nfs4_uid_to_name(3)                                                                                          nfs4_uid_to_name(3)



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 correspond-
       ing 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 buf-
       fer 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  corre-
       sponding 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_grou-
       plist_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 mes-
       sages 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)