[PATCH v2 05/20] InterfaceManager: fix rescan_devices method

[Ondrej Lichtner]

From: Ondrej Lichtner

The rescan_devices method destroyed the entire _devices dictionary and
recreated it from scratch. This caused problems when a Device object was
carying {Net, Nm}ConfigDevice object that's needed for device
deconfiguration.

Instead of recreating the whole dictionary from scratch we now keep it
and just call update_netlink methods for the existing Device objects.
New objects are added as before and Device objects for NICs that don't
exist anymore are removed. No deconfigration is called since there's
nothing to do when the device doesn't exist anymore.

Finally the method now also recognizes RTM_NEWADDR messages received
from the scan_netdevs method and sends them to the Device objects.

v2: don't remove Devices that were moved to a different network
namespace

Signed-off-by: Ondrej Lichtner 
---
 lnst/Slave/InterfaceManager.py | 30 +++++++++++++++++++++++++++---
 1 file changed, 27 insertions(+), 3 deletions(-)

diff --git a/lnst/Slave/InterfaceManager.py b/lnst/Slave/InterfaceManager.py
index 1999ed8..21c4fc0 100644
--- a/lnst/Slave/InterfaceManager.py
+++ b/lnst/Slave/InterfaceManager.py
@@ -14,6 +14,7 @@ [e-mail] (Ondrej Lichtner)

import re
 import select
+import logging
 from lnst.Slave.NetConfigDevice import NetConfigDevice
 from lnst.Slave.NetConfigCommon import get_option
 from lnst.Common.NetUtils import normalize_hwaddr
@@ -85,14 +86,37 @@ class InterfaceManager(object):
         return self._nl_socket

def rescan_devices(self):
-        self._devices = {}
+        devices_to_remove = self._devices.keys()
         devs = scan_netdevs()
         for dev in devs:
             if dev['index'] not in self._devices:
-                device = Device(self)
+                device = None
+                for if_id, d in self._tmp_mapping.items():
+                    d_cfg = d.get_conf_dict()
+                    if d_cfg["name"] == dev["name"]:
+                        device = d
+                        self._id_mapping[if_id] = dev['index']
+                        del self._tmp_mapping[if_id]
+                        break
+                if device == None:
+                    device = Device(self)
                 device.init_netlink(dev['netlink_msg'])
-
                 self._devices[dev['index']] = device
+            else:
+                self._devices[dev['index']].update_netlink(dev['netlink_msg'])
+                devices_to_remove.remove(dev['index'])
+
+            self._devices[dev['index']].clear_ips()
+            for addr_msg in dev['ip_addrs']:
+                self._devices[dev['index']].update_netlink(addr_msg)
+        for i in devices_to_remove:
+            if self._devices[i].get_netns() != None:
+                continue
+
+            dev_name = self._devices[i].get_name()
+            logging.debug("Deleting Device with if_index %d, name %s because "\
+                          "it doesn't exist anymore." % (i, dev_name))
+            del self._devices[i]

def handle_netlink_msgs(self, msgs):
         for msg in msgs: