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_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 options */
 201 #define DCCP_SOCKOPT_PACKET_SIZE        1 /* XXX deprecated, without effect */
 202 #define DCCP_SOCKOPT_SERVICE            2
 203 #define DCCP_SOCKOPT_CHANGE_L           3
 204 #define DCCP_SOCKOPT_CHANGE_R           4
 205 #define DCCP_SOCKOPT_GET_CUR_MPS        5
 206 #define DCCP_SOCKOPT_SERVER_TIMEWAIT    6
 207 #define DCCP_SOCKOPT_SEND_CSCOV         10
 208 #define DCCP_SOCKOPT_RECV_CSCOV         11
 209 #define DCCP_SOCKOPT_AVAILABLE_CCIDS    12
 210 #define DCCP_SOCKOPT_CCID               13
 211 #define DCCP_SOCKOPT_TX_CCID            14
 212 #define DCCP_SOCKOPT_RX_CCID            15
 213 #define DCCP_SOCKOPT_CCID_RX_INFO       128
 214 #define DCCP_SOCKOPT_CCID_TX_INFO       192
 215
 216 /* maximum number of services provided on the same listening port */
 217 #define DCCP_SERVICE_LIST_MAX_LEN      32
 218
 219 #ifdef __KERNEL__
 220
 221 #include <linux/in.h>
 222 #include <linux/ktime.h>
 223 #include <linux/list.h>
 224 #include <linux/uio.h>
 225 #include <linux/workqueue.h>
 226
 227 #include <net/inet_connection_sock.h>
 228 #include <net/inet_sock.h>
 229 #include <net/inet_timewait_sock.h>
 230 #include <net/tcp_states.h>
 231
 232 enum dccp_state {
 233         DCCP_OPEN            = TCP_ESTABLISHED,
 234         DCCP_REQUESTING      = TCP_SYN_SENT,
 235         DCCP_LISTEN          = TCP_LISTEN,
 236         DCCP_RESPOND         = TCP_SYN_RECV,
 237         /*
 238          * States involved in closing a DCCP connection:
 239          * 1) ACTIVE_CLOSEREQ is entered by a server sending a CloseReq.
 240          *
 241          * 2) CLOSING can have three different meanings (RFC 4340, 8.3):
 242          *  a. Client has performed active-close, has sent a Close to the server
 243          *     from state OPEN or PARTOPEN, and is waiting for the final Reset
 244          *     (in this case, SOCK_DONE == 1).
 245          *  b. Client is asked to perform passive-close, by receiving a CloseReq
 246          *     in (PART)OPEN state. It sends a Close and waits for final Reset
 247          *     (in this case, SOCK_DONE == 0).
 248          *  c. Server performs an active-close as in (a), keeps TIMEWAIT state.
 249          *
 250          * 3) The following intermediate states are employed to give passively
 251          *    closing nodes a chance to process their unread data:
 252          *    - PASSIVE_CLOSE    (from OPEN => CLOSED) and
 253          *    - PASSIVE_CLOSEREQ (from (PART)OPEN to CLOSING; case (b) above).
 254          */
 255         DCCP_ACTIVE_CLOSEREQ = TCP_FIN_WAIT1,
 256         DCCP_PASSIVE_CLOSE   = TCP_CLOSE_WAIT,  /* any node receiving a Close */
 257         DCCP_CLOSING         = TCP_CLOSING,
 258         DCCP_TIME_WAIT       = TCP_TIME_WAIT,
 259         DCCP_CLOSED          = TCP_CLOSE,
 260         DCCP_PARTOPEN        = TCP_MAX_STATES,
 261         DCCP_PASSIVE_CLOSEREQ,                  /* clients receiving CloseReq */
 262         DCCP_MAX_STATES
 263 };
 264
 265 #define DCCP_STATE_MASK 0x1f
 266
 267 enum {
 268         DCCPF_OPEN            = TCPF_ESTABLISHED,
 269         DCCPF_REQUESTING      = TCPF_SYN_SENT,
 270         DCCPF_LISTEN          = TCPF_LISTEN,
 271         DCCPF_RESPOND         = TCPF_SYN_RECV,
 272         DCCPF_ACTIVE_CLOSEREQ = TCPF_FIN_WAIT1,
 273         DCCPF_CLOSING         = TCPF_CLOSING,
 274         DCCPF_TIME_WAIT       = TCPF_TIME_WAIT,
 275         DCCPF_CLOSED          = TCPF_CLOSE,
 276         DCCPF_PARTOPEN        = (1 << DCCP_PARTOPEN),
 277 };
 278
 279 static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
 280 {
 281         return (struct dccp_hdr *)skb_transport_header(skb);
 282 }
 283
 284 static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen)
 285 {
 286         skb_push(skb, headlen);
 287         skb_reset_transport_header(skb);
 288         return memset(skb_transport_header(skb), 0, headlen);
 289 }
 290
 291 static inline struct dccp_hdr_ext *dccp_hdrx(const struct dccp_hdr *dh)
 292 {
 293         return (struct dccp_hdr_ext *)((unsigned char *)dh + sizeof(*dh));
 294 }
 295
 296 static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
 297 {
 298         return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
 299 }
 300
 301 static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
 302 {
 303         const struct dccp_hdr *dh = dccp_hdr(skb);
 304         return __dccp_basic_hdr_len(dh);
 305 }
 306
 307 static inline __u64 dccp_hdr_seq(const struct dccp_hdr *dh)
 308 {
 309         __u64 seq_nr =  ntohs(dh->dccph_seq);
 310
 311         if (dh->dccph_x != 0)
 312                 seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(dh)->dccph_seq_low);
 313         else
