/*
 * Copyright (C) 2012 by Darren Reed.
 *
 * See the IPFILTER.LICENCE file for details on licencing.
 */
#if defined(KERNEL) || defined(_KERNEL)
# undef KERNEL
# undef _KERNEL
# define        KERNEL  1
# define        _KERNEL 1
#endif
#include <sys/errno.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/file.h>
# include <sys/fcntl.h>
#if !defined(_KERNEL) && !defined(__KERNEL__)
# include <stdio.h>
# include <string.h>
# include <stdlib.h>
# include <ctype.h>
# define _KERNEL
# include <sys/uio.h>
# undef _KERNEL
#endif
# include <sys/protosw.h>
#include <sys/socket.h>
#if defined(_KERNEL)
#ifdef __FreeBSD__
#  include <sys/ctype.h>
# endif
# include <sys/systm.h>
# if !defined(__SVR4)
#  include <sys/mbuf.h>
# endif
#endif
#if defined(_KERNEL) && defined(__FreeBSD__)
# include <sys/filio.h>
# include <sys/fcntl.h>
#else
# include <sys/ioctl.h>
#endif
#if defined(__SVR4)
# include <sys/byteorder.h>
# ifdef _KERNEL
#  include <sys/dditypes.h>
# endif
# include <sys/stream.h>
# include <sys/kmem.h>
#endif
#ifdef __FreeBSD__
# include <sys/queue.h>
#endif
#include <net/if.h>
#if defined(__FreeBSD__) && defined(_KERNEL)
#include <net/vnet.h>
#else
#define CURVNET_SET(arg)
#define CURVNET_RESTORE()
#define VNET_DEFINE(_t, _v)     _t _v
#define VNET_DECLARE(_t, _v)    extern _t _v
#define VNET(arg)       arg
#endif
#ifdef sun
# include <net/af.h>
#endif
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
# include <netinet/ip_var.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <netinet/ip_icmp.h>
#include "netinet/ip_compat.h"
#include <netinet/tcpip.h>
#include "netinet/ip_fil.h"
#include "netinet/ip_nat.h"
#include "netinet/ip_state.h"
#include "netinet/ip_proxy.h"
#if defined(__FreeBSD__)
# include <sys/malloc.h>
#endif

/* END OF INCLUDES */

#include "netinet/ip_ftp_pxy.c"
#include "netinet/ip_tftp_pxy.c"
#include "netinet/ip_rcmd_pxy.c"
#include "netinet/ip_pptp_pxy.c"
#if defined(_KERNEL)
# include "netinet/ip_irc_pxy.c"
# include "netinet/ip_raudio_pxy.c"
# include "netinet/ip_netbios_pxy.c"
#endif
#include "netinet/ip_ipsec_pxy.c"
#include "netinet/ip_rpcb_pxy.c"


#define AP_SESS_SIZE    53

static int ipf_proxy_fixseqack(fr_info_t *, ip_t *, ap_session_t *, int );
static aproxy_t *ipf_proxy_create_clone(ipf_main_softc_t *, aproxy_t *);

typedef struct ipf_proxy_softc_s {
        int             ips_proxy_debug;
        int             ips_proxy_session_size;
        ap_session_t    **ips_sess_tab;
        ap_session_t    *ips_sess_list;
        aproxy_t        *ips_proxies;
        int             ips_init_run;
        ipftuneable_t   *ipf_proxy_tune;
} ipf_proxy_softc_t;

static ipftuneable_t ipf_proxy_tuneables[] = {
        { { (void *)offsetof(ipf_proxy_softc_t, ips_proxy_debug) },
                "proxy_debug",  0,      0x1f,
                stsizeof(ipf_proxy_softc_t, ips_proxy_debug),
                0,      NULL,   NULL },
        { { NULL },             NULL,                   0,      0,
                0,
                0,      NULL,   NULL}
};

