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 14 u32 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_cmp() 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(c->user, c->role, c->type, hash); 30 hash = mls_range_hash(&c->range, hash); 31 return hash; 32 } 33