1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _NF_REJECT_H
3#define _NF_REJECT_H
4
5#include <linux/types.h>
6#include <uapi/linux/in.h>
7
8static inline bool nf_reject_verify_csum(struct sk_buff *skb, int dataoff,
9					  __u8 proto)
10{
11	/* Skip protocols that don't use 16-bit one's complement checksum
12	 * of the entire payload.
13	 */
14	switch (proto) {
15		/* Protocols with optional checksums. */
16		case IPPROTO_UDP: {
17			const struct udphdr *udp_hdr;
18			struct udphdr _udp_hdr;
19
20			udp_hdr = skb_header_pointer(skb, dataoff,
21						     sizeof(_udp_hdr),
22						     &_udp_hdr);
23			if (!udp_hdr || udp_hdr->check)
24				return true;
25
26			return false;
27		}
28		case IPPROTO_GRE:
29
30		/* Protocols with other integrity checks. */
31		case IPPROTO_AH:
32		case IPPROTO_ESP:
33		case IPPROTO_SCTP:
34
35		/* Protocols with partial checksums. */
36		case IPPROTO_UDPLITE:
37		case IPPROTO_DCCP:
38			return false;
39	}
40	return true;
41}
42
43#endif /* _NF_REJECT_H */
44