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 /* \summary: Bidirectional Forwarding Detection (BFD) printer */
  17
  18 #ifdef HAVE_CONFIG_H
  19 #include "config.h"
  20 #endif
  21
  22 #include <netdissect-stdinc.h>
  23
  24 #include "netdissect.h"
  25 #include "extract.h"
  26
  27 #include "udp.h"
  28
  29 /*
  30  * Control packet, BFDv0, draft-katz-ward-bfd-01.txt
  31  *
  32  *     0                   1                   2                   3
  33  *     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
  34  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  35  *    |Vers |  Diag   |H|D|P|F| Rsvd  |  Detect Mult  |    Length     |
  36  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  37  *    |                       My Discriminator                        |
  38  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  39  *    |                      Your Discriminator                       |
  40  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  41  *    |                    Desired Min TX Interval                    |
  42  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  43  *    |                   Required Min RX Interval                    |
  44  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  45  *    |                 Required Min Echo RX Interval                 |
  46  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  47  */
  48
  49 /*
  50  *  Control packet, BFDv1, draft-ietf-bfd-base-02.txt
  51  *
  52  *     0                   1                   2                   3
  53  *     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
  54  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  55  *    |Vers |  Diag   |Sta|P|F|C|A|D|R|  Detect Mult  |    Length     |
  56  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  57  *    |                       My Discriminator                        |
  58  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  59  *    |                      Your Discriminator                       |
  60  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  61  *    |                    Desired Min TX Interval                    |
  62  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  63  *    |                   Required Min RX Interval                    |
  64  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  65  *    |                 Required Min Echo RX Interval                 |
  66  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  67  */
  68
  69 struct bfd_header_t {
  70     uint8_t version_diag;
  71     uint8_t flags;
  72     uint8_t detect_time_multiplier;
  73     uint8_t length;
  74     uint8_t my_discriminator[4];
  75     uint8_t your_discriminator[4];
  76     uint8_t desired_min_tx_interval[4];
  77     uint8_t required_min_rx_interval[4];
  78     uint8_t required_min_echo_interval[4];
  79 };
  80
  81 /*
  82  *    An optional Authentication Header may be present
  83  *
  84  *     0                   1                   2                   3
  85  *     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
  86  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  87  *    |   Auth Type   |   Auth Len    |    Authentication Data...     |
  88  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  89  */
  90
  91 struct bfd_auth_header_t {
  92     uint8_t auth_type;
  93     uint8_t auth_len;
  94     uint8_t auth_data;
  95 };
  96
  97 static const struct tok bfd_v1_authentication_values[] = {
  98     { 0,        "Reserved" },
  99     { 1,        "Simple Password" },
 100     { 2,        "Keyed MD5" },
 101     { 3,        "Meticulous Keyed MD5" },
 102     { 4,        "Keyed SHA1" },
 103     { 5,        "Meticulous Keyed SHA1" },
 104     { 0, NULL }
 105 };
 106
 107 #define BFD_EXTRACT_VERSION(x) (((x)&0xe0)>>5)
 108 #define BFD_EXTRACT_DIAG(x)     ((x)&0x1f)
 109
 110 static const struct tok bfd_port_values[] = {
 111     { BFD_CONTROL_PORT, "Control" },
 112     { BFD_ECHO_PORT,    "Echo" },
 113     { 0, NULL }
 114 };
 115
 116
 117 static const struct tok bfd_diag_values[] = {
 118     { 0, "No Diagnostic" },
 119     { 1, "Control Detection Time Expired" },
 120     { 2, "Echo Function Failed" },
 121     { 3, "Neighbor Signaled Session Down" },
 122     { 4, "Forwarding Plane Reset" },
 123     { 5, "Path Down" },
 124     { 6, "Concatenated Path Down" },
 125     { 7, "Administratively Down" },
 126     { 8, "Reverse Concatenated Path Down" },
 127     { 0, NULL }
 128 };
 129
 130 static const struct tok bfd_v0_flag_values[] = {
 131     { 0x80,     "I Hear You" },
 132     { 0x40,     "Demand" },
 133     { 0x20,     "Poll" },
 134     { 0x10,     "Final" },
 135     { 0x08,     "Reserved" },
 136     { 0x04,     "Reserved" },
 137     { 0x02,     "Reserved" },
 138     { 0x01,     "Reserved" },
 139     { 0, NULL }
 140 };
 141
 142 #define BFD_FLAG_AUTH 0x04
 143
 144 static const struct tok bfd_v1_flag_values[] = {
 145     { 0x20, "Poll" },
 146     { 0x10, "Final" },
 147     { 0x08, "Control Plane Independent" },
 148     { BFD_FLAG_AUTH, "Authentication Present" },
 149     { 0x02, "Demand" },
 150     { 0x01, "Reserved" },
 151     { 0, NULL }
 152 };
 153
 154 static const struct tok bfd_v1_state_values[] = {
 155     { 0, "AdminDown" },
 156     { 1, "Down" },
 157     { 2, "Init" },
 158     { 3, "Up" },
 159     { 0, NULL }
 160 };
 161
 162 void
 163 bfd_print(netdissect_options *ndo, register const u_char *pptr,
 164           register u_int len, register u_int port)
 165 {
 166         const struct bfd_header_t *bfd_header;
 167         const struct bfd_auth_header_t *bfd_auth_header;
 168         uint8_t version = 0;
 169
 170         bfd_header = (const struct bfd_header_t *)pptr;
 171         if (port == BFD_CONTROL_PORT) {
 172             ND_TCHECK(*bfd_header);
