LINT */
86
87 ip = fin->fin_ip;
88 m = *(mb_t **)fin->fin_mp;
89 off = fin->fin_hlen + sizeof(udphdr_t);
90 dlen = M_LEN(m);
91 dlen -= off;
92
93 /*
94 * no net bios datagram could possibly be shorter than this
95 */
96 if (dlen < 11)
97 return 0;
98
99 udp = (udphdr_t *)fin->fin_dp;
100
101 /*
102 * move past the
103 * ip header;
104 * udp header;
105 * 4 bytes into the net bios dgm header.
106 * According to rfc1002, this should be the exact location of
107 * the source address/port
108 */
109 off += 4;
110
111 /* Copy NATed source Address/port*/
112 dgmbuf[0] = (char)((ip->ip_src.s_addr ) &0xFF);
113 dgmbuf[1] = (char)((ip->ip_src.s_addr >> 8) &0xFF);
114 dgmbuf[2] = (char)((ip->ip_src.s_addr >> 16)&0xFF);
115 dgmbuf[3] = (char)((ip->ip_src.s_addr >> 24)&0xFF);
116
117 dgmbuf[4] = (char)((udp->uh_sport )&0xFF);
118 dgmbuf[5] = (char)((udp->uh_sport >> 8)&0xFF);
119
120 /* replace data in packet */
121 COPYBACK(m, off, sizeof(dgmbuf), dgmbuf);
122
123 return 0;
124 }
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