// Module: Mcastws1.c // // Purpose: // This sample illustrates IP multicasting using the Winsock 1 // method of joining and leaving an multicast group. This sample // may be invoked as either a sender or a receiver. In both cases, // the specified multicast group is joined. // // Compile: // cl -o Mcastws1 Mcastws1.c Wsock32.lib // // Command Line Options/Parameters // mcastws1.exe [-s] [-m:str] [-p:int] [-i:str] [-l] [-n:int] // -s Act as sender; otherwise receive data // -m:str Dotted decimal IP multicast address to join // -p:int Port number to use // -i:str Local interface to use // -l Disable the loopback // -n:int Number of messages to send or receive // #include <windows.h> #include <winsock.h>#include <stdio.h> #include <stdlib.h>#define MCASTADDR "234.5.6.7" #define MCASTPORT 25000 #define BUFSIZE 1024 #define DEFAULT_COUNT 500BOOL bSender = FALSE, // Act as sender? bLoopBack = FALSE; // Disable loopback?DWORD dwInterface, // Local interface to bind to dwMulticastGroup, // Multicast group to join dwCount; // Number of messages to send/receiveshort iPort; // Port number to use// // Function: usage // // Description: // Print usage information and exit // void usage(char *progname) { printf("usage: %s -s -m:str -p:int -i:str -l -n:int\n", progname); printf(" -s Act as server (send data); otherwise\n"); printf(" receive data.\n"); printf(" -m:str Dotted decimal multicast IP addres to join\n"); printf(" The default group is: %s\n", MCASTADDR); printf(" -p:int Port number to use\n"); printf(" The default port is: %d\n", MCASTPORT); printf(" -i:str Local interface to bind to; by default \n"); printf(" use INADDRY_ANY\n"); printf(" -l Disable loopback\n"); printf(" -n:int Number of messages to send/receive\n"); ExitProcess(-1); }// // Function: ValidateArgs // // Description: // Parse the command line arguments and set some global flags, // depending on the values // void ValidateArgs(int argc, char **argv) { int i; dwInterface = INADDR_ANY; dwMulticastGroup = inet_addr(MCASTADDR); iPort = MCASTPORT; dwCount = DEFAULT_COUNT; for(i = 1; i < argc; i++) { if ((argv[i][0] == '-') || (argv[i][0] == '/')) { switch (tolower(argv[i][1])) { case 's': // Sender bSender = TRUE; break; case 'm': // Multicast group to join if (strlen(argv[i]) > 3) dwMulticastGroup = inet_addr(&argv[i][3]); break; case 'i': // Local interface to use if (strlen(argv[i]) > 3) dwInterface = inet_addr(&argv[i][3]); break; case 'p': // Port number to use if (strlen(argv[i]) > 3) iPort = atoi(&argv[i][3]); break; case 'l': // Disable loopback? bLoopBack = TRUE; break; case 'n': // Number of messages to send/recv dwCount = atoi(&argv[i][3]); break; default: usage(argv[0]); break; } } } return; }// // Function: main // // Description: // Parse the command line arguments, load the Winsock library, // create a socket and join the multicast group. If this program // is started as a sender then begin sending messages to the // multicast group; otherwise, call recvfrom() to read messages // sent to the group. // int main(int argc, char **argv) { WSADATA wsd; struct sockaddr_in local, remote, from; struct ip_mreq mcast; SOCKET sockM; TCHAR recvbuf[BUFSIZE], sendbuf[BUFSIZE]; int len = sizeof(struct sockaddr_in), optval, ret; DWORD i=0; // Parse the command line and load Winsock // ValidateArgs(argc, argv);
