[PATCH net 0/3] selftests/net: Isolate l2_tos_ttl_inherit.sh in its own netns.

[PATCH net 0/3] selftests/net: Isolate l2_tos_ttl_inherit.sh in its own netns.

[Guillaume Nault]

l2_tos_ttl_inherit.sh uses a veth pair to run its tests, but only one
of the veth interfaces runs in a dedicated netns. The other one remains
in the initial namespace where the existing network configuration can
interfere with the setup used for the tests.

Isolate both veth devices in their own netns and ensure everything gets
cleaned up when the script exits.

Link: https://lore.kernel.org/netdev/924f1062-ab59-9b88-3b43-c44e73a30387@alu.unizg.hr/

Guillaume Nault (3):
  selftests/net: l2_tos_ttl_inherit.sh: Set IPv6 addresses with "nodad".
  selftests/net: l2_tos_ttl_inherit.sh: Run tests in their own netns.
  selftests/net: l2_tos_ttl_inherit.sh: Ensure environment cleanup on
    failure.

 .../selftests/net/l2_tos_ttl_inherit.sh       | 202 +++++++++++-------
 1 file changed, 129 insertions(+), 73 deletions(-)

-- 
2.30.2

[PATCH net 1/3] selftests/net: l2_tos_ttl_inherit.sh: Set IPv6 addresses with "nodad".

[Guillaume Nault]

The ping command can run before DAD completes. In that case, ping may
fail and break the selftest.

We don't need DAD here since we're working on isolated device pairs.

Fixes: b690842d12fd ("selftests/net: test l2 tunnel TOS/TTL inheriting")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
---
 tools/testing/selftests/net/l2_tos_ttl_inherit.sh | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/net/l2_tos_ttl_inherit.sh b/tools/testing/selftests/net/l2_tos_ttl_inherit.sh
index dca1e6f777a8..e2574b08eabc 100755
--- a/tools/testing/selftests/net/l2_tos_ttl_inherit.sh
+++ b/tools/testing/selftests/net/l2_tos_ttl_inherit.sh
@@ -137,8 +137,8 @@ setup() {
 		if [ "$type" = "gre" ]; then
 			type="ip6gretap"
 		fi
-		ip addr add fdd1:ced0:5d88:3fce::1/64 dev veth0
-		$ns ip addr add fdd1:ced0:5d88:3fce::2/64 dev veth1
+		ip addr add fdd1:ced0:5d88:3fce::1/64 dev veth0 nodad
+		$ns ip addr add fdd1:ced0:5d88:3fce::2/64 dev veth1 nodad
 		ip link add name tep0 type $type $local_addr1 \
 		remote fdd1:ced0:5d88:3fce::2 tos $test_tos ttl $test_ttl \
 		$vxlan $geneve
@@ -170,8 +170,8 @@ setup() {
 		ip addr add 198.19.0.1/24 brd + dev ${parent}0
 		$ns ip addr add 198.19.0.2/24 brd + dev ${parent}1
 	elif [ "$inner" = "6" ]; then
-		ip addr add fdd4:96cf:4eae:443b::1/64 dev ${parent}0
-		$ns ip addr add fdd4:96cf:4eae:443b::2/64 dev ${parent}1
+		ip addr add fdd4:96cf:4eae:443b::1/64 dev ${parent}0 nodad
+		$ns ip addr add fdd4:96cf:4eae:443b::2/64 dev ${parent}1 nodad
 	fi
 }
 
-- 
2.30.2

[PATCH net 2/3] selftests/net: l2_tos_ttl_inherit.sh: Run tests in their own netns.

[Guillaume Nault]

This selftest currently runs half in the current namespace and half in
a netns of its own. Therefore, the test can fail if the current
namespace is already configured with incompatible parameters (for
example if it already has a veth0 interface).

Adapt the script to put both ends of the veth pair in their own netns.
Now veth0 is created in NS0 instead of the current namespace, while
veth1 is set up in NS1 (instead of the 'testing' netns).

