mirror of https://github.com/saitohirga/WSJT-X.git
68 lines
1.5 KiB
C
68 lines
1.5 KiB
C
#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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/* The following don't seem to be needed?
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#include <time.h>
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#include <stdio.h>
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*/
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#include <arpa/inet.h>
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#include <string.h>
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#include <stdlib.h>
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#define HELLO_PORT 50004
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#define HELLO_GROUP "239.255.0.0"
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#define MSGBUFSIZE 1416
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struct sockaddr_in addr;
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int fd;
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void setup_rsocket_(void)
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{
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struct ip_mreq mreq;
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u_int yes=1;
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/* create what looks like an ordinary UDP socket */
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if ((fd=socket(AF_INET,SOCK_DGRAM,0)) < 0) {
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perror("socket");
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exit(1);
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}
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/* allow multiple sockets to use the same PORT number */
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if (setsockopt(fd,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(yes)) < 0) {
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perror("Reusing ADDR failed");
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exit(1);
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}
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/* set up destination address */
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memset(&addr,0,sizeof(addr));
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addr.sin_family=AF_INET;
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addr.sin_addr.s_addr=htonl(INADDR_ANY); /* N.B.: differs from sender */
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addr.sin_port=htons(HELLO_PORT);
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/* bind to receive address */
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if (bind(fd,(struct sockaddr *) &addr,sizeof(addr)) < 0) {
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perror("bind");
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exit(1);
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}
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/* use setsockopt() to request that the kernel join a multicast group */
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mreq.imr_multiaddr.s_addr=inet_addr(HELLO_GROUP);
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mreq.imr_interface.s_addr=htonl(INADDR_ANY);
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if (setsockopt(fd,IPPROTO_IP,IP_ADD_MEMBERSHIP,&mreq,sizeof(mreq)) < 0) {
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perror("setsockopt");
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exit(1);
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}
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}
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void recv_pkt_(char buf[])
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{
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int addrlen,nbytes;
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addrlen=sizeof(addr);
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if ((nbytes=recvfrom(fd,buf,1416,0,
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(struct sockaddr *) &addr,&addrlen)) < 0) {
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perror("recvfrom");
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exit(1);
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}
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}
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