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 {
 180         DCCPF_RESERVED = 0,
 181         DCCPF_CCID = 1,
 182         DCCPF_SHORT_SEQNOS = 2,         /* XXX: not yet implemented */
 183         DCCPF_SEQUENCE_WINDOW = 3,
 184         DCCPF_ECN_INCAPABLE = 4,        /* XXX: not yet implemented */
 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,        /* XXX: not yet implemented */
 190         /* 10-127 reserved */
 191         DCCPF_MIN_CCID_SPECIFIC = 128,
 192         DCCPF_MAX_CCID_SPECIFIC = 255,
 193 };
 194
 195 /* this structure is argument to DCCP_SOCKOPT_CHANGE_X */
 196 struct dccp_so_feat {
 197         __u8 dccpsf_feat;
 198         __u8 __user *dccpsf_val;
 199         __u8 dccpsf_len;
 200 };
 201
 202 /* DCCP socket options */
 203 #define DCCP_SOCKOPT_PACKET_SIZE        1 /* XXX deprecated, without effect */
 204 #define DCCP_SOCKOPT_SERVICE            2
 205 #define DCCP_SOCKOPT_CHANGE_L           3
 206 #define DCCP_SOCKOPT_CHANGE_R           4
 207 #define DCCP_SOCKOPT_GET_CUR_MPS        5
 208 #define DCCP_SOCKOPT_SEND_CSCOV         10
 209 #define DCCP_SOCKOPT_RECV_CSCOV         11
 210 #define DCCP_SOCKOPT_CCID_RX_INFO       128
 211 #define DCCP_SOCKOPT_CCID_TX_INFO       192
 212
 213 /* maximum number of services provided on the same listening port */
 214 #define DCCP_SERVICE_LIST_MAX_LEN      32
 215
 216 #ifdef __KERNEL__
 217
 218 #include <linux/in.h>
 219 #include <linux/ktime.h>
 220 #include <linux/list.h>
 221 #include <linux/uio.h>
 222 #include <linux/workqueue.h>
 223
 224 #include <net/inet_connection_sock.h>
 225 #include <net/inet_sock.h>
 226 #include <net/inet_timewait_sock.h>
 227 #include <net/tcp_states.h>
 228
 229 enum dccp_state {
 230         DCCP_OPEN       = TCP_ESTABLISHED,
 231         DCCP_REQUESTING = TCP_SYN_SENT,
 232         DCCP_PARTOPEN   = TCP_FIN_WAIT1, /* FIXME:
 233                                             This mapping is horrible, but TCP has
 234                                             no matching state for DCCP_PARTOPEN,
 235                                             as TCP_SYN_RECV is already used by
 236                                             DCCP_RESPOND, why don't stop using TCP
 237                                             mapping of states? OK, now we don't use
 238                                             sk_stream_sendmsg anymore, so doesn't
 239                                             seem to exist any reason for us to
 240                                             do the TCP mapping here */
 241         DCCP_LISTEN     = TCP_LISTEN,
 242         DCCP_RESPOND    = TCP_SYN_RECV,
 243         DCCP_CLOSING    = TCP_CLOSING,
 244         DCCP_TIME_WAIT  = TCP_TIME_WAIT,
 245         DCCP_CLOSED     = TCP_CLOSE,
 246         DCCP_MAX_STATES = TCP_MAX_STATES,
 247 };
 248
 249 #define DCCP_STATE_MASK 0xf
 250 #define DCCP_ACTION_FIN (1<<7)
 251
 252 enum {
 253         DCCPF_OPEN       = TCPF_ESTABLISHED,
 254         DCCPF_REQUESTING = TCPF_SYN_SENT,
 255         DCCPF_PARTOPEN   = TCPF_FIN_WAIT1,
 256         DCCPF_LISTEN     = TCPF_LISTEN,
 257         DCCPF_RESPOND    = TCPF_SYN_RECV,
 258         DCCPF_CLOSING    = TCPF_CLOSING,
 259         DCCPF_TIME_WAIT  = TCPF_TIME_WAIT,
 260         DCCPF_CLOSED     = TCPF_CLOSE,
 261 };
 262
 263 static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
 264 {
 265         return (struct dccp_hdr *)skb_transport_header(skb);
 266 }
 267
 268 static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen)
 269 {
 270         skb_push(skb, headlen);
 271         skb_reset_transport_header(skb);
 272         return memset(skb_transport_header(skb), 0, headlen);
 273 }
 274
 275 static inline struct dccp_hdr_ext *dccp_hdrx(const struct dccp_hdr *dh)
 276 {
 277         return (struct dccp_hdr_ext *)((unsigned char *)dh + sizeof(*dh));
 278 }
 279
 280 static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
 281 {
 282         return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
 283 }
 284
 285 static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
 286 {
 287         const struct dccp_hdr *dh = dccp_hdr(skb);
 288         return __dccp_basic_hdr_len(dh);
 289 }
 290
 291 static inline __u64 dccp_hdr_seq(const struct dccp_hdr *dh)
 292 {
 293         __u64 seq_nr =  ntohs(dh->dccph_seq);
 294
 295         if (dh->dccph_x != 0)
 296                 seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(dh)->dccph_seq_low);
 297         else
 298                 seq_nr += (u32)dh->dccph_seq2 << 16;
 299
 300         return seq_nr;
 301 }
 302
 303 static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb)
 304 {
 305         return (struct dccp_hdr_request *)(skb_transport_header(skb) +
 306                                            dccp_basic_hdr_len(skb));
 307 }
 308
 309 static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb)
