1 files changed, 142 insertions, 0 deletions
diff --git a/lib/dnspython/dns/edns.py b/lib/dnspython/dns/edns.py
new file mode 100644
index 0000000000..1731cedde4
--- /dev/null
+++ b/lib/dnspython/dns/edns.py
@@ -0,0 +1,142 @@
+# Copyright (C) 2009 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose with or without fee is hereby granted,
+# provided that the above copyright notice and this permission notice
+# appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+"""EDNS Options"""
+
+NSID = 3
+
+class Option(object):
+    """Base class for all EDNS option types.
+    """
+
+    def __init__(self, otype):
+        """Initialize an option.
+        @param rdtype: The rdata type
+        @type rdtype: int
+        """
+        self.otype = otype
+
+    def to_wire(self, file):
+        """Convert an option to wire format.
+        """
+        raise NotImplementedError
+
+    def from_wire(cls, otype, wire, current, olen):
+        """Build an EDNS option object from wire format
+
+        @param otype: The option type
+        @type otype: int
+        @param wire: The wire-format message
+        @type wire: string
+        @param current: The offet in wire of the beginning of the rdata.
+        @type current: int
+        @param olen: The length of the wire-format option data
+        @type olen: int
+        @rtype: dns.ends.Option instance"""
+        raise NotImplementedError
+
+    from_wire = classmethod(from_wire)
+
+    def _cmp(self, other):
+        """Compare an ENDS option with another option of the same type.
+        Return < 0 if self < other, 0 if self == other, and > 0 if self > other.
+        """
+        raise NotImplementedError
+
+    def __eq__(self, other):
+        if not isinstance(other, Option):
+            return False
+        if self.otype != other.otype:
+            return False
+        return self._cmp(other) == 0
+
+    def __ne__(self, other):
+        if not isinstance(other, Option):
+            return False
+        if self.otype != other.otype:
+            return False
+        return self._cmp(other) != 0
+
+    def __lt__(self, other):
+        if not isinstance(other, Option) or \
+               self.otype != other.otype:
+            return NotImplemented
+        return self._cmp(other) < 0
+
+    def __le__(self, other):
+        if not isinstance(other, Option) or \
+               self.otype != other.otype:
+            return NotImplemented
+        return self._cmp(other) <= 0
+
+    def __ge__(self, other):
+        if not isinstance(other, Option) or \
+               self.otype != other.otype:
+            return NotImplemented
+        return self._cmp(other) >= 0
+
+    def __gt__(self, other):
+        if not isinstance(other, Option) or \
+               self.otype != other.otype:
+            return NotImplemented
+        return self._cmp(other) > 0
+
+
+class GenericOption(Option):
+    """Generate Rdata Class
+
+    This class is used for EDNS option types for which we have no better
+    implementation.
+    """
+
+    def __init__(self, otype, data):
+        super(GenericOption, self).__init__(otype)
+        self.data = data
+
+    def to_wire(self, file):
+        file.write(self.data)
+
+    def from_wire(cls, otype, wire, current, olen):
+        return cls(otype, wire[current : current + olen])
+
+    from_wire = classmethod(from_wire)
+
+    def _cmp(self, other):
+	return cmp(self.data, other.data)
+
+_type_to_class = {
+}
+
+def get_option_class(otype):
+    cls = _type_to_class.get(otype)
+    if cls is None:
+        cls = GenericOption
+    return cls
+
+def option_from_wire(otype, wire, current, olen):
+    """Build an EDNS option object from wire format
+
+    @param otype: The option type
+    @type otype: int
+    @param wire: The wire-format message
+    @type wire: string
+    @param current: The offet in wire of the beginning of the rdata.
+    @type current: int
+    @param olen: The length of the wire-format option data
+    @type olen: int
+    @rtype: dns.ends.Option instance"""
+
+    cls = get_option_class(otype)
+    return cls.from_wire(otype, wire, current, olen)