LXR linux/include/net/inet_connection

   1/*
   2 * NET          Generic infrastructure for INET connection oriented protocols.
   3 *
   4 *              Definitions for inet_connection_sock 
   5 *
   6 * Authors:     Many people, see the TCP sources
   7 *
   8 *              From code originally in TCP
   9 *
  10 *              This program is free software; you can redistribute it and/or
  11 *              modify it under the terms of the GNU General Public License
  12 *              as published by the Free Software Foundation; either version
  13 *              2 of the License, or (at your option) any later version.
  14 */
  15#ifndef _INET_CONNECTION_SOCK_H
  16#define _INET_CONNECTION_SOCK_H
  17
  18#include <linux/compiler.h>
  19#include <linux/string.h>
  20#include <linux/timer.h>
  21#include <linux/poll.h>
  22
  23#include <net/inet_sock.h>
  24#include <net/request_sock.h>
  25
  26#define INET_CSK_DEBUG 1
  27
  28/* Cancel timers, when they are not required. */
  29#undef INET_CSK_CLEAR_TIMERS
  30
  31struct inet_bind_bucket;
  32struct tcp_congestion_ops;
  33
  34/*
  35 * Pointers to address related TCP functions
  36 * (i.e. things that depend on the address family)
  37 */
  38struct inet_connection_sock_af_ops {
  39        int         (*queue_xmit)(struct sk_buff *skb, int ipfragok);
  40        void        (*send_check)(struct sock *sk, int len,
  41                                  struct sk_buff *skb);
  42        int         (*rebuild_header)(struct sock *sk);
  43        int         (*conn_request)(struct sock *sk, struct sk_buff *skb);
  44        struct sock *(*syn_recv_sock)(struct sock *sk, struct sk_buff *skb,
  45                                      struct request_sock *req,
  46                                      struct dst_entry *dst);
  47        int         (*remember_stamp)(struct sock *sk);
  48        u16         net_header_len;
  49        u16         sockaddr_len;
  50        int         (*setsockopt)(struct sock *sk, int level, int optname, 
  51                                  char __user *optval, int optlen);
  52        int         (*getsockopt)(struct sock *sk, int level, int optname, 
  53                                  char __user *optval, int __user *optlen);
  54        int         (*compat_setsockopt)(struct sock *sk,
  55                                int level, int optname,
  56                                char __user *optval, int optlen);
  57        int         (*compat_getsockopt)(struct sock *sk,
  58                                int level, int optname,
  59                                char __user *optval, int __user *optlen);
  60        void        (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
  61        int         (*bind_conflict)(const struct sock *sk,
  62                                     const struct inet_bind_bucket *tb);
  63};
  64
  65/** inet_connection_sock - INET connection oriented sock
  66 *
  67 * @icsk_accept_queue:     FIFO of established children 
  68 * @icsk_bind_hash:        Bind node
  69 * @icsk_timeout:          Timeout
  70 * @icsk_retransmit_timer: Resend (no ack)
  71 * @icsk_rto:              Retransmit timeout
  72 * @icsk_pmtu_cookie       Last pmtu seen by socket
  73 * @icsk_ca_ops            Pluggable congestion control hook
  74 * @icsk_af_ops            Operations which are AF_INET{4,6} specific
  75 * @icsk_ca_state:         Congestion control state
  76 * @icsk_retransmits:      Number of unrecovered [RTO] timeouts
  77 * @icsk_pending:          Scheduled timer event
  78 * @icsk_backoff:          Backoff
  79 * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
  80 * @icsk_probes_out:       unanswered 0 window probes
  81 * @icsk_ext_hdr_len:      Network protocol overhead (IP/IPv6 options)
  82 * @icsk_ack:              Delayed ACK control data
  83 * @icsk_mtup;             MTU probing control data
  84 */
  85struct inet_connection_sock {
  86        /* inet_sock has to be the first member! */
  87        struct inet_sock          icsk_inet;
  88        struct request_sock_queue icsk_accept_queue;
  89        struct inet_bind_bucket   *icsk_bind_hash;
  90        unsigned long             icsk_timeout;
  91        struct timer_list         icsk_retransmit_timer;
  92        struct timer_list         icsk_delack_timer;
  93        __u32                     icsk_rto;
  94        __u32                     icsk_pmtu_cookie;
  95        const struct tcp_congestion_ops *icsk_ca_ops;
  96        const struct inet_connection_sock_af_ops *icsk_af_ops;
  97        unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
  98        __u8                      icsk_ca_state;
  99        __u8                      icsk_retransmits;
 100        __u8                      icsk_pending;
 101        __u8                      icsk_backoff;
