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ip_ecn.c revision 1.15.102.1 
      1 /*	$NetBSD: ip_ecn.c,v 1.15.102.1 2017/12/03 11:39:04 jdolecek 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 1.15.102.1 2017/12/03 11:39:04 jdolecek 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  */
     63 void
     64 ip_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  */
     85 void
     86 ip_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
    103 void
    104 ip6_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 
    118 void
    119 ip6_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