tests/ipfw: add a simple fuzzing test for ipfw tables

Reviewed by:		pouria, ae
Differential Revision:	https://reviews.freebsd.org/D54579

tests/sys/netpfil/ipfw/Makefile

@@ -3,7 +3,8 @@ PACKAGE=	tests
 TESTSDIR=       ${TESTSBASE}/sys/netpfil/ipfw
 
 ATF_TESTS_SH+=	fwd \
-		divert
+		divert \
+		table
 
 ${PACKAGE}FILES+=	fwd_inetd.conf
 

tests/sys/netpfil/ipfw/table.sh

@@ -0,0 +1,96 @@
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# Copyright (c) 2026 Gleb Smirnoff <glebius@FreeBSD.org>
+#
+# 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.
+
+. $(atf_get_srcdir)/../common/utils.subr
+
+atf_test_case "fuzz" "cleanup"
+fuzz_head()
+{
+	atf_set descr 'Create couple tables and fuzzes them'
+	atf_set require.user root
+}
+
+fuzz_body()
+{
+	firewall_init "ipfw"
+
+	epair=$(vnet_mkepair)
+	vnet_mkjail sender ${epair}a
+	jexec sender ifconfig ${epair}a 192.0.2.0/31 up
+	jexec sender route add 10.0.0.0/8 192.0.2.1
+
+	vnet_mkjail receiver ${epair}b
+	jexec receiver ifconfig lo0 127.0.0.1/8 up
+	jexec receiver ifconfig ${epair}b 192.0.2.1/31 up
+	jexec receiver route add 10.0.0.0/8 -blackhole -iface lo0
+
+	jexec receiver ipfw add 100 count ip from any to table\(tb0\)
+	jexec receiver ipfw add 200 count ip from any to table\(tb1\)
+
+	( jexec sender sh -c \
+	    'while true; do \
+		oct=$(od -An -N1 -tu1 < /dev/urandom); \
+		oct=$(echo $oct); \
+		ping -c 5 -i .01 -W .01 10.0.0.${oct} >/dev/null; \
+	    done' ) &
+	pinger=$!
+
+	( jexec receiver sh -c \
+	    'while true; do \
+		set -- $(od -An -N2 -tu1 < /dev/urandom); \
+		ipfw -q table tb$(($1 % 2)) add 10.0.0.$2; \
+	     done' ) &
+	adder=$!
+
+	( jexec receiver sh -c \
+	    'while true; do \
+		set -- $(od -An -N2 -tu1 < /dev/urandom); \
+		ipfw -q table tb$(($1 % 2)) del 10.0.0.$2; \
+	     done' ) &
+	deleter=$!
+
+	( jexec receiver sh -c \
+	    'while true; do \
+		ipfw table tb0 swap tb1; \
+		sleep .25; \
+	    done' ) &
+	swapper=$!
+
+	sleep 30
+	kill $pinger
+	kill $adder
+	kill $deleter
+	kill $swapper
+}
+
+fuzz_cleanup()
+{
+	firewall_cleanup $1
+}
+
+atf_init_test_cases()
+{
+	atf_add_test_case "fuzz"
+}