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 13 int _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 33 SEC("test1") 34 int 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