 310 {
 311         return (struct dccp_hdr_ack_bits *)(skb_transport_header(skb) +
 312                                             dccp_basic_hdr_len(skb));
 313 }
 314
 315 static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb)
 316 {
 317         const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb);
 318         return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + ntohl(dhack->dccph_ack_nr_low);
 319 }
 320
 321 static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb)
 322 {
 323         return (struct dccp_hdr_response *)(skb_transport_header(skb) +
 324                                             dccp_basic_hdr_len(skb));
 325 }
 326
 327 static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb)
 328 {
 329         return (struct dccp_hdr_reset *)(skb_transport_header(skb) +
 330                                          dccp_basic_hdr_len(skb));
 331 }
 332
 333 static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
 334 {
 335         return __dccp_basic_hdr_len(dh) +
 336                dccp_packet_hdr_len(dh->dccph_type);
 337 }
 338
 339 static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
 340 {
 341         return __dccp_hdr_len(dccp_hdr(skb));
 342 }
 343
 344
 345 /* initial values for each feature */
 346 #define DCCPF_INITIAL_SEQUENCE_WINDOW           100
 347 #define DCCPF_INITIAL_ACK_RATIO                 2
 348 #define DCCPF_INITIAL_CCID                      DCCPC_CCID2
 349 #define DCCPF_INITIAL_SEND_ACK_VECTOR           1
 350 /* FIXME: for now we're default to 1 but it should really be 0 */
 351 #define DCCPF_INITIAL_SEND_NDP_COUNT            1
 352
 353 #define DCCP_NDP_LIMIT 0xFFFFFF
 354
 355 /**
 356   * struct dccp_minisock - Minimal DCCP connection representation
 357   *
 358   * Will be used to pass the state from dccp_request_sock to dccp_sock.
 359   *
 360   * @dccpms_sequence_window - Sequence Window Feature (section 7.5.2)
 361   * @dccpms_ccid - Congestion Control Id (CCID) (section 10)
 362   * @dccpms_send_ack_vector - Send Ack Vector Feature (section 11.5)
 363   * @dccpms_send_ndp_count - Send NDP Count Feature (7.7.2)
 364   * @dccpms_ack_ratio - Ack Ratio Feature (section 11.3)
 365   * @dccpms_pending - List of features being negotiated
 366   * @dccpms_conf -
 367   */
 368 struct dccp_minisock {
 369         __u64                   dccpms_sequence_window;
 370         __u8                    dccpms_rx_ccid;
 371         __u8                    dccpms_tx_ccid;
 372         __u8                    dccpms_send_ack_vector;
 373         __u8                    dccpms_send_ndp_count;
 374         __u8                    dccpms_ack_ratio;
 375         struct list_head        dccpms_pending;
 376         struct list_head        dccpms_conf;
 377 };
 378
 379 struct dccp_opt_conf {
 380         __u8                    *dccpoc_val;
 381         __u8                    dccpoc_len;
 382 };
 383
 384 struct dccp_opt_pend {
 385         struct list_head        dccpop_node;
 386         __u8                    dccpop_type;
 387         __u8                    dccpop_feat;
 388         __u8                    *dccpop_val;
 389         __u8                    dccpop_len;
 390         int                     dccpop_conf;
 391         struct dccp_opt_conf    *dccpop_sc;
 392 };
 393
 394 extern void dccp_minisock_init(struct dccp_minisock *dmsk);
 395
 396 extern int dccp_parse_options(struct sock *sk, struct sk_buff *skb);
 397
 398 struct dccp_request_sock {
 399         struct inet_request_sock dreq_inet_rsk;
 400         __u64                    dreq_iss;
 401         __u64                    dreq_isr;
 402         __be32                   dreq_service;
 403 };
 404
 405 static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
 406 {
 407         return (struct dccp_request_sock *)req;
 408 }
 409
 410 extern struct inet_timewait_death_row dccp_death_row;
 411
 412 struct dccp_options_received {
 413         u32     dccpor_ndp; /* only 24 bits */
 414         u32     dccpor_timestamp;
 415         u32     dccpor_timestamp_echo;
 416         u32     dccpor_elapsed_time;
 417 };
 418
 419 struct ccid;
 420
 421 enum dccp_role {
 422         DCCP_ROLE_UNDEFINED,
 423         DCCP_ROLE_LISTEN,
 424         DCCP_ROLE_CLIENT,
 425         DCCP_ROLE_SERVER,
 426 };
 427
 428 struct dccp_service_list {
 429         __u32   dccpsl_nr;
 430         __be32  dccpsl_list[0];
 431 };
 432
 433 #define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
 434 #define DCCP_SERVICE_CODE_IS_ABSENT             0
 435
 436 static inline int dccp_list_has_service(const struct dccp_service_list *sl,
 437                                         const __be32 service)
 438 {
 439         if (likely(sl != NULL)) {
 440                 u32 i = sl->dccpsl_nr;
 441                 while (i--)
