2 * Copyright (C) Arnaldo Carvalho de Melo 2004
3 * Copyright (C) Ian McDonald 2005
4 * Copyright (C) Yoshifumi Nishida 2005
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
10 #define NETDISSECT_REWORKED
15 #include <tcpdump-stdinc.h>
20 #include "interface.h"
21 #include "addrtoname.h"
22 #include "extract.h" /* must come after interface.h */
29 /* RFC4340: Datagram Congestion Control Protocol (DCCP) */
32 * struct dccp_hdr - generic part of DCCP packet header, with a 24-bit
35 * @dccph_sport - Relevant port on the endpoint that sent this packet
36 * @dccph_dport - Relevant port on the other endpoint
37 * @dccph_doff - Data Offset from the start of the DCCP header, in 32-bit words
38 * @dccph_ccval - Used by the HC-Sender CCID
39 * @dccph_cscov - Parts of the packet that are covered by the Checksum field
40 * @dccph_checksum - Internet checksum, depends on dccph_cscov
41 * @dccph_x - 0 = 24 bit sequence number, 1 = 48
42 * @dccph_type - packet type, see DCCP_PKT_ prefixed macros
43 * @dccph_seq - 24-bit sequence number
49 uint8_t dccph_ccval_cscov
;
50 uint16_t dccph_checksum
;
56 * struct dccp_hdr_ext - generic part of DCCP packet header, with a 48-bit
59 * @dccph_sport - Relevant port on the endpoint that sent this packet
60 * @dccph_dport - Relevant port on the other endpoint
61 * @dccph_doff - Data Offset from the start of the DCCP header, in 32-bit words
62 * @dccph_ccval - Used by the HC-Sender CCID
63 * @dccph_cscov - Parts of the packet that are covered by the Checksum field
64 * @dccph_checksum - Internet checksum, depends on dccph_cscov
65 * @dccph_x - 0 = 24 bit sequence number, 1 = 48
66 * @dccph_type - packet type, see DCCP_PKT_ prefixed macros
67 * @dccph_seq - 48-bit sequence number
73 uint8_t dccph_ccval_cscov
;
74 uint16_t dccph_checksum
;
80 #define DCCPH_CCVAL(dh) (((dh)->dccph_ccval_cscov >> 4) & 0xF)
81 #define DCCPH_CSCOV(dh) (((dh)->dccph_ccval_cscov) & 0xF)
83 #define DCCPH_X(dh) ((dh)->dccph_xtr & 1)
84 #define DCCPH_TYPE(dh) (((dh)->dccph_xtr >> 1) & 0xF)
87 * struct dccp_hdr_request - Conection initiation request header
89 * @dccph_req_service - Service to which the client app wants to connect
91 struct dccp_hdr_request
{
92 uint32_t dccph_req_service
;
96 * struct dccp_hdr_response - Conection initiation response header
98 * @dccph_resp_ack - 48 bit ack number, contains GSR
99 * @dccph_resp_service - Echoes the Service Code on a received DCCP-Request
101 struct dccp_hdr_response
{
102 uint8_t dccph_resp_ack
[8]; /* always 8 bytes */
103 uint32_t dccph_resp_service
;
107 * struct dccp_hdr_reset - Unconditionally shut down a connection
109 * @dccph_resp_ack - 48 bit ack number
110 * @dccph_reset_service - Echoes the Service Code on a received DCCP-Request
112 struct dccp_hdr_reset
{
113 uint8_t dccph_reset_ack
