# # # Copyright (C) 2010 Google Inc. # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, but # WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU # General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA # 02110-1301, USA. """Ganeti network utility module. This module holds functions that can be used in both daemons (all) and the command line scripts. """ import errno import os import re import socket import struct import IN import logging from ganeti import constants from ganeti import errors from ganeti import utils # Structure definition for getsockopt(SOL_SOCKET, SO_PEERCRED, ...): # struct ucred { pid_t pid; uid_t uid; gid_t gid; }; # # The GNU C Library defines gid_t and uid_t to be "unsigned int" and # pid_t to "int". # # IEEE Std 1003.1-2008: # "nlink_t, uid_t, gid_t, and id_t shall be integer types" # "blksize_t, pid_t, and ssize_t shall be signed integer types" _STRUCT_UCRED = "iII" _STRUCT_UCRED_SIZE = struct.calcsize(_STRUCT_UCRED) # Regexes used to find IP addresses in the output of ip. _IP_RE_TEXT = r"[.:a-z0-9]+" # separate for testing purposes _IP_FAMILY_RE = re.compile(r"(?P<family>inet6?)\s+(?P<ip>%s)/" % _IP_RE_TEXT, re.IGNORECASE) # Dict used to convert from a string representing an IP family to an IP # version _NAME_TO_IP_VER = { "inet": constants.IP4_VERSION, "inet6": constants.IP6_VERSION, } def _GetIpAddressesFromIpOutput(ip_output): """Parses the output of the ip command and retrieves the IP addresses and version. @param ip_output: string containing the output of the ip command; @rtype: dict; (int, list) @return: a dict having as keys the IP versions and as values the corresponding list of addresses found in the IP output. """ addr = dict((i, []) for i in _NAME_TO_IP_VER.values()) for row in ip_output.splitlines(): match = _IP_FAMILY_RE.search(row) if match and IPAddress.IsValid(match.group("ip")): addr[_NAME_TO_IP_VER[match.group("family")]].append(match.group("ip")) return addr def GetSocketCredentials(sock): """Returns the credentials of the foreign process connected to a socket. @param sock: Unix socket @rtype: tuple; (number, number, number) @return: The PID, UID and GID of the connected foreign process. """ peercred = sock.getsockopt(socket.SOL_SOCKET, IN.SO_PEERCRED, _STRUCT_UCRED_SIZE) return struct.unpack(_STRUCT_UCRED, peercred) def IsValidInterface(ifname): """Validate an interface name. @type ifname: string @param ifname: Name of the network interface @return: boolean indicating whether the interface name is valid or not. """ return os.path.exists(utils.PathJoin("/sys/class/net", ifname)) def GetInterfaceIpAddresses(ifname): """Returns the IP addresses associated to the interface. @type ifname: string @param ifname: Name of the network interface @return: A dict having for keys the IP version (either L{constants.IP4_VERSION} or L{constants.IP6_VERSION}) and for values the lists of IP addresses of the respective version associated to the interface """ result = utils.RunCmd([constants.IP_COMMAND_PATH, "-o", "addr", "show", ifname]) if result.failed: logging.error("Error running the ip command while getting the IP" " addresses of %s", ifname) return None return _GetIpAddressesFromIpOutput(result.output) def GetHostname(name=None, family=None): """Returns a Hostname object. @type name: str @param name: hostname or None @type family: int @param family: AF_INET | AF_INET6 | None @rtype: L{Hostname} @return: Hostname object @raise errors.OpPrereqError: in case of errors in resolving """ try: return Hostname(name=name, family=family) except errors.ResolverError, err: raise errors.OpPrereqError("The given name (%s) does not resolve: %s" % (err[0], err[2]), errors.ECODE_RESOLVER) class Hostname: """Class implementing resolver and hostname functionality. """ _VALID_NAME_RE = re.compile("^[a-z0-9._-]{1,255}$") def __init__(self, name=None, family=None): """Initialize the host name object. If the name argument is None, it will use this system's name. @type family: int @param family: AF_INET | AF_INET6 | None @type name: str @param name: hostname or None """ self.name = self.GetNormalizedName(self.GetFqdn(name)) self.ip = self.GetIP(self.name, family=family) @classmethod def GetSysName(cls): """Legacy method the get the current system's name. """ return cls.GetFqdn() @staticmethod def GetFqdn(hostname=None): """Return fqdn. If hostname is None the system's fqdn is returned. @type hostname: str @param hostname: name to be fqdn'ed @rtype: str @return: fqdn of given name, if it exists, unmodified name otherwise """ if hostname is None: return socket.getfqdn() else: return socket.getfqdn(hostname) @staticmethod def GetIP(hostname, family=None): """Return IP address of given hostname. Supports both IPv4 and IPv6. @type hostname: str @param hostname: hostname to look up @type family: int @param family: AF_INET | AF_INET6 | None @rtype: str @return: IP address @raise errors.ResolverError: in case of errors in resolving """ try: if family in (socket.AF_INET, socket.AF_INET6): result = socket.getaddrinfo(hostname, None, family) else: result = socket.getaddrinfo(hostname, None) except (socket.gaierror, socket.herror, socket.error), err: # hostname not found in DNS, or other socket exception in the # (code, description format) raise errors.ResolverError(hostname, err.args[0], err.args[1]) # getaddrinfo() returns a list of 5-tupes (family, socktype, proto, # canonname, sockaddr). We return the first tuple's first address in # sockaddr try: return result[0][4][0] except IndexError, err: raise errors.ResolverError("Unknown error in getaddrinfo(): %s" % err) @classmethod def GetNormalizedName(cls, hostname): """Validate and normalize the given hostname. @attention: the validation is a bit more relaxed than the standards require; most importantly, we allow underscores in names @raise errors.OpPrereqError: when the name is not valid """ hostname = hostname.lower() if (not cls._VALID_NAME_RE.match(hostname) or # double-dots, meaning empty label ".." in hostname or # empty initial label hostname.startswith(".")): raise errors.OpPrereqError("Invalid hostname '%s'" % hostname, errors.ECODE_INVAL) if hostname.endswith("."): hostname = hostname.rstrip(".") return hostname def TcpPing(target, port, timeout=10, live_port_needed=False, source=None): """Simple ping implementation using TCP connect(2). Check if the given IP is reachable by doing attempting a TCP connect to it. @type target: str @param target: the IP to ping @type port: int @param port: the port to connect to @type timeout: int @param timeout: the timeout on the connection attempt @type live_port_needed: boolean @param live_port_needed: whether a closed port will cause the function to return failure, as if there was a timeout @type source: str or None @param source: if specified, will cause the connect to be made from this specific source address; failures to bind other than C{EADDRNOTAVAIL} will be ignored """ try: family = IPAddress.GetAddressFamily(target) except errors.GenericError: return False sock = socket.socket(family, socket.SOCK_STREAM) success = False if source is not None: try: sock.bind((source, 0)) except socket.error, (errcode, _): if errcode == errno.EADDRNOTAVAIL: success = False sock.settimeout(timeout) try: sock.connect((target, port)) sock.close() success = True except socket.timeout: success = False except socket.error, (errcode, _): success = (not live_port_needed) and (errcode == errno.ECONNREFUSED) return success def GetDaemonPort(daemon_name): """Get the daemon port for this cluster. Note that this routine does not read a ganeti-specific file, but instead uses C{socket.getservbyname} to allow pre-customization of this parameter outside of Ganeti. @type daemon_name: string @param daemon_name: daemon name (in constants.DAEMONS_PORTS) @rtype: int """ if daemon_name not in constants.DAEMONS_PORTS: raise errors.ProgrammerError("Unknown daemon: %s" % daemon_name) (proto, default_port) = constants.DAEMONS_PORTS[daemon_name] try: port = socket.getservbyname(daemon_name, proto) except