root / lib / confd / server.py @ 48166551
History | View | Annotate | Download (5.2 kB)
1 |
#!/usr/bin/python
|
---|---|
2 |
#
|
3 |
|
4 |
# Copyright (C) 2009, Google Inc.
|
5 |
#
|
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.
|
10 |
#
|
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.
|
15 |
#
|
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
|
19 |
# 02110-1301, USA.
|
20 |
|
21 |
|
22 |
"""Ganeti configuration daemon server library.
|
23 |
|
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.
|
26 |
|
27 |
"""
|
28 |
|
29 |
import logging |
30 |
import time |
31 |
|
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 |
37 |
from ganeti import ssconf |
38 |
|
39 |
from ganeti.confd import querylib |
40 |
|
41 |
|
42 |
class ConfdProcessor(object): |
43 |
"""A processor for confd requests.
|
44 |
|
45 |
@ivar reader: confd SimpleConfigReader
|
46 |
@ivar disabled: whether confd serving is disabled
|
47 |
|
48 |
"""
|
49 |
DISPATCH_TABLE = { |
50 |
constants.CONFD_REQ_PING: querylib.PingQuery, |
51 |
constants.CONFD_REQ_NODE_ROLE_BYNAME: querylib.NodeRoleQuery, |
52 |
constants.CONFD_REQ_NODE_PIP_BY_INSTANCE_IP: |
53 |
querylib.InstanceIpToNodePrimaryIpQuery, |
54 |
constants.CONFD_REQ_CLUSTER_MASTER: querylib.ClusterMasterQuery, |
55 |
} |
56 |
|
57 |
def __init__(self): |
58 |
"""Constructor for ConfdProcessor
|
59 |
|
60 |
"""
|
61 |
self.disabled = True |
62 |
self.hmac_key = utils.ReadFile(constants.HMAC_CLUSTER_KEY)
|
63 |
self.reader = None |
64 |
assert \
|
65 |
not constants.CONFD_REQS.symmetric_difference(self.DISPATCH_TABLE), \ |
66 |
"DISPATCH_TABLE is unaligned with CONFD_REQS"
|
67 |
|
68 |
def Enable(self): |
69 |
try:
|
70 |
self.reader = ssconf.SimpleConfigReader()
|
71 |
self.disabled = False |
72 |
except errors.ConfigurationError:
|
73 |
self.disabled = True |
74 |
raise
|
75 |
|
76 |
def Disable(self): |
77 |
self.disabled = True |
78 |
self.reader = None |
79 |
|
80 |
def ExecQuery(self, payload_in, ip, port): |
81 |
"""Process a single UDP request from a client.
|
82 |
|
83 |
@type payload_in: string
|
84 |
@param payload_in: request raw data
|
85 |
@type ip: string
|
86 |
@param ip: source ip address
|
87 |
@param port: integer
|
88 |
@type port: source port
|
89 |
|
90 |
"""
|
91 |
if self.disabled: |
92 |
logging.debug('Confd is disabled. Ignoring query.')
|
93 |
return
|
94 |
try:
|
95 |
request = self.ExtractRequest(payload_in)
|
96 |
reply, rsalt = self.ProcessRequest(request)
|
97 |
payload_out = self.PackReply(reply, rsalt)
|
98 |
return payload_out
|
99 |
except errors.ConfdRequestError, err:
|
100 |
logging.info('Ignoring broken query from %s:%d: %s' % (ip, port, err))
|
101 |
return None |
102 |
|
103 |
def ExtractRequest(self, payload): |
104 |
"""Extracts a ConfdRequest object from a serialized hmac signed string.
|
105 |
|
106 |
This functions also performs signature/timestamp validation.
|
107 |
|
108 |
"""
|
109 |
current_time = time.time() |
110 |
logging.debug("Extracting request with size: %d" % (len(payload))) |
111 |
try:
|
112 |
(message, salt) = serializer.LoadSigned(payload, self.hmac_key)
|
113 |
except errors.SignatureError, err:
|
114 |
msg = "invalid signature: %s" % err
|
115 |
raise errors.ConfdRequestError(msg)
|
116 |
try:
|
117 |
message_timestamp = int(salt)
|
118 |
except (ValueError, TypeError): |
119 |
msg = "non-integer timestamp: %s" % salt
|
120 |
raise errors.ConfdRequestError(msg)
|
121 |
|
122 |
skew = abs(current_time - message_timestamp)
|
123 |
if skew > constants.CONFD_MAX_CLOCK_SKEW:
|
124 |
msg = "outside time range (skew: %d)" % skew
|
125 |
raise errors.ConfdRequestError(msg)
|
126 |
|
127 |
try:
|
128 |
request = objects.ConfdRequest.FromDict(message) |
129 |
except AttributeError, err: |
130 |
raise errors.ConfdRequestError('%s' % err) |
131 |
|
132 |
return request
|
133 |
|
134 |
def ProcessRequest(self, request): |
135 |
"""Process one ConfdRequest request, and produce an answer
|
136 |
|
137 |
@type request: L{objects.ConfdRequest}
|
138 |
@rtype: (L{objects.ConfdReply}, string)
|
139 |
@return: tuple of reply and salt to add to the signature
|
140 |
|
141 |
"""
|
142 |
logging.debug("Processing request: %s" % request)
|
143 |
if request.protocol != constants.CONFD_PROTOCOL_VERSION:
|
144 |
msg = "wrong protocol version %d" % request.protocol
|
145 |
raise errors.ConfdRequestError(msg)
|
146 |
|
147 |
if request.type not in constants.CONFD_REQS: |
148 |
msg = "wrong request type %d" % request.type
|
149 |
raise errors.ConfdRequestError(msg)
|
150 |
|
151 |
rsalt = request.rsalt |
152 |
if not rsalt: |
153 |
msg = "missing requested salt"
|
154 |
raise errors.ConfdRequestError(msg)
|
155 |
|
156 |
query_object = self.DISPATCH_TABLE[request.type](self.reader) |
157 |
status, answer = query_object.Exec(request.query) |
158 |
reply = objects.ConfdReply( |
159 |
protocol=constants.CONFD_PROTOCOL_VERSION, |
160 |
status=status, |
161 |
answer=answer, |
162 |
serial=self.reader.GetConfigSerialNo(),
|
163 |
) |
164 |
|
165 |
logging.debug("Sending reply: %s" % reply)
|
166 |
|
167 |
return (reply, rsalt)
|
168 |
|
169 |
def PackReply(self, reply, rsalt): |
170 |
"""Serialize and sign the given reply, with salt rsalt
|
171 |
|
172 |
@type reply: L{objects.ConfdReply}
|
173 |
@type rsalt: string
|
174 |
|
175 |
"""
|
176 |
return serializer.DumpSigned(reply.ToDict(), self.hmac_key, rsalt) |
177 |
|