1 /** 2 * Copyright (c) 2012 3 * 4 * Gregory Detal <gregory.detal (at) uclouvain.be> 5 * Christoph Paasch <christoph.paasch (at) 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 /* \summary: Multipath TCP (MPTCP) printer */ 36 37 /* specification: RFC 6824 */ 38 39 #ifdef HAVE_CONFIG_H 40 #include "config.h" 41 #endif 42 43 #include <netdissect-stdinc.h> 44 45 #include "netdissect.h" 46 #include "extract.h" 47 #include "addrtoname.h" 48 49 #include "tcp.h" 50 51 #define MPTCP_SUB_CAPABLE 0x0 52 #define MPTCP_SUB_JOIN 0x1 53 #define MPTCP_SUB_DSS 0x2 54 #define MPTCP_SUB_ADD_ADDR 0x3 55 #define MPTCP_SUB_REMOVE_ADDR 0x4 56 #define MPTCP_SUB_PRIO 0x5 57 #define MPTCP_SUB_FAIL 0x6 58 #define MPTCP_SUB_FCLOSE 0x7 59 60 struct mptcp_option { 61 uint8_t kind; 62 uint8_t len; 63 uint8_t sub_etc; /* subtype upper 4 bits, other stuff lower 4 bits */ 64 }; 65 66 #define MPTCP_OPT_SUBTYPE(sub_etc) (((sub_etc) >> 4) & 0xF) 67 68 struct mp_capable { 69 uint8_t kind; 70 uint8_t len; 71 uint8_t sub_ver; 72 uint8_t flags; 73 uint8_t sender_key[8]; 74 uint8_t receiver_key[8]; 75 }; 76 77 #define MP_CAPABLE_OPT_VERSION(sub_ver) (((sub_ver) >> 0) & 0xF) 78 #define MP_CAPABLE_C 0x80 79 #define MP_CAPABLE_S 0x01 80 81 struct mp_join { 82 uint8_t kind; 83 uint8_t len; 84 uint8_t sub_b; 85 uint8_t addr_id; 86 union { 87 struct { 88 uint8_t token[4]; 89 uint8_t nonce[4]; 90 } syn; 91 struct { 92 uint8_t mac[8]; 93 uint8_t nonce[4]; 94 } synack; 95 struct { 96 uint8_t mac[20]; 97 } ack; 98 } u; 99 }; 100 101 #define MP_JOIN_B 0x01 102 103 struct mp_dss { 104 uint8_t kind; 105 uint8_t len; 106 uint8_t sub; 107 uint8_t flags; 108 }; 109 110 #define MP_DSS_F 0x10 111 #define MP_DSS_m 0x08 112 #define MP_DSS_M 0x04 113 #define MP_DSS_a 0x02 114 #define MP_DSS_A 0x01 115 116 struct mp_add_addr { 117 uint8_t kind; 118 uint8_t len; 119 uint8_t sub_ipver; 120 uint8_t addr_id; 121 union { 122 struct { 123 uint8_t addr[4]; 124 uint8_t port[2]; 125 } v4; 126 struct { 127 uint8_t addr[16]; 128 uint8_t port[2]; 129 } v6; 130 } u; 131 }; 132 133 #define MP_ADD_ADDR_IPVER(sub_ipver) (((sub_ipver) >> 0) & 0xF) 134 135 struct mp_remove_addr { 136 uint8_t kind; 137 uint8_t len; 138 uint8_t sub; 139 /* list of addr_id */ 140 uint8_t addrs_id; 141 }; 142 143 struct mp_fail { 144 uint8_t kind; 145 uint8_t len; 146 uint8_t sub; 147 uint8_t resv; 148 uint8_t data_seq[8]; 149 }; 150 151 struct mp_close { 152 uint8_t kind; 153 uint8_t len; 154 uint8_t sub; 155 uint8_t rsv; 156 uint8_t key[8]; 157 }; 158 159 struct mp_prio { 160 uint8_t kind; 161 uint8_t len; 162 uint8_t sub_b; 163 uint8_t addr_id; 164 }; 165 166 #define MP_PRIO_B 0x01 167 168 static int 169 dummy_print(netdissect_options *ndo _U_, 170 const u_char *opt _U_, u_int opt_len _U_, u_char flags _U_) 171 { 172 return 1; 173 } 174 175 static int 176 mp_capable_print(netdissect_options *ndo, 177 const u_char *opt, u_int opt_len, u_char flags) 178 { 179 const struct mp_capable *mpc = (const struct mp_capable *) opt; 180 181 if (!(opt_len == 12 && (flags & TH_SYN)) && 182 !