1 files changed, 46 insertions, 0 deletions
diff --git a/python/vyos/configdict.py b/python/vyos/configdict.py
index 4a4a767f3..58ecd3f17 100644
--- a/python/vyos/configdict.py
+++ b/python/vyos/configdict.py
@@ -228,6 +228,41 @@ def is_member(conf, interface, intftype=None):
     old_level = conf.set_level(old_level)
     return ret_val
 
+def is_source_interface(conf, interface, intftype=None):
+    """
+    Checks if passed interface is configured as source-interface of other
+    interfaces of specified type. intftype is optional, if not passed it will
+    search all known types (currently pppoe, macsec, pseudo-ethernet, tunnel
+    and vxlan)
+
+    Returns:
+    None -> Interface is not a member
+    interface name -> Interface is a member of this interface
+    False -> interface type cannot have members
+    """
+    ret_val = None
+    intftypes = ['macsec', 'pppoe', 'pseudo-ethernet', 'tunnel', 'vxlan']
+    if intftype not in intftypes + [None]:
+        raise ValueError(f'unknown interface type "{intftype}" or it can not '
+            'have a source-interface')
+
+    intftype = intftypes if intftype == None else [intftype]
+
+    # set config level to root
+    old_level = conf.get_level()
+    conf.set_level([])
+
+    for it in intftype:
+        base = ['interfaces', it]
+        for intf in conf.list_nodes(base):
+            lower_intf = base + [intf, 'source-interface']
+            if conf.exists(lower_intf) and interface in conf.return_values(lower_intf):
+                ret_val = intf
+                break
+
+    old_level = conf.set_level(old_level)
+    return ret_val
+
 def get_interface_dict(config, base, ifname=''):
     """
     Common utility function to retrieve and mandgle the interfaces available
@@ -284,6 +319,17 @@ def get_interface_dict(config, base, ifname=''):
     bond = is_member(config, ifname, 'bonding')
     if bond: dict.update({'is_bond_member' : bond})
 
+    # Some interfaces come with a source_interface which must also not be part
+    # of any other bond or bridge interface as it is exclusivly assigned as the
+    # Kernels "lower" interface to this new "virtual/upper" interface.
+    if 'source_interface' in dict:
+        # Check if source interface is member of another bridge
+        tmp = is_member(config, dict['source_interface'], 'bridge')
+        if tmp: dict.update({'source_interface_is_bridge_member' : tmp})
+
+        # Check if source interface is member of another bridge
+        tmp = is_member(config, dict['source_interface'], 'bonding')
+        if tmp: dict.update({'source_interface_is_bond_member' : tmp})
 
     mac = leaf_node_changed(config, ['mac'])
     if mac: dict.update({'mac_old' : mac})