NAME

       nfs4_uid_to_name,        nfs4_gid_to_name,       nfs4_name_to_uid,       nfs4_name_to_gid,
       nfs4_init_name_mapping,          nfs4_get_default_domain,           nfs4_gss_princ_to_ids,
       nfs4_gss_princ_to_grouplist,   nfs4_gss_princ_to_ids_ex,   nfs4_gss_princ_to_grouplist_ex,
       nfs4_set_debug - ID mapping routines used for NFSv4

SYNOPSIS

       #include <nfs4_idmap.h>

       int nfs4_init_name_mapping(char *conffile);

       int nfs4_get_default_domain(char *server, char *domain, size_t len);

       int nfs4_uid_to_name(uid_t uid, char *domain, char *name, size_t len);

       int nfs4_uid_to_owner(uid_t uid, char *domain, char *name, size_t len);

       int nfs4_gid_to_name(gid_t gid, char *domain, char *name, size_t len);

       int nfs4_gid_to_owner(gid_t gid, char *domain, char *name, size_t len);

       int nfs4_name_to_uid(char *name, uid_t *uid);

       int nfs4_name_to_gid(char *name, gid_t *gid);

       int nfs4_owner_to_uid(char *name, uid_t *uid);

       int nfs4_owner_to_gid(char *name, gid_t *gid);

       int nfs4_gss_princ_to_ids(char *secname, char *princ, uid_t *uid, gid_t *gid);

       int nfs4_gss_princ_to_grouplist(char *secname, char *princ, gid_t *groups, int *ngroups);

       int  nfs4_gss_princ_to_ids_ex(char  *secname,  char  *princ,  uid_t  *uid,   gid_t   *gid,
       extra_mapping_params **ex);

       int   nfs4_gss_princ_to_grouplist_ex(char   *secname,  char  *princ,  gid_t  *groups,  int
       *ngroups, extra_mapping_params **ex);

       void nfs4_set_debug(int dbg_level, void (*logger)(const char *, ...));

DESCRIPTION

       NFSv4 uses names of the form user@domain.  To write code that helps the kernel  map  uid's
       (as  rpc.idmapd does) or that processes NFSv4 ACLs, you need to be able to convert between
       NFSv4 names and local uids and gids.

       The nfs4_uid_to_name() and nfs4_gid_to_name() functions, given uid or gid and domain (as a
       null-terminated  string),  write  the corresponding nfsv4 name into the buffer provided in
       name, which must be of length at least len.

       The nfs4_uid_to_owner() and nfs4_gid_to_group_owner() functions,  given  uid  or  gid  and
       domain  (as  a null-terminated string), write the corresponding nfsv4 name into the buffer
       provided in name, which must be of length at least len.  If there is no valid mapping from
       uid or gid to name, then the numerical string representing uid or gid is returned instead.

       The  nfs4_name_to_uid() and nfs4_name_to_gid() functions, given name (as a null-terminated
       string), return the corresponding uid or gid in the second parameter.

       The nfs4_owner_to_uid() and nfs4_group_owner_to_gid() functions, given name  (as  a  null-
       terminated string), return the corresponding uid or gid in the second parameter.  If there
       is no valid mapping from name to uid or gid the value for the user or group "nobody"  will
       be returned instead.

       The  nfs4_init_name_mapping() function must be called before using any of these functions.
       It  reads  defaults  from  the  configuration  file  at   the   provided   path,   usually
       "etc/idmapd.conf".

       The  domain  argument  to  the id-to-name functions is there to provide a hint to the name
       mapper in the case where an id might be mapped to names  in  multiple  domains.   In  most
       cases,  this  argument  should  just  be  the  name  returned  in  the  domain argument to
       nfs4_get_default_domain() which should be called with server  set  to  NULL.   The  domain
       should  be  a  buffer  of  length  len.   The  constant NFS4_MAX_DOMAIN_LEN may be used to
       determine a reasonable value for that length.

       The function nfs4_get_grouplist(), given a name, fills the provided array groups  with  up
       to *ngroups group IDs corresponding to which the user name belongs to, setting *ngroups to
       the actual number of such groups.  If the user belongs to more than *ngroups groups,  then
       an error is returned and the actual number of groups is stored in *ngroups.

       Functions              nfs4_gss_princ_to_ids(),             nfs4_gss_princ_to_grouplist(),
       nfs4_gss_princ_to_ids_ex(), and nfs4_gss_princ_to_grouplist_ex() are used to convert  from
       a  gss  principal  name  (as  returned by gss_display_name()) to a uid and gid, or list of
       gids.

       Finally, nfs4_set_debug() allows the application to set a debugging level to produce extra
       debugging  information from within the library.  The optional logger function specifies an
       alternative logging function to call for  the  debug  messages  rather  than  the  default
       internal function within the library.

RETURN VALUE

       All functions return 0 or, in the case of error, -ERRNO.

                                            2004-08-05                        nfs4_uid_to_name(3)