dccp: Deprecate Ack Ratio sysctl
[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 /* DCCP socket options */
197 #define DCCP_SOCKOPT_PACKET_SIZE        1 /* XXX deprecated, without effect */
198 #define DCCP_SOCKOPT_SERVICE            2
199 #define DCCP_SOCKOPT_CHANGE_L           3
200 #define DCCP_SOCKOPT_CHANGE_R           4
201 #define DCCP_SOCKOPT_GET_CUR_MPS        5
202 #define DCCP_SOCKOPT_SERVER_TIMEWAIT    6
203 #define DCCP_SOCKOPT_SEND_CSCOV         10
204 #define DCCP_SOCKOPT_RECV_CSCOV         11
205 #define DCCP_SOCKOPT_AVAILABLE_CCIDS    12
206 #define DCCP_SOCKOPT_CCID_RX_INFO       128
207 #define DCCP_SOCKOPT_CCID_TX_INFO       192
208
209 /* maximum number of services provided on the same listening port */
210 #define DCCP_SERVICE_LIST_MAX_LEN      32
211
212 #ifdef __KERNEL__
213
214 #include <linux/in.h>
215 #include <linux/ktime.h>
216 #include <linux/list.h>
217 #include <linux/uio.h>
218 #include <linux/workqueue.h>
219
220 #include <net/inet_connection_sock.h>
221 #include <net/inet_sock.h>
222 #include <net/inet_timewait_sock.h>
223 #include <net/tcp_states.h>
224
225 enum dccp_state {
226         DCCP_OPEN            = TCP_ESTABLISHED,
227         DCCP_REQUESTING      = TCP_SYN_SENT,
228         DCCP_LISTEN          = TCP_LISTEN,
229         DCCP_RESPOND         = TCP_SYN_RECV,
230         /*
231          * States involved in closing a DCCP connection:
232          * 1) ACTIVE_CLOSEREQ is entered by a server sending a CloseReq.
233          *
234          * 2) CLOSING can have three different meanings (RFC 4340, 8.3):
235          *  a. Client has performed active-close, has sent a Close to the server
236          *     from state OPEN or PARTOPEN, and is waiting for the final Reset
237          *     (in this case, SOCK_DONE == 1).
238          *  b. Client is asked to perform passive-close, by receiving a CloseReq
239          *     in (PART)OPEN state. It sends a Close and waits for final Reset
240          *     (in this case, SOCK_DONE == 0).
241          *  c. Server performs an active-close as in (a), keeps TIMEWAIT state.
242          *
243          * 3) The following intermediate states are employed to give passively
244          *    closing nodes a chance to process their unread data:
245          *    - PASSIVE_CLOSE    (from OPEN => CLOSED) and
246          *    - PASSIVE_CLOSEREQ (from (PART)OPEN to CLOSING; case (b) above).
247          */
248         DCCP_ACTIVE_CLOSEREQ = TCP_FIN_WAIT1,
249         DCCP_PASSIVE_CLOSE   = TCP_CLOSE_WAIT,  /* any node receiving a Close */
250         DCCP_CLOSING         = TCP_CLOSING,
251         DCCP_TIME_WAIT       = TCP_TIME_WAIT,
252         DCCP_CLOSED          = TCP_CLOSE,
253         DCCP_PARTOPEN        = TCP_MAX_STATES,
254         DCCP_PASSIVE_CLOSEREQ,                  /* clients receiving CloseReq */
255         DCCP_MAX_STATES
256 };
257
258 #define DCCP_STATE_MASK 0x1f
259
260 enum {
261         DCCPF_OPEN            = TCPF_ESTABLISHED,
262         DCCPF_REQUESTING      = TCPF_SYN_SENT,
263         DCCPF_LISTEN          = TCPF_LISTEN,
264         DCCPF_RESPOND         = TCPF_SYN_RECV,
265         DCCPF_ACTIVE_CLOSEREQ = TCPF_FIN_WAIT1,
266         DCCPF_CLOSING         = TCPF_CLOSING,
267         DCCPF_TIME_WAIT       = TCPF_TIME_WAIT,
268         DCCPF_CLOSED          = TCPF_CLOSE,
269         DCCPF_PARTOPEN        = (1 << DCCP_PARTOPEN),
270 };
271
272 static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
273 {
274         return (struct dccp_hdr *)skb_transport_header(skb);
275 }
276
277 static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen)
278 {
279         skb_push(skb, headlen);
280         skb_reset_transport_header(skb);
281         return memset(skb_transport_header(skb), 0, headlen);
282 }
283
284 static inline struct dccp_hdr_ext *dccp_hdrx(const struct dccp_hdr *dh)
285 {
286         return (struct dccp_hdr_ext *)((unsigned char *)dh + sizeof(*dh));
287 }
288
289 static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
290 {
291         return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
292 }
293
294 static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
295 {
296         const struct dccp_hdr *dh = dccp_hdr(skb);
297         return __dccp_basic_hdr_len(dh);
298 }
299
300 static inline __u64 dccp_hdr_seq(const struct dccp_hdr *dh)
301 {
302         __u64 seq_nr =  ntohs(dh->dccph_seq);
303
304         if (dh->dccph_x != 0)
305                 seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(dh)->dccph_seq_low);
306         else
307                 seq_nr += (u32)dh->dccph_seq2 << 16;
308
309         return seq_nr;
310 }
311
312 static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb)
313 {
314         return (struct dccp_hdr_request *)(skb_transport_header(skb) +
315                                            dccp_basic_hdr_len(skb));
316 }
317
318 static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb)
319 {
320         return (struct dccp_hdr_ack_bits *)(skb_transport_header(skb) +
321                                             dccp_basic_hdr_len(skb));
322 }
323
324 static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb)
325 {
