selftests: pmtu: Introduce support for multiple tests

Introduce list of tests and their descriptions, and loop on it
in main body.

Tests will now just take care of calling setup with a list of
"units" they need, and return 0 on success, 1 on failure, 2 if
the test had to be skipped.

Main script body will take care of displaying results and
cleaning up after every test. Introduce guard variable so that
we don't clean up twice in case of interrupts or unexpected
failures.

The pmtu_vti6_exception test can now run its third step even if
the previous one failed, as we can return values from it.

Also introduce support to display test descriptions, and display
aligned OK/FAIL/SKIP test outcomes. Buffer error strings so that
in case of failure we can display them right under the outcome
for each test.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/pmtu.sh

@@ -5,13 +5,16 @@
 #
 # Tests currently implemented:
 #
-# - test_pmtu_vti6_exception
+# - pmtu_vti6_exception
 #	Set up vti6 tunnel on top of veth, with xfrm states and policies, in two
 #	namespaces with matching endpoints. Check that route exception is
 #	created by exceeding link layer MTU with ping to other endpoint. Then
 #	decrease and increase MTU of tunnel, checking that route exception PMTU
 #	changes accordingly
 
+tests="
+	pmtu_vti6_exception	vti6: PMTU exceptions"
+
 NS_A="ns-$(mktemp -u XXXXXX)"
 NS_B="ns-$(mktemp -u XXXXXX)"
 ns_a="ip netns exec ${NS_A}"
@@ -25,6 +28,19 @@ vti6_a_addr="fd00:2::a"
 vti6_b_addr="fd00:2::b"
 vti6_mask="64"
 
+cleanup_done=1
+err_buf=
+
+err() {
+	err_buf="${err_buf}${1}
+"
+}
+
+err_flush() {
+	echo -n "${err_buf}"
+	err_buf=
+}
+
 setup_namespaces() {
 	ip netns add ${NS_A} || return 1
 	ip netns add ${NS_B}
@@ -67,26 +83,19 @@ setup_xfrm() {
 }
 
 setup() {
-	tunnel_type="$1"
-
-	[ "$(id -u)" -ne 0 ] && echo "SKIP: need to run as root" && exit 0
-
-	setup_namespaces || { echo "SKIP: namespaces not supported"; exit 0; }
-	setup_veth || { echo "SKIP: veth not supported"; exit 0; }
+	[ "$(id -u)" -ne 0 ] && echo "  need to run as root" && return 1
 
-	case ${tunnel_type} in
-	"vti6")
-		setup_vti6 || { echo "SKIP: vti6 not supported"; exit 0; }
-		setup_xfrm || { echo "SKIP: xfrm not supported"; exit 0; }
-		;;
-	*)
-		;;
-	esac
+	cleanup_done=0
+	for arg do
+		eval setup_${arg} || { echo "  ${arg} not supported"; return 1; }
+	done
 }
 
 cleanup() {
+	[ ${cleanup_done} -eq 1 ] && return
 	ip netns del ${NS_A} 2 > /dev/null
 	ip netns del ${NS_B} 2 > /dev/null
+	cleanup_done=1
 }
 
 mtu() {
@@ -122,7 +131,8 @@ route_get_dst_pmtu_from_exception() {
 }
 
 test_pmtu_vti6_exception() {
-	setup vti6
+	setup namespaces veth vti6 xfrm || return 2
+	fail=0
 
 	# Create route exception by exceeding link layer MTU
 	mtu "${ns_a}" veth_a 4000
@@ -133,30 +143,55 @@ test_pmtu_vti6_exception() {
 
 	# Check that exception was created
 	if [ "$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti6_b_addr})" = "" ]; then
-		echo "FAIL: Tunnel exceeding link layer MTU didn't create route exception"
-		exit 1
+		err "  tunnel exceeding link layer MTU didn't create route exception"
+		return 1
 	fi
 
 	# Decrease tunnel MTU, check for PMTU decrease in route exception
 	mtu "${ns_a}" vti_a 3000
 
 	if [ "$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti6_b_addr})" -ne 3000 ]; then
-		echo "FAIL: Decreasing tunnel MTU didn't decrease route exception PMTU"
-		exit 1
+		err "  decreasing tunnel MTU didn't decrease route exception PMTU"
+		fail=1
 	fi
 
 	# Increase tunnel MTU, check for PMTU increase in route exception
 	mtu "${ns_a}" vti_a 9000
 	if [ "$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti6_b_addr})" -ne 9000 ]; then
-		echo "FAIL: Increasing tunnel MTU didn't increase route exception PMTU"
-		exit 1
+		err "  increasing tunnel MTU didn't increase route exception PMTU"
+		fail=1
 	fi
 
-	echo "PASS"
+	return ${fail}
 }
 
 trap cleanup EXIT
 
-test_pmtu_vti6_exception
-
-exit 0
+exitcode=0
+desc=0
+IFS="	
+"
+for t in ${tests}; do
+	[ $desc -eq 0 ] && name="${t}" && desc=1 && continue || desc=0
+
+	(
+		unset IFS
+		eval test_${name}
+		ret=$?
+		cleanup
+
+		if [ $ret -eq 0 ]; then
+			printf "TEST: %-60s  [ OK ]\n" "${t}"
+		elif [ $ret -eq 1 ]; then
+			printf "TEST: %-60s  [FAIL]\n" "${t}"
+			err_flush
+			exit 1
+		elif [ $ret -eq 2 ]; then
+			printf "TEST: %-60s  [SKIP]\n" "${t}"
+			err_flush
+		fi
+	)
+	[ $? -ne 0 ] && exitcode=1
+done
+
+exit ${exitcode}