xref: /openbmc/linux/include/linux/dccp.h (revision 75f25bd3)
1 #ifndef _LINUX_DCCP_H
2 #define _LINUX_DCCP_H
3 
4 #include <linux/types.h>
5 #include <asm/byteorder.h>
6 
7 /**
8  * struct dccp_hdr - generic part of DCCP packet header
9  *
10  * @dccph_sport - Relevant port on the endpoint that sent this packet
11  * @dccph_dport - Relevant port on the other endpoint
12  * @dccph_doff - Data Offset from the start of the DCCP header, in 32-bit words
13  * @dccph_ccval - Used by the HC-Sender CCID
14  * @dccph_cscov - Parts of the packet that are covered by the Checksum field
15  * @dccph_checksum - Internet checksum, depends on dccph_cscov
16  * @dccph_x - 0 = 24 bit sequence number, 1 = 48
17  * @dccph_type - packet type, see DCCP_PKT_ prefixed macros
18  * @dccph_seq - sequence number high or low order 24 bits, depends on dccph_x
19  */
20 struct dccp_hdr {
21 	__be16	dccph_sport,
22 		dccph_dport;
23 	__u8	dccph_doff;
24 #if defined(__LITTLE_ENDIAN_BITFIELD)
25 	__u8	dccph_cscov:4,
26 		dccph_ccval:4;
27 #elif defined(__BIG_ENDIAN_BITFIELD)
28 	__u8	dccph_ccval:4,
29 		dccph_cscov:4;
30 #else
31 #error  "Adjust your <asm/byteorder.h> defines"
32 #endif
33 	__sum16	dccph_checksum;
34 #if defined(__LITTLE_ENDIAN_BITFIELD)
35 	__u8	dccph_x:1,
36 		dccph_type:4,
37 		dccph_reserved:3;
38 #elif defined(__BIG_ENDIAN_BITFIELD)
39 	__u8	dccph_reserved:3,
40 		dccph_type:4,
41 		dccph_x:1;
42 #else
43 #error  "Adjust your <asm/byteorder.h> defines"
44 #endif
45 	__u8	dccph_seq2;
46 	__be16	dccph_seq;
47 };
48 
49 /**
50  * struct dccp_hdr_ext - the low bits of a 48 bit seq packet
51  *
52  * @dccph_seq_low - low 24 bits of a 48 bit seq packet
53  */
54 struct dccp_hdr_ext {
55 	__be32	dccph_seq_low;
56 };
57 
58 /**
59  * struct dccp_hdr_request - Connection initiation request header
60  *
61  * @dccph_req_service - Service to which the client app wants to connect
62  */
63 struct dccp_hdr_request {
64 	__be32	dccph_req_service;
65 };
66 /**
67  * struct dccp_hdr_ack_bits - acknowledgment bits common to most packets
68  *
69  * @dccph_resp_ack_nr_high - 48 bit ack number high order bits, contains GSR
70  * @dccph_resp_ack_nr_low - 48 bit ack number low order bits, contains GSR
71  */
72 struct dccp_hdr_ack_bits {
73 	__be16	dccph_reserved1;
74 	__be16	dccph_ack_nr_high;
75 	__be32	dccph_ack_nr_low;
76 };
77 /**
78  * struct dccp_hdr_response - Connection initiation response header
79  *
80  * @dccph_resp_ack - 48 bit Acknowledgment Number Subheader (5.3)
81  * @dccph_resp_service - Echoes the Service Code on a received DCCP-Request
82  */
83 struct dccp_hdr_response {
84 	struct dccp_hdr_ack_bits	dccph_resp_ack;
