1 /*
2 * Copyright (C) Arnaldo Carvalho de Melo 2004
3 * Copyright (C) Ian McDonald 2005
4 * Copyright (C) Yoshifumi Nishida 2005
5 *
6 * This software may be distributed either under the terms of the
7 * BSD-style license that accompanies tcpdump or the GNU GPL version 2
8 */
9
10 #ifndef lint
11 static const char rcsid[] _U_ =
12 "@(#) $Header: /tcpdump/master/tcpdump/print-dccp.c,v 1.1.2.6 2006/02/19 05:08:44 guy Exp $ (LBL)";
13 #endif
14
15 #ifdef HAVE_CONFIG_H
16 #include "config.h"
17 #endif
18
19 #include <tcpdump-stdinc.h>
20
21 #include "dccp.h"
22
23 #include <stdio.h>
24 #include <string.h>
25
26 #include "interface.h"
27 #include "addrtoname.h"
28 #include "extract.h" /* must come after interface.h */
29 #include "ip.h"
30 #ifdef INET6
31 #include "ip6.h"
32 #endif
33 #include "ipproto.h"
34
35 static const char *dccp_reset_codes[] = {
36 "unspecified",
37 "closed",
38 "aborted",
39 "no_connection",
40 "packet_error",
41 "option_error",
42 "mandatory_error",
43 "connection_refused",
44 "bad_service_code",
45 "too_busy",
46 "bad_init_cookie",
47 "aggression_penalty",
48 };
49
50 static const char *dccp_feature_nums[] = {
51 "reserved",
52 "ccid",
53 "allow_short_seqno",
54 "sequence_window",
55 "ecn_incapable",
56 "ack_ratio",
57 "send_ack_vector",
58 "send_ndp_count",
59 "minimum checksum coverage",
60 "check data checksum",
61 };
62
dccp_cksum(const struct ip * ip,const struct dccp_hdr * dh,u_int len)63 static int dccp_cksum(const struct ip *ip,
64 const struct dccp_hdr *dh, u_int len)
65 {
66 union phu {
67 struct phdr {
68 u_int32_t src;
69 u_int32_t dst;
70 u_char mbz;
71 u_char proto;
72 u_int16_t len;
73 } ph;
74 u_int16_t pa[6];
75 } phu;
76 const u_int16_t *sp;
77
78 /* pseudo-header.. */
79 phu.ph.mbz = 0;
80 phu.ph.len = htons(len);
81 phu.ph.proto = IPPROTO_DCCP;
82 memcpy(&phu.ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t));
83 if (IP_HL(ip) == 5)
84 memcpy(&phu.ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t));
85 else
86 phu.ph.dst = ip_finddst(ip);
87
88 sp = &phu.pa[0];
89 return in_cksum((u_short *)dh, len, sp[0]+sp[1]+sp[2]+sp[3]+sp[4]+sp[5]);
90 }
91
92 #ifdef INET6
dccp6_cksum(const struct ip6_hdr * ip6,const struct dccp_hdr * dh,u_int len)93 static int dccp6_cksum(const struct ip6_hdr *ip6, const struct dccp_hdr *dh, u_int len)
94 {
95 size_t i;
96 const u_int16_t *sp;
97 u_int32_t sum;
98 union {
99 struct {
100 struct in6_addr ph_src;
101 struct in6_addr ph_dst;
102 u_int32_t ph_len;
103 u_int8_t ph_zero[3];
104 u_int8_t ph_nxt;
105 } ph;
106 u_int16_t pa[20];
107 } phu;
108
109 /* pseudo-header */
110 memset(&phu, 0, sizeof(phu));
111 phu.ph.ph_src = ip6->ip6_src;
112 phu.ph.ph_dst = ip6->ip6_dst;
113 phu.ph.ph_len = htonl(len);
114 phu.ph.ph_nxt = IPPROTO_DCCP;
115
116 sum = 0;
117 for (i = 0; i < sizeof(phu.pa) / sizeof(phu.pa[0]); i++)
118 sum += phu.pa[i];
119
120 sp = (const u_int16_t *)dh;
121
122 for (i = 0; i < (len & ~1); i += 2)
123 sum += *sp++;
124
125 if (len & 1)
126 sum += htons((*(const u_int8_t *)sp) << 8);
127
128 while (sum > 0xffff)
129 sum = (sum & 0xffff) + (sum >> 16);
130 sum = ~sum & 0xffff;
131
132 return (sum);
133 }
134 #endif
135
dccp_reset_code(u_int8_t code)136 static const char *dccp_reset_code(u_int8_t code)
137 {
138 if (code >= __DCCP_RESET_CODE_LAST)
139 return "invalid";
