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 /* \summary: Datagram Congestion Control Protocol (DCCP) printer */
16 #include <netdissect-stdinc.h>
21 #include "netdissect.h"
22 #include "addrtoname.h"
28 /* RFC4340: Datagram Congestion Control Protocol (DCCP) */
31 * struct dccp_hdr - generic part of DCCP packet header, with a 24-bit
34 * @dccph_sport - Relevant port on the endpoint that sent this packet
35 * @dccph_dport - Relevant port on the other endpoint
36 * @dccph_doff - Data Offset from the start of the DCCP header, in 32-bit words
37 * @dccph_ccval - Used by the HC-Sender CCID
38 * @dccph_cscov - Parts of the packet that are covered by the Checksum field
39 * @dccph_checksum - Internet checksum, depends on dccph_cscov
40 * @dccph_x - 0 = 24 bit sequence number, 1 = 48
41 * @dccph_type - packet type, see DCCP_PKT_ prefixed macros
42 * @dccph_seq - 24-bit sequence number
48 uint8_t dccph_ccval_cscov;
49 uint16_t dccph_checksum;
55 * struct dccp_hdr_ext - generic part of DCCP packet header, with a 48-bit
58 * @dccph_sport - Relevant port on the endpoint that sent this packet
59 * @dccph_dport - Relevant port on the other endpoint
60 * @dccph_doff - Data Offset from the start of the DCCP header, in 32-bit words
61 * @dccph_ccval - Used by the HC-Sender CCID
62 * @dccph_cscov - Parts of the packet that are covered by the Checksum field
63 * @dccph_checksum - Internet checksum, depends on dccph_cscov
64 * @dccph_x - 0 = 24 bit sequence number, 1 = 48
65 * @dccph_type - packet type, see DCCP_PKT_ prefixed macros
66 * @dccph_seq - 48-bit sequence number
72 uint8_t dccph_ccval_cscov;
73 uint16_t dccph_checksum;
79 #define DCCPH_CCVAL(dh) (((dh)->dccph_ccval_cscov >> 4) & 0xF)
80 #define DCCPH_CSCOV(dh) (((dh)->dccph_ccval_cscov) & 0xF)
82 #define DCCPH_X(dh) ((dh)->dccph_xtr & 1)
83 #define DCCPH_TYPE(dh) (((dh)->dccph_xtr >> 1) & 0xF)
86 * struct dccp_hdr_request - Conection initiation request header
88 * @dccph_req_service - Service to which the client app wants to connect
90 struct dccp_hdr_request {
91 uint32_t dccph_req_service;
95 * struct dccp_hdr_response - Conection initiation response header
97 * @dccph_resp_ack - 48 bit ack number, contains GSR
98 * @dccph_resp_service - Echoes the Service Code on a received DCCP-Request
100 struct dccp_hdr_response {
101 uint8_t dccph_resp_ack[8]; /* always 8 bytes */
102 uint32_t dccph_resp_service;
106 * struct dccp_hdr_reset - Unconditionally shut down a connection
108 * @dccph_resp_ack - 48 bit ack number
109 * @dccph_reset_service - Echoes the Service Code on a received DCCP-Request
111 struct dccp_hdr_reset {
112 uint8_t dccph_reset_ack[8]; /* always 8 bytes */
113 uint8_t dccph_reset_code,
118 DCCP_PKT_REQUEST = 0,
130 static const struct tok dccp_pkt_type_str[] = {
131 { DCCP_PKT_REQUEST, "DCCP-Request" },
132 { DCCP_PKT_RESPONSE, "DCCP-Response" },
