1 /*
2  * Simple netbios-dgm transparent proxy for in-kernel use.
3  * For use with the NAT code.
4  * $Id: ip_netbios_pxy.c,v 2.8.2.1 2005/07/15 21:56:51 darrenr Exp $
5  */
6 
7 /*-
8  * Copyright (c) 2002-2003 Paul J. Ledbetter III
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  * $Id: ip_netbios_pxy.c,v 2.8.2.1 2005/07/15 21:56:51 darrenr Exp $
33  *
34  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
35  * Use is subject to license terms.
36  */
37 
38 #pragma ident	"%Z%%M%	%I%	%E% SMI"
39 
40 #define	IPF_NETBIOS_PROXY
41 
42 typedef struct ifs_netbiospxy {
43 	frentry_t	netbiosfr;
44 	int		netbios_proxy_init;
45 } ifs_netbiospxy_t;
46 
47 int ippr_netbios_init __P((void **, ipf_stack_t *));
48 void ippr_netbios_fini __P((void **, ipf_stack_t *));
49 int ippr_netbios_out __P((fr_info_t *, ap_session_t *, nat_t *, void *));
50 
51 /*
52  * Initialize local structures.
53  */
54 /*ARGSUSED*/
55 int ippr_netbios_init(private, ifs)
56 void **private;
57 ipf_stack_t *ifs;
58 {
59 	ifs_netbiospxy_t *ifsnetbios;
60 
61 	KMALLOC(ifsnetbios, ifs_netbiospxy_t *);
62 	if (ifsnetbios == NULL)
63 		return -1;
64 
65 	bzero((char *)&ifsnetbios->netbiosfr, sizeof(ifsnetbios->netbiosfr));
66 	ifsnetbios->netbiosfr.fr_ref = 1;
67 	ifsnetbios->netbiosfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
68 	MUTEX_INIT(&ifsnetbios->netbiosfr.fr_lock, "NETBIOS proxy rule lock");
69 	ifsnetbios->netbios_proxy_init = 1;
70 
71 	*private = (void *)ifsnetbios;
72 
73 	return 0;
74 }
75 
76 
77 /*ARGSUSED*/
78 void ippr_netbios_fini(private, ifs)
79 void **private;
80 ipf_stack_t *ifs;
81 {
82 	ifs_netbiospxy_t *ifsnetbios = *((ifs_netbiospxy_t **)private);
83 
84 	if (ifsnetbios->netbios_proxy_init == 1) {
85 		MUTEX_DESTROY(&ifsnetbios->netbiosfr.fr_lock);
86 		ifsnetbios->netbios_proxy_init = 0;
87 	}
88 
89 	KFREE(ifsnetbios);
90 	*private = NULL;
91 }
92 
93 
94 /*ARGSUSED*/
95 int ippr_netbios_out(fin, aps, nat, private)
96 fr_info_t *fin;
97 ap_session_t *aps;
98 nat_t *nat;
99 void *private;
100 {
101 	char dgmbuf[6];
102 	int off, dlen;
103 	udphdr_t *udp;
104 	ip_t *ip;
105 	mb_t *m;
106 
107 	aps = aps;	/* LINT */
108 	nat = nat;	/* LINT */
109 
110 	m = fin->fin_m;
111 	dlen = fin->fin_dlen - sizeof(*udp);
112 	/*
113 	 * no net bios datagram could possibly be shorter than this
114 	 */
115 	if (dlen < 11)
116 		return 0;
117 
118 	ip = fin->fin_ip;
119 	udp = (udphdr_t *)fin->fin_dp;
120 	off = (char *)udp - (char *)ip + sizeof(*udp) + fin->fin_ipoff;
121 
122 	/*
123 	 * move past the
124 	 *	ip header;
125 	 *	udp header;
126 	 *	4 bytes into the net bios dgm header.
127 	 *  According to rfc1002, this should be the exact location of
128 	 *  the source address/port
129 	 */
130 	off += 4;
131 
132 	/* Copy NATed source Address/port*/
133 	dgmbuf[0] = (char)((ip->ip_src.s_addr     ) &0xFF);
134 	dgmbuf[1] = (char)((ip->ip_src.s_addr >> 8) &0xFF);
135 	dgmbuf[2] = (char)((ip->ip_src.s_addr >> 16)&0xFF);
136 	dgmbuf[3] = (char)((ip->ip_src.s_addr >> 24)&0xFF);
137 
138 	dgmbuf[4] = (char)((udp->uh_sport     )&0xFF);
139 	dgmbuf[5] = (char)((udp->uh_sport >> 8)&0xFF);
140 
141 	/* replace data in packet */
142 	COPYBACK(m, off, sizeof(dgmbuf), dgmbuf);
143 
144 	return 0;
145 }
146