How to create virtual CAN port on linux? (C++)

Question

I want to create program that would emulate CAN port for testing purposes for another big application. Program should send previously recorded data through this virtual CAN. Anyone has any experience with such thing?

I'm thinking to establish virtual COM, and send through it data packed in CAN Frames. Could it work? And how could I establish virtual COM on linux? Found this thread Virtual Serial Port for Linux but sadly I don't get how could it be implemented into source code of program (beginner linux user and programmer under linux).

Would love to read your experience and suggestions.

Answer 1

You need SocketCAN driver, that is available on modern Linux distributions like Ubuntu etc. SocketCAN provides a virtual CAN port driver:

sudo modprobe vcan
sudo ip link add dev vcan0 type vcan
sudo ip link set up vcan0

Now you can send and receive CAN frames over vcan0 device. Wikipedia article provides simple code example on how to use SocketCAN.

You'll also need can-utils for testing purposes.

You'll find more information about SocketCAN and its usage on eLinux.org

Answer 2

Tutorial

PART 1 - Creating a program to emulate CAN

---

• You can use the following bash program to create a virtual CAN port (vcan) in Linux:

  setup_vcan.sh

  #!/bin/bash
  
  # Using can1 as an example
  CAN_PORT="can1"
  
  sudo modprobe vcan
  sudo ip link add dev $CAN_PORT type vcan
  sudo ip link set up $CAN_PORT
  

• Make the bash program executable:

  chmod +x setup_vcan.sh
  

• Run the bash program:

  ./setup_vcan.sh
  

PART 2 - Recording and Playback of CAN messages

---

• Record the CAN messages into a log file (Replace $CAN_PORT with the name of your CAN port):

  candump -L $CAN_PORT > myfile.log
  

• Playback the CAN messages from the log file:

  canplayer -I myfile.log
  

• You can verify the playback by checking the output of candump:

  candump $CAN_PORT
  

References

• @yegorich's Answer
• Canplayer won't replay candump files