1/* 2 * Simple netbios-dgm transparent proxy for in-kernel use. 3 * For use with the NAT code. 4 * $Id$ 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 * $Id$ 33 */ 34 35#define IPF_NETBIOS_PROXY 36 37void ipf_p_netbios_main_load __P((void)); 38void ipf_p_netbios_main_unload __P((void)); 39int ipf_p_netbios_out __P((void *, fr_info_t *, ap_session_t *, nat_t *)); 40 41static frentry_t netbiosfr; 42 43int netbios_proxy_init = 0; 44 45/* 46 * Initialize local structures. 47 */ 48void 49ipf_p_netbios_main_load() 50{ 51 bzero((char *)&netbiosfr, sizeof(netbiosfr)); 52 netbiosfr.fr_ref = 1; 53 netbiosfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE; 54 MUTEX_INIT(&netbiosfr.fr_lock, "NETBIOS proxy rule lock"); 55 netbios_proxy_init = 1; 56} 57 58 59void 60ipf_p_netbios_main_unload() 61{ 62 if (netbios_proxy_init == 1) { 63 MUTEX_DESTROY(&netbiosfr.fr_lock); 64 netbios_proxy_init = 0; 65 } 66} 67 68 69int 70ipf_p_netbios_out(arg, fin, aps, nat) 71 void *arg; 72 fr_info_t *fin; 73 ap_session_t *aps; 74 nat_t *nat; 75{ 76 char dgmbuf[6]; 77 int off, dlen; 78 udphdr_t *udp; 79 ip_t *ip; 80 mb_t *m; 81 82 aps = aps; /* LINT */ 83 nat = nat; /* LINT */ 84 85 m = fin->fin_m; 86 dlen = fin->fin_dlen - sizeof(*udp); 87 /* 88 * no net bios datagram could possibly be shorter than this 89 */ 90 if (dlen < 11) 91 return 0; 92 93 ip = fin->fin_ip; 94 udp = (udphdr_t *)fin->fin_dp; 95 off = (char *)udp - (char *)ip + sizeof(*udp) + fin->fin_ipoff; 96 97 /* 98 * move past the 99 * ip header; 100 * udp header; 101 * 4 bytes into the net bios dgm header. 102 * According to rfc1002, this should be the exact location of 103 * the source address/port 104 */ 105 off += 4; 106 107 /* Copy NATed source Address/port*/ 108 dgmbuf[0] = (char)((ip->ip_src.s_addr ) &0xFF); 109 dgmbuf[1] = (char)((ip->ip_src.s_addr >> 8) &0xFF); 110 dgmbuf[2] = (char)((ip->ip_src.s_addr >> 16)&0xFF); 111 dgmbuf[3] = (char)((ip->ip_src.s_addr >> 24)&0xFF); 112 113 dgmbuf[4] = (char)((udp->uh_sport )&0xFF); 114 dgmbuf[5] = (char)((udp->uh_sport >> 8)&0xFF); 115 116 /* replace data in packet */ 117 COPYBACK(m, off, sizeof(dgmbuf), dgmbuf); 118 119 return 0; 120} 121