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

   1 /*
   2  * Redistribution and use in source and binary forms, with or without
   3  * modification, are permitted provided that: (1) source code
   4  * distributions retain the above copyright notice and this paragraph
   5  * in its entirety, and (2) distributions including binary code include
   6  * the above copyright notice and this paragraph in its entirety in
   7  * the documentation or other materials provided with the distribution.
   8  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
   9  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
  10  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  11  * FOR A PARTICULAR PURPOSE.
  12  *
  13  * Original code by Hannes Gredler (hannes@juniper.net)
  14  */
  15
  16 #define NETDISSECT_REWORKED
  17 #ifdef HAVE_CONFIG_H
  18 #include "config.h"
  19 #endif
  20
  21 #include <tcpdump-stdinc.h>
  22
  23 #include "interface.h"
  24 #include "extract.h"
  25
  26 #include "udp.h"
  27
  28 /*
  29  * Control packet, BFDv0, draft-katz-ward-bfd-01.txt
  30  *
  31  *     0                   1                   2                   3
  32  *     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
  33  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  34  *    |Vers |  Diag   |H|D|P|F| Rsvd  |  Detect Mult  |    Length     |
  35  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  36  *    |                       My Discriminator                        |
  37  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  38  *    |                      Your Discriminator                       |
  39  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  40  *    |                    Desired Min TX Interval                    |
  41  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  42  *    |                   Required Min RX Interval                    |
  43  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  44  *    |                 Required Min Echo RX Interval                 |
  45  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  46  */
  47
  48 /*
  49  *  Control packet, BFDv1, draft-ietf-bfd-base-02.txt
  50  *
  51  *     0                   1                   2                   3
  52  *     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
  53  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  54  *    |Vers |  Diag   |Sta|P|F|C|A|D|R|  Detect Mult  |    Length     |
  55  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  56  *    |                       My Discriminator                        |
  57  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  58  *    |                      Your Discriminator                       |
  59  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  60  *    |                    Desired Min TX Interval                    |
  61  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  62  *    |                   Required Min RX Interval                    |
  63  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  64  *    |                 Required Min Echo RX Interval                 |
  65  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  66  */
  67
  68 struct bfd_header_t {
  69     uint8_t version_diag;
  70     uint8_t flags;
  71     uint8_t detect_time_multiplier;
  72     uint8_t length;
  73     uint8_t my_discriminator[4];
  74     uint8_t your_discriminator[4];
  75     uint8_t desired_min_tx_interval[4];
  76     uint8_t required_min_rx_interval[4];
  77     uint8_t required_min_echo_interval[4];
  78 };
  79
  80 /*
  81  *    An optional Authentication Header may be present
  82  *
  83  *     0                   1                   2                   3
  84  *     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
  85  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  86  *    |   Auth Type   |   Auth Len    |    Authentication Data...     |
  87  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  88  */
  89
  90 struct bfd_auth_header_t {
  91     uint8_t auth_type;
  92     uint8_t auth_len;
  93     uint8_t auth_data;
  94 };
