#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
#
# author: Andrea Mayer <[email protected]>
# author: Paolo Lungaroni <[email protected]>
# This test is designed for evaluating the new SRv6 End.DT46 Behavior used for
# implementing IPv4/IPv6 L3 VPN use cases.
#
# The current SRv6 code in the Linux kernel only implements SRv6 End.DT4 and
# End.DT6 Behaviors which can be used respectively to support IPv4-in-IPv6 and
# IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a
# single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic.
# The SRv6 End.DT46 Behavior implementation is meant to support the
# decapsulation of IPv4 and IPv6 traffic coming from a single SRv6 tunnel.
# Therefore, the SRv6 End.DT46 Behavior in the Linux kernel greatly simplifies
# the setup and operations of SRv6 VPNs.
#
# Hereafter a network diagram is shown, where two different tenants (named 100
# and 200) offer IPv4/IPv6 L3 VPN services allowing hosts to communicate with
# each other across an IPv6 network.
#
# Only hosts belonging to the same tenant (and to the same VPN) can communicate
# with each other. Instead, the communication among hosts of different tenants
# is forbidden.
# In other words, hosts hs-t100-1 and hs-t100-2 are connected through the
# IPv4/IPv6 L3 VPN of tenant 100 while hs-t200-3 and hs-t200-4 are connected
# using the IPv4/IPv6 L3 VPN of tenant 200. Cross connection between tenant 100
# and tenant 200 is forbidden and thus, for example, hs-t100-1 cannot reach
# hs-t200-3 and vice versa.
#
# Routers rt-1 and rt-2 implement IPv4/IPv6 L3 VPN services leveraging the SRv6
# architecture. The key components for such VPNs are: a) SRv6 Encap behavior,
# b) SRv6 End.DT46 Behavior and c) VRF.
#
# To explain how an IPv4/IPv6 L3 VPN based on SRv6 works, let us briefly
# consider an example where, within the same domain of tenant 100, the host
# hs-t100-1 pings the host hs-t100-2.
#
# First of all, L2 reachability of the host hs-t100-2 is taken into account by
# the router rt-1 which acts as a arp/ndp proxy.
#
# When the host hs-t100-1 sends an IPv6 or IPv4 packet destined to hs-t100-2,
# the router rt-1 receives the packet on the internal veth-t100 interface. Such
# interface is enslaved to the VRF vrf-100 whose associated table contains the
# SRv6 Encap route for encapsulating any IPv6 or IPv4 packet in a IPv6 plus the
# Segment Routing Header (SRH) packet. This packet is sent through the (IPv6)
# core network up to the router rt-2 that receives it on veth0 interface.
#
# The rt-2 router uses the 'localsid' routing table to process incoming
# IPv6+SRH packets which belong to the VPN of the tenant 100. For each of these
# packets, the SRv6 End.DT46 Behavior removes the outer IPv6+SRH headers and
# performs the lookup on the vrf-100 table using the destination address of
# the decapsulated IPv6 or IPv4 packet. Afterwards, the packet is sent to the
# host hs-t100-2 through the veth-t100 interface.
#
# The ping response follows the same processing but this time the roles of rt-1
# and rt-2 are swapped.
#
# Of course, the IPv4/IPv6 L3 VPN for tenant 200 works exactly as the IPv4/IPv6
# L3 VPN for tenant 100. In this case, only hosts hs-t200-3 and hs-t200-4 are
# able to connect with each other.
#
#
# +-------------------+ +-------------------+
# | | | |
# | hs-t100-1 netns | | hs-t100-2 netns |
# | | | |
# | +-------------+ | | +-------------+ |
# | | veth0 | | | | veth0 | |
# | | cafe::1/64 | | | | cafe::2/64 | |
# | | 10.0.0.1/24 | | | | 10.0.0.2/24 | |
# | +-------------+ | | +-------------+ |
# | . | | . |
# +-------------------+ +-------------------+
# . .
# . .
# . .
# +-----------------------------------+ +-----------------------------------+
# | . | | . |
# | +---------------+ | | +---------------- |
# | | veth-t100 | | | | veth-t100 | |
# | | cafe::254/64 | | | | cafe::254/64 | |
# | | 10.0.0.254/24 | +----------+ | | +----------+ | 10.0.0.254/24 | |
# | +-------+-------+ | localsid | | | | localsid | +-------+-------- |
# | | | table | | | | table | | |
# | +----+----+ +----------+ | | +----------+ +----+----+ |
# | | vrf-100 | | | | vrf-100 | |
# | +---------+ +------------+ | | +------------+ +---------+ |
# | | veth0 | | | | veth0 | |
# | | fd00::1/64 |.