Always compile PFIL_HOOKS into the kernel and remove the associated kernel

compile option.  All FreeBSD packet filters now use the PFIL_HOOKS API and
thus it becomes a standard part of the network stack.

If no hooks are connected the entire packet filter hooks section and related
activities are jumped over.  This removes any performance impact if no hooks
are active.

Both OpenBSD and DragonFlyBSD have integrated PFIL_HOOKS permanently as well.

1 files changed, 11 insertions, 17 deletions

diff --git a/sys/netinet/ip_input.c b/sys/netinet/ip_input.c
index 98e1185..4d8c813 100644
--- a/sys/netinet/ip_input.c
+++ b/sys/netinet/ip_input.c
@@ -35,7 +35,6 @@
 #include "opt_ipstealth.h"
 #include "opt_ipsec.h"
 #include "opt_mac.h"
-#include "opt_pfil_hooks.h"
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -156,9 +155,8 @@ SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
 #ifdef DIAGNOSTIC
 static int	ipprintfs = 0;
 #endif
-#ifdef PFIL_HOOKS
-struct pfil_head inet_pfil_hook;
-#endif
+
+struct pfil_head inet_pfil_hook;	/* Packet filter hooks */
 
 static struct	ifqueue ipintrq;
 static int	ipqmaxlen = IFQ_MAXLEN;
@@ -264,13 +262,12 @@ ip_init()
 		    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
 			ip_protox[pr->pr_protocol] = pr - inetsw;
 
-#ifdef PFIL_HOOKS
+	/* Initialize packet filter hooks. */
 	inet_pfil_hook.ph_type = PFIL_TYPE_AF;
 	inet_pfil_hook.ph_af = AF_INET;
 	if ((i = pfil_head_register(&inet_pfil_hook)) != 0)
 		printf("%s: WARNING: unable to register pfil hook, "
 			"error %d\n", __func__, i);
-#endif /* PFIL_HOOKS */
 
 	IPQ_LOCK_INIT();
 	for (i = 0; i < IPREASS_NHASH; i++)
@@ -298,9 +295,7 @@ ip_input(struct mbuf *m)
 	int    checkif, hlen = 0;
 	u_short sum;
 	int dchg = 0;				/* dest changed after fw */
-#ifdef PFIL_HOOKS
 	struct in_addr odst;			/* original dst address */
-#endif
 #ifdef FAST_IPSEC
 	struct m_tag *mtag;
 	struct tdb_ident *tdbi;
@@ -414,17 +409,16 @@ tooshort:
 	 * Bypass packet filtering for packets from a tunnel (gif).
 	 */
 	if (ipsec_getnhist(m))
-		goto pass;
+		goto passin;
 #endif
 #if defined(FAST_IPSEC) && !defined(IPSEC_FILTERGIF)
 	/*
 	 * Bypass packet filtering for packets from a tunnel (gif).
 	 */
 	if (m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL)
-		goto pass;
+		goto passin;
 #endif
 
-#ifdef PFIL_HOOKS
 	/*
 	 * Run through list of hooks for input packets.
 	 *
@@ -432,6 +426,11 @@ tooshort:
 	 *     by NAT rewriting).  When this happens, tell
 	 *     ip_forward to do the right thing.
 	 */
+
+	/* Jump over all PFIL processing if hooks are not active. */
+	if (inet_pfil_hook.ph_busy_count == -1)
+		goto passin;
+
 	odst = ip->ip_dst;
 	if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
 	    PFIL_IN) != 0)
@@ -450,12 +449,7 @@ tooshort:
 	dchg = (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL);
 #endif /* IPFIREWALL_FORWARD */
 
-#endif /* PFIL_HOOKS */
-
-#if (defined(FAST_IPSEC) || defined(IPSEC)) && !defined(IPSEC_FILTERGIF)
-pass:
-#endif
-
+passin:
 	/*
 	 * Process options and, if not destined for us,
 	 * ship it on.  ip_dooptions returns 1 when an