selftests: pmtu: disable DAD in all namespaces

Otherwise, the configured IPv6 address could be still "tentative"
at test time, possibly causing tests failures.
We can also drop some sleep along the code and decrease the
timeout for most commands so that the test runtime decreases.

v1 -> v2:
 - fix comment (Stefano)

Fixes: d1f1b9c ("selftests: net: Introduce first PMTU test")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: Paolo Abeni

tools/testing/selftests/net/pmtu.sh

@@ -263,8 +263,6 @@ setup_fou_or_gue() {
 
 	${ns_a} ip link set ${encap}_a up
 	${ns_b} ip link set ${encap}_b up
-
-	sleep 1
 }
 
 setup_fou44() {
@@ -302,6 +300,10 @@ setup_gue66() {
 setup_namespaces() {
 	for n in ${NS_A} ${NS_B} ${NS_R1} ${NS_R2}; do
 		ip netns add ${n} || return 1
+
+		# Disable DAD, so that we don't have to wait to use the
+		# configured IPv6 addresses
+		ip netns exec ${n} sysctl -q net/ipv6/conf/default/accept_dad=0
 	done
 }
 
@@ -337,8 +339,6 @@ setup_vti() {
 
 	${ns_a} ip link set vti${proto}_a up
 	${ns_b} ip link set vti${proto}_b up
-
-	sleep 1
 }
 
 setup_vti4() {
@@ -375,8 +375,6 @@ setup_vxlan_or_geneve() {
 
 	${ns_a} ip link set ${type}_a up
 	${ns_b} ip link set ${type}_b up
-
-	sleep 1
 }
 
 setup_geneve4() {
@@ -588,8 +586,8 @@ test_pmtu_ipvX() {
 	mtu "${ns_b}"  veth_B-R2 1500
 
 	# Create route exceptions
-	${ns_a} ${ping} -q -M want -i 0.1 -w 2 -s 1800 ${dst1} > /dev/null
-	${ns_a} ${ping} -q -M want -i 0.1 -w 2 -s 1800 ${dst2} > /dev/null
+	${ns_a} ${ping} -q -M want -i 0.1 -w 1 -s 1800 ${dst1} > /dev/null
+	${ns_a} ${ping} -q -M want -i 0.1 -w 1 -s 1800 ${dst2} > /dev/null
 
 	# Check that exceptions have been created with the correct PMTU
 	pmtu_1="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst1})"
@@ -621,7 +619,7 @@ test_pmtu_ipvX() {
 	# Decrease remote MTU on path via R2, get new exception
 	mtu "${ns_r2}" veth_R2-B 400
 	mtu "${ns_b}"  veth_B-R2 400
-	${ns_a} ${ping} -q -M want -i 0.1 -w 2 -s 1400 ${dst2} > /dev/null
+	${ns_a} ${ping} -q -M want -i 0.1 -w 1 -s 1400 ${dst2} > /dev/null
 	pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst2})"
 	check_pmtu_value "lock 552" "${pmtu_2}" "exceeding MTU, with MTU < min_pmtu" || return 1
 
@@ -638,7 +636,7 @@ test_pmtu_ipvX() {
 	check_pmtu_value "1500" "${pmtu_2}" "increasing local MTU" || return 1
 
 	# Get new exception
-	${ns_a} ${ping} -q -M want -i 0.1 -w 2 -s 1400 ${dst2} > /dev/null
+	${ns_a} ${ping} -q -M want -i 0.1 -w 1 -s 1400 ${dst2} > /dev/null
 	pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst2})"
 	check_pmtu_value "lock 552" "${pmtu_2}" "exceeding MTU, with MTU < min_pmtu" || return 1
 }
@@ -687,7 +685,7 @@ test_pmtu_ipvX_over_vxlanY_or_geneveY_exception() {
 
 	mtu "${ns_a}" ${type}_a $((${ll_mtu} + 1000))
 	mtu "${ns_b}" ${type}_b $((${ll_mtu} + 1000))
-	${ns_a} ${ping} -q -M want -i 0.1 -w 2 -s $((${ll_mtu} + 500)) ${dst} > /dev/null
+	${ns_a} ${ping} -q -M want -i 0.1 -w 1 -s $((${ll_mtu} + 500)) ${dst} > /dev/null
 
 	# Check that exception was created
 	pmtu="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst})"
@@ -767,7 +765,7 @@ test_pmtu_ipvX_over_fouY_or_gueY() {
 
 	mtu "${ns_a}" ${encap}_a $((${ll_mtu} + 1000))
 	mtu "${ns_b}" ${encap}_b $((${ll_mtu} + 1000))
-	${ns_a} ${ping} -q -M want -i 0.1 -w 2 -s $((${ll_mtu} + 500)) ${dst} > /dev/null
+	${ns_a} ${ping} -q -M want -i 0.1 -w 1 -s $((${ll_mtu} + 500)) ${dst} > /dev/null
 
 	# Check that exception was created
 	pmtu="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst})"
@@ -825,13 +823,13 @@ test_pmtu_vti4_exception() {
 
 	# Send DF packet without exceeding link layer MTU, check that no
 	# exception is created
-	${ns_a} ping -q -M want -i 0.1 -w 2 -s ${ping_payload} ${tunnel4_b_addr} > /dev/null
+	${ns_a} ping -q -M want -i 0.1 -w 1 -s ${ping_payload} ${tunnel4_b_addr} > /dev/null
 	pmtu="$(route_get_dst_pmtu_from_exception "${ns_a}" ${tunnel4_b_addr})"
 	check_pmtu_value "" "${pmtu}" "sending packet smaller than PMTU (IP payload length ${esp_payload_rfc4106})" || return 1
 
 	# Now exceed link layer MTU by one byte, check that exception is created
 	# with the right PMTU value
-	${ns_a} ping -q -M want -i 0.1 -w 2 -s $((ping_payload + 1)) ${tunnel4_b_addr} > /dev/null
+	${ns_a} ping -q -M want -i 0.1 -w 1 -s $((ping_payload + 1)) ${tunnel4_b_addr} > /dev/null
 	pmtu="$(route_get_dst_pmtu_from_exception "${ns_a}" ${tunnel4_b_addr})"
 	check_pmtu_value "${esp_payload_rfc4106}" "${pmtu}" "exceeding PMTU (IP payload length $((esp_payload_rfc4106 + 1)))"
 }
@@ -847,7 +845,7 @@ test_pmtu_vti6_exception() {
 	mtu "${ns_b}" veth_b 4000
 	mtu "${ns_a}" vti6_a 5000
 	mtu "${ns_b}" vti6_b 5000
-	${ns_a} ${ping6} -q -i 0.1 -w 2 -s 60000 ${tunnel6_b_addr} > /dev/null
+	${ns_a} ${ping6} -q -i 0.1 -w 1 -s 60000 ${tunnel6_b_addr} > /dev/null
 
 	# Check that exception was created
 	pmtu="$(route_get_dst_pmtu_from_exception "${ns_a}" ${tunnel6_b_addr})"