326         const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb);
327         return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + ntohl(dhack->dccph_ack_nr_low);
328 }
329
330 static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb)
331 {
332         return (struct dccp_hdr_response *)(skb_transport_header(skb) +
333                                             dccp_basic_hdr_len(skb));
334 }
335
336 static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb)
337 {
338         return (struct dccp_hdr_reset *)(skb_transport_header(skb) +
339                                          dccp_basic_hdr_len(skb));
340 }
341
342 static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
343 {
344         return __dccp_basic_hdr_len(dh) +
345                dccp_packet_hdr_len(dh->dccph_type);
346 }
347
348 static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
349 {
350         return __dccp_hdr_len(dccp_hdr(skb));
351 }
352
353
354 /* initial values for each feature */
355 #define DCCPF_INITIAL_SEQUENCE_WINDOW           100
356 #define DCCPF_INITIAL_ACK_RATIO                 2
357 #define DCCPF_INITIAL_CCID                      DCCPC_CCID2
358 #define DCCPF_INITIAL_SEND_ACK_VECTOR           1
359 /* FIXME: for now we're default to 1 but it should really be 0 */
360 #define DCCPF_INITIAL_SEND_NDP_COUNT            1
361
362 /**
363   * struct dccp_minisock - Minimal DCCP connection representation
364   *
365   * Will be used to pass the state from dccp_request_sock to dccp_sock.
366   *
367   * @dccpms_sequence_window - Sequence Window Feature (section 7.5.2)
368   * @dccpms_ccid - Congestion Control Id (CCID) (section 10)
369   * @dccpms_send_ack_vector - Send Ack Vector Feature (section 11.5)
370   * @dccpms_send_ndp_count - Send NDP Count Feature (7.7.2)
371   * @dccpms_pending - List of features being negotiated
372   * @dccpms_conf -
373   */
374 struct dccp_minisock {
375         __u64                   dccpms_sequence_window;
376         __u8                    dccpms_rx_ccid;
377         __u8                    dccpms_tx_ccid;
378         __u8                    dccpms_send_ack_vector;
379         __u8                    dccpms_send_ndp_count;
380         struct list_head        dccpms_pending;
381         struct list_head        dccpms_conf;
382 };
383
384 struct dccp_opt_conf {
385         __u8                    *dccpoc_val;
386         __u8                    dccpoc_len;
387 };
388
389 struct dccp_opt_pend {
390         struct list_head        dccpop_node;
391         __u8                    dccpop_type;
392         __u8                    dccpop_feat;
393         __u8                    *dccpop_val;
394         __u8                    dccpop_len;
395         int                     dccpop_conf;
396         struct dccp_opt_conf    *dccpop_sc;
397 };
398
399 extern void dccp_minisock_init(struct dccp_minisock *dmsk);
400
401 /**
402  * struct dccp_request_sock  -  represent DCCP-specific connection request
403  * @dreq_inet_rsk: structure inherited from
404  * @dreq_iss: initial sequence number sent on the Response (RFC 4340, 7.1)
405  * @dreq_isr: initial sequence number received on the Request
406  * @dreq_service: service code present on the Request (there is just one)
407  * @dreq_featneg: feature negotiation options for this connection
408  * The following two fields are analogous to the ones in dccp_sock:
409  * @dreq_timestamp_echo: last received timestamp to echo (13.1)
410  * @dreq_timestamp_echo: the time of receiving the last @dreq_timestamp_echo
411  */
412 struct dccp_request_sock {
413         struct inet_request_sock dreq_inet_rsk;
414         __u64                    dreq_iss;
415         __u64                    dreq_isr;
416         __be32                   dreq_service;
417         struct list_head         dreq_featneg;
418         __u32                    dreq_timestamp_echo;
419         __u32                    dreq_timestamp_time;
420 };
421
422 static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
423 {
424         return (struct dccp_request_sock *)req;
425 }
426
427 extern struct inet_timewait_death_row dccp_death_row;
428
429 extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
430                               struct sk_buff *skb);
431
432 struct dccp_options_received {
433         u64     dccpor_ndp:48;
434         u32     dccpor_timestamp;
435         u32     dccpor_timestamp_echo;
436         u32     dccpor_elapsed_time;
437 };
438
439 struct ccid;
440
441 enum dccp_role {
442         DCCP_ROLE_UNDEFINED,
443         DCCP_ROLE_LISTEN,
444         DCCP_ROLE_CLIENT,
445         DCCP_ROLE_SERVER,
446 };
447
448 struct dccp_service_list {
449         __u32   dccpsl_nr;
450         __be32  dccpsl_list[0];
451 };
452
453 #define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
454 #define DCCP_SERVICE_CODE_IS_ABSENT             0
455
456 static inline int dccp_list_has_service(const struct dccp_service_list *sl,
457                                         const __be32 service)
458 {
459         if (likely(sl != NULL)) {
460                 u32 i = sl->dccpsl_nr;
461                 while (i--)
462                         if (sl->dccpsl_list[i] == service)
