4 # Copyright (C) 2009, Google Inc.
6 # This program is free software; you can redistribute it and/or modify
7 # it under the terms of the GNU General Public License as published by
8 # the Free Software Foundation; either version 2 of the License, or
9 # (at your option) any later version.
11 # This program is distributed in the hope that it will be useful, but
12 # WITHOUT ANY WARRANTY; without even the implied warranty of
13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 # General Public License for more details.
16 # You should have received a copy of the GNU General Public License
17 # along with this program; if not, write to the Free Software
18 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
22 """Ganeti configuration daemon server library.
24 Ganeti-confd is a daemon to query master candidates for configuration values.
25 It uses UDP+HMAC for authentication with a global cluster key.
32 from ganeti import constants
33 from ganeti import objects
34 from ganeti import errors
35 from ganeti import utils
36 from ganeti import serializer
38 from ganeti.confd import querylib
41 class ConfdProcessor(object):
42 """A processor for confd requests.
46 constants.CONFD_REQ_PING: querylib.PingQuery,
47 constants.CONFD_REQ_NODE_ROLE_BYNAME: querylib.ConfdQuery,
48 constants.CONFD_REQ_NODE_PIP_BY_INSTANCE_IP: querylib.ConfdQuery,
51 def __init__(self, reader):
52 """Constructor for ConfdProcessor
54 @type reader: L{ssconf.SimpleConfigReader}
55 @param reader: ConfigReader to use to access the config
59 self.hmac_key = utils.ReadFile(constants.HMAC_CLUSTER_KEY)
61 not constants.CONFD_REQS.symmetric_difference(self.DISPATCH_TABLE), \
62 "DISPATCH_TABLE is unaligned with CONFD_REQS"
64 def ExecQuery(self, payload_in, ip, port):
65 """Process a single UDP request from a client.
67 @type payload_in: string
68 @param payload_in: request raw data
70 @param ip: source ip address
72 @type port: source port
76 request = self.ExtractRequest(payload_in)
77 reply, rsalt = self.ProcessRequest(request)
78 payload_out = self.PackReply(reply, rsalt)
80 except errors.ConfdRequestError, err:
81 logging.info('Ignoring broken query from %s:%d: %s' % (ip, port, err))
84 def ExtractRequest(self, payload):
85 """Extracts a ConfdRequest object from a serialized hmac signed string.
87 This functions also performs signature/timestamp validation.
90 current_time = time.time()
91 logging.debug("Extracting request with size: %d" % (len(payload)))
93 (message, salt) = serializer.LoadSigned(payload, self.hmac_key)
94 except errors.SignatureError, err:
95 msg = "invalid signature: %s" % err
96 raise errors.ConfdRequestError(msg)
98 message_timestamp = int(salt)
99 except (ValueError, TypeError):
100 msg = "non-integer timestamp: %s" % salt
101 raise errors.ConfdRequestError(msg)
103 skew = abs(current_time - message_timestamp)
104 if skew > constants.CONFD_MAX_CLOCK_SKEW:
105 msg = "outside time range (skew: %d)" % skew
106 raise errors.ConfdRequestError(msg)
109 request = objects.ConfdRequest.FromDict(message)
110 except AttributeError, err:
111 raise errors.ConfdRequestError('%s' % err)
115 def ProcessRequest(self, request):
116 """Process one ConfdRequest request, and produce an answer
118 @type request: L{objects.ConfdRequest}
119 @rtype: (L{objects.ConfdReply}, string)
120 @return: tuple of reply and salt to add to the signature
123 logging.debug("Processing request: %s" % request)
124 if request.protocol != constants.CONFD_PROTOCOL_VERSION:
125 msg = "wrong protocol version %d" % request.protocol
126 raise errors.ConfdRequestError(msg)
128 if request.type not in constants.CONFD_REQS:
129 msg = "wrong request type %d" % request.type
130 raise errors.ConfdRequestError(msg)
132 rsalt = request.rsalt
134 msg = "missing requested salt"
135 raise errors.ConfdRequestError(msg)
137 query_object = self.DISPATCH_TABLE[request.type](self.reader)
138 status, answer = query_object.Exec(request.query)
139 reply = objects.ConfdReply(
140 protocol=constants.CONFD_PROTOCOL_VERSION,
143 serial=self.reader.GetConfigSerialNo(),
146 logging.debug("Sending reply: %s" % reply)
148 return (reply, rsalt)
150 def PackReply(self, reply, rsalt):
151 """Serialize and sign the given reply, with salt rsalt
153 @type reply: L{objects.ConfdReply}
157 return serializer.DumpSigned(reply.ToDict(), self.hmac_key, rsalt)