--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/bin/pvl.hosts-dns	Mon Dec 16 18:37:08 2013 +0200
@@ -0,0 +1,129 @@
+#!/usr/bin/env python
+
+
+import pvl.args
+import pvl.dns.zone
+
+import configobj
+import ipaddr
+import logging; log = logging.getLogger('pvl.hosts-dns')
+import math
+import optparse
+
+def apply_hosts_file (options, file) :
+    """
+        Load hosts from a file.
+    """
+    config = configobj.ConfigObj(file,
+            encoding    = options.hosts_charset,
+    )
+
+    for host in config.sections :
+        yield host, config[host]
+
+def apply_hosts (options, args) :
+    """
+        Load hosts from arguments.
+    """
+
+    for file in pvl.args.apply_files(args, 'r') :
+        for host in apply_hosts_file(options, file) :
+            yield host
+
+def process_hosts_forward (options, hosts) :
+    for host, fields in hosts :
+        domain = fields.get('domain', options.hosts_domain)
+
+        if options.forward_zone and domain != options.forward_zone :
+            continue
+        
+        ip = fields.get('ip')
+
+        if ip :
+            yield pvl.dns.zone.ZoneRecord.A(host, value)
+        
+        # aliases
+        for field, value in fields.iteritems() :
+            if field.startswith('alias.') :
+                yield pvl.dns.zone.ZoneRecord.CNAME(value, host)
+
+def apply_reverse_zone (options, prefix, address) :
+    """
+        Determine the correct reverse-dns name for the given address with the reverse zone for the given prefix.
+    """
+
+    assert prefix.version == address.version
+    
+    hostbits = prefix.max_prefixlen - prefix.prefixlen
+
+    if prefix.version == 4 :
+        labelbytes = int(math.ceil(hostbits / 8.0))
+        labelraw = address.packed[-labelbytes:]
+
+        return '.'.join(reversed([str(ord(x)) for x in labelraw]))
+    else :
+        raise ValueError("unsupported address version: %s" % (prefix, ))
+
+def process_hosts_reverse (options, hosts) :
+    for host, fields in hosts :
+        domain = fields.get('domain', options.hosts_domain)
+        ip = fields.get('ip')
+
+        if ip :
+            ip = ipaddr.IPAddress(ip)
+
+        if not ip or ip not in options.reverse_zone :
+            continue
+        
+        # reverse against the prefix origin
+        ptr = apply_reverse_zone(options, options.reverse_zone, ip)
+        
+        yield pvl.dns.zone.ZoneRecord.PTR(ptr, pvl.dns.zone.fqdn(host, domain))
+
+def main (argv) :
+    """
+        Generate bind zonefiles from host definitions.
+    """
+
+    parser = optparse.OptionParser(main.__doc__)
+    parser.add_option_group(pvl.args.parser(parser))
+    
+    hosts = optparse.OptionGroup(parser, "Hosts input")
+    hosts.add_option('--hosts-charset',         metavar='CHARSET',  default='utf-8', 
+            help="Encoding used for host files")
+
+    hosts.add_option('--hosts-domain',          metavar='DOMAIN',
+            help="Default domain for hosts")
+    
+    parser.add_option_group(hosts)
+
+    parser.add_option('--forward-zone',         metavar='DOMAIN',
+            help="Generate forward zone for domain")
+
+    parser.add_option('--reverse-zone',         metavar='PREFIX',
+            help="Generate reverse zone for prefx")
+
+    options, args = parser.parse_args(argv[1:])
+    pvl.args.apply(options)
+
+    # input
+    hosts = list(apply_hosts(options, args))
+
+
+    if options.forward_zone :
+        zone = process_hosts_forward(options, hosts)
+    
+    elif options.reverse_zone :
+        options.reverse_zone = ipaddr.IPNetwork(options.reverse_zone)
+
+        zone = process_hosts_reverse(options, hosts)
+
+    else :
+        log.error("nothing to do")
+        return 1
+    
+    for record in zone :
+        print unicode(record)
+
+if __name__ == '__main__':
+    pvl.args.main(main)