netpfil tests: Basic dummynet pipe test

Test dummynet pipes (i.e. bandwidth limitation) with ipfw. This is put
in the common tests because we hope to add dummynet support to pf in the
near future.

MFC after:	2 weeks
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D30380

tests/sys/netpfil/common/Makefile

@@ -6,6 +6,7 @@ TESTSDIR=	${TESTSBASE}/sys/netpfil/common
 
 
 ATF_TESTS_SH+=	\
+		dummynet \
 		pass_block \
 		nat \
 		tos \

tests/sys/netpfil/common/dummynet.sh

@@ -0,0 +1,75 @@
+# $FreeBSD$
+#
+# SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+#
+# Copyright (c) 2021 Rubicon Communications, LLC (Netgate)
+#
+# 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.
+
+. $(atf_get_srcdir)/utils.subr
+. $(atf_get_srcdir)/runner.subr
+
+pipe_head()
+{
+	atf_set descr 'Basic pipe test'
+	atf_set require.user root
+}
+
+pipe_body()
+{
+	fw=$1
+	firewall_init $fw
+	dummynet_init $fw
+
+	epair=$(vnet_mkepair)
+	vnet_mkjail alcatraz ${epair}b
+
+	ifconfig ${epair}a 192.0.2.1/24 up
+	jexec alcatraz ifconfig ${epair}b 192.0.2.2/24 up
+
+	# Sanity check
+	atf_check -s exit:0 -o ignore ping -i .1 -c 3 -s 1200 192.0.2.2
+
+	jexec alcatraz dnctl pipe 1 config bw 30Byte/s
+
+	firewall_config alcatraz ${fw} \
+		"ipfw"	\
+			"ipfw add 1000 pipe 1 ip from any to any"
+
+	# single ping succeeds just fine
+	atf_check -s exit:0 -o ignore ping -c 1 192.0.2.2
+
+	# Saturate the link
+	ping -i .1 -c 5 -s 1200 192.0.2.2
+
+	# We should now be hitting the limits and get this packet dropped.
+	atf_check -s exit:2 -o ignore ping -c 1 -s 1200 192.0.2.2
+}
+
+pipe_cleanup()
+{
+	firewall_cleanup $1
+}
+
+setup_tests		\
+	pipe		\
+		ipfw

tests/sys/netpfil/common/utils.subr

@@ -103,6 +103,21 @@ firewall_init()
 
 }
 
+dummynet_init()
+{
+	firewall=$1
+
+	if ! kldstat -q -m dummynet; then
+		atf_skip "This test requires dummynet"
+	fi
+
+	if [ ${firewall} == "ipfw" ]; then
+		# Nothing. This is okay.
+	else
+		atf_skip "${firewall} does not support dummynet"
+	fi
+}
+
 nat_init()
 {
 	firewall=$1