UDP-server服务器代码

第一版

/*
	UDP socket server
	server:socket-->bind-->recvfrom-->sendto-->close
*/

#include <stdlib.h>
#include <stdio.h>
#include <sys/socket.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>     // 包含AF_INET相关结构
#include <arpa/inet.h>      // 包含AF_INET相关操作函数
#include <string.h>
 
#define SERVER_PORT 8000
#define BUFF_LEN 1024

void handle_udp_msg(int fd);


int main(int argc, char * argv[])
{
	int server_fd, ret;
	struct sockaddr_in ser_addr; 
	
	server_fd = socket(AF_INET, SOCK_DGRAM, 0); //AF_INET:IPV4;SOCK_DGRAM:UDP
	if(server_fd < 0)
	{
		printf("create socket fail!\n");
		return -1;
	}
	
	//memset(&ser_addr, 0, sizeof(ser_addr));
	ser_addr.sin_family = AF_INET;
	//ser_addr.sin_addr.s_addr = htonl(INADDR_ANY);	//IP地址，需要进行网络序转换，INADDR_ANY：本地地址
	ser_addr.sin_addr.s_addr = inet_addr("192.168.101.128");
	ser_addr.sin_port = htons(SERVER_PORT);  		//端口号，需要网络序转换
	
	ret = bind(server_fd, (struct sockaddr*)&ser_addr, sizeof(ser_addr));
	if(ret < 0)
	{
		printf("socket bind fail!\n");
		return -1;
	}
	
	//handle_udp_msg(server_fd);   	//处理接收到的数据
	int count;
	socklen_t len;
	char buf[BUFF_LEN];
	struct sockaddr_in clent_addr;

	memset(buf, 0, BUFF_LEN);
	len = sizeof(clent_addr);
	count = recvfrom(server_fd, buf, BUFF_LEN, 0, (struct sockaddr*)&clent_addr, &len);  //recvfrom是拥塞函数，没有数据就一直拥塞
	if(count == -1)
	{
		printf("recieve data fail!\n");
	}
	else
	{
		printf("recieve data success:%d\n", count);
	}
	
	close(server_fd);
	exit(EXIT_SUCCESS);
}



void handle_udp_msg(int fd)
{
	char buf[BUFF_LEN];  //接收缓冲区，1024字节
    socklen_t len;
    int count;
    struct sockaddr_in clent_addr;  //clent_addr用于记录发送方的地址信息
    while(1)
    {
        memset(buf, 0, BUFF_LEN);
        len = sizeof(clent_addr);
        count = recvfrom(fd, buf, BUFF_LEN, 0, (struct sockaddr*)&clent_addr, &len);  //recvfrom是拥塞函数，没有数据就一直拥塞
        if(count == -1)
        {
            printf("recieve data fail!\n");
            return;
        }
        printf("client:%s\n",buf);  //打印client发过来的信息
        memset(buf, 0, BUFF_LEN);
        sprintf(buf, "I have recieved %d bytes data!\n", count);  //回复client
        printf("server:%s\n",buf);  //打印自己发送的信息给
        sendto(fd, buf, BUFF_LEN, 0, (struct sockaddr*)&clent_addr, len);  //发送信息给client，注意使用了clent_addr结构体指针
 
    }
}