We introduce two callbacks used for customizing the creation/destruction of a SRv6 behavior. Such callbacks are defined in the new struct seg6_local_lwtunnel_ops and hereafter we provide a brief description of them:

- build_state(...): used for calling the custom constructor of the behavior during its initialization phase and after all the attributes have been parsed successfully;

- destroy_state(...): used for calling the custom destructor of the behavior before it is completely destroyed.

Signed-off-by: Andrea Mayer andrea.mayer@uniroma2.it --- net/ipv6/seg6_local.c | 64 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+)

diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c index 63a82e2fdea9..4b0f155d641d 100644 --- a/net/ipv6/seg6_local.c +++ b/net/ipv6/seg6_local.c @@ -33,11 +33,23 @@

struct seg6_local_lwt;

+typedef int (*slwt_build_state_t)(struct seg6_local_lwt *slwt, const void *cfg, + struct netlink_ext_ack *extack); +typedef void (*slwt_destroy_state_t)(struct seg6_local_lwt *slwt); + +/* callbacks used for customizing the creation and destruction of a behavior */ +struct seg6_local_lwtunnel_ops { + slwt_build_state_t build_state; + slwt_destroy_state_t destroy_state; +}; + struct seg6_action_desc { int action; unsigned long attrs; int (*input)(struct sk_buff *skb, struct seg6_local_lwt *slwt); int static_headroom; + + struct seg6_local_lwtunnel_ops slwt_ops; };

struct bpf_lwt_prog { @@ -1015,6 +1027,45 @@ static void destroy_attrs(struct seg6_local_lwt *slwt) __destroy_attrs(attrs, 0, SEG6_LOCAL_MAX + 1, slwt); }

+/* call the custom constructor of the behavior during its initialization phase + * and after that all its attributes have been parsed successfully. + */ +static int +seg6_local_lwtunnel_build_state(struct seg6_local_lwt *slwt, const void *cfg, + struct netlink_ext_ack *extack) +{ + slwt_build_state_t build_func; + struct seg6_action_desc *desc; + int err = 0; + + desc = slwt->desc; + if (!desc) + return -EINVAL; + + build_func = desc->slwt_ops.build_state; + if (build_func) + err = build_func(slwt, cfg, extack); + + return err; +} + +/* call the custom destructor of the behavior which is invoked before the + * tunnel is going to be destroyed. + */ +static void seg6_local_lwtunnel_destroy_state(struct seg6_local_lwt *slwt) +{ + slwt_destroy_state_t destroy_func; + struct seg6_action_desc *desc; + + desc = slwt->desc; + if (!desc) + return; + + destroy_func = desc->slwt_ops.destroy_state; + if (destroy_func) + destroy_func(slwt); +} + static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt) { struct seg6_action_param *param; @@ -1090,8 +1141,16 @@ static int seg6_local_build_state(struct net *net, struct nlattr *nla,

err = parse_nla_action(tb, slwt); if (err < 0) + /* In case of error, the parse_nla_action() takes care of + * releasing resources which have been acquired during the + * processing of attributes. + */ goto out_free;

+ err = seg6_local_lwtunnel_build_state(slwt, cfg, extack); + if (err < 0) + goto free_attrs; + newts->type = LWTUNNEL_ENCAP_SEG6_LOCAL; newts->flags = LWTUNNEL_STATE_INPUT_REDIRECT; newts->headroom = slwt->headroom; @@ -1100,6 +1159,9 @@ static int seg6_local_build_state(struct net *net, struct nlattr *nla,

return 0;

+free_attrs: + destroy_attrs(slwt); + out_free: kfree(newts); return err; @@ -1109,6 +1171,8 @@ static void seg6_local_destroy_state(struct lwtunnel_state *lwt) { struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);

+ seg6_local_lwtunnel_destroy_state(slwt); + destroy_attrs(slwt);

return;

this selftest is designed for evaluating the new SRv6 End.DT4 behavior used, in this example, for implementing IPv4 L3 VPN use cases.

Signed-off-by: Andrea Mayer andrea.mayer@uniroma2.it --- .../selftests/net/srv6_end_dt4_l3vpn_test.sh | 494 ++++++++++++++++++ 1 file changed, 494 insertions(+) create mode 100755 tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh

diff --git a/tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh b/tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh new file mode 100755 index 000000000000..a5547fed5048 --- /dev/null +++ b/tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh @@ -0,0 +1,494 @@ +#!/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 table 100| +# +----------------------------------------------+ +# |fc00:21:200::6004|apply SRv6 End.DT4 table 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 table 100| +# +----------------------------------------------+ +# |fc00:12:200::6004|apply SRv6 End.DT4 table 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 | +# +---------------------------------------------------+ +# + +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 + + # 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 ${nsname} addr add ${IPv6_RT_NETWORK}::${rt}/64 dev veth0 + 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 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 ${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 + + # 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 + + # 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 ${rtname} sysctl -wq net.ipv4.conf.${rtveth}.rp_filter=0 + + 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-${rtdst} + local vpn_sid=${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 table ${tid} dev vrf-${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_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 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=$2 + + ip netns exec rt-${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} \ + ${IPv4_HS_NETWORK}.${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 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}