addons: set interface mtu and alias through netlink, instead of sysfs

ifupdown2/addons/address.py

@@ -412,7 +412,7 @@ def syntax_check_mtu(self, ifaceobj, ifaceobj_getfunc):
             except ValueError as e:
                 self.logger.warning("%s: invalid mtu %s: %s" % (ifaceobj.name, mtu_str, str(e)))
                 return False
-            return self._check_mtu_config(ifaceobj, mtu_str, mtu_int, ifaceobj_getfunc, syntaxcheck=True)
+            return self._check_mtu_config(ifaceobj, mtu_int, ifaceobj_getfunc, syntaxcheck=True)
         return True
 
     def syntax_check_addr_allowed_on(self, ifaceobj, syntax_check=False):
@@ -790,7 +790,14 @@ def _get_prev_gateway(self, ifaceobj, gateways):
             return ipv
         return prev_gateways
 
-    def _check_mtu_config(self, ifaceobj, mtu_str, mtu_int, ifaceobj_getfunc, syntaxcheck=False):
+    def _check_mtu_config(self, ifaceobj, mtu, ifaceobj_getfunc, syntaxcheck=False):
+        """
+        :param ifaceobj:
+        :param mtu: integer
+        :param ifaceobj_getfunc:
+        :param syntaxcheck: boolean
+        """
+
         retval = True
         if (ifaceobj.link_kind & ifaceLinkKind.BRIDGE):
             if syntaxcheck:
@@ -804,10 +811,10 @@ def _check_mtu_config(self, ifaceobj, mtu_str, mtu_int, ifaceobj_getfunc, syntax
                 masterobj = ifaceobj_getfunc(ifaceobj.upperifaces[0])
                 if masterobj:
                     master_mtu = masterobj[0].get_attr_value_first('mtu')
-                    if master_mtu and master_mtu != mtu_str:
+                    if master_mtu and master_mtu != str(mtu):
                         log_msg = ("%s: bond slave mtu %s is different from bond master %s mtu %s. "
                                   "There is no need to configure mtu on a bond slave." %
-                                   (ifaceobj.name, mtu_str, masterobj[0].name, master_mtu))
+                                   (ifaceobj.name, mtu, masterobj[0].name, master_mtu))
                         if syntaxcheck:
                             self.logger.warning(log_msg)
                             retval = False
@@ -821,24 +828,30 @@ def _check_mtu_config(self, ifaceobj, mtu_str, mtu_int, ifaceobj_getfunc, syntax
                         lowerdev_mtu = int(lowerobj[0].get_attr_value_first('mtu') or 0)
                     else:
                         lowerdev_mtu = self.cache.get_link_mtu(lowerobj[0].name)  # return type: int
-                    if lowerdev_mtu and mtu_int > lowerdev_mtu:
+                    if lowerdev_mtu and mtu > lowerdev_mtu:
                         self.logger.warning('%s: vlan dev mtu %s is greater than lower realdev %s mtu %s'
-                                         %(ifaceobj.name, mtu_str, lowerobj[0].name, lowerdev_mtu))
+                                         %(ifaceobj.name, mtu, lowerobj[0].name, lowerdev_mtu))
                         retval = False
                     elif (not lowerobj[0].link_kind and
                           not (lowerobj[0].link_privflags & ifaceLinkPrivFlags.LOOPBACK) and
-                          not lowerdev_mtu and self.default_mtu and (mtu_int > self.default_mtu_int)):
+                          not lowerdev_mtu and self.default_mtu and (mtu > self.default_mtu_int)):
                         # only check default mtu on lower device which is a physical interface
                         self.logger.warning('%s: vlan dev mtu %s is greater than lower realdev %s mtu %s'
-                                         %(ifaceobj.name, mtu_str, lowerobj[0].name, self.default_mtu))
+                                         %(ifaceobj.name, mtu, lowerobj[0].name, self.default_mtu))
                         retval = False
-            if self.max_mtu and mtu_int > self.max_mtu:
+            if self.max_mtu and mtu > self.max_mtu:
                 self.logger.warning('%s: specified mtu %s is greater than max mtu %s'
-                                 %(ifaceobj.name, mtu_str, self.max_mtu))
+                                 %(ifaceobj.name, mtu, self.max_mtu))
                 retval = False
         return retval
 