|...|.| fd00::2/64 | |
# | +---------+ +------------+ | | +------------+ +---------+ |
# | | vrf-200 | | | | vrf-200 | |
# | +----+----+ | | +----+----+ |
# | | | | | |
# | +-------+-------+ | | +-------+-------- |
# | | veth-t200 | | | | veth-t200 | |
# | | cafe::254/64 | | | | cafe::254/64 | |
# | | 10.0.0.254/24 | | | | 10.0.0.254/24 | |
# | +---------------+ rt-1 netns | | rt-2 netns +---------------- |
# | . | | . |
# +-----------------------------------+ +-----------------------------------+
# . .
# . .
# . .
# . .
# +-------------------+ +-------------------+
# | . | | . |
# | +-------------+ | | +-------------+ |
# | | veth0 | | | | veth0 | |
# | | cafe::3/64 | | | | cafe::4/64 | |
# | | 10.0.0.3/24 | | | | 10.0.0.4/24 | |
# | +-------------+ | | +-------------+ |
# | | | |
# | hs-t200-3 netns | | hs-t200-4 netns |
# | | | |
# +-------------------+ +-------------------+
#
#
# ~~~~~~~~~~~~~~~~~~~~~~~~~
# | Network configuration |
# ~~~~~~~~~~~~~~~~~~~~~~~~~
#
# rt-1: localsid table (table 90)
# +--------------------------------------------------+
# |SID |Action |
# +--------------------------------------------------+
# |fc00:21:100::6046|apply SRv6 End.DT46 vrftable 100|
# +--------------------------------------------------+
# |fc00:21:200::6046|apply SRv6 End.DT46 vrftable 200|
# +--------------------------------------------------+
#
# rt-1: VRF tenant 100 (table 100)
# +---------------------------------------------------+
# |host |Action |
# +---------------------------------------------------+
# |cafe::2 |apply seg6 encap segs fc00:12:100::6046|
# +---------------------------------------------------+
# |cafe::/64 |forward to dev veth-t100 |
# +---------------------------------------------------+
# |10.0.0.2 |apply seg6 encap segs fc00:12:100::6046|
# +---------------------------------------------------+
# |10.0.0.0/24|forward to dev veth-t100 |
# +---------------------------------------------------+
#
# rt-1: VRF tenant 200 (table 200)
# +---------------------------------------------------+
# |host |Action |
# +---------------------------------------------------+
# |cafe::4 |apply seg6 encap segs fc00:12:200::6046|
# +---------------------------------------------------+
# |cafe::/64 |forward to dev veth-t200 |
# +---------------------------------------------------+
# |10.0.0.4 |apply seg6 encap segs fc00:12:200::6046|
# +---------------------------------------------------+
# |10.0.0.0/24|forward to dev veth-t200 |
# +---------------------------------------------------+
#
#
# rt-2: localsid table (table 90)
# +--------------------------------------------------+
# |SID |Action |
# +--------------------------------------------------+
# |fc00:12:100::6046|apply SRv6 End.DT46 vrftable 100|
# +--------------------------------------------------+
# |fc00:12:200::6046|apply SRv6 End.DT46 vrftable 200|
# +--------------------------------------------------+
#
# rt-2: VRF tenant 100 (table 100)
# +---------------------------------------------------+
# |host |Action |
# +---------------------------------------------------+
# |cafe::1 |apply seg6 encap segs fc00:21:100::6046|
# +---------------------------------------------------+
# |cafe::/64 |forward to dev veth-t100 |
# +---------------------------------------------------+
# |10.0.0.1 |apply seg6 encap segs fc00:21:100::6046|
# +---------------------------------------------------+
# |10.0.0.0/24|forward to dev veth-t100 |
# +---------------------------------------------------+
#
# rt-2: VRF tenant 200 (table 200)
# +---------------------------------------------------+
# |host |Action |
# +---------------------------------------------------+
# |cafe::3 |apply seg6 encap segs fc00:21:200::6046|
# +---------------------------------------------------+
# |cafe::/64 |forward to dev veth-t200 |
# +---------------------------------------------------+
# |10.0.0.3 |apply seg6 encap segs fc00:21:200::6046|
# +---------------------------------------------------+
# |10.0.0.0/24|forward to dev veth-t200 |
# +---------------------------------------------------+
#
source lib.sh
