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
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
/* $KAME: ip_ecn.c,v 1.12 2002/01/07 11:34:47 kjc Exp $ */
/*-
* Copyright (C) 1999 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
/*
* ECN consideration on tunnel ingress/egress operation.
* http://www.aciri.org/floyd/papers/draft-ipsec-ecn-00.txt
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#ifdef INET6
#include <netinet/ip6.h>
#endif
#include <netinet/ip_ecn.h>
#ifdef INET6
#include <netinet6/ip6_ecn.h>
#endif
/*
* ECN and TOS (or TCLASS) processing rules at tunnel encapsulation and
* decapsulation from RFC3168:
*
* Outer Hdr at Inner Hdr at
* Encapsulator Decapsulator
* Header fields: -------------------- ------------
* DS Field copied from inner hdr no change
* ECN Field constructed by (I) constructed by (E)
*
* ECN_ALLOWED (full functionality):
* (I) if the ECN field in the inner header is set to CE, then set the
* ECN field in the outer header to ECT(0).
* otherwise, copy the ECN field to the outer header.
*
* (E) if the ECN field in the outer header is set to CE and the ECN
* field of the inner header is not-ECT, drop the packet.
* if the ECN field in the inner header is set to ECT(0) or ECT(1)
* and the ECN field in the outer header is set to CE, then copy CE to
* the inner header. otherwise, make no change to the inner header.
*
* ECN_FORBIDDEN (limited functionality):
* (I) set the ECN field to not-ECT in the outer header.
*
* (E) if the ECN field in the outer header is set to CE, drop the packet.
* otherwise, make no change to the ECN field in the inner header.
*
* the drop rule is for backward compatibility and protection against
* erasure of CE.
*/
/*
* modify outer ECN (TOS) field on ingress operation (tunnel encapsulation).
*/
void
ip_ecn_ingress(int mode, u_int8_t *outer, const u_int8_t *inner)
{
if (!outer || !inner)
panic("NULL pointer passed to ip_ecn_ingress");
*outer = *inner;
switch (mode) {
case ECN_ALLOWED: /* ECN allowed */
/*
* full-functionality: if the inner is CE, set ECT(0)
* to the outer. otherwise, copy the ECN field.
*/
if ((*inner & IPTOS_ECN_MASK) == IPTOS_ECN_CE)
*outer &= ~IPTOS_ECN_ECT1;
break;
case ECN_FORBIDDEN: /* ECN forbidden */
/*
* limited-functionality: set not-ECT to the outer
*/
*outer &= ~IPTOS_ECN_MASK;
break;
case ECN_NOCARE: /* no consideration to ECN */
break;
}
}
/*
* modify inner ECN (TOS) field on egress operation (tunnel decapsulation).
* the caller should drop the packet if the return value is 0.
*/
int
ip_ecn_egress(int mode, const u_int8_t *outer, u_int8_t *inner)
{
if (!outer || !inner)
panic("NULL pointer passed to ip_ecn_egress");
switch (mode) {
case ECN_ALLOWED:
/*
* full-functionality: if the outer is CE and the inner is
* not-ECT, should drop it. otherwise, copy CE.
*/
if ((*outer & IPTOS_ECN_MASK) == IPTOS_ECN_CE) {
if ((*inner & IPTOS_ECN_MASK) == IPTOS_ECN_NOTECT)
return (0);
*inner |= IPTOS_ECN_CE;
}
break;
case ECN_FORBIDDEN: /* ECN forbidden */
/*
* limited-functionality: if the outer is CE, should drop it.
* otherwise, leave the inner.
*/
if ((*outer & IPTOS_ECN_MASK) == IPTOS_ECN_CE)
return (0);
break;
case ECN_NOCARE: /* no consideration to ECN */
break;
}
return (1);
}
#ifdef INET6
void
ip6_ecn_ingress(int mode, u_int32_t *outer, const u_int32_t *inner)
{
u_int8_t outer8, inner8;
if (!outer || !inner)
panic("NULL pointer passed to ip6_ecn_ingress");
inner8 = (ntohl(*inner) >> 20) & 0xff;
ip_ecn_ingress(mode, &outer8, &inner8);
*outer &= ~htonl(0xff << 20);
*outer |= htonl((u_int32_t)outer8 << 20);
}
int
ip6_ecn_egress(int mode, const u_int32_t *outer, u_int32_t *inner)
{
u_int8_t outer8, inner8, oinner8;
if (!outer || !inner)
panic("NULL pointer passed to ip6_ecn_egress");
outer8 = (ntohl(*outer) >> 20) & 0xff;
inner8 = oinner8 = (ntohl(*inner) >> 20) & 0xff;
if (ip_ecn_egress(mode, &outer8, &inner8) == 0)
return (0);
if (inner8 != oinner8) {
*inner &= ~htonl(0xff << 20);
*inner |= htonl((u_int32_t)inner8 << 20);
}
return (1);
}
#endif
|
