text: /*	$FreeBSD$	*/
  
  /*
   * 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>
  #if !defined(AIX)
  # include <sys/fcntl.h>
  #endif
  #if !defined(_KERNEL) && !defined(__KERNEL__)
  # include <stdio.h>
  # include <string.h>
  # include <stdlib.h>
  # include <ctype.h>
  # define _KERNEL
  # ifdef __OpenBSD__
  struct file;
  # endif
  # include <sys/uio.h>
  # undef _KERNEL
  #endif
  #if !defined(linux)
  # include <sys/protosw.h>
  #endif
  #include <sys/socket.h>
  #if defined(_KERNEL)
  # if !defined(__NetBSD__) && !defined(sun) && !defined(__osf__) && \
       !defined(__OpenBSD__) && !defined(__hpux) && !defined(__sgi) && \
       !defined(AIX)
  #  include <sys/ctype.h>
  # endif
  # include <sys/systm.h>
  # if !defined(__SVR4) && !defined(__svr4__)
  #  include <sys/mbuf.h>
  # endif
  #endif
  #if defined(_KERNEL) && (__FreeBSD_version >= 220000)
  # include <sys/filio.h>
  # include <sys/fcntl.h>
  #else
  # include <sys/ioctl.h>
  #endif
  #if defined(__SVR4) || defined(__svr4__)
  # include <sys/byteorder.h>
  # ifdef _KERNEL
  #  include <sys/dditypes.h>
  # endif
  # include <sys/stream.h>
  # include <sys/kmem.h>
  #endif
  #if __FreeBSD_version >= 300000
  # include <sys/queue.h>
  #endif
  #include <net/if.h>
  #if defined(__FreeBSD_version) && (__FreeBSD_version >= 800000) && 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>
  #ifndef linux
  # include <netinet/ip_var.h>
  #endif
  #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 (__FreeBSD_version >= 300000)
  # 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"
  
  #if !defined(lint)
  static const char rcsid[] = "@(#)$Id$";
  #endif
  
  #define	AP_SESS_SIZE	53
  
  static int ipf_proxy_fixseqack __P((fr_info_t *, ip_t *, ap_session_t *, int ));
  static aproxy_t *ipf_proxy_create_clone __P((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()
  {
  	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()
  {
  	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(softc)
  	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(softc, orig)
  	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(softc, arg)
  	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(softc, arg)
  	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(softc, arg)
  	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(arg, how)
  	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(arg, ap)
  	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(softc, arg, 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(ap)
  	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(fin, tcp, np)
  	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(softc, data, cmd, mode, ctx)
  	ipf_main_softc_t *softc;
  	caddr_t data;
  	ioctlcmd_t cmd;
  	int mode;
  	void *ctx;
  {
  	ap_ctl_t ctl;
  	caddr_t ptr;
  	int error;
  
  	mode = mode;	/* LINT */
  
  	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 = copyinptr(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(fin, nat)
  	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(fin, nat)
  	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, 0 == 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(fin, nat)
  	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) || defined(MENTAT) || defined(__sgi)
  	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 defined(MENTAT) || 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) || defined(MENTAT) || defined(__sgi)
  		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;
  	}
  	return 0;
  }
  
  
  /* ------------------------------------------------------------------------ */
  /* 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 an proxy by the protocol it is being used with and its name.  */
  /* ------------------------------------------------------------------------ */
  aproxy_t *
  ipf_proxy_lookup(arg, pr, name)
  	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(ap)
  	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(softc, aps)
  	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(fin, ip, aps, inc)
  	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)
  	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);
  		} else {
  #ifdef USE_INET6
  			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);
  		} else {
  #ifdef USE_INET6
  			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)
  	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);
  	} else {
  #ifdef USE_INET6
  		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;
  }
  