[PATCH 3/3] selftests: Add VRF route leaking tests
From: Mathieu Desnoyers
Date: Mon Oct 12 2020 - 10:50:56 EST
From: Michael Jeanson <mjeanson@xxxxxxxxxxxx>
The objective of the tests is to check that ICMP errors generated while
crossing between VRFs are properly routed back to the source host.
The first ttl test sends a ping with a ttl of 1 from h1 to h2 and parses the
output of the command to check that a ttl expired error is received.
The second ttl test runs traceroute from h1 to h2 and parses the output to
check for a hop on r1.
The mtu test sends a ping with a payload of 1450 from h1 to h2, through
r1 which has an interface with a mtu of 1400 and parses the output of the
command to check that a fragmentation needed error is received.
[ The IPv6 MTU test still fails with the symmetric routing setup. It
appears to be caused by source address selection picking ::1. Fixing
this is beyond the scope of this series. ]
Signed-off-by: Michael Jeanson <mjeanson@xxxxxxxxxxxx>
Reviewed-by: David Ahern <dsahern@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
---
Changes since v2:
- Renamed test script to vrf_route_leaking.sh
- Added a default symmetric routing topology
- Documented the asymmetric routing topology
Changes since v1:
- Formating and indentation fixes
- Added '-t' to getopts
- Reworked verbose output of grep'd commands with a new function
- Expanded ip command names
- Added fragmentation tests
---
tools/testing/selftests/net/Makefile | 1 +
.../selftests/net/vrf_route_leaking.sh | 626 ++++++++++++++++++
2 files changed, 627 insertions(+)
create mode 100755 tools/testing/selftests/net/vrf_route_leaking.sh
diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index 9491bbaa0831..3e7fb1e70c77 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -19,6 +19,7 @@ TEST_PROGS += txtimestamp.sh
TEST_PROGS += vrf-xfrm-tests.sh
TEST_PROGS += rxtimestamp.sh
TEST_PROGS += devlink_port_split.py
+TEST_PROGS += vrf_route_leaking.sh
TEST_PROGS_EXTENDED := in_netns.sh
TEST_GEN_FILES = socket nettest
TEST_GEN_FILES += psock_fanout psock_tpacket msg_zerocopy reuseport_addr_any
diff --git a/tools/testing/selftests/net/vrf_route_leaking.sh b/tools/testing/selftests/net/vrf_route_leaking.sh
new file mode 100755
index 000000000000..23cf924754a5
--- /dev/null
+++ b/tools/testing/selftests/net/vrf_route_leaking.sh
@@ -0,0 +1,626 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (c) 2019 David Ahern <dsahern@xxxxxxxxx>. All rights reserved.
+# Copyright (c) 2020 Michael Jeanson <mjeanson@xxxxxxxxxxxx>. All rights reserved.
+#
+# Requires CONFIG_NET_VRF, CONFIG_VETH, CONFIG_BRIDGE and CONFIG_NET_NS.
+#
+#
+# Symmetric routing topology
+#
+# blue red
+# +----+ .253 +----+ .253 +----+
+# | h1 |-------------------| r1 |-------------------| h2 |
+# +----+ .1 +----+ .2 +----+
+# 172.16.1/24 172.16.2/24
+# 2001:db8:16:1/64 2001:db8:16:2/64
+#
+#
+# Route from h1 to h2 and back goes through r1, incoming vrf blue has a route
+# to the outgoing vrf red for the n2 network and red has a route back to n1.
+# The red VRF interface has a MTU of 1400.
+#
+# The first test sends a ping with a ttl of 1 from h1 to h2 and parses the
+# output of the command to check that a ttl expired error is received.
+#
+# The second test runs traceroute from h1 to h2 and parses the output to check
+# for a hop on r1.
+#
+# The third test sends a ping with a packet size of 1450 from h1 to h2 and
+# parses the output of the command to check that a fragmentation error is
+# received.
+#
+#
+# Asymmetric routing topology
+#
+# This topology represents a customer setup where the issue with icmp errors
+# and VRF route leaking was initialy reported. The MTU test isn't done here
+# because of the lack of a return route in the red VRF.
