.\" DO NOT MODIFY THIS FILE! It was generated by setup.py 1.2. .TH UNPACK 3 "21 March 2023" "NFStest 3.2" "unpack 2.4" .SH NAME packet.unpack - Unpack module .SH DESCRIPTION Provides the object for managing and unpacking raw data from a working buffer. .SH CLASSES .SS class Unpack(builtins.object) .nf Unpack object Usage: from packet.unpack import Unpack x = Unpack(buffer) # Get 32 bytes from the working buffer and move the offset pointer data = x.read(32) # Get all the unprocessed bytes from the working buffer # (all bytes starting from the offset pointer) # Do not move the offset pointer data = x.getbytes() # Get all bytes from the working buffer from the given offset # Do not move the offset pointer data = x.getbytes(offset) # Return the number of unprocessed bytes left in the working buffer size = x.size() size = len(x) # Get the offset pointer offset = x.tell() # Set the offset pointer x.seek(offset) # Append the given data to the working buffer x.append(data) # Insert the given data to the working buffer right before the # offset pointer. This resets the working buffer completely # and the offset pointer is initialized to zero. It is like # re-instantiating the object like: # x = Unpack(data + x.getbytes()) x.insert(data) # Save state sid = x.save_state() # Restore state x.restore_state(sid) # Unpack an 'unsigned short' (2 bytes in network order) short_int = x.unpack(2, '!H')[0] # Unpack different basic types char = x.unpack_char() uchar = x.unpack_uchar() short = x.unpack_short() ushort = x.unpack_ushort() int = x.unpack_int() uint = x.unpack_uint() int64 = x.unpack_int64() uint64 = x.unpack_uint64() data1 = x.unpack_opaque() data2 = x.unpack_opaque(64) # Length of opaque must be <= 64 data3 = x.unpack_fopaque(32) # Get string where length is given as an unsigned integer buffer = x.unpack_string() # Get string of fixed length buffer = x.unpack_string(32) # Get string where length is given as a short integer buffer = x.unpack_string(Unpack.unpack_short) buffer = x.unpack_string(ltype=Unpack.unpack_short) # Get string padded to a 4 byte boundary, discard padding bytes buffer = x.unpack_string(pad=4) # Get an array of unsigned integers alist = x.unpack_array() # Get a fixed length array of unsigned integers alist = x.unpack_array(ltype=10) # Get an array of short integers alist = x.unpack_array(Unpack.unpack_short) # Get an array of strings, the length of the array is given # by a short integer alist = x.unpack_array(Unpack.unpack_string, Unpack.unpack_short) # Get an array of strings, the length of each string is given by # a short integer and each string is padded to a 4 byte boundary alist = x.unpack_array(Unpack.unpack_string, uargs={'ltype':Unpack.unpack_short, 'pad':4}) # Get an array of objects decoded by item_obj where the first # argument to item_obj is the unpack object, e.g., item = item_obj(x) alist = x.unpack_array(item_obj) # Get a list of unsigned integers alist = x.unpack_list() # Get a list of short integers alist = x.unpack_list(Unpack.unpack_short) # Get a list of strings, the next item flag is given # by a short integer alist = x.unpack_list(Unpack.unpack_string, Unpack.unpack_short) # Get a list of strings, the length of each string is given by # a short integer and each string is padded to a 4 byte boundary alist = x.unpack_list(Unpack.unpack_string, uargs={'ltype':Unpack.unpack_short, 'pad':4}) # Unpack a conditional, it unpacks a conditional flag first and # if it is true it unpacks the item given and returns it. If the # conditional flag decoded is false, the method returns None buffer = x.unpack_conditional(Unpack.unpack_opaque) # Unpack an array of unsigned integers and convert array into # a single long integer bitmask = unpack_bitmap() .P .B Methods defined here: --------------------- .P .B __init__(self, data) Constructor Initialize object's private data. .RS .TP .B data: Raw packet data .RE .P .B __len__ = size(self) .P .B append(self, data) Append