xref: /freebsd/contrib/tcpdump/print-dccp.c (revision 7aa383846770374466b1dcb2cefd71bde9acf463) 
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 1.7.2.1 2007-11-09 00:45:16 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 
63 static inline 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 
73 static int dccp_cksum(const struct ip *ip,
74 	const struct dccp_hdr *dh, u_int len)
75 {
76 	int cov = dccp_csum_coverage(dh, len);
77 	union phu {
78 		struct phdr {
79 			u_int32_t src;
80 			u_int32_t dst;
81 			u_char mbz;
82 			u_char proto;
83 			u_int16_t len;
84 		} ph;
85 		u_int16_t pa[6];
86 	} phu;
87 	const u_int16_t *sp;
88 
89 	/* pseudo-header.. */
90 	phu.ph.mbz = 0;
91 	phu.ph.len = htons(len);
92 	phu.ph.proto = IPPROTO_DCCP;
93 	memcpy(&phu.ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t));
94 	if (IP_HL(ip) == 5)
95 		memcpy(&phu.ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t));
96 	else
97 		phu.ph.dst = ip_finddst(ip);
98 
99 	sp = &phu.pa[0];
100 	return in_cksum((u_short *)dh, cov, sp[0]+sp[1]+sp[2]+sp[3]+sp[4]+sp[5]);
101 }
102 
103 #ifdef INET6
104 static int dccp6_cksum(const struct ip6_hdr *ip6, const struct dccp_hdr *dh, u_int len)
105 {
106 	size_t i;
107 	u_int32_t sum = 0;
108 	int cov = dccp_csum_coverage(dh, len);
109 	union {
110 		struct {
111 			struct in6_addr ph_src;
112 			struct in6_addr ph_dst;
113 			u_int32_t   ph_len;
114 			u_int8_t    ph_zero[3];
115 			u_int8_t    ph_nxt;
116 		} ph;
117 		u_int16_t pa[20];
118 	} phu;
119 
120 	/* pseudo-header */
121 	memset(&phu, 0, sizeof(phu));
122 	phu.ph.ph_src = ip6->ip6_src;
123 	phu.ph.ph_dst = ip6->ip6_dst;
124 	phu.ph.ph_len = htonl(len);
125 	phu.ph.ph_nxt = IPPROTO_DCCP;
126 
127 	for (i = 0; i < sizeof(phu.pa) / sizeof(phu.pa[0]); i++)
128 		sum += phu.pa[i];
129 
130 	return in_cksum((u_short *)dh, cov, sum);
131 }
132 #endif
133 
134 static const char *dccp_reset_code(u_int8_t code)
135 {
136 	if (code >= __DCCP_RESET_CODE_LAST)
137 		return "invalid";
138 	return dccp_reset_codes[code];
139 }
140 
141 static u_int64_t dccp_seqno(const struct dccp_hdr *dh)
142 {
143 	u_int32_t seq_high = DCCPH_SEQ(dh);
144 	u_int64_t seqno = EXTRACT_24BITS(&seq_high) & 0xFFFFFF;
145 
146 	if (DCCPH_X(dh) != 0) {
147 		const struct dccp_hdr_ext *dhx = (void *)(dh + 1);
148 		u_int32_t seq_low = dhx->dccph_seq_low;
149 		seqno &= 0x00FFFF;  /* clear reserved field */
150 		seqno = (seqno << 32) + EXTRACT_32BITS(&seq_low);
151 	}
152 
153 	return seqno;
154 }
155 
156 static inline unsigned int dccp_basic_hdr_len(const struct dccp_hdr *dh)
157 {
158 	return sizeof(*dh) + (DCCPH_X(dh) ? sizeof(struct dccp_hdr_ext) : 0);
159 }
160 
161 static void dccp_print_ack_no(const u_char *bp)
162 {
163 	const struct dccp_hdr *dh = (const struct dccp_hdr *)bp;
164 	const struct dccp_hdr_ack_bits *dh_ack =
165 		(struct dccp_hdr_ack_bits *)(bp + dccp_basic_hdr_len(dh));
166 	u_int32_t ack_high;
167 	u_int64_t ackno;
168 
169 	TCHECK2(*dh_ack,4);
170 	ack_high = DCCPH_ACK(dh_ack);