+#
+# blue red
+# .253 +----+ .253
+# +----| r1 |----+
+# | +----+ |
+# +----+ | | +----+
+# | h1 |--------------+ +--------------| h2 |
+# +----+ .1 | | .2 +----+
+# 172.16.1/24 | +----+ | 172.16.2/24
+# 2001:db8:16:1/64 +----| r2 |----+ 2001:db8:16:2/64
+# .254 +----+ .254
+#
+#
+# Route from h1 to h2 goes through r1, incoming vrf blue has a route to the
+# outgoing vrf red for the n2 network but red doesn't have a route back to n1.
+# Route from h2 to h1 goes through r2.
+#
+# The objective is to check that the incoming vrf routing table is selected
+# to send an ICMP error back to the source when the ttl of a packet reaches 1
+# while it is forwarded between different vrfs.
+
+VERBOSE=0
+PAUSE_ON_FAIL=no
+DEFAULT_TTYPE=sym
+
+H1_N1=172.16.1.0/24
+H1_N1_6=2001:db8:16:1::/64
+
+H1_N1_IP=172.16.1.1
+R1_N1_IP=172.16.1.253
+R2_N1_IP=172.16.1.254
+
+H1_N1_IP6=2001:db8:16:1::1
+R1_N1_IP6=2001:db8:16:1::253
+R2_N1_IP6=2001:db8:16:1::254
+
+H2_N2=172.16.2.0/24
+H2_N2_6=2001:db8:16:2::/64
+
+H2_N2_IP=172.16.2.2
+R1_N2_IP=172.16.2.253
+R2_N2_IP=172.16.2.254
+
+H2_N2_IP6=2001:db8:16:2::2
+R1_N2_IP6=2001:db8:16:2::253
+R2_N2_IP6=2001:db8:16:2::254
+
+################################################################################
+# helpers
+
+log_section()
+{
+ echo
+ echo "###########################################################################"
+ echo "$*"
+ echo "###########################################################################"
+ echo
+}
+
+log_test()
+{
+ local rc=$1
+ local expected=$2
+ local msg="$3"
+
+ if [ "${rc}" -eq "${expected}" ]; then
+ printf "TEST: %-60s [ OK ]\n" "${msg}"
+ nsuccess=$((nsuccess+1))
+ else
+ ret=1
+ nfail=$((nfail+1))
+ printf "TEST: %-60s [FAIL]\n" "${msg}"
+ if [ "${PAUSE_ON_FAIL}" = "yes" ]; then
+ echo
+ echo "hit enter to continue, 'q' to quit"
+ read -r a
+ [ "$a" = "q" ] && exit 1
+ fi
+ fi
+}
+
+run_cmd()
+{
+ local cmd="$*"
+ local out
+ local rc
+
+ if [ "$VERBOSE" = "1" ]; then
+ echo "COMMAND: $cmd"
+ fi
+
+ # shellcheck disable=SC2086
+ out=$(eval $cmd 2>&1)
+ rc=$?
+ if [ "$VERBOSE" = "1" ] && [ -n "$out" ]; then
+ echo "$out"
+ fi
+
+ [ "$VERBOSE" = "1" ] && echo
+
+ return $rc
+}
+
+run_cmd_grep()
+{
+ local grep_pattern="$1"
+ shift
+ local cmd="$*"
+ local out
+ local rc
+
+ if [ "$VERBOSE" = "1" ]; then
+ echo "COMMAND: $cmd"
+ fi
+
+ # shellcheck disable=SC2086
+ out=$(eval $cmd 2>&1)
+ if [ "$VERBOSE" = "1" ] && [ -n "$out" ]; then
+ echo "$out"
+ fi
+
+ echo "$out" | grep -q "$grep_pattern"
+ rc=$?
