--- /dev/null
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# redirect test
+#
+# .253 +----+
+# +----| r1 |
+# | +----+
+# +----+ | |.1
+# | h1 |--------------+ | 10.1.1.0/30 2001:db8:1::0/126
+# +----+ .1 | |.2
+# 172.16.1/24 | +----+ +----+
+# 2001:db8:16:1/64 +----| r2 |-------------------| h2 |
+# .254 +----+ .254 .2 +----+
+# 172.16.2/24
+# 2001:db8:16:2/64
+#
+# Route from h1 to h2 goes through r1, eth1 - connection between r1 and r2.
+# Route on r1 changed to go to r2 via eth0. This causes a redirect to be sent
+# from r1 to h1 telling h1 to use r2 when talking to h2.
+
+VERBOSE=0
+PAUSE_ON_FAIL=no
+
+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
+
+R1_R2_N1_IP=10.1.1.1
+R2_R1_N1_IP=10.1.1.2
+
+R1_R2_N1_IP6=2001:db8:1::1
+R2_R1_N1_IP6=2001:db8:1::2
+
+H2_N2=172.16.2.0/24
+H2_N2_6=2001:db8:16:2::/64
+H2_N2_IP=172.16.2.2
+R2_N2_IP=172.16.2.254
+H2_N2_IP6=2001:db8:16:2::2
+R2_N2_IP6=2001:db8:16:2::254
+
+VRF=red
+VRF_TABLE=1111
+
+################################################################################
+# 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 a
+ [ "$a" = "q" ] && exit 1
+ fi
+ fi
+}
+
+run_cmd()
+{
+ local cmd="$*"
+ local out
+ local rc
+
+ if [ "$VERBOSE" = "1" ]; then
+ echo "COMMAND: $cmd"
+ fi
+
+ out=$(eval $cmd 2>&1)
+ rc=$?
+ if [ "$VERBOSE" = "1" -a -n "$out" ]; then
+ echo "$out"
+ fi
+
+ [ "$VERBOSE" = "1" ] && echo
+
+ return $rc
+}
+
+get_linklocal()
+{
+ local ns=$1
+ local dev=$2
+ local addr
+
+ addr=$(ip -netns $ns -6 -br addr show dev ${dev} | \
+ awk '{
+ for (i = 3; i <= NF; ++i) {
+ if ($i ~ /^fe80/)
+ print $i
+ }
+ }'
+ )
+ addr=${addr/\/*}
+
+ [ -z "$addr" ] && return 1
+
+ echo $addr
+
+ return 0
+}
+
+################################################################################
+# setup and teardown
+
+cleanup()
+{
+ local ns
+
+ for ns in h1 h2 r1 r2; do
+ ip netns del $ns 2>/dev/null
+ done
+}
+
+create_vrf()
+{
+ local ns=$1
+
+ ip -netns ${ns} link add ${VRF} type vrf table ${VRF_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
+
+ ip -netns ${ns} ru del pref 0
+ ip -netns ${ns} ru add pref 32765 from all lookup local
+ ip -netns ${ns} -6 ru del pref 0
+ ip -netns ${ns} -6 ru add pref 32765 from all lookup local
+}
+
+setup()
+{
+ local ns
+
+ #
+ # create nodes as namespaces
+ #
+ for ns in h1 h2 r1 r2; do
+ ip netns add $ns
+ ip -netns $ns li set lo up
+
+ case "${ns}" in
+ h[12]) ip netns exec $ns sysctl -q -w net.ipv4.conf.all.accept_redirects=1
+ ip netns exec $ns sysctl -q -w net.ipv6.conf.all.accept_redirects=1
+ 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.ipv4.conf.all.send_redirects=1
+
+ ip netns exec $ns sysctl -q -w net.ipv6.conf.all.forwarding=1
+ ip netns exec $ns sysctl -q -w net.ipv6.route.mtu_expires=10
+ esac
+ done
+
+ #
+ # create interconnects
+ #
+ ip -netns h1 li add eth0 type veth peer name r1h1
+ ip -netns h1 li set r1h1 netns r1 name eth0 up
+
+ ip -netns h1 li add eth1 type veth peer name r2h1
+ ip -netns h1 li set r2h1 netns r2 name eth0 up
+
