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) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.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/dccp.h>
  16 #include <net/snmp.h>
  17 #include <net/sock.h>
  18 #include <net/tcp.h>
  19 #include "ackvec.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 /* RFC 1122, 4.2.3.1 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 /* is seq1 < seq2 ? */
  62 static inline int before48(const u64 seq1, const u64 seq2)
  63 {
  64         return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
  65 }
  66
  67 /* is seq1 > seq2 ? */
  68 static inline int after48(const u64 seq1, const u64 seq2)
  69 {
  70         return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
  71 }
  72
  73 /* is seq2 <= seq1 <= seq3 ? */
  74 static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
  75 {
  76         return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
  77 }
  78
  79 static inline u64 max48(const u64 seq1, const u64 seq2)
  80 {
  81         return after48(seq1, seq2) ? seq1 : seq2;
  82 }
  83
  84 /* is seq1 next seqno after seq2 */
  85 static inline int follows48(const u64 seq1, const u64 seq2)
  86 {
  87         int diff = (seq1 & 0xFFFF) - (seq2 & 0xFFFF);
  88
  89         return diff==1;
  90 }
  91
  92 enum {
  93         DCCP_MIB_NUM = 0,
  94         DCCP_MIB_ACTIVEOPENS,                   /* ActiveOpens */
  95         DCCP_MIB_ESTABRESETS,                   /* EstabResets */
  96         DCCP_MIB_CURRESTAB,                     /* CurrEstab */
  97         DCCP_MIB_OUTSEGS,                       /* OutSegs */
  98         DCCP_MIB_OUTRSTS,
  99         DCCP_MIB_ABORTONTIMEOUT,
 100         DCCP_MIB_TIMEOUTS,
 101         DCCP_MIB_ABORTFAILED,
 102         DCCP_MIB_PASSIVEOPENS,
 103         DCCP_MIB_ATTEMPTFAILS,
 104         DCCP_MIB_OUTDATAGRAMS,
 105         DCCP_MIB_INERRS,
 106         DCCP_MIB_OPTMANDATORYERROR,
 107         DCCP_MIB_INVALIDOPT,
 108         __DCCP_MIB_MAX
 109 };
 110
 111 #define DCCP_MIB_MAX    __DCCP_MIB_MAX
 112 struct dccp_mib {
 113         unsigned long   mibs[DCCP_MIB_MAX];
 114 } __SNMP_MIB_ALIGN__;
 115
 116 DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
 117 #define DCCP_INC_STATS(field)       SNMP_INC_STATS(dccp_statistics, field)
 118 #define DCCP_INC_STATS_BH(field)    SNMP_INC_STATS_BH(dccp_statistics, field)
 119 #define DCCP_INC_STATS_USER(field)  SNMP_INC_STATS_USER(dccp_statistics, field)
 120 #define DCCP_DEC_STATS(field)       SNMP_DEC_STATS(dccp_statistics, field)
 121 #define DCCP_ADD_STATS_BH(field, val) \
 122                         SNMP_ADD_STATS_BH(dccp_statistics, field, val)
 123 #define DCCP_ADD_STATS_USER(field, val) \
 124                         SNMP_ADD_STATS_USER(dccp_statistics, field, val)
 125
 126 extern int  dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
 127
 128 extern void dccp_send_ack(struct sock *sk);
 129 extern void dccp_send_delayed_ack(struct sock *sk);
 130 extern void dccp_send_sync(struct sock *sk, const u64 seq,
 131                            const enum dccp_pkt_type pkt_type);
 132
 133 extern void dccp_write_xmit(struct sock *sk, int block);
 134 extern void dccp_write_space(struct sock *sk);
 135
 136 extern void dccp_init_xmit_timers(struct sock *sk);
 137 static inline void dccp_clear_xmit_timers(struct sock *sk)
 138 {
 139         inet_csk_clear_xmit_timers(sk);
 140 }
 141
 142 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
 143
 144 extern const char *dccp_packet_name(const int type);
 145 extern const char *dccp_state_name(const int state);
 146
 147 extern void dccp_set_state(struct sock *sk, const int state);
 148 extern void dccp_done(struct sock *sk);
 149
 150 static inline void dccp_openreq_init(struct request_sock *req,
 151                                      struct dccp_sock *dp,
 152                                      struct sk_buff *skb)
 153 {
 154         /*
 155          * FIXME: fill in the other req fields from the DCCP options
 156          * received
 157          */
 158         inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
 159         inet_rsk(req)->acked    = 0;
 160         req->rcv_wnd = 0;
 161 }
 162
 163 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
 164
 165 extern struct sock *dccp_create_openreq_child(struct sock *sk,
 166                                               const struct request_sock *req,
 167                                               const struct sk_buff *skb);
 168
 169 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
 170
 171 extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
 172                                               struct sk_buff *skb,
 173                                               struct request_sock *req,
