Import of Darren Reed's IPFilter 3.3.4, including OpenBSD patches.

Many, many enhancements and improvements, including new in-kernel
proxies, enhancements to logging, and many bugfixes.

Note: Man pages have not yet been re-converted to mdoc.

1 files changed, 376 insertions, 171 deletions

diff --git a/sys/netinet/ip_fil.c b/sys/netinet/ip_fil.c
index 95428bf29f9..7885d41230e 100644
--- a/sys/netinet/ip_fil.c
+++ b/sys/netinet/ip_fil.c
@@ -1,4 +1,4 @@
-/*    $OpenBSD: ip_fil.c,v 1.26 1999/12/13 10:41:56 itojun Exp $    */
+/*    $OpenBSD: ip_fil.c,v 1.27 1999/12/15 05:20:21 kjell Exp $    */
 /*
  * Copyright (C) 1993-1998 by Darren Reed.
  *
@@ -8,7 +8,7 @@
  */
 #if !defined(lint)
 static const char sccsid[] = "@(#)ip_fil.c	2.41 6/5/96 (C) 1993-1995 Darren Reed";
-static const char rcsid[] = "@(#)$Id: ip_fil.c,v 1.26 1999/12/13 10:41:56 itojun Exp $";
+static const char rcsid[] = "@(#)$Id: ip_fil.c,v 1.27 1999/12/15 05:20:21 kjell Exp $";
 #endif
 
 #ifndef	SOLARIS
@@ -18,6 +18,11 @@ static const char rcsid[] = "@(#)$Id: ip_fil.c,v 1.26 1999/12/13 10:41:56 itojun
 #if defined(KERNEL) && !defined(_KERNEL)
 # define	_KERNEL
 #endif
+#include <sys/param.h>
+#if defined(__NetBSD__) && (NetBSD >= 199905) && !defined(IPFILTER_LKM) && \
+    defined(_KERNEL)
+# include "opt_ipfilter_log.h"
+#endif
 #ifdef	__FreeBSD__
 # if defined(_KERNEL) && !defined(IPFILTER_LKM)
 #  include <sys/osreldate.h>
@@ -30,10 +35,10 @@ static const char rcsid[] = "@(#)$Id: ip_fil.c,v 1.26 1999/12/13 10:41:56 itojun
 # include <string.h>
 # include <stdlib.h>
 # include <ctype.h>
+# include <fcntl.h>
 #endif
 #include <sys/errno.h>
 #include <sys/types.h>
-#include <sys/param.h>
 #include <sys/file.h>
 #if __FreeBSD_version >= 220000 && defined(_KERNEL)
 # include <sys/fcntl.h>
@@ -47,7 +52,7 @@ static const char rcsid[] = "@(#)$Id: ip_fil.c,v 1.26 1999/12/13 10:41:56 itojun
 #endif
 #include <sys/uio.h>
 #if !SOLARIS
-# if (NetBSD > 199609) || (OpenBSD > 199603)
+# if (NetBSD > 199609) || (OpenBSD > 199603) || (__FreeBSD_version >= 300000)
 #  include <sys/dirent.h>
 # else
 #  include <sys/dir.h>
@@ -65,6 +70,9 @@ static const char rcsid[] = "@(#)$Id: ip_fil.c,v 1.26 1999/12/13 10:41:56 itojun
 #endif
 #if __FreeBSD_version >= 300000
 # include <net/if_var.h>
+# if defined(_KERNEL) && !defined(IPFILTER_LKM)
+#  include "opt_ipfilter.h"
+# endif
 #endif
 #ifdef __sgi
 #include <sys/debug.h>
@@ -75,7 +83,7 @@ static const char rcsid[] = "@(#)$Id: ip_fil.c,v 1.26 1999/12/13 10:41:56 itojun
 #include <net/route.h>
 #include <netinet/in.h>
 #if !(defined(__sgi) && !defined(IFF_DRVRLOCK)) /* IRIX < 6 */
-#include <netinet/in_var.h>
+# include <netinet/in_var.h>
 #endif
 #include <netinet/in_systm.h>
 #include <netinet/ip.h>
@@ -85,23 +93,24 @@ static const char rcsid[] = "@(#)$Id: ip_fil.c,v 1.26 1999/12/13 10:41:56 itojun
 #include <netinet/tcpip.h>
 #include <netinet/ip_icmp.h>
 #ifndef	_KERNEL
+# include <unistd.h>
 # include <syslog.h>
 #endif
-#if defined(__OpenBSD__)
 #include <netinet/ip_fil_compat.h>
-#else
-#include <netinet/ip_compat.h>
-#endif
 #include <netinet/ip_fil.h>
 #include <netinet/ip_proxy.h>
 #include <netinet/ip_nat.h>
 #include <netinet/ip_frag.h>
 #include <netinet/ip_state.h>
 #include <netinet/ip_auth.h>
+#if defined(__FreeBSD_version) && (__FreeBSD_version >= 300000)
+# include <sys/malloc.h>
+#endif
 #ifndef	MIN
-#define	MIN(a,b)	(((a)<(b))?(a):(b))
+# define	MIN(a,b)	(((a)<(b))?(a):(b))
 #endif
-#if	!SOLARIS && defined(_KERNEL)
+#if !SOLARIS && defined(_KERNEL) && !defined(__sgi)
+# include <sys/kernel.h>
 extern	int	ip_optcopy __P((struct ip *, struct ip *));
 #endif
 