85 	__be32				dccph_resp_service;
86 };
87 
88 /**
89  * struct dccp_hdr_reset - Unconditionally shut down a connection
90  *
91  * @dccph_reset_ack - 48 bit Acknowledgment Number Subheader (5.6)
92  * @dccph_reset_code - one of %dccp_reset_codes
93  * @dccph_reset_data - the Data 1 ... Data 3 fields from 5.6
94  */
95 struct dccp_hdr_reset {
96 	struct dccp_hdr_ack_bits	dccph_reset_ack;
97 	__u8				dccph_reset_code,
98 					dccph_reset_data[3];
99 };
100 
101 enum dccp_pkt_type {
102 	DCCP_PKT_REQUEST = 0,
103 	DCCP_PKT_RESPONSE,
104 	DCCP_PKT_DATA,
105 	DCCP_PKT_ACK,
106 	DCCP_PKT_DATAACK,
107 	DCCP_PKT_CLOSEREQ,
108 	DCCP_PKT_CLOSE,
109 	DCCP_PKT_RESET,
110 	DCCP_PKT_SYNC,
111 	DCCP_PKT_SYNCACK,
112 	DCCP_PKT_INVALID,
113 };
114 
115 #define DCCP_NR_PKT_TYPES DCCP_PKT_INVALID
116 
117 static inline unsigned int dccp_packet_hdr_len(const __u8 type)
118 {
119 	if (type == DCCP_PKT_DATA)
120 		return 0;
121 	if (type == DCCP_PKT_DATAACK	||
122 	    type == DCCP_PKT_ACK	||
123 	    type == DCCP_PKT_SYNC	||
124 	    type == DCCP_PKT_SYNCACK	||
125 	    type == DCCP_PKT_CLOSE	||
126 	    type == DCCP_PKT_CLOSEREQ)
127 		return sizeof(struct dccp_hdr_ack_bits);
128 	if (type == DCCP_PKT_REQUEST)
129 		return sizeof(struct dccp_hdr_request);
130 	if (type == DCCP_PKT_RESPONSE)
131 		return sizeof(struct dccp_hdr_response);
132 	return sizeof(struct dccp_hdr_reset);
133 }
134 enum dccp_reset_codes {
135 	DCCP_RESET_CODE_UNSPECIFIED = 0,
136 	DCCP_RESET_CODE_CLOSED,
137 	DCCP_RESET_CODE_ABORTED,
138 	DCCP_RESET_CODE_NO_CONNECTION,
139 	DCCP_RESET_CODE_PACKET_ERROR,
140 	DCCP_RESET_CODE_OPTION_ERROR,
141 	DCCP_RESET_CODE_MANDATORY_ERROR,
142 	DCCP_RESET_CODE_CONNECTION_REFUSED,
143 	DCCP_RESET_CODE_BAD_SERVICE_CODE,
144 	DCCP_RESET_CODE_TOO_BUSY,
145 	DCCP_RESET_CODE_BAD_INIT_COOKIE,
146 	DCCP_RESET_CODE_AGGRESSION_PENALTY,
147 
148 	DCCP_MAX_RESET_CODES		/* Leave at the end!  */
149 };
150 
151 /* DCCP options */
152 enum {
153 	DCCPO_PADDING = 0,
154 	DCCPO_MANDATORY = 1,
155 	DCCPO_MIN_RESERVED = 3,
156 	DCCPO_MAX_RESERVED = 31,
157 	DCCPO_CHANGE_L = 32,
158 	DCCPO_CONFIRM_L = 33,
159 	DCCPO_CHANGE_R = 34,
160 	DCCPO_CONFIRM_R = 35,
161 	DCCPO_NDP_COUNT = 37,
162 	DCCPO_ACK_VECTOR_0 = 38,
163 	DCCPO_ACK_VECTOR_1 = 39,
164 	DCCPO_TIMESTAMP = 41,
165 	DCCPO_TIMESTAMP_ECHO = 42,
166 	DCCPO_ELAPSED_TIME = 43,
167 	DCCPO_MAX = 45,
168 	DCCPO_MIN_RX_CCID_SPECIFIC = 128,	/* from sender to receiver */
169 	DCCPO_MAX_RX_CCID_SPECIFIC = 191,
170 	DCCPO_MIN_TX_CCID_SPECIFIC = 192,	/* from receiver to sender */
171 	DCCPO_MAX_TX_CCID_SPECIFIC = 255,
172 };
