dccp: Per-socket initialisation of feature negotiation
[safe/jmp/linux-2.6] / include / linux / dccp.h
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_CCID_SPECIFIC = 128,
169         DCCPO_MAX_CCID_SPECIFIC = 255,
170 };
171
172 /* DCCP CCIDS */
173 enum {
174         DCCPC_CCID2 = 2,
175         DCCPC_CCID3 = 3,
176 };
177
178 /* DCCP features (RFC 4340 section 6.4) */
179 enum dccp_feature_numbers {
180         DCCPF_RESERVED = 0,
181         DCCPF_CCID = 1,
182         DCCPF_SHORT_SEQNOS = 2,
183         DCCPF_SEQUENCE_WINDOW = 3,
184         DCCPF_ECN_INCAPABLE = 4,
185         DCCPF_ACK_RATIO = 5,
186         DCCPF_SEND_ACK_VECTOR = 6,
187         DCCPF_SEND_NDP_COUNT = 7,
188         DCCPF_MIN_CSUM_COVER = 8,
189         DCCPF_DATA_CHECKSUM = 9,
190         /* 10-127 reserved */
191         DCCPF_MIN_CCID_SPECIFIC = 128,
192         DCCPF_SEND_LEV_RATE = 192,      /* RFC 4342, sec. 8.4 */
193         DCCPF_MAX_CCID_SPECIFIC = 255,
194 };
195
196 /* this structure is argument to DCCP_SOCKOPT_CHANGE_X */
197 struct dccp_so_feat {
198         __u8 dccpsf_feat;
199         __u8 __user *dccpsf_val;
200         __u8 dccpsf_len;
201 };
202
203 /* DCCP socket options */
204 #define DCCP_SOCKOPT_PACKET_SIZE        1 /* XXX deprecated, without effect */
205 #define DCCP_SOCKOPT_SERVICE            2
206 #define DCCP_SOCKOPT_CHANGE_L           3
207 #define DCCP_SOCKOPT_CHANGE_R           4
208 #define DCCP_SOCKOPT_GET_CUR_MPS        5
209 #define DCCP_SOCKOPT_SERVER_TIMEWAIT    6
210 #define DCCP_SOCKOPT_SEND_CSCOV         10
211 #define DCCP_SOCKOPT_RECV_CSCOV         11
212 #define DCCP_SOCKOPT_CCID_RX_INFO       128
213 #define DCCP_SOCKOPT_CCID_TX_INFO       192
214
215 /* maximum number of services provided on the same listening port */
216 #define DCCP_SERVICE_LIST_MAX_LEN      32
217
218 #ifdef __KERNEL__
219
220 #include <linux/in.h>
221 #include <linux/ktime.h>
222 #include <linux/list.h>
223 #include <linux/uio.h>
224 #include <linux/workqueue.h>
225
226 #include <net/inet_connection_sock.h>
227 #include <net/inet_sock.h>
228 #include <net/inet_timewait_sock.h>
229 #include <net/tcp_states.h>
230
231 enum dccp_state {
232         DCCP_OPEN            = TCP_ESTABLISHED,
233         DCCP_REQUESTING      = TCP_SYN_SENT,
234         DCCP_LISTEN          = TCP_LISTEN,
235         DCCP_RESPOND         = TCP_SYN_RECV,
236         /*
237          * States involved in closing a DCCP connection:
238          * 1) ACTIVE_CLOSEREQ is entered by a server sending a CloseReq.
239          *
240          * 2) CLOSING can have three different meanings (RFC 4340, 8.3):
241          *  a. Client has performed active-close, has sent a Close to the server
242          *     from state OPEN or PARTOPEN, and is waiting for the final Reset
243          *     (in this case, SOCK_DONE == 1).
244          *  b. Client is asked to perform passive-close, by receiving a CloseReq
245          *     in (PART)OPEN state. It sends a Close and waits for final Reset
246          *     (in this case, SOCK_DONE == 0).
247          *  c. Server performs an active-close as in (a), keeps TIMEWAIT state.
248          *
249          * 3) The following intermediate states are employed to give passively
250          *    closing nodes a chance to process their unread data:
251          *    - PASSIVE_CLOSE    (from OPEN => CLOSED) and
252          *    - PASSIVE_CLOSEREQ (from (PART)OPEN to CLOSING; case (b) above).
