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source: server/lib/ippvalue.py @ c269bc7

no-cups

Last change on this file since c269bc7 was c269bc7, checked in by Jessica B. Hamrick <jhamrick@…>, 13 years ago
Update API for Value, Attribute, and AttributeGroup?
Property mode set to `100644`
File size: 15.5 KB

Rev	Line
[8979f90]	1	#!/usr/bin/python
	2
	3	import sys, struct, logging
[2646571]	4	from ippconstants import *
[8979f90]	5
	6	# initialize logger
	7	logger = logging.getLogger("ippLogger")
	8
[ebf327d]	9	class Value():
[8979f90]	10	"""
[5cfb358]	11	An IPP value consists of a tag and a value.
[8979f90]	12
	13	From RFC 2565:
	14	-----------------------------------------------
	15	\| value-tag \| 1 byte
	16	-----------------------------------------------
[5cfb358]	17	\| name-length (value is 0x0000) \| 2 bytes
[8979f90]	18	-----------------------------------------------
	19	\| value-length (value is v) \| 2 bytes
	20	-----------------------------------------------
	21	\| value \| v bytes
	22	-----------------------------------------------
	23	"""
	24
[5cfb358]	25	def __init__(self, value_tag=None, value=None, unpack=True):
[8979f90]	26	"""
[5cfb358]	27	Initialize a Value. There are three different ways you can
	28	call this method:
	29
	30	Value() -- creates an empty Value instance
	31
	32	Value(value_tag, value) -- creates a Value instance from
	33	binary values
	34
	35	Value(value_tag, value, unpack=False) -- creates a Value
	36	instance from non-binary values
	37
	38	If you create an empty Value instance, once you have set
	39	value_tag and value, you should call pack(), or if you set
	40	value_tag and binary_value, call unpack().
[8979f90]	41
	42	Arguments:
	43
	44	value_tag -- one byte, identifying the type of value
	45
[5cfb358]	46	value -- variable size, containing the actual value. If
	47	unpack is True, then this should be a binary value,
	48	otherwise it should be a string or number.
	49
	50	unpack -- boolean which indicates whether the value passed
	51	in is binary (i.e., should be unpacked) or not (i.e., does
	52	not need to be unpacked)
[8979f90]	53	"""
	54
[5cfb358]	55	# make sure the arguments are valid
	56	if value_tag is not None:
	57	assert value is not None, \
	58	"value must not be null because " + \
	59	"value_tag is not null!"
	60	elif value_tag is None:
	61	assert value is None, \
	62	"value must be null because value_tag is null!"
[8979f90]	63
[5cfb358]	64	# initialize member variables
	65	self.value_tag = None # one byte, the type of value
	66	self.value = None # non-binary value of self.value
[c269bc7]	67	self.tag_size = 1 # length of the tag in bytes
	68	self.value_size = None # size of self.value in bytes
[5cfb358]	69	self.binary_value = None # binary value of self.value
	70
	71	if value_tag is not None and value is not None:
	72	if unpack:
	73	self.value_tag = value_tag
	74	self.binary_value = value
[c269bc7]	75	self.value_size, self.value = self.unpack()
[5cfb358]	76	else:
	77	self.value_tag = value_tag
	78	self.value = value
[c269bc7]	79	self.value_size, self.binary_value = self.pack()
	80
	81	self.verify()
[5cfb358]	82
	83	def unpack(self):
	84	"""
	85	Given self.value_tag and self.binary_value, unpack the binary
	86	value into either a string or number. These values MUST NOT
	87	be null. Furthermore, if self.value and self.value_size are
	88	set, this method will check to make sure that unpacking
	89	self.binary_value matches up.
	90
	91	Returns: tuple of (value_size, value)
	92	"""
[8979f90]	93
[5cfb358]	94	assert self.value_tag is not None, \
	95	"Cannot unpack values with unspecified value tag!"
	96	assert self.binary_value is not None, \
	97	"Cannot unpack null values!"
