1/* Copyright (c) 2017 Facebook
2 *
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
6 */
7#include <stddef.h>
8#include <string.h>
9#include <linux/bpf.h>
10#include <linux/pkt_cls.h>
11#include "bpf_helpers.h"
12
13int _version SEC("version") = 1;
14
15#if  __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
16#define TEST_FIELD(TYPE, FIELD, MASK)					\
17	{								\
18		TYPE tmp = *(volatile TYPE *)&skb->FIELD;		\
19		if (tmp != ((*(volatile __u32 *)&skb->FIELD) & MASK))	\
20			return TC_ACT_SHOT;				\
21	}
22#else
23#define TEST_FIELD_OFFSET(a, b)	((sizeof(a) - sizeof(b)) / sizeof(b))
24#define TEST_FIELD(TYPE, FIELD, MASK)					\
25	{								\
26		TYPE tmp = *((volatile TYPE *)&skb->FIELD +		\
27			      TEST_FIELD_OFFSET(skb->FIELD, TYPE));	\
28		if (tmp != ((*(volatile __u32 *)&skb->FIELD) & MASK))	\
29			return TC_ACT_SHOT;				\
30	}
31#endif
32
33SEC("test1")
34int process(struct __sk_buff *skb)
35{
36	TEST_FIELD(__u8,  len, 0xFF);
37	TEST_FIELD(__u16, len, 0xFFFF);
38	TEST_FIELD(__u32, len, 0xFFFFFFFF);
39	TEST_FIELD(__u16, protocol, 0xFFFF);
40	TEST_FIELD(__u32, protocol, 0xFFFFFFFF);
41	TEST_FIELD(__u8,  hash, 0xFF);
42	TEST_FIELD(__u16, hash, 0xFFFF);
43	TEST_FIELD(__u32, hash, 0xFFFFFFFF);
44
45	return TC_ACT_OK;
46}
47