[8]; /* always 8 bytes */
114 uint8_t dccph_reset_code
,
119 DCCP_PKT_REQUEST
= 0,
131 static const struct tok dccp_pkt_type_str
[] = {
132 { DCCP_PKT_REQUEST
, "DCCP-Request" },
133 { DCCP_PKT_RESPONSE
, "DCCP-Response" },
134 { DCCP_PKT_DATA
, "DCCP-Data" },
135 { DCCP_PKT_ACK
, "DCCP-Ack" },
136 { DCCP_PKT_DATAACK
, "DCCP-DataAck" },
137 { DCCP_PKT_CLOSEREQ
, "DCCP-CloseReq" },
138 { DCCP_PKT_CLOSE
, "DCCP-Close" },
139 { DCCP_PKT_RESET
, "DCCP-Reset" },
140 { DCCP_PKT_SYNC
, "DCCP-Sync" },
141 { DCCP_PKT_SYNCACK
, "DCCP-SyncAck" },
145 enum dccp_reset_codes
{
146 DCCP_RESET_CODE_UNSPECIFIED
= 0,
147 DCCP_RESET_CODE_CLOSED
,
148 DCCP_RESET_CODE_ABORTED
,
149 DCCP_RESET_CODE_NO_CONNECTION
,
150 DCCP_RESET_CODE_PACKET_ERROR
,
151 DCCP_RESET_CODE_OPTION_ERROR
,
152 DCCP_RESET_CODE_MANDATORY_ERROR
,
153 DCCP_RESET_CODE_CONNECTION_REFUSED
,
154 DCCP_RESET_CODE_BAD_SERVICE_CODE
,
155 DCCP_RESET_CODE_TOO_BUSY
,
156 DCCP_RESET_CODE_BAD_INIT_COOKIE
,
157 DCCP_RESET_CODE_AGGRESSION_PENALTY
,
158 __DCCP_RESET_CODE_LAST
161 static const char tstr
[] = "[|dccp]";
163 static const char *dccp_reset_codes
[] = {
171 "connection_refused",
175 "aggression_penalty",
178 static const char *dccp_feature_nums
[] = {
187 "minimum checksum coverage",
188 "check data checksum",
191 static inline u_int
dccp_csum_coverage(const struct dccp_hdr
* dh
, u_int len
)
195 if (DCCPH_CSCOV(dh
) == 0)
197 cov
= (dh
->dccph_doff
+ DCCPH_CSCOV(dh
) - 1) * sizeof(uint32_t);
198 return (cov
> len
)? len
: cov
;
201 static int dccp_cksum(netdissect_options
*ndo
, const struct ip
*ip
,
202 const struct dccp_hdr
*dh
, u_int len
)
204 return nextproto4_cksum(ndo
, ip
, (const uint8_t *)(void *)dh
, len
,
205 dccp_csum_coverage(dh
, len
), IPPROTO_DCCP
);
209 static int dccp6_cksum(const struct ip6_hdr
*ip6
, const struct dccp_hdr
*dh
, u_int len
)
211 return nextproto6_cksum(ip6
, (const uint8_t *)(void *)dh
, len
,
212 dccp_csum_coverage(dh
, len
), IPPROTO_DCCP
);
216 static const char *dccp_reset_code(uint8_t code
)
218 if (code
>= __DCCP_RESET_CODE_LAST
)
220 return dccp_reset_codes
[code
];
223 static uint64_t dccp_seqno(const u_char
*bp
)
225 const struct dccp_hdr
*dh
= (const struct dccp_hdr
*)bp
;
228 if (DCCPH_X(dh
) != 0) {
229 const struct dccp_hdr_ext
*dhx
= (const struct dccp_hdr_ext
*)bp
;
230 seqno
= EXTRACT_48BITS(dhx
->dccph_seq
);
232 seqno
= EXTRACT_24BITS(dh
->dccph_seq
);
238 static inline unsigned int dccp_basic_hdr_len(const struct dccp_hdr
*dh
)
240 return DCCPH_X(dh
) ? sizeof(struct dccp_hdr_ext
) : sizeof(struct dccp_hdr
);
243 static void dccp_print_ack_no(netdissect_options
*ndo
, const u_char
*bp
)
245 const struct dccp_hdr
*dh
= (const struct dccp_hdr
*)bp
;
246 const u_char
*ackp
= bp
+ dccp_basic_hdr_len(dh
);
249 if (DCCPH_X(dh
) != 0) {
