C Linux get macaddress via ioctl

mac.c

#include <stdlib.h>
#include <errno.h>
#include <netinet/in.h>
#include <net/if.h>
#include <stdio.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/socket.h>

#define MAC_ADDRESS_LENGTH (6)

#define new(type) ((type*)malloc(sizeof(type)))
#define new_array(type, length) ((type*)malloc(sizeof(type) * length))

const char *getMacAddress(const char *interfaceName);

int main() {
    const char *interfaceName = "eth-bond";
    const char *macAddress = getMacAddress(interfaceName);
    printf("MAC address of %s is %s.\n", interfaceName, macAddress);
}

const char *getMacAddress(const char *interfaceName) {
    // init socket
    int socketHandler = socket(AF_UNIX, SOCK_DGRAM, IPPROTO_IP);

    if (socketHandler == EOF) {
        printf("Can't init ioctl.\n");
        return NULL;
    }

    // init ioctl request
    struct ifreq *request = new(struct ifreq);
    strcpy(request->ifr_name, interfaceName);

    // call ioctl
    if (ioctl(socketHandler, SIOCGIFHWADDR, request) == EOF) {
        printf("Can't get address of interface via ioctl.(%d: %s)\n", errno, strerror(errno));
        return NULL;
    }

    // copy mac address in binary
    uint8_t manInBinary[6];
    memcpy(manInBinary, (request->ifr_hwaddr.sa_data), sizeof(uint8_t) * MAC_ADDRESS_LENGTH);

    // convert binary address to string
    char *result = new_array(char, MAC_ADDRESS_LENGTH * 2 + MAC_ADDRESS_LENGTH - 1);
    sprintf(result, "%02x", manInBinary[0]);
    for (int i = 1; i < MAC_ADDRESS_LENGTH; ++i) {
        sprintf(result + (2 + (i - 1) * 3), ":%02x", manInBinary[i]);
    }
    return result;
}