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
  39 extern void dccp_time_wait(struct sock *sk, int state, int timeo);
  40
  41 /*
  42  *  Set safe upper bounds for header and option length. Since Data Offset is 8
  43  *  bits (RFC 4340, sec. 5.1), the total header length can never be more than
  44  *  4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1):
  45  *    - DCCP-Response with ACK Subheader and 4 bytes of Service code      OR
  46  *    - DCCP-Reset    with ACK Subheader and 4 bytes of Reset Code fields
  47  *  Hence a safe upper bound for the maximum option length is 1020-28 = 992
  48  */
  49 #define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(int))
  50 #define DCCP_MAX_PACKET_HDR 28
  51 #define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR)
  52 #define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER)
  53
  54 #define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
  55                                      * state, about 60 seconds */
  56
  57 /* RFC 1122, 4.2.3.1 initial RTO value */
  58 #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
  59
  60 /* Maximal interval between probes for local resources.  */
  61 #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
  62
  63 #define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
  64
  65 /* is seq1 < seq2 ? */
  66 static inline int before48(const u64 seq1, const u64 seq2)
  67 {
  68         return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
  69 }
  70
  71 /* is seq1 > seq2 ? */
  72 static inline int after48(const u64 seq1, const u64 seq2)
  73 {
  74         return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
  75 }
  76
  77 /* is seq2 <= seq1 <= seq3 ? */
  78 static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
  79 {
  80         return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
  81 }
  82
  83 static inline u64 max48(const u64 seq1, const u64 seq2)
  84 {
  85         return after48(seq1, seq2) ? seq1 : seq2;
  86 }
  87
  88 /* is seq1 next seqno after seq2 */
  89 static inline int follows48(const u64 seq1, const u64 seq2)
  90 {
  91         int diff = (seq1 & 0xFFFF) - (seq2 & 0xFFFF);
  92
  93         return diff==1;
  94 }
  95
  96 enum {
  97         DCCP_MIB_NUM = 0,
  98         DCCP_MIB_ACTIVEOPENS,                   /* ActiveOpens */
  99         DCCP_MIB_ESTABRESETS,                   /* EstabResets */
 100         DCCP_MIB_CURRESTAB,                     /* CurrEstab */
 101         DCCP_MIB_OUTSEGS,                       /* OutSegs */
 102         DCCP_MIB_OUTRSTS,
 103         DCCP_MIB_ABORTONTIMEOUT,
 104         DCCP_MIB_TIMEOUTS,
 105         DCCP_MIB_ABORTFAILED,
 106         DCCP_MIB_PASSIVEOPENS,
 107         DCCP_MIB_ATTEMPTFAILS,
 108         DCCP_MIB_OUTDATAGRAMS,
 109         DCCP_MIB_INERRS,
 110         DCCP_MIB_OPTMANDATORYERROR,
 111         DCCP_MIB_INVALIDOPT,
 112         __DCCP_MIB_MAX
 113 };
 114
 115 #define DCCP_MIB_MAX    __DCCP_MIB_MAX
 116 struct dccp_mib {
 117         unsigned long   mibs[DCCP_MIB_MAX];
 118 } __SNMP_MIB_ALIGN__;
 119
 120 DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
 121 #define DCCP_INC_STATS(field)       SNMP_INC_STATS(dccp_statistics, field)
 122 #define DCCP_INC_STATS_BH(field)    SNMP_INC_STATS_BH(dccp_statistics, field)
 123 #define DCCP_INC_STATS_USER(field)  SNMP_INC_STATS_USER(dccp_statistics, field)
 124 #define DCCP_DEC_STATS(field)       SNMP_DEC_STATS(dccp_statistics, field)
 125 #define DCCP_ADD_STATS_BH(field, val) \
 126                         SNMP_ADD_STATS_BH(dccp_statistics, field, val)
 127 #define DCCP_ADD_STATS_USER(field, val) \
 128                         SNMP_ADD_STATS_USER(dccp_statistics, field, val)
 129
 130 extern int  dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
 131
 132 extern void dccp_send_ack(struct sock *sk);
 133 extern void dccp_send_delayed_ack(struct sock *sk);
 134 extern void dccp_reqsk_send_ack(struct sk_buff *sk, struct request_sock *rsk);
 135
 136 extern void dccp_send_sync(struct sock *sk, const u64 seq,
 137                            const enum dccp_pkt_type pkt_type);
 138
 139 extern void dccp_write_xmit(struct sock *sk, int block);
 140 extern void dccp_write_space(struct sock *sk);
 141
 142 extern void dccp_init_xmit_timers(struct sock *sk);
 143 static inline void dccp_clear_xmit_timers(struct sock *sk)
 144 {
 145         inet_csk_clear_xmit_timers(sk);
 146 }
 147
 148 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
 149
 150 extern const char *dccp_packet_name(const int type);
 151 extern const char *dccp_state_name(const int state);
 152
 153 extern void dccp_set_state(struct sock *sk, const int state);
 154 extern void dccp_done(struct sock *sk);
 155
 156 static inline void dccp_openreq_init(struct request_sock *req,
 157                                      struct dccp_sock *dp,
 158                                      struct sk_buff *skb)
 159 {
 160         /*
 161          * FIXME: fill in the other req fields from the DCCP options
 162          * received
 163          */
 164         inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
