server.c

实现udp包传输的client和server

#include <sys/types.h>
#include <sys/socket.h>
#include<netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <errno.h>

#define PORT 3478

int main()
{
	int sockfd,len;
	struct sockaddr_in addr;
	int addr_len;
	char buffer[256];

	addr_len = sizeof(addr);
	if((sockfd = socket(AF_INET,SOCK_DGRAM,0)) == -1)
	{
		fprintf(stderr,"open socket error:%s\n",strerror(errno));
		exit(1);
	}
	bzero(&addr,addr_len);
	addr.sin_family = AF_INET;
	addr.sin_port = htons(PORT);
	addr.sin_addr.s_addr = htonl(INADDR_ANY);
	if(bind(sockfd,(struct sockaddr *)&addr,addr_len) == -1)
	{
		fprintf(stderr,"bind error:%s\n",strerror(errno));
		exit(1);	
	}
	
	while(1)
	{
		bzero(buffer,sizeof(buffer));
		len = recvfrom(sockfd,buffer,sizeof(buffer),
				0,(struct sockaddr *)&addr,&addr_len);
		//display address of cilent
		printf("receive from %s\n",inet_ntoa(addr.sin_addr));
		sendto(sockfd,buffer,len,0,(struct sockaddr *)&addr,addr_len);
	}

	return 0;		
}