 442                         if (sl->dccpsl_list[i] == service)
 443                                 return 1;
 444         }
 445         return 0;
 446 }
 447
 448 struct dccp_ackvec;
 449
 450 /**
 451  * struct dccp_sock - DCCP socket state
 452  *
 453  * @dccps_swl - sequence number window low
 454  * @dccps_swh - sequence number window high
 455  * @dccps_awl - acknowledgement number window low
 456  * @dccps_awh - acknowledgement number window high
 457  * @dccps_iss - initial sequence number sent
 458  * @dccps_isr - initial sequence number received
 459  * @dccps_osr - first OPEN sequence number received
 460  * @dccps_gss - greatest sequence number sent
 461  * @dccps_gsr - greatest valid sequence number received
 462  * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
 463  * @dccps_service - first (passive sock) or unique (active sock) service code
 464  * @dccps_service_list - second .. last service code on passive socket
 465  * @dccps_timestamp_time - time of latest TIMESTAMP option
 466  * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
 467  * @dccps_l_ack_ratio - feature-local Ack Ratio
 468  * @dccps_r_ack_ratio - feature-remote Ack Ratio
 469  * @dccps_pcslen - sender   partial checksum coverage (via sockopt)
 470  * @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
 471  * @dccps_ndp_count - number of Non Data Packets since last data packet
 472  * @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
 473  * @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
 474  * @dccps_minisock - associated minisock (accessed via dccp_msk)
 475  * @dccps_hc_rx_ackvec - rx half connection ack vector
 476  * @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
 477  * @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
 478  * @dccps_options_received - parsed set of retrieved options
 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_xmit_timer - timer for when CCID is not ready to send
 483  * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs)
 484  */
 485 struct dccp_sock {
 486         /* inet_connection_sock has to be the first member of dccp_sock */
 487         struct inet_connection_sock     dccps_inet_connection;
 488 #define dccps_syn_rtt                   dccps_inet_connection.icsk_ack.lrcvtime
 489         __u64                           dccps_swl;
 490         __u64                           dccps_swh;
 491         __u64                           dccps_awl;
 492         __u64                           dccps_awh;
 493         __u64                           dccps_iss;
 494         __u64                           dccps_isr;
 495         __u64                           dccps_osr;
 496         __u64                           dccps_gss;
 497         __u64                           dccps_gsr;
 498         __u64                           dccps_gar;
 499         __be32                          dccps_service;
 500         struct dccp_service_list        *dccps_service_list;
 501         ktime_t                         dccps_timestamp_time;
 502         __u32                           dccps_timestamp_echo;
 503         __u16                           dccps_l_ack_ratio;
 504         __u16                           dccps_r_ack_ratio;
 505         __u16                           dccps_pcslen;
 506         __u16                           dccps_pcrlen;
 507         unsigned long                   dccps_ndp_count;
 508         __u32                           dccps_mss_cache;
 509         unsigned long                   dccps_rate_last;
 510         struct dccp_minisock            dccps_minisock;
 511         struct dccp_ackvec              *dccps_hc_rx_ackvec;
 512         struct ccid                     *dccps_hc_rx_ccid;
 513         struct ccid                     *dccps_hc_tx_ccid;
 514         struct dccp_options_received    dccps_options_received;
 515         enum dccp_role                  dccps_role:2;
 516         __u8                            dccps_hc_rx_insert_options:1;
 517         __u8                            dccps_hc_tx_insert_options:1;
 518         struct timer_list               dccps_xmit_timer;
 519 };
 520
 521 static inline struct dccp_sock *dccp_sk(const struct sock *sk)
 522 {
 523         return (struct dccp_sock *)sk;
 524 }
 525
 526 static inline struct dccp_minisock *dccp_msk(const struct sock *sk)
 527 {
 528         return (struct dccp_minisock *)&dccp_sk(sk)->dccps_minisock;
 529 }
 530
 531 static inline const char *dccp_role(const struct sock *sk)
 532 {
 533         switch (dccp_sk(sk)->dccps_role) {
 534         case DCCP_ROLE_UNDEFINED: return "undefined";
 535         case DCCP_ROLE_LISTEN:    return "listen";
 536         case DCCP_ROLE_SERVER:    return "server";
 537         case DCCP_ROLE_CLIENT:    return "client";
 538         }
 539         return NULL;
 540 }
 541
 542 #endif /* __KERNEL__ */
 543
 544 #endif /* _LINUX_DCCP_H */