The Tcpdump Group git mirrors - tcpdump/blob - print-erspan.c

   1 /*      $OpenBSD: print-gre.c,v 1.6 2002/10/30 03:04:04 fgsch Exp $     */
   2
   3 /*
   4  * Copyright (c) 2002 Jason L. Wright (jason@thought.net)
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  25  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  26  * POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /* \summary: Cisco ERSPAN printer */
  30
  31 /*
  32  * Specifications: I-D draft-foschiano-erspan-03.
  33  */
  34
  35 #include <config.h>
  36
  37 #include "netdissect-stdinc.h"
  38
  39 #define ND_LONGJMP_FROM_TCHECK
  40 #include "netdissect.h"
  41 #include "extract.h"
  42 #include "gre.h"
  43
  44 /*
  45  * ERSPAN Type II.
  46  */
  47 #define ERSPAN2_VER_SHIFT       28
  48 #define ERSPAN2_VER_MASK        (0xfU << ERSPAN2_VER_SHIFT)
  49 #define ERSPAN2_VER             (0x1U << ERSPAN2_VER_SHIFT)
  50 #define ERSPAN2_VLAN_SHIFT      16
  51 #define ERSPAN2_VLAN_MASK       (0xfffU << ERSPAN2_VLAN_SHIFT)
  52 #define ERSPAN2_COS_SHIFT       13
  53 #define ERSPAN2_COS_MASK        (0x7U << ERSPAN2_COS_SHIFT)
  54 #define ERSPAN2_EN_SHIFT        11
  55 #define ERSPAN2_EN_MASK         (0x3U << ERSPAN2_EN_SHIFT)
  56 #define ERSPAN2_EN_NONE         (0x0U << ERSPAN2_EN_SHIFT)
  57 #define ERSPAN2_EN_ISL          (0x1U << ERSPAN2_EN_SHIFT)
  58 #define ERSPAN2_EN_DOT1Q        (0x2U << ERSPAN2_EN_SHIFT)
  59 #define ERSPAN2_EN_VLAN         (0x3U << ERSPAN2_EN_SHIFT)
  60 #define ERSPAN2_T_SHIFT         10
  61 #define ERSPAN2_T_MASK          (0x1U << ERSPAN2_T_SHIFT)
  62 #define ERSPAN2_SID_SHIFT       0
  63 #define ERSPAN2_SID_MASK        (0x3ffU << ERSPAN2_SID_SHIFT)
  64
  65 #define ERSPAN2_INDEX_SHIFT     0
  66 #define ERSPAN2_INDEX_MASK      (0xfffffU << ERSPAN2_INDEX_SHIFT)
  67
  68 void
  69 erspan_i_ii_print(netdissect_options *ndo, uint16_t flags, const u_char *bp, u_int len)
  70 {
  71         uint32_t hdr, ver, vlan, cos, en, sid, index;
  72
  73         ndo->ndo_protocol = "erspan";
  74         nd_print_protocol(ndo);
  75
  76         if (!(flags & GRE_SP)) {
  77                 /*
  78                  * ERSPAN Type I; no header, just a raw Ethernet frame.
  79                  */
  80                 ND_PRINT(" type1: ");
  81                 ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
  82                 return;
  83         }
  84
  85         /*
  86          * ERSPAN Type II.
  87          */
  88         ND_ICHECK_U(len, <, 4);
  89         hdr = GET_BE_U_4(bp);
  90         bp += 4;
  91         len -= 4;
  92
  93         ver = hdr & ERSPAN2_VER_MASK;
  94         if (ver != ERSPAN2_VER) {
  95                 /*
  96                  * Not Type II.
