org.apache.hadoop.security
Class JniBasedUnixGroupsNetgroupMapping

java.lang.Object
  org.apache.hadoop.security.JniBasedUnixGroupsMapping
      org.apache.hadoop.security.JniBasedUnixGroupsNetgroupMapping

public class JniBasedUnixGroupsNetgroupMapping
extends JniBasedUnixGroupsMapping

A JNI-based implementation of GroupMappingServiceProvider that invokes libC calls to get the group memberships of a given user.

Constructor Summary

JniBasedUnixGroupsNetgroupMapping()

Method Summary

void	cacheGroupsAdd(List<String> groups) Caches the group user information
void	cacheGroupsRefresh() Refresh the cache of groups and user mapping
List<String>	getGroups(String user) Gets unix groups and netgroups for the user.
protected List<String>	getUsersForNetgroup(String netgroup) Calls JNI function to get users for a netgroup, since C functions are not reentrant we need to make this synchronized (see documentation for setnetgrent, getnetgrent and endnetgrent)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

JniBasedUnixGroupsNetgroupMapping

public JniBasedUnixGroupsNetgroupMapping()

Method Detail

getGroups

public List<String> getGroups(String user)
                       throws IOException

Gets unix groups and netgroups for the user. It gets all unix groups as returned by id -Gn but it only returns netgroups that are used in ACLs (there is no way to get all netgroups for a given user, see documentation for getent netgroup)

Overrides:

getGroups in class JniBasedUnixGroupsMapping

Parameters:

user - User's name

Returns:

group memberships of user

Throws:

IOException

cacheGroupsRefresh

public void cacheGroupsRefresh()
                        throws IOException

Refresh the cache of groups and user mapping

Overrides:

cacheGroupsRefresh in class JniBasedUnixGroupsMapping

Throws:

IOException

cacheGroupsAdd

public void cacheGroupsAdd(List<String> groups)
                    throws IOException

Caches the group user information

Overrides:

cacheGroupsAdd in class JniBasedUnixGroupsMapping

Parameters:

groups - list of groups to add to cache

Throws:

IOException

getUsersForNetgroup

protected List<String> getUsersForNetgroup(String netgroup)

Calls JNI function to get users for a netgroup, since C functions are not reentrant we need to make this synchronized (see documentation for setnetgrent, getnetgrent and endnetgrent)