readonly LOCALSID_TABLE_ID=90
readonly IPv6_RT_NETWORK=fd00
readonly IPv6_HS_NETWORK=cafe
readonly IPv4_HS_NETWORK=10.0.0
readonly VPN_LOCATOR_SERVICE=fc00
PING_TIMEOUT_SEC=4
ret=0
PAUSE_ON_FAIL=${PAUSE_ON_FAIL:=no}
log_test()
{
local rc=$1
local expected=$2
local msg="$3"
if [ ${rc} -eq ${expected} ]; then
nsuccess=$((nsuccess+1))
printf "\n TEST: %-60s [ OK ]\n" "${msg}"
else
ret=1
nfail=$((nfail+1))
printf "\n TEST: %-60s [FAIL]\n" "${msg}"
if [ "${PAUSE_ON_FAIL}" = "yes" ]; then
echo
echo "hit enter to continue, 'q' to quit"
read a
[ "$a" = "q" ] && exit 1
fi
fi
}
print_log_test_results()
{
if [ "$TESTS" != "none" ]; then
printf "\nTests passed: %3d\n" ${nsuccess}
printf "Tests failed: %3d\n" ${nfail}
fi
}
log_section()
{
echo
echo "################################################################################"
echo "TEST SECTION: $*"
echo "################################################################################"
}
cleanup()
{
ip link del veth-rt-1 2>/dev/null || true
ip link del veth-rt-2 2>/dev/null || true
cleanup_all_ns
}
# Setup the basic networking for the routers
setup_rt_networking()
{
local id=$1
eval local nsname=\${rt_${id}}
ip link set veth-rt-${id} netns ${nsname}
ip -netns ${nsname} link set veth-rt-${id} name veth0
ip netns exec ${nsname} sysctl -wq net.ipv6.conf.all.accept_dad=0
ip netns exec ${nsname} sysctl -wq net.ipv6.conf.default.accept_dad=0
ip -netns ${nsname} addr add ${IPv6_RT_NETWORK}::${id}/64 dev veth0 nodad
ip -netns ${nsname} link set veth0 up
ip -netns ${nsname} link set lo up
ip netns exec ${nsname} sysctl -wq net.ipv4.ip_forward=1
ip netns exec ${nsname} sysctl -wq net.ipv6.conf.all.forwarding=1
}
setup_hs()
{
local hid=$1
local rid=$2
local tid=$3
eval local hsname=\${hs_t${tid}_${hid}}
eval local rtname=\${rt_${rid}}
local rtveth=veth-t${tid}
# set the networking for the host
ip netns exec ${hsname} sysctl -wq net.ipv6.conf.all.accept_dad=0
ip netns exec ${hsname} sysctl -wq net.ipv6.conf.default.accept_dad=0
# disable the rp_filter otherwise the kernel gets confused about how
# to route decap ipv4 packets.
ip netns exec ${rtname} sysctl -wq net.ipv4.conf.all.rp_filter=0
ip netns exec ${rtname} sysctl -wq net.ipv4.conf.default.rp_filter=0
ip -netns ${hsname} link add veth0 type veth peer name ${rtveth}
ip -netns ${hsname} link set ${rtveth} netns ${rtname}
ip -netns ${hsname} addr add ${IPv6_HS_NETWORK}::${hid}/64 dev veth0 nodad
ip -netns ${hsname} addr add ${IPv4_HS_NETWORK}.${hid}/24 dev veth0
ip -netns ${hsname} link set veth0 up
ip -netns ${hsname} link set lo up
# configure the VRF for the tenant X on the router which is directly
# connected to the source host.
ip -netns ${rtname} link add vrf-${tid} type vrf table ${tid}
ip -netns ${rtname} link set vrf-${tid} up
ip netns exec ${rtname} sysctl -wq net.ipv6.conf.all.accept_dad=0
ip netns exec ${rtname} sysctl -wq net.ipv6.conf.default.accept_dad=0
# enslave the veth-tX interface to the vrf-X in the access router
ip -netns ${rtname} link set ${rtveth} master vrf-${tid}
ip -netns ${rtname} addr add ${IPv6_HS_NETWORK}::254/64 dev ${rtveth} nodad
ip -netns ${rtname} addr add ${IPv4_HS_NETWORK}.254/24 dev ${rtveth}
ip -netns ${rtname} link set ${rtveth} up
ip netns exec ${rtname} sysctl -wq net.ipv6.conf.${rtveth}.proxy_ndp=1
ip netns exec ${rtname} sysctl -wq net.ipv4.conf.${rtveth}.proxy_arp=1
ip netns exec ${rtname} sh -c "echo 1 > /proc/sys/net/vrf/strict_mode"
}
setup_vpn_config()
{
local hssrc=$1
local rtsrc=$2
local hsdst=$3
local rtdst=$4
local tid=$5
eval local rtsrc_name=\${rt_${rtsrc}}
eval local rtdst_name=\${rt_${rtdst}}
local rtveth=veth-t${tid}
local vpn_sid=${VPN_LOCATOR_SERVICE}:${hssrc}${hsdst}:${tid}::6046
ip -netns ${rtsrc_name} -6 neigh add proxy ${IPv6_HS_NETWORK}::${hsdst} dev ${rtveth}