171 	ackno = EXTRACT_24BITS(&ack_high) & 0xFFFFFF;
172 
173 	if (DCCPH_X(dh) != 0) {
174 		u_int32_t ack_low;
175 
176 		TCHECK2(*dh_ack,8);
177 		ack_low = dh_ack->dccph_ack_nr_low;
178 
179 		ackno &= 0x00FFFF;  /* clear reserved field */
180 		ackno = (ackno << 32) + EXTRACT_32BITS(&ack_low);
181 	}
182 
183 	(void)printf("(ack=%" PRIu64 ") ", ackno);
184 trunc:
185 	return;
186 }
187 
188 static inline unsigned int dccp_packet_hdr_len(const u_int8_t type)
189 {
190 	if (type == DCCP_PKT_DATA)
191 		return 0;
192 	if (type == DCCP_PKT_DATAACK	||
193 	    type == DCCP_PKT_ACK	||
194 	    type == DCCP_PKT_SYNC	||
195 	    type == DCCP_PKT_SYNCACK	||
196 	    type == DCCP_PKT_CLOSE	||
197 	    type == DCCP_PKT_CLOSEREQ)
198 		return sizeof(struct dccp_hdr_ack_bits);
199 	if (type == DCCP_PKT_REQUEST)
200 		return sizeof(struct dccp_hdr_request);
201 	if (type == DCCP_PKT_RESPONSE)
202 		return sizeof(struct dccp_hdr_response);
203 	return sizeof(struct dccp_hdr_reset);
204 }
205 
206 static int dccp_print_option(const u_char *option);
207 
208 /**
209  * dccp_print - show dccp packet
210  * @bp - beginning of dccp packet
211  * @data2 - beginning of enclosing
212  * @len - lenght of ip packet
213  */
214 void dccp_print(const u_char *bp, const u_char *data2, u_int len)
215 {
216 	const struct dccp_hdr *dh;
217 	const struct ip *ip;
218 #ifdef INET6
219 	const struct ip6_hdr *ip6;
220 #endif
221 	const u_char *cp;
222 	u_short sport, dport;
223 	u_int hlen;
224 	u_int extlen = 0;
225 
226 	dh = (const struct dccp_hdr *)bp;
227 
228 	ip = (struct ip *)data2;
229 #ifdef INET6
230 	if (IP_V(ip) == 6)
231 		ip6 = (const struct ip6_hdr *)data2;
232 	else
233 		ip6 = NULL;
234 #endif /*INET6*/
235 	cp = (const u_char *)(dh + 1);
236 	if (cp > snapend) {
237 		printf("[Invalid packet|dccp]");
238 		return;
239 	}
240 
241 	if (len < sizeof(struct dccp_hdr)) {
242 		printf("truncated-dccp - %ld bytes missing!",
243 			     (long)len - sizeof(struct dccp_hdr));
244 		return;
245 	}
246 
247 	sport = EXTRACT_16BITS(&dh->dccph_sport);
248 	dport = EXTRACT_16BITS(&dh->dccph_dport);
249 	hlen = dh->dccph_doff * 4;
250 
251 #ifdef INET6
252 	if (ip6) {
253 		(void)printf("%s.%d > %s.%d: ",
254 			     ip6addr_string(&ip6->ip6_src), sport,
255 			     ip6addr_string(&ip6->ip6_dst), dport);
256 	} else
257 #endif /*INET6*/
258 	{
259 		(void)printf("%s.%d > %s.%d: ",
260 			     ipaddr_string(&ip->ip_src), sport,
261 			     ipaddr_string(&ip->ip_dst), dport);
262 	}
263 	fflush(stdout);
264 
265 	if (qflag) {
266 		(void)printf(" %d", len - hlen);
267 		if (hlen > len) {
268 			(void)printf("dccp [bad hdr length %u - too long, > %u]",
269 			    hlen, len);
270 		}
271 		return;
272 	}
273 
274 	/* other variables in generic header */
275 	if (vflag) {
276 		(void)printf("CCVal %d, CsCov %d, ", DCCPH_CCVAL(dh), DCCPH_CSCOV(dh));
277 	}
278 
279 	/* checksum calculation */
280 	if (vflag && TTEST2(bp[0], len)) {
281 		u_int16_t sum = 0, dccp_sum;
282 
283 		dccp_sum = EXTRACT_16BITS(&dh->dccph_checksum);
