net/dccp/dccp.h

   1 #ifndef _DCCP_H
   2 #define _DCCP_H
   3 /*
   4  *  net/dccp/dccp.h
   5  *
   6  *  An implementation of the DCCP protocol
   7  *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
   8  *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
   9  *
  10  *      This program is free software; you can redistribute it and/or modify it
  11  *      under the terms of the GNU General Public License version 2 as
  12  *      published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/config.h>
  16 #include <linux/dccp.h>
  17 #include <net/snmp.h>
  18 #include <net/sock.h>
  19 #include <net/tcp.h>
  20
  21 #ifdef CONFIG_IP_DCCP_DEBUG
  22 extern int dccp_debug;
  23
  24 #define dccp_pr_debug(format, a...) \
  25         do { if (dccp_debug) \
  26                 printk(KERN_DEBUG "%s: " format, __FUNCTION__ , ##a); \
  27         } while (0)
  28 #define dccp_pr_debug_cat(format, a...) do { if (dccp_debug) \
  29                                              printk(format, ##a); } while (0)
  30 #else
  31 #define dccp_pr_debug(format, a...)
  32 #define dccp_pr_debug_cat(format, a...)
  33 #endif
  34
  35 extern struct inet_hashinfo dccp_hashinfo;
  36
  37 extern atomic_t dccp_orphan_count;
  38 extern int dccp_tw_count;
  39 extern void dccp_tw_deschedule(struct inet_timewait_sock *tw);
  40
  41 extern void dccp_time_wait(struct sock *sk, int state, int timeo);
  42
  43 /* FIXME: Right size this */
  44 #define DCCP_MAX_OPT_LEN 128
  45
  46 #define DCCP_MAX_PACKET_HDR 32
  47
  48 #define MAX_DCCP_HEADER  (DCCP_MAX_PACKET_HDR + DCCP_MAX_OPT_LEN + MAX_HEADER)
  49
  50 #define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
  51                                      * state, about 60 seconds */
  52
  53 /* draft-ietf-dccp-spec-11.txt initial RTO value */
  54 #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
  55
  56 /* Maximal interval between probes for local resources.  */
  57 #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
  58
  59 #define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
  60
  61 extern struct proto dccp_v4_prot;
  62
  63 /* is seq1 < seq2 ? */
  64 static inline int before48(const u64 seq1, const u64 seq2)
  65 {
  66         return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
  67 }
  68
  69 /* is seq1 > seq2 ? */
  70 static inline int after48(const u64 seq1, const u64 seq2)
  71 {
  72         return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
  73 }
  74
  75 /* is seq2 <= seq1 <= seq3 ? */
  76 static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
  77 {
  78         return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
  79 }
  80
  81 static inline u64 max48(const u64 seq1, const u64 seq2)
  82 {
  83         return after48(seq1, seq2) ? seq1 : seq2;
  84 }
  85
  86 enum {
  87         DCCP_MIB_NUM = 0,
  88         DCCP_MIB_ACTIVEOPENS,                   /* ActiveOpens */
  89         DCCP_MIB_ESTABRESETS,                   /* EstabResets */
  90         DCCP_MIB_CURRESTAB,                     /* CurrEstab */
  91         DCCP_MIB_OUTSEGS,                       /* OutSegs */
  92         DCCP_MIB_OUTRSTS,
  93         DCCP_MIB_ABORTONTIMEOUT,
  94         DCCP_MIB_TIMEOUTS,
  95         DCCP_MIB_ABORTFAILED,
  96         DCCP_MIB_PASSIVEOPENS,