static  aproxy_t        *ap_proxylist = NULL;
static  aproxy_t        ips_proxies[] = {
#ifdef  IPF_FTP_PROXY
        { NULL, NULL, "ftp", (char)IPPROTO_TCP, 0, 0, 0,
          ipf_p_ftp_main_load, ipf_p_ftp_main_unload,
          ipf_p_ftp_soft_create, ipf_p_ftp_soft_destroy,
          NULL, NULL,
          ipf_p_ftp_new, ipf_p_ftp_del, ipf_p_ftp_in, ipf_p_ftp_out, NULL,
          NULL, NULL, NULL, NULL },
#endif
#ifdef  IPF_TFTP_PROXY
        { NULL, NULL, "tftp", (char)IPPROTO_UDP, 0, 0, 0,
          ipf_p_tftp_main_load, ipf_p_tftp_main_unload,
          ipf_p_tftp_soft_create, ipf_p_tftp_soft_destroy,
          NULL, NULL,
          ipf_p_tftp_new, ipf_p_tftp_del,
          ipf_p_tftp_in, ipf_p_tftp_out, NULL,
          NULL, NULL, NULL, NULL },
#endif
#ifdef  IPF_IRC_PROXY
        { NULL, NULL, "irc", (char)IPPROTO_TCP, 0, 0, 0,
          ipf_p_irc_main_load, ipf_p_irc_main_unload,
          NULL, NULL,
          NULL, NULL,
          ipf_p_irc_new, NULL, NULL, ipf_p_irc_out, NULL,
          NULL, NULL, NULL, NULL },
#endif
#ifdef  IPF_RCMD_PROXY
        { NULL, NULL, "rcmd", (char)IPPROTO_TCP, 0, 0, 0,
          ipf_p_rcmd_main_load, ipf_p_rcmd_main_unload,
          NULL, NULL,
          NULL, NULL,
          ipf_p_rcmd_new, ipf_p_rcmd_del,
          ipf_p_rcmd_in, ipf_p_rcmd_out, NULL,
          NULL, NULL, NULL, NULL },
#endif
#ifdef  IPF_RAUDIO_PROXY
        { NULL, NULL, "raudio", (char)IPPROTO_TCP, 0, 0, 0,
          ipf_p_raudio_main_load, ipf_p_raudio_main_unload,
          NULL, NULL,
          NULL, NULL,
          ipf_p_raudio_new, NULL, ipf_p_raudio_in, ipf_p_raudio_out, NULL,
          NULL, NULL, NULL, NULL },
#endif
#ifdef  IPF_MSNRPC_PROXY
        { NULL, NULL, "msnrpc", (char)IPPROTO_TCP, 0, 0, 0,
          ipf_p_msnrpc_init, ipf_p_msnrpc_fini,
          NULL, NULL,
          NULL, NULL,
          ipf_p_msnrpc_new, NULL, ipf_p_msnrpc_in, ipf_p_msnrpc_out, NULL,
          NULL, NULL, NULL, NULL },
#endif
#ifdef  IPF_NETBIOS_PROXY
        { NULL, NULL, "netbios", (char)IPPROTO_UDP, 0, 0, 0,
          ipf_p_netbios_main_load, ipf_p_netbios_main_unload,
          NULL, NULL,
          NULL, NULL,
          NULL, NULL, NULL, ipf_p_netbios_out, NULL,
          NULL, NULL, NULL, NULL },
#endif
#ifdef  IPF_IPSEC_PROXY
        { NULL, NULL, "ipsec", (char)IPPROTO_UDP, 0, 0, 0,
          NULL, NULL,
          ipf_p_ipsec_soft_create, ipf_p_ipsec_soft_destroy,
          ipf_p_ipsec_soft_init, ipf_p_ipsec_soft_fini,
          ipf_p_ipsec_new, ipf_p_ipsec_del,
          ipf_p_ipsec_inout, ipf_p_ipsec_inout, ipf_p_ipsec_match,
          NULL, NULL, NULL, NULL },
#endif
#ifdef  IPF_DNS_PROXY
        { NULL, NULL, "dns", (char)IPPROTO_UDP, 0, 0, 0,
          NULL, NULL,
          ipf_p_dns_soft_create, ipf_p_dns_soft_destroy,
          NULL, NULL,
          ipf_p_dns_new, ipf_p_ipsec_del,
          ipf_p_dns_inout, ipf_p_dns_inout, ipf_p_dns_match,
          ipf_p_dns_ctl, NULL, NULL, NULL },
#endif
#ifdef  IPF_PPTP_PROXY
        { NULL, NULL, "pptp", (char)IPPROTO_TCP, 0, 0, 0,
          ipf_p_pptp_main_load, ipf_p_pptp_main_unload,
          NULL, NULL,
          NULL, NULL,
          ipf_p_pptp_new, ipf_p_pptp_del,
          ipf_p_pptp_inout, ipf_p_pptp_inout, NULL,
          NULL, NULL, NULL, NULL },
#endif
#ifdef  IPF_RPCB_PROXY
# ifndef _KERNEL
        { NULL, NULL, "rpcbt", (char)IPPROTO_TCP, 0, 0, 0,
          NULL, NULL,
          NULL, NULL,
          NULL, NULL,
          ipf_p_rpcb_new, ipf_p_rpcb_del,
          ipf_p_rpcb_in, ipf_p_rpcb_out, NULL,
          NULL, NULL, NULL, NULL },
# endif
        { NULL, NULL, "rpcbu", (char)IPPROTO_UDP, 0, 0, 0,
          ipf_p_rpcb_main_load, ipf_p_rpcb_main_unload,
          NULL, NULL,
          NULL, NULL,
          ipf_p_rpcb_new, ipf_p_rpcb_del,
          ipf_p_rpcb_in, ipf_p_rpcb_out, NULL,
          NULL, NULL, NULL, NULL },
#endif
        { NULL, NULL, "", '\0', 0, 0, 0,
          NULL, NULL,
          NULL, NULL,
          NULL, NULL,
          NULL, NULL,
          NULL, NULL, NULL,
          NULL, NULL, NULL, NULL }
};


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_main_load                                         */
/* Returns:     int    - 0 == success, else failure.                        */
/* Parameters:  Nil                                                         */
/*                                                                          */
/* Initialise hook for kernel application proxies.                          */
/* Call the initialise routine for all the compiled in kernel proxies.      */
/* ------------------------------------------------------------------------ */
int
ipf_proxy_main_load(void)
{
        aproxy_t *ap;

        for (ap = ips_proxies; ap->apr_p; ap++) {
                if (ap->apr_load != NULL)
                        (*ap->apr_load)();
        }
        return (0);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_main_unload                                       */
/* Returns:     int - 0 == success, else failure.                           */
/* Parameters:  Nil                                                         */
/*                                                                          */
/* Unload hook for kernel application proxies.                              */
/* Call the finialise routine for all the compiled in kernel proxies.       */
/* ------------------------------------------------------------------------ */
int
ipf_proxy_main_unload(void)
{
        aproxy_t *ap;

        for (ap = ips_proxies; ap->apr_p; ap++)
                if (ap->apr_unload != NULL)
                        (*ap->apr_unload)();
        for (ap = ap_proxylist; ap; ap = ap->apr_next)
                if (ap->apr_unload != NULL)
                        (*ap->apr_unload)();

        return (0);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_soft_create                                       */
/* Returns:     void *   -                                                  */
/* Parameters:  softc(I) - pointer to soft context main structure           */
/*                                                                          */
/* Build the structure to hold all of the run time data to support proxies. */
/* ------------------------------------------------------------------------ */
void *
ipf_proxy_soft_create(ipf_main_softc_t *softc)
{
        ipf_proxy_softc_t *softp;
        aproxy_t *last;
        aproxy_t *apn;
        aproxy_t *ap;

        KMALLOC(softp, ipf_proxy_softc_t *);
        if (softp == NULL)
                return (softp);

        bzero((char *)softp, sizeof(*softp));

#if defined(_KERNEL)
        softp->ips_proxy_debug = 0;
#else
        softp->ips_proxy_debug = 2;
#endif
        softp->ips_proxy_session_size = AP_SESS_SIZE;

        softp->ipf_proxy_tune = ipf_tune_array_copy(softp,
                                                    sizeof(ipf_proxy_tuneables),
                                                    ipf_proxy_tuneables);
        if (softp->ipf_proxy_tune == NULL) {
                ipf_proxy_soft_destroy(softc, softp);
                return (NULL);
        }
        if (ipf_tune_array_link(softc, softp->ipf_proxy_tune) == -1) {
                ipf_proxy_soft_destroy(softc, softp);
                return (NULL);
        }

        last = NULL;
        for (ap = ips_proxies; ap->apr_p; ap++) {
                apn = ipf_proxy_create_clone(softc, ap);
                if (apn == NULL)
                        goto failed;
                if (last != NULL)
                        last->apr_next = apn;
                else
                        softp->ips_proxies = apn;
                last = apn;
        }
        for (ap = ips_proxies; ap != NULL; ap = ap->apr_next) {
                apn = ipf_proxy_create_clone(softc, ap);
                if (apn == NULL)
                        goto failed;
                if (last != NULL)
                        last->apr_next = apn;
                else
                        softp->ips_proxies = apn;
                last = apn;
        }

        return (softp);
failed:
        ipf_proxy_soft_destroy(softc, softp);
        return (NULL);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_soft_create                                       */
/* Returns:     void *   -                                                  */
/* Parameters:  softc(I) - pointer to soft context main structure           */
/*              orig(I)  - pointer to proxy definition to copy              */
/*                                                                          */
/* This function clones a proxy definition given by orig and returns a      */
/* a pointer to that copy.                                                  */
/* ------------------------------------------------------------------------ */
static aproxy_t *
ipf_proxy_create_clone(ipf_main_softc_t *softc, aproxy_t *orig)
{
        aproxy_t *apn;