+
+ [ "$VERBOSE" = "1" ] && echo
+
+ return $rc
+}
+
+################################################################################
+# setup and teardown
+
+cleanup()
+{
+ local ns
+
+ for ns in h1 h2 r1 r2; do
+ ip netns del $ns 2>/dev/null
+ done
+}
+
+setup_vrf()
+{
+ local ns=$1
+
+ ip -netns "${ns}" rule del pref 0
+ ip -netns "${ns}" rule add pref 32765 from all lookup local
+ ip -netns "${ns}" -6 rule del pref 0
+ ip -netns "${ns}" -6 rule add pref 32765 from all lookup local
+}
+
+create_vrf()
+{
+ local ns=$1
+ local vrf=$2
+ local table=$3
+
+ ip -netns "${ns}" link add "${vrf}" type vrf table "${table}"
+ ip -netns "${ns}" link set "${vrf}" up
+ ip -netns "${ns}" route add vrf "${vrf}" unreachable default metric 8192
+ ip -netns "${ns}" -6 route add vrf "${vrf}" unreachable default metric 8192
+
+ ip -netns "${ns}" addr add 127.0.0.1/8 dev "${vrf}"
+ ip -netns "${ns}" -6 addr add ::1 dev "${vrf}" nodad
+}
+
+setup_sym()
+{
+ local ns
+
+ # make sure we are starting with a clean slate
+ cleanup
+
+ #
+ # create nodes as namespaces
+ #
+ for ns in h1 h2 r1; do
+ ip netns add $ns
+ ip -netns $ns link set lo up
+
+ case "${ns}" in
+ h[12]) ip netns exec $ns sysctl -q -w net.ipv6.conf.all.forwarding=0
+ ip netns exec $ns sysctl -q -w net.ipv6.conf.all.keep_addr_on_down=1
+ ;;
+ r1) ip netns exec $ns sysctl -q -w net.ipv4.ip_forward=1
+ ip netns exec $ns sysctl -q -w net.ipv6.conf.all.forwarding=1
+ esac
+ done
+
+ #
+ # create interconnects
+ #
+ ip -netns h1 link add eth0 type veth peer name r1h1
+ ip -netns h1 link set r1h1 netns r1 name eth0 up
+
+ ip -netns h2 link add eth0 type veth peer name r1h2
+ ip -netns h2 link set r1h2 netns r1 name eth1 up
+
+ #
+ # h1
+ #
+ ip -netns h1 addr add dev eth0 ${H1_N1_IP}/24
+ ip -netns h1 -6 addr add dev eth0 ${H1_N1_IP6}/64 nodad
+ ip -netns h1 link set eth0 up
+
+ # h1 to h2 via r1
+ ip -netns h1 route add ${H2_N2} via ${R1_N1_IP} dev eth0
+ ip -netns h1 -6 route add ${H2_N2_6} via "${R1_N1_IP6}" dev eth0
+
+ #
+ # h2
+ #
+ ip -netns h2 addr add dev eth0 ${H2_N2_IP}/24
+ ip -netns h2 -6 addr add dev eth0 ${H2_N2_IP6}/64 nodad
+ ip -netns h2 link set eth0 up
+
+ # h2 to h1 via r1
+ ip -netns h2 route add default via ${R1_N2_IP} dev eth0
+ ip -netns h2 -6 route add default via ${R1_N2_IP6} dev eth0
+
+ #
+ # r1
+ #
+ setup_vrf r1
+ create_vrf r1 blue 1101
+ create_vrf r1 red 1102
+ ip -netns r1 link set mtu 1400 dev eth1
+ ip -netns r1 link set eth0 vrf blue up
+ ip -netns r1 link set eth1 vrf red up
+ ip -netns r1 addr add dev eth0 ${R1_N1_IP}/24
+ ip -netns r1 -6 addr add dev eth0 ${R1_N1_IP6}/64 nodad
+ ip -netns r1 addr add dev eth1 ${R1_N2_IP}/24
+ ip -netns r1 -6 addr add dev eth1 ${R1_N2_IP6}/64 nodad
+
+ # Route leak from blue to red
+ ip -netns r1 route add vrf blue ${H2_N2} dev red
+ ip -netns r1 -6 route add vrf blue ${H2_N2_6} dev red
+
+ # Route leak from red to blue
+ ip -netns r1 route add vrf red ${H1_N1} dev blue
