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, 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)(struct sock *sk, struct sk_buff *skb,
  45                                      struct request_sock *req,
  46                                      struct dst_entry *dst);
  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        int         (*bind_conflict)(const struct sock *sk,
  64                                     const struct inet_bind_bucket *tb, bool relax);
  65};
  66
  67/** inet_connection_sock - INET connection oriented sock
  68 *
  69 * @icsk_accept_queue:     FIFO of established children 
  70 * @icsk_bind_hash:        Bind node
  71 * @icsk_timeout:          Timeout
  72 * @icsk_retransmit_timer: Resend (no ack)
  73 * @icsk_rto:              Retransmit timeout
  74 * @icsk_pmtu_cookie       Last pmtu seen by socket
  75 * @icsk_ca_ops            Pluggable congestion control hook
  76 * @icsk_af_ops            Operations which are AF_INET{4,6} specific
  77 * @icsk_ca_state:         Congestion control state
  78 * @icsk_retransmits:      Number of unrecovered [RTO] timeouts
  79 * @icsk_pending:          Scheduled timer event
  80 * @icsk_backoff:          Backoff
  81 * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
  82 * @icsk_probes_out:       unanswered 0 window probes
  83 * @icsk_ext_hdr_len:      Network protocol overhead (IP/IPv6 options)
  84 * @icsk_ack:              Delayed ACK control data
  85 * @icsk_mtup;             MTU probing control data
  86 */
  87struct inet_connection_sock {
  88        /* inet_sock has to be the first member! */
  89        struct inet_sock          icsk_inet;
  90        struct request_sock_queue icsk_accept_queue;
  91        struct inet_bind_bucket   *icsk_bind_hash;
  92        unsigned long             icsk_timeout;
  93        struct timer_list         icsk_retransmit_timer;
  94        struct timer_list         icsk_delack_timer;
  95        __u32                     icsk_rto;
  96        __u32                     icsk_pmtu_cookie;
  97        const struct tcp_congestion_ops *icsk_ca_ops;
  98        const struct inet_connection_sock_af_ops *icsk_af_ops;
  99        unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
 100        __u8                      icsk_ca_state;
 101        __u8                      icsk_retransmits;
 102        __u8                      icsk_pending;
 103        __u8                      icsk_backoff;
 104        __u8                      icsk_syn_retries;
 105        __u8                      icsk_probes_out;
 106        __u16                     icsk_ext_hdr_len;
 107        struct {
 108                __u8              pending;       /* ACK is pending                         */
 109                __u8              quick;         /* Scheduled number of quick acks         */
 110                __u8              pingpong;      /* The session is interactive             */
 111                __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 112                __u32             ato;           /* Predicted tick of soft clock           */
 113                unsigned long     timeout;       /* Currently scheduled timeout            */
 114                __u32             lrcvtime;      /* timestamp of last received data packet */
 115                __u16             last_seg_size; /* Size of last incoming segment          */
 116                __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */ 
 117        } icsk_ack;
 118        struct {
 119                int               enabled;
 120
 121                /* Range of MTUs to search */
 122                int               search_high;
 123                int               search_low;
 124
 125                /* Information on the current probe. */
 126                int               probe_size;
 127        } icsk_mtup;
 128        u32                       icsk_ca_priv[16];
 129        u32                       icsk_user_timeout;
 130#define ICSK_CA_PRIV_SIZE       (16 * sizeof(u32))
 131};
 132
 133#define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 134#define ICSK_TIME_DACK          2       /* Delayed ack timer */
 135#define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 136#define ICSK_TIME_EARLY_RETRANS 4       /* Early retransmit timer */
 137#define ICSK_TIME_LOSS_PROBE    5       /* Tail loss probe timer */
 138
 139static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 140{
 141        return (struct inet_connection_sock *)sk;
 142}
 143
 144static inline void *inet_csk_ca(const struct sock *sk)
 145{
 146        return (void *)inet_csk(sk)->icsk_ca_priv;
 147}
 148
 149extern struct sock *inet_csk_clone_lock(const struct sock *sk,
 150                                        const struct request_sock *req,
 151                                        const gfp_t priority);
 152
 153enum inet_csk_ack_state_t {
 154        ICSK_ACK_SCHED  = 1,
 155        ICSK_ACK_TIMER  = 2,
 156        ICSK_ACK_PUSHED = 4,
 157        ICSK_ACK_PUSHED2 = 8
 158};
 159
 160extern void inet_csk_init_xmit_timers(struct sock *sk,
 161                                      void (*retransmit_handler)(unsigned long),
 162                                      void (*delack_handler)(unsigned long),
 163                                      void (*keepalive_handler)(unsigned long));
 164extern void inet_csk_clear_xmit_timers(struct sock *sk);
 165
 166static inline void inet_csk_schedule_ack(struct sock *sk)
 167{
 168        inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 169}
 170
 171static inline int inet_csk_ack_scheduled(const struct sock *sk)
 172{
 173        return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 174}
 175
 176static inline void inet_csk_delack_init(struct sock *sk)
 177{
 178        memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 179}
 180
 181extern void inet_csk_delete_keepalive_timer(struct sock *sk);
 182extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 183
 184#ifdef INET_CSK_DEBUG
 185extern const char inet_csk_timer_bug_msg[];
 186#endif
 187
 188static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 189{
 190        struct inet_connection_sock *icsk = inet_csk(sk);
 191        