284 		(void)printf("cksum 0x%04x ", dccp_sum);
285 		if (IP_V(ip) == 4)
286 			sum = dccp_cksum(ip, dh, len);
287 #ifdef INET6
288 		else if (IP_V(ip) == 6)
289 			sum = dccp6_cksum(ip6, dh, len);
290 #endif
291 		if (sum != 0)
292 			(void)printf("(incorrect -> 0x%04x), ",in_cksum_shouldbe(dccp_sum, sum));
293 		else
294 			(void)printf("(correct), ");
295 	}
296 
297 	switch (DCCPH_TYPE(dh)) {
298 	case DCCP_PKT_REQUEST: {
299 		struct dccp_hdr_request *dhr =
300 			(struct dccp_hdr_request *)(bp + dccp_basic_hdr_len(dh));
301 		TCHECK(*dhr);
302 		(void)printf("request (service=%d) ",
303 			     EXTRACT_32BITS(&dhr->dccph_req_service));
304 		extlen += 4;
305 		break;
306 	}
307 	case DCCP_PKT_RESPONSE: {
308 		struct dccp_hdr_response *dhr =
309 			(struct dccp_hdr_response *)(bp + dccp_basic_hdr_len(dh));
310 		TCHECK(*dhr);
311 		(void)printf("response (service=%d) ",
312 			     EXTRACT_32BITS(&dhr->dccph_resp_service));
313 		extlen += 12;
314 		break;
315 	}
316 	case DCCP_PKT_DATA:
317 		(void)printf("data ");
318 		break;
319 	case DCCP_PKT_ACK: {
320 		(void)printf("ack ");
321 		extlen += 8;
322 		break;
323 	}
324 	case DCCP_PKT_DATAACK: {
325 		(void)printf("dataack ");
326 		extlen += 8;
327 		break;
328 	}
329 	case DCCP_PKT_CLOSEREQ:
330 		(void)printf("closereq ");
331 		extlen += 8;
332 		break;
333 	case DCCP_PKT_CLOSE:
334 		(void)printf("close ");
335 		extlen += 8;
336 		break;
337 	case DCCP_PKT_RESET: {
338 		struct dccp_hdr_reset *dhr =
339 			(struct dccp_hdr_reset *)(bp + dccp_basic_hdr_len(dh));
340 		TCHECK(*dhr);
341 		(void)printf("reset (code=%s) ",
342 			     dccp_reset_code(dhr->dccph_reset_code));
343 		extlen += 12;
344 		break;
345 	}
346 	case DCCP_PKT_SYNC:
347 		(void)printf("sync ");
348 		extlen += 8;
349 		break;
350 	case DCCP_PKT_SYNCACK:
351 		(void)printf("syncack ");
352 		extlen += 8;
353 		break;
354 	default:
355 		(void)printf("invalid ");
356 		break;
357 	}
358 
359 	if ((DCCPH_TYPE(dh) != DCCP_PKT_DATA) &&
360 			(DCCPH_TYPE(dh) != DCCP_PKT_REQUEST))
361 		dccp_print_ack_no(bp);
362 
363 	if (vflag < 2)
364 		return;
365 
366 	(void)printf("seq %" PRIu64, dccp_seqno(dh));
367 
368 	/* process options */
369 	if (hlen > dccp_basic_hdr_len(dh) + extlen){
370 		const u_char *cp;
371 		u_int optlen;
372 		cp = bp + dccp_basic_hdr_len(dh) + extlen;
373 		printf(" <");
374 
375 		hlen -= dccp_basic_hdr_len(dh) + extlen;
376 		while(1){
377 			TCHECK(*cp);
378 			optlen = dccp_print_option(cp);
379 			if (!optlen) goto trunc2;
380 			if (hlen <= optlen) break;
381 			hlen -= optlen;
382 			cp += optlen;
383 			printf(", ");
384 		}
385 		printf(">");
386 	}
387 	return;
388 trunc:
389 	printf("[|dccp]");
390 trunc2:
391 	return;
392 }
393 
394 static int dccp_print_option(const u_char *option)
395 {
396 	u_int8_t optlen, i;
397 	u_int32_t *ts;
398 	u_int16_t *var16;
399 	u_int32_t *var32;
400 
401 	TCHECK(*option);
402 
403 	if (*option >= 32) {
404 		TCHECK(*(option+1));
405 		optlen = *(option +1);
406 		if (optlen < 2) {