The user visible netns names are randomised to minimise the risk of
conflicts with already existing namespaces. The cleanup() function
doesn't need to remove the virtual interface anymore: deleting NS0 and
NS1 automatically removes the virtual interfaces they contained.

We can remove $ns, which was only used to run ip commands in the
'testing' netns (let's use the builtin "-netns" option instead).
However, we still need a similar functionality as ping and tcpdump
now need to run in NS0. So we now have $RUN_NS0 for that.

Fixes: b690842d12fd ("selftests/net: test l2 tunnel TOS/TTL inheriting")
Reported-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Tested-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Signed-off-by: Guillaume Nault <gnault@redhat.com>
---
 .../selftests/net/l2_tos_ttl_inherit.sh       | 162 ++++++++++--------
 1 file changed, 93 insertions(+), 69 deletions(-)

diff --git a/tools/testing/selftests/net/l2_tos_ttl_inherit.sh b/tools/testing/selftests/net/l2_tos_ttl_inherit.sh
index e2574b08eabc..cf56680d598f 100755
--- a/tools/testing/selftests/net/l2_tos_ttl_inherit.sh
+++ b/tools/testing/selftests/net/l2_tos_ttl_inherit.sh
@@ -25,6 +25,11 @@ expected_tos="0x00"
 expected_ttl="0"
 failed=false
 
+readonly NS0=$(mktemp -u ns0-XXXXXXXX)
+readonly NS1=$(mktemp -u ns1-XXXXXXXX)
+
+RUN_NS0="ip netns exec ${NS0}"
+
 get_random_tos() {
 	# Get a random hex tos value between 0x00 and 0xfc, a multiple of 4
 	echo "0x$(tr -dc '0-9a-f' < /dev/urandom | head -c 1)\
@@ -61,7 +66,6 @@ setup() {
 	local vlan="$5"
 	local test_tos="0x00"
 	local test_ttl="0"
-	local ns="ip netns exec testing"
 
 	# We don't want a test-tos of 0x00,
 	# because this is the value that we get when no tos is set.
@@ -94,14 +98,15 @@ setup() {
 	printf "│%7s │%6s │%6s │%13s │%13s │%6s │" \
 	"$type" "$outer" "$inner" "$tos" "$ttl" "$vlan"
 
-	# Create 'testing' netns, veth pair and connect main ns with testing ns
-	ip netns add testing
-	ip link add type veth
-	ip link set veth1 netns testing
-	ip link set veth0 up
-	$ns ip link set veth1 up
-	ip addr flush dev veth0
-	$ns ip addr flush dev veth1
+	# Create netns NS0 and NS1 and connect them with a veth pair
+	ip netns add "${NS0}"
+	ip netns add "${NS1}"
+	ip link add name veth0 netns "${NS0}" type veth \
+		peer name veth1 netns "${NS1}"
+	ip -netns "${NS0}" link set dev veth0 up
+	ip -netns "${NS1}" link set dev veth1 up
+	ip -netns "${NS0}" address flush dev veth0
+	ip -netns "${NS1}" address flush dev veth1
 
