To make the examples easier to configure docker it is required to pull strongSwan docker image. The networking is done using Linux' veth interfaces and namespaces.
First a topology:
192.168.3.2 192.168.5.2
+ loopback
| +
+----+----+ 192.168.10.2 +-----+----+
| VPP | |strongSwan|
|initiator+----------------------+responder |
+---------+ +----------+
192.168.10.1
Create veth interfaces and namespaces and configure them:
sudo ip link add gw type veth peer name swanif
sudo ip link set dev gw up
sudo ip netns add ns
sudo ip link add veth_priv type veth peer name priv
sudo ip link set dev priv up
sudo ip link set dev veth_priv up netns ns
sudo ip netns exec ns \
bash -c "
ip link set dev lo up
ip addr add 192.168.3.2/24 dev veth_priv
ip route add 192.168.5.0/24 via 192.168.3.1"
Create directory with strongswan configs that will be mounted to the docker container
mkdir /tmp/sswan
Create the ipsec.conf file in the /tmp/sswan directory with following content:
config setup strictcrlpolicy=no conn initiator mobike=no auto=add type=tunnel keyexchange=ikev2 ike=aes256gcm16-prfsha256-modp2048! esp=aes256gcm16-esn! # local: leftauth=psk leftid=@sswan.vpn.example.com leftsubnet=192.168.5.0/24 # remote: (gateway) rightid=@roadwarrior.vpp right=192.168.10.2 rightauth=psk rightsubnet=192.168.3.0/24
/tmp/sswan/ipsec.secrets
: PSK 'Vpp123'
/tmp/sswan/strongswan.conf
charon {
load_modular = yes
plugins {
include strongswan.d/charon/*.conf
}
filelog {
/tmp/charon.log {
time_format = %b %e %T
ike_name = yes
append = no
default = 2
flush_line = yes
}
}
}
include strongswan.d/*.conf
Start docker container with strongSwan:
docker run --name sswan -d --privileged --rm --net=none \ -v /tmp/sswan:/conf -v /tmp/sswan:/etc/ipsec.d philplckthun/strongswan
Finish configuration of initiator's private network:
pid=$(docker inspect --format "{{.State.Pid}}" sswan)
sudo ip link set netns $pid dev swanif
sudo nsenter -t $pid -n ip addr add 192.168.10.1/24 dev swanif
sudo nsenter -t $pid -n ip link set dev swanif up
sudo nsenter -t $pid -n ip addr add 192.168.5.2/32 dev lo
sudo nsenter -t $pid -n ip link set dev lo up
Start VPP ...
sudo /usr/bin/vpp unix { \
cli-listen /tmp/vpp.sock \
gid $(id -g) } \
api-segment { prefix vpp } \
plugins { plugin dpdk_plugin.so { disable } }
... and configure it:
create host-interface name gw set interface ip addr host-gw 192.168.10.2/24 set interface state host-gw up create host-interface name priv set interface ip addr host-priv 192.168.3.1/24 set interface state host-priv up ikev2 profile add pr1 ikev2 profile set pr1 auth shared-key-mic string Vpp123 ikev2 profile set pr1 id local fqdn roadwarrior.vpp ikev2 profile set pr1 id remote fqdn sswan.vpn.example.com ikev2 profile set pr1 traffic-selector local ip-range 192.168.3.0 - 192.168.3.255 port-range 0 - 65535 protocol 0 ikev2 profile set pr1 traffic-selector remote ip-range 192.168.5.0 - 192.168.5.255 port-range 0 - 65535 protocol 0 ikev2 profile set pr1 responder host-gw 192.168.10.1 ikev2 profile set pr1 ike-crypto-alg aes-gcm-16 256 ike-dh modp-2048 ikev2 profile set pr1 esp-crypto-alg aes-gcm-16 256 create ipip tunnel src 192.168.10.2 dst 192.168.10.1 ikev2 profile set pr1 tunnel ipip0 ip route add 192.168.5.0/24 via 192.168.10.1 ipip0 set interface unnumbered ipip0 use host-gw
Initiate the IKEv2 connection:
vpp# ikev2 initiate sa-init pr1
vpp# show ikev2 sa details
iip 192.168.10.2 ispi f717b0cbd17e27c3 rip 192.168.10.1 rspi e9b7af7fc9b13361
encr:aes-gcm-16 prf:hmac-sha2-256 dh-group:modp-2048
nonce i:eb0354613b268c6372061bbdaab13deca37c8a625b1f65c073d25df2ecfe672e
r:70e1248ac09943047064f6a2135fa2a424778ba03038ab9c4c2af8aba179ed84
SK_d 96bd4feb59be2edf1930a12a3a5d22e30195ee9f56ea203c5fb6cba5dd2bb80f
SK_e i:00000000: 5b75b9d808c8467fd00a0923c06efee2a4eb1d033c57532e05f9316ed9c56fe9
00000020: c4db9114
r:00000000: 95121b63372d20b83558dc3e209b9affef042816cf071c86a53543677b40c15b
00000020: f169ab67
SK_p i:fb40d1114c347ddc3228ba004d4759d58f9c1ae6f1746833f908d39444ef92b1
r:aa049828240cb242e1d5aa625cd5914dc8f8e980a74de8e06883623d19384902
identifier (i) id-type fqdn data roadwarrior.vpp
identifier (r) id-type fqdn data sswan.vpn.example.com
child sa 0:encr:aes-gcm-16 esn:yes
spi(i) 9dffd57a spi(r) c4e0ef53
SK_e i:290c681694f130b33d511335dd257e78721635b7e8aa87930dd77bb1d6dd3f42
r:0a09fa18cf1cf65c6324df02b46dcc998b84e5397cf911b63e0c096053946c2e
traffic selectors (i):0 type 7 protocol_id 0 addr 192.168.3.0 - 192.168.3.255 port 0 - 65535
traffic selectors (r):0 type 7 protocol_id 0 addr 192.168.5.0 - 192.168.5.255 port 0 - 65535
Now we can generate some traffic between responder's and initiator's private networks and see it works.
$ sudo ip netns exec ns ping 192.168.5.2 PING 192.168.5.2 (192.168.5.2) 56(84) bytes of data. 64 bytes from 192.168.5.2: icmp_seq=1 ttl=63 time=0.450 ms 64 bytes from 192.168.5.2: icmp_seq=2 ttl=63 time=0.630 ms