slapformat: WIP: Tap IPv6: default to last address of range

slapos/format.py

@@ -474,7 +474,7 @@ class Tap(object):
         "Options %r and %r for tap %s must either both be provided or neither",
         'ipv4_gateway', 'ipv4_address', name
       )
-    elif ipv4_address:
+    if ipv4_address:
       self.ipv4_gateway = ipaddress.IPv4Interface(ipv4_gateway)
       self.ipv4_address = ipaddress.IPv4Interface(ipv4_address)
     elif interface.tap_ipv4_network:
@@ -482,23 +482,27 @@ class Tap(object):
       self.ipv4_address = interface.getTapIPv4Range(index)
     # Tap IPv6: host-to-tap gateway and tap-to-host address
     ipv6_gateway = options['ipv6_gateway']
-    if ipv6_gateway:
-      self.ipv6_gateway = ipaddress.IPv4Interface(ipv6_gateway)
     ipv6_address = options['ipv6_address']
+    if not ipv6_gateway and ipv6_address:
+      conf.wrong(
+        "Options %r for tap %s must not be provided without option %r",
+        'ipv6_address', 'ipv6_gateway', name
+      )
+    if ipv6_gateway:
+      self.ipv6_gateway = ipv6_gateway = ipaddress.IPv6Interface(ipv6_gateway)
       if ipv6_address:
         self.ipv6_address = ipaddress.IPv6Interface(ipv6_address)
+      else:
+        self.ipv6_address = addressFromNetwork(ipv6_gateway.network, -1)
     elif conf.tap_ipv6:
-      self.ipv6_gateway = interface.getTapIPv6Range(index)
-    # If needed, ipv6_address will be set to link-local in format
+      self.ipv6_gateway = ipv6_gateway = interface.getTapIPv6Range(index)
+      self.ipv6_address = addressFromNetwork(ipv6_gateway.network, -1)
 
   def format(self, interface, user):
     tap = self.name
     conf = interface.conf
     # Create/ensure TAP interface
     self.ensureTap(user, conf)
-    # Find link local address if needed
-    if self.ipv6_gateway and not self.ipv6_address:
-      self.ipv6_address = interface.getIPv6LinkLocalAddress(tap)
     # Create/ensure IPv4 routes
     self.ensureIPv4Routes(conf)
     # Create/ensure IPv6 routes
@@ -663,22 +667,6 @@ class Interface(object):
           result = network
     return result
 
-  def getIPv6LinkLocalAddress(self, interface):
-    try:
-      addresses = netifaces.ifaddresses(interface)[AF_INET6]
-    except KeyError:
-      addresses = ()
-    for a in addresses:
-      address = a['addr'].split('%')[0]
-      netmask = a['netmask'].split('/')[-1]
-      ip = ipaddress.IPv6Interface('%s/%s' % (address, netmask))
-      if ip.is_link_local:
-        return ip
-    self.conf.abort(
-      "No link-local IPv6 address found on %s",
-      interface
-    )
-
   def getComputerIPv6Addr(self):
     return addressFromNetwork(self.ipv6_network, 1)