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);
  40        void        (*send_check)(struct sock *sk, struct sk_buff *skb);
  41        int         (*rebuild_header)(struct sock *sk);
  42        int         (*conn_request)(struct sock *sk, struct sk_buff *skb);
  43        struct sock *(*syn_recv_sock)(struct sock *sk, struct sk_buff *skb,
  44                                      struct request_sock *req,
  45                                      struct dst_entry *dst);
  46        struct inet_peer *(*get_peer)(struct sock *sk, bool *release_it);
  47        u16         net_header_len;
  48        u16         sockaddr_len;
  49        int         (*setsockopt)(struct sock *sk, int level, int optname, 
  50                                  char __user *optval, unsigned int optlen);
  51        int         (*getsockopt)(struct sock *sk, int level, int optname, 
  52                                  char __user *optval, int __user *optlen);
  53#ifdef CONFIG_COMPAT
  54        int         (*compat_setsockopt)(struct sock *sk,
  55                                int level, int optname,
  56                                char __user *optval, unsigned int optlen);
  57        int         (*compat_getsockopt)(struct sock *sk,
  58                                int level, int optname,
  59                                char __user *optval, int __user *optlen);
  60#endif
  61        void        (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
  62        int         (*bind_conflict)(const struct sock *sk,
  63                                     const struct inet_bind_bucket *tb);
  64};
  65
  66/** inet_connection_sock - INET connection oriented sock
  67 *
  68 * @icsk_accept_queue:     FIFO of established children 
  69 * @icsk_bind_hash:        Bind node
  70 * @icsk_timeout:          Timeout
  71 * @icsk_retransmit_timer: Resend (no ack)
  72 * @icsk_rto:              Retransmit timeout
  73 * @icsk_pmtu_cookie       Last pmtu seen by socket
  74 * @icsk_ca_ops            Pluggable congestion control hook
  75 * @icsk_af_ops            Operations which are AF_INET{4,6} specific
  76 * @icsk_ca_state:         Congestion control state
  77 * @icsk_retransmits:      Number of unrecovered [RTO] timeouts
  78 * @icsk_pending:          Scheduled timer event
  79 * @icsk_backoff:          Backoff
  80 * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
  81 * @icsk_probes_out:       unanswered 0 window probes
  82 * @icsk_ext_hdr_len:      Network protocol overhead (IP/IPv6 options)
  83 * @icsk_ack:              Delayed ACK control data
  84 * @icsk_mtup;             MTU probing control data
  85 */
  86struct inet_connection_sock {
  87        /* inet_sock has to be the first member! */
  88        struct inet_sock          icsk_inet;
  89        struct request_sock_queue icsk_accept_queue;
  90        struct inet_bind_bucket   *icsk_bind_hash;
  91        unsigned long             icsk_timeout;
  92        struct timer_list         icsk_retransmit_timer;
  93        struct timer_list         icsk_delack_timer;
  94        __u32                     icsk_rto;
  95        __u32                     icsk_pmtu_cookie;
  96        const struct tcp_congestion_ops *icsk_ca_ops;
  97        const struct inet_connection_sock_af_ops *icsk_af_ops;
  98        unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
  99        __u8                      icsk_ca_state;
 100        __u8                      icsk_retransmits;
 101        __u8                      icsk_pending;
 102        __u8                      icsk_backoff;
 103        __u8                      icsk_syn_retries;
 104        __u8                      icsk_probes_out;
 105        __u16                     icsk_ext_hdr_len;
 106        struct {
 107                __u8              pending;       /* ACK is pending                         */
 108                __u8              quick;         /* Scheduled number of quick acks         */
 109                __u8              pingpong;      /* The session is interactive             */
 110                __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 111                __u32             ato;           /* Predicted tick of soft clock           */
 112                unsigned long     timeout;       /* Currently scheduled timeout            */
 113                __u32             lrcvtime;      /* timestamp of last received data packet */
 114                __u16             last_seg_size; /* Size of last incoming segment          */
 115                __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */ 
 116        } icsk_ack;
 117        struct {
 118                int               enabled;
 119
 120                /* Range of MTUs to search */
 121                int               search_high;
 122                int               search_low;
 123
 124                /* Information on the current probe. */
 125                int               probe_size;
 126        } icsk_mtup;
 127        u32                       icsk_ca_priv[16];
 128        u32                       icsk_user_timeout;
 129#define ICSK_CA_PRIV_SIZE       (16 * sizeof(u32))
 130};
 131
 132#define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 133#define ICSK_TIME_DACK          2       /* Delayed ack timer */
 134#define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 135
 136static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 137{
 138        return (struct inet_connection_sock *)sk;
 139}
 140
 141static inline void *inet_csk_ca(const struct sock *sk)
 142{
 143        return (void *)inet_csk(sk)->icsk_ca_priv;
 144}
 145
 146extern struct sock *inet_csk_clone(struct sock *sk,
 147                                   const struct request_sock *req,
 148                                   const gfp_t priority);
 149
 150enum inet_csk_ack_state_t {
 151        ICSK_ACK_SCHED  = 1,
 152        ICSK_ACK_TIMER  = 2,
 153        ICSK_ACK_PUSHED = 4,
 154        ICSK_ACK_PUSHED2 = 8
 155};
 156
 157extern void inet_csk_init_xmit_timers(struct sock *sk,
 158                                      void (*retransmit_handler)(unsigned long),
 159                                      void (*delack_handler)(unsigned long),
 160                                      void (*keepalive_handler)(unsigned long));
 161extern void inet_csk_clear_xmit_timers(struct sock *sk);
 162
 163static inline void inet_csk_schedule_ack(struct sock *sk)
 164{
 165        inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 166}
 167
 168static inline int inet_csk_ack_scheduled(const struct sock *sk)
 169{
