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/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 #else 18 #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 #endif 27 28 SEC("tc") 29 int 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