selftests: netfilter: bridge_brouter.sh: move to lib.sh infra

Doing so gets us dynamically generated netns names.

Also:
* do not assume rp_filter is disabled, if its on script failed
* reduce timeout (-W) for "expected to fail" ping commands
* don't print PASS line for basic sanity ping
* shellcheck cleanups
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20240411233624.8129-3-fw@strlen.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/net/netfilter/bridge_brouter.sh

@@ -5,142 +5,118 @@
 # part of a bridge.
 
 #           eth0    br0     eth0
-# setup is: ns1 <-> ns0 <-> ns2
+# setup is: ns1 <-> nsbr <-> ns2
 
-# Kselftest framework requirement - SKIP code is 4.
-ksft_skip=4
-ret=0
+source lib.sh
 
-ebtables -V > /dev/null 2>&1
-if [ $? -ne 0 ];then
+if ! ebtables -V > /dev/null 2>&1;then
 	echo "SKIP: Could not run test without ebtables"
 	exit $ksft_skip
 fi
 
-ip -Version > /dev/null 2>&1
-if [ $? -ne 0 ];then
-	echo "SKIP: Could not run test without ip tool"
-	exit $ksft_skip
-fi
+cleanup() {
+	cleanup_all_ns
+}
 
-ip netns add ns0
-ip netns add ns1
-ip netns add ns2
+trap cleanup EXIT
 
-ip link add veth0 netns ns0 type veth peer name eth0 netns ns1
-if [ $? -ne 0 ]; then
+setup_ns nsbr ns1 ns2
+
+ip netns exec "$nsbr" sysctl -q net.ipv4.conf.default.rp_filter=0
+ip netns exec "$nsbr" sysctl -q net.ipv4.conf.all.rp_filter=0
+if ! ip link add veth0 netns "$nsbr" type veth peer name eth0 netns "$ns1"; then
 	echo "SKIP: Can't create veth device"
 	exit $ksft_skip
 fi
-ip link add veth1 netns ns0 type veth peer name eth0 netns ns2
-
-ip -net ns0 link set lo up
-ip -net ns0 link set veth0 up
-ip -net ns0 link set veth1 up
+ip link add veth1 netns "$nsbr" type veth peer name eth0 netns "$ns2"
 
-ip -net ns0 link add br0 type bridge
-if [ $? -ne 0 ]; then
+if ! ip -net "$nsbr" link add br0 type bridge; then
 	echo "SKIP: Can't create bridge br0"
 	exit $ksft_skip
 fi
 
-ip -net ns0 link set veth0 master br0
-ip -net ns0 link set veth1 master br0
-ip -net ns0 link set br0 up
-ip -net ns0 addr add 10.0.0.1/24 dev br0
+ip -net "$nsbr" link set veth0 up
+ip -net "$nsbr" link set veth1 up
+
+ip -net "$nsbr" link set veth0 master br0
+ip -net "$nsbr" link set veth1 master br0
+ip -net "$nsbr" link set br0 up
+ip -net "$nsbr" addr add 10.0.0.1/24 dev br0
 
-# place both in same subnet, ns1 and ns2 connected via ns0:br0
-for i in 1 2; do
-  ip -net ns$i link set lo up
-  ip -net ns$i link set eth0 up
-  ip -net ns$i addr add 10.0.0.1$i/24 dev eth0
-done
+# place both in same subnet, ${ns1} and ${ns2} connected via ${nsbr}:br0
+ip -net "$ns1" link set eth0 up
+ip -net "$ns2" link set eth0 up
+ip -net "$ns1" addr add 10.0.0.11/24 dev eth0
+ip -net "$ns2" addr add 10.0.0.12/24 dev eth0
 
 test_ebtables_broute()
 {
-	local cipt
-
 	# redirect is needed so the dstmac is rewritten to the bridge itself,
 	# ip stack won't process OTHERHOST (foreign unicast mac) packets.
-	ip netns exec ns0 ebtables -t broute -A BROUTING -p ipv4 --ip-protocol icmp -j redirect --redirect-target=DROP
-	if [ $? -ne 0 ]; then
+	if ! ip netns exec "$nsbr" ebtables -t broute -A BROUTING -p ipv4 --ip-protocol icmp -j redirect --redirect-target=DROP; then
 		echo "SKIP: Could not add ebtables broute redirect rule"
 		return $ksft_skip
 	fi
 
-	# ping netns1, expected to not work (ip forwarding is off)
-	ip netns exec ns1 ping -q -c 1 10.0.0.12 > /dev/null 2>&1
-	if [ $? -eq 0 ]; then
+	ip netns exec "$nsbr" sysctl -q net.ipv4.conf.veth0.forwarding=0
+
+	# ping net${ns1}, expected to not work (ip forwarding is off)
+	if ip netns exec "$ns1" ping -q -c 1 10.0.0.12 -W 0.5 > /dev/null 2>&1; then
 		echo "ERROR: ping works, should have failed" 1>&2
 		return 1
 	fi
 
