aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/dccp.h
blob: 010e2d87ed7568ea1019f57447f671666e56fbb3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
#ifndef _LINUX_DCCP_H
#define _LINUX_DCCP_H

#include <linux/types.h>
#include <asm/byteorder.h>

/**
 * struct dccp_hdr - generic part of DCCP packet header
 *
 * @dccph_sport - Relevant port on the endpoint that sent this packet
 * @dccph_dport - Relevant port on the other endpoint
 * @dccph_doff - Data Offset from the start of the DCCP header, in 32-bit words
 * @dccph_ccval - Used by the HC-Sender CCID
 * @dccph_cscov - Parts of the packet that are covered by the Checksum field
 * @dccph_checksum - Internet checksum, depends on dccph_cscov
 * @dccph_x - 0 = 24 bit sequence number, 1 = 48
 * @dccph_type - packet type, see DCCP_PKT_ prefixed macros
 * @dccph_seq - sequence number high or low order 24 bits, depends on dccph_x
 */
struct dccp_hdr {
	__be16	dccph_sport,
		dccph_dport;
	__u8	dccph_doff;
#if defined(__LITTLE_ENDIAN_BITFIELD)
	__u8	dccph_cscov:4,
		dccph_ccval:4;
#elif defined(__BIG_ENDIAN_BITFIELD)
	__u8	dccph_ccval:4,
		dccph_cscov:4;
#else
#error  "Adjust your <asm/byteorder.h> defines"
#endif
	__sum16	dccph_checksum;
#if defined(__LITTLE_ENDIAN_BITFIELD)
	__u8	dccph_x:1,
		dccph_type:4,
		dccph_reserved:3;
#elif defined(__BIG_ENDIAN_BITFIELD)
	__u8	dccph_reserved:3,
		dccph_type:4,
		dccph_x:1;
#else
#error  "Adjust your <asm/byteorder.h> defines"
#endif
	__u8	dccph_seq2;
	__be16	dccph_seq;
};

/**
 * struct dccp_hdr_ext - the low bits of a 48 bit seq packet
 *
 * @dccph_seq_low - low 24 bits of a 48 bit seq packet
 */
struct dccp_hdr_ext {
	__be32	dccph_seq_low;
};

/**
 * struct dccp_hdr_request - Connection initiation request header
 *
 * @dccph_req_service - Service to which the client app wants to connect
 */
struct dccp_hdr_request {
	__be32	dccph_req_service;
};
/**
 * struct dccp_hdr_ack_bits - acknowledgment bits common to most packets
 *
 * @dccph_resp_ack_nr_high - 48 bit ack number high order bits, contains GSR
 * @dccph_resp_ack_nr_low - 48 bit ack number low order bits, contains GSR
 */
struct dccp_hdr_ack_bits {
	__be16	dccph_reserved1;
	__be16	dccph_ack_nr_high;
	__be32	dccph_ack_nr_low;
};
/**
 * struct dccp_hdr_response - Connection initiation response header
 *
 * @dccph_resp_ack - 48 bit Acknowledgment Number Subheader (5.3)
 * @dccph_resp_service - Echoes the Service Code on a received DCCP-Request
 */
struct dccp_hdr_response {
	struct dccp_hdr_ack_bits	dccph_resp_ack;
	__be32				dccph_resp_service;
};

/**
 * struct dccp_hdr_reset - Unconditionally shut down a connection
 *
 * @dccph_reset_ack - 48 bit Acknowledgment Number Subheader (5.6)
 * @dccph_reset_code - one of %dccp_reset_codes
 * @dccph_reset_data - the Data 1 ... Data 3 fields from 5.6
 */
struct dccp_hdr_reset {
	struct dccp_hdr_ack_bits	dccph_reset_ack;
	__u8				dccph_reset_code,
					dccph_reset_data[3];
};

enum dccp_pkt_type {
	DCCP_PKT_REQUEST = 0,
	DCCP_PKT_RESPONSE,
	DCCP_PKT_DATA,
	DCCP_PKT_ACK,
	DCCP_PKT_DATAACK,
	DCCP_PKT_CLOSEREQ,
	DCCP_PKT_CLOSE,
	DCCP_PKT_RESET,
	DCCP_PKT_SYNC,
	DCCP_PKT_SYNCACK,
	DCCP_PKT_INVALID,
};

