avc_netlink_open(3) — Linux manual page


avc_netlink_loop(3)       SELinux API documentation      avc_netlink_loop(3)

NAME         top

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

SYNOPSIS         top

       #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);

DESCRIPTION         top

       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).  If no such socket
       descriptor exists, avc_netlink_acquire_fd(3) will first call
       avc_netlink_open(3) and then return the resulting fd.

       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

       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.

RETURN VALUE         top

       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.

AUTHOR         top

       Originally KaiGai Kohei. Updated by Mike Palmiotto

SEE ALSO         top

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

COLOPHON         top

       This page is part of the selinux (Security-Enhanced Linux user-space
       libraries and tools) project.  Information about the project can be
       found at ⟨https://github.com/SELinuxProject/selinux/wiki⟩.  If you
       have a bug report for this manual page, see
       ⟨https://github.com/SELinuxProject/selinux/wiki/Contributing⟩.  This
       page was obtained from the project's upstream Git repository
       ⟨https://github.com/SELinuxProject/selinux⟩ on 2020-11-01.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-10-31.)  If you discover any rendering problems in
       this HTML version of the page, or you believe there is a better or
       more up-to-date source for the page, or you have corrections or im‐
       provements to the information in this COLOPHON (which is not part of
       the original manual page), send a mail to man-pages@man7.org

                                 30 Mar 2009             avc_netlink_loop(3)

Pages that refer to this page: and(3)avc_netlink_acquire_fd(3)avc_netlink_check_nb(3)avc_netlink_close(3)avc_netlink_loop(3)avc_netlink_open(3)avc_netlink_release_fd(3)selinux_set_callback(3)selinux_status_close(3)selinux_status_deny_unknown(3)selinux_status_getenforce(3)selinux_status_open(3)selinux_status_policyload(3)selinux_status_updated(3)