133 { DCCP_PKT_DATA, "DCCP-Data" },
134 { DCCP_PKT_ACK, "DCCP-Ack" },
135 { DCCP_PKT_DATAACK, "DCCP-DataAck" },
136 { DCCP_PKT_CLOSEREQ, "DCCP-CloseReq" },
137 { DCCP_PKT_CLOSE, "DCCP-Close" },
138 { DCCP_PKT_RESET, "DCCP-Reset" },
139 { DCCP_PKT_SYNC, "DCCP-Sync" },
140 { DCCP_PKT_SYNCACK, "DCCP-SyncAck" },
144 enum dccp_reset_codes {
145 DCCP_RESET_CODE_UNSPECIFIED = 0,
146 DCCP_RESET_CODE_CLOSED,
147 DCCP_RESET_CODE_ABORTED,
148 DCCP_RESET_CODE_NO_CONNECTION,
149 DCCP_RESET_CODE_PACKET_ERROR,
150 DCCP_RESET_CODE_OPTION_ERROR,
151 DCCP_RESET_CODE_MANDATORY_ERROR,
152 DCCP_RESET_CODE_CONNECTION_REFUSED,
153 DCCP_RESET_CODE_BAD_SERVICE_CODE,
154 DCCP_RESET_CODE_TOO_BUSY,
155 DCCP_RESET_CODE_BAD_INIT_COOKIE,
156 DCCP_RESET_CODE_AGGRESSION_PENALTY,
157 __DCCP_RESET_CODE_LAST
160 static const char tstr[] = "[|dccp]";
162 static const char *dccp_reset_codes[] = {
170 "connection_refused",
174 "aggression_penalty",
177 static const char *dccp_feature_nums[] = {
186 "minimum checksum coverage",
187 "check data checksum",
190 static inline u_int dccp_csum_coverage(const struct dccp_hdr* dh, u_int len)
194 if (DCCPH_CSCOV(dh) == 0)
196 cov = (dh->dccph_doff + DCCPH_CSCOV(dh) - 1) * sizeof(uint32_t);
197 return (cov > len)? len : cov;
200 static int dccp_cksum(netdissect_options *ndo, const struct ip *ip,
201 const struct dccp_hdr *dh, u_int len)
203 return nextproto4_cksum(ndo, ip, (const uint8_t *)(const void *)dh, len,
204 dccp_csum_coverage(dh, len), IPPROTO_DCCP);
207 static int dccp6_cksum(netdissect_options *ndo, const struct ip6_hdr *ip6,
208 const struct dccp_hdr *dh, u_int len)
210 return nextproto6_cksum(ndo, ip6, (const uint8_t *)(const void *)dh, len,
211 dccp_csum_coverage(dh, len), IPPROTO_DCCP);
214 static const char *dccp_reset_code(uint8_t code)
216 if (code >= __DCCP_RESET_CODE_LAST)
218 return dccp_reset_codes[code];
221 static uint64_t dccp_seqno(const u_char *bp)
223 const struct dccp_hdr *dh = (const struct dccp_hdr *)bp;
226 if (DCCPH_X(dh) != 0) {
227 const struct dccp_hdr_ext *dhx = (const struct dccp_hdr_ext *)bp;
228 seqno = EXTRACT_48BITS(dhx->dccph_seq);
230 seqno = EXTRACT_24BITS(dh->dccph_seq);
236 static inline unsigned int dccp_basic_hdr_len(const struct dccp_hdr *dh)
238 return DCCPH_X(dh) ? sizeof(struct dccp_hdr_ext) : sizeof(struct dccp_hdr);
241 static void dccp_print_ack_no(netdissect_options *ndo, const u_char *bp)
243 const struct dccp_hdr *dh = (const struct dccp_hdr *)bp;
244 const u_char *ackp = bp + dccp_basic_hdr_len(dh);
247 if (DCCPH_X(dh) != 0) {
248 ND_TCHECK2(*ackp, 8);
249 ackno = EXTRACT_48BITS(ackp + 2);
251 ND_TCHECK2(*ackp, 4);
252 ackno = EXTRACT_24BITS(ackp + 1);
255 ND_PRINT((ndo, "(ack=%" PRIu64 ") ", ackno));
260 static int dccp_print_option(netdissect_options *, const u_char *, u_int);
263 * dccp_print - show dccp packet
264 * @bp - beginning of dccp packet