 165         inet_rsk(req)->acked    = 0;
 166         req->rcv_wnd = 0;
 167 }
 168
 169 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
 170
 171 extern struct sock *dccp_create_openreq_child(struct sock *sk,
 172                                               const struct request_sock *req,
 173                                               const struct sk_buff *skb);
 174
 175 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
 176
 177 extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
 178                                               struct sk_buff *skb,
 179                                               struct request_sock *req,
 180                                               struct dst_entry *dst);
 181 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
 182                                    struct request_sock *req,
 183                                    struct request_sock **prev);
 184
 185 extern int dccp_child_process(struct sock *parent, struct sock *child,
 186                               struct sk_buff *skb);
 187 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 188                                   struct dccp_hdr *dh, unsigned len);
 189 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
 190                                 const struct dccp_hdr *dh, const unsigned len);
 191
 192 extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
 193 extern int dccp_destroy_sock(struct sock *sk);
 194
 195 extern void             dccp_close(struct sock *sk, long timeout);
 196 extern struct sk_buff   *dccp_make_response(struct sock *sk,
 197                                             struct dst_entry *dst,
 198                                             struct request_sock *req);
 199
 200 extern int         dccp_connect(struct sock *sk);
 201 extern int         dccp_disconnect(struct sock *sk, int flags);
 202 extern void        dccp_hash(struct sock *sk);
 203 extern void        dccp_unhash(struct sock *sk);
 204 extern int         dccp_getsockopt(struct sock *sk, int level, int optname,
 205                                    char __user *optval, int __user *optlen);
 206 extern int         dccp_setsockopt(struct sock *sk, int level, int optname,
 207                                    char __user *optval, int optlen);
 208 #ifdef CONFIG_COMPAT
 209 extern int         compat_dccp_getsockopt(struct sock *sk,
 210                                 int level, int optname,
 211                                 char __user *optval, int __user *optlen);
 212 extern int         compat_dccp_setsockopt(struct sock *sk,
 213                                 int level, int optname,
 214                                 char __user *optval, int optlen);
 215 #endif
 216 extern int         dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
 217 extern int         dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
 218                                 struct msghdr *msg, size_t size);
 219 extern int         dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
 220                                 struct msghdr *msg, size_t len, int nonblock,
 221                                 int flags, int *addr_len);
 222 extern void        dccp_shutdown(struct sock *sk, int how);
 223 extern int         inet_dccp_listen(struct socket *sock, int backlog);
 224 extern unsigned int dccp_poll(struct file *file, struct socket *sock,
 225                              poll_table *wait);
 226 extern void        dccp_v4_send_check(struct sock *sk, int len,
 227                                       struct sk_buff *skb);
 228 extern int         dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
 229                                    int addr_len);
 230
 231 extern int         dccp_v4_checksum(const struct sk_buff *skb,
 232                                     const __be32 saddr, const __be32 daddr);
 233
 234 extern int         dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
 235 extern void        dccp_send_close(struct sock *sk, const int active);
 236 extern int         dccp_invalid_packet(struct sk_buff *skb);
 237
 238 static inline int dccp_bad_service_code(const struct sock *sk,
 239                                         const __be32 service)
 240 {
 241         const struct dccp_sock *dp = dccp_sk(sk);
 242
 243         if (dp->dccps_service == service)
 244                 return 0;
 245         return !dccp_list_has_service(dp->dccps_service_list, service);
 246 }
 247
 248 struct dccp_skb_cb {
 249         __u8  dccpd_type:4;
 250         __u8  dccpd_ccval:4;
 251         __u8  dccpd_reset_code;
 252         __u16 dccpd_opt_len;
 253         __u64 dccpd_seq;
 254         __u64 dccpd_ack_seq;
 255 };
 256
 257 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
 258
 259 static inline int dccp_non_data_packet(const struct sk_buff *skb)
 260 {
 261         const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
 262
 263         return type == DCCP_PKT_ACK      ||
 264                type == DCCP_PKT_CLOSE    ||
 265                type == DCCP_PKT_CLOSEREQ ||
 266                type == DCCP_PKT_RESET    ||