socket.error: port = default_port return port class IPAddress(object): """Class that represents an IP address. """ iplen = 0 family = None loopback_cidr = None @staticmethod def _GetIPIntFromString(address): """Abstract method to please pylint. """ raise NotImplementedError @classmethod def IsValid(cls, address): """Validate a IP address. @type address: str @param address: IP address to be checked @rtype: bool @return: True if valid, False otherwise """ if cls.family is None: try: family = cls.GetAddressFamily(address) except errors.IPAddressError: return False else: family = cls.family try: socket.inet_pton(family, address) return True except socket.error: return False @classmethod def ValidateNetmask(cls, netmask): """Validate a netmask suffix in CIDR notation. @type netmask: int @param netmask: netmask suffix to validate @rtype: bool @return: True if valid, False otherwise """ assert (isinstance(netmask, (int, long))) return 0 < netmask <= cls.iplen @classmethod def Own(cls, address): """Check if the current host has the the given IP address. This is done by trying to bind the given address. We return True if we succeed or false if a socket.error is raised. @type address: str @param address: IP address to be checked @rtype: bool @return: True if we own the address, False otherwise """ if cls.family is None: try: family = cls.GetAddressFamily(address) except errors.IPAddressError: return False else: family = cls.family s = socket.socket(family, socket.SOCK_DGRAM) success = False try: try: s.bind((address, 0)) success = True except socket.error: success = False finally: s.close() return success @classmethod def InNetwork(cls, cidr, address): """Determine whether an address is within a network. @type cidr: string @param cidr: Network in CIDR notation, e.g. '192.0.2.0/24', '2001:db8::/64' @type address: str @param address: IP address @rtype: bool @return: True if address is in cidr, False otherwise """ address_int = cls._GetIPIntFromString(address) subnet = cidr.split("/") assert len(subnet) == 2 try: prefix = int(subnet[1]) except ValueError: return False assert 0 <= prefix <= cls.iplen target_int = cls._GetIPIntFromString(subnet[0]) # Convert prefix netmask to integer value of netmask netmask_int = (2 ** cls.iplen) - 1 ^ ((2 ** cls.iplen) - 1 >> prefix) # Calculate hostmask hostmask_int = netmask_int ^ (2 ** cls.iplen) - 1 # Calculate network address by and'ing netmask network_int = target_int & netmask_int # Calculate broadcast address by or'ing hostmask broadcast_int = target_int | hostmask_int return network_int <= address_int <= broadcast_int @staticmethod def GetAddressFamily(address): """Get the address family of the given address. @type address: str @param address: ip address whose family will be returned @rtype: int @return: C{socket.AF_INET} or C{socket.AF_INET6} @raise errors.GenericError: for invalid addresses """ try: return IP4Address(address).family except errors.IPAddressError: pass try: return IP6Address(address).family except errors.IPAddressError: pass raise errors.IPAddressError("Invalid address '%s'" % address) @staticmethod def GetVersionFromAddressFamily(family): """Convert an IP address family to the corresponding IP version. @type family: int @param family: IP address family, one of socket.AF_INET or socket.AF_INET6 @return: an int containing the IP version, one of L{constants.IP4_VERSION} or L{constants.IP6_VERSION} @raise errors.ProgrammerError: for unknown families """ if family == socket.AF_INET: return constants.IP4_VERSION elif family == socket.AF_INET6: return constants.IP6_VERSION raise errors.ProgrammerError("%s is not a valid IP address family" % family) @staticmethod def GetAddressFamilyFromVersion(version): """Convert an IP version to the corresponding IP address family. @type version: int @param version: IP version, one of L{constants.IP4_VERSION} or L{constants.IP6_VERSION} @return: an int containing the IP address family, one of C{socket.AF_INET} or C{socket.AF_INET6} @raise