1/* $NetBSD: ip_ecn.c,v 1.16 2015/08/24 22:21:26 pooka Exp $ */
2/* $KAME: ip_ecn.c,v 1.11 2001/05/03 16:09:29 itojun Exp $ */
3
4/*
5 * Copyright (C) 1999 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 */
33/*
34 * ECN consideration on tunnel ingress/egress operation.
35 * http://www.aciri.org/floyd/papers/draft-ipsec-ecn-00.txt
36 */
37
38#include <sys/cdefs.h>
39__KERNEL_RCSID(0, "$NetBSD: ip_ecn.c,v 1.16 2015/08/24 22:21:26 pooka Exp $");
40
41#ifdef _KERNEL_OPT
42#include "opt_inet.h"
43#endif
44
45#include <sys/param.h>
46#include <sys/systm.h>
47#include <sys/malloc.h>
48#include <sys/mbuf.h>
49#include <sys/errno.h>
50
51#include <netinet/in.h>
52#include <netinet/in_systm.h>
53#include <netinet/ip.h>
54#ifdef INET6
55#include <netinet/ip6.h>
56#endif
57
58#include <netinet/ip_ecn.h>
59
60/*
61 * modify outer ECN (TOS) field on ingress operation (tunnel encapsulation).
62 */
63void
64ip_ecn_ingress(int mode, u_int8_t *outer, const u_int8_t *inner)
65{
66 if (!outer || !inner)
67 panic("NULL pointer passed to ip_ecn_ingress");
68
69 *outer = *inner;
70 switch (mode) {
71 case ECN_ALLOWED: /* ECN allowed */
72 *outer &= ~IPTOS_ECN_CE;
73 break;
74 case ECN_FORBIDDEN: /* ECN forbidden */
75 *outer &= ~(IPTOS_ECN_ECT0 | IPTOS_ECN_CE);
76 break;
77 case ECN_NOCARE: /* no consideration to ECN */
78 break;
79 }
80}
81
82/*
83 * modify inner ECN (TOS) field on egress operation (tunnel decapsulation).
84 */
85void
86ip_ecn_egress(int mode, const u_int8_t *outer, u_int8_t *inner)
87{
88 if (!outer || !inner)
89 panic("NULL pointer passed to ip_ecn_egress");
90
91 switch (mode) {
92 case ECN_ALLOWED:
93 if (*outer & IPTOS_ECN_CE)
94 *inner |= IPTOS_ECN_CE;
95 break;
96 case ECN_FORBIDDEN: /* ECN forbidden */
97 case ECN_NOCARE: /* no consideration to ECN */
98 break;
99 }
100}
101
102#ifdef INET6
103void
104ip6_ecn_ingress(int mode, u_int32_t *outer, const u_int32_t *inner)
105{
106 u_int8_t outer8, inner8;
107
108 if (!outer || !inner)
109 panic("NULL pointer passed to ip6_ecn_ingress");
110
111 outer8 = (ntohl(*outer) >> 20) & 0xff;
112 inner8 = (ntohl(*inner) >> 20) & 0xff;
113 ip_ecn_ingress(mode, &outer8, &inner8);
114 *outer &= ~htonl(0xff << 20);
115 *outer |= htonl((u_int32_t)outer8 << 20);
116}
117
118void
119ip6_ecn_egress(int mode, const u_int32_t *outer, u_int32_t *inner)
120{
121 u_int8_t outer8, inner8;
122
123 if (!outer || !inner)
124 panic("NULL pointer passed to ip6_ecn_egress");
125
126 outer8 = (ntohl(*outer) >> 20) & 0xff;
127 inner8 = (ntohl(*inner) >> 20) & 0xff;
128 ip_ecn_egress(mode, &outer8, &inner8);
129 *inner &= ~htonl(0xff << 20);
130 *inner |= htonl((u_int32_t)inner8 << 20);
131}
132#endif
133