 267                type == DCCP_PKT_SYNC     ||
 268                type == DCCP_PKT_SYNCACK;
 269 }
 270
 271 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
 272 {
 273         const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
 274
 275         return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
 276 }
 277
 278 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
 279 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
 280
 281 static inline void dccp_set_seqno(u64 *seqno, u64 value)
 282 {
 283         if (value > DCCP_MAX_SEQNO)
 284                 value -= DCCP_MAX_SEQNO + 1;
 285         *seqno = value;
 286 }
 287
 288 static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
 289 {
 290         return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
 291 }
 292
 293 static inline void dccp_inc_seqno(u64 *seqno)
 294 {
 295         if (++*seqno > DCCP_MAX_SEQNO)
 296                 *seqno = 0;
 297 }
 298
 299 static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
 300 {
 301         struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
 302                                                            sizeof(*dh));
 303         dh->dccph_seq2 = 0;
 304         dh->dccph_seq = htons((gss >> 32) & 0xfffff);
 305         dhx->dccph_seq_low = htonl(gss & 0xffffffff);
 306 }
 307
 308 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
 309                                     const u64 gsr)
 310 {
 311         dhack->dccph_reserved1 = 0;
 312         dhack->dccph_ack_nr_high = htons(gsr >> 32);
 313         dhack->dccph_ack_nr_low  = htonl(gsr & 0xffffffff);
 314 }
 315
 316 static inline void dccp_update_gsr(struct sock *sk, u64 seq)
 317 {
 318         struct dccp_sock *dp = dccp_sk(sk);
 319         const struct dccp_minisock *dmsk = dccp_msk(sk);
 320
 321         dp->dccps_gsr = seq;
 322         dccp_set_seqno(&dp->dccps_swl,
 323                        dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
 324         dccp_set_seqno(&dp->dccps_swh,
 325                        dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4);
 326 }
 327
 328 static inline void dccp_update_gss(struct sock *sk, u64 seq)
 329 {
 330         struct dccp_sock *dp = dccp_sk(sk);
 331
 332         dp->dccps_awh = dp->dccps_gss = seq;
 333         dccp_set_seqno(&dp->dccps_awl,
 334                        (dp->dccps_gss -
 335                         dccp_msk(sk)->dccpms_sequence_window + 1));
 336 }
 337
 338 static inline int dccp_ack_pending(const struct sock *sk)
 339 {
 340         const struct dccp_sock *dp = dccp_sk(sk);
 341         return dp->dccps_timestamp_echo != 0 ||
 342 #ifdef CONFIG_IP_DCCP_ACKVEC
 343                (dccp_msk(sk)->dccpms_send_ack_vector &&
 344                 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||
 345 #endif
 346                inet_csk_ack_scheduled(sk);
 347 }
 348
 349 extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
 350 extern int dccp_insert_option_elapsed_time(struct sock *sk,
 351                                             struct sk_buff *skb,
 352                                             u32 elapsed_time);
 353 extern int dccp_insert_option_timestamp(struct sock *sk,
 354                                          struct sk_buff *skb);
 355 extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
 356                                unsigned char option,
 357                                const void *value, unsigned char len);
 358
 359 extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);
 360
 361 static inline suseconds_t timeval_usecs(const struct timeval *tv)
 362 {
 363         return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
 364 }
 365
 366 static inline suseconds_t timeval_delta(const struct timeval *large,
 367                                         const struct timeval *small)
 368 {
 369         time_t      secs  = large->tv_sec  - small->tv_sec;
 370         suseconds_t usecs = large->tv_usec - small->tv_usec;
 371
 372         if (usecs < 0) {
 373                 secs--;
 374                 usecs += USEC_PER_SEC;
 375         }
 376         return secs * USEC_PER_SEC + usecs;
 377 }
 378
 379 static inline void timeval_add_usecs(struct timeval *tv,
 380                                      const suseconds_t usecs)
 381 {
 382         tv->tv_usec += usecs;
 383         while (tv->tv_usec >= USEC_PER_SEC) {
 384                 tv->tv_sec++;
 385                 tv->tv_usec -= USEC_PER_SEC;
 386         }
 387 }
 388
 389 static inline void timeval_sub_usecs(struct timeval *tv,
 390                                      const suseconds_t usecs)
 391 {
 392         tv->tv_usec -= usecs;
 393         while (tv->tv_usec < 0) {
 394                 tv->tv_sec--;
 395                 tv->tv_usec += USEC_PER_SEC;
 396         }
 397 }
 398
 399 #ifdef CONFIG_SYSCTL
 400 extern int dccp_sysctl_init(void);
 401 extern void dccp_sysctl_exit(void);
 402 #else
 403 static inline int dccp_sysctl_init(void)
 404 {
 405         return 0;
 406 }
 407
 408 static inline void dccp_sysctl_exit(void)
 409 {
 410 }
 411 #endif
 412
 413 #endif /* _DCCP_H */