Add addon module for B.A.T.M.A.N. advanced interface configuration. (#12)

* Add addon module for B.A.T.M.A.N. advanced interface configuration.

  This commit adds support for configuring B.A.T.M.A.N. advanced interfaces
  with ifupdown2. B.A.T.M.A.N. advanced is a protocol to build Layer2 based
  mesh networks with. It's supported in the Linux kernel and thus available
  in many Linux environments.

  A configuration could look like this

  auto bat0
  iface bat0
      batman-ifaces eth1 eth2.23
      batman-ifaces-ignore-regex .*_nodes
      batman-hop-penalty 23
      #
      address 192.0.2.42/24

  where »bat0« would be the local connection to the mesh network.

  The interfaces »eth1« and »eth2.23« would be used by the B.A.T.M.A.N. adv.
  protocol to communicate to other member of the mesh network.

  Any interfaces matching the »ifaces-ignore-regex« will be gently ignored
  by ifquery and ifreload as there might be some tunnels or interfaces
  added to the mesh network by other means which should not be removed by
  any subsequent ifreload run.

  The »hop-penalty» parameter set the penalty of this node within the mesh
  network.

Signed-off-by: Maximilian Wilhelm <max@rfc2324.org>

* addons: batman_adv: replacing rtnetlink by netlink api call and iproute2 instantiation fix

These changes are due to modifications we introduced in debian-prep2.
We no longer use the rtnetlink_api but a new one "netlink" build on top of python-nlmanager.

* Reflect upstream change where flags are stored.

