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 /*
 133  *      Checksumming routines
 134  */
 135 static inline int dccp_csum_coverage(const struct sk_buff *skb)
 136 {
 137         const struct dccp_hdr* dh = dccp_hdr(skb);
 138
 139         if (dh->dccph_cscov == 0)
 140                 return skb->len;
 141         return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32);
 142 }
 143
 144 static inline void dccp_csum_outgoing(struct sk_buff *skb)
 145 {
 146         int cov = dccp_csum_coverage(skb);
 147
 148         if (cov >= skb->len)
 149                 dccp_hdr(skb)->dccph_cscov = 0;
 150
 151         skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0);
 152 }
 153
 154 extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
 155
 156 extern int  dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
 157
 158 extern void dccp_send_ack(struct sock *sk);
 159 extern void dccp_send_delayed_ack(struct sock *sk);
 160 extern void dccp_reqsk_send_ack(struct sk_buff *sk, struct request_sock *rsk);
 161
 162 extern void dccp_send_sync(struct sock *sk, const u64 seq,
 163                            const enum dccp_pkt_type pkt_type);
 164
 165 extern void dccp_write_xmit(struct sock *sk, int block);
 166 extern void dccp_write_space(struct sock *sk);
 167
 168 extern void dccp_init_xmit_timers(struct sock *sk);
 169 static inline void dccp_clear_xmit_timers(struct sock *sk)
 170 {
 171         inet_csk_clear_xmit_timers(sk);
 172 }
 173
 174 extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
 175
 176 extern const char *dccp_packet_name(const int type);
 177 extern const char *dccp_state_name(const int state);
 178
 179 extern void dccp_set_state(struct sock *sk, const int state);
 180 extern void dccp_done(struct sock *sk);
 181
 182 extern void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb);
 183
 184 extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
 185
 186 extern struct sock *dccp_create_openreq_child(struct sock *sk,
 187                                               const struct request_sock *req,
 188                                               const struct sk_buff *skb);
 189
 190 extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
 191
 192 extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
 193                                               struct sk_buff *skb,
 194                                               struct request_sock *req,
 195                                               struct dst_entry *dst);
 196 extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
 197                                    struct request_sock *req,
 198                                    struct request_sock **prev);
 199
 200 extern int dccp_child_process(struct sock *parent, struct sock *child,
 201                               struct sk_buff *skb);
 202 extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 203                                   struct dccp_hdr *dh, unsigned len);
 204 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
 205                                 const struct dccp_hdr *dh, const unsigned len);
 206
 207 extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
 208 extern int dccp_destroy_sock(struct sock *sk);
 209
 210 extern void             dccp_close(struct sock *sk, long timeout);
 211 extern struct sk_buff   *dccp_make_response(struct sock *sk,
 212                                             struct dst_entry *dst,
 213                                             struct request_sock *req);
 214
 215 extern int         dccp_connect(struct sock *sk);
 216 extern int         dccp_disconnect(struct sock *sk, int flags);
 217 extern void        dccp_hash(struct sock *sk);
 218 extern void        dccp_unhash(struct sock *sk);
 219 extern int         dccp_getsockopt(struct sock *sk, int level, int optname,
 220                                    char __user *optval, int __user *optlen);
 221 extern int         dccp_setsockopt(struct sock *sk, int level, int optname,
 222                                    char __user *optval, int optlen);
 223 #ifdef CONFIG_COMPAT
 224 extern int         compat_dccp_getsockopt(struct sock *sk,
 225                                 int level, int optname,
 226                                 char __user *optval, int __user *optlen);
 227 extern int         compat_dccp_setsockopt(struct sock *sk,
 228                                 int level, int optname,
 229                                 char __user *optval, int optlen);
 230 #endif
 231 extern int         dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
 232 extern int         dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
 233                                 struct msghdr *msg, size_t size);
 234 extern int         dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
 235                                 struct msghdr *msg, size_t len, int nonblock,
 236                                 int flags, int *addr_len);
 237 extern void        dccp_shutdown(struct sock *sk, int how);
 238 extern int         inet_dccp_listen(struct socket *sock, int backlog);
 239 extern unsigned int dccp_poll(struct file *file, struct socket *sock,
 240                              poll_table *wait);
 241 extern int         dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
 242                                    int addr_len);
 243
 244 extern int         dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
 245 extern void        dccp_send_close(struct sock *sk, const int active);
 246 extern int         dccp_invalid_packet(struct sk_buff *skb);
 247
 248 static inline int dccp_bad_service_code(const struct sock *sk,
 249                                         const __be32 service)
 250 {
 251         const struct dccp_sock *dp = dccp_sk(sk);
 252
 253         if (dp->dccps_service == service)
 254                 return 0;