(opt_len == 20 && (flags & (TH_SYN | TH_ACK)) == TH_ACK)) 183 return 0; 184 185 if (MP_CAPABLE_OPT_VERSION(mpc->sub_ver) != 0) { 186 ND_PRINT((ndo, " Unknown Version (%d)", MP_CAPABLE_OPT_VERSION(mpc->sub_ver))); 187 return 1; 188 } 189 190 if (mpc->flags & MP_CAPABLE_C) 191 ND_PRINT((ndo, " csum")); 192 ND_PRINT((ndo, " {0x%" PRIx64, EXTRACT_64BITS(mpc->sender_key))); 193 if (opt_len == 20) /* ACK */ 194 ND_PRINT((ndo, ",0x%" PRIx64, EXTRACT_64BITS(mpc->receiver_key))); 195 ND_PRINT((ndo, "}")); 196 return 1; 197 } 198 199 static int 200 mp_join_print(netdissect_options *ndo, 201 const u_char *opt, u_int opt_len, u_char flags) 202 { 203 const struct mp_join *mpj = (const struct mp_join *) opt; 204 205 if (!(opt_len == 12 && (flags & TH_SYN)) && 206 !(opt_len == 16 && (flags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) && 207 !(opt_len == 24 && (flags & TH_ACK))) 208 return 0; 209 210 if (opt_len != 24) { 211 if (mpj->sub_b & MP_JOIN_B) 212 ND_PRINT((ndo, " backup")); 213 ND_PRINT((ndo, " id %u", mpj->addr_id)); 214 } 215 216 switch (opt_len) { 217 case 12: /* SYN */ 218 ND_PRINT((ndo, " token 0x%x" " nonce 0x%x", 219 EXTRACT_32BITS(mpj->u.syn.token), 220 EXTRACT_32BITS(mpj->u.syn.nonce))); 221 break; 222 case 16: /* SYN/ACK */ 223 ND_PRINT((ndo, " hmac 0x%" PRIx64 " nonce 0x%x", 224 EXTRACT_64BITS(mpj->u.synack.mac), 225 EXTRACT_32BITS(mpj->u.synack.nonce))); 226 break; 227 case 24: {/* ACK */ 228 size_t i; 229 ND_PRINT((ndo, " hmac 0x")); 230 for (i = 0; i < sizeof(mpj->u.ack.mac); ++i) 231 ND_PRINT((ndo, "%02x", mpj->u.ack.mac[i])); 232 } 233 default: 234 break; 235 } 236 return 1; 237 } 238 239 static int 240 mp_dss_print(netdissect_options *ndo, 241 const u_char *opt, u_int opt_len, u_char flags) 242 { 243 const struct mp_dss *mdss = (const struct mp_dss *) opt; 244 245 /* We need the flags, at a minimum. */ 246 if (opt_len < 4) 247 return 0; 248 249 if (flags & TH_SYN) 250 return 0; 251 252 if (mdss->flags & MP_DSS_F) 253 ND_PRINT((ndo, " fin")); 254 255 opt += 4; 256 opt_len -= 4; 257 if (mdss->flags & MP_DSS_A) { 258 /* Ack present */ 259 ND_PRINT((ndo, " ack ")); 260 /* 261 * If the a flag is set, we have an 8-byte ack; if it's 262 * clear, we have a 4-byte ack. 263 */ 264 if (mdss->flags & MP_DSS_a) { 265 if (opt_len < 8) 266 return 0; 267 ND_PRINT((ndo, "%" PRIu64, EXTRACT_64BITS(opt))); 268 opt += 8; 269 opt_len -= 8; 270 } else { 271 if (opt_len < 4) 272 return 0; 273 ND_PRINT((ndo, "%u", EXTRACT_32BITS(opt))); 274 opt += 4; 275 opt_len -= 4; 276 } 277 } 278 279 if (mdss->flags & MP_DSS_M) { 280 /* 281 * Data Sequence Number (DSN), Subflow Sequence Number (SSN), 282 * Data-Level Length present, and Checksum possibly present. 283 */ 284 ND_PRINT((ndo, " seq ")); 285 /* 286 * If the m flag is set, we have an 8-byte NDS; if it's clear, 287 * we have a 4-byte DSN. 288 */ 289 if (mdss->flags & MP_DSS_m) { 290 if (opt_len < 8) 291 return 0; 292 ND_PRINT((ndo, "%" PRIu64, EXTRACT_64BITS(opt))); 293 opt += 8; 294 opt_len -= 8; 295 } else { 296 if (opt_len < 4) 297 return 0; 298 ND_PRINT((ndo, "%u", EXTRACT_32BITS(opt))); 299 opt += 4; 300 opt_len -= 4; 301 } 302 if (opt_len < 4) 303 return 0; 304 ND_PRINT((ndo, " subseq %u", EXTRACT_32BITS(opt))); 305 opt += 4; 306 opt_len -= 4; 307 if (opt_len < 2) 308 return 0; 309 ND_PRINT((ndo, " len %u", EXTRACT_16BITS(opt))); 310 opt += 2; 311 opt_len -= 2; 312 313 /* 314 * The Checksum is present only if negotiated. 315 * If there are at least 2 bytes left, process the next 2 316 * bytes as the Checksum. 