  97         DCCP_MIB_ATTEMPTFAILS,
  98         DCCP_MIB_OUTDATAGRAMS,
  99         DCCP_MIB_INERRS,
 100         DCCP_MIB_OPTMANDATORYERROR,
 101         DCCP_MIB_INVALIDOPT,
 102         __DCCP_MIB_MAX
 103 };
 104
 105 #define DCCP_MIB_MAX    __DCCP_MIB_MAX
 106 struct dccp_mib {
 107         unsigned long   mibs[DCCP_MIB_MAX];
 108 } __SNMP_MIB_ALIGN__;
 109
 110 DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
 111 #define DCCP_INC_STATS(field)       SNMP_INC_STATS(dccp_statistics, field)
 112 #define DCCP_INC_STATS_BH(field)    SNMP_INC_STATS_BH(dccp_statistics, field)
 113 #define DCCP_INC_STATS_USER(field)  SNMP_INC_STATS_USER(dccp_statistics, field)
 114 #define DCCP_DEC_STATS(field)       SNMP_DEC_STATS(dccp_statistics, field)
 115 #define DCCP_ADD_STATS_BH(field, val) \
 116                         SNMP_ADD_STATS_BH(dccp_statistics, field, val)
 117 #define DCCP_ADD_STATS_USER(field, val) \
 118                         SNMP_ADD_STATS_USER(dccp_statistics, field, val)
 119
 120 extern int  dccp_transmit_skb(struct sock *sk, struct sk_buff *skb);
 121 extern int  dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
 122
 123 extern int dccp_send_response(struct sock *sk);
 124 extern void dccp_send_ack(struct sock *sk);
 125 extern void dccp_send_delayed_ack(struct sock *sk);
 126 extern void dccp_send_sync(struct sock *sk, const u64 seq,
 127                            const enum dccp_pkt_type pkt_type);
 128
 129 extern int dccp_write_xmit(struct sock *sk, struct sk_buff *skb, long *timeo);
 130 extern void dccp_write_space(struct sock *sk);
 131
 132 extern void dccp_init_xmit_timers(struct sock *sk);
 133 static inline void dccp_clear_xmit_timers(struct sock *sk)
 134 {
 135         inet_csk_clear_xmit_timers(sk);
 136 }
 137
 138 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
 139
 140 extern const char *dccp_packet_name(const int type);
 141 extern const char *dccp_state_name(const int state);
 142
 143 static inline void dccp_set_state(struct sock *sk, const int state)
 144 {
 145         const int oldstate = sk->sk_state;
 146
 147         dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
 148                       dccp_role(sk), sk,
 149                       dccp_state_name(oldstate), dccp_state_name(state));
 150         WARN_ON(state == oldstate);
 151
 152         switch (state) {
 153         case DCCP_OPEN:
 154                 if (oldstate != DCCP_OPEN)
 155                         DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
 156                 break;
 157
 158         case DCCP_CLOSED:
 159                 if (oldstate == DCCP_CLOSING || oldstate == DCCP_OPEN)
 160                         DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
 161
 162                 sk->sk_prot->unhash(sk);
 163                 if (inet_csk(sk)->icsk_bind_hash != NULL &&
 164                     !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
 165                         inet_put_port(&dccp_hashinfo, sk);
 166                 /* fall through */
 167         default:
 168                 if (oldstate == DCCP_OPEN)
 169                         DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
 170         }
 171
 172         /* Change state AFTER socket is unhashed to avoid closed
 173          * socket sitting in hash tables.
