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 #include "ackvec.h"
  21
  22 #ifdef CONFIG_IP_DCCP_DEBUG
  23 extern int dccp_debug;
  24
  25 #define dccp_pr_debug(format, a...) \
  26         do { if (dccp_debug) \
  27                 printk(KERN_DEBUG "%s: " format, __FUNCTION__ , ##a); \
  28         } while (0)
  29 #define dccp_pr_debug_cat(format, a...) do { if (dccp_debug) \
  30                                              printk(format, ##a); } while (0)
  31 #else
  32 #define dccp_pr_debug(format, a...)
  33 #define dccp_pr_debug_cat(format, a...)
  34 #endif
  35
  36 extern struct inet_hashinfo dccp_hashinfo;
  37
  38 extern atomic_t dccp_orphan_count;
  39 extern int dccp_tw_count;
  40 extern void dccp_tw_deschedule(struct inet_timewait_sock *tw);
  41
  42 extern void dccp_time_wait(struct sock *sk, int state, int timeo);
  43
  44 /* FIXME: Right size this */
  45 #define DCCP_MAX_OPT_LEN 128
  46
  47 #define DCCP_MAX_PACKET_HDR 32
  48
  49 #define MAX_DCCP_HEADER  (DCCP_MAX_PACKET_HDR + DCCP_MAX_OPT_LEN + MAX_HEADER)
  50
  51 #define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
  52                                      * state, about 60 seconds */
  53
  54 /* draft-ietf-dccp-spec-11.txt initial RTO value */
  55 #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
  56
  57 /* Maximal interval between probes for local resources.  */
  58 #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
  59
  60 #define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
  61
  62 extern struct proto dccp_v4_prot;
  63
  64 /* is seq1 < seq2 ? */
  65 static inline int before48(const u64 seq1, const u64 seq2)
  66 {
  67         return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
  68 }
  69
  70 /* is seq1 > seq2 ? */
  71 static inline int after48(const u64 seq1, const u64 seq2)
  72 {
  73         return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
  74 }
  75
  76 /* is seq2 <= seq1 <= seq3 ? */
  77 static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
  78 {
  79         return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
  80 }
  81
  82 static inline u64 max48(const u64 seq1, const u64 seq2)
  83 {
  84         return after48(seq1, seq2) ? seq1 : seq2;
  85 }
  86
  87 enum {
  88         DCCP_MIB_NUM = 0,
  89         DCCP_MIB_ACTIVEOPENS,                   /* ActiveOpens */
  90         DCCP_MIB_ESTABRESETS,                   /* EstabResets */
  91         DCCP_MIB_CURRESTAB,                     /* CurrEstab */
  92         DCCP_MIB_OUTSEGS,                       /* OutSegs */
  93         DCCP_MIB_OUTRSTS,
  94         DCCP_MIB_ABORTONTIMEOUT,
  95         DCCP_MIB_TIMEOUTS,
  96         DCCP_MIB_ABORTFAILED,
  97         DCCP_MIB_PASSIVEOPENS,
  98         DCCP_MIB_ATTEMPTFAILS,
  99         DCCP_MIB_OUTDATAGRAMS,
 100         DCCP_MIB_INERRS,
 101         DCCP_MIB_OPTMANDATORYERROR,
 102         DCCP_MIB_INVALIDOPT,
 103         __DCCP_MIB_MAX
 104 };
 105
 106 #define DCCP_MIB_MAX    __DCCP_MIB_MAX
 107 struct dccp_mib {
 108         unsigned long   mibs[DCCP_MIB_MAX];
 109 } __SNMP_MIB_ALIGN__;
 110
 111 DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
 112 #define DCCP_INC_STATS(field)       SNMP_INC_STATS(dccp_statistics, field)
 113 #define DCCP_INC_STATS_BH(field)    SNMP_INC_STATS_BH(dccp_statistics, field)
 114 #define DCCP_INC_STATS_USER(field)  SNMP_INC_STATS_USER(dccp_statistics, field)
 115 #define DCCP_DEC_STATS(field)       SNMP_DEC_STATS(dccp_statistics, field)
 116 #define DCCP_ADD_STATS_BH(field, val) \
 117                         SNMP_ADD_STATS_BH(dccp_statistics, field, val)
 118 #define DCCP_ADD_STATS_USER(field, val) \
 119                         SNMP_ADD_STATS_USER(dccp_statistics, field, val)
 120
 121 extern int  dccp_transmit_skb(struct sock *sk, struct sk_buff *skb);
 122 extern int  dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
 123
 124 extern int dccp_send_response(struct sock *sk);
 125 extern void dccp_send_ack(struct sock *sk);
 126 extern void dccp_send_delayed_ack(struct sock *sk);
 127 extern void dccp_send_sync(struct sock *sk, const u64 seq,
 128                            const enum dccp_pkt_type pkt_type);
 129
 130 extern int dccp_write_xmit(struct sock *sk, struct sk_buff *skb, long *timeo);
 131 extern void dccp_write_space(struct sock *sk);
