1// SPDX-License-Identifier: GPL-2.0
  2/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
  3
  4#include "vmlinux.h"
  5#include "bpf_tracing_net.h"
  6#include <bpf/bpf_helpers.h>
  7#include <bpf/bpf_endian.h>
  8#include <bpf/bpf_tracing.h>
  9#include "bpf_misc.h"
 10#include "bpf_kfuncs.h"
 11#include "crypto_common.h"
 12
 13const volatile unsigned int len = 16;
 14char cipher[128] = {};
 15u32 key_len, authsize;
 16char dst[256] = {};
 17u8 key[256] = {};
 18long hits = 0;
 19int status;
 20
 21SEC("syscall")
 22int crypto_setup(void *args)
 23{
 24	struct bpf_crypto_ctx *cctx;
 25	struct bpf_crypto_params params = {
 26		.type = "skcipher",
 27		.key_len = key_len,
 28		.authsize = authsize,
 29	};
 30	int err = 0;
 31
 32	status = 0;
 33
 34	if (!cipher[0] || !key_len || key_len > 256) {
 35		status = -EINVAL;
 36		return 0;
 37	}
 38
 39	__builtin_memcpy(&params.algo, cipher, sizeof(cipher));
 40	__builtin_memcpy(&params.key, key, sizeof(key));
 41	cctx = bpf_crypto_ctx_create(&params, sizeof(params), &err);
 42
 43	if (!cctx) {
 44		status = err;
 45		return 0;
 46	}
 47
 48	err = crypto_ctx_insert(cctx);
 49	if (err && err != -EEXIST)
 50		status = err;
 51
 52	return 0;
 53}
 54
 55SEC("tc")
 56int crypto_encrypt(struct __sk_buff *skb)
 57{
 58	struct __crypto_ctx_value *v;
 59	struct bpf_crypto_ctx *ctx;
 60	struct bpf_dynptr psrc, pdst;
 61
 62	v = crypto_ctx_value_lookup();
 63	if (!v) {
 64		status = -ENOENT;
 65		return 0;
 66	}
 67
 68	ctx = v->ctx;
 69	if (!ctx) {
 70		status = -ENOENT;
 71		return 0;
 72	}
 73
 74	bpf_dynptr_from_skb(skb, 0, &psrc);
 75	bpf_dynptr_from_mem(dst, len, 0, &pdst);
 76
 77	status = bpf_crypto_encrypt(ctx, &psrc, &pdst, NULL);
 78	__sync_add_and_fetch(&hits, 1);
 79
 80	return 0;
 81}
 82
 83SEC("tc")
 84int crypto_decrypt(struct __sk_buff *skb)
 85{
 86	struct bpf_dynptr psrc, pdst;
 87	struct __crypto_ctx_value *v;
 88	struct bpf_crypto_ctx *ctx;
 89
 90	v = crypto_ctx_value_lookup();
 91	if (!v)
 92		return -ENOENT;
 93
 94	ctx = v->ctx;
 95	if (!ctx)
 96		return -ENOENT;
 97
 98	bpf_dynptr_from_skb(skb, 0, &psrc);
 99	bpf_dynptr_from_mem(dst, len, 0, &pdst);
100
101	status = bpf_crypto_decrypt(ctx, &psrc, &pdst, NULL);
102	__sync_add_and_fetch(&hits, 1);
103
104	return 0;
105}
106
107char __license[] SEC("license") = "GPL";