/// <summary>
/// Sends contents of a file to a client.
/// </summary>
/// <param name="reader">StreamReader used to ask the client for acknowledgement.</param>
/// <param name="writer">StreamWriter used to send the data.</param>
/// <param name="name">Path to the file.</param>
/// <returns></returns>
private bool SendFileContents(StreamReader reader, StreamWriter writer, string name)
{
try
{
using (var fileReader = new StreamReader(System.IO.File.OpenRead(name), encoding))
{
string line;
writer.WriteLine(name);
if (ProtocolHelper.ExtractProtocol(reader.ReadLine()) != Protocol.SUCCESS)
{
return(true);
}
while ((line = fileReader.ReadLine()) != null)
{
writer.WriteLine(line);
}
writer.WriteLine(Protocol.TRANSMISSION_END);
}
return(true);
}
catch (IOException)
{
try
{
writer.WriteLine(Protocol.FAIL);
return(true);
}
catch (IOException)
{
return(false);
}
}
}
/// <summary>
/// Requests (and reads if authorized) contents of a given file from
/// the server.
/// </summary>
/// <param name="reader">StreamReader used to read authorization result and the contents of the file.</param>
/// <param name="writer">StreamWriter used to send the request.</param>
/// <param name="file">Path to the file.</param>
private void RequestFileContents(StreamReader reader, StreamWriter writer, string file)
{
writer.WriteLine(Protocol.REQUEST_FILE_CONTENTS);
writer.WriteLine(subTreePrefix + file);
string line = reader.ReadLine();
string tmpFile = file + ".tmp";
if (ProtocolHelper.ExtractProtocol(line) == Protocol.SUCCESS)
{
DB.File tmp = null;
if (!db.GetFiles().TryGet(file, out tmp))
{
tmp = new DB.File(file);
db.GetFiles().Add(tmp);
}
try
{
reader.ReadLine(); // File name resent, here we can discard it.
writer.WriteLine(Protocol.SUCCESS);
Directory.CreateDirectory(Path.GetDirectoryName(file));
using (var stream = System.IO.File.OpenWrite(tmpFile))
using (var fileWriter = new StreamWriter(stream, encoding))
{
while ((line = reader.ReadLine()) != null && line != "TRANSMISSION_END" && line != "FAIL")
{
fileWriter.WriteLine(line);
}
}
FileHelper.Move(tmpFile, file);
tmp.DateModified = System.IO.File.GetLastWriteTime(file);
}
catch (SocketException)
{ // This should be connection interruption or time out.
FileHelper.Delete(tmpFile);
}
catch (IOException)
{ // Target file in use or nonexistent.
FileHelper.Delete(tmpFile);
}
}
}
/// <summary>
/// Asks the server for information (modification time) about all files
/// this client has read access to and requests contents if necessary.
/// </summary>
private void PerformInitialRequest()
{
var filesToRequest = new List <string>();
var filesOnServer = new List <string>();
TcpClient client = null;
try
{
client = ConnectToServer();
if (client == null)
{
return;
}
using (var stream = client.GetStream())
using (var reader = new StreamReader(stream, encoding))
using (var writer = new StreamWriter(stream, encoding))
{
writer.AutoFlush = true;
reader.BaseStream.ReadTimeout = 10000;
string line;
string fileName;
DB.File file;
Protocol message;
writer.WriteLine(Protocol.AUTHENTICATE);
writer.WriteLine(name);
writer.WriteLine(passwordHash);
line = reader.ReadLine();
message = ProtocolHelper.ExtractProtocol(line);
if (message != Protocol.SUCCESS)
{
return;
}
writer.WriteLine(Protocol.REQUEST_INITIAL_INFO);
line = reader.ReadLine();
message = ProtocolHelper.ExtractProtocol(line);
if (message == Protocol.SUCCESS)
{
var files = db.GetFiles();
while (true)
{
fileName = reader.ReadLine();
if (fileName.StartsWith(subTreePrefix + TrackedDirectory + @"\"))
{
fileName = fileName.Substring(subTreePrefix.Length);
}
else if (fileName == "TRANSMISSION_END")
{
break;
}
else
{
reader.ReadLine(); // Skip modification time.
continue;
}
filesOnServer.Add(fileName);
line = reader.ReadLine();
if (!files.TryGet(fileName, out file) || file.OlderThan(DateTime.Parse(line)))
{
filesToRequest.Add(fileName);
}
}
foreach (var f in filesToRequest)
{
RequestFileContents(reader, writer, f);
}
}
writer.WriteLine(Protocol.TRANSMISSION_END);
client.Close();
var filesToDelete = db.GetFiles().GetDictionary().Keys.ToList().Except(filesOnServer);
foreach (var f in filesToDelete)
{
db.GetFiles().Remove(f);
FileHelper.Delete(f);
}
}
}
catch (SocketException)
{ /* Time out. */ }
catch (IOException)
{ /* File probably already deleted as RequestFileContents does not throw. */ }
finally
{
db.Save();
if (client != null)
{
client.Close();
}
}
}
/// <summary>
/// Informs server about all changes found during the last
/// directory checks.
