42 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/* Copyright (c) 2017 Facebook3 */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#else18#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#endif27 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