        KMALLOC(apn, aproxy_t *);
        if (apn == NULL)
                return (NULL);

        bcopy((char *)orig, (char *)apn, sizeof(*apn));
        apn->apr_next = NULL;
        apn->apr_soft = NULL;

        if (apn->apr_create != NULL) {
                apn->apr_soft = (*apn->apr_create)(softc);
                if (apn->apr_soft == NULL) {
                        KFREE(apn);
                        return (NULL);
                }
        }

        apn->apr_parent = orig;
        orig->apr_clones++;

        return (apn);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_soft_create                                       */
/* Returns:     int      - 0 == success, else failure.                      */
/* Parameters:  softc(I) - pointer to soft context main structure           */
/*              arg(I)   - pointer to proxy contect data                    */
/*                                                                          */
/* Initialise the proxy context and walk through each of the proxies and    */
/* call its initialisation function. This allows for proxies to do any      */
/* local setup prior to actual use.                                         */
/* ------------------------------------------------------------------------ */
int
ipf_proxy_soft_init(ipf_main_softc_t *softc, void *arg)
{
        ipf_proxy_softc_t *softp;
        aproxy_t *ap;
        u_int size;
        int err;

        softp = arg;
        size = softp->ips_proxy_session_size * sizeof(ap_session_t *);

        KMALLOCS(softp->ips_sess_tab, ap_session_t **, size);

        if (softp->ips_sess_tab == NULL)
                return (-1);

        bzero(softp->ips_sess_tab, size);

        for (ap = softp->ips_proxies; ap != NULL; ap = ap->apr_next) {
                if (ap->apr_init != NULL) {
                        err = (*ap->apr_init)(softc, ap->apr_soft);
                        if (err != 0)
                                return (-2);
                }
        }
        softp->ips_init_run = 1;

        return (0);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_soft_create                                       */
/* Returns:     int      - 0 == success, else failure.                      */
/* Parameters:  softc(I) - pointer to soft context main structure           */
/*              arg(I)   - pointer to proxy contect data                    */
/*                                                                          */
/* This function should always succeed. It is responsible for ensuring that */
/* the proxy context can be safely called when ipf_proxy_soft_destroy is    */
/* called and suring all of the proxies have similarly been instructed.     */
/* ------------------------------------------------------------------------ */
int
ipf_proxy_soft_fini(ipf_main_softc_t *softc, void *arg)
{
        ipf_proxy_softc_t *softp = arg;
        aproxy_t *ap;

        for (ap = softp->ips_proxies; ap != NULL; ap = ap->apr_next) {
                if (ap->apr_fini != NULL) {
                        (*ap->apr_fini)(softc, ap->apr_soft);
                }
        }

        if (softp->ips_sess_tab != NULL) {
                KFREES(softp->ips_sess_tab,
                       softp->ips_proxy_session_size * sizeof(ap_session_t *));
                softp->ips_sess_tab = NULL;
        }
        softp->ips_init_run = 0;

        return (0);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_soft_destroy                                      */
/* Returns:     Nil                                                         */
/* Parameters:  softc(I) - pointer to soft context main structure           */
/*              arg(I)   - pointer to proxy contect data                    */
/*                                                                          */
/* Free up all of the local data structures allocated during creation.      */
/* ------------------------------------------------------------------------ */
void
ipf_proxy_soft_destroy(ipf_main_softc_t *softc, void *arg)
{
        ipf_proxy_softc_t *softp = arg;
        aproxy_t *ap;

        while ((ap = softp->ips_proxies) != NULL) {
                softp->ips_proxies = ap->apr_next;
                if (ap->apr_destroy != NULL)
                        (*ap->apr_destroy)(softc, ap->apr_soft);
                ap->apr_parent->apr_clones--;
                KFREE(ap);
        }

        if (softp->ipf_proxy_tune != NULL) {
                ipf_tune_array_unlink(softc, softp->ipf_proxy_tune);
                KFREES(softp->ipf_proxy_tune, sizeof(ipf_proxy_tuneables));
                softp->ipf_proxy_tune = NULL;
        }

        KFREE(softp);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_flush                                             */
/* Returns:     Nil                                                         */
/* Parameters:  arg(I)   - pointer to proxy contect data                    */
/*              how(I)   - indicates the type of flush operation            */
/*                                                                          */
/* Walk through all of the proxies and pass on the flush command as either  */
/* a flush or a clear.                                                      */
/* ------------------------------------------------------------------------ */
void
ipf_proxy_flush(void *arg, int how)
{
        ipf_proxy_softc_t *softp = arg;
        aproxy_t *ap;

        switch (how)
        {
        case 0 :
                for (ap = softp->ips_proxies; ap; ap = ap->apr_next)
                        if (ap->apr_flush != NULL)
                                (*ap->apr_flush)(ap, how);
                break;
        case 1 :
                for (ap = softp->ips_proxies; ap; ap = ap->apr_next)
                        if (ap->apr_clear != NULL)
                                (*ap->apr_clear)(ap);
                break;
        default :
                break;
        }
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_add                                               */
/* Returns:     int   - 0 == success, else failure.                         */
/* Parameters:  ap(I) - pointer to proxy structure                          */
/*                                                                          */
/* Dynamically add a new kernel proxy.  Ensure that it is unique in the     */
/* collection compiled in and dynamically added.                            */
/* ------------------------------------------------------------------------ */
int
ipf_proxy_add(void *arg, aproxy_t *ap)
{
        ipf_proxy_softc_t *softp = arg;

        aproxy_t *a;