407 			printf("Option %d optlen too short",*option);
408 			return 1;
409 		}
410 	} else optlen = 1;
411 
412 	TCHECK2(*option,optlen);
413 
414 	switch (*option){
415 	case 0:
416 		printf("nop");
417 		break;
418 	case 1:
419 		printf("mandatory");
420 		break;
421 	case 2:
422 		printf("slowreceiver");
423 		break;
424 	case 32:
425 		printf("change_l");
426 		if (*(option +2) < 10){
427 			printf(" %s", dccp_feature_nums[*(option +2)]);
428 			for (i = 0; i < optlen -3; i ++) printf(" %d", *(option +3 + i));
429 		}
430 		break;
431 	case 33:
432 		printf("confirm_l");
433 		if (*(option +2) < 10){
434 			printf(" %s", dccp_feature_nums[*(option +2)]);
435 			for (i = 0; i < optlen -3; i ++) printf(" %d", *(option +3 + i));
436 		}
437 		break;
438 	case 34:
439 	        printf("change_r");
440 		if (*(option +2) < 10){
441 			printf(" %s", dccp_feature_nums[*(option +2)]);
442 			for (i = 0; i < optlen -3; i ++) printf(" %d", *(option +3 + i));
443 		}
444 		break;
445 	case 35:
446 		printf("confirm_r");
447 		if (*(option +2) < 10){
448 			printf(" %s", dccp_feature_nums[*(option +2)]);
449 			for (i = 0; i < optlen -3; i ++) printf(" %d", *(option +3 + i));
450 		}
451 		break;
452 	case 36:
453 		printf("initcookie 0x");
454 		for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
455 		break;
456 	case 37:
457 		printf("ndp_count");
458 		for (i = 0; i < optlen -2; i ++) printf(" %d", *(option +2 + i));
459 		break;
460 	case 38:
461 		printf("ack_vector0 0x");
462 		for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
463 		break;
464 	case 39:
465 		printf("ack_vector1 0x");
466 		for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
467 		break;
468 	case 40:
469 		printf("data_dropped 0x");
470 		for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
471 		break;
472 	case 41:
473 		ts = (u_int32_t *)(option + 2);
474 		printf("timestamp %u", (u_int32_t)ntohl(*ts));
475 		break;
476 	case 42:
477 		ts = (u_int32_t *)(option + 2);
478 		printf("timestamp_echo %u", (u_int32_t)ntohl(*ts));
479 		break;
480 	case 43:
481 		printf("elapsed_time ");
482 		if (optlen == 6){
483 			ts = (u_int32_t *)(option + 2);
484 			printf("%u", (u_int32_t)ntohl(*ts));
485 		} else {
486 			var16 = (u_int16_t *)(option + 2);
487 			printf("%u", ntohs(*var16));
488 		}
489 		break;
490 	case 44:
491 		printf("data_checksum ");
492 		for (i = 0; i < optlen -2; i ++) printf("%02x", *(option +2 + i));
493 		break;
494 	default :
495 		if (*option >= 128) {
496 			printf("CCID option %d",*option);
497 			switch (optlen) {
498 				case 4:
499 					var16 = (u_int16_t *)(option + 2);
500 					printf(" %u",ntohs(*var16));
501 					break;
502 				case 6:
503 					var32 = (u_int32_t *)(option + 2);
504 					printf(" %u",(u_int32_t)ntohl(*var32));
505 					break;
506 				default:
507 					break;
508 			}
509 			break;
510 		}
511 
512 		printf("unknown_opt %d", *option);
513 		break;
514 	}
515 
516 	return optlen;
517 trunc:
518 	printf("[|dccp]");
519 	return 0;
520 }
521