 	# enable forwarding on both interfaces.
 	# neither needs an ip address, but at least the bridge needs
-	# an ip address in same network segment as ns1 and ns2 (ns0
+	# an ip address in same network segment as ${ns1} and ${ns2} (${nsbr}
 	# needs to be able to determine route for to-be-forwarded packet).
-	ip netns exec ns0 sysctl -q net.ipv4.conf.veth0.forwarding=1
-	ip netns exec ns0 sysctl -q net.ipv4.conf.veth1.forwarding=1
-
-	sleep 1
+	ip netns exec "$nsbr" sysctl -q net.ipv4.conf.veth0.forwarding=1
+	ip netns exec "$nsbr" sysctl -q net.ipv4.conf.veth1.forwarding=1
 
-	ip netns exec ns1 ping -q -c 1 10.0.0.12 > /dev/null
-	if [ $? -ne 0 ]; then
+	if ! ip netns exec "$ns1" ping -q -c 1 10.0.0.12 > /dev/null; then
 		echo "ERROR: ping did not work, but it should (broute+forward)" 1>&2
 		return 1
 	fi
 
-	echo "PASS: ns1/ns2 connectivity with active broute rule"
-	ip netns exec ns0 ebtables -t broute -F
+	echo "PASS: ${ns1}/${ns2} connectivity with active broute rule"
+	ip netns exec "$nsbr" ebtables -t broute -F
 
-	# ping netns1, expected to work (frames are bridged)
-	ip netns exec ns1 ping -q -c 1 10.0.0.12 > /dev/null
-	if [ $? -ne 0 ]; then
+	# ping net${ns1}, expected to work (frames are bridged)
+	if ! ip netns exec "$ns1" ping -q -c 1 10.0.0.12 > /dev/null; then
 		echo "ERROR: ping did not work, but it should (bridged)" 1>&2
 		return 1
 	fi
 
-	ip netns exec ns0 ebtables -t filter -A FORWARD -p ipv4 --ip-protocol icmp -j DROP
+	ip netns exec "$nsbr" ebtables -t filter -A FORWARD -p ipv4 --ip-protocol icmp -j DROP
 
-	# ping netns1, expected to not work (DROP in bridge forward)
-	ip netns exec ns1 ping -q -c 1 10.0.0.12 > /dev/null 2>&1
-	if [ $? -eq 0 ]; then
+	# ping net${ns1}, expected to not work (DROP in bridge forward)
+	if ip netns exec "$ns1" ping -q -c 1 10.0.0.12 -W 0.5 > /dev/null 2>&1; then
 		echo "ERROR: ping works, should have failed (icmp forward drop)" 1>&2
 		return 1
 	fi
 
 	# re-activate brouter
-	ip netns exec ns0 ebtables -t broute -A BROUTING -p ipv4 --ip-protocol icmp -j redirect --redirect-target=DROP
+	ip netns exec "$nsbr" ebtables -t broute -A BROUTING -p ipv4 --ip-protocol icmp -j redirect --redirect-target=DROP
 
-	ip netns exec ns2 ping -q -c 1 10.0.0.11 > /dev/null
-	if [ $? -ne 0 ]; then
+	if ! ip netns exec "$ns2" ping -q -c 1 10.0.0.11 > /dev/null; then
 		echo "ERROR: ping did not work, but it should (broute+forward 2)" 1>&2
 		return 1
 	fi
 
-	echo "PASS: ns1/ns2 connectivity with active broute rule and bridge forward drop"
+	echo "PASS: ${ns1}/${ns2} connectivity with active broute rule and bridge forward drop"
 	return 0
 }
 
 # test basic connectivity
-ip netns exec ns1 ping -c 1 -q 10.0.0.12 > /dev/null
-if [ $? -ne 0 ]; then
-    echo "ERROR: Could not reach ns2 from ns1" 1>&2
-    ret=1
+if ! ip netns exec "$ns1" ping -c 1 -q 10.0.0.12 > /dev/null; then
+    echo "ERROR: Could not reach ${ns2} from ${ns1}" 1>&2
+    exit 1
 fi
 
-ip netns exec ns2 ping -c 1 -q 10.0.0.11 > /dev/null
-if [ $? -ne 0 ]; then
-    echo "ERROR: Could not reach ns1 from ns2" 1>&2
-    ret=1
-fi
-
-if [ $ret -eq 0 ];then
-    echo "PASS: netns connectivity: ns1 and ns2 can reach each other"
+if ! ip netns exec "$ns2" ping -c 1 -q 10.0.0.11 > /dev/null; then
+    echo "ERROR: Could not reach ${ns1} from ${ns2}" 1>&2
+    exit 1
 fi
 
 test_ebtables_broute
-ret=$?
-for i in 0 1 2; do ip netns del ns$i;done
-
-exit $ret
+exit $?