	98
	99	value_size = None
	100	value = None
[8979f90]	101
	102	# out-of-band value tags
[2646571]	103	if self.value_tag == OutOfBandTags.UNSUPPORTED or \
	104	self.value_tag == OutOfBandTags.DEFAULT or \
	105	self.value_tag == OutOfBandTags.UNKNOWN or \
	106	self.value_tag == OutOfBandTags.NO_VALUE:
[5cfb358]	107	value_size = 0
	108	value = ''
[8979f90]	109
	110	# integer value tags
[2646571]	111	elif self.value_tag == IntegerTags.INTEGER:
[5cfb358]	112	value_size = 4
	113	value = struct.unpack('>i', self.binary_value)[0]
[2646571]	114	elif self.value_tag == IntegerTags.BOOLEAN:
[5cfb358]	115	value_size = 1
	116	value = struct.unpack('>?', self.binary_value)[0]
[2646571]	117	elif self.value_tag == IntegerTags.ENUM:
[5cfb358]	118	value_size = 4
	119	value = struct.unpack('>i', self.binary_value)[0]
[8979f90]	120
	121
[2646571]	122	elif self.value_tag == OctetStringTags.DATETIME:
[8979f90]	123	# field octets contents range
	124	# ----- ------ -------- -----
	125	# 1 1-2 year 0..65536
	126	# 2 3 month 1..12
	127	# 3 4 day 1..31
	128	# 4 5 hour 0..23
	129	# 5 6 minutes 0..59
	130	# 6 7 seconds 0..60
	131	# (use 60 for leap-second)
	132	# 7 8 deci-seconds 0..9
	133	# 8 9 direction from UTC '+' / '-'
	134	# 9 10 hours from UTC 0..11
	135	# 10 11 minutes from UTC 0..59
	136
[5cfb358]	137	value_size = 11
	138	value = struct.unpack('>hbbbbbbcbb', self.binary_value)[0]
[8979f90]	139
[2646571]	140	elif self.value_tag == OctetStringTags.RESOLUTION:
[8979f90]	141	# OCTET-STRING consisting of nine octets of 2
	142	# SIGNED-INTEGERs followed by a SIGNED-BYTE. The first
	143	# SIGNED-INTEGER contains the value of cross feed
	144	# direction resolution. The second SIGNED-INTEGER contains
	145	# the value of feed direction resolution. The SIGNED-BYTE
	146	# contains the units
	147
[5cfb358]	148	value_size = 9
	149	value = struct.unpack('>iib', self.binary_value)
[8979f90]	150
[2646571]	151	elif self.value_tag == OctetStringTags.RANGE_OF_INTEGER:
[8979f90]	152	# Eight octets consisting of 2 SIGNED-INTEGERs. The first
	153	# SIGNED-INTEGER contains the lower bound and the second
	154	# SIGNED-INTEGER contains the upper bound.
	155
[5cfb358]	156	value_size = 8
	157	value = struct.unpack('>ii', self.binary_value)
[8979f90]	158
[2646571]	159	elif self.value_tag == OctetStringTags.TEXT_WITH_LANGUAGE or \
	160	self.value_tag == OctetStringTags.NAME_WITH_LANGUAGE:
[5cfb358]	161	a = struct.unpack('>h', self.binary_value[:2])[0]
	162	b = struct.unpack('>%ss' % a, self.binary_value[2:a+2])[0]
	163	c = struct.unpack('>h', self.binary_value[a+2:a+4])[0]
	164	d = struct.unpack('>%ss' % c, self.binary_value[a+4:][0])
	165	value_size = 4 + a + c
	166	value = (a, b, c, d)
[8979f90]	167
	168	# character string value tags
[5cfb358]	169	elif self.value_tag == \
	170	CharacterStringTags.TEXT_WITHOUT_LANGUAGE or \
	171	self.value_tag == \
	172	CharacterStringTags.NAME_WITHOUT_LANGUAGE:
	173	value_size = len(str(self.binary_value))
	174	value = str(self.binary_value)
[2646571]	175	elif self.value_tag == CharacterStringTags.GENERIC or \
	176	self.value_tag == CharacterStringTags.KEYWORD or \
	177	self.value_tag == CharacterStringTags.URI or \
	178	self.value_tag == CharacterStringTags.URI_SCHEME or \
	179	self.value_tag == CharacterStringTags.CHARSET or \
	180	self.value_tag == CharacterStringTags.NATURAL_LANGUAGE or \
	181	self.value_tag == CharacterStringTags.MIME_MEDIA_TYPE:
[5cfb358]	182	value_size = len(str(self.binary_value))
	183	value = str(self.binary_value)
[8979f90]	184
[5cfb358]	185	# anything else that we didn't handle
	186	else:
	187	if value_size is None and value is None:
	188	value_size = len(self.binary_value)
	189	value = self.binary_value
	190
	191	if self.value_size is not None:
	192	assert value_size == self.value_size, \
	193	"unpacked value_size is not the same " + \
	194	"as self.value_size!"
