1/*
2 * Copyright (c) 2007-2011 Grégoire Henry, Juliusz Chroboczek
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 * 3. Neither the name of the project nor the names of its contributors
13 *    may be used to endorse or promote products derived from this software
14 *    without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#ifdef HAVE_CONFIG_H
30#include "config.h"
31#endif
32
33#include <tcpdump-stdinc.h>
34
35#include <stdio.h>
36#include <string.h>
37
38#include "addrtoname.h"
39#include "interface.h"
40#include "extract.h"
41
42static void babel_print_v2(const u_char *cp, u_int length);
43
44void
45babel_print(const u_char *cp, u_int length) {
46    printf("babel");
47
48    TCHECK2(*cp, 4);
49
50    if(cp[0] != 42) {
51        printf(" malformed header");
52        return;
53    } else {
54        printf(" %d", cp[1]);
55    }
56
57    switch(cp[1]) {
58    case 2:
59        babel_print_v2(cp,length);
60        break;
61    default:
62        printf(" unknown version");
63        break;
64    }
65
66    return;
67
68 trunc:
69    printf(" [|babel]");
70    return;
71}
72
73#define MESSAGE_PAD1 0
74#define MESSAGE_PADN 1
75#define MESSAGE_ACK_REQ 2
76#define MESSAGE_ACK 3
77#define MESSAGE_HELLO 4
78#define MESSAGE_IHU 5
79#define MESSAGE_ROUTER_ID 6
80#define MESSAGE_NH 7
81#define MESSAGE_UPDATE 8
82#define MESSAGE_REQUEST 9
83#define MESSAGE_MH_REQUEST 10
84#define MESSAGE_TSPC 11
85#define MESSAGE_HMAC 12
86
87static const char *
88format_id(const u_char *id)
89{
90    static char buf[25];
91    snprintf(buf, 25, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x",
92             id[0], id[1], id[2], id[3], id[4], id[5], id[6], id[7]);
93    buf[24] = '\0';
94    return buf;
95}
96
97static const unsigned char v4prefix[16] =
98    {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 };
99
100static const char *
101format_prefix(const u_char *prefix, unsigned char plen)
102{
103    static char buf[50];
104    if(plen >= 96 && memcmp(prefix, v4prefix, 12) == 0)
105        snprintf(buf, 50, "%s/%u", ipaddr_string(prefix + 12), plen - 96);
106    else
107#ifdef INET6
108        snprintf(buf, 50, "%s/%u", ip6addr_string(prefix), plen);
109#else
110        snprintf(buf, 50, "IPv6 addresses not supported");
111#endif
112    buf[49] = '\0';
113    return buf;
114}
115
116static const char *
117format_address(const u_char *prefix)
118{
119    if(memcmp(prefix, v4prefix, 12) == 0)
120        return ipaddr_string(prefix + 12);
121    else
122#ifdef INET6
123        return ip6addr_string(prefix);
124#else
125        return "IPv6 addresses not supported";
126#endif
127}
128
129static int
130network_prefix(int ae, int plen, unsigned int omitted,
131               const unsigned char *p, const unsigned char *dp,
132               unsigned int len, unsigned char *p_r)
133{
134    unsigned pb;
135    unsigned char prefix[16];
136
137    if(plen >= 0)
138        pb = (plen + 7) / 8;
139    else if(ae == 1)
140        pb = 4;
141    else
142        pb = 16;
143
144    if(pb > 16)
145        return -1;
146
147    memset(prefix, 0, 16);
148
149    switch(ae) {
150    case 0: break;
151    case 1:
152        if(omitted > 4 || pb > 4 || (pb > omitted && len < pb - omitted))
153            return -1;
154        memcpy(prefix, v4prefix, 12);
155        if(omitted) {
156            if (dp == NULL) return -1;
157            memcpy(prefix, dp, 12 + omitted);
158        }
159        if(pb > omitted) memcpy(prefix + 12 + omitted, p, pb - omitted);
160        break;
161    case 2:
162        if(omitted > 16 || (pb > omitted && len < pb - omitted))
163            return -1;
164        if(omitted) {
165            if (dp == NULL) return -1;
166            memcpy(prefix, dp, omitted);
167        }
168        if(pb > omitted) memcpy(prefix + omitted, p, pb - omitted);
169        break;
170    case 3:
171        if(pb > 8 && len < pb - 8) return -1;
172        prefix[0] = 0xfe;
173        prefix[1] = 0x80;
174        if(pb > 8) memcpy(prefix + 8, p, pb - 8);
175        break;
176    default:
177        return -1;
178    }
179
180    memcpy(p_r, prefix, 16);
181    return 1;
182}
183
184static int
185network_address(int ae, const unsigned char *a, unsigned int len,
186                unsigned char *a_r)
187{
188    return network_prefix(ae, -1, 0, a, NULL, len, a_r);
189}
190
191#define ICHECK(i, l) \
192	if ((i) + (l) > bodylen || (i) + (l) > length) goto corrupt;
193
194static void