        for (a = ips_proxies; a->apr_p; a++)
                if ((a->apr_p == ap->apr_p) &&
                    !strncmp(a->apr_label, ap->apr_label,
                             sizeof(ap->apr_label))) {
                        if (softp->ips_proxy_debug & 0x01)
                                printf("ipf_proxy_add: %s/%d present (B)\n",
                                       a->apr_label, a->apr_p);
                        return (-1);
                }

        for (a = ap_proxylist; (a != NULL); a = a->apr_next)
                if ((a->apr_p == ap->apr_p) &&
                    !strncmp(a->apr_label, ap->apr_label,
                             sizeof(ap->apr_label))) {
                        if (softp->ips_proxy_debug & 0x01)
                                printf("ipf_proxy_add: %s/%d present (D)\n",
                                       a->apr_label, a->apr_p);
                        return (-1);
                }
        ap->apr_next = ap_proxylist;
        ap_proxylist = ap;
        if (ap->apr_load != NULL)
                (*ap->apr_load)();
        return (0);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_ctl                                               */
/* Returns:     int    - 0 == success, else error                           */
/* Parameters:  softc(I) - pointer to soft context main structure           */
/*              arg(I)   - pointer to proxy context                         */
/*              ctl(I)   - pointer to proxy control structure               */
/*                                                                          */
/* Check to see if the proxy this control request has come through for      */
/* exists, and if it does and it has a control function then invoke that    */
/* control function.                                                        */
/* ------------------------------------------------------------------------ */
int
ipf_proxy_ctl(ipf_main_softc_t *softc, void *arg, ap_ctl_t *ctl)
{
        ipf_proxy_softc_t *softp = arg;
        aproxy_t *a;
        int error;

        a = ipf_proxy_lookup(arg, ctl->apc_p, ctl->apc_label);
        if (a == NULL) {
                if (softp->ips_proxy_debug & 0x01)
                        printf("ipf_proxy_ctl: can't find %s/%d\n",
                                ctl->apc_label, ctl->apc_p);
                IPFERROR(80001);
                error = ESRCH;
        } else if (a->apr_ctl == NULL) {
                if (softp->ips_proxy_debug & 0x01)
                        printf("ipf_proxy_ctl: no ctl function for %s/%d\n",
                                ctl->apc_label, ctl->apc_p);
                IPFERROR(80002);
                error = ENXIO;
        } else {
                error = (*a->apr_ctl)(softc, a->apr_soft, ctl);
                if ((error != 0) && (softp->ips_proxy_debug & 0x02))
                        printf("ipf_proxy_ctl: %s/%d ctl error %d\n",
                                a->apr_label, a->apr_p, error);
        }
        return (error);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_del                                               */
/* Returns:     int   - 0 == success, else failure.                         */
/* Parameters:  ap(I) - pointer to proxy structure                          */
/*                                                                          */
/* Delete a proxy that has been added dynamically from those available.     */
/* If it is in use, return 1 (do not destroy NOW), not in use 0 or -1       */
/* if it cannot be matched.                                                 */
/* ------------------------------------------------------------------------ */
int
ipf_proxy_del(aproxy_t *ap)
{
        aproxy_t *a, **app;

        for (app = &ap_proxylist; ((a = *app) != NULL); app = &a->apr_next) {
                if (a == ap) {
                        a->apr_flags |= APR_DELETE;
                        if (ap->apr_ref == 0 && ap->apr_clones == 0) {
                                *app = a->apr_next;
                                return (0);
                        }
                        return (1);
                }
        }

        return (-1);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_ok                                                */
/* Returns:     int    - 1 == good match else not.                          */
/* Parameters:  fin(I) - pointer to packet information                      */
/*              tcp(I) - pointer to TCP/UDP header                          */
/*              nat(I) - pointer to current NAT session                     */
/*                                                                          */
/* This function extends the NAT matching to ensure that a packet that has  */
/* arrived matches the proxy information attached to the NAT rule. Notably, */
/* if the proxy is scheduled to be deleted then packets will not match the  */
/* rule even if the rule is still active.                                   */
/* ------------------------------------------------------------------------ */
int
ipf_proxy_ok(fr_info_t *fin, tcphdr_t *tcp, ipnat_t *np)
{
        aproxy_t *apr = np->in_apr;
        u_short dport = np->in_odport;

        if ((apr == NULL) || (apr->apr_flags & APR_DELETE) ||
            (fin->fin_p != apr->apr_p))
                return (0);
        if ((tcp == NULL) && dport)
                return (0);
        return (1);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_ioctl                                             */
/* Returns:     int    - 0 == success, else error                           */
/* Parameters:  softc(I) - pointer to soft context main structure           */
/*              data(I)  - pointer to ioctl data                            */
/*              cmd(I)   - ioctl command                                    */
/*              mode(I)  - mode bits for device                             */
/*              ctx(I)   - pointer to context information                   */
/*                                                                          */
/* ------------------------------------------------------------------------ */
int
ipf_proxy_ioctl(ipf_main_softc_t *softc, caddr_t data, ioctlcmd_t cmd,
        int mode __unused, void *ctx)
{
        ap_ctl_t ctl;
        caddr_t ptr;
        int error;

        switch (cmd)
        {
        case SIOCPROXY :
                error = ipf_inobj(softc, data, NULL, &ctl, IPFOBJ_PROXYCTL);
                if (error != 0) {
                        return (error);
                }
                ptr = NULL;

                if (ctl.apc_dsize > 0) {
                        KMALLOCS(ptr, caddr_t, ctl.apc_dsize);
                        if (ptr == NULL) {
                                IPFERROR(80003);
                                error = ENOMEM;
                        } else {
                                error = ipf_copyin_indirect(softc, ctl.apc_data,
                                                            ptr, ctl.apc_dsize);
                                if (error == 0)
                                        ctl.apc_data = ptr;
                        }
                } else {
                        ctl.apc_data = NULL;
                        error = 0;
                }

                if (error == 0)
                        error = ipf_proxy_ctl(softc, softc->ipf_proxy_soft,
                                              &ctl);

                if ((error != 0) && (ptr != NULL)) {
                        KFREES(ptr, ctl.apc_dsize);
                }
                break;

        default :
                IPFERROR(80004);
                error = EINVAL;
        }
        return (error);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_match                                             */
/* Returns:     int    - 0 == success, else error                           */
/* Parameters:  fin(I) - pointer to packet information                      */
/*              nat(I) - pointer to current NAT session                     */
/*                                                                          */
/* If a proxy has a match function, call that to do extended packet         */
/* matching. Whilst other parts of the NAT code are rather lenient when it  */
/* comes to the quality of the packet that it will transform, the proxy     */
/* matching is not because they need to work with data, not just headers.   */
/* ------------------------------------------------------------------------ */
int
ipf_proxy_match(fr_info_t *fin, nat_t *nat)
{
        ipf_main_softc_t *softc = fin->fin_main_soft;
        ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
        aproxy_t *apr;
        ipnat_t *ipn;
        int result;