 192        if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 193                icsk->icsk_pending = 0;
 194#ifdef INET_CSK_CLEAR_TIMERS
 195                sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 196#endif
 197        } else if (what == ICSK_TIME_DACK) {
 198                icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 199#ifdef INET_CSK_CLEAR_TIMERS
 200                sk_stop_timer(sk, &icsk->icsk_delack_timer);
 201#endif
 202        }
 203#ifdef INET_CSK_DEBUG
 204        else {
 205                pr_debug("%s", inet_csk_timer_bug_msg);
 206        }
 207#endif
 208}
 209
 210/*
 211 *      Reset the retransmission timer
 212 */
 213static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 214                                             unsigned long when,
 215                                             const unsigned long max_when)
 216{
 217        struct inet_connection_sock *icsk = inet_csk(sk);
 218
 219        if (when > max_when) {
 220#ifdef INET_CSK_DEBUG
 221                pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 222                         sk, what, when, current_text_addr());
 223#endif
 224                when = max_when;
 225        }
 226
 227        if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
 228            what == ICSK_TIME_EARLY_RETRANS || what ==  ICSK_TIME_LOSS_PROBE) {
 229                icsk->icsk_pending = what;
 230                icsk->icsk_timeout = jiffies + when;
 231                sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 232        } else if (what == ICSK_TIME_DACK) {
 233                icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 234                icsk->icsk_ack.timeout = jiffies + when;
 235                sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 236        }
 237#ifdef INET_CSK_DEBUG
 238        else {
 239                pr_debug("%s", inet_csk_timer_bug_msg);
 240        }
 241#endif
 242}
 243
 244extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
 245
 246extern struct request_sock *inet_csk_search_req(const struct sock *sk,
 247                                                struct request_sock ***prevp,
 248                                                const __be16 rport,
 249                                                const __be32 raddr,
 250                                                const __be32 laddr);
 251extern int inet_csk_bind_conflict(const struct sock *sk,
 252                                  const struct inet_bind_bucket *tb, bool relax);
 253extern int inet_csk_get_port(struct sock *sk, unsigned short snum);
 254
 255extern struct dst_entry* inet_csk_route_req(struct sock *sk,
 256                                            struct flowi4 *fl4,
 257                                            const struct request_sock *req);
 258extern struct dst_entry* inet_csk_route_child_sock(struct sock *sk,
 259                                                   struct sock *newsk,
 260                                                   const struct request_sock *req);
 261
 262static inline void inet_csk_reqsk_queue_add(struct sock *sk,
 263                                            struct request_sock *req,
 264                                            struct sock *child)
 265{
 266        reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
 267}
 268
 269extern void inet_csk_reqsk_queue_hash_add(struct sock *sk,
 270                                          struct request_sock *req,
 271                                          unsigned long timeout);
 272
 273static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
 274                                                struct request_sock *req)
 275{
 276        if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
 277                inet_csk_delete_keepalive_timer(sk);
 278}
 279
 280static inline void inet_csk_reqsk_queue_added(struct sock *sk,
 281                                              const unsigned long timeout)
 282{
 283        if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
 284                inet_csk_reset_keepalive_timer(sk, timeout);
 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 reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
 300}
 301
 302static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
 303                                               struct request_sock *req,
 304                                               struct request_sock **prev)
 305{
 306        reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
 307}
 308
 309static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
 310                                             struct request_sock *req,
 311                                             struct request_sock **prev)
 312{
 313        inet_csk_reqsk_queue_unlink(sk, req, prev);
 314        inet_csk_reqsk_queue_removed(sk, req);
 315        reqsk_free(req);
 316}
 317
 318extern void inet_csk_reqsk_queue_prune(struct sock *parent,
 319                                       const unsigned long interval,
 320                                       const unsigned long timeout,
 321                                       const unsigned long max_rto);
 322
 323extern void inet_csk_destroy_sock(struct sock *sk);
 324extern void inet_csk_prepare_forced_close(struct sock *sk);
 325
 326/*
 327 * LISTEN is a special case for poll..
 328 */
 329static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
 330{
 331        return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 332                        (POLLIN | POLLRDNORM) : 0;
 333}
 334
 335extern int  inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
 336extern void inet_csk_listen_stop(struct sock *sk);
 337
 338extern void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 339
 340extern int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 341                                      char __user *optval, int __user *optlen);
 342extern int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 343                                      char __user *optval, unsigned int optlen);
 344
 345extern struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
 346#endif /* _INET_CONNECTION_SOCK_H */
 347