# set the encap route for encapsulating packets which arrive from the
# host hssrc and destined to the access router rtsrc.
ip -netns ${rtsrc_name} -6 route add ${IPv6_HS_NETWORK}::${hsdst}/128 vrf vrf-${tid} \
encap seg6 mode encap segs ${vpn_sid} dev veth0
ip -netns ${rtsrc_name} -4 route add ${IPv4_HS_NETWORK}.${hsdst}/32 vrf vrf-${tid} \
encap seg6 mode encap segs ${vpn_sid} dev veth0
ip -netns ${rtsrc_name} -6 route add ${vpn_sid}/128 vrf vrf-${tid} \
via fd00::${rtdst} dev veth0
# set the decap route for decapsulating packets which arrive from
# the rtdst router and destined to the hsdst host.
ip -netns ${rtdst_name} -6 route add ${vpn_sid}/128 table ${LOCALSID_TABLE_ID} \
encap seg6local action End.DT46 vrftable ${tid} dev vrf-${tid}
# all sids for VPNs start with a common locator which is fc00::/16.
# Routes for handling the SRv6 End.DT46 behavior instances are grouped
# together in the 'localsid' table.
#
# NOTE: added only once
if [ -z "$(ip -netns ${rtdst_name} -6 rule show | \
grep "to ${VPN_LOCATOR_SERVICE}::/16 lookup ${LOCALSID_TABLE_ID}")" ]; then
ip -netns ${rtdst_name} -6 rule add \
to ${VPN_LOCATOR_SERVICE}::/16 \
lookup ${LOCALSID_TABLE_ID} prio 999
fi
# set default routes to unreachable for both ipv4 and ipv6
ip -netns ${rtsrc_name} -6 route add unreachable default metric 4278198272 \
vrf vrf-${tid}
ip -netns ${rtsrc_name} -4 route add unreachable default metric 4278198272 \
vrf vrf-${tid}
}
setup()
{
ip link add veth-rt-1 type veth peer name veth-rt-2
# setup the networking for router rt-1 and router rt-2
setup_ns rt_1 rt_2
setup_rt_networking 1
setup_rt_networking 2
# setup two hosts for the tenant 100.
# - host hs-1 is directly connected to the router rt-1;
# - host hs-2 is directly connected to the router rt-2.
setup_ns hs_t100_1 hs_t100_2
setup_hs 1 1 100 #args: host router tenant
setup_hs 2 2 100
# setup two hosts for the tenant 200
# - host hs-3 is directly connected to the router rt-1;
# - host hs-4 is directly connected to the router rt-2.
setup_ns hs_t200_3 hs_t200_4
setup_hs 3 1 200
setup_hs 4 2 200
# setup the IPv4/IPv6 L3 VPN which connects the host hs-t100-1 and host
# hs-t100-2 within the same tenant 100.
setup_vpn_config 1 1 2 2 100 #args: src_host src_router dst_host dst_router tenant