/// </summary>
private void InformServer()
{
if ((filesCreated.Count == 0 || !canCreateFiles) &&
filesChecked.Count == db.GetFiles().Count&& filesChanged.Count == 0)
{
// If checked == db files, we still need to clear the checked files otherwise deletes would be ignored
// next time we check.
lock (filesChecked)
{
if (filesChecked.Count > 0)
{
filesChecked.Clear();
}
}
return;
}
try
{
var client = ConnectToServer();
if (client == null)
{
return;
}
var files = db.GetFiles();
using (var stream = client.GetStream())
using (var writer = new StreamWriter(stream, encoding))
using (var reader = new StreamReader(stream, encoding))
{
writer.AutoFlush = true;
// Authentication of this session.
writer.WriteLine(Protocol.AUTHENTICATE);
writer.WriteLine(name);
writer.WriteLine(passwordHash);
if (ProtocolHelper.ExtractProtocol(reader.ReadLine()) != Protocol.SUCCESS)
{
writer.WriteLine(Protocol.TRANSMISSION_END);
Console.WriteLine("[ERROR] Refused because of wrong credentials.");
ClearLists();
return;
}
lock (filesCreated)
{
bool removeCreatedFiles = false;
foreach (var file in filesCreated)
{
writer.WriteLine(Protocol.FILE_CREATED);
writer.WriteLine(subTreePrefix + file);
if (ProtocolHelper.ExtractProtocol(reader.ReadLine()) == Protocol.SUCCESS)
{
SendFileContents(writer, file);
}
else
{
writer.WriteLine(Protocol.TRANSMISSION_END);
canCreateFiles = false;
removeCreatedFiles = true;
break;
}
}
if (removeCreatedFiles)
{ // This removes those recently tracked and canCreateFiles == false will prevent new tracking.
foreach (var file in filesCreated)
{
files.Remove(file);
}
}
filesCreated.Clear();
}
lock (filesChanged)
{
foreach (var file in filesChanged)
{
writer.WriteLine(Protocol.FILE_CHANGED);
writer.WriteLine(subTreePrefix + file);
if (ProtocolHelper.ExtractProtocol(reader.ReadLine()) == Protocol.SUCCESS)
{
SendFileContents(writer, file);
}
else
{
files.Remove(file); // Leave it physically on the disk, but do not track it.
}
}
filesChanged.Clear();
}
lock (filesDeleted)
{
filesDeleted = db.GetFiles().GetDictionary().Keys.ToList().Except(filesChecked).ToList();
lock (filesChecked)
{
filesChecked.Clear();
}
foreach (var file in filesDeleted)
{
writer.WriteLine(Protocol.FILE_DELETED);
writer.WriteLine(subTreePrefix + file);
db.GetFiles().Remove(file);
/*
* Note: This is either SUCCESS or FAIL (depending of authorization).
* Currently is ignored, assuming the user just wants to get rid of the file,
* but it may be useful to add a config option to request the data of deleted
* files to recover them if the deletion fails on the server.
*/
reader.ReadLine();
}
filesDeleted.Clear();
}
writer.WriteLine(Protocol.TRANSMISSION_END);
}
}
catch (IOException e)
{
Console.WriteLine("[ERROR] Cannot inform the server: {0}", e.Message);
ClearLists();
}
finally
{
db.Save();
}
}
/// <summary>
/// Performs initial authentication either from config file, or
/// (if it's missing or manual authentication is forced) from
/// the console (and saves info on success).
/// </summary>
/// <returns>True if authentication succeeded, false otherwise.</returns>
private bool Authenticate()
{
bool register = false;
bool consoleAuthentication = false;
if (forceManualAuthentization || !System.IO.File.Exists(userData))
{ // Console authentication.
consoleAuthentication = true;
register = GetCredentialsFromConsole(out name, out passwordHash);
}
else
{ // Saved authentication.
using (var stream = System.IO.File.OpenRead(userData))
using (var reader = new StreamReader(stream))
{
name = reader.ReadLine();
passwordHash = reader.ReadLine();
}
}
bool authenticated = false;
using (var client = ConnectToServer())
{
if (client == null)
{
return(false);
}
using (var stream = client.GetStream())
using (var writer = new StreamWriter(stream, encoding))
using (var reader = new StreamReader(stream, encoding))
{ // Actual authentication communication.
writer.AutoFlush = true;
writer.WriteLine(register ? Protocol.REGISTER : Protocol.AUTHENTICATE);
writer.WriteLine(name);
writer.WriteLine(passwordHash);
Protocol response = ProtocolHelper.ExtractProtocol(reader.ReadLine());
authenticated = (response == Protocol.SUCCESS);
if (authenticated)
{
writer.WriteLine(Protocol.NEW_CONNECTION);
writer.WriteLine(listenPort);
writer.WriteLine(Protocol.TRANSMISSION_END);
}
}
}
if (consoleAuthentication && authenticated)
{ // Save the credentials for later use.
using (var stream = System.IO.File.Open(userData, FileMode.Create))
using (var writer = new StreamWriter(stream, encoding))
{
writer.WriteLine(name);
writer.WriteLine(passwordHash);
writer.WriteLine(listenPort);
}
}
return(authenticated);
}
/// <summary>
/// Handles a notification from the server (mostly
/// regardin file changes).