 174          */
 175         sk->sk_state = state;
 176 }
 177
 178 static inline void dccp_done(struct sock *sk)
 179 {
 180         dccp_set_state(sk, DCCP_CLOSED);
 181         dccp_clear_xmit_timers(sk);
 182
 183         sk->sk_shutdown = SHUTDOWN_MASK;
 184
 185         if (!sock_flag(sk, SOCK_DEAD))
 186                 sk->sk_state_change(sk);
 187         else
 188                 inet_csk_destroy_sock(sk);
 189 }
 190
 191 static inline void dccp_openreq_init(struct request_sock *req,
 192                                      struct dccp_sock *dp,
 193                                      struct sk_buff *skb)
 194 {
 195         /*
 196          * FIXME: fill in the other req fields from the DCCP options
 197          * received
 198          */
 199         inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
 200         inet_rsk(req)->acked    = 0;
 201         req->rcv_wnd = 0;
 202 }
 203
 204 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
 205
 206 extern struct sock *dccp_create_openreq_child(struct sock *sk,
 207                                               const struct request_sock *req,
 208                                               const struct sk_buff *skb);
 209
 210 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
 211
 212 extern void dccp_v4_err(struct sk_buff *skb, u32);
 213
 214 extern int dccp_v4_rcv(struct sk_buff *skb);
 215
 216 extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
 217                                               struct sk_buff *skb,
 218                                               struct request_sock *req,
 219                                               struct dst_entry *dst);
 220 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
 221                                    struct request_sock *req,
 222                                    struct request_sock **prev);
 223
 224 extern int dccp_child_process(struct sock *parent, struct sock *child,
 225                               struct sk_buff *skb);
 226 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 227                                   struct dccp_hdr *dh, unsigned len);
 228 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
 229                                 const struct dccp_hdr *dh, const unsigned len);
 230
 231 extern void             dccp_close(struct sock *sk, long timeout);
 232 extern struct sk_buff   *dccp_make_response(struct sock *sk,
 233                                             struct dst_entry *dst,
 234                                             struct request_sock *req);
 235 extern struct sk_buff   *dccp_make_reset(struct sock *sk,
 236                                          struct dst_entry *dst,
 237                                          enum dccp_reset_codes code);
 238
 239 extern int         dccp_connect(struct sock *sk);
 240 extern int         dccp_disconnect(struct sock *sk, int flags);
 241 extern int         dccp_getsockopt(struct sock *sk, int level, int optname,
 242                                    char __user *optval, int __user *optlen);
 243 extern int         dccp_setsockopt(struct sock *sk, int level, int optname,
 244                                    char __user *optval, int optlen);
 245 extern int         dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
 246 extern int         dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
 247                                 struct msghdr *msg, size_t size);
 248 extern int         dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
 249                                 struct msghdr *msg, size_t len, int nonblock,
 250                                 int flags, int *addr_len);
 251 extern void        dccp_shutdown(struct sock *sk, int how);
 252
 253 extern int         dccp_v4_checksum(const struct sk_buff *skb,
 254                                     const u32 saddr, const u32 daddr);
 255
 256 extern int         dccp_v4_send_reset(struct sock *sk,
 257                                       enum dccp_reset_codes code);
 258 extern void        dccp_send_close(struct sock *sk, const int active);
 259
 260 struct dccp_skb_cb {
 261         __u8 dccpd_type;
 262         __u8 dccpd_reset_code;
 263         __u8 dccpd_service;
 264         __u8 dccpd_ccval;
 265         __u64 dccpd_seq;
 266         __u64 dccpd_ack_seq;
 267         int  dccpd_opt_len;
 268 };
 269
 270 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
 271
 272 static inline int dccp_non_data_packet(const struct sk_buff *skb)
 273 {
 274         const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
 275
 276         return type == DCCP_PKT_ACK      ||
 277                type == DCCP_PKT_CLOSE    ||
 278                type == DCCP_PKT_CLOSEREQ ||
 279                type == DCCP_PKT_RESET    ||
