1 | #!/usr/bin/python |
---|
2 | |
---|
3 | import sys, struct, logging |
---|
4 | from ippattributegroup import IPPAttributeGroup |
---|
5 | from ippattribute import IPPAttribute |
---|
6 | from ippvalue import IPPValue |
---|
7 | |
---|
8 | # initialize logger |
---|
9 | logger = logging.getLogger("ippLogger") |
---|
10 | |
---|
11 | class IPPRequest(): |
---|
12 | """ |
---|
13 | From RFC 2565: |
---|
14 | |
---|
15 | The encoding for an operation request or response consists of: |
---|
16 | ----------------------------------------------- |
---|
17 | | version-number | 2 bytes - required |
---|
18 | ----------------------------------------------- |
---|
19 | | operation-id (request) | |
---|
20 | | or | 2 bytes - required |
---|
21 | | status-code (response) | |
---|
22 | ----------------------------------------------- |
---|
23 | | request-id | 4 bytes - required |
---|
24 | ----------------------------------------------------------- |
---|
25 | | xxx-attributes-tag | 1 byte | |
---|
26 | ----------------------------------------------- |-0 or more |
---|
27 | | xxx-attribute-sequence | n bytes | |
---|
28 | ----------------------------------------------------------- |
---|
29 | | end-of-attributes-tag | 1 byte - required |
---|
30 | ----------------------------------------------- |
---|
31 | | data | q bytes - optional |
---|
32 | ----------------------------------------------- |
---|
33 | """ |
---|
34 | |
---|
35 | # either give the version, operation_id, request_id, |
---|
36 | # attribute_sequence, and data, or a file handler (request) which |
---|
37 | # can be read from to get the request |
---|
38 | def __init__(self, version=None, operation_id=None, request_id=None, |
---|
39 | attribute_groups=[], data=None, request=None, length=sys.maxint): |
---|
40 | """ |
---|
41 | Create an IPPRequest. Takes either the segments of the |
---|
42 | request separately, or a file handle for the request to parse. |
---|
43 | If the file handle is passed in, all other arguments are |
---|
44 | ignored. |
---|
45 | |
---|
46 | Keyword arguments for passing in the segments of the request: |
---|
47 | |
---|
48 | version -- a tuple of two signed chars, identifying the |
---|
49 | major version and minor version numbers of the |
---|
50 | request |
---|
51 | |
---|
52 | operation_id -- a signed short, identifying the id of the |
---|
53 | requested operation |
---|
54 | |
---|
55 | request_id -- a signed int, identifying the id of the |
---|
56 | request itself. |
---|
57 | |
---|
58 | attribute_groups -- a list of IPPAttributes, at least length 1 |
---|
59 | |
---|
60 | data -- (optional) variable length, containing the actual |
---|
61 | data of the request |
---|
62 | |
---|
63 | Keyword arguments for passing in the raw request: |
---|
64 | |
---|
65 | request -- a file handle that supports the read() |
---|
66 | operation |
---|
67 | """ |
---|
68 | |
---|
69 | if request is None: |
---|
70 | # make sure the version number isn't empty |
---|
71 | assert version is not None |
---|
72 | # make sure verison is a tuple of length 2 |
---|
73 | assert isinstance(version, tuple) |
---|
74 | assert len(version) == 2 |
---|
75 | # make sure the operation id isn't empty |
---|
76 | assert operation_id is not None |
---|
77 | # make sure the request id isn't empty |
---|
78 | assert request_id is not None |
---|
79 | # make sure attribute_groups is a list of IPPAttributes |
---|
80 | assert len(attribute_groups) > 0 |
---|
81 | for a in attribute_groups: assert isinstance(a, IPPAttributeGroup) |
---|
82 | |
---|
83 | # if the request isn't None, then we'll read directly from |
---|
84 | # that file handle |
---|
85 | if request is not None: |
---|
86 | # read the version-number (two signed chars) |
---|
87 | self.version = struct.unpack('>bb', request.read(2)) |
---|
88 | length -= 2 |
---|
89 | logger.debug("version-number : (0x%X, 0x%X)" % self.version) |
---|
90 | |
---|
91 | # read the operation-id (or status-code, but that's only |
---|
92 | # for a response) (signed short) |
---|
93 | self.operation_id = struct.unpack('>h', request.read(2))[0] |
---|
94 | length -= 2 |
---|
95 | logger.debug("operation-id : 0x%X" % self.operation_id) |
---|
96 | |
---|
97 | # read the request-id (signed int) |
---|
98 | self.request_id = struct.unpack('>i', request.read(4))[0] |
---|
99 | length -= 4 |
---|
100 | logger.debug("request-id : 0x%X" % self.request_id) |
---|
101 | |
---|
102 | # now we have to read in the attributes. Each attribute |
---|
103 | # has a tag (1 byte) and a sequence of values (n bytes) |
---|
104 | self.attribute_groups = [] |
---|
105 | |
---|
106 | # read in the next byte |
---|
107 | next_byte = struct.unpack('>b', request.read(1))[0] |
---|
108 | length -=1 |