265 * @data2 - beginning of enclosing
266 * @len - lenght of ip packet
268 void dccp_print(netdissect_options *ndo, const u_char *bp, const u_char *data2,
271 const struct dccp_hdr *dh;
273 const struct ip6_hdr *ip6;
275 u_short sport, dport;
280 dh = (const struct dccp_hdr *)bp;
282 ip = (const struct ip *)data2;
284 ip6 = (const struct ip6_hdr *)data2;
288 /* make sure we have enough data to look at the X bit */
289 cp = (const u_char *)(dh + 1);
290 if (cp > ndo->ndo_snapend) {
291 ND_PRINT((ndo, "[Invalid packet|dccp]"));
294 if (len < sizeof(struct dccp_hdr)) {
295 ND_PRINT((ndo, "truncated-dccp - %u bytes missing!",
296 len - (u_int)sizeof(struct dccp_hdr)));
300 /* get the length of the generic header */
301 fixed_hdrlen = dccp_basic_hdr_len(dh);
302 if (len < fixed_hdrlen) {
303 ND_PRINT((ndo, "truncated-dccp - %u bytes missing!",
304 len - fixed_hdrlen));
307 ND_TCHECK2(*dh, fixed_hdrlen);
309 sport = EXTRACT_16BITS(&dh->dccph_sport);
310 dport = EXTRACT_16BITS(&dh->dccph_dport);
311 hlen = dh->dccph_doff * 4;
314 ND_PRINT((ndo, "%s.%d > %s.%d: ",
315 ip6addr_string(ndo, &ip6->ip6_src), sport,
316 ip6addr_string(ndo, &ip6->ip6_dst), dport));
318 ND_PRINT((ndo, "%s.%d > %s.%d: ",
319 ipaddr_string(ndo, &ip->ip_src), sport,
320 ipaddr_string(ndo, &ip->ip_dst), dport));
323 ND_PRINT((ndo, "DCCP"));
325 if (ndo->ndo_qflag) {
326 ND_PRINT((ndo, " %d", len - hlen));
328 ND_PRINT((ndo, " [bad hdr length %u - too long, > %u]",
334 /* other variables in generic header */
335 if (ndo->ndo_vflag) {
336 ND_PRINT((ndo, " (CCVal %d, CsCov %d, ", DCCPH_CCVAL(dh), DCCPH_CSCOV(dh)));
339 /* checksum calculation */
340 if (ndo->ndo_vflag && ND_TTEST2(bp[0], len)) {
341 uint16_t sum = 0, dccp_sum;
343 dccp_sum = EXTRACT_16BITS(&dh->dccph_checksum);
344 ND_PRINT((ndo, "cksum 0x%04x ", dccp_sum));
346 sum = dccp_cksum(ndo, ip, dh, len);
347 else if (IP_V(ip) == 6)
348 sum = dccp6_cksum(ndo, ip6, dh, len);
350 ND_PRINT((ndo, "(incorrect -> 0x%04x)",in_cksum_shouldbe(dccp_sum, sum)));
352 ND_PRINT((ndo, "(correct)"));
356 ND_PRINT((ndo, ")"));
357 ND_PRINT((ndo, " "));
359 dccph_type = DCCPH_TYPE(dh);
360 switch (dccph_type) {
361 case DCCP_PKT_REQUEST: {
362 const struct dccp_hdr_request *dhr =
363 (const struct dccp_hdr_request *)(bp + fixed_hdrlen);
365 if (len < fixed_hdrlen) {
366 ND_PRINT((ndo, "truncated-%s - %u bytes missing!",
367 tok2str(dccp_pkt_type_str, "", dccph_type),
368 len - fixed_hdrlen));
372 ND_PRINT((ndo, "%s (service=%d) ",
373 tok2str(dccp_pkt_type_str, "", dccph_type),
374 EXTRACT_32BITS(&dhr->dccph_req_service)));
377 case DCCP_PKT_RESPONSE: {
378 const struct dccp_hdr_response *dhr =
379 (const struct dccp_hdr_response *)(bp + fixed_hdrlen);
381 if (len < fixed_hdrlen) {
382 ND_PRINT((ndo, "truncated-%s - %u bytes missing!",
383 tok2str(dccp_pkt_type_str, "", dccph_type),
384 len - fixed_hdrlen));
