pf: Basic automated test using VIMAGE

If VIMAGE is present we can start jails with their own pf instance. This
makes it fairly easy to run tests.
For example, this basic test verifies that drop/pass and icmp
classification works. It's a basic sanity test for pf, and hopefully an
example on how to write more pf tests.

The tests are skipped if VIMAGE is not enabled.

This work is inspired by the GSoC work of Panagiotes Mousikides.

Differential Revision:	https://reviews.freebsd.org/D12580

etc/mtree/BSD.tests.dist

@@ -476,6 +476,10 @@
         ..
         netinet
         ..
+        netpfil
+            pf
+            ..
+        ..
         opencrypto
         ..
         pjdfstest

tests/sys/Makefile

@@ -13,6 +13,7 @@ TESTS_SUBDIRS+=		kqueue
 TESTS_SUBDIRS+=		mac
 TESTS_SUBDIRS+=		mqueue
 TESTS_SUBDIRS+=		netinet
+TESTS_SUBDIRS+=		netpfil
 TESTS_SUBDIRS+=		opencrypto
 TESTS_SUBDIRS+=		posixshm
 TESTS_SUBDIRS+=		sys

tests/sys/netpfil/Makefile

@@ -0,0 +1,7 @@
+# $FreeBSD$
+
+TESTSDIR=		${TESTSBASE}/sys/netpfil
+
+TESTS_SUBDIRS+=		pf
+
+.include <bsd.test.mk>

tests/sys/netpfil/pf/Makefile

@@ -0,0 +1,11 @@
+# $FreeBSD$
+
+PACKAGE=	tests
+
+TESTSDIR=       ${TESTSBASE}/sys/netpfil/pf
+
+ATF_TESTS_SH+=	pass_block
+
+${PACKAGE}FILES+=	utils.subr
+
+.include <bsd.test.mk>

tests/sys/netpfil/pf/pass_block.sh

@@ -0,0 +1,91 @@
+# $FreeBSD$
+
+. $(atf_get_srcdir)/utils.subr
+
+atf_test_case "v4" "cleanup"
+v4_head()
+{
+	atf_set descr 'Basic pass/block test for IPv4'
+	atf_set require.user root
+}
+
+v4_body()
+{
+	pft_init
+
+	epair=$(pft_mkepair)
+	ifconfig ${epair}a 192.0.2.1/24 up
+
+	# Set up a simple jail with one interface
+	pft_mkjail alcatraz ${epair}b
+	jexec alcatraz ifconfig ${epair}b 192.0.2.2/24 up
+
+	# Trivial ping to the jail, without pf
+	atf_check -s exit:0 -o ignore ping -c 1 -t 1 192.0.2.2
+
+	# pf without policy will let us ping
+	jexec alcatraz pfctl -e
+	atf_check -s exit:0 -o ignore ping -c 1 -t 1 192.0.2.2
+
+	# Block everything
+	printf "block in\n" | jexec alcatraz pfctl -f -
+	atf_check -s exit:2 -o ignore ping -c 1 -t 1 192.0.2.2
+
+	# Block everything but ICMP
+	printf "block in\npass in proto icmp\n" | jexec alcatraz pfctl -f -
+	atf_check -s exit:0 -o ignore ping -c 1 -t 1 192.0.2.2
+}
+
+v4_cleanup()
+{
+	pft_cleanup
+}
+
+atf_test_case "v6" "cleanup"
+v6_head()
+{
+	atf_set descr 'Basic pass/block test for IPv6'
+	atf_set require.user root
+}
+
+v6_body()
+{
+	pft_init
+
+	epair=$(pft_mkepair)
+	ifconfig ${epair}a inet6 2001:db8:42::1/64 up no_dad
+
+	# Set up a simple jail with one interface
+	pft_mkjail alcatraz ${epair}b
+	jexec alcatraz ifconfig ${epair}b inet6 2001:db8:42::2/64 up no_dad
+
+	# Trivial ping to the jail, without pf
+	atf_check -s exit:0 -o ignore ping6 -c 1 -x 1 2001:db8:42::2
+
+	# pf without policy will let us ping
+	jexec alcatraz pfctl -e
+	atf_check -s exit:0 -o ignore ping6 -c 1 -x 1 2001:db8:42::2
+
+	# Block everything
+	printf "block in\n" | jexec alcatraz pfctl -f -
+	atf_check -s exit:2 -o ignore ping6 -c 1 -x 1 2001:db8:42::2
+
+	# Block everything but ICMP
+	printf "block in\npass in proto icmp6\n" | jexec alcatraz pfctl -f -
+	atf_check -s exit:0 -o ignore ping6 -c 1 -x 1 2001:db8:42::2
+
+	# Allowing ICMPv4 does not allow ICMPv6
+	printf "block in\npass in proto icmp\n" | jexec alcatraz pfctl -f -
+	atf_check -s exit:2 -o ignore ping6 -c 1 -x 1 2001:db8:42::2
+}
+
+v6_cleanup()
+{
+	pft_cleanup
+}
+
+atf_init_test_cases()
+{
+	atf_add_test_case "v4"
+	atf_add_test_case "v6"
+}

tests/sys/netpfil/pf/utils.subr

@@ -0,0 +1,47 @@
+# $FreeBSD$
+# Utility functions
+##
+
+pft_init()
+{
+	if [ ! -c /dev/pf ]; then
+		atf_skip "This test requires pf"
+	fi
+
+	if [ "`sysctl -i -n kern.features.vimage`" != 1 ]; then
+		atf_skip "This test requires VIMAGE"
+	fi
+}
+
+pft_mkepair()
+{
+	ifname=$(ifconfig epair create)
+	echo $ifname >> created_interfaces.lst
+	echo ${ifname%a}
+}
+
+pft_mkjail()
+{
+	jailname=$1
+	ifname=$2
+	jail -c name=${jailname} persist vnet vnet.interface=${ifname}
+
+	echo $jailname >> created_jails.lst
+}
+
+pft_cleanup()
+{
+	if [ -f created_interfaces.lst ]; then
+		for ifname in `cat created_interfaces.lst`
+		do
+			ifconfig ${ifname} destroy
+		done
+	fi
+
+	if [ -f created_jails.lst ]; then
+		for jailname in `cat created_jails.lst`
+		do
+			jail -r ${jailname}
+		done
+	fi
+}