Small improvements for cluster verify

[ganeti-local] / lib / netutils.py

diff --git a/lib/netutils.py b/lib/netutils.py
index 8b51e46..11d5150 100644 (file)
--- a/lib/netutils.py
+++ b/lib/netutils.py
@@ -28,13 +28,16 @@ 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; };
@@ -48,6 +51,38 @@ from ganeti import errors
 _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.
@@ -62,6 +97,39 @@ def GetSocketCredentials(sock):
   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.
 
@@ -366,7 +434,7 @@ class IPAddress(object):
     @type address: str
     @param address: ip address whose family will be returned
     @rtype: int
-    @return: socket.AF_INET or socket.AF_INET6
+    @return: C{socket.AF_INET} or C{socket.AF_INET6}
     @raise errors.GenericError: for invalid addresses
 
     """
@@ -382,6 +450,43 @@ class IPAddress(object):
 
     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)
+
   @classmethod
   def IsLoopback(cls, address):
     """Determine whether it is a loopback address.