463                                 return 1;
464         }
465         return 0;
466 }
467
468 struct dccp_ackvec;
469
470 /**
471  * struct dccp_sock - DCCP socket state
472  *
473  * @dccps_swl - sequence number window low
474  * @dccps_swh - sequence number window high
475  * @dccps_awl - acknowledgement number window low
476  * @dccps_awh - acknowledgement number window high
477  * @dccps_iss - initial sequence number sent
478  * @dccps_isr - initial sequence number received
479  * @dccps_osr - first OPEN sequence number received
480  * @dccps_gss - greatest sequence number sent
481  * @dccps_gsr - greatest valid sequence number received
482  * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
483  * @dccps_service - first (passive sock) or unique (active sock) service code
484  * @dccps_service_list - second .. last service code on passive socket
485  * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
486  * @dccps_timestamp_time - time of receiving latest @dccps_timestamp_echo
487  * @dccps_l_ack_ratio - feature-local Ack Ratio
488  * @dccps_r_ack_ratio - feature-remote Ack Ratio
489  * @dccps_pcslen - sender   partial checksum coverage (via sockopt)
490  * @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
491  * @dccps_ndp_count - number of Non Data Packets since last data packet
492  * @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
493  * @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
494  * @dccps_minisock - associated minisock (accessed via dccp_msk)
495  * @dccps_featneg - tracks feature-negotiation state (mostly during handshake)
496  * @dccps_hc_rx_ackvec - rx half connection ack vector
497  * @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
498  * @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
499  * @dccps_options_received - parsed set of retrieved options
500  * @dccps_role - role of this sock, one of %dccp_role
501  * @dccps_hc_rx_insert_options - receiver wants to add options when acking
502  * @dccps_hc_tx_insert_options - sender wants to add options when sending
503  * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3)
504  * @dccps_xmit_timer - timer for when CCID is not ready to send
505  * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs)
506  */
507 struct dccp_sock {
508         /* inet_connection_sock has to be the first member of dccp_sock */
509         struct inet_connection_sock     dccps_inet_connection;
510 #define dccps_syn_rtt                   dccps_inet_connection.icsk_ack.lrcvtime
511         __u64                           dccps_swl;
512         __u64                           dccps_swh;
513         __u64                           dccps_awl;
514         __u64                           dccps_awh;
515         __u64                           dccps_iss;
516         __u64                           dccps_isr;
517         __u64                           dccps_osr;
518         __u64                           dccps_gss;
519         __u64                           dccps_gsr;
520         __u64                           dccps_gar;
521         __be32                          dccps_service;
522         __u32                           dccps_mss_cache;
523         struct dccp_service_list        *dccps_service_list;
524         __u32                           dccps_timestamp_echo;
525         __u32                           dccps_timestamp_time;
526         __u16                           dccps_l_ack_ratio;
527         __u16                           dccps_r_ack_ratio;
528         __u8                            dccps_pcslen:4;
529         __u8                            dccps_pcrlen:4;
530         __u64                           dccps_ndp_count:48;
531         unsigned long                   dccps_rate_last;
532         struct dccp_minisock            dccps_minisock;
533         struct list_head                dccps_featneg;
534         struct dccp_ackvec              *dccps_hc_rx_ackvec;
535         struct ccid                     *dccps_hc_rx_ccid;
536         struct ccid                     *dccps_hc_tx_ccid;
537         struct dccp_options_received    dccps_options_received;
538         enum dccp_role                  dccps_role:2;
539         __u8                            dccps_hc_rx_insert_options:1;
540         __u8                            dccps_hc_tx_insert_options:1;
541         __u8                            dccps_server_timewait:1;
542         struct timer_list               dccps_xmit_timer;
543 };
544
545 static inline struct dccp_sock *dccp_sk(const struct sock *sk)
546 {
547         return (struct dccp_sock *)sk;
548 }
549
550 static inline struct dccp_minisock *dccp_msk(const struct sock *sk)
551 {
552         return (struct dccp_minisock *)&dccp_sk(sk)->dccps_minisock;
553 }
554
555 static inline const char *dccp_role(const struct sock *sk)
556 {
557         switch (dccp_sk(sk)->dccps_role) {
558         case DCCP_ROLE_UNDEFINED: return "undefined";
559         case DCCP_ROLE_LISTEN:    return "listen";
560         case DCCP_ROLE_SERVER:    return "server";
561         case DCCP_ROLE_CLIENT:    return "client";
562         }
563         return NULL;
564 }
565
566 #endif /* __KERNEL__ */
567
568 #endif /* _LINUX_DCCP_H */