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 /* \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
dummy_print(netdissect_options * ndo _U_,const u_char * opt _U_,u_int opt_len _U_,u_char flags _U_)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
mp_capable_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags)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
mp_join_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags)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
mp_dss_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags)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
add_addr_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags _U_)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
remove_addr_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags _U_)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
mp_prio_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags _U_)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
mp_fail_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags _U_)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
mp_fast_close_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags _U_)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
mptcp_print(netdissect_options * ndo,const u_char * cp,u_int len,u_char flags)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