blob: 16bfcfb63f8594683d5f26bf71e8fe828307ec0f [file] [log] [blame]
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
#include <unistd.h>
#include <sys/types.h>
#include <stdlib.h>
#include <errno.h>
#include "selinux_internal.h"
#include <selinux/avc.h>
#include "avc_internal.h"
static pthread_once_t once = PTHREAD_ONCE_INIT;
static int selinux_enabled;
static int avc_reset_callback(uint32_t event __attribute__((unused)),
security_id_t ssid __attribute__((unused)),
security_id_t tsid __attribute__((unused)),
security_class_t tclass __attribute__((unused)),
access_vector_t perms __attribute__((unused)),
access_vector_t *out_retained __attribute__((unused)))
{
flush_class_cache();
return 0;
}
static void avc_init_once(void)
{
selinux_enabled = is_selinux_enabled();
if (selinux_enabled == 1) {
if (avc_open(NULL, 0))
return;
avc_add_callback(avc_reset_callback, AVC_CALLBACK_RESET,
0, 0, 0, 0);
}
}
int selinux_check_access(const char *scon, const char *tcon, const char *class, const char *perm, void *aux) {
int rc;
security_id_t scon_id;
security_id_t tcon_id;
security_class_t sclass;
access_vector_t av;
__selinux_once(once, avc_init_once);
if (selinux_enabled != 1)
return 0;
rc = avc_context_to_sid(scon, &scon_id);
if (rc < 0)
return rc;
rc = avc_context_to_sid(tcon, &tcon_id);
if (rc < 0)
return rc;
(void) avc_netlink_check_nb();
sclass = string_to_security_class(class);
if (sclass == 0) {
rc = errno;
avc_log(SELINUX_ERROR, "Unknown class %s", class);
if (security_deny_unknown() == 0)
return 0;
errno = rc;
return -1;
}
av = string_to_av_perm(sclass, perm);
if (av == 0) {
rc = errno;
avc_log(SELINUX_ERROR, "Unknown permission %s for class %s", perm, class);
if (security_deny_unknown() == 0)
return 0;
errno = rc;
return -1;
}
return avc_has_perm (scon_id, tcon_id, sclass, av, NULL, aux);
}
int selinux_check_passwd_access(access_vector_t requested)
{
int status = -1;
char *user_context;
if (is_selinux_enabled() == 0)
return 0;
if (getprevcon_raw(&user_context) == 0) {
security_class_t passwd_class;
struct av_decision avd;
int retval;
passwd_class = string_to_security_class("passwd");
if (passwd_class == 0) {
freecon(user_context);
return 0;
}
retval = security_compute_av_raw(user_context,
user_context,
passwd_class,
requested,
&avd);
if ((retval == 0) && ((requested & avd.allowed) == requested)) {
status = 0;
}
freecon(user_context);
}
if (status != 0 && security_getenforce() == 0)
status = 0;
return status;
}
hidden_def(selinux_check_passwd_access)
int checkPasswdAccess(access_vector_t requested)
{
return selinux_check_passwd_access(requested);
}