WSJT-X/plrr_subs_win.c
Joe Taylor 48713421d0 Cleaned up more buffering of multicast receiving socket.
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/map65@476 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2007-07-09 11:45:49 +00:00

99 lines
2.7 KiB
C

#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdlib.h>
#include <stdio.h>
#define HELLO_PORT 50004
#define HELLO_GROUP "239.255.0.0"
#define MSGBUFSIZE 1416
struct sockaddr_in addr;
int fd;
//void __stdcall SETUP_RSOCKET(void)
void setup_rsocket_(void)
{
struct ip_mreq mreq;
u_int yes=1;
int i,j,k;
// Make sure that we have compatible Winsock support
WORD wVersionRequested;
WSADATA wsaData;
int err;
wVersionRequested = MAKEWORD( 2, 2 );
err = WSAStartup( wVersionRequested, &wsaData );
if ( err != 0 ) {
/* Tell the user that we could not find a usable */
/* WinSock DLL. */
exit(1);
}
/* Confirm that the WinSock DLL supports 2.2.*/
/* Note that if the DLL supports versions greater */
/* than 2.2 in addition to 2.2, it will still return */
/* 2.2 in wVersion since that is the version we */
/* requested. */
if ( LOBYTE( wsaData.wVersion ) != 2 ||
HIBYTE( wsaData.wVersion ) != 2 ) {
/* Tell the user that we could not find a usable */
/* WinSock DLL. */
WSACleanup( );
exit(1);
}
/* The WinSock DLL is acceptable. Proceed. */
/* create what looks like an ordinary UDP socket */
if ((fd=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP)) < 0) {
perror("socket");
exit(1);
}
k=sizeof(int);
i=256*1024;
err=setsockopt(fd, SOL_SOCKET, SO_RCVBUF, (char *)&i,k);
if (err<0) {
j=WSAGetLastError();
printf("Error: %d %d\n",err,j);
}
/* allow multiple sockets to use the same PORT number */
if (setsockopt(fd,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(yes)) < 0) {
perror("Reusing ADDR failed");
exit(1);
}
/* set up destination address */
memset(&addr,0,sizeof(addr));
addr.sin_family=AF_INET;
addr.sin_addr.s_addr=htonl(INADDR_ANY); /* N.B.: differs from sender */
addr.sin_port=htons(HELLO_PORT);
/* bind to receive address */
if (bind(fd,(struct sockaddr *) &addr,sizeof(addr)) < 0) {
perror("bind");
exit(1);
}
/* use setsockopt() to request that the kernel join a multicast group */
mreq.imr_multiaddr.s_addr=inet_addr(HELLO_GROUP);
mreq.imr_interface.s_addr=htonl(INADDR_ANY);
if (setsockopt(fd,IPPROTO_IP,IP_ADD_MEMBERSHIP,&mreq,sizeof(mreq)) < 0) {
perror("setsockopt");
exit(1);
}
}
//void __stdcall RECV_PKT(char buf[])
void recv_pkt_(char buf[])
{
int addrlen,nbytes;
addrlen=sizeof(addr);
if ((nbytes=recvfrom(fd,buf,1416,0,
(struct sockaddr *) &addr,&addrlen)) < 0) {
perror("recvfrom");
exit(1);
}
}