linux UDP 获取数据

#include 
#include "unistd.h"
#include           /* See NOTES */
#include 
#include 
#include 

#define SUCCESS 0
#define BUFF_LEN 1024
#define PORT 8083
int CreateUDPScoket()
{
    int sfd =  socket(AF_INET, SOCK_DGRAM, 0);
    if(sfd == -1){
        printf("Create Socket failed!\n");
    }
    return sfd;
}

int BindPortUDP(int sfd)
{
    struct sockaddr_in addr;
    memset(&addr, 0 , sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = htonl(INADDR_ANY);  //注意网络序转换
    addr.sin_port = htons(PORT);  //注意网络序转换

    int ret = bind(sfd, (struct sockaddr *)&addr ,sizeof(addr));
    if(ret < 0)
    {
       printf("socket bind fail!\n");
       return -1;
    }

    return 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
    }
}

int main()
{
    int Serverfd = CreateUDPScoket();
    BindPortUDP(Serverfd);
    handle_udp_msg(Serverfd);

    return 0;
}