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_rto_min;
 100        __u32                     icsk_delack_max;
 101        __u32                     icsk_pmtu_cookie;
 102        const struct tcp_congestion_ops *icsk_ca_ops;
 103        const struct inet_connection_sock_af_ops *icsk_af_ops;
 104        const struct tcp_ulp_ops  *icsk_ulp_ops;
 105        void __rcu                *icsk_ulp_data;
 106        void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq);
 107        struct hlist_node         icsk_listen_portaddr_node;
 108        unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
 109        __u8                      icsk_ca_state:5,
 110                                  icsk_ca_initialized:1,
 111                                  icsk_ca_setsockopt:1,
 112                                  icsk_ca_dst_locked:1;
 113        __u8                      icsk_retransmits;
 114        __u8                      icsk_pending;
 115        __u8                      icsk_backoff;
 116        __u8                      icsk_syn_retries;
 117        __u8                      icsk_probes_out;
 118        __u16                     icsk_ext_hdr_len;
 119        struct {
 120                __u8              pending;       /* ACK is pending                         */
 121                __u8              quick;         /* Scheduled number of quick acks         */
 122                __u8              pingpong;      /* The session is interactive             */
 123                __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 124                __u32             ato;           /* Predicted tick of soft clock           */
 125                unsigned long     timeout;       /* Currently scheduled timeout            */
 126                __u32             lrcvtime;      /* timestamp of last received data packet */
 127                __u16             last_seg_size; /* Size of last incoming segment          */
 128                __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */
 129        } icsk_ack;
 130        struct {
 131                int               enabled;
 132
 133                /* Range of MTUs to search */
 134                int               search_high;
 135                int               search_low;
 136
 137                /* Information on the current probe. */
 138                int               probe_size;
 139
 140                u32               probe_timestamp;
 141        } icsk_mtup;
 142        u32                       icsk_user_timeout;
 143
 144        u64                       icsk_ca_priv[104 / sizeof(u64)];
 145#define ICSK_CA_PRIV_SIZE      (13 * sizeof(u64))
 146};
 147
 148#define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 149#define ICSK_TIME_DACK          2       /* Delayed ack timer */
 150#define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 151#define ICSK_TIME_EARLY_RETRANS 4       /* Early retransmit timer */
 152#define ICSK_TIME_LOSS_PROBE    5       /* Tail loss probe timer */
 153#define ICSK_TIME_REO_TIMEOUT   6       /* Reordering timer */
 154
 155static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 156{
 157        return (struct inet_connection_sock *)sk;
 158}
 159
 160static inline void *inet_csk_ca(const struct sock *sk)
 161{
 162        return (void *)inet_csk(sk)->icsk_ca_priv;
 163}
 164
 165struct sock *inet_csk_clone_lock(const struct sock *sk,
 166                                 const struct request_sock *req,
 167                                 const gfp_t priority);
 168
 169enum inet_csk_ack_state_t {
 170        ICSK_ACK_SCHED  = 1,
 171        ICSK_ACK_TIMER  = 2,
 172        ICSK_ACK_PUSHED = 4,
 173        ICSK_ACK_PUSHED2 = 8,
 174        ICSK_ACK_NOW = 16       /* Send the next ACK immediately (once) */
 175};
 176
 177void inet_csk_init_xmit_timers(struct sock *sk,
 178                               void (*retransmit_handler)(struct timer_list *),
 179                               void (*delack_handler)(struct timer_list *),
 180                               void (*keepalive_handler)(struct timer_list *));
 181void inet_csk_clear_xmit_timers(struct sock *sk);
 182
 183static inline void inet_csk_schedule_ack(struct sock *sk)
 184{
 185        inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 186}
 187
 188static inline int inet_csk_ack_scheduled(const struct sock *sk)
 189{
 190        return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 191}
 192
 193static inline void inet_csk_delack_init(struct sock *sk)
 194{
 195        memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 196}
 197
 198void inet_csk_delete_keepalive_timer(struct sock *sk);
 199void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 200
 201static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 202{
 203        struct inet_connection_sock *icsk = inet_csk(sk);
 204
 205        if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 206                icsk->icsk_pending = 0;
 207#ifdef INET_CSK_CLEAR_TIMERS
 208                sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 209#endif
 210        } else if (what == ICSK_TIME_DACK) {