388 ND_PRINT((ndo, "%s (service=%d) ",
389 tok2str(dccp_pkt_type_str, "", dccph_type),
390 EXTRACT_32BITS(&dhr->dccph_resp_service)));
394 ND_PRINT((ndo, "%s ", tok2str(dccp_pkt_type_str, "", dccph_type)));
398 if (len < fixed_hdrlen) {
399 ND_PRINT((ndo, "truncated-%s - %u bytes missing!",
400 tok2str(dccp_pkt_type_str, "", dccph_type),
401 len - fixed_hdrlen));
404 ND_PRINT((ndo, "%s ", tok2str(dccp_pkt_type_str, "", dccph_type)));
407 case DCCP_PKT_DATAACK: {
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_CLOSEREQ:
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)));
430 if (len < fixed_hdrlen) {
431 ND_PRINT((ndo, "truncated-%s - %u bytes missing!",
432 tok2str(dccp_pkt_type_str, "", dccph_type),
433 len - fixed_hdrlen));
436 ND_PRINT((ndo, "%s ", tok2str(dccp_pkt_type_str, "", dccph_type)));
438 case DCCP_PKT_RESET: {
439 const struct dccp_hdr_reset *dhr =
440 (const struct dccp_hdr_reset *)(bp + fixed_hdrlen);
442 if (len < fixed_hdrlen) {
443 ND_PRINT((ndo, "truncated-%s - %u bytes missing!",
444 tok2str(dccp_pkt_type_str, "", dccph_type),
445 len - fixed_hdrlen));
449 ND_PRINT((ndo, "%s (code=%s) ",
450 tok2str(dccp_pkt_type_str, "", dccph_type),
451 dccp_reset_code(dhr->dccph_reset_code)));
456 if (len < fixed_hdrlen) {
457 ND_PRINT((ndo, "truncated-%s - %u bytes missing!",
458 tok2str(dccp_pkt_type_str, "", dccph_type),
459 len - fixed_hdrlen));
462 ND_PRINT((ndo, "%s ", tok2str(dccp_pkt_type_str, "", dccph_type)));
464 case DCCP_PKT_SYNCACK:
466 if (len < fixed_hdrlen) {
467 ND_PRINT((ndo, "truncated-%s - %u bytes missing!",
468 tok2str(dccp_pkt_type_str, "", dccph_type),
469 len - fixed_hdrlen));
472 ND_PRINT((ndo, "%s ", tok2str(dccp_pkt_type_str, "", dccph_type)));
475 ND_PRINT((ndo, "%s ", tok2str(dccp_pkt_type_str, "unknown-type-%u", dccph_type)));
479 if ((DCCPH_TYPE(dh) != DCCP_PKT_DATA) &&
480 (DCCPH_TYPE(dh) != DCCP_PKT_REQUEST))
481 dccp_print_ack_no(ndo, bp);
483 if (ndo->ndo_vflag < 2)
486 ND_PRINT((ndo, "seq %" PRIu64, dccp_seqno(bp)));
488 /* process options */
489 if (hlen > fixed_hdrlen){
491 cp = bp + fixed_hdrlen;
492 ND_PRINT((ndo, " <"));
494 hlen -= fixed_hdrlen;
496 optlen = dccp_print_option(ndo, cp, hlen);
503 ND_PRINT((ndo, ", "));
505 ND_PRINT((ndo, ">"));
509 ND_PRINT((ndo, "%s", tstr));
513 static const struct tok dccp_option_values[] = {
516 { 2, "slowreceiver" },
521 { 36, "initcookie" },
523 { 38, "ack_vector0" },
524 { 39, "ack_vector1" },
525 { 40, "data_dropped" },
527 { 42, "timestamp_echo" },
528 { 43, "elapsed_time" },
529 { 44, "data_checksum" },
534 dccp_print_option(netdissect_options *ndo, const u_char *option, u_int hlen)
541 ND_TCHECK(*(option+1));
542 optlen = *(option +1);
545 ND_PRINT((ndo, "CCID option %u optlen too short", *option));
547 ND_PRINT((ndo, "%s optlen too short",
548 tok2str(dccp_option_values, "Option %u", *option)));
