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, 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