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 <tcpdump-stdinc.h>
40
41#include <stdio.h>
42#include <string.h>
43
44#include "interface.h"
45#include "extract.h"
46#include "addrtoname.h"
47
48#include "ipproto.h"
49#include "mptcp.h"
50#include "tcp.h"
51
52static int dummy_print(const u_char *opt _U_, u_int opt_len _U_, u_char flags _U_)
53{
54        return 1;
55}
56
57static int mp_capable_print(const u_char *opt, u_int opt_len, u_char flags)
58{
59        struct mp_capable *mpc = (struct mp_capable *) opt;
60
61        if (!(opt_len == 12 && flags & TH_SYN) &&
62            !(opt_len == 20 && (flags & (TH_SYN | TH_ACK)) == TH_ACK))
63                return 0;
64
65        if (MP_CAPABLE_OPT_VERSION(mpc->sub_ver) != 0) {
66                printf(" Unknown Version (%d)", MP_CAPABLE_OPT_VERSION(mpc->sub_ver));
67                return 1;
68        }
69
70        if (mpc->flags & MP_CAPABLE_C)
71                printf(" csum");
72        printf(" {0x%" PRIx64, EXTRACT_64BITS(mpc->sender_key));
73        if (opt_len == 20) /* ACK */
74                printf(",0x%" PRIx64, EXTRACT_64BITS(mpc->receiver_key));
75        printf("}");
76        return 1;
77}
78
79static int mp_join_print(const u_char *opt, u_int opt_len, u_char flags)
80{
81        struct mp_join *mpj = (struct mp_join *) opt;
82
83        if (!(opt_len == 12 && flags & TH_SYN) &&
84            !(opt_len == 16 && (flags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) &&
85            !(opt_len == 24 && flags & TH_ACK))
86                return 0;
87
88        if (opt_len != 24) {
89                if (mpj->sub_b & MP_JOIN_B)
90                        printf(" backup");
91                printf(" id %u", mpj->addr_id);
92        }
93
94        switch (opt_len) {
95        case 12: /* SYN */
96                printf(" token 0x%x" " nonce 0x%x",
97                        EXTRACT_32BITS(mpj->u.syn.token),
98                        EXTRACT_32BITS(mpj->u.syn.nonce));
99                break;
100        case 16: /* SYN/ACK */
101                printf(" hmac 0x%" PRIx64 " nonce 0x%x",
102                        EXTRACT_64BITS(mpj->u.synack.mac),
103                        EXTRACT_32BITS(mpj->u.synack.nonce));
104                break;
105        case 24: {/* ACK */
106                size_t i;
107                printf(" hmac 0x");
108                for (i = 0; i < sizeof(mpj->u.ack.mac); ++i)
109                        printf("%02x", mpj->u.ack.mac[i]);
110        }
111        default:
112                break;
113        }
114        return 1;
115}
116
117static u_int mp_dss_len(struct mp_dss *m, int csum)
118{
119        u_int len;
120
121        len = 4;
122        if (m->flags & MP_DSS_A) {
123                /* Ack present - 4 or 8 octets */
124                len += (m->flags & MP_DSS_a) ? 8 : 4;
125        }
126        if (m->flags & MP_DSS_M) {
127                /*
128                 * Data Sequence Number (DSN), Subflow Sequence Number (SSN),
129                 * Data-Level Length present, and Checksum possibly present.
130                 * All but the Checksum are 10 bytes if the m flag is
131                 * clear (4-byte DSN) and 14 bytes if the m flag is set
132                 * (8-byte DSN).
133                 */
134                len += (m->flags & MP_DSS_m) ? 14 : 10;
135
136                /*
137                 * The Checksum is present only if negotiated.
