Virtual Serial Port Router (vsp-router)

Create virtual serial ports, connect them to physical serial ports, and create routes between them all.

vsp-router was created to connect two terminal emulators to the same physical RS-232 serial console.

Use Cases

Multiplex two virutal serial ports to a single physical serial port.

sh vsp-router \ --virtual 0 \ --virtual 1 \ --physical 2:/dev/ttyUSB0 \ --route 0:2 \ --route 1:2 \ --route 2:0 \ --route 2:1

Multiplex two virutal serial ports to a third virtual serial port.

sh vsp-router \ --virtual 0 \ --virtual 1 \ --virtual 2 \ --route 0:2 \ --route 1:2 \ --route 2:0 \ --route 2:1

Example

In terminal A

sh cargo run -- \ --virtual 0 \ --virtual 1 \ --virtual 2 \ --route 0:2 \ --route 1:2 \ --route 2:0 \ --route 2:1

In terminal 0

sh picocom 0

In terminal 1

sh picocom 1

In terminal 2

sh picocom 2

Characters entered in terminal 0 will be sent to terminal 2 only. Characters entered in terminal 1 will be sent to terminal 2 only. Characters entered in terminal 2 will be sent to both terminals 0 and 1.

Comparison to TTYBUS

vsp-router is similar to TTYBUS.

The key differences is in how data is written. TTYBUS broadcasts data to all ports. vsp-router routes data to select ports.

The following 3-port configurations are the equivalent.

TTYBUS

sh tty_bus -d -s bus tty_fake -d -s bus 0 tty_fake -d -s bus 1 tty_fake -d -s bus 2

vsp-router

sh vsp-router \ --virtual 0 \ --virtual 1 \ --virtual 2 \ --route 0:1 \ --route 0:2 \ --route 1:0 \ --route 1:2 \ --route 2:0 \ --route 2:1

Comparison to socat

Socat establishes a bidirectional channel between two end points. Vsp-router establishes a multi-directional channel between N end points. Socat supports several different types of end points. Vsp-router supports two: virtual serial ports and physical serial ports.

Vsp-router could be combined with socat to enable interesting use cases. For example, vsp-router could be used to snoop a physical serial port and paired with socat to send the snooped data over UDP.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.