 314                 seq_nr += (u32)dh->dccph_seq2 << 16;
 315
 316         return seq_nr;
 317 }
 318
 319 static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb)
 320 {
 321         return (struct dccp_hdr_request *)(skb_transport_header(skb) +
 322                                            dccp_basic_hdr_len(skb));
 323 }
 324
 325 static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb)
 326 {
 327         return (struct dccp_hdr_ack_bits *)(skb_transport_header(skb) +
 328                                             dccp_basic_hdr_len(skb));
 329 }
 330
 331 static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb)
 332 {
 333         const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb);
 334         return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + ntohl(dhack->dccph_ack_nr_low);
 335 }
 336
 337 static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb)
 338 {
 339         return (struct dccp_hdr_response *)(skb_transport_header(skb) +
 340                                             dccp_basic_hdr_len(skb));
 341 }
 342
 343 static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb)
 344 {
 345         return (struct dccp_hdr_reset *)(skb_transport_header(skb) +
 346                                          dccp_basic_hdr_len(skb));
 347 }
 348
 349 static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
 350 {
 351         return __dccp_basic_hdr_len(dh) +
 352                dccp_packet_hdr_len(dh->dccph_type);
 353 }
 354
 355 static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
 356 {
 357         return __dccp_hdr_len(dccp_hdr(skb));
 358 }
 359
 360 /**
 361  * struct dccp_request_sock  -  represent DCCP-specific connection request
 362  * @dreq_inet_rsk: structure inherited from
 363  * @dreq_iss: initial sequence number sent on the Response (RFC 4340, 7.1)
 364  * @dreq_isr: initial sequence number received on the Request
 365  * @dreq_service: service code present on the Request (there is just one)
 366  * @dreq_featneg: feature negotiation options for this connection
 367  * The following two fields are analogous to the ones in dccp_sock:
 368  * @dreq_timestamp_echo: last received timestamp to echo (13.1)
 369  * @dreq_timestamp_echo: the time of receiving the last @dreq_timestamp_echo
 370  */
 371 struct dccp_request_sock {
 372         struct inet_request_sock dreq_inet_rsk;
 373         __u64                    dreq_iss;
 374         __u64                    dreq_isr;
 375         __be32                   dreq_service;
 376         struct list_head         dreq_featneg;
 377         __u32                    dreq_timestamp_echo;
 378         __u32                    dreq_timestamp_time;
 379 };
 380
 381 static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
 382 {
 383         return (struct dccp_request_sock *)req;
 384 }
 385
 386 extern struct inet_timewait_death_row dccp_death_row;
 387
 388 extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
 389                               struct sk_buff *skb);
 390
 391 struct dccp_options_received {
 392         u64     dccpor_ndp:48;
 393         u32     dccpor_timestamp;
 394         u32     dccpor_timestamp_echo;
 395         u32     dccpor_elapsed_time;
 396 };
 397
 398 struct ccid;
 399
 400 enum dccp_role {
 401         DCCP_ROLE_UNDEFINED,
 402         DCCP_ROLE_LISTEN,
 403         DCCP_ROLE_CLIENT,
 404         DCCP_ROLE_SERVER,
 405 };
 406
 407 struct dccp_service_list {
 408         __u32   dccpsl_nr;
 409         __be32  dccpsl_list[0];
 410 };
 411
 412 #define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
 413 #define DCCP_SERVICE_CODE_IS_ABSENT             0
 414
 415 static inline int dccp_list_has_service(const struct dccp_service_list *sl,
 416                                         const __be32 service)
 417 {
 418         if (likely(sl != NULL)) {
 419                 u32 i = sl->dccpsl_nr;
 420                 while (i--)
 421                         if (sl->dccpsl_list[i] == service)
 422                                 return 1;
 423         }
 424         return 0;
 425 }
 426
 427 struct dccp_ackvec;
 428
 429 /**
 430  * struct dccp_sock - DCCP socket state
 431  *
 432  * @dccps_swl - sequence number window low
 433  * @dccps_swh - sequence number window high
 434  * @dccps_awl - acknowledgement number window low
 435  * @dccps_awh - acknowledgement number window high
 436  * @dccps_iss - initial sequence number sent
 437  * @dccps_isr - initial sequence number received
 438  * @dccps_osr - first OPEN sequence number received
 439  * @dccps_gss - greatest sequence number sent
 440  * @dccps_gsr - greatest valid sequence number received
 441  * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
 442  * @dccps_service - first (passive sock) or unique (active sock) service code
