#serial #virtual #router #socat #ttybus

bin+lib vsp-router

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

5 releases (2 stable)

1.0.1 Aug 2, 2023
0.2.0 Oct 29, 2022
0.1.1 Sep 12, 2022
0.1.0 Sep 11, 2022

#517 in Command line utilities

MIT/Apache

24KB
352 lines

Virtual Serial Port Router (vsp-router)

Build status Crates.io

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.

asciicast

Supported Operating Systems

  • Linux: Yes, tested on Red Hat Enterprise Linux 8
  • macOS: Yes, tested on macOS Ventura 13.1
  • Windows: Yes*, tested on Windows 10

*The Windows version does not support creation of virtual serial ports. A third-party tool like com0com can be used instead.

Use Cases

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

vsp-router \
    --create 0 \
    --create 1 \
    --attach 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.

vsp-router \
    --create 0 \
    --create 1 \
    --create 2 \
    --route 0:2 \
    --route 1:2 \
    --route 2:0 \
    --route 2:1

Example

In terminal A

cargo run -- \
    --create 0 \
    --create 1 \
    --create 2 \
    --route 0:2 \
    --route 1:2 \
    --route 2:0 \
    --route 2:1

In terminal 0

picocom 0

In terminal 1

picocom 1

In terminal 2

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

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

vsp-router \
    --create 0 \
    --create 1 \
    --create 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

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.

Dependencies

~9–20MB
~255K SLoC