 280                type == DCCP_PKT_SYNC     ||
 281                type == DCCP_PKT_SYNCACK;
 282 }
 283
 284 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
 285 {
 286         const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
 287
 288         return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
 289 }
 290
 291 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
 292 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
 293
 294 static inline void dccp_set_seqno(u64 *seqno, u64 value)
 295 {
 296         if (value > DCCP_MAX_SEQNO)
 297                 value -= DCCP_MAX_SEQNO + 1;
 298         *seqno = value;
 299 }
 300
 301 static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
 302 {
 303         return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
 304 }
 305
 306 static inline void dccp_inc_seqno(u64 *seqno)
 307 {
 308         if (++*seqno > DCCP_MAX_SEQNO)
 309                 *seqno = 0;
 310 }
 311
 312 static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
 313 {
 314         struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
 315                                                            sizeof(*dh));
 316
 317 #if defined(__LITTLE_ENDIAN_BITFIELD)
 318         dh->dccph_seq      = htonl((gss >> 32)) >> 8;
 319 #elif defined(__BIG_ENDIAN_BITFIELD)
 320         dh->dccph_seq      = htonl((gss >> 32));
 321 #else
 322 #error  "Adjust your <asm/byteorder.h> defines"
 323 #endif
 324         dhx->dccph_seq_low = htonl(gss & 0xffffffff);
 325 }
 326
 327 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
 328                                     const u64 gsr)
 329 {
 330 #if defined(__LITTLE_ENDIAN_BITFIELD)
 331         dhack->dccph_ack_nr_high = htonl((gsr >> 32)) >> 8;
 332 #elif defined(__BIG_ENDIAN_BITFIELD)
 333         dhack->dccph_ack_nr_high = htonl((gsr >> 32));
 334 #else
 335 #error  "Adjust your <asm/byteorder.h> defines"
 336 #endif
 337         dhack->dccph_ack_nr_low  = htonl(gsr & 0xffffffff);
 338 }
 339
 340 static inline void dccp_update_gsr(struct sock *sk, u64 seq)
 341 {
 342         struct dccp_sock *dp = dccp_sk(sk);
 343
 344         dp->dccps_gsr = seq;
 345         dccp_set_seqno(&dp->dccps_swl,
 346                        (dp->dccps_gsr + 1 -
 347                         (dp->dccps_options.dccpo_sequence_window / 4)));
 348         dccp_set_seqno(&dp->dccps_swh,
 349                        (dp->dccps_gsr +
 350                         (3 * dp->dccps_options.dccpo_sequence_window) / 4));
 351 }
 352
 353 static inline void dccp_update_gss(struct sock *sk, u64 seq)
 354 {
 355         struct dccp_sock *dp = dccp_sk(sk);
 356
 357         dp->dccps_awh = dp->dccps_gss = seq;
 358         dccp_set_seqno(&dp->dccps_awl,
 359                        (dp->dccps_gss -
 360                         dp->dccps_options.dccpo_sequence_window + 1));
 361 }
 362
 363 extern void dccp_insert_options(struct sock *sk, struct sk_buff *skb);
 364 extern void dccp_insert_option_elapsed_time(struct sock *sk,
 365                                             struct sk_buff *skb,
 366                                             u32 elapsed_time);
 367 extern void dccp_insert_option_timestamp(struct sock *sk,
 368                                          struct sk_buff *skb);
 369 extern void dccp_insert_option(struct sock *sk, struct sk_buff *skb,
 370                                unsigned char option,
 371                                const void *value, unsigned char len);
 372
 373 extern struct socket *dccp_ctl_socket;
 374
 375 #define DCCP_ACKPKTS_STATE_RECEIVED     0
 376 #define DCCP_ACKPKTS_STATE_ECN_MARKED   (1 << 6)
 377 #define DCCP_ACKPKTS_STATE_NOT_RECEIVED (3 << 6)
 378
 379 #define DCCP_ACKPKTS_STATE_MASK         0xC0 /* 11000000 */
 380 #define DCCP_ACKPKTS_LEN_MASK           0x3F /* 00111111 */
 381
 382 /** struct dccp_ackpkts - acknowledgeable packets
 383  *
 384  * This data structure is the one defined in the DCCP draft
 385  * Appendix A.
 386  *
 387  * @dccpap_buf_head - circular buffer head
 388  * @dccpap_buf_tail - circular buffer tail
 389  * @dccpap_buf_ackno - ack # of the most recent packet acknowledgeable in the
 390  *                     buffer (i.e. %dccpap_buf_head)
 391  * @dccpap_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
 392  *                     by the buffer with State 0
 393  *
 394  * Additionally, the HC-Receiver must keep some information about the
 395  * Ack Vectors it has recently sent. For each packet sent carrying an
 396  * Ack Vector, it remembers four variables:
 397  *
 398  * @dccpap_ack_seqno - the Sequence Number used for the packet
 399  *                     (HC-Receiver seqno)
 400  * @dccpap_ack_ptr - the value of buf_head at the time of acknowledgement.