195babel_print_v2(const u_char *cp, u_int length) {
196    u_int i;
197    u_short bodylen;
198    u_char v4_prefix[16] =
199        {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 };
200    u_char v6_prefix[16] = {0};
201
202    TCHECK2(*cp, 4);
203    if (length < 4)
204        goto corrupt;
205    bodylen = EXTRACT_16BITS(cp + 2);
206    printf(" (%u)", bodylen);
207
208    /* Process the TLVs in the body */
209    i = 0;
210    while(i < bodylen) {
211        const u_char *message;
212        u_int type, len;
213
214        message = cp + 4 + i;
215        TCHECK2(*message, 2);
216        ICHECK(i, 2);
217        type = message[0];
218        len = message[1];
219
220        TCHECK2(*message, 2 + len);
221        ICHECK(i, 2 + len);
222
223        switch(type) {
224        case MESSAGE_PAD1: {
225            if(!vflag)
226                printf(" pad1");
227            else
228                printf("\n\tPad 1");
229        }
230            break;
231
232        case MESSAGE_PADN: {
233            if(!vflag)
234                printf(" padN");
235            else
236                printf("\n\tPad %d", len + 2);
237        }
238            break;
239
240        case MESSAGE_ACK_REQ: {
241            u_short nonce, interval;
242            if(!vflag)
243                printf(" ack-req");
244            else {
245                printf("\n\tAcknowledgment Request ");
246                if(len < 6) goto corrupt;
247                nonce = EXTRACT_16BITS(message + 4);
248                interval = EXTRACT_16BITS(message + 6);
249                printf("%04x %d", nonce, interval);
250            }
251        }
252            break;
253
254        case MESSAGE_ACK: {
255            u_short nonce;
256            if(!vflag)
257                printf(" ack");
258            else {
259                printf("\n\tAcknowledgment ");
260                if(len < 2) goto corrupt;
261                nonce = EXTRACT_16BITS(message + 2);
262                printf("%04x", nonce);
263            }
264        }
265            break;
266
267        case MESSAGE_HELLO:  {
268            u_short seqno, interval;
269            if(!vflag)
270                printf(" hello");
271            else {
272                printf("\n\tHello ");
273                if(len < 6) goto corrupt;
274                seqno = EXTRACT_16BITS(message + 4);
275                interval = EXTRACT_16BITS(message + 6);
276                printf("seqno %u interval %u", seqno, interval);
277            }
278        }
279            break;
280
281        case MESSAGE_IHU: {
282            unsigned short txcost, interval;
283            if(!vflag)
284                printf(" ihu");
285            else {
286                u_char address[16];
287                int rc;
288                printf("\n\tIHU ");
289                if(len < 6) goto corrupt;
290                txcost = EXTRACT_16BITS(message + 4);
291                interval = EXTRACT_16BITS(message + 6);
292                rc = network_address(message[2], message + 8, len - 6, address);
293                if(rc < 0) { printf("[|babel]"); break; }
294                printf("%s txcost %u interval %d",
295                       format_address(address), txcost, interval);
296            }
297        }
298            break;
299
300        case MESSAGE_ROUTER_ID: {
301            if(!vflag)
302                printf(" router-id");
303            else {
304                printf("\n\tRouter Id");
305                if(len < 10) goto corrupt;
306                printf(" %s", format_id(message + 4));
307            }
308        }
309            break;
310
311        case MESSAGE_NH: {
312            if(!vflag)
313                printf(" nh");
314            else {
315                int rc;
316                u_char nh[16];
317                printf("\n\tNext Hop");
318                if(len < 2) goto corrupt;
319                rc = network_address(message[2], message + 4, len - 2, nh);
320                if(rc < 0) goto corrupt;
321                printf(" %s", format_address(nh));
322            }
323        }
324            break;
325
326        case MESSAGE_UPDATE: {
327            if(!vflag) {
328                printf(" update");
329                if(len < 1)
330                    printf("/truncated");
331                else
332                    printf("%s%s%s",
333                           (message[3] & 0x80) ? "/prefix": "",
