LXR linux/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 */
  20struct 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 */
  54struct 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 */
  63struct 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 */
  72struct 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 */
  83struct 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 */
  95struct dccp_hdr_reset {
  96        struct dccp_hdr_ack_bits        dccph_reset_ack;
  97        __u8                            dccph_reset_code,
  98                                        dccph_reset_data[3];
  99};
 100
 101enum 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
 117static 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}
 134enum 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 */
 152enum {
 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/* maximum size of a single TLV-encoded DCCP option (sans type/len bytes) */
 172#define DCCP_SINGLE_OPT_MAXLEN  253
 173
 174/* DCCP CCIDS */
 175enum {
 176        DCCPC_CCID2 = 2,
 177        DCCPC_CCID3 = 3,
 178};
 179
 180/* DCCP features (RFC 4340 section 6.4) */
 181enum dccp_feature_numbers {
 182        DCCPF_RESERVED = 0,
 183        DCCPF_CCID = 1,
 184        DCCPF_SHORT_SEQNOS = 2,
 185        DCCPF_SEQUENCE_WINDOW = 3,
 186        DCCPF_ECN_INCAPABLE = 4,
 187        DCCPF_ACK_RATIO = 5,
 188        DCCPF_SEND_ACK_VECTOR = 6,
 189        DCCPF_SEND_NDP_COUNT = 7,
 190        DCCPF_MIN_CSUM_COVER = 8,
 191        DCCPF_DATA_CHECKSUM = 9,
 192        /* 10-127 reserved */
 193        DCCPF_MIN_CCID_SPECIFIC = 128,
 194        DCCPF_SEND_LEV_RATE = 192,      /* RFC 4342, sec. 8.4 */
 195        DCCPF_MAX_CCID_SPECIFIC = 255,
 196};
 197
 198/* DCCP socket options */
 199#define DCCP_SOCKOPT_PACKET_SIZE        1 /* XXX deprecated, without effect */
 200#define DCCP_SOCKOPT_SERVICE            2
 201#define DCCP_SOCKOPT_CHANGE_L           3
 202#define DCCP_SOCKOPT_CHANGE_R           4
 203#define DCCP_SOCKOPT_GET_CUR_MPS        5
 204#define DCCP_SOCKOPT_SERVER_TIMEWAIT    6
 205#define DCCP_SOCKOPT_SEND_CSCOV         10
 206#define DCCP_SOCKOPT_RECV_CSCOV         11
 207#define DCCP_SOCKOPT_AVAILABLE_CCIDS    12
 208#define DCCP_SOCKOPT_CCID               13
 209#define DCCP_SOCKOPT_TX_CCID            14
 210#define DCCP_SOCKOPT_RX_CCID            15
 211#define DCCP_SOCKOPT_CCID_RX_INFO       128
 212#define DCCP_SOCKOPT_CCID_TX_INFO       192
 213
 214/* maximum number of services provided on the same listening port */
 215#define DCCP_SERVICE_LIST_MAX_LEN      32
 216
 217#ifdef __KERNEL__
 218
 219#include <linux/in.h>
 220#include <linux/ktime.h>
 221#include <linux/list.h>
 222#include <linux/uio.h>
 223#include <linux/workqueue.h>
 224
 225#include <net/inet_connection_sock.h>
 226#include <net/inet_sock.h>
 227#include <net/inet_timewait_sock.h>
 228#include <net/tcp_states.h>
 229
 230enum dccp_state {
 231        DCCP_OPEN            = TCP_ESTABLISHED,
 232        DCCP_REQUESTING      = TCP_SYN_SENT,
 233        DCCP_LISTEN          = TCP_LISTEN,
 234        DCCP_RESPOND         = TCP_SYN_RECV,
 235        /*
 236         * States involved in closing a DCCP connection:
 237         * 1) ACTIVE_CLOSEREQ is entered by a server sending a CloseReq.