 401  * @dccpap_ack_ackno - the Acknowledgement Number used for the packet
 402  *                     (HC-Sender seqno)
 403  * @dccpap_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
 404  *
 405  * @dccpap_buf_len - circular buffer length
 406  * @dccpap_time         - the time in usecs
 407  * @dccpap_buf - circular buffer of acknowledgeable packets
 408  */
 409 struct dccp_ackpkts {
 410         unsigned int            dccpap_buf_head;
 411         unsigned int            dccpap_buf_tail;
 412         u64                     dccpap_buf_ackno;
 413         u64                     dccpap_ack_seqno;
 414         u64                     dccpap_ack_ackno;
 415         unsigned int            dccpap_ack_ptr;
 416         unsigned int            dccpap_buf_vector_len;
 417         unsigned int            dccpap_ack_vector_len;
 418         unsigned int            dccpap_buf_len;
 419         struct timeval          dccpap_time;
 420         u8                      dccpap_buf_nonce;
 421         u8                      dccpap_ack_nonce;
 422         u8                      dccpap_buf[0];
 423 };
 424
 425 extern struct dccp_ackpkts *
 426                 dccp_ackpkts_alloc(unsigned int len,
 427                                   const unsigned int __nocast priority);
 428 extern void dccp_ackpkts_free(struct dccp_ackpkts *ap);
 429 extern int dccp_ackpkts_add(struct dccp_ackpkts *ap, u64 ackno, u8 state);
 430 extern void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap,
 431                                          struct sock *sk, u64 ackno);
 432
 433 static inline suseconds_t timeval_usecs(const struct timeval *tv)
 434 {
 435         return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
 436 }
 437
 438 static inline suseconds_t timeval_delta(const struct timeval *large,
 439                                         const struct timeval *small)
 440 {
 441         time_t      secs  = large->tv_sec  - small->tv_sec;
 442         suseconds_t usecs = large->tv_usec - small->tv_usec;
 443
 444         if (usecs < 0) {
 445                 secs--;
 446                 usecs += USEC_PER_SEC;
 447         }
 448         return secs * USEC_PER_SEC + usecs;
 449 }
 450
 451 static inline void timeval_add_usecs(struct timeval *tv,
 452                                      const suseconds_t usecs)
 453 {
 454         tv->tv_usec += usecs;
 455         while (tv->tv_usec >= USEC_PER_SEC) {
 456                 tv->tv_sec++;
 457                 tv->tv_usec -= USEC_PER_SEC;
 458         }
 459 }
 460
 461 static inline void timeval_sub_usecs(struct timeval *tv,
 462                                      const suseconds_t usecs)
 463 {
 464         tv->tv_usec -= usecs;
 465         while (tv->tv_usec < 0) {
 466                 tv->tv_sec--;
 467                 tv->tv_usec += USEC_PER_SEC;
 468         }
 469 }
 470
 471 /*
 472  * Returns the difference in usecs between timeval
 473  * passed in and current time
 474  */
 475 static inline suseconds_t timeval_now_delta(const struct timeval *tv)
 476 {
 477         struct timeval now;
 478         do_gettimeofday(&now);
 479         return timeval_delta(&now, tv);
 480 }
 481
 482 #ifdef CONFIG_IP_DCCP_DEBUG
 483 extern void dccp_ackvector_print(const u64 ackno,
 484                                  const unsigned char *vector, int len);
 485 extern void dccp_ackpkts_print(const struct dccp_ackpkts *ap);
 486 #else
 487 static inline void dccp_ackvector_print(const u64 ackno,
 488                                         const unsigned char *vector,
 489                                         int len) { }
 490 static inline void dccp_ackpkts_print(const struct dccp_ackpkts *ap) { }
 491 #endif
 492
 493 #endif /* _DCCP_H */