 	local local_addr1=""
 	local local_addr2=""
@@ -127,51 +132,59 @@ setup() {
 		if [ "$type" = "gre" ]; then
 			type="gretap"
 		fi
-		ip addr add 198.18.0.1/24 dev veth0
-		$ns ip addr add 198.18.0.2/24 dev veth1
-		ip link add name tep0 type $type $local_addr1 remote \
-		198.18.0.2 tos $test_tos ttl $test_ttl $vxlan $geneve
-		$ns ip link add name tep1 type $type $local_addr2 remote \
-		198.18.0.1 tos $test_tos ttl $test_ttl $vxlan $geneve
+		ip -netns "${NS0}" address add 198.18.0.1/24 dev veth0
+		ip -netns "${NS1}" address add 198.18.0.2/24 dev veth1
+		ip -netns "${NS0}" link add name tep0 type $type $local_addr1 \
+			remote 198.18.0.2 tos $test_tos ttl $test_ttl         \
+			$vxlan $geneve
+		ip -netns "${NS1}" link add name tep1 type $type $local_addr2 \
+			remote 198.18.0.1 tos $test_tos ttl $test_ttl         \
+			$vxlan $geneve
 	elif [ "$outer" = "6" ]; then
 		if [ "$type" = "gre" ]; then
 			type="ip6gretap"
 		fi
-		ip addr add fdd1:ced0:5d88:3fce::1/64 dev veth0 nodad
-		$ns ip addr add fdd1:ced0:5d88:3fce::2/64 dev veth1 nodad
-		ip link add name tep0 type $type $local_addr1 \
-		remote fdd1:ced0:5d88:3fce::2 tos $test_tos ttl $test_ttl \
-		$vxlan $geneve
-		$ns ip link add name tep1 type $type $local_addr2 \
-		remote fdd1:ced0:5d88:3fce::1 tos $test_tos ttl $test_ttl \
-		$vxlan $geneve
+		ip -netns "${NS0}" address add fdd1:ced0:5d88:3fce::1/64 \
+			dev veth0 nodad
+		ip -netns "${NS1}" address add fdd1:ced0:5d88:3fce::2/64 \
+			dev veth1 nodad
+		ip -netns "${NS0}" link add name tep0 type $type $local_addr1 \
+			remote fdd1:ced0:5d88:3fce::2 tos $test_tos           \
+			ttl $test_ttl $vxlan $geneve
+		ip -netns "${NS1}" link add name tep1 type $type $local_addr2 \
+			remote fdd1:ced0:5d88:3fce::1 tos $test_tos           \
+			ttl $test_ttl $vxlan $geneve
 	fi
 
 	# Bring L2-tunnel link up and create VLAN on top
-	ip link set tep0 up
-	$ns ip link set tep1 up
-	ip addr flush dev tep0
-	$ns ip addr flush dev tep1
+	ip -netns "${NS0}" link set tep0 up
+	ip -netns "${NS1}" link set tep1 up
+	ip -netns "${NS0}" address flush dev tep0
+	ip -netns "${NS1}" address flush dev tep1
 	local parent
 	if $vlan; then
 		parent="vlan99-"
-		ip link add link tep0 name ${parent}0 type vlan id 99
-		$ns ip link add link tep1 name ${parent}1 type vlan id 99
-		ip link set ${parent}0 up
-		$ns ip link set ${parent}1 up
-		ip addr flush dev ${parent}0
-		$ns ip addr flush dev ${parent}1
+		ip -netns "${NS0}" link add link tep0 name ${parent}0 \
+			type vlan id 99
+		ip -netns "${NS1}" link add link tep1 name ${parent}1 \
+			type vlan id 99
+		ip -netns "${NS0}" link set dev ${parent}0 up
+		ip -netns "${NS1}" link set dev ${parent}1 up
+		ip -netns "${NS0}" address flush dev ${parent}0
+		ip -netns "${NS1}" address flush dev ${parent}1
 	else
 		parent="tep"
 	fi
 
 	# Assign inner IPv4/IPv6 addresses
 	if [ "$inner" = "4" ] || [ "$inner" = "other" ]; then
-		ip addr add 198.19.0.1/24 brd + dev ${parent}0
-		$ns ip addr add 198.19.0.2/24 brd + dev ${parent}1
+		ip -netns "${NS0}" address add 198.19.0.1/24 brd + dev ${parent}0
+		ip -netns "${NS1}" address add 198.19.0.2/24 brd + dev ${parent}1
 	elif [ "$inner" = "6" ]; then
-		ip addr add fdd4:96cf:4eae:443b::1/64 dev ${parent}0 nodad
-		$ns ip addr add fdd4:96cf:4eae:443b::2/64 dev ${parent}1 nodad
+		ip -netns "${NS0}" address add fdd4:96cf:4eae:443b::1/64 \
+			dev ${parent}0 nodad
+		ip -netns "${NS1}" address add fdd4:96cf:4eae:443b::2/64 \
+			dev ${parent}1 nodad
 	fi
 }
 
