1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
|
/* 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
|