if (WSAStartup(MAKEWORD(1, 1), &wsd) != 0) { printf("WSAStartup failed\n"); return -1; } // Create the socket. In Winsock 1 you don't need any special // flags to indicate multicasting. // if ((sockM = socket(AF_INET, SOCK_DGRAM, 0)) == INVALID_SOCKET) { printf("socket failed with: %d\n", WSAGetLastError()); WSACleanup(); return -1; } // Bind the socket to the local interface. This is done so // that we can receive data. // local.sin_family = AF_INET; local.sin_port = htons(iPort); local.sin_addr.s_addr = dwInterface; if (bind(sockM, (struct sockaddr *)&local, sizeof(local)) == SOCKET_ERROR) { printf("bind failed with: %d\n", WSAGetLastError()); closesocket(sockM); WSACleanup(); return -1; } // Setup the im_req structure to indicate what group we want // to join as well as the interface // remote.sin_family = AF_INET; remote.sin_port = htons(iPort); remote.sin_addr.s_addr = dwMulticastGroup; mcast.imr_multiaddr.s_addr = dwMulticastGroup; mcast.imr_interface.s_addr = dwInterface; if (setsockopt(sockM, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *)&mcast, sizeof(mcast)) == SOCKET_ERROR) { printf("setsockopt(IP_ADD_MEMBERSHIP) failed: %d\n", WSAGetLastError()); closesocket(sockM); WSACleanup(); return -1; } // Set the TTL to something else. The default TTL is 1. // optval = 8; if (setsockopt(sockM, IPPROTO_IP, IP_MULTICAST_TTL, (char *)&optval, sizeof(int)) == SOCKET_ERROR) { printf("setsockopt(IP_MULTICAST_TTL) failed: %d\n", WSAGetLastError()); closesocket(sockM); WSACleanup(); return -1; } // Disable the loopback if selected. Note that on NT4 and Win95 // you cannot disable it. // if (bLoopBack) { optval = 0; if (setsockopt(sockM, IPPROTO_IP, IP_MULTICAST_LOOP, (char *)&optval, sizeof(optval)) == SOCKET_ERROR) { printf("setsockopt(IP_MULTICAST_LOOP) failed: %d\n", WSAGetLastError()); closesocket(sockM); WSACleanup(); return -1; } } if (!bSender) // Receiver { // Receive some data // for(i = 0; i < dwCount; i++) { if ((ret = recvfrom(sockM, recvbuf, BUFSIZE, 0, (struct sockaddr *)&from, &len)) == SOCKET_ERROR) { printf("recvfrom failed with: %d\n", WSAGetLastError()); closesocket(sockM); WSACleanup(); return -1; } recvbuf[ret] = 0; printf("RECV: '%s' from <%s>\n", recvbuf, inet_ntoa(from.sin_addr)); } } else // Sender { // Send some data // for(i = 0; i < dwCount; i++) { sprintf(sendbuf, "server 1: This is a test: %d", i); if (sendto(sockM, (char *)sendbuf, strlen(sendbuf), 0, (struct sockaddr *)&remote, sizeof(remote)) == SOCKET_ERROR) { printf("sendto failed with: %d\n", WSAGetLastError()); closesocket(sockM); WSACleanup(); return -1; } Sleep(500); } } // Drop group membership // if (setsockopt(sockM, IPPROTO_IP, IP_DROP_MEMBERSHIP, (char *)&mcast, sizeof(mcast)) == SOCKET_ERROR) { printf("setsockopt(IP_DROP_MEMBERSHIP) failed: %d\n", WSAGetLastError()); } closesocket(sockM); WSACleanup(); return 0; }
// Module: Mcastws2.c // // Purpose: // This sample illustrates IP multicasting using the Winsock 2 // method of joining and leaving a multicast group. This sample // may be invoked as either a sender or a receiver. In both // cases, the specified multicast group is joined. // // Compile: // cl -o Mcastws2 Mcastws2.c Ws2_32.lib // // Command Line Options/Parameters // Mcastws2.exe [-s] [-m:str] [-p:int] [-i:str] [-l] [-n:int] // -s Act as sender; otherwise receive data // -m:str Dotted decimal IP multicast address to join // -p:int Port number to use // -i:str Local interface to use // -l Disable the loopback // -n:int Number of messages to send or receive // #include <winsock2.h> #include <ws2tcpip.h>#include <stdio.h> #include <stdlib.h>#define MCASTADDR "234.5.6.7" #define MCASTPORT 25000 #define BUFSIZE 1024 #define DEFAULT_COUNT 500BOOL bSender = FALSE, // Act as a sender? bLoopBack = FALSE; // Disable loopback?DWORD dwInterface, // Local interface to bind to dwMulticastGroup, // Multicast group to join dwCount; // Number of messages to send/receiveshort iPort; // Port number to use// // Function: usage // // Description: // Print usage information and exit // void usage(char *progname) { printf("usage: %s -s -m:str -p:int -i:str -l -n:int\n", progname); printf(" -s Act as server (send data); otherwise\n"); printf(" receive data.