	195	if self.value is not None:
	196	assert value == self.value, \
	197	"unpacked value is not the same as self.value!"
	198
	199	return value_size, value
	200
	201	def pack(self):
	202	"""
	203	Given self.value_tag and self.value, pack the value into
	204	binary formo. These values MUST NOT be null. Furthermore, if
	205	self.binary_value and self.value_size are set, this method
	206	will check to make sure that packing self.value matches up.
	207
	208	Returns: tuple of (value_size, binary_value)
	209	"""
	210
	211	assert self.value_tag is not None, \
	212	"cannot pack value with null value tag!"
	213	assert self.value is not None, \
	214	"cannot pack null value!"
	215
	216	value_size = None
	217	binary_value = None
[8979f90]	218
	219	# out-of-band value tags
[2646571]	220	if self.value_tag == OutOfBandTags.UNSUPPORTED or \
	221	self.value_tag == OutOfBandTags.DEFAULT or \
	222	self.value_tag == OutOfBandTags.UNKNOWN or \
	223	self.value_tag == OutOfBandTags.NO_VALUE:
[5cfb358]	224	value_size = 0
	225	binary_value = ''
[8979f90]	226
	227	# integer value tags
[2646571]	228	elif self.value_tag == IntegerTags.INTEGER:
[5cfb358]	229	value_size = 4
	230	binary_value = struct.pack('>i', self.value)
[2646571]	231	elif self.value_tag == IntegerTags.BOOLEAN:
[5cfb358]	232	value_size = 1
	233	binary_value = struct.pack('>?', self.value)
[2646571]	234	elif self.value_tag == IntegerTags.ENUM:
[5cfb358]	235	value_size = 4
	236	binary_value = struct.pack('>i', self.value)
[8979f90]	237
	238	# octet string value tags
[2646571]	239	elif self.value_tag == OctetStringTags.DATETIME:
[8979f90]	240	# field octets contents range
	241	# ----- ------ -------- -----
	242	# 1 1-2 year 0..65536
	243	# 2 3 month 1..12
	244	# 3 4 day 1..31
	245	# 4 5 hour 0..23
	246	# 5 6 minutes 0..59
	247	# 6 7 seconds 0..60
	248	# (use 60 for leap-second)
	249	# 7 8 deci-seconds 0..9
	250	# 8 9 direction from UTC '+' / '-'
	251	# 9 10 hours from UTC 0..11
	252	# 10 11 minutes from UTC 0..59
[5cfb358]	253
	254	value_size = 11
	255	binary_value = struct.pack('>hbbbbbbcbb', self.value)
[8979f90]	256
[2646571]	257	elif self.value_tag == OctetStringTags.RESOLUTION:
[8979f90]	258	# OCTET-STRING consisting of nine octets of 2
	259	# SIGNED-INTEGERs followed by a SIGNED-BYTE. The first
	260	# SIGNED-INTEGER contains the value of cross feed
	261	# direction resolution. The second SIGNED-INTEGER contains
	262	# the value of feed direction resolution. The SIGNED-BYTE
	263	# contains the units
[5cfb358]	264
	265	value_size = 9
	266	binary_value = truct.pack('>iib', self.value)
[8979f90]	267
[2646571]	268	elif self.value_tag == OctetStringTags.RANGE_OF_INTEGER:
[8979f90]	269	# Eight octets consisting of 2 SIGNED-INTEGERs. The first
	270	# SIGNED-INTEGER contains the lower bound and the second
	271	# SIGNED-INTEGER contains the upper bound.