@@ -113,27 +122,21 @@ extern	struct	protosw	inetsw[];
 static	struct	ifnet **ifneta = NULL;
 static	int	nifs = 0;
 #else
-# if	(BSD < 199306) && !defined(__sgi)
-static	int	(*fr_saveslowtimo) __P((void));
-# else
-static	void	(*fr_saveslowtimo) __P((void));
-# endif
 # if	(BSD < 199306) || defined(__sgi)
 extern	int	tcp_ttl;
 # endif
 #endif
 
 int	ipl_inited = 0;
-#if defined(__OpenBSD__)
+# if defined (__OpenBSD__)
 int	ipl_unreach = ICMP_UNREACH_FILTER_PROHIB;
-#else
+# else
 int	ipl_unreach = ICMP_UNREACH_FILTER;
-#endif
+# endif
+
 u_long	ipl_frouteok[2] = {0, 0};
 
-static	void	fixskip __P((frentry_t **, frentry_t *, int));
 static	void	frzerostats __P((caddr_t));
-static	void	frsync __P((void));
 #if defined(__NetBSD__) || defined(__OpenBSD__)
 static	int	frrequest __P((int, u_long, caddr_t, int));
 #else
@@ -141,8 +144,10 @@ static	int	frrequest __P((int, int, caddr_t, int));
 #endif
 #ifdef	_KERNEL
 static	int	(*fr_savep) __P((ip_t *, int, void *, int, struct mbuf **));
+static	int	send_ip __P((struct mbuf *, ip_t *));
 # ifdef	__sgi
 extern  kmutex_t        ipf_rw;
+extern	KRWLOCK_T	ipf_mutex;
 # endif
 #else
 int	ipllog __P((void));
@@ -159,6 +164,15 @@ static int	write_output __P((struct ifnet *, struct mbuf *,
 				  struct sockaddr *, struct rtentry *));
 # endif
 #endif
+#if defined(IPFILTER_LKM)
+int	fr_running = 1;
+#else
+int	fr_running = 0;
+#endif
+
+#if (__FreeBSD_version >= 300000) && defined(_KERNEL)
+struct callout_handle ipfr_slowtimer_ch;
+#endif
 
 #if (_BSDI_VERSION >= 199510) && defined(_KERNEL)
 # include <sys/device.h>
@@ -207,7 +221,8 @@ void
 ipfilterattach(count)
 int count;
 {
-	iplattach();
+	if (iplattach() != 0)
+		printf("IP Filter failed to attach\n");
 }
 # endif
 
@@ -239,6 +254,16 @@ int iplattach()
 		return EBUSY;
 	}
 
+# ifdef	IPFILTER_LOG
+	ipflog_init();
+# endif
+	if (nat_init() == -1)
+		return -1;
+	if (fr_stateinit() == -1)
+		return -1;
+	if (appr_init() == -1)
+		return -1;
+
 # ifdef NETBSD_PF
 	pfil_add_hook((void *)fr_check, PFIL_IN|PFIL_OUT);
 # endif
@@ -253,15 +278,9 @@ int iplattach()
 
 	ipl_inited = 1;
 	bzero((char *)frcache, sizeof(frcache));
-	bzero((char *)nat_table, sizeof(nat_table));
 	fr_savep = fr_checkp;
 	fr_checkp = fr_check;
-	fr_saveslowtimo = inetsw[0].pr_slowtimo;
-	inetsw[0].pr_slowtimo = ipfr_slowtimer;
 
-# ifdef	IPFILTER_LOG
-	ipflog_init();
-# endif
 	SPL_X(s);
 	if (fr_pass & FR_PASS)
 		defpass = "pass";
@@ -277,6 +296,14 @@ int iplattach()
 # else
 		"disabled");
 # endif
+	printf("%s\n", ipfilter_version);
+#ifdef	_KERNEL
+# if (__FreeBSD_version >= 300000) && defined(_KERNEL)
+	ipfr_slowtimer_ch = timeout(ipfr_slowtimer, NULL, hz/2);
+# else
+	timeout(ipfr_slowtimer, NULL, hz/2);
+# endif
+#endif
 	return 0;
 }
 
@@ -293,6 +320,17 @@ int ipldetach()
 {
 	int s, i = FR_INQUE|FR_OUTQUE;
 
+#ifdef	_KERNEL
+# if (__FreeBSD_version >= 300000)
+	untimeout(ipfr_slowtimer, NULL, ipfr_slowtimer_ch);
+# else
+#  ifdef __sgi
+	untimeout(ipfr_slowtimer);
+#  else
+	untimeout(ipfr_slowtimer, NULL);
+#  endif
+# endif
+#endif
 	SPL_NET(s);
 	if (!ipl_inited)
 	{
@@ -302,8 +340,7 @@ int ipldetach()
 	}
 
 	fr_checkp = fr_savep;
-	inetsw[0].pr_slowtimo = fr_saveslowtimo;
-	frflush(IPL_LOGIPF, &i);
+	i = frflush(IPL_LOGIPF, i);
 	ipl_inited = 0;
 
