Mock ptp

demo_ptp.c

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>

#include <linux/ptp_clock.h>

struct external_timestamp
{
	int64_t timestamp; // ns
	int     index;
};

#define EVAL(expr) #expr, expr

#define READ  0
#define WRITE 1

int main()
{
	int fd[2];

	printf("%-50s: %zu\n", EVAL(sizeof(struct external_timestamp)));
	printf("%-50s: %zu\n", EVAL(sizeof(struct ptp_extts_event)));
	printf("\n");
	pipe(fd);

	if (!fork())
	{
		struct external_timestamp A = { .timestamp = 'n' + ('s' << 24), .index = 'I'};
		struct ptp_extts_event    B = {
			.t = {.sec = 's', .nsec = 'n'},
			.index = 'I', .flags = 'F'};

		close(fd[READ]);
		write(fd[WRITE], &A, sizeof(A));
		write(fd[WRITE], &B, sizeof(B));
		exit(0);
	}
	else
	{
		close(fd[WRITE]);

		uint8_t buffer[1024];
		ssize_t count = read(fd[READ], buffer, sizeof(buffer));

		print_memory(buffer, count);
	}
	return 0;
}

$ ./demo_ptp 
sizeof(struct external_timestamp)                 : 16
sizeof(struct ptp_extts_event)                    : 32

6e00 0073 0000 0000 4900 0000 0000 0000 n..s....I.......
7300 0000 0000 0000 6e00 0000 0000 0000 s.......n.......
4900 0000 4600 0000 0000 0000 0000 0000 I...F...........