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 sock *sk, struct sk_buff *skb, struct flowi *fl);
  40        void        (*send_check)(struct sock *sk, struct sk_buff *skb);
  41        int         (*rebuild_header)(struct sock *sk);
  42        void        (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb);
  43        int         (*conn_request)(struct sock *sk, struct sk_buff *skb);
  44        struct sock *(*syn_recv_sock)(const struct sock *sk, struct sk_buff *skb,
  45                                      struct request_sock *req,
  46                                      struct dst_entry *dst,
  47                                      struct request_sock *req_unhash,
  48                                      bool *own_req);
  49        u16         net_header_len;
  50        u16         net_frag_header_len;
  51        u16         sockaddr_len;
  52        int         (*setsockopt)(struct sock *sk, int level, int optname, 
  53                                  char __user *optval, unsigned int optlen);
  54        int         (*getsockopt)(struct sock *sk, int level, int optname, 
  55                                  char __user *optval, int __user *optlen);
  56#ifdef CONFIG_COMPAT
  57        int         (*compat_setsockopt)(struct sock *sk,
  58                                int level, int optname,
  59                                char __user *optval, unsigned int optlen);
  60        int         (*compat_getsockopt)(struct sock *sk,
  61                                int level, int optname,
  62                                char __user *optval, int __user *optlen);
  63#endif
  64        void        (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
  65        int         (*bind_conflict)(const struct sock *sk,
  66                                     const struct inet_bind_bucket *tb,
  67                                     bool relax, bool soreuseport_ok);
  68        void        (*mtu_reduced)(struct sock *sk);
  69};
  70
  71/** inet_connection_sock - INET connection oriented sock
  72 *
  73 * @icsk_accept_queue:     FIFO of established children 
  74 * @icsk_bind_hash:        Bind node
  75 * @icsk_timeout:          Timeout
  76 * @icsk_retransmit_timer: Resend (no ack)
  77 * @icsk_rto:              Retransmit timeout
  78 * @icsk_pmtu_cookie       Last pmtu seen by socket
  79 * @icsk_ca_ops            Pluggable congestion control hook
  80 * @icsk_af_ops            Operations which are AF_INET{4,6} specific
  81 * @icsk_ca_state:         Congestion control state
  82 * @icsk_retransmits:      Number of unrecovered [RTO] timeouts
  83 * @icsk_pending:          Scheduled timer event
  84 * @icsk_backoff:          Backoff
  85 * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
  86 * @icsk_probes_out:       unanswered 0 window probes
  87 * @icsk_ext_hdr_len:      Network protocol overhead (IP/IPv6 options)
  88 * @icsk_ack:              Delayed ACK control data
  89 * @icsk_mtup;             MTU probing control data
  90 */
  91struct inet_connection_sock {
  92        /* inet_sock has to be the first member! */
  93        struct inet_sock          icsk_inet;
  94        struct request_sock_queue icsk_accept_queue;
  95        struct inet_bind_bucket   *icsk_bind_hash;
  96        unsigned long             icsk_timeout;
  97        struct timer_list         icsk_retransmit_timer;
  98        struct timer_list         icsk_delack_timer;
  99        __u32                     icsk_rto;
 100        __u32                     icsk_pmtu_cookie;
 101        const struct tcp_congestion_ops *icsk_ca_ops;
 102        const struct inet_connection_sock_af_ops *icsk_af_ops;
 103        unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
 104        __u8                      icsk_ca_state:6,
 105                                  icsk_ca_setsockopt:1,
 106                                  icsk_ca_dst_locked:1;
 107        __u8                      icsk_retransmits;
 108        __u8                      icsk_pending;
 109        __u8                      icsk_backoff;
 110        __u8                      icsk_syn_retries;
 111        __u8                      icsk_probes_out;
 112        __u16                     icsk_ext_hdr_len;
 113        struct {
 114                __u8              pending;       /* ACK is pending                         */
 115                __u8              quick;         /* Scheduled number of quick acks         */
 116                __u8              pingpong;      /* The session is interactive             */
 117                __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 118                __u32             ato;           /* Predicted tick of soft clock           */
 119                unsigned long     timeout;       /* Currently scheduled timeout            */
 120                __u32             lrcvtime;      /* timestamp of last received data packet */
 121                __u16             last_seg_size; /* Size of last incoming segment          */
 122                __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */ 
 123        } icsk_ack;
 124        struct {
 125                int               enabled;
 126
 127                /* Range of MTUs to search */
 128                int               search_high;
 129                int               search_low;
 130
 131                /* Information on the current probe. */
 132                int               probe_size;
 133
 134                u32               probe_timestamp;
 135        } icsk_mtup;
 136        u32                       icsk_user_timeout;
 137
 138        u64                       icsk_ca_priv[88 / sizeof(u64)];
 139#define ICSK_CA_PRIV_SIZE      (11 * sizeof(u64))
 140};
 141
 142#define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 143#define ICSK_TIME_DACK          2       /* Delayed ack timer */
 144#define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 145#define ICSK_TIME_EARLY_RETRANS 4       /* Early retransmit timer */
 146#define ICSK_TIME_LOSS_PROBE    5       /* Tail loss probe timer */
 147
 148static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 149{
 150        return (struct inet_connection_sock *)sk;
 151}
 152
 153static inline void *inet_csk_ca(const struct sock *sk)
 154{
 155        return (void *)inet_csk(sk)->icsk_ca_priv;
 156}
 157
 158struct sock *inet_csk_clone_lock(const struct sock *sk,
