PCAN-USB FD with libpcap on Raspberry Pi 3

[nypdmax]

Hello all,

I posted same issue in libpcap's github repo.

I have a program woking well on my PC (ubuntu 16.04 amd64, with libpcap0.8 and libpcap0.8-dev installed from ubuntu apt repo, version 1.7.4) . Now I'm running that CAN bus monitor in my raspberry pi 3 and I found some issues.

While I'm opening a socketcan interface with libpcap.

Code: Select all

     char err_buff[PCAP_ERRBUF_SIZE];
     pcap_t *hl;

     hl = pcap_open_live(CAN_DEV.c_str(), BUFSIZ, 1, 1000, err_buff);
     if (hl == NULL)
     {
         /* open failed */
         std::cout << "Couldn't open device " << CAN_DEV << std::endl;
         std::cout <<" Error: " << err_buff << std::endl;
         return -1;
     }
 
     if (pcap_datalink(hl) != DLT_CAN_SOCKETCAN)
     {
         // it is not a socketCAN frame 
         std::cout << "Device doesn't use socketCAN, it use " << pcap_datalink(hl) << std::endl;
         return -1;
     } 

In both master and libpcap-1.8 branches, pcap_datalink(hl) returned 113 (DLT_LINUX_SLL) instead of 227 (DLT_CAN_SOCKETCAN).

However on my PC it's working as expected.

FYI, my raspberry pi 3 is running Linux 4.14.33. I've recompiled the kernel to support CAN devices and my PCAN-USB FD adapter.
And I set up the CAN interface using:

Code: Select all

sudo ip link set can0 type can bitrate 500000 triple-sampling on
sudo ifconfig can0 up

I used a simple socketcan program to test sending and receiving frames and found no problem.
So I guess the problem lies in somewhere else like kernel configuration or other libraries missing or something else?
Please advice... Is there anyone ever encountered samilar issue? Any help is appreciated!

[nypdmax]

Problem solved. For anyone interested, see here:
https://github.com/the-tcpdump-group/libpcap/issues/699