        ipn = nat->nat_ptr;
        if (softp->ips_proxy_debug & 0x04)
                printf("ipf_proxy_match(%lx,%lx) aps %lx ptr %lx\n",
                        (u_long)fin, (u_long)nat, (u_long)nat->nat_aps,
                        (u_long)ipn);

        if ((fin->fin_flx & (FI_SHORT|FI_BAD)) != 0) {
                if (softp->ips_proxy_debug & 0x08)
                        printf("ipf_proxy_match: flx 0x%x (BAD|SHORT)\n",
                                fin->fin_flx);
                return (-1);
        }

        apr = ipn->in_apr;
        if ((apr == NULL) || (apr->apr_flags & APR_DELETE)) {
                if (softp->ips_proxy_debug & 0x08)
                        printf("ipf_proxy_match:apr %lx apr_flags 0x%x\n",
                                (u_long)apr, apr ? apr->apr_flags : 0);
                return (-1);
        }

        if (apr->apr_match != NULL) {
                result = (*apr->apr_match)(fin, nat->nat_aps, nat);
                if (result != 0) {
                        if (softp->ips_proxy_debug & 0x08)
                                printf("ipf_proxy_match: result %d\n", result);
                        return (-1);
                }
        }
        return (0);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_new                                               */
/* Returns:     int    - 0 == success, else error                           */
/* Parameters:  fin(I) - pointer to packet information                      */
/*              nat(I) - pointer to current NAT session                     */
/*                                                                          */
/* Allocate a new application proxy structure and fill it in with the       */
/* relevant details.  call the init function once complete, prior to        */
/* returning.                                                               */
/* ------------------------------------------------------------------------ */
int
ipf_proxy_new(fr_info_t *fin, nat_t *nat)
{
        ipf_main_softc_t *softc = fin->fin_main_soft;
        ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
        register ap_session_t *aps;
        aproxy_t *apr;

        if (softp->ips_proxy_debug & 0x04)
                printf("ipf_proxy_new(%lx,%lx) \n", (u_long)fin, (u_long)nat);

        if ((nat->nat_ptr == NULL) || (nat->nat_aps != NULL)) {
                if (softp->ips_proxy_debug & 0x08)
                        printf("ipf_proxy_new: nat_ptr %lx nat_aps %lx\n",
                                (u_long)nat->nat_ptr, (u_long)nat->nat_aps);
                return (-1);
        }

        apr = nat->nat_ptr->in_apr;

        if ((apr->apr_flags & APR_DELETE) ||
            (fin->fin_p != apr->apr_p)) {
                if (softp->ips_proxy_debug & 0x08)
                        printf("ipf_proxy_new: apr_flags 0x%x p %d/%d\n",
                                apr->apr_flags, fin->fin_p, apr->apr_p);
                return (-1);
        }

        KMALLOC(aps, ap_session_t *);
        if (!aps) {
                if (softp->ips_proxy_debug & 0x08)
                        printf("ipf_proxy_new: malloc failed (%lu)\n",
                                (u_long)sizeof(ap_session_t));
                return (-1);
        }

        bzero((char *)aps, sizeof(*aps));
        aps->aps_data = NULL;
        aps->aps_apr = apr;
        aps->aps_psiz = 0;
        if (apr->apr_new != NULL)
                if ((*apr->apr_new)(apr->apr_soft, fin, aps, nat) == -1) {
                        if ((aps->aps_data != NULL) && (aps->aps_psiz != 0)) {
                                KFREES(aps->aps_data, aps->aps_psiz);
                        }
                        KFREE(aps);
                        if (softp->ips_proxy_debug & 0x08)
                                printf("ipf_proxy_new: new(%lx) failed\n",
                                        (u_long)apr->apr_new);
                        return (-1);
                }
        aps->aps_nat = nat;
        aps->aps_next = softp->ips_sess_list;
        softp->ips_sess_list = aps;
        nat->nat_aps = aps;

        return (0);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_check                                             */
/* Returns:     int - -1 == error, 1 == success                             */
/* Parameters:  fin(I) - pointer to packet information                      */
/*              nat(I) - pointer to current NAT session                     */
/*                                                                          */
/* Check to see if a packet should be passed through an active proxy        */
/* routine if one has been setup for it.  We don't need to check the        */
/* checksum here if IPFILTER_CKSUM is defined because if it is, a failed    */
/* check causes FI_BAD to be set.                                           */
/* ------------------------------------------------------------------------ */
int
ipf_proxy_check(fr_info_t *fin, nat_t *nat)
{
        ipf_main_softc_t *softc = fin->fin_main_soft;
        ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
#if SOLARIS && defined(_KERNEL) && defined(ICK_VALID)
        mb_t *m;
#endif
        tcphdr_t *tcp = NULL;
        udphdr_t *udp = NULL;
        ap_session_t *aps;
        aproxy_t *apr;
        short adjlen;
        int dosum;
        ip_t *ip;
        short rv;
        int err;
#if !defined(_KERNEL) || SOLARIS || defined(__FreeBSD__)
        u_32_t s1, s2, sd;
#endif

        if (fin->fin_flx & FI_BAD) {
                if (softp->ips_proxy_debug & 0x08)
                        printf("ipf_proxy_check: flx 0x%x (BAD)\n",
                               fin->fin_flx);
                return (-1);
        }

