Commit d1f1b9cbf34c ("selftests: net: Introduce first PMTU test") and
follow-ups introduced some PMTU tests, but they all rely on tunneling,
and, particularly, on VTI.
These new tests use simple routing to exercise the generation and
update of PMTU exceptions in IPv4 and IPv6.
Signed-off-by: Sabrina Dubroca
Signed-off-by: Stefano Brivio
---
tools/testing/selftests/net/pmtu.sh | 207 +++-
1 file changed, 203 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/net/pmtu.sh
b/tools/testing/selftests/net/pmtu.sh
index 03e56a27f69c..b9cdb68df4c5 100755
--- a/tools/testing/selftests/net/pmtu.sh
+++ b/tools/testing/selftests/net/pmtu.sh
@@ -6,6 +6,26 @@
#
# Tests currently implemented:
#
+# - pmtu_ipv4
+# Set up two namespaces, A and B, with two paths between them over routers
+# R1 and R2 (also implemented with namespaces), with different MTUs:
+#
+#segment a_r1segment b_r1 a_r1: 2000
+# .--R1--.a_r2: 1500
+# A B a_r3: 2000
+# '--R2--'a_r4: 1400
+#segment a_r2segment b_r2
+#
+# Check that PMTU exceptions with the correct PMTU are created. Then
+# decrease and increase the MTU of the local link for one of the paths,
+# A to R1, checking that route exception PMTU changes accordingly over
+# this path. Also check that locked exceptions are created when an ICMP
+# message advertising a PMTU smaller than net.ipv4.route.min_pmtu is
+# received
+#
+# - pmtu_ipv6
+# Same as pmtu_ipv4, except for locked PMTU tests, using IPv6
+#
# - pmtu_vti4_exception
# Set up vti tunnel on top of veth, with xfrm states and policies, in two
# namespaces with matching endpoints. Check that route exception is not
@@ -50,6 +70,8 @@ ksft_skip=4
which ping6 > /dev/null 2>&1 && ping6=$(which ping6) || ping6=$(which ping)
tests="
+ pmtu_ipv4_exception ipv4: PMTU exceptions
+ pmtu_ipv6_exception ipv6: PMTU exceptions
pmtu_vti6_exception vti6: PMTU exceptions
pmtu_vti4_exception vti4: PMTU exceptions
pmtu_vti4_default_mtu vti4: default MTU assignment
@@ -60,8 +82,45 @@ tests="
NS_A="ns-$(mktemp -u XX)"
NS_B="ns-$(mktemp -u XX)"
+NS_R1="ns-$(mktemp -u XX)"
+NS_R2="ns-$(mktemp -u XX)"
ns_a="ip netns exec ${NS_A}"
ns_b="ip netns exec ${NS_B}"
+ns_r1="ip netns exec ${NS_R1}"
+ns_r2="ip netns exec ${NS_R2}"
+
+# Addressing and routing for tests with routers: four network segments, with
+# index SEGMENT between 1 and 4, a common prefix (PREFIX4 or PREFIX6) and an
+# identifier ID, which is 1 for hosts (A and B), 2 for routers (R1 and R2).
+# Addresses are:
+# - IPv4: PREFIX4.SEGMENT.ID (/24)
+# - IPv6: PREFIX6:SEGMENT::ID (/64)
+prefix4="192.168"
+prefix6="fd00"
+a_r1=1
+a_r2=2
+b_r1=3
+b_r2=4
+# ns peersegment
+routing_addrs="
+ A R1 ${a_r1}
+ A R2 ${a_r2}
+ B R1 ${b_r1}
+ B R2 ${b_r2}
+"
+# Traffic from A to B goes through R1 by default, and through R2, if destined
to
+# B's address on the b_r2 segment.
+# Traffic from B to A goes through R1.
+# ns destination gateway
+routes="
+ A default ${prefix4}.${a_r1}.2
+ A ${prefix4}.${b_r2}.1${prefix4}.${a_r2}.2
+ B default ${prefix4}.${b_r1}.2
+
+ A default ${prefix6}:${a_r1}::2
+ A ${prefix6}:${b_r2}::1 ${prefix6}:${a_r2}::2
+ B default ${prefix6}:${b_r1}::2
+"
veth4_a_addr="192.168.1.1"
veth4_b_addr="192.168.1.2"
@@ -94,9 +153,15 @@ err_flush() {
err_buf=
}
+# Find the auto-generated name for this namespace
+nsname() {
+ eval echo \$NS_$1
+}
+
setup_namespaces() {
- ip netns add ${NS_A} || return 1
- ip netns add ${NS_B}
+ for n in ${NS_A} ${NS_B} ${NS_R1} ${NS_R2}; do
+ ip netns add ${n} || return 1
+ done
}
setup_veth() {
@@ -167,6 +232,49 @@ setup_xfrm6() {
setup_xfrm 6 ${veth6_a_addr} ${veth6_b_addr}
}
+setup_routing() {
+ for i in ${NS_R1} ${NS_R2}; do
+ ip netns exec ${i} sysctl -q net/ipv4/ip_forward=1
+ ip netns exec ${i} sysctl -q net/ipv6/conf/all/forwarding=1
+ done
+
+ for i in ${routing_addrs}; do
+ [ "${ns}" = "" ]&& ns="${i}"&& continue
+ [ "${peer}" = "" ] && peer="${i}" && continue
+ [ "${segment}" = "" ] && segment="${i}"
+
+ ns_name="$(nsname ${ns})"
+ peer_name="$(nsname ${peer})"
+ if="veth_${ns}-${peer}"
+ ifpeer="veth_${peer}-${ns}"
+
+ # Create veth links
+ ip link add ${if} up netns
