selftests: add selftest for the SRv6 End.DT6 (VRF) behavior
authorAndrea Mayer <andrea.mayer@uniroma2.it>
Wed, 2 Dec 2020 13:05:17 +0000 (14:05 +0100)
committerJakub Kicinski <kuba@kernel.org>
Fri, 4 Dec 2020 21:30:51 +0000 (13:30 -0800)
this selftest is designed for evaluating the new SRv6 End.DT6 (VRF) behavior
used, in this example, for implementing IPv6 L3 VPN use cases.

Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Signed-off-by: Paolo Lungaroni <paolo.lungaroni@cnit.it>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
tools/testing/selftests/net/srv6_end_dt6_l3vpn_test.sh [new file with mode: 0755]

diff --git a/tools/testing/selftests/net/srv6_end_dt6_l3vpn_test.sh b/tools/testing/selftests/net/srv6_end_dt6_l3vpn_test.sh
new file mode 100755 (executable)
index 0000000..68708f5
--- /dev/null
@@ -0,0 +1,502 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# author: Andrea Mayer <andrea.mayer@uniroma2.it>
+# author: Paolo Lungaroni <paolo.lungaroni@cnit.it>
+
+# This test is designed for evaluating the new SRv6 End.DT6 behavior used for
+# implementing IPv6 L3 VPN use cases.
+#
+# Hereafter a network diagram is shown, where two different tenants (named 100
+# and 200) offer 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 IPv6
+# L3 VPN of tenant 100 while hs-t200-3 and hs-t200-4 are connected using the
+# 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 IPv6 L3 VPN services leveraging the SRv6
+# architecture. The key components for such VPNs are: a) SRv6 Encap behavior,
+# b) SRv6 End.DT6 behavior and c) VRF.
+#
+# To explain how an 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 ndp proxy.
+#
+# When the host hs-t100-1 sends an IPv6 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 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.DT6 behavior removes the outer IPv6+SRH headers and
+# performs the lookup on the vrf-100 table using the destination address of
+# the decapsulated IPv6 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 IPv6 L3 VPN for tenant 200 works exactly as the 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 |  |
+# |  +-------------+  |                                   |  +-------------+  |
+# |        .          |                                   |         .         |
+# +-------------------+                                   +-------------------+
+#          .                                                        .
+#          .                                                        .
+#          .                                                        .
+# +-----------------------------------+   +-----------------------------------+
+# |        .                          |   |                         .         |
+# | +---------------+                 |   |                 +---------------- |
+# | |   veth-t100   |                 |   |                 |   veth-t100   | |
+# | |  cafe::254/64 |    +----------+ |   | +----------+    |  cafe::254/64 | |
+# | +-------+-------+    | 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 | |
+# | +---------------+      rt-1 netns |   | rt-2 netns      +---------------- |
+# |        .                          |   |                          .        |
+# +-----------------------------------+   +-----------------------------------+
+#          .                                                         .
+#          .                                                         .
+#          .                                                         .
+#          .                                                         .
+# +-------------------+                                   +-------------------+
+# |        .          |                                   |          .        |
+# |  +-------------+  |                                   |  +-------------+  |
+# |  |    veth0    |  |                                   |  |    veth0    |  |
+# |  |  cafe::3/64 |  |                                   |  |  cafe::4/64 |  |
+# |  +-------------+  |                                   |  +-------------+  |
+# |                   |                                   |                   |
+# |  hs-t200-3 netns  |                                   |  hs-t200-4 netns  |
+# |                   |                                   |                   |
+# +-------------------+                                   +-------------------+
+#
+#
+# ~~~~~~~~~~~~~~~~~~~~~~~~~
+# | Network configuration |
+# ~~~~~~~~~~~~~~~~~~~~~~~~~
+#
+# rt-1: localsid table (table 90)
+# +-------------------------------------------------+
+# |SID              |Action                         |
+# +-------------------------------------------------+
+# |fc00:21:100::6006|apply SRv6 End.DT6 vrftable 100|
+# +-------------------------------------------------+
+# |fc00:21:200::6006|apply SRv6 End.DT6 vrftable 200|
+# +-------------------------------------------------+
+#
+# rt-1: VRF tenant 100 (table 100)
+# +---------------------------------------------------+
+# |host       |Action                                 |
