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
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
|
#ifndef _INET_ECN_H_
#define _INET_ECN_H_
#include <linux/ip.h>
#include <linux/skbuff.h>
#include <net/inet_sock.h>
#include <net/dsfield.h>
enum {
INET_ECN_NOT_ECT = 0,
INET_ECN_ECT_1 = 1,
INET_ECN_ECT_0 = 2,
INET_ECN_CE = 3,
INET_ECN_MASK = 3,
};
static inline int INET_ECN_is_ce(__u8 dsfield)
{
return (dsfield & INET_ECN_MASK) == INET_ECN_CE;
}
static inline int INET_ECN_is_not_ect(__u8 dsfield)
{
return (dsfield & INET_ECN_MASK) == INET_ECN_NOT_ECT;
}
static inline int INET_ECN_is_capable(__u8 dsfield)
{
return dsfield & INET_ECN_ECT_0;
}
/*
* RFC 3168 9.1.1
* The full-functionality option for ECN encapsulation is to copy the
* ECN codepoint of the inside header to the outside header on
* encapsulation if the inside header is not-ECT or ECT, and to set the
* ECN codepoint of the outside header to ECT(0) if the ECN codepoint of
* the inside header is CE.
*/
static inline __u8 INET_ECN_encapsulate(__u8 outer, __u8 inner)
{
outer &= ~INET_ECN_MASK;
outer |= !INET_ECN_is_ce(inner) ? (inner & INET_ECN_MASK) :
INET_ECN_ECT_0;
return outer;
}
static inline void INET_ECN_xmit(struct sock *sk)
{
inet_sk(sk)->tos |= INET_ECN_ECT_0;
if (inet6_sk(sk) != NULL)
inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
}
static inline void INET_ECN_dontxmit(struct sock *sk)
{
inet_sk(sk)->tos &= ~INET_ECN_MASK;
if (inet6_sk(sk) != NULL)
inet6_sk(sk)->tclass &= ~INET_ECN_MASK;
}
#define IP6_ECN_flow_init(label) do { \
(label) &= ~htonl(INET_ECN_MASK << 20); \
} while (0)
#define IP6_ECN_flow_xmit(sk, label) do { \
if (INET_ECN_is_capable(inet6_sk(sk)->tclass)) \
(label) |= htonl(INET_ECN_ECT_0 << 20); \
} while (0)
static inline int IP_ECN_set_ce(struct iphdr *iph)
{
u32 check = (__force u32)iph->check;
u32 ecn = (iph->tos + 1) & INET_ECN_MASK;
/*
* After the last operation we have (in binary):
* INET_ECN_NOT_ECT => 01
* INET_ECN_ECT_1 => 10
* INET_ECN_ECT_0 => 11
* INET_ECN_CE => 00
*/
if (!(ecn & 2))
return !ecn;
/*
* The following gives us:
* INET_ECN_ECT_1 => check += htons(0xFFFD)
* INET_ECN_ECT_0 => check += htons(0xFFFE)
*/
check += (__force u16)htons(0xFFFB) + (__force u16)htons(ecn);
iph->check = (__force __sum16)(check + (check>=0xFFFF));
iph->tos |= INET_ECN_CE;
return 1;
}
static inline void IP_ECN_clear(struct iphdr *iph)
{
iph->tos &= ~INET_ECN_MASK;
}
static inline void ipv4_copy_dscp(unsigned int dscp, struct iphdr *inner)
{
dscp &= ~INET_ECN_MASK;
ipv4_change_dsfield(inner, INET_ECN_MASK, dscp);
}
struct ipv6hdr;
static inline int IP6_ECN_set_ce(struct ipv6hdr *iph)
{
if (INET_ECN_is_not_ect(ipv6_get_dsfield(iph)))
return 0;
*(__be32*)iph |= htonl(INET_ECN_CE << 20);
return 1;
}
static inline void IP6_ECN_clear(struct ipv6hdr *iph)
{
*(__be32*)iph &= ~htonl(INET_ECN_MASK << 20);
}
static inline void ipv6_copy_dscp(unsigned int dscp, struct ipv6hdr *inner)
{
dscp &= ~INET_ECN_MASK;
ipv6_change_dsfield(inner, INET_ECN_MASK, dscp);
}
static inline int INET_ECN_set_ce(struct sk_buff *skb)
{
switch (skb->protocol) {
case cpu_to_be16(ETH_P_IP):
if (skb->network_header + sizeof(struct iphdr) <= skb->tail)
return IP_ECN_set_ce(ip_hdr(skb));
break;
case cpu_to_be16(ETH_P_IPV6):
if (skb->network_header + sizeof(struct ipv6hdr) <= skb->tail)
return IP6_ECN_set_ce(ipv6_hdr(skb));
break;
}
return 0;
}
#endif
|
