1/* include/net/dsfield.h - Manipulation of the Differentiated Services field */
2
3/* Written 1998-2000 by Werner Almesberger, EPFL ICA */
4
5
6#ifndef __NET_DSFIELD_H
7#define __NET_DSFIELD_H
8
9#include <linux/types.h>
10#include <linux/ip.h>
11#include <linux/ipv6.h>
12#include <asm/byteorder.h>
13
14
15static inline __u8 ipv4_get_dsfield(struct iphdr *iph)
16{
17	return iph->tos;
18}
19
20
21static inline __u8 ipv6_get_dsfield(struct ipv6hdr *ipv6h)
22{
23	return ntohs(*(__be16 *) ipv6h) >> 4;
24}
25
26
27static inline void ipv4_change_dsfield(struct iphdr *iph,__u8 mask,
28    __u8 value)
29{
30        __u32 check = ntohs((__force __be16)iph->check);
31	__u8 dsfield;
32
33	dsfield = (iph->tos & mask) | value;
34	check += iph->tos;
35	if ((check+1) >> 16) check = (check+1) & 0xffff;
36	check -= dsfield;
37	check += check >> 16; /* adjust carry */
38	iph->check = (__force __sum16)htons(check);
39	iph->tos = dsfield;
40}
41
42
43static inline void ipv6_change_dsfield(struct ipv6hdr *ipv6h,__u8 mask,
44    __u8 value)
45{
46        __u16 tmp;
47
48	tmp = ntohs(*(__be16 *) ipv6h);
49	tmp = (tmp & ((mask << 4) | 0xf00f)) | (value << 4);
50	*(__be16 *) ipv6h = htons(tmp);
51}
52
53
54#endif
55