This is an original Core Protocol command. This command is deprecated. Clients SHOULD use SMB_COM_READ_ANDX (section

This command is used to read bytes from a regular file. If the client has negotiated a protocol that supports named pipes or directly accessible devices, this command can also be used to read from those objects. The end of file condition is indicated by the server returning fewer bytes than the client requested. A read request starting at or beyond the end of the file returns zero bytes. If a read requests more data than can be placed in a message of MaxBufferSize for the SMB connection, the server MUST abort the connection to the client. Because this client request supports 32-bit offsets only, it is inappropriate for files that have 64-bit offsets. The client MUST have at least read access to the file.