 159                                 const struct request_sock *req,
 160                                 const gfp_t priority);
 161
 162enum inet_csk_ack_state_t {
 163        ICSK_ACK_SCHED  = 1,
 164        ICSK_ACK_TIMER  = 2,
 165        ICSK_ACK_PUSHED = 4,
 166        ICSK_ACK_PUSHED2 = 8
 167};
 168
 169void inet_csk_init_xmit_timers(struct sock *sk,
 170                               void (*retransmit_handler)(unsigned long),
 171                               void (*delack_handler)(unsigned long),
 172                               void (*keepalive_handler)(unsigned long));
 173void inet_csk_clear_xmit_timers(struct sock *sk);
 174
 175static inline void inet_csk_schedule_ack(struct sock *sk)
 176{
 177        inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 178}
 179
 180static inline int inet_csk_ack_scheduled(const struct sock *sk)
 181{
 182        return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 183}
 184
 185static inline void inet_csk_delack_init(struct sock *sk)
 186{
 187        memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 188}
 189
 190void inet_csk_delete_keepalive_timer(struct sock *sk);
 191void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 192
 193#ifdef INET_CSK_DEBUG
 194extern const char inet_csk_timer_bug_msg[];
 195#endif
 196
 197static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 198{
 199        struct inet_connection_sock *icsk = inet_csk(sk);
 200        
 201        if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 202                icsk->icsk_pending = 0;
 203#ifdef INET_CSK_CLEAR_TIMERS
 204                sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 205#endif
 206        } else if (what == ICSK_TIME_DACK) {
 207                icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 208#ifdef INET_CSK_CLEAR_TIMERS
 209                sk_stop_timer(sk, &icsk->icsk_delack_timer);
 210#endif
 211        }
 212#ifdef INET_CSK_DEBUG
 213        else {
 214                pr_debug("%s", inet_csk_timer_bug_msg);
 215        }
 216#endif
 217}
 218
 219/*
 220 *      Reset the retransmission timer
 221 */
 222static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 223                                             unsigned long when,
 224                                             const unsigned long max_when)
 225{
 226        struct inet_connection_sock *icsk = inet_csk(sk);
 227
 228        if (when > max_when) {
 229#ifdef INET_CSK_DEBUG
 230                pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 231                         sk, what, when, current_text_addr());
 232#endif
 233                when = max_when;
 234        }
 235
 236        if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
 237            what == ICSK_TIME_EARLY_RETRANS || what ==  ICSK_TIME_LOSS_PROBE) {
 238                icsk->icsk_pending = what;
 239                icsk->icsk_timeout = jiffies + when;
 240                sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 241        } else if (what == ICSK_TIME_DACK) {
 242                icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 243                icsk->icsk_ack.timeout = jiffies + when;
 244                sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 245        }
 246#ifdef INET_CSK_DEBUG
 247        else {
 248                pr_debug("%s", inet_csk_timer_bug_msg);
 249        }
 250#endif
 251}
 252
 253static inline unsigned long
 254inet_csk_rto_backoff(const struct inet_connection_sock *icsk,
 255                     unsigned long max_when)
 256{
 257        u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff;
 258
 259        return (unsigned long)min_t(u64, when, max_when);
 260}
 261
 262struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
 263
 264int inet_csk_bind_conflict(const struct sock *sk,
 265                           const struct inet_bind_bucket *tb, bool relax,
 266                           bool soreuseport_ok);
 267int inet_csk_get_port(struct sock *sk, unsigned short snum);
 268
 269struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4,
 270                                     const struct request_sock *req);
 271struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
 272                                            struct sock *newsk,
 273                                            const struct request_sock *req);
 274
 275struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
 276                                      struct request_sock *req,
 277                                      struct sock *child);
 278void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 279                                   unsigned long timeout);
 280struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
 281                                         struct request_sock *req,
 282                                         bool own_req);
 283
 284static inline void inet_csk_reqsk_queue_added(struct sock *sk)
 285{
 286        reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);
 287}
 288
 289static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
 290{
 291        return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
 292}
 293
 294static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
 295{
 296        return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog;
 297}
 298
 299void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
 300void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req);
 301
 302void inet_csk_destroy_sock(struct sock *sk);
 303void inet_csk_prepare_forced_close(struct sock *sk);
 304
 305/*
 306 * LISTEN is a special case for poll..
 307 */
 308static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
 309{
 310        return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 311                        (POLLIN | POLLRDNORM) : 0;
 312}
 313
 314int inet_csk_listen_start(struct sock *sk, int backlog);
 315void inet_csk_listen_stop(struct sock *sk);
 316
 317void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 318
 319int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 320                               char __user *optval, int __user *optlen);
 321int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 322                               char __user *optval, unsigned int optlen);
 323
 324struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
 325#endif /* _INET_CONNECTION_SOCK_H */
 326