#!/usr/bin/python
#
# Check state of interfaces configured with ifupdown2
#
# Maximilian Wilhelm <max@rfc2324.org>
#  --  Fri, 14 Apr 2017 20:05:45 +0200
#

import argparse
import re
import subprocess
import sys

parser = argparse.ArgumentParser (description = 'Check interface configuration.')
parser.add_argument ("--ok_string", help = "Ifupdown success string", required = True)
args = parser.parse_args ()

cmd = [ "/usr/bin/sudo", "/sbin/ifquery", "-c", "-a" ]


try:
	ifquery = subprocess.Popen (cmd, bufsize = 4194304, stdout = subprocess.PIPE, stderr = subprocess.PIPE).stdout

# cmd exited with non-zero code
except subprocess.CalledProcessError as c:
	print "Failed to run %s: %s" % (" ".join (cmd), c.output)
	sys.exit (1)

# This should not have happend.
except Exception as e:
	print "Unknown error while running %s: %s" % (" ".join (cmd), str (e))
	sys.exit (3)

################################################################################
#          Parse all entries from ifquery output into interfaces dict          #
################################################################################

interfaces_ok = []
interfaces_err = []

interface_re = re.compile (r'^iface (\S+)\s+\[(.+)\]$')
ignore_re = re.compile (r'^(auto .*)?$')
line_re = re.compile (r'^\s+(\S+)\s+(.+)\s+\[(.+)\]$')

# Parse session list
interface = None
interface_dict = None
for line in ifquery.readlines ():
	line = line.rstrip ()

	# Preamble or empty string
	if ignore_re.search (line):
		if not interface_dict:
			continue

		if interface_dict['ok']:
			interfaces_ok.append (interface)

		else:
			del interface_dict['ok']

			errors = ",".join (sorted (interface_dict.keys ()))
			if errors == "":
				errors = "DOWN"

			interfaces_err.append ("%s: %s" % (interface, errors))

		interface = None
		interface_dict = None
		continue

	# Start of a new interface
	match = interface_re.search (line)
	if match:
		interface = match.group (1)
		interface_dict = {
			'ok' : True if match.group (2) == args.ok_string else False,
		}

		continue

	# Ignore any non-BGP protocols, empty lines, etc.  XXX
	if interface == None:
		continue

	# Parse and store any interesting lines / fields
	match = line_re.search (line)
	if not match:
		continue

	attr = match.group (1)
	value = match.group (2)
	status = match.group (3)

	if status != args.ok_string:
		interface_dict['ok'] = False
		interface_dict[attr] = value


ret_code = 0
if len (interfaces_err) > 0:
	print "ERR: %s" % "; ".join (interfaces_err)
	ret_code = 2

if len (interfaces_ok) > 0:
	print "OK: %s" % ", ".join (interfaces_ok)

sys.exit (ret_code)