NAME

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

SYNOPSIS

       cifs.idmap [--help|-h] [--timeout|-t] [--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.

       This program is only called if a share is mounted with the cifsaclmount option. The kernel
       will only upcall to do this conversion if that mount option is specified.

       cifs.idmap relies on a plugin to handle the ID mapping. If it can't find the  plugin  then
       it   will   not   work   properly.   The   plugin   (or  a  symlink  to  it)  must  be  at
       /etc/cifs-utils/idmap-plugin.

       In the case where cifs.idmap or the plugin are unavailable,  file  objects  in  a  mounted
       share  are  assigned uid and gid of the credentials of the process that mounted the share.
       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 in this situation.

OPTIONS

       --help|-h
          Print the usage message and exit.

       --timeout|-t
          Set  the  expiration  timer,  in  seconds  on  the  key. The default is 600 seconds (10
          minutes). Setting this to 0 will cause the key to never expire.

       --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.IDMAP(8)