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 37 void ipf_p_netbios_main_load(void); 38 void ipf_p_netbios_main_unload(void); 39 int ipf_p_netbios_out(void *, fr_info_t *, ap_session_t *, nat_t *); 40 41 static frentry_t netbiosfr; 42 43 int netbios_proxy_init = 0; 44 45 /* 46 * Initialize local structures. 47 */ 48 void 49 ipf_p_netbios_main_load(void) 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 59 void 60 ipf_p_netbios_main_unload(void) 61 { 62 if (netbios_proxy_init == 1) { 63 MUTEX_DESTROY(&netbiosfr.fr_lock); 64 netbios_proxy_init = 0; 65 } 66 } 67 68 69 int 70 ipf_p_netbios_out(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat) 71 { 72 char dgmbuf[6]; 73 int off, dlen; 74 udphdr_t *udp; 75 ip_t *ip; 76 mb_t *m; 77 78 aps = aps; /* LINT */ 79 nat = nat; /* LINT */ 80 81 m = fin->fin_m; 82 dlen = fin->fin_dlen - sizeof(*udp); 83 /* 84 * no net bios datagram could possibly be shorter than this 85 */ 86 if (dlen < 11) 87 return (0); 88 89 ip = fin->fin_ip; 90 udp = (udphdr_t *)fin->fin_dp; 91 off = (char *)udp - (char *)ip + sizeof(*udp) + fin->fin_ipoff; 92 93 /* 94 * move past the 95 * ip header; 96 * udp header; 97 * 4 bytes into the net bios dgm header. 98 * According to rfc1002, this should be the exact location of 99 * the source address/port 100 */ 101 off += 4; 102 103 /* Copy NATed source Address/port*/ 104 dgmbuf[0] = (char)((ip->ip_src.s_addr ) &0xFF); 105 dgmbuf[1] = (char)((ip->ip_src.s_addr >> 8) &0xFF); 106 dgmbuf[2] = (char)((ip->ip_src.s_addr >> 16)&0xFF); 107 dgmbuf[3] = (char)((ip->ip_src.s_addr >> 24)&0xFF); 108 109 dgmbuf[4] = (char)((udp->uh_sport )&0xFF); 110 dgmbuf[5] = (char)((udp->uh_sport >> 8)&0xFF); 111 112 /* replace data in packet */ 113 COPYBACK(m, off, sizeof(dgmbuf), dgmbuf); 114 115 return (0); 116 } 117