# HG changeset patch
# User Tero Marttila <terom@paivola.fi>
# Date 1332348236 -7200
# Node ID 21b33b9090d02a7e863309c72e1a918963047da3
# Parent  620f4594a09d953b8057c015f7c4e345defd2148
check-dhcp-hosts: parse dhcp conf for fixed-address stanzas, and ensure that they resolve..

diff -r 620f4594a09d -r 21b33b9090d0 bin/check-dhcp-hosts
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/bin/check-dhcp-hosts	Wed Mar 21 18:43:56 2012 +0200
@@ -0,0 +1,201 @@
+#!/usr/bin/env python
+
+"""
+    Go through a dhcp conf file looking for fixed-address stanzas, and make sure that they are valid.
+"""
+
+__version__ = '0.0.1-dev'
+
+import optparse
+import codecs
+import logging
+
+import socket
+
+log = logging.getLogger('main')
+
+# command-line options, global state
+options = None
+
+def parse_options (argv) :
+    """
+        Parse command-line arguments.
+    """
+
+    prog = argv[0]
+
+    parser = optparse.OptionParser(
+            prog        = prog,
+            usage       = '%prog: [options]',
+            version     = __version__,
+
+            # module docstring
+            description = __doc__,
+    )
+
+    # logging
+    general = optparse.OptionGroup(parser, "General Options")
+
+    general.add_option('-q', '--quiet',     dest='loglevel', action='store_const', const=logging.ERROR, help="Less output")
+    general.add_option('-v', '--verbose',   dest='loglevel', action='store_const', const=logging.INFO,  help="More output")
+    general.add_option('-D', '--debug',     dest='loglevel', action='store_const', const=logging.DEBUG, help="Even more output")
+
+    parser.add_option_group(general)
+
+    # input/output
+    parser.add_option('-c', '--input-charset',  metavar='CHARSET',  default='utf-8', 
+            help="Encoding used for input files")
+
+    # 
+    parser.add_option('--doctest',              action='store_true',
+            help="Run module doctests")
+
+    # defaults
+    parser.set_defaults(
+        loglevel            = logging.WARN,
+    )
+    
+    # parse
+    options, args = parser.parse_args(argv[1:])
+
+    # configure
+    logging.basicConfig(
+        format  = prog + ': %(name)s: %(levelname)s %(funcName)s : %(message)s',
+        level   = options.loglevel,
+    )
+
+    return options, args
+
+def parse_fixedaddrs (file) :
+    """
+        Go through lines in given .conf file, looking for fixed-address stanzas.
+    """
+
+    filename = file.name
+
+    for lineno, line in enumerate(file) :
+        # comments?
+        if '#' in line :
+            line, comment = line.split('#', 1)
+
+        else :
+            comment = None
+
+        # whitespace
+        line = line.strip()
+
+        if not line :
+            # empty
+            continue
+       
+        # grep
+        if 'fixed-address' in line :
+            # great parsing :)
+            fixedaddr = line.replace('fixed-address', '').replace(';', '').strip()
+
+            log.debug("%s:%d: %s: %s", filename, lineno, fixedaddr, line)
+        
+            yield lineno, fixedaddr
+
+def resolve_addr (addr, af=socket.AF_INET, socktype=socket.SOCK_STREAM) :
+    """
+        Resolve given address for given AF_INET, returning a list of resolved addresses.
+
+        Raises an Exception if failed.
+
+        >>> resolve_addr('127.0.0.1')
+        ['127.0.0.1']
+    """
+
+    if not addr :
+        raise Exception("Empty addr: %r", addr)
+
+    # resolve
+    result = socket.getaddrinfo(addr, None, af, socktype)
+   
+    #log.debug("%s: %s", addr, result)
+
+    # addresses
+    addrs = list(sorted(set(sockaddr[0] for family, socktype, proto, canonname, sockaddr in result)))
+
+    return addrs
+
+def check_file_hosts (file) :
+    """
+        Check all fixed-address parameters in given file.
+    """
+
+    filename = file.name
+    fail = 0
+
+    for lineno, addr in parse_fixedaddrs(file) :
+        # lookup
+        try :
+            resolved = resolve_addr(addr)
+
+        except Exception as e:
+            log.warning("%s:%d: failed to resolve: %s: %s", filename, lineno, addr, e)
+            fail += 1
+
+        else :
+            log.debug("%s:%d: %s: %r", filename, lineno, addr, resolved)
+
+    return fail
+
+def open_file (path, mode, charset) :
+    """
+        Open unicode-enabled file from path, with - using stdio.
+    """
+
+    if path == '-' :
+        # use stdin/out based on mode
+        stream, func = {
+            'r':    (sys.stdin, codecs.getreader),
+            'w':    (sys.stdout, codecs.getwriter),
+        }[mode[0]]
+
+        # wrap
+        return func(charset)(stream)
+
+    else :
+        # open
+        return codecs.open(path, mode, charset)
+
+def main (argv) :
+    global options
+    
+    options, args = parse_options(argv)
+
+    if options.doctest :
+        import doctest
+        fail, total = doctest.testmod()
+        return fail
+
+    if args :
+        # open files
+        input_files = [open_file(path, 'r', options.input_charset) for path in args]
+
+    else :
+        # default to stdout
+        input_files = [open_file('-', 'r', options.input_charset)]
+   
+    # process zone data
+    for file in input_files :
+        log.info("Reading zone: %s", file)
+    
+        fail = check_file_hosts(file)
+
+        if fail :
+            log.warn("DHCP hosts check failed: %d", fail)
+            return 2
+
+        else :
+            log.info("DHCP hosts check OK")
+
+    return 0
+
+if __name__ == '__main__':
+    import sys
+
+    sys.exit(main(sys.argv))
+