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 1.8 2007-11-09 00:44:09 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_csum_coverage(const struct dccp_hdr * dh,u_int len)63 static inline u_int dccp_csum_coverage(const struct dccp_hdr* dh, u_int len)
64 {
65 u_int cov;
66
67 if (DCCPH_CSCOV(dh) == 0)
68 return len;
69 cov = (dh->dccph_doff + DCCPH_CSCOV(dh) - 1) * sizeof(u_int32_t);
70 return (cov > len)? len : cov;
71 }
72
dccp_cksum(const struct ip * ip,const struct dccp_hdr * dh,u_int len)73 static int dccp_cksum(const struct ip *ip,
74 const struct dccp_hdr *dh, u_int len)
75 {
76 return nextproto4_cksum(ip, (const u_int8_t *)(void *)dh,
77 dccp_csum_coverage(dh, len), IPPROTO_DCCP);
78 }
79
80 #ifdef INET6
dccp6_cksum(const struct ip6_hdr * ip6,const struct dccp_hdr * dh,u_int len)81 static int dccp6_cksum(const struct ip6_hdr *ip6, const struct dccp_hdr *dh, u_int len)
82 {
83 return nextproto6_cksum(ip6, (const u_int8_t *)(void *)dh,
84 dccp_csum_coverage(dh, len), IPPROTO_DCCP);
85 }
86 #endif
87
dccp_reset_code(u_int8_t code)88 static const char *dccp_reset_code(u_int8_t code)
89 {
90 if (code >= __DCCP_RESET_CODE_LAST)
91 return "invalid";
92 return dccp_reset_codes[code];
93 }
94
dccp_seqno(const struct dccp_hdr * dh)95 static u_int64_t dccp_seqno(const struct dccp_hdr *dh)
96 {
97 u_int32_t seq_high = DCCPH_SEQ(dh);
98 u_int64_t seqno = EXTRACT_24BITS(&seq_high) & 0xFFFFFF;
99
100 if (DCCPH_X(dh) != 0) {
101 const struct dccp_hdr_ext *dhx = (void *)(dh + 1);
102 u_int32_t seq_low = dhx->dccph_seq_low;
103 seqno &= 0x00FFFF; /* clear reserved field */
104 seqno = (seqno << 32) + EXTRACT_32BITS(&seq_low);
105 }
106
107 return seqno;
108 }
109
dccp_basic_hdr_len(const struct dccp_hdr * dh)110 static inline unsigned int dccp_basic_hdr_len(const struct dccp_hdr *dh)
111 {
112 return sizeof(*dh) + (DCCPH_X(dh) ? sizeof(struct dccp_hdr_ext) : 0);
113 }
114
dccp_print_ack_no(const u_char * bp)115 static void dccp_print_ack_no(const u_char *bp)
116 {
117 const struct dccp_hdr *dh = (const struct dccp_hdr *)bp;
118 const struct dccp_hdr_ack_bits *dh_ack =
119 (struct dccp_hdr_ack_bits *)(bp + dccp_basic_hdr_len(dh));
120 u_int32_t ack_high;
121 u_int64_t ackno;
122
123 TCHECK2(*dh_ack,4);
124 ack_high = DCCPH_ACK(dh_ack);
125 ackno = EXTRACT_24BITS(&ack_high) & 0xFFFFFF;
126
127 if (DCCPH_X(dh) != 0) {
128 u_int32_t ack_low;
129
130 TCHECK2(*dh_ack,8);
131 ack_low = dh_ack->dccph_ack_nr_low;
132
133 ackno &= 0x00FFFF; /* clear reserved field */
134 ackno = (ackno << 32) + EXTRACT_32BITS(&ack_low);
135 }
136
137 (void)printf("(ack=%" PRIu64 ") ", ackno);
138 trunc:
139 return;
140 }
141
dccp_packet_hdr_len(const u_int8_t type)142 static inline unsigned int dccp_packet_hdr_len(const u_int8_t type)
143 {
144 if (type == DCCP_PKT_DATA)
145 return 0;
146 if (type == DCCP_PKT_DATAACK ||
147 type == DCCP_PKT_ACK ||
148 type == DCCP_PKT_SYNC ||
149 type == DCCP_PKT_SYNCACK ||
150 type == DCCP_PKT_CLOSE ||
151 type == DCCP_PKT_CLOSEREQ)
152 return sizeof(struct dccp_hdr_ack_bits);
153 if (type == DCCP_PKT_REQUEST)
154 return sizeof(struct dccp_hdr_request);
155 if (type == DCCP_PKT_RESPONSE)
156 return sizeof(struct dccp_hdr_response);
157 return sizeof(struct dccp_hdr_reset);
158 }
159
160 static int dccp_print_option(const u_char *option);
161
162 /**
163 * dccp_print - show dccp packet
164 * @bp - beginning of dccp packet
165 * @data2 - beginning of enclosing
166 * @len - lenght of ip packet
167 */
