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

   1 /*
   2  * Copyright (c) 2014 VMware, Inc. All Rights Reserved.
   3  *
   4  * Jesse Gross <jesse@nicira.com>
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that: (1) source code
   8  * distributions retain the above copyright notice and this paragraph
   9  * in its entirety, and (2) distributions including binary code include
  10  * the above copyright notice and this paragraph in its entirety in
  11  * the documentation or other materials provided with the distribution.
  12  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
  13  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
  14  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  15  * FOR A PARTICULAR PURPOSE.
  16  */
  17
  18 #ifdef HAVE_CONFIG_H
  19 #include "config.h"
  20 #endif
  21
  22 #include <tcpdump-stdinc.h>
  23
  24 #include "interface.h"
  25 #include "extract.h"
  26 #include "ethertype.h"
  27
  28 /*
  29  * Geneve header, draft-gross-geneve-02
  30  *
  31  *    0                   1                   2                   3
  32  *    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  33  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  34  *    |Ver|  Opt Len  |O|C|    Rsvd.  |          Protocol Type        |
  35  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  36  *    |        Virtual Network Identifier (VNI)       |    Reserved   |
  37  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  38  *    |                    Variable Length Options                    |
  39  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  40  *
  41  * Options:
  42  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  43  *    |          Option Class         |      Type     |R|R|R| Length  |
  44  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  45  *    |                      Variable Option Data                     |
  46  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  47  */
  48
  49 #define VER_SHIFT 6
  50 #define HDR_OPTS_LEN_MASK 0x3F
  51
  52 #define FLAG_OAM      (1 << 7)
  53 #define FLAG_CRITICAL (1 << 6)
  54 #define FLAG_R1       (1 << 5)
  55 #define FLAG_R2       (1 << 4)
  56 #define FLAG_R3       (1 << 3)
  57 #define FLAG_R4       (1 << 2)
  58 #define FLAG_R5       (1 << 1)
  59 #define FLAG_R6       (1 << 0)
  60
  61 #define OPT_TYPE_CRITICAL (1 << 7)
  62 #define OPT_LEN_MASK 0x1F
  63
  64 static const struct tok geneve_flag_values[] = {
  65         { FLAG_OAM, "O" },
  66         { FLAG_CRITICAL, "C" },
  67         { FLAG_R1, "R1" },
  68         { FLAG_R2, "R2" },
  69         { FLAG_R3, "R3" },
  70         { FLAG_R4, "R4" },
  71         { FLAG_R5, "R5" },
  72         { FLAG_R6, "R6" },
  73         { 0, NULL }
  74 };
  75
  76 static const char *
  77 format_opt_class(uint16_t opt_class)
  78 {
  79     if (opt_class <= 0xff)
  80         return "Standard";
  81     else if (opt_class == 0xffff)
  82         return "Experimental";
  83     else
  84         return "Unknown";
  85 }
  86
  87 static void
  88 geneve_opts_print(netdissect_options *ndo, const u_char *bp, u_int len)
  89 {
  90     const char *sep = "";
  91
  92     while (len > 0) {
  93         uint16_t opt_class;
  94         uint8_t opt_type;
  95         uint8_t opt_len;
  96
  97         ND_PRINT((ndo, "%s", sep));
  98         sep = ", ";
  99
 100         opt_class = EXTRACT_16BITS(bp);
 101         opt_type = *(bp + 2);
 102         opt_len = 4 + ((*(bp + 3) & OPT_LEN_MASK) * 4);
 103
 104         ND_PRINT((ndo, "class %s (0x%x) type 0x%x%s len %u",
 105                   format_opt_class(opt_class), opt_class, opt_type,
 106                   opt_type & OPT_TYPE_CRITICAL ? "(C)" : "", opt_len));
 107
 108         if (opt_len > len) {
 109             ND_PRINT((ndo, " [bad length]"));
 110             return;
 111         }
 112
 113         if (ndo->ndo_vflag > 1 && opt_len > 4) {
 114             const uint32_t *print_data = (const uint32_t *)(bp + 4);
 115             int i;
 116
 117             ND_PRINT((ndo, " data"));
 118
 119             for (i = 4; i < opt_len; i += 4) {
 120                 ND_PRINT((ndo, " %08x", EXTRACT_32BITS(print_data)));
 121                 print_data++;
 122             }
 123         }
 124
 125         bp += opt_len;
 126         len -= opt_len;
 127     }
 128 }
 129
 130 void
 131 geneve_print(netdissect_options *ndo, const u_char *bp, u_int len)
 132 {
 133     uint8_t ver_opt;
 134     uint version;
 135     uint8_t flags;
 136     uint16_t prot;
 137     uint32_t vni;
 138     uint8_t reserved;
 139     u_int opts_len;
 140
 141     ND_PRINT((ndo, "Geneve"));
 142
 143     ND_TCHECK2(*bp, 8);
 144
 145     ver_opt = *bp;
 146     bp += 1;
 147     len -= 1;
 148
 149     version = ver_opt >> VER_SHIFT;
 150     if (version != 0) {
 151         ND_PRINT((ndo, " ERROR: unknown-version %u", version));
 152         return;
 153     }
 154
 155     flags = *bp;
 156     bp += 1;
 157     len -= 1;
 158
 159     prot = EXTRACT_16BITS(bp);
 160     bp += 2;
 161     len -= 2;
 162
 163     vni = EXTRACT_24BITS(bp);
 164     bp += 3;
 165     len -= 3;
 166
 167     reserved = *bp;
 168     bp += 1;
 169     len -= 1;
 170
 171     ND_PRINT((ndo, ", Flags [%s]",
 172               bittok2str_nosep(geneve_flag_values, "none", flags)));
 173     ND_PRINT((ndo, ", vni 0x%x", vni));
 174
 175     if (reserved)
 176         ND_PRINT((ndo, ", rsvd 0x%x", reserved));
 177
 178     if (ndo->ndo_eflag)
 179         ND_PRINT((ndo, ", proto %s (0x%04x)",
 180                   tok2str(ethertype_values, "unknown", prot), prot));
 181
 182     opts_len = (ver_opt & HDR_OPTS_LEN_MASK) * 4;
 183
 184     if (len < opts_len) {
 185         ND_PRINT((ndo, " truncated-geneve - %u bytes missing",
 186                   len - opts_len));
 187         return;
 188     }
 189
 190     ND_TCHECK2(*bp, opts_len);
 191
 192     if (opts_len > 0) {
 193         ND_PRINT((ndo, ", options ["));
 194
 195         if (ndo->ndo_vflag)
 196             geneve_opts_print(ndo, bp, opts_len);
 197         else
 198             ND_PRINT((ndo, "%u bytes", opts_len));
 199
 200         ND_PRINT((ndo, "]"));
 201     }
 202
 203     bp += opts_len;
 204     len -= opts_len;
 205
 206     if (ndo->ndo_vflag < 1)
 207         ND_PRINT((ndo, ": "));
 208     else
 209         ND_PRINT((ndo, "\n\t"));
 210
 211     if (ethertype_print(ndo, prot, bp, len, len) == 0) {
 212         if (prot == ETHERTYPE_TEB)
 213             ether_print(ndo, bp, len, len, NULL, NULL);
 214         else
 215             ND_PRINT((ndo, "geneve-proto-0x%x", prot));
 216     }
 217
 218     return;
 219
 220 trunc:
 221     ND_PRINT((ndo, " [|geneve]"));
 222 }