1 files changed, 131 insertions, 0 deletions
diff --git a/python/vyos/ifconfig/section.py b/python/vyos/ifconfig/section.py
new file mode 100644
index 000000000..ab340d247
--- /dev/null
+++ b/python/vyos/ifconfig/section.py
@@ -0,0 +1,131 @@
+# Copyright 2020 VyOS maintainers and contributors <maintainers@vyos.io>
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+
+import netifaces
+
+
+class Section:
+    # the known interface prefixes
+    _prefixes = {}
+    _classes = []
+
+    # class need to define: definition['prefixes']
+    # the interface prefixes declared by a class used to name interface with
+    # prefix[0-9]*(\.[0-9]+)?(\.[0-9]+)?, such as lo, eth0 or eth0.1.2
+
+    @classmethod
+    def register(cls, klass):
+        """
+        A function to use as decorator the interfaces classes
+        It register the prefix for the interface (eth, dum, vxlan, ...)
+        with the class which can handle it (EthernetIf, DummyIf,VXLANIf, ...)
+        """
+        if not klass.definition.get('prefixes',[]):
+            raise RuntimeError(f'valid interface prefixes not defined for {klass.__name__}')
+
+        cls._classes.append(klass)
+
+        for ifprefix in klass.definition['prefixes']:
+            if ifprefix in cls._prefixes:
+                raise RuntimeError(f'only one class can be registered for prefix "{ifprefix}" type')
+            cls._prefixes[ifprefix] = klass
+
+        return klass
+
+    @classmethod
+    def _basename (cls, name, vlan):
+        """
+        remove the number at the end of interface name
+        name: name of the interface
+        vlan: if vlan is True, do not stop at the vlan number
+        """
+        name = name.rstrip('0123456789')
+        name = name.rstrip('.')
+        if vlan:
+            name = name.rstrip('0123456789')
+        return name
+
+    @classmethod
+    def section(cls, name, vlan=True):
+        """
+        return the name of a section an interface should be under
+        name: name of the interface (eth0, dum1, ...)
+        vlan: should we try try to remove the VLAN from the number
+        """
+        name = cls._basename(name, vlan)
+
+        if name in cls._prefixes:
+            return cls._prefixes[name].definition['section']
+        return ''
+ 
+    @classmethod
+    def klass(cls, name, vlan=True):
+        name = cls._basename(name, vlan)
+        if name in cls._prefixes:
+            return cls._prefixes[name]
+        raise ValueError(f'No type found for interface name: {name}')
+
+    @classmethod
+    def _intf_under_section (cls,section=''):
+        """
+        return a generator with the name of the interface which are under a section
+        """
+        interfaces = netifaces.interfaces()
+
+        for ifname in interfaces:
+            ifsection = cls.section(ifname)
+            if not ifsection:
+                continue
+
+            if section and ifsection != section:
+                continue
+
+            yield ifname
+
+    @classmethod
+    def interfaces(cls, section=''):
+        """
+        return a list of the name of the interface which are under a section
+        if no section is provided, then it returns all configured interfaces
+        """
+        return list(cls._intf_under_section(section))
+
+    @classmethod
+    def _intf_with_feature(cls, feature=''):
+        """
+        return a generator with the name of the interface which have 
+        a particular feature set in their definition such as:
+        bondable, broadcast, bridgeable, ...
+        """
+        for klass in cls._classes:
+            if klass.definition[feature]:
+                yield klass.definition['section']
+
+    @classmethod
+    def feature(cls, feature=''):
+        """
+        return list with the name of the interface which have 
+        a particular feature set in their definition such as:
+        bondable, broadcast, bridgeable, ...
+        """
+        return list(cls._intf_with_feature(feature))
+
+    @classmethod
+    def reserved(cls):
+        """
+        return list with the interface name prefixes
+        eth, lo, vxlan, dum, ...
+        """
+        return list(cls._prefixes.keys())