 102        __u8                      icsk_syn_retries;
 103        __u8                      icsk_probes_out;
 104        __u16                     icsk_ext_hdr_len;
 105        struct {
 106                __u8              pending;       /* ACK is pending                         */
 107                __u8              quick;         /* Scheduled number of quick acks         */
 108                __u8              pingpong;      /* The session is interactive             */
 109                __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 110                __u32             ato;           /* Predicted tick of soft clock           */
 111                unsigned long     timeout;       /* Currently scheduled timeout            */
 112                __u32             lrcvtime;      /* timestamp of last received data packet */
 113                __u16             last_seg_size; /* Size of last incoming segment          */
 114                __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */ 
 115        } icsk_ack;
 116        struct {
 117                int               enabled;
 118
 119                /* Range of MTUs to search */
 120                int               search_high;
 121                int               search_low;
 122
 123                /* Information on the current probe. */
 124                int               probe_size;
 125        } icsk_mtup;
 126        u32                       icsk_ca_priv[16];
 127#define ICSK_CA_PRIV_SIZE       (16 * sizeof(u32))
 128};
 129
 130#define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 131#define ICSK_TIME_DACK          2       /* Delayed ack timer */
 132#define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 133#define ICSK_TIME_KEEPOPEN      4       /* Keepalive timer */
 134
 135static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 136{
 137        return (struct inet_connection_sock *)sk;
 138}
 139
 140static inline void *inet_csk_ca(const struct sock *sk)
 141{
 142        return (void *)inet_csk(sk)->icsk_ca_priv;
 143}
 144
 145extern struct sock *inet_csk_clone(struct sock *sk,
 146                                   const struct request_sock *req,
 147                                   const gfp_t priority);
 148
 149enum inet_csk_ack_state_t {
 150        ICSK_ACK_SCHED  = 1,
 151        ICSK_ACK_TIMER  = 2,
 152        ICSK_ACK_PUSHED = 4,
 153        ICSK_ACK_PUSHED2 = 8
 154};
 155
 156extern void inet_csk_init_xmit_timers(struct sock *sk,
 157                                      void (*retransmit_handler)(unsigned long),
 158                                      void (*delack_handler)(unsigned long),
 159                                      void (*keepalive_handler)(unsigned long));
 160extern void inet_csk_clear_xmit_timers(struct sock *sk);
 161
 162static inline void inet_csk_schedule_ack(struct sock *sk)
 163{
 164        inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 165}
 166
 167static inline int inet_csk_ack_scheduled(const struct sock *sk)
 168{
 169        return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 170}
 171
 172static inline void inet_csk_delack_init(struct sock *sk)
 173{
 174        memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 175}
 176
 177extern void inet_csk_delete_keepalive_timer(struct sock *sk);
 178extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 179
 180#ifdef INET_CSK_DEBUG
 181extern const char inet_csk_timer_bug_msg[];
 182#endif
 183
 184static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 185{
 186        struct inet_connection_sock *icsk = inet_csk(sk);
 187        
 188        if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 189                icsk->icsk_pending = 0;
 190#ifdef INET_CSK_CLEAR_TIMERS
 191                sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 192#endif
 193        } else if (what == ICSK_TIME_DACK) {
 194                icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 195#ifdef INET_CSK_CLEAR_TIMERS
 196                sk_stop_timer(sk, &icsk->icsk_delack_timer);
 197#endif
 198        }
 199#ifdef INET_CSK_DEBUG
 200        else {
 201                pr_debug("%s", inet_csk_timer_bug_msg);
 202        }
 203#endif
 204}
 205
 206/*
 207 *      Reset the retransmission timer
 208 */
 209static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 210                                             unsigned long when,
 211                                             const unsigned long max_when)
 212{
 213        struct inet_connection_sock *icsk = inet_csk(sk);
 214
 215        if (when > max_when) {
 216#ifdef INET_CSK_DEBUG
 217                pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 218                         sk, what, when, current_text_addr());
 219#endif
 220                when = max_when;
