121 lines
3.3 KiB
C
121 lines
3.3 KiB
C
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/*++
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Copyright (c) 2000, Microsoft Corporation
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Module Name:
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limitbcast.c
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Abstract:
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This module implements a program demonstrating the use of the
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SIO_LIMIT_BROADCASTS socket option. The default behavior of the system
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is to send limited broadcasts (i.e. broadcasts sent to 255.255.255.255)
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on all local interfaces, which violates the IETF Host Requirements stating
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that limited broadcasts appear only on the sending socket's interface.
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This socket option allows an application to specify that a socket's
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limited-broadcasts obey the traditional semantics.
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Author:
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Abolade Gbadegesin (aboladeg) 29-October-1998
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Revision History:
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--*/
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#include <winsock2.h>
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#include <mstcpip.h>
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#include <stdio.h>
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#include <stdlib.h>
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int __cdecl
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main(
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int argc,
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char* argv[]
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)
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{
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SOCKADDR_IN DestAddrIn;
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SOCKADDR_IN LocalAddrIn;
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ULONG Option;
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SOCKET Socket;
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WSADATA WsaData;
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//
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// Check command-line arguments
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//
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ZeroMemory(&LocalAddrIn, sizeof(LocalAddrIn));
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LocalAddrIn.sin_family = AF_INET;
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if (argc != 3 ||
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!(LocalAddrIn.sin_addr.s_addr = inet_addr(argv[1])) ||
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!(LocalAddrIn.sin_port = ntohs((USHORT)atol(argv[2])))) {
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printf("Usage: %s <local IP address> <target port>\n", argv[0]);
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return 0;
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}
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//
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// Initialize Windows sockets, create a UDP socket,
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// and enable broadcasts on the socket.
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// Then bind it to the specified local IP address.
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//
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WSAStartup(0x0202, &WsaData);
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if ((Socket = socket(AF_INET, SOCK_DGRAM, 0)) == INVALID_SOCKET) {
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printf("socket: %d\n", WSAGetLastError());
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return 0;
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}
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Option = 1;
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if (setsockopt(
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Socket, SOL_SOCKET, SO_BROADCAST, (PCHAR)&Option, sizeof(Option)
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) == SOCKET_ERROR) {
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printf("setsockopt: %d\n", WSAGetLastError());
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}
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if (bind(Socket, (PSOCKADDR)&LocalAddrIn, sizeof(LocalAddrIn))
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== SOCKET_ERROR) {
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printf("bind: %d\n", WSAGetLastError());
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return 0;
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}
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//
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// Initialize the destination address,
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// and enter a loop where we prompt for the limit-broadcasts setting
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// and send a message using the specified setting.
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//
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ZeroMemory(&DestAddrIn, sizeof(DestAddrIn));
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DestAddrIn.sin_family = AF_INET;
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DestAddrIn.sin_addr.s_addr = INADDR_BROADCAST;
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DestAddrIn.sin_port = LocalAddrIn.sin_port;
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do {
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ULONG Length;
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ULONG LimitBroadcasts;
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printf("Enter a value (0 or 1) for the SIO_LIMIT_BROADCASTS option.\n");
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printf("bcast> ");
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if (!scanf("%d", &LimitBroadcasts)) {
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break;
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}
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if (WSAIoctl(
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Socket, SIO_LIMIT_BROADCASTS,
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(PCHAR)&LimitBroadcasts, sizeof(LimitBroadcasts),
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NULL, 0, &Length, NULL, NULL
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) == SOCKET_ERROR) {
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printf("WSAIoctl: %d\n", WSAGetLastError());
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}
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if (sendto(
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Socket,
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(PCHAR)&DestAddrIn,
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sizeof(DestAddrIn),
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0,
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(PSOCKADDR)&DestAddrIn,
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sizeof(DestAddrIn)
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) == SOCKET_ERROR) {
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printf("sendto: %d\n", WSAGetLastError());
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}
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} while(TRUE);
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closesocket(Socket);
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WSACleanup();
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return 0;
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}
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