#define DCCP_NR_PKT_TYPES DCCP_PKT_INVALID

static inline unsigned int dccp_packet_hdr_len(const __u8 type)
{
	if (type == DCCP_PKT_DATA)
		return 0;
	if (type == DCCP_PKT_DATAACK	||
	    type == DCCP_PKT_ACK	||
	    type == DCCP_PKT_SYNC	||
	    type == DCCP_PKT_SYNCACK	||
	    type == DCCP_PKT_CLOSE	||
	    type == DCCP_PKT_CLOSEREQ)
		return sizeof(struct dccp_hdr_ack_bits);
	if (type == DCCP_PKT_REQUEST)
		return sizeof(struct dccp_hdr_request);
	if (type == DCCP_PKT_RESPONSE)
		return sizeof(struct dccp_hdr_response);
	return sizeof(struct dccp_hdr_reset);
}
enum dccp_reset_codes {
	DCCP_RESET_CODE_UNSPECIFIED = 0,
	DCCP_RESET_CODE_CLOSED,
	DCCP_RESET_CODE_ABORTED,
	DCCP_RESET_CODE_NO_CONNECTION,
	DCCP_RESET_CODE_PACKET_ERROR,
	DCCP_RESET_CODE_OPTION_ERROR,
	DCCP_RESET_CODE_MANDATORY_ERROR,
	DCCP_RESET_CODE_CONNECTION_REFUSED,
	DCCP_RESET_CODE_BAD_SERVICE_CODE,
	DCCP_RESET_CODE_TOO_BUSY,
	DCCP_RESET_CODE_BAD_INIT_COOKIE,
	DCCP_RESET_CODE_AGGRESSION_PENALTY,

	DCCP_MAX_RESET_CODES		/* Leave at the end!  */
};

/* DCCP options */
enum {
	DCCPO_PADDING = 0,
	DCCPO_MANDATORY = 1,
	DCCPO_MIN_RESERVED = 3,
	DCCPO_MAX_RESERVED = 31,
	DCCPO_CHANGE_L = 32,
	DCCPO_CONFIRM_L = 33,
	DCCPO_CHANGE_R = 34,
	DCCPO_CONFIRM_R = 35,
	DCCPO_NDP_COUNT = 37,
	DCCPO_ACK_VECTOR_0 = 38,
	DCCPO_ACK_VECTOR_1 = 39,
	DCCPO_TIMESTAMP = 41,
	DCCPO_TIMESTAMP_ECHO = 42,
	DCCPO_ELAPSED_TIME = 43,
	DCCPO_MAX = 45,
	DCCPO_MIN_RX_CCID_SPECIFIC = 128,	/* from sender to receiver */
	DCCPO_MAX_RX_CCID_SPECIFIC = 191,
	DCCPO_MIN_TX_CCID_SPECIFIC = 192,	/* from receiver to sender */
	DCCPO_MAX_TX_CCID_SPECIFIC = 255,
};
/* maximum size of a single TLV-encoded DCCP option (sans type/len bytes) */
#define DCCP_SINGLE_OPT_MAXLEN	253

/* DCCP CCIDS */
enum {
	DCCPC_CCID2 = 2,
	DCCPC_CCID3 = 3,
};

/* DCCP features (RFC 4340 section 6.4) */
enum dccp_feature_numbers {
	DCCPF_RESERVED = 0,
	DCCPF_CCID = 1,
	DCCPF_SHORT_SEQNOS = 2,
	DCCPF_SEQUENCE_WINDOW = 3,
	DCCPF_ECN_INCAPABLE = 4,
	DCCPF_ACK_RATIO = 5,
	DCCPF_SEND_ACK_VECTOR = 6,
	DCCPF_SEND_NDP_COUNT = 7,
	DCCPF_MIN_CSUM_COVER = 8,
	DCCPF_DATA_CHECKSUM = 9,
	/* 10-127 reserved */
	DCCPF_MIN_CCID_SPECIFIC = 128,
	DCCPF_SEND_LEV_RATE = 192,	/* RFC 4342, sec. 8.4 */
	DCCPF_MAX_CCID_SPECIFIC = 255,
};

/* DCCP socket control message types for cmsg */
enum dccp_cmsg_type {
	DCCP_SCM_PRIORITY = 1,
	DCCP_SCM_QPOLICY_MAX = 0xFFFF,
	/* ^-- Up to here reserved exclusively for qpolicy parameters */
	DCCP_SCM_MAX
};