-    def _propagate_mtu_to_upper_devs(self, ifaceobj, mtu_str, mtu_int, ifaceobj_getfunc):
+    def _propagate_mtu_to_upper_devs(self, ifaceobj, mtu, ifaceobj_getfunc):
+        """
+        :param ifaceobj:
+        :param mtu: integer
+        :param ifaceobj_getfunc:
+        """
+
         if not (
                 (not ifupdownflags.flags.ALL or ifupdownconfig.diff_mode) and
                 not ifaceobj.link_kind and
@@ -863,16 +876,22 @@ def _propagate_mtu_to_upper_devs(self, ifaceobj, mtu_str, mtu_int, ifaceobj_getf
             umtu = upperobjs[0].get_attr_value_first('mtu')
             if not umtu:
                 running_mtu = self.cache.get_link_mtu(upperobjs[0].name)
-                if not running_mtu or running_mtu != mtu_int:
-                    self.sysfs.link_set_mtu(u, mtu_str=mtu_str, mtu_int=mtu_int)
+                if not running_mtu or running_mtu != mtu:
+                    self.netlink.link_set_mtu(u, mtu)
+
+    def _process_mtu_config_mtu_valid(self, ifaceobj, ifaceobj_getfunc, mtu):
+        """
+        :param ifaceobj:
+        :param ifaceobj_getfunc:
+        :param mtu: integer
+        """
 
-    def _process_mtu_config_mtu_valid(self, ifaceobj, ifaceobj_getfunc, mtu_str, mtu_int):
-        if not self._check_mtu_config(ifaceobj, mtu_str, mtu_int, ifaceobj_getfunc):
+        if not self._check_mtu_config(ifaceobj, mtu, ifaceobj_getfunc):
             return
 
-        if mtu_int != self.cache.get_link_mtu(ifaceobj.name):
-            self.sysfs.link_set_mtu(ifaceobj.name, mtu_str=mtu_str, mtu_int=mtu_int)
-            self._propagate_mtu_to_upper_devs(ifaceobj, mtu_str, mtu_int, ifaceobj_getfunc)
+        if mtu != self.cache.get_link_mtu(ifaceobj.name):
+            self.netlink.link_set_mtu(ifaceobj.name, mtu)
+            self._propagate_mtu_to_upper_devs(ifaceobj, mtu, ifaceobj_getfunc)
 
     def _process_mtu_config_mtu_none(self, ifaceobj, ifaceobj_getfunc):
         if (ifaceobj.link_privflags & ifaceLinkPrivFlags.MGMT_INTF):
@@ -888,7 +907,7 @@ def _process_mtu_config_mtu_none(self, ifaceobj, ifaceobj_getfunc):
                     or ifaceobj.link_kind & ifaceLinkKind.BRIDGE \
                     or ifaceobj.link_kind & ifaceLinkKind.OTHER:
                 if cached_link_mtu != self.default_mtu_int:
-                    self.sysfs.link_set_mtu(ifaceobj.name, mtu_str=self.default_mtu, mtu_int=self.default_mtu_int)
+                    self.netlink.link_set_mtu(ifaceobj.name, self.default_mtu_int)
                 return
 
             # set vlan interface mtu to lower device mtu
@@ -898,10 +917,10 @@ def _process_mtu_config_mtu_none(self, ifaceobj, ifaceobj_getfunc):
                 and ifaceobj.link_kind & ifaceLinkKind.VLAN
             ):
                 lower_iface = ifaceobj.lowerifaces[0]
-                lower_iface_mtu_int = self.cache.get_link_mtu(lower_iface)
+                lower_iface_mtu = self.cache.get_link_mtu(lower_iface)
 
