xref: /netbsd-src/sys/netinet/ip_ecn.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
1 /*	$NetBSD: ip_ecn.c,v 1.10 2001/05/10 01:37:42 itojun 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 "opt_inet.h"
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.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 
55 /*
56  * modify outer ECN (TOS) field on ingress operation (tunnel encapsulation).
57  */
58 void
59 ip_ecn_ingress(mode, outer, inner)
60 	int mode;
61 	u_int8_t *outer;
62 	const u_int8_t *inner;
63 {
64 	if (!outer || !inner)
65 		panic("NULL pointer passed to ip_ecn_ingress");
66 
67 	*outer = *inner;
68 	switch (mode) {
69 	case ECN_ALLOWED:		/* ECN allowed */
70 		*outer &= ~IPTOS_CE;
71 		break;
72 	case ECN_FORBIDDEN:		/* ECN forbidden */
73 		*outer &= ~(IPTOS_ECT | IPTOS_CE);
74 		break;
75 	case ECN_NOCARE:	/* no consideration to ECN */
76 		break;
77 	}
78 }
79 
80 /*
81  * modify inner ECN (TOS) field on egress operation (tunnel decapsulation).
82  */
83 void
84 ip_ecn_egress(mode, outer, inner)
85 	int mode;
86 	const u_int8_t *outer;
87 	u_int8_t *inner;
88 {
89 	if (!outer || !inner)
90 		panic("NULL pointer passed to ip_ecn_egress");
91 
92 	switch (mode) {
93 	case ECN_ALLOWED:
94 		if (*outer & IPTOS_CE)
95 			*inner |= IPTOS_CE;
96 		break;
97 	case ECN_FORBIDDEN:		/* ECN forbidden */
98 	case ECN_NOCARE:	/* no consideration to ECN */
99 		break;
100 	}
101 }
102 
103 #ifdef INET6
104 void
105 ip6_ecn_ingress(mode, outer, inner)
106 	int mode;
107 	u_int32_t *outer;
108 	const u_int32_t *inner;
109 {
110 	u_int8_t outer8, inner8;
111 
112 	if (!outer || !inner)
113 		panic("NULL pointer passed to ip6_ecn_ingress");
114 
115 	inner8 = (ntohl(*inner) >> 20) & 0xff;
116 	ip_ecn_ingress(mode, &outer8, &inner8);
117 	*outer &= ~htonl(0xff << 20);
118 	*outer |= htonl((u_int32_t)outer8 << 20);
119 }
120 
121 void
122 ip6_ecn_egress(mode, outer, inner)
123 	int mode;
124 	const u_int32_t *outer;
125 	u_int32_t *inner;
126 {
127 	u_int8_t outer8, inner8;
128 
129 	if (!outer || !inner)
130 		panic("NULL pointer passed to ip6_ecn_egress");
131 
132 	outer8 = (ntohl(*outer) >> 20) & 0xff;
133 	ip_ecn_egress(mode, &outer8, &inner8);
134 	*inner &= ~htonl(0xff << 20);
135 	*inner |= htonl((u_int32_t)inner8 << 20);
136 }
137 #endif
138