| 1 | #!/usr/bin/python |
|---|
| 2 | |
|---|
| 3 | import sys, struct, logging |
|---|
| 4 | from ippattributegroup import AttributeGroup |
|---|
| 5 | from ippattribute import Attribute |
|---|
| 6 | from ippvalue import Value |
|---|
| 7 | from ippconstants import * |
|---|
| 8 | |
|---|
| 9 | # initialize logger |
|---|
| 10 | logger = logging.getLogger("ippLogger") |
|---|
| 11 | |
|---|
| 12 | class Request(): |
|---|
| 13 | """ |
|---|
| 14 | From RFC 2565: |
|---|
| 15 | |
|---|
| 16 | The encoding for an operation request or response consists of: |
|---|
| 17 | ----------------------------------------------- |
|---|
| 18 | | version-number | 2 bytes - required |
|---|
| 19 | ----------------------------------------------- |
|---|
| 20 | | operation-id (request) | |
|---|
| 21 | | or | 2 bytes - required |
|---|
| 22 | | status-code (response) | |
|---|
| 23 | ----------------------------------------------- |
|---|
| 24 | | request-id | 4 bytes - required |
|---|
| 25 | ----------------------------------------------------------- |
|---|
| 26 | | xxx-attributes-tag | 1 byte | |
|---|
| 27 | ----------------------------------------------- |-0 or more |
|---|
| 28 | | xxx-attribute-sequence | n bytes | |
|---|
| 29 | ----------------------------------------------------------- |
|---|
| 30 | | end-of-attributes-tag | 1 byte - required |
|---|
| 31 | ----------------------------------------------- |
|---|
| 32 | | data | q bytes - optional |
|---|
| 33 | ----------------------------------------------- |
|---|
| 34 | """ |
|---|
| 35 | |
|---|
| 36 | # either give the version, operation_id, request_id, |
|---|
| 37 | # attribute_sequence, and data, or a file handler (request) which |
|---|
| 38 | # can be read from to get the request |
|---|
| 39 | def __init__(self, version=None, operation_id=None, request_id=None, |
|---|
| 40 | attribute_groups=[], data=None, request=None, length=sys.maxint): |
|---|
| 41 | """ |
|---|
| 42 | Create a Request. Takes either the segments of the request |
|---|
| 43 | separately, or a file handle for the request to parse. If the |
|---|
| 44 | file handle is passed in, all other arguments are 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 Attributes, 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 Attributes |
|---|
| 80 | assert len(attribute_groups) > 0 |
|---|
| 81 | for a in attribute_groups: assert isinstance(a, AttributeGroup) |
|---|
| 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 = Value.unpack(value_tag, value) |
|---|
| 151 | logger.debug("value : %s" % ippvalue.value) |
|---|
| 152 | |
|---|
| 153 | # create a new Attribute from the data we just |
|---|
| 154 | # read in, and add it to our attributes list |
|---|
| 155 | attributes.append(Attribute(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 = Value.unpack(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(AttributeGroup( |
|---|
| 178 | attribute_group_tag, attributes)) |
|---|
| 179 | |
|---|
| 180 | # once we hit the end-of-attributes tag, the only thing |
|---|
| 181 | # left is the data, so go ahead and read all of it |
|---|
| 182 | assert length >= 0 |
|---|
| 183 | self.data = request.read(length) |
|---|
| 184 | logger.debug("data : %s" % self.data) |
|---|
| 185 | |
|---|
| 186 | # otherwise, just set the class variables to the keyword |
|---|
| 187 | # arguments passed in |
|---|
| 188 | else: |
|---|
| 189 | self.version = (version[0], version[1]) |
|---|
| 190 | self.operation_id = operation_id |
|---|
| 191 | self.request_id = request_id |
|---|
| 192 | self.attribute_groups = attribute_groups |
|---|
| 193 | self.data = data |
|---|
| 194 | |
|---|
| 195 | def getAttributeGroup(self, tag): |
|---|
| 196 | return filter(lambda x: x.attribute_group_tag == tag, |
|---|
| 197 | self.attribute_groups) |
|---|
| 198 | |
|---|
| 199 | @property |
|---|
| 200 | def packed_value(self): |
|---|
| 201 | """ |
|---|
| 202 | Packs the value data into binary data. |
|---|
| 203 | """ |
|---|
| 204 | |
|---|
| 205 | # convert the version, operation id, and request id to binary |
|---|
| 206 | preattributes = struct.pack('>bbhi', |
|---|
| 207 | self.version[0], |
|---|
| 208 | self.version[1], |
|---|
| 209 | self.operation_id, |
|---|
| 210 | self.request_id) |
|---|
| 211 | |
|---|
| 212 | # convert the attribute groups to binary |
|---|
| 213 | attribute_groups = ''.join([a.packed_value for a in self.attribute_groups]) |
|---|
| 214 | |
|---|
| 215 | # conver the end-of-attributes-tag to binary |
|---|
| 216 | end_of_attributes_tag = struct.pack('>b', AttributeTags.END) |
|---|
| 217 | |
|---|
| 218 | # convert the data to binary |
|---|
| 219 | if self.data is not None: |
|---|
| 220 | data = ''.join([struct.pack('>b', x) for x in self.data]) |
|---|
| 221 | else: |
|---|
| 222 | data = '' |
|---|
| 223 | |
|---|
| 224 | # append everything together and return it |
|---|
| 225 | return preattributes + attribute_groups + end_of_attributes_tag + data |
|---|