\n"); printf(" -m:str Dotted decimal multicast IP addres " "to join\n"); printf(" The default group is: %s\n", MCASTADDR); printf(" -p:int Port number to use\n"); printf(" The default port is: %d\n", MCASTPORT); printf(" -i:str Local interface to bind to; by default \n"); printf(" use INADDRY_ANY\n"); printf(" -l Disable loopback\n"); printf(" -n:int Number of messages to send/receive\n"); ExitProcess(-1); }// // Function: ValidateArgs // // Description // Parse the command line arguments and set some global flags // depeding on the values // void ValidateArgs(int argc, char **argv) { int i; dwInterface = INADDR_ANY; dwMulticastGroup = inet_addr(MCASTADDR); iPort = MCASTPORT; dwCount = DEFAULT_COUNT; for(i=1; i < argc ;i++) { if ((argv[i][0] == '-') || (argv[i][0] == '/')) { switch (tolower(argv[i][1])) { case 's': // Sender bSender = TRUE; break; case 'm': // Multicast group to join if (strlen(argv[i]) > 3) dwMulticastGroup = inet_addr(&argv[i][3]); break; case 'i': // Local interface to use if (strlen(argv[i]) > 3) dwInterface = inet_addr(&argv[i][3]); break; case 'p': // Port to use if (strlen(argv[i]) > 3) iPort = atoi(&argv[i][3]); break; case 'l': // Disable loopback bLoopBack = TRUE; break; case 'n': // Number of messages to send/recv dwCount = atoi(&argv[i][3]); break; default: usage(argv[0]); break; } } } return; }// // Function: main // // Description: // Parse the command line arguments, load the Winsock library, // create a socket and join the multicast group. If this program // is run as a sender then begin sending messages to the multicast // group; otherwise, call recvfrom() to read messages sent to the // group. // int main(int argc, char **argv) { WSADATA wsd; struct sockaddr_in local, remote, from; SOCKET sock, sockM; TCHAR recvbuf[BUFSIZE], sendbuf[BUFSIZE]; int len = sizeof(struct sockaddr_in), optval, ret; DWORD i=0; // Parse the command line and load Winsock // ValidateArgs(argc, argv); if (WSAStartup(MAKEWORD(2, 2), &wsd) != 0) { printf("WSAStartup() failed\n"); return -1; } // Create the socket. In Winsock 2 you do have to specify the // multicast attributes that this socket will be used with. // if ((sock = WSASocket(AF_INET, SOCK_DGRAM, 0, NULL, 0, WSA_FLAG_MULTIPOINT_C_LEAF | WSA_FLAG_MULTIPOINT_D_LEAF | WSA_FLAG_OVERLAPPED)) == INVALID_SOCKET) { printf("socket failed with: %d\n", WSAGetLastError()); WSACleanup(); return -1; } // Bind to the local interface. This is done to receive data. local.sin_family = AF_INET; local.sin_port = htons(iPort); local.sin_addr.s_addr = dwInterface;
if (bind(sock, (struct sockaddr *)&local, sizeof(local)) == SOCKET_ERROR) { printf("bind failed with: %d\n", WSAGetLastError()); closesocket(sock); WSACleanup(); return -1; } // Setup the SOCKADDR_IN structure describing the multicast // group we want to join // remote.sin_family = AF_INET; remote.sin_port = htons(iPort); remote.sin_addr.s_addr = dwMulticastGroup; // // Change the TTL to something more appropriate // optval = 8; if (setsockopt(sock, IPPROTO_IP, IP_MULTICAST_TTL, (char *)&optval, sizeof(int)) == SOCKET_ERROR) { printf("setsockopt(IP_MULTICAST_TTL) failed: %d\n", WSAGetLastError()); closesocket(sock); WSACleanup(); return -1; } // Disable loopback if needed // if (bLoopBack) { optval = 0; if (setsockopt(sock, IPPROTO_IP, IP_MULTICAST_LOOP, (char *)&optval, sizeof(optval)) == SOCKET_ERROR) { printf("setsockopt(IP_MULTICAST_LOOP) failed: %d\n", WSAGetLastError()); closesocket(sock); WSACleanup(); return -1; } } // Join the multicast group. Note that sockM is not used // to send or receive data. It is used when you want to // leave the multicast group. You simply call closesocket() // on