C++基础tcp通信练习问题 客户端连接服务端失败 返回值10038 求答

Question

客户端代码

#define WIN32_LEAN_AND_MEAN
#define _WINSOCK_DEPRECATED_NO_WARNINGS
#include<WinSock2.h>
#include<windows.h>
#include<stdio.h>
#pragma comment(lib,"ws2_32.lib")

int main()
{
    //启动Windows socket2.x环境
    WORD ver = MAKEWORD(2, 2);
    WSADATA dat;
    WSAStartup(ver, &dat);
    ///-----------------
    //1 建立一个socket
    SOCKET _sock = (AF_INET, SOCK_STREAM, 0);
    if (INVALID_SOCKET == _sock)
    {
        printf("error sock\n");
    }
    else
    {
        printf("success sock\n");
    }
    //2 连接服务器 connect
    sockaddr_in _sin = {};
    _sin.sin_family = AF_INET;
    _sin.sin_port = htons(1234);
    _sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
    int ret = connect(_sock, (sockaddr*)&_sin, sizeof(_sin));
    if (SOCKET_ERROR == ret)
    {
        printf("error connect\n");
    }
    else
    {
        printf("success connect\n");
    }
    //3 接收服务器信息 recv
    char recvBuf[256] = {};
    int nlen = recv(_sock, recvBuf, 256, 0);
    if (nlen > 0)
    {
        printf("recv:%s", recvBuf);
    }
    //4 关闭 closesocket
    closesocket(_sock);
    ///-----------------
    WSACleanup();
    getchar();
    return 0;
}

服务端代码

#define WIN32_LEAN_AND_MEAN
#define _WINSOCK_DEPRECATED_NO_WARNINGS
#include<WinSock2.h>
#include<windows.h>
#include<stdio.h>
#pragma comment(lib,"ws2_32.lib")

int main()
{
    //启动Windows socket2.x环境
    WORD ver = MAKEWORD(2, 2);
    WSADATA dat;
    WSAStartup(ver, &dat);
    ///-----------------
    //1 建立一个socket
    SOCKET _sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    //2 bind 绑定用于接受客户端连接的网络端口
    sockaddr_in _sin = {};
    _sin.sin_family = AF_INET;
    _sin.sin_port = htons(1234);//htons = host to net unsigned short
    _sin.sin_addr.S_un.S_addr = INADDR_ANY;//inet_addr("127.0.0.1");
    if (SOCKET_ERROR == bind(_sock, (sockaddr*)&_sin, sizeof(_sin)))
    {
        printf("bind error\n");
    }
    else
    {
        printf("bind success\n");
    }
    //3 listen 监听网络端口
    if (SOCKET_ERROR == listen(_sock, 5))
    {
        printf("listen error\n");
    }
    else
    {
        printf("listen success\n");
    }
    //4 accept 等待接受客户端连接
    sockaddr_in clientAddr = {};
    int nAddrLen = sizeof(sockaddr_in);
    SOCKET _cSock = INVALID_SOCKET;
    char msgBuf[] = "can't find work";
    while (true)
    {
        _cSock = accept(_sock, (sockaddr*)&clientAddr, &nAddrLen);
        if (INVALID_SOCKET == _cSock)
        {
            printf("client error\n");
        }
        printf("new client: ip = %s \n", inet_ntoa(clientAddr.sin_addr));
        //5 send 向客户端发送一条数据

        send(_cSock, msgBuf, strlen(msgBuf) + 1, 0);
    }

    //6 closeSocket 关闭
    closesocket(_sock);
    ///-----------------
    //清除Windows socket 环境
    WSACleanup();
    return 0;
}

运行结果

求大神解答！！！！
///////////////////////////////////
再使用了GetLastError后返回的值是10038

Answer 1

//创建套接字（与服务端保持一致）

//1 建立一个socket
SOCKET _sock = (AF_INET, SOCK_STREAM, 0);

//1 建立一个socket
SOCKET _sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

有以下定义
/*

• Protocols / #define IPPROTO_IP 0 / dummy for IP / #define IPPROTO_ICMP 1 / control message protocol / #define IPPROTO_IGMP 2 / internet group management protocol / #define IPPROTO_GGP 3 / gateway^2 (deprecated) / #define IPPROTO_TCP 6 / tcp / #define IPPROTO_PUP 12 / pup / #define IPPROTO_UDP 17 / user datagram protocol / #define IPPROTO_IDP 22 / xns idp / #define IPPROTO_ND 77 / UNOFFICIAL net disk proto / #define IPPROTO_RAW 255 / raw IP packet */ #define IPPROTO_MAX 256

---

WSADATA WSAData;
if (WSAStartup(MAKEWORD(2, 0), &WSAData) == SOCKET_ERROR)  //WSAStartup()函数对Winsock DLL进行初始化
{
printf("Socket initialize fail!\n");
continue;
}
/*
* windows下使用socket必须用WSAStartup初始化，否则不能调用
*/
if (WSAStartup(MAKEWORD(2, 2), &WSAData)) //加载socket 2.2通讯协议库
{
printf("WSA failed\n");
return -1;
}

SOCKET sock; //客户端进程创建套接字
if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == SOCKET_ERROR)  //创建流套接字（与服务端保持一致）
{
printf("Socket create fail!\n");
WSACleanup();
continue;
}

#pragma warning(disable : 4996)
struct hostent* host_addr = gethostbyname(IP);
sockaddr_in sin;
sin.sin_family = AF_INET;
sin.sin_port = htons((unsigned short)PORT);
sin.sin_addr.s_addr = *((unsigned long*)*host_addr->h_addr_list);


if (connect(sock, (LPSOCKADDR)&sin, sizeof(sin)) == SOCKET_ERROR)  //调用connect()函数，向服务器进程发出连接请求  
{
printf("Connect fail!\n");
closesocket(sock);
WSACleanup();
continue;
}
int ret = send(sock, sndBuf, strlen(sndBuf) + 1, 0);                 //向服务器发送数据 
//循环读取
ret = recv(sock, rcvBuf, sizeof(rcvBuf), 0);