org.apache.hadoop.security

Class JniBasedUnixGroupsNetgroupMapping

java.lang.Object

org.apache.hadoop.security.JniBasedUnixGroupsMapping

org.apache.hadoop.security.JniBasedUnixGroupsNetgroupMapping

All Implemented Interfaces:

GroupMappingServiceProvider

@InterfaceAudience.LimitedPrivate(value={"HDFS","MapReduce"})
@InterfaceStability.Evolving
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

Constructors

Constructor and Description
JniBasedUnixGroupsNetgroupMapping()

Method Summary

Methods

Modifier and Type	Method and Description
void	cacheGroupsAdd(List<String> groups) Add a group to cache, only netgroups are cached
void	cacheGroupsRefresh() Refresh the netgroup cache
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)

Specified by:

getGroups in interface GroupMappingServiceProvider

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 netgroup cache

Specified by:

cacheGroupsRefresh in interface GroupMappingServiceProvider

Overrides:

cacheGroupsRefresh in class JniBasedUnixGroupsMapping

Throws:

IOException

cacheGroupsAdd

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

Add a group to cache, only netgroups are cached

Specified by:

cacheGroupsAdd in interface GroupMappingServiceProvider

Overrides:

cacheGroupsAdd in class JniBasedUnixGroupsMapping

Parameters:

groups - list of group names 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)

Parameters:

netgroup - return users for this netgroup

Returns:

list of users for a given netgroup