/*
 * Simple netbios-dgm transparent proxy for in-kernel use.
 * For use with the NAT code.
 * $Id: ip_netbios_pxy.c,v 2.8.2.1 2005/07/15 21:56:51 darrenr Exp $
 */

/*-
 * Copyright (c) 2002-2003 Paul J. Ledbetter III
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $Id: ip_netbios_pxy.c,v 2.8.2.1 2005/07/15 21:56:51 darrenr Exp $
 *
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#define IPF_NETBIOS_PROXY

typedef struct ifs_netbiospxy {
        frentry_t       netbiosfr;
        int             netbios_proxy_init;
} ifs_netbiospxy_t;

int ippr_netbios_init __P((void **, ipf_stack_t *));
void ippr_netbios_fini __P((void **, ipf_stack_t *));
int ippr_netbios_out __P((fr_info_t *, ap_session_t *, nat_t *, void *));

/*
 * Initialize local structures.
 */
/*ARGSUSED*/
int ippr_netbios_init(private, ifs)
void **private;
ipf_stack_t *ifs;
{
        ifs_netbiospxy_t *ifsnetbios;

        KMALLOC(ifsnetbios, ifs_netbiospxy_t *);
        if (ifsnetbios == NULL)
                return -1;

        bzero((char *)&ifsnetbios->netbiosfr, sizeof(ifsnetbios->netbiosfr));
        ifsnetbios->netbiosfr.fr_ref = 1;
        ifsnetbios->netbiosfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
        MUTEX_INIT(&ifsnetbios->netbiosfr.fr_lock, "NETBIOS proxy rule lock");
        ifsnetbios->netbios_proxy_init = 1;

        *private = (void *)ifsnetbios;

        return 0;
}


/*ARGSUSED*/
void ippr_netbios_fini(private, ifs)
void **private;
ipf_stack_t *ifs;
{
        ifs_netbiospxy_t *ifsnetbios = *((ifs_netbiospxy_t **)private);

        if (ifsnetbios->netbios_proxy_init == 1) {
                MUTEX_DESTROY(&ifsnetbios->netbiosfr.fr_lock);
                ifsnetbios->netbios_proxy_init = 0;
        }

        KFREE(ifsnetbios);
        *private = NULL;
}


/*ARGSUSED*/
int ippr_netbios_out(fin, aps, nat, private)
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
void *private;
{
        char dgmbuf[6];
        int off, dlen;
        udphdr_t *udp;
        ip_t *ip;
        mb_t *m;

        aps = aps;      /* LINT */
        nat = nat;      /* LINT */

        m = fin->fin_m;
        dlen = fin->fin_dlen - sizeof(*udp);
        /*
         * no net bios datagram could possibly be shorter than this
         */
        if (dlen < 11)
                return 0;

        ip = fin->fin_ip;
        udp = (udphdr_t *)fin->fin_dp;
        off = (char *)udp - (char *)ip + sizeof(*udp) + fin->fin_ipoff;

        /*
         * move past the
         *      ip header;
         *      udp header;
         *      4 bytes into the net bios dgm header.
         *  According to rfc1002, this should be the exact location of
         *  the source address/port
         */
        off += 4;

        /* Copy NATed source Address/port*/
        dgmbuf[0] = (char)((ip->ip_src.s_addr     ) &0xFF);
        dgmbuf[1] = (char)((ip->ip_src.s_addr >> 8) &0xFF);
        dgmbuf[2] = (char)((ip->ip_src.s_addr >> 16)&0xFF);
        dgmbuf[3] = (char)((ip->ip_src.s_addr >> 24)&0xFF);

        dgmbuf[4] = (char)((udp->uh_sport     )&0xFF);
        dgmbuf[5] = (char)((udp->uh_sport >> 8)&0xFF);

        /* replace data in packet */
        COPYBACK(m, off, sizeof(dgmbuf), dgmbuf);

        return 0;
}