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We're having an issue uploading files to a particular SFTP server.

From what I can tell, I think this server may not allow the automatic FXP_FSTAT called after opening a file. Is there a way to disable this?

Here's an example failed upload attempt:

OpenFile:
    DllDate: Oct 19 2016
    ChilkatVersion: 9.5.0.62
    UnlockPrefix: ------
    Architecture: Little Endian; 64-bit
    Language: Linux Perl
    VerboseLogging: 1
    SshVersion: SSH-2.0-TIBCO BusinessConnect Plug-in for SFTP Server
    SftpVersion: 3
    sftpOpenFile:
        remotePath: /2967115.txt
        access: writeOnly
        createDisposition: createNew,blockWrite,blockDelete,blockRead
        v3Flags: 0x2a
        sendPacket:
            channelSendData2:
                sendMessageInOnePacket:
                    (leaveContext 1ms)
                (leaveContext 1ms)
            (leaveContext 1ms)
        Sent FXP_OPEN
        readSftpPacket:
            readChannelData:
                dataLen: 38
                clientWinSize: 327633
                (leaveContext 194ms)
            (leaveContext 194ms)
        handle: 32313837353530393436363235323638333231343139303639
        (leaveContext 195ms)
    Success.
    (leaveContext 195ms)
WriteFileText:
    DllDate: Oct 19 2016
    ChilkatVersion: 9.5.0.62
    UnlockPrefix: -------
    Architecture: Little Endian; 64-bit
    Language: Linux Perl
    VerboseLogging: 1
    SshVersion: SSH-2.0-TIBCO BusinessConnect Plug-in for SFTP Server
    SftpVersion: 3
    handle: 32313837353530393436363235323638333231343139303639
    charset: ansi
    getFileSize:
        fetchAttributes:
            bFollowLinks: 0
            bIsHandle: 1
            bSizeOnly: 0
            handle: 32313837353530393436363235323638333231343139303639
            serverVersion: 3
            Using FXP_FSTAT
            sendPacket:
                channelSendData2:
                    sendMessageInOnePacket:
                        (leaveContext)
                    (leaveContext)
                (leaveContext)
            Sent message to fetch attributes.
            readSftpPacket:
                readChannelData:
                    dataLen: 21
                    clientWinSize: 327612
                    (leaveContext 162ms)
                (leaveContext 162ms)
            StatusResponseFromServer:
                Request: FXP_FSTAT
                InformationReceivedFromServer:
                    StatusCode: 4
                    StatusMessage:
                    (leaveContext)
                (leaveContext)
            (leaveContext 162ms)
        (leaveContext 162ms)
    offset: 0
    writeDataSource:
        serverWindowSize: 130941
        Using specialized upload for small server window size...
        smallWindowSizeUpload:
            startingOffset: 0
            uploadChunkSize: 1024
            serverWindowSize: 130941
            sendPacket:
                channelSendData2:
                    sendMessageInOnePacket:
                        (leaveContext)
                    (leaveContext 1ms)
                (leaveContext 1ms)
***TRUNCATED***
            sendPacket:
                channelSendData2:
                    sendMessageInOnePacket:
                        (leaveContext)
                    (leaveContext)
                (leaveContext 1ms)
            End of data stream...
            ------------------------------------------------
            getWriteStatusReplies:
                StatusResponseFromServer:
                    Request: SSH_FXP_WRITE
                    InformationReceivedFromServer:
                        StatusCode: 4
                        StatusMessage:
                        (leaveContext)
                    (leaveContext)
                (leaveContext 197ms)
            totalNumBytesSent: 37981
            totalTimeSendingMs: 11
            totalTimeReadingMs: 0
            (leaveContext 208ms)
        (leaveContext 208ms)
    Success.
    (leaveContext 371ms)

CloseHandle:
    DllDate: Oct 19 2016
    ChilkatVersion: 9.5.0.62
    UnlockPrefix: NIHALTSSH
    Architecture: Little Endian; 64-bit
    Language: Linux Perl
    VerboseLogging: 1
    SshVersion: SSH-2.0-TIBCO BusinessConnect Plug-in for SFTP Server
    SftpVersion: 3
    handle: 32313837353530393436363235323638333231343139303639
    sftpCloseHandle:
        handle: 32313837353530393436363235323638333231343139303639
        sendPacket:
            channelSendData2:
                sendMessageInOnePacket:
                    (leaveContext)
                (leaveContext)
            (leaveContext)
        Sent FXP_CLOSE
        readSftpPacket:
            readChannelData:
                dataLen: 21
                clientWinSize: 327570
                (leaveContext 4ms)
            (leaveContext 4ms)
        StatusResponseFromServer:
            Request: FXP_CLOSE
            InformationReceivedFromServer:
                StatusCode: 4
                StatusMessage:
                (leaveContext)
            (leaveContext)
        Received a failed status response.
        (leaveContext 5ms)
    Failed.
    (leaveContext 6ms)

asked Apr 13 at 15:31

titan's gravatar image

titan
11

edited Apr 14 at 10:22


OK, I found that if I send a file using the UploadFileByName method, the library does not attempt to get the file attributes using FXP_FSTAT.

