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