sys/dist/ipf/netinet/ip_netbios_pxy.c

   1 /*      $NetBSD: ip_netbios_pxy.c,v 1.3 2006/04/04 16:17:19 martti 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 2.8.2.1 2005/08/20 13:48:23 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 2.8.2.1 2005/08/20 13:48:23 darrenr Exp
  35  */
  36
  37 #include <sys/cdefs.h>
  38 __KERNEL_RCSID(1, "$NetBSD: ip_netbios_pxy.c,v 1.3 2006/04/04 16:17:19 martti Exp $");
  39
  40 #define IPF_NETBIOS_PROXY
  41
  42 int ippr_netbios_init __P((void));
  43 void ippr_netbios_fini __P((void));
  44 int ippr_netbios_out __P((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 int ippr_netbios_init()
  54 {
  55         bzero((char *)&netbiosfr, sizeof(netbiosfr));
  56         netbiosfr.fr_ref = 1;
  57         netbiosfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
  58         MUTEX_INIT(&netbiosfr.fr_lock, "NETBIOS proxy rule lock");
  59         netbios_proxy_init = 1;
  60
  61         return 0;
  62 }
  63
  64
  65 void ippr_netbios_fini()
  66 {
  67         if (netbios_proxy_init == 1) {
  68                 MUTEX_DESTROY(&netbiosfr.fr_lock);
  69                 netbios_proxy_init = 0;
  70         }
  71 }
  72
  73
  74 int ippr_netbios_out(fin, aps, nat)
  75 fr_info_t *fin;
  76 ap_session_t *aps;
  77 nat_t *nat;
  78 {
  79         char dgmbuf[6];
  80         int off, dlen;
  81         udphdr_t *udp;
  82         ip_t *ip;
  83         mb_t *m;
  84
  85         aps = aps;      /* LINT */
  86         nat = nat;      /* LINT */
  87
  88         m = fin->fin_m;
  89         dlen = fin->fin_dlen - sizeof(*udp);
  90         /*
  91          * no net bios datagram could possibly be shorter than this
  92          */
  93         if (dlen < 11)
  94                 return 0;
  95
  96         ip = fin->fin_ip;
  97         udp = (udphdr_t *)fin->fin_dp;
  98         off = (char *)udp - (char *)ip + sizeof(*udp) + fin->fin_ipoff;
  99
 100         /*
 101          * move past the
 102          *      ip header;
 103          *      udp header;
 104          *      4 bytes into the net bios dgm header.
 105          *  According to rfc1002, this should be the exact location of
 106          *  the source address/port
 107          */
 108         off += 4;
 109
 110         /* Copy NATed source Address/port*/
 111         dgmbuf[0] = (char)((ip->ip_src.s_addr     ) &0xFF);
 112         dgmbuf[1] = (char)((ip->ip_src.s_addr >> 8) &0xFF);
 113         dgmbuf[2] = (char)((ip->ip_src.s_addr >> 16)&0xFF);
 114         dgmbuf[3] = (char)((ip->ip_src.s_addr >> 24)&0xFF);
 115
 116         dgmbuf[4] = (char)((udp->uh_sport     )&0xFF);
 117         dgmbuf[5] = (char)((udp->uh_sport >> 8)&0xFF);
 118
 119         /* replace data in packet */
 120         COPYBACK(m, off, sizeof(dgmbuf), dgmbuf);
 121
 122         return 0;
 123 }