 238         *
 239         * 2) CLOSING can have three different meanings (RFC 4340, 8.3):
 240         *  a. Client has performed active-close, has sent a Close to the server
 241         *     from state OPEN or PARTOPEN, and is waiting for the final Reset
 242         *     (in this case, SOCK_DONE == 1).
 243         *  b. Client is asked to perform passive-close, by receiving a CloseReq
 244         *     in (PART)OPEN state. It sends a Close and waits for final Reset
 245         *     (in this case, SOCK_DONE == 0).
 246         *  c. Server performs an active-close as in (a), keeps TIMEWAIT state.
 247         *
 248         * 3) The following intermediate states are employed to give passively
 249         *    closing nodes a chance to process their unread data:
 250         *    - PASSIVE_CLOSE    (from OPEN => CLOSED) and
 251         *    - PASSIVE_CLOSEREQ (from (PART)OPEN to CLOSING; case (b) above).
 252         */
 253        DCCP_ACTIVE_CLOSEREQ = TCP_FIN_WAIT1,
 254        DCCP_PASSIVE_CLOSE   = TCP_CLOSE_WAIT,  /* any node receiving a Close */
 255        DCCP_CLOSING         = TCP_CLOSING,
 256        DCCP_TIME_WAIT       = TCP_TIME_WAIT,
 257        DCCP_CLOSED          = TCP_CLOSE,
 258        DCCP_PARTOPEN        = TCP_MAX_STATES,
 259        DCCP_PASSIVE_CLOSEREQ,                  /* clients receiving CloseReq */
 260        DCCP_MAX_STATES
 261};
 262
 263#define DCCP_STATE_MASK 0x1f
 264
 265enum {
 266        DCCPF_OPEN            = TCPF_ESTABLISHED,
 267        DCCPF_REQUESTING      = TCPF_SYN_SENT,
 268        DCCPF_LISTEN          = TCPF_LISTEN,
 269        DCCPF_RESPOND         = TCPF_SYN_RECV,
 270        DCCPF_ACTIVE_CLOSEREQ = TCPF_FIN_WAIT1,
 271        DCCPF_CLOSING         = TCPF_CLOSING,
 272        DCCPF_TIME_WAIT       = TCPF_TIME_WAIT,
 273        DCCPF_CLOSED          = TCPF_CLOSE,
 274        DCCPF_PARTOPEN        = (1 << DCCP_PARTOPEN),
 275};
 276
 277static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
 278{
 279        return (struct dccp_hdr *)skb_transport_header(skb);
 280}
 281
 282static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen)
 283{
 284        skb_push(skb, headlen);
 285        skb_reset_transport_header(skb);
 286        return memset(skb_transport_header(skb), 0, headlen);
 287}
 288
 289static inline struct dccp_hdr_ext *dccp_hdrx(const struct dccp_hdr *dh)
 290{
 291        return (struct dccp_hdr_ext *)((unsigned char *)dh + sizeof(*dh));
 292}
 293
 294static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
 295{
 296        return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
 297}
 298
 299static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
 300{
 301        const struct dccp_hdr *dh = dccp_hdr(skb);
 302        return __dccp_basic_hdr_len(dh);
 303}
 304
 305static inline __u64 dccp_hdr_seq(const struct dccp_hdr *dh)
 306{
 307        __u64 seq_nr =  ntohs(dh->dccph_seq);
 308
 309        if (dh->dccph_x != 0)
 310                seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(dh)->dccph_seq_low);
 311        else
 312                seq_nr += (u32)dh->dccph_seq2 << 16;
 313
 314        return seq_nr;
 315}
 316
 317static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb)
 318{
 319        return (struct dccp_hdr_request *)(skb_transport_header(skb) +
 320                                           dccp_basic_hdr_len(skb));
 321}
 322
 323static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb)
 324{
 325        return (struct dccp_hdr_ack_bits *)(skb_transport_header(skb) +
 326                                            dccp_basic_hdr_len(skb));
 327}
 328
 329static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb)
 330{
 331        const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb);
 332        return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + ntohl(dhack->dccph_ack_nr_low);
 333}
 334
 335static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb)
 336{
 337        return (struct dccp_hdr_response *)(skb_transport_header(skb) +
 338                                            dccp_basic_hdr_len(skb));