 # ifdef NETBSD_PF
@@ -328,7 +365,7 @@ int ipldetach()
 static	void	frzerostats(data)
 caddr_t	data;
 {
-	struct	friostat	fio;
+	friostat_t fio;
 
 	bcopy((char *)frstats, (char *)fio.f_st,
 		sizeof(struct filterstats) * 2);
@@ -367,7 +404,8 @@ struct proc *p;
 )
 #endif
 dev_t dev;
-#if defined(__NetBSD__) || defined(__OpenBSD__) || (_BSDI_VERSION >= 199701)
+#if defined(__NetBSD__) || defined(__OpenBSD__) || \
+	 (_BSDI_VERSION >= 199701) || (__FreeBSD_version >= 300000)
 u_long cmd;
 #else
 int cmd;
@@ -381,12 +419,17 @@ int mode;
 #endif
 	int error = 0, unit = 0, tmp;
 
+#if (BSD >= 199306) && defined(_KERNEL)
+	if ((securelevel >= 2) && (mode & FWRITE))
+		return EPERM;
+#endif
 #ifdef	_KERNEL
 	unit = GET_MINOR(dev);
 	if ((IPL_LOGMAX < unit) || (unit < 0))
 		return ENXIO;
 
 # if defined(__OpenBSD__)
+       	/* Prevent IPF and NAT changes when securelevel > 1 */
 	if (securelevel > 1) {
 		switch (cmd) {
 #  ifndef IPFILTER_LKM
@@ -414,7 +457,9 @@ int mode;
 		}
 	}
 # endif /* OpenBSD */
-#endif /* _KERNEL */
+#else /* _KERNEL */
+	unit = dev;
+#endif
 
 	SPL_NET(s);
 
@@ -428,7 +473,6 @@ int mode;
 		SPL_X(s);
 		return error;
 	}
-
 	switch (cmd) {
 	case FIONREAD :
 #ifdef IPFILTER_LOG
@@ -445,16 +489,23 @@ int mode;
 			error = EPERM;
 		else {
 			IRCOPY(data, (caddr_t)&enable, sizeof(enable));
-			if (enable)
+			if (enable) {
 # if defined(__OpenBSD__)
 				error = ipl_enable();
-			else
-				error = ipl_disable();
 # else
 				error = iplattach();
-			else
+# endif
+				if (error == 0)
+					fr_running = 1;
+			} else {
+# if defined(__OpenBSD__)
+				error = ipl_disable();
+# else
 				error = ipldetach();
-# endif /* OpenBSD */
+# endif
+				if (error == 0)
+					fr_running = 0;
+			}
 		}
 		break;
 	}
@@ -512,6 +563,21 @@ int mode;
 		fio.f_active = fr_active;
 		fio.f_froute[0] = ipl_frouteok[0];
 		fio.f_froute[1] = ipl_frouteok[1];
+		fio.f_running = fr_running;
+		fio.f_groups[0][0] = ipfgroups[0][0];
+		fio.f_groups[0][1] = ipfgroups[0][1];
+		fio.f_groups[1][0] = ipfgroups[1][0];
+		fio.f_groups[1][1] = ipfgroups[1][1];
+		fio.f_groups[2][0] = ipfgroups[2][0];
+		fio.f_groups[2][1] = ipfgroups[2][1];
+#ifdef	IPFILTER_LOG
+		fio.f_logging = 1;
+#else
+		fio.f_logging = 0;
+#endif
+		fio.f_defpass = fr_pass;
+		strncpy(fio.f_version, ipfilter_version,
+			sizeof(fio.f_version));
 		IWCOPY((caddr_t)&fio, data, sizeof(fio));
 		break;
 	}
@@ -526,7 +592,7 @@ int mode;
 			error = EPERM;
 		else {
 			IRCOPY(data, (caddr_t)&tmp, sizeof(tmp));
-			frflush(unit, &tmp);
+			tmp = frflush(unit, tmp);
 			IWCOPY((caddr_t)&tmp, data, sizeof(tmp));
 		}
 		break;
@@ -569,37 +635,26 @@ int mode;
 }
 
 
-static void frsync()
+void fr_forgetifp(ifp)
+void *ifp;
 {
-#ifdef _KERNEL
-	struct ifnet *ifp;
-
-# if defined(__OpenBSD__) || (NetBSD >= 199511)
-	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_list.tqe_next)
-# else
-	for (ifp = ifnet; ifp; ifp = ifp->if_next)
-# endif
-		ip_natsync(ifp);
-#endif
-}
-
-
-static void fixskip(listp, rp, addremove)
-frentry_t **listp, *rp;
-int addremove;
-{
-	frentry_t *fp;
-	int rules = 0, rn = 0;
-
-	for (fp = *listp; fp && (fp != rp); fp = fp->fr_next, rules++)
-		;
-
-	if (!fp)
-		return;
-
-	for (fp = *listp; fp && (fp != rp); fp = fp->fr_next, rn++)
-		if (fp->fr_skip && (rn + fp->fr_skip >= rules))
-			fp->fr_skip += addremove;
+	register frentry_t *f;
+
+	WRITE_ENTER(&ipf_mutex);
+	for (f = ipacct[0][fr_active]; (f != NULL); f = f->fr_next)
+		if (f->fr_ifa == ifp)
+			f->fr_ifa = (void *)-1;
+	for (f = ipacct[1][fr_active]; (f != NULL); f = f->fr_next)
+		if (f->fr_ifa == ifp)
+			f->fr_ifa = (void *)-1;
+	for (f = ipfilter[0][fr_active]; (f != NULL); f = f->fr_next)
+		if (f->fr_ifa == ifp)
+			f->fr_ifa = (void *)-1;
+	for (f = ipfilter[1][fr_active]; (f != NULL); f = f->fr_next)
+		if (f->fr_ifa == ifp)
+			f->fr_ifa = (void *)-1;
+	RWLOCK_EXIT(&ipf_mutex);
+	ip_natsync(ifp);
 }
 
