selftests: netfilter: add selftest for directional zone support

Add a script to exercise NAT port clash resolution with directional zones.

Add net namespaces that use the same IP address and connect them to a
gateway.

Gateway uses policy routing based on iif/mark and conntrack zones to
isolate the client namespaces.  In server direction, same zone with NAT
to single address is used.

Then, connect to a server from each client netns, using identical
connection id, i.e.  saddr:sport -> daddr:dport.

Expectation is for all connections to succeeed: NAT gatway is
supposed to do port reallocation for each of the (clashing) connections.

This is based on the description/use case provided in the commit message of
deedb59039 ("netfilter: nf_conntrack: add direction support for zones").

Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Florian Westphal 2021-09-08 14:28:38 +02:00 committed by Pablo Neira Ayuso
parent d2966dc77b
commit 0f1148abb2
1 changed files with 309 additions and 0 deletions

View File

@ -0,0 +1,309 @@
#!/bin/bash
#
# Test connection tracking zone and NAT source port reallocation support.
#
# Kselftest framework requirement - SKIP code is 4.
ksft_skip=4
# Don't increase too much, 2000 clients should work
# just fine but script can then take several minutes with
# KASAN/debug builds.
maxclients=100
have_iperf=1
ret=0
# client1---.
# veth1-.
# |
# NAT Gateway --veth0--> Server
# | |
# veth2-' |
# client2---' |
# .... |
# clientX----vethX---'
# All clients share identical IP address.
# NAT Gateway uses policy routing and conntrack zones to isolate client
# namespaces. Each client connects to Server, each with colliding tuples:
# clientsaddr:10000 -> serveraddr:dport
# NAT Gateway is supposed to do port reallocation for each of the
# connections.
sfx=$(mktemp -u "XXXXXXXX")
gw="ns-gw-$sfx"
cl1="ns-cl1-$sfx"
cl2="ns-cl2-$sfx"
srv="ns-srv-$sfx"
v4gc1=$(sysctl -n net.ipv4.neigh.default.gc_thresh1 2>/dev/null)
v4gc2=$(sysctl -n net.ipv4.neigh.default.gc_thresh2 2>/dev/null)
v4gc3=$(sysctl -n net.ipv4.neigh.default.gc_thresh3 2>/dev/null)
v6gc1=$(sysctl -n net.ipv6.neigh.default.gc_thresh1 2>/dev/null)
v6gc2=$(sysctl -n net.ipv6.neigh.default.gc_thresh2 2>/dev/null)
v6gc3=$(sysctl -n net.ipv6.neigh.default.gc_thresh3 2>/dev/null)
cleanup()
{
ip netns del $gw
ip netns del $srv
for i in $(seq 1 $maxclients); do
ip netns del ns-cl$i-$sfx 2>/dev/null
done
sysctl -q net.ipv4.neigh.default.gc_thresh1=$v4gc1 2>/dev/null
sysctl -q net.ipv4.neigh.default.gc_thresh2=$v4gc2 2>/dev/null
sysctl -q net.ipv4.neigh.default.gc_thresh3=$v4gc3 2>/dev/null
sysctl -q net.ipv6.neigh.default.gc_thresh1=$v6gc1 2>/dev/null
sysctl -q net.ipv6.neigh.default.gc_thresh2=$v6gc2 2>/dev/null
sysctl -q net.ipv6.neigh.default.gc_thresh3=$v6gc3 2>/dev/null
}
nft --version > /dev/null 2>&1
if [ $? -ne 0 ];then
echo "SKIP: Could not run test without nft tool"
exit $ksft_skip
fi
ip -Version > /dev/null 2>&1
if [ $? -ne 0 ];then
echo "SKIP: Could not run test without ip tool"
exit $ksft_skip
fi
conntrack -V > /dev/null 2>&1
if [ $? -ne 0 ];then
echo "SKIP: Could not run test without conntrack tool"
exit $ksft_skip
fi
iperf3 -v >/dev/null 2>&1
if [ $? -ne 0 ];then
have_iperf=0
fi
ip netns add "$gw"
if [ $? -ne 0 ];then
echo "SKIP: Could not create net namespace $gw"
