1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
3 
4 #ifndef _CRYPTO_COMMON_H
5 #define _CRYPTO_COMMON_H
6 
7 #include "errno.h"
8 #include <stdbool.h>
9 
10 struct bpf_crypto_ctx *bpf_crypto_ctx_create(const struct bpf_crypto_params *params,
11 					     u32 params__sz, int *err) __ksym;
12 struct bpf_crypto_ctx *bpf_crypto_ctx_acquire(struct bpf_crypto_ctx *ctx) __ksym;
13 void bpf_crypto_ctx_release(struct bpf_crypto_ctx *ctx) __ksym;
14 int bpf_crypto_encrypt(struct bpf_crypto_ctx *ctx, const struct bpf_dynptr *src,
15 		       const struct bpf_dynptr *dst, const struct bpf_dynptr *iv) __ksym;
16 int bpf_crypto_decrypt(struct bpf_crypto_ctx *ctx, const struct bpf_dynptr *src,
17 		       const struct bpf_dynptr *dst, const struct bpf_dynptr *iv) __ksym;
18 
19 struct __crypto_ctx_value {
20 	struct bpf_crypto_ctx __kptr * ctx;
21 };
22 
23 struct array_map {
24 	__uint(type, BPF_MAP_TYPE_ARRAY);
25 	__type(key, int);
26 	__type(value, struct __crypto_ctx_value);
27 	__uint(max_entries, 1);
28 } __crypto_ctx_map SEC(".maps");
29 
crypto_ctx_value_lookup(void)30 static inline struct __crypto_ctx_value *crypto_ctx_value_lookup(void)
31 {
32 	u32 key = 0;
33 
34 	return bpf_map_lookup_elem(&__crypto_ctx_map, &key);
35 }
36 
crypto_ctx_insert(struct bpf_crypto_ctx * ctx)37 static inline int crypto_ctx_insert(struct bpf_crypto_ctx *ctx)
38 {
39 	struct __crypto_ctx_value local, *v;
40 	struct bpf_crypto_ctx *old;
41 	u32 key = 0;
42 	int err;
43 
44 	local.ctx = NULL;
45 	err = bpf_map_update_elem(&__crypto_ctx_map, &key, &local, 0);
46 	if (err) {
47 		bpf_crypto_ctx_release(ctx);
48 		return err;
49 	}
50 
51 	v = bpf_map_lookup_elem(&__crypto_ctx_map, &key);
52 	if (!v) {
53 		bpf_crypto_ctx_release(ctx);
54 		return -ENOENT;
55 	}
56 
57 	old = bpf_kptr_xchg(&v->ctx, ctx);
58 	if (old) {
59 		bpf_crypto_ctx_release(old);
60 		return -EEXIST;
61 	}
62 
63 	return 0;
64 }
65 
66 #endif /* _CRYPTO_COMMON_H */
67