C++

Question

这是我正在尝试制作的非常简单的服务器的代码：

Network.h:

#include <WinSock2.h>
#include <WS2tcpip.h>
#include <system_error>
#include <string>
#include <iostream>

#pragma once

class WSASession
{
public:
    WSASession()
    {
        int ret = WSAStartup(MAKEWORD(2, 2), &data);
        if (ret != 0)
            throw std::system_error(WSAGetLastError(), std::system_category(), "WSAStartup Failed");
    }
    ~WSASession()
    {
        WSACleanup();
    }
private:
    WSAData data;
};

class UDPSocket
{
public:
    UDPSocket()
    {
        sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
        if (sock == INVALID_SOCKET)
            throw std::system_error(WSAGetLastError(), std::system_category(), "Error opening socket");
    }
    ~UDPSocket()
    {
        closesocket(sock);
    }

    void SendTo(const std::string& address, unsigned short port, const char* buffer, int len, int flags = 0)
    {
        sockaddr_in add;
        add.sin_family = AF_INET;
        add.sin_addr.s_addr = inet_addr(address.c_str());
        add.sin_port = htons(port);
        int ret = sendto(sock, buffer, len, flags, reinterpret_cast<SOCKADDR *>(&add), sizeof(add));
        if (ret < 0)
            throw std::system_error(WSAGetLastError(), std::system_category(), "sendto failed");
    }
    void SendTo(sockaddr_in& address, const char* buffer, int len, int flags = 0)
    {
        int ret = sendto(sock, buffer, len, flags, reinterpret_cast<SOCKADDR *>(&address), sizeof(address));
        if (ret < 0)
            throw std::system_error(WSAGetLastError(), std::system_category(), "sendto failed");
    }
    sockaddr_in RecvFrom(char* buffer, int len, int flags = 0)
    {
        sockaddr_in from;
        int size = sizeof(from);
        int ret = recvfrom(sock, buffer, len, flags, reinterpret_cast<SOCKADDR *>(&from), &size);
        if (ret < 0)
            throw std::system_error(WSAGetLastError(), std::system_category(), "recvfrom failed");

        // make the buffer zero terminated
        buffer[ret] = 0;
        return from;
    }
    void Bind(unsigned short port)
    {
        sockaddr_in add;
        add.sin_family = AF_INET;
        add.sin_addr.s_addr = htonl(INADDR_ANY);
        add.sin_port = htons(port);

        int ret = bind(sock, reinterpret_cast<SOCKADDR *>(&add), sizeof(add));
        if (ret < 0)
            throw std::system_error(WSAGetLastError(), std::system_category(), "Bind failed");
    }

private:
    SOCKET sock;
};

监听器服务器：

   try
    {
        WSASession Session;
        UDPSocket Socket;
        char buffer[512];

        Socket.Bind(22);
        while (1)
        {
            sockaddr_in add = Socket.RecvFrom(buffer, sizeof(buffer));

            std::string srecv(buffer);
        }
    }
    catch (std::system_error& e)
    {
        std::cout << e.what();
    }

在接受来自客户端的连接之前，一切都是完美的。 recvfrom 函数失败并出现错误 "No such file or directory"

有人看到问题了吗？我知道该端口没有问题，因为我正在从一个运行良好的 .net 应用程序监听同一个端口。

Answer 1

你有：

const std::string& address, unsigned short port, const char* buffer, int len, int flags = 0)

和

    int ret = sendto(sock, buffer, len, flags, reinterpret_cast<SOCKADDR *>(&add)

演员阵容无效。 std::string 不是 SOCKADDR。你必须 convert, 可能通过调用 getaddrinfo().

C++ - Windows - recvfrom() 在简单服务器上因 "No such file or directory" 失败

C++ - Windows - recvfrom() failing with "No such file or directory" on simple server

winsock