nfs4uidtoname(3) Library Functions Manual nfs4uidtoname(3)

NAME
       nfs4uidtoname, nfs4gidtoname, nfs4nametouid, nfs4nametogid,
       nfs4initnamemapping, nfs4getdefaultdomain, nfs4gssprinctoids,
       nfs4gssprinctogrouplist,                  nfs4gssprinctoidsex,
       nfs4gssprinctogrouplistex, nfs4setdebug -  ID  mapping  routines
       used for NFSv4

SYNOPSIS
       #include 

       int nfs4initnamemapping(char *conffile);

       int nfs4getdefaultdomain(char *server, char *domain, sizet len);

       int nfs4uidtoname(uidt uid, char *domain, char *name, sizet len);

       int nfs4uidtoowner(uidt uid, char *domain, char *name, sizet len);

       int nfs4gidtoname(gidt gid, char *domain, char *name, sizet len);

       int nfs4gidtoowner(gidt gid, char *domain, char *name, sizet len);

       int nfs4nametouid(char *name, uidt *uid);

       int nfs4nametogid(char *name, gidt *gid);

       int nfs4ownertouid(char *name, uidt *uid);

       int nfs4ownertogid(char *name, gidt *gid);

       int nfs4gssprinctoids(char *secname, char *princ, uidt *uid, gidt
       *gid);

       int  nfs4gssprinctogrouplist(char  *secname,  char  *princ,   gidt
       *groups, int *ngroups);

       int  nfs4gssprinctoidsex(char  *secname,  char *princ, uidt *uid,
       gidt *gid, extramappingparams **ex);

       int nfs4gssprinctogrouplistex(char *secname,  char  *princ,  gidt
       *groups, int *ngroups, extramappingparams **ex);

       void nfs4setdebug(int dbglevel, 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  nfs4uidtoname()  and nfs4gidtoname() 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 nfs4uidtoowner() and nfs4gidtogroupowner() functions,  given
       uid  or  gid and domain (as a null-terminated string), write the corre‐
       sponding 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 nfs4nametouid() and nfs4nametogid() functions, given name (as
       a null-terminated string), return the corresponding uid or gid  in  the
       second parameter.

       The  nfs4ownertouid() and nfs4groupownertogid() 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  nfs4initnamemapping()  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  nfs4getdefaultdomain()
       which should be called with server set to NULL.  The domain should be a
       buffer of length len.  The constant NFS4MAXDOMAINLEN may be used  to
       determine a reasonable value for that length.

       The  function  nfs4getgrouplist(),  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    nfs4gssprinctoids(),    nfs4gssprinctogrouplist(),
       nfs4gssprinctoidsex(),  and  nfs4gssprinctogrouplistex()  are
       used to convert from a gss principal  name  (as  returned  by  gssdis‐
       playname()) to a uid and gid, or list of gids.

       Finally,  nfs4setdebug()  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  func‐
       tion within the library.

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



                                  2004-08-05               nfs4uidtoname(3)