253          */
254         DCCP_ACTIVE_CLOSEREQ = TCP_FIN_WAIT1,
255         DCCP_PASSIVE_CLOSE   = TCP_CLOSE_WAIT,  /* any node receiving a Close */
256         DCCP_CLOSING         = TCP_CLOSING,
257         DCCP_TIME_WAIT       = TCP_TIME_WAIT,
258         DCCP_CLOSED          = TCP_CLOSE,
259         DCCP_PARTOPEN        = TCP_MAX_STATES,
260         DCCP_PASSIVE_CLOSEREQ,                  /* clients receiving CloseReq */
261         DCCP_MAX_STATES
262 };
263
264 #define DCCP_STATE_MASK 0x1f
265
266 enum {
267         DCCPF_OPEN            = TCPF_ESTABLISHED,
268         DCCPF_REQUESTING      = TCPF_SYN_SENT,
269         DCCPF_LISTEN          = TCPF_LISTEN,
270         DCCPF_RESPOND         = TCPF_SYN_RECV,
271         DCCPF_ACTIVE_CLOSEREQ = TCPF_FIN_WAIT1,
272         DCCPF_CLOSING         = TCPF_CLOSING,
273         DCCPF_TIME_WAIT       = TCPF_TIME_WAIT,
274         DCCPF_CLOSED          = TCPF_CLOSE,
275         DCCPF_PARTOPEN        = (1 << DCCP_PARTOPEN),
276 };
277
278 static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
279 {
280         return (struct dccp_hdr *)skb_transport_header(skb);
281 }
282
283 static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen)
284 {
285         skb_push(skb, headlen);
286         skb_reset_transport_header(skb);
287         return memset(skb_transport_header(skb), 0, headlen);
288 }
289
290 static inline struct dccp_hdr_ext *dccp_hdrx(const struct dccp_hdr *dh)
291 {
292         return (struct dccp_hdr_ext *)((unsigned char *)dh + sizeof(*dh));
293 }
294
295 static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
296 {
297         return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
298 }
299
300 static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
301 {
302         const struct dccp_hdr *dh = dccp_hdr(skb);
303         return __dccp_basic_hdr_len(dh);
304 }
305
306 static inline __u64 dccp_hdr_seq(const struct dccp_hdr *dh)
307 {
308         __u64 seq_nr =  ntohs(dh->dccph_seq);
309
310         if (dh->dccph_x != 0)
311                 seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(dh)->dccph_seq_low);
312         else
313                 seq_nr += (u32)dh->dccph_seq2 << 16;
314
315         return seq_nr;
316 }
317
318 static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb)
319 {
320         return (struct dccp_hdr_request *)(skb_transport_header(skb) +
321                                            dccp_basic_hdr_len(skb));
322 }
323
324 static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb)
325 {
326         return (struct dccp_hdr_ack_bits *)(skb_transport_header(skb) +
327                                             dccp_basic_hdr_len(skb));
328 }
329
330 static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb)
331 {
332         const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb);
333         return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + ntohl(dhack->dccph_ack_nr_low);
334 }
335
336 static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb)
337 {
338         return (struct dccp_hdr_response *)(skb_transport_header(skb) +
339                                             dccp_basic_hdr_len(skb));
340 }
341
342 static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb)
343 {
344         return (struct dccp_hdr_reset *)(skb_transport_header(skb) +
345                                          dccp_basic_hdr_len(skb));
346 }
347
348 static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
349 {
350         return __dccp_basic_hdr_len(dh) +
351                dccp_packet_hdr_len(dh->dccph_type);
352 }
353
354 static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
355 {
356         return __dccp_hdr_len(dccp_hdr(skb));
357 }
358
359
360 /* initial values for each feature */
361 #define DCCPF_INITIAL_SEQUENCE_WINDOW           100
362 #define DCCPF_INITIAL_ACK_RATIO                 2
363 #define DCCPF_INITIAL_CCID                      DCCPC_CCID2
364 #define DCCPF_INITIAL_SEND_ACK_VECTOR           1
365 /* FIXME: for now we're default to 1 but it should really be 0 */
366 #define DCCPF_INITIAL_SEND_NDP_COUNT            1
367
368 /**
369   * struct dccp_minisock - Minimal DCCP connection representation
370   *
371   * Will be used to pass the state from dccp_request_sock to dccp_sock.
