selftests: add selftest for the SRv6 End.DX4 behavior with netfilter

this selftest is designed for evaluating the SRv6 End.DX4 behavior
used with netfilter(rpfilter), in this example, for implementing
IPv4 L3 VPN use cases.

Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Jianguo Wu 2024-06-13 17:42:48 +08:00 committed by Pablo Neira Ayuso
parent a2225e0250
commit 72e50ef994
3 changed files with 337 additions and 0 deletions

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@ -43,6 +43,7 @@ TEST_PROGS += srv6_hl2encap_red_l2vpn_test.sh
TEST_PROGS += srv6_end_next_csid_l3vpn_test.sh
TEST_PROGS += srv6_end_x_next_csid_l3vpn_test.sh
TEST_PROGS += srv6_end_flavors_test.sh
TEST_PROGS += srv6_end_dx4_netfilter_test.sh
TEST_PROGS += vrf_strict_mode_test.sh
TEST_PROGS += arp_ndisc_evict_nocarrier.sh
TEST_PROGS += ndisc_unsolicited_na_test.sh

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@ -101,3 +101,4 @@ CONFIG_NETFILTER_XT_MATCH_POLICY=m
CONFIG_CRYPTO_ARIA=y
CONFIG_XFRM_INTERFACE=m
CONFIG_XFRM_USER=m
CONFIG_IP_NF_MATCH_RPFILTER=m

