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      1 /*
      2  * Copyright (c) 2014 VMware, Inc. All Rights Reserved.
      3  *
      4  * Jesse Gross <jesse (at) 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 }
    238