2.2.4.9.1 Client Request Extensions

An SMB_COM_NT_CREATE_ANDX request is sent by a client to open a file or device on the server. This extension adds the following:

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

• An additional parameter value is added to the ImpersonationLevel field. SECURITY_DELEGATION is added to allow the server to call other servers while impersonating the original client.

• 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 2.2.4.64.1.<49>

 SMB_Parameters
   {
   UCHAR WordCount;
   Words
     {
     UCHAR         AndXCommand;
     UCHAR         AndXReserved;
     USHORT        AndXOffset;
     UCHAR         Reserved;
     USHORT        NameLength;
     ULONG         Flags;
     ULONG         RootDirectoryFID;
     ULONG         DesiredAccess;
     LARGE_INTEGER AllocationSize;
     SMB_EXT_FILE_ATTR      ExtFileAttributes;
     ULONG         ShareAccess;
     ULONG         CreateDisposition;
     ULONG         CreateOptions;
     ULONG         ImpersonationLevel;
     UCHAR         SecurityFlags;
     }
   }
 SMB_Data
   {
   USHORT ByteCount;
   Bytes
     {
     SMB_STRING FileName;
     }
   }

SMB_Parameters

Words (48 bytes):

0	1	2	3	4	5	6	7	8	9	1 0	1	2	3	4	5	6	7	8	9	2 0	1	2	3	4	5	6	7	8	9	3 0	1
AndXCommand								AndXReserved								AndXOffset
Reserved								NameLength																Flags
...																								RootDirectoryFID
...																								DesiredAccess
...																								AllocationSize
...
...																								ExtFileAttributes
...																								ShareAccess
...																								CreateDisposition
...																								CreateOptions
...																								ImpersonationLevel
...																								SecurityFlags

Flags (4 bytes): A set of flags that modify the client request, as defined in the table below. NT_CREATE_REQUEST_EXTENDED_RESPONSE is new to MS-SMB. All other flags are included in the table for completeness. Unused bits SHOULD be set to zero by the client when sending a request and MUST be ignored when received by the server.

Name & bitmask	Meaning
NT_CREATE_REQUEST_OPLOCK 0x00000002	If set, then the client is requesting an oplock.
NT_CREATE_REQUEST_OPBATCH 0x00000004	If set, then the client is requesting a batch oplock.
NT_CREATE_OPEN_TARGET_DIR 0x00000008	If set, then the client indicates that the parent directory of the target is to be opened.
NT_CREATE_REQUEST_EXTENDED_RESPONSE 0x00000010	If set, then the client is requesting extended information 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.