diff -r 58347fad0298 sys/modules/khelp/Makefile
--- a/sys/modules/khelp/Makefile	Fri Dec 10 11:48:19 2010 +1100
+++ b/sys/modules/khelp/Makefile	Fri Dec 10 11:48:35 2010 +1100
@@ -1,5 +1,7 @@
 # $FreeBSD$
 
-SUBDIR=	h_ertt
+SUBDIR=	h_ertt \
+	h_test1 \
+	h_test2
 
 .include <bsd.subdir.mk>
diff -r 58347fad0298 sys/modules/khelp/h_test1/Makefile
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/modules/khelp/h_test1/Makefile	Fri Dec 10 11:48:35 2010 +1100
@@ -0,0 +1,9 @@
+# $FreeBSD$
+
+.include <bsd.own.mk>
+
+.PATH: ${.CURDIR}/../../../netinet
+KMOD=	h_test1
+SRCS=	h_test1.c
+
+.include <bsd.kmod.mk>
diff -r 58347fad0298 sys/modules/khelp/h_test2/Makefile
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/modules/khelp/h_test2/Makefile	Fri Dec 10 11:48:35 2010 +1100
@@ -0,0 +1,9 @@
+# $FreeBSD$
+
+.include <bsd.own.mk>
+
+.PATH: ${.CURDIR}/../../../netinet
+KMOD=	h_test2
+SRCS=	h_test2.c
+
+.include <bsd.kmod.mk>
diff -r 58347fad0298 sys/netinet/h_test1.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/netinet/h_test1.c	Fri Dec 10 11:48:35 2010 +1100
@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2010 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed at the Centre for Advanced Internet
+ * Architectures, Swinburne University of Technology, Melbourne, Australia by
+ * Lawrence Stewart under sponsorship from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/hhook.h>
+#include <sys/khelp.h>
+#include <sys/module.h>
+#include <sys/module_khelp.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+
+#include <netinet/tcp_var.h>
+
+#include <vm/uma.h>
+
+static int test1_mod_init(void);
+static int test1_mod_destroy(void);
+
+struct test1 {
+	uint32_t est_in_count;
+	uint32_t est_out_count;
+};
+
+struct helper test1_helper = {
+	.mod_init = test1_mod_init,
+	.mod_destroy = test1_mod_destroy,
+	.h_flags = HELPER_NEEDS_OSD,
+	.h_classes = HELPER_CLASS_TCP
+};
+
+static void
+test1_hook(int hhook_type, int hhook_id, void *udata,
+    void *ctx_data, void *hdata, struct osd *hosd)
+{
+	struct test1 *data;
+
+	data = hdata;
+
+	if (hhook_id == HHOOK_TCP_EST_IN)
+		data->est_in_count++;
+	else if (hhook_id == HHOOK_TCP_EST_OUT)
+		data->est_out_count++;
+}
+
+static int
+test1_mod_init(void)
+{
+	int ret;
+
+	ret = hhook_add_hook_lookup(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN,
+	    &test1_helper, &test1_hook, NULL, HHOOK_WAITOK);
+	if (ret)
+		return (ret);
+
+	return hhook_add_hook_lookup(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT,
+	    &test1_helper, &test1_hook, NULL, HHOOK_WAITOK);
+}
+
+static int
+test1_mod_destroy(void)
+{
+	int ret;
+
+	ret = hhook_remove_hook_lookup(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN,
+	    &test1_hook, NULL);
+	ret += hhook_remove_hook_lookup(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT,
+	    &test1_hook, NULL);
+
+	return (ret);
+}
+
+
+DECLARE_HELPER_UMA(test1, &test1_helper, 1, sizeof(struct test1), NULL, NULL);
diff -r 58347fad0298 sys/netinet/h_test2.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/netinet/h_test2.c	Fri Dec 10 11:48:35 2010 +1100
@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2010 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed at the Centre for Advanced Internet
+ * Architectures, Swinburne University of Technology, Melbourne, Australia by
+ * Lawrence Stewart under sponsorship from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/hhook.h>
+#include <sys/khelp.h>
+#include <sys/module.h>
+#include <sys/module_khelp.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+
+#include <netinet/tcp_var.h>
+
+#include <vm/uma.h>
+
+static int test2_mod_init(void);
+static int test2_mod_destroy(void);
+
+struct test2 {
+	uint32_t est_in_count;
+	uint32_t est_out_count;
+};
+
+struct helper test2_helper = {
+	.mod_init = test2_mod_init,
+	.mod_destroy = test2_mod_destroy,
+	.h_flags = HELPER_NEEDS_OSD,
+	.h_classes = HELPER_CLASS_TCP
+};
+
+static void
+test2_hook(int hhook_type, int hhook_id, void *udata,
+    void *ctx_data, void *hdata, struct osd *hosd)
+{
+	struct test2 *data;
+
+	data = hdata;
+
+	if (hhook_id == HHOOK_TCP_EST_IN)
+		data->est_in_count++;
+	else if (hhook_id == HHOOK_TCP_EST_OUT)
+		data->est_out_count++;
+}
+
+static int
+test2_mod_init(void)
+{
+	int ret;
+
+	ret = hhook_add_hook_lookup(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN,
+	    &test2_helper, &test2_hook, NULL, HHOOK_WAITOK);
+	if (ret)
+		return (ret);
+
+	return hhook_add_hook_lookup(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT,
+	    &test2_helper, &test2_hook, NULL, HHOOK_WAITOK);
+}
+
+static int
+test2_mod_destroy(void)
+{
+	int ret;
+
+	ret = hhook_remove_hook_lookup(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN,
+	    &test2_hook, NULL);
+	ret += hhook_remove_hook_lookup(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT,
+	    &test2_hook, NULL);
+
+	return (ret);
+}
+
+
+DECLARE_HELPER_UMA(test2, &test2_helper, 1, sizeof(struct test2), NULL, NULL);