+ ip -netns r1 -6 route add vrf red ${H1_N1_6} dev blue
+
+
+ # Wait for ip config to settle
+ sleep 2
+}
+
+setup_asym()
+{
+ local ns
+
+ # make sure we are starting with a clean slate
+ cleanup
+
+ #
+ # create nodes as namespaces
+ #
+ for ns in h1 h2 r1 r2; do
+ ip netns add $ns
+ ip -netns $ns link set lo up
+
+ case "${ns}" in
+ h[12]) ip netns exec $ns sysctl -q -w net.ipv6.conf.all.forwarding=0
+ ip netns exec $ns sysctl -q -w net.ipv6.conf.all.keep_addr_on_down=1
+ ;;
+ r[12]) ip netns exec $ns sysctl -q -w net.ipv4.ip_forward=1
+ ip netns exec $ns sysctl -q -w net.ipv6.conf.all.forwarding=1
+ esac
+ done
+
+ #
+ # create interconnects
+ #
+ ip -netns h1 link add eth0 type veth peer name r1h1
+ ip -netns h1 link set r1h1 netns r1 name eth0 up
+
+ ip -netns h1 link add eth1 type veth peer name r2h1
+ ip -netns h1 link set r2h1 netns r2 name eth0 up
+
+ ip -netns h2 link add eth0 type veth peer name r1h2
+ ip -netns h2 link set r1h2 netns r1 name eth1 up
+
+ ip -netns h2 link add eth1 type veth peer name r2h2
+ ip -netns h2 link set r2h2 netns r2 name eth1 up
+
+ #
+ # h1
+ #
+ ip -netns h1 link add br0 type bridge
+ ip -netns h1 link set br0 up
+ ip -netns h1 addr add dev br0 ${H1_N1_IP}/24
+ ip -netns h1 -6 addr add dev br0 ${H1_N1_IP6}/64 nodad
+ ip -netns h1 link set eth0 master br0 up
+ ip -netns h1 link set eth1 master br0 up
+
+ # h1 to h2 via r1
+ ip -netns h1 route add ${H2_N2} via ${R1_N1_IP} dev br0
+ ip -netns h1 -6 route add ${H2_N2_6} via "${R1_N1_IP6}" dev br0
+
+ #
+ # h2
+ #
+ ip -netns h2 link add br0 type bridge
+ ip -netns h2 link set br0 up
+ ip -netns h2 addr add dev br0 ${H2_N2_IP}/24
+ ip -netns h2 -6 addr add dev br0 ${H2_N2_IP6}/64 nodad
+ ip -netns h2 link set eth0 master br0 up
+ ip -netns h2 link set eth1 master br0 up
+
+ # h2 to h1 via r2
+ ip -netns h2 route add default via ${R2_N2_IP} dev br0
+ ip -netns h2 -6 route add default via ${R2_N2_IP6} dev br0
+
+ #
+ # r1
+ #
+ setup_vrf r1
+ create_vrf r1 blue 1101
+ create_vrf r1 red 1102
+ ip -netns r1 link set mtu 1400 dev eth1
+ ip -netns r1 link set eth0 vrf blue up
+ ip -netns r1 link set eth1 vrf red up
+ ip -netns r1 addr add dev eth0 ${R1_N1_IP}/24
+ ip -netns r1 -6 addr add dev eth0 ${R1_N1_IP6}/64 nodad
+ ip -netns r1 addr add dev eth1 ${R1_N2_IP}/24
+ ip -netns r1 -6 addr add dev eth1 ${R1_N2_IP6}/64 nodad
+
+ # Route leak from blue to red
+ ip -netns r1 route add vrf blue ${H2_N2} dev red
+ ip -netns r1 -6 route add vrf blue ${H2_N2_6} dev red
+
+ # No route leak from red to blue
+
+ #
+ # r2
+ #
+ ip -netns r2 addr add dev eth0 ${R2_N1_IP}/24
+ ip -netns r2 -6 addr add dev eth0 ${R2_N1_IP6}/64 nodad
+ ip -netns r2 addr add dev eth1 ${R2_N2_IP}/24
+ ip -netns r2 -6 addr add dev eth1 ${R2_N2_IP6}/64 nodad
+
+ # Wait for ip config to settle
+ sleep 2
+}
+
+check_connectivity()
+{
+ ip netns exec h1 ping -c1 -w1 ${H2_N2_IP} >/dev/null 2>&1
+ log_test $? 0 "Basic IPv4 connectivity"
+ return $?