 221        }
 222
 223        if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 224                icsk->icsk_pending = what;
 225                icsk->icsk_timeout = jiffies + when;
 226                sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 227        } else if (what == ICSK_TIME_DACK) {
 228                icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 229                icsk->icsk_ack.timeout = jiffies + when;
 230                sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 231        }
 232#ifdef INET_CSK_DEBUG
 233        else {
 234                pr_debug("%s", inet_csk_timer_bug_msg);
 235        }
 236#endif
 237}
 238
 239extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
 240
 241extern struct request_sock *inet_csk_search_req(const struct sock *sk,
 242                                                struct request_sock ***prevp,
 243                                                const __be16 rport,
 244                                                const __be32 raddr,
 245                                                const __be32 laddr);
 246extern int inet_csk_bind_conflict(const struct sock *sk,
 247                                  const struct inet_bind_bucket *tb);
 248extern int inet_csk_get_port(struct sock *sk, unsigned short snum);
 249
 250extern struct dst_entry* inet_csk_route_req(struct sock *sk,
 251                                            const struct request_sock *req);
 252
 253static inline void inet_csk_reqsk_queue_add(struct sock *sk,
 254                                            struct request_sock *req,
 255                                            struct sock *child)
 256{
 257        reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
 258}
 259
 260extern void inet_csk_reqsk_queue_hash_add(struct sock *sk,
 261                                          struct request_sock *req,
 262                                          unsigned long timeout);
 263
 264static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
 265                                                struct request_sock *req)
 266{
 267        if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
 268                inet_csk_delete_keepalive_timer(sk);
 269}
 270
 271static inline void inet_csk_reqsk_queue_added(struct sock *sk,
 272                                              const unsigned long timeout)
 273{
 274        if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
 275                inet_csk_reset_keepalive_timer(sk, timeout);
 276}
 277
 278static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
 279{
 280        return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
 281}
 282
 283static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
 284{
 285        return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
 286}
 287
 288static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
 289{
 290        return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
 291}
 292
 293static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
 294                                               struct request_sock *req,
 295                                               struct request_sock **prev)
 296{
 297        reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
 298}
 299
 300static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
 301                                             struct request_sock *req,
 302                                             struct request_sock **prev)
 303{
 304        inet_csk_reqsk_queue_unlink(sk, req, prev);
 305        inet_csk_reqsk_queue_removed(sk, req);
 306        reqsk_free(req);
 307}
 308
 309extern void inet_csk_reqsk_queue_prune(struct sock *parent,
 310                                       const unsigned long interval,
 311                                       const unsigned long timeout,
 312                                       const unsigned long max_rto);
 313
 314extern void inet_csk_destroy_sock(struct sock *sk);
 315
 316/*
 317 * LISTEN is a special case for poll..
 318 */
 319static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
 320{
 321        return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 322                        (POLLIN | POLLRDNORM) : 0;
 323}
 324
 325extern int  inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
 326extern void inet_csk_listen_stop(struct sock *sk);
 327
 328extern void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 329
 330extern int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 331                                      char __user *optval, int __user *optlen);
 332extern int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 333                                      char __user *optval, int optlen);
 334#endif /* _INET_CONNECTION_SOCK_H */
 335