173 /* maximum size of a single TLV-encoded DCCP option (sans type/len bytes) */
174 #define DCCP_SINGLE_OPT_MAXLEN	253
175 
176 /* DCCP CCIDS */
177 enum {
178 	DCCPC_CCID2 = 2,
179 	DCCPC_CCID3 = 3,
180 };
181 
182 /* DCCP features (RFC 4340 section 6.4) */
183 enum dccp_feature_numbers {
184 	DCCPF_RESERVED = 0,
185 	DCCPF_CCID = 1,
186 	DCCPF_SHORT_SEQNOS = 2,
187 	DCCPF_SEQUENCE_WINDOW = 3,
188 	DCCPF_ECN_INCAPABLE = 4,
189 	DCCPF_ACK_RATIO = 5,
190 	DCCPF_SEND_ACK_VECTOR = 6,
191 	DCCPF_SEND_NDP_COUNT = 7,
192 	DCCPF_MIN_CSUM_COVER = 8,
193 	DCCPF_DATA_CHECKSUM = 9,
194 	/* 10-127 reserved */
195 	DCCPF_MIN_CCID_SPECIFIC = 128,
196 	DCCPF_SEND_LEV_RATE = 192,	/* RFC 4342, sec. 8.4 */
197 	DCCPF_MAX_CCID_SPECIFIC = 255,
198 };
199 
200 /* DCCP socket control message types for cmsg */
201 enum dccp_cmsg_type {
202 	DCCP_SCM_PRIORITY = 1,
203 	DCCP_SCM_QPOLICY_MAX = 0xFFFF,
204 	/* ^-- Up to here reserved exclusively for qpolicy parameters */
205 	DCCP_SCM_MAX
206 };
207 
208 /* DCCP priorities for outgoing/queued packets */
209 enum dccp_packet_dequeueing_policy {
210 	DCCPQ_POLICY_SIMPLE,
211 	DCCPQ_POLICY_PRIO,
212 	DCCPQ_POLICY_MAX
213 };
214 
215 /* DCCP socket options */
216 #define DCCP_SOCKOPT_PACKET_SIZE	1 /* XXX deprecated, without effect */
217 #define DCCP_SOCKOPT_SERVICE		2
218 #define DCCP_SOCKOPT_CHANGE_L		3
219 #define DCCP_SOCKOPT_CHANGE_R		4
220 #define DCCP_SOCKOPT_GET_CUR_MPS	5
221 #define DCCP_SOCKOPT_SERVER_TIMEWAIT	6
222 #define DCCP_SOCKOPT_SEND_CSCOV		10
223 #define DCCP_SOCKOPT_RECV_CSCOV		11
224 #define DCCP_SOCKOPT_AVAILABLE_CCIDS	12
225 #define DCCP_SOCKOPT_CCID		13
226 #define DCCP_SOCKOPT_TX_CCID		14
227 #define DCCP_SOCKOPT_RX_CCID		15
228 #define DCCP_SOCKOPT_QPOLICY_ID		16
229 #define DCCP_SOCKOPT_QPOLICY_TXQLEN	17
230 #define DCCP_SOCKOPT_CCID_RX_INFO	128
231 #define DCCP_SOCKOPT_CCID_TX_INFO	192
232 
233 /* maximum number of services provided on the same listening port */
234 #define DCCP_SERVICE_LIST_MAX_LEN      32
235 
236 #ifdef __KERNEL__
237 
238 #include <linux/in.h>
239 #include <linux/interrupt.h>
240 #include <linux/ktime.h>
241 #include <linux/list.h>
242 #include <linux/uio.h>
243 #include <linux/workqueue.h>
244 
245 #include <net/inet_connection_sock.h>
246 #include <net/inet_sock.h>
247 #include <net/inet_timewait_sock.h>
248 #include <net/tcp_states.h>
249 
250 enum dccp_state {
251 	DCCP_OPEN	     = TCP_ESTABLISHED,
252 	DCCP_REQUESTING	     = TCP_SYN_SENT,
253 	DCCP_LISTEN	     = TCP_LISTEN,
254 	DCCP_RESPOND	     = TCP_SYN_RECV,
255 	/*
256 	 * States involved in closing a DCCP connection:
257 	 * 1) ACTIVE_CLOSEREQ is entered by a server sending a CloseReq.