 
@@ -618,20 +673,22 @@ caddr_t data;
 	frentry_t frd;
 	frdest_t *fdp;
 	frgroup_t *fg = NULL;
-	int error = 0, in, group;
+	int error = 0, in;
+	u_int group;
 
 	fp = &frd;
 	IRCOPY(data, (caddr_t)fp, sizeof(*fp));
+	fp->fr_ref = 0;
 
 	/*
 	 * Check that the group number does exist and that if a head group
 	 * has been specified, doesn't exist.
 	 */
-	if (fp->fr_grhead &&
-	    fr_findgroup(fp->fr_grhead, fp->fr_flags, unit, set, NULL))
+	if ((req != SIOCZRLST) && fp->fr_grhead &&
+	    fr_findgroup((u_int)fp->fr_grhead, fp->fr_flags, unit, set, NULL))
 		return EEXIST;
-	if (fp->fr_group &&
-	    !fr_findgroup(fp->fr_group, fp->fr_flags, unit, set, NULL))
+	if ((req != SIOCZRLST) && fp->fr_group &&
+	    !fr_findgroup((u_int)fp->fr_group, fp->fr_flags, unit, set, NULL))
 		return ESRCH;
 
 	in = (fp->fr_flags & FR_INQUE) ? 0 : 1;
@@ -658,6 +715,13 @@ caddr_t data;
 		if (!fp->fr_ifa)
 			fp->fr_ifa = (void *)-1;
 	}
+#if BSD >= 199306
+	if (*fp->fr_oifname) {
+		fp->fr_oifa = GETUNIT(fp->fr_oifname);
+		if (!fp->fr_oifa)
+			fp->fr_oifa = (void *)-1;
+	}
+#endif
 
 	fdp = &fp->fr_dif;
 	fp->fr_flags &= ~FR_DUP;
@@ -698,13 +762,14 @@ caddr_t data;
 	}
 
 	if (!f) {
-		ftail = fprev;
-		if (req != SIOCINAFR && req != SIOCINIFR)
-			while ((f = *ftail))
-				ftail = &f->fr_next;
-		else if (fp->fr_hits)
-			while (--fp->fr_hits && (f = *ftail))
-				ftail = &f->fr_next;
+		if (req == SIOCINAFR || req == SIOCINIFR) {
+			ftail = fprev;
+			if (fp->fr_hits) {
+				while (--fp->fr_hits && (f = *ftail)) {
+					ftail = &f->fr_next;
+				}
+			}
+		}
 		f = NULL;
 	}
 
@@ -719,8 +784,8 @@ caddr_t data;
 			if (unit == IPL_LOGAUTH)
 				return fr_auth_ioctl(data, req, f, ftail);
 			if (f->fr_grhead)
-				fr_delgroup(f->fr_grhead, fp->fr_flags, unit,
-					    set);
+				fr_delgroup((u_int)f->fr_grhead, fp->fr_flags,
+					    unit, set);
 			fixskip(fprev, f, -1);
 			*ftail = f->fr_next;
 			KFREE(f);
@@ -731,7 +796,7 @@ caddr_t data;
 		else {
 			if (unit == IPL_LOGAUTH)
 				return fr_auth_ioctl(data, req, f, ftail);
-			KMALLOC(f, frentry_t *, sizeof(*f));
+			KMALLOC(f, frentry_t *);
 			if (f != NULL) {
 				if (fg && fg->fg_head)
 					fg->fg_head->fr_ref++;
@@ -757,33 +822,33 @@ caddr_t data;
 /*
  * routines below for saving IP headers to buffer
  */
-#ifdef __sgi
-# ifdef _KERNEL
+# ifdef __sgi
+#  ifdef _KERNEL
 int IPL_EXTERN(open)(dev_t *pdev, int flags, int devtype, cred_t *cp)
-# else
+#  else
 int IPL_EXTERN(open)(dev_t dev, int flags)
-# endif
-#else
+#  endif
+# else
 int IPL_EXTERN(open)(dev, flags
-# if ((_BSDI_VERSION >= 199510) || (BSD >= 199506) || (NetBSD >= 199511) || \
+#  if ((_BSDI_VERSION >= 199510) || (BSD >= 199506) || (NetBSD >= 199511) || \
      (__FreeBSD_version >= 220000) || defined(__OpenBSD__)) && defined(_KERNEL)
 , devtype, p)
 int devtype;
 struct proc *p;
-# else
+#  else
 )
-# endif
+#  endif
 dev_t dev;
 int flags;
-#endif /* __sgi */
+# endif /* __sgi */
 {
-#if defined(__sgi) && defined(_KERNEL)
+# if defined(__sgi) && defined(_KERNEL)
 	u_int min = geteminor(*pdev);
-#else
+# else
 	u_int min = GET_MINOR(dev);
-#endif
+# endif
 