 443  * @dccps_service_list - second .. last service code on passive socket
 444  * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
 445  * @dccps_timestamp_time - time of receiving latest @dccps_timestamp_echo
 446  * @dccps_l_ack_ratio - feature-local Ack Ratio
 447  * @dccps_r_ack_ratio - feature-remote Ack Ratio
 448  * @dccps_l_seq_win - local Sequence Window (influences ack number validity)
 449  * @dccps_r_seq_win - remote Sequence Window (influences seq number validity)
 450  * @dccps_pcslen - sender   partial checksum coverage (via sockopt)
 451  * @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
 452  * @dccps_send_ndp_count - local Send NDP Count feature (7.7.2)
 453  * @dccps_ndp_count - number of Non Data Packets since last data packet
 454  * @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
 455  * @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
 456  * @dccps_featneg - tracks feature-negotiation state (mostly during handshake)
 457  * @dccps_hc_rx_ackvec - rx half connection ack vector
 458  * @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
 459  * @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
 460  * @dccps_options_received - parsed set of retrieved options
 461  * @dccps_role - role of this sock, one of %dccp_role
 462  * @dccps_hc_rx_insert_options - receiver wants to add options when acking
 463  * @dccps_hc_tx_insert_options - sender wants to add options when sending
 464  * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3)
 465  * @dccps_sync_scheduled - flag which signals "send out-of-band message soon"
 466  * @dccps_xmit_timer - timer for when CCID is not ready to send
 467  * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs)
 468  */
 469 struct dccp_sock {
 470         /* inet_connection_sock has to be the first member of dccp_sock */
 471         struct inet_connection_sock     dccps_inet_connection;
 472 #define dccps_syn_rtt                   dccps_inet_connection.icsk_ack.lrcvtime
 473         __u64                           dccps_swl;
 474         __u64                           dccps_swh;
 475         __u64                           dccps_awl;
 476         __u64                           dccps_awh;
 477         __u64                           dccps_iss;
 478         __u64                           dccps_isr;
 479         __u64                           dccps_osr;
 480         __u64                           dccps_gss;
 481         __u64                           dccps_gsr;
 482         __u64                           dccps_gar;
 483         __be32                          dccps_service;
 484         __u32                           dccps_mss_cache;
 485         struct dccp_service_list        *dccps_service_list;
 486         __u32                           dccps_timestamp_echo;
 487         __u32                           dccps_timestamp_time;
 488         __u16                           dccps_l_ack_ratio;
 489         __u16                           dccps_r_ack_ratio;
 490         __u64                           dccps_l_seq_win:48;
 491         __u64                           dccps_r_seq_win:48;
 492         __u8                            dccps_pcslen:4;
 493         __u8                            dccps_pcrlen:4;
 494         __u8                            dccps_send_ndp_count:1;
 495         __u64                           dccps_ndp_count:48;
 496         unsigned long                   dccps_rate_last;
 497         struct list_head                dccps_featneg;
 498         struct dccp_ackvec              *dccps_hc_rx_ackvec;
 499         struct ccid                     *dccps_hc_rx_ccid;
 500         struct ccid                     *dccps_hc_tx_ccid;
 501         struct dccp_options_received    dccps_options_received;
 502         enum dccp_role                  dccps_role:2;
 503         __u8                            dccps_hc_rx_insert_options:1;
 504         __u8                            dccps_hc_tx_insert_options:1;
 505         __u8                            dccps_server_timewait:1;
 506         __u8                            dccps_sync_scheduled:1;
 507         struct timer_list               dccps_xmit_timer;
 508 };
 509
 510 static inline struct dccp_sock *dccp_sk(const struct sock *sk)
 511 {
 512         return (struct dccp_sock *)sk;
 513 }
 514
 515 static inline const char *dccp_role(const struct sock *sk)
 516 {
 517         switch (dccp_sk(sk)->dccps_role) {
 518         case DCCP_ROLE_UNDEFINED: return "undefined";
 519         case DCCP_ROLE_LISTEN:    return "listen";
 520         case DCCP_ROLE_SERVER:    return "server";
 521         case DCCP_ROLE_CLIENT:    return "client";
 522         }
 523         return NULL;
 524 }
 525
 526 #endif /* __KERNEL__ */
 527
 528 #endif /* _LINUX_DCCP_H */