/* DCCP priorities for outgoing/queued packets */
enum dccp_packet_dequeueing_policy {
	DCCPQ_POLICY_SIMPLE,
	DCCPQ_POLICY_PRIO,
	DCCPQ_POLICY_MAX
};

/* DCCP socket options */
#define DCCP_SOCKOPT_PACKET_SIZE	1 /* XXX deprecated, without effect */
#define DCCP_SOCKOPT_SERVICE		2
#define DCCP_SOCKOPT_CHANGE_L		3
#define DCCP_SOCKOPT_CHANGE_R		4
#define DCCP_SOCKOPT_GET_CUR_MPS	5
#define DCCP_SOCKOPT_SERVER_TIMEWAIT	6
#define DCCP_SOCKOPT_SEND_CSCOV		10
#define DCCP_SOCKOPT_RECV_CSCOV		11
#define DCCP_SOCKOPT_AVAILABLE_CCIDS	12
#define DCCP_SOCKOPT_CCID		13
#define DCCP_SOCKOPT_TX_CCID		14
#define DCCP_SOCKOPT_RX_CCID		15
#define DCCP_SOCKOPT_QPOLICY_ID		16
#define DCCP_SOCKOPT_QPOLICY_TXQLEN	17
#define DCCP_SOCKOPT_CCID_RX_INFO	128
#define DCCP_SOCKOPT_CCID_TX_INFO	192

/* maximum number of services provided on the same listening port */
#define DCCP_SERVICE_LIST_MAX_LEN      32

#ifdef __KERNEL__

#include <linux/in.h>
#include <linux/ktime.h>
#include <linux/list.h>
#include <linux/uio.h>
#include <linux/workqueue.h>

#include <net/inet_connection_sock.h>
#include <net/inet_sock.h>
#include <net/inet_timewait_sock.h>
#include <net/tcp_states.h>

enum dccp_state {
	DCCP_OPEN	     = TCP_ESTABLISHED,
	DCCP_REQUESTING	     = TCP_SYN_SENT,
	DCCP_LISTEN	     = TCP_LISTEN,
	DCCP_RESPOND	     = TCP_SYN_RECV,
	/*
	 * States involved in closing a DCCP connection:
	 * 1) ACTIVE_CLOSEREQ is entered by a server sending a CloseReq.
	 *
	 * 2) CLOSING can have three different meanings (RFC 4340, 8.3):
	 *  a. Client has performed active-close, has sent a Close to the server
	 *     from state OPEN or PARTOPEN, and is waiting for the final Reset
	 *     (in this case, SOCK_DONE == 1).
	 *  b. Client is asked to perform passive-close, by receiving a CloseReq
	 *     in (PART)OPEN state. It sends a Close and waits for final Reset
	 *     (in this case, SOCK_DONE == 0).
	 *  c. Server performs an active-close as in (a), keeps TIMEWAIT state.
	 *
	 * 3) The following intermediate states are employed to give passively
	 *    closing nodes a chance to process their unread data:
	 *    - PASSIVE_CLOSE    (from OPEN => CLOSED) and
	 *    - PASSIVE_CLOSEREQ (from (PART)OPEN to CLOSING; case (b) above).
	 */
	DCCP_ACTIVE_CLOSEREQ = TCP_FIN_WAIT1,
	DCCP_PASSIVE_CLOSE   = TCP_CLOSE_WAIT,	/* any node receiving a Close */
	DCCP_CLOSING	     = TCP_CLOSING,
	DCCP_TIME_WAIT	     = TCP_TIME_WAIT,
	DCCP_CLOSED	     = TCP_CLOSE,
	DCCP_PARTOPEN	     = TCP_MAX_STATES,
	DCCP_PASSIVE_CLOSEREQ,			/* clients receiving CloseReq */
	DCCP_MAX_STATES
};

