root / lib / netutils.py @ 17385bd2
History | View | Annotate | Download (16.9 kB)
1 |
#
|
---|---|
2 |
#
|
3 |
|
4 |
# Copyright (C) 2010 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 network utility module.
|
23 |
|
24 |
This module holds functions that can be used in both daemons (all) and
|
25 |
the command line scripts.
|
26 |
|
27 |
"""
|
28 |
|
29 |
|
30 |
import errno |
31 |
import os |
32 |
import re |
33 |
import socket |
34 |
import struct |
35 |
import IN |
36 |
import logging |
37 |
|
38 |
from ganeti import constants |
39 |
from ganeti import errors |
40 |
from ganeti import utils |
41 |
|
42 |
# Structure definition for getsockopt(SOL_SOCKET, SO_PEERCRED, ...):
|
43 |
# struct ucred { pid_t pid; uid_t uid; gid_t gid; };
|
44 |
#
|
45 |
# The GNU C Library defines gid_t and uid_t to be "unsigned int" and
|
46 |
# pid_t to "int".
|
47 |
#
|
48 |
# IEEE Std 1003.1-2008:
|
49 |
# "nlink_t, uid_t, gid_t, and id_t shall be integer types"
|
50 |
# "blksize_t, pid_t, and ssize_t shall be signed integer types"
|
51 |
_STRUCT_UCRED = "iII"
|
52 |
_STRUCT_UCRED_SIZE = struct.calcsize(_STRUCT_UCRED) |
53 |
|
54 |
# Regexes used to find IP addresses in the output of ip.
|
55 |
_IP_RE_TEXT = r"[.:a-z0-9]+" # separate for testing purposes |
56 |
_IP_FAMILY_RE = re.compile(r"(?P<family>inet6?)\s+(?P<ip>%s)/" % _IP_RE_TEXT,
|
57 |
re.IGNORECASE) |
58 |
|
59 |
# Dict used to convert from a string representing an IP family to an IP
|
60 |
# version
|
61 |
_NAME_TO_IP_VER = { |
62 |
"inet": constants.IP4_VERSION,
|
63 |
"inet6": constants.IP6_VERSION,
|
64 |
} |
65 |
|
66 |
|
67 |
def _GetIpAddressesFromIpOutput(ip_output): |
68 |
"""Parses the output of the ip command and retrieves the IP addresses and
|
69 |
version.
|
70 |
|
71 |
@param ip_output: string containing the output of the ip command;
|
72 |
@rtype: dict; (int, list)
|
73 |
@return: a dict having as keys the IP versions and as values the
|
74 |
corresponding list of addresses found in the IP output.
|
75 |
|
76 |
"""
|
77 |
addr = dict((i, []) for i in _NAME_TO_IP_VER.values()) |
78 |
|
79 |
for row in ip_output.splitlines(): |
80 |
match = _IP_FAMILY_RE.search(row) |
81 |
if match and IPAddress.IsValid(match.group("ip")): |
82 |
addr[_NAME_TO_IP_VER[match.group("family")]].append(match.group("ip")) |
83 |
|
84 |
return addr
|
85 |
|
86 |
|
87 |
def GetSocketCredentials(sock): |
88 |
"""Returns the credentials of the foreign process connected to a socket.
|
89 |
|
90 |
@param sock: Unix socket
|
91 |
@rtype: tuple; (number, number, number)
|
92 |
@return: The PID, UID and GID of the connected foreign process.
|
93 |
|
94 |
"""
|
95 |
peercred = sock.getsockopt(socket.SOL_SOCKET, IN.SO_PEERCRED, |
96 |
_STRUCT_UCRED_SIZE) |
97 |
return struct.unpack(_STRUCT_UCRED, peercred)
|
98 |
|
99 |
|
100 |
def IsValidInterface(ifname): |
101 |
"""Validate an interface name.
|
102 |
|
103 |
@type ifname: string
|
104 |
@param ifname: Name of the network interface
|
105 |
@return: boolean indicating whether the interface name is valid or not.
