public async Task <bool> TakeLock(string key, Guid lockToken, double milliseconds)
{
LockElement lockElement;
if (!_lockDictionary.TryGetValue(key, out lockElement))
{
lockElement = new LockElement
{
LockToken = lockToken,
Expiry = DateTime.UtcNow.AddMilliseconds(milliseconds)
};
var result = _lockDictionary.TryAdd(key, lockElement);
return(result);
}
else
{
if (lockElement.Expiry >= DateTime.UtcNow)
{
var newLockElement = new LockElement
{
LockToken = Guid.NewGuid(),
Expiry = DateTime.UtcNow.AddMilliseconds(milliseconds)
};
var result = _lockDictionary.TryUpdate(key, newLockElement, lockElement);
return(result);
}
}
return(false);
}
public bool TakeLock(string key, out string lockToken, double milliseconds)
{
LockElement lockElement;
if (!_lockDictionary.TryGetValue(key, out lockElement))
{
lockElement = new LockElement
{
LockToken = Guid.NewGuid(),
Expiry = DateTime.UtcNow.AddMilliseconds(milliseconds)
};
lockToken = lockElement.LockToken.ToString();
_lockDictionary.TryAdd(key, lockElement);
return(true);
}
else
{
if (lockElement.Expiry >= DateTime.UtcNow)
{
var newLockElement = new LockElement
{
LockToken = Guid.NewGuid(),
Expiry = DateTime.UtcNow.AddMilliseconds(milliseconds)
};
lockToken = lockElement.LockToken.ToString();
_lockDictionary.TryUpdate(key, newLockElement, lockElement);
return(true);
}
}
lockToken = null;
return(false);
}
internal static SMB2Command GetLockResponse(LockRequest request, ISMBShare share, SMB2ConnectionState state)
{
SMB2Session session = state.GetSession(request.Header.SessionID);
OpenFileObject openFile = session.GetOpenFileObject(request.FileId);
if (openFile == null)
{
state.LogToServer(Severity.Verbose, "Lock failed. Invalid FileId. (SessionID: {0}, TreeID: {1}, FileId: {2})", request.Header.SessionID, request.Header.TreeID, request.FileId.Volatile);
return(new ErrorResponse(request.CommandName, NTStatus.STATUS_FILE_CLOSED));
}
if (request.Locks.Count == 0)
{
// [MS-SMB2] The lock count MUST be greater than or equal to 1
state.LogToServer(Severity.Verbose, "Lock: Invalid number of locks, must be greater than 0.");
return(new ErrorResponse(request.CommandName, NTStatus.STATUS_INVALID_PARAMETER));
}
// [MS-SMB2] If the flags of the initial SMB2_LOCK_ELEMENT in the Locks array of the request has
// SMB2_LOCKFLAG_UNLOCK set, the server MUST process the lock array as a series of unlocks.
// Otherwise, it MUST process the lock array as a series of lock requests.
bool unlock = request.Locks[0].Unlock;
foreach (LockElement lockElement in request.Locks)
{
if (unlock)
{
if (lockElement.SharedLock || lockElement.ExclusiveLock)
{
state.LogToServer(Severity.Verbose, "Lock: Invalid parameter: Lock in a series of unlocks.");
return(new ErrorResponse(request.CommandName, NTStatus.STATUS_INVALID_PARAMETER));
}
}
else
{
if (lockElement.Unlock)
{
state.LogToServer(Severity.Verbose, "Lock: Invalid parameter: Unlock in a series of locks.");
return(new ErrorResponse(request.CommandName, NTStatus.STATUS_INVALID_PARAMETER));
}
if (lockElement.SharedLock && lockElement.ExclusiveLock)
{
state.LogToServer(Severity.Verbose, "Lock: Invalid parameter: SMB2_LOCKFLAG_SHARED_LOCK and SMB2_LOCKFLAG_EXCLUSIVE_LOCK are mutually exclusive.");
return(new ErrorResponse(request.CommandName, NTStatus.STATUS_INVALID_PARAMETER));
}
if (request.Locks.Count > 1 && !lockElement.FailImmediately)
{
state.LogToServer(Severity.Verbose, "Lock: Invalid parameter: SMB2_LOCKFLAG_FAIL_IMMEDIATELY not set in a series of locks.");
return(new ErrorResponse(request.CommandName, NTStatus.STATUS_INVALID_PARAMETER));
}
}
}
for (int lockIndex = 0; lockIndex < request.Locks.Count; lockIndex++)
{
LockElement lockElement = request.Locks[lockIndex];
if (unlock)
{
NTStatus status = share.FileStore.UnlockFile(openFile.Handle, (long)lockElement.Offset, (long)lockElement.Length);
if (status != NTStatus.STATUS_SUCCESS)
{
// [MS-SMB2] If the unlock operation fails, the server MUST fail the operation with the error code received from the object store and stop processing further entries in the Locks array.
state.LogToServer(Severity.Information, "Lock: Unlocking '{0}{1}' failed. Offset: {2}, Length: {3}. NTStatus: {4}.", share.Name, openFile.Path, lockElement.Offset, lockElement.Length, status);
return(new ErrorResponse(request.CommandName, status));
}
state.LogToServer(Severity.Information, "Lock: Unlocking '{0}{1}' succeeded. Offset: {2}, Length: {3}.", share.Name, openFile.Path, lockElement.Offset, lockElement.Length);
}
else
{
NTStatus status = share.FileStore.LockFile(openFile.Handle, (long)lockElement.Offset, (long)lockElement.Length, lockElement.ExclusiveLock);
if (status != NTStatus.STATUS_SUCCESS)
{
// [MS-SMB2] If the lock operation fails, the server MUST unlock any ranges locked as part of processing the previous entries in the Locks array of this request.
state.LogToServer(Severity.Information, "Lock: Locking '{0}{1}' failed. Offset: {2}, Length: {3}. NTStatus: {4}.", share.Name, openFile.Path, lockElement.Offset, lockElement.Length, status);
for (int index = 0; index < lockIndex; index++)
{
share.FileStore.UnlockFile(openFile.Handle, (long)request.Locks[index].Offset, (long)request.Locks[index].Length);
}
return(new ErrorResponse(request.CommandName, status));
}
state.LogToServer(Severity.Information, "Lock: Locking '{0}{1}' succeeded. Offset: {2}, Length: {3}.", share.Name, openFile.Path, lockElement.Offset, lockElement.Length);
}
}
return(new LockResponse());
}
