Defines the packets available to version 1 of the SFTP protocol, as well as their formats. These packets are:
- open( id, path, flags, attrs )
- close( id, handle )
- read( id, handle, offset, length )
- write( id, handle, offset, data )
- opendir( id, path )
- readdir( id, handle )
- remove( id, filename )
- stat( id, path )
- lstat( id, path )
- fstat( id, handle )
- setstat( id, path, attrs )
- fsetstat( id, handle, attrs )
- mkdir( id, path, attrs )
- rmdir( id, path )
- realpath( id, path )