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@ -0,0 +1,335 @@
#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
#
# author: Jianguo Wu <wujianguo@chinatelecom.cn>
#
# Mostly copied from tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh.
#
# This script is designed for testing the support of netfilter hooks for
# SRv6 End.DX4 behavior.
#
# Hereafter a network diagram is shown, where one tenants (named 100) offer
# IPv4 L3 VPN services allowing hosts to communicate with each other across
# an IPv6 network.
#
# 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.DX4 behavior.
#
# 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-1 pings
# the host hs-2.
#
# First of all, L2 reachability of the host hs-2 is taken into account by
# the router rt-1 which acts as an arp proxy.
#
# When the host hs-1 sends an IPv4 packet destined to hs-2, the router rt-1
# receives the packet on the internal veth-t100 interface, rt-1 contains the
# SRv6 Encap route for encapsulating the 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.DX4 behavior removes the outer IPv6+SRH headers and
# routs the packet to the specified nexthop. Afterwards, the packet is sent to
# the host hs-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.
#
# And when net.netfilter.nf_hooks_lwtunnel is set to 1 in rt-1 or rt-2, and a
# rpfilter iptables rule is added, SRv6 packets will go through netfilter PREROUTING
# hooks.
#
#
# +-------------------+ +-------------------+
# | | | |
# | hs-1 netns | | hs-2 netns |
# | | | |
# | +-------------+ | | +-------------+ |
# | | veth0 | | | | veth0 | |
# | | 10.0.0.1/24 | | | | 10.0.0.2/24 | |
# | +-------------+ | | +-------------+ |
# | . | | . |
# +-------------------+ +-------------------+
# . .
# . .
# . .
# +-----------------------------------+ +-----------------------------------+
# | . | | . |
# | +---------------+ | | +---------------- |
# | | veth-t100 | | | | veth-t100 | |
# | | 10.0.0.11/24 | +----------+ | | +----------+ | 10.0.0.22/24 | |
# | +-------+-------+ | route | | | | route | +-------+-------- |
# | | table | | | | table | |
# | +----------+ | | +----------+ |
# | +--------------+ | | +--------------+ |
# | | veth0 | | | | veth0 | |
# | | 2001:11::1/64 |.|...|.| 2001:11::2/64 | |
# | +--------------+ | | +--------------+ |
# | | | |
# | rt-1 netns | | rt-2 netns |
# | | | |
# +-----------------------------------+ +-----------------------------------+
#
# ~~~~~~~~~~~~~~~~~~~~~~~~~
# | Network configuration |
# ~~~~~~~~~~~~~~~~~~~~~~~~~
#
# rt-1: localsid table
# +----------------------------------------------------------------+
# |SID |Action |
# +----------------------------------------------------------------+
# |fc00:21:100::6004|apply SRv6 End.DX4 nh4 10.0.0.1 dev veth-t100 |
# +----------------------------------------------------------------+
#
# rt-1: route table
# +---------------------------------------------------+
# |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-2: localsid table
# +---------------------------------------------------------------+
# |SID |Action |
# +---------------------------------------------------------------+
# |fc00:12:100::6004|apply SRv6 End.DX4 nh4 10.0.0.2 dev veth-t100|
# +---------------------------------------------------------------+
#
# rt-2: route table
# +---------------------------------------------------+
# |host |Action |
# +---------------------------------------------------+
# |10.0.0.1 |apply seg6 encap segs fc00:21:100::6004|
# +---------------------------------------------------+
# |10.0.0.0/24|forward to dev veth_t100 |
# +---------------------------------------------------+
#
# Kselftest framework requirement - SKIP code is 4.
ksft_skip=4
readonly IPv6_RT_NETWORK=2001:11
readonly IPv4_HS_NETWORK=10.0.0
readonly SID_LOCATOR=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 netns exec ${nsname} sysctl -wq net.ipv6.conf.all.accept_dad=0
ip netns exec ${nsname} sysctl -wq net.ipv6.conf.default.accept_dad=0
ip link set veth-rt-${rt} netns ${nsname}
ip -netns ${nsname} link set veth-rt-${rt} name veth0
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.ipv4.ip_forward=1
ip netns exec ${nsname} sysctl -wq net.ipv6.conf.all.forwarding=1
}
setup_rt_netfilter()
{
local rt=$1
local nsname=rt-${rt}
ip netns exec ${nsname} sysctl -wq net.netfilter.nf_hooks_lwtunnel=1
ip netns exec ${nsname} iptables -t raw -A PREROUTING -m rpfilter --invert -j DROP
}
setup_hs()
{
local hs=$1
local rt=$2
local tid=$3
local hsname=hs-${hs}
local rtname=rt-${rt}
local rtveth=veth-t${tid}
# set the networking for the host
ip netns add ${hsname}
ip -netns ${hsname} link add veth0 type veth peer name ${rtveth}
ip -netns ${hsname} link set ${rtveth} netns ${rtname}
ip -netns ${hsname} addr add ${IPv4_HS_NETWORK}.${hs}/24 dev veth0
ip -netns ${hsname} link set veth0 up
ip -netns ${hsname} link set lo up
ip -netns ${rtname} addr add ${IPv4_HS_NETWORK}.${rt}${hs}/24 dev ${rtveth}
ip -netns ${rtname} link set ${rtveth} up
ip netns exec ${rtname} sysctl -wq net.ipv4.conf.${rtveth}.proxy_arp=1
}
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-${rtdst}
local vpn_sid=${SID_LOCATOR}:${hssrc}${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 \
encap seg6 mode encap segs ${vpn_sid} dev veth0
ip -netns ${rtsrc_name} -6 route add ${vpn_sid}/128 \
via 2001:11::${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 \
encap seg6local action End.DX4 nh4 ${IPv4_HS_NETWORK}.${hsdst} dev veth-t${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_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
setup_hs 2 2 100
# setup the IPv4 L3 VPN which connects the host hs-1 and host hs-2.
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
}
check_hs_connectivity()
{
local hssrc=$1
local hsdst=$2
local tid=$3
ip netns exec hs-${hssrc} 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 $? 0 "Hosts connectivity: hs-${hssrc} -> hs-${hsdst} (tenant ${tid})"
}
host_tests()
{
log_section "SRv6 VPN connectivity test among hosts in the same tenant"
check_and_log_hs_connectivity 1 2 100
check_and_log_hs_connectivity 2 1 100
}
router_netfilter_tests()
{
log_section "SRv6 VPN connectivity test with netfilter enabled in routers"
setup_rt_netfilter 1
setup_rt_netfilter 2
check_and_log_hs_connectivity 1 2 100
check_and_log_hs_connectivity 2 1 100
}
if [ "$(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
cleanup &>/dev/null
setup
host_tests
router_netfilter_tests
print_log_test_results
cleanup &>/dev/null
exit ${ret}