@@ -192,10 +205,10 @@ verify() {
 		ping_dst="198.19.0.3" # Generates ARPs which are not IPv4/IPv6
 	fi
 	if [ "$tos_ttl" = "inherit" ]; then
-		ping -i 0.1 $ping_dst -Q "$expected_tos" -t "$expected_ttl" \
-		2>/dev/null 1>&2 & ping_pid="$!"
+		${RUN_NS0} ping -i 0.1 $ping_dst -Q "$expected_tos"          \
+			 -t "$expected_ttl" 2>/dev/null 1>&2 & ping_pid="$!"
 	else
-		ping -i 0.1 $ping_dst 2>/dev/null 1>&2 & ping_pid="$!"
+		${RUN_NS0} ping -i 0.1 $ping_dst 2>/dev/null 1>&2 & ping_pid="$!"
 	fi
 	local tunnel_type_offset tunnel_type_proto req_proto_offset req_offset
 	if [ "$type" = "gre" ]; then
@@ -216,10 +229,12 @@ verify() {
 				req_proto_offset="$((req_proto_offset + 4))"
 				req_offset="$((req_offset + 4))"
 			fi
-			out="$(tcpdump --immediate-mode -p -c 1 -v -i veth0 -n \
-			ip[$tunnel_type_offset] = $tunnel_type_proto and \
-			ip[$req_proto_offset] = 0x01 and \
-			ip[$req_offset] = 0x08 2>/dev/null | head -n 1)"
+			out="$(${RUN_NS0} tcpdump --immediate-mode -p -c 1 -v \
+				-i veth0 -n                                   \
+				ip[$tunnel_type_offset] = $tunnel_type_proto and \
+				ip[$req_proto_offset] = 0x01 and              \
+				ip[$req_offset] = 0x08 2>/dev/null            \
+				| head -n 1)"
 		elif [ "$inner" = "6" ]; then
 			req_proto_offset="44"
 			req_offset="78"
@@ -231,10 +246,12 @@ verify() {
 				req_proto_offset="$((req_proto_offset + 4))"
 				req_offset="$((req_offset + 4))"
 			fi
-			out="$(tcpdump --immediate-mode -p -c 1 -v -i veth0 -n \
-			ip[$tunnel_type_offset] = $tunnel_type_proto and \
-			ip[$req_proto_offset] = 0x3a and \
-			ip[$req_offset] = 0x80 2>/dev/null | head -n 1)"
+			out="$(${RUN_NS0} tcpdump --immediate-mode -p -c 1 -v \
+				-i veth0 -n                                   \
+				ip[$tunnel_type_offset] = $tunnel_type_proto and \
+				ip[$req_proto_offset] = 0x3a and              \
+				ip[$req_offset] = 0x80 2>/dev/null            \
+				| head -n 1)"
 		elif [ "$inner" = "other" ]; then
 			req_proto_offset="36"
 			req_offset="45"
@@ -250,11 +267,13 @@ verify() {
 				expected_tos="0x00"
 				expected_ttl="64"
 			fi
-			out="$(tcpdump --immediate-mode -p -c 1 -v -i veth0 -n \
-			ip[$tunnel_type_offset] = $tunnel_type_proto and \
-			ip[$req_proto_offset] = 0x08 and \
-			ip[$((req_proto_offset + 1))] = 0x06 and \
-			ip[$req_offset] = 0x01 2>/dev/null | head -n 1)"
+			out="$(${RUN_NS0} tcpdump --immediate-mode -p -c 1 -v \
+				-i veth0 -n                                   \