-	if (2 < min)
+	if (IPL_LOGMAX < min)
 		min = ENXIO;
 	else
 		min = 0;
@@ -791,25 +856,25 @@ int flags;
 }
 
 
-#ifdef __sgi
+# ifdef __sgi
 int IPL_EXTERN(close)(dev_t dev, int flags, int devtype, cred_t *cp)
 #else
 int IPL_EXTERN(close)(dev, flags
-# if ((_BSDI_VERSION >= 199510) || (BSD >= 199506) || (NetBSD >= 199511) || \
+#  if ((_BSDI_VERSION >= 199510) || (BSD >= 199506) || (NetBSD >= 199511) || \
      (__FreeBSD_version >= 220000) || defined(__OpenBSD__)) && defined(_KERNEL)
 , devtype, p)
 int devtype;
 struct proc *p;
-# else
+#  else
 )
-# endif
+#  endif
 dev_t dev;
 int flags;
-#endif /* __sgi */
+# endif /* __sgi */
 {
 	u_int	min = GET_MINOR(dev);
 
-	if (2 < min)
+	if (IPL_LOGMAX < min)
 		min = ENXIO;
 	else
 		min = 0;
@@ -822,9 +887,9 @@ int flags;
  * called during packet processing and cause an inconsistancy to appear in
  * the filter lists.
  */
-#ifdef __sgi
+# ifdef __sgi
 int IPL_EXTERN(read)(dev_t dev, uio_t *uio, cred_t *crp)
-#else
+# else
 #  if BSD >= 199306
 int IPL_EXTERN(read)(dev, uio, ioflag)
 int ioflag;
@@ -833,13 +898,13 @@ int IPL_EXTERN(read)(dev, uio)
 #  endif
 dev_t dev;
 register struct uio *uio;
-#endif /* __sgi */
+# endif /* __sgi */
 {
-#  ifdef IPFILTER_LOG
+# ifdef IPFILTER_LOG
 	return ipflog_read(GET_MINOR(dev), uio);
-#  else
+# else
 	return ENXIO;
-#  endif
+# endif
 }
 
 
@@ -847,77 +912,171 @@ register struct uio *uio;
  * send_reset - this could conceivably be a call to tcp_respond(), but that
  * requires a large amount of setting up and isn't any more efficient.
  */
-int send_reset(ti)
-struct tcpiphdr *ti;
+int send_reset(fin, oip)
+fr_info_t *fin;
+struct ip *oip;
 {
+	struct tcphdr *tcp, *tcp2;
 	struct tcpiphdr *tp;
-	struct tcphdr *tcp;
 	struct mbuf *m;
-	int tlen = 0, err;
+	int tlen = 0;
 	ip_t *ip;
-# if defined(__FreeBSD_version) && (__FreeBSD_version >= 220000)
-	struct route ro;
-# endif
 
-	if (ti->ti_flags & TH_RST)
+	tcp = (struct tcphdr *)fin->fin_dp;
+	if (tcp->th_flags & TH_RST)
 		return -1;		/* feedback loop */
 # if	(BSD < 199306) || defined(__sgi)
 	m = m_get(M_DONTWAIT, MT_HEADER);
 # else
 	m = m_gethdr(M_DONTWAIT, MT_HEADER);
-	m->m_data += max_linkhdr;
 # endif
 	if (m == NULL)
+		return ENOBUFS;
+	if (m == NULL)
 		return -1;
 
