Fix usage of netaddr '.broadcast'

netaddr 0.7.16 changed the behavior of ipnetworks with /31 and /32
prefixes to make their 'broadcast' attribute return none. this patch
replaces the use of the attribute with a -1 index lookup to get the
last address instead.

for stable kilo we also fix neutron/db/db_base_plugin_v2.py which had
the checks in neutron/ipam/utils.py for Liberty.

closes-bug: #1490380
(cherry picked from commit 6324f7f23d)

conflicts:
	neutron/ipam/utils.py
	neutron/plugins/linuxbridge/agent/linuxbridge_neutron_agent.py

Change-Id: I97d71c4051882ddd9e496c78cfbce840ad7a2b67

neutron/agent/l3/link_local_allocator.py

@@ -22,8 +22,10 @@ class LinkLocalAddressPair(netaddr.IPNetwork):
 
     def get_pair(self):
         """Builds an address pair from the first and last addresses. """
+        # TODO(kevinbenton): the callers of this seem only interested in an IP,
+        # so we should just return two IPAddresses.
         return (netaddr.IPNetwork("%s/%s" % (self.network, self.prefixlen)),
-                netaddr.IPNetwork("%s/%s" % (self.broadcast, self.prefixlen)))
+                netaddr.IPNetwork("%s/%s" % (self[-1], self.prefixlen)))
 
 
 class LinkLocalAllocator(object):

neutron/agent/linux/ip_lib.py

@@ -342,7 +342,7 @@ class IpAddrCommand(IpDeviceCommandBase):
                 'scope', scope,
                 'dev', self.name]
         if net.version == 4:
-            args += ['brd', str(net.broadcast)]
+            args += ['brd', str(net[-1])]
         self._as_root([net.version], tuple(args))
 
     def delete(self, cidr):

neutron/db/db_base_plugin_v2.py

@@ -343,7 +343,7 @@ class NeutronDbPluginV2(neutron_plugin_base_v2.NeutronPluginBaseV2,
         # Check that the IP is valid on subnet. This cannot be the
         # network or the broadcast address
         if (ip != net.network and
-                ip != net.broadcast and
+                ip != net[-1] and
                 net.netmask & ip == net.network):
             return True
         return False

neutron/tests/common/net_helpers.py

@@ -48,7 +48,7 @@ def increment_ip_cidr(ip_cidr, offset=1):
     net0 = netaddr.IPNetwork(ip_cidr)
     net = netaddr.IPNetwork(ip_cidr)
     net.value += offset
-    if not net0.network < net.ip < net0.broadcast:
+    if not net0.network < net.ip < net0[-1]:
         tools.fail(
             'Incorrect ip_cidr,offset tuple (%s,%s): "incremented" ip_cidr is '
             'outside ip_cidr' % (ip_cidr, offset))