  95
  96 static const struct tok bfd_v1_authentication_values[] = {
  97     { 0,        "Reserved" },
  98     { 1,        "Simple Password" },
  99     { 2,        "Keyed MD5" },
 100     { 3,        "Meticulous Keyed MD5" },
 101     { 4,        "Keyed SHA1" },
 102     { 5,        "Meticulous Keyed SHA1" },
 103     { 0, NULL }
 104 };
 105
 106 #define BFD_EXTRACT_VERSION(x) (((x)&0xe0)>>5)
 107 #define BFD_EXTRACT_DIAG(x)     ((x)&0x1f)
 108
 109 static const struct tok bfd_port_values[] = {
 110     { BFD_CONTROL_PORT, "Control" },
 111     { BFD_ECHO_PORT,    "Echo" },
 112     { 0, NULL }
 113 };
 114
 115
 116 static const struct tok bfd_diag_values[] = {
 117     { 0, "No Diagnostic" },
 118     { 1, "Control Detection Time Expired" },
 119     { 2, "Echo Function Failed" },
 120     { 3, "Neighbor Signaled Session Down" },
 121     { 4, "Forwarding Plane Reset" },
 122     { 5, "Path Down" },
 123     { 6, "Concatenated Path Down" },
 124     { 7, "Administratively Down" },
 125     { 8, "Reverse Concatenated Path Down" },
 126     { 0, NULL }
 127 };
 128
 129 static const struct tok bfd_v0_flag_values[] = {
 130     { 0x80,     "I Hear You" },
 131     { 0x40,     "Demand" },
 132     { 0x20,     "Poll" },
 133     { 0x10,     "Final" },
 134     { 0x08,     "Reserved" },
 135     { 0x04,     "Reserved" },
 136     { 0x02,     "Reserved" },
 137     { 0x01,     "Reserved" },
 138     { 0, NULL }
 139 };
 140
 141 #define BFD_FLAG_AUTH 0x04
 142
 143 static const struct tok bfd_v1_flag_values[] = {
 144     { 0x20, "Poll" },
 145     { 0x10, "Final" },
 146     { 0x08, "Control Plane Independent" },
 147     { BFD_FLAG_AUTH, "Authentication Present" },
 148     { 0x02, "Demand" },
 149     { 0x01, "Reserved" },
 150     { 0, NULL }
 151 };
 152
 153 static const struct tok bfd_v1_state_values[] = {
 154     { 0, "AdminDown" },
 155     { 1, "Down" },
 156     { 2, "Init" },
 157     { 3, "Up" },
 158     { 0, NULL }
 159 };
 160
 161 void
 162 bfd_print(netdissect_options *ndo, register const u_char *pptr,
 163           register u_int len, register u_int port)
 164 {
 165         const struct bfd_header_t *bfd_header;
 166         const struct bfd_auth_header_t *bfd_auth_header;
 167         uint8_t version = 0;
 168
 169         bfd_header = (const struct bfd_header_t *)pptr;
 170         if (port == BFD_CONTROL_PORT) {
 171             ND_TCHECK(*bfd_header);
 172             version = BFD_EXTRACT_VERSION(bfd_header->version_diag);
 173         } else if (port == BFD_ECHO_PORT) {
 174             /* Echo is BFD v1 only */
 175             version = 1;
 176         }
 177         switch ((port << 8) | version) {
 178
 179             /* BFDv0 */
 180         case (BFD_CONTROL_PORT << 8):
 181             if (ndo->ndo_vflag < 1)
 182             {
 183                 ND_PRINT((ndo, "BFDv%u, %s, Flags: [%s], length: %u",
 184                        version,
 185                        tok2str(bfd_port_values, "unknown (%u)", port),
 186                        bittok2str(bfd_v0_flag_values, "none", bfd_header->flags),
 187                        len));
 188                 return;
 189             }
 190
 191             ND_PRINT((ndo, "BFDv%u, length: %u\n\t%s, Flags: [%s], Diagnostic: %s (0x%02x)",
 192                    version,
 193                    len,
 194                    tok2str(bfd_port_values, "unknown (%u)", port),
 195                    bittok2str(bfd_v0_flag_values, "none", bfd_header->flags),
 196                    tok2str(bfd_diag_values,"unknown",BFD_EXTRACT_DIAG(bfd_header->version_diag)),
 197                    BFD_EXTRACT_DIAG(bfd_header->version_diag)));
 198
 199             ND_PRINT((ndo, "\n\tDetection Timer Multiplier: %u (%u ms Detection time), BFD Length: %u",
 200                    bfd_header->detect_time_multiplier,
 201                    bfd_header->detect_time_multiplier * EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000,
 202                    bfd_header->length));
 203
 204
 205             ND_PRINT((ndo, "\n\tMy Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->my_discriminator)));