#define DCCP_STATE_MASK 0x1f

enum {
	DCCPF_OPEN	      = TCPF_ESTABLISHED,
	DCCPF_REQUESTING      = TCPF_SYN_SENT,
	DCCPF_LISTEN	      = TCPF_LISTEN,
	DCCPF_RESPOND	      = TCPF_SYN_RECV,
	DCCPF_ACTIVE_CLOSEREQ = TCPF_FIN_WAIT1,
	DCCPF_CLOSING	      = TCPF_CLOSING,
	DCCPF_TIME_WAIT	      = TCPF_TIME_WAIT,
	DCCPF_CLOSED	      = TCPF_CLOSE,
	DCCPF_PARTOPEN	      = (1 << DCCP_PARTOPEN),
};

static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
{
	return (struct dccp_hdr *)skb_transport_header(skb);
}

static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen)
{
	skb_push(skb, headlen);
	skb_reset_transport_header(skb);
	return memset(skb_transport_header(skb), 0, headlen);
}

static inline struct dccp_hdr_ext *dccp_hdrx(const struct dccp_hdr *dh)
{
	return (struct dccp_hdr_ext *)((unsigned char *)dh + sizeof(*dh));
}

static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
{
	return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
}

static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
{
	const struct dccp_hdr *dh = dccp_hdr(skb);
	return __dccp_basic_hdr_len(dh);
}

static inline __u64 dccp_hdr_seq(const struct dccp_hdr *dh)
{
	__u64 seq_nr =  ntohs(dh->dccph_seq);

	if (dh->dccph_x != 0)
		seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(dh)->dccph_seq_low);
	else
		seq_nr += (u32)dh->dccph_seq2 << 16;

	return seq_nr;
}

static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb)
{
	return (struct dccp_hdr_request *)(skb_transport_header(skb) +
					   dccp_basic_hdr_len(skb));
}

static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb)
{
	return (struct dccp_hdr_ack_bits *)(skb_transport_header(skb) +
					    dccp_basic_hdr_len(skb));
}

static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb)
{
	const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb);
	return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + ntohl(dhack->dccph_ack_nr_low);
}

static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb)
{
	return (struct dccp_hdr_response *)(skb_transport_header(skb) +
					    dccp_basic_hdr_len(skb));
}

static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb)
{
	return (struct dccp_hdr_reset *)(skb_transport_header(skb) +
					 dccp_basic_hdr_len(skb));
}

static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
{
	return __dccp_basic_hdr_len(dh) +
	       dccp_packet_hdr_len(dh->dccph_type);
}

static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
{
	return __dccp_hdr_len(dccp_hdr(skb));
}

/**
 * struct dccp_request_sock  -  represent DCCP-specific connection request
 * @dreq_inet_rsk: structure inherited from
 * @dreq_iss: initial sequence number sent on the Response (RFC 4340, 7.1)
 * @dreq_isr: initial sequence number received on the Request
 * @dreq_service: service code present on the Request (there is just one)
 * @dreq_featneg: feature negotiation options for this connection
 * The following two fields are analogous to the ones in dccp_sock:
 * @dreq_timestamp_echo: last received timestamp to echo (13.1)
 * @dreq_timestamp_echo: the time of receiving the last @dreq_timestamp_echo
 */
struct dccp_request_sock {
	struct inet_request_sock dreq_inet_rsk;
	__u64			 dreq_iss;
	__u64			 dreq_isr;
	__be32			 dreq_service;
	struct list_head	 dreq_featneg;
	__u32			 dreq_timestamp_echo;
	__u32			 dreq_timestamp_time;
};

static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
{
	return (struct dccp_request_sock *)req;
}

extern struct inet_timewait_death_row dccp_death_row;

extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
			      struct sk_buff *skb);

struct dccp_options_received {
	u64	dccpor_ndp:48;
	u32	dccpor_timestamp;
	u32	dccpor_timestamp_echo;
	u32	dccpor_elapsed_time;
};

struct ccid;

enum dccp_role {
	DCCP_ROLE_UNDEFINED,
	DCCP_ROLE_LISTEN,
	DCCP_ROLE_CLIENT,
	DCCP_ROLE_SERVER,
};

struct dccp_service_list {
	__u32	dccpsl_nr;
	__be32	dccpsl_list[0];
};

#define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
#define DCCP_SERVICE_CODE_IS_ABSENT		0

static inline int dccp_list_has_service(const struct dccp_service_list *sl,
					const __be32 service)
{
	if (likely(sl != NULL)) {
		u32 i = sl->dccpsl_nr;
		while (i--)
			if (sl->dccpsl_list[i] == service)
				return 1;
	}
	return 0;
}

struct dccp_ackvec;

