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 /* \summary: Generic Network Virtualization Encapsulation (Geneve) printer */
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #include <netdissect-stdinc.h>
  25
  26 #include "netdissect.h"
  27 #include "extract.h"
  28 #include "ethertype.h"
  29
  30 /*
  31  * Geneve header, draft-ietf-nvo3-geneve
  32  *
  33  *    0                   1                   2                   3
  34  *    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
  35  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  36  *    |Ver|  Opt Len  |O|C|    Rsvd.  |          Protocol Type        |
  37  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  38  *    |        Virtual Network Identifier (VNI)       |    Reserved   |
  39  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  40  *    |                    Variable Length Options                    |
  41  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  42  *
  43  * Options:
  44  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  45  *    |          Option Class         |      Type     |R|R|R| Length  |
  46  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  47  *    |                      Variable Option Data                     |
  48  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  49  */
  50
  51 #define VER_SHIFT 6
  52 #define HDR_OPTS_LEN_MASK 0x3F
  53
  54 #define FLAG_OAM      (1 << 7)
  55 #define FLAG_CRITICAL (1 << 6)
  56 #define FLAG_R1       (1 << 5)
  57 #define FLAG_R2       (1 << 4)
  58 #define FLAG_R3       (1 << 3)
  59 #define FLAG_R4       (1 << 2)
  60 #define FLAG_R5       (1 << 1)
  61 #define FLAG_R6       (1 << 0)
  62
  63 #define OPT_TYPE_CRITICAL (1 << 7)
  64 #define OPT_LEN_MASK 0x1F
  65
  66 static const struct tok geneve_flag_values[] = {
  67         { FLAG_OAM, "O" },
  68         { FLAG_CRITICAL, "C" },
  69         { FLAG_R1, "R1" },
  70         { FLAG_R2, "R2" },
  71         { FLAG_R3, "R3" },
  72         { FLAG_R4, "R4" },
  73         { FLAG_R5, "R5" },
  74         { FLAG_R6, "R6" },
  75         { 0, NULL }
  76 };
  77
  78 static const char *
  79 format_opt_class(uint16_t opt_class)
  80 {
  81     switch (opt_class) {
  82     case 0x0100:
  83         return "Linux";
  84     case 0x0101:
  85         return "Open vSwitch";
  86     case 0x0102:
  87         return "Open Virtual Networking (OVN)";
  88     case 0x0103:
  89         return "In-band Network Telemetry (INT)";
  90     case 0x0104:
  91         return "VMware";
  92     default:
  93         if (opt_class <= 0x00ff)
  94             return "Standard";
  95         else if (opt_class >= 0xfff0)
  96             return "Experimental";
  97     }
  98
  99     return "Unknown";
 100 }
 101
 102 static void
 103 geneve_opts_print(netdissect_options *ndo, const u_char *bp, u_int len)
 104 {
 105     const char *sep = "";
 106
 107     while (len > 0) {
 108         uint16_t opt_class;
 109         uint8_t opt_type;
 110         uint8_t opt_len;
 111
 112         ND_PRINT((ndo, "%s", sep));
 113         sep = ", ";
 114
 115         opt_class = EXTRACT_16BITS(bp);
 116         opt_type = *(bp + 2);
 117         opt_len = 4 + ((*(bp + 3) & OPT_LEN_MASK) * 4);
 118
 119         ND_PRINT((ndo, "class %s (0x%x) type 0x%x%s len %u",
 120                   format_opt_class(opt_class), opt_class, opt_type,
 121                   opt_type & OPT_TYPE_CRITICAL ? "(C)" : "", opt_len));
 122
 123         if (opt_len > len) {
 124             ND_PRINT((ndo, " [bad length]"));
 125             return;
 126         }
 127
 128         if (ndo->ndo_vflag > 1 && opt_len > 4) {
 129             const uint32_t *data = (const uint32_t *)(bp + 4);
 130             int i;
 131
 132             ND_PRINT((ndo, " data"));
 133
 134             for (i = 4; i < opt_len; i += 4) {
 135                 ND_PRINT((ndo, " %08x", EXTRACT_32BITS(data)));
 136                 data++;
 137             }
 138         }
 139
 140         bp += opt_len;
 141         len -= opt_len;
 142     }
 143 }
 144
 145 void
 146 geneve_print(netdissect_options *ndo, const u_char *bp, u_int len)
 147 {
 148     uint8_t ver_opt;
 149     u_int version;
 150     uint8_t flags;
 151     uint16_t prot;
 152     uint32_t vni;
 153     uint8_t reserved;
 154     u_int opts_len;
 155
 156     ND_PRINT((ndo, "Geneve"));
 157
 158     ND_TCHECK2(*bp, 8);
 159
 160     ver_opt = *bp;
 161     bp += 1;
 162     len -= 1;
 163
 164     version = ver_opt >> VER_SHIFT;
 165     if (version != 0) {
 166         ND_PRINT((ndo, " ERROR: unknown-version %u", version));
 167         return;
 168     }
 169
 170     flags = *bp;
 171     bp += 1;
 172     len -= 1;
 173
 174     prot = EXTRACT_16BITS(bp);
 175     bp += 2;
 176     len -= 2;
 177
 178     vni = EXTRACT_24BITS(bp);
 179     bp += 3;
 180     len -= 3;
 181
 182     reserved = *bp;
 183     bp += 1;
 184     len -= 1;
 185
 186     ND_PRINT((ndo, ", Flags [%s]",
 187               bittok2str_nosep(geneve_flag_values, "none", flags)));
 188     ND_PRINT((ndo, ", vni 0x%x", vni));
 189
 190     if (reserved)
 191         ND_PRINT((ndo, ", rsvd 0x%x", reserved));
 192
 193     if (ndo->ndo_eflag)
 194         ND_PRINT((ndo, ", proto %s (0x%04x)",
 195                   tok2str(ethertype_values, "unknown", prot), prot));
 196
 197     opts_len = (ver_opt & HDR_OPTS_LEN_MASK) * 4;
 198
 199     if (len < opts_len) {
 200         ND_PRINT((ndo, " truncated-geneve - %u bytes missing",
 201                   opts_len - len));
 202         return;
 203     }
 204
 205     ND_TCHECK2(*bp, opts_len);
 206
 207     if (opts_len > 0) {
 208         ND_PRINT((ndo, ", options ["));
 209
 210         if (ndo->ndo_vflag)
 211             geneve_opts_print(ndo, bp, opts_len);
 212         else
 213             ND_PRINT((ndo, "%u bytes", opts_len));
 214
 215         ND_PRINT((ndo, "]"));
 216     }
 217
 218     bp += opts_len;
 219     len -= opts_len;
 220
 221     if (ndo->ndo_vflag < 1)
 222         ND_PRINT((ndo, ": "));
 223     else
 224         ND_PRINT((ndo, "\n\t"));
 225
 226     if (ethertype_print(ndo, prot, bp, len, ndo->ndo_snapend - bp, NULL, NULL) == 0) {
 227         if (prot == ETHERTYPE_TEB)
 228             ether_print(ndo, bp, len, ndo->ndo_snapend - bp, NULL, NULL);
 229         else
 230             ND_PRINT((ndo, "geneve-proto-0x%x", prot));
 231     }
 232
 233     return;
 234
 235 trunc:
 236     ND_PRINT((ndo, " [|geneve]"));
 237 }