 132
 133 extern void dccp_init_xmit_timers(struct sock *sk);
 134 static inline void dccp_clear_xmit_timers(struct sock *sk)
 135 {
 136         inet_csk_clear_xmit_timers(sk);
 137 }
 138
 139 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
 140
 141 extern const char *dccp_packet_name(const int type);
 142 extern const char *dccp_state_name(const int state);
 143
 144 static inline void dccp_set_state(struct sock *sk, const int state)
 145 {
 146         const int oldstate = sk->sk_state;
 147
 148         dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
 149                       dccp_role(sk), sk,
 150                       dccp_state_name(oldstate), dccp_state_name(state));
 151         WARN_ON(state == oldstate);
 152
 153         switch (state) {
 154         case DCCP_OPEN:
 155                 if (oldstate != DCCP_OPEN)
 156                         DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
 157                 break;
 158
 159         case DCCP_CLOSED:
 160                 if (oldstate == DCCP_CLOSING || oldstate == DCCP_OPEN)
 161                         DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
 162
 163                 sk->sk_prot->unhash(sk);
 164                 if (inet_csk(sk)->icsk_bind_hash != NULL &&
 165                     !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
 166                         inet_put_port(&dccp_hashinfo, sk);
 167                 /* fall through */
 168         default:
 169                 if (oldstate == DCCP_OPEN)
 170                         DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
 171         }
 172
 173         /* Change state AFTER socket is unhashed to avoid closed
 174          * socket sitting in hash tables.
 175          */
 176         sk->sk_state = state;
 177 }
 178
 179 static inline void dccp_done(struct sock *sk)
 180 {
 181         dccp_set_state(sk, DCCP_CLOSED);
 182         dccp_clear_xmit_timers(sk);
 183
 184         sk->sk_shutdown = SHUTDOWN_MASK;
 185
 186         if (!sock_flag(sk, SOCK_DEAD))
 187                 sk->sk_state_change(sk);
 188         else
 189                 inet_csk_destroy_sock(sk);
 190 }
 191
 192 static inline void dccp_openreq_init(struct request_sock *req,
 193                                      struct dccp_sock *dp,
 194                                      struct sk_buff *skb)
 195 {
 196         /*
 197          * FIXME: fill in the other req fields from the DCCP options
 198          * received
 199          */
 200         inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
 201         inet_rsk(req)->acked    = 0;
 202         req->rcv_wnd = 0;
 203 }
 204
 205 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
 206
 207 extern struct sock *dccp_create_openreq_child(struct sock *sk,
 208                                               const struct request_sock *req,
 209                                               const struct sk_buff *skb);
 210
 211 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
 212
 213 extern void dccp_v4_err(struct sk_buff *skb, u32);
 214
 215 extern int dccp_v4_rcv(struct sk_buff *skb);
 216
 217 extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
 218                                               struct sk_buff *skb,
 219                                               struct request_sock *req,
 220                                               struct dst_entry *dst);
 221 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
 222                                    struct request_sock *req,
 223                                    struct request_sock **prev);
 224
 225 extern int dccp_child_process(struct sock *parent, struct sock *child,
 226                               struct sk_buff *skb);
 227 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 228                                   struct dccp_hdr *dh, unsigned len);
 229 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
 230                                 const struct dccp_hdr *dh, const unsigned len);
 231
 232 extern void             dccp_close(struct sock *sk, long timeout);
 233 extern struct sk_buff   *dccp_make_response(struct sock *sk,
 234                                             struct dst_entry *dst,
 235                                             struct request_sock *req);