+}
+
+check_connectivity6()
+{
+ ip netns exec h1 "${ping6}" -c1 -w1 ${H2_N2_IP6} >/dev/null 2>&1
+ log_test $? 0 "Basic IPv6 connectivity"
+ return $?
+}
+
+check_traceroute()
+{
+ if [ ! -x "$(command -v traceroute)" ]; then
+ echo "SKIP: Could not run IPV4 test without traceroute"
+ return 1
+ fi
+}
+
+check_traceroute6()
+{
+ if [ ! -x "$(command -v traceroute6)" ]; then
+ echo "SKIP: Could not run IPV6 test without traceroute6"
+ return 1
+ fi
+}
+
+ipv4_traceroute()
+{
+ local ttype="$1"
+
+ [ "x$ttype" = "x" ] && ttype="$DEFAULT_TTYPE"
+
+ log_section "IPv4 ($ttype route): VRF ICMP error route lookup traceroute"
+
+ check_traceroute || return
+
+ setup_"$ttype"
+
+ check_connectivity || return
+
+ run_cmd_grep "${R1_N1_IP}" ip netns exec h1 traceroute ${H2_N2_IP}
+ log_test $? 0 "Traceroute reports a hop on r1"
+}
+
+ipv4_traceroute_asym()
+{
+ ipv4_traceroute asym
+}
+
+ipv6_traceroute()
+{
+ local ttype="$1"
+
+ [ "x$ttype" = "x" ] && ttype="$DEFAULT_TTYPE"
+
+ log_section "IPv6 ($ttype route): VRF ICMP error route lookup traceroute"
+
+ check_traceroute6 || return
+
+ setup_"$ttype"
+
+ check_connectivity6 || return
+
+ run_cmd_grep "${R1_N1_IP6}" ip netns exec h1 traceroute6 ${H2_N2_IP6}
+ log_test $? 0 "Traceroute6 reports a hop on r1"
+}
+
+ipv6_traceroute_asym()
+{
+ ipv6_traceroute asym
+}
+
+ipv4_ping_ttl()
+{
+ local ttype="$1"
+
+ [ "x$ttype" = "x" ] && ttype="$DEFAULT_TTYPE"
+
+ log_section "IPv4 ($ttype route): VRF ICMP ttl error route lookup ping"
+
+ setup_"$ttype"
+
+ check_connectivity || return
+
+ run_cmd_grep "Time to live exceeded" ip netns exec h1 ping -t1 -c1 -W2 ${H2_N2_IP}
+ log_test $? 0 "Ping received ICMP ttl exceeded"
+}
+
+ipv4_ping_ttl_asym()
+{
+ ipv4_ping_ttl asym
+}
+
+ipv4_ping_frag()
+{
+ local ttype="$1"
+
+ [ "x$ttype" = "x" ] && ttype="$DEFAULT_TTYPE"
+
+ log_section "IPv4 ($ttype route): VRF ICMP fragmentation error route lookup ping"
+
+ setup_"$ttype"
+
+ check_connectivity || return
+
+ run_cmd_grep "Frag needed" ip netns exec h1 ping -s 1450 -Mdo -c1 -W2 ${H2_N2_IP}
+ log_test $? 0 "Ping received ICMP Frag needed"
+}
+
+ipv4_ping_frag_asym()
+{
+ ipv4_ping_frag asym
+}
+
+ipv6_ping_ttl()
+{
+ local ttype="$1"
+
+ [ "x$ttype" = "x" ] && ttype="$DEFAULT_TTYPE"
+
+ log_section "IPv6 ($ttype route): VRF ICMP ttl error route lookup ping"
+
+ setup_"$ttype"
+
+ check_connectivity6 || return
+
+ run_cmd_grep "Time exceeded: Hop limit" ip netns exec h1 "${ping6}" -t1 -c1 -W2 ${H2_N2_IP6}
+ log_test $? 0 "Ping received ICMP Hop limit"
