Backport DAD handling to the stable branch

ifupdown2/addons/address.py

@@ -5,6 +5,9 @@
 #
 
 import socket
+import json
+import time
+import subprocess
 
 from ipaddr import IPNetwork, IPv4Network, IPv6Network, _BaseV6
 
@@ -111,6 +114,20 @@ class address(moduleBase):
                               'validvals': ['yes', 'no'],
                               'default' : 'no',
                               'example' : ['mpls-enable yes']},
+                    'dad-attempts': {
+                        'help': 'Number of attempts to settle DAD (0 to disable DAD). '
+                                'To use this feature, the ipv6_dad_handling_enabled '
+                                'module global must be set to true',
+                        'example': ['dad-attempts 0'],
+                        'default': '60',
+                    },
+                    'dad-interval': {
+                        'help': 'DAD state polling interval in seconds. '
+                                'To use this feature, the ipv6_dad_handling_enabled '
+                                'module global must be set to true',
+                        'example': ['dad-interval 0.5'],
+                        'default': '0.1',
+                    },
                     'ipv6-addrgen': {
                         'help': 'enable disable ipv6 link addrgenmode',
                         'validvals': ['on', 'off'],
@@ -137,6 +154,13 @@ def __init__(self, *args, **kargs):
                 'enable_l3_iface_forwarding_checks'
             )
         )
+        self.ipv6_dad_handling_enabled = utils.get_boolean_from_string(
+            policymanager.policymanager_api.get_module_globals(
+                self.__class__.__name__,
+                'ipv6_dad_handling_enabled'
+            ),
+            default=False
+        )
 
         if not self.default_mtu:
             self.default_mtu = '1500'
@@ -338,7 +362,7 @@ def _inet_address_convert_to_cidr(self, ifaceobjlist):
 
                 attrs = {}
                 for a in ['broadcast', 'pointopoint', 'scope',
-                        'preferred-lifetime']:
+                        'preferred-lifetime', 'dad-attempts', 'dad-interval']:
                     aval = ifaceobj.get_attr_value_n(a, addr_index)
                     if aval:
                         attrs[a] = aval
@@ -351,6 +375,11 @@ def _inet_address_list_config(self, ifaceobj, newaddrs, newaddr_attrs):
         for addr_index in range(0, len(newaddrs)):
             try:
                 if newaddr_attrs:
+                    nodad = False
+                    if self.ipv6_dad_handling_enabled and ifaceobj.addr_family[addr_index] == "inet6":
+                        dad_attempts = newaddr_attrs.get(newaddrs[addr_index], {}).get('dad-attempts')
+                        if dad_attempts == "0":
+                            nodad = True
                     self.ipcmd.addr_add(ifaceobj.name, newaddrs[addr_index],
                         newaddr_attrs.get(newaddrs[addr_index],
                                           {}).get('broadcast'),
@@ -359,7 +388,8 @@ def _inet_address_list_config(self, ifaceobj, newaddrs, newaddr_attrs):
                         newaddr_attrs.get(newaddrs[addr_index],
                                           {}).get('scope'),
                         newaddr_attrs.get(newaddrs[addr_index],
-                                          {}).get('preferred-lifetime'))
+                                          {}).get('preferred-lifetime'),
+                        nodad=nodad)
                 else:
                     self.ipcmd.addr_add(ifaceobj.name, newaddrs[addr_index])
             except Exception, e:
@@ -866,6 +896,12 @@ def _up(self, ifaceobj, ifaceobj_getfunc=None):
 
         self.up_hwaddress(ifaceobj)
 
