test_tunnel_bpf.sh

#!/bin/bash
# In Namespace 0 (at_ns0) using native tunnel
# Overlay IP: 10.1.1.100
# local 192.16.1.100 remote 192.16.1.200
# veth0 IP: 172.16.1.100, tunnel dev <type>00

# Out of Namespace using BPF set/get on lwtunnel
# Overlay IP: 10.1.1.200
# local 172.16.1.200 remote 172.16.1.100
# veth1 IP: 172.16.1.200, tunnel dev <type>11

set -e

function config_device {
	ip netns add at_ns0
	ip link add veth0 type veth peer name veth1
	ip link set veth0 netns at_ns0
	ip netns exec at_ns0 ip addr add 172.16.1.100/24 dev veth0
	ip netns exec at_ns0 ip link set dev veth0 up
	ip link set dev veth1 up
	ip addr add dev veth1 172.16.1.200/24
}

function add_gre_tunnel {
	# in namespace
	ip netns exec at_ns0 \
		ip link add dev $DEV_NS type $TYPE key 2 local 172.16.1.100 remote 172.16.1.200
	ip netns exec at_ns0 ip link set dev $DEV_NS up
	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24

	# out of namespace
	ip link add dev $DEV type $TYPE key 2 external
	ip link set dev $DEV up
	ip addr add dev $DEV 10.1.1.200/24
}

function add_vxlan_tunnel {
	# Set static ARP entry here because iptables set-mark works
	# on L3 packet, as a result not applying to ARP packets,
	# causing errors at get_tunnel_{key/opt}.

	# in namespace
	ip netns exec at_ns0 \
		ip link add dev $DEV_NS type $TYPE id 2 dstport 4789 gbp remote 172.16.1.200
	ip netns exec at_ns0 ip link set dev $DEV_NS address 52:54:00:d9:01:00 up
	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
	ip netns exec at_ns0 arp -s 10.1.1.200 52:54:00:d9:02:00
	ip netns exec at_ns0 iptables -A OUTPUT -j MARK --set-mark 0x800FF

	# out of namespace
	ip link add dev $DEV type $TYPE external gbp dstport 4789
	ip link set dev $DEV address 52:54:00:d9:02:00 up
	ip addr add dev $DEV 10.1.1.200/24
	arp -s 10.1.1.100 52:54:00:d9:01:00
}

function add_geneve_tunnel {
	# in namespace
	ip netns exec at_ns0 \
		ip link add dev $DEV_NS type $TYPE id 2 dstport 6081 remote 172.16.1.200
	ip netns exec at_ns0 ip link set dev $DEV_NS up
	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24

	# out of namespace
	ip link add dev $DEV type $TYPE dstport 6081 external
	ip link set dev $DEV up
	ip addr add dev $DEV 10.1.1.200/24
}

function attach_bpf {
	DEV=$1
	SET_TUNNEL=$2
	GET_TUNNEL=$3
	tc qdisc add dev $DEV clsact
	tc filter add dev $DEV egress bpf da obj tcbpf2_kern.o sec $SET_TUNNEL
	tc filter add dev $DEV ingress bpf da obj tcbpf2_kern.o sec $GET_TUNNEL
}

function test_gre {
	TYPE=gretap
	DEV_NS=gretap00
	DEV=gretap11
	config_device
	add_gre_tunnel
	attach_bpf $DEV gre_set_tunnel gre_get_tunnel
	ping -c 1 10.1.1.100
	ip netns exec at_ns0 ping -c 1 10.1.1.200
}

function test_vxlan {
	TYPE=vxlan
	DEV_NS=vxlan00
	DEV=vxlan11
	config_device
	add_vxlan_tunnel
	attach_bpf $DEV vxlan_set_tunnel vxlan_get_tunnel
	ping -c 1 10.1.1.100
	ip netns exec at_ns0 ping -c 1 10.1.1.200
}

function test_geneve {
	TYPE=geneve
	DEV_NS=geneve00
	DEV=geneve11
	config_device
	add_geneve_tunnel
	attach_bpf $DEV geneve_set_tunnel geneve_get_tunnel
	ping -c 1 10.1.1.100
	ip netns exec at_ns0 ping -c 1 10.1.1.200
}

function cleanup {
	ip netns delete at_ns0
	ip link del veth1
	ip link del $DEV
}

echo "Testing GRE tunnel..."
test_gre
cleanup
echo "Testing VXLAN tunnel..."
test_vxlan
cleanup
echo "Testing GENEVE tunnel..."
test_geneve
cleanup
echo "Success"