317 */ 318 if (opt_len >= 2) { 319 ND_PRINT((ndo, " csum 0x%x", EXTRACT_16BITS(opt))); 320 opt_len -= 2; 321 } 322 } 323 if (opt_len != 0) 324 return 0; 325 return 1; 326 } 327 328 static int 329 add_addr_print(netdissect_options *ndo, 330 const u_char *opt, u_int opt_len, u_char flags _U_) 331 { 332 const struct mp_add_addr *add_addr = (const struct mp_add_addr *) opt; 333 u_int ipver = MP_ADD_ADDR_IPVER(add_addr->sub_ipver); 334 335 if (!((opt_len == 8 || opt_len == 10) && ipver == 4) && 336 !((opt_len == 20 || opt_len == 22) && ipver == 6)) 337 return 0; 338 339 ND_PRINT((ndo, " id %u", add_addr->addr_id)); 340 switch (ipver) { 341 case 4: 342 ND_PRINT((ndo, " %s", ipaddr_string(ndo, add_addr->u.v4.addr))); 343 if (opt_len == 10) 344 ND_PRINT((ndo, ":%u", EXTRACT_16BITS(add_addr->u.v4.port))); 345 break; 346 case 6: 347 ND_PRINT((ndo, " %s", ip6addr_string(ndo, add_addr->u.v6.addr))); 348 if (opt_len == 22) 349 ND_PRINT((ndo, ":%u", EXTRACT_16BITS(add_addr->u.v6.port))); 350 break; 351 default: 352 return 0; 353 } 354 355 return 1; 356 } 357 358 static int 359 remove_addr_print(netdissect_options *ndo, 360 const u_char *opt, u_int opt_len, u_char flags _U_) 361 { 362 const struct mp_remove_addr *remove_addr = (const struct mp_remove_addr *) opt; 363 const uint8_t *addr_id = &remove_addr->addrs_id; 364 365 if (opt_len < 4) 366 return 0; 367 368 opt_len -= 3; 369 ND_PRINT((ndo, " id")); 370 while (opt_len--) 371 ND_PRINT((ndo, " %u", *addr_id++)); 372 return 1; 373 } 374 375 static int 376 mp_prio_print(netdissect_options *ndo, 377 const u_char *opt, u_int opt_len, u_char flags _U_) 378 { 379 const struct mp_prio *mpp = (const struct mp_prio *) opt; 380 381 if (opt_len != 3 && opt_len != 4) 382 return 0; 383 384 if (mpp->sub_b & MP_PRIO_B) 385 ND_PRINT((ndo, " backup")); 386 else 387 ND_PRINT((ndo, " non-backup")); 388 if (opt_len == 4) 389 ND_PRINT((ndo, " id %u", mpp->addr_id)); 390 391 return 1; 392 } 393 394 static int 395 mp_fail_print(netdissect_options *ndo, 396 const u_char *opt, u_int opt_len, u_char flags _U_) 397 { 398 if (opt_len != 12) 399 return 0; 400 401 ND_PRINT((ndo, " seq %" PRIu64, EXTRACT_64BITS(opt + 4))); 402 return 1; 403 } 404 405 static int 406 mp_fast_close_print(netdissect_options *ndo, 407 const u_char *opt, u_int opt_len, u_char flags _U_) 408 { 409 if (opt_len != 12) 410 return 0; 411 412 ND_PRINT((ndo, " key 0x%" PRIx64, EXTRACT_64BITS(opt + 4))); 413 return 1; 414 } 415 416 static const struct { 417 const char *name; 418 int (*print)(netdissect_options *, const u_char *, u_int, u_char); 419 } mptcp_options[] = { 420 { "capable", mp_capable_print}, 421 { "join", mp_join_print }, 422 { "dss", mp_dss_print }, 423 { "add-addr", add_addr_print }, 424 { "rem-addr", remove_addr_print }, 425 { "prio", mp_prio_print }, 426 { "fail", mp_fail_print }, 427 { "fast-close", mp_fast_close_print }, 428 { "unknown", dummy_print }, 429 }; 430 431 int 432 mptcp_print(netdissect_options *ndo, 433 const u_char *cp, u_int len, u_char flags) 434 { 435 const struct mptcp_option *opt; 436 u_int subtype; 437 438 if (len < 3) 439 return 0; 440 441 opt = (const struct mptcp_option *) cp; 442 subtype = min(MPTCP_OPT_SUBTYPE(opt->sub_etc), MPTCP_SUB_FCLOSE + 1); 443 444 ND_PRINT((ndo, " %s", mptcp_options[subtype].name)); 445 return mptcp_options[subtype].print(ndo, cp, len, flags); 446 } 447
