xref: /openbsd-src/sys/netinet/ip_ecn.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: ip_ecn.c,v 1.3 2001/06/08 03:53:45 angelos Exp $	*/
2 /*	$KAME: ip_ecn.c,v 1.9 2000/10/01 12:44:48 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/param.h>
39 #include <sys/systm.h>
40 #include <sys/mbuf.h>
41 
42 #ifdef INET
43 #include <netinet/in.h>
44 #include <netinet/in_systm.h>
45 #include <netinet/ip.h>
46 #endif
47 
48 #ifdef INET6
49 #ifndef INET
50 #include <netinet/in.h>
51 #endif
52 #include <netinet/ip6.h>
53 #endif
54 
55 #include <netinet/ip_ecn.h>
56 
57 /*
58  * modify outer ECN (TOS) field on ingress operation (tunnel encapsulation).
59  * call it after you've done the default initialization/copy for the outer.
60  */
61 void
62 ip_ecn_ingress(mode, outer, inner)
63 	int mode;
64 	u_int8_t *outer;
65 	u_int8_t *inner;
66 {
67 	if (!outer || !inner)
68 		panic("NULL pointer passed to ip_ecn_ingress");
69 
70 	switch (mode) {
71 	case ECN_ALLOWED:		/* ECN allowed */
72 		*outer &= ~IPTOS_CE;
73 		break;
74 	case ECN_FORBIDDEN:		/* ECN forbidden */
75 		*outer &= ~(IPTOS_ECT | IPTOS_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  * call it after you've done the default initialization/copy for the inner.
85  */
86 void
87 ip_ecn_egress(mode, outer, inner)
88 	int mode;
89 	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
107 void
108 ip6_ecn_ingress(mode, outer, inner)
109 	int mode;
110 	u_int32_t *outer;
111 	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 
125 void
126 ip6_ecn_egress(mode, outer, inner)
127 	int mode;
128 	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