250 ND_TCHECK2(*ackp
, 8);
251 ackno
= EXTRACT_48BITS(ackp
+ 2);
253 ND_TCHECK2(*ackp
, 4);
254 ackno
= EXTRACT_24BITS(ackp
+ 1);
257 ND_PRINT((ndo
, "(ack=%" PRIu64
") ", ackno
));
262 static int dccp_print_option(netdissect_options
*, const u_char
*, u_int
);
265 * dccp_print - show dccp packet
266 * @bp - beginning of dccp packet
267 * @data2 - beginning of enclosing
268 * @len - lenght of ip packet
270 void dccp_print(netdissect_options
*ndo
, const u_char
*bp
, const u_char
*data2
,
273 const struct dccp_hdr
*dh
;
276 const struct ip6_hdr
*ip6
;
279 u_short sport
, dport
;
284 dh
= (const struct dccp_hdr
*)bp
;
286 ip
= (struct ip
*)data2
;
289 ip6
= (const struct ip6_hdr
*)data2
;
294 /* make sure we have enough data to look at the X bit */
295 cp
= (const u_char
*)(dh
+ 1);
296 if (cp
> ndo
->ndo_snapend
) {
297 ND_PRINT((ndo
, "[Invalid packet|dccp]"));
300 if (len
< sizeof(struct dccp_hdr
)) {
301 ND_PRINT((ndo
, "truncated-dccp - %u bytes missing!",
302 len
- (u_int
)sizeof(struct dccp_hdr
)));
306 /* get the length of the generic header */
307 fixed_hdrlen
= dccp_basic_hdr_len(dh
);
308 if (len
< fixed_hdrlen
) {
309 ND_PRINT((ndo
, "truncated-dccp - %u bytes missing!",
310 len
- fixed_hdrlen
));
313 ND_TCHECK2(*dh
, fixed_hdrlen
);
315 sport
= EXTRACT_16BITS(&dh
->dccph_sport
);
316 dport
= EXTRACT_16BITS(&dh
->dccph_dport
);
317 hlen
= dh
->dccph_doff
* 4;
321 ND_PRINT((ndo
, "%s.%d > %s.%d: ",
322 ip6addr_string(ndo
, &ip6
->ip6_src
), sport
,
323 ip6addr_string(ndo
, &ip6
->ip6_dst
), dport
));
327 ND_PRINT((ndo
, "%s.%d > %s.%d: ",
328 ipaddr_string(ndo
, &ip
->ip_src
), sport
,
329 ipaddr_string(ndo
, &ip
->ip_dst
), dport
));
332 ND_PRINT((ndo
, "DCCP"));
334 if (ndo
->ndo_qflag
) {
335 ND_PRINT((ndo
, " %d", len
- hlen
));
337 ND_PRINT((ndo
, " [bad hdr length %u - too long, > %u]",
343 /* other variables in generic header */
344 if (ndo
->ndo_vflag
) {
345 ND_PRINT((ndo
, " (CCVal %d, CsCov %d, ", DCCPH_CCVAL(dh
), DCCPH_CSCOV(dh
)));
348 /* checksum calculation */
349 if (ndo
->ndo_vflag
&& ND_TTEST2(bp
[0], len
)) {
350 uint16_t sum
= 0, dccp_sum
;
352 dccp_sum
= EXTRACT_16BITS(&dh
->dccph_checksum
);
353 ND_PRINT((ndo
, "cksum 0x%04x ", dccp_sum
));
355 sum
= dccp_cksum(ndo
, ip
, dh
, len
);
357 else if (IP_V(ip
) == 6)
358 sum
= dccp6_cksum(ip6
, dh
, len
);
361 ND_PRINT((ndo
, "(incorrect -> 0x%04x)",in_cksum_shouldbe(dccp_sum
, sum
)));
363 ND_PRINT((ndo
, "(correct)"));
367 ND_PRINT((ndo
, ")"));
368 ND_PRINT((ndo
, " "));
370 dccph_type
= DCCPH_TYPE(dh
);
371 switch (dccph_type
) {
372 case DCCP_PKT_REQUEST
: {
373 struct dccp_hdr_request
*dhr
=
374 (struct dccp_hdr_request
*)(bp
+ fixed_hdrlen
);
376 if (len
< fixed_hdrlen
) {
377 ND_PRINT((ndo
, "truncated-%s - %u bytes missing!",
378 tok2str(dccp_pkt_type_str