it. // if ((sockM = WSAJoinLeaf(sock, (SOCKADDR *)&remote, sizeof(remote), NULL, NULL, NULL, NULL, JL_BOTH)) == INVALID_SOCKET) { printf("WSAJoinLeaf() failed: %d\n", WSAGetLastError()); closesocket(sock); WSACleanup(); return -1; } if (!bSender) // Receiver { // Receive data // for(i = 0; i < dwCount; i++) { if ((ret = recvfrom(sock, recvbuf, BUFSIZE, 0, (struct sockaddr *)&from, &len)) == SOCKET_ERROR) { printf("recvfrom failed with: %d\n", WSAGetLastError()); closesocket(sockM); closesocket(sock); WSACleanup(); return -1; } recvbuf[ret] = 0; printf("RECV: '%s' from <%s>\n", recvbuf, inet_ntoa(from.sin_addr)); } } else // Sender { // Send data // for(i = 0; i < dwCount; i++) { sprintf(sendbuf, "server 1: This is a test: %d", i); if (sendto(sock, (char *)sendbuf, strlen(sendbuf), 0, (struct sockaddr *)&remote, sizeof(remote)) == SOCKET_ERROR) { printf("sendto failed with: %d\n", WSAGetLastError()); closesocket(sockM); closesocket(sock); WSACleanup(); return -1; } Sleep(500); } } // Leave the multicast group by closing sock // For non-rooted control and data plane schemes, WSAJoinLeaf // returns the same socket handle that you pass into it. // closesocket(sock); WSACleanup(); return -1; }
//
// Purpose:
// This sample illustrates IP multicasting using the Winsock 1
// method of joining and leaving an multicast group. This sample
// may be invoked as either a sender or a receiver. In both cases,
// the specified multicast group is joined.
//
// Compile:
// cl -o Mcastws1 Mcastws1.c Wsock32.lib
//
// Command Line Options/Parameters
// mcastws1.exe [-s] [-m:str] [-p:int] [-i:str] [-l] [-n:int]
// -s Act as sender; otherwise receive data
// -m:str Dotted decimal IP multicast address to join
// -p:int Port number to use
// -i:str Local interface to use
// -l Disable the loopback
// -n:int Number of messages to send or receive
//
#include <windows.h>
#include <winsock.h>#include <stdio.h>
#include <stdlib.h>#define MCASTADDR "234.5.6.7"
#define MCASTPORT 25000
#define BUFSIZE 1024
#define DEFAULT_COUNT 500BOOL bSender = FALSE, // Act as sender?
bLoopBack = FALSE; // Disable loopback?DWORD dwInterface, // Local interface to bind to
dwMulticastGroup, // Multicast group to join
dwCount; // Number of messages to send/receiveshort iPort; // Port number to use//
// Function: usage
//
// Description:
// Print usage information and exit
//
void usage(char *progname)
{
printf("usage: %s -s -m:str -p:int -i:str -l -n:int\n",
progname);
printf(" -s Act as server (send data); otherwise\n");
printf(" receive data.\n");
printf(" -m:str Dotted decimal multicast IP addres to join\n");
printf(" The default group is: %s\n", MCASTADDR);
printf(" -p:int Port number to use\n");
printf(" The default port is: %d\n", MCASTPORT);
printf(" -i:str Local interface to bind to; by default \n");
printf(" use INADDRY_ANY\n");
printf(" -l Disable loopback\n");
printf(" -n:int Number of messages to send/receive\n");
ExitProcess(-1);
}//
// Function: ValidateArgs
//
// Description:
// Parse the command line arguments and set some global flags,
// depending on the values
//
void ValidateArgs(int argc, char **argv)
{
int i; dwInterface = INADDR_ANY;
dwMulticastGroup = inet_addr(MCASTADDR);
iPort = MCASTPORT;
dwCount = DEFAULT_COUNT; for(i = 1; i < argc; i++)
{
if ((argv[i][0] == '-') || (argv[i][0] == '/'))
{
switch (tolower(argv[i][1]))
{
case 's': // Sender
bSender = TRUE;
break;
case 'm': // Multicast group to join
if (strlen(argv[i]) > 3)
dwMulticastGroup = inet_addr(&argv[i][3]);
break;
case 'i': // Local interface to use
if (strlen(argv[i]) > 3)
dwInterface = inet_addr(&argv[i][3]);
break;
case 'p': // Port number to use
if (strlen(argv[i]) > 3)
iPort = atoi(&argv[i][3]);
break;
case 'l': // Disable loopback?
