Man Linux: Main Page and Category List


       avc_netlink_open,       avc_netlink_close,      avc_netlink_acquire_fd,
       avc_netlink_release_fd,   avc_netlink_check_nb,   avc_netlink_loop    -
       SELinux netlink processing.


       #include <selinux/selinux.h>

       #include <selinux/avc.h>

       int avc_netlink_open(int blocking);

       void avc_netlink_close(void);

       int avc_netlink_acquire_fd(void);

       void avc_netlink_release_fd(void);

       void avc_netlink_loop(void);

       int avc_netlink_check_nb(void);


       These  functions  enable applications to handle notification of SELinux
       events via netlink.  The userspace  AVC  normally  checks  for  netlink
       messages  on  each  call  to avc_has_perm(3).  Applications may wish to
       override this behavior  and  check  for  notification  separately,  for
       example  in  a  select(2)  loop.   These  functions also permit netlink
       monitoring without requiring a call to avc_open(3).

       avc_netlink_open  opens   a   netlink   socket   to   receive   SELinux
       notifications.    The  socket  descriptor  is  stored  internally;  use
       avc_netlink_acquire_fd(3) to take ownership of it in application  code.
       The  blocking  argument  controls whether the O_NONBLOCK flag is set on
       the socket descriptor.  avc_open(3)  calls  this  function  internally,
       specifying non-blocking behavior.

       avc_netlink_close  closes  the netlink socket.  This function is called
       automatically by avc_destroy(3).

       avc_netlink_acquire_fd returns the netlink socket descriptor number and
       informs   the   userspace  AVC  not  to  check  the  socket  descriptor
       automatically on calls to avc_has_perm(3).

       avc_netlink_release_fd returns control of the  netlink  socket  to  the
       userspace AVC, re-enabling automatic processing of notifications.

       avc_netlink_check_nb checks the netlink socket for pending messages and
       processes them.  Callbacks for policyload and enforcing changes will be
       called; see selinux_set_callback(3).  This function does not block.

       avc_netlink_loop  enters  a  loop  blocking  on  the netlink socket and
       processing messages as they  are  received.   This  function  will  not
       return  unless  an error occurs on the socket, in which case the socket
       is closed.


       avc_netlink_acquire_fd returns a non-negative file descriptor number on
       success.   Other  functions with a return value return zero on success.
       On error, -1 is returned and errno is set appropriately.


       avc_open(3), selinux_set_callback(3), selinux(8)

                                  30 Mar 2009              avc_netlink_loop(3)