-                if lower_iface_mtu_int != cached_link_mtu:
-                    self.sysfs.link_set_mtu(ifaceobj.name, mtu_str=str(lower_iface_mtu_int), mtu_int=lower_iface_mtu_int)
+                if lower_iface_mtu != cached_link_mtu:
+                    self.netlink.link_set_mtu(ifaceobj.name, lower_iface_mtu)
 
         elif (
             ifaceobj.name != 'lo'
@@ -918,9 +937,9 @@ def _process_mtu_config_mtu_none(self, ifaceobj, ifaceobj_getfunc):
             # config by the kernel in play, we try to be cautious here
             # on which devices we want to reset mtu to default.
             # essentially only physical interfaces which are not bond slaves
-            self.sysfs.link_set_mtu(ifaceobj.name, mtu_str=self.default_mtu, mtu_int=self.default_mtu_int)
+            self.netlink.link_set_mtu(ifaceobj.name, self.default_mtu_int)
             if ifupdownconfig.diff_mode:
-                self._propagate_mtu_to_upper_devs(ifaceobj, self.default_mtu, self.default_mtu_int, ifaceobj_getfunc)
+                self._propagate_mtu_to_upper_devs(ifaceobj, self.default_mtu_int, ifaceobj_getfunc)
 
     def _set_bridge_forwarding(self, ifaceobj):
         """ set ip forwarding to 0 if bridge interface does not have a
@@ -1063,7 +1082,7 @@ def process_mtu(self, ifaceobj, ifaceobj_getfunc):
                     self.logger.warning("%s: invalid MTU value: %s" % (ifaceobj.name, str(e)))
                 return
 
-            self._process_mtu_config_mtu_valid(ifaceobj, ifaceobj_getfunc, mtu_str, mtu_int)
+            self._process_mtu_config_mtu_valid(ifaceobj, ifaceobj_getfunc, mtu_int)
         else:
             self._process_mtu_config_mtu_none(ifaceobj, ifaceobj_getfunc)
 
@@ -1133,7 +1152,7 @@ def _pre_up(self, ifaceobj, ifaceobj_getfunc=None):
         #
         # alias
         #
-        self.sysfs.link_set_alias(ifaceobj.name, ifaceobj.get_attr_value_first("alias"))
+        self.netlink.link_set_alias(ifaceobj.name, ifaceobj.get_attr_value_first("alias"))
 
         self._sysctl_config(ifaceobj)
 
@@ -1358,15 +1377,15 @@ def _down(self, ifaceobj, ifaceobj_getfunc=None):
             # ifupdown2. If this MTU is different from our default mtu,
             # if so we need to reset it back to default.
             if not ifaceobj.link_kind and self.default_mtu and ifaceobj.get_attr_value_first('mtu') and self.cache.get_link_mtu(ifaceobj.name) != self.default_mtu_int:
-                self.sysfs.link_set_mtu(ifaceobj.name, mtu_str=self.default_mtu, mtu_int=self.default_mtu_int)
+                self.netlink.link_set_mtu(ifaceobj.name, self.default_mtu_int)
 
             #
             # alias
             # only reset alias on non-logical device
             if not ifaceobj.link_kind:
                 alias = ifaceobj.get_attr_value_first("alias")
                 if alias:
-                    self.sysfs.link_set_alias(ifaceobj.name, None)  # None to reset alias.
+                    self.netlink.link_set_alias(ifaceobj.name, None)  # None to reset alias.
 
             hwaddress = self.process_hwaddress_reset_to_default(ifaceobj)
             if hwaddress != None and not ifaceobj.link_kind:

ifupdown2/addons/addressvirtual.py

@@ -432,13 +432,12 @@ def create_macvlan_and_apply_config(self, ifaceobj, intf_config_list, vrrp=False
         purge_existing = False if ifupdownflags.flags.PERFMODE else True
         ifname = ifaceobj.name
 
