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

   1 /**
   2  * Copyright (c) 2012
   3  *
   4  * Gregory Detal <gregory.detal@uclouvain.be>
   5  * Christoph Paasch <christoph.paasch@uclouvain.be>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  *
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * 3. Neither the name of the University nor of the Laboratory may be used
  19  *    to endorse or promote products derived from this software without
  20  *    specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #ifdef HAVE_CONFIG_H
  36 #include "config.h"
  37 #endif
  38
  39 #include <netdissect-stdinc.h>
  40
  41 #include "netdissect.h"
  42 #include "extract.h"
  43 #include "addrtoname.h"
  44
  45 #include "tcp.h"
  46
  47 #define MPTCP_SUB_CAPABLE       0x0
  48 #define MPTCP_SUB_JOIN          0x1
  49 #define MPTCP_SUB_DSS           0x2
  50 #define MPTCP_SUB_ADD_ADDR      0x3
  51 #define MPTCP_SUB_REMOVE_ADDR   0x4
  52 #define MPTCP_SUB_PRIO          0x5
  53 #define MPTCP_SUB_FAIL          0x6
  54 #define MPTCP_SUB_FCLOSE        0x7
  55
  56 struct mptcp_option {
  57         uint8_t        kind;
  58         uint8_t        len;
  59         uint8_t        sub_etc;        /* subtype upper 4 bits, other stuff lower 4 bits */
  60 };
  61
  62 #define MPTCP_OPT_SUBTYPE(sub_etc)      (((sub_etc) >> 4) & 0xF)
  63
  64 struct mp_capable {
  65         uint8_t        kind;
  66         uint8_t        len;
  67         uint8_t        sub_ver;
  68         uint8_t        flags;
  69         uint8_t        sender_key[8];
  70         uint8_t        receiver_key[8];
  71 };
  72
  73 #define MP_CAPABLE_OPT_VERSION(sub_ver) (((sub_ver) >> 0) & 0xF)
  74 #define MP_CAPABLE_C                    0x80
  75 #define MP_CAPABLE_S                    0x01
  76
  77 struct mp_join {
  78         uint8_t        kind;
  79         uint8_t        len;
  80         uint8_t        sub_b;
  81         uint8_t        addr_id;
  82         union {
  83                 struct {
  84                         uint8_t         token[4];
  85                         uint8_t         nonce[4];
  86                 } syn;
  87                 struct {
  88                         uint8_t         mac[8];
  89                         uint8_t         nonce[4];
  90                 } synack;
  91                 struct {
  92                         uint8_t        mac[20];
  93                 } ack;
  94         } u;
  95 };
  96
  97 #define MP_JOIN_B                       0x01
  98
  99 struct mp_dss {
 100         uint8_t        kind;
 101         uint8_t        len;
 102         uint8_t        sub;
 103         uint8_t        flags;
 104 };
 105
 106 #define MP_DSS_F                        0x10
 107 #define MP_DSS_m                        0x08
 108 #define MP_DSS_M                        0x04
 109 #define MP_DSS_a                        0x02
 110 #define MP_DSS_A                        0x01
 111
 112 struct mp_add_addr {
 113         uint8_t        kind;
 114         uint8_t        len;
 115         uint8_t        sub_ipver;
 116         uint8_t        addr_id;
 117         union {
 118                 struct {
 119                         uint8_t         addr[4];
 120                         uint8_t         port[2];
 121                 } v4;
 122                 struct {
 123                         uint8_t         addr[16];
 124                         uint8_t         port[2];
 125                 } v6;
 126         } u;
 127 };
 128
 129 #define MP_ADD_ADDR_IPVER(sub_ipver)    (((sub_ipver) >> 0) & 0xF)
 130
 131 struct mp_remove_addr {
 132         uint8_t        kind;
 133         uint8_t        len;
 134         uint8_t        sub;
 135         /* list of addr_id */
 136         uint8_t        addrs_id;
 137 };
 138
 139 struct mp_fail {
 140         uint8_t        kind;
