[tor-commits] [bridgedb/master] Add bridgerequest module for abstracting info about bridge types requested.

[isis at torproject.org]

commit 92ca7cbefe7eec0fe30452e47e752bd4fb820839
Author: Isis Lovecruft <isis at torproject.org>
Date:   Mon May 5 19:13:39 2014 +0000

    Add bridgerequest module for abstracting info about bridge types requested.
---
 lib/bridgedb/bridgerequest.py |  128 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 128 insertions(+)

diff --git a/lib/bridgedb/bridgerequest.py b/lib/bridgedb/bridgerequest.py
new file mode 100644
index 0000000..4f32f67
--- /dev/null
+++ b/lib/bridgedb/bridgerequest.py
@@ -0,0 +1,128 @@
+# -*- coding: utf-8 ; test-case-name: bridgedb.test.test_bridgerequest ; -*-
+#_____________________________________________________________________________
+#
+# This file is part of BridgeDB, a Tor bridge distribution system.
+#
+# :authors: Isis Lovecruft 0xA3ADB67A2CDB8B35 <isis at torproject.org>
+#           please also see AUTHORS file
+# :copyright: (c) 2007-2014, The Tor Project, Inc.
+#             (c) 2014, Isis Lovecruft
+# :license: see LICENSE for licensing information
+#_____________________________________________________________________________
+
+
+import logging
+
+import ipaddr
+
+from zope.interface import implements
+from zope.interface import Attribute
+from zope.interface import Interface
+
+from bridgedb import Filters
+
+
+class IBridgeRequest(Interface):
+    """Interface specification of client options for requested bridges."""
+
+    addressClass = Attribute(
+        "The IP version of bridges addresses to distribute to the client.")
+    filters = Attribute(
+        "A list of callables used to filter bridges from a hashring.")
+    transports = Attribute(
+        "A list of strings of Pluggable Transport types requested.")
+    notBlockedIn = Attribute(
+        "A list of 2-4 letter country codes. The distributed bridges should "
+        "not be blocked in these countries.")
+    valid = Attribute(
+        "A boolean. Should be ``True`` if the client's request was valid.")
+
+    def addFilter():
+        """Add a filter to the list of ``filters``."""
+
+    def clearFilters():
+        """Clear the list of ``filters``."""
+
+    def generateFilters():
+        """Build the list of callables, ``filters``, according to the current
+        contents of the lists of ``transports``, ``notBlockedIn``, and the
+        ``addressClass``.
+        """
+
+    def isValid():
+        """Determine if the request is ``valid`` according to some parameters."""
+
+    def withIPv4():
+        """Set the ``addressClass`` to IPv4."""
+
+    def withIPv6():
+        """Set the ``addressClass`` to IPv6."""
+
+    def withPluggableTransportType(typeOfPT):
+        """Add this **typeOfPT** to the list of requested ``transports``."""
+
+    def withoutBlockInCountry(countryCode):
+        """Add this **countryCode** to the list of countries which distributed
+        bridges should not be blocked in (``notBlockedIn``).
+        """
+
+
+class BridgeRequestBase(object):
+    """A generic base class for storing options of a client bridge request."""
+    implements(IBridgeRequest)
+
+    def __init__(self, addressClass=None):
+        self.addressClass = addressClass
+        if not isinstance(self.addressClass,
+                          (ipaddr.IPv4Address, ipaddr.IPv6Address)):
+            self.addressClass = ipaddr.IPv4Address
+        self.filters = list()
+        self.transports = list()
+        self.notBlockedIn = list()
+        self.valid = False
+
+    def isValid(self):
+        pass
+
+    def withIPv4(self):
+        self.addressClass = ipaddr.IPv4Address
+
+    def withIPv6(self):
+        self.addressClass = ipaddr.IPv6Address
+
+    def withoutBlockInCountry(self, country):
+        self.notBlockedIn.append(country)
+
+    def withPluggableTransportType(self, pt):
+        self.transports.append(pt)
+
+    def addFilter(self, filtre):
+        self.filters.append(filtre)
+
+    def clearFilters(self):
+        self.filters = []
+
+    def justOnePTType(self):
+        """Get just one bridge PT type at a time!"""
+        ptType = None
+        try:
+            ptType = self.transports[-1]  # Use the last PT requested
+        except IndexError:
+            logging.debug("No pluggable transports were requested.")
+        return ptType
+
+    def generateFilters(self):
+        if self.addressClass is ipaddr.IPv6Address:
+            self.addFilter(Filters.filterBridgesByIP6)
+        else:
+            self.addFilter(Filters.filterBridgesByIP4)
+
+        transport = self.justOnePTType()
+        if transport:
+            self.clearFilters()
+            self.addFilter(Filters.filterBridgesByTransport(transport,
+                                                            self.addressClass))
+        for country in self.notBlockedIn:
+            self.addFilter(Filters.filterBridgesByNotBlockedIn(country,
+                                                               self.addressClass,
+                                                               transport))