#ifndef IPFILTER_CKSUM
        if ((fin->fin_out == 0) && (ipf_checkl4sum(fin) == -1)) {
                if (softp->ips_proxy_debug & 0x08)
                        printf("ipf_proxy_check: l4 checksum failure %d\n",
                                fin->fin_p);
                if (fin->fin_p == IPPROTO_TCP)
                        softc->ipf_stats[fin->fin_out].fr_tcpbad++;
                return (-1);
        }
#endif

        aps = nat->nat_aps;
        if (aps != NULL) {
                /*
                 * If there is data in this packet to be proxied then try and
                 * get it all into the one buffer, else drop it.
                 */
#if SOLARIS || defined(HAVE_M_PULLDOWN)
                if ((fin->fin_dlen > 0) && !(fin->fin_flx & FI_COALESCE))
                        if (ipf_coalesce(fin) == -1) {
                                if (softp->ips_proxy_debug & 0x08)
                                        printf("ipf_proxy_check: %s %x\n",
                                               "coalesce failed", fin->fin_flx);
                                return (-1);
                        }
#endif
                ip = fin->fin_ip;
                if (fin->fin_cksum > FI_CK_SUMOK)
                        dosum = 0;
                else
                        dosum = 1;

                switch (fin->fin_p)
                {
                case IPPROTO_TCP :
                        tcp = (tcphdr_t *)fin->fin_dp;
#if SOLARIS && defined(_KERNEL) && defined(ICK_VALID)
                        m = fin->fin_qfm;
                        if (dohwcksum && (m->b_ick_flag == ICK_VALID))
                                dosum = 0;
#endif
                        break;
                case IPPROTO_UDP :
                        udp = (udphdr_t *)fin->fin_dp;
                        break;
                default :
                        break;
                }

                apr = aps->aps_apr;
                err = 0;
                if (fin->fin_out != 0) {
                        if (apr->apr_outpkt != NULL)
                                err = (*apr->apr_outpkt)(apr->apr_soft, fin,
                                                         aps, nat);
                } else {
                        if (apr->apr_inpkt != NULL)
                                err = (*apr->apr_inpkt)(apr->apr_soft, fin,
                                                        aps, nat);
                }

                rv = APR_EXIT(err);
                if (((softp->ips_proxy_debug & 0x08) && (rv != 0)) ||
                    (softp->ips_proxy_debug & 0x04))
                        printf("ipf_proxy_check: out %d err %x rv %d\n",
                                fin->fin_out, err, rv);
                if (rv == 1)
                        return (-1);

                if (rv == 2) {
                        ipf_proxy_deref(apr);
                        nat->nat_aps = NULL;
                        return (-1);
                }

                /*
                 * If err != 0 then the data size of the packet has changed
                 * so we need to recalculate the header checksums for the
                 * packet.
                 */
                adjlen = APR_INC(err);
#if !defined(_KERNEL) || SOLARIS || defined(__FreeBSD__)
                s1 = LONG_SUM(fin->fin_plen - adjlen);
                s2 = LONG_SUM(fin->fin_plen);
                CALC_SUMD(s1, s2, sd);
                if ((err != 0) && (fin->fin_cksum < FI_CK_L4PART) &&
                    fin->fin_v == 4)
                        ipf_fix_outcksum(0, &ip->ip_sum, sd, 0);
#endif
                if (fin->fin_flx & FI_DOCKSUM)
                        dosum = 1;

                /*
                 * For TCP packets, we may need to adjust the sequence and
                 * acknowledgement numbers to reflect changes in size of the
                 * data stream.
                 *
                 * For both TCP and UDP, recalculate the layer 4 checksum,
                 * regardless, as we can't tell (here) if data has been
                 * changed or not.
                 */
                if (tcp != NULL) {
                        err = ipf_proxy_fixseqack(fin, ip, aps, adjlen);
                        if (fin->fin_cksum == FI_CK_L4PART) {
                                u_short sum = ntohs(tcp->th_sum);
                                sum += adjlen;
                                tcp->th_sum = htons(sum);
                        } else if (fin->fin_cksum < FI_CK_L4PART) {
                                tcp->th_sum = fr_cksum(fin, ip,
                                                       IPPROTO_TCP, tcp);
                        }
                } else if ((udp != NULL) && (udp->uh_sum != 0)) {
                        if (fin->fin_cksum == FI_CK_L4PART) {
                                u_short sum = ntohs(udp->uh_sum);
                                sum += adjlen;
                                udp->uh_sum = htons(sum);
                        } else if (dosum) {
                                udp->uh_sum = fr_cksum(fin, ip,
                                                       IPPROTO_UDP, udp);
                        }
                }
                aps->aps_bytes += fin->fin_plen;
                aps->aps_pkts++;
        }
        return (1);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_lookup                                            */
/* Returns:     int - -1 == error, 0 == success                             */
/* Parameters:  arg(I)  - pointer to proxy context information              */
/*              pr(I)   - protocol number for proxy                         */
/*              name(I) - proxy name                                        */
/*                                                                          */
/* Search for a proxy by the protocol being used and by its name.           */
/* ------------------------------------------------------------------------ */
aproxy_t *
ipf_proxy_lookup(void *arg, u_int pr, char *name)
{
        ipf_proxy_softc_t *softp = arg;
        aproxy_t *ap;

        if (softp->ips_proxy_debug & 0x04)
                printf("ipf_proxy_lookup(%d,%s)\n", pr, name);

        for (ap = softp->ips_proxies; ap != NULL; ap = ap->apr_next)
                if ((ap->apr_p == pr) &&
                    !strncmp(name, ap->apr_label, sizeof(ap->apr_label))) {
                        ap->apr_ref++;
                        return (ap);
                }

        if (softp->ips_proxy_debug & 0x08)
                printf("ipf_proxy_lookup: failed for %d/%s\n", pr, name);
        return (NULL);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_deref                                             */
/* Returns:     Nil                                                         */
/* Parameters:  ap(I) - pointer to proxy structure                          */
/*                                                                          */
/* Drop the reference counter associated with the proxy.                    */
/* ------------------------------------------------------------------------ */
void
ipf_proxy_deref(aproxy_t *ap)
{
        ap->apr_ref--;
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_free                                              */
/* Returns:     Nil                                                         */
/* Parameters:  softc(I) - pointer to soft context main structure           */
/*              aps(I)   - pointer to current proxy session                 */
/* Locks Held:  ipf_nat_new, ipf_nat(W)                                     */
/*                                                                          */
/* Free up proxy session information allocated to be used with a NAT        */
/* session.                                                                 */
/* ------------------------------------------------------------------------ */
void
ipf_proxy_free(ipf_main_softc_t *softc, ap_session_t *aps)
{
        ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
        ap_session_t *a, **ap;
        aproxy_t *apr;

        if (!aps)
                return;

        for (ap = &softp->ips_sess_list; ((a = *ap) != NULL); ap = &a->aps_next)
                if (a == aps) {
                        *ap = a->aps_next;
                        break;
                }

        apr = aps->aps_apr;
        if ((apr != NULL) && (apr->apr_del != NULL))
                (*apr->apr_del)(softc, aps);

