unbound-querycachedb.py revision 356345 
1#!/usr/bin/env python
2
3import hashlib
4import sys
5import struct
6import socket
7import time
8from optparse import OptionParser
9
10import dns.message
11import dns.name
12import dns.rdataclass
13import dns.rdatatype
14
15def _calc_hashkey(qname, secret, qtype):
16    qclass = 'IN'           # CLASS is fixed for simplicity
17    hobj = hashlib.sha256()
18    hobj.update(dns.name.from_text(qname).to_wire())
19    hobj.update(struct.pack('HH',
20                            socket.htons(dns.rdatatype.from_text(qtype)),
21                            socket.htons(dns.rdataclass.from_text(qclass))))
22    hobj.update(secret)
23    return hobj.hexdigest().upper()
24
25def _redis_get(options, key):
26    import redis
27    return redis.Redis(options.address, int(options.port)).get(key)
28
29def _dump_value(options, qname, key, value):
30    print(';; query=%s/IN/%s' % (qname, options.qtype))
31    print(';; key=%s' % key)
32    if value is None:
33        print(';; no value')
34        return
35    if len(value) < 16:
36        print(';; broken value, short length: %d' % len(value))
37        return
38    now = int(time.time())
39    timestamp = struct.unpack('!Q', value[-16:-8])[0]
40    expire = struct.unpack('!Q', value[-8:])[0]
41    print(';; Now=%d, TimeStamp=%d, Expire=%d, TTL=%d' %
42          (now, timestamp, expire, max(expire - now, 0)))
43    print(dns.message.from_wire(value[:-16]))
44
45def main():
46    parser = OptionParser(usage='usage: %prog [options] query_name')
47    parser.add_option("-a", "--address", dest="address", action="store",
48                      default='127.0.0.1', help="backend-server address",
49                      metavar='ADDRESS')
50    parser.add_option("-b", "--backend", dest="backend", action="store",
51                      default='redis', help="backend name",
52                      metavar='BACKEND')
53    parser.add_option("-p", "--port", dest="port", action="store",
54                      default='6379', help="backend-server port",
55                      metavar='PORT')
56    parser.add_option("-s", "--secret", dest="secret", action="store",
57                      default='default', help="secret seed", metavar='SECRET')
58    parser.add_option("-t", "--qtype", dest="qtype", action="store",
59                      default='A', help="query RR type", metavar='QTYPE')
60
61    (options, args) = parser.parse_args()
62    if len(args) < 1:
63        parser.error('qname is missing')
64    if options.backend == 'redis':
65        get_func = _redis_get
66    else:
67        raise Exception('unknown backend name: %s\n' % options.backend)
68    key = _calc_hashkey(args[0], options.secret, options.qtype)
69    value = get_func(options, key)
70    _dump_value(options, args[0], key, value)
71
72if __name__ == '__main__':
73    try:
74        main()
75    except Exception as e:
76        sys.stderr.write('%s\n' % e)
77        exit(1)
78