258 	 *
259 	 * 2) CLOSING can have three different meanings (RFC 4340, 8.3):
260 	 *  a. Client has performed active-close, has sent a Close to the server
261 	 *     from state OPEN or PARTOPEN, and is waiting for the final Reset
262 	 *     (in this case, SOCK_DONE == 1).
263 	 *  b. Client is asked to perform passive-close, by receiving a CloseReq
264 	 *     in (PART)OPEN state. It sends a Close and waits for final Reset
265 	 *     (in this case, SOCK_DONE == 0).
266 	 *  c. Server performs an active-close as in (a), keeps TIMEWAIT state.
267 	 *
268 	 * 3) The following intermediate states are employed to give passively
269 	 *    closing nodes a chance to process their unread data:
270 	 *    - PASSIVE_CLOSE    (from OPEN => CLOSED) and
271 	 *    - PASSIVE_CLOSEREQ (from (PART)OPEN to CLOSING; case (b) above).
272 	 */
273 	DCCP_ACTIVE_CLOSEREQ = TCP_FIN_WAIT1,
274 	DCCP_PASSIVE_CLOSE   = TCP_CLOSE_WAIT,	/* any node receiving a Close */
275 	DCCP_CLOSING	     = TCP_CLOSING,
276 	DCCP_TIME_WAIT	     = TCP_TIME_WAIT,
277 	DCCP_CLOSED	     = TCP_CLOSE,
278 	DCCP_PARTOPEN	     = TCP_MAX_STATES,
279 	DCCP_PASSIVE_CLOSEREQ,			/* clients receiving CloseReq */
280 	DCCP_MAX_STATES
281 };
282 
283 enum {
284 	DCCPF_OPEN	      = TCPF_ESTABLISHED,
285 	DCCPF_REQUESTING      = TCPF_SYN_SENT,
286 	DCCPF_LISTEN	      = TCPF_LISTEN,
287 	DCCPF_RESPOND	      = TCPF_SYN_RECV,
288 	DCCPF_ACTIVE_CLOSEREQ = TCPF_FIN_WAIT1,
289 	DCCPF_CLOSING	      = TCPF_CLOSING,
290 	DCCPF_TIME_WAIT	      = TCPF_TIME_WAIT,
291 	DCCPF_CLOSED	      = TCPF_CLOSE,
292 	DCCPF_PARTOPEN	      = (1 << DCCP_PARTOPEN),
293 };
294 
295 static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
296 {
297 	return (struct dccp_hdr *)skb_transport_header(skb);
298 }
299 
300 static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen)
301 {
302 	skb_push(skb, headlen);
303 	skb_reset_transport_header(skb);
304 	return memset(skb_transport_header(skb), 0, headlen);
305 }
306 
307 static inline struct dccp_hdr_ext *dccp_hdrx(const struct dccp_hdr *dh)
308 {
309 	return (struct dccp_hdr_ext *)((unsigned char *)dh + sizeof(*dh));
310 }
311 
312 static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
313 {
314 	return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
315 }
316 
317 static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
318 {
319 	const struct dccp_hdr *dh = dccp_hdr(skb);
320 	return __dccp_basic_hdr_len(dh);
321 }
322 
323 static inline __u64 dccp_hdr_seq(const struct dccp_hdr *dh)
324 {
325 	__u64 seq_nr =  ntohs(dh->dccph_seq);
326 
327 	if (dh->dccph_x != 0)
328 		seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(dh)->dccph_seq_low);
329 	else
330 		seq_nr += (u32)dh->dccph_seq2 << 16;
331 
332 	return seq_nr;
333 }
334 
335 static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb)
336 {
337 	return (struct dccp_hdr_request *)(skb_transport_header(skb) +
338 					   dccp_basic_hdr_len(skb));
339 }
340 
341 static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb)
342 {
343 	return (struct dccp_hdr_ack_bits *)(skb_transport_header(skb) +
344 					    dccp_basic_hdr_len(skb));
345 }
346 
347 static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb)
348 {
349 	const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb);
350 	return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + ntohl(dhack->dccph_ack_nr_low);
351 }
352 
353 static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb)
354 {
355 	return (struct dccp_hdr_response *)(skb_transport_header(skb) +
356 					    dccp_basic_hdr_len(skb));
357 }
358 
