os_net_config should map nics that are down if nic is in mapping file

Currently os-net_config will map nics from a user-supplied mapping file
only if the nic is active (operstate = up).  This can cause problems
if a nic is in a bond and one of the bond's nics has no carrier.
This fix will map the nic from the mapping file if the nic is defined
on the system, regardless of the operstate status.

The fix implements a new function to return a list of available nics
(no check of operstate) for use if a mapping file is supplied.  The
list of active nics must still be used in the default case when
numbering nics (no mapping file supplied).  There is also some
cleanup to check if a user-supplied mac is in the mapping file before
attempting to convert the mac to a nic.

Change-Id: Ia5d8c8b49b7ac0b51ee42a754f06e5e53587a5f6
Closes-Bug: 1679787

1 files changed, 24 insertions, 6 deletions

diff --git a/os_net_config/utils.py b/os_net_config/utils.py
index 98bfe99..84e719e 100644
--- a/os_net_config/utils.py
+++ b/os_net_config/utils.py
@@ -92,20 +92,30 @@ def interface_mac(name):
 
 
 def _is_active_nic(interface_name):
+    return _is_available_nic(interface_name, True)
+
+
+def _is_available_nic(interface_name, check_active=True):
     try:
         if interface_name == 'lo':
             return False
 
         device_dir = _SYS_CLASS_NET + '/%s/device' % interface_name
         has_device_dir = os.path.isdir(device_dir)
+        if not has_device_dir:
+            return False
 
         operstate = None
         with open(_SYS_CLASS_NET + '/%s/operstate' % interface_name, 'r') as f:
             operstate = f.read().rstrip().lower()
+        if check_active and operstate != 'up':
+            return False
 
         address = None
         with open(_SYS_CLASS_NET + '/%s/address' % interface_name, 'r') as f:
             address = f.read().rstrip()
+        if not address:
+            return False
 
         # If SR-IOV Virtual Functions (VF) are enabled in an interface, there
         # will be additional nics created for each VF. It has to be ignored in
@@ -114,12 +124,12 @@ def _is_active_nic(interface_name):
         # ignored.
         vf_path_check = _SYS_CLASS_NET + '/%s/device/physfn' % interface_name
         is_sriov_vf = os.path.isdir(vf_path_check)
-
-        if (has_device_dir and operstate == 'up' and address and
-                not is_sriov_vf):
-            return True
-        else:
+        if is_sriov_vf:
             return False
+
+        # nic is available
+        return True
+
     except IOError:
         return False
 
@@ -136,13 +146,21 @@ def _is_embedded_nic(nic):
     return False
 
 
+def ordered_available_nics():
+    return _ordered_nics(False)
+
+
 def ordered_active_nics():
+    return _ordered_nics(True)
+
+
+def _ordered_nics(check_active):
     embedded_nics = []
     nics = []
     logger.debug("Finding active nics")
     for name in glob.iglob(_SYS_CLASS_NET + '/*'):
         nic = name[(len(_SYS_CLASS_NET) + 1):]
-        if _is_active_nic(nic):
+        if _is_available_nic(nic, check_active):
             if _is_embedded_nic(nic):
                 logger.debug("%s is an embedded active nic" % nic)
                 embedded_nics.append(nic)