140 return dccp_reset_codes[code];
141 }
142
dccp_seqno(const struct dccp_hdr * dh)143 static u_int64_t dccp_seqno(const struct dccp_hdr *dh)
144 {
145 u_int32_t seq_high = DCCPH_SEQ(dh);
146 u_int64_t seqno = EXTRACT_24BITS(&seq_high) & 0xFFFFFF;
147
148 if (DCCPH_X(dh) != 0) {
149 const struct dccp_hdr_ext *dhx = (void *)(dh + 1);
150 u_int32_t seq_low = dhx->dccph_seq_low;
151 seqno &= 0x00FFFF; /* clear reserved field */
152 seqno = (seqno << 32) + EXTRACT_32BITS(&seq_low);
153 }
154
155 return seqno;
156 }
157
dccp_basic_hdr_len(const struct dccp_hdr * dh)158 static inline unsigned int dccp_basic_hdr_len(const struct dccp_hdr *dh)
159 {
160 return sizeof(*dh) + (DCCPH_X(dh) ? sizeof(struct dccp_hdr_ext) : 0);
161 }
162
dccp_print_ack_no(const u_char * bp)163 static void dccp_print_ack_no(const u_char *bp)
164 {
165 const struct dccp_hdr *dh = (const struct dccp_hdr *)bp;
166 const struct dccp_hdr_ack_bits *dh_ack =
167 (struct dccp_hdr_ack_bits *)(bp + dccp_basic_hdr_len(dh));
168 u_int32_t ack_high;
169 u_int64_t ackno;
170
171 TCHECK2(*dh_ack,4);
172 ack_high = DCCPH_ACK(dh_ack);
173 ackno = EXTRACT_24BITS(&ack_high) & 0xFFFFFF;
174
175 if (DCCPH_X(dh) != 0) {
176 u_int32_t ack_low;
177
178 TCHECK2(*dh_ack,8);
179 ack_low = dh_ack->dccph_ack_nr_low;
180
181 ackno &= 0x00FFFF; /* clear reserved field */
182 ackno = (ackno << 32) + EXTRACT_32BITS(&ack_low);
183 }
184
185 (void)printf("(ack=%" PRIu64 ") ", ackno);
186 trunc:
187 return;
188 }
189
dccp_packet_hdr_len(const u_int8_t type)190 static inline unsigned int dccp_packet_hdr_len(const u_int8_t type)
191 {
192 if (type == DCCP_PKT_DATA)
193 return 0;
194 if (type == DCCP_PKT_DATAACK ||
195 type == DCCP_PKT_ACK ||
196 type == DCCP_PKT_SYNC ||
197 type == DCCP_PKT_SYNCACK ||
198 type == DCCP_PKT_CLOSE ||
199 type == DCCP_PKT_CLOSEREQ)
200 return sizeof(struct dccp_hdr_ack_bits);
201 if (type == DCCP_PKT_REQUEST)
202 return sizeof(struct dccp_hdr_request);
203 if (type == DCCP_PKT_RESPONSE)
204 return sizeof(struct dccp_hdr_response);
205 return sizeof(struct dccp_hdr_reset);
206 }
207
208 static int dccp_print_option(const u_char *option);
209
210 /**
211 * dccp_print - show dccp packet
212 * @bp - beginning of dccp packet
213 * @data2 - beginning of enclosing
214 * @len - lenght of ip packet
215 */
dccp_print(const u_char * bp,const u_char * data2,u_int len)216 void dccp_print(const u_char *bp, const u_char *data2, u_int len)
217 {
218 const struct dccp_hdr *dh;
219 const struct ip *ip;
220 #ifdef INET6
221 const struct ip6_hdr *ip6;
222 #endif
223 const u_char *cp;
224 u_short sport, dport;
225 u_int hlen;
226 u_int extlen = 0;
227
228 dh = (const struct dccp_hdr *)bp;
229
230 ip = (struct ip *)data2;
231 #ifdef INET6
232 if (IP_V(ip) == 6)
233 ip6 = (const struct ip6_hdr *)data2;
234 else
235 ip6 = NULL;
236 #endif /*INET6*/
237 cp = (const u_char *)(dh + 1);
238 if (cp > snapend) {
239 printf("[Invalid packet|dccp]");
240 return;
241 }
242
243 if (len < sizeof(struct dccp_hdr)) {
244 printf("truncated-dccp - %ld bytes missing!",
245 (long)len - sizeof(struct dccp_hdr));
246 return;
247 }
248
249 sport = EXTRACT_16BITS(&dh->dccph_sport);
250 dport = EXTRACT_16BITS(&dh->dccph_dport);
251 hlen = dh->dccph_doff * 4;
252
253 #ifdef INET6
254 if (ip6) {
255 (void)printf("%s.%d > %s.%d: ",
