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 #define DCCP_XMIT_TIMEO 30000 /* Time/msecs for blocking transmit per packet */
  66
  67 /* is seq1 < seq2 ? */
  68 static inline int before48(const u64 seq1, const u64 seq2)
  69 {
  70         return (s64)((seq1 << 16) - (seq2 << 16)) < 0;
  71 }
  72
  73 /* is seq1 > seq2 ? */
  74 static inline int after48(const u64 seq1, const u64 seq2)
  75 {
  76         return (s64)((seq2 << 16) - (seq1 << 16)) < 0;
  77 }
  78
  79 /* is seq2 <= seq1 <= seq3 ? */
  80 static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
  81 {
  82         return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
  83 }
  84
  85 static inline u64 max48(const u64 seq1, const u64 seq2)
  86 {
  87         return after48(seq1, seq2) ? seq1 : seq2;
  88 }
  89
  90 /* is seq1 next seqno after seq2 */
  91 static inline int follows48(const u64 seq1, const u64 seq2)
  92 {
  93         int diff = (seq1 & 0xFFFF) - (seq2 & 0xFFFF);
  94
  95         return diff==1;
  96 }
  97
  98 enum {
  99         DCCP_MIB_NUM = 0,
 100         DCCP_MIB_ACTIVEOPENS,                   /* ActiveOpens */
 101         DCCP_MIB_ESTABRESETS,                   /* EstabResets */
 102         DCCP_MIB_CURRESTAB,                     /* CurrEstab */
 103         DCCP_MIB_OUTSEGS,                       /* OutSegs */
 104         DCCP_MIB_OUTRSTS,
 105         DCCP_MIB_ABORTONTIMEOUT,
 106         DCCP_MIB_TIMEOUTS,
 107         DCCP_MIB_ABORTFAILED,
 108         DCCP_MIB_PASSIVEOPENS,
 109         DCCP_MIB_ATTEMPTFAILS,
 110         DCCP_MIB_OUTDATAGRAMS,
 111         DCCP_MIB_INERRS,
 112         DCCP_MIB_OPTMANDATORYERROR,
 113         DCCP_MIB_INVALIDOPT,
 114         __DCCP_MIB_MAX
 115 };
 116
 117 #define DCCP_MIB_MAX    __DCCP_MIB_MAX
 118 struct dccp_mib {
 119         unsigned long   mibs[DCCP_MIB_MAX];
 120 } __SNMP_MIB_ALIGN__;
 121
 122 DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
 123 #define DCCP_INC_STATS(field)       SNMP_INC_STATS(dccp_statistics, field)
 124 #define DCCP_INC_STATS_BH(field)    SNMP_INC_STATS_BH(dccp_statistics, field)
 125 #define DCCP_INC_STATS_USER(field)  SNMP_INC_STATS_USER(dccp_statistics, field)
 126 #define DCCP_DEC_STATS(field)       SNMP_DEC_STATS(dccp_statistics, field)
 127 #define DCCP_ADD_STATS_BH(field, val) \
 128                         SNMP_ADD_STATS_BH(dccp_statistics, field, val)
 129 #define DCCP_ADD_STATS_USER(field, val) \
 130                         SNMP_ADD_STATS_USER(dccp_statistics, field, val)
 131
 132 extern int  dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
 133
 134 extern void dccp_send_ack(struct sock *sk);
 135 extern void dccp_send_delayed_ack(struct sock *sk);
 136 extern void dccp_reqsk_send_ack(struct sk_buff *sk, struct request_sock *rsk);
 137
 138 extern void dccp_send_sync(struct sock *sk, const u64 seq,
 139                            const enum dccp_pkt_type pkt_type);
 140
 141 extern void dccp_write_xmit(struct sock *sk, int block);
 142 extern void dccp_write_space(struct sock *sk);
 143
 144 extern void dccp_init_xmit_timers(struct sock *sk);
 145 static inline void dccp_clear_xmit_timers(struct sock *sk)
 146 {
 147         inet_csk_clear_xmit_timers(sk);
 148 }
 149
 150 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
 151
 152 extern const char *dccp_packet_name(const int type);
 153 extern const char *dccp_state_name(const int state);
 154
 155 extern void dccp_set_state(struct sock *sk, const int state);
 156 extern void dccp_done(struct sock *sk);
 157
 158 static inline void dccp_openreq_init(struct request_sock *req,
 159                                      struct dccp_sock *dp,
 160                                      struct sk_buff *skb)
 161 {
 162         /*
 163          * FIXME: fill in the other req fields from the DCCP options
 164          * received
 165          */
 166         inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
 167         inet_rsk(req)->acked    = 0;
 168         req->rcv_wnd = 0;
 169 }
 170
 171 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
 172
 173 extern struct sock *dccp_create_openreq_child(struct sock *sk,
 174                                               const struct request_sock *req,
 175                                               const struct sk_buff *skb);
 176
 177 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
 178
 179 extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
 180                                               struct sk_buff *skb,
 181                                               struct request_sock *req,
 182                                               struct dst_entry *dst);
 183 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
