linux CAN收发程序

linux CAN收发程序

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <linux/can.h>
#include <linux/can/raw.h>


int main(int argc, char *argv[])
{
	int s, nbytes;
	char *array[2] = { "-r", "-s" };
	struct sockaddr_can addr;
	struct ifreq ifr;
	struct can_frame frame;
	struct can_filter rfilter[1];


	/* handle (optional) flags first */
	if (argc != 3) {
		fprintf(stderr, "Usage:  %s <-r> <can interface name> for receiving\nor <-s> <can interface name> for sending\n", argv[0]);
		exit(1);
	}
	/* create socket */
	if ((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0)
	{
		perror("Create socket failed");
		exit(-1);
	}

	/* set up can interface */
	strcpy(ifr.ifr_name, argv[2]);
	printf("can port is %s\n", ifr.ifr_name);
	/* assign can device */
	ioctl(s, SIOCGIFINDEX, &ifr);
	addr.can_family = AF_CAN;
	addr.can_ifindex = ifr.ifr_ifindex;
	/* bind can device */
	if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0)
	{
		perror("Bind can device failed\n");
		close(s);
		exit(-2);
	}

	/* configure receiving */
	if (!strcmp(argv[1], array[0]))
	{
		/* set filter for only receiving packet with can id 0x1F */
		rfilter[0].can_id = 0x1F;
		rfilter[0].can_mask = CAN_SFF_MASK;
		if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, &rfilter, sizeof(rfilter)) < 0)
		{
			perror("set receiving filter error\n");
			close(s);
			exit(-3);
		}
		/* keep reading */
		while (1) {
			nbytes = read(s, &frame, sizeof(frame));
			if (nbytes > 0)
			{
				printf("%s ID=%#x data length=%d\n", ifr.ifr_name, frame.can_id, frame.can_dlc);
				for (int i = 0; i < frame.can_dlc; i++)
					printf("%#x ", frame.data[i]);
				printf("\n");
			}
		}
	}
	/* configure sending */
	else if (!strcmp(argv[1], array[1]))
	{
		/* configure can_id and can data length */
		frame.can_id = 0x1F;
		frame.can_dlc = 8;
		printf("%s ID=%#x data length=%d\n", ifr.ifr_name, frame.can_id, frame.can_dlc);
		/* prepare data for sending: 0x11,0x22...0x88 */
		for (int i = 0; i < 8; i++)
		{
			frame.data[i] = ((i + 1) << 4) | (i + 1);
			printf("%#x ", frame.data[i]);
		}
		printf("Sent out\n");
		/* Sending data */
		if (write(s, &frame, sizeof(frame)) < 0)
		{
			perror("Send failed");
			close(s);
			exit(-4);
		}
	}
	/* wrong parameter input situation */
	else
	{
		printf("wrong parameter input\n");
	}

	close(s);
	return 0;
}