dccp_print(const u_char * bp,const u_char * data2,u_int len)168 void dccp_print(const u_char *bp, const u_char *data2, u_int len)
169 {
170 const struct dccp_hdr *dh;
171 const struct ip *ip;
172 #ifdef INET6
173 const struct ip6_hdr *ip6;
174 #endif
175 const u_char *cp;
176 u_short sport, dport;
177 u_int hlen;
178 u_int extlen = 0;
179
180 dh = (const struct dccp_hdr *)bp;
181
182 ip = (struct ip *)data2;
183 #ifdef INET6
184 if (IP_V(ip) == 6)
185 ip6 = (const struct ip6_hdr *)data2;
186 else
187 ip6 = NULL;
188 #endif /*INET6*/
189 cp = (const u_char *)(dh + 1);
190 if (cp > snapend) {
191 printf("[Invalid packet|dccp]");
192 return;
193 }
194
195 if (len < sizeof(struct dccp_hdr)) {
196 printf("truncated-dccp - %ld bytes missing!",
197 (long)len - sizeof(struct dccp_hdr));
198 return;
199 }
200
201 sport = EXTRACT_16BITS(&dh->dccph_sport);
202 dport = EXTRACT_16BITS(&dh->dccph_dport);
203 hlen = dh->dccph_doff * 4;
204
205 #ifdef INET6
206 if (ip6) {
207 (void)printf("%s.%d > %s.%d: ",
208 ip6addr_string(&ip6->ip6_src), sport,
209 ip6addr_string(&ip6->ip6_dst), dport);
210 } else
211 #endif /*INET6*/
212 {
213 (void)printf("%s.%d > %s.%d: ",
214 ipaddr_string(&ip->ip_src), sport,
215 ipaddr_string(&ip->ip_dst), dport);
216 }
217 fflush(stdout);
218
219 if (qflag) {
220 (void)printf(" %d", len - hlen);
221 if (hlen > len) {
222 (void)printf("dccp [bad hdr length %u - too long, > %u]",
223 hlen, len);
224 }
225 return;
226 }
227
228 /* other variables in generic header */
229 if (vflag) {
230 (void)printf("CCVal %d, CsCov %d, ", DCCPH_CCVAL(dh), DCCPH_CSCOV(dh));
231 }
232
233 /* checksum calculation */
234 if (vflag && TTEST2(bp[0], len)) {
235 u_int16_t sum = 0, dccp_sum;
236
237 dccp_sum = EXTRACT_16BITS(&dh->dccph_checksum);
238 (void)printf("cksum 0x%04x ", dccp_sum);
239 if (IP_V(ip) == 4)
240 sum = dccp_cksum(ip, dh, len);
241 #ifdef INET6
242 else if (IP_V(ip) == 6)
243 sum = dccp6_cksum(ip6, dh, len);
244 #endif
245 if (sum != 0)
246 (void)printf("(incorrect -> 0x%04x), ",in_cksum_shouldbe(dccp_sum, sum));
247 else
248 (void)printf("(correct), ");
249 }
250
251 switch (DCCPH_TYPE(dh)) {
252 case DCCP_PKT_REQUEST: {
253 struct dccp_hdr_request *dhr =
254 (struct dccp_hdr_request *)(bp + dccp_basic_hdr_len(dh));
255 TCHECK(*dhr);
256 (void)printf("request (service=%d) ",
257 EXTRACT_32BITS(&dhr->dccph_req_service));
258 extlen += 4;
259 break;
260 }
261 case DCCP_PKT_RESPONSE: {
262 struct dccp_hdr_response *dhr =
263 (struct dccp_hdr_response *)(bp + dccp_basic_hdr_len(dh));
264 TCHECK(*dhr);
265 (void)printf("response (service=%d) ",
266 EXTRACT_32BITS(&dhr->dccph_resp_service));
267 extlen += 12;
268 break;
269 }
270 case DCCP_PKT_DATA:
271 (void)printf("data ");
272 break;
273 case DCCP_PKT_ACK: {
274 (void)printf("ack ");
275 extlen += 8;
276 break;
277 }
278 case DCCP_PKT_DATAACK: {
279 (void)printf("dataack ");
280 extlen += 8;
281 break;
282 }
283 case DCCP_PKT_CLOSEREQ:
284 (void)printf("closereq ");
285 extlen += 8;
286 break;
287 case DCCP_PKT_CLOSE:
288 (void)printf("close ");
289 extlen += 8;
290 break;
291 case DCCP_PKT_RESET: {
292 struct dccp_hdr_reset *dhr =
293 (struct dccp_hdr_reset *)(bp + dccp_basic_hdr_len(dh));
294 TCHECK(*dhr);
295 (void)printf("reset (code=%s) ",
296 dccp_reset_code(dhr->dccph_reset_code));
297 extlen += 12;
298 break;
299 }
300 case DCCP_PKT_SYNC:
301 (void)printf("sync ");
302 extlen += 8;
303 break;
304 case DCCP_PKT_SYNCACK:
305 (void)printf("syncack ");
306 extlen += 8;
307 break;
308 default:
309 (void)printf("invalid ");
310 break;
311 }
312
313 if ((DCCPH_TYPE(dh) != DCCP_PKT_DATA) &&