-        update_mtu = lower_iface_mtu = lower_iface_mtu_str = None
+        update_mtu = lower_iface_mtu = None
         if ifupdownconfig.config.get("adjust_logical_dev_mtu", "1") != "0" and ifaceobj.lowerifaces and intf_config_list:
             update_mtu = True
 
         if update_mtu:
             lower_iface_mtu = self.cache.get_link_mtu(ifaceobj.name)
-            lower_iface_mtu_str = str(lower_iface_mtu)
 
         self.iproute2.batch_start()  # TODO: make sure we only do 1 ip link set down and set up (only one flap in the batch)
 
@@ -556,7 +555,7 @@ def create_macvlan_and_apply_config(self, ifaceobj, intf_config_list, vrrp=False
                     update_mtu = False
 
                     try:
-                        self.sysfs.link_set_mtu(macvlan_ifname, mtu_str=lower_iface_mtu_str, mtu_int=lower_iface_mtu)
+                        self.netlink.link_set_mtu(macvlan_ifname, lower_iface_mtu)
                     except Exception as e:
                         self.logger.info('%s: failed to set mtu %s: %s' % (macvlan_ifname, lower_iface_mtu, e))
 

ifupdown2/addons/bridge.py

@@ -2861,7 +2861,7 @@ def up_bridge(self, ifaceobj, ifaceobj_getfunc):
 
             bridge_mtu = self.get_bridge_mtu(ifaceobj)
             if bridge_mtu:
-                self.sysfs.link_set_mtu(ifname, bridge_mtu, int(bridge_mtu))
+                self.netlink.link_set_mtu(ifname, int(bridge_mtu))
         else:
             link_just_created = False
             self.logger.info('%s: bridge already exists' % ifname)

ifupdown2/lib/iproute2.py

@@ -521,10 +521,7 @@ def link_set_ipv6_addrgen(self, ifname, addrgen, link_created):
             self.logger.info("%s: cannot set addrgen: ipv6 is disabled on this device" % ifname)
             return False
 
-        if link_created:
-            link_mtu = self.sysfs.link_get_mtu(ifname)
-        else:
-            link_mtu = self.cache.get_link_mtu(ifname)
+        link_mtu = self.cache.get_link_mtu(ifname)
 
         if link_mtu < 1280:
             self.logger.info("%s: ipv6 addrgen is disabled on device with MTU "

ifupdown2/lib/nlcache.py

@@ -60,6 +60,7 @@
         NLM_F_REQUEST, \
         NLM_F_CREATE, \
         NLM_F_ACK, \
+        NLM_F_REPLACE, \
         RT_SCOPES, \
         INFINITY_LIFE_TIME
 
@@ -91,6 +92,7 @@
         NLM_F_REQUEST, \
         NLM_F_CREATE, \
         NLM_F_ACK, \
+        NLM_F_REPLACE, \
         RT_SCOPES, \
         INFINITY_LIFE_TIME
 
@@ -407,6 +409,19 @@ def override_link_mtu(self, ifname, mtu):
         except Exception:
             pass
 
+    def override_link_alias(self, ifname, alias):
+        """
+        Manually override link alias in the cache and ignore any failures
+        :param ifname: Name of the interface to update
+        :param alias: New interface alias
+        """
+        try:
+            with self._cache_lock:
+                self._link_cache[ifname].attributes[Link.IFLA_IFALIAS].value = alias
+        except Exception:
+            pass
+
+
     def override_cache_unslave_link(self, slave, master):
         """
         Manually update the cache unslaving SLAVE from MASTER
@@ -3137,6 +3152,69 @@ def link_set_brport_with_info_slave_data_dry_run(self, ifname, kind, ifla_info_d
         self.log_info_ifname_dry_run(ifname, "netlink: ip link set dev %s: bridge port attributes" % ifname)
         self.logger.debug("attributes: %s" % ifla_info_slave_data)
 