---|
109 | logger.debug("next byte : 0x%X" % next_byte) |
---|
110 | |
---|
111 | # as long as the next byte isn't signaling the end of the |
---|
112 | # attributes, keep looping and parsing attributes |
---|
113 | while next_byte != AttributeTags.END: |
---|
114 | |
---|
115 | attribute_group_tag = next_byte |
---|
116 | logger.debug("attribute-tag : %i" % attribute_group_tag) |
---|
117 | |
---|
118 | attributes = [] |
---|
119 | |
---|
120 | next_byte = struct.unpack('>b', request.read(1))[0] |
---|
121 | length -= 1 |
---|
122 | logger.debug("next byte : 0x%X" % next_byte) |
---|
123 | |
---|
124 | while next_byte > 0x0F: |
---|
125 | |
---|
126 | # read in the value tag (signed char) |
---|
127 | value_tag = next_byte |
---|
128 | logger.debug("value-tag : 0x%X" % value_tag) |
---|
129 | |
---|
130 | # read in the length of the name (signed short) |
---|
131 | name_length = struct.unpack('>h', request.read(2))[0] |
---|
132 | length -= 2 |
---|
133 | logger.debug("name-length : %i" % name_length) |
---|
134 | |
---|
135 | if name_length != AttributeTags.ZERO_NAME_LENGTH: |
---|
136 | # read the name (a string of name_length bytes) |
---|
137 | name = request.read(name_length) |
---|
138 | length -= name_length |
---|
139 | logger.debug("name : %s" % name) |
---|
140 | |
---|
141 | # read in the length of the value (signed short) |
---|
142 | value_length = struct.unpack('>h', request.read(2))[0] |
---|
143 | length -= 2 |
---|
144 | logger.debug("value-length : %i" % value_length) |
---|
145 | |
---|
146 | # read in the value (string of value_length bytes) |
---|
147 | value = request.read(value_length) |
---|
148 | length -= value_length |
---|
149 | |
---|
150 | ippvalue = IPPValue(value_tag, value) |
---|
151 | logger.debug("value : %s" % ippvalue.value) |
---|
152 | |
---|
153 | # create a new IPPAttribute from the data we just |
---|
154 | # read in, and add it to our attributes list |
---|
155 | attributes.append(IPPAttribute(name, [ippvalue])) |
---|
156 | |
---|
157 | else: |
---|
158 | # read in the length of the value (signed short) |
---|
159 | value_length = struct.unpack('>h', request.read(2))[0] |
---|
160 | length -= 2 |
---|
161 | logger.debug("value-length : %i" % value_length) |
---|
162 | |
---|
163 | # read in the value (string of value_length bytes) |
---|
164 | value = request.read(value_length) |
---|
165 | length -= value_length |
---|
166 | |
---|
167 | ippvalue = IPPValue(value_tag, value) |
---|
168 | logger.debug("value : %s" % ippvalue.value) |
---|
169 | |
---|
170 | # add another value to the last attribute |
---|
171 | attributes[-1].values.append(ippvalue) |
---|
172 | |
---|
173 | # read another byte |
---|
174 | next_byte = struct.unpack('>b', request.read(1))[0] |
---|
175 | length -= 1 |
---|
176 | |
---|
177 | self.attribute_groups.append(IPPAttributeGroup(attribute_group_tag, attributes)) |
---|
178 | |
---|
179 | # once we hit the end-of-attributes tag, the only thing |
---|
180 | # left is the data, so go ahead and read all of it |
---|
181 | assert length >= 0 |
---|
182 | self.data = request.read(length) |
---|
183 | logger.debug("data : %s" % self.data) |
---|
184 | |
---|
185 | # otherwise, just set the class variables to the keyword |
---|
186 | # arguments passed in |
---|
187 | else: |
---|
188 | self.version = (version[0], version[1]) |
---|
189 | self.operation_id = operation_id |
---|
190 | self.request_id = request_id |
---|
191 | self.attribute_groups = attribute_groups |
---|
192 | self.data = data |
---|
193 | |
---|
194 | def getAttributeGroup(self, tag): |
---|
195 | return filter(lambda x: x.attribute_group_tag == tag, |
---|
196 | self.attribute_groups) |
---|
197 | |
---|
198 | def toBinaryData(self): |
---|
199 | """ |
---|
200 | Packs the value data into binary data. |
---|
201 | """ |
---|
202 | |
---|
203 | # convert the version, operation id, and request id to binary |
---|
204 | preattributes = struct.pack('>bbhi', |
---|
205 | self.version[0], |
---|
206 | self.version[1], |
---|
207 | self.operation_id, |
---|
208 | self.request_id) |
---|
209 | |
---|
210 | # convert the attribute groups to binary |
---|
211 | attribute_groups = ''.join([a.toBinaryData() for a in self.attribute_groups]) |
---|
212 | |
---|
213 | # conver the end-of-attributes-tag to binary |
---|
214 | end_of_attributes_tag = struct.pack('>b', AttributeTags.END) |
---|
215 | |
---|
216 | # convert the data to binary |
---|
217 | if self.data is not None: |
---|
218 | data = ''.join([struct.pack('>b', x) for x in self.data]) |
---|
219 | else: |
---|
220 | data = '' |
---|
221 | |
---|
222 | # append everything together and return it |
---|
223 | return preattributes + attribute_groups + end_of_attributes_tag + data |
---|