exit $ksft_skip
fi
ip -net "$gw" link set lo up
trap cleanup EXIT
ip netns add "$srv"
if [ $? -ne 0 ];then
echo "SKIP: Could not create server netns $srv"
exit $ksft_skip
fi
ip link add veth0 netns "$gw" type veth peer name eth0 netns "$srv"
ip -net "$gw" link set veth0 up
ip -net "$srv" link set lo up
ip -net "$srv" link set eth0 up
sysctl -q net.ipv6.neigh.default.gc_thresh1=512 2>/dev/null
sysctl -q net.ipv6.neigh.default.gc_thresh2=1024 2>/dev/null
sysctl -q net.ipv6.neigh.default.gc_thresh3=4096 2>/dev/null
sysctl -q net.ipv4.neigh.default.gc_thresh1=512 2>/dev/null
sysctl -q net.ipv4.neigh.default.gc_thresh2=1024 2>/dev/null
sysctl -q net.ipv4.neigh.default.gc_thresh3=4096 2>/dev/null
for i in $(seq 1 $maxclients);do
cl="ns-cl$i-$sfx"
ip netns add "$cl"
if [ $? -ne 0 ];then
echo "SKIP: Could not create client netns $cl"
exit $ksft_skip
fi
ip link add veth$i netns "$gw" type veth peer name eth0 netns "$cl" > /dev/null 2>&1
if [ $? -ne 0 ];then
echo "SKIP: No virtual ethernet pair device support in kernel"
exit $ksft_skip
fi
done
for i in $(seq 1 $maxclients);do
cl="ns-cl$i-$sfx"
echo netns exec "$cl" ip link set lo up
echo netns exec "$cl" ip link set eth0 up
echo netns exec "$cl" sysctl -q net.ipv4.tcp_syn_retries=2
echo netns exec "$gw" ip link set veth$i up
echo netns exec "$gw" sysctl -q net.ipv4.conf.veth$i.arp_ignore=2
echo netns exec "$gw" sysctl -q net.ipv4.conf.veth$i.rp_filter=0
# clients have same IP addresses.
echo netns exec "$cl" ip addr add 10.1.0.3/24 dev eth0
echo netns exec "$cl" ip addr add dead:1::3/64 dev eth0
echo netns exec "$cl" ip route add default via 10.1.0.2 dev eth0
echo netns exec "$cl" ip route add default via dead:1::2 dev eth0
# NB: same addresses on client-facing interfaces.
echo netns exec "$gw" ip addr add 10.1.0.2/24 dev veth$i
echo netns exec "$gw" ip addr add dead:1::2/64 dev veth$i
# gw: policy routing
echo netns exec "$gw" ip route add 10.1.0.0/24 dev veth$i table $((1000+i))
echo netns exec "$gw" ip route add dead:1::0/64 dev veth$i table $((1000+i))
echo netns exec "$gw" ip route add 10.3.0.0/24 dev veth0 table $((1000+i))
echo netns exec "$gw" ip route add dead:3::0/64 dev veth0 table $((1000+i))
echo netns exec "$gw" ip rule add fwmark $i lookup $((1000+i))
done | ip -batch /dev/stdin
ip -net "$gw" addr add 10.3.0.1/24 dev veth0
ip -net "$gw" addr add dead:3::1/64 dev veth0
ip -net "$srv" addr add 10.3.0.99/24 dev eth0
ip -net "$srv" addr add dead:3::99/64 dev eth0
ip netns exec $gw nft -f /dev/stdin<<EOF
table inet raw {
map iiftomark {
type ifname : mark
}
map iiftozone {
typeof iifname : ct zone
}
set inicmp {
flags dynamic
type ipv4_addr . ifname . ipv4_addr
}
set inflows {
flags dynamic
type ipv4_addr . inet_service . ifname . ipv4_addr . inet_service
}
set inflows6 {
flags dynamic
type ipv6_addr . inet_service . ifname . ipv6_addr . inet_service
}
chain prerouting {
type filter hook prerouting priority -64000; policy accept;
ct original zone set meta iifname map @iiftozone
meta mark set meta iifname map @iiftomark
tcp flags & (syn|ack) == ack add @inflows { ip saddr . tcp sport . meta iifname . ip daddr . tcp dport counter }
add @inflows6 { ip6 saddr . tcp sport . meta iifname . ip6 daddr . tcp dport counter }
ip protocol icmp add @inicmp { ip saddr . meta iifname . ip daddr counter }
}