314 (DCCPH_TYPE(dh) != DCCP_PKT_REQUEST))
315 dccp_print_ack_no(bp);
316
317 if (vflag < 2)
318 return;
319
320 (void)printf("seq %" PRIu64, dccp_seqno(dh));
321
322 /* process options */
323 if (hlen > dccp_basic_hdr_len(dh) + extlen){
324 const u_char *cp;
325 u_int optlen;
326 cp = bp + dccp_basic_hdr_len(dh) + extlen;
327 printf(" <");
328
329 hlen -= dccp_basic_hdr_len(dh) + extlen;
330 while(1){
331 TCHECK(*cp);
332 optlen = dccp_print_option(cp);
333 if (!optlen) goto trunc2;
334 if (hlen <= optlen) break;
335 hlen -= optlen;
336 cp += optlen;
337 printf(", ");
338 }
339 printf(">");
340 }
341 return;
342 trunc:
343 printf("[|dccp]");
344 trunc2:
345 return;
346 }
347
dccp_print_option(const u_char * option)348 static int dccp_print_option(const u_char *option)
349 {
350 u_int8_t optlen, i;
351
352 TCHECK(*option);
353
354 if (*option >= 32) {
355 TCHECK(*(option+1));
356 optlen = *(option +1);
357 if (optlen < 2) {
358 printf("Option %d optlen too short",*option);
359 return 1;
360 }
361 } else optlen = 1;
362
363 TCHECK2(*option,optlen);
364
365 switch (*option){
366 case 0:
367 printf("nop");
368 break;
369 case 1:
370 printf("mandatory");
371 break;
372 case 2:
373 printf("slowreceiver");
374 break;
375 case 32:
376 printf("change_l");
377 if (*(option +2) < 10){
378 printf(" %s", dccp_feature_nums[*(option +2)]);
379 for (i = 0; i < optlen -3; i ++) printf(" %d", *(option +3 + i));
380 }
381 break;
382 case 33:
383 printf("confirm_l");
384 if (*(option +2) < 10){
385 printf(" %s", dccp_feature_nums[*(option +2)]);
386 for (i = 0; i < optlen -3; i ++) printf(" %d", *(option +3 + i));
387 }
388 break;
389 case 34:
390 printf("change_r");
391 if (*(option +2) < 10){
392 printf(" %s", dccp_feature_nums[*(option +2)]);
393 for (i = 0; i < optlen -3; i ++) printf(" %d", *(option +3 + i));
394 }
395 break;
396 case 35:
397 printf("confirm_r");
398 if (*(option +2) < 10){
399 printf(" %s", dccp_feature_nums[*(option +2)]);
400 for (i = 0; i < optlen -3; i ++) printf(" %d", *(option +3 + i));
401 }
402 break;
403 case 36:
404 printf("initcookie 0x");
405 for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
406 break;
407 case 37:
408 printf("ndp_count");
409 for (i = 0; i < optlen -2; i ++) printf(" %d", *(option +2 + i));
410 break;
411 case 38:
412 printf("ack_vector0 0x");
413 for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
414 break;
415 case 39:
416 printf("ack_vector1 0x");
417 for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
418 break;
419 case 40:
420 printf("data_dropped 0x");
421 for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
422 break;
423 case 41:
424 printf("timestamp %u", EXTRACT_32BITS(option + 2));
425 break;
426 case 42:
427 printf("timestamp_echo %u", EXTRACT_32BITS(option + 2));
428 break;
429 case 43:
430 printf("elapsed_time ");
431 if (optlen == 6)
432 printf("%u", EXTRACT_32BITS(option + 2));
433 else
434 printf("%u", EXTRACT_16BITS(option + 2));
435 break;
436 case 44:
437 printf("data_checksum ");
438 for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
439 break;
440 default :
441 if (*option >= 128) {
442 printf("CCID option %d",*option);
443 switch (optlen) {
444 case 4:
445 printf(" %u", EXTRACT_16BITS(option + 2));
446 break;
447 case 6:
448 printf(" %u", EXTRACT_32BITS(option + 2));
449 break;
450 default:
451 break;
452 }
453 break;
454 }
455
456 printf("unknown_opt %d", *option);
457 break;
458 }
459
460 return optlen;
461 trunc:
462 printf("[|dccp]");
463 return 0;
464 }
465