include/net/inet_timewait_sock.h

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              Definitions for a generic INET TIMEWAIT sock
   7  *
   8  *              From code originally in net/tcp.h
   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_TIMEWAIT_SOCK_
  16 #define _INET_TIMEWAIT_SOCK_
  17
  18
  19 #include <linux/kmemcheck.h>
  20 #include <linux/list.h>
  21 #include <linux/timer.h>
  22 #include <linux/types.h>
  23 #include <linux/workqueue.h>
  24
  25 #include <net/inet_sock.h>
  26 #include <net/sock.h>
  27 #include <net/tcp_states.h>
  28 #include <net/timewait_sock.h>
  29
  30 #include <linux/atomic.h>
  31
  32 struct inet_hashinfo;
  33
  34 struct inet_timewait_death_row {
  35         atomic_t                tw_count;
  36
  37         struct inet_hashinfo    *hashinfo ____cacheline_aligned_in_smp;
  38         int                     sysctl_tw_recycle;
  39         int                     sysctl_max_tw_buckets;
  40 };
  41
  42 struct inet_bind_bucket;
  43
  44 /*
  45  * This is a TIME_WAIT sock. It works around the memory consumption
  46  * problems of sockets in such a state on heavily loaded servers, but
  47  * without violating the protocol specification.
  48  */
  49 struct inet_timewait_sock {
  50         /*
  51          * Now struct sock also uses sock_common, so please just
  52          * don't add nothing before this first member (__tw_common) --acme
  53          */
  54         struct sock_common      __tw_common;
  55 #define tw_family               __tw_common.skc_family
  56 #define tw_state                __tw_common.skc_state
  57 #define tw_reuse                __tw_common.skc_reuse
  58 #define tw_ipv6only             __tw_common.skc_ipv6only
  59 #define tw_bound_dev_if         __tw_common.skc_bound_dev_if
  60 #define tw_node                 __tw_common.skc_nulls_node
  61 #define tw_bind_node            __tw_common.skc_bind_node
  62 #define tw_refcnt               __tw_common.skc_refcnt
  63 #define tw_hash                 __tw_common.skc_hash
  64 #define tw_prot                 __tw_common.skc_prot
  65 #define tw_net                  __tw_common.skc_net
  66 #define tw_daddr                __tw_common.skc_daddr
  67 #define tw_v6_daddr             __tw_common.skc_v6_daddr
  68 #define tw_rcv_saddr            __tw_common.skc_rcv_saddr
  69 #define tw_v6_rcv_saddr         __tw_common.skc_v6_rcv_saddr
  70 #define tw_dport                __tw_common.skc_dport
  71 #define tw_num                  __tw_common.skc_num
  72 #define tw_cookie               __tw_common.skc_cookie
  73 #define tw_dr                   __tw_common.skc_tw_dr
  74
  75         int                     tw_timeout;
  76         volatile unsigned char  tw_substate;
  77         unsigned char           tw_rcv_wscale;
  78
  79         /* Socket demultiplex comparisons on incoming packets. */
  80         /* these three are in inet_sock */
  81         __be16                  tw_sport;
  82         kmemcheck_bitfield_begin(flags);
  83         /* And these are ours. */
  84         unsigned int            tw_kill         : 1,
  85                                 tw_transparent  : 1,
  86                                 tw_flowlabel    : 20,
  87                                 tw_pad          : 2,    /* 2 bits hole */
  88                                 tw_tos          : 8;
  89         kmemcheck_bitfield_end(flags);
  90         struct timer_list       tw_timer;
  91         struct inet_bind_bucket *tw_tb;
  92 };
  93 #define tw_tclass tw_tos
  94
  95 static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
  96 {
  97         return (struct inet_timewait_sock *)sk;
  98 }
  99
 100 void inet_twsk_free(struct inet_timewait_sock *tw);
 101 void inet_twsk_put(struct inet_timewait_sock *tw);
 102
 103 void inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
 104                            struct inet_hashinfo *hashinfo);
 105
 106 struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
 107                                            struct inet_timewait_death_row *dr,
 108                                            const int state);
 109
 110 void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
 111                            struct inet_hashinfo *hashinfo);
 112
 113 void __inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo,
 114                           bool rearm);
 115
 116 static inline void inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo)
 117 {
 118         __inet_twsk_schedule(tw, timeo, false);
 119 }
 120
 121 static inline void inet_twsk_reschedule(struct inet_timewait_sock *tw, int timeo)
 122 {
 123         __inet_twsk_schedule(tw, timeo, true);
 124 }
 125
 126 void inet_twsk_deschedule_put(struct inet_timewait_sock *tw);
 127
 128 void inet_twsk_purge(struct inet_hashinfo *hashinfo,
 129                      struct inet_timewait_death_row *twdr, int family);
 130
 131 static inline
 132 struct net *twsk_net(const struct inet_timewait_sock *twsk)
 133 {
 134         return read_pnet(&twsk->tw_net);
 135 }
 136
 137 static inline
 138 void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net)
 139 {
 140         write_pnet(&twsk->tw_net, net);
 141 }
 142 #endif  /* _INET_TIMEWAIT_SOCK_ */