[PATCH net-next 0/2] selftests: pmtu: Add test choice and captures

[PATCH net-next 0/2] selftests: pmtu: Add test choice and captures

[Stefano Brivio]

This series adds a couple of features useful for debugging: 1/2
allows selecting single tests and 2/2 adds optional traffic
captures.

Semantics for current invocation of test script are preserved.

Stefano Brivio (2):
  selftests: pmtu: Allow selection of single tests
  selftests: pmtu: Add optional traffic captures for single tests

 tools/testing/selftests/net/pmtu.sh | 69 ++++++++++++++++++++++++++++-
 1 file changed, 68 insertions(+), 1 deletion(-)

-- 
2.19.1

[PATCH net-next 1/2] selftests: pmtu: Allow selection of single tests

[Stefano Brivio]

As number of tests is growing, it's quite convenient to allow
single tests to be run.

Display usage when the script is run with any invalid argument,
keep existing semantics when no arguments are passed so that
automated runs won't break.

Instead of just looping on the list of requested tests, if any,
check first that they exist, and go through them in a nested
loop to keep the existing way to display test descriptions.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
---
 tools/testing/selftests/net/pmtu.sh | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/tools/testing/selftests/net/pmtu.sh b/tools/testing/selftests/net/pmtu.sh
index b9cdb68df4c5..8278a24f5ba6 100755
--- a/tools/testing/selftests/net/pmtu.sh
+++ b/tools/testing/selftests/net/pmtu.sh
@@ -641,6 +641,20 @@ test_pmtu_vti6_link_change_mtu() {
 	return ${fail}
 }
 
+usage() {
+	echo
+	echo "$0 [TEST]..."
+	echo "If no TEST argument is given, all tests will be run."
+	echo
+	echo "Available tests${tests}"
+	exit 1
+}
+
+for arg do
+	# Check first that all requested tests are available before running any
+	command -v > /dev/null "test_${arg}" || { echo "=== Test ${arg} not found"; usage; }
+done
+
 trap cleanup EXIT
 
 exitcode=0
@@ -650,6 +664,13 @@ IFS="
 for t in ${tests}; do
 	[ $desc -eq 0 ] && name="${t}" && desc=1 && continue || desc=0
 
+	run_this=1
+	for arg do
+		[ "${arg}" = "${name}" ] && run_this=1 && break
+		run_this=0
+	done
+	[ $run_this -eq 0 ] && continue
+
 	(
 		unset IFS
 		eval test_${name}
-- 
2.19.1

[PATCH net-next 2/2] selftests: pmtu: Add optional traffic captures for single tests

[Stefano Brivio]

If --trace is passed as an option and tcpdump is available,
capture traffic for all relevant interfaces to per-test pcap
files named <test>_<interface>.pcap.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
---
 tools/testing/selftests/net/pmtu.sh | 60 +++++++++++++++++++++++++----
 1 file changed, 53 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/net/pmtu.sh b/tools/testing/selftests/net/pmtu.sh
index 8278a24f5ba6..ed549c03d2a7 100755
--- a/tools/testing/selftests/net/pmtu.sh
+++ b/tools/testing/selftests/net/pmtu.sh
@@ -142,6 +142,7 @@ dummy6_mask="64"
 
 cleanup_done=1
 err_buf=
+tcpdump_pids=
 
 err() {
 	err_buf="${err_buf}${1}
@@ -284,7 +285,24 @@ setup() {
 	done
 }
 
+trace() {
+	[ $tracing -eq 0 ] && return
+
+	for arg do
+		[ "${ns_cmd}" = "" ] && ns_cmd="${arg}" && continue
+		${ns_cmd} tcpdump -s 0 -i "${arg}" -w "${name}_${arg}.pcap" 2> /dev/null &
+		tcpdump_pids="${tcpdump_pids} $!"
+		ns_cmd=
+	done
+	sleep 1
+}
+
 cleanup() {
+	for pid in ${tcpdump_pids}; do
+		kill ${pid}
+	done
+	tcpdump_pids=
+
 	[ ${cleanup_done} -eq 1 ] && return
 	for n in ${NS_A} ${NS_B} ${NS_R1} ${NS_R2}; do
 		ip netns del ${n} 2> /dev/null
@@ -357,6 +375,10 @@ test_pmtu_ipvX() {
 	family=${1}
 