Signed-off-by: Maximilian Wilhelm <max@rfc2324.org>

addons/batman_adv.py

@@ -0,0 +1,265 @@
+#!/usr/bin/python
+#
+# Copyright 2016 Maximilian Wilhelm <max@rfc2324.org>
+# Author: Maximilian Wilhelm, max@rfc2324.org
+#
+
+from ifupdown.iface import *
+from ifupdownaddons.modulebase import moduleBase
+from ifupdownaddons.iproute2 import iproute2
+from ifupdown.netlink import netlink
+import ifupdown.ifupdownflags as ifupdownflags
+import logging
+import re
+import subprocess
+
+
+class batman_adv (moduleBase):
+    """  ifupdown2 addon module to configure B.A.T.M.A.N. advanced interfaces """
+
+    _modinfo = {'mhelp' : 'batman_adv module configures B.A.T.M.A.N. advanced interfaces.' +
+                        'Every B.A.T.M.A.N. advanced interface needs at least on ethernet ' +
+                        'interface to be creatable. You can specify a space separated list' +
+                        'of interfaces by using the "batma-ifaces" paramater. If this parameter' +
+                        'is set for an interfaces this module will do the magic.',
+                'attrs' : {
+                        'batman-ifaces' :
+                            {'help' : 'Interfaces to be part of this B.A.T.M.A.N. advanced instance'},
+                        'batman-ifaces-ignore-regex' :
+                            {'help' : 'Interfaces to ignore when verifying configuration (regexp)'},
+                        'batman-hop-penalty' :
+                            {'help' : 'B.A.T.M.A.N. hop penalty'}}}
+
+
+    def __init__ (self, *args, **kargs):
+        moduleBase.__init__ (self, *args, **kargs)
+        self.ipcmd = None
+
+
+    def _is_batman_device (self, ifaceobj):
+        if ifaceobj.get_attr_value_first ('batman-ifaces'):
+            return True
+        return False
+
+
+    def _get_batman_ifaces (self, ifaceobj ):
+        batman_ifaces = ifaceobj.get_attr_value_first ('batman-ifaces')
+        if batman_ifaces:
+            return sorted (batman_ifaces.split ())
+        return None
+
+
+    def _get_batman_ifaces_ignore_regex (self, ifaceobj):
+        ifaces_ignore_regex = ifaceobj.get_attr_value_first ('batman-ifaces-ignore-regex')
+        if ifaces_ignore_regex:
+            return re.compile (r"%s" % ifaces_ignore_regex)
+        return None
+
+
+    def _get_batman_hop_penalty (self, ifaceobj):
+        # XXX config option for default value?
+        hop_penalty = ifaceobj.get_attr_value_first ('batman-hop-penalty')
+        if hop_penalty:
+            return int (hop_penalty)
+        return 15
+
+    def _read_current_hop_penalty (self, ifaceobj):
+        hop_penalty_file_path = "/sys/class/net/%s/mesh/hop_penalty" % ifaceobj.name
+        try:
+            with open (hop_penalty_file_path, "r") as fh:
+                 return int (fh.readline ().strip ())
+        except IOError as i:
+             raise Exception (i)
+        except ValueError:
+             raise Exception ("Hop penalty not an integer value!")
+
+
+    def _set_hop_penalty (self, ifaceobj, hop_penalty):
+        hop_penalty_file_path = "/sys/class/net/%s/mesh/hop_penalty" % ifaceobj.name
+        try:
+            with open (hop_penalty_file_path, "w") as fh:
+                 fh.write ("%d\n" % int (hop_penalty))
+        except IOError as i:
+             raise Exception (i)
+        except ValueError:
+             raise Exception ("Hop penalty not an integer value!")
+
+
+    def _sysfs_mgmt_member_if (self, bat_iface, mesh_iface, op):
+        if op not in [ 'add', 'del' ]:
+            raise Exception ("_sysfs_mgmt_member_if() called with invalid \"op\" value: %s" % op)
+
+        try:
+            batctl_output = subprocess.check_output (["batctl", "-m", bat_iface, "if", op, mesh_iface], stderr = subprocess.STDOUT)
+        except subprocess.CalledProcessError as c:
+            raise Exception ("Command \"batctl -m %s if %s %s\" failed: %s" % (bat_iface, op, mesh_iface, c.output))
+
+
+    def _find_member_ifaces (self, ifaceobj, ignore = True):
+        members = []
+        iface_ignore_re = self._get_batman_ifaces_ignore_regex (ifaceobj)
+        batctl_fh = subprocess.Popen (["batctl", "-m", ifaceobj.name, "if"], bufsize = 4194304, stdout = subprocess.PIPE).stdout
+        for line in batctl_fh.readlines ():
+            iface = line.split (':')[0]
+            if iface_ignore_re and iface_ignore_re.match (iface) and ignore:
+                 continue
+
+            members.append (iface)
+
+        return sorted (members)
+
+
+    def get_dependent_ifacenames (self, ifaceobj, ifaceobjs_all=None):
+        if not self._is_batman_device (ifaceobj):
+            return None
+
+        ifaceobj.link_kind |= ifaceLinkKind.BATMAN_ADV
+        batman_ifaces = self._get_batman_ifaces (ifaceobj)
+        if batman_ifaces:
+            return batman_ifaces
+
+        return [None]
+
+
+    def _up (self, ifaceobj):
+        batman_ifaces = self._get_batman_ifaces (ifaceobj)
+        if batman_ifaces == None:
+            raise Exception ('could not determine batman interfacaes')
+
+        # Verify existance of batman interfaces (should be present already)
+        for iface in batman_ifaces:
+            if not self.ipcmd.link_exists (iface):
+                raise Exception ('batman iface %s not present' % iface)
+
+        if_ignore_re = self._get_batman_ifaces_ignore_regex (ifaceobj)
+        # Is the batman main interface already present?
+        if self.ipcmd.link_exists (ifaceobj.name):
+            # Verify which member interfaces are present
+            members = self._find_member_ifaces (ifaceobj)
+            for iface in members:
+                if iface not in batman_ifaces:
+                    self._sysfs_mgmt_member_if (ifaceobj.name, iface, 'del')
+            for iface in batman_ifaces:
+                if iface not in members:
+                    self._sysfs_mgmt_member_if (ifaceobj.name, iface, 'add')
+        else:
+            for iface in batman_ifaces:
+                self._sysfs_mgmt_member_if (ifaceobj.name, iface, 'add')
+
+        # Check/set Hop Penalty
+        hop_penalty_cfg = self._get_batman_hop_penalty (ifaceobj)
+        if hop_penalty_cfg != self._read_current_hop_penalty (ifaceobj):
+            self._set_hop_penalty (ifaceobj, hop_penalty_cfg)
+
+        if ifaceobj.addr_method == 'manual':
+            netlink.link_set_updown(ifaceobj.name, "up")
+
+
+
+    def _down (self, ifaceobj):
+        if not ifupdownflags.flags.PERFMODE and not self.ipcmd.link_exists (ifaceobj.name):
+           return
+
+        members = self._find_member_ifaces (ifaceobj)
+        for iface in members:
+            self._sysfs_mgmt_member_if (ifaceobj.name, iface, 'del')
+
+        # The main interface will automagically vanish after the last member
+        # interface has been deleted.
+
+
+    def _query_check (self, ifaceobj, ifaceobjcurr):
+        if not self.ipcmd.link_exists (ifaceobj.name):
+            return
+
+        hop_penalty = self._get_batman_hop_penalty (ifaceobj)
+        hop_penalty_curr = self._read_current_hop_penalty (ifaceobj)
+        batman_ifaces_cfg = self._get_batman_ifaces (ifaceobj)
+        batman_ifaces_real = self._find_member_ifaces (ifaceobj, False)
+        # Produce list of all current interfaces, tag interfaces ignore by
+        # regex with () around the iface name.
+        batman_ifaces_real_tagged = []
+        iface_ignore_re_str = ifaceobj.get_attr_value_first ('batman-ifaces-ignore-regex')
+        iface_ignore_re = self._get_batman_ifaces_ignore_regex (ifaceobj)
+
+        # Assume everything's fine and wait for reality to prove us otherwise
+        ifaces_ok = 0
+        # Interfaces configured but not active?
+        for iface in batman_ifaces_cfg:
+            if iface not in batman_ifaces_real:
+                 ifaces_ok = 1
+
+        # Interfaces active but not configured (or ignored)?
+        for iface in batman_ifaces_real:
+            if iface not in batman_ifaces_cfg:
+                 if iface_ignore_re and iface_ignore_re.match (iface):
+                     batman_ifaces_real_tagged.append ("(%s)" % iface)
+                     continue
+                 ifaces_ok = 1
+            else:
+                batman_ifaces_real_tagged.append (iface)
+
+        # Produce sorted list of active and ignored interfaces
+        ifaces_str = " ".join (batman_ifaces_real_tagged)
+        ifaceobjcurr.update_config_with_status ('batman-ifaces', ifaces_str, ifaces_ok)
+        ifaceobjcurr.update_config_with_status ('batman-ifaces-ignore-regex', iface_ignore_re_str, 0)
+
+        # Check Hop Penalty
+        hop_penalty_ok = 0
+        if hop_penalty != hop_penalty_curr:
+             hop_penalty_ok = 1
+        ifaceobjcurr.update_config_with_status ('batman-hop-penalty', hop_penalty_curr, hop_penalty_ok)
+
+
+    def _query_running (self, ifaceobjrunning):
+        if not self.ipcmd.link_exists (ifaceobjrunning.name):
+            return
+
+        # XXX Now what?
+
+
+    _run_ops = {'pre-up' : _up,
+               'post-down' : _down,
+               'query-checkcurr' : _query_check}
+# XXX              'query-running' : _query_running}
+
+
+    def get_ops (self):
+        """ returns list of ops supported by this module """
+        return self._run_ops.keys ()
+
+
+    def _init_command_handlers (self):
+        if not self.ipcmd:
+            self.ipcmd = iproute2()
+
+
+    def run (self, ifaceobj, operation, query_ifaceobj = None, **extra_args):
+        """ run B.A.T.M.A.N. configuration on the interface object passed as argument
+
+        Args:
+            **ifaceobj** (object): iface object
+
+            **operation** (str): any of 'pre-up', 'post-down', 'query-checkcurr',
+                                 'query-running'
+        Kwargs:
+            **query_ifaceobj** (object): query check ifaceobject. This is only
+                valid when op is 'query-checkcurr'. It is an object same as
+                ifaceobj, but contains running attribute values and its config
+                status. The modules can use it to return queried running state
+                of interfaces. status is success if the running state is same
+                as user required state in ifaceobj. error otherwise.
+        """
+        op_handler = self._run_ops.get (operation)
+        if not op_handler:
+            return
+
+        if (operation != 'query-running' and not self._is_batman_device (ifaceobj)):
+            return
+
+        self._init_command_handlers ()
+
+        if operation == 'query-checkcurr':
+            op_handler (self, ifaceobj, query_ifaceobj)
+        else:
+            op_handler (self, ifaceobj)