+# +---------------------------------------------------+
+# |cafe::2    |apply seg6 encap segs fc00:12:100::6006|
+# +---------------------------------------------------+
+# |cafe::/64  |forward to dev veth_t100               |
+# +---------------------------------------------------+
+#
+# rt-1: VRF tenant 200 (table 200)
+# +---------------------------------------------------+
+# |host       |Action                                 |
+# +---------------------------------------------------+
+# |cafe::4    |apply seg6 encap segs fc00:12:200::6006|
+# +---------------------------------------------------+
+# |cafe::/64  |forward to dev veth_t200               |
+# +---------------------------------------------------+
+#
+#
+# rt-2: localsid table (table 90)
+# +-------------------------------------------------+
+# |SID              |Action                         |
+# +-------------------------------------------------+
+# |fc00:12:100::6006|apply SRv6 End.DT6 vrftable 100|
+# +-------------------------------------------------+
+# |fc00:12:200::6006|apply SRv6 End.DT6 vrftable 200|
+# +-------------------------------------------------+
+#
+# rt-2: VRF tenant 100 (table 100)
+# +---------------------------------------------------+
+# |host       |Action                                 |
+# +---------------------------------------------------+
+# |cafe::1    |apply seg6 encap segs fc00:21:100::6006|
+# +---------------------------------------------------+
+# |cafe::/64  |forward to dev veth_t100               |
+# +---------------------------------------------------+
+#
+# rt-2: VRF tenant 200 (table 200)
+# +---------------------------------------------------+
+# |host       |Action                                 |
+# +---------------------------------------------------+
+# |cafe::3    |apply seg6 encap segs fc00:21:200::6006|
+# +---------------------------------------------------+
+# |cafe::/64  |forward to dev veth_t200               |
+# +---------------------------------------------------+
+#
+
+readonly LOCALSID_TABLE_ID=90
+readonly IPv6_RT_NETWORK=fd00
+readonly IPv6_HS_NETWORK=cafe
+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
+
+       # destroy routers rt-* and hosts hs-*
+       for ns in $(ip netns show | grep -E 'rt-*|hs-*'); do
+               ip netns del ${ns} || true
+       done
+}
+
+# Setup the basic networking for the routers
+setup_rt_networking()
+{
+       local rt=$1
+       local nsname=rt-${rt}
+
+       ip netns add ${nsname}
+       ip link set veth-rt-${rt} netns ${nsname}
+       ip -netns ${nsname} link set veth-rt-${rt} 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 ${IPv6_RT_NETWORK}::${rt}/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.ipv6.conf.all.forwarding=1
+}
+
+setup_hs()
+{
+       local hs=$1
+       local rt=$2
+       local tid=$3
+       local hsname=hs-t${tid}-${hs}
+       local rtname=rt-${rt}
+       local rtveth=veth-t${tid}
+
+       # set the networking for the host
+       ip netns add ${hsname}
+
+       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
+
+       ip -netns ${hsname} link add veth0 type veth peer name ${rtveth}
+       ip -netns ${hsname} link set ${rtveth} netns ${rtname}
+       ip -netns ${hsname} addr add ${IPv6_HS_NETWORK}::${hs}/64 dev veth0 nodad
+       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} link set ${rtveth} up
+
+       ip netns exec ${rtname} sysctl -wq net.ipv6.conf.${rtveth}.proxy_ndp=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=$5
+
+       local hssrc_name=hs-t${tid}-${hssrc}
+       local hsdst_name=hs-t${tid}-${hsdst}
+       local rtsrc_name=rt-${rtsrc}
+       local rtdst_name=rt-${rtdst}
+       local rtveth=veth-t${tid}
+       local vpn_sid=${VPN_LOCATOR_SERVICE}:${hssrc}${hsdst}:${tid}::6006
+
+       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} -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.DT6 vrftable ${tid} dev vrf-${tid}
+
+       # all sids for VPNs start with a common locator which is fc00::/16.
+       # Routes for handling the SRv6 End.DT6 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_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_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_hs 3 1 200
+       setup_hs 4 2 200
+
+       # setup the 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 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=$2
+
+       ip netns exec rt-${rtsrc} 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=$3
+
+       ip netns exec hs-t${tid}-${hssrc} ping -c 1 -W ${PING_TIMEOUT_SEC} \
+               ${IPv6_HS_NETWORK}::${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 "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 0
+fi
+
+if [ ! -x "$(command -v ip)" ]; then
+       echo "SKIP: Could not run test without ip tool"
+       exit 0
+fi
+
+modprobe vrf &>/dev/null
+if [ ! -e /proc/sys/net/vrf/strict_mode ]; then
+        echo "SKIP: vrf sysctl does not exist"
+        exit 0
+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}