 206             ND_PRINT((ndo, ", Your Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->your_discriminator)));
 207             ND_PRINT((ndo, "\n\t  Desired min Tx Interval:    %4u ms", EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000));
 208             ND_PRINT((ndo, "\n\t  Required min Rx Interval:   %4u ms", EXTRACT_32BITS(bfd_header->required_min_rx_interval)/1000));
 209             ND_PRINT((ndo, "\n\t  Required min Echo Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_echo_interval)/1000));
 210             break;
 211
 212             /* BFDv1 */
 213         case (BFD_CONTROL_PORT << 8 | 1):
 214             if (ndo->ndo_vflag < 1)
 215             {
 216                 ND_PRINT((ndo, "BFDv%u, %s, State %s, Flags: [%s], length: %u",
 217                        version,
 218                        tok2str(bfd_port_values, "unknown (%u)", port),
 219                        tok2str(bfd_v1_state_values, "unknown (%u)", (bfd_header->flags & 0xc0) >> 6),
 220                        bittok2str(bfd_v1_flag_values, "none", bfd_header->flags & 0x3f),
 221                        len));
 222                 return;
 223             }
 224
 225             ND_PRINT((ndo, "BFDv%u, length: %u\n\t%s, State %s, Flags: [%s], Diagnostic: %s (0x%02x)",
 226                    version,
 227                    len,
 228                    tok2str(bfd_port_values, "unknown (%u)", port),
 229                    tok2str(bfd_v1_state_values, "unknown (%u)", (bfd_header->flags & 0xc0) >> 6),
 230                    bittok2str(bfd_v1_flag_values, "none", bfd_header->flags & 0x3f),
 231                    tok2str(bfd_diag_values,"unknown",BFD_EXTRACT_DIAG(bfd_header->version_diag)),
 232                    BFD_EXTRACT_DIAG(bfd_header->version_diag)));
 233
 234             ND_PRINT((ndo, "\n\tDetection Timer Multiplier: %u (%u ms Detection time), BFD Length: %u",
 235                    bfd_header->detect_time_multiplier,
 236                    bfd_header->detect_time_multiplier * EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000,
 237                    bfd_header->length));
 238
 239
 240             ND_PRINT((ndo, "\n\tMy Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->my_discriminator)));
 241             ND_PRINT((ndo, ", Your Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->your_discriminator)));
 242             ND_PRINT((ndo, "\n\t  Desired min Tx Interval:    %4u ms", EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000));
 243             ND_PRINT((ndo, "\n\t  Required min Rx Interval:   %4u ms", EXTRACT_32BITS(bfd_header->required_min_rx_interval)/1000));
 244             ND_PRINT((ndo, "\n\t  Required min Echo Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_echo_interval)/1000));
 245
 246             if (bfd_header->flags & BFD_FLAG_AUTH) {
 247                 pptr += sizeof (const struct bfd_header_t);
 248                 bfd_auth_header = (const struct bfd_auth_header_t *)pptr;
 249                 ND_TCHECK2(*bfd_auth_header, sizeof(const struct bfd_auth_header_t));
 250                 ND_PRINT((ndo, "\n\t%s (%u) Authentication, length %u present",
 251                        tok2str(bfd_v1_authentication_values,"Unknown",bfd_auth_header->auth_type),
 252                        bfd_auth_header->auth_type,
 253                        bfd_auth_header->auth_len));
 254             }
 255             break;
 256
 257             /* BFDv0 */
 258         case (BFD_ECHO_PORT << 8): /* not yet supported - fall through */
 259             /* BFDv1 */
 260         case (BFD_ECHO_PORT << 8 | 1):
 261
 262         default:
 263             ND_PRINT((ndo, "BFD, %s, length: %u",
 264                    tok2str(bfd_port_values, "unknown (%u)", port),
 265                    len));
 266             if (ndo->ndo_vflag >= 1) {
 267                     if(!print_unknown_data(ndo, pptr,"\n\t",len))
 268                             return;
 269             }
 270             break;
 271         }
 272         return;
 273
 274 trunc:
 275         ND_PRINT((ndo, "[|BFD]"));
 276 }
 277 /*
 278  * Local Variables:
 279  * c-style: whitesmith
 280  * c-basic-offset: 8
 281  * End:
 282  */