372   *
373   * @dccpms_sequence_window - Sequence Window Feature (section 7.5.2)
374   * @dccpms_ccid - Congestion Control Id (CCID) (section 10)
375   * @dccpms_send_ack_vector - Send Ack Vector Feature (section 11.5)
376   * @dccpms_send_ndp_count - Send NDP Count Feature (7.7.2)
377   * @dccpms_ack_ratio - Ack Ratio Feature (section 11.3)
378   * @dccpms_pending - List of features being negotiated
379   * @dccpms_conf -
380   */
381 struct dccp_minisock {
382         __u64                   dccpms_sequence_window;
383         __u8                    dccpms_rx_ccid;
384         __u8                    dccpms_tx_ccid;
385         __u8                    dccpms_send_ack_vector;
386         __u8                    dccpms_send_ndp_count;
387         __u8                    dccpms_ack_ratio;
388         struct list_head        dccpms_pending;
389         struct list_head        dccpms_conf;
390 };
391
392 struct dccp_opt_conf {
393         __u8                    *dccpoc_val;
394         __u8                    dccpoc_len;
395 };
396
397 struct dccp_opt_pend {
398         struct list_head        dccpop_node;
399         __u8                    dccpop_type;
400         __u8                    dccpop_feat;
401         __u8                    *dccpop_val;
402         __u8                    dccpop_len;
403         int                     dccpop_conf;
404         struct dccp_opt_conf    *dccpop_sc;
405 };
406
407 extern void dccp_minisock_init(struct dccp_minisock *dmsk);
408
409 /**
410  * struct dccp_request_sock  -  represent DCCP-specific connection request
411  * @dreq_inet_rsk: structure inherited from
412  * @dreq_iss: initial sequence number sent on the Response (RFC 4340, 7.1)
413  * @dreq_isr: initial sequence number received on the Request
414  * @dreq_service: service code present on the Request (there is just one)
415  * @dreq_featneg: feature negotiation options for this connection
416  * The following two fields are analogous to the ones in dccp_sock:
417  * @dreq_timestamp_echo: last received timestamp to echo (13.1)
418  * @dreq_timestamp_echo: the time of receiving the last @dreq_timestamp_echo
419  */
420 struct dccp_request_sock {
421         struct inet_request_sock dreq_inet_rsk;
422         __u64                    dreq_iss;
423         __u64                    dreq_isr;
424         __be32                   dreq_service;
425         struct list_head         dreq_featneg;
426         __u32                    dreq_timestamp_echo;
427         __u32                    dreq_timestamp_time;
428 };
429
430 static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
431 {
432         return (struct dccp_request_sock *)req;
433 }
434
435 extern struct inet_timewait_death_row dccp_death_row;
436
437 extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
438                               struct sk_buff *skb);
439
440 struct dccp_options_received {
441         u64     dccpor_ndp:48;
442         u32     dccpor_timestamp;
443         u32     dccpor_timestamp_echo;
444         u32     dccpor_elapsed_time;
445 };
446
447 struct ccid;
448
449 enum dccp_role {
450         DCCP_ROLE_UNDEFINED,
451         DCCP_ROLE_LISTEN,
452         DCCP_ROLE_CLIENT,
453         DCCP_ROLE_SERVER,
454 };
455
456 struct dccp_service_list {
457         __u32   dccpsl_nr;
458         __be32  dccpsl_list[0];
459 };
460
461 #define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
462 #define DCCP_SERVICE_CODE_IS_ABSENT             0
463
464 static inline int dccp_list_has_service(const struct dccp_service_list *sl,
465                                         const __be32 service)
466 {
467         if (likely(sl != NULL)) {
468                 u32 i = sl->dccpsl_nr;
469                 while (i--)
470                         if (sl->dccpsl_list[i] == service)
471                                 return 1;
472         }
473         return 0;
474 }
475
476 struct dccp_ackvec;
477
478 /**
479  * struct dccp_sock - DCCP socket state
480  *
481  * @dccps_swl - sequence number window low
482  * @dccps_swh - sequence number window high
483  * @dccps_awl - acknowledgement number window low
484  * @dccps_awh - acknowledgement number window high
485  * @dccps_iss - initial sequence number sent
486  * @dccps_isr - initial sequence number received
487  * @dccps_osr - first OPEN sequence number received
488  * @dccps_gss - greatest sequence number sent
489  * @dccps_gsr - greatest valid sequence number received
490  * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