|
106 |
|
107 |
"""
|
108 |
return os.path.exists(utils.PathJoin("/sys/class/net", ifname)) |
109 |
|
110 |
|
111 |
def GetInterfaceIpAddresses(ifname): |
112 |
"""Returns the IP addresses associated to the interface.
|
113 |
|
114 |
@type ifname: string
|
115 |
@param ifname: Name of the network interface
|
116 |
@return: A dict having for keys the IP version (either
|
117 |
L{constants.IP4_VERSION} or L{constants.IP6_VERSION}) and for
|
118 |
values the lists of IP addresses of the respective version
|
119 |
associated to the interface
|
120 |
|
121 |
"""
|
122 |
result = utils.RunCmd([constants.IP_COMMAND_PATH, "-o", "addr", "show", |
123 |
ifname]) |
124 |
|
125 |
if result.failed:
|
126 |
logging.error("Error running the ip command while getting the IP"
|
127 |
" addresses of %s", ifname)
|
128 |
return None |
129 |
|
130 |
return _GetIpAddressesFromIpOutput(result.output)
|
131 |
|
132 |
|
133 |
def GetHostname(name=None, family=None): |
134 |
"""Returns a Hostname object.
|
135 |
|
136 |
@type name: str
|
137 |
@param name: hostname or None
|
138 |
@type family: int
|
139 |
@param family: AF_INET | AF_INET6 | None
|
140 |
@rtype: L{Hostname}
|
141 |
@return: Hostname object
|
142 |
@raise errors.OpPrereqError: in case of errors in resolving
|
143 |
|
144 |
"""
|
145 |
try:
|
146 |
return Hostname(name=name, family=family)
|
147 |
except errors.ResolverError, err:
|
148 |
raise errors.OpPrereqError("The given name (%s) does not resolve: %s" % |
149 |
(err[0], err[2]), errors.ECODE_RESOLVER) |
150 |
|
151 |
|
152 |
class Hostname: |
153 |
"""Class implementing resolver and hostname functionality.
|
154 |
|
155 |
"""
|
156 |
_VALID_NAME_RE = re.compile("^[a-z0-9._-]{1,255}$")
|
157 |
|
158 |
def __init__(self, name=None, family=None): |
159 |
"""Initialize the host name object.
|
160 |
|
161 |
If the name argument is None, it will use this system's name.
|
162 |
|
163 |
@type family: int
|
164 |
@param family: AF_INET | AF_INET6 | None
|
165 |
@type name: str
|
166 |
@param name: hostname or None
|
167 |
|
168 |
"""
|
169 |
self.name = self.GetNormalizedName(self.GetFqdn(name)) |
170 |
self.ip = self.GetIP(self.name, family=family) |
171 |
|
172 |
@classmethod
|
173 |
def GetSysName(cls): |
174 |
"""Legacy method the get the current system's name.
|
175 |
|
176 |
"""
|
177 |
return cls.GetFqdn()
|
178 |
|
179 |
@staticmethod
|
180 |
def GetFqdn(hostname=None): |
181 |
"""Return fqdn.
|
182 |
|
183 |
If hostname is None the system's fqdn is returned.
|
184 |
|
185 |
@type hostname: str
|
186 |
@param hostname: name to be fqdn'ed
|
187 |
@rtype: str
|
188 |
@return: fqdn of given name, if it exists, unmodified name otherwise
|
189 |
|
190 |
"""
|
191 |
if hostname is None: |
192 |
return socket.getfqdn()
|
193 |
else:
|
194 |
return socket.getfqdn(hostname)
|
195 |
|
196 |
@staticmethod
|
197 |
def GetIP(hostname, family=None): |
198 |
"""Return IP address of given hostname.
|
199 |
|
200 |
Supports both IPv4 and IPv6.
