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 /* specification: RFC 8926 */
  20
  21 #ifdef HAVE_CONFIG_H
  22 #include <config.h>
  23 #endif
  24
  25 #include "netdissect-stdinc.h"
  26
  27 #define ND_LONGJMP_FROM_TCHECK
  28 #include "netdissect.h"
  29 #include "extract.h"
  30 #include "ethertype.h"
  31
  32 /*
  33  * Geneve header:
  34  *
  35  *    0                   1                   2                   3
  36  *    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
  37  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  38  *    |Ver|  Opt Len  |O|C|    Rsvd.  |          Protocol Type        |
  39  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  40  *    |        Virtual Network Identifier (VNI)       |    Reserved   |
  41  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  42  *    |                                                               |
  43  *    ~                    Variable-Length Options                    ~
  44  *    |                                                               |
  45  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  46  *
  47  * Options:
  48  *    0                   1                   2                   3
  49  *    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
  50  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  51  *    |          Option Class         |      Type     |R|R|R| Length  |
  52  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  53  *    |                                                               |
  54  *    ~                  Variable-Length Option Data                  ~
  55  *    |                                                               |
  56  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  57  */
  58
  59 #define VER_SHIFT 6
  60 #define HDR_OPTS_LEN_MASK 0x3F
  61
  62 #define FLAG_OAM      (1 << 7)
  63 #define FLAG_CRITICAL (1 << 6)
  64 #define FLAG_R1       (1 << 5)
  65 #define FLAG_R2       (1 << 4)
  66 #define FLAG_R3       (1 << 3)
  67 #define FLAG_R4       (1 << 2)
  68 #define FLAG_R5       (1 << 1)
  69 #define FLAG_R6       (1 << 0)
  70
  71 #define OPT_TYPE_CRITICAL (1 << 7)
  72 #define OPT_LEN_MASK 0x1F
  73
  74 static const struct tok geneve_flag_values[] = {
  75         { FLAG_OAM, "O" },
  76         { FLAG_CRITICAL, "C" },
  77         { FLAG_R1, "R1" },
  78         { FLAG_R2, "R2" },
  79         { FLAG_R3, "R3" },
  80         { FLAG_R4, "R4" },
  81         { FLAG_R5, "R5" },
  82         { FLAG_R6, "R6" },
  83         { 0, NULL }
  84 };
  85
  86 static const char *
  87 format_opt_class(const uint16_t opt_class)
  88 {
  89     switch (opt_class) {
  90     case 0x0100:
  91         return "Linux";
  92     case 0x0101:
  93         return "Open vSwitch";
  94     case 0x0102:
  95         return "Open Virtual Networking (OVN)";
  96     case 0x0103:
  97         return "In-band Network Telemetry (INT)";
  98     case 0x0104:
  99         return "VMware";
 100     default:
 101         if (opt_class <= 0x00ff)
 102             return "Standard";
 103         else if (opt_class >= 0xfff0)
 104             return "Experimental";
 105     }
 106
 107     return "Unknown";
 108 }
 109
 110 static unsigned
 111 geneve_opts_print(netdissect_options *ndo, const u_char *bp, u_int len)
 112 {
 113     const char *sep = "";
 114
 115     while (len > 0) {
 116         uint16_t opt_class;
 117         uint8_t opt_type;
 118         uint8_t opt_len;
 119
 120         if (len < 4) {
 121             ND_PRINT(" (remaining options length %u < 4)", len);
 122             goto invalid;
 123         }
