name : srv6_end_dt4_l3vpn_test.sh #!/bin/bash # SPDX-License-Identifier: GPL-2.0 # # author: Andrea Mayer <andrea.mayer@uniroma2.it> # This test is designed for evaluating the new SRv6 End.DT4 behavior used for # implementing IPv4 L3 VPN use cases. # # Hereafter a network diagram is shown, where two different tenants (named 100 # and 200) offer IPv4 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 # L3 VPN of tenant 100 while hs-t200-3 and hs-t200-4 are connected using the # IPv4 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 L3 VPN services leveraging the SRv6 # architecture. The key components for such VPNs are: a) SRv6 Encap behavior, # b) SRv6 End.DT4 behavior and c) VRF. # # To explain how an IPv4 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 an arp proxy. # # When the host hs-t100-1 sends an 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 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.DT4 behavior removes the outer IPv6+SRH headers and # performs the lookup on the vrf-100 table using the destination address of # the decapsulated 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 role of rt-1 # and rt-2 are swapped. # # Of course, the IPv4 L3 VPN for tenant 200 works exactly as the IPv4 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 | | # | | 10.0.0.1/24 | | | | 10.0.0.2/24 | | # | +-------------+ | | +-------------+ | # | . | | . | # +-------------------+ +-------------------+ # . . # . . # . . # +-----------------------------------+ +-----------------------------------+ # | . | | . | # | +---------------+ | | +---------------- | # | | veth-t100 | | | | veth-t100 | | # | | 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 | | # | | 10.0.0.254/24 | | | | 10.0.0.254/24 | | # | +---------------+ rt-1 netns | | rt-2 netns +---------------- | # | . | | . | # +-----------------------------------+ +-----------------------------------+ # . . # . . # . . # . . # +-------------------+ +-------------------+ # | . | | . | # | +-------------+ | | +-------------+ | # | | veth0 | | | | veth0 | | # | | 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::6004|apply SRv6 End.DT4 vrftable 100| # +-------------------------------------------------+ # |fc00:21:200::6004|apply SRv6 End.DT4 vrftable 200| # +-------------------------------------------------+ # # rt-1: VRF tenant 100 (table 100) # +---------------------------------------------------+ # |host |Action | # +---------------------------------------------------+ # |10.0.0.2 |apply seg6 encap segs fc00:12:100::6004| # +---------------------------------------------------+ # |10.0.0.0/24|forward to dev veth_t100 | # +---------------------------------------------------+ # # rt-1: VRF tenant 200 (table 200) # +---------------------------------------------------+ # |host |Action | # +---------------------------------------------------+ # |10.0.0.4 |apply seg6 encap segs fc00:12:200::6004| # +---------------------------------------------------+ # |10.0.0.0/24|forward to dev veth_t200 | # +---------------------------------------------------+ # # # rt-2: localsid table (table 90) # +-------------------------------------------------+ # |SID |Action | # +-------------------------------------------------+ # |fc00:12:100::6004|apply SRv6 End.DT4 vrftable 100| # +-------------------------------------------------+ # |fc00:12:200::6004|apply SRv6 End.DT4 vrftable 200| # +-------------------------------------------------+ # # rt-2: VRF tenant 100 (table 100) # +---------------------------------------------------+ # |host |Action | # +---------------------------------------------------+ # |10.0.0.1 |apply seg6 encap segs fc00:21:100::6004| # +---------------------------------------------------+ # |10.0.0.0/24|forward to dev veth_t100 | # +---------------------------------------------------+ # # rt-2: VRF tenant 200 (table 200) # +---------------------------------------------------+ # |host |Action | # +---------------------------------------------------+ # |10.0.0.3 |apply seg6 encap segs fc00:21:200::6004| # +---------------------------------------------------+ # |10.0.0.0/24|forward to dev veth_t200 | # +---------------------------------------------------+ # source lib.sh readonly LOCALSID_TABLE_ID=90 readonly IPv6_RT_NETWORK=fd00 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 netns exec ${nsname} sysctl -wq net.ipv6.conf.all.accept_dad=0 ip netns exec ${nsname} sysctl -wq net.ipv6.conf.default.accept_dad=0 ip link set veth-rt-${id} netns ${nsname} ip -netns ${nsname} link set veth-rt-${id} name veth0 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} # 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 ${IPv4_HS_NETWORK}.${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 # 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 ${IPv4_HS_NETWORK}.254/24 dev ${rtveth} ip -netns ${rtname} link set ${rtveth} up 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_${rtdst}} local vpn_sid=${VPN_LOCATOR_SERVICE}:${hssrc}${hsdst}:${tid}::6004 # set the encap route for encapsulating packets which arrive from the # host hssrc and destined to the access router rtsrc. 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.DT4 vrftable ${tid} dev vrf-${tid} # all sids for VPNs start with a common locator which is fc00::/16. # Routes for handling the SRv6 End.DT4 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 } 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 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 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_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_connectivity ${hssrc} ${hsdst} ${tid} log_test $? 0 "Hosts connectivity: hs-t${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_connectivity ${hssrc} ${hsdst} ${tidsrc} # NOTE: ping should fail log_test $? 1 "Hosts isolation: hs-t${tidsrc}-${hssrc} -X-> hs-t${tiddst}-${hsdst}" } check_and_log_hs2gw_connectivity() { local hssrc=$1 local tid=$2 check_hs_connectivity ${hssrc} 254 ${tid} log_test $? 0 "Hosts connectivity: hs-t${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 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}