bLoopBack = TRUE;
break;
case 'n': // Number of messages to send/recv
dwCount = atoi(&argv[i][3]);
break;
default:
usage(argv[0]);
break;
}
}
}
return;
}//
// Function: main
//
// Description:
// Parse the command line arguments, load the Winsock library,
// create a socket and join the multicast group. If this program
// is started as a sender then begin sending messages to the
// multicast group; otherwise, call recvfrom() to read messages
// sent to the group.
//
int main(int argc, char **argv)
{
WSADATA wsd;
struct sockaddr_in local,
remote,
from;
struct ip_mreq mcast;
SOCKET sockM;
TCHAR recvbuf[BUFSIZE],
sendbuf[BUFSIZE];
int len = sizeof(struct sockaddr_in),
optval,
ret;
DWORD i=0; // Parse the command line and load Winsock
//
ValidateArgs(argc, argv);
if (WSAStartup(MAKEWORD(1, 1), &wsd) != 0)
{
printf("WSAStartup failed\n");
return -1;
}
// Create the socket. In Winsock 1 you don't need any special
// flags to indicate multicasting.
//
if ((sockM = socket(AF_INET, SOCK_DGRAM, 0)) == INVALID_SOCKET)
{
printf("socket failed with: %d\n", WSAGetLastError());
WSACleanup();
return -1;
}
// Bind the socket to the local interface. This is done so
// that we can receive data.
//
local.sin_family = AF_INET;
local.sin_port = htons(iPort);
local.sin_addr.s_addr = dwInterface; if (bind(sockM, (struct sockaddr *)&local,
sizeof(local)) == SOCKET_ERROR)
{
printf("bind failed with: %d\n", WSAGetLastError());
closesocket(sockM);
WSACleanup();
return -1;
} // Setup the im_req structure to indicate what group we want
// to join as well as the interface
//
remote.sin_family = AF_INET;
remote.sin_port = htons(iPort);
remote.sin_addr.s_addr = dwMulticastGroup; mcast.imr_multiaddr.s_addr = dwMulticastGroup;
mcast.imr_interface.s_addr = dwInterface; if (setsockopt(sockM, IPPROTO_IP, IP_ADD_MEMBERSHIP,
(char *)&mcast, sizeof(mcast)) == SOCKET_ERROR)
{
printf("setsockopt(IP_ADD_MEMBERSHIP) failed: %d\n",
WSAGetLastError());
closesocket(sockM);
WSACleanup();
return -1;
}
// Set the TTL to something else. The default TTL is 1.
//
optval = 8;
if (setsockopt(sockM, IPPROTO_IP, IP_MULTICAST_TTL,
(char *)&optval, sizeof(int)) == SOCKET_ERROR)
{
printf("setsockopt(IP_MULTICAST_TTL) failed: %d\n",
WSAGetLastError());
closesocket(sockM);
WSACleanup();
return -1;
}
// Disable the loopback if selected. Note that on NT4 and Win95
// you cannot disable it.
//
if (bLoopBack)
{
optval = 0;
if (setsockopt(sockM, IPPROTO_IP, IP_MULTICAST_LOOP,
(char *)&optval, sizeof(optval)) == SOCKET_ERROR)
{
printf("setsockopt(IP_MULTICAST_LOOP) failed: %d\n",
WSAGetLastError());
closesocket(sockM);
WSACleanup();
return -1;
}
} if (!bSender) // Receiver
{
// Receive some data
//
for(i = 0; i < dwCount; i++)
{
if ((ret = recvfrom(sockM, recvbuf, BUFSIZE, 0,
(struct sockaddr *)&from, &len)) == SOCKET_ERROR)
{
printf("recvfrom failed with: %d\n",
WSAGetLastError());
closesocket(sockM);
WSACleanup();
return -1;
}
recvbuf[ret] = 0;
printf("RECV: '%s' from <%s>\n", recvbuf,
inet_ntoa(from.sin_addr));
}
}
else // Sender
{
// Send some data
//
for(i = 0; i < dwCount; i++)
{
sprintf(sendbuf, "server 1: This is a test: %d", i);
if (sendto(sockM, (char *)sendbuf, strlen(sendbuf), 0,
(struct sockaddr *)&remote,
sizeof(remote)) == SOCKET_ERROR)
{
printf("sendto failed with: %d\n",
WSAGetLastError());
closesocket(sockM);
WSACleanup();
return -1;
}
Sleep(500);
}
}
// Drop group membership
//
if (setsockopt(sockM, IPPROTO_IP, IP_DROP_MEMBERSHIP,
(char *)&mcast, sizeof(mcast)) == SOCKET_ERROR)
{
printf("setsockopt(IP_DROP_MEMBERSHIP) failed: %d\n",
WSAGetLastError());
}
closesocket(sockM); WSACleanup();
return 0;
}
//
// Purpose:
// This sample illustrates IP multicasting using the Winsock 2
// method of joining and leaving a multicast group. This sample
// may be invoked as either a sender or a receiver. In both
// cases, the specified multicast group is joined.
