sys/netinet/ip_ecn.c

   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_ECN_CE;
  71                 break;
  72         case ECN_FORBIDDEN:             /* ECN forbidden */
  73                 *outer &= ~(IPTOS_ECN_ECT0 | IPTOS_ECN_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_ECN_CE)
  92                         *inner |= IPTOS_ECN_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