//==================================================== file = magicSend.c =====
//=  Program to send a Magic Packet to wake-up a sleeping target computer     =
//=============================================================================
//=    1) Compiles for WinSock                                                =
//=    2) A Magic Packet is a frame containing anywhere within its payload    =
//=       6 bytes of ones followed by sixteen repetitions of the target       =
//=       computer's MAC address.                                             =
//=    3) The target computer must be enabled for wake-up by a Magic Packet   =
//=    4) The target computer IP address and MAC address must be defined in   =
//=       the #define below                                                   =
//=---------------------------------------------------------------------------=
//=  Example execution:                                                       =
//=  Sending Magic Packet to target...                                        =
//=    Target IP address  = 131.247.3.77                                      =
//=    Target MAC address = 00-19-B9-32-BC-76                                 =
//=---------------------------------------------------------------------------=
//=  Build: bcc32 magicSend.c or cl magicSend.c wsock32.lib for Winsock       =
//=---------------------------------------------------------------------------=
//=  History:                                                                 =
//=    KJC (01/30/09) - Genesis                                               =
//=============================================================================
//----- Include files ---------------------------------------------------------
#include <stdio.h>          // Needed for printf()
#include <windows.h>        // Needed for all Winsock stuff

//----- Defines ---------------------------------------------------------------
#define  PORT_NUM           1050  // Port number
#define  IP_ADDR   "131.247.3.77" // IP address of target
#define  MAC_BYTE1          0x00  // MAC address byte #1 of target
#define  MAC_BYTE2          0x19  // MAC address byte #2 of target
#define  MAC_BYTE3          0xB9  // MAC address byte #3 of target
#define  MAC_BYTE4          0x32  // MAC address byte #4 of target
#define  MAC_BYTE5          0xBC  // MAC address byte #5 of target
#define  MAC_BYTE6          0x76  // MAC address byte #6 of target

//===== Main program ==========================================================
void main(void)
{
  WORD wVersionRequested = MAKEWORD(1,1);  // Stuff for WSA functions
  WSADATA wsaData;                         // Stuff for WSA functions
  int                  client_s;           // Client socket descriptor
  struct sockaddr_in   target_addr;        // Target Internet address
  int                  addr_len;           // Internet address length
  int                  pkt_len;            // Packet length
  char                 out_buf[1024];      // Output buffer for data
  int                  retcode;            // Return code
  int                  i;                  // Loop counter

  // This stuff initializes winsock
  WSAStartup(wVersionRequested, &wsaData);

  // Create a client socket
  client_s = socket(AF_INET, SOCK_DGRAM, 0);
  if (client_s < 0)
  {
    printf("*** ERROR - socket() failed \n");
    exit(-1);
  }

  // Fill-in target address information
  target_addr.sin_family = AF_INET;
  target_addr.sin_port = htons(PORT_NUM);
  target_addr.sin_addr.s_addr = inet_addr(IP_ADDR);

  // Load the Magic Packet pattern into the output buffer
  for(i=0; i<6; i++)
    out_buf[i] = 0xff;
  for(i=0; i<16; i++)
  {
    out_buf[(i+1)*6 + 0] = MAC_BYTE1;
    out_buf[(i+1)*6 + 1] = MAC_BYTE2;
    out_buf[(i+1)*6 + 2] = MAC_BYTE3;
    out_buf[(i+1)*6 + 3] = MAC_BYTE4;
    out_buf[(i+1)*6 + 4] = MAC_BYTE5;
    out_buf[(i+1)*6 + 5] = MAC_BYTE6;
  }
  pkt_len = 102;

  // Now send the Magic Packet to the target
  printf("Sending Magic Packet to target... \n");
  printf("  Target IP address  = %s \n", IP_ADDR);
  printf("  Target MAC address = %02X-%02X-%02X-%02X-%02X-%02X \n",
    MAC_BYTE1, MAC_BYTE2, MAC_BYTE3, MAC_BYTE4, MAC_BYTE5, MAC_BYTE6);
  retcode = sendto(client_s, out_buf, pkt_len, 0,
    (struct sockaddr *)&target_addr, sizeof(target_addr));
  if (retcode < 0)
  {
    printf("*** ERROR - sendto() failed \n");
    exit(-1);
  }

  // Wait for 0.5 seconds for the packet to be sent
  Sleep(500);

  // Close client socket and clean-up
  retcode = closesocket(client_s);
  if (retcode < 0)
  {
    printf("*** ERROR - closesocket() failed \n");
    exit(-1);
  }
  WSACleanup();
}