 141         uint8_t        len;
 142         uint8_t        sub;
 143         uint8_t        resv;
 144         uint8_t        data_seq[8];
 145 };
 146
 147 struct mp_close {
 148         uint8_t        kind;
 149         uint8_t        len;
 150         uint8_t        sub;
 151         uint8_t        rsv;
 152         uint8_t        key[8];
 153 };
 154
 155 struct mp_prio {
 156         uint8_t        kind;
 157         uint8_t        len;
 158         uint8_t        sub_b;
 159         uint8_t        addr_id;
 160 };
 161
 162 #define MP_PRIO_B                       0x01
 163
 164 static int
 165 dummy_print(netdissect_options *ndo _U_,
 166             const u_char *opt _U_, u_int opt_len _U_, u_char flags _U_)
 167 {
 168         return 1;
 169 }
 170
 171 static int
 172 mp_capable_print(netdissect_options *ndo,
 173                  const u_char *opt, u_int opt_len, u_char flags)
 174 {
 175         const struct mp_capable *mpc = (const struct mp_capable *) opt;
 176
 177         if (!(opt_len == 12 && flags & TH_SYN) &&
 178             !(opt_len == 20 && (flags & (TH_SYN | TH_ACK)) == TH_ACK))
 179                 return 0;
 180
 181         if (MP_CAPABLE_OPT_VERSION(mpc->sub_ver) != 0) {
 182                 ND_PRINT((ndo, " Unknown Version (%d)", MP_CAPABLE_OPT_VERSION(mpc->sub_ver)));
 183                 return 1;
 184         }
 185
 186         if (mpc->flags & MP_CAPABLE_C)
 187                 ND_PRINT((ndo, " csum"));
 188         ND_PRINT((ndo, " {0x%" PRIx64, EXTRACT_64BITS(mpc->sender_key)));
 189         if (opt_len == 20) /* ACK */
 190                 ND_PRINT((ndo, ",0x%" PRIx64, EXTRACT_64BITS(mpc->receiver_key)));
 191         ND_PRINT((ndo, "}"));
 192         return 1;
 193 }
 194
 195 static int
 196 mp_join_print(netdissect_options *ndo,
 197               const u_char *opt, u_int opt_len, u_char flags)
 198 {
 199         const struct mp_join *mpj = (const struct mp_join *) opt;
 200
 201         if (!(opt_len == 12 && flags & TH_SYN) &&
 202             !(opt_len == 16 && (flags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) &&
 203             !(opt_len == 24 && flags & TH_ACK))
 204                 return 0;
 205
 206         if (opt_len != 24) {
 207                 if (mpj->sub_b & MP_JOIN_B)
 208                         ND_PRINT((ndo, " backup"));
 209                 ND_PRINT((ndo, " id %u", mpj->addr_id));
 210         }
 211
 212         switch (opt_len) {
 213         case 12: /* SYN */
 214                 ND_PRINT((ndo, " token 0x%x" " nonce 0x%x",
 215                         EXTRACT_32BITS(mpj->u.syn.token),
 216                         EXTRACT_32BITS(mpj->u.syn.nonce)));
 217                 break;
 218         case 16: /* SYN/ACK */
 219                 ND_PRINT((ndo, " hmac 0x%" PRIx64 " nonce 0x%x",
 220                         EXTRACT_64BITS(mpj->u.synack.mac),
 221                         EXTRACT_32BITS(mpj->u.synack.nonce)));
 222                 break;
 223         case 24: {/* ACK */
 224                 size_t i;
 225                 ND_PRINT((ndo, " hmac 0x"));
 226                 for (i = 0; i < sizeof(mpj->u.ack.mac); ++i)
 227                         ND_PRINT((ndo, "%02x", mpj->u.ack.mac[i]));
 228         }
 229         default:
 230                 break;
 231         }
 232         return 1;
 233 }
 234
 235 static u_int mp_dss_len(const  struct mp_dss *m, int csum)
 236 {
 237         u_int len;
 238
 239         len = 4;
 240         if (m->flags & MP_DSS_A) {
 241                 /* Ack present - 4 or 8 octets */
 242                 len += (m->flags & MP_DSS_a) ? 8 : 4;
 243         }
 244         if (m->flags & MP_DSS_M) {
 245                 /*
 246                  * Data Sequence Number (DSN), Subflow Sequence Number (SSN),
 247                  * Data-Level Length present, and Checksum possibly present.
