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

   1 // Copyright (c) 2018 Arista Networks, Inc.  All rights reserved.
   2
   3 /* \summary: EtherType protocol for Arista Networks printer */
   4
   5 #ifdef HAVE_CONFIG_H
   6 #include <config.h>
   7 #endif
   8
   9 #include "netdissect-stdinc.h"
  10
  11 #include "netdissect.h"
  12 #include "extract.h"
  13 #include "addrtoname.h"
  14
  15 /*
  16
  17 From Bill Fenner:
  18
  19 The Arista timestamp header consists of the following fields:
  20 1. The Arista ethertype (0xd28b)
  21 2. A 2-byte subtype field; 0x01 indicates the timestamp header
  22 3. A 2-byte version field, described below.
  23 4. A 48-bit or 64-bit timestamp field, depending on the contents of the version field
  24
  25 This header is then followed by the original ethertype and the remainder of the original packet.
  26
  27  0                   1                   2                   3
  28  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
  29 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  30 |                            dst mac                            |
  31 +                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  32 |                               |                               |
  33 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               +
  34 |                            src mac                            |
  35 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  36 |        ethertype 0xd28b       |          subtype 0x1          |
  37 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  38 |            version            |                               |
  39 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               +
  40 |                          timestamp...                         |
  41 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  42
  43 The two-byte version value is split into 3 fields:
  44 1. The timescale in use.  Currently assigned values include:
  45     0 = TAI
  46     1 = UTC
  47 2. The timestamp format and length.  Currently assigned values include:
  48     1 = 64-bit timestamp
  49     2 = 48-bit timestamp
  50 3. The hardware info
  51     0 = R/R2 series
  52     1 = R3 series
  53
  54  0                   1
  55  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
  56 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  57 |   timescale   | format|hw info|
  58 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  59
  60 */
  61
  62 #define ARISTA_SUBTYPE_TIMESTAMP 0x0001
  63 static const struct tok subtype_str[] = {
  64         { ARISTA_SUBTYPE_TIMESTAMP, "Timestamp" },
  65         { 0, NULL }
  66 };
  67
  68 static const struct tok ts_timescale_str[] = {
  69         { 0, "TAI" },
  70         { 1, "UTC" },
  71         { 0, NULL }
  72 };
  73
  74 #define FORMAT_64BIT 0x1
  75 #define FORMAT_48BIT 0x2
  76 static const struct tok ts_format_str[] = {
  77         { FORMAT_64BIT, "64-bit" },
  78         { FORMAT_48BIT, "48-bit" },
  79         { 0, NULL }
  80 };
  81
  82 static const struct tok hw_info_str[] = {
  83         { 0, "R/R2" },
  84         { 1, "R3" },
  85         { 0, NULL }
  86 };
  87
  88 static inline void
  89 arista_print_date_hms_time(netdissect_options *ndo, uint32_t seconds,
  90                 uint32_t nanoseconds)
  91 {
  92         time_t ts;
  93         struct tm *tm;
  94         char buf[BUFSIZE];
  95
  96         ts = seconds + (nanoseconds / 1000000000);
  97         nanoseconds %= 1000000000;
  98         if (NULL == (tm = gmtime(&ts)))
  99                 ND_PRINT("gmtime() error");
 100         else if (0 == strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S", tm))
 101                 ND_PRINT("strftime() error");
 102         else
 103                 ND_PRINT("%s.%09u", buf, nanoseconds);
 104 }
 105
 106 int
 107 arista_ethertype_print(netdissect_options *ndo, const u_char *bp, u_int len _U_)
 108 {
 109         uint16_t subTypeId;
 110         u_short bytesConsumed = 0;
 111
 112         ndo->ndo_protocol = "arista";
 113
 114         subTypeId = GET_BE_U_2(bp);
 115         bp += 2;
 116         bytesConsumed += 2;
 117
 118         ND_PRINT("SubType %s (0x%04x), ",
 119                  tok2str(subtype_str, "Unknown", subTypeId),
 120                  subTypeId);
 121
 122         // TapAgg Header Timestamping
 123         if (subTypeId == ARISTA_SUBTYPE_TIMESTAMP) {
 124                 uint64_t seconds;
 125                 uint32_t nanoseconds;
 126                 uint8_t ts_timescale = GET_U_1(bp);
 127                 bp += 1;
 128                 bytesConsumed += 1;
 129                 ND_PRINT("Timescale %s (%u), ",
 130                          tok2str(ts_timescale_str, "Unknown", ts_timescale),
 131                          ts_timescale);
 132
 133                 uint8_t ts_format = GET_U_1(bp) >> 4;
 134                 uint8_t hw_info = GET_U_1(bp) & 0x0f;
 135                 bp += 1;
 136                 bytesConsumed += 1;
 137
 138                 // Timestamp has 32-bit lsb in nanosec and remaining msb in sec
 139                 ND_PRINT("Format %s (%u), HwInfo %s (%u), Timestamp ",
 140                          tok2str(ts_format_str, "Unknown", ts_format),
 141                          ts_format,
 142                          tok2str(hw_info_str, "Unknown", hw_info),
 143                          hw_info);
 144                 switch (ts_format) {
 145                 case FORMAT_64BIT:
 146                         seconds = GET_BE_U_4(bp);
 147                         nanoseconds = GET_BE_U_4(bp + 4);
 148                         arista_print_date_hms_time(ndo, seconds, nanoseconds);
 149                         bytesConsumed += 8;
 150                         break;
 151                 case FORMAT_48BIT:
 152                         seconds = GET_BE_U_2(bp);
 153                         nanoseconds = GET_BE_U_4(bp + 2);
 154                         seconds += nanoseconds / 1000000000;
 155                         nanoseconds %= 1000000000;
 156                         ND_PRINT("%" PRIu64 ".%09u", seconds, nanoseconds);
 157                         bytesConsumed += 6;
 158                         break;
 159                 default:
 160                         return -1;
 161                 }
 162         } else {
 163                 return -1;
 164         }
 165         ND_PRINT(": ");
 166         return bytesConsumed;
 167 }