556 ND_PRINT((ndo, "CCID option %u optlen goes past header length",
559 ND_PRINT((ndo, "%s optlen goes past header length",
560 tok2str(dccp_option_values, "Option %u", *option)));
563 ND_TCHECK2(*option, optlen);
565 if (*option >= 128) {
566 ND_PRINT((ndo, "CCID option %d", *option));
569 ND_PRINT((ndo, " %u", EXTRACT_16BITS(option + 2)));
572 ND_PRINT((ndo, " %u", EXTRACT_32BITS(option + 2)));
578 ND_PRINT((ndo, "%s", tok2str(dccp_option_values, "Option %u", *option)));
585 ND_PRINT((ndo, " optlen too short"));
588 if (*(option + 2) < 10){
589 ND_PRINT((ndo, " %s", dccp_feature_nums[*(option + 2)]));
590 for (i = 0; i < optlen - 3; i++)
591 ND_PRINT((ndo, " %d", *(option + 3 + i)));
596 ND_PRINT((ndo, " 0x"));
597 for (i = 0; i < optlen - 2; i++)
598 ND_PRINT((ndo, "%02x", *(option + 2 + i)));
602 for (i = 0; i < optlen - 2; i++)
603 ND_PRINT((ndo, " %d", *(option + 2 + i)));
607 ND_PRINT((ndo, " 0x"));
608 for (i = 0; i < optlen - 2; i++)
609 ND_PRINT((ndo, "%02x", *(option + 2 + i)));
614 ND_PRINT((ndo, " 0x"));
615 for (i = 0; i < optlen - 2; i++)
616 ND_PRINT((ndo, "%02x", *(option + 2 + i)));
621 ND_PRINT((ndo, " 0x"));
622 for (i = 0; i < optlen - 2; i++)
623 ND_PRINT((ndo, "%02x", *(option + 2 + i)));
628 * 13.1. Timestamp Option
630 * +--------+--------+--------+--------+--------+--------+
631 * |00101001|00000110| Timestamp Value |
632 * +--------+--------+--------+--------+--------+--------+
636 ND_PRINT((ndo, " %u", EXTRACT_32BITS(option + 2)));
638 ND_PRINT((ndo, " [optlen != 6]"));
642 * 13.3. Timestamp Echo Option
644 * +--------+--------+--------+--------+--------+--------+
645 * |00101010|00000110| Timestamp Echo |
646 * +--------+--------+--------+--------+--------+--------+
649 * +--------+--------+------- ... -------+--------+--------+
650 * |00101010|00001000| Timestamp Echo | Elapsed Time |
651 * +--------+--------+------- ... -------+--------+--------+
652 * Type=42 Len=8 (4 bytes)
654 * +--------+--------+------- ... -------+------- ... -------+
655 * |00101010|00001010| Timestamp Echo | Elapsed Time |
656 * +--------+--------+------- ... -------+------- ... -------+
657 * Type=42 Len=10 (4 bytes) (4 bytes)
661 ND_PRINT((ndo, " %u", EXTRACT_32BITS(option + 2)));
664 ND_PRINT((ndo, " %u", EXTRACT_32BITS(option + 2)));
665 ND_PRINT((ndo, " (elapsed time %u)", EXTRACT_16BITS(option + 6)));
668 ND_PRINT((ndo, " %u", EXTRACT_32BITS(option + 2)));
669 ND_PRINT((ndo, " (elapsed time %u)", EXTRACT_32BITS(option + 6)));
672 ND_PRINT((ndo, " [optlen != 6 or 8 or 10]"));
678 ND_PRINT((ndo, " %u", EXTRACT_32BITS(option + 2)));
679 else if (optlen == 4)
680 ND_PRINT((ndo, " %u", EXTRACT_16BITS(option + 2)));
682 ND_PRINT((ndo, " [optlen != 4 or 6]"));
686 ND_PRINT((ndo, " "));
687 for (i = 0; i < optlen - 2; i++)
688 ND_PRINT((ndo, "%02x", *(option + 2 + i)));
696 ND_PRINT((ndo, "%s", tstr));