add cache.get_link_inet6_accept_ra && autoconf, and fix parsing of em…

…pty netlink cache

factorize with adding_get_netlink_cache_accept_ra && _get_netlink_cache_auto
and correctly test if cache exist or not

the netlink cache can have empty value for an interface,
if the interface was not existing when we have populate the cache.
for example, a vlan interface created in pre-up by vlan module.

In this case, we return an empty string

ifupdown2/addons/address.py

@@ -629,8 +629,8 @@ def process_addresses(self, ifaceobj, ifaceobj_getfunc=None, force_reapply=False
                 return
 
             purge_v6_addresses = True
-            inet6conf = self.cache.get_link_inet6_conf(ifaceobj.name)
-            if not squash_addr_config and 'accept_ra' in inet6conf and inet6conf['accept_ra'] == 1:
+            running_accept_ra = self.cache.get_link_inet6_accept_ra(ifaceobj)
+            if running_accept_ra == '1' and not squash_addr_config:
                 self.logger.warning("%s: interface has ipv6 slaac enabled, skip purging existing ipv6 addresses" % ifname)
                 purge_v6_addresses = False
 
@@ -993,11 +993,8 @@ def _sysctl_config(self, ifaceobj):
         addr_method = ifaceobj.addr_method
         if addr_method not in ["auto"]:
 
-            inet6conf = self.cache.get_link_inet6_conf(ifaceobj.name)
-            running_accept_ra = str(inet6conf['accept_ra'])
-            running_autoconf = str(inet6conf['autoconf'])
-
             try:
+                running_accept_ra = self.cache.get_link_inet6_accept_ra(ifaceobj)
                 accept_ra = ifaceobj.get_attr_value_first('accept-ra')
                 if accept_ra is None:
                     accept_ra = '0'
@@ -1007,6 +1004,7 @@ def _sysctl_config(self, ifaceobj):
                                     %('/'.join(ifaceobj.name.split("."))),
                                     accept_ra)
 
+                running_autoconf = self.cache.get_link_inet6_autoconf(ifaceobj)
                 autoconf = ifaceobj.get_attr_value_first('autoconf')
                 if autoconf is None:
                     autoconf = '0'
@@ -1370,16 +1368,16 @@ def _query_sysctl(self, ifaceobj, ifaceobjcurr):
 
         accept_ra = ifaceobj.get_attr_value_first('accept-ra')
         if accept_ra:
-            inet6conf = self.cache.get_link_inet6_conf(ifaceobj.name)
-            running_accept_ra = str(inet6conf['accept_ra'])
+            running_accept_ra = self.cache.get_link_inet6_accept_ra(ifaceobj)
+
             ifaceobjcurr.update_config_with_status('accept_ra',
                                                    running_accept_ra,
                                             accept_ra != running_accept_ra)
 
         autoconf = ifaceobj.get_attr_value_first('autoconf')
         if autoconf:
-            inet6conf = self.cache.get_link_inet6_conf(ifaceobj.name)
-            running_autoconf = str(inet6conf['autoconf'])
+            running_autoconf = self.cache.get_link_inet6_autoconf(ifaceobj)
+
             ifaceobjcurr.update_config_with_status('autoconf',
                                                    running_autoconf,
                                             autoconf != running_autoconf)

ifupdown2/addons/auto.py

@@ -52,12 +52,13 @@ def _up(self, ifaceobj):
 
         try:
             if 'inet6' in ifaceobj.addr_family:
-                inet6conf = self.cache.get_link_inet6_conf(ifaceobj.name)
-                if 'accept_ra' in inet6conf and inet6conf['accept_ra'] != 1:
+                running_accept_ra = self.cache.get_link_inet6_accept_ra(ifaceobj)
+                if running_accept_ra != '1':
                     self.sysctl_set('net.ipv6.conf.%s.accept_ra'
                                     %('/'.join(ifaceobj.name.split("."))),
                                     1)
-                if 'autoconf' in inet6conf and inet6conf['autoconf'] != 1:
+                running_autoconf = self.cache.get_link_inet6_autoconf(ifaceobj)
+                if running_autoconf != '1':
                     self.sysctl_set('net.ipv6.conf.%s.autoconf'
                                     %('/'.join(ifaceobj.name.split("."))),
                                     1)

ifupdown2/lib/nlcache.py

@@ -1188,6 +1188,22 @@ def get_link_inet6_conf(self, ifname):
         except TypeError as e:
             return self.__handle_type_error(inspect.currentframe().f_code.co_name, ifname, str(e), return_value=False)
 
+    def get_link_inet6_accept_ra(self, ifaceobj):
+        inet6conf = self.get_link_inet6_conf(ifaceobj.name)
+        if inet6conf and 'accept_ra' in inet6conf:
+            accept_ra = str(inet6conf['accept_ra'])
+        else:
+            accept_ra = ''
+        return accept_ra
+
+    def get_link_inet6_autoconf(self, ifaceobj):
+        inet6conf = self.get_link_inet6_conf(ifaceobj.name)
+        if inet6conf and 'autoconf' in inet6conf:
+            autoconf = str(inet6conf['autoconf'])
+        else:
+            autoconf = ''
+        return autoconf
+
     #####################################################
     #####################################################
     #####################################################