 211                icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 212#ifdef INET_CSK_CLEAR_TIMERS
 213                sk_stop_timer(sk, &icsk->icsk_delack_timer);
 214#endif
 215        } else {
 216                pr_debug("inet_csk BUG: unknown timer value\n");
 217        }
 218}
 219
 220/*
 221 *      Reset the retransmission timer
 222 */
 223static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 224                                             unsigned long when,
 225                                             const unsigned long max_when)
 226{
 227        struct inet_connection_sock *icsk = inet_csk(sk);
 228
 229        if (when > max_when) {
 230                pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 231                         sk, what, when, current_text_addr());
 232                when = max_when;
 233        }
 234
 235        if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
 236            what == ICSK_TIME_EARLY_RETRANS || what == ICSK_TIME_LOSS_PROBE ||
 237            what == ICSK_TIME_REO_TIMEOUT) {
 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        } else {
 246                pr_debug("inet_csk BUG: unknown timer value\n");
 247        }
 248}
 249
 250static inline unsigned long
 251inet_csk_rto_backoff(const struct inet_connection_sock *icsk,
 252                     unsigned long max_when)
 253{
 254        u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff;
 255
 256        return (unsigned long)min_t(u64, when, max_when);
 257}
 258
 259struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern);
 260
 261int inet_csk_get_port(struct sock *sk, unsigned short snum);
 262
 263struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4,
 264                                     const struct request_sock *req);
 265struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
 266                                            struct sock *newsk,
 267                                            const struct request_sock *req);
 268
 269struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
 270                                      struct request_sock *req,
 271                                      struct sock *child);
 272void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 273                                   unsigned long timeout);
 274struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
 275                                         struct request_sock *req,
 276                                         bool own_req);
 277
 278static inline void inet_csk_reqsk_queue_added(struct sock *sk)
 279{
 280        reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);
 281}
 282
 283static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
 284{
 285        return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
 286}
 287
 288static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
 289{
 290        return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog;
 291}
 292
 293bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
 294void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req);
 295
 296static inline void inet_csk_prepare_for_destroy_sock(struct sock *sk)
 297{
 298        /* The below has to be done to allow calling inet_csk_destroy_sock */
 299        sock_set_flag(sk, SOCK_DEAD);
 300        percpu_counter_inc(sk->sk_prot->orphan_count);
 301}
 302
 303void inet_csk_destroy_sock(struct sock *sk);
 304void inet_csk_prepare_forced_close(struct sock *sk);
 305
 306/*
 307 * LISTEN is a special case for poll..
 308 */
 309static inline __poll_t inet_csk_listen_poll(const struct sock *sk)
 310{
 311        return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 312                        (EPOLLIN | EPOLLRDNORM) : 0;
 313}
 314
 315int inet_csk_listen_start(struct sock *sk, int backlog);
 316void inet_csk_listen_stop(struct sock *sk);
 317
 318void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 319
 320/* update the fast reuse flag when adding a socket */
 321void inet_csk_update_fastreuse(struct inet_bind_bucket *tb,
 322                               struct sock *sk);
 323
 324int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 325                               char __user *optval, int __user *optlen);
 326int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 327                               char __user *optval, unsigned int optlen);
 328
 329struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
 330
 331#define TCP_PINGPONG_THRESH     1
 332
 333static inline void inet_csk_enter_pingpong_mode(struct sock *sk)
 334{
 335        inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH;
 336}
 337
 338static inline void inet_csk_exit_pingpong_mode(struct sock *sk)
 339{
 340        inet_csk(sk)->icsk_ack.pingpong = 0;
 341}
 342
 343static inline bool inet_csk_in_pingpong_mode(struct sock *sk)
 344{
 345        return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH;
 346}
 347
 348static inline bool inet_csk_has_ulp(struct sock *sk)
 349{
 350        return inet_sk(sk)->is_icsk && !!inet_csk(sk)->icsk_ulp_ops;
 351}
 352
 353#endif /* _INET_CONNECTION_SOCK_H */
 354