/**
 * struct dccp_sock - DCCP socket state
 *
 * @dccps_swl - sequence number window low
 * @dccps_swh - sequence number window high
 * @dccps_awl - acknowledgement number window low
 * @dccps_awh - acknowledgement number window high
 * @dccps_iss - initial sequence number sent
 * @dccps_isr - initial sequence number received
 * @dccps_osr - first OPEN sequence number received
 * @dccps_gss - greatest sequence number sent
 * @dccps_gsr - greatest valid sequence number received
 * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
 * @dccps_service - first (passive sock) or unique (active sock) service code
 * @dccps_service_list - second .. last service code on passive socket
 * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
 * @dccps_timestamp_time - time of receiving latest @dccps_timestamp_echo
 * @dccps_l_ack_ratio - feature-local Ack Ratio
 * @dccps_r_ack_ratio - feature-remote Ack Ratio
 * @dccps_l_seq_win - local Sequence Window (influences ack number validity)
 * @dccps_r_seq_win - remote Sequence Window (influences seq number validity)
 * @dccps_pcslen - sender   partial checksum coverage (via sockopt)
 * @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
 * @dccps_send_ndp_count - local Send NDP Count feature (7.7.2)
 * @dccps_ndp_count - number of Non Data Packets since last data packet
 * @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
 * @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
 * @dccps_featneg - tracks feature-negotiation state (mostly during handshake)
 * @dccps_hc_rx_ackvec - rx half connection ack vector
 * @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
 * @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
 * @dccps_options_received - parsed set of retrieved options
 * @dccps_qpolicy - TX dequeueing policy, one of %dccp_packet_dequeueing_policy
 * @dccps_tx_qlen - maximum length of the TX queue
 * @dccps_role - role of this sock, one of %dccp_role
 * @dccps_hc_rx_insert_options - receiver wants to add options when acking
 * @dccps_hc_tx_insert_options - sender wants to add options when sending
 * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3)
 * @dccps_sync_scheduled - flag which signals "send out-of-band message soon"
 * @dccps_xmitlet - tasklet scheduled by the TX CCID to dequeue data packets
 * @dccps_xmit_timer - used by the TX CCID to delay sending (rate-based pacing)
 * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs)
 */
struct dccp_sock {
	/* inet_connection_sock has to be the first member of dccp_sock */
	struct inet_connection_sock	dccps_inet_connection;
#define dccps_syn_rtt			dccps_inet_connection.icsk_ack.lrcvtime
	__u64				dccps_swl;
	__u64				dccps_swh;
	__u64				dccps_awl;
	__u64				dccps_awh;
	__u64				dccps_iss;
	__u64				dccps_isr;
	__u64				dccps_osr;
	__u64				dccps_gss;
	__u64				dccps_gsr;
	__u64				dccps_gar;
	__be32				dccps_service;
	__u32				dccps_mss_cache;
	struct dccp_service_list	*dccps_service_list;
	__u32				dccps_timestamp_echo;
	__u32				dccps_timestamp_time;
	__u16				dccps_l_ack_ratio;
	__u16				dccps_r_ack_ratio;
	__u64				dccps_l_seq_win:48;
	__u64				dccps_r_seq_win:48;
	__u8				dccps_pcslen:4;
	__u8				dccps_pcrlen:4;
	__u8				dccps_send_ndp_count:1;
	__u64				dccps_ndp_count:48;
	unsigned long			dccps_rate_last;
	struct list_head		dccps_featneg;
	struct dccp_ackvec		*dccps_hc_rx_ackvec;
	struct ccid			*dccps_hc_rx_ccid;
	struct ccid			*dccps_hc_tx_ccid;
	struct dccp_options_received	dccps_options_received;
	__u8				dccps_qpolicy;
	__u32				dccps_tx_qlen;
	enum dccp_role			dccps_role:2;
	__u8				dccps_hc_rx_insert_options:1;
	__u8				dccps_hc_tx_insert_options:1;
	__u8				dccps_server_timewait:1;
	__u8				dccps_sync_scheduled:1;
	struct tasklet_struct		dccps_xmitlet;
	struct timer_list		dccps_xmit_timer;
};

static inline struct dccp_sock *dccp_sk(const struct sock *sk)
{
	return (struct dccp_sock *)sk;
}

static inline const char *dccp_role(const struct sock *sk)
{
	switch (dccp_sk(sk)->dccps_role) {
	case DCCP_ROLE_UNDEFINED: return "undefined";
	case DCCP_ROLE_LISTEN:	  return "listen";
	case DCCP_ROLE_SERVER:	  return "server";
	case DCCP_ROLE_CLIENT:	  return "client";
	}
	return NULL;
}

#endif /* __KERNEL__ */

#endif /* _LINUX_DCCP_H */