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 #define NETDISSECT_REWORKED
36 #ifdef HAVE_CONFIG_H
37 #include "config.h"
38 #endif
39
40 #include <tcpdump-stdinc.h>
41
42 #include "interface.h"
43 #include "extract.h"
44 #include "addrtoname.h"
45
46 #include "tcp.h"
47
48 #define MPTCP_SUB_CAPABLE 0x0
49 #define MPTCP_SUB_JOIN 0x1
50 #define MPTCP_SUB_DSS 0x2
51 #define MPTCP_SUB_ADD_ADDR 0x3
52 #define MPTCP_SUB_REMOVE_ADDR 0x4
53 #define MPTCP_SUB_PRIO 0x5
54 #define MPTCP_SUB_FAIL 0x6
55 #define MPTCP_SUB_FCLOSE 0x7
56
57 struct mptcp_option {
58 uint8_t kind;
59 uint8_t len;
60 uint8_t sub_etc; /* subtype upper 4 bits, other stuff lower 4 bits */
61 };
62
63 #define MPTCP_OPT_SUBTYPE(sub_etc) (((sub_etc) >> 4) & 0xF)
64
65 struct mp_capable {
66 uint8_t kind;
67 uint8_t len;
68 uint8_t sub_ver;
69 uint8_t flags;
70 uint8_t sender_key[8];
71 uint8_t receiver_key[8];
72 };
73
74 #define MP_CAPABLE_OPT_VERSION(sub_ver) (((sub_ver) >> 0) & 0xF)
75 #define MP_CAPABLE_C 0x80
76 #define MP_CAPABLE_S 0x01
77
78 struct mp_join {
79 uint8_t kind;
80 uint8_t len;
81 uint8_t sub_b;
82 uint8_t addr_id;
83 union {
84 struct {
85 uint8_t token[4];
86 uint8_t nonce[4];
87 } syn;
88 struct {
89 uint8_t mac[8];
90 uint8_t nonce[4];
91 } synack;
92 struct {
93 uint8_t mac[20];
94 } ack;
95 } u;
96 };
97
98 #define MP_JOIN_B 0x01
99
100 struct mp_dss {
101 uint8_t kind;
102 uint8_t len;
103 uint8_t sub;
104 uint8_t flags;
105 };
106
107 #define MP_DSS_F 0x10
108 #define MP_DSS_m 0x08
109 #define MP_DSS_M 0x04
110 #define MP_DSS_a 0x02
111 #define MP_DSS_A 0x01
112
113 struct mp_add_addr {
114 uint8_t kind;
115 uint8_t len;
116 uint8_t sub_ipver;
117 uint8_t addr_id;
118 union {
119 struct {
120 uint8_t addr[4];
121 uint8_t port[2];
122 } v4;
123 struct {
124 uint8_t addr[16];
125 uint8_t port[2];
126 } v6;
127 } u;
128 };
129
130 #define MP_ADD_ADDR_IPVER(sub_ipver) (((sub_ipver) >> 0) & 0xF)
131
132 struct mp_remove_addr {
133 uint8_t kind;
134 uint8_t len;
135 uint8_t sub;
136 /* list of addr_id */
137 uint8_t addrs_id;
138 };
139
140 struct mp_fail {
141 uint8_t kind;
142 uint8_t len;
143 uint8_t sub;
144 uint8_t resv;
145 uint8_t data_seq[8];
146 };
147
148 struct mp_close {
149 uint8_t kind;
150 uint8_t len;
151 uint8_t sub;
152 uint8_t rsv;
153 uint8_t key[8];
154 };
155
156 struct mp_prio {
157 uint8_t kind;
158 uint8_t len;
159 uint8_t sub_b;
160 uint8_t addr_id;
161 };
162
163 #define MP_PRIO_B 0x01
164
165 static int
dummy_print(netdissect_options * ndo _U_,const u_char * opt _U_,u_int opt_len _U_,u_char flags _U_)166 dummy_print(netdissect_options *ndo _U_,
167 const u_char *opt _U_, u_int opt_len _U_, u_char flags _U_)
168 {
169 return 1;
170 }
171
172 static int
mp_capable_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags)173 mp_capable_print(netdissect_options *ndo,
174 const u_char *opt, u_int opt_len, u_char flags)
175 {
176 struct mp_capable *mpc = (struct mp_capable *) opt;
177
178 if (!(opt_len == 12 && flags & TH_SYN) &&
179 !(opt_len == 20 && (flags & (TH_SYN | TH_ACK)) == TH_ACK))
180 return 0;
181
182 if (MP_CAPABLE_OPT_VERSION(mpc->sub_ver) != 0) {
183 ND_PRINT((ndo, " Unknown Version (%d)", MP_CAPABLE_OPT_VERSION(mpc->sub_ver)));
184 return 1;
185 }
186
187 if (mpc->flags & MP_CAPABLE_C)
188 ND_PRINT((ndo, " csum"));
189 ND_PRINT((ndo, " {0x%" PRIx64, EXTRACT_64BITS(mpc->sender_key)));
190 if (opt_len == 20) /* ACK */
