[MS-SMB2]: SMB2 SET_INFO Request (2024)

The SMB2 SET_INFO Request packet is sent by a client to setinformation on a file or underlying object store. This request consists of an SMB2 header, as specifiedin section 2.2.1, followed by this request structure.

StructureSize (2 bytes): The client MUST setthis field to 33, indicating the size of the request structure, not includingthe header. The client MUST set this field to this value regardless of how longBuffer[] actually is in the request being sent.

InfoType (1 byte): The type of informationbeing set. The valid values are as follows.

Value	Meaning
SMB2_0_INFO_FILE 0x01	The file information is being set.
SMB2_0_INFO_FILESYSTEM 0x02	The underlying object store information is being set.
SMB2_0_INFO_SECURITY 0x03	The security information is being set.
SMB2_0_INFO_QUOTA 0x04	The underlying object store quota information is being set.

FileInfoClass (1 byte): For setting fileinformation, this field MUST contain one of the followingFILE_INFORMATION_CLASS values, as specified in section 3.3.5.21.1 and [MS-FSCC]section 2.4:

• FileAllocationInformation

  See Also

  Packet Carving with SMB and SMB2 | Chris Sanders[MS-SMB2]: OverviewSMB Most Important Features | Visuality SystemsSMB2 - Wireshark Wiki

• FileBasicInformation

• FileDispositionInformation

• FileEndOfFileInformation

• FileFullEaInformation

• FileLinkInformation

• FileModeInformation

• FilePipeInformation

  See Also

  SMB security enhancements

• FilePositionInformation

• FileRenameInformation

• FileShortNameInformation

• FileValidDataLengthInformation

For setting underlying objectstore information, this field MUST contain one of the following FS_INFORMATION_CLASSvalues, as specified in [MS-FSCC] section 2.5:

• FileFsControlInformation

• FileFsObjectIdInformation

For setting quota and securityinformation, this field MUST be 0.

BufferLength (4 bytes): The length, in bytes,of the information to be set.

BufferOffset (2 bytes): The offset, in bytes,from the beginning of the SMB2 header to the information to be set.<78>

Reserved (2 bytes): This field MUST NOT beused and MUST be reserved. The client MUST set this field to 0, and the serverMUST ignore it on receipt.

AdditionalInformation (4 bytes): Providesadditional information to the server.

If security information is being set, this valueMUST contain a 4-byte bit field of flags indicating what security attributesMUST be applied. For more information about security descriptors, see [MS-DTYP]section 2.4.6.

Value	Meaning
OWNER_SECURITY_INFORMATION 0x00000001	The client is setting the owner in the security descriptor of the file or named pipe.
GROUP_SECURITY_INFORMATION 0x00000002	The client is setting the group in the security descriptor of the file or named pipe.
DACL_SECURITY_INFORMATION 0x00000004	The client is setting the discretionary access control list in the security descriptor of the file or named pipe.
SACL_SECURITY_INFORMATION 0x00000008	The client is setting the system access control list in the security descriptor of the file or named pipe.
LABEL_SECURITY_INFORMATION 0x00000010	The client is setting the integrity label in the security descriptor of the file or named pipe.
ATTRIBUTE_SECURITY_INFORMATION 0x00000020	The client is setting the resource attribute in the security descriptor of the file or named pipe.
SCOPE_SECURITY_INFORMATION 0x00000040	The client is setting the central access policy of the resource in the security descriptor of the file or named pipe.
BACKUP_SECURITY_INFORMATION 0x00010000	The client is setting the backup operation information in the security descriptor of the file or named pipe.

For all other set requests, thisfield MUST be 0.

FileId (16 bytes): An SMB2_FILEID identifier ofthe file or named pipe on which to perform the set. Set operations forunderlying object store and quota information are directed to the volume onwhich the file resides.

Buffer (variable): A variable-length bufferthat contains the information being set for the request, as described by the BufferOffsetand BufferLength fields. Buffer format depends on InfoType andthe AdditionalInformation, as follows.

InfoType	AdditionalInformation	Buffer format specification
SMB2_0_INFO_FILE		See [MS-FSCC] section 2.4.
SMB2_0_INFO_FILESYSTEM		See [MS-FSCC] section 2.5.
SMB2_0_INFO_SECURITY	Any combination of the values: OWNER_SECURITY_INFORMATION GROUP_SECURITY_INFORMATION LABEL_SECURITY_INFORMATION DACL_SECURITY_INFORMATION SACL_SECURITY_INFORMATION	The security descriptor data structure, as specified in [MS-DTYP] section 2.4.6, populated with the data specified by the AdditionalInformation value.
SMB2_0_INFO_QUOTA		See [MS-FSCC] section 2.4.36.