套接字僅接收46位元組的資料

我正在為我和我的伙伴創建一個個人遠程檔案資源管理器。在大多數情況下，它按預期作業，它列舉給定目錄并將其發送回服務器查看。問題是如果緩沖區接收到超過 46 個位元組，它會將剩余的緩沖區覆寫為奇怪的 ASCII 字串。

客戶端發送的內容 - C:\Users\Test\NTUSER.DAT{53b39e88-18c4-11ea-a811-000d3aa4692b}.TM.blf 大小：69

服務器看到的內容 - C:\Users\Test\NTUSER.DAT{53b39e88-18c4-1■?_y·? 大小：46

兩個程式的默認緩沖區大小都是 512 位元組

編輯：在您詢問 FileManager 是個人代碼之前，它對客戶端所做的唯一事情就是收集字串中的路徑以供客戶端發送到服務器。

客戶端發送代碼

        //Gets Path From Server(recvbuf&recvbuflen buffer size = 512)
        std::string fldr = GetReply(ConnectSocket, recvbuf, recvbuflen);
        std::cout << "Reply: " << fldr << "\n";
        //Gets Directory Struct using given path from server
        FileManager::Directory* dir = f.GetDir(fldr);
        //Sends initial size to iterate through on server side
        send(ConnectSocket, std::to_string(dir->TotalList.size()).c_str(), dir->TotalList.size(), 0);
        //dir->TotalList holds a vector of strings that contain paths in directory
        for (std::string rV : dir->TotalList) {
            //Sleep for 75ms, without it the data would be sent to fast
            Sleep(75);
            //Sends the elements in TotalList
            //had to use sizeof(rV) because (int)strlen would overwrite the buffer fsr
            send(ConnectSocket, rV.c_str(), sizeof(rV), 0);
            std::cout << "Sent: " << rV << " Size: " << (int)strlen(rV.c_str()) << "\n";
        }

服務器接收代碼

        while (1) {
            //Send Command, memset(sndbuf, 0, sizeof(sndbuf) is called before loop
            std::cout << "\n\nEnter Folder: "; std::cin.getline(sndbuf, sizeof(sndbuf));
            //DirList is a string vector holding all the previous paths that clients sent
            //CheckIfExists iterates through the vector and checks if sndbuf is a valid path
            //if false it restarts loop
            if (CheckIfExists(sndbuf, DirList)) {
                //if true sends path, again if I used (int)strlen(sndbuf)
                //instead of sizeof(sndbuf) it would cause it to overwrite
                //the buffer on client side, again idky
                send(cSock, sndbuf, sizeof(sndbuf), 0);
                //zeros out the buffer for the replys from client
                memset(recvbuf, 0, sizeof(recvbuf));
                //Display reply loops recv and clears then adds new elements to vector
                DisplayReply(cSock, recvbuf, recvbuflen, &DirList);
                break;
            }
            else
                std::cout << "Folder Doesn't Exist...";
        }

服務器顯示回復代碼

void DisplayReply(SOCKET cSock, char* recvbuf, int recvbuflen, std::vector<std::string>* list) {
    //Gets the # of paths client has
    int r = std::stoi(GetReply(cSock, recvbuf, recvbuflen));
    std::cout << "Size: " << r << "\n";
    //Again zeroing the buffer, then clearing the vector
    memset(recvbuf, 0, sizeof(recvbuf)); list->clear();
    for (int i = 0; i < r; i  ) {
        //Sleep for 75ms so all data sends properly
        Sleep(75);
        //Recieve replys from client, GetReply returns string
        //Using any other variable doesnt work either, all caps out at 46 bytes
        //ex const char* or char*
        std::string rV = GetReply(cSock, recvbuf, recvbuflen);
        std::cout << rV << " Size: " << (int)strlen(rV.c_str()) << "\n";
        //Add path to vector using vector pointer
        list->push_back(recvbuf);
    }
}

服務器獲取回復碼

std::string GetReply(SOCKET cSock, char* recvbuf, int recvbuflen) {
    int iResult = 0;
    do {
        iResult = recv(cSock, recvbuf, recvbuflen, 0);
        if (iResult > 0) {
            return (std::string)recvbuf;
        }
        else {
            printf("recv failed with error: %d\n", WSAGetLastError());
            return "";
        }

    } while (iResult > 0);
}

uj5u.com熱心網友回復：

您很可能將沒有的緩沖區歸零。

標籤：C 视窗插座windows-socket-api

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