 255         return !dccp_list_has_service(dp->dccps_service_list, service);
 256 }
 257
 258 struct dccp_skb_cb {
 259         __u8  dccpd_type:4;
 260         __u8  dccpd_ccval:4;
 261         __u8  dccpd_reset_code;
 262         __u16 dccpd_opt_len;
 263         __u64 dccpd_seq;
 264         __u64 dccpd_ack_seq;
 265 };
 266
 267 #define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
 268
 269 static inline int dccp_non_data_packet(const struct sk_buff *skb)
 270 {
 271         const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
 272
 273         return type == DCCP_PKT_ACK      ||
 274                type == DCCP_PKT_CLOSE    ||
 275                type == DCCP_PKT_CLOSEREQ ||
 276                type == DCCP_PKT_RESET    ||
 277                type == DCCP_PKT_SYNC     ||
 278                type == DCCP_PKT_SYNCACK;
 279 }
 280
 281 static inline int dccp_packet_without_ack(const struct sk_buff *skb)
 282 {
 283         const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
 284
 285         return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
 286 }
 287
 288 #define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
 289 #define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
 290
 291 static inline void dccp_set_seqno(u64 *seqno, u64 value)
 292 {
 293         if (value > DCCP_MAX_SEQNO)
 294                 value -= DCCP_MAX_SEQNO + 1;
 295         *seqno = value;
 296 }
 297
 298 static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
 299 {
 300         return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
 301 }
 302
 303 static inline void dccp_inc_seqno(u64 *seqno)
 304 {
 305         if (++*seqno > DCCP_MAX_SEQNO)
 306                 *seqno = 0;
 307 }
 308
 309 static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
 310 {
 311         struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
 312                                                            sizeof(*dh));
 313         dh->dccph_seq2 = 0;
 314         dh->dccph_seq = htons((gss >> 32) & 0xfffff);
 315         dhx->dccph_seq_low = htonl(gss & 0xffffffff);
 316 }
 317
 318 static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
 319                                     const u64 gsr)
 320 {
 321         dhack->dccph_reserved1 = 0;
 322         dhack->dccph_ack_nr_high = htons(gsr >> 32);
 323         dhack->dccph_ack_nr_low  = htonl(gsr & 0xffffffff);
 324 }
 325
 326 static inline void dccp_update_gsr(struct sock *sk, u64 seq)
 327 {
 328         struct dccp_sock *dp = dccp_sk(sk);
 329         const struct dccp_minisock *dmsk = dccp_msk(sk);
 330
 331         dp->dccps_gsr = seq;
 332         dccp_set_seqno(&dp->dccps_swl,
 333                        dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
 334         dccp_set_seqno(&dp->dccps_swh,
 335                        dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4);
 336 }
 337
 338 static inline void dccp_update_gss(struct sock *sk, u64 seq)
 339 {
 340         struct dccp_sock *dp = dccp_sk(sk);
 341
 342         dp->dccps_awh = dp->dccps_gss = seq;
 343         dccp_set_seqno(&dp->dccps_awl,
 344                        (dp->dccps_gss -
 345                         dccp_msk(sk)->dccpms_sequence_window + 1));
 346 }
 347
 348 static inline int dccp_ack_pending(const struct sock *sk)
 349 {
 350         const struct dccp_sock *dp = dccp_sk(sk);
 351         return dp->dccps_timestamp_echo != 0 ||
 352 #ifdef CONFIG_IP_DCCP_ACKVEC
 353                (dccp_msk(sk)->dccpms_send_ack_vector &&
 354                 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||
 355 #endif
 356                inet_csk_ack_scheduled(sk);
 357 }
 358
 359 extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
 360 extern int dccp_insert_option_elapsed_time(struct sock *sk,
 361                                             struct sk_buff *skb,
 362                                             u32 elapsed_time);
 363 extern int dccp_insert_option_timestamp(struct sock *sk,
 364                                          struct sk_buff *skb);
 365 extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
 366                                unsigned char option,
 367                                const void *value, unsigned char len);
 368
 369 extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);
 370
 371 static inline suseconds_t timeval_usecs(const struct timeval *tv)
 372 {
 373         return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
 374 }
 375
 376 static inline suseconds_t timeval_delta(const struct timeval *large,
 377                                         const struct timeval *small)
 378 {
 379         time_t      secs  = large->tv_sec  - small->tv_sec;
 380         suseconds_t usecs = large->tv_usec - small->tv_usec;
 381
 382         if (usecs < 0) {
 383                 secs--;
 384                 usecs += USEC_PER_SEC;
 385         }
 386         return secs * USEC_PER_SEC + usecs;
 387 }
 388
 389 static inline void timeval_add_usecs(struct timeval *tv,
 390                                      const suseconds_t usecs)
 391 {
 392         tv->tv_usec += usecs;
 393         while (tv->tv_usec >= USEC_PER_SEC) {
 394                 tv->tv_sec++;
 395                 tv->tv_usec -= USEC_PER_SEC;
 396         }
 397 }
 398
 399 static inline void timeval_sub_usecs(struct timeval *tv,
 400                                      const suseconds_t usecs)
 401 {
 402         tv->tv_usec -= usecs;
 403         while (tv->tv_usec < 0) {
 404                 tv->tv_sec--;
 405                 tv->tv_usec += USEC_PER_SEC;
 406         }
 407 }
 408
 409 #ifdef CONFIG_SYSCTL
 410 extern int dccp_sysctl_init(void);
 411 extern void dccp_sysctl_exit(void);
 412 #else
 413 static inline int dccp_sysctl_init(void)
 414 {
 415         return 0;
 416 }
 417
 418 static inline void dccp_sysctl_exit(void)
 419 {
 420 }
 421 #endif
 422
 423 #endif /* _DCCP_H */