 236 extern struct sk_buff   *dccp_make_reset(struct sock *sk,
 237                                          struct dst_entry *dst,
 238                                          enum dccp_reset_codes code);
 239
 240 extern int         dccp_connect(struct sock *sk);
 241 extern int         dccp_disconnect(struct sock *sk, int flags);
 242 extern int         dccp_getsockopt(struct sock *sk, int level, int optname,
 243                                    char __user *optval, int __user *optlen);
 244 extern int         dccp_setsockopt(struct sock *sk, int level, int optname,
 245                                    char __user *optval, int optlen);
 246 extern int         dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
 247 extern int         dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
 248                                 struct msghdr *msg, size_t size);
 249 extern int         dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
 250                                 struct msghdr *msg, size_t len, int nonblock,
 251                                 int flags, int *addr_len);
 252 extern void        dccp_shutdown(struct sock *sk, int how);
 253
 254 extern int         dccp_v4_checksum(const struct sk_buff *skb,
 255                                     const u32 saddr, const u32 daddr);
 256
 257 extern int         dccp_v4_send_reset(struct sock *sk,
 258                                       enum dccp_reset_codes code);
 259 extern void        dccp_send_close(struct sock *sk, const int active);
 260
 261 struct dccp_skb_cb {
 262         __u8  dccpd_type:4;
 263         __u8  dccpd_ccval:4;
 264         __u8  dccpd_reset_code;
 265         __u16 dccpd_opt_len;
 266         __u64 dccpd_seq;
 267         __u64 dccpd_ack_seq;
 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 static inline int dccp_ack_pending(const struct sock *sk)
 364 {
 365         const struct dccp_sock *dp = dccp_sk(sk);
 366         return dp->dccps_timestamp_echo != 0 ||
 367 #ifdef CONFIG_IP_DCCP_ACKVEC
 368                (dp->dccps_options.dccpo_send_ack_vector &&
 369                 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||
 370 #endif
 371                inet_csk_ack_scheduled(sk);
 372 }
 373
 374 extern void dccp_insert_options(struct sock *sk, struct sk_buff *skb);
 375 extern void dccp_insert_option_elapsed_time(struct sock *sk,
 376                                             struct sk_buff *skb,
 377                                             u32 elapsed_time);
 378 extern void dccp_insert_option_timestamp(struct sock *sk,
 379                                          struct sk_buff *skb);
 380 extern void dccp_insert_option(struct sock *sk, struct sk_buff *skb,
 381                                unsigned char option,
 382                                const void *value, unsigned char len);
 383
 384 extern struct socket *dccp_ctl_socket;
 385
 386 extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);
 387
 388 static inline suseconds_t timeval_usecs(const struct timeval *tv)
 389 {
 390         return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
 391 }
 392
 393 static inline suseconds_t timeval_delta(const struct timeval *large,
 394                                         const struct timeval *small)
 395 {
 396         time_t      secs  = large->tv_sec  - small->tv_sec;
 397         suseconds_t usecs = large->tv_usec - small->tv_usec;
 398
 399         if (usecs < 0) {
 400                 secs--;
 401                 usecs += USEC_PER_SEC;
 402         }
 403         return secs * USEC_PER_SEC + usecs;
 404 }
 405
 406 static inline void timeval_add_usecs(struct timeval *tv,
 407                                      const suseconds_t usecs)
 408 {
 409         tv->tv_usec += usecs;
 410         while (tv->tv_usec >= USEC_PER_SEC) {
 411                 tv->tv_sec++;
 412                 tv->tv_usec -= USEC_PER_SEC;
 413         }
 414 }
 415
 416 static inline void timeval_sub_usecs(struct timeval *tv,
 417                                      const suseconds_t usecs)
 418 {
 419         tv->tv_usec -= usecs;
 420         while (tv->tv_usec < 0) {
 421                 tv->tv_sec--;
 422                 tv->tv_usec += USEC_PER_SEC;
 423         }
 424 }
 425
 426 #endif /* _DCCP_H */