本人初入计算机网络,最近在编写一个简单的UDP模型,主要功能是1.Server先开启监听 2.Client用sendto发送一条信息 3.Server用recvfrom接收 4.再用sendto回复 5.Client用recvfrom接收
参考了一些例子,但是从第四步开始总出错,ERRNO为97(#define EAFNOSUPPORT 97 /* Address family not supported by protocol */)在网上搜索无果,希望有经验的朋友们帮助一下我,十分谢谢!!!
我用C语言在UBUNTU18.10下实现。
以下是代码及运行结果:
UDPServer.c
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#define PORT 8004 //远端地址端口号
void main(void)
{
int serverSocket,peerlen,buflen;
char buf[200];
struct sockaddr_in local_addr,addr_from;
if(-1==(serverSocket=socket(AF_INET,SOCK_DGRAM,0)))
puts("socket开启失败");
else
puts("socket开启成功");
bzero(&local_addr, sizeof(local_addr));//清空字节
local_addr.sin_family = AF_INET;
local_addr.sin_port = htons(PORT);
local_addr.sin_addr.s_addr =INADDR_ANY;//s_addr到底是个什么类型?
//inet_addr是一个计算机函数,功能是将一个点分十进制的IP
//转换成一个长整数型数(u_long类型)等同于inet_addr()。
if(bind(serverSocket,(struct sockaddr*)&local_addr,
sizeof(local_addr))==-1)
printf("%s\n","绑定失败");
else
printf("%s\n","绑定成功");
if(-1==(buflen=recvfrom(serverSocket,buf,strlen(buf),0,(struct sockaddr *)&addr_from,&peerlen)))
puts("接受失败\n");
else
puts("接受成功\n");
puts(buf);
if(-1==(int)sendto(serverSocket,"REC",strlen("REC"),0,
(struct sockaddr *)&addr_from,sizeof(addr_from)))
puts("发送失败\n");
else
puts("发送成功\n");
close(serverSocket);
printf("%d",errno);
}
UDPClient.c
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#define PORT 8004 //远端地址端口号
void main(void)
{
int clientSocket,buflen,addrlen,peerlen;
char addr[]="10.14.21.68",buf[200];
struct sockaddr_in remoteaddr,addr_from;
if(-1==(clientSocket=socket(AF_INET,SOCK_DGRAM,0)))
puts("socket开启失败");
else
puts("socket开启成功");
bzero(&remoteaddr, sizeof(remoteaddr));//清空字节
remoteaddr.sin_family = AF_INET;
remoteaddr.sin_port = htons(PORT);
remoteaddr.sin_addr.s_addr =inet_addr(addr);
if(-1==(sendto(clientSocket,"HI",strlen("HI"),0,
(struct sockaddr *)&remoteaddr,addrlen=sizeof(remoteaddr))))
puts("发送失败\n");
else
puts("发送成功\n");
if(-1==(buflen=recvfrom(clientSocket,buf,sizeof(buf),0,
(struct sockaddr *)&remoteaddr,&addrlen)))
puts("接受失败\n");
else
puts("接受成功\n");
puts(buf);
close(clientSocket);
}
运行结果
Server:
socket开启成功
绑定成功
接受成功
HI3Z�
发送失败
97
Client:
socket开启成功
发送成功