+ ip -netns h2 li add eth0 type veth peer name r2h2
+ ip -netns h2 li set eth0 up
+ ip -netns h2 li set r2h2 netns r2 name eth2 up
+
+ ip -netns r1 li add eth1 type veth peer name r2r1
+ ip -netns r1 li set eth1 up
+ ip -netns r1 li set r2r1 netns r2 name eth1 up
+
+ #
+ # h1
+ #
+ if [ "${WITH_VRF}" = "yes" ]; then
+ create_vrf "h1"
+ H1_VRF_ARG="vrf ${VRF}"
+ H1_PING_ARG="-I ${VRF}"
+ else
+ H1_VRF_ARG=
+ H1_PING_ARG=
+ fi
+ ip -netns h1 li add br0 type bridge
+ if [ "${WITH_VRF}" = "yes" ]; then
+ ip -netns h1 li set br0 vrf ${VRF} up
+ else
+ ip -netns h1 li set br0 up
+ fi
+ 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 li set eth0 master br0 up
+ ip -netns h1 li set eth1 master br0 up
+
+ #
+ # h2
+ #
+ ip -netns h2 addr add dev eth0 ${H2_N2_IP}/24
+ ip -netns h2 ro add default via ${R2_N2_IP} dev eth0
+ ip -netns h2 -6 addr add dev eth0 ${H2_N2_IP6}/64 nodad
+ ip -netns h2 -6 ro add default via ${R2_N2_IP6} dev eth0
+
+ #
+ # r1
+ #
+ 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_R2_N1_IP}/30
+ ip -netns r1 -6 addr add dev eth1 ${R1_R2_N1_IP6}/126 nodad
+
+ #
+ # 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_R1_N1_IP}/30
+ ip -netns r2 -6 addr add dev eth1 ${R2_R1_N1_IP6}/126 nodad
+ ip -netns r2 addr add dev eth2 ${R2_N2_IP}/24
+ ip -netns r2 -6 addr add dev eth2 ${R2_N2_IP6}/64 nodad
+
+ sleep 2
+
+ R1_LLADDR=$(get_linklocal r1 eth0)
+ if [ $? -ne 0 ]; then
+ echo "Error: Failed to get link-local address of r1's eth0"
+ exit 1
+ fi
+
+ R2_LLADDR=$(get_linklocal r2 eth0)
+ if [ $? -ne 0 ]; then
+ echo "Error: Failed to get link-local address of r2's eth0"
+ exit 1
+ fi
+}
+
+change_h2_mtu()
+{
+ local mtu=$1
+
+ run_cmd ip -netns h2 li set eth0 mtu ${mtu}
+ run_cmd ip -netns r2 li set eth2 mtu ${mtu}
+}
+
+check_exception()
+{
+ local mtu="$1"
+ local with_redirect="$2"
+ local desc="$3"
+
+ # From 172.16.1.101: icmp_seq=1 Redirect Host(New nexthop: 172.16.1.102)
+ if [ "$VERBOSE" = "1" ]; then
+ echo "Commands to check for exception:"
+ run_cmd ip -netns h1 ro get ${H1_VRF_ARG} ${H2_N2_IP}
+ run_cmd ip -netns h1 -6 ro get ${H1_VRF_ARG} ${H2_N2_IP6}
+ fi
+
+ if [ -n "${mtu}" ]; then
+ mtu=" mtu ${mtu}"
+ fi
+ if [ "$with_redirect" = "yes" ]; then
+ ip -netns h1 ro get ${H1_VRF_ARG} ${H2_N2_IP} | \
+ grep -q "cache <redirected> expires [0-9]*sec${mtu}"
+ elif [ -n "${mtu}" ]; then
+ ip -netns h1 ro get ${H1_VRF_ARG} ${H2_N2_IP} | \
+ grep -q "cache expires [0-9]*sec${mtu}"
+ else
+ ip -netns h1 ro get ${H1_VRF_ARG} ${H2_N2_IP} | \
+ grep -q "cache"
+ fi
+ log_test $? 0 "IPv4: ${desc}"
+
+ if [ "$with_redirect" = "yes" ]; then
+ ip -netns h1 -6 ro get ${H1_VRF_ARG} ${H2_N2_IP6} | grep -q "${H2_N2_IP6} from :: via ${R2_LLADDR} dev br0.*${mtu}"
+ else
+ ip -netns h1 -6 ro get ${H1_VRF_ARG} ${H2_N2_IP6} | grep -q "${mtu}"
+ fi
+ log_test $? 0 "IPv6: ${desc}"
+}
+
+run_ping()
+{
+ local sz=$1
+
+ run_cmd ip netns exec h1 ping -q -M want -i 0.2 -c 10 -w 2 -s ${sz} ${H1_PING_ARG} ${H2_N2_IP}
+ run_cmd ip netns exec h1 ${ping6} -q -M want -i 0.2 -c 10 -w 2 -s ${sz} ${H1_PING_ARG} ${H2_N2_IP6}