191 ND_PRINT((ndo, ",0x%" PRIx64, EXTRACT_64BITS(mpc->receiver_key)));
192 ND_PRINT((ndo, "}"));
193 return 1;
194 }
195
196 static int
mp_join_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags)197 mp_join_print(netdissect_options *ndo,
198 const u_char *opt, u_int opt_len, u_char flags)
199 {
200 struct mp_join *mpj = (struct mp_join *) opt;
201
202 if (!(opt_len == 12 && flags & TH_SYN) &&
203 !(opt_len == 16 && (flags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) &&
204 !(opt_len == 24 && flags & TH_ACK))
205 return 0;
206
207 if (opt_len != 24) {
208 if (mpj->sub_b & MP_JOIN_B)
209 ND_PRINT((ndo, " backup"));
210 ND_PRINT((ndo, " id %u", mpj->addr_id));
211 }
212
213 switch (opt_len) {
214 case 12: /* SYN */
215 ND_PRINT((ndo, " token 0x%x" " nonce 0x%x",
216 EXTRACT_32BITS(mpj->u.syn.token),
217 EXTRACT_32BITS(mpj->u.syn.nonce)));
218 break;
219 case 16: /* SYN/ACK */
220 ND_PRINT((ndo, " hmac 0x%" PRIx64 " nonce 0x%x",
221 EXTRACT_64BITS(mpj->u.synack.mac),
222 EXTRACT_32BITS(mpj->u.synack.nonce)));
223 break;
224 case 24: {/* ACK */
225 size_t i;
226 ND_PRINT((ndo, " hmac 0x"));
227 for (i = 0; i < sizeof(mpj->u.ack.mac); ++i)
228 ND_PRINT((ndo, "%02x", mpj->u.ack.mac[i]));
229 }
230 default:
231 break;
232 }
233 return 1;
234 }
235
mp_dss_len(struct mp_dss * m,int csum)236 static u_int mp_dss_len(struct mp_dss *m, int csum)
237 {
238 u_int len;
239
240 len = 4;
241 if (m->flags & MP_DSS_A) {
242 /* Ack present - 4 or 8 octets */
243 len += (m->flags & MP_DSS_a) ? 8 : 4;
244 }
245 if (m->flags & MP_DSS_M) {
246 /*
247 * Data Sequence Number (DSN), Subflow Sequence Number (SSN),
248 * Data-Level Length present, and Checksum possibly present.
249 * All but the Checksum are 10 bytes if the m flag is
250 * clear (4-byte DSN) and 14 bytes if the m flag is set
251 * (8-byte DSN).
252 */
253 len += (m->flags & MP_DSS_m) ? 14 : 10;
254
255 /*
256 * The Checksum is present only if negotiated.
257 */
258 if (csum)
259 len += 2;
260 }
261 return len;
262 }
263
264 static int
mp_dss_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags)265 mp_dss_print(netdissect_options *ndo,
266 const u_char *opt, u_int opt_len, u_char flags)
267 {
268 struct mp_dss *mdss = (struct mp_dss *) opt;
269
270 if ((opt_len != mp_dss_len(mdss, 1) &&
271 opt_len != mp_dss_len(mdss, 0)) || flags & TH_SYN)
272 return 0;
273
274 if (mdss->flags & MP_DSS_F)
275 ND_PRINT((ndo, " fin"));
276
277 opt += 4;
278 if (mdss->flags & MP_DSS_A) {
279 ND_PRINT((ndo, " ack "));
280 if (mdss->flags & MP_DSS_a) {
281 ND_PRINT((ndo, "%" PRIu64, EXTRACT_64BITS(opt)));
282 opt += 8;
283 } else {
284 ND_PRINT((ndo, "%u", EXTRACT_32BITS(opt)));
285 opt += 4;
286 }
287 }
288
289 if (mdss->flags & MP_DSS_M) {
290 ND_PRINT((ndo, " seq "));
291 if (mdss->flags & MP_DSS_m) {
292 ND_PRINT((ndo, "%" PRIu64, EXTRACT_64BITS(opt)));
293 opt += 8;
294 } else {
295 ND_PRINT((ndo, "%u", EXTRACT_32BITS(opt)));
296 opt += 4;
297 }
298 ND_PRINT((ndo, " subseq %u", EXTRACT_32BITS(opt)));
299 opt += 4;
300 ND_PRINT((ndo, " len %u", EXTRACT_16BITS(opt)));
301 opt += 2;
302
303 if (opt_len == mp_dss_len(mdss, 1))
304 ND_PRINT((ndo, " csum 0x%x", EXTRACT_16BITS(opt)));
305 }
306 return 1;
307 }
308
309 static int
add_addr_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags _U_)310 add_addr_print(netdissect_options *ndo,
311 const u_char *opt, u_int opt_len, u_char flags _U_)
312 {
