连接到IP地址而不是本地主机？

Question

这是我的第二次尝试，我已经编写了一个服务器应用程序，如下所示，它输出客户端发送的任何内容。我有一个server.exe版本，它使用INADDR_ANY监听任何东西，已经完成了这项工作，如果我指定客户端连接到本地主机(这一切都很好)，我就可以使用我的客户端并连接到服务器。

但是如果我对客户机使用自己的IP地址而不是localhost，我就不能连接到服务器。我不能以这种方式连接到服务器吗？

我使用了另一个server.exe，它被硬编码为使用我的IP地址，没有INADDR_ANY，但它不能对传入连接执行bind()或listen()操作。我对如何继续下去感到困惑。

(我在同一台机器上运行服务器和客户端，这有问题吗？)

服务器

#include <iostream>
#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
using namespace std;

#define PORT 3490
#define IP "118.93.0.164"
#define BACKLOG 10

const int winsockversion = 2;

int main(void){
    WSADATA wsadata;
    if ( (WSAStartup(MAKEWORD(winsockversion,0),&wsadata)) == 0){
        cout<<"-WSAStartup Initialized." << endl;

        struct sockaddr_in serv;
        memset(&serv,0,sizeof serv);
        serv.sin_family = AF_INET;
        serv.sin_port = htons(PORT);
        serv.sin_addr.s_addr = inet_addr(IP);//INADDR_ANY;//inet_addr(IP);
        //---------------------------------------
        struct addrinfo serv_addrinfo;
        serv_addrinfo.ai_family = AF_INET;
        serv_addrinfo.ai_socktype = SOCK_STREAM;
        serv_addrinfo.ai_protocol = IPPROTO_TCP;
        serv_addrinfo.ai_addrlen = sizeof(serv);
        serv_addrinfo.ai_addr = (sockaddr*)&serv;


        //---------------------------------------
        SOCKET serv_con;
        serv_con = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
        if (serv_con != INVALID_SOCKET){
            cout<<"-Server Socket created." << endl;
        }

        if (bind(serv_con,serv_addrinfo.ai_addr,serv_addrinfo.ai_addrlen) != -1){
            cout<<"-Binding Successful." << endl;
        }

        if( listen(serv_con,BACKLOG) != -1){
            cout<<"-Listening for incoming connections." << endl;
        }
        //--------------------------------------------------------------------
        SOCKET recv_socket;
        struct sockaddr_in client_info;
        int client_info_size = sizeof(client_info);

        char *con_addr = inet_ntoa(client_info.sin_addr);




        recv_socket = accept(serv_con,(sockaddr*)&client_info,&client_info_size);

        if( recv_socket != INVALID_SOCKET ){
            cout<<"-Connection Established!. " << endl;
            cout<<"-Connected to: [" << con_addr << "] " << endl;
        //----------------------------------------------------------------------
            char buffer[80];
            int bytes_in;
            while(true){

                bytes_in = recv(recv_socket,buffer,sizeof(buffer),0);
                if ( bytes_in > 0 ){
                    cout<<"[" << con_addr << "]" << buffer << endl;
                }

                if (bytes_in == 0 ){
                    cout<<"[" << con_addr << "] has disconnected." << endl;
                    break;
                }
                if (bytes_in == -1 ){
                    cout<<"-Possible Abrupt disconnecton from [" << con_addr << "]" << endl;
                    break;
                }
            }

            closesocket(recv_socket);
            closesocket(serv_con);

        }

    }else{
        cout<<"-WSAStartup Initialization failed." << endl;
    }

    if( WSACleanup()!= -1){
        cout<<"-WSACleanp Successful." << endl;
    }

    WSAGetLastError();


    return 0;
}

客户端

/*client*/
#define _WIN32_WINNT 0x501
#include <iostream>
#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
using namespace std;

#define PORT "3490"
#define SERVER "118.93.0.164" // and localhost 
const int winsockVersion = 2;


int main(void){

    WSADATA wsadata;
    if ( (WSAStartup(MAKEWORD(2,0),&wsadata)) == 0){
        cout<<"-WSAStartup Initialized." << endl;

        struct addrinfo hints, *res;
        int sockfd;

        memset(&hints,0,sizeof hints);
        hints.ai_family = AF_UNSPEC;
        hints.ai_socktype = SOCK_STREAM;

        if (getaddrinfo(SERVER,PORT,&hints,&res) != 0){
            cout<<"-getaddrinfo unsuccessful." << endl;
        }

        if ( (sockfd = socket(res->ai_family,res->ai_socktype,res->ai_protocol)) == -1 ){
            cout<<"-Unable to create socket." << endl;
        }

        if ( (connect(sockfd,res->ai_addr,res->ai_addrlen)) != -1 ){
            cout<<"-Connection Established." << endl;
        }

        cout<<"-Client connecting to: " << res->ai_addr << endl;

        while(true){
            string text_buff;
            cout<<"Enter text: ";
            getline(cin,text_buff);
            if( (send(sockfd,text_buff.c_str(),text_buff.length()+1,0)) != -1 ){
                cout<<"-text_buff sent!." << endl;
            }

        }

    }else{
        cout<<"-WSAStartup Initialization failed." << endl;
        if(WSACleanup()!=0){
            cout<<"-WSACleanup Successful." << endl;
        }else{
            cout<<"-WSACleanup Failed." << endl;
        }
    }

    return 0;
}

Answer 1

如果您有路由器，则必须设置Port forwarding。这真的取决于你有什么类型的路由器，所以你必须为你的特定路由器查找它。

您不能绑定到ISP的IP地址，因为您不拥有它(路由器拥有)。您必须通过windows中的ipconfig /all找到您的计算机实际拥有的IP地址。然后，确保将路由器中服务器端口号的流量转发到计算机拥有的内部in地址。

Answer 2

您可以尝试使用cmd从客户端ping服务器IP，以查看是否存在连接问题。

而且我觉得这个

#define PORT "3490"

在客户端是错误的，因为端口应该是一个整数。

Answer 3

当您尝试连接回服务器时，您使用的是localhost/127.0.0.1，还是您正在侦听的IP地址？

可能是试图连接到“localhost”尝试使用回送接口，而您的程序并未侦听该接口。我不是100%确定它在Windows中是如何工作的。

我可以问一个更重要的问题，它可能会促使您更改设计:为什么要绑定到特定的IP (和本地主机)？