NAME
avc_open, avc_destroy, avc_reset, avc_cleanup - userspace SELinux AVC
setup and teardown.
SYNOPSIS
#include <selinux/selinux.h>
#include <selinux/avc.h>
int avc_open(struct selinux_opt *options, unsigned nopt);
void avc_destroy(void);
int avc_reset(void);
void avc_cleanup(void);
DESCRIPTION
avc_open initializes the userspace AVC and must be called before any
other AVC operation can be performed.
avc_destroy destroys the userspace AVC, freeing all internal memory
structures. After this call has been made, avc_open must be called
again before any AVC operations can be performed.
avc_reset flushes the userspace AVC, causing it to forget any cached
access decisions. The userspace AVC normally calls this function
automatically when needed, see NETLINK NOTIFICATION below.
avc_cleanup attempts to free unused memory within the userspace AVC,
but does not flush any cached access decisions. Under normal
operation, calling this function should not be necessary.
OPTIONS
The userspace AVC obeys callbacks set via selinux_set_callback(3), in
particular the logging and audit callbacks.
The options which may be passed to avc_open include the following:
AVC_OPT_SETENFORCE
This option forces the userspace AVC into enforcing mode if the
option value is non-NULL; permissive mode otherwise. The system
enforcing mode will be ignored.
NETLINK NOTIFICATION
Beginning with version 2.6.4, the Linux kernel supports SELinux status
change notification via netlink. Two message types are currently
implemented, indicating changes to the enforcing mode and to the loaded
policy in the kernel, respectively. The userspace AVC listens for
these messages and takes the appropriate action, modifying the behavior
of avc_has_perm(3) to reflect the current enforcing mode and flushing
the cache on receipt of a policy load notification. Audit messages are
produced when netlink notifications are processed.
RETURN VALUE
Functions with a return value return zero on success. On error, -1 is
returned and errno is set appropriately.
AUTHOR
Eamon Walsh <ewalsh@tycho.nsa.gov>
SEE ALSO
selinux(8), avc_has_perm(3), avc_context_to_sid(3), avc_cache_stats(3),
avc_add_callback(3), selinux_set_callback(3), security_compute_av(3)
12 Jun 2008 avc_open(3)