-	if (ti->ti_flags & TH_SYN)
+	if (tcp->th_flags & TH_SYN)
 		tlen = 1;
-	m->m_len = sizeof (struct tcpiphdr);
+	m->m_len = sizeof(*tcp2) + sizeof(*ip);
 # if	BSD >= 199306
-	m->m_pkthdr.len = sizeof (struct tcpiphdr);
+	m->m_data += max_linkhdr;
+	m->m_pkthdr.len = m->m_len;
 	m->m_pkthdr.rcvif = (struct ifnet *)0;
 # endif
 	bzero(mtod(m, char *), sizeof(struct tcpiphdr));
 	ip = mtod(m, struct ip *);
 	tp = mtod(m, struct tcpiphdr *);
-	tcp = (struct tcphdr *)((char *)ip + sizeof(struct ip));
-
-	ip->ip_src.s_addr = ti->ti_dst.s_addr;
-	ip->ip_dst.s_addr = ti->ti_src.s_addr;
-	tcp->th_dport = ti->ti_sport;
-	tcp->th_sport = ti->ti_dport;
-	tcp->th_ack = htonl(ntohl(ti->ti_seq) + tlen);
-	tcp->th_off = sizeof(struct tcphdr) >> 2;
-	tcp->th_flags = TH_RST|TH_ACK;
-	tp->ti_pr = ((struct ip *)ti)->ip_p;
+	tcp2 = (struct tcphdr *)((char *)ip + sizeof(*ip));
+
+	ip->ip_src.s_addr = oip->ip_dst.s_addr;
+	ip->ip_dst.s_addr = oip->ip_src.s_addr;
+	tcp2->th_dport = tcp->th_sport;
+	tcp2->th_sport = tcp->th_dport;
+	tcp2->th_ack = ntohl(tcp->th_seq);
+	tcp2->th_ack += tlen;
+	tcp2->th_ack = htonl(tcp2->th_ack);
+	tcp2->th_off = sizeof(*tcp2) >> 2;
+	tcp2->th_flags = TH_RST|TH_ACK;
+	tp->ti_pr = oip->ip_p;
 	tp->ti_len = htons(sizeof(struct tcphdr));
-	tcp->th_sum = in_cksum(m, sizeof(struct tcpiphdr));
+	tcp2->th_sum = in_cksum(m, sizeof(*ip) + sizeof(*tcp2));
+
+	ip->ip_tos = oip->ip_tos;
+	ip->ip_p = oip->ip_p;
+	ip->ip_len = sizeof(*ip) + sizeof(*tcp2);
+
+	return send_ip(m, ip);
+}
+
+
+static int send_ip(m, ip)
+struct mbuf *m;
+ip_t *ip;
+{
+# if (defined(__FreeBSD_version) && (__FreeBSD_version >= 220000)) || \
+     (defined(_BSDI_VERSION) && (_BSDI_VERSION >= 199802))
+	struct route ro;
+# endif
 
-	ip->ip_tos = ((struct ip *)ti)->ip_tos;
-	ip->ip_p = ((struct ip *)ti)->ip_p;
-	ip->ip_len = sizeof (struct tcpiphdr);
 # if (BSD < 199306) || defined(__sgi)
 	ip->ip_ttl = tcp_ttl;
 # else
 	ip->ip_ttl = ip_defttl;
 # endif
 
+# ifdef	IPSEC
+	m->m_pkthdr.rcvif = NULL;
+# endif
 # if defined(__FreeBSD_version) && (__FreeBSD_version >= 220000)
+	{
+	int err;
+
 	bzero((char *)&ro, sizeof(ro));
 	err = ip_output(m, (struct mbuf *)0, &ro, 0, 0);
 	if (ro.ro_rt)
 		RTFREE(ro.ro_rt);
+	return err;
+	}
 # else
 	/*
 	 * extra 0 in case of multicast
 	 */
-#  ifdef __OpenBSD__
-	err = ip_output(m, (struct mbuf *)0, 0, 0, 0, 0);
+#  if _BSDI_VERSION >= 199802
+	return ip_output(m, (struct mbuf *)0, &ro, 0, 0, NULL);
 #  else
-	err = ip_output(m, (struct mbuf *)0, 0, 0, 0);
+#   if defined(__OpenBSD__)
+       return ip_output(m, (struct mbuf *)0, 0, 0, 0, NULL);
+#   else
+	return ip_output(m, (struct mbuf *)0, 0, 0, 0);
+#   endif
 #  endif
 # endif
-	return err;
+}
+
+
+int send_icmp_err(oip, type, code, ifp, dst)
+ip_t *oip;
+int type, code;
+void *ifp;
+struct in_addr	dst;
+{
+	struct icmp *icmp;
+	struct mbuf *m;
+	ip_t *nip;
+
+# if	(BSD < 199306) || defined(__sgi)
+	m = m_get(M_DONTWAIT, MT_HEADER);
+# else
+	m = m_gethdr(M_DONTWAIT, MT_HEADER);
+# endif
+	if (m == NULL)
+		return ENOBUFS;
+	m->m_len = sizeof(*nip) + sizeof(*icmp) + 8;
+# if	BSD >= 199306
+	m->m_data += max_linkhdr;
+	m->m_pkthdr.len = sizeof(*nip) + sizeof(*icmp) + 8;
+	m->m_pkthdr.rcvif = (struct ifnet *)0;
+# endif
+
+	bzero(mtod(m, char *), (size_t)sizeof(*nip) + sizeof(*icmp) + 8);
+	nip = mtod(m, ip_t *);
+	icmp = (struct icmp *)(nip + 1);
+
+	nip->ip_v = IPVERSION;
+	nip->ip_hl = (sizeof(*nip) >> 2);
+	nip->ip_p = IPPROTO_ICMP;
+	nip->ip_id = oip->ip_id;
+	nip->ip_sum = 0;
+	nip->ip_ttl = 60;
+	nip->ip_tos = oip->ip_tos;
+	nip->ip_len = sizeof(*nip) + sizeof(*icmp) + 8;
+	if (dst.s_addr == 0) {
+		if (fr_ifpaddr(ifp, &dst) == -1)
+			return -1;
+		dst.s_addr = htonl(dst.s_addr);
+	}
+	nip->ip_src = dst;
+	nip->ip_dst = oip->ip_src;
+
+	icmp->icmp_type = type;
+	icmp->icmp_code = code;
+	icmp->icmp_cksum = 0;
+	bcopy((char *)oip, (char *)&icmp->icmp_ip, sizeof(*oip));
+	bcopy((char *)oip + (oip->ip_hl << 2),
+	      (char *)&icmp->icmp_ip + sizeof(*oip), 8);	/* 64 bits */
+# ifndef	sparc
+	{
+	register u_short	__iplen, __ipoff;
+	ip_t *ip = &icmp->icmp_ip;
+
+	__iplen = ip->ip_len;
+	__ipoff = ip->ip_off;
+	ip->ip_len = htons(__iplen);
+	ip->ip_off = htons(__ipoff);
+	}
+# endif
+	icmp->icmp_cksum = ipf_cksum((u_short *)icmp, sizeof(*icmp) + 8);
+	return send_ip(m, nip);
 }
 