 173             version = BFD_EXTRACT_VERSION(bfd_header->version_diag);
 174         } else if (port == BFD_ECHO_PORT) {
 175             /* Echo is BFD v1 only */
 176             version = 1;
 177         }
 178         switch ((port << 8) | version) {
 179
 180             /* BFDv0 */
 181         case (BFD_CONTROL_PORT << 8):
 182             if (ndo->ndo_vflag < 1)
 183             {
 184                 ND_PRINT((ndo, "BFDv%u, %s, Flags: [%s], length: %u",
 185                        version,
 186                        tok2str(bfd_port_values, "unknown (%u)", port),
 187                        bittok2str(bfd_v0_flag_values, "none", bfd_header->flags),
 188                        len));
 189                 return;
 190             }
 191
 192             ND_PRINT((ndo, "BFDv%u, length: %u\n\t%s, Flags: [%s], Diagnostic: %s (0x%02x)",
 193                    version,
 194                    len,
 195                    tok2str(bfd_port_values, "unknown (%u)", port),
 196                    bittok2str(bfd_v0_flag_values, "none", bfd_header->flags),
 197                    tok2str(bfd_diag_values,"unknown",BFD_EXTRACT_DIAG(bfd_header->version_diag)),
 198                    BFD_EXTRACT_DIAG(bfd_header->version_diag)));
 199
 200             ND_PRINT((ndo, "\n\tDetection Timer Multiplier: %u (%u ms Detection time), BFD Length: %u",
 201                    bfd_header->detect_time_multiplier,
 202                    bfd_header->detect_time_multiplier * EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000,
 203                    bfd_header->length));
 204
 205
 206             ND_PRINT((ndo, "\n\tMy Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->my_discriminator)));
 207             ND_PRINT((ndo, ", Your Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->your_discriminator)));
 208             ND_PRINT((ndo, "\n\t  Desired min Tx Interval:    %4u ms", EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000));
 209             ND_PRINT((ndo, "\n\t  Required min Rx Interval:   %4u ms", EXTRACT_32BITS(bfd_header->required_min_rx_interval)/1000));
 210             ND_PRINT((ndo, "\n\t  Required min Echo Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_echo_interval)/1000));
 211             break;
 212
 213             /* BFDv1 */
 214         case (BFD_CONTROL_PORT << 8 | 1):
 215             if (ndo->ndo_vflag < 1)
 216             {
 217                 ND_PRINT((ndo, "BFDv%u, %s, State %s, Flags: [%s], length: %u",
 218                        version,
 219                        tok2str(bfd_port_values, "unknown (%u)", port),
 220                        tok2str(bfd_v1_state_values, "unknown (%u)", (bfd_header->flags & 0xc0) >> 6),
 221                        bittok2str(bfd_v1_flag_values, "none", bfd_header->flags & 0x3f),
 222                        len));
 223                 return;
 224             }
 225
 226             ND_PRINT((ndo, "BFDv%u, length: %u\n\t%s, State %s, Flags: [%s], Diagnostic: %s (0x%02x)",
 227                    version,
 228                    len,
 229                    tok2str(bfd_port_values, "unknown (%u)", port),
 230                    tok2str(bfd_v1_state_values, "unknown (%u)", (bfd_header->flags & 0xc0) >> 6),
 231                    bittok2str(bfd_v1_flag_values, "none", bfd_header->flags & 0x3f),
 232                    tok2str(bfd_diag_values,"unknown",BFD_EXTRACT_DIAG(bfd_header->version_diag)),
 233                    BFD_EXTRACT_DIAG(bfd_header->version_diag)));
 234
 235             ND_PRINT((ndo, "\n\tDetection Timer Multiplier: %u (%u ms Detection time), BFD Length: %u",
 236                    bfd_header->detect_time_multiplier,
 237                    bfd_header->detect_time_multiplier * EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000,
 238                    bfd_header->length));
 239
 240
 241             ND_PRINT((ndo, "\n\tMy Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->my_discriminator)));
 242             ND_PRINT((ndo, ", Your Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->your_discriminator)));
 243             ND_PRINT((ndo, "\n\t  Desired min Tx Interval:    %4u ms", EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000));
 244             ND_PRINT((ndo, "\n\t  Required min Rx Interval:   %4u ms", EXTRACT_32BITS(bfd_header->required_min_rx_interval)/1000));
 245             ND_PRINT((ndo, "\n\t  Required min Echo Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_echo_interval)/1000));
 246
 247             if (bfd_header->flags & BFD_FLAG_AUTH) {
 248                 pptr += sizeof (const struct bfd_header_t);
 249                 bfd_auth_header = (const struct bfd_auth_header_t *)pptr;
 250                 ND_TCHECK2(*bfd_auth_header, sizeof(const struct bfd_auth_header_t));
 251                 ND_PRINT((ndo, "\n\t%s (%u) Authentication, length %u present",
 252                        tok2str(bfd_v1_authentication_values,"Unknown",bfd_auth_header->auth_type),
 253                        bfd_auth_header->auth_type,
 254                        bfd_auth_header->auth_len));
 255             }
 256             break;
 257
 258             /* BFDv0 */
 259         case (BFD_ECHO_PORT << 8): /* not yet supported - fall through */
 260             /* BFDv1 */
 261         case (BFD_ECHO_PORT << 8 | 1):
 262
 263         default:
 264             ND_PRINT((ndo, "BFD, %s, length: %u",
 265                    tok2str(bfd_port_values, "unknown (%u)", port),
 266                    len));
 267             if (ndo->ndo_vflag >= 1) {
 268                     if(!print_unknown_data(ndo, pptr,"\n\t",len))
 269                             return;
 270             }
 271             break;
 272         }
 273         return;
 274
 275 trunc:
 276         ND_PRINT((ndo, "[|BFD]"));
 277 }
 278 /*
 279  * Local Variables:
 280  * c-style: whitesmith
 281  * c-basic-offset: 8
 282  * End:
 283  */