  97                  */
  98                 ver >>= ERSPAN2_VER_SHIFT;
  99                 ND_PRINT(" erspan-unknown-version-%x", ver);
 100                 return;
 101         }
 102
 103         if (ndo->ndo_vflag)
 104                 ND_PRINT(" type2");
 105
 106         sid = (hdr & ERSPAN2_SID_MASK) >> ERSPAN2_SID_SHIFT;
 107         ND_PRINT(" session %u", sid);
 108
 109         en = hdr & ERSPAN2_EN_MASK;
 110         vlan = (hdr & ERSPAN2_VLAN_MASK) >> ERSPAN2_VLAN_SHIFT;
 111         switch (en) {
 112         case ERSPAN2_EN_NONE:
 113                 break;
 114         case ERSPAN2_EN_ISL:
 115                 ND_PRINT(" isl %u", vlan);
 116                 break;
 117         case ERSPAN2_EN_DOT1Q:
 118                 ND_PRINT(" vlan %u", vlan);
 119                 break;
 120         case ERSPAN2_EN_VLAN:
 121                 ND_PRINT(" vlan payload");
 122                 break;
 123         }
 124
 125         if (ndo->ndo_vflag) {
 126                 cos = (hdr & ERSPAN2_COS_MASK) >> ERSPAN2_COS_SHIFT;
 127                 ND_PRINT(" cos %u", cos);
 128
 129                 if (hdr & ERSPAN2_T_MASK)
 130                         ND_PRINT(" truncated");
 131         }
 132
 133         ND_ICHECK_U(len, <, 4);
 134         hdr = GET_BE_U_4(bp);
 135         bp += 4;
 136         len -= 4;
 137
 138         if (ndo->ndo_vflag) {
 139                 index = (hdr & ERSPAN2_INDEX_MASK) >> ERSPAN2_INDEX_SHIFT;
 140                 ND_PRINT(" index %u", index);
 141         }
 142
 143         ND_PRINT(": ");
 144         ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
 145         return;
 146
 147 invalid:
 148         nd_print_invalid(ndo);
 149 }
 150
 151 /*
 152  * ERSPAN Type III.
 153  */
 154 #define ERSPAN3_VER_SHIFT               28
 155 #define ERSPAN3_VER_MASK                (0xfU << ERSPAN3_VER_SHIFT)
 156 #define ERSPAN3_VER                     (0x2U << ERSPAN3_VER_SHIFT)
 157 #define ERSPAN3_VLAN_SHIFT              16
 158 #define ERSPAN3_VLAN_MASK               (0xfffU << ERSPAN3_VLAN_SHIFT)
 159 #define ERSPAN3_COS_SHIFT               13
 160 #define ERSPAN3_COS_MASK                (0x7U << ERSPAN3_COS_SHIFT)
 161 #define ERSPAN3_BSO_SHIFT               11
 162 #define ERSPAN3_BSO_MASK                (0x3U << ERSPAN3_BSO_SHIFT)
 163 #define ERSPAN3_BSO_GOOD_UNKNOWN        0x0U
 164 #define ERSPAN3_BSO_BAD                 0x3U
 165 #define ERSPAN3_BSO_SHORT               0x1U
 166 #define ERSPAN3_BSO_OVERSIZED           0x2U
 167 #define ERSPAN3_T_SHIFT                 10
 168 #define ERSPAN3_T_MASK                  (0x1U << ERSPAN3_T_SHIFT)
 169 #define ERSPAN3_SID_SHIFT               0
 170 #define ERSPAN3_SID_MASK                (0x3ffU << ERSPAN3_SID_SHIFT)
 171 #define ERSPAN3_P_SHIFT                 15
 172 #define ERSPAN3_P_MASK                  (0x1U << ERSPAN3_P_SHIFT)
 173 #define ERSPAN3_FT_SHIFT                10
 174 #define ERSPAN3_FT_MASK                 (0x1fU << ERSPAN3_FT_SHIFT)
 175 #define ERSPAN3_FT_ETHERNET             0
 176 #define ERSPAN3_FT_IP                   2
 177 #define ERSPAN3_HW_ID_SHIFT             4
 178 #define ERSPAN3_HW_ID_MASK              (0x3fU << ERSPAN3_HW_ID_SHIFT)
 179 #define ERSPAN3_D_SHIFT                 3
 180 #define ERSPAN3_D_MASK                  (0x1U << ERSPAN3_D_SHIFT)
 181 #define ERSPAN3_GRA_SHIFT               1
 182 #define ERSPAN3_GRA_MASK                (0x3U << ERSPAN3_GRA_SHIFT)
 183 #define ERSPAN3_O_SHIFT                 0
 184 #define ERSPAN3_O_MASK                  (0x1U << ERSPAN3_O_SHIFT)
 185
 186 static const struct tok erspan3_bso_values[] = {
 187         { ERSPAN3_BSO_GOOD_UNKNOWN, "Good/unknown" },
 188         { ERSPAN3_BSO_BAD,          "Bad" },
 189         { ERSPAN3_BSO_SHORT,        "Short" },
 190         { ERSPAN3_BSO_OVERSIZED,    "Oversized" },
 191         { 0, NULL }
 192 };
 193
 194 static const struct tok erspan3_ft_values[] = {
 195         { ERSPAN3_FT_ETHERNET, "Ethernet" },
 196         { ERSPAN3_FT_IP, "IP" },
 197         { 0, NULL }
 198 };
 199
 200 void
 201 erspan_iii_print(netdissect_options *ndo, const u_char *bp, u_int len)
 202 {
 203         uint32_t hdr, hdr2, ver, cos, sid, ft;
 204
 205         ndo->ndo_protocol = "erspan";
 206         nd_print_protocol(ndo);
 207
 208         /*
 209          * We do not check the GRE flags; ERSPAN Type III always
 210          * has an ERSPAN header.