//
// Compile:
// cl -o Mcastws2 Mcastws2.c Ws2_32.lib
//
// Command Line Options/Parameters
// Mcastws2.exe [-s] [-m:str] [-p:int] [-i:str] [-l] [-n:int]
// -s Act as sender; otherwise receive data
// -m:str Dotted decimal IP multicast address to join
// -p:int Port number to use
// -i:str Local interface to use
// -l Disable the loopback
// -n:int Number of messages to send or receive
//
#include <winsock2.h>
#include <ws2tcpip.h>#include <stdio.h>
#include <stdlib.h>#define MCASTADDR "234.5.6.7"
#define MCASTPORT 25000
#define BUFSIZE 1024
#define DEFAULT_COUNT 500BOOL bSender = FALSE, // Act as a sender?
bLoopBack = FALSE; // Disable loopback?DWORD dwInterface, // Local interface to bind to
dwMulticastGroup, // Multicast group to join
dwCount; // Number of messages to send/receiveshort iPort; // Port number to use//
// Function: usage
//
// Description:
// Print usage information and exit
//
void usage(char *progname)
{
printf("usage: %s -s -m:str -p:int -i:str -l -n:int\n",
progname);
printf(" -s Act as server (send data); otherwise\n");
printf(" receive data.\n");
printf(" -m:str Dotted decimal multicast IP addres "
"to join\n");
printf(" The default group is: %s\n", MCASTADDR);
printf(" -p:int Port number to use\n");
printf(" The default port is: %d\n", MCASTPORT);
printf(" -i:str Local interface to bind to; by default \n");
printf(" use INADDRY_ANY\n");
printf(" -l Disable loopback\n");
printf(" -n:int Number of messages to send/receive\n");
ExitProcess(-1);
}//
// Function: ValidateArgs
//
// Description
// Parse the command line arguments and set some global flags
// depeding on the values
//
void ValidateArgs(int argc, char **argv)
{
int i; dwInterface = INADDR_ANY;
dwMulticastGroup = inet_addr(MCASTADDR);
iPort = MCASTPORT;
dwCount = DEFAULT_COUNT; for(i=1; i < argc ;i++)
{
if ((argv[i][0] == '-') || (argv[i][0] == '/'))
{
switch (tolower(argv[i][1]))
{
case 's': // Sender
bSender = TRUE;
break;
case 'm': // Multicast group to join
if (strlen(argv[i]) > 3)
dwMulticastGroup = inet_addr(&argv[i][3]);
break;
case 'i': // Local interface to use
if (strlen(argv[i]) > 3)
dwInterface = inet_addr(&argv[i][3]);
break;
case 'p': // Port to use
if (strlen(argv[i]) > 3)
iPort = atoi(&argv[i][3]);
break;
case 'l': // Disable loopback
bLoopBack = TRUE;
break;
case 'n': // Number of messages to send/recv
dwCount = atoi(&argv[i][3]);
break;
default:
usage(argv[0]);
break;
}
}
}
return;
}//
// Function: main
//
// Description:
// Parse the command line arguments, load the Winsock library,
// create a socket and join the multicast group. If this program
// is run as a sender then begin sending messages to the multicast
// group; otherwise, call recvfrom() to read messages sent to the
// group.