 248                  * All but the Checksum are 10 bytes if the m flag is
 249                  * clear (4-byte DSN) and 14 bytes if the m flag is set
 250                  * (8-byte DSN).
 251                  */
 252                 len += (m->flags & MP_DSS_m) ? 14 : 10;
 253
 254                 /*
 255                  * The Checksum is present only if negotiated.
 256                  */
 257                 if (csum)
 258                         len += 2;
 259         }
 260         return len;
 261 }
 262
 263 static int
 264 mp_dss_print(netdissect_options *ndo,
 265              const u_char *opt, u_int opt_len, u_char flags)
 266 {
 267         const struct mp_dss *mdss = (const struct mp_dss *) opt;
 268
 269         if ((opt_len != mp_dss_len(mdss, 1) &&
 270              opt_len != mp_dss_len(mdss, 0)) || flags & TH_SYN)
 271                 return 0;
 272
 273         if (mdss->flags & MP_DSS_F)
 274                 ND_PRINT((ndo, " fin"));
 275
 276         opt += 4;
 277         if (mdss->flags & MP_DSS_A) {
 278                 ND_PRINT((ndo, " ack "));
 279                 if (mdss->flags & MP_DSS_a) {
 280                         ND_PRINT((ndo, "%" PRIu64, EXTRACT_64BITS(opt)));
 281                         opt += 8;
 282                 } else {
 283                         ND_PRINT((ndo, "%u", EXTRACT_32BITS(opt)));
 284                         opt += 4;
 285                 }
 286         }
 287
 288         if (mdss->flags & MP_DSS_M) {
 289                 ND_PRINT((ndo, " seq "));
 290                 if (mdss->flags & MP_DSS_m) {
 291                         ND_PRINT((ndo, "%" PRIu64, EXTRACT_64BITS(opt)));
 292                         opt += 8;
 293                 } else {
 294                         ND_PRINT((ndo, "%u", EXTRACT_32BITS(opt)));
 295                         opt += 4;
 296                 }
 297                 ND_PRINT((ndo, " subseq %u", EXTRACT_32BITS(opt)));
 298                 opt += 4;
 299                 ND_PRINT((ndo, " len %u", EXTRACT_16BITS(opt)));
 300                 opt += 2;
 301
 302                 if (opt_len == mp_dss_len(mdss, 1))
 303                         ND_PRINT((ndo, " csum 0x%x", EXTRACT_16BITS(opt)));
 304         }
 305         return 1;
 306 }
 307
 308 static int
 309 add_addr_print(netdissect_options *ndo,
 310                const u_char *opt, u_int opt_len, u_char flags _U_)
 311 {
 312         const struct mp_add_addr *add_addr = (const struct mp_add_addr *) opt;
 313         u_int ipver = MP_ADD_ADDR_IPVER(add_addr->sub_ipver);
 314
 315         if (!((opt_len == 8 || opt_len == 10) && ipver == 4) &&
 316             !((opt_len == 20 || opt_len == 22) && ipver == 6))
 317                 return 0;
 318
 319         ND_PRINT((ndo, " id %u", add_addr->addr_id));
 320         switch (ipver) {
 321         case 4:
 322                 ND_PRINT((ndo, " %s", ipaddr_string(ndo, add_addr->u.v4.addr)));
 323                 if (opt_len == 10)
 324                         ND_PRINT((ndo, ":%u", EXTRACT_16BITS(add_addr->u.v4.port)));
 325                 break;
 326         case 6:
 327                 ND_PRINT((ndo, " %s", ip6addr_string(ndo, add_addr->u.v6.addr)));
