avc_netlink_loop(3) SELinux API documentation avc_netlink_loop(3)NAME
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
#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
These functions enable applications to handle notification of SELinux
events via netlink. The userspace AVC normally checks for netlink mes‐
sages on each call to avc_has_perm(3). Applications may wish to over‐
ride 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 notifica‐
tions. 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 automati‐
cally 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 pro‐
cessing 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
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.
SEE ALSOavc_open(3), selinux_set_callback(3), selinux(8)
30 Mar 2009 avc_netlink_loop(3)