Mono DllImport libsmbclient not authenticating

我需要能够使用特定的凭据从Mono访问Samba/Cifs共享。

到目前为止我发现最好的选择是使用libsmbclient。不幸的是，我无法鉴定。为了排除防火墙/安全等，我试过使用smbclient可执行文件，它可以毫无问题地连接。

底层的DLLImport和一些硬编码的测试代码…

public static void Initialise() {
    log.Trace("Initialising libsmbclient wrapper");
    try {
        smbc_init(callbackAuth, 1);
    } catch (Exception e) {
        log.Trace(String.Format("{0}: {1}", e.GetType().Name, e.ToString()));
        throw;
    }
}
public static void callbackAuth(
    [MarshalAs(UnmanagedType.LPStr)]String server,
    [MarshalAs(UnmanagedType.LPStr)]String share,
    [MarshalAs(UnmanagedType.LPStr)]String workgroup, int workgroupMaxLen,
    [MarshalAs(UnmanagedType.LPStr)]String username, int usernameMaxLen,
    [MarshalAs(UnmanagedType.LPStr)]String password, int passwordMaxLen) {
    server = "targetserver";
    share = "Public";
    username = "Management.Service";
    password = @"{SomeComplexPassword}";
    workgroup = "targetserver";
    usernameMaxLen = username.Length;
    passwordMaxLen = password.Length;
    workgroupMaxLen = workgroup.Length;
}
[DllImport("libsmbclient.so", SetLastError = true)]
extern internal static int smbc_init(smbCGetAuthDataFn callBackAuth, int debug);
[DllImport("libsmbclient.so", SetLastError = true)]
extern internal static int smbc_opendir([MarshalAs(UnmanagedType.LPStr)]String durl);

我想这样使用它…

public bool DirectoryExists(string path) {
    log.Trace("Checking directory exists {0}", path);
    int handle;
    string fullpath = @"smb:" + parseUNCPath(path);
    handle = SambaWrapper.smbc_opendir(fullpath);
    if (handle < 0) {
    var error = Stdlib.GetLastError().ToString();
        if (error == "ENOENT"
           |error == "EINVAL")
            return false;
        else
            throw new Exception(error);
    } else {
    WrapperSambaClient.smbc_close(fd);
    return true;
}
}

Initialise()调用成功，但当DirectoryExists调用SambaWrapper.smbc_opendir(fullpath)时，我得到一个负句柄并抛出以下异常…

Slurpy.Exceptions。FetchException: Exception: Failed to fetch: EACCES> (file:////targetserver/Public/ValidSubfolder) --> System。例外:EACCES

我做错了什么?有什么方法可以调试这个吗?

Edit:似乎问题是来自auth回调的值没有效果(但回调肯定被称为日志语句在那里被处理)。我想知道这是否与字符串的不变性和一个新的字符串实例正在用新的值创建，而不是覆盖旧的?

编辑:从libsmbclient试图连接删除完整的调试输出。如果需要，您可以在编辑历史记录中看到它。

按照要求，方法的定义来自头文件…

/**@ingroup misc
 * Initialize the samba client library.
 *
 * Must be called before using any of the smbclient API function
 *  
 * @param fn        The function that will be called to obtaion 
 *                  authentication credentials.
 *
 * @param debug     Allows caller to set the debug level. Can be
 *                  changed in smb.conf file. Allows caller to set
 *                  debugging if no smb.conf.
 *   
 * @return          0 on success, < 0 on error with errno set:
 *                  - ENOMEM Out of memory
 *                  - ENOENT The smb.conf file would not load
 *
 */
int smbc_init(smbc_get_auth_data_fn fn, int debug);
/**@ingroup callback
 * Authentication callback function type (traditional method)
 * 
 * Type for the the authentication function called by the library to
 * obtain authentication credentals
 *
 * For kerberos support the function should just be called without
 * prompting the user for credentials. Which means a simple 'return'
 * should work. Take a look at examples/libsmbclient/get_auth_data_fn.h
 * and examples/libsmbclient/testbrowse.c.
 *
 * @param srv       Server being authenticated to
 *
 * @param shr       Share being authenticated to
 *
 * @param wg        Pointer to buffer containing a "hint" for the
 *                  workgroup to be authenticated.  Should be filled in
 *                  with the correct workgroup if the hint is wrong.
 * 
 * @param wglen     The size of the workgroup buffer in bytes
 *
 * @param un        Pointer to buffer containing a "hint" for the
 *                  user name to be use for authentication. Should be
 *                  filled in with the correct workgroup if the hint is
 *                  wrong.
 * 
 * @param unlen     The size of the username buffer in bytes
 *
 * @param pw        Pointer to buffer containing to which password 
 *                  copied
 * 
 * @param pwlen     The size of the password buffer in bytes
 *           
 */
typedef void (*smbc_get_auth_data_fn)(const char *srv, 
                                      const char *shr,
                                      char *wg, int wglen, 
                                      char *un, int unlen,
                                      char *pw, int pwlen);

public static void callbackAuth(
    [MarshalAs(UnmanagedType.LPStr)]String server,
    [MarshalAs(UnmanagedType.LPStr)]String share,
    IntPtr workgroup, int workgroupMaxLen,
    IntPtr username, int usernameMaxLen,
    IntPtr password, int passwordMaxLen) 
{
    //server = "targetserver";
    //share = "Public"; 
    // should not be assigned - 
    // you must provide credentials for specified server
    SetString(username, "Management.Service", username.Length);
    SetString(password, @"{SomeComplexPassword}", password.Length);
    SetString(workgroup, "targetserver", workgroup.Length);
}
private void SetString(IntPtr dest, string str, int maxLen)
{
    // include null string terminator
    byte[] buffer = Encoding.ASCII.GetBytes(str + "'0");
    if (buffer.Length >= maxLen) return; // buffer is not big enough
    Marshal.Copy(buffer, 0, dest, buffer.Length);
}