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/* Cancel timers, when they are not required. */
  27#undef INET_CSK_CLEAR_TIMERS
  28
  29struct inet_bind_bucket;
  30struct tcp_congestion_ops;
  31
  32/*
  33 * Pointers to address related TCP functions
  34 * (i.e. things that depend on the address family)
  35 */
  36struct inet_connection_sock_af_ops {
  37        int         (*queue_xmit)(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
  38        void        (*send_check)(struct sock *sk, struct sk_buff *skb);
  39        int         (*rebuild_header)(struct sock *sk);
  40        void        (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb);
  41        int         (*conn_request)(struct sock *sk, struct sk_buff *skb);
  42        struct sock *(*syn_recv_sock)(const struct sock *sk, struct sk_buff *skb,
  43                                      struct request_sock *req,
  44                                      struct dst_entry *dst,
  45                                      struct request_sock *req_unhash,
  46                                      bool *own_req);
  47        u16         net_header_len;
  48        u16         net_frag_header_len;
  49        u16         sockaddr_len;
  50        int         (*setsockopt)(struct sock *sk, int level, int optname,
  51                                  char __user *optval, unsigned int optlen);
  52        int         (*getsockopt)(struct sock *sk, int level, int optname,
  53                                  char __user *optval, int __user *optlen);
  54#ifdef CONFIG_COMPAT
  55        int         (*compat_setsockopt)(struct sock *sk,
  56                                int level, int optname,
  57                                char __user *optval, unsigned int optlen);
  58        int         (*compat_getsockopt)(struct sock *sk,
  59                                int level, int optname,
  60                                char __user *optval, int __user *optlen);
  61#endif
  62        void        (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
  63        void        (*mtu_reduced)(struct sock *sk);
  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_ulp_ops           Pluggable ULP control hook
  77 * @icsk_ulp_data          ULP private data
  78 * @icsk_clean_acked       Clean acked data hook
  79 * @icsk_listen_portaddr_node   hash to the portaddr listener hashtable
  80 * @icsk_ca_state:         Congestion control state
  81 * @icsk_retransmits:      Number of unrecovered [RTO] timeouts
  82 * @icsk_pending:          Scheduled timer event
  83 * @icsk_backoff:          Backoff
  84 * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
  85 * @icsk_probes_out:       unanswered 0 window probes
  86 * @icsk_ext_hdr_len:      Network protocol overhead (IP/IPv6 options)
  87 * @icsk_ack:              Delayed ACK control data
  88 * @icsk_mtup;             MTU probing control data
  89 */
  90struct inet_connection_sock {
  91        /* inet_sock has to be the first member! */
  92        struct inet_sock          icsk_inet;
  93        struct request_sock_queue icsk_accept_queue;
  94        struct inet_bind_bucket   *icsk_bind_hash;
  95        unsigned long             icsk_timeout;
  96        struct timer_list         icsk_retransmit_timer;
  97        struct timer_list         icsk_delack_timer;
  98        __u32                     icsk_rto;
  99        __u32                     icsk_pmtu_cookie;
 100        const struct tcp_congestion_ops *icsk_ca_ops;
 101        const struct inet_connection_sock_af_ops *icsk_af_ops;
 102        const struct tcp_ulp_ops  *icsk_ulp_ops;
 103        void __rcu                *icsk_ulp_data;
 104        void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq);
 105        struct hlist_node         icsk_listen_portaddr_node;
 106        unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
 107        __u8                      icsk_ca_state:6,
 108                                  icsk_ca_setsockopt:1,
 109                                  icsk_ca_dst_locked:1;
 110        __u8                      icsk_retransmits;
 111        __u8                      icsk_pending;
 112        __u8                      icsk_backoff;
 113        __u8                      icsk_syn_retries;
 114        __u8                      icsk_probes_out;
 115        __u16                     icsk_ext_hdr_len;
 116        struct {
 117                __u8              pending;       /* ACK is pending                         */
 118                __u8              quick;         /* Scheduled number of quick acks         */
 119                __u8              pingpong;      /* The session is interactive             */
 120                __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 121                __u32             ato;           /* Predicted tick of soft clock           */
 122                unsigned long     timeout;       /* Currently scheduled timeout            */
 123                __u32             lrcvtime;      /* timestamp of last received data packet */
 124                __u16             last_seg_size; /* Size of last incoming segment          */
 125                __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */
 126        } icsk_ack;
 127        struct {
 128                int               enabled;
 129
 130                /* Range of MTUs to search */
 131                int               search_high;
 132                int               search_low;
 133
 134                /* Information on the current probe. */
 135                int               probe_size;
 136
 137                u32               probe_timestamp;
 138        } icsk_mtup;
 139        u32                       icsk_user_timeout;
 140
 141        u64                       icsk_ca_priv[104 / sizeof(u64)];
 142#define ICSK_CA_PRIV_SIZE      (13 * sizeof(u64))
 143};
 144
 145#define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 146#define ICSK_TIME_DACK          2       /* Delayed ack timer */
 147#define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 148#define ICSK_TIME_EARLY_RETRANS 4       /* Early retransmit timer */
 149#define ICSK_TIME_LOSS_PROBE    5       /* Tail loss probe timer */
 150#define ICSK_TIME_REO_TIMEOUT   6       /* Reordering timer */
 151
 152static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 153{
 154        return (struct inet_connection_sock *)sk;
 155}
 156
 157static inline void *inet_csk_ca(const struct sock *sk)
 158{
 159        return (void *)inet_csk(sk)->icsk_ca_priv;
 160}
 161
 162struct sock *inet_csk_clone_lock(const struct sock *sk,
 163                                 const struct request_sock *req,
 164                                 const gfp_t priority);
 165
 166enum inet_csk_ack_state_t {
 167        ICSK_ACK_SCHED  = 1,
 168        ICSK_ACK_TIMER  = 2,
 169        ICSK_ACK_PUSHED = 4,
 170        ICSK_ACK_PUSHED2 = 8,
 171        ICSK_ACK_NOW = 16       /* Send the next ACK immediately (once) */