 170        return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 171}
 172
 173static inline void inet_csk_delack_init(struct sock *sk)
 174{
 175        memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 176}
 177
 178extern void inet_csk_delete_keepalive_timer(struct sock *sk);
 179extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 180
 181#ifdef INET_CSK_DEBUG
 182extern const char inet_csk_timer_bug_msg[];
 183#endif
 184
 185static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 186{
 187        struct inet_connection_sock *icsk = inet_csk(sk);
 188        
 189        if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 190                icsk->icsk_pending = 0;
 191#ifdef INET_CSK_CLEAR_TIMERS
 192                sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 193#endif
 194        } else if (what == ICSK_TIME_DACK) {
 195                icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 196#ifdef INET_CSK_CLEAR_TIMERS
 197                sk_stop_timer(sk, &icsk->icsk_delack_timer);
 198#endif
 199        }
 200#ifdef INET_CSK_DEBUG
 201        else {
 202                pr_debug("%s", inet_csk_timer_bug_msg);
 203        }
 204#endif
 205}
 206
 207/*
 208 *      Reset the retransmission timer
 209 */
 210static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 211                                             unsigned long when,
 212                                             const unsigned long max_when)
 213{
 214        struct inet_connection_sock *icsk = inet_csk(sk);
 215
 216        if (when > max_when) {
 217#ifdef INET_CSK_DEBUG
 218                pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 219                         sk, what, when, current_text_addr());
 220#endif
 221                when = max_when;
 222        }
 223
 224        if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 225                icsk->icsk_pending = what;
 226                icsk->icsk_timeout = jiffies + when;
 227                sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 228        } else if (what == ICSK_TIME_DACK) {
 229                icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 230                icsk->icsk_ack.timeout = jiffies + when;
 231                sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 232        }
 233#ifdef INET_CSK_DEBUG
 234        else {
 235                pr_debug("%s", inet_csk_timer_bug_msg);
 236        }
 237#endif
 238}
 239
 240extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
 241
 242extern struct request_sock *inet_csk_search_req(const struct sock *sk,
 243                                                struct request_sock ***prevp,
 244                                                const __be16 rport,
 245                                                const __be32 raddr,
 246                                                const __be32 laddr);
 247extern int inet_csk_bind_conflict(const struct sock *sk,
 248                                  const struct inet_bind_bucket *tb);
 249extern int inet_csk_get_port(struct sock *sk, unsigned short snum);
 250
 251extern struct dst_entry* inet_csk_route_req(struct sock *sk,
 252                                            const struct request_sock *req);
 253
 254static inline void inet_csk_reqsk_queue_add(struct sock *sk,
 255                                            struct request_sock *req,
 256                                            struct sock *child)
 257{
 258        reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
 259}
 260
 261extern void inet_csk_reqsk_queue_hash_add(struct sock *sk,
 262                                          struct request_sock *req,
 263                                          unsigned long timeout);
 264
 265static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
 266                                                struct request_sock *req)
 267{
 268        if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
 269                inet_csk_delete_keepalive_timer(sk);
 270}
 271
 272static inline void inet_csk_reqsk_queue_added(struct sock *sk,
 273                                              const unsigned long timeout)
 274{
 275        if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
 276                inet_csk_reset_keepalive_timer(sk, timeout);
 277}
 278
 279static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
 280{
 281        return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
 282}
 283
 284static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
 285{
 286        return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
 287}
 288
 289static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
 290{
 291        return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
 292}
 293
 294static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
 295                                               struct request_sock *req,
 296                                               struct request_sock **prev)
 297{
 298        reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
 299}
 300
 301static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
 302                                             struct request_sock *req,
 303                                             struct request_sock **prev)
 304{
 305        inet_csk_reqsk_queue_unlink(sk, req, prev);
 306        inet_csk_reqsk_queue_removed(sk, req);
 307        reqsk_free(req);
 308}
 309
 310extern void inet_csk_reqsk_queue_prune(struct sock *parent,
 311                                       const unsigned long interval,
 312                                       const unsigned long timeout,
 313                                       const unsigned long max_rto);
 314
 315extern void inet_csk_destroy_sock(struct sock *sk);
 316
 317/*
 318 * LISTEN is a special case for poll..
 319 */
 320static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
 321{
 322        return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 323                        (POLLIN | POLLRDNORM) : 0;
 324}
 325
 326extern int  inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
 327extern void inet_csk_listen_stop(struct sock *sk);
 328
 329extern void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 330
 331extern int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 332                                      char __user *optval, int __user *optlen);
 333extern int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 334                                      char __user *optval, unsigned int optlen);
 335#endif /* _INET_CONNECTION_SOCK_H */
 336