 184                                    struct request_sock *req,
 185                                    struct request_sock **prev);
 186
 187 extern int dccp_child_process(struct sock *parent, struct sock *child,
 188                               struct sk_buff *skb);
 189 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 190                                   struct dccp_hdr *dh, unsigned len);
 191 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
 192                                 const struct dccp_hdr *dh, const unsigned len);
 193
 194 extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
 195 extern int dccp_destroy_sock(struct sock *sk);
 196
 197 extern void             dccp_close(struct sock *sk, long timeout);
 198 extern struct sk_buff   *dccp_make_response(struct sock *sk,
 199                                             struct dst_entry *dst,
 200                                             struct request_sock *req);
 201
 202 extern int         dccp_connect(struct sock *sk);
 203 extern int         dccp_disconnect(struct sock *sk, int flags);
 204 extern void        dccp_hash(struct sock *sk);
 205 extern void        dccp_unhash(struct sock *sk);
 206 extern int         dccp_getsockopt(struct sock *sk, int level, int optname,
 207                                    char __user *optval, int __user *optlen);
 208 extern int         dccp_setsockopt(struct sock *sk, int level, int optname,
 209                                    char __user *optval, int optlen);
 210 #ifdef CONFIG_COMPAT
 211 extern int         compat_dccp_getsockopt(struct sock *sk,
 212                                 int level, int optname,
 213                                 char __user *optval, int __user *optlen);
 214 extern int         compat_dccp_setsockopt(struct sock *sk,
 215                                 int level, int optname,
 216                                 char __user *optval, int optlen);
 217 #endif
 218 extern int         dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
 219 extern int         dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
 220                                 struct msghdr *msg, size_t size);
 221 extern int         dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
 222                                 struct msghdr *msg, size_t len, int nonblock,
 223                                 int flags, int *addr_len);
 224 extern void        dccp_shutdown(struct sock *sk, int how);
 225 extern int         inet_dccp_listen(struct socket *sock, int backlog);
 226 extern unsigned int dccp_poll(struct file *file, struct socket *sock,
 227                              poll_table *wait);
 228 extern void        dccp_v4_send_check(struct sock *sk, int len,
 229                                       struct sk_buff *skb);
 230 extern int         dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
 231                                    int addr_len);
 232
 233 extern int         dccp_v4_checksum(const struct sk_buff *skb,
 234                                     const __be32 saddr, const __be32 daddr);
 235
 236 extern int         dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
 237 extern void        dccp_send_close(struct sock *sk, const int active);
 238 extern int         dccp_invalid_packet(struct sk_buff *skb);
 239
 240 static inline int dccp_bad_service_code(const struct sock *sk,
 241                                         const __be32 service)
 242 {
 243         const struct dccp_sock *dp = dccp_sk(sk);
 244
 245         if (dp->dccps_service == service)
 246                 return 0;
 247         return !dccp_list_has_service(dp->dccps_service_list, service);
 248 }
 249
 250 struct dccp_skb_cb {
 251         __u8  dccpd_type:4;
 252         __u8  dccpd_ccval:4;
 253         __u8  dccpd_reset_code;
 254         __u16 dccpd_opt_len;
 255         __u64 dccpd_seq;
 256         __u64 dccpd_ack_seq;
 257 };
 258
 259 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
 260
 261 static inline int dccp_non_data_packet(const struct sk_buff *skb)
 262 {
 263         const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
 264
 265         return type == DCCP_PKT_ACK      ||
 266                type == DCCP_PKT_CLOSE    ||
 267                type == DCCP_PKT_CLOSEREQ ||
 268                type == DCCP_PKT_RESET    ||
 269                type == DCCP_PKT_SYNC     ||
 270                type == DCCP_PKT_SYNCACK;
 271 }
 272
 273 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
 274 {
 275         const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
 276
 277         return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
 278 }
 279
 280 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