 
@@ -937,11 +1096,12 @@ iplinit()
 	/* must explicitly enable with 'ipf -E'
 	 * which invokes ipl_enable(); */
 #  else
-	(void) iplattach();
+	if (iplattach() != 0)
+		printf("IP Filter failed to attach\n");
 #  endif
 	ip_init();
 }
-# endif /* !LKM, !sgi, FreeBSD < 3 */
+# endif /* ! __NetBSD__ */
 
 
 size_t mbufchainlen(m0)
@@ -955,7 +1115,7 @@ register struct mbuf *m0;
 }
 
 
-void ipfr_fastroute(m0, fin, fdp)
+int ipfr_fastroute(m0, fin, fdp)
 struct mbuf *m0;
 fr_info_t *fin;
 frdest_t *fdp;
@@ -963,12 +1123,13 @@ frdest_t *fdp;
 	register struct ip *ip, *mhip;
 	register struct mbuf *m = m0;
 	register struct route *ro;
-	struct ifnet *ifp = fdp->fd_ifp;
-	int len, off, error = 0;
-	int hlen = fin->fin_hlen;
-	struct route iproute;
+	int len, off, error = 0, hlen;
 	struct sockaddr_in *dst;
+	struct route iproute;
+	struct ifnet *ifp;
+	frentry_t *fr;
 
+	hlen = fin->fin_hlen;
 	ip = mtod(m0, struct ip *);
 	/*
 	 * Route packet.
@@ -977,13 +1138,25 @@ frdest_t *fdp;
 	bzero((caddr_t)ro, sizeof (*ro));
 	dst = (struct sockaddr_in *)&ro->ro_dst;
 	dst->sin_family = AF_INET;
-	dst->sin_addr = fdp->fd_ip.s_addr ? fdp->fd_ip : ip->ip_dst;
+
+	fr = fin->fin_fr;
+	ifp = fdp->fd_ifp;
+	/*
+	 * In case we're here due to "to <if>" being used with "keep state",
+	 * check that we're going in the correct direction.
+	 */
+	if ((fr != NULL) && (fin->fin_rev != 0)) {
+		if ((ifp != NULL) && (fdp == &fr->fr_tif))
+			return -1;
+		dst->sin_addr = ip->ip_dst;
+	} else
+		dst->sin_addr = fdp->fd_ip.s_addr ? fdp->fd_ip : ip->ip_dst;
 # ifdef	__bsdi__
 	dst->sin_len = sizeof(*dst);
 # endif
 # if	(BSD >= 199306) && !defined(__NetBSD__) && !defined(__bsdi__) && \
 	!defined(__OpenBSD__)
-# ifdef	RTF_CLONING
+#  ifdef	RTF_CLONING
 	rtalloc_ign(ro, RTF_CLONING);
 #  else
 	rtalloc_ign(ro, RTF_PRCLONING);
@@ -1014,15 +1187,17 @@ frdest_t *fdp;
 	 * go back through output filtering and miss their chance to get
 	 * NAT'd and counted.
 	 */
+	fin->fin_ifp = ifp;
 	if (fin->fin_out == 0) {
+		fin->fin_out = 1;
 		if ((fin->fin_fr = ipacct[1][fr_active]) &&
-		    (FR_SCANLIST(FR_NOMATCH, ip, fin, m) & FR_ACCOUNT)) {
+		    (fr_scanlist(FR_NOMATCH, ip, fin, m) & FR_ACCOUNT)) {
 			ATOMIC_INC(frstats[1].fr_acct);
 		}
 		fin->fin_fr = NULL;
-		(void) ip_natout(ip, hlen, fin);
-	}
-	if (fin->fin_out)
+		(void) fr_checkstate(ip, fin);
+		(void) ip_natout(ip, fin);
+	} else
 		ip->ip_sum = 0;
 	/*
 	 * If small enough for interface, can just send directly.
@@ -1066,7 +1241,11 @@ frdest_t *fdp;
 	m0 = m;
 	mhlen = sizeof (struct ip);
 	for (off = hlen + len; off < ip->ip_len; off += len) {
+# ifdef	MGETHDR
+		MGETHDR(m, M_DONTWAIT, MT_HEADER);
+# else
 		MGET(m, M_DONTWAIT, MT_HEADER);
+# endif
 		if (m == 0) {
 			error = ENOBUFS;
 			goto bad;
@@ -1096,6 +1275,10 @@ frdest_t *fdp;
 			error = ENOBUFS;	/* ??? */
 			goto sendorfree;
 		}
+# if BSD >= 199306
+		m->m_pkthdr.len = mhlen + len;
+		m->m_pkthdr.rcvif = NULL;
+# endif
 		mhip->ip_off = htons((u_short)mhip->ip_off);
 		mhip->ip_sum = 0;
 		mhip->ip_sum = in_cksum(m, mhlen);
@@ -1135,50 +1318,60 @@ done:
 
