4 # Copyright (C) 2010 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 network utility module.
24 This module holds functions that can be used in both daemons (all) and
25 the command line scripts.
38 from ganeti import constants
39 from ganeti import errors
40 from ganeti import utils
42 # Structure definition for getsockopt(SOL_SOCKET, SO_PEERCRED, ...):
43 # struct ucred { pid_t pid; uid_t uid; gid_t gid; };
45 # The GNU C Library defines gid_t and uid_t to be "unsigned int" and
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"
52 _STRUCT_UCRED_SIZE = struct.calcsize(_STRUCT_UCRED)
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,
59 # Dict used to convert from a string representing an IP family to an IP
62 "inet": constants.IP4_VERSION,
63 "inet6": constants.IP6_VERSION,
67 def _GetIpAddressesFromIpOutput(ip_output):
68 """Parses the output of the ip command and retrieves the IP addresses and
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.
77 addr = dict((i, []) for i in _NAME_TO_IP_VER.values())
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"))
87 def GetSocketCredentials(sock):
88 """Returns the credentials of the foreign process connected to a socket.
90 @param sock: Unix socket
91 @rtype: tuple; (number, number, number)
92 @return: The PID, UID and GID of the connected foreign process.
95 peercred = sock.getsockopt(socket.SOL_SOCKET, IN.SO_PEERCRED,
97 return struct.unpack(_STRUCT_UCRED, peercred)
100 def IsValidInterface(ifname):
101 """Validate an interface name.
104 @param ifname: Name of the network interface
105 @return: boolean indicating whether the interface name is valid or not.
108 return os.path.exists(utils.PathJoin("/sys/class/net", ifname))
111 def GetInterfaceIpAddresses(ifname):
112 """Returns the IP addresses associated to the interface.
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
122 result = utils.RunCmd([constants.IP_COMMAND_PATH, "-o", "addr", "show",
126 logging.error("Error running the ip command while getting the IP"
127 " addresses of %s", ifname)
130 return _GetIpAddressesFromIpOutput(result.output)
133 def GetHostname(name=None, family=None):
134 """Returns a Hostname object.
137 @param name: hostname or None
139 @param family: AF_INET | AF_INET6 | None
141 @return: Hostname object
142 @raise errors.OpPrereqError: in case of errors in resolving
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)
153 """Class implementing resolver and hostname functionality.
156 _VALID_NAME_RE = re.compile("^[a-z0-9._-]{1,255}$")
158 def __init__(self, name=None, family=None):
159 """Initialize the host name object.
161 If the name argument is None, it will use this system's name.
164 @param family: AF_INET | AF_INET6 | None
166 @param name: hostname or None
169 self.name = self.GetNormalizedName(self.GetFqdn(name))
170 self.ip = self.GetIP(self.name, family=family)
174 """Legacy method the get the current system's name.
180 def GetFqdn(hostname=None):
183 If hostname is None the system's fqdn is returned.
186 @param hostname: name to be fqdn'ed
188 @return: fqdn of given name, if it exists, unmodified name otherwise
192 return socket.getfqdn()
194 return socket.getfqdn(hostname)
197 def GetIP(hostname, family=None):
198 """Return IP address of given hostname.
200 Supports both IPv4 and IPv6.
203 @param hostname: hostname to look up
205 @param family: AF_INET | AF_INET6 | None
208 @raise errors.ResolverError: in case of errors in resolving
212 if family in (socket.AF_INET, socket.AF_INET6):
213 result = socket.getaddrinfo(hostname, None, family)
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])
221 # getaddrinfo() returns a list of 5-tupes (family, socktype, proto,
222 # canonname, sockaddr). We return the first tuple's first address in
225 return result[0][4][0]
226 except IndexError, err:
227 raise errors.ResolverError("Unknown error in getaddrinfo(): %s" % err)
230 def GetNormalizedName(cls, hostname):
231 """Validate and normalize the given hostname.
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
238 hostname = hostname.lower()
239 if (not cls._VALID_NAME_RE.match(hostname) or
240 # double-dots, meaning empty label
242 # empty initial label
243 hostname.startswith(".")):
244 raise errors.OpPrereqError("Invalid hostname '%s'" % hostname,
246 if hostname.endswith("."):
247 hostname = hostname.rstrip(".")
251 def TcpPing(target, port, timeout=10, live_port_needed=False, source=None):
252 """Simple ping implementation using TCP connect(2).
254 Check if the given IP is reachable by doing attempting a TCP connect
258 @param target: the IP to ping
260 @param port: the port to connect to
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
273 family = IPAddress.GetAddressFamily(target)
274 except errors.GenericError:
277 sock = socket.socket(family, socket.SOCK_STREAM)
280 if source is not None:
282 sock.bind((source, 0))
283 except socket.error, (errcode, _):
284 if errcode == errno.EADDRNOTAVAIL:
287 sock.settimeout(timeout)
290 sock.connect((target, port))
293 except socket.timeout:
295 except socket.error, (errcode, _):
296 success = (not live_port_needed) and (errcode == errno.ECONNREFUSED)
301 def GetDaemonPort(daemon_name):
302 """Get the daemon port for this cluster.
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.