+				ip[$tunnel_type_offset] = $tunnel_type_proto and \
+				ip[$req_proto_offset] = 0x08 and              \
+				ip[$((req_proto_offset + 1))] = 0x06 and      \
+				ip[$req_offset] = 0x01 2>/dev/null            \
+				| head -n 1)"
 		fi
 	elif [ "$outer" = "6" ]; then
 		if [ "$type" = "gre" ]; then
@@ -273,10 +292,12 @@ verify() {
 				req_proto_offset="$((req_proto_offset + 4))"
 				req_offset="$((req_offset + 4))"
 			fi
-			out="$(tcpdump --immediate-mode -p -c 1 -v -i veth0 -n \
-			ip6[$tunnel_type_offset] = $tunnel_type_proto and \
-			ip6[$req_proto_offset] = 0x01 and \
-			ip6[$req_offset] = 0x08 2>/dev/null | head -n 1)"
+			out="$(${RUN_NS0} tcpdump --immediate-mode -p -c 1 -v \
+				-i veth0 -n                                   \
+				ip6[$tunnel_type_offset] = $tunnel_type_proto and \
+				ip6[$req_proto_offset] = 0x01 and             \
+				ip6[$req_offset] = 0x08 2>/dev/null           \
+				| head -n 1)"
 		elif [ "$inner" = "6" ]; then
 			local req_proto_offset="72"
 			local req_offset="106"
@@ -288,10 +309,12 @@ verify() {
 				req_proto_offset="$((req_proto_offset + 4))"
 				req_offset="$((req_offset + 4))"
 			fi
-			out="$(tcpdump --immediate-mode -p -c 1 -v -i veth0 -n \
-			ip6[$tunnel_type_offset] = $tunnel_type_proto and \
-			ip6[$req_proto_offset] = 0x3a and \
-			ip6[$req_offset] = 0x80 2>/dev/null | head -n 1)"
+			out="$(${RUN_NS0} tcpdump --immediate-mode -p -c 1 -v \
+				-i veth0 -n                                   \
+				ip6[$tunnel_type_offset] = $tunnel_type_proto and \
+				ip6[$req_proto_offset] = 0x3a and             \
+				ip6[$req_offset] = 0x80 2>/dev/null           \
+				| head -n 1)"
 		elif [ "$inner" = "other" ]; then
 			local req_proto_offset="64"
 			local req_offset="73"
@@ -307,11 +330,13 @@ verify() {
 				expected_tos="0x00"
 				expected_ttl="64"
 			fi
-			out="$(tcpdump --immediate-mode -p -c 1 -v -i veth0 -n \
-			ip6[$tunnel_type_offset] = $tunnel_type_proto and \
-			ip6[$req_proto_offset] = 0x08 and \
-			ip6[$((req_proto_offset + 1))] = 0x06 and \
-			ip6[$req_offset] = 0x01 2>/dev/null | head -n 1)"
+			out="$(${RUN_NS0} tcpdump --immediate-mode -p -c 1 -v \
+				-i veth0 -n                                   \
+				ip6[$tunnel_type_offset] = $tunnel_type_proto and \
+				ip6[$req_proto_offset] = 0x08 and             \
+				ip6[$((req_proto_offset + 1))] = 0x06 and     \
+				ip6[$req_offset] = 0x01 2>/dev/null           \
+				| head -n 1)"
 		fi
 	fi
 	kill -9 $ping_pid
@@ -351,9 +376,8 @@ verify() {
 }
 
