usr/src/uts/common/ipp/dscpmk/dscpmk.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #include <sys/types.h>
  28 #include <sys/atomic.h>
  29 #include <sys/pattr.h>
  30 #include <netinet/in.h>
  31 #include <netinet/ip6.h>
  32 #include <inet/common.h>
  33 #include <inet/ip.h>
  34 #include <inet/ip6.h>
  35 #include <ipp/dscpmk/dscpmk_impl.h>
  36
  37 /* Module to mark the ToS/DS field for a given packet */
  38
  39 /* Debug level */
  40 int dscpmk_debug = 0;
  41
  42 /*
  43  * Given a packet, this routine marks the ToS or DSCP for IPv4 and IPv6 resp.
  44  * using the configured dscp_map.
  45  * Note that this module does not change the ECN bits.
  46  */
  47 int
  48 dscpmk_process(mblk_t **mpp, dscpmk_data_t *dscpmk_data, ip_proc_t proc)
  49 {
  50         ipha_t *ipha;
  51         ip6_t *ip6_hdr;
  52         boolean_t is_v4;
  53         uint8_t dscp, new_dscp;
  54         mblk_t *mp;
  55
  56         ASSERT((mpp != NULL) && (*mpp != NULL));
  57         mp = *mpp;
  58
  59         /*
  60          * The action module will receive an M_DATA or an M_CTL followed
  61          * by an M_DATA. In the latter case skip the M_CTL.
  62          */
  63         if (mp->b_datap->db_type != M_DATA) {
  64                 if ((mp->b_cont != NULL) &&
  65                     (mp->b_cont->b_datap->db_type == M_DATA)) {
  66                         mp = mp->b_cont;
  67                 } else {
  68                         dscpmk0dbg(("dscpmk_process: no data\n"));
  69                         atomic_inc_64(&dscpmk_data->epackets);
  70                         return (EINVAL);
  71                 }
  72         }
  73
  74         /* Pull-up needed? */
  75         if ((mp->b_wptr - mp->b_rptr) < IP_SIMPLE_HDR_LENGTH) {
  76                 if (!pullupmsg(mp, IP_SIMPLE_HDR_LENGTH)) {
  77                         dscpmk0dbg(("dscpmk_process: pullup failed\n"));
  78                         atomic_inc_64(&dscpmk_data->epackets);
  79                         return (EINVAL);
  80                 }
  81         }
  82         ipha = (ipha_t *)mp->b_rptr;
  83
  84         /* Update global stats */
  85         atomic_inc_64(&dscpmk_data->npackets);
  86
  87         /*
  88          * This should only be called for outgoing packets. For inbound packets
  89          * proceed with the next action.
  90          */
  91         if ((proc == IPP_LOCAL_IN) || (proc == IPP_FWD_IN)) {
  92                 dscpmk2dbg(("dscpmk_process: cannot mark incoming packets\n"));
  93                 atomic_inc_64(&dscpmk_data->ipackets);
  94                 return (0);
  95         }
  96
  97         /* Figure out the ToS or the Traffic Class from the message */
  98         if (IPH_HDR_VERSION(ipha) == IPV4_VERSION) {
  99                 dscp = ipha->ipha_type_of_service;
 100                 is_v4 = B_TRUE;
 101         } else {
 102                 ip6_hdr = (ip6_t *)mp->b_rptr;
 103                 dscp = __IPV6_TCLASS_FROM_FLOW(ip6_hdr->ip6_vcf);
 104                 is_v4 = B_FALSE;
 105         }
 106
 107         /*
 108          * Select the new dscp from the dscp_map after ignoring the
 109          * ECN/CU from dscp (hence dscp >> 2). new_dscp will be the
 110          * 6-bit DSCP value.
 111          */
 112         new_dscp = dscpmk_data->dscp_map[dscp >> 2];
 113
 114         /* Update stats for this new_dscp */
 115         atomic_inc_64(&dscpmk_data->dscp_stats[new_dscp].npackets);
 116
 117         /*
 118          * if new_dscp is same as the original, update stats and
 119          * return.
 120          */
 121         if (new_dscp == (dscp >> 2)) {
 122                 atomic_inc_64(&dscpmk_data->unchanged);
 123                 return (0);
 124         }
 125
 126         /* Get back the ECN/CU value from the original dscp */
 127         new_dscp = (new_dscp << 2) | (dscp & 0x3);
 128
 129         atomic_inc_64(&dscpmk_data->changed);
 130         /*
 131          * IPv4 : ToS structure -- RFC 791
 132          *
 133          *        0   1   2   3   4   5   6   7
 134          *      +---+---+---+---+---+---+---+---+
 135          *      | IP Precd  | D | T | R | 0 | 0 |
 136          *      |           |   |   |   |   |   |
 137          *      +---+---+---+---+---+---+---+---+
 138          *
 139          * For Backward Compatability the diff serv DSCP will be mapped
 140          * to the 3-bits Precedence field. DTR is not supported. Thus,
 141          * the following Class Seletor CodePoints are reserved from this
 142          * purpose : xxx000; where x is 0 or 1 (note the last 2 bits are
 143          * 00) -- see RFC 2474.
 144          */
 145
 146         if (is_v4) {
 147                 ipha->ipha_type_of_service = new_dscp;
 148                 /*
 149                  * If the hardware supports checksumming, we don't need
 150                  * to do anything.
 151                  */
 152                 if (!(mp->b_datap->db_struioun.cksum.flags &
 153                     HCK_IPV4_HDRCKSUM)) {
 154                         ipha->ipha_hdr_checksum = 0;
 155                         ipha->ipha_hdr_checksum = ip_csum_hdr(ipha);
 156                 }
 157         } else {
 158
 159         /*
 160          * IPv6 : DSCP field structure is as given -- RFC 2474
 161          *
 162          *        0   1   2   3   4   5   6   7
 163          *      +---+---+---+---+---+---+---+---+
 164          *      |       DSCP            | CU    |
 165          *      |                       |       |
 166          *      +---+---+---+---+---+---+---+---+
 167          *
 168          * CU -- Currently Unused
 169          *
 170          * the 32 bit vcf consists of version (4 bits), Traffic class (8 bits)
 171          * and flow id (20 bits). Need to take care of Big/Little-Endianess.
 172          */
 173 #ifdef _BIG_ENDIAN
 174                 ip6_hdr->ip6_vcf = (ip6_hdr->ip6_vcf & TCLASS_MASK) |
 175                     (new_dscp << 20);
 176 #else
 177                 ip6_hdr->ip6_vcf = (ip6_hdr->ip6_vcf & TCLASS_MASK) |
 178                     ((new_dscp >> 4) | ((new_dscp << 12) & 0xF000));
 179 #endif
 180         }
 181
 182         return (0);
 183 }