 328                 if (opt_len == 22)
 329                         ND_PRINT((ndo, ":%u", EXTRACT_16BITS(add_addr->u.v6.port)));
 330                 break;
 331         default:
 332                 return 0;
 333         }
 334
 335         return 1;
 336 }
 337
 338 static int
 339 remove_addr_print(netdissect_options *ndo,
 340                   const u_char *opt, u_int opt_len, u_char flags _U_)
 341 {
 342         const struct mp_remove_addr *remove_addr = (const struct mp_remove_addr *) opt;
 343         const uint8_t *addr_id = &remove_addr->addrs_id;
 344
 345         if (opt_len < 4)
 346                 return 0;
 347
 348         opt_len -= 3;
 349         ND_PRINT((ndo, " id"));
 350         while (opt_len--)
 351                 ND_PRINT((ndo, " %u", *addr_id++));
 352         return 1;
 353 }
 354
 355 static int
 356 mp_prio_print(netdissect_options *ndo,
 357               const u_char *opt, u_int opt_len, u_char flags _U_)
 358 {
 359         const struct mp_prio *mpp = (const struct mp_prio *) opt;
 360
 361         if (opt_len != 3 && opt_len != 4)
 362                 return 0;
 363
 364         if (mpp->sub_b & MP_PRIO_B)
 365                 ND_PRINT((ndo, " backup"));
 366         else
 367                 ND_PRINT((ndo, " non-backup"));
 368         if (opt_len == 4)
 369                 ND_PRINT((ndo, " id %u", mpp->addr_id));
 370
 371         return 1;
 372 }
 373
 374 static int
 375 mp_fail_print(netdissect_options *ndo,
 376               const u_char *opt, u_int opt_len, u_char flags _U_)
 377 {
 378         if (opt_len != 12)
 379                 return 0;
 380
 381         ND_PRINT((ndo, " seq %" PRIu64, EXTRACT_64BITS(opt + 4)));
 382         return 1;
 383 }
 384
 385 static int
 386 mp_fast_close_print(netdissect_options *ndo,
 387                     const u_char *opt, u_int opt_len, u_char flags _U_)
 388 {
 389         if (opt_len != 12)
 390                 return 0;
 391
 392         ND_PRINT((ndo, " key 0x%" PRIx64, EXTRACT_64BITS(opt + 4)));
 393         return 1;
 394 }
 395
 396 static const struct {
 397         const char *name;
 398         int (*print)(netdissect_options *, const u_char *, u_int, u_char);
 399 } mptcp_options[] = {
 400         { "capable", mp_capable_print},
 401         { "join",       mp_join_print },
 402         { "dss",        mp_dss_print },
 403         { "add-addr",   add_addr_print },
 404         { "rem-addr",   remove_addr_print },
 405         { "prio",       mp_prio_print },
 406         { "fail",       mp_fail_print },
 407         { "fast-close", mp_fast_close_print },
 408         { "unknown",    dummy_print },
 409 };
 410
 411 int
 412 mptcp_print(netdissect_options *ndo,
 413             const u_char *cp, u_int len, u_char flags)
 414 {
 415         const struct mptcp_option *opt;
 416         u_int subtype;
 417
 418         if (len < 3)
 419                 return 0;
 420
 421         opt = (const struct mptcp_option *) cp;
 422         subtype = min(MPTCP_OPT_SUBTYPE(opt->sub_etc), MPTCP_SUB_FCLOSE + 1);
 423
 424         ND_PRINT((ndo, " %s", mptcp_options[subtype].name));
 425         return mptcp_options[subtype].print(ndo, cp, len, flags);
 426 }