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_helpers.h" 9 10 int _version SEC("version") = 1; 11 12 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ 13 #define TEST_FIELD(TYPE, FIELD, MASK) \ 14 { \ 15 TYPE tmp = *(volatile TYPE *)&skb->FIELD; \ 16 if (tmp != ((*(volatile __u32 *)&skb->FIELD) & MASK)) \ 17 return TC_ACT_SHOT; \ 18 } 19 #else 20 #define TEST_FIELD_OFFSET(a, b) ((sizeof(a) - sizeof(b)) / sizeof(b)) 21 #define TEST_FIELD(TYPE, FIELD, MASK) \ 22 { \ 23 TYPE tmp = *((volatile TYPE *)&skb->FIELD + \ 24 TEST_FIELD_OFFSET(skb->FIELD, TYPE)); \ 25 if (tmp != ((*(volatile __u32 *)&skb->FIELD) & MASK)) \ 26 return TC_ACT_SHOT; \ 27 } 28 #endif 29 30 SEC("classifier/test_pkt_md_access") 31 int test_pkt_md_access(struct __sk_buff *skb) 32 { 33 TEST_FIELD(__u8, len, 0xFF); 34 TEST_FIELD(__u16, len, 0xFFFF); 35 TEST_FIELD(__u32, len, 0xFFFFFFFF); 36 TEST_FIELD(__u16, protocol, 0xFFFF); 37 TEST_FIELD(__u32, protocol, 0xFFFFFFFF); 38 TEST_FIELD(__u8, hash, 0xFF); 39 TEST_FIELD(__u16, hash, 0xFFFF); 40 TEST_FIELD(__u32, hash, 0xFFFFFFFF); 41 42 return TC_ACT_OK; 43 } 44