1// SPDX-License-Identifier: GPL-2.0-only
2/* Copyright (c) 2017 Facebook
3 */
4#include <stddef.h>
5#include <string.h>
6#include <linux/bpf.h>
7#include <linux/pkt_cls.h>
8#include <bpf/bpf_helpers.h>
9
10#if  __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
11#define TEST_FIELD(TYPE, FIELD, MASK)					\
12	{								\
13		TYPE tmp = *(volatile TYPE *)&skb->FIELD;		\
14		if (tmp != ((*(volatile __u32 *)&skb->FIELD) & MASK))	\
15			return TC_ACT_SHOT;				\
16	}
17#else
18#define TEST_FIELD_OFFSET(a, b)	((sizeof(a) - sizeof(b)) / sizeof(b))
19#define TEST_FIELD(TYPE, FIELD, MASK)					\
20	{								\
21		TYPE tmp = *((volatile TYPE *)&skb->FIELD +		\
22			      TEST_FIELD_OFFSET(skb->FIELD, TYPE));	\
23		if (tmp != ((*(volatile __u32 *)&skb->FIELD) & MASK))	\
24			return TC_ACT_SHOT;				\
25	}
26#endif
27
28SEC("tc")
29int test_pkt_md_access(struct __sk_buff *skb)
30{
31	TEST_FIELD(__u8,  len, 0xFF);
32	TEST_FIELD(__u16, len, 0xFFFF);
33	TEST_FIELD(__u32, len, 0xFFFFFFFF);
34	TEST_FIELD(__u16, protocol, 0xFFFF);
35	TEST_FIELD(__u32, protocol, 0xFFFFFFFF);
36	TEST_FIELD(__u8,  hash, 0xFF);
37	TEST_FIELD(__u16, hash, 0xFFFF);
38	TEST_FIELD(__u32, hash, 0xFFFFFFFF);
39
40	return TC_ACT_OK;
41}
42