[5cfb358]	272
	273	value_size = 8
	274	binary_value = struct.pack('>ii', self.value)
[8979f90]	275
[2646571]	276	elif self.value_tag == OctetStringTags.TEXT_WITH_LANGUAGE or \
	277	self.value_tag == OctetStringTags.NAME_WITH_LANGUAGE:
[5cfb358]	278
[8979f90]	279	a_bin = struct.pack('>h', self.value[0])
	280	b_bin = struct.pack('>%ss' % self.value[0], self.value[1])
	281	c_bin = struct.pack('>h', self.value[2])
	282	d_bin = struct.pack('>%ss' % self.value[2], self.value[3])
[5cfb358]	283
	284	value_size = 4 + self.value[0] + self.value[2]
	285	binary_value = a_bin + b_bin + c_bin + d_bin
[8979f90]	286
	287	# character string value tags
[5cfb358]	288	elif self.value_tag == \
	289	CharacterStringTags.TEXT_WITHOUT_LANGUAGE or \
	290	self.value_tag == \
	291	CharacterStringTags.NAME_WITHOUT_LANGUAGE:
	292
	293	value_size = len(self.value)
	294	binary_value = struct.pack('>%ss' % len(self.value),
	295	self.value)
	296
[2646571]	297	elif self.value_tag == CharacterStringTags.GENERIC or \
	298	self.value_tag == CharacterStringTags.KEYWORD or \
	299	self.value_tag == CharacterStringTags.URI or \
	300	self.value_tag == CharacterStringTags.URI_SCHEME or \
	301	self.value_tag == CharacterStringTags.CHARSET or \
	302	self.value_tag == CharacterStringTags.NATURAL_LANGUAGE or \
	303	self.value_tag == CharacterStringTags.MIME_MEDIA_TYPE:
[5cfb358]	304
	305	value_size = len(self.value)
	306	binary_value = struct.pack('>%ss' % len(self.value),
	307	self.value)
	308
	309	else:
	310	value_size = len(self.value)
	311	binary_value = self.value
	312
	313	return value_size, binary_value
	314
	315	def verify(self):
	316	"""
	317	Verifies that the binary and non-binary values for this Value
	318	instance line up. All of self.value, self.binary_value,
	319	self.value_size, and self.value_tag must be defined.
	320
	321	This function will throw an assertion error if the Value
	322	instance is not valid.
	323	"""
	324
	325	assert self.value is not None, \
	326	"value is null!"
	327	assert self.binary_value is not None, \
	328	"binary value is null!"
	329	assert self.value_size is not None, \
	330	"value size is unknown!"
	331	assert self.value_tag is not None, \
	332	"value type is unknown!"
	333
[c269bc7]	334	value_size1, binary_value = self.pack()
	335	value_size2, value = self.unpack()
	336
	337	assert value_size1 == value_size2, \
	338	"packed value size is not the same as " + \
	339	"unpacked value size!"
	340	assert value_size == self.value_size, \
	341	"packed value size is not the same as " + \
	342	"self.value_size!"
	343	assert binary_value == self.binary_value, \
	344	"packed binary value is not the same as " + \
	345	"self.binary_value!"
[5cfb358]	346
	347	def getValue(self):
	348	"""
	349	Get the non-binary value.
	350	"""
	351
	352	return self.value
	353
	354	def getBinaryValue(self):
	355	"""
	356	Get the binary value.
	357	"""
	358
	359	return self.binary_value
	360
	361	def getValueTag(self):
	362	"""
	363	Get the value tag (type of value). This is an integer
	364	corresponding to a value in ippconstants.
	365	"""
	366
	367	return self.value_tag
	368
[c269bc7]	369	def getValueSize(self):
[5cfb358]	370	"""
	371	Get the size of the value in bytes.
	372	"""
	373
	374	return self.value_size
	375
[c269bc7]	376	def getTagSize(self):
	377	"""
	378	Get the size of the value tag in bytes.
	379	"""
	380
	381	return self.tag_size
	382
[5cfb358]	383	def setValue(self, value):
	384	"""
	385	Set the non-binary value.
	386	"""
[c269bc7]	387
[5cfb358]	388	self.value = value
	389
	390	def setBinaryValue(self, binary_value):
	391	"""
	392	Set the binary value.
	393	"""
[c269bc7]	394
[5cfb358]	395	self.binary_value = binary_value
	396
	397	def setValueTag(self, value_tag):
	398	"""
	399	Set the type (tag) of the value. This should correspond to an
	400	integer defined in ippconstants.
	401	"""
	402
	403	self.value_tag = value_tag
	404
[c269bc7]	405	def setValueSize(self, size):
[5cfb358]	406	"""
	407	Set the size of the value in bytes.
	408	"""
	409
	410	self.value_size = size
[8979f90]	411
[c269bc7]	412	def getTotalSize(self):
	413	"""
	414	Get the total size of the IPP value.
	415	"""
	416
	417	return self.value_size + self.tag_size
	418
[5cfb358]	419	def __str__(self):
	420	return self.value

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