//
int main(int argc, char **argv)
{
WSADATA wsd;
struct sockaddr_in local,
remote,
from;
SOCKET sock, sockM;
TCHAR recvbuf[BUFSIZE],
sendbuf[BUFSIZE];
int len = sizeof(struct sockaddr_in),
optval,
ret;
DWORD i=0; // Parse the command line and load Winsock
//
ValidateArgs(argc, argv); if (WSAStartup(MAKEWORD(2, 2), &wsd) != 0)
{
printf("WSAStartup() failed\n");
return -1;
}
// Create the socket. In Winsock 2 you do have to specify the
// multicast attributes that this socket will be used with.
//
if ((sock = WSASocket(AF_INET, SOCK_DGRAM, 0, NULL, 0,
WSA_FLAG_MULTIPOINT_C_LEAF
| WSA_FLAG_MULTIPOINT_D_LEAF
| WSA_FLAG_OVERLAPPED)) == INVALID_SOCKET)
{
printf("socket failed with: %d\n", WSAGetLastError());
WSACleanup();
return -1;
}
// Bind to the local interface. This is done to receive data.
local.sin_family = AF_INET;
local.sin_port = htons(iPort);
local.sin_addr.s_addr = dwInterface;
if (bind(sock, (struct sockaddr *)&local,
sizeof(local)) == SOCKET_ERROR)
{
printf("bind failed with: %d\n", WSAGetLastError());
closesocket(sock);
WSACleanup();
return -1;
}
// Setup the SOCKADDR_IN structure describing the multicast
// group we want to join
//
remote.sin_family = AF_INET;
remote.sin_port = htons(iPort);
remote.sin_addr.s_addr = dwMulticastGroup;
//
// Change the TTL to something more appropriate
//
optval = 8;
if (setsockopt(sock, IPPROTO_IP, IP_MULTICAST_TTL,
(char *)&optval, sizeof(int)) == SOCKET_ERROR)
{
printf("setsockopt(IP_MULTICAST_TTL) failed: %d\n",
WSAGetLastError());
closesocket(sock);
WSACleanup();
return -1;
}
// Disable loopback if needed
//
if (bLoopBack)
{
optval = 0;
if (setsockopt(sock, IPPROTO_IP, IP_MULTICAST_LOOP,
(char *)&optval, sizeof(optval)) == SOCKET_ERROR)
{
printf("setsockopt(IP_MULTICAST_LOOP) failed: %d\n",
WSAGetLastError());
closesocket(sock);
WSACleanup();
return -1;
}
}
// Join the multicast group. Note that sockM is not used
// to send or receive data. It is used when you want to
// leave the multicast group. You simply call closesocket()
// on it.
//
if ((sockM = WSAJoinLeaf(sock, (SOCKADDR *)&remote,
sizeof(remote), NULL, NULL, NULL, NULL,
JL_BOTH)) == INVALID_SOCKET)
{
printf("WSAJoinLeaf() failed: %d\n", WSAGetLastError());
closesocket(sock);
WSACleanup();
return -1;
} if (!bSender) // Receiver
{
// Receive data
//
for(i = 0; i < dwCount; i++)
{
if ((ret = recvfrom(sock, recvbuf, BUFSIZE, 0,
(struct sockaddr *)&from, &len)) == SOCKET_ERROR)
{
printf("recvfrom failed with: %d\n",
WSAGetLastError());
closesocket(sockM);
closesocket(sock);
WSACleanup();
return -1;
}
recvbuf[ret] = 0;
printf("RECV: '%s' from <%s>\n", recvbuf,
inet_ntoa(from.sin_addr));
}
}
else // Sender
{
// Send data
//
for(i = 0; i < dwCount; i++)
{
sprintf(sendbuf, "server 1: This is a test: %d", i);
if (sendto(sock, (char *)sendbuf, strlen(sendbuf), 0,
(struct sockaddr *)&remote,
sizeof(remote)) == SOCKET_ERROR)
{
printf("sendto failed with: %d\n",
WSAGetLastError());
closesocket(sockM);
closesocket(sock);
WSACleanup();
return -1;
}
Sleep(500);
}
}
// Leave the multicast group by closing sock
// For non-rooted control and data plane schemes, WSAJoinLeaf
// returns the same socket handle that you pass into it.
//
closesocket(sock); WSACleanup();
return -1;
}
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