util-linux/lib/selinux-utils.c

86 lines
1.7 KiB
C

/*
* No copyright is claimed. This code is in the public domain; do with
* it what you wish.
*
* Written by Karel Zak <kzak@redhat.com> [January 2021]
*/
#include <selinux/context.h>
#include <selinux/selinux.h>
#include <selinux/label.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <errno.h>
#include "selinux-utils.h"
/* set the SELinux security context used for _creating_ a new file system object
*
* returns 0 on success,
* or <0 on error
*/
int ul_setfscreatecon_from_file(char *orig_file)
{
if (is_selinux_enabled() > 0) {
char *scontext = NULL;
if (getfilecon(orig_file, &scontext) < 0)
return -1;
if (setfscreatecon(scontext) < 0) {
freecon(scontext);
return -1;
}
freecon(scontext);
}
return 0;
}
/* returns 1 if user has access to @class and @perm ("passwd", "chfn")
* or 0 on error,
* or 0 if has no access -- in this case sets @user_cxt to user-context
*/
int ul_selinux_has_access(const char *classstr, const char *perm, char **user_cxt)
{
char *user;
int rc;
if (user_cxt)
*user_cxt = NULL;
if (getprevcon(&user) != 0)
return 0;
rc = selinux_check_access(user, user, classstr, perm, NULL);
if (rc != 0 && user_cxt)
*user_cxt = user;
else
freecon(user);
return rc == 0 ? 1 : 0;
}
/* Gets the default context for @path and @st_mode.
*
* returns 0 on success,
* or <0 on error
*/
int ul_selinux_get_default_context(const char *path, int st_mode, char **cxt)
{
struct selabel_handle *hnd;
struct selinux_opt options[SELABEL_NOPT] = {};
int rc = 0;
*cxt = NULL;
hnd = selabel_open(SELABEL_CTX_FILE, options, SELABEL_NOPT);
if (!hnd)
return -errno;
if (selabel_lookup(hnd, cxt, path, st_mode) != 0)
rc = -errno
;
selabel_close(hnd);
return rc;
}