 174                                               struct dst_entry *dst);
 175 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
 176                                    struct request_sock *req,
 177                                    struct request_sock **prev);
 178
 179 extern int dccp_child_process(struct sock *parent, struct sock *child,
 180                               struct sk_buff *skb);
 181 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 182                                   struct dccp_hdr *dh, unsigned len);
 183 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
 184                                 const struct dccp_hdr *dh, const unsigned len);
 185
 186 extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
 187 extern int dccp_destroy_sock(struct sock *sk);
 188
 189 extern void             dccp_close(struct sock *sk, long timeout);
 190 extern struct sk_buff   *dccp_make_response(struct sock *sk,
 191                                             struct dst_entry *dst,
 192                                             struct request_sock *req);
 193
 194 extern int         dccp_connect(struct sock *sk);
 195 extern int         dccp_disconnect(struct sock *sk, int flags);
 196 extern void        dccp_hash(struct sock *sk);
 197 extern void        dccp_unhash(struct sock *sk);
 198 extern int         dccp_getsockopt(struct sock *sk, int level, int optname,
 199                                    char __user *optval, int __user *optlen);
 200 extern int         dccp_setsockopt(struct sock *sk, int level, int optname,
 201                                    char __user *optval, int optlen);
 202 #ifdef CONFIG_COMPAT
 203 extern int         compat_dccp_getsockopt(struct sock *sk,
 204                                 int level, int optname,
 205                                 char __user *optval, int __user *optlen);
 206 extern int         compat_dccp_setsockopt(struct sock *sk,
 207                                 int level, int optname,
 208                                 char __user *optval, int optlen);
 209 #endif
 210 extern int         dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
 211 extern int         dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
 212                                 struct msghdr *msg, size_t size);
 213 extern int         dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
 214                                 struct msghdr *msg, size_t len, int nonblock,
 215                                 int flags, int *addr_len);
 216 extern void        dccp_shutdown(struct sock *sk, int how);
 217 extern int         inet_dccp_listen(struct socket *sock, int backlog);
 218 extern unsigned int dccp_poll(struct file *file, struct socket *sock,
 219                              poll_table *wait);
 220 extern void        dccp_v4_send_check(struct sock *sk, int len,
 221                                       struct sk_buff *skb);
 222 extern int         dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
 223                                    int addr_len);
 224
 225 extern int         dccp_v4_checksum(const struct sk_buff *skb,
 226                                     const __be32 saddr, const __be32 daddr);
 227
 228 extern int         dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
 229 extern void        dccp_send_close(struct sock *sk, const int active);
 230 extern int         dccp_invalid_packet(struct sk_buff *skb);
 231
 232 static inline int dccp_bad_service_code(const struct sock *sk,
 233                                         const __be32 service)
 234 {
 235         const struct dccp_sock *dp = dccp_sk(sk);
 236
 237         if (dp->dccps_service == service)
 238                 return 0;
 239         return !dccp_list_has_service(dp->dccps_service_list, service);
 240 }
 241
 242 struct dccp_skb_cb {
 243         __u8  dccpd_type:4;
 244         __u8  dccpd_ccval:4;
 245         __u8  dccpd_reset_code;
 246         __u16 dccpd_opt_len;
 247         __u64 dccpd_seq;
 248         __u64 dccpd_ack_seq;
 249 };
 250
 251 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
 252
 253 static inline int dccp_non_data_packet(const struct sk_buff *skb)
 254 {
 255         const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
 256
 257         return type == DCCP_PKT_ACK      ||
 258                type == DCCP_PKT_CLOSE    ||
 259                type == DCCP_PKT_CLOSEREQ ||
 260                type == DCCP_PKT_RESET    ||
 261                type == DCCP_PKT_SYNC     ||
 262                type == DCCP_PKT_SYNCACK;
 263 }
 264
 265 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
 266 {
 267         const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
 268
 269         return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
 270 }
 271