359 static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb)
360 {
361 	return (struct dccp_hdr_reset *)(skb_transport_header(skb) +
362 					 dccp_basic_hdr_len(skb));
363 }
364 
365 static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
366 {
367 	return __dccp_basic_hdr_len(dh) +
368 	       dccp_packet_hdr_len(dh->dccph_type);
369 }
370 
371 static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
372 {
373 	return __dccp_hdr_len(dccp_hdr(skb));
374 }
375 
376 /**
377  * struct dccp_request_sock  -  represent DCCP-specific connection request
378  * @dreq_inet_rsk: structure inherited from
379  * @dreq_iss: initial sequence number sent on the Response (RFC 4340, 7.1)
380  * @dreq_isr: initial sequence number received on the Request
381  * @dreq_service: service code present on the Request (there is just one)
382  * @dreq_featneg: feature negotiation options for this connection
383  * The following two fields are analogous to the ones in dccp_sock:
384  * @dreq_timestamp_echo: last received timestamp to echo (13.1)
385  * @dreq_timestamp_echo: the time of receiving the last @dreq_timestamp_echo
386  */
387 struct dccp_request_sock {
388 	struct inet_request_sock dreq_inet_rsk;
389 	__u64			 dreq_iss;
390 	__u64			 dreq_isr;
391 	__be32			 dreq_service;
392 	struct list_head	 dreq_featneg;
393 	__u32			 dreq_timestamp_echo;
394 	__u32			 dreq_timestamp_time;
395 };
396 
397 static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
398 {
399 	return (struct dccp_request_sock *)req;
400 }
401 
402 extern struct inet_timewait_death_row dccp_death_row;
403 
404 extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
405 			      struct sk_buff *skb);
406 
407 struct dccp_options_received {
408 	u64	dccpor_ndp:48;
409 	u32	dccpor_timestamp;
410 	u32	dccpor_timestamp_echo;
411 	u32	dccpor_elapsed_time;
412 };
413 
414 struct ccid;
415 
416 enum dccp_role {
417 	DCCP_ROLE_UNDEFINED,
418 	DCCP_ROLE_LISTEN,
419 	DCCP_ROLE_CLIENT,
420 	DCCP_ROLE_SERVER,
421 };
422 
423 struct dccp_service_list {
424 	__u32	dccpsl_nr;
425 	__be32	dccpsl_list[0];
426 };
427 
428 #define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
429 #define DCCP_SERVICE_CODE_IS_ABSENT		0
430 
431 static inline int dccp_list_has_service(const struct dccp_service_list *sl,
432 					const __be32 service)
433 {
434 	if (likely(sl != NULL)) {
435 		u32 i = sl->dccpsl_nr;
436 		while (i--)
437 			if (sl->dccpsl_list[i] == service)
438 				return 1;
439 	}
440 	return 0;
441 }
442 
443 struct dccp_ackvec;
444 
445 /**
446  * struct dccp_sock - DCCP socket state
447  *
448  * @dccps_swl - sequence number window low
449  * @dccps_swh - sequence number window high
450  * @dccps_awl - acknowledgement number window low
451  * @dccps_awh - acknowledgement number window high
452  * @dccps_iss - initial sequence number sent
453  * @dccps_isr - initial sequence number received
454  * @dccps_osr - first OPEN sequence number received
455  * @dccps_gss - greatest sequence number sent
456  * @dccps_gsr - greatest valid sequence number received
457  * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
458  * @dccps_service - first (passive sock) or unique (active sock) service code
459  * @dccps_service_list - second .. last service code on passive socket
460  * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
461  * @dccps_timestamp_time - time of receiving latest @dccps_timestamp_echo
462  * @dccps_l_ack_ratio - feature-local Ack Ratio
463  * @dccps_r_ack_ratio - feature-remote Ack Ratio
464  * @dccps_l_seq_win - local Sequence Window (influences ack number validity)
