k_unlog(3)

NAME

     k_hasafs, k_hasafs_recheck, k_pioctl, k_unlog, k_setpag,
     k_afs_cell_of_file, kafs_set_verbose, kafs_settoken_rxkad, kafs_settoken,
     krb_afslog, krb_afslog_uid, kafs_settoken5, krb5_afslog, krb5_afslog_uid
     -- AFS library

LIBRARY

     AFS cache manager access library (libkafs, -lkafs)

SYNOPSIS

     #include <kafs.h>

     int
     k_afs_cell_of_file(const char *path, char *cell, int len);

     int
     k_hasafs(void);

     int
     k_hasafs_recheck(void);

     int
     k_pioctl(char *a_path, int o_opcode, struct ViceIoctl *a_paramsP,
         int a_followSymlinks);

     int
     k_setpag(void);

     int
     k_unlog(void);

     void
     kafs_set_verbose(void (*func)(void *, const char *, int), void *);

     int
     kafs_settoken_rxkad(const char *cell, struct ClearToken *token,
         void *ticket, size_t ticket_len);

     int
     kafs_settoken(const char *cell, uid_t uid, CREDENTIALS *c);

     krb_afslog(char *cell, char *realm);

     int
     krb_afslog_uid(char *cell, char *realm, uid_t uid);

     krb5_error_code
     krb5_afslog_uid(krb5_context context, krb5_ccache id, const char *cell,
         krb5_const_realm realm, uid_t uid);

     int
     kafs_settoken5(const char *cell, uid_t uid, krb5_creds *c);

     krb5_error_code
     krb5_afslog(krb5_context context, krb5_ccache id, const char *cell,
         krb5_const_realm realm);

DESCRIPTION

     k_hasafs() initializes some library internal structures, and tests for
     the presence of AFS in the kernel, none of the other functions should be
     called before k_hasafs() is called, or if it fails.

     k_hasafs_recheck() forces a recheck if a AFS client has started since
     last time k_hasafs() or k_hasafs_recheck() was called.

     kafs_set_verbose() set a log function that will be called each time the
     kafs library does something important so that the application using
     libkafs can output verbose logging.  Calling the function
     kafs_set_verbose with the function argument set to NULL will stop libkafs
     from calling the logging function (if set).

     kafs_settoken_rxkad() set rxkad with the token and ticket (that have the
     length ticket_len) for a given cell.

     kafs_settoken() and kafs_settoken5() work the same way as
     kafs_settoken_rxkad() but internally converts the Kerberos 4 or 5 creden-
     tial to a afs cleartoken and ticket.

     krb_afslog(), and krb_afslog_uid() obtains new tokens (and possibly tick-
     ets) for the specified cell and realm.  If cell is NULL, the local cell
     is used. If realm is NULL, the function tries to guess what realm to use.
     Unless you  have some good knowledge of what cell or realm to use, you
     should pass NULL.  krb_afslog() will use the real user-id for the ViceId
     field in the token, krb_afslog_uid() will use uid.

     krb5_afslog(), and krb5_afslog_uid() are the Kerberos 5 equivalents of
     krb_afslog(), and krb_afslog_uid().

     krb5_afslog(), kafs_settoken5() can be configured to behave differently
     via a krb5_appdefault option afs-use-524 in krb5.conf.  Possible values
     for afs-use-524 are:

     yes    use the 524 server in the realm to convert the ticket

     no     use the Kerberos 5 ticket directly, can be used with if the afs
            cell support 2b token.

     local, 2b
            convert the Kerberos 5 credential to a 2b token locally (the same
            work as a 2b 524 server should have done).

     Example:

     [appdefaults]
             SU.SE = { afs-use-524 = local }
             PDC.KTH.SE = { afs-use-524 = yes }
             afs-use-524 = yes

     libkafs will use the libkafs as application name when running the
     krb5_appdefault function call.

     The (uppercased) cell name is used as the realm to the krb5_appdefault
     function.

     k_afs_cell_of_file() will in cell return the cell of a specified file, no
     more than len characters is put in cell.

     k_pioctl() does a pioctl() system call with the specified arguments. This
     function is equivalent to lpioctl().

     k_setpag() initializes a new PAG.

     k_unlog() removes destroys all tokens in the current PAG.

RETURN VALUES

     k_hasafs() returns 1 if AFS is present in the kernel, 0 otherwise.
     krb_afslog() and krb_afslog_uid() returns 0 on success, or a Kerberos
     error number on failure.  k_afs_cell_of_file(), k_pioctl(), k_setpag(),
     and k_unlog() all return the value of the underlaying system call, 0 on
     success.

ENVIRONMENT

     The following environment variable affect the mode of operation of kafs:

     AFS_SYSCALL  Normally, kafs will try to figure out the correct system
                  call(s) that are used by AFS by itself.  If it does not man-
                  age to do that, or does it incorrectly, you can set this
                  variable to the system call number or list of system call
                  numbers that should be used.

EXAMPLES

     The following code from login will obtain a new PAG and tokens for the
     local cell and the cell of the users home directory.

     if (k_hasafs()) {
             char cell[64];
             k_setpag();
             if(k_afs_cell_of_file(pwd->pw_dir, cell, sizeof(cell)) == 0)
                     krb_afslog(cell, NULL);
             krb_afslog(NULL, NULL);
     }

ERRORS

     If any of these functions (apart from k_hasafs()) is called without AFS
     being present in the kernel, the process will usually (depending on the
     operating system) receive a SIGSYS signal.

SEE ALSO

     krb5_appdefault(3), krb5.conf(5)

     Transarc Corporation, "File Server/Cache Manager Interface", AFS-3
     Programmer's Reference, 1991.

BUGS

     AFS_SYSCALL has no effect under AIX.

HEIMDAL                           May 1, 2006                          HEIMDAL