 124         ND_PRINT("%s", sep);
 125         sep = ", ";
 126
 127         opt_class = GET_BE_U_2(bp);
 128         opt_type = GET_U_1(bp + 2);
 129         opt_len = 4 + ((GET_U_1(bp + 3) & OPT_LEN_MASK) * 4);
 130
 131         ND_PRINT("class %s (0x%x) type 0x%x%s len %u",
 132                   format_opt_class(opt_class), opt_class, opt_type,
 133                   opt_type & OPT_TYPE_CRITICAL ? "(C)" : "", opt_len);
 134
 135         if (opt_len > len) {
 136             ND_PRINT(" [bad length]");
 137             goto invalid;
 138         }
 139
 140         if (ndo->ndo_vflag > 1 && opt_len > 4) {
 141             const uint32_t *data = (const uint32_t *)(bp + 4);
 142             int i;
 143
 144             ND_PRINT(" data");
 145
 146             for (i = 4; i < opt_len; i += 4) {
 147                 ND_PRINT(" %08x", GET_BE_U_4(data));
 148                 data++;
 149             }
 150         }
 151
 152         bp += opt_len;
 153         len -= opt_len;
 154     }
 155     return 1;
 156 invalid:
 157     ND_TCHECK_LEN(bp, len);
 158     return 0;
 159 }
 160
 161 void
 162 geneve_print(netdissect_options *ndo, const u_char *bp, u_int len)
 163 {
 164     uint8_t ver_opt;
 165     u_int version;
 166     uint8_t flags;
 167     uint16_t prot;
 168     uint32_t vni;
 169     uint8_t reserved;
 170     u_int opts_len;
 171
 172     ndo->ndo_protocol = "geneve";
 173     ND_PRINT("Geneve");
 174
 175     if (len < 8) {
 176         ND_PRINT(" [length %u < 8]", len);
 177         goto invalid;
 178     }
 179
 180     ver_opt = GET_U_1(bp);
 181     bp += 1;
 182     len -= 1;
 183
 184     version = ver_opt >> VER_SHIFT;
 185     if (version != 0) {
 186         ND_PRINT(" ERROR: unknown-version %u", version);
 187         goto invalid;
 188     }
 189
 190     flags = GET_U_1(bp);
 191     bp += 1;
 192     len -= 1;
 193
 194     prot = GET_BE_U_2(bp);
 195     bp += 2;
 196     len -= 2;
 197
 198     vni = GET_BE_U_3(bp);
 199     bp += 3;
 200     len -= 3;
 201
 202     reserved = GET_U_1(bp);
 203     bp += 1;
 204     len -= 1;
 205
 206     ND_PRINT(", Flags [%s]",
 207               bittok2str_nosep(geneve_flag_values, "none", flags));
 208     ND_PRINT(", vni 0x%x", vni);
 209
 210     if (reserved)
 211         ND_PRINT(", rsvd 0x%x", reserved);
 212
 213     if (ndo->ndo_eflag)
 214         ND_PRINT(", proto %s (0x%04x)",
 215                   tok2str(ethertype_values, "unknown", prot), prot);
 216
 217     opts_len = (ver_opt & HDR_OPTS_LEN_MASK) * 4;
 218
 219     if (len < opts_len) {
 220         ND_PRINT(" (opts_len %u > %u", opts_len, len);
 221         goto invalid;
 222     }
 223
 224     if (opts_len > 0) {
 225         ND_PRINT(", options [");
 226
 227         if (ndo->ndo_vflag) {
 228             if (! geneve_opts_print(ndo, bp, opts_len))
 229                 goto invalid;
 230         }
 231         else {
 232             ND_TCHECK_LEN(bp, opts_len);
 233             ND_PRINT("%u bytes", opts_len);
 234         }
 235
 236         ND_PRINT("]");
 237     }
 238
 239     bp += opts_len;
 240     len -= opts_len;
 241
 242     if (ndo->ndo_vflag < 1)
 243         ND_PRINT(": ");
 244     else
 245         ND_PRINT("\n\t");
 246
 247     if (ethertype_print(ndo, prot, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL) == 0) {
 248         if (prot == ETHERTYPE_TEB)
 249             ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
 250         else {
 251             ND_PRINT("geneve-proto-0x%x", prot);
 252             ND_TCHECK_LEN(bp, len);
 253         }
 254     }
 255
 256     return;
 257
 258 invalid:
 259     nd_print_invalid(ndo);
 260 }