Introduction

etherws is an implementation of Ethernet over WebSocket tunnel based on Linux Universal TUN/TAP device driver.

Usage

For example, if you want to make virtual ethernet link for VM1 and VM2 whose hypervisor's broadcast domains were split by router R:

+------------------+            +------------------+
| Hypervisor1      |            |      Hypervisor2 |
|  +-----+         |            |         +-----+  |
|  | VM1 |         |            |         | VM2 |  |
|  +--+--+         |            |         +--+--+  |
|     | (vnet0)    |            |    (vnet0) |     |
|  +--+--+         |            |         +--+--+  |
|  | br0 |         |            |         | br0 |  |
|  +--+--+         |            |         +--+--+  |
|     |            |            |            |     |
| (ethws0)  (eth0) |            | (eth0)  (ethws0) |
+----||--------+---+            +----+-------||----+
     ||        |        +---+        |       ||
     ||   -----+--------| R |--------+-----  ||
     ||                 +---+                ||
     ||                                      ||
     ``======================================''
          (Ethernet over WebSocket tunnel)

then you can type following commands.

on Hypervisor1:

# etherws server
# brctl addbr br0
# brctl addif br0 vnet0
# brctl addif br0 ethws0
# ifconfig br0 up

on Hypervisor2:

# etherws client --uri ws://<Hypervisor1's IP address>/
# brctl addbr br0
# brctl addif br0 vnet0
# brctl addif br0 ethws0
# ifconfig br0 up

If connection through this tunnel is unstable, then you may fix it by changing VM's MTU to under 1500.

Also etherws supports SSL/TLS connection (but client does not validate server certificates and server does not authenticate client yet), so if you want to encrypt this tunnel, then you can use following options.

on Hypervisor1 (options keyfile and certfile were specified):

# etherws server --keyfile ssl.key --certfile ssl.crt

on Hypervisor2 (option uri's scheme was changed to wss):

# etherws client --uri wss://<Hypervisor1's IP address>/

History

0.2 (2012-05-16 JST)

• SSL/TLS connection support

0.1 (2012-05-15 JST)

• First release