|
201 |
|
202 |
@type hostname: str
|
203 |
@param hostname: hostname to look up
|
204 |
@type family: int
|
205 |
@param family: AF_INET | AF_INET6 | None
|
206 |
@rtype: str
|
207 |
@return: IP address
|
208 |
@raise errors.ResolverError: in case of errors in resolving
|
209 |
|
210 |
"""
|
211 |
try:
|
212 |
if family in (socket.AF_INET, socket.AF_INET6): |
213 |
result = socket.getaddrinfo(hostname, None, family)
|
214 |
else:
|
215 |
result = socket.getaddrinfo(hostname, None)
|
216 |
except (socket.gaierror, socket.herror, socket.error), err:
|
217 |
# hostname not found in DNS, or other socket exception in the
|
218 |
# (code, description format)
|
219 |
raise errors.ResolverError(hostname, err.args[0], err.args[1]) |
220 |
|
221 |
# getaddrinfo() returns a list of 5-tupes (family, socktype, proto,
|
222 |
# canonname, sockaddr). We return the first tuple's first address in
|
223 |
# sockaddr
|
224 |
try:
|
225 |
return result[0][4][0] |
226 |
except IndexError, err: |
227 |
raise errors.ResolverError("Unknown error in getaddrinfo(): %s" % err) |
228 |
|
229 |
@classmethod
|
230 |
def GetNormalizedName(cls, hostname): |
231 |
"""Validate and normalize the given hostname.
|
232 |
|
233 |
@attention: the validation is a bit more relaxed than the standards
|
234 |
require; most importantly, we allow underscores in names
|
235 |
@raise errors.OpPrereqError: when the name is not valid
|
236 |
|
237 |
"""
|
238 |
hostname = hostname.lower() |
239 |
if (not cls._VALID_NAME_RE.match(hostname) or |
240 |
# double-dots, meaning empty label
|
241 |
".." in hostname or |
242 |
# empty initial label
|
243 |
hostname.startswith(".")):
|
244 |
raise errors.OpPrereqError("Invalid hostname '%s'" % hostname, |
245 |
errors.ECODE_INVAL) |
246 |
if hostname.endswith("."): |
247 |
hostname = hostname.rstrip(".")
|
248 |
return hostname
|
249 |
|
250 |
|
251 |
def TcpPing(target, port, timeout=10, live_port_needed=False, source=None): |
252 |
"""Simple ping implementation using TCP connect(2).
|
253 |
|
254 |
Check if the given IP is reachable by doing attempting a TCP connect
|
255 |
to it.
|
256 |
|
257 |
@type target: str
|
258 |
@param target: the IP to ping
|
259 |
@type port: int
|
260 |
@param port: the port to connect to
|
261 |
@type timeout: int
|
262 |
@param timeout: the timeout on the connection attempt
|
263 |
@type live_port_needed: boolean
|
264 |
@param live_port_needed: whether a closed port will cause the
|
265 |
function to return failure, as if there was a timeout
|
266 |
@type source: str or None
|
267 |
@param source: if specified, will cause the connect to be made
|
268 |
from this specific source address; failures to bind other
|
269 |
than C{EADDRNOTAVAIL} will be ignored
|
270 |
|
271 |
"""
|
272 |
try:
|
273 |
family = IPAddress.GetAddressFamily(target) |
274 |
except errors.GenericError:
|
275 |
return False |
276 |
|
277 |
sock = socket.socket(family, socket.SOCK_STREAM) |
278 |
success = False
|
279 |
|
280 |
if source is not None: |
281 |
try:
|
282 |
sock.bind((source, 0))
|
283 |
except socket.error, (errcode, _):
|
284 |
if errcode == errno.EADDRNOTAVAIL:
|
285 |
success = False
|
286 |
|
287 |
sock.settimeout(timeout) |
288 |
|
289 |
try:
|
290 |
sock.connect((target, port)) |
291 |
sock.close() |
292 |
success = True
|
293 |
except socket.timeout:
|
294 |
success = False
|
295 |
except socket.error, (errcode, _):
|
296 |
success = (not live_port_needed) and (errcode == errno.ECONNREFUSED) |
297 |
|
298 |
return success
|
299 |
|
300 |
|
301 |
def GetDaemonPort(daemon_name): |
302 |
"""Get the daemon port for this cluster.
|
303 |
|
304 |
Note that this routine does not read a ganeti-specific file, but
|
305 |
instead uses C{socket.getservbyname} to allow pre-customization of
|
306 |
this parameter outside of Ganeti.