 339}
 340
 341static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb)
 342{
 343        return (struct dccp_hdr_reset *)(skb_transport_header(skb) +
 344                                         dccp_basic_hdr_len(skb));
 345}
 346
 347static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
 348{
 349        return __dccp_basic_hdr_len(dh) +
 350               dccp_packet_hdr_len(dh->dccph_type);
 351}
 352
 353static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
 354{
 355        return __dccp_hdr_len(dccp_hdr(skb));
 356}
 357
 358/**
 359 * struct dccp_request_sock  -  represent DCCP-specific connection request
 360 * @dreq_inet_rsk: structure inherited from
 361 * @dreq_iss: initial sequence number sent on the Response (RFC 4340, 7.1)
 362 * @dreq_isr: initial sequence number received on the Request
 363 * @dreq_service: service code present on the Request (there is just one)
 364 * @dreq_featneg: feature negotiation options for this connection
 365 * The following two fields are analogous to the ones in dccp_sock:
 366 * @dreq_timestamp_echo: last received timestamp to echo (13.1)
 367 * @dreq_timestamp_echo: the time of receiving the last @dreq_timestamp_echo
 368 */
 369struct dccp_request_sock {
 370        struct inet_request_sock dreq_inet_rsk;
 371        __u64                    dreq_iss;
 372        __u64                    dreq_isr;
 373        __be32                   dreq_service;
 374        struct list_head         dreq_featneg;
 375        __u32                    dreq_timestamp_echo;
 376        __u32                    dreq_timestamp_time;
 377};
 378
 379static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
 380{
 381        return (struct dccp_request_sock *)req;
 382}
 383
 384extern struct inet_timewait_death_row dccp_death_row;
 385
 386extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
 387                              struct sk_buff *skb);
 388
 389struct dccp_options_received {
 390        u64     dccpor_ndp:48;
 391        u32     dccpor_timestamp;
 392        u32     dccpor_timestamp_echo;
 393        u32     dccpor_elapsed_time;
 394};
 395
 396struct ccid;
 397
 398enum dccp_role {
 399        DCCP_ROLE_UNDEFINED,
 400        DCCP_ROLE_LISTEN,
 401        DCCP_ROLE_CLIENT,
 402        DCCP_ROLE_SERVER,
 403};
 404
 405struct dccp_service_list {
 406        __u32   dccpsl_nr;
 407        __be32  dccpsl_list[0];
 408};
 409
 410#define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
 411#define DCCP_SERVICE_CODE_IS_ABSENT             0
 412
 413static inline int dccp_list_has_service(const struct dccp_service_list *sl,
 414                                        const __be32 service)
 415{
 416        if (likely(sl != NULL)) {
 417                u32 i = sl->dccpsl_nr;
 418                while (i--)
 419                        if (sl->dccpsl_list[i] == service)
 420                                return 1;
 421        }
 422        return 0;
 423}
 424
 425struct dccp_ackvec;
 426
 427/**
 428 * struct dccp_sock - DCCP socket state
 429 *
 430 * @dccps_swl - sequence number window low
 431 * @dccps_swh - sequence number window high
 432 * @dccps_awl - acknowledgement number window low
 433 * @dccps_awh - acknowledgement number window high
 434 * @dccps_iss - initial sequence number sent
 435 * @dccps_isr - initial sequence number received
 436 * @dccps_osr - first OPEN sequence number received
 437 * @dccps_gss - greatest sequence number sent
 438 * @dccps_gsr - greatest valid sequence number received
 439 * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
 440 * @dccps_service - first (passive sock) or unique (active sock) service code
 441 * @dccps_service_list - second .. last service code on passive socket
 442 * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
 443 * @dccps_timestamp_time - time of receiving latest @dccps_timestamp_echo
 444 * @dccps_l_ack_ratio - feature-local Ack Ratio
 445 * @dccps_r_ack_ratio - feature-remote Ack Ratio
 446 * @dccps_l_seq_win - local Sequence Window (influences ack number validity)
 447 * @dccps_r_seq_win - remote Sequence Window (influences seq number validity)
