/*
 * Copyright 2009, Michael Lotz, mmlr@mlotz.ch.
 * Distributed under the terms of the MIT License.
 */

#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>

int
main(int argc, char *argv[])
{
        if (argc < 2) {
                printf("usage: %s <MAC address>\n", argv[0]);
                return 1;
        }

        unsigned char mac[6];
        if (sscanf(argv[1], "%2x%*c%2x%*c%2x%*c%2x%*c%2x%*c%2x", &mac[0], &mac[1],
                &mac[2], &mac[3], &mac[4], &mac[5]) != 6) {
                printf("unrecognized MAC format\n");
                return 2;
        }

        char buffer[102];
        memset(buffer, 0xff, 6);
        for (int i = 1; i <= 16; i++)
                memcpy(buffer + i * 6, mac, sizeof(mac));

        int sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
        if (sock < 0) {
                printf("failed to create socket: %s\n", strerror(sock));
                return 3;
        }

        int value = 1;
        int result = setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &value,
                sizeof(value));
        if (result < 0) {
                printf("failed to set broadcast socket option: %s\n", strerror(result));
                return 4;
        }

        sockaddr_in address;
        address.sin_family = AF_INET;
        address.sin_addr.s_addr = 0xffffffff;
        address.sin_port = 0;

        result = sendto(sock, buffer, sizeof(buffer), 0,
                (struct sockaddr *)&address, sizeof(address));
        if (result < 0) {
                printf("failed to send magic packet: %s\n", strerror(result));
                return 5;
        }

        printf("magic packet sent to %02x:%02x:%02x:%02x:%02x:%02x\n", mac[0],
                mac[1], mac[2], mac[3], mac[4], mac[5]);
        return 0;
}