errors.ProgrammerError: for unknown IP versions """ if version == constants.IP4_VERSION: return socket.AF_INET elif version == constants.IP6_VERSION: return socket.AF_INET6 raise errors.ProgrammerError("%s is not a valid IP version" % version) @staticmethod def GetClassFromIpVersion(version): """Return the IPAddress subclass for the given IP version. @type version: int @param version: IP version, one of L{constants.IP4_VERSION} or L{constants.IP6_VERSION} @return: a subclass of L{netutils.IPAddress} @raise errors.ProgrammerError: for unknowo IP versions """ if version == constants.IP4_VERSION: return IP4Address elif version == constants.IP6_VERSION: return IP6Address raise errors.ProgrammerError("%s is not a valid IP version" % version) @staticmethod def GetClassFromIpFamily(family): """Return the IPAddress subclass for the given IP family. @param family: IP family (one of C{socket.AF_INET} or C{socket.AF_INET6} @return: a subclass of L{netutils.IPAddress} @raise errors.ProgrammerError: for unknowo IP versions """ return IPAddress.GetClassFromIpVersion( IPAddress.GetVersionFromAddressFamily(family)) @classmethod def IsLoopback(cls, address): """Determine whether it is a loopback address. @type address: str @param address: IP address to be checked @rtype: bool @return: True if loopback, False otherwise """ try: return cls.InNetwork(cls.loopback_cidr, address) except errors.IPAddressError: return False class IP4Address(IPAddress): """IPv4 address class. """ iplen = 32 family = socket.AF_INET loopback_cidr = "127.0.0.0/8" def __init__(self, address): """Constructor for IPv4 address. @type address: str @param address: IP address @raises errors.IPAddressError: if address invalid """ IPAddress.__init__(self) if not self.IsValid(address): raise errors.IPAddressError("IPv4 Address %s invalid" % address) self.address = address @staticmethod def _GetIPIntFromString(address): """Get integer value of IPv4 address. @type address: str @param address: IPv6 address @rtype: int @return: integer value of given IP address """ address_int = 0 parts = address.split(".") assert len(parts) == 4 for part in parts: address_int = (address_int << 8) | int(part) return address_int class IP6Address(IPAddress): """IPv6 address class. """ iplen = 128 family = socket.AF_INET6 loopback_cidr = "::1/128" def __init__(self, address): """Constructor for IPv6 address. @type address: str @param address: IP address @raises errors.IPAddressError: if address invalid """ IPAddress.__init__(self) if not self.IsValid(address): raise errors.IPAddressError("IPv6 Address [%s] invalid" % address) self.address = address @staticmethod def _GetIPIntFromString(address): """Get integer value of IPv6 address. @type address: str @param address: IPv6 address @rtype: int @return: integer value of given IP address """ doublecolons = address.count("::") assert not doublecolons > 1 if doublecolons == 1: # We have a shorthand address, expand it parts = [] twoparts = address.split("::") sep = len(twoparts[0].split(":")) + len(twoparts[1].split(":")) parts = twoparts[0].split(":") parts.extend(["0"] * (8 - sep)) parts += twoparts[1].split(":") else: parts = address.split(":") address_int = 0 for part in parts: address_int = (address_int << 16) + int(part or "0", 16) return address_int def FormatAddress(address, family=None): """Format a socket address @type address: family specific (usually tuple) @param address: address, as reported by this class @type family: integer @param family: socket family (one of socket.AF_*) or None """ if family is None: try: family = IPAddress.GetAddressFamily(address[0]) except errors.IPAddressError: raise errors.ParameterError(address) if family == socket.AF_UNIX and len(address) == 3: return "pid=%s, uid=%s, gid=%s" % address if family in (socket.AF_INET, socket.AF_INET6) and len(address) == 2: host, port = address if family == socket.AF_INET6: res = "[%s]" % host else: res = host if port is not None: res += ":%s" % port return res raise errors.ParameterError(family, address)