        if ((aps->aps_data != NULL) && (aps->aps_psiz != 0))
                KFREES(aps->aps_data, aps->aps_psiz);
        KFREE(aps);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_fixseqack                                         */
/* Returns:     int    - 2 if TCP ack/seq is changed, else 0                */
/* Parameters:  fin(I) - pointer to packet information                      */
/*              ip(I)  - pointer to IP header                               */
/*              nat(I) - pointer to current NAT session                     */
/*              inc(I) - delta to apply to TCP sequence numbering           */
/*                                                                          */
/* Adjust the TCP sequence/acknowledge numbers in the TCP header based on   */
/* whether or not the new header is past the point at which an adjustment   */
/* occurred. This might happen because of (say) an FTP string being changed */
/* and the new string being a different length to the old.                  */
/* ------------------------------------------------------------------------ */
static int
ipf_proxy_fixseqack(fr_info_t *fin, ip_t *ip, ap_session_t *aps, int inc)
{
        ipf_main_softc_t *softc = fin->fin_main_soft;
        ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
        int sel, ch = 0, out, nlen;
        u_32_t seq1, seq2;
        tcphdr_t *tcp;
        short inc2;

        tcp = (tcphdr_t *)fin->fin_dp;
        out = fin->fin_out;
        /*
         * ip_len has already been adjusted by 'inc'.
         */
        nlen = fin->fin_dlen;
        nlen -= (TCP_OFF(tcp) << 2);

        inc2 = inc;
        inc = (int)inc2;

        if (out != 0) {
                seq1 = (u_32_t)ntohl(tcp->th_seq);
                sel = aps->aps_sel[out];

                /* switch to other set ? */
                if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) &&
                    (seq1 > aps->aps_seqmin[!sel])) {
                        if (softp->ips_proxy_debug & 0x10)
                                printf("proxy out switch set seq %d -> %d %x > %x\n",
                                        sel, !sel, seq1,
                                        aps->aps_seqmin[!sel]);
                        sel = aps->aps_sel[out] = !sel;
                }

                if (aps->aps_seqoff[sel]) {
                        seq2 = aps->aps_seqmin[sel] - aps->aps_seqoff[sel];
                        if (seq1 > seq2) {
                                seq2 = aps->aps_seqoff[sel];
                                seq1 += seq2;
                                tcp->th_seq = htonl(seq1);
                                ch = 1;
                        }
                }

                if (inc && (seq1 > aps->aps_seqmin[!sel])) {
                        aps->aps_seqmin[sel] = seq1 + nlen - 1;
                        aps->aps_seqoff[sel] = aps->aps_seqoff[sel] + inc;
                        if (softp->ips_proxy_debug & 0x10)
                                printf("proxy seq set %d at %x to %d + %d\n",
                                        sel, aps->aps_seqmin[sel],
                                        aps->aps_seqoff[sel], inc);
                }

                /***/

                seq1 = ntohl(tcp->th_ack);
                sel = aps->aps_sel[1 - out];

                /* switch to other set ? */
                if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) &&
                    (seq1 > aps->aps_ackmin[!sel])) {
                        if (softp->ips_proxy_debug & 0x10)
                                printf("proxy out switch set ack %d -> %d %x > %x\n",
                                        sel, !sel, seq1,
                                        aps->aps_ackmin[!sel]);
                        sel = aps->aps_sel[1 - out] = !sel;
                }

                if (aps->aps_ackoff[sel] && (seq1 > aps->aps_ackmin[sel])) {
                        seq2 = aps->aps_ackoff[sel];
                        tcp->th_ack = htonl(seq1 - seq2);
                        ch = 1;
                }
        } else {
                seq1 = ntohl(tcp->th_seq);
                sel = aps->aps_sel[out];

                /* switch to other set ? */
                if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) &&
                    (seq1 > aps->aps_ackmin[!sel])) {
                        if (softp->ips_proxy_debug & 0x10)
                                printf("proxy in switch set ack %d -> %d %x > %x\n",
                                        sel, !sel, seq1, aps->aps_ackmin[!sel]);
                        sel = aps->aps_sel[out] = !sel;
                }

                if (aps->aps_ackoff[sel]) {
                        seq2 = aps->aps_ackmin[sel] - aps->aps_ackoff[sel];
                        if (seq1 > seq2) {
                                seq2 = aps->aps_ackoff[sel];
                                seq1 += seq2;
                                tcp->th_seq = htonl(seq1);
                                ch = 1;
                        }
                }

                if (inc && (seq1 > aps->aps_ackmin[!sel])) {
                        aps->aps_ackmin[!sel] = seq1 + nlen - 1;
                        aps->aps_ackoff[!sel] = aps->aps_ackoff[sel] + inc;

                        if (softp->ips_proxy_debug & 0x10)
                                printf("proxy ack set %d at %x to %d + %d\n",
                                        !sel, aps->aps_seqmin[!sel],
                                        aps->aps_seqoff[sel], inc);
                }

                /***/

                seq1 = ntohl(tcp->th_ack);
                sel = aps->aps_sel[1 - out];

                /* switch to other set ? */
                if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) &&
                    (seq1 > aps->aps_seqmin[!sel])) {
                        if (softp->ips_proxy_debug & 0x10)
                                printf("proxy in switch set seq %d -> %d %x > %x\n",
                                        sel, !sel, seq1, aps->aps_seqmin[!sel]);
                        sel = aps->aps_sel[1 - out] = !sel;
                }

                if (aps->aps_seqoff[sel] != 0) {
                        if (softp->ips_proxy_debug & 0x10)
                                printf("sel %d seqoff %d seq1 %x seqmin %x\n",
                                        sel, aps->aps_seqoff[sel], seq1,
                                        aps->aps_seqmin[sel]);
                        if (seq1 > aps->aps_seqmin[sel]) {
                                seq2 = aps->aps_seqoff[sel];
                                tcp->th_ack = htonl(seq1 - seq2);
                                ch = 1;
                        }
                }
        }

        if (softp->ips_proxy_debug & 0x10)
                printf("ipf_proxy_fixseqack: seq %u ack %u\n",
                        (u_32_t)ntohl(tcp->th_seq), (u_32_t)ntohl(tcp->th_ack));
        return (ch ? 2 : 0);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_rule_rev                                          */
/* Returns:     ipnat_t * - NULL = failure, else pointer to new rule        */
/* Parameters:  nat(I) - pointer to NAT session to create rule from         */
/*                                                                          */
/* This function creates a NAT rule that is based upon the reverse packet   */
/* flow associated with this NAT session. Thus if this NAT session was      */
/* created with a map rule then this function will create a rdr rule.       */
/* Only address fields and network interfaces are assigned in this function */
/* and the address fields are formed such that an exact is required. If the */
/* original rule had a netmask, that is not replicated here not is it       */
/* desired. The ultimate goal here is to create a NAT rule to support a NAT */
/* session being created that does not have a user configured rule. The     */
/* classic example is supporting the FTP proxy, where a data channel needs  */
/* to be setup, based on the addresses used for the control connection. In  */
/* that case, this function is used to handle creating NAT rules to support */
/* data connections with the PORT and EPRT commands.                        */
/* ------------------------------------------------------------------------ */
ipnat_t *
ipf_proxy_rule_rev(nat_t *nat)
{
        ipnat_t *old;
        ipnat_t *ipn;
        int size;

        old = nat->nat_ptr;
        size = old->in_size;