465  * @dccps_r_seq_win - remote Sequence Window (influences seq number validity)
466  * @dccps_pcslen - sender   partial checksum coverage (via sockopt)
467  * @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
468  * @dccps_send_ndp_count - local Send NDP Count feature (7.7.2)
469  * @dccps_ndp_count - number of Non Data Packets since last data packet
470  * @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
471  * @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
472  * @dccps_featneg - tracks feature-negotiation state (mostly during handshake)
473  * @dccps_hc_rx_ackvec - rx half connection ack vector
474  * @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
475  * @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
476  * @dccps_options_received - parsed set of retrieved options
477  * @dccps_qpolicy - TX dequeueing policy, one of %dccp_packet_dequeueing_policy
478  * @dccps_tx_qlen - maximum length of the TX queue
479  * @dccps_role - role of this sock, one of %dccp_role
480  * @dccps_hc_rx_insert_options - receiver wants to add options when acking
481  * @dccps_hc_tx_insert_options - sender wants to add options when sending
482  * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3)
483  * @dccps_sync_scheduled - flag which signals "send out-of-band message soon"
484  * @dccps_xmitlet - tasklet scheduled by the TX CCID to dequeue data packets
485  * @dccps_xmit_timer - used by the TX CCID to delay sending (rate-based pacing)
486  * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs)
487  */
488 struct dccp_sock {
489 	/* inet_connection_sock has to be the first member of dccp_sock */
490 	struct inet_connection_sock	dccps_inet_connection;
491 #define dccps_syn_rtt			dccps_inet_connection.icsk_ack.lrcvtime
492 	__u64				dccps_swl;
493 	__u64				dccps_swh;
494 	__u64				dccps_awl;
495 	__u64				dccps_awh;
496 	__u64				dccps_iss;
497 	__u64				dccps_isr;
498 	__u64				dccps_osr;
499 	__u64				dccps_gss;
500 	__u64				dccps_gsr;
501 	__u64				dccps_gar;
502 	__be32				dccps_service;
503 	__u32				dccps_mss_cache;
504 	struct dccp_service_list	*dccps_service_list;
505 	__u32				dccps_timestamp_echo;
506 	__u32				dccps_timestamp_time;
507 	__u16				dccps_l_ack_ratio;
508 	__u16				dccps_r_ack_ratio;
509 	__u64				dccps_l_seq_win:48;
510 	__u64				dccps_r_seq_win:48;
511 	__u8				dccps_pcslen:4;
512 	__u8				dccps_pcrlen:4;
513 	__u8				dccps_send_ndp_count:1;
514 	__u64				dccps_ndp_count:48;
515 	unsigned long			dccps_rate_last;
516 	struct list_head		dccps_featneg;
517 	struct dccp_ackvec		*dccps_hc_rx_ackvec;
518 	struct ccid			*dccps_hc_rx_ccid;
519 	struct ccid			*dccps_hc_tx_ccid;
520 	struct dccp_options_received	dccps_options_received;
521 	__u8				dccps_qpolicy;
522 	__u32				dccps_tx_qlen;
523 	enum dccp_role			dccps_role:2;
524 	__u8				dccps_hc_rx_insert_options:1;
525 	__u8				dccps_hc_tx_insert_options:1;
526 	__u8				dccps_server_timewait:1;
527 	__u8				dccps_sync_scheduled:1;
528 	struct tasklet_struct		dccps_xmitlet;
529 	struct timer_list		dccps_xmit_timer;
530 };
531 
532 static inline struct dccp_sock *dccp_sk(const struct sock *sk)
533 {
534 	return (struct dccp_sock *)sk;
535 }
536 
537 static inline const char *dccp_role(const struct sock *sk)
538 {
539 	switch (dccp_sk(sk)->dccps_role) {
540 	case DCCP_ROLE_UNDEFINED: return "undefined";
541 	case DCCP_ROLE_LISTEN:	  return "listen";
542 	case DCCP_ROLE_SERVER:	  return "server";
543 	case DCCP_ROLE_CLIENT:	  return "client";
544 	}
545 	return NULL;
546 }
547 
548 #endif /* __KERNEL__ */
549 
550 #endif /* _LINUX_DCCP_H */
551