256 ip6addr_string(&ip6->ip6_src), sport,
257 ip6addr_string(&ip6->ip6_dst), dport);
258 } else
259 #endif /*INET6*/
260 {
261 (void)printf("%s.%d > %s.%d: ",
262 ipaddr_string(&ip->ip_src), sport,
263 ipaddr_string(&ip->ip_dst), dport);
264 }
265 fflush(stdout);
266
267 if (qflag) {
268 (void)printf(" %d", len - hlen);
269 if (hlen > len) {
270 (void)printf("dccp [bad hdr length %u - too long, > %u]",
271 hlen, len);
272 }
273 return;
274 }
275
276 /* other variables in generic header */
277 if (vflag) {
278 (void)printf("CCVal %d, CsCov %d, ", DCCPH_CCVAL(dh), DCCPH_CSCOV(dh));
279 }
280
281 /* checksum calculation */
282 #ifdef INET6
283 if (ip6) {
284 if (ip6->ip6_plen && vflag) {
285 u_int16_t sum, dccp_sum;
286
287 sum = dccp6_cksum(ip6, dh, len);
288 dccp_sum = EXTRACT_16BITS(&dh->dccph_checksum);
289 printf("cksum 0x%04x", dccp_sum);
290 if (sum != 0) {
291 (void)printf(" (incorrect (-> 0x%04x), ",in_cksum_shouldbe(dccp_sum, sum));
292 } else
293 (void)printf(" (correct), ");
294 }
295 } else
296 #endif /* INET6 */
297 if (vflag)
298 {
299 u_int16_t sum, dccp_sum;
300
301 sum = dccp_cksum(ip, dh, len);
302 dccp_sum = EXTRACT_16BITS(&dh->dccph_checksum);
303 printf("cksum 0x%04x", dccp_sum);
304 if (sum != 0) {
305 (void)printf(" (incorrect (-> 0x%04x), ",in_cksum_shouldbe(dccp_sum, sum));
306 } else
307 (void)printf(" (correct), ");
308 }
309
310 switch (DCCPH_TYPE(dh)) {
311 case DCCP_PKT_REQUEST: {
312 struct dccp_hdr_request *dhr =
313 (struct dccp_hdr_request *)(bp + dccp_basic_hdr_len(dh));
314 TCHECK(*dhr);
315 (void)printf("request (service=%d) ",
316 EXTRACT_32BITS(&dhr->dccph_req_service));
317 extlen += 4;
318 break;
319 }
320 case DCCP_PKT_RESPONSE: {
321 struct dccp_hdr_response *dhr =
322 (struct dccp_hdr_response *)(bp + dccp_basic_hdr_len(dh));
323 TCHECK(*dhr);
324 (void)printf("response (service=%d) ",
325 EXTRACT_32BITS(&dhr->dccph_resp_service));
326 extlen += 12;
327 break;
328 }
329 case DCCP_PKT_DATA:
330 (void)printf("data ");
331 break;
332 case DCCP_PKT_ACK: {
333 (void)printf("ack ");
334 extlen += 8;
335 break;
336 }
337 case DCCP_PKT_DATAACK: {
338 (void)printf("dataack ");
339 extlen += 8;
340 break;
341 }
342 case DCCP_PKT_CLOSEREQ:
343 (void)printf("closereq ");
344 extlen += 8;
345 break;
346 case DCCP_PKT_CLOSE:
347 (void)printf("close ");
348 extlen += 8;
349 break;
350 case DCCP_PKT_RESET: {
351 struct dccp_hdr_reset *dhr =
352 (struct dccp_hdr_reset *)(bp + dccp_basic_hdr_len(dh));
353 TCHECK(*dhr);
354 (void)printf("reset (code=%s) ",
355 dccp_reset_code(dhr->dccph_reset_code));
356 extlen += 12;
357 break;
358 }
359 case DCCP_PKT_SYNC:
360 (void)printf("sync ");
361 extlen += 8;
362 break;
363 case DCCP_PKT_SYNCACK:
364 (void)printf("syncack ");
365 extlen += 8;
366 break;
367 default:
368 (void)printf("invalid ");
369 break;
370 }
371
372 if ((DCCPH_TYPE(dh) != DCCP_PKT_DATA) &&
373 (DCCPH_TYPE(dh) != DCCP_PKT_REQUEST))
374 dccp_print_ack_no(bp);
375
376 if (vflag < 2)
377 return;
378
379 (void)printf("seq %" PRIu64, dccp_seqno(dh));
380
381 /* process options */
382 if (hlen > dccp_basic_hdr_len(dh) + extlen){
383 const u_char *cp;
384 u_int optlen;
385 cp = bp + dccp_basic_hdr_len(dh) + extlen;
386 printf(" <");
387
388 hlen -= dccp_basic_hdr_len(dh) + extlen;
389 while(1){
390 TCHECK(*cp);
391 optlen = dccp_print_option(cp);
