NAME

       recursive_key_scan - Apply a function to all keys in a keyring tree
       recursive_session_key_scan - Apply a function to all keys in the session keyring tree

SYNOPSIS

       #include <keyutils.h>

       typedef int (*recursive_key_scanner_t)(key_serial_t parent,
           key_serial_t key, char *desc, int desc_len, void *data);

       long recursive_key_scan(key_serial_t keyring,
           recursive_key_scanner_t func, void *data);
       long recursive_session_key_scan(recursive_key_scanner_t func,
           void *data);

DESCRIPTION

       recursive_key_scan()  performs  a depth-first recursive scan of the specified keyring tree
       and applies func to every link found in the accessible keyrings in  that  tree.   data  is
       passed to each invocation of func.

       The return values of func are summed and returned as the overall return value.  Errors are
       ignored.  Inaccessible keyrings are not scanned, but links to them  are  still  passed  to
       func.

       recursive_session_key_scan()  works  exactly  like  recursive_key_scan() with the caller's
       session keyring specified as the starting keyring.

       The callback function is called for each link found in all the keyrings in  the  nominated
       tree  and  so  may  be called multiple times for a particular key if that key has multiple
       links to it.

       The callback function is passed the following parameters:

       parent The keyring containing the link or 0 for the initial key.

       key    The key to which the link points.

       desc and desc_len
              A  pointer  to  the  raw   description   and   its   length   as   retrieved   with
              keyctl_describe_alloc().  These will be NULL and -1 respectively if the description
              couldn't be retrieved and errno will retain the error from keyctl_describe_alloc().

       data   The data passed to the scanner function.

RETURN VALUE

       These functions return the sum of the results of the callback functions they invoke.

ERRORS

       Ignored.

LINKING

       When linking, -lkeyutils should be specified to the linker.

SEE ALSO

       keyctl(3), keyctl_describe_alloc(3)