But when uploading data that's in memory, using openFile,WriteFileBytes,CloseHandle the FXP_FSTAT is automatic.

Is that necessary? Would be great if I could disable this.

Thanks!

link

answered Apr 14 at 14:43

titan's gravatar image

titan
11

The FXP_FSTAT is not the cause of the problem. Your server has no trouble with it.

Also, the FXP_FSTAT is required, because an SFTP packet to write data to a file must specify an offset. To append to a file, one must know the size of the file so the correct SFTP write packet (with the correct offset) can be sent.

In this case, the UploadFileByName is suppressing the erroneous non-success response to the FXP_CLOSE. Your application can simply do the same..

link

answered Apr 15 at 11:55

chilkat's gravatar image

chilkat ♦♦
12.8k317363471

Thanks for your reply.

Doesn't the log indicate it is trying to get the file attributes on the newly opened file before sending data? But receives a "StatusCode: 4" back?

getFileSize:
    fetchAttributes:
        bFollowLinks: 0
        bIsHandle: 1
        bSizeOnly: 0
        handle: 32313837353530393436363235323638333231343139303639
        serverVersion: 3
        Using FXP_FSTAT
        sendPacket:
            channelSendData2:
                sendMessageInOnePacket:
                    (leaveContext)
                (leaveContext)
            (leaveContext)
        Sent message to fetch attributes.
        readSftpPacket:
            readChannelData:
                dataLen: 21
                clientWinSize: 327612
                (leaveContext 162ms)
            (leaveContext 162ms)
        StatusResponseFromServer:
            Request: FXP_FSTAT
            InformationReceivedFromServer:
                StatusCode: 4
                StatusMessage:
                (leaveContext)
            (leaveContext)
        (leaveContext 162ms)
    (leaveContext 162ms)

The remote server also acts like the file transfer was not successful, so ignoring the failure to close won't work.

However, UploadFileByName doesn't appear to request the file attributes on the new file immediately before writing to it.

 ServerInitialWindowSize: 0
    uploadFileByName:
        remoteFilePath: /2969065.TXT
        localFilePath: /2969065.TXT
        remoteFilePathUtf8_QP: /2969065.TXT
        localFilePathUtf8_QP: /2969065.TXT
        localFileSize: 246816
        sftpOpenFile:
            filepathUtf8_QP: /2969065.TXT
            remotePath: /2969065.TXT
            access: writeOnly
            createDisposition: createTruncate
            v3Flags: 0x1a
            sendPacket:
                channelSendData2:
                    (leaveContext)
                (leaveContext 1ms)
            Sent FXP_OPEN
            readSftpPacket:
                readChannelData:
                    (leaveContext 162ms)
                (leaveContext 162ms)
            handle: 3232373139373730303231353833393131303132343931313939
            (leaveContext 163ms)
        timeToOpenMs: Elapsed time: 163 millisec
        uploadFile:
            socketOptions:
                SO_SNDBUF: 262142
                SO_RCVBUF: 262142
                TCP_NODELAY: 1
                SO_KEEPALIVE: 0
                (leaveContext)
            handle: 3232373139373730303231353833393131303132343931313939
            fromLocalPath: /2969065.TXT
            sendAheadMaxCount: 12
            localFileSize2: 246816
            writeDataSource:
                startingOffset: 0
                uploadChunkSize: 32000
                sendPacket:
                    channelSendData2:
                        (leaveContext 1ms)
                    (leaveContext 1ms)
link

answered Apr 17 at 14:16

titan's gravatar image

titan
11

Thanks. I think the correct behavior is that the WriteFileText should've returned a failed status. I don't think the FXP_FSTAT matters -- the server responded to both it and the FXP_WRITE with a status code of 4 (failure).

It may be that your call to OpenFile passed an absolute path:

        remotePath: /2967115.txt
        access: writeOnly
        createDisposition: createNew,blockWrite,blockDelete,blockRead
I would think the server would interpret this as wanting to create the file "2967115.txt" in the filesystem's root directory. Try opening "2967115.txt" without the "/" to open/create a file in the HOME directory of your SSH user account, which is probably what you want, right?

Also, some servers can be picky or fragile with "writeOnly". Try "readWrite" instead. Also.. only use "blockWrite,blockDelete, etc. " if you know for sure that you want it.

link

answered Apr 17 at 15:20

chilkat's gravatar image

chilkat ♦♦
12.8k317363471

PS> I'm testing the sequence of OpenFile, WriteFileText, and CloseFile, and will simulate an error to verify the behavior is correct (and will fix if not..)

link

answered Apr 17 at 15:22

chilkat's gravatar image

chilkat ♦♦
12.8k317363471

You're currently using v9.5.0.62. I tested v9.5.0.66 and the upload correctly fails if a status reply having value 4 (failure) is received.

link

answered Apr 17 at 15:39

chilkat's gravatar image

chilkat ♦♦
12.8k317363471

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Asked: Apr 13 at 15:31

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Last updated: Apr 17 at 15:39

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