 	if (ro->ro_rt)
 		RTFREE(ro->ro_rt);
-	return;
+	return 0;
 bad:
+# if BSD >= 199306
+	if (error == EMSGSIZE) {
+		/* Send ICMP error here */
+		struct mbuf *mcopy;
+
+		mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
+		if (mcopy) {
+			mcopy->m_pkthdr.rcvif = (struct ifnet *)ifp;
+			icmp_error(mcopy, ICMP_UNREACH, ICMP_UNREACH_NEEDFRAG,
+				   ip->ip_dst.s_addr, ifp);
+		}
+	}
+# endif
 	m_freem(m);
 	goto done;
 }
 #else /* #ifdef _KERNEL */
 
 
-#ifdef __sgi
+# ifdef __sgi
 static int no_output __P((struct ifnet *ifp, struct mbuf *m,
 			   struct sockaddr *s))
-#else
+# else
 static int no_output __P((struct ifnet *ifp, struct mbuf *m,
 			   struct sockaddr *s, struct rtentry *rt))
-#endif
+# endif
 {
 	return 0;
 }
 
 
 # ifdef __STDC__
-#ifdef __sgi
+#  ifdef __sgi
 static int write_output __P((struct ifnet *ifp, struct mbuf *m,
 			     struct sockaddr *s))
-#else
+#  else
 static int write_output __P((struct ifnet *ifp, struct mbuf *m,
 			     struct sockaddr *s, struct rtentry *rt))
-#endif
+#  endif
 {
-# if !(defined(NetBSD) && (NetBSD <= 1991011) && (NetBSD >= 199606)) || \
-	(defined(OpenBSD) && (OpenBSD >= 199603))
 	ip_t *ip = (ip_t *)m;
-#  endif
 # else
 static int write_output(ifp, ip)
 struct ifnet *ifp;
 ip_t *ip;
 {
 # endif
-	FILE *fp;
 	char fname[32];
+	FILE *fp;
 
 # if (defined(NetBSD) && (NetBSD <= 1991011) && (NetBSD >= 199606)) || \
-    (defined(OpenBSD) && (OpenBSD >= 199603))
+	(defined(OpenBSD) && (OpenBSD >= 199603))
 #    if defined __OpenBSD__
 	sprintf(fname, "/var/run/%s", ifp->if_xname);
 #    else
@@ -1258,7 +1451,6 @@ char *name;
 
 void init_ifp()
 {
-
 	struct ifnet *ifp, **ifa;
 	char fname[32];
 	int fd;
@@ -1271,8 +1463,11 @@ void init_ifp()
 		sprintf(fname, "/var/run/%s", ifp->if_xname);
 #    else
 		sprintf(fname, "/tmp/%s", ifp->if_xname);
-#endif
-		if ((fd = open(fname, O_WRONLY|O_CREAT|O_EXCL, 0600)) != -1)
+#    endif
+		fd = open(fname, O_WRONLY|O_CREAT|O_EXCL|O_TRUNC, 0600);
+		if (fd == -1)
+			perror("open");
+		else
 			close(fd);
 	}
 # else
@@ -1280,14 +1475,17 @@ void init_ifp()
 	for (ifa = ifneta; ifa && (ifp = *ifa); ifa++) {
 		ifp->if_output = write_output;
 		sprintf(fname, "/tmp/%s%d", ifp->if_name, ifp->if_unit);
-		if ((fd = open(fname, O_WRONLY|O_CREAT|O_EXCL, 0600)) != -1)
+		fd = open(fname, O_WRONLY|O_CREAT|O_EXCL|O_TRUNC, 0600);
+		if (fd == -1)
+			perror("open");
+		else
 			close(fd);
 	}
 # endif
 }
 
 
-void ipfr_fastroute(ip, fin, fdp)
+int ipfr_fastroute(ip, fin, fdp)
 ip_t *ip;
 fr_info_t *fin;
 frdest_t *fdp;
@@ -1295,7 +1493,7 @@ frdest_t *fdp;
 	struct ifnet *ifp = fdp->fd_ifp;
 
 	if (!ifp)
-		return;	/* no routing table out here */
+		return 0;	/* no routing table out here */
 
 	ip->ip_len = htons((u_short)ip->ip_len);
 	ip->ip_off = htons((u_short)(ip->ip_off | IP_MF));
@@ -1305,6 +1503,7 @@ frdest_t *fdp;
 #else
 	(*ifp->if_output)(ifp, (void *)ip, NULL, 0);
 #endif
+	return 0;
 }
 
 
@@ -1331,4 +1530,10 @@ struct ifnet *ifp;
 	verbose("- TCP RST sent\n");
 	return 0;
 }
+
+
+void frsync()
+{
+	return;
+}
 #endif /* _KERNEL */