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, bool relax);
  67        void        (*mtu_reduced)(struct sock *sk);
  68};
  69
  70/** inet_connection_sock - INET connection oriented sock
  71 *
  72 * @icsk_accept_queue:     FIFO of established children 
  73 * @icsk_bind_hash:        Bind node
  74 * @icsk_timeout:          Timeout
  75 * @icsk_retransmit_timer: Resend (no ack)
  76 * @icsk_rto:              Retransmit timeout
  77 * @icsk_pmtu_cookie       Last pmtu seen by socket
  78 * @icsk_ca_ops            Pluggable congestion control hook
  79 * @icsk_af_ops            Operations which are AF_INET{4,6} specific
  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        unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
 103        __u8                      icsk_ca_state:6,
 104                                  icsk_ca_setsockopt:1,
 105                                  icsk_ca_dst_locked:1;
 106        __u8                      icsk_retransmits;
 107        __u8                      icsk_pending;
 108        __u8                      icsk_backoff;
 109        __u8                      icsk_syn_retries;
 110        __u8                      icsk_probes_out;
 111        __u16                     icsk_ext_hdr_len;
 112        struct {
 113                __u8              pending;       /* ACK is pending                         */
 114                __u8              quick;         /* Scheduled number of quick acks         */
 115                __u8              pingpong;      /* The session is interactive             */
 116                __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 117                __u32             ato;           /* Predicted tick of soft clock           */
 118                unsigned long     timeout;       /* Currently scheduled timeout            */
 119                __u32             lrcvtime;      /* timestamp of last received data packet */
 120                __u16             last_seg_size; /* Size of last incoming segment          */
 121                __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */ 
 122        } icsk_ack;
 123        struct {
 124                int               enabled;
 125
 126                /* Range of MTUs to search */
 127                int               search_high;
 128                int               search_low;
 129
 130                /* Information on the current probe. */
 131                int               probe_size;
 132
 133                u32               probe_timestamp;
 134        } icsk_mtup;
 135        u32                       icsk_user_timeout;
 136
 137        u64                       icsk_ca_priv[64 / sizeof(u64)];
 138#define ICSK_CA_PRIV_SIZE      (8 * sizeof(u64))
 139};
 140
 141#define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 142#define ICSK_TIME_DACK          2       /* Delayed ack timer */
 143#define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 144#define ICSK_TIME_EARLY_RETRANS 4       /* Early retransmit timer */
 145#define ICSK_TIME_LOSS_PROBE    5       /* Tail loss probe timer */
 146
 147static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 148{
 149        return (struct inet_connection_sock *)sk;
 150}
 151
 152static inline void *inet_csk_ca(const struct sock *sk)
 153{
 154        return (void *)inet_csk(sk)->icsk_ca_priv;
 155}
 156
 157struct sock *inet_csk_clone_lock(const struct sock *sk,
 158                                 const struct request_sock *req,
 159                                 const gfp_t priority);
 160
 161enum inet_csk_ack_state_t {
 162        ICSK_ACK_SCHED  = 1,
 163        ICSK_ACK_TIMER  = 2,
 164        ICSK_ACK_PUSHED = 4,
 165        ICSK_ACK_PUSHED2 = 8
 166};
 167
 168void inet_csk_init_xmit_timers(struct sock *sk,
 169                               void (*retransmit_handler)(unsigned long),
 170                               void (*delack_handler)(unsigned long),
 171                               void (*keepalive_handler)(unsigned long));
 172void inet_csk_clear_xmit_timers(struct sock *sk);
 173
 174static inline void inet_csk_schedule_ack(struct sock *sk)
 175{
 176        inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 177}
 178
 179static inline int inet_csk_ack_scheduled(const struct sock *sk)
 180{
 181        return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 182}
 183
 184static inline void inet_csk_delack_init(struct sock *sk)
 185{
 186        memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 187}
 188
 189void inet_csk_delete_keepalive_timer(struct sock *sk);
 190void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 191
 192#ifdef INET_CSK_DEBUG
 193extern const char inet_csk_timer_bug_msg[];
 194#endif
 195
 196static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 197{
 198        struct inet_connection_sock *icsk = inet_csk(sk);
 199        
 200        if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 201                icsk->icsk_pending = 0;
 202#ifdef INET_CSK_CLEAR_TIMERS
 203                sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 204#endif
 205        } else if (what == ICSK_TIME_DACK) {
 206                icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 207#ifdef INET_CSK_CLEAR_TIMERS
 208                sk_stop_timer(sk, &icsk->icsk_delack_timer);
 209#endif
 210        }
 211#ifdef INET_CSK_DEBUG
 212        else {
 213                pr_debug("%s", inet_csk_timer_bug_msg);
 214        }
 215#endif
 216}
 217
 218/*
 219 *      Reset the retransmission timer
 220 */
 221static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 222                                             unsigned long when,
 223                                             const unsigned long max_when)
 224{
 225        struct inet_connection_sock *icsk = inet_csk(sk);
 226
 227        if (when > max_when) {
 228#ifdef INET_CSK_DEBUG
 229                pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 230                         sk, what, when, current_text_addr());
 231#endif
 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                icsk->icsk_pending = what;
 238                icsk->icsk_timeout = jiffies + when;
 239                sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 240        } else if (what == ICSK_TIME_DACK) {
 241                icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 242                icsk->icsk_ack.timeout = jiffies + when;
 243                sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 244        }
 245#ifdef INET_CSK_DEBUG
 246        else {
 247                pr_debug("%s", inet_csk_timer_bug_msg);
 248        }
 249#endif
 250}
 251
 252static inline unsigned long
 253inet_csk_rto_backoff(const struct inet_connection_sock *icsk,
 254                     unsigned long max_when)
 255{
 256        u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff;
 257
 258        return (unsigned long)min_t(u64, when, max_when);
 259}
 260
 261struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
 262
 263int inet_csk_bind_conflict(const struct sock *sk,
 264                           const struct inet_bind_bucket *tb, bool relax);
 265int inet_csk_get_port(struct sock *sk, unsigned short snum);
 266
 267struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4,
 268                                     const struct request_sock *req);
 269struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
 270                                            struct sock *newsk,
 271                                            const struct request_sock *req);
 272
 273struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
 274                                      struct request_sock *req,
 275                                      struct sock *child);
 276void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 277                                   unsigned long timeout);
 278struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
 279                                         struct request_sock *req,
 280                                         bool own_req);
 281
 282static inline void inet_csk_reqsk_queue_added(struct sock *sk)
 283{
 284        reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);
 285}
 286
 287static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
 288{
 289        return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
 290}
 291
 292static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
 293{
 294        return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
 295}
 296
 297static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
 298{
 299        return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog;
 300}
 301
 302void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
 303void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req);
 304
 305void inet_csk_destroy_sock(struct sock *sk);
 306void inet_csk_prepare_forced_close(struct sock *sk);
 307
 308/*
 309 * LISTEN is a special case for poll..
 310 */
 311static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
 312{
 313        return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 314                        (POLLIN | POLLRDNORM) : 0;
 315}
 316
 317int inet_csk_listen_start(struct sock *sk, int backlog);
 318void inet_csk_listen_stop(struct sock *sk);
 319
 320void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 321
 322int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 323                               char __user *optval, int __user *optlen);
 324int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 325                               char __user *optval, unsigned int optlen);
 326
 327struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
 328#endif /* _INET_CONNECTION_SOCK_H */
 329