 172};
 173
 174void inet_csk_init_xmit_timers(struct sock *sk,
 175                               void (*retransmit_handler)(struct timer_list *),
 176                               void (*delack_handler)(struct timer_list *),
 177                               void (*keepalive_handler)(struct timer_list *));
 178void inet_csk_clear_xmit_timers(struct sock *sk);
 179
 180static inline void inet_csk_schedule_ack(struct sock *sk)
 181{
 182        inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 183}
 184
 185static inline int inet_csk_ack_scheduled(const struct sock *sk)
 186{
 187        return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 188}
 189
 190static inline void inet_csk_delack_init(struct sock *sk)
 191{
 192        memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 193}
 194
 195void inet_csk_delete_keepalive_timer(struct sock *sk);
 196void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 197
 198static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 199{
 200        struct inet_connection_sock *icsk = inet_csk(sk);
 201
 202        if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 203                icsk->icsk_pending = 0;
 204#ifdef INET_CSK_CLEAR_TIMERS
 205                sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 206#endif
 207        } else if (what == ICSK_TIME_DACK) {
 208                icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 209#ifdef INET_CSK_CLEAR_TIMERS
 210                sk_stop_timer(sk, &icsk->icsk_delack_timer);
 211#endif
 212        } else {
 213                pr_debug("inet_csk BUG: unknown timer value\n");
 214        }
 215}
 216
 217/*
 218 *      Reset the retransmission timer
 219 */
 220static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 221                                             unsigned long when,
 222                                             const unsigned long max_when)
 223{
 224        struct inet_connection_sock *icsk = inet_csk(sk);
 225
 226        if (when > max_when) {
 227                pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 228                         sk, what, when, current_text_addr());
 229                when = max_when;
 230        }
 231
 232        if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
 233            what == ICSK_TIME_EARLY_RETRANS || what == ICSK_TIME_LOSS_PROBE ||
 234            what == ICSK_TIME_REO_TIMEOUT) {
 235                icsk->icsk_pending = what;
 236                icsk->icsk_timeout = jiffies + when;
 237                sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 238        } else if (what == ICSK_TIME_DACK) {
 239                icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 240                icsk->icsk_ack.timeout = jiffies + when;
 241                sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 242        } else {
 243                pr_debug("inet_csk BUG: unknown timer value\n");
 244        }
 245}
 246
 247static inline unsigned long
 248inet_csk_rto_backoff(const struct inet_connection_sock *icsk,
 249                     unsigned long max_when)
 250{
 251        u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff;
 252
 253        return (unsigned long)min_t(u64, when, max_when);
 254}
 255
 256struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern);
 257
 258int inet_csk_get_port(struct sock *sk, unsigned short snum);
 259
 260struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4,
 261                                     const struct request_sock *req);
 262struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
 263                                            struct sock *newsk,
 264                                            const struct request_sock *req);
 265
 266struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
 267                                      struct request_sock *req,
 268                                      struct sock *child);
 269void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 270                                   unsigned long timeout);
 271struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
 272                                         struct request_sock *req,
 273                                         bool own_req);
 274
 275static inline void inet_csk_reqsk_queue_added(struct sock *sk)
 276{
 277        reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);
 278}
 279
 280static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
 281{
 282        return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
 283}
 284
 285static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
 286{
 287        return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog;
 288}
 289
 290void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
 291void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req);
 292
 293static inline void inet_csk_prepare_for_destroy_sock(struct sock *sk)
 294{
 295        /* The below has to be done to allow calling inet_csk_destroy_sock */
 296        sock_set_flag(sk, SOCK_DEAD);
 297        percpu_counter_inc(sk->sk_prot->orphan_count);
 298}
 299
 300void inet_csk_destroy_sock(struct sock *sk);
 301void inet_csk_prepare_forced_close(struct sock *sk);
 302
 303/*
 304 * LISTEN is a special case for poll..
 305 */
 306static inline __poll_t inet_csk_listen_poll(const struct sock *sk)
 307{
 308        return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 309                        (EPOLLIN | EPOLLRDNORM) : 0;
 310}
 311
 312int inet_csk_listen_start(struct sock *sk, int backlog);
 313void inet_csk_listen_stop(struct sock *sk);
 314
 315void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 316
 317/* update the fast reuse flag when adding a socket */
 318void inet_csk_update_fastreuse(struct inet_bind_bucket *tb,
 319                               struct sock *sk);
 320
 321int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 322                               char __user *optval, int __user *optlen);
 323int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 324                               char __user *optval, unsigned int optlen);
 325
 326struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
 327
 328#define TCP_PINGPONG_THRESH     1
 329
 330static inline void inet_csk_enter_pingpong_mode(struct sock *sk)
 331{
 332        inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH;
 333}
 334
 335static inline void inet_csk_exit_pingpong_mode(struct sock *sk)
 336{
 337        inet_csk(sk)->icsk_ack.pingpong = 0;
 338}
 339
 340static inline bool inet_csk_in_pingpong_mode(struct sock *sk)
 341{
 342        return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH;
 343}
 344
 345static inline bool inet_csk_has_ulp(struct sock *sk)
 346{
 347        return inet_sk(sk)->is_icsk && !!inet_csk(sk)->icsk_ulp_ops;
 348}
 349
 350#endif /* _INET_CONNECTION_SOCK_H */
 351