Merge branch 'selftests-forwarding-sysctl'

Petr Machata says:

====================
selftests: forwarding: Updates to sysctl handling

Some selftests need to adjust sysctl settings. In order to be neutral to
the system that the test is run on, it is a good practice to change back
to the original setting after the test ends. That involves some
boilerplate that can be abstracted away.

In patch #1, introduce two functions, sysctl_set() and sysctl_restore().
The former stores the current value of a given setting, and sets a new
value. The latter restores the setting to the previously-stored value.

In patch #2, use these wrappers in a number of tests.

Additionally in patch #3, fix a problem in mirror_gre_nh.sh, which
neglected to set a sysctl that's crucial for the test to work.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/forwarding/lib.sh

@@ -381,19 +381,33 @@ bridge_ageing_time_get()
 	echo $((ageing_time / 100))
 }
 
-forwarding_enable()
+declare -A SYSCTL_ORIG
+sysctl_set()
+{
+	local key=$1; shift
+	local value=$1; shift
+
+	SYSCTL_ORIG[$key]=$(sysctl -n $key)
+	sysctl -qw $key=$value
+}
+
+sysctl_restore()
 {
-       ipv4_fwd=$(sysctl -n net.ipv4.conf.all.forwarding)
-       ipv6_fwd=$(sysctl -n net.ipv6.conf.all.forwarding)
+	local key=$1; shift
 
-       sysctl -q -w net.ipv4.conf.all.forwarding=1
-       sysctl -q -w net.ipv6.conf.all.forwarding=1
+	sysctl -qw $key=${SYSCTL_ORIG["$key"]}
+}
+
+forwarding_enable()
+{
+	sysctl_set net.ipv4.conf.all.forwarding 1
+	sysctl_set net.ipv6.conf.all.forwarding 1
 }
 
 forwarding_restore()
 {
-       sysctl -q -w net.ipv6.conf.all.forwarding=$ipv6_fwd
-       sysctl -q -w net.ipv4.conf.all.forwarding=$ipv4_fwd
+	sysctl_restore net.ipv6.conf.all.forwarding
+	sysctl_restore net.ipv4.conf.all.forwarding
 }
 
 tc_offload_check()

tools/testing/selftests/net/forwarding/mirror_gre_changes.sh

@@ -36,9 +36,7 @@ setup_prepare()
 
 	# This test downs $swp3, which deletes the configured IPv6 address
 	# unless this sysctl is set.
-	local key=net.ipv6.conf.$swp3.keep_addr_on_down
-	SWP3_KEEP_ADDR_ON_DOWN=$(sysctl -n $key)
-	sysctl -qw $key=1
+	sysctl_set net.ipv6.conf.$swp3.keep_addr_on_down 1
 
 	ip address add dev $swp3 192.0.2.129/28
 	ip address add dev $h3 192.0.2.130/28
@@ -57,8 +55,7 @@ cleanup()
 	ip address del dev $h3 192.0.2.130/28
 	ip address del dev $swp3 192.0.2.129/28
 
-	local key=net.ipv6.conf.$swp3.keep_addr_on_down
-	sysctl -qw $key=$SWP3_KEEP_ADDR_ON_DOWN
+	sysctl_restore net.ipv6.conf.$swp3.keep_addr_on_down
 
 	mirror_gre_topo_destroy
 	vrf_cleanup

tools/testing/selftests/net/forwarding/mirror_gre_nh.sh

@@ -29,6 +29,9 @@ setup_prepare()
 	swp3=${NETIFS[p5]}
 	h3=${NETIFS[p6]}
 
+	sysctl_set net.ipv4.conf.all.rp_filter 0
+	sysctl_set net.ipv4.conf.$h3.rp_filter 0
+
 	vrf_prepare
 	mirror_gre_topo_create
 
@@ -60,6 +63,9 @@ cleanup()
 
 	mirror_gre_topo_destroy
 	vrf_cleanup
+
+	sysctl_restore net.ipv4.conf.$h3.rp_filter
+	sysctl_restore net.ipv4.conf.all.rp_filter
 }
 
 test_gretap()

tools/testing/selftests/net/forwarding/router_multipath.sh

@@ -205,13 +205,11 @@ multipath4_test()
        local weight_rp13=$3
        local t0_rp12 t0_rp13 t1_rp12 t1_rp13
        local packets_rp12 packets_rp13
-       local hash_policy
 
        # Transmit multiple flows from h1 to h2 and make sure they are
        # distributed between both multipath links (rp12 and rp13)
        # according to the configured weights.
-       hash_policy=$(sysctl -n net.ipv4.fib_multipath_hash_policy)
-       sysctl -q -w net.ipv4.fib_multipath_hash_policy=1
+       sysctl_set net.ipv4.fib_multipath_hash_policy 1
        ip route replace 198.51.100.0/24 vrf vrf-r1 \
                nexthop via 169.254.2.22 dev $rp12 weight $weight_rp12 \
                nexthop via 169.254.3.23 dev $rp13 weight $weight_rp13
@@ -233,7 +231,7 @@ multipath4_test()
        ip route replace 198.51.100.0/24 vrf vrf-r1 \
                nexthop via 169.254.2.22 dev $rp12 \
                nexthop via 169.254.3.23 dev $rp13
-       sysctl -q -w net.ipv4.fib_multipath_hash_policy=$hash_policy
+       sysctl_restore net.ipv4.fib_multipath_hash_policy
 }
 
 multipath6_l4_test()
@@ -243,13 +241,11 @@ multipath6_l4_test()
        local weight_rp13=$3
        local t0_rp12 t0_rp13 t1_rp12 t1_rp13
        local packets_rp12 packets_rp13
-       local hash_policy
 
        # Transmit multiple flows from h1 to h2 and make sure they are
        # distributed between both multipath links (rp12 and rp13)
        # according to the configured weights.
-       hash_policy=$(sysctl -n net.ipv6.fib_multipath_hash_policy)
-       sysctl -q -w net.ipv6.fib_multipath_hash_policy=1
+       sysctl_set net.ipv6.fib_multipath_hash_policy 1
 
        ip route replace 2001:db8:2::/64 vrf vrf-r1 \
 	       nexthop via fe80:2::22 dev $rp12 weight $weight_rp12 \
@@ -272,7 +268,7 @@ multipath6_l4_test()
 	       nexthop via fe80:2::22 dev $rp12 \
 	       nexthop via fe80:3::23 dev $rp13
 
-       sysctl -q -w net.ipv6.fib_multipath_hash_policy=$hash_policy
+       sysctl_restore net.ipv6.fib_multipath_hash_policy
 }
 
 multipath6_test()