config/addons.conf

@@ -1,5 +1,6 @@
 pre-up,link
 pre-up,bond
+pre-up,batman_adv
 pre-up,vlan
 pre-up,vxlan
 pre-up,clagd
@@ -31,5 +32,6 @@ post-down,bridge
 post-down,vxlan
 post-down,vlan
 post-down,bond
+post-down,batman_adv
 post-down,usercmds
 post-down,link

ifupdown/iface.py

@@ -46,12 +46,13 @@ class ifaceLinkKind():
         bond have an ifaceobj.role attribute of SLAVE and the bridge or
         bond itself has ifaceobj.role of MASTER.
     """
-    UNKNOWN = 0x000000
-    BRIDGE =  0x000001
-    BOND =    0x000010
-    VLAN =    0x000100
-    VXLAN =   0x001000
-    VRF =     0x010000
+    UNKNOWN =    0x000000
+    BRIDGE =     0x000001
+    BOND =       0x000010
+    VLAN =       0x000100
+    VXLAN =      0x001000
+    VRF =        0x010000
+    BATMAN_ADV = 0x100000
 
 class ifaceLinkPrivFlags():
     """ This corresponds to kernel netdev->priv_flags

setup.py

@@ -17,7 +17,7 @@ setup(name='ifupdown2',
                       'addons/ethtool.py',
                       'addons/addressvirtual.py', 'addons/vxlan.py',
                       'addons/link.py', 'addons/vrf.py',
-                      'addons/bridgevlan.py']),
+                      'addons/bridgevlan.py', 'addons/batman_adv.py']),
                    ('/usr/share/ifupdown2/nlmanager/',
                     ['nlmanager/nllistener.py',
                      'nlmanager/nlmanager.py',