Add ipwhois library + dependencies

lib/dns/node.py

@@ -0,0 +1,178 @@
+# Copyright (C) 2001-2007, 2009-2011 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.
+
+"""DNS nodes.  A node is a set of rdatasets."""
+
+from io import StringIO
+
+import dns.rdataset
+import dns.rdatatype
+import dns.renderer
+
+
+class Node(object):
+
+    """A DNS node.
+
+    A node is a set of rdatasets
+
+    @ivar rdatasets: the node's rdatasets
+    @type rdatasets: list of dns.rdataset.Rdataset objects"""
+
+    __slots__ = ['rdatasets']
+
+    def __init__(self):
+        """Initialize a DNS node.
+        """
+
+        self.rdatasets = []
+
+    def to_text(self, name, **kw):
+        """Convert a node to text format.
+
+        Each rdataset at the node is printed.  Any keyword arguments
+        to this method are passed on to the rdataset's to_text() method.
+        @param name: the owner name of the rdatasets
+        @type name: dns.name.Name object
+        @rtype: string
+        """
+
+        s = StringIO()
+        for rds in self.rdatasets:
+            if len(rds) > 0:
+                s.write(rds.to_text(name, **kw))
+                s.write(u'\n')
+        return s.getvalue()[:-1]
+
+    def __repr__(self):
+        return '<DNS node ' + str(id(self)) + '>'
+
+    def __eq__(self, other):
+        """Two nodes are equal if they have the same rdatasets.
+
+        @rtype: bool
+        """
+        #
+        # This is inefficient.  Good thing we don't need to do it much.
+        #
+        for rd in self.rdatasets:
+            if rd not in other.rdatasets:
+                return False
+        for rd in other.rdatasets:
+            if rd not in self.rdatasets:
+                return False
+        return True
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def __len__(self):
+        return len(self.rdatasets)
+
+    def __iter__(self):
+        return iter(self.rdatasets)
+
+    def find_rdataset(self, rdclass, rdtype, covers=dns.rdatatype.NONE,
+                      create=False):
+        """Find an rdataset matching the specified properties in the
+        current node.
+
+        @param rdclass: The class of the rdataset
+        @type rdclass: int
+        @param rdtype: The type of the rdataset
+        @type rdtype: int
+        @param covers: The covered type.  Usually this value is
+        dns.rdatatype.NONE, but if the rdtype is dns.rdatatype.SIG or
+        dns.rdatatype.RRSIG, then the covers value will be the rdata
+        type the SIG/RRSIG covers.  The library treats the SIG and RRSIG
+        types as if they were a family of
+        types, e.g. RRSIG(A), RRSIG(NS), RRSIG(SOA).  This makes RRSIGs much
+        easier to work with than if RRSIGs covering different rdata
+        types were aggregated into a single RRSIG rdataset.
+        @type covers: int
+        @param create: If True, create the rdataset if it is not found.
+        @type create: bool
+        @raises KeyError: An rdataset of the desired type and class does
+        not exist and I{create} is not True.
+        @rtype: dns.rdataset.Rdataset object
+        """
+
+        for rds in self.rdatasets:
+            if rds.match(rdclass, rdtype, covers):
+                return rds
+        if not create:
+            raise KeyError
+        rds = dns.rdataset.Rdataset(rdclass, rdtype)
+        self.rdatasets.append(rds)
+        return rds
+
+    def get_rdataset(self, rdclass, rdtype, covers=dns.rdatatype.NONE,
+                     create=False):
+        """Get an rdataset matching the specified properties in the
+        current node.
+
+        None is returned if an rdataset of the specified type and
+        class does not exist and I{create} is not True.
+
+        @param rdclass: The class of the rdataset
+        @type rdclass: int
+        @param rdtype: The type of the rdataset
+        @type rdtype: int
+        @param covers: The covered type.
+        @type covers: int
+        @param create: If True, create the rdataset if it is not found.
+        @type create: bool
+        @rtype: dns.rdataset.Rdataset object or None
+        """
+
+        try:
+            rds = self.find_rdataset(rdclass, rdtype, covers, create)
+        except KeyError:
+            rds = None
+        return rds
+
+    def delete_rdataset(self, rdclass, rdtype, covers=dns.rdatatype.NONE):
+        """Delete the rdataset matching the specified properties in the
+        current node.
+
+        If a matching rdataset does not exist, it is not an error.
+
+        @param rdclass: The class of the rdataset
+        @type rdclass: int
+        @param rdtype: The type of the rdataset
+        @type rdtype: int
+        @param covers: The covered type.
+        @type covers: int
+        """
+
+        rds = self.get_rdataset(rdclass, rdtype, covers)
+        if rds is not None:
+            self.rdatasets.remove(rds)
+
+    def replace_rdataset(self, replacement):
+        """Replace an rdataset.
+
+        It is not an error if there is no rdataset matching I{replacement}.
+
+        Ownership of the I{replacement} object is transferred to the node;
+        in other words, this method does not store a copy of I{replacement}
+        at the node, it stores I{replacement} itself.
+        """
+
+        if not isinstance(replacement, dns.rdataset.Rdataset):
+            raise ValueError('replacement is not an rdataset')
+        self.delete_rdataset(replacement.rdclass, replacement.rdtype,
+                             replacement.covers)
+        self.rdatasets.append(replacement)