334                           (message[3] & 0x40) ? "/id" : "",
335                           (message[3] & 0x3f) ? "/unknown" : "");
336            } else {
337                u_short interval, seqno, metric;
338                u_char plen;
339                int rc;
340                u_char prefix[16];
341                printf("\n\tUpdate");
342                if(len < 10) goto corrupt;
343                plen = message[4] + (message[2] == 1 ? 96 : 0);
344                rc = network_prefix(message[2], message[4], message[5],
345                                    message + 12,
346                                    message[2] == 1 ? v4_prefix : v6_prefix,
347                                    len - 10, prefix);
348                if(rc < 0) goto corrupt;
349                interval = EXTRACT_16BITS(message + 6);
350                seqno = EXTRACT_16BITS(message + 8);
351                metric = EXTRACT_16BITS(message + 10);
352                printf("%s%s%s %s metric %u seqno %u interval %u",
353                       (message[3] & 0x80) ? "/prefix": "",
354                       (message[3] & 0x40) ? "/id" : "",
355                       (message[3] & 0x3f) ? "/unknown" : "",
356                       format_prefix(prefix, plen),
357                       metric, seqno, interval);
358                if(message[3] & 0x80) {
359                    if(message[2] == 1)
360                        memcpy(v4_prefix, prefix, 16);
361                    else
362                        memcpy(v6_prefix, prefix, 16);
363                }
364            }
365        }
366            break;
367
368        case MESSAGE_REQUEST: {
369            if(!vflag)
370                printf(" request");
371            else {
372                int rc;
373                u_char prefix[16], plen;
374                printf("\n\tRequest ");
375                if(len < 2) goto corrupt;
376                plen = message[3] + (message[2] == 1 ? 96 : 0);
377                rc = network_prefix(message[2], message[3], 0,
378                                    message + 4, NULL, len - 2, prefix);
379                if(rc < 0) goto corrupt;
380                plen = message[3] + (message[2] == 1 ? 96 : 0);
381                printf("for %s",
382                       message[2] == 0 ? "any" : format_prefix(prefix, plen));
383            }
384        }
385            break;
386
387        case MESSAGE_MH_REQUEST : {
388            if(!vflag)
389                printf(" mh-request");
390            else {
391                int rc;
392                u_short seqno;
393                u_char prefix[16], plen;
394                printf("\n\tMH-Request ");
395                if(len < 14) goto corrupt;
396                seqno = EXTRACT_16BITS(message + 4);
397                rc = network_prefix(message[2], message[3], 0,
398                                    message + 16, NULL, len - 14, prefix);
399                if(rc < 0) goto corrupt;
400                plen = message[3] + (message[2] == 1 ? 96 : 0);
401                printf("(%u hops) for %s seqno %u id %s",
402                       message[6], format_prefix(prefix, plen),
403                       seqno, format_id(message + 8));
404            }
405        }
406            break;
407        case MESSAGE_TSPC :
408            if(!vflag)
409                printf(" tspc");
410            else {
411                printf("\n\tTS/PC ");
412                if(len < 6) goto corrupt;
413                printf("timestamp %u packetcounter %u", EXTRACT_32BITS (message + 4),
414                       EXTRACT_16BITS(message + 2));
415            }
416            break;
417        case MESSAGE_HMAC : {
418            if(!vflag)
419                printf(" hmac");
420            else {
421                unsigned j;
422                printf("\n\tHMAC ");
423                if(len < 18) goto corrupt;
424                printf("key-id %u digest-%u ", EXTRACT_16BITS(message + 2), len - 2);
425                for (j = 0; j < len - 2; j++)
426                    printf ("%02X", message[4 + j]);
427            }
428        }
429            break;
430        default:
431            if(!vflag)
432                printf(" unknown");
433            else
434                printf("\n\tUnknown message type %d", type);
435        }
436        i += len + 2;
437    }
438    return;
439
440 trunc:
441    printf(" [|babel]");
442    return;
443
444 corrupt:
445    printf(" (corrupt)");
446    return;
447}
448