RECURSIVE_KEY_SCAN(3)	    Linux Key Utility Calls	 RECURSIVE_KEY_SCAN(3)



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 ses-
       sion 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 spec-
       ified keyring tree and applies func to every link found in the accessi-
       ble 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 partic-
       ular 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 respec-
	      tively  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)



Linux				  10 Mar 2011		 RECURSIVE_KEY_SCAN(3)