/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* Definitions for the IP protocol.
*
* Version: @(#)ip.h 1.0.2 04/28/93
*
* Authors: Fred N. van Kempen, <[email protected]>
*/
#ifndef _LINUX_IP_H
#define _LINUX_IP_H
#include <linux/skbuff.h>
#include <uapi/linux/ip.h>
static inline struct iphdr *ip_hdr(const struct sk_buff *skb)
{
return (struct iphdr *)skb_network_header(skb);
}
static inline struct iphdr *inner_ip_hdr(const struct sk_buff *skb)
{
return (struct iphdr *)skb_inner_network_header(skb);
}
static inline struct iphdr *ipip_hdr(const struct sk_buff *skb)
{
return (struct iphdr *)skb_transport_header(skb);
}
static inline unsigned int ip_transport_len(const struct sk_buff *skb)
{
return ntohs(ip_hdr(skb)->tot_len) - skb_network_header_len(skb);
}
static inline unsigned int iph_totlen(const struct sk_buff *skb, const struct iphdr *iph)
{
u32 len = ntohs(iph->tot_len);
return (len || !skb_is_gso(skb) || !skb_is_gso_tcp(skb)) ?
len : skb->len - skb_network_offset(skb);
}
static inline unsigned int skb_ip_totlen(const struct sk_buff *skb)
{
return iph_totlen(skb, ip_hdr(skb));
}
/* IPv4 datagram length is stored into 16bit field (tot_len) */
#define IP_MAX_MTU 0xFFFFU
static inline void iph_set_totlen(struct iphdr *iph, unsigned int len)
{
iph->tot_len = len <= IP_MAX_MTU ? htons(len) : 0;
}
#endif /* _LINUX_IP_H */