2.2.6.1.1 Request

The TRANS2_OPEN2 request and response formats are a special case of SMB_COM_TRANSACTION2 (section 2.2.4.46) SMB. Only the TRANS2_OPEN2 request specifics are described here.

SMB_Parameters

WordCount (1 byte): This field MUST be0x0F.

Words (30 bytes):

TotalDataCount (2 bytes): This field MUST be zero (0x0000) if no Trans2_Data is being supplied. This field MUST be the total size of the Trans2_Data if extended attributes are being provided.

SetupCount (1 byte): This field MUST be 0x01.

Setup (2 bytes): This field MUST be TRANS2_OPEN2 (0x0000).

Trans2_Parameters

 Trans2_Parameters
   {
   USHORT              Flags;
   USHORT              AccessMode;
   USHORT              Reserved1;
   SMB_FILE_ATTRIBUTES FileAttributes;
   UTIME               CreationTime;
   USHORT              OpenMode;
   ULONG               AllocationSize;
   USHORT              Reserved[5];
   SMB_STRING          FileName;
   }

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Flags																AccessMode
Reserved1																FileAttributes
CreationTime
OpenMode																AllocationSize
...																Reserved
...
...
FileName (variable)
...

Flags (2 bytes): This 16-bit field of flags is used to request that the server take certain actions.

Bitmask	Meaning
REQ_ATTRIB 0x0001	Return additional information in the response; populate the CreationTime, FileDataSize, AccessMode, ResourceType, and NMPipeStatus fields in the response.
REQ_OPLOCK 0x0002	Exclusive OpLock requested.
REQ_OPBATCH 0x0004	Batch OpLock requested.
REQ_EASIZE 0x0008	Return total length of Extended Attributes (EAs); populate the ExtendedAttributeLength field in the response.

AccessMode (2 bytes): A 16-bit field for encoding the requested access mode. See section 3.2.4.5.1 for a discussion on sharing modes.

Name and bitmask	Values	Meaning
AccessMode 0x0007	0	Open for reading.
	1	Open for writing.
	2	Open for reading and writing.
	3	Open for execution.
0x0008	Reserved
SharingMode 0x0070	0	Compatibility mode
	1	Deny read/write/execute to others (exclusive use requested).
	2	Deny write to others.
	3	Deny read/execute to others.
	4	Deny nothing to others.
0x0080	Reserved
ReferenceLocality 0x0700	0	Unknown locality of reference
	1	Mainly sequential access
	2	Mainly random access
	3	Random access with some locality
	4 - 7	Undefined
0x0800	Reserved
CacheMode 0x1000	0	Perform caching on file.
	1	Do not cache the file.
0x2000	Reserved
WritethroughMode 0x4000	0	Write-through mode. If this flag is set, then no read ahead or write behind is allowed on this file or device. When the response is returned, data is expected to be on the disk or device.
	1
0x8000	Reserved

Reserved1 (2 bytes): This field MUST be set to zero (0x0000) and MUST be ignored by the server.

FileAttributes (2 bytes): Attributes to apply to the file if it needs to be created.

CreationTime (4 bytes): A 32-bit integer time value to be assigned to the file as the time of creation if the file is to be created.

OpenMode (2 bytes): A 16-bit field that controls the way that a file SHOULD be treated when it is opened for use by certain extended SMB requests.

Name and bitmask	Values	Meaning
FileExistsOpts 0x0003	0	The request SHOULD fail and an error SHOULD be returned indicating the prior existence of the file.
	1	The file is to be appended.
	2	The file is to be truncated to zero (0) length.
	3	Reserved
CreateFile 0x0010	0	If the file does not exist, return error.
	1	If the file does not exist, create it.

All other bits are reserved; they SHOULD NOT be used by the client and MUST be ignored by the server.

AllocationSize (4 bytes): The number of bytes to reserve for the file if the file is being created or truncated.

          

Reserved (10 bytes): All entries in this field MUST be set to zero (0x0000).

FileName (variable): A buffer containing the name of the file to be opened, created, or truncated. The string MUST be null terminated.

Trans2_Data

 Trans2_Data
   {
            
   SMB_FEA_LIST ExtendedAttributeList;
   }

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ExtendedAttributeList (variable)
...

ExtendedAttributeList (variable): A list of extended attribute (EA) name/value pairs that are to be assigned to the file.