313 struct mp_add_addr *add_addr = (struct mp_add_addr *) opt;
314 u_int ipver = MP_ADD_ADDR_IPVER(add_addr->sub_ipver);
315
316 if (!((opt_len == 8 || opt_len == 10) && ipver == 4) &&
317 !((opt_len == 20 || opt_len == 22) && ipver == 6))
318 return 0;
319
320 ND_PRINT((ndo, " id %u", add_addr->addr_id));
321 switch (ipver) {
322 case 4:
323 ND_PRINT((ndo, " %s", ipaddr_string(ndo, add_addr->u.v4.addr)));
324 if (opt_len == 10)
325 ND_PRINT((ndo, ":%u", EXTRACT_16BITS(add_addr->u.v4.port)));
326 break;
327 case 6:
328 #ifdef INET6
329 ND_PRINT((ndo, " %s", ip6addr_string(ndo, add_addr->u.v6.addr)));
330 #endif
331 if (opt_len == 22)
332 ND_PRINT((ndo, ":%u", EXTRACT_16BITS(add_addr->u.v6.port)));
333 break;
334 default:
335 return 0;
336 }
337
338 return 1;
339 }
340
341 static int
remove_addr_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags _U_)342 remove_addr_print(netdissect_options *ndo,
343 const u_char *opt, u_int opt_len, u_char flags _U_)
344 {
345 struct mp_remove_addr *remove_addr = (struct mp_remove_addr *) opt;
346 uint8_t *addr_id = &remove_addr->addrs_id;
347
348 if (opt_len < 4)
349 return 0;
350
351 opt_len -= 3;
352 ND_PRINT((ndo, " id"));
353 while (opt_len--)
354 ND_PRINT((ndo, " %u", *addr_id++));
355 return 1;
356 }
357
358 static int
mp_prio_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags _U_)359 mp_prio_print(netdissect_options *ndo,
360 const u_char *opt, u_int opt_len, u_char flags _U_)
361 {
362 struct mp_prio *mpp = (struct mp_prio *) opt;
363
364 if (opt_len != 3 && opt_len != 4)
365 return 0;
366
367 if (mpp->sub_b & MP_PRIO_B)
368 ND_PRINT((ndo, " backup"));
369 else
370 ND_PRINT((ndo, " non-backup"));
371 if (opt_len == 4)
372 ND_PRINT((ndo, " id %u", mpp->addr_id));
373
374 return 1;
375 }
376
377 static int
mp_fail_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags _U_)378 mp_fail_print(netdissect_options *ndo,
379 const u_char *opt, u_int opt_len, u_char flags _U_)
380 {
381 if (opt_len != 12)
382 return 0;
383
384 ND_PRINT((ndo, " seq %" PRIu64, EXTRACT_64BITS(opt + 4)));
385 return 1;
386 }
387
388 static int
mp_fast_close_print(netdissect_options * ndo,const u_char * opt,u_int opt_len,u_char flags _U_)389 mp_fast_close_print(netdissect_options *ndo,
390 const u_char *opt, u_int opt_len, u_char flags _U_)
391 {
392 if (opt_len != 12)
393 return 0;
394
395 ND_PRINT((ndo, " key 0x%" PRIx64, EXTRACT_64BITS(opt + 4)));
396 return 1;
397 }
398
399 static const struct {
400 const char *name;
401 int (*print)(netdissect_options *, const u_char *, u_int, u_char);
402 } mptcp_options[] = {
403 { "capable", mp_capable_print},
404 { "join", mp_join_print },
405 { "dss", mp_dss_print },
406 { "add-addr", add_addr_print },
407 { "rem-addr", remove_addr_print },
408 { "prio", mp_prio_print },
409 { "fail", mp_fail_print },
410 { "fast-close", mp_fast_close_print },
411 { "unknown", dummy_print },
412 };
413
414 int
mptcp_print(netdissect_options * ndo,const u_char * cp,u_int len,u_char flags)415 mptcp_print(netdissect_options *ndo,
416 const u_char *cp, u_int len, u_char flags)
417 {
418 struct mptcp_option *opt;
419 u_int subtype;
420
421 if (len < 3)
422 return 0;
423
424 opt = (struct mptcp_option *) cp;
425 subtype = min(MPTCP_OPT_SUBTYPE(opt->sub_etc), MPTCP_SUB_FCLOSE + 1);
426
427 ND_PRINT((ndo, " %s", mptcp_options[subtype].name));
428 return mptcp_options[subtype].print(ndo, cp, len, flags);
429 }
430