Seastar comes with a native, sharded TCP/IP stack. Usually it is used with the DPDK environment, but there are also vhost drivers for testing in a development environment.
To enable the native network stack, pass the --network-stack native parameter to a seastar application.
To test the native stack without dpdk, install and start the libvirt daemon. This will create a bridge device named virbr0, which seastar will connect to.
Seastar's vhost driver will need a tap device to connect to. The scripts scripts/tap.sh will set up a tap device and bind it to virbr0:
$ sh ./scripts/tap.sh
Set 'tap0' nonpersistent
bridge name bridge id STP enabled interfaces
virbr0 8000.5254008be729 no tap0
virbr0-nic
virbr0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.122.1 netmask 255.255.255.0 broadcast 192.168.122.255
ether 52:54:00:8b:e7:29 txqueuelen 1000 (Ethernet)
RX packets 384938 bytes 21866184 (20.8 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 547098 bytes 2508723098 (2.3 GiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
You can now run a seastar application; for example, the http server:
$ ./build/release/apps/httpd/httpd --network-stack native
DHCP sending discover
DHCP Got offer for 192.168.122.18
DHCP sending request for 192.168.122.18
DHCP Got ack on request
DHCP ip: 192.168.122.18
DHCP nm: 255.255.255.0
DHCP gw: 192.168.122.1
Seastar HTTP server listening on port 10000 ...
You can now ping the IP address shown (192.168.122.18) or connect to it:
$ ping 192.168.122.18
PING 192.168.122.18 (192.168.122.18) 56(84) bytes of data.
64 bytes from 192.168.122.18: icmp_seq=1 ttl=64 time=0.160 ms
64 bytes from 192.168.122.18: icmp_seq=2 ttl=64 time=0.110 ms
64 bytes from 192.168.122.18: icmp_seq=3 ttl=64 time=0.116 ms
64 bytes from 192.168.122.18: icmp_seq=4 ttl=64 time=0.112 ms
64 bytes from 192.168.122.18: icmp_seq=5 ttl=64 time=0.093 ms
64 bytes from 192.168.122.18: icmp_seq=6 ttl=64 time=0.108 ms
^C
--- 192.168.122.18 ping statistics ---
6 packets transmitted, 6 received, 0% packet loss, time 4999ms
rtt min/avg/max/mdev = 0.093/0.116/0.160/0.023 ms
$ curl http://192.168.122.18:10000/
"hello"