ip_ecn.c revision 94394 
1/*	$FreeBSD: head/sys/netinet/ip_ecn.c 94394 2002-04-11 02:14:21Z suz $	*/
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 "opt_inet.h"
39#include "opt_inet6.h"
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/mbuf.h>
44#include <sys/errno.h>
45
46#include <netinet/in.h>
47#include <netinet/in_systm.h>
48#include <netinet/ip.h>
49#ifdef INET6
50#include <netinet/ip6.h>
51#endif
52
53#include <netinet/ip_ecn.h>
54#ifdef INET6
55#include <netinet6/ip6_ecn.h>
56#endif
57
58/*
59 * modify outer ECN (TOS) field on ingress operation (tunnel encapsulation).
60 */
61void
62ip_ecn_ingress(mode, outer, inner)
63	int mode;
64	u_int8_t *outer;
65	const u_int8_t *inner;
66{
67	if (!outer || !inner)
68		panic("NULL pointer passed to ip_ecn_ingress");
69
70	*outer = *inner;
71	switch (mode) {
72	case ECN_ALLOWED:		/* ECN allowed */
73		*outer &= ~IPTOS_CE;
74		break;
75	case ECN_FORBIDDEN:		/* ECN forbidden */
76		*outer &= ~(IPTOS_ECT | IPTOS_CE);
77		break;
78	case ECN_NOCARE:	/* no consideration to ECN */
79		break;
80	}
81}
82
83/*
84 * modify inner ECN (TOS) field on egress operation (tunnel decapsulation).
85 */
86void
87ip_ecn_egress(mode, outer, inner)
88	int mode;
89	const u_int8_t *outer;
90	u_int8_t *inner;
91{
92	if (!outer || !inner)
93		panic("NULL pointer passed to ip_ecn_egress");
94
95	switch (mode) {
96	case ECN_ALLOWED:
97		if (*outer & IPTOS_CE)
98			*inner |= IPTOS_CE;
99		break;
100	case ECN_FORBIDDEN:		/* ECN forbidden */
101	case ECN_NOCARE:	/* no consideration to ECN */
102		break;
103	}
104}
105
106#ifdef INET6
107void
108ip6_ecn_ingress(mode, outer, inner)
109	int mode;
110	u_int32_t *outer;
111	const u_int32_t *inner;
112{
113	u_int8_t outer8, inner8;
114
115	if (!outer || !inner)
116		panic("NULL pointer passed to ip6_ecn_ingress");
117
118	outer8 = (ntohl(*outer) >> 20) & 0xff;
119	inner8 = (ntohl(*inner) >> 20) & 0xff;
120	ip_ecn_ingress(mode, &outer8, &inner8);
121	*outer &= ~htonl(0xff << 20);
122	*outer |= htonl((u_int32_t)outer8 << 20);
123}
124
125void
126ip6_ecn_egress(mode, outer, inner)
127	int mode;
128	const u_int32_t *outer;
129	u_int32_t *inner;
130{
131	u_int8_t outer8, inner8;
132
133	if (!outer || !inner)
134		panic("NULL pointer passed to ip6_ecn_egress");
135
136	outer8 = (ntohl(*outer) >> 20) & 0xff;
137	inner8 = (ntohl(*inner) >> 20) & 0xff;
138	ip_ecn_egress(mode, &outer8, &inner8);
139	*inner &= ~htonl(0xff << 20);
140	*inner |= htonl((u_int32_t)inner8 << 20);
141}
142#endif
143