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)