1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Definitions for the IP protocol.
8 *
9 * Version: @(#)ip.h 1.0.2 04/28/93
10 *
11 * Authors: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 */
13#ifndef _LINUX_IP_H
14#define _LINUX_IP_H
15
16#include <linux/skbuff.h>
17#include <uapi/linux/ip.h>
18
19static inline struct iphdr *ip_hdr(const struct sk_buff *skb)
20{
21 return (struct iphdr *)skb_network_header(skb);
22}
23
24static inline struct iphdr *inner_ip_hdr(const struct sk_buff *skb)
25{
26 return (struct iphdr *)skb_inner_network_header(skb);
27}
28
29static inline struct iphdr *ipip_hdr(const struct sk_buff *skb)
30{
31 return (struct iphdr *)skb_transport_header(skb);
32}
33
34static inline unsigned int ip_transport_len(const struct sk_buff *skb)
35{
36 return ntohs(ip_hdr(skb)->tot_len) - skb_network_header_len(skb);
37}
38
39static inline unsigned int iph_totlen(const struct sk_buff *skb, const struct iphdr *iph)
40{
41 u32 len = ntohs(iph->tot_len);
42
43 return (len || !skb_is_gso(skb) || !skb_is_gso_tcp(skb)) ?
44 len : skb->len - skb_network_offset(skb);
45}
46
47static inline unsigned int skb_ip_totlen(const struct sk_buff *skb)
48{
49 return iph_totlen(skb, iph: ip_hdr(skb));
50}
51
52/* IPv4 datagram length is stored into 16bit field (tot_len) */
53#define IP_MAX_MTU 0xFFFFU
54
55static inline void iph_set_totlen(struct iphdr *iph, unsigned int len)
56{
57 iph->tot_len = len <= IP_MAX_MTU ? htons(len) : 0;
58}
59#endif /* _LINUX_IP_H */
60