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ip_ecn.c revision 1.14 
      1 /*	$NetBSD: ip_ecn.c,v 1.14 2005/12/11 12:24:57 christos 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 1.14 2005/12/11 12:24:57 christos Exp $");
     40 
     41 #include "opt_inet.h"
     42 
     43 #include <sys/param.h>
     44 #include <sys/systm.h>
     45 #include <sys/malloc.h>
     46 #include <sys/mbuf.h>
     47 #include <sys/errno.h>
     48 
     49 #include <netinet/in.h>
     50 #include <netinet/in_systm.h>
     51 #include <netinet/ip.h>
     52 #ifdef INET6
     53 #include <netinet/ip6.h>
     54 #endif
     55 
     56 #include <netinet/ip_ecn.h>
     57 
     58 /*
     59  * modify outer ECN (TOS) field on ingress operation (tunnel encapsulation).
     60  */
     61 void
     62 ip_ecn_ingress(int mode, u_int8_t *outer, 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(int mode, const u_int8_t *outer, u_int8_t *inner)
     85 {
     86 	if (!outer || !inner)
     87 		panic("NULL pointer passed to ip_ecn_egress");
     88 
     89 	switch (mode) {
     90 	case ECN_ALLOWED:
     91 		if (*outer & IPTOS_CE)
     92 			*inner |= IPTOS_CE;
     93 		break;
     94 	case ECN_FORBIDDEN:		/* ECN forbidden */
     95 	case ECN_NOCARE:	/* no consideration to ECN */
     96 		break;
     97 	}
     98 }
     99 
    100 #ifdef INET6
    101 void
    102 ip6_ecn_ingress(int mode, u_int32_t *outer, const u_int32_t *inner)
    103 {
    104 	u_int8_t outer8, inner8;
    105 
    106 	if (!outer || !inner)
    107 		panic("NULL pointer passed to ip6_ecn_ingress");
    108 
    109 	outer8 = (ntohl(*outer) >> 20) & 0xff;
    110 	inner8 = (ntohl(*inner) >> 20) & 0xff;
    111 	ip_ecn_ingress(mode, &outer8, &inner8);
    112 	*outer &= ~htonl(0xff << 20);
    113 	*outer |= htonl((u_int32_t)outer8 << 20);
    114 }
    115 
    116 void
    117 ip6_ecn_egress(int mode, const u_int32_t *outer, u_int32_t *inner)
    118 {
    119 	u_int8_t outer8, inner8;
    120 
    121 	if (!outer || !inner)
    122 		panic("NULL pointer passed to ip6_ecn_egress");
    123 
    124 	outer8 = (ntohl(*outer) >> 20) & 0xff;
    125 	inner8 = (ntohl(*inner) >> 20) & 0xff;
    126 	ip_ecn_egress(mode, &outer8, &inner8);
    127 	*inner &= ~htonl(0xff << 20);
    128 	*inner |= htonl((u_int32_t)inner8 << 20);
    129 }
    130 #endif
    131