+        # settle dad
+        if self.ipv6_dad_handling_enabled and self.ipcmd.link_exists(ifaceobj.name):
+            addrlist = ifaceobj.get_attr_value('address')
+            if any((":"in ip for ip in addrlist)):
+                self._settle_dad(ifaceobj, [ip for ip in addrlist if ":" in ip])
+
         gateways = ifaceobj.get_attr_value('gateway')
         if not gateways:
             gateways = []
@@ -1212,3 +1248,51 @@ def run(self, ifaceobj, operation, query_ifaceobj=None, ifaceobj_getfunc=None):
         else:
             op_handler(self, ifaceobj,
                        ifaceobj_getfunc=ifaceobj_getfunc)
+
+    def _settle_dad(self, ifaceobj, ips):
+        """ Settle dad for any given ips """
+        def ip_addr_list(what):
+            raw = json.loads(utils.exec_commandl([
+                'ip', '-j', '-o', '-6', 'address', 'list', 'dev',
+                ifaceobj.name, what
+            ]))
+            addr_infos = (x for t in raw for x in t.get('addr_info', []))
+            ip_list = ['%s/%s' % (x["local"], x["prefixlen"]) for x in addr_infos if x]
+            return ip_list
+
+        def get_param(key, default=None):
+            return (ifaceobj.get_attr_value_first(key)
+                    or policymanager.policymanager_api.get_iface_default(
+                        self.__class__.__name__, ifaceobj.name, key)
+                    or default)
+
+        interval = float(get_param('dad-interval', '0.1'))  # 0.1: ifupdown default value
+        attempts = int(get_param('dad-attempts', '60'))     # 60: ifupdown default value
+        if not attempts or not ips:
+            return
+        try:
+
+            for _attempt in range(0, attempts):
+                tentative = ip_addr_list('tentative')
+                if all(str(ip) not in tentative for ip in ips):
+                    break
+                time.sleep(interval)
+            else:
+                timeout = ','.join(ip for ip in ips if str(ip) not in tentative)
+                self.logger.warning('address: %s: dad timeout "%s"', ifaceobj.name, timeout)
+                return
+            failure = ip_addr_list('dadfailed')
+            if failure:
+                self.logger.warning('address: %s: dad failure "%s"', ifaceobj.name, ','.join(failure))
+        except subprocess.CalledProcessError as exc:
+            self.logger.error('address: %s: could not settle dad %s', ifaceobj.name, str(exc))
+
+    def _get_ifaceobjs(self, ifaceobj, ifaceobj_getfunc):
+        squash_addr_config = ifupdownconfig.config.get("addr_config_squash", "0") == "1"
+        if not squash_addr_config:
+            return [ifaceobj]  # no squash, returns current ifaceobj
+        if not ifaceobj.flags & ifaceobj.YOUNGEST_SIBLING:
+            return []  # when squash is present, work only on the youngest sibling
+        if ifaceobj.flags & iface.HAS_SIBLINGS:
+            return ifaceobj_getfunc(ifaceobj.name) # get sibling interfaces
+        return [ifaceobj]

ifupdown2/ifupdown/policymanager.py

@@ -177,7 +177,6 @@ def get_module_globals(self,module_name=None,attr=None):
         We first check the user_policy_array and return that value. But if
         the user did not specify an override, we use the system_policy_array.
         '''
-
         if (not attr or not module_name):
             return None
         # users can specify defaults to override the systemwide settings

ifupdown2/ifupdownaddons/LinkUtils.py

@@ -852,7 +852,8 @@ def link_show(ifacename=None):
                                         '-o', '-d', 'link', 'show'])
 
     def addr_add(self, ifacename, address, broadcast=None,
-                 peer=None, scope=None, preferred_lifetime=None, metric=None):
+                 peer=None, scope=None, preferred_lifetime=None, metric=None,
+                 nodad=None):
         if not address:
             return
         cmd = 'addr add %s' % address
@@ -869,6 +870,9 @@ def addr_add(self, ifacename, address, broadcast=None,
         if metric:
             cmd += ' metric %s' % metric
 
+        if nodad:
+            cmd += ' nodad'
+
         if LinkUtils.ipbatch and not LinkUtils.ipbatch_pause:
             self.add_to_batch(cmd)
         else:
@@ -1022,7 +1026,7 @@ def compare_user_config_vs_running_state(running_addrs, user_addrs):
 
         return running_ipobj == (ip4 + ip6)
 
-    def addr_add_multiple(self, ifaceobj, ifacename, addrs, purge_existing=False, metric=None):
+    def addr_add_multiple(self, ifaceobj, ifacename, addrs, purge_existing=False, metric=None, nodad=False):
         # purges address
         if purge_existing:
             # if perfmode is not set and also if iface has no sibling
@@ -1049,7 +1053,7 @@ def addr_add_multiple(self, ifaceobj, ifacename, addrs, purge_existing=False, me
                 self.logger.warning('%s: %s' % (ifacename, str(e)))
         for a in addrs:
             try:
-                self.addr_add(ifacename, a, metric=metric)
+                self.addr_add(ifacename, a, metric=metric, nodad=nodad)
             except Exception, e:
                 self.logger.error(str(e))