我写过（而不是从教程中复制：P）一个winsock服务器，用c ++等待客户端发送消息然后关闭。当客户端和服务器都在我的PC上时服务器工作，但是当我将客户端移动到另一台计算机时，它会失败。
我认为这是我的ip地址的一个问题，但我在命令提示符下输入ipconfig \all时得到的是192.168.254.4。
//******************************************************************************
//
// Main.cpp
//
// Main source file of the Listener program, which employs blocking sockets and
// Winsock to listen for outside connections.
//
// If you are not using the included Dev-C++ project file, be sure to link with
// the Winsock library, usually wsock32.lib or something similarly named.
//
// Author: Johnnie Rose, Jr. (johnnie2@hal-pc.org)
// Date: 1/08/03 (version 2)
// Website: http://www.hal-pc.org/~johnnie2/winsock.html
//
//******************************************************************************
#include <windows.h>
#include <winsock2.h>
#include <stdio.h>
#include <iostream>
#define NETWORK_ERROR -1
#define NETWORK_OK 0
void ReportError(int, const char *);
using namespace std;
int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, LPSTR lpCmd, int nShow) {
WORD sockVersion;
WSADATA wsaData;
int nret;
sockVersion = MAKEWORD(2, 2); // We'd like Winsock version 1.1
// We begin by initializing Winsock
WSAStartup(sockVersion, &wsaData);
// Next, create the listening socket
SOCKET listeningSocket;
listeningSocket = socket(AF_INET, // Go over TCP/IP
SOCK_STREAM, // This is a stream-oriented socket
IPPROTO_TCP); // Use TCP rather than UDP
if (listeningSocket == INVALID_SOCKET) {
nret = WSAGetLastError(); // Get a more detailed error
ReportError(nret, "socket()"); // Report the error with our custom function
WSACleanup(); // Shutdown Winsock
return NETWORK_ERROR; // Return an error value
}
// Use a SOCKADDR_IN struct to fill in address information
SOCKADDR_IN serverInfo;
serverInfo.sin_family = AF_INET;
serverInfo.sin_addr.s_addr = INADDR_ANY; // Since this socket is listening for
// connections, any local address will do
serverInfo.sin_port = htons(8888); // Convert integer 8888 to network-byte order
// and insert into the port field
// Bind the socket to our local server address
nret = bind(listeningSocket, (LPSOCKADDR)&serverInfo, sizeof(struct sockaddr));
if (nret == SOCKET_ERROR) {
nret = WSAGetLastError();
ReportError(nret, "bind()");
WSACleanup();
return NETWORK_ERROR;
}
// Make the socket listen
nret = listen(listeningSocket, 10); // Up to 10 connections may wait at any
// one time to be accept()'ed
if (nret == SOCKET_ERROR) {
nret = WSAGetLastError();
ReportError(nret, "listen()");
WSACleanup();
return NETWORK_ERROR;
}
// Wait for a client
cout << "Waiting for client" << endl;
SOCKET theClient;
theClient = accept(listeningSocket,
NULL, // Address of a sockaddr structure (see explanation below)
NULL); // Address of a variable containing size of sockaddr struct
if (theClient == INVALID_SOCKET) {
nret = WSAGetLastError();
ReportError(nret, "accept()");
WSACleanup();
return NETWORK_ERROR;
}
char Buffer[256];
recv(theClient, Buffer, 256, 0);
printf(Buffer, 2);
// Send and receive from the client, and finally,
closesocket(theClient);
closesocket(listeningSocket);
// Shutdown Winsock
WSACleanup();
system("PAUSE");
return NETWORK_OK;
}
void ReportError(int errorCode, const char *whichFunc) {
char errorMsg[92]; // Declare a buffer to hold
// the generated error message
ZeroMemory(errorMsg, 92); // Automatically NULL-terminate the string
// The following line copies the phrase, whichFunc string, and integer errorCode into the buffer
sprintf(errorMsg, "Call to %s returned error %d!", (char *)whichFunc, errorCode);
MessageBox(NULL, errorMsg, "socketIndication", MB_OK);
}
//******************************************************************************
//
// Main.cpp
//
// Main source file of the Connector program, which employs blocking sockets and
// Winsock to connect to an outside server.