, "", dccph_type
),
379 len
- fixed_hdrlen
));
383 ND_PRINT((ndo
, "%s (service=%d) ",
384 tok2str(dccp_pkt_type_str
, "", dccph_type
),
385 EXTRACT_32BITS(&dhr
->dccph_req_service
)));
388 case DCCP_PKT_RESPONSE
: {
389 struct dccp_hdr_response
*dhr
=
390 (struct dccp_hdr_response
*)(bp
+ fixed_hdrlen
);
392 if (len
< fixed_hdrlen
) {
393 ND_PRINT((ndo
, "truncated-%s - %u bytes missing!",
394 tok2str(dccp_pkt_type_str
, "", dccph_type
),
395 len
- fixed_hdrlen
));
399 ND_PRINT((ndo
, "%s (service=%d) ",
400 tok2str(dccp_pkt_type_str
, "", dccph_type
),
401 EXTRACT_32BITS(&dhr
->dccph_resp_service
)));
405 ND_PRINT((ndo
, "%s ", tok2str(dccp_pkt_type_str
, "", dccph_type
)));
409 if (len
< fixed_hdrlen
) {
410 ND_PRINT((ndo
, "truncated-%s - %u bytes missing!",
411 tok2str(dccp_pkt_type_str
, "", dccph_type
),
412 len
- fixed_hdrlen
));
415 ND_PRINT((ndo
, "%s ", tok2str(dccp_pkt_type_str
, "", dccph_type
)));
418 case DCCP_PKT_DATAACK
: {
420 if (len
< fixed_hdrlen
) {
421 ND_PRINT((ndo
, "truncated-%s - %u bytes missing!",
422 tok2str(dccp_pkt_type_str
, "", dccph_type
),
423 len
- fixed_hdrlen
));
426 ND_PRINT((ndo
, "%s ", tok2str(dccp_pkt_type_str
, "", dccph_type
)));
429 case DCCP_PKT_CLOSEREQ
:
431 if (len
< fixed_hdrlen
) {
432 ND_PRINT((ndo
, "truncated-%s - %u bytes missing!",
433 tok2str(dccp_pkt_type_str
, "", dccph_type
),
434 len
- fixed_hdrlen
));
437 ND_PRINT((ndo
, "%s ", tok2str(dccp_pkt_type_str
, "", dccph_type
)));
441 if (len
< fixed_hdrlen
) {
442 ND_PRINT((ndo
, "truncated-%s - %u bytes missing!",
443 tok2str(dccp_pkt_type_str
, "", dccph_type
),
444 len
- fixed_hdrlen
));
447 ND_PRINT((ndo
, "%s ", tok2str(dccp_pkt_type_str
, "", dccph_type
)));
449 case DCCP_PKT_RESET
: {
450 struct dccp_hdr_reset
*dhr
=
451 (struct dccp_hdr_reset
*)(bp
+ fixed_hdrlen
);
453 if (len
< fixed_hdrlen
) {
454 ND_PRINT((ndo
, "truncated-%s - %u bytes missing!",
455 tok2str(dccp_pkt_type_str
, "", dccph_type
),
456 len
- fixed_hdrlen
));
460 ND_PRINT((ndo
, "%s (code=%s) ",
461 tok2str(dccp_pkt_type_str
, "", dccph_type
),
462 dccp_reset_code(dhr
->dccph_reset_code
)));
467 if (len
< fixed_hdrlen
) {
468 ND_PRINT((ndo
, "truncated-%s - %u bytes missing!",
469 tok2str(dccp_pkt_type_str
, "", dccph_type
),
470 len
- fixed_hdrlen
));
473 ND_PRINT((ndo
, "%s ", tok2str(dccp_pkt_type_str
, "", dccph_type
)));
475 case DCCP_PKT_SYNCACK
:
477 if (len
< fixed_hdrlen
) {
478 ND_PRINT((ndo
, "truncated-%s - %u bytes missing!",
479 tok2str(dccp_pkt_type_str
, "", dccph_type
),
480 len
- fixed_hdrlen
));
483 ND_PRINT((ndo
, "%s ", tok2str(dccp_pkt_type_str
, "", dccph_type
)));
486 ND_PRINT((ndo
, "%s ", tok2str(dccp_pkt_type_str
, "unknown-type-%u", dccph_type
)));
490 if ((DCCPH_TYPE(dh
) != DCCP_PKT_DATA
) &&
491 (DCCPH_TYPE(dh
) != DCCP_PKT_REQUEST