|
307 |
|
308 |
@type daemon_name: string
|
309 |
@param daemon_name: daemon name (in constants.DAEMONS_PORTS)
|
310 |
@rtype: int
|
311 |
|
312 |
"""
|
313 |
if daemon_name not in constants.DAEMONS_PORTS: |
314 |
raise errors.ProgrammerError("Unknown daemon: %s" % daemon_name) |
315 |
|
316 |
(proto, default_port) = constants.DAEMONS_PORTS[daemon_name] |
317 |
try:
|
318 |
port = socket.getservbyname(daemon_name, proto) |
319 |
except socket.error:
|
320 |
port = default_port |
321 |
|
322 |
return port
|
323 |
|
324 |
|
325 |
class IPAddress(object): |
326 |
"""Class that represents an IP address.
|
327 |
|
328 |
"""
|
329 |
iplen = 0
|
330 |
family = None
|
331 |
loopback_cidr = None
|
332 |
|
333 |
@staticmethod
|
334 |
def _GetIPIntFromString(address): |
335 |
"""Abstract method to please pylint.
|
336 |
|
337 |
"""
|
338 |
raise NotImplementedError |
339 |
|
340 |
@classmethod
|
341 |
def IsValid(cls, address): |
342 |
"""Validate a IP address.
|
343 |
|
344 |
@type address: str
|
345 |
@param address: IP address to be checked
|
346 |
@rtype: bool
|
347 |
@return: True if valid, False otherwise
|
348 |
|
349 |
"""
|
350 |
if cls.family is None: |
351 |
try:
|
352 |
family = cls.GetAddressFamily(address) |
353 |
except errors.IPAddressError:
|
354 |
return False |
355 |
else:
|
356 |
family = cls.family |
357 |
|
358 |
try:
|
359 |
socket.inet_pton(family, address) |
360 |
return True |
361 |
except socket.error:
|
362 |
return False |
363 |
|
364 |
@classmethod
|
365 |
def Own(cls, address): |
366 |
"""Check if the current host has the the given IP address.
|
367 |
|
368 |
This is done by trying to bind the given address. We return True if we
|
369 |
succeed or false if a socket.error is raised.
|
370 |
|
371 |
@type address: str
|
372 |
@param address: IP address to be checked
|
373 |
@rtype: bool
|
374 |
@return: True if we own the address, False otherwise
|
375 |
|
376 |
"""
|
377 |
if cls.family is None: |
378 |
try:
|
379 |
family = cls.GetAddressFamily(address) |
380 |
except errors.IPAddressError:
|
381 |
return False |
382 |
else:
|
383 |
family = cls.family |
384 |
|
385 |
s = socket.socket(family, socket.SOCK_DGRAM) |
386 |
success = False
|
387 |
try:
|
388 |
try:
|
389 |
s.bind((address, 0))
|
390 |
success = True
|
391 |
except socket.error:
|
392 |
success = False
|
393 |
finally:
|
394 |
s.close() |
395 |
return success
|
396 |
|
397 |
@classmethod
|
398 |
def InNetwork(cls, cidr, address): |
399 |
"""Determine whether an address is within a network.
|
400 |
|
401 |
@type cidr: string
|
402 |
@param cidr: Network in CIDR notation, e.g. '192.0.2.0/24', '2001:db8::/64'
|
403 |
@type address: str
|
404 |
@param address: IP address
|
405 |
@rtype: bool
|
406 |
@return: True if address is in cidr, False otherwise
|
407 |
|
408 |
"""
|
409 |
address_int = cls._GetIPIntFromString(address) |
410 |
subnet = cidr.split("/")
|
411 |
assert len(subnet) == 2 |
412 |
try:
|
413 |
prefix = int(subnet[1]) |
414 |
except ValueError: |
415 |
return False |
416 |
|
417 |
assert 0 <= prefix <= cls.iplen |
418 |
target_int = cls._GetIPIntFromString(subnet[0])
|
419 |
# Convert prefix netmask to integer value of netmask
|
420 |
netmask_int = (2 ** cls.iplen) - 1 ^ ((2 ** cls.iplen) - 1 >> prefix) |
421 |
# Calculate hostmask
|
422 |
hostmask_int = netmask_int ^ (2 ** cls.iplen) - 1 |
423 |
# Calculate network address by and'ing netmask
|
424 |
network_int = target_int & netmask_int |
425 |
# Calculate broadcast address by or'ing hostmask
|
426 |
broadcast_int = target_int | hostmask_int |
427 |
|
428 |
return network_int <= address_int <= broadcast_int
|
429 |
|
430 |
@staticmethod
|
431 |
def GetAddressFamily(address): |
432 |
"""Get the address family of the given address.