        KMALLOCS(ipn, ipnat_t *, size);
        if (ipn == NULL)
                return (NULL);

        bzero((char *)ipn, size);

        ipn->in_use = 1;
        ipn->in_hits = 1;
        ipn->in_ippip = 1;
        ipn->in_apr = NULL;
        ipn->in_size = size;
        ipn->in_pr[0] = old->in_pr[1];
        ipn->in_pr[1] = old->in_pr[0];
        ipn->in_v[0] = old->in_v[1];
        ipn->in_v[1] = old->in_v[0];
        ipn->in_ifps[0] = old->in_ifps[1];
        ipn->in_ifps[1] = old->in_ifps[0];
        ipn->in_flags = (old->in_flags | IPN_PROXYRULE);

        ipn->in_nsrcip6 = nat->nat_odst6;
        ipn->in_osrcip6 = nat->nat_ndst6;

        if ((old->in_redir & NAT_REDIRECT) != 0) {
                ipn->in_redir = NAT_MAP;
                if (ipn->in_v[0] == 4) {
                        ipn->in_snip = ntohl(nat->nat_odstaddr);
                        ipn->in_dnip = ntohl(nat->nat_nsrcaddr);
#ifdef USE_INET6
                } else {
                        ipn->in_snip6 = nat->nat_odst6;
                        ipn->in_dnip6 = nat->nat_nsrc6;
#endif
                }
                ipn->in_ndstip6 = nat->nat_nsrc6;
                ipn->in_odstip6 = nat->nat_osrc6;
        } else {
                ipn->in_redir = NAT_REDIRECT;
                if (ipn->in_v[0] == 4) {
                        ipn->in_snip = ntohl(nat->nat_odstaddr);
                        ipn->in_dnip = ntohl(nat->nat_osrcaddr);
#ifdef USE_INET6
                } else {
                        ipn->in_snip6 = nat->nat_odst6;
                        ipn->in_dnip6 = nat->nat_osrc6;
#endif
                }
                ipn->in_ndstip6 = nat->nat_osrc6;
                ipn->in_odstip6 = nat->nat_nsrc6;
        }

        IP6_SETONES(&ipn->in_osrcmsk6);
        IP6_SETONES(&ipn->in_nsrcmsk6);
        IP6_SETONES(&ipn->in_odstmsk6);
        IP6_SETONES(&ipn->in_ndstmsk6);

        ipn->in_namelen = old->in_namelen;
        ipn->in_ifnames[0] = old->in_ifnames[1];
        ipn->in_ifnames[1] = old->in_ifnames[0];
        bcopy(old->in_names, ipn->in_names, ipn->in_namelen);
        MUTEX_INIT(&ipn->in_lock, "ipnat rev rule lock");

        return (ipn);
}


/* ------------------------------------------------------------------------ */
/* Function:    ipf_proxy_rule_fwd                                          */
/* Returns:     ipnat_t * - NULL = failure, else pointer to new rule        */
/* Parameters:  nat(I) - pointer to NAT session to create rule from         */
/*                                                                          */
/* The purpose and rationale of this function is much the same as the above */
/* function, ipf_proxy_rule_rev, except that a rule is created that matches */
/* the same direction as that of the existing NAT session. Thus if this NAT */
/* session was created with a map rule then this function will also create  */
/* a data structure to represent a map rule. Whereas ipf_proxy_rule_rev is  */
/* used to support PORT/EPRT, this function supports PASV/EPSV.             */
/* ------------------------------------------------------------------------ */
ipnat_t *
ipf_proxy_rule_fwd(nat_t *nat)
{
        ipnat_t *old;
        ipnat_t *ipn;
        int size;

        old = nat->nat_ptr;
        size = old->in_size;

        KMALLOCS(ipn, ipnat_t *, size);
        if (ipn == NULL)
                return (NULL);

        bzero((char *)ipn, size);

        ipn->in_use = 1;
        ipn->in_hits = 1;
        ipn->in_ippip = 1;
        ipn->in_apr = NULL;
        ipn->in_size = size;
        ipn->in_pr[0] = old->in_pr[0];
        ipn->in_pr[1] = old->in_pr[1];
        ipn->in_v[0] = old->in_v[0];
        ipn->in_v[1] = old->in_v[1];
        ipn->in_ifps[0] = nat->nat_ifps[0];
        ipn->in_ifps[1] = nat->nat_ifps[1];
        ipn->in_flags = (old->in_flags | IPN_PROXYRULE);

        ipn->in_nsrcip6 = nat->nat_nsrc6;
        ipn->in_osrcip6 = nat->nat_osrc6;
        ipn->in_ndstip6 = nat->nat_ndst6;
        ipn->in_odstip6 = nat->nat_odst6;
        ipn->in_redir = old->in_redir;

        if (ipn->in_v[0] == 4) {
                ipn->in_snip = ntohl(nat->nat_nsrcaddr);
                ipn->in_dnip = ntohl(nat->nat_ndstaddr);
#ifdef USE_INET6
        } else {
                ipn->in_snip6 = nat->nat_nsrc6;
                ipn->in_dnip6 = nat->nat_ndst6;
#endif
        }

        IP6_SETONES(&ipn->in_osrcmsk6);
        IP6_SETONES(&ipn->in_nsrcmsk6);
        IP6_SETONES(&ipn->in_odstmsk6);
        IP6_SETONES(&ipn->in_ndstmsk6);

        ipn->in_namelen = old->in_namelen;
        ipn->in_ifnames[0] = old->in_ifnames[0];
        ipn->in_ifnames[1] = old->in_ifnames[1];
        bcopy(old->in_names, ipn->in_names, ipn->in_namelen);
        MUTEX_INIT(&ipn->in_lock, "ipnat fwd rule lock");

        return (ipn);
}