 448 * @dccps_pcslen - sender   partial checksum coverage (via sockopt)
 449 * @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
 450 * @dccps_send_ndp_count - local Send NDP Count feature (7.7.2)
 451 * @dccps_ndp_count - number of Non Data Packets since last data packet
 452 * @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
 453 * @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
 454 * @dccps_featneg - tracks feature-negotiation state (mostly during handshake)
 455 * @dccps_hc_rx_ackvec - rx half connection ack vector
 456 * @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
 457 * @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
 458 * @dccps_options_received - parsed set of retrieved options
 459 * @dccps_role - role of this sock, one of %dccp_role
 460 * @dccps_hc_rx_insert_options - receiver wants to add options when acking
 461 * @dccps_hc_tx_insert_options - sender wants to add options when sending
 462 * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3)
 463 * @dccps_xmit_timer - timer for when CCID is not ready to send
 464 * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs)
 465 */
 466struct dccp_sock {
 467        /* inet_connection_sock has to be the first member of dccp_sock */
 468        struct inet_connection_sock     dccps_inet_connection;
 469#define dccps_syn_rtt                   dccps_inet_connection.icsk_ack.lrcvtime
 470        __u64                           dccps_swl;
 471        __u64                           dccps_swh;
 472        __u64                           dccps_awl;
 473        __u64                           dccps_awh;
 474        __u64                           dccps_iss;
 475        __u64                           dccps_isr;
 476        __u64                           dccps_osr;
 477        __u64                           dccps_gss;
 478        __u64                           dccps_gsr;
 479        __u64                           dccps_gar;
 480        __be32                          dccps_service;
 481        __u32                           dccps_mss_cache;
 482        struct dccp_service_list        *dccps_service_list;
 483        __u32                           dccps_timestamp_echo;
 484        __u32                           dccps_timestamp_time;
 485        __u16                           dccps_l_ack_ratio;
 486        __u16                           dccps_r_ack_ratio;
 487        __u64                           dccps_l_seq_win:48;
 488        __u64                           dccps_r_seq_win:48;
 489        __u8                            dccps_pcslen:4;
 490        __u8                            dccps_pcrlen:4;
 491        __u8                            dccps_send_ndp_count:1;
 492        __u64                           dccps_ndp_count:48;
 493        unsigned long                   dccps_rate_last;
 494        struct list_head                dccps_featneg;
 495        struct dccp_ackvec              *dccps_hc_rx_ackvec;
 496        struct ccid                     *dccps_hc_rx_ccid;
 497        struct ccid                     *dccps_hc_tx_ccid;
 498        struct dccp_options_received    dccps_options_received;
 499        enum dccp_role                  dccps_role:2;
 500        __u8                            dccps_hc_rx_insert_options:1;
 501        __u8                            dccps_hc_tx_insert_options:1;
 502        __u8                            dccps_server_timewait:1;
 503        struct timer_list               dccps_xmit_timer;
 504};
 505
 506static inline struct dccp_sock *dccp_sk(const struct sock *sk)
 507{
 508        return (struct dccp_sock *)sk;
 509}
 510
 511static inline const char *dccp_role(const struct sock *sk)
 512{
 513        switch (dccp_sk(sk)->dccps_role) {
 514        case DCCP_ROLE_UNDEFINED: return "undefined";
 515        case DCCP_ROLE_LISTEN:    return "listen";
 516        case DCCP_ROLE_SERVER:    return "server";
 517        case DCCP_ROLE_CLIENT:    return "client";
 518        }
 519        return NULL;
 520}
 521
 522#endif /* __KERNEL__ */
 523
 524#endif /* _LINUX_DCCP_H */
 525