 272 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
 273 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
 274
 275 static inline void dccp_set_seqno(u64 *seqno, u64 value)
 276 {
 277         if (value > DCCP_MAX_SEQNO)
 278                 value -= DCCP_MAX_SEQNO + 1;
 279         *seqno = value;
 280 }
 281
 282 static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
 283 {
 284         return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
 285 }
 286
 287 static inline void dccp_inc_seqno(u64 *seqno)
 288 {
 289         if (++*seqno > DCCP_MAX_SEQNO)
 290                 *seqno = 0;
 291 }
 292
 293 static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
 294 {
 295         struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
 296                                                            sizeof(*dh));
 297         dh->dccph_seq2 = 0;
 298         dh->dccph_seq = htons((gss >> 32) & 0xfffff);
 299         dhx->dccph_seq_low = htonl(gss & 0xffffffff);
 300 }
 301
 302 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
 303                                     const u64 gsr)
 304 {
 305         dhack->dccph_reserved1 = 0;
 306         dhack->dccph_ack_nr_high = htons(gsr >> 32);
 307         dhack->dccph_ack_nr_low  = htonl(gsr & 0xffffffff);
 308 }
 309
 310 static inline void dccp_update_gsr(struct sock *sk, u64 seq)
 311 {
 312         struct dccp_sock *dp = dccp_sk(sk);
 313         const struct dccp_minisock *dmsk = dccp_msk(sk);
 314
 315         dp->dccps_gsr = seq;
 316         dccp_set_seqno(&dp->dccps_swl,
 317                        dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
 318         dccp_set_seqno(&dp->dccps_swh,
 319                        dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4);
 320 }
 321
 322 static inline void dccp_update_gss(struct sock *sk, u64 seq)
 323 {
 324         struct dccp_sock *dp = dccp_sk(sk);
 325
 326         dp->dccps_awh = dp->dccps_gss = seq;
 327         dccp_set_seqno(&dp->dccps_awl,
 328                        (dp->dccps_gss -
 329                         dccp_msk(sk)->dccpms_sequence_window + 1));
 330 }
 331
 332 static inline int dccp_ack_pending(const struct sock *sk)
 333 {
 334         const struct dccp_sock *dp = dccp_sk(sk);
 335         return dp->dccps_timestamp_echo != 0 ||
 336 #ifdef CONFIG_IP_DCCP_ACKVEC
 337                (dccp_msk(sk)->dccpms_send_ack_vector &&
 338                 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||
 339 #endif
 340                inet_csk_ack_scheduled(sk);
 341 }
 342
 343 extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
 344 extern int dccp_insert_option_elapsed_time(struct sock *sk,
 345                                             struct sk_buff *skb,
 346                                             u32 elapsed_time);
 347 extern int dccp_insert_option_timestamp(struct sock *sk,
 348                                          struct sk_buff *skb);
 349 extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
 350                                unsigned char option,
 351                                const void *value, unsigned char len);
 352
 353 extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);
 354
 355 static inline suseconds_t timeval_usecs(const struct timeval *tv)
 356 {
 357         return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
 358 }
 359
 360 static inline suseconds_t timeval_delta(const struct timeval *large,
 361                                         const struct timeval *small)
 362 {
 363         time_t      secs  = large->tv_sec  - small->tv_sec;
 364         suseconds_t usecs = large->tv_usec - small->tv_usec;
 365
 366         if (usecs < 0) {
 367                 secs--;
 368                 usecs += USEC_PER_SEC;
 369         }
 370         return secs * USEC_PER_SEC + usecs;
 371 }
 372
 373 static inline void timeval_add_usecs(struct timeval *tv,
 374                                      const suseconds_t usecs)
 375 {
 376         tv->tv_usec += usecs;
 377         while (tv->tv_usec >= USEC_PER_SEC) {
 378                 tv->tv_sec++;
 379                 tv->tv_usec -= USEC_PER_SEC;
 380         }
 381 }
 382
 383 static inline void timeval_sub_usecs(struct timeval *tv,
 384                                      const suseconds_t usecs)
 385 {
 386         tv->tv_usec -= usecs;
 387         while (tv->tv_usec < 0) {
 388                 tv->tv_sec--;
 389                 tv->tv_usec += USEC_PER_SEC;
 390         }
 391 }
 392
 393 #ifdef CONFIG_SYSCTL
 394 extern int dccp_sysctl_init(void);
 395 extern void dccp_sysctl_exit(void);
 396 #else
 397 static inline int dccp_sysctl_init(void)
 398 {
 399         return 0;
 400 }
 401
 402 static inline void dccp_sysctl_exit(void)
 403 {
 404 }
 405 #endif
 406
 407 #endif /* _DCCP_H */