 	setup namespaces routing || return 2
+	trace "${ns_a}"  veth_A-R1    "${ns_r1}" veth_R1-A \
+	      "${ns_r1}" veth_R1-B    "${ns_b}"  veth_B-R1 \
+	      "${ns_a}"  veth_A-R2    "${ns_r2}" veth_R2-A \
+	      "${ns_r2}" veth_R2-B    "${ns_b}"  veth_B-R2
 
 	if [ ${family} -eq 4 ]; then
 		ping=ping
@@ -445,6 +467,8 @@ test_pmtu_ipv6_exception() {
 
 test_pmtu_vti4_exception() {
 	setup namespaces veth vti4 xfrm4 || return 2
+	trace "${ns_a}" veth_a    "${ns_b}" veth_b \
+	      "${ns_a}" vti4_a    "${ns_b}" vti4_b
 
 	veth_mtu=1500
 	vti_mtu=$((veth_mtu - 20))
@@ -473,6 +497,8 @@ test_pmtu_vti4_exception() {
 
 test_pmtu_vti6_exception() {
 	setup namespaces veth vti6 xfrm6 || return 2
+	trace "${ns_a}" veth_a    "${ns_b}" veth_b \
+	      "${ns_a}" vti6_a    "${ns_b}" vti6_b
 	fail=0
 
 	# Create route exception by exceeding link layer MTU
@@ -643,29 +669,49 @@ test_pmtu_vti6_link_change_mtu() {
 
 usage() {
 	echo
-	echo "$0 [TEST]..."
+	echo "$0 [OPTIONS] [TEST]..."
 	echo "If no TEST argument is given, all tests will be run."
 	echo
+	echo "Options"
+	echo "  --trace: capture traffic to TEST_INTERFACE.pcap"
+	echo
 	echo "Available tests${tests}"
 	exit 1
 }
 
+exitcode=0
+desc=0
+IFS="	
+"
+
+tracing=0
 for arg do
-	# Check first that all requested tests are available before running any
-	command -v > /dev/null "test_${arg}" || { echo "=== Test ${arg} not found"; usage; }
+	if [ "${arg}" != "${arg#--*}" ]; then
+		opt="${arg#--}"
+		if [ "${opt}" = "trace" ]; then
+			if which tcpdump > /dev/null 2>&1; then
+				tracing=1
+			else
+				echo "=== tcpdump not available, tracing disabled"
+			fi
+		else
+			usage
+		fi
+	else
+		# Check first that all requested tests are available before
+		# running any
+		command -v > /dev/null "test_${arg}" || { echo "=== Test ${arg} not found"; usage; }
+	fi
 done
 
 trap cleanup EXIT
 
-exitcode=0
-desc=0
-IFS="	
-"
 for t in ${tests}; do
 	[ $desc -eq 0 ] && name="${t}" && desc=1 && continue || desc=0
 
 	run_this=1
 	for arg do
+		[ "${arg}" != "${arg#--*}" ] && continue
 		[ "${arg}" = "${name}" ] && run_this=1 && break
 		run_this=0
 	done
-- 
2.19.1

Re: [PATCH net-next 0/2] selftests: pmtu: Add test choice and captures

[David Miller]

From: Stefano Brivio <sbrivio@redhat.com>
Date: Fri, 12 Oct 2018 23:54:12 +0200

> This series adds a couple of features useful for debugging: 1/2
> allows selecting single tests and 2/2 adds optional traffic
> captures.
> 
> Semantics for current invocation of test script are preserved.

M0AR SELF TESTS!

I love it.

Keep them coming.

Series applied, thanks.