+    ###
+
+    def link_set_mtu(self, ifname, mtu):
+        """
+        Sets the MTU of the given link, updating the cache on success.
+
+        :param ifname: str - Name of the interface to update
+        :param mtu: int - New MTU to set for the interface.
+        :return: True if the operation was successful
+        """
+
+        if self.cache.get_link_mtu(ifname) == mtu:
+            # no need to update
+            return
+
+        self.logger.info(f'{ifname}: netlink: ip link set dev {ifname} mtu {mtu}')
+
+        debug = RTM_SETLINK in self.debug
+        try:
+            link = Link(RTM_SETLINK, debug, use_color=self.use_color)
+            link.flags = NLM_F_REPLACE | NLM_F_REQUEST | NLM_F_ACK
+            link.body = struct.pack('Bxxxiii', socket.AF_UNSPEC, 0, 0, 0)
+            link.add_attribute(Link.IFLA_IFNAME, ifname)
+            link.add_attribute(Link.IFLA_MTU, mtu)
+            link.build_message(next(self.sequence), self.pid)
+            result = self.tx_nlpacket_get_response_with_error(link)
+            self.cache.override_link_mtu(ifname, mtu)
+
+            return result
+        except Exception as e:
+            raise Exception(f'{ifname}: netlink: failed to set mtu to {mtu}: {str(e)}')
+
+    def link_set_alias(self, ifname, alias):
+        """
+        Sets the alias of the given link, updating the cache on success.
+
+        :param ifname: Name of the interface to update
+        :param alias: New alias to set for the interface.
+        :return: True if the operation was successful
+        """
+
+        if self.cache.get_link_alias(ifname) == alias:
+            # no need to update
+            return
+
+        self.logger.info(f'{ifname}: netlink: ip link set dev {ifname} alias {alias}')
+
+        debug = RTM_SETLINK in self.debug
+        try:
+            link = Link(RTM_SETLINK, debug, use_color=self.use_color)
+            link.flags = NLM_F_REPLACE | NLM_F_REQUEST | NLM_F_ACK
+            link.body = struct.pack('Bxxxiii', socket.AF_UNSPEC, 0, 0, 0)
+            link.add_attribute(Link.IFLA_IFNAME, ifname)
+            link.add_attribute(Link.IFLA_IFALIAS, alias or '') # empty string removes alias
+            link.build_message(next(self.sequence), self.pid)
+            result = self.tx_nlpacket_get_response_with_error(link)
+            self.cache.override_link_alias(ifname, alias)
+
+            return result
+        except Exception as e:
+            raise Exception(f'{ifname}: netlink: failed to set alias to {alias}: {str(e)}')
+
+
     ############################################################################
     # ADDRESS
     ############################################################################

ifupdown2/lib/sysfs.py

@@ -106,44 +106,6 @@ def get_link_address(self, ifname):
         """
         return self.read_file_oneline("/sys/class/net/%s/address" % ifname)
 
-    #
-    # MTU
-    #
-
-    def link_get_mtu(self, ifname):
-        return int(self.read_file_oneline("/sys/class/net/%s/mtu" % ifname) or 0)
-
-    def link_set_mtu(self, ifname, mtu_str, mtu_int):
-        if self.cache.get_link_mtu(ifname) != mtu_int:
-            if self.write_to_file('/sys/class/net/%s/mtu' % ifname, mtu_str):
-                self.cache.override_link_mtu(ifname, mtu_int)
-
-    def link_set_mtu_dry_run(self, ifname, mtu_str, mtu_int):
-        # we can remove the cache check in DRYRUN mode
-        self.write_to_file('/sys/class/net/%s/mtu' % ifname, mtu_str)
-
-    #
-    # ALIAS
-    #
-
-    def link_set_alias(self, ifname, alias):
-        cached_alias = self.cache.get_link_alias(ifname)
-
-        if cached_alias == alias:
-            return
-
-        if not alias:
-            alias = "\n"
-
-        if self.write_to_file("/sys/class/net/%s/ifalias" % ifname, alias):
-            pass # self.cache.override_link_mtu(ifname, mtu_int)
-
-    def link_set_alias_dry_run(self, ifname, alias):
-        # we can remove the cache check in DRYRUN mode
-        if not alias:
-            alias = ""
-        self.write_to_file("/sys/class/net/%s/ifalias" % ifname, alias)
-
     ############################################################################
     # BRIDGE
     ############################################################################