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

   1 /*
   2  * Copyright (c) 2000 Ben Smithurst <ben@scientia.demon.co.uk>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  */
  21
  22 /* \summary: Berkeley UNIX Time Synchronization Protocol */
  23
  24 /* specification: https://docs.freebsd.org/44doc/smm/12.timed/paper.pdf */
  25
  26 #ifdef HAVE_CONFIG_H
  27 #include <config.h>
  28 #endif
  29
  30 #include "netdissect-stdinc.h"
  31
  32 #include "netdissect.h"
  33 #include "extract.h"
  34
  35 struct tsp_timeval {
  36         nd_int32_t      tv_sec;
  37         nd_int32_t      tv_usec;
  38 };
  39
  40 struct tsp {
  41         nd_uint8_t      tsp_type;
  42         nd_uint8_t      tsp_vers;
  43         nd_uint16_t     tsp_seq;
  44         union {
  45                 struct tsp_timeval tspu_time;
  46                 nd_int8_t tspu_hopcnt;
  47         } tsp_u;
  48         nd_byte         tsp_name[256];  /* null-terminated string up to 256 */
  49 };
  50
  51 #define tsp_time        tsp_u.tspu_time
  52 #define tsp_hopcnt      tsp_u.tspu_hopcnt
  53
  54 /*
  55  * Command types.
  56  */
  57 #define TSP_ANY                 0       /* match any types */
  58 #define TSP_ADJTIME             1       /* send adjtime */
  59 #define TSP_ACK                 2       /* generic acknowledgement */
  60 #define TSP_MASTERREQ           3       /* ask for master's name */
  61 #define TSP_MASTERACK           4       /* acknowledge master request */
  62 #define TSP_SETTIME             5       /* send network time */
  63 #define TSP_MASTERUP            6       /* inform slaves that master is up */
  64 #define TSP_SLAVEUP             7       /* slave is up but not polled */
  65 #define TSP_ELECTION            8       /* advance candidature for master */
  66 #define TSP_ACCEPT              9       /* support candidature of master */
  67 #define TSP_REFUSE              10      /* reject candidature of master */
  68 #define TSP_CONFLICT            11      /* two or more masters present */
  69 #define TSP_RESOLVE             12      /* masters' conflict resolution */
  70 #define TSP_QUIT                13      /* reject candidature if master is up */
  71 #define TSP_DATE                14      /* reset the time (date command) */
  72 #define TSP_DATEREQ             15      /* remote request to reset the time */
  73 #define TSP_DATEACK             16      /* acknowledge time setting  */
  74 #define TSP_TRACEON             17      /* turn tracing on */
  75 #define TSP_TRACEOFF            18      /* turn tracing off */
  76 #define TSP_MSITE               19      /* find out master's site */
  77 #define TSP_MSITEREQ            20      /* remote master's site request */
  78 #define TSP_TEST                21      /* for testing election algo */
  79 #define TSP_SETDATE             22      /* New from date command */
  80 #define TSP_SETDATEREQ          23      /* New remote for above */
  81 #define TSP_LOOP                24      /* loop detection packet */
  82
  83 #define TSPTYPENUMBER           25
  84
  85
  86 static const char *tsptype[TSPTYPENUMBER] =
  87   { "ANY", "ADJTIME", "ACK", "MASTERREQ", "MASTERACK", "SETTIME", "MASTERUP",
  88   "SLAVEUP", "ELECTION", "ACCEPT", "REFUSE", "CONFLICT", "RESOLVE", "QUIT",
  89   "DATE", "DATEREQ", "DATEACK", "TRACEON", "TRACEOFF", "MSITE", "MSITEREQ",
  90   "TEST", "SETDATE", "SETDATEREQ", "LOOP" };
  91
  92 void
  93 timed_print(netdissect_options *ndo,
  94             const u_char *bp)
  95 {
  96         const struct tsp *tsp = (const struct tsp *)bp;
  97         uint8_t tsp_type;
  98         int sec, usec;
  99
 100         ndo->ndo_protocol = "timed";
 101         tsp_type = GET_U_1(tsp->tsp_type);
 102         if (tsp_type < TSPTYPENUMBER)
 103                 ND_PRINT("TSP_%s", tsptype[tsp_type]);
 104         else
 105                 ND_PRINT("(tsp_type %#x)", tsp_type);
 106
 107         ND_PRINT(" vers %u", GET_U_1(tsp->tsp_vers));
 108
 109         ND_PRINT(" seq %u", GET_BE_U_2(tsp->tsp_seq));
 110
 111         switch (tsp_type) {
 112         case TSP_LOOP:
 113                 ND_PRINT(" hopcnt %u", GET_U_1(tsp->tsp_hopcnt));
 114                 break;
 115         case TSP_SETTIME:
 116         case TSP_ADJTIME:
 117         case TSP_SETDATE:
 118         case TSP_SETDATEREQ:
 119                 sec = GET_BE_S_4(tsp->tsp_time.tv_sec);
 120                 usec = GET_BE_S_4(tsp->tsp_time.tv_usec);
 121                 /* XXX The comparison below is always false? */
 122                 if (usec < 0)
 123                         /* invalid, skip the rest of the packet */
 124                         return;
 125                 ND_PRINT(" time ");
 126                 if (sec < 0 && usec != 0) {
 127                         sec++;
 128                         if (sec == 0)
 129                                 ND_PRINT("-");
 130                         usec = 1000000 - usec;
 131                 }
 132                 ND_PRINT("%d.%06d", sec, usec);
 133                 break;
 134         }
 135         ND_PRINT(" name ");
 136         if (nd_printzp(ndo, tsp->tsp_name, sizeof(tsp->tsp_name),
 137                        ndo->ndo_snapend))
 138                 goto trunc;
 139         return;
 140
 141 trunc:
 142         nd_print_trunc(ndo);
 143 }