2.2.7.1.1 Client Request Extensions

An SMB_COM_NT_TRANSACT (section 2.2.4.8) command with an NT_TRANSACT_CREATE subcommand is sent by a client to open a file or device on the server. The NT_TRANSACT_CREATE subcommand is specified in [MS-CIFS] section 2.2.7.1. This extension adds the following:

• An additional flag bit is added to the Flags field. The additional flag, NT_CREATE_REQUEST_EXTENDED_RESPONSE, is used to request an extended response from the server.

• An additional parameter value, SECURITY_DELEGATION, is added to the ImpersonationLevel field.

• An additional flag bit is added to the CreateOptions field. The additional flag, FILE_OPEN_REPARSE_POINT, is used to open a reparse point file itself.

All other fields are as specified in [MS-CIFS] section 2.2.7.1.

 NT_Trans_Parameters
   {
   ULONG         Flags;
   ULONG         RootDirectoryFID;
   ULONG         DesiredAccess;
   LARGE_INTEGER AllocationSize;
   SMB_EXT_FILE_ATTR ExtFileAttributes;
   ULONG         ShareAccess;
   ULONG         CreateDisposition;
   ULONG         CreateOptions;
   ULONG         SecurityDescriptorLength;
   ULONG         EALength;
   ULONG         NameLength;
   ULONG         ImpersonationLevel;
   UCHAR         SecurityFlags;
   UCHAR         Name[NameLength];
   }
 NT_Trans_Data
   {
   SECURITY_DESCRIPTOR      SecurityDescriptor;
   FILE_FULL_EA_INFORMATION ExtendedAttributes[];
   }

NT_Trans_Parameters (variable):

Flags (4 bytes): A 32-bit field containing a set of flags that modify the client request. Unused bits SHOULD be set to 0 by the client when sending a message and MUST be ignored when received by the server.

Name & bitmask	Meaning
NT_CREATE_REQUEST_OPLOCK 0x00000002	Level I (exclusive) OpLock requested.
NT_CREATE_REQUEST_OPBATCH 0x00000004	Batch OpLock requested.
NT_CREATE_OPEN_TARGET_DIR 0x00000008	Parent directory of the target is to be opened.
NT_CREATE_REQUEST_EXTENDED_RESPONSE 0x00000010	Extended information is requested in the response.

ImpersonationLevel (4 bytes): This field specifies the impersonation level requested by the application that is issuing the create request, and MUST contain one of the following values.

Impersonation is described in [MS-WPO] section 9.7; for more information about impersonation, see [MSDN-IMPERS].

Value	Meaning
SECURITY_ANONYMOUS 0x00000000	The application-requested impersonation level is Anonymous.
SECURITY_IDENTIFICATION 0x00000001	The application-requested impersonation level is Identification.
SECURITY_IMPERSONATION 0x00000002	The application-requested impersonation level is Impersonation.
SECURITY_DELEGATION 0x00000003	The application-requested impersonation level is Delegation.

CreateOptions (4 bytes): A 32-bit field containing flag options for creating a file or directory. In addition to the flags specified in [MS-CIFS] section 2.2.4.64, the following modifications and extensions apply to the CreateOptions field. FILE_OPEN_REPARSE_POINT is a new flag to SMB. The CreateOptions field MUST be set to 0x00000000 or to a combination of the flags specified in the [MS-CIFS] section 2.2.4.64 CreateOptions table and the following table. Unused bit fields SHOULD be set to 0 when sent and MUST be ignored on receipt. Server implementations SHOULD reserve all bits not specified in the [MS-CIFS] section 2.2.4.64 CreateOptions table and the following table.

Name and bitmask	Meaning
FILE_OPEN_REPARSE_POINT 0x00200000	If the file or directory being opened is a reparse point, open the reparse point itself rather than the target that the reparse point references.