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