Python/ifconfig: T1557: bugfix removing Q-in-Q VLAN interfaces

VLAN interfaces have not been removed "in order". What does it mean? We need to
delete Q-in-Q interfaces prior to deleting the underlaying VLAN interface
(vif-s). This was not the case and that triggered an exception that a non
existing interface was about to be removed.

Tested using adding and deleting the following config:

set interfaces ethernet eth2 address 192.0.2.1/24
set interfaces ethernet eth2 description "VyOS bonding"
set interfaces ethernet eth2 disable-link-detect
set interfaces ethernet eth2 mac 00:91:00:00:00:01
set interfaces ethernet eth2 mtu 9000
set interfaces ethernet eth2 vif-s 100 address 192.168.10.1/24
set interfaces ethernet eth2 vif-s 100 description "802.1ad service VLAN 100"
set interfaces ethernet eth2 vif-s 100 mtu 1500
set interfaces ethernet eth2 vif-s 100 mac 00:91:00:00:00:02
set interfaces ethernet eth2 vif-s 100 vif-c 110 address "192.168.110.1/24"
set interfaces ethernet eth2 vif-s 100 vif-c 110 description "client VLAN 110"
set interfaces ethernet eth2 vif-s 100 vif-c 120 address "192.168.120.1/24"
set interfaces ethernet eth2 vif-s 100 vif-c 120 description "client VLAN 120"
set interfaces ethernet eth2 vif-s 100 vif-c 130 address "192.168.130.1/24"
set interfaces ethernet eth2 vif-s 100 vif-c 130 description "client VLAN 130"
set interfaces ethernet eth2 vif 400 address 192.168.40.1/24
set interfaces ethernet eth2 vif 400 description "802.1q VLAN 400"
set interfaces ethernet eth2 vif 400 mtu 1500
set interfaces ethernet eth2 vif 400 mac 00:91:00:00:00:03

1 files changed, 16 insertions, 7 deletions

diff --git a/python/vyos/ifconfig.py b/python/vyos/ifconfig.py
index 8f81bc9f6..a959e55d8 100644
--- a/python/vyos/ifconfig.py
+++ b/python/vyos/ifconfig.py
@@ -818,12 +818,22 @@ class VLANIf(Interface):
         >>> i = Interface('eth0')
         >>> i.remove()
         """
-        # do we have sub interfaces (VLANs)?
-        # we apply a regex matching subinterfaces (indicated by a .) of a
-        # parent interface. 'bond0(?:\.\d+){1,2}' will match vif and vif-s/vif-c
-        # subinterfaces
+        # Do we have sub interfaces (VLANs)? We apply a regex matching
+        # subinterfaces (indicated by a .) of a parent interface.
+        #
+        # As interfaces need to be deleted "in order" starting from Q-in-Q
+        # we delete them first.
+        vlan_ifs = [f for f in os.listdir(r'/sys/class/net') \
+                        if re.match(self._ifname + r'(?:\.\d+)(?:\.\d+)', f)]
+
+        for vlan in vlan_ifs:
+            Interface(vlan).remove()
+
+        # After deleting all Q-in-Q interfaces delete other VLAN interfaces
+        # which probably acted as parent to Q-in-Q or have been regular 802.1q
+        # interface.
         vlan_ifs = [f for f in os.listdir(r'/sys/class/net') \
-                       if re.match(self._ifname + r'(?:\.\d+){1,2}', f)]
+                        if re.match(self._ifname + r'(?:\.\d+)', f)]
 
         for vlan in vlan_ifs:
             Interface(vlan).remove()
@@ -897,8 +907,7 @@ class VLANIf(Interface):
         >>> i.del_vlan()
         """
         vlan_ifname = self._ifname + '.' + str(vlan_id)
-        tmp = VLANIf(vlan_ifname)
-        tmp.remove()
+        VLANIf(vlan_ifname).remove()
 
 
 class EthernetIf(VLANIf):