Re: kvaser leaf and SocketCAN

[Leo Stan <leo.stanislas@qut.edu.au>]

Actually I spoke too soon...

When I try this simple code from the documentation :


#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
 
#include <net/if.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
 
#include <linux/can.h>
#include <linux/can/raw.h>
 
int main(void)
{
	int s;
	int nbytes;
	struct sockaddr_can addr;
	struct can_frame frame;
	struct ifreq ifr;
 
	char *ifname = "can0";
 
	if((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0) {
		perror("Error while opening socket");
		return -1;
	}
 
	strcpy(ifr.ifr_name, ifname);
	ioctl(s, SIOCGIFINDEX, &ifr);
 
	addr.can_family  = AF_CAN;
	addr.can_ifindex = ifr.ifr_ifindex; 
 
	printf("%s at index %d\n", ifname, ifr.ifr_ifindex);
 
	if(bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
		perror("Error in socket bind");
		return -2;
	}

	// Reading the CAN port


	nbytes=read(s,&frame,sizeof(struct can_frame));

	if (nbytes < 0) {
            perror("can raw socket read");
            return 1;
        }

        /* paranoid check ... */
        if (nbytes < sizeof(struct can_frame)) {
            fprintf(stderr, "read: incomplete CAN frame\n");
            return 1;
        }

        printf("dlc = %d, data = %s, %d bytes read\n", 
frame.can_dlc,frame.data,nbytes);

        close(s);
	
        return 0;
}

I get this flag :

can0 at index 3
can raw socket read: Network is down



Which means that nothing has been read from the CAN I guess, however I'm 
sure that data comes from it because I can see it using CANking software on 
Windows.

When I run "ifconfig -a"  RX and TX are also empty:

can0      Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-
00-00-00  
          NOARP  MTU:16  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:10 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)


Here are the settings of my BUS on Canking :

No init access
Speed : 500000 Bit/s
Bit timing : Q=8, S1=5,S2=3,Sampling point= 62.5%, SJW=1
DLC = 8

Any help would be really appreciated