setup_vpn_config 2 2 1 1 100
# setup the IPv4/IPv6 L3 VPN which connects the host hs-t200-3 and host
# hs-t200-4 within the same tenant 200.
setup_vpn_config 3 1 4 2 200
setup_vpn_config 4 2 3 1 200
}
check_rt_connectivity()
{
local rtsrc=$1
local rtdst=$2
eval local nsname=\${rt_${rtsrc}}
ip netns exec ${nsname} ping -c 1 -W 1 ${IPv6_RT_NETWORK}::${rtdst} \
>/dev/null 2>&1
}
check_and_log_rt_connectivity()
{
local rtsrc=$1
local rtdst=$2
check_rt_connectivity ${rtsrc} ${rtdst}
log_test $? 0 "Routers connectivity: rt-${rtsrc} -> rt-${rtdst}"
}
check_hs_ipv6_connectivity()
{
local hssrc=$1
local hsdst=$2
local tid=$3
eval local nsname=\${hs_t${tid}_${hssrc}}
ip netns exec ${nsname} ping -c 1 -W ${PING_TIMEOUT_SEC} \
${IPv6_HS_NETWORK}::${hsdst} >/dev/null 2>&1
}
check_hs_ipv4_connectivity()
{
local hssrc=$1
local hsdst=$2
local tid=$3
eval local nsname=\${hs_t${tid}_${hssrc}}
ip netns exec ${nsname} ping -c 1 -W ${PING_TIMEOUT_SEC} \
${IPv4_HS_NETWORK}.${hsdst} >/dev/null 2>&1
}
check_and_log_hs_connectivity()
{
local hssrc=$1
local hsdst=$2
local tid=$3
check_hs_ipv6_connectivity ${hssrc} ${hsdst} ${tid}
log_test $? 0 "IPv6 Hosts connectivity: hs-t${tid}-${hssrc} -> hs-t${tid}-${hsdst} (tenant ${tid})"
check_hs_ipv4_connectivity ${hssrc} ${hsdst} ${tid}
log_test $? 0 "IPv4 Hosts connectivity: hs-t${tid}-${hssrc} -> hs-t${tid}-${hsdst} (tenant ${tid})"
}
check_and_log_hs_isolation()
{
local hssrc=$1
local tidsrc=$2
local hsdst=$3
local tiddst=$4
check_hs_ipv6_connectivity ${hssrc} ${hsdst} ${tidsrc}
# NOTE: ping should fail
log_test $? 1 "IPv6 Hosts isolation: hs-t${tidsrc}-${hssrc} -X-> hs-t${tiddst}-${hsdst}"
check_hs_ipv4_connectivity ${hssrc} ${hsdst} ${tidsrc}
# NOTE: ping should fail
log_test $? 1 "IPv4 Hosts isolation: hs-t${tidsrc}-${hssrc} -X-> hs-t${tiddst}-${hsdst}"
}
check_and_log_hs2gw_connectivity()
{
local hssrc=$1
local tid=$2
check_hs_ipv6_connectivity ${hssrc} 254 ${tid}
log_test $? 0 "IPv6 Hosts connectivity: hs-t${tid}-${hssrc} -> gw (tenant ${tid})"
check_hs_ipv4_connectivity ${hssrc} 254 ${tid}
log_test $? 0 "IPv4 Hosts connectivity: hs-t${tid}-${hssrc} -> gw (tenant ${tid})"
}
router_tests()
{
log_section "IPv6 routers connectivity test"
check_and_log_rt_connectivity 1 2
check_and_log_rt_connectivity 2 1
}
host2gateway_tests()
{
log_section "IPv4/IPv6 connectivity test among hosts and gateway"
check_and_log_hs2gw_connectivity 1 100
check_and_log_hs2gw_connectivity 2 100
check_and_log_hs2gw_connectivity 3 200
check_and_log_hs2gw_connectivity 4 200
}
host_vpn_tests()
{
log_section "SRv6 VPN connectivity test among hosts in the same tenant"
check_and_log_hs_connectivity 1 2 100
check_and_log_hs_connectivity 2 1 100
check_and_log_hs_connectivity 3 4 200
check_and_log_hs_connectivity 4 3 200
}
host_vpn_isolation_tests()
{
local i
local j
local k
local tmp
local l1="1 2"
local l2="3 4"
local t1=100
local t2=200
log_section "SRv6 VPN isolation test among hosts in different tentants"
for k in 0 1; do
for i in ${l1}; do
for j in ${l2}; do
check_and_log_hs_isolation ${i} ${t1} ${j} ${t2}
done
done
# let us test the reverse path
tmp="${l1}"; l1="${l2}"; l2="${tmp}"
tmp=${t1}; t1=${t2}; t2=${tmp}
done
}
if [ "$(id -u)" -ne 0 ];then
echo "SKIP: Need root privileges"
exit $ksft_skip
fi
if [ ! -x "$(command -v ip)" ]; then
echo "SKIP: Could not run test without ip tool"
exit $ksft_skip
fi
modprobe vrf &>/dev/null
if [ ! -e /proc/sys/net/vrf/strict_mode ]; then
echo "SKIP: vrf sysctl does not exist"
exit $ksft_skip
fi
cleanup &>/dev/null
setup
router_tests
host2gateway_tests
host_vpn_tests
host_vpn_isolation_tests
print_log_test_results
cleanup &>/dev/null
exit ${ret}
Codebase Browser
linux