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