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 #include <config.h>
  27
  28 #include "netdissect-stdinc.h"
  29
  30 #include "netdissect.h"
  31 #include "extract.h"
  32
  33 struct tsp_timeval {
  34         nd_int32_t      tv_sec;
  35         nd_int32_t      tv_usec;
  36 };
  37
  38 struct tsp {
  39         nd_uint8_t      tsp_type;
  40         nd_uint8_t      tsp_vers;
  41         nd_uint16_t     tsp_seq;
  42         union {
  43                 struct tsp_timeval tspu_time;
  44                 nd_int8_t tspu_hopcnt;
  45         } tsp_u;
  46         nd_byte         tsp_name[256];  /* null-terminated string up to 256 */
  47 };
  48
  49 #define tsp_time        tsp_u.tspu_time
  50 #define tsp_hopcnt      tsp_u.tspu_hopcnt
  51
  52 /*
  53  * Command types.
  54  */
  55 #define TSP_ANY                 0       /* match any types */
  56 #define TSP_ADJTIME             1       /* send adjtime */
  57 #define TSP_ACK                 2       /* generic acknowledgement */
  58 #define TSP_MASTERREQ           3       /* ask for master's name */
  59 #define TSP_MASTERACK           4       /* acknowledge master request */
  60 #define TSP_SETTIME             5       /* send network time */
  61 #define TSP_MASTERUP            6       /* inform slaves that master is up */
  62 #define TSP_SLAVEUP             7       /* slave is up but not polled */
  63 #define TSP_ELECTION            8       /* advance candidature for master */
  64 #define TSP_ACCEPT              9       /* support candidature of master */
  65 #define TSP_REFUSE              10      /* reject candidature of master */
  66 #define TSP_CONFLICT            11      /* two or more masters present */
  67 #define TSP_RESOLVE             12      /* masters' conflict resolution */
  68 #define TSP_QUIT                13      /* reject candidature if master is up */
  69 #define TSP_DATE                14      /* reset the time (date command) */
  70 #define TSP_DATEREQ             15      /* remote request to reset the time */
  71 #define TSP_DATEACK             16      /* acknowledge time setting  */
  72 #define TSP_TRACEON             17      /* turn tracing on */
  73 #define TSP_TRACEOFF            18      /* turn tracing off */
  74 #define TSP_MSITE               19      /* find out master's site */
  75 #define TSP_MSITEREQ            20      /* remote master's site request */
  76 #define TSP_TEST                21      /* for testing election algo */
  77 #define TSP_SETDATE             22      /* New from date command */
  78 #define TSP_SETDATEREQ          23      /* New remote for above */
  79 #define TSP_LOOP                24      /* loop detection packet */
  80 static const struct tok tsptype_str[] = {
  81         { TSP_ANY,        "TSP_ANY"        },
  82         { TSP_ADJTIME,    "TSP_ADJTIME"    },
  83         { TSP_ACK,        "TSP_ACK"        },
  84         { TSP_MASTERREQ,  "TSP_MASTERREQ"  },
  85         { TSP_MASTERACK,  "TSP_MASTERACK"  },
  86         { TSP_SETTIME,    "TSP_SETTIME"    },
  87         { TSP_MASTERUP,   "TSP_MASTERUP"   },
  88         { TSP_SLAVEUP,    "TSP_SLAVEUP"    },
  89         { TSP_ELECTION,   "TSP_ELECTION"   },
  90         { TSP_ACCEPT,     "TSP_ACCEPT"     },
  91         { TSP_REFUSE,     "TSP_REFUSE"     },
  92         { TSP_CONFLICT,   "TSP_CONFLICT"   },
  93         { TSP_RESOLVE,    "TSP_RESOLVE"    },
  94         { TSP_QUIT,       "TSP_QUIT"       },
  95         { TSP_DATE,       "TSP_DATE"       },
  96         { TSP_DATEREQ,    "TSP_DATEREQ"    },
  97         { TSP_DATEACK,    "TSP_DATEACK"    },
  98         { TSP_TRACEON,    "TSP_TRACEON"    },
  99         { TSP_TRACEOFF,   "TSP_TRACEOFF"   },
 100         { TSP_MSITE,      "TSP_MSITE"      },
 101         { TSP_MSITEREQ,   "TSP_MSITEREQ"   },
 102         { TSP_TEST,       "TSP_TEST"       },
 103         { TSP_SETDATE,    "TSP_SETDATE"    },
 104         { TSP_SETDATEREQ, "TSP_SETDATEREQ" },
 105         { TSP_LOOP,       "TSP_LOOP"       },
 106         { 0, NULL }
 107 };
 108
 109 void
 110 timed_print(netdissect_options *ndo,
 111             const u_char *bp)
 112 {
 113         const struct tsp *tsp = (const struct tsp *)bp;
 114         uint8_t tsp_type;
 115         int sec, usec;
 116
 117         ndo->ndo_protocol = "timed";
 118         tsp_type = GET_U_1(tsp->tsp_type);
 119         ND_PRINT("%s", tok2str(tsptype_str, "(tsp_type %#x)", tsp_type));
 120
 121         ND_PRINT(" vers %u", GET_U_1(tsp->tsp_vers));
 122
 123         ND_PRINT(" seq %u", GET_BE_U_2(tsp->tsp_seq));
 124
 125         switch (tsp_type) {
 126         case TSP_LOOP:
 127                 ND_PRINT(" hopcnt %u", GET_U_1(tsp->tsp_hopcnt));
 128                 break;
 129         case TSP_SETTIME:
 130         case TSP_ADJTIME:
 131         case TSP_SETDATE:
 132         case TSP_SETDATEREQ:
 133                 sec = GET_BE_S_4(tsp->tsp_time.tv_sec);
 134                 usec = GET_BE_S_4(tsp->tsp_time.tv_usec);
 135                 /* XXX The comparison below is always false? */
 136                 if (usec < 0)
 137                         /* invalid, skip the rest of the packet */
 138                         return;
 139                 ND_PRINT(" time ");
 140                 if (sec < 0 && usec != 0) {
 141                         sec++;
 142                         if (sec == 0)
 143                                 ND_PRINT("-");
 144                         usec = 1000000 - usec;
 145                 }
 146                 ND_PRINT("%d.%06d", sec, usec);
 147                 break;
 148         }
 149         ND_PRINT(" name ");
 150         nd_printjnp(ndo, tsp->tsp_name, sizeof(tsp->tsp_name));
 151 }