308 @type daemon_name: string
309 @param daemon_name: daemon name (in constants.DAEMONS_PORTS)
313 if daemon_name not in constants.DAEMONS_PORTS:
314 raise errors.ProgrammerError("Unknown daemon: %s" % daemon_name)
316 (proto, default_port) = constants.DAEMONS_PORTS[daemon_name]
318 port = socket.getservbyname(daemon_name, proto)
325 class IPAddress(object):
326 """Class that represents an IP address.
334 def _GetIPIntFromString(address):
335 """Abstract method to please pylint.
338 raise NotImplementedError
341 def IsValid(cls, address):
342 """Validate a IP address.
345 @param address: IP address to be checked
347 @return: True if valid, False otherwise
350 if cls.family is None:
352 family = cls.GetAddressFamily(address)
353 except errors.IPAddressError:
359 socket.inet_pton(family, address)
365 def Own(cls, address):
366 """Check if the current host has the the given IP address.
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.
372 @param address: IP address to be checked
374 @return: True if we own the address, False otherwise
377 if cls.family is None:
379 family = cls.GetAddressFamily(address)
380 except errors.IPAddressError:
385 s = socket.socket(family, socket.SOCK_DGRAM)
398 def InNetwork(cls, cidr, address):
399 """Determine whether an address is within a network.
402 @param cidr: Network in CIDR notation, e.g. '192.0.2.0/24', '2001:db8::/64'
404 @param address: IP address
406 @return: True if address is in cidr, False otherwise
409 address_int = cls._GetIPIntFromString(address)
410 subnet = cidr.split("/")
411 assert len(subnet) == 2
413 prefix = int(subnet[1])
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)
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
428 return network_int <= address_int <= broadcast_int
431 def GetAddressFamily(address):
432 """Get the address family of the given address.
435 @param address: ip address whose family will be returned
437 @return: C{socket.AF_INET} or C{socket.AF_INET6}
438 @raise errors.GenericError: for invalid addresses
442 return IP4Address(address).family
443 except errors.IPAddressError:
447 return IP6Address(address).family
448 except errors.IPAddressError:
451 raise errors.IPAddressError("Invalid address '%s'" % address)
454 def GetVersionFromAddressFamily(family):
455 """Convert an IP address family to the corresponding IP version.
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
464 if family == socket.AF_INET:
465 return constants.IP4_VERSION
466 elif family == socket.AF_INET6:
467 return constants.IP6_VERSION
469 raise errors.ProgrammerError("%s is not a valid IP address family" % family)
472 def GetAddressFamilyFromVersion(version):
473 """Convert an IP version to the corresponding IP address family.
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
483 if version == constants.IP4_VERSION:
484 return socket.AF_INET
485 elif version == constants.IP6_VERSION:
486 return socket.AF_INET6
488 raise errors.ProgrammerError("%s is not a valid IP version" % version)
491 def IsLoopback(cls, address):
492 """Determine whether it is a loopback address.
495 @param address: IP address to be checked
497 @return: True if loopback, False otherwise
501 return cls.InNetwork(cls.loopback_cidr, address)
502 except errors.IPAddressError:
506 class IP4Address(IPAddress):
507 """IPv4 address class.
511 family = socket.AF_INET
512 loopback_cidr = "127.0.0.0/8"
514 def __init__(self, address):
515 """Constructor for IPv4 address.
518 @param address: IP address
519 @raises errors.IPAddressError: if address invalid
522 IPAddress.__init__(self)
523 if not self.IsValid(address):
524 raise errors.IPAddressError("IPv4 Address %s invalid" % address)
526 self.address = address
529 def _GetIPIntFromString(address):
530 """Get integer value of IPv4 address.
533 @param address: IPv6 address
535 @return: integer value of given IP address
539 parts = address.split(".")
540 assert len(parts) == 4
542 address_int = (address_int << 8) | int(part)
547 class IP6Address(IPAddress):
548 """IPv6 address class.
552 family = socket.AF_INET6
553 loopback_cidr = "::1/128"
555 def __init__(self, address):
556 """Constructor for IPv6 address.
559 @param address: IP address
560 @raises errors.IPAddressError: if address invalid
563 IPAddress.__init__(self)
564 if not self.IsValid(address):
565 raise errors.IPAddressError("IPv6 Address [%s] invalid" % address)
566 self.address = address
569 def _GetIPIntFromString(address):
570 """Get integer value of IPv6 address.
573 @param address: IPv6 address
575 @return: integer value of given IP address
578 doublecolons = address.count("::")
579 assert not doublecolons > 1
580 if doublecolons == 1:
581 # We have a shorthand address, expand it
583 twoparts = address.split("::")
584 sep = len(twoparts[0].split(":")) + len(twoparts[1].split(":"))
585 parts = twoparts[0].split(":")
586 [parts.append("0") for _ in range(8 - sep)]
587 parts += twoparts[1].split(":")
589 parts = address.split(":")
593 address_int = (address_int << 16) + int(part or "0", 16)
598 def FormatAddress(address, family=None):
599 """Format a socket address
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
609 family = IPAddress.GetAddressFamily(address[0])
610 except errors.IPAddressError:
611 raise errors.ParameterError(address)
613 if family == socket.AF_UNIX and len(address) == 3:
614 return "pid=%s, uid=%s, gid=%s" % address
616 if family in (socket.AF_INET, socket.AF_INET6) and len(address) == 2:
618 if family == socket.AF_INET6:
628 raise errors.ParameterError(family, address)