 211          */
 212         ND_ICHECK_U(len, <, 4);
 213         hdr = GET_BE_U_4(bp);
 214         bp += 4;
 215         len -= 4;
 216
 217         ver = hdr & ERSPAN3_VER_MASK;
 218         if (ver != ERSPAN3_VER) {
 219                 /*
 220                  * Not Type III.
 221                  */
 222                 ver >>= ERSPAN3_VER_SHIFT;
 223                 ND_PRINT(" erspan-unknown-version-%x", ver);
 224                 return;
 225         }
 226
 227         if (ndo->ndo_vflag)
 228                 ND_PRINT(" type3");
 229
 230         sid = (hdr & ERSPAN3_SID_MASK) >> ERSPAN3_SID_SHIFT;
 231         ND_PRINT(" session %u", sid);
 232
 233         ND_PRINT(" bso %s",
 234                  tok2str(erspan3_bso_values, "unknown %x",
 235                          (hdr & ERSPAN3_BSO_MASK) >> ERSPAN3_BSO_SHIFT));
 236
 237         if (ndo->ndo_vflag) {
 238                 cos = (hdr & ERSPAN3_COS_MASK) >> ERSPAN3_COS_SHIFT;
 239                 ND_PRINT(" cos %u", cos);
 240
 241                 if (hdr & ERSPAN3_T_MASK)
 242                         ND_PRINT(" truncated");
 243         }
 244
 245         /* Skip timestamp */
 246         ND_ICHECK_U(len, <, 4);
 247         ND_TCHECK_4(bp);
 248         bp += 4;
 249         len -= 4;
 250
 251         /* Skip SGT */
 252         ND_ICHECK_U(len, <, 2);
 253         ND_TCHECK_2(bp);
 254         bp += 2;
 255         len -= 2;
 256
 257         /* Additional fields */
 258         ND_ICHECK_U(len, <, 2);
 259         hdr2 = GET_BE_U_2(bp);
 260         bp += 2;
 261         len -= 2;
 262
 263         ft = (hdr2 & ERSPAN3_FT_MASK) >> ERSPAN3_FT_SHIFT;
 264         ND_PRINT(" ft %s",
 265                  tok2str(erspan3_ft_values, "unknown %x", ft));
 266
 267
 268         /* Do we have the platform-specific header? */
 269         if (hdr2 & ERSPAN3_O_MASK) {
 270                 /* Yes.  Skip it. */
 271                 ND_ICHECK_U(len, <, 8);
 272                 ND_TCHECK_8(bp);
 273                 bp += 8;
 274                 len -= 8;
 275         }
 276
 277         ND_PRINT(": ");
 278
 279         switch (ft) {
 280
 281         case ERSPAN3_FT_ETHERNET:
 282                 ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
 283                 break;
 284
 285         default:
 286                 ND_PRINT("Frame type unknown");
 287                 break;
 288         }
 289         return;
 290
 291 invalid:
 292         nd_print_invalid(ndo);
 293 }