 281 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
 282
 283 static inline void dccp_set_seqno(u64 *seqno, u64 value)
 284 {
 285         if (value > DCCP_MAX_SEQNO)
 286                 value -= DCCP_MAX_SEQNO + 1;
 287         *seqno = value;
 288 }
 289
 290 static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
 291 {
 292         return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
 293 }
 294
 295 static inline void dccp_inc_seqno(u64 *seqno)
 296 {
 297         if (++*seqno > DCCP_MAX_SEQNO)
 298                 *seqno = 0;
 299 }
 300
 301 static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
 302 {
 303         struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
 304                                                            sizeof(*dh));
 305         dh->dccph_seq2 = 0;
 306         dh->dccph_seq = htons((gss >> 32) & 0xfffff);
 307         dhx->dccph_seq_low = htonl(gss & 0xffffffff);
 308 }
 309
 310 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
 311                                     const u64 gsr)
 312 {
 313         dhack->dccph_reserved1 = 0;
 314         dhack->dccph_ack_nr_high = htons(gsr >> 32);
 315         dhack->dccph_ack_nr_low  = htonl(gsr & 0xffffffff);
 316 }
 317
 318 static inline void dccp_update_gsr(struct sock *sk, u64 seq)
 319 {
 320         struct dccp_sock *dp = dccp_sk(sk);
 321         const struct dccp_minisock *dmsk = dccp_msk(sk);
 322
 323         dp->dccps_gsr = seq;
 324         dccp_set_seqno(&dp->dccps_swl,
 325                        dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
 326         dccp_set_seqno(&dp->dccps_swh,
 327                        dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4);
 328 }
 329
 330 static inline void dccp_update_gss(struct sock *sk, u64 seq)
 331 {
 332         struct dccp_sock *dp = dccp_sk(sk);
 333
 334         dp->dccps_awh = dp->dccps_gss = seq;
 335         dccp_set_seqno(&dp->dccps_awl,
 336                        (dp->dccps_gss -
 337                         dccp_msk(sk)->dccpms_sequence_window + 1));
 338 }
 339
 340 static inline int dccp_ack_pending(const struct sock *sk)
 341 {
 342         const struct dccp_sock *dp = dccp_sk(sk);
 343         return dp->dccps_timestamp_echo != 0 ||
 344 #ifdef CONFIG_IP_DCCP_ACKVEC
 345                (dccp_msk(sk)->dccpms_send_ack_vector &&
 346                 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||
 347 #endif
 348                inet_csk_ack_scheduled(sk);
 349 }
 350
 351 extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
 352 extern int dccp_insert_option_elapsed_time(struct sock *sk,
 353                                             struct sk_buff *skb,
 354                                             u32 elapsed_time);
 355 extern int dccp_insert_option_timestamp(struct sock *sk,
 356                                          struct sk_buff *skb);
 357 extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
 358                                unsigned char option,
 359                                const void *value, unsigned char len);
 360
 361 extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);
 362
 363 static inline suseconds_t timeval_usecs(const struct timeval *tv)
 364 {
 365         return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
 366 }
 367
 368 static inline suseconds_t timeval_delta(const struct timeval *large,
 369                                         const struct timeval *small)
 370 {
 371         time_t      secs  = large->tv_sec  - small->tv_sec;
 372         suseconds_t usecs = large->tv_usec - small->tv_usec;
 373
 374         if (usecs < 0) {
 375                 secs--;
 376                 usecs += USEC_PER_SEC;
 377         }
 378         return secs * USEC_PER_SEC + usecs;
 379 }
 380
 381 static inline void timeval_add_usecs(struct timeval *tv,
 382                                      const suseconds_t usecs)
 383 {
 384         tv->tv_usec += usecs;
 385         while (tv->tv_usec >= USEC_PER_SEC) {
 386                 tv->tv_sec++;
 387                 tv->tv_usec -= USEC_PER_SEC;
 388         }
 389 }
 390
 391 static inline void timeval_sub_usecs(struct timeval *tv,
 392                                      const suseconds_t usecs)
 393 {
 394         tv->tv_usec -= usecs;
 395         while (tv->tv_usec < 0) {
 396                 tv->tv_sec--;
 397                 tv->tv_usec += USEC_PER_SEC;
 398         }
 399 }
 400
 401 #ifdef CONFIG_SYSCTL
 402 extern int dccp_sysctl_init(void);
 403 extern void dccp_sysctl_exit(void);
 404 #else
 405 static inline int dccp_sysctl_init(void)
 406 {
 407         return 0;
 408 }
 409
 410 static inline void dccp_sysctl_exit(void)
 411 {
 412 }
 413 #endif
 414
 415 #endif /* _DCCP_H */