|
433 |
|
434 |
@type address: str
|
435 |
@param address: ip address whose family will be returned
|
436 |
@rtype: int
|
437 |
@return: C{socket.AF_INET} or C{socket.AF_INET6}
|
438 |
@raise errors.GenericError: for invalid addresses
|
439 |
|
440 |
"""
|
441 |
try:
|
442 |
return IP4Address(address).family
|
443 |
except errors.IPAddressError:
|
444 |
pass
|
445 |
|
446 |
try:
|
447 |
return IP6Address(address).family
|
448 |
except errors.IPAddressError:
|
449 |
pass
|
450 |
|
451 |
raise errors.IPAddressError("Invalid address '%s'" % address) |
452 |
|
453 |
@staticmethod
|
454 |
def GetVersionFromAddressFamily(family): |
455 |
"""Convert an IP address family to the corresponding IP version.
|
456 |
|
457 |
@type family: int
|
458 |
@param family: IP address family, one of socket.AF_INET or socket.AF_INET6
|
459 |
@return: an int containing the IP version, one of L{constants.IP4_VERSION}
|
460 |
or L{constants.IP6_VERSION}
|
461 |
@raise errors.ProgrammerError: for unknown families
|
462 |
|
463 |
"""
|
464 |
if family == socket.AF_INET:
|
465 |
return constants.IP4_VERSION
|
466 |
elif family == socket.AF_INET6:
|
467 |
return constants.IP6_VERSION
|
468 |
|
469 |
raise errors.ProgrammerError("%s is not a valid IP address family" % family) |
470 |
|
471 |
@staticmethod
|
472 |
def GetAddressFamilyFromVersion(version): |
473 |
"""Convert an IP version to the corresponding IP address family.
|
474 |
|
475 |
@type version: int
|
476 |
@param version: IP version, one of L{constants.IP4_VERSION} or
|
477 |
L{constants.IP6_VERSION}
|
478 |
@return: an int containing the IP address family, one of C{socket.AF_INET}
|
479 |
or C{socket.AF_INET6}
|
480 |
@raise errors.ProgrammerError: for unknown IP versions
|
481 |
|
482 |
"""
|
483 |
if version == constants.IP4_VERSION:
|
484 |
return socket.AF_INET
|
485 |
elif version == constants.IP6_VERSION:
|
486 |
return socket.AF_INET6
|
487 |
|
488 |
raise errors.ProgrammerError("%s is not a valid IP version" % version) |
489 |
|
490 |
@classmethod
|
491 |
def IsLoopback(cls, address): |
492 |
"""Determine whether it is a loopback address.
|
493 |
|
494 |
@type address: str
|
495 |
@param address: IP address to be checked
|
496 |
@rtype: bool
|
497 |
@return: True if loopback, False otherwise
|
498 |
|
499 |
"""
|
500 |
try:
|
501 |
return cls.InNetwork(cls.loopback_cidr, address)
|
502 |
except errors.IPAddressError:
|
503 |
return False |
504 |
|
505 |
|
506 |
class IP4Address(IPAddress): |
507 |
"""IPv4 address class.
|
508 |
|
509 |
"""
|
510 |
iplen = 32
|
511 |
family = socket.AF_INET |
512 |
loopback_cidr = "127.0.0.0/8"
|
513 |
|
514 |
def __init__(self, address): |
515 |
"""Constructor for IPv4 address.
