NAME

       selinux_set_mapping - establish dynamic object class and permission mapping

SYNOPSIS

       #include <selinux/selinux.h>

       struct security_class_mapping {
            const char *name;
            const char *perms[];
       };

       int selinux_set_mapping(struct security_class_mapping *map);

DESCRIPTION

       selinux_set_mapping()  establishes  a  mapping  from  a  user-provided  ordering of object
       classes and permissions to the numbers actually used by the loaded system policy. If using
       this   function,  applications  should  also  set  a  SELINUX_CB_POLICYLOAD  callback  via
       selinux_set_callback(3) that calls this function again upon a policy reload  to  re-create
       the mapping in case the class or permission values change in the new policy.  Generally it
       is  preferred  to  instead  use  selinux_check_access(3)  instead  of  avc_has_perm(3)  or
       security_compute_av(3) and not use this function at all.

       After  the  mapping  is  established,  all  libselinux functions that operate on class and
       permission values take the user-provided numbers, which are determined as follows:

       The map argument consists of an array of security_class_mapping structures, which must  be
       terminated  by  a structure having a NULL name field.  Except for this last structure, the
       name field should refer to the string name of an object class, and the corresponding perms
       field should refer to an array of permission bit names terminated by a NULL string.

       The object classes named in the mapping and the bit indexes of each set of permission bits
       named in the mapping are numbered in order starting from 1.  These numbers are the  values
       that should be passed to subsequent libselinux calls.

RETURN VALUE

       Zero is returned on success.  On error, -1 is returned and errno is set appropriately.

ERRORS

       EINVAL One of the class or permission names requested in the mapping is not present in the
              loaded policy.

       ENOMEM An attempt to allocate memory failed.

EXAMPLE

              struct security_class_mapping map[] = {
                  { "file", { "create", "unlink", "read", "write", NULL } },
                  { "socket", { "bind", NULL } },
                  { "process", { "signal", NULL } },
                  { NULL }
              };

              if (selinux_set_mapping(map) < 0)
                  exit(1);

       In this example, after the call has succeeded, classes file, socket, and process  will  be
       identified  by 1, 2 and 3, respectively.  Permissions create, unlink, read, and write (for
       the file class) will  be  identified  by  1,  2,  4,  and  8  respectively.   Classes  and
       permissions not listed in the mapping cannot be used.

AUTHOR

       Originally Eamon Walsh.  Updated by Stephen Smalley <sds@tycho.nsa.gov>

SEE ALSO

       selinux_check_access(3), selinux_set_callback(3), avc_has_perm(3), selinux(8)

                                           12 Jun 2008                     selinux_set_mapping(3)