/* SPDX-License-Identifier: GPL-2.0 */

  /* include/net/dsfield.h - Manipulation of the Differentiated Services field */
  
  /* Written 1998-2000 by Werner Almesberger, EPFL ICA */
  
  
  #ifndef __NET_DSFIELD_H
  #define __NET_DSFIELD_H
  
  #include <linux/types.h>
  #include <linux/ip.h>
  #include <linux/ipv6.h>
  #include <asm/byteorder.h>

  static inline __u8 ipv4_get_dsfield(const struct iphdr *iph)

  {
  	return iph->tos;
  }

  static inline __u8 ipv6_get_dsfield(const struct ipv6hdr *ipv6h)

  {

  	return ntohs(*(const __be16 *)ipv6h) >> 4;

  }
  
  
  static inline void ipv4_change_dsfield(struct iphdr *iph,__u8 mask,
      __u8 value)
  {

          __u32 check = ntohs((__force __be16)iph->check);

  	__u8 dsfield;
  
  	dsfield = (iph->tos & mask) | value;
  	check += iph->tos;
  	if ((check+1) >> 16) check = (check+1) & 0xffff;
  	check -= dsfield;
  	check += check >> 16; /* adjust carry */

  	iph->check = (__force __sum16)htons(check);

  	iph->tos = dsfield;
  }
  
  
  static inline void ipv6_change_dsfield(struct ipv6hdr *ipv6h,__u8 mask,
      __u8 value)
  {

  	__be16 *p = (__force __be16 *)ipv6h;

  	*p = (*p & htons((((u16)mask << 4) | 0xf00f))) | htons((u16)value << 4);

  }
  
  
  #endif