138                 */
139                if (csum)
140                        len += 2;
141	}
142	return len;
143}
144
145static int mp_dss_print(const u_char *opt, u_int opt_len, u_char flags)
146{
147        struct mp_dss *mdss = (struct mp_dss *) opt;
148
149        if ((opt_len != mp_dss_len(mdss, 1) &&
150             opt_len != mp_dss_len(mdss, 0)) || flags & TH_SYN)
151                return 0;
152
153        if (mdss->flags & MP_DSS_F)
154                printf(" fin");
155
156        opt += 4;
157        if (mdss->flags & MP_DSS_A) {
158                printf(" ack ");
159                if (mdss->flags & MP_DSS_a) {
160                        printf("%" PRIu64, EXTRACT_64BITS(opt));
161                        opt += 8;
162                } else {
163                        printf("%u", EXTRACT_32BITS(opt));
164                        opt += 4;
165                }
166        }
167
168        if (mdss->flags & MP_DSS_M) {
169                printf(" seq ");
170                if (mdss->flags & MP_DSS_m) {
171                        printf("%" PRIu64, EXTRACT_64BITS(opt));
172                        opt += 8;
173                } else {
174                        printf("%u", EXTRACT_32BITS(opt));
175                        opt += 4;
176                }
177                printf(" subseq %u", EXTRACT_32BITS(opt));
178                opt += 4;
179                printf(" len %u", EXTRACT_16BITS(opt));
180                opt += 2;
181
182                if (opt_len == mp_dss_len(mdss, 1))
183                        printf(" csum 0x%x", EXTRACT_16BITS(opt));
184        }
185        return 1;
186}
187
188static int add_addr_print(const u_char *opt, u_int opt_len, u_char flags _U_)
189{
190        struct mp_add_addr *add_addr = (struct mp_add_addr *) opt;
191        u_int ipver = MP_ADD_ADDR_IPVER(add_addr->sub_ipver);
192
193        if (!((opt_len == 8 || opt_len == 10) && ipver == 4) &&
194            !((opt_len == 20 || opt_len == 22) && ipver == 6))
195                return 0;
196
197        printf(" id %u", add_addr->addr_id);
198        switch (ipver) {
199        case 4:
200                printf(" %s", ipaddr_string(add_addr->u.v4.addr));
201                if (opt_len == 10)
202                        printf(":%u", EXTRACT_16BITS(add_addr->u.v4.port));
203                break;
204        case 6:
205#ifdef INET6
206                printf(" %s", ip6addr_string(add_addr->u.v6.addr));
207#endif
208                if (opt_len == 22)
209                        printf(":%u", EXTRACT_16BITS(add_addr->u.v6.port));
210                break;
211        default:
212                return 0;
213        }
214
215        return 1;
216}
217
218static int remove_addr_print(const u_char *opt, u_int opt_len, u_char flags _U_)
219{
220        struct mp_remove_addr *remove_addr = (struct mp_remove_addr *) opt;
221        u_int8_t *addr_id = &remove_addr->addrs_id;
222
223        if (opt_len < 4)
224                return 0;
225
226        opt_len -= 3;
227        printf(" id");
228        while (opt_len--)
229                printf(" %u", *addr_id++);
230        return 1;
231}
232
233static int mp_prio_print(const u_char *opt, u_int opt_len, u_char flags _U_)
234{
235        struct mp_prio *mpp = (struct mp_prio *) opt;
236
237        if (opt_len != 3 && opt_len != 4)
238                return 0;
239
240        if (mpp->sub_b & MP_PRIO_B)
241                printf(" backup");
242        else
243                printf(" non-backup");
244        if (opt_len == 4)
245                printf(" id %u", mpp->addr_id);
246
247        return 1;
248}
249
250static int mp_fail_print(const u_char *opt, u_int opt_len, u_char flags _U_)
251{
252        if (opt_len != 12)
253                return 0;
254
255        printf(" seq %" PRIu64, EXTRACT_64BITS(opt + 4));
256        return 1;
257}
258
259static int mp_fast_close_print(const u_char *opt, u_int opt_len, u_char flags _U_)
260{
261        if (opt_len != 12)
262                return 0;
263
264        printf(" key 0x%" PRIx64, EXTRACT_64BITS(opt + 4));
265        return 1;
266}
267
268static struct {
269        const char *name;
270        int (*print)(const u_char *, u_int, u_char);
271} mptcp_options[] = {
272        { "capable", mp_capable_print},
273        { "join",       mp_join_print },
274        { "dss",        mp_dss_print },
275        { "add-addr",   add_addr_print },
276        { "rem-addr",   remove_addr_print },
277        { "prio",       mp_prio_print },
278        { "fail",       mp_fail_print },
279        { "fast-close", mp_fast_close_print },
280        { "unknown",    dummy_print },
281};
282
283int mptcp_print(const u_char *cp, u_int len, u_char flags)
284{
285        struct mptcp_option *opt;
286        u_int subtype;
287
288        if (len < 3)
289                return 0;
290
291        opt = (struct mptcp_option *) cp;
292        subtype = min(MPTCP_OPT_SUBTYPE(opt->sub_etc), MPTCP_SUB_FCLOSE + 1);
293
294        printf(" %s", mptcp_options[subtype].name);
295        return mptcp_options[subtype].print(cp, len, flags);
296}
297