+}
+
+ipv6_ping_ttl_asym()
+{
+ ipv6_ping_ttl asym
+}
+
+ipv6_ping_frag()
+{
+ local ttype="$1"
+
+ [ "x$ttype" = "x" ] && ttype="$DEFAULT_TTYPE"
+
+ log_section "IPv6 ($ttype route): VRF ICMP fragmentation error route lookup ping"
+
+ setup_"$ttype"
+
+ check_connectivity6 || return
+
+ run_cmd_grep "Packet too big" ip netns exec h1 "${ping6}" -s 1450 -Mdo -c1 -W2 ${H2_N2_IP6}
+ log_test $? 0 "Ping received ICMP Packet too big"
+}
+
+ipv6_ping_frag_asym()
+{
+ ipv6_ping_frag asym
+}
+
+################################################################################
+# usage
+
+usage()
+{
+ cat <<EOF
+usage: ${0##*/} OPTS
+
+ -4 Run IPv4 tests only
+ -6 Run IPv6 tests only
+ -t TEST Run only TEST
+ -p Pause on fail
+ -v verbose mode (show commands and output)
+EOF
+}
+
+################################################################################
+# main
+
+# Some systems don't have a ping6 binary anymore
+command -v ping6 > /dev/null 2>&1 && ping6=$(command -v ping6) || ping6=$(command -v ping)
+
+TESTS_IPV4="ipv4_ping_ttl ipv4_traceroute ipv4_ping_frag ipv4_ping_ttl_asym ipv4_traceroute_asym"
+TESTS_IPV6="ipv6_ping_ttl ipv6_traceroute ipv6_ping_frag ipv6_ping_ttl_asym ipv6_traceroute_asym"
+
+ret=0
+nsuccess=0
+nfail=0
+
+while getopts :46t:pvh o
+do
+ case $o in
+ 4) TESTS=ipv4;;
+ 6) TESTS=ipv6;;
+ t) TESTS=$OPTARG;;
+ p) PAUSE_ON_FAIL=yes;;
+ v) VERBOSE=1;;
+ h) usage; exit 0;;
+ *) usage; exit 1;;
+ esac
+done
+
+#
+# show user test config
+#
+if [ -z "$TESTS" ]; then
+ TESTS="$TESTS_IPV4 $TESTS_IPV6"
+elif [ "$TESTS" = "ipv4" ]; then
+ TESTS="$TESTS_IPV4"
+elif [ "$TESTS" = "ipv6" ]; then
+ TESTS="$TESTS_IPV6"
+fi
+
+for t in $TESTS
+do
+ case $t in
+ ipv4_ping_ttl|ping) ipv4_ping_ttl;;&
+ ipv4_ping_ttl_asym|ping) ipv4_ping_ttl_asym;;&
+ ipv4_traceroute|traceroute) ipv4_traceroute;;&
+ ipv4_traceroute_asym|traceroute) ipv4_traceroute_asym;;&
+ ipv4_ping_frag|ping) ipv4_ping_frag;;&
+
+ ipv6_ping_ttl|ping) ipv6_ping_ttl;;&
+ ipv6_ping_ttl_asym|ping) ipv6_ping_ttl_asym;;&
+ ipv6_traceroute|traceroute) ipv6_traceroute;;&
+ ipv6_traceroute_asym|traceroute) ipv6_traceroute_asym;;&
+ ipv6_ping_frag|ping) ipv6_ping_frag;;&
+
+ # setup namespaces and config, but do not run any tests
+ setup_sym|setup) setup_sym; exit 0;;
+ setup_asym) setup_asym; exit 0;;
+
+ help) echo "Test names: $TESTS"; exit 0;;
+ esac
+done
+
+cleanup
+
+printf "\nTests passed: %3d\n" ${nsuccess}
+printf "Tests failed: %3d\n" ${nfail}
+
+exit $ret
--
2.17.1