data to the working buffer. .P .B getbytes(self, offset=None) Get the number of bytes given from the working buffer. Do not move the offset pointer. .RS .TP .B offset: Starting offset of data to return [default: current offset] .RE .P .B insert(self, data) Insert data to the beginning of the current working buffer. .P .B read(self, size, pad=0) Get the number of bytes given from the working buffer. Move the offset pointer. .RS .TP .B size: Length of data to get .TP .B pad: Get and discard padding bytes [default: 0] If given, data is padded to this byte boundary .RE .P .B restore_state(self, sid) Restore state given by the state id .P .B save_state(self) Save state and return the state id .P .B seek(self, offset) Set the offset pointer. .P .B size(self) Return the number of unprocessed bytes left in the working buffer .P .B tell(self) Get the offset pointer. .P .B unpack(self, size, fmt) Get the number of bytes given from the working buffer and process it according to the given format. Return a tuple of unpack items, see struct.unpack. .RS .TP .B size: Length of data to process .TP .B fmt: Format string on how to process data .RE .P .B unpack_array(self, unpack_item=, ltype=, uargs={}, maxcount=0, islist=False) Get a variable length array, the type of objects in the array is given by the unpacking function unpack_item and the type to decode the length of the array is given by ltype .RS .TP .B unpack_item: Unpack function for each item in the array [default: unpack_uint] .TP .B ltype: Function to decode length of array [default: unpack_uint] Could also be given as an integer to have a fixed length array .TP .B uargs: Named arguments to pass to unpack_item function [default: {}] .TP .B maxcount: Maximum length of array [default: any length] .RE .P .B unpack_bitmap(self) Unpack an array of unsigned integers and convert array into a single long integer .P .B unpack_char(self) Get a signed char .P .B unpack_conditional(self, unpack_item=, ltype=, uargs={}) Get an item if condition flag given by ltype is true, if condition flag is false then return None .RS .TP .B unpack_item: Unpack function for item if condition is true [default: unpack_uint] .TP .B ltype: Function to decode the condition flag [default: unpack_uint] .TP .B uargs: Named arguments to pass to unpack_item function [default: {}] .RE .P .B unpack_fopaque(self, size) Get a fixed length opaque .P .B unpack_futf8(self, size) Get a fixed length utf8 string .P .B unpack_int(self) Get a signed integer .P .B unpack_int64(self) Get a signed 64 bit integer .P .B unpack_list(self, *kwts, **kwds) Get an indeterminate size list, the type of objects in the list is given by the unpacking function unpack_item and the type to decode the next item flag is given by ltype .RS .TP .B unpack_item: Unpack function for each item in the list [default: unpack_uint] .TP .B ltype: Function to decode the next item flag [default: unpack_uint] .TP .B uargs: Named arguments to pass to unpack_item function [default: {}] .RE .P .B unpack_opaque(self, maxcount=0) Get a variable length opaque up to a maximum length of maxcount .P .B unpack_short(self) Get a signed short integer .P .B unpack_string(self, ltype=, pad=0, maxcount=0) Get a variable length string .RS .TP .B ltype: Function to decode length of string [default: unpack_uint] Could also be given as an integer to have a fixed length string .TP .B pad: Get and discard padding bytes [default: 0] If given, string is padded to this byte boundary .TP .B maxcount: Maximum length of string [default: any length] .RE .P .B unpack_uchar(self) Get an unsigned char .P .B unpack_uint(self) Get an unsigned integer .P .B unpack_uint64(self) Get an unsigned 64 bit integer .P .B unpack_ushort(self) Get an unsigned short integer .P .B unpack_utf8(self, maxcount=0) Get a variable length utf8 string up to a maximum length of maxcount .fi .SH BUGS No known bugs. .SH AUTHOR Jorge Mora (mora@netapp.com)