CIFS.IDMAP(8)						    System Administration tools 					     CIFS.IDMAP(8)

NAME

       cifs.idmap - Userspace helper for mapping ids for Common Internet File System (CIFS)

SYNOPSIS

       cifs.idmap [--version|-v] {keyid}

DESCRIPTION

       This tool is part of the cifs-utils suite.

       cifs.idmap is a userspace helper program for the linux CIFS client filesystem. There are a number of activities that the kernel cannot
       easily do itself. This program is a callout program that does these things for the kernel and then returns the result.

       cifs.idmap is generally intended to be run when the kernel calls request-key(8) for a particular key type. While it can be run directly
       from the command-line, it is not generally intended to be run that way.

       cifs.idmap works in conjuction with winbind facility of Samba suite to map owner and group SIDs to uids and gids respectively.  It is best
       utilized when
       - a mount option of cifsacl is specified when mounting a cifs share
       - winbind is specified as one of the search entries for passwd and group databases in file /etc/nsswitch.conf
       - file smb.conf has winbind specific entries
       - winbind daemon program is running

       In case winbind and cifs.idmap facilities are unavailable, file objects in a mounted share are assigned uid and gid of the credentials of
       the process that mounted the share. So it is strongly recomemended to use mount options of uid and gid to specify a default uid and gid to
       map owner SIDs and group SIDs respectively in case services of winbind and cifs.idmap facility are unavailable.

OPTIONS

       --version|-v
	   Print version number and exit.

CONFIGURATION FOR KEYCTL

       cifs.idmap is designed to be called from the kernel via the request-key callout program. This requires that request-key be told where and
       how to call this program. Currently cifs.idmap handles a key type of:

       cifs.idmap
	   This keytype is for mapping a SID to either an uid or a gid

       To make this program useful for CIFS, you will need to set up entry for it in request-key.conf(5). Here is an example of an entry for this
       key type:

	   #OPERATION  TYPE	      D C PROGRAM ARG1 ARG2...
	   #=========  =============  = = ================================
	   create      cifs.idmap     * * /usr/sbin/cifs.idmap %k

       See request-key.conf(5) for more info on each field.

NOTES

       Support for upcalls to cifs.idmap was initially introduced in the 3.0 kernel.

SEE ALSO

       request-key.conf(5), mount.cifs(8)

AUTHOR

       Shirish Pargaonkar wrote the cifs.idmap program.

       The Linux CIFS Mailing list is the preferred place to ask questions regarding these programs.

cifs-utils							    05/26/2011							     CIFS.IDMAP(8)