1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Implementations of the security context functions.
4 *
5 * Author: Ondrej Mosnacek <omosnacek@gmail.com>
6 * Copyright (C) 2020 Red Hat, Inc.
7 */
8
9#include <linux/jhash.h>
10
11#include "context.h"
12#include "mls.h"
13
14u32 context_compute_hash(const struct context *c)
15{
16 u32 hash = 0;
17
18 /*
19 * If a context is invalid, it will always be represented by a
20 * context struct with only the len & str set (and vice versa)
21 * under a given policy. Since context structs from different
22 * policies should never meet, it is safe to hash valid and
23 * invalid contexts differently. The context_equal() function
24 * already operates under the same assumption.
25 */
26 if (c->len)
27 return full_name_hash(NULL, c->str, c->len);
28
29 hash = jhash_3words(a: c->user, b: c->role, c: c->type, initval: hash);
30 hash = mls_range_hash(r: &c->range, hash);
31 return hash;
32}
33