multicast
Bruce D. McLeod
b.mcleod@opengroup.org
Wed Mar 19 18:13:00 GMT 1997
This seems to be due to the mapping of IP_ADD_MEMBERSHIP to 35
in cygwin32/socket.h as opposed to 5 in winsock.h. I hardcoded
the option at 5, and it works fine.
Bruce
>Date: Wed, 19 Mar 1997 11:16:14 -0500
>To: gnu-win32@cygnus.com
>From: "Bruce D. McLeod" <b.mcleod@opengroup.org>
>Subject: multicast
>
>Has anyone successfully used multicast using the sys/sockets.h version
>of the network stuff? I am getting "This option is unsupported"
>for the setsockopt:
>
> err = setsockopt( gListener, IPPROTO_IP, IP_ADD_MEMBERSHIP,
> (char *) &multiStruct, sizeof(multiStruct) );
>
>Bruce
>
>The full code...
>
>
>#include <sys/socket.h>
>#include <netinet/in.h>
>#include <netdb.h>
>#include <stdio.h>
>
>#define PANIC() printf("panic\n"); exit(1);
>#define ASSERT( x ) if ( (x) == 0 ) { PANIC(); }
>
>const static int gMyPort = 5500;
>const static char* gMyMultiIp = "225.1.1.88";
>int gListener;
>
>main( int argc, char **argv )
>{
> if (argc > 1) {
> struct sockaddr_in localAddr;
> int err, value;
> struct ip_mreq multiStruct;
> char hostName[200];
> struct hostent* myHostent;
>
> // Set up listening socket.
> gListener = socket( AF_INET, SOCK_DGRAM, 0 );
> ASSERT( gListener != -1 );
>
> value = 1;
> err = setsockopt( gListener, SOL_SOCKET, SO_REUSEADDR,
> (char *) &value, sizeof(value) );
> ASSERT( err != -1 );
>
> err = gethostname( hostName, 200 );
> ASSERT( err != -1 );
> myHostent = gethostbyname( hostName );
> ASSERT( myHostent != NULL );
>
> localAddr.sin_family = AF_INET;
> localAddr.sin_addr.s_addr = *((long *) myHostent->h_addr_list[0]);
> localAddr.sin_port = htons( gMyPort );
>
> err = bind( gListener, (struct sockaddr *) &localAddr,
sizeof(localAddr) );
> ASSERT( err != -1 );
>
> multiStruct.imr_multiaddr.s_addr = inet_addr( gMyMultiIp );
> multiStruct.imr_interface.s_addr = *((long *) myHostent->h_addr_list[0]);
> err = setsockopt( gListener, IPPROTO_IP, IP_ADD_MEMBERSHIP,
> (char *) &multiStruct, sizeof(multiStruct) );
> if (err == -1) perror("setsockopt failed");
> ASSERT( err != -1 );
>
> for (;;) {
> static const int bufsize = 200;
> char buf[bufsize];
> struct sockaddr fromAddr;
> int fromAddrLen, bytes;
>
> printf( "MultiTest: waiting for data\n" );
>
> fromAddrLen = sizeof(fromAddr);
> bytes = recvfrom( gListener, buf, bufsize, 0,
> &fromAddr, &fromAddrLen );
> ASSERT( bytes >= 0 );
>
> if (bytes == 0) {
> printf( "MultiTest: disconnect received\n" );
> close( gListener );
> return 1;
> }
>
> printf( "MultiTest: msg received: %s\n", buf );
> }
> } else {
> static const char msg[] = "Hello world.";
> struct sockaddr_in remoteAddr;
> int bytes;
>
> int s = socket( AF_INET, SOCK_DGRAM, 0 );
> ASSERT( s != -1 );
>
> remoteAddr.sin_family = AF_INET;
> remoteAddr.sin_port = htons( gMyPort );
> remoteAddr.sin_addr.s_addr = inet_addr( gMyMultiIp );
>
> bytes = sendto( s, msg, strlen( msg ) + 1, 0,
> (struct sockaddr *) &remoteAddr, sizeof(remoteAddr) );
> ASSERT( bytes == (int) strlen( msg ) + 1 );
> printf("MultiTest: msg sent\n");
>
> close( s );
> }
>
> return 0;
>}
>
-
For help on using this list, send a message to
"gnu-win32-request@cygnus.com" with one line of text: "help".
More information about the Cygwin
mailing list