//
// If you are not using the included Dev-C++ project file, be sure to link with
// the Winsock library, usually wsock32.lib or something similarly named.
//
// Author: Johnnie Rose, Jr. (johnnie2@hal-pc.org)
// Date: 1/08/03 (version 2)
// Website: http://www.hal-pc.org/~johnnie2/winsock.html
//
//******************************************************************************
#include <windows.h>
#include <winsock2.h>
#include <stdio.h>
#include <iostream>
#define NETWORK_ERROR -1
#define NETWORK_OK 0
void ReportError(int, const char *);
using namespace std;
int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, LPSTR lpCmd, int nShow) {
WORD sockVersion;
WSADATA wsaData;
int nret;
cout <<"Loading WinSock" << endl;
sockVersion = MAKEWORD(2, 2);
// Initialize Winsock as before
WSAStartup(sockVersion, &wsaData);
// Store information about the server
LPHOSTENT hostEntry;
in_addr iaHost;
iaHost.s_addr = inet_addr("192.168.254.4");
hostEntry = gethostbyaddr((const char *)&iaHost, sizeof(struct in_addr), AF_INET); // Specifying the server by its name;
// another option is gethostbyaddr()
if (!hostEntry) {
nret = WSAGetLastError();
ReportError(nret, "gethostbyaddr()"); // Report the error as before
WSACleanup();
return NETWORK_ERROR;
}
// Create the socket
cout <<"Creating Socket";
SOCKET theSocket;
theSocket = socket(AF_INET, // Go over TCP/IP
SOCK_STREAM, // This is a stream-oriented socket
IPPROTO_TCP); // Use TCP rather than UDP
if (theSocket == INVALID_SOCKET) {
nret = WSAGetLastError();
ReportError(nret, "socket()");
WSACleanup();
return NETWORK_ERROR;
}
// Fill a SOCKADDR_IN struct with address information
SOCKADDR_IN serverInfo;
serverInfo.sin_family = AF_INET;
serverInfo.sin_addr = *((LPIN_ADDR)*hostEntry->h_addr_list); // See the explanation in the tutorial
serverInfo.sin_port = htons(8888); // Change to network-byte order and
// insert into port field
cout << "Connecting to server" << endl;
// Connect to the server
nret = connect(theSocket,
(LPSOCKADDR)&serverInfo,
sizeof(struct sockaddr));
if (nret == SOCKET_ERROR) {
nret = WSAGetLastError();
ReportError(nret, "connect()");
WSACleanup();
return NETWORK_ERROR;
}
// Successfully connected!
char* Buffer;
send(theSocket, "A", 1, 0);
recv(theSocket, Buffer, 256,0);
printf(Buffer,256);
// Send/receive, then cleanup:
closesocket(theSocket);
WSACleanup();
system("PAUSE");
return 0;
}
void ReportError(int errorCode, const char *whichFunc) {
char errorMsg[92]; // Declare a buffer to hold
// the generated error message
ZeroMemory(errorMsg, 92); // Automatically NULL-terminate the string
// The following line copies the phrase, whichFunc string, and integer errorCode into the buffer
sprintf(errorMsg, "Call to %s returned error %d!", (char *)whichFunc, errorCode);
MessageBox(NULL, errorMsg, "socketIndication", MB_OK);
}
答案 0 :(得分：3)
如果您在另一台计算机上运行未修改的客户端代码，它可能仍在尝试连接到“localhost”上的服务器，这不是您想要的。 [编辑：OP已更新其客户端代码，现在正在使用IP地址。]
在典型的家庭/办公室局域网设置中，您可能希望使用IP地址而不是 主机名，用于指定要使用的服务器。您可能还需要检查网络 您指定的端口未被客户端或服务器上的软件防火墙阻止 机器，或服务器和客户端之间的硬件防火墙或路由器。
调试此类问题的一种方法是使用Wireshark之类的工具进行监控 客户端和服务器之间的网络流量。数据包在尝试建立连接时是否离开客户端的计算机？服务器的机器是否看到了请求？一侧或另一侧是否过早关闭连接？请记住，防火墙可以阻止传出流量以及传入流量......