ether functions do not work with -std=c11

ether.c

#include "netinet/ether.h"
#include "net/ethernet.h"

#include "stdio.h"
#include <stdlib.h>
#include <string.h>

int main(int argc, char *argv[]) {
    struct ether_addr address;
    char buffer[30];
    ether_aton_r("f8:b1:56:fb:e9:57", &address);
    memset(buffer, 0, 30);
    ether_ntoa_r((const struct ether_addr*)&address, buffer);

    printf("%s\n", buffer);
    return EXIT_SUCCESS;
}