392 if (!optlen) goto trunc2;
393 if (hlen <= optlen) break;
394 hlen -= optlen;
395 cp += optlen;
396 printf(", ");
397 }
398 printf(">");
399 }
400 return;
401 trunc:
402 printf("[|dccp]");
403 trunc2:
404 return;
405 }
406
dccp_print_option(const u_char * option)407 static int dccp_print_option(const u_char *option)
408 {
409 u_int8_t optlen, i;
410 u_int32_t *ts;
411 u_int16_t *var16;
412 u_int32_t *var32;
413
414 TCHECK(*option);
415
416 if (*option >= 32) {
417 TCHECK(*(option+1));
418 optlen = *(option +1);
419 if (optlen < 2) {
420 printf("Option %d optlen too short",*option);
421 return 1;
422 }
423 } else optlen = 1;
424
425 TCHECK2(*option,optlen);
426
427 switch (*option){
428 case 0:
429 printf("nop");
430 break;
431 case 1:
432 printf("mandatory");
433 break;
434 case 2:
435 printf("slowreceiver");
436 break;
437 case 32:
438 printf("change_l");
439 if (*(option +2) < 10){
440 printf(" %s", dccp_feature_nums[*(option +2)]);
441 for (i = 0; i < optlen -3; i ++) printf(" %d", *(option +3 + i));
442 }
443 break;
444 case 33:
445 printf("confirm_l");
446 if (*(option +2) < 10){
447 printf(" %s", dccp_feature_nums[*(option +2)]);
448 for (i = 0; i < optlen -3; i ++) printf(" %d", *(option +3 + i));
449 }
450 break;
451 case 34:
452 printf("change_r");
453 if (*(option +2) < 10){
454 printf(" %s", dccp_feature_nums[*(option +2)]);
455 for (i = 0; i < optlen -3; i ++) printf(" %d", *(option +3 + i));
456 }
457 break;
458 case 35:
459 printf("confirm_r");
460 if (*(option +2) < 10){
461 printf(" %s", dccp_feature_nums[*(option +2)]);
462 for (i = 0; i < optlen -3; i ++) printf(" %d", *(option +3 + i));
463 }
464 break;
465 case 36:
466 printf("initcookie 0x");
467 for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
468 break;
469 case 37:
470 printf("ndp_count");
471 for (i = 0; i < optlen -2; i ++) printf(" %d", *(option +2 + i));
472 break;
473 case 38:
474 printf("ack_vector0 0x");
475 for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
476 break;
477 case 39:
478 printf("ack_vector1 0x");
479 for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
480 break;
481 case 40:
482 printf("data_dropped 0x");
483 for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
484 break;
485 case 41:
486 ts = (u_int32_t *)(option + 2);
487 printf("timestamp %u", (u_int32_t)ntohl(*ts));
488 break;
489 case 42:
490 ts = (u_int32_t *)(option + 2);
491 printf("timestamp_echo %u", (u_int32_t)ntohl(*ts));
492 break;
493 case 43:
494 printf("elapsed_time ");
495 if (optlen == 6){
496 ts = (u_int32_t *)(option + 2);
497 printf("%u", (u_int32_t)ntohl(*ts));
498 } else {
499 var16 = (u_int16_t *)(option + 2);
500 printf("%u", ntohs(*var16));
501 }
502 break;
503 case 44:
504 printf("data_checksum ");
505 for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
506 break;
507 default :
508 if (*option >= 128) {
509 printf("CCID option %d",*option);
510 switch (optlen) {
511 case 4:
512 var16 = (u_int16_t *)(option + 2);
513 printf(" %u",ntohs(*var16));
514 break;
515 case 6:
516 var32 = (u_int32_t *)(option + 2);
517 printf(" %u",(u_int32_t)ntohl(*var32));
518 break;
519 default:
520 break;
521 }
522 break;
523 }
524
525 printf("unknown_opt %d", *option);
526 break;
527 }
528
529 return optlen;
530 trunc:
531 printf("[|dccp]");
532 return 0;
533 }
534