1 /* $NetBSD: ip_netbios_pxy.c,v 1.3 2012/07/22 14:27:51 darrenr 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 1.1.1.2 2012/07/22 13:45:30 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 1.1.1.2 2012/07/22 13:45:30 darrenr Exp
35 */
36
37 #include <sys/cdefs.h>
38 __KERNEL_RCSID(1, "$NetBSD: ip_netbios_pxy.c,v 1.3 2012/07/22 14:27:51 darrenr Exp $");
39
40 #define IPF_NETBIOS_PROXY
41
42 void ipf_p_netbios_main_load(void);
43 void ipf_p_netbios_main_unload(void);
44 int ipf_p_netbios_out(void *, fr_info_t *, ap_session_t *, nat_t *);
45
46 static frentry_t netbiosfr;
47
48 int netbios_proxy_init = 0;
49
50 /*
51 * Initialize local structures.
52 */
53 void
ipf_p_netbios_main_load(void)54 ipf_p_netbios_main_load(void)
55 {
56 bzero((char *)&netbiosfr, sizeof(netbiosfr));
57 netbiosfr.fr_ref = 1;
58 netbiosfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
59 MUTEX_INIT(&netbiosfr.fr_lock, "NETBIOS proxy rule lock");
60 netbios_proxy_init = 1;
61 }
62
63
64 void
ipf_p_netbios_main_unload(void)65 ipf_p_netbios_main_unload(void)
66 {
67 if (netbios_proxy_init == 1) {
68 MUTEX_DESTROY(&netbiosfr.fr_lock);
69 netbios_proxy_init = 0;
70 }
71 }
72
73
74 int
ipf_p_netbios_out(void * arg,fr_info_t * fin,ap_session_t * aps,nat_t * nat)75 ipf_p_netbios_out(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat)
76 {
77 char dgmbuf[6];
78 int off, dlen;
79 udphdr_t *udp;
80 ip_t *ip;
81 mb_t *m;
82
83 aps = aps; /* LINT */
84 nat = nat; /* LINT */
85
86 m = fin->fin_m;
87 dlen = fin->fin_dlen - sizeof(*udp);
88 /*
89 * no net bios datagram could possibly be shorter than this
90 */
91 if (dlen < 11)
92 return 0;
93
94 ip = fin->fin_ip;
95 udp = (udphdr_t *)fin->fin_dp;
96 off = (char *)udp - (char *)ip + sizeof(*udp) + fin->fin_ipoff;
97
98 /*
99 * move past the
100 * ip header;
101 * udp header;
102 * 4 bytes into the net bios dgm header.
103 * According to rfc1002, this should be the exact location of
104 * the source address/port
105 */
106 off += 4;
107
108 /* Copy NATed source Address/port*/
109 dgmbuf[0] = (char)((ip->ip_src.s_addr ) &0xFF);
110 dgmbuf[1] = (char)((ip->ip_src.s_addr >> 8) &0xFF);
111 dgmbuf[2] = (char)((ip->ip_src.s_addr >> 16)&0xFF);
112 dgmbuf[3] = (char)((ip->ip_src.s_addr >> 24)&0xFF);
113
114 dgmbuf[4] = (char)((udp->uh_sport )&0xFF);
115 dgmbuf[5] = (char)((udp->uh_sport >> 8)&0xFF);
116
117 /* replace data in packet */
118 COPYBACK(m, off, sizeof(dgmbuf), dgmbuf);
119
120 return 0;
121 }
122