/* Copyright (c) 2017 Facebook * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. */ #include <stddef.h> #include <string.h> #include <linux/bpf.h> #include <linux/pkt_cls.h> #include "bpf_helpers.h" int _version SEC("version") = 1; #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ #define TEST_FIELD(TYPE, FIELD, MASK) \ { \ TYPE tmp = *(volatile TYPE *)&skb->FIELD; \ if (tmp != ((*(volatile __u32 *)&skb->FIELD) & MASK)) \ return TC_ACT_SHOT; \ } #else #define TEST_FIELD_OFFSET(a, b) ((sizeof(a) - sizeof(b)) / sizeof(b)) #define TEST_FIELD(TYPE, FIELD, MASK) \ { \ TYPE tmp = *((volatile TYPE *)&skb->FIELD + \ TEST_FIELD_OFFSET(skb->FIELD, TYPE)); \ if (tmp != ((*(volatile __u32 *)&skb->FIELD) & MASK)) \ return TC_ACT_SHOT; \ } #endif SEC("test1") int process(struct __sk_buff *skb) { TEST_FIELD(__u8, len, 0xFF); TEST_FIELD(__u16, len, 0xFFFF); TEST_FIELD(__u32, len, 0xFFFFFFFF); TEST_FIELD(__u16, protocol, 0xFFFF); TEST_FIELD(__u32, protocol, 0xFFFFFFFF); TEST_FIELD(__u8, hash, 0xFF); TEST_FIELD(__u16, hash, 0xFFFF); TEST_FIELD(__u32, hash, 0xFFFFFFFF); return TC_ACT_OK; }