491  * @dccps_service - first (passive sock) or unique (active sock) service code
492  * @dccps_service_list - second .. last service code on passive socket
493  * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
494  * @dccps_timestamp_time - time of receiving latest @dccps_timestamp_echo
495  * @dccps_l_ack_ratio - feature-local Ack Ratio
496  * @dccps_r_ack_ratio - feature-remote Ack Ratio
497  * @dccps_pcslen - sender   partial checksum coverage (via sockopt)
498  * @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
499  * @dccps_ndp_count - number of Non Data Packets since last data packet
500  * @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
501  * @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
502  * @dccps_minisock - associated minisock (accessed via dccp_msk)
503  * @dccps_featneg - tracks feature-negotiation state (mostly during handshake)
504  * @dccps_hc_rx_ackvec - rx half connection ack vector
505  * @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
506  * @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
507  * @dccps_options_received - parsed set of retrieved options
508  * @dccps_role - role of this sock, one of %dccp_role
509  * @dccps_hc_rx_insert_options - receiver wants to add options when acking
510  * @dccps_hc_tx_insert_options - sender wants to add options when sending
511  * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3)
512  * @dccps_xmit_timer - timer for when CCID is not ready to send
513  * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs)
514  */
515 struct dccp_sock {
516         /* inet_connection_sock has to be the first member of dccp_sock */
517         struct inet_connection_sock     dccps_inet_connection;
518 #define dccps_syn_rtt                   dccps_inet_connection.icsk_ack.lrcvtime
519         __u64                           dccps_swl;
520         __u64                           dccps_swh;
521         __u64                           dccps_awl;
522         __u64                           dccps_awh;
523         __u64                           dccps_iss;
524         __u64                           dccps_isr;
525         __u64                           dccps_osr;
526         __u64                           dccps_gss;
527         __u64                           dccps_gsr;
528         __u64                           dccps_gar;
529         __be32                          dccps_service;
530         __u32                           dccps_mss_cache;
531         struct dccp_service_list        *dccps_service_list;
532         __u32                           dccps_timestamp_echo;
533         __u32                           dccps_timestamp_time;
534         __u16                           dccps_l_ack_ratio;
535         __u16                           dccps_r_ack_ratio;
536         __u16                           dccps_pcslen;
537         __u16                           dccps_pcrlen;
538         __u64                           dccps_ndp_count:48;
539         unsigned long                   dccps_rate_last;
540         struct dccp_minisock            dccps_minisock;
541         struct list_head                dccps_featneg;
542         struct dccp_ackvec              *dccps_hc_rx_ackvec;
543         struct ccid                     *dccps_hc_rx_ccid;
544         struct ccid                     *dccps_hc_tx_ccid;
545         struct dccp_options_received    dccps_options_received;
546         enum dccp_role                  dccps_role:2;
547         __u8                            dccps_hc_rx_insert_options:1;
548         __u8                            dccps_hc_tx_insert_options:1;
549         __u8                            dccps_server_timewait:1;
550         struct timer_list               dccps_xmit_timer;
551 };
552
553 static inline struct dccp_sock *dccp_sk(const struct sock *sk)
554 {
555         return (struct dccp_sock *)sk;
556 }
557
558 static inline struct dccp_minisock *dccp_msk(const struct sock *sk)
559 {
560         return (struct dccp_minisock *)&dccp_sk(sk)->dccps_minisock;
561 }
562
563 static inline const char *dccp_role(const struct sock *sk)
564 {
565         switch (dccp_sk(sk)->dccps_role) {
566         case DCCP_ROLE_UNDEFINED: return "undefined";
567         case DCCP_ROLE_LISTEN:    return "listen";
568         case DCCP_ROLE_SERVER:    return "server";
569         case DCCP_ROLE_CLIENT:    return "client";
570         }
571         return NULL;
572 }
573
574 #endif /* __KERNEL__ */
575
576 #endif /* _LINUX_DCCP_H */