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 |
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 |
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 |
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 | |