|
516 |
|
517 |
@type address: str
|
518 |
@param address: IP address
|
519 |
@raises errors.IPAddressError: if address invalid
|
520 |
|
521 |
"""
|
522 |
IPAddress.__init__(self)
|
523 |
if not self.IsValid(address): |
524 |
raise errors.IPAddressError("IPv4 Address %s invalid" % address) |
525 |
|
526 |
self.address = address
|
527 |
|
528 |
@staticmethod
|
529 |
def _GetIPIntFromString(address): |
530 |
"""Get integer value of IPv4 address.
|
531 |
|
532 |
@type address: str
|
533 |
@param address: IPv6 address
|
534 |
@rtype: int
|
535 |
@return: integer value of given IP address
|
536 |
|
537 |
"""
|
538 |
address_int = 0
|
539 |
parts = address.split(".")
|
540 |
assert len(parts) == 4 |
541 |
for part in parts: |
542 |
address_int = (address_int << 8) | int(part) |
543 |
|
544 |
return address_int
|
545 |
|
546 |
|
547 |
class IP6Address(IPAddress): |
548 |
"""IPv6 address class.
|
549 |
|
550 |
"""
|
551 |
iplen = 128
|
552 |
family = socket.AF_INET6 |
553 |
loopback_cidr = "::1/128"
|
554 |
|
555 |
def __init__(self, address): |
556 |
"""Constructor for IPv6 address.
|
557 |
|
558 |
@type address: str
|
559 |
@param address: IP address
|
560 |
@raises errors.IPAddressError: if address invalid
|
561 |
|
562 |
"""
|
563 |
IPAddress.__init__(self)
|
564 |
if not self.IsValid(address): |
565 |
raise errors.IPAddressError("IPv6 Address [%s] invalid" % address) |
566 |
self.address = address
|
567 |
|
568 |
@staticmethod
|
569 |
def _GetIPIntFromString(address): |
570 |
"""Get integer value of IPv6 address.
|
571 |
|
572 |
@type address: str
|
573 |
@param address: IPv6 address
|
574 |
@rtype: int
|
575 |
@return: integer value of given IP address
|
576 |
|
577 |
"""
|
578 |
doublecolons = address.count("::")
|
579 |
assert not doublecolons > 1 |
580 |
if doublecolons == 1: |
581 |
# We have a shorthand address, expand it
|
582 |
parts = [] |
583 |
twoparts = address.split("::")
|
584 |
sep = len(twoparts[0].split(":")) + len(twoparts[1].split(":")) |
585 |
parts = twoparts[0].split(":") |
586 |
parts.extend(["0"] * (8 - sep)) |
587 |
parts += twoparts[1].split(":") |
588 |
else:
|
589 |
parts = address.split(":")
|
590 |
|
591 |
address_int = 0
|
592 |
for part in parts: |
593 |
address_int = (address_int << 16) + int(part or "0", 16) |
594 |
|
595 |
return address_int
|
596 |
|
597 |
|
598 |
def FormatAddress(address, family=None): |
599 |
"""Format a socket address
|
600 |
|
601 |
@type address: family specific (usually tuple)
|
602 |
@param address: address, as reported by this class
|
603 |
@type family: integer
|
604 |
@param family: socket family (one of socket.AF_*) or None
|
605 |
|
606 |
"""
|
607 |
if family is None: |
608 |
try:
|
609 |
family = IPAddress.GetAddressFamily(address[0])
|
610 |
except errors.IPAddressError:
|
611 |
raise errors.ParameterError(address)
|
612 |
|
613 |
if family == socket.AF_UNIX and len(address) == 3: |
614 |
return "pid=%s, uid=%s, gid=%s" % address |
615 |
|
616 |
if family in (socket.AF_INET, socket.AF_INET6) and len(address) == 2: |
617 |
host, port = address |
618 |
if family == socket.AF_INET6:
|
619 |
res = "[%s]" % host
|
620 |
else:
|
621 |
res = host |
622 |
|
623 |
if port is not None: |
624 |
res += ":%s" % port
|
625 |
|
626 |
return res
|
627 |
|
628 |
raise errors.ParameterError(family, address)
|