 cleanup() {
-	ip link del veth0 2>/dev/null
-	ip netns del testing 2>/dev/null
-	ip link del tep0 2>/dev/null
+	ip netns del "${NS0}" 2>/dev/null
+	ip netns del "${NS1}" 2>/dev/null
 }
 
 printf "┌────────┬───────┬───────┬──────────────┬"
-- 
2.30.2

[PATCH net 3/3] selftests/net: l2_tos_ttl_inherit.sh: Ensure environment cleanup on failure.

[Guillaume Nault]

Use 'set -e' and an exit handler to stop the script if a command fails
and ensure the test environment is cleaned up in any case. Also, handle
the case where the script is interrupted by SIGINT.

The only command that's expected to fail is 'wait $ping_pid', since
it's killed by the script. Handle this case with '|| true' to make it
play well with 'set -e'.

Finally, return the Kselftest SKIP code (4) when the script breaks
because of an environment problem or a command line failure. The 0 and
1 return codes should now reliably indicate that all tests have been
run (0: all tests run and passed, 1: all tests run but at least one
failed, 4: test script didn't run completely).

Fixes: b690842d12fd ("selftests/net: test l2 tunnel TOS/TTL inheriting")
Reported-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Tested-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Signed-off-by: Guillaume Nault <gnault@redhat.com>
---
 .../selftests/net/l2_tos_ttl_inherit.sh       | 40 +++++++++++++++++--
 1 file changed, 36 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/net/l2_tos_ttl_inherit.sh b/tools/testing/selftests/net/l2_tos_ttl_inherit.sh
index cf56680d598f..f11756e7df2f 100755
--- a/tools/testing/selftests/net/l2_tos_ttl_inherit.sh
+++ b/tools/testing/selftests/net/l2_tos_ttl_inherit.sh
@@ -12,13 +12,16 @@
 # In addition this script also checks if forcing a specific field in the
 # outer header is working.
 
+# Return 4 by default (Kselftest SKIP code)
+ERR=4
+
 if [ "$(id -u)" != "0" ]; then
 	echo "Please run as root."
-	exit 0
+	exit $ERR
 fi
 if ! which tcpdump > /dev/null 2>&1; then
 	echo "No tcpdump found. Required for this test."
-	exit 0
+	exit $ERR
 fi
 
 expected_tos="0x00"
@@ -340,7 +343,7 @@ verify() {
 		fi
 	fi
 	kill -9 $ping_pid
-	wait $ping_pid 2>/dev/null
+	wait $ping_pid 2>/dev/null || true
 	result="FAIL"
 	if [ "$outer" = "4" ]; then
 		captured_ttl="$(get_field "ttl" "$out")"
@@ -380,6 +383,31 @@ cleanup() {
 	ip netns del "${NS1}" 2>/dev/null
 }
 
+exit_handler() {
+	# Don't exit immediately if one of the intermediate commands fails.
+	# We might be called at the end of the script, when the network
+	# namespaces have already been deleted. So cleanup() may fail, but we
+	# still need to run until 'exit $ERR' or the script won't return the
+	# correct error code.
+	set +e
+
+	cleanup
+
+	exit $ERR
+}
+
+# Restore the default SIGINT handler (just in case) and exit.
+# The exit handler will take care of cleaning everything up.
+interrupted() {
+	trap - INT
+
+	exit $ERR
+}
+
+set -e
+trap exit_handler EXIT
+trap interrupted INT
+
 printf "┌────────┬───────┬───────┬──────────────┬"
 printf "──────────────┬───────┬────────┐\n"
 for type in gre vxlan geneve; do
@@ -409,6 +437,10 @@ done
 printf "└────────┴───────┴───────┴──────────────┴"
 printf "──────────────┴───────┴────────┘\n"
 
+# All tests done.
+# Set ERR appropriately: it will be returned by the exit handler.
 if $failed; then
-	exit 1
+	ERR=1
+else
+	ERR=0
 fi
-- 
2.30.2

Re: [PATCH net 0/3] selftests/net: Isolate l2_tos_ttl_inherit.sh in its own netns.

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (master)
by Paolo Abeni <pabeni@redhat.com>:

On Sun, 8 Jan 2023 16:45:31 +0100 you wrote:
> l2_tos_ttl_inherit.sh uses a veth pair to run its tests, but only one
> of the veth interfaces runs in a dedicated netns. The other one remains
> in the initial namespace where the existing network configuration can
> interfere with the setup used for the tests.
> 
> Isolate both veth devices in their own netns and ensure everything gets
> cleaned up when the script exits.
> 
> [...]

Here is the summary with links:
  - [net,1/3] selftests/net: l2_tos_ttl_inherit.sh: Set IPv6 addresses with "nodad".
    https://git.kernel.org/netdev/net/c/e59370b2e96e
  - [net,2/3] selftests/net: l2_tos_ttl_inherit.sh: Run tests in their own netns.
    https://git.kernel.org/netdev/net/c/c53cb00f7983
  - [net,3/3] selftests/net: l2_tos_ttl_inherit.sh: Ensure environment cleanup on failure.
    https://git.kernel.org/netdev/net/c/d68ff8ad3351

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html