/// </summary>
/// <param name="s">Socket used for the communication.</param>
private void HandleServerNotice(Socket s)
{
try
{
using (var stream = new NetworkStream(s))
using (var reader = new StreamReader(stream, encoding))
using (var writer = new StreamWriter(stream, encoding))
{
writer.AutoFlush = true;
//reader.BaseStream.ReadTimeout = 10000;
var message = ProtocolHelper.ExtractProtocol(reader.ReadLine());
string name = reader.ReadLine();
if (name.StartsWith(subTreePrefix + TrackedDirectory + @"\"))
{
name = name.Substring(subTreePrefix.Length);
if (message != Protocol.FILE_DELETED)
{
writer.WriteLine(Protocol.SUCCESS);
}
else
{
reader.ReadLine(); // T_E token, can be ignored here.
}
}
else
{
if (message != Protocol.FILE_DELETED)
{
writer.WriteLine(Protocol.FAIL);
}
else
{
reader.ReadLine(); // T_E token, can be ignored here.
}
writer.WriteLine(Protocol.TRANSMISSION_END);
return;
}
if (message == Protocol.NONE || name == null)
{
return;
}
DB.File file = null;
if (message == Protocol.FILE_CREATED ||
(name != null && !db.GetFiles().TryGet(name, out file) && message != Protocol.FILE_DELETED))
{
file = new DB.File(name);
file.DateModified = FileHelper.Create(file.Name);
if (file.DateModified != DateTime.MaxValue)
{
db.GetFiles().Add(file);
}
}
if (message == Protocol.FILE_DELETED)
{
FileHelper.Delete(name);
if (file != null)
{
db.GetFiles().Remove(file);
}
reader.ReadLine(); // T_E token, can be ignored here.
}
else
{
lock (file)
{
string tmpName = name + ".tmp";
try
{
string line;
using (var fstream = System.IO.File.OpenWrite(tmpName))
using (var fileWriter = new StreamWriter(fstream, encoding))
{
while ((line = reader.ReadLine()) != null && line != "TRANSMISSION_END")
{
fileWriter.WriteLine(line);
}
fileWriter.BaseStream.SetLength(fileWriter.BaseStream.Position);
}
FileHelper.Move(tmpName, file.Name);
file.DateModified = System.IO.File.GetLastWriteTime(file.Name);
}
catch (IOException e)
{
Console.WriteLine(e);
// TODO:
FileHelper.Delete(tmpName);
}
}
}
}
}
catch (IOException e)
{
// TODO:
Console.WriteLine("HUH? {0}", e.Message);
}
finally
{
db.Save();
}
}
/// <summary>
/// Handles communication with a single client.
/// </summary>
/// <param name="s">Socket used for communication with the client.</param>
private void HandleConnection(Socket s)
{
int newPort = 0;
try
{
// Resend the client to another port.
using (var writer = new StreamWriter(new NetworkStream(s), encoding))
{
writer.AutoFlush = true;
newPort = GetNewPort();
writer.WriteLine(newPort);
var tmpListener = new TcpListener(IPAddress.Parse(serverAddress), newPort);
tmpListener.Start();
// Just to be sure, close the original after establishing a new connection.
var tmpSocket = tmpListener.AcceptSocket();
tmpListener.Stop();
s.Close();
s = tmpSocket;
}
using (var stream = new NetworkStream(s))
using (var reader = new StreamReader(stream, encoding))
using (var writer = new StreamWriter(stream, encoding))
{
writer.AutoFlush = true;
reader.BaseStream.ReadTimeout = 10000;
string msg;
User user = null;
bool running = true;
while (running)
{
msg = reader.ReadLine();
Protocol protocol = ProtocolHelper.ExtractProtocol(msg);
if (protocol == Protocol.NONE) // Client crash/hang.
{
return;
}
switch (protocol)
{
case Protocol.AUTHENTICATE:
user = HandleUserAuthentication(s, reader, writer);
if (user == null)
{
running = false;
}
break;
case Protocol.REGISTER:
user = HandleUserRegistration(s, reader, writer);
if (user == null)
{
running = false;
}
break;
case Protocol.FILE_CHANGED:
case Protocol.FILE_CREATED:
case Protocol.FILE_DELETED:
HandleFileUpdate(s, reader, writer, protocol, user);
break;
case Protocol.REQUEST_INITIAL_INFO:
if (!SendInitialInfo(writer, user))
{
running = false;
}
break;
case Protocol.REQUEST_FILE_CONTENTS:
HandleFileRequest(reader, writer, user);
break;
case Protocol.TRANSMISSION_END:
running = false;
break;
case Protocol.NEW_CONNECTION:
GetClientListenPort(reader, user);
break;
}
}
}
}
catch (IOException)
{ /* This should be timeout or connection close. */ }
finally
{
ReleasePort(newPort);
s.Close();
}
}