+}
+
+replace_route_legacy()
+{
+ # r1 to h2 via r2 and eth0
+ run_cmd ip -netns r1 ro replace ${H2_N2} via ${R2_N1_IP} dev eth0
+ run_cmd ip -netns r1 -6 ro replace ${H2_N2_6} via ${R2_LLADDR} dev eth0
+}
+
+initial_route_legacy()
+{
+ # r1 to h2 via r2 and eth1
+ run_cmd ip -netns r1 ro add ${H2_N2} via ${R2_R1_N1_IP} dev eth1
+ run_cmd ip -netns r1 -6 ro add ${H2_N2_6} via ${R2_R1_N1_IP6} dev eth1
+
+ # h1 to h2 via r1
+ # - IPv6 redirect only works if gateway is the LLA
+ run_cmd ip -netns h1 ro add ${H1_VRF_ARG} ${H2_N2} via ${R1_N1_IP} dev br0
+ run_cmd ip -netns h1 -6 ro add ${H1_VRF_ARG} ${H2_N2_6} via ${R1_LLADDR} dev br0
+}
+
+check_connectivity()
+{
+ local rc
+
+ run_cmd ip netns exec h1 ping -c1 -w1 ${H1_PING_ARG} ${H2_N2_IP}
+ rc=$?
+ run_cmd ip netns exec h1 ${ping6} -c1 -w1 ${H1_PING_ARG} ${H2_N2_IP6}
+ [ $? -ne 0 ] && rc=$?
+
+ return $rc
+}
+
+do_test()
+{
+ local ttype="$1"
+
+ eval initial_route_${ttype}
+
+ # verify connectivity
+ check_connectivity
+ if [ $? -ne 0 ]; then
+ echo "Error: Basic connectivity is broken"
+ ret=1
+ return
+ fi
+
+ # redirect exception followed by mtu
+ eval replace_route_${ttype}
+ run_ping 64
+ check_exception "" "yes" "redirect exception"
+
+ check_connectivity
+ if [ $? -ne 0 ]; then
+ echo "Error: Basic connectivity is broken after redirect"
+ ret=1
+ return
+ fi
+
+ change_h2_mtu 1300
+ run_ping 1350
+ check_exception "1300" "yes" "redirect exception plus mtu"
+
+ # remove exceptions and restore routing
+ change_h2_mtu 1500
+ ip -netns h1 li set br0 down
+ ip -netns h1 li set br0 up
+ eval initial_route_${ttype}
+
+ check_connectivity
+ if [ $? -ne 0 ]; then
+ echo "Error: Basic connectivity is broken after reset"
+ ret=1
+ return
+ fi
+ check_exception "" "no" "routing reset"
+
+ # MTU exception followed by redirect
+ change_h2_mtu 1300
+ run_ping 1350
+ check_exception "1300" "no" "mtu exception"
+
+ eval replace_route_${ttype}
+ run_ping 64
+ check_exception "1300" "yes" "mtu exception plus redirect"
+
+ check_connectivity
+ if [ $? -ne 0 ]; then
+ echo "Error: Basic connectivity is broken after redirect"
+ ret=1
+ return
+ fi
+}
+
+################################################################################
+# usage
+
+usage()
+{
+ cat <<EOF
+usage: ${0##*/} OPTS
+
+ -p Pause on fail
+ -v verbose mode (show commands and output)
+EOF
+}
+
+################################################################################
+# main
+
+# Some systems don't have a ping6 binary anymore
+which ping6 > /dev/null 2>&1 && ping6=$(which ping6) || ping6=$(which ping)
+
+ret=0
+nsuccess=0
+nfail=0
+
+while getopts :pv o
+do
+ case $o in
+ p) PAUSE_ON_FAIL=yes;;
+ v) VERBOSE=$(($VERBOSE + 1));;
+ *) usage; exit 1;;
+ esac
+done
+
+trap cleanup EXIT
+
+cleanup
+WITH_VRF=no
+setup
+
+log_section "Legacy routing"
+do_test "legacy"
+
+cleanup
+log_section "Legacy routing with VRF"
+WITH_VRF=yes
+setup
+do_test "legacy"
+
+printf "\nTests passed: %3d\n" ${nsuccess}
+printf "Tests failed: %3d\n" ${nfail}
+
+exit $ret