chain nat_postrouting {
type nat hook postrouting priority 0; policy accept;
ct mark set meta mark meta oifname veth0 masquerade
}
chain mangle_prerouting {
type filter hook prerouting priority -100; policy accept;
ct direction reply meta mark set ct mark
}
}
EOF
( echo add element inet raw iiftomark \{
for i in $(seq 1 $((maxclients-1))); do
echo \"veth$i\" : $i,
done
echo \"veth$maxclients\" : $maxclients \}
echo add element inet raw iiftozone \{
for i in $(seq 1 $((maxclients-1))); do
echo \"veth$i\" : $i,
done
echo \"veth$maxclients\" : $maxclients \}
) | ip netns exec $gw nft -f /dev/stdin
ip netns exec "$gw" sysctl -q net.ipv4.conf.all.forwarding=1 > /dev/null
ip netns exec "$gw" sysctl -q net.ipv6.conf.all.forwarding=1 > /dev/null
ip netns exec "$gw" sysctl -q net.ipv4.conf.all.rp_filter=0 >/dev/null
# useful for debugging: allows to use 'ping' from clients to gateway.
ip netns exec "$gw" sysctl -q net.ipv4.fwmark_reflect=1 > /dev/null
ip netns exec "$gw" sysctl -q net.ipv6.fwmark_reflect=1 > /dev/null
for i in $(seq 1 $maxclients); do
cl="ns-cl$i-$sfx"
ip netns exec $cl ping -i 0.5 -q -c 3 10.3.0.99 > /dev/null 2>&1 &
if [ $? -ne 0 ]; then
echo FAIL: Ping failure from $cl 1>&2
ret=1
break
fi
done
wait
for i in $(seq 1 $maxclients); do
ip netns exec $gw nft get element inet raw inicmp "{ 10.1.0.3 . \"veth$i\" . 10.3.0.99 }" | grep -q "{ 10.1.0.3 . \"veth$i\" . 10.3.0.99 counter packets 3 bytes 252 }"
if [ $? -ne 0 ];then
ret=1
echo "FAIL: counter icmp mismatch for veth$i" 1>&2
ip netns exec $gw nft get element inet raw inicmp "{ 10.1.0.3 . \"veth$i\" . 10.3.0.99 }" 1>&2
break
fi
done
ip netns exec $gw nft get element inet raw inicmp "{ 10.3.0.99 . \"veth0\" . 10.3.0.1 }" | grep -q "{ 10.3.0.99 . \"veth0\" . 10.3.0.1 counter packets $((3 * $maxclients)) bytes $((252 * $maxclients)) }"
if [ $? -ne 0 ];then
ret=1
echo "FAIL: counter icmp mismatch for veth0: { 10.3.0.99 . \"veth0\" . 10.3.0.1 counter packets $((3 * $maxclients)) bytes $((252 * $maxclients)) }"
ip netns exec $gw nft get element inet raw inicmp "{ 10.3.99 . \"veth0\" . 10.3.0.1 }" 1>&2
fi
if [ $ret -eq 0 ]; then
echo "PASS: ping test from all $maxclients namespaces"
fi
if [ $have_iperf -eq 0 ];then
echo "SKIP: iperf3 not installed"
if [ $ret -ne 0 ];then
exit $ret
fi
exit $ksft_skip
fi
ip netns exec $srv iperf3 -s > /dev/null 2>&1 &
iperfpid=$!
sleep 1
for i in $(seq 1 $maxclients); do
if [ $ret -ne 0 ]; then
break
fi
cl="ns-cl$i-$sfx"
ip netns exec $cl iperf3 -c 10.3.0.99 --cport 10000 -n 1 > /dev/null
if [ $? -ne 0 ]; then
echo FAIL: Failure to connect for $cl 1>&2
ip netns exec $gw conntrack -S 1>&2
ret=1
fi
done
if [ $ret -eq 0 ];then
echo "PASS: iperf3 connections for all $maxclients net namespaces"
fi
kill $iperfpid
wait
for i in $(seq 1 $maxclients); do
ip netns exec $gw nft get element inet raw inflows "{ 10.1.0.3 . 10000 . \"veth$i\" . 10.3.0.99 . 5201 }" > /dev/null
if [ $? -ne 0 ];then
ret=1
echo "FAIL: can't find expected tcp entry for veth$i" 1>&2
break
fi
done
if [ $ret -eq 0 ];then
echo "PASS: Found client connection for all $maxclients net namespaces"
fi
ip netns exec $gw nft get element inet raw inflows "{ 10.3.0.99 . 5201 . \"veth0\" . 10.3.0.1 . 10000 }" > /dev/null
if [ $? -ne 0 ];then
ret=1
echo "FAIL: cannot find return entry on veth0" 1>&2
fi
exit $ret