//server.cpp
#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <string.h>

char * host_name = "192.168.0.255";
int port = 10051;

int main(void)
{
struct sockaddr_in serv_addr,addr;
char buf[256];

int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
if (sockfd == -1)
{
perror("Error: socket";
return -1;
}
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = inet_addr(host_name);//htonl(INADDR_ANY);//

int bd = bind(sockfd, (struct sockaddr*)&addr, sizeof(struct sockaddr_in));
while(1)
{
int len = sizeof(serv_addr);
memset(&serv_addr, 0, len);
int ret = recvfrom(sockfd,buf,sizeof(buf),0,(struct sockaddr*)&serv_addr,(socklen_t*)&len);
printf("recv=%d buf=%s
",ret, buf);
printf("RecvieIPs Recive Portd
", inet_ntoa(serv_addr.sin_addr),
ntohs(serv_addr.sin_port));
ret = sendto(sockfd,buf,sizeof(buf),0,(struct sockaddr*)&serv_addr,sizeof(struct sockaddr_in));
}

}


//client.cpp

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <string.h>

char * host_name = "192.168.0.255";

int port = 10051;
int main(void)
{
int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
if (sockfd == -1)
{
perror("Error: socket";
return -1;
}

struct sockaddr_in serv_addr;
memset(&serv_addr, 0, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
serv_addr.sin_port = htons(port);
serv_addr.sin_addr.s_addr = inet_addr(host_name);
int so_broadcast;
setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, &so_broadcast,
sizeof(so_broadcast));

char buf[256]="client .............";
sockaddr from ;
int len;
sendto(sockfd,buf,sizeof(buf),0,(struct sockaddr*)&serv_addr,sizeof(struct sockaddr_in));
while(1)
{
recvfrom(sockfd,buf,sizeof(buf),0,(struct sockaddr*)&serv_addr,(socklen_t*)&len);
printf("server buf= %s
",buf);
}
}