contrib/tcpdump/print-udld.c

   1 /*
   2  * Copyright (c) 1998-2007 The TCPDUMP project
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that: (1) source code
   6  * distributions retain the above copyright notice and this paragraph
   7  * in its entirety, and (2) distributions including binary code include
   8  * the above copyright notice and this paragraph in its entirety in
   9  * the documentation or other materials provided with the distribution.
  10  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
  11  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
  12  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  13  * FOR A PARTICULAR PURPOSE.
  14  *
  15  * UNIDIRECTIONAL LINK DETECTION (UDLD) as per
  16  * http://www.ietf.org/internet-drafts/draft-foschiano-udld-02.txt
  17  *
  18  * Original code by Carles Kishimoto <carles.kishimoto@gmail.com>
  19  */
  20
  21 #ifdef HAVE_CONFIG_H
  22 #include "config.h"
  23 #endif
  24
  25 #include <tcpdump-stdinc.h>
  26
  27 #include <stdio.h>
  28 #include <string.h>
  29
  30 #include "interface.h"
  31 #include "addrtoname.h"
  32 #include "extract.h"
  33 #include "nlpid.h"
  34
  35 #define UDLD_HEADER_LEN                 4
  36 #define UDLD_DEVICE_ID_TLV              0x0001
  37 #define UDLD_PORT_ID_TLV                0x0002
  38 #define UDLD_ECHO_TLV                   0x0003
  39 #define UDLD_MESSAGE_INTERVAL_TLV       0x0004
  40 #define UDLD_TIMEOUT_INTERVAL_TLV       0x0005
  41 #define UDLD_DEVICE_NAME_TLV            0x0006
  42 #define UDLD_SEQ_NUMBER_TLV             0x0007
  43
  44 static struct tok udld_tlv_values[] = {
  45     { UDLD_DEVICE_ID_TLV, "Device-ID TLV"},
  46     { UDLD_PORT_ID_TLV, "Port-ID TLV"},
  47     { UDLD_ECHO_TLV, "Echo TLV"},
  48     { UDLD_MESSAGE_INTERVAL_TLV, "Message Interval TLV"},
  49     { UDLD_TIMEOUT_INTERVAL_TLV, "Timeout Interval TLV"},
  50     { UDLD_DEVICE_NAME_TLV, "Device Name TLV"},
  51     { UDLD_SEQ_NUMBER_TLV,"Sequence Number TLV"},
  52     { 0, NULL}
  53 };
  54
  55 static struct tok udld_code_values[] = {
  56     { 0x00, "Reserved"},
  57     { 0x01, "Probe message"},
  58     { 0x02, "Echo message"},
  59     { 0x03, "Flush message"},
  60     { 0, NULL}
  61 };
  62
  63 static struct tok udld_flags_values[] = {
  64     { 0x00, "RT"},
  65     { 0x01, "RSY"},
  66     { 0, NULL}
  67 };
  68
  69 /*
  70  *
  71  * 0                   1                   2                   3
  72  * 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
  73  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  74  * | Ver | Opcode  |     Flags     |           Checksum            |
  75  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  76  * |               List of TLVs (variable length list)             |
  77  * |                              ...                              |
  78  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  79  *
  80  */
  81
  82 #define UDLD_EXTRACT_VERSION(x) (((x)&0xe0)>>5)
  83 #define UDLD_EXTRACT_OPCODE(x) ((x)&0x1f)
  84
  85 void
  86 udld_print (const u_char *pptr, u_int length)
  87 {
  88     int code, type, len;
  89     const u_char *tptr;
  90
  91     if (length < UDLD_HEADER_LEN)
  92         goto trunc;
  93
  94     tptr = pptr;
  95
  96     if (!TTEST2(*tptr, UDLD_HEADER_LEN))
  97         goto trunc;
  98
  99     code = UDLD_EXTRACT_OPCODE(*tptr);
 100
 101     printf("UDLDv%u, Code %s (%x), Flags [%s] (0x%02x), length %u",
 102            UDLD_EXTRACT_VERSION(*tptr),
 103            tok2str(udld_code_values, "Reserved", code),
 104            code,
 105            bittok2str(udld_flags_values, "none", *(tptr+1)),
 106            *(tptr+1),
 107            length);
 108
 109     /*
 110      * In non-verbose mode, just print version and opcode type
 111      */
 112     if (vflag < 1) {
 113         return;
 114     }
 115
 116     printf("\n\tChecksum 0x%04x (unverified)", EXTRACT_16BITS(tptr+2));
 117
 118     tptr += UDLD_HEADER_LEN;
 119
 120     while (tptr < (pptr+length)) {
 121
 122         if (!TTEST2(*tptr, 4))
 123             goto trunc;
 124
 125         type = EXTRACT_16BITS(tptr);
 126         len  = EXTRACT_16BITS(tptr+2);
 127         len -= 4;
 128         tptr += 4;
 129
 130         /* infinite loop check */
 131         if (type == 0 || len == 0) {
 132             return;
 133         }
 134
 135         printf("\n\t%s (0x%04x) TLV, length %u",
 136                tok2str(udld_tlv_values, "Unknown", type),
 137                type, len);
 138
 139         switch (type) {
 140         case UDLD_DEVICE_ID_TLV:
 141         case UDLD_PORT_ID_TLV:
 142         case UDLD_ECHO_TLV:
 143         case UDLD_DEVICE_NAME_TLV:
 144             printf(", %s", tptr);
 145             break;
 146
 147         case UDLD_MESSAGE_INTERVAL_TLV:
 148         case UDLD_TIMEOUT_INTERVAL_TLV:
 149             printf(", %us", (*tptr));
 150             break;
 151
 152         case UDLD_SEQ_NUMBER_TLV:
 153             printf(", %u", EXTRACT_32BITS(tptr));
 154             break;
 155
 156         default:
 157             break;
 158         }
 159         tptr += len;
 160     }
 161
 162     return;
 163
 164  trunc:
 165     printf("[|udld]");
 166 }
 167
 168 /*
 169  * Local Variables:
 170  * c-style: whitesmith
 171  * c-basic-offset: 4
 172  * End:
 173  */