))
492 dccp_print_ack_no(ndo
, bp
);
494 if (ndo
->ndo_vflag
< 2)
497 ND_PRINT((ndo
, "seq %" PRIu64
, dccp_seqno(bp
)));
499 /* process options */
500 if (hlen
> fixed_hdrlen
){
503 cp
= bp
+ fixed_hdrlen
;
504 ND_PRINT((ndo
, " <"));
506 hlen
-= fixed_hdrlen
;
508 optlen
= dccp_print_option(ndo
, cp
, hlen
);
515 ND_PRINT((ndo
, ", "));
517 ND_PRINT((ndo
, ">"));
521 ND_PRINT((ndo
, "%s", tstr
));
525 static const struct tok dccp_option_values
[] = {
528 { 2, "slowreceiver" },
533 { 36, "initcookie" },
535 { 38, "ack_vector0" },
536 { 39, "ack_vector1" },
537 { 40, "data_dropped" },
539 { 42, "timestamp_echo" },
540 { 43, "elapsed_time" },
541 { 44, "data_checksum" },
545 static int dccp_print_option(netdissect_options
*ndo
, const u_char
*option
, u_int hlen
)
552 ND_TCHECK(*(option
+1));
553 optlen
= *(option
+1);
556 ND_PRINT((ndo
, "CCID option %u optlen too short", *option
));
558 ND_PRINT((ndo
, "%s optlen too short",
559 tok2str(dccp_option_values
, "Option %u", *option
)));
567 ND_PRINT((ndo
, "CCID option %u optlen goes past header length",
570 ND_PRINT((ndo
, "%s optlen goes past header length",
571 tok2str(dccp_option_values
, "Option %u", *option
)));
574 ND_TCHECK2(*option
, optlen
);
576 if (*option
>= 128) {
577 ND_PRINT((ndo
, "CCID option %d", *option
));
580 ND_PRINT((ndo
, " %u", EXTRACT_16BITS(option
+ 2)));
583 ND_PRINT((ndo
, " %u", EXTRACT_32BITS(option
+ 2)));
589 ND_PRINT((ndo
, "%s", tok2str(dccp_option_values
, "Option %u", *option
)));
596 ND_PRINT((ndo
, " optlen too short"));
599 if (*(option
+ 2) < 10){
600 ND_PRINT((ndo
, " %s", dccp_feature_nums
[*(option
+ 2)]));
601 for (i
= 0; i
< optlen
- 3; i
++)
602 ND_PRINT((ndo
, " %d", *(option
+ 3 + i
)));
607 ND_PRINT((ndo
, " 0x"));
608 for (i
= 0; i
< optlen
- 2; i
++)
609 ND_PRINT((ndo
, "%02x", *(option
+ 2 + i
)));
613 for (i
= 0; i
< optlen
- 2; i
++)
614 ND_PRINT((ndo
, " %d", *(option
+ 2 + i
)));
618 ND_PRINT((ndo
, " 0x"));
619 for (i
= 0; i
< optlen
- 2; i
++)
620 ND_PRINT((ndo
, "%02x", *(option
+ 2 + i
)));
625 ND_PRINT((ndo
, " 0x"));
626 for (i
= 0; i
< optlen
- 2; i
++)
627 ND_PRINT((ndo
, "%02x", *(option
+ 2 + i
)));
632 ND_PRINT((ndo
, " 0x"));
633 for (i
= 0; i
< optlen
- 2; i
++)
634 ND_PRINT((ndo
, "%02x", *(option
+ 2 + i
)));
639 ND_PRINT((ndo
, " %u", EXTRACT_32BITS(option
+ 2)));
641 ND_PRINT((ndo
, " optlen != 4"));
645 ND_PRINT((ndo
, " %u", EXTRACT_32BITS(option
+ 2)));
647 ND_PRINT((ndo
, " optlen != 4"));
651 ND_PRINT((ndo
, " %u", EXTRACT_32BITS(option
+ 2)));
652 else if (optlen
== 4)
653 ND_PRINT((ndo
, " %u", EXTRACT_16BITS(option
+ 2)));
655 ND_PRINT((ndo
, " optlen != 4 or 6"));
659 ND_PRINT((ndo
, " "));
660 for (i
= 0; i
< optlen
- 2; i
++)
661 ND_PRINT((ndo
, "%02x", *(option
+ 2 + i
)));
669 ND_PRINT((ndo
, "%s", tstr
));