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