inet_timewait_sock.h 6.6 KB

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  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. #include <linux/list.h>
  18. #include <linux/module.h>
  19. #include <linux/timer.h>
  20. #include <linux/types.h>
  21. #include <linux/workqueue.h>
  22. #include <net/inet_sock.h>
  23. #include <net/sock.h>
  24. #include <net/tcp_states.h>
  25. #include <net/timewait_sock.h>
  26. #include <asm/atomic.h>
  27. struct inet_hashinfo;
  28. #define INET_TWDR_RECYCLE_SLOTS_LOG 5
  29. #define INET_TWDR_RECYCLE_SLOTS (1 << INET_TWDR_RECYCLE_SLOTS_LOG)
  30. /*
  31. * If time > 4sec, it is "slow" path, no recycling is required,
  32. * so that we select tick to get range about 4 seconds.
  33. */
  34. #if HZ <= 16 || HZ > 4096
  35. # error Unsupported: HZ <= 16 or HZ > 4096
  36. #elif HZ <= 32
  37. # define INET_TWDR_RECYCLE_TICK (5 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
  38. #elif HZ <= 64
  39. # define INET_TWDR_RECYCLE_TICK (6 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
  40. #elif HZ <= 128
  41. # define INET_TWDR_RECYCLE_TICK (7 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
  42. #elif HZ <= 256
  43. # define INET_TWDR_RECYCLE_TICK (8 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
  44. #elif HZ <= 512
  45. # define INET_TWDR_RECYCLE_TICK (9 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
  46. #elif HZ <= 1024
  47. # define INET_TWDR_RECYCLE_TICK (10 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
  48. #elif HZ <= 2048
  49. # define INET_TWDR_RECYCLE_TICK (11 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
  50. #else
  51. # define INET_TWDR_RECYCLE_TICK (12 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
  52. #endif
  53. /* TIME_WAIT reaping mechanism. */
  54. #define INET_TWDR_TWKILL_SLOTS 8 /* Please keep this a power of 2. */
  55. #define INET_TWDR_TWKILL_QUOTA 100
  56. struct inet_timewait_death_row {
  57. /* Short-time timewait calendar */
  58. int twcal_hand;
  59. unsigned long twcal_jiffie;
  60. struct timer_list twcal_timer;
  61. struct hlist_head twcal_row[INET_TWDR_RECYCLE_SLOTS];
  62. spinlock_t death_lock;
  63. int tw_count;
  64. int period;
  65. u32 thread_slots;
  66. struct work_struct twkill_work;
  67. struct timer_list tw_timer;
  68. int slot;
  69. struct hlist_head cells[INET_TWDR_TWKILL_SLOTS];
  70. struct inet_hashinfo *hashinfo;
  71. int sysctl_tw_recycle;
  72. int sysctl_max_tw_buckets;
  73. };
  74. extern void inet_twdr_hangman(unsigned long data);
  75. extern void inet_twdr_twkill_work(struct work_struct *work);
  76. extern void inet_twdr_twcal_tick(unsigned long data);
  77. #if (BITS_PER_LONG == 64)
  78. #define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 8
  79. #else
  80. #define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 4
  81. #endif
  82. struct inet_bind_bucket;
  83. /*
  84. * This is a TIME_WAIT sock. It works around the memory consumption
  85. * problems of sockets in such a state on heavily loaded servers, but
  86. * without violating the protocol specification.
  87. */
  88. struct inet_timewait_sock {
  89. /*
  90. * Now struct sock also uses sock_common, so please just
  91. * don't add nothing before this first member (__tw_common) --acme
  92. */
  93. struct sock_common __tw_common;
  94. #define tw_family __tw_common.skc_family
  95. #define tw_state __tw_common.skc_state
  96. #define tw_reuse __tw_common.skc_reuse
  97. #define tw_bound_dev_if __tw_common.skc_bound_dev_if
  98. #define tw_node __tw_common.skc_node
  99. #define tw_bind_node __tw_common.skc_bind_node
  100. #define tw_refcnt __tw_common.skc_refcnt
  101. #define tw_hash __tw_common.skc_hash
  102. #define tw_prot __tw_common.skc_prot
  103. volatile unsigned char tw_substate;
  104. /* 3 bits hole, try to pack */
  105. unsigned char tw_rcv_wscale;
  106. /* Socket demultiplex comparisons on incoming packets. */
  107. /* these five are in inet_sock */
  108. __be16 tw_sport;
  109. __be32 tw_daddr __attribute__((aligned(INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES)));
  110. __be32 tw_rcv_saddr;
  111. __be16 tw_dport;
  112. __u16 tw_num;
  113. /* And these are ours. */
  114. __u8 tw_ipv6only:1;
  115. /* 15 bits hole, try to pack */
  116. __u16 tw_ipv6_offset;
  117. int tw_timeout;
  118. unsigned long tw_ttd;
  119. struct inet_bind_bucket *tw_tb;
  120. struct hlist_node tw_death_node;
  121. };
  122. static inline void inet_twsk_add_node(struct inet_timewait_sock *tw,
  123. struct hlist_head *list)
  124. {
  125. hlist_add_head(&tw->tw_node, list);
  126. }
  127. static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw,
  128. struct hlist_head *list)
  129. {
  130. hlist_add_head(&tw->tw_bind_node, list);
  131. }
  132. static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw)
  133. {
  134. return !hlist_unhashed(&tw->tw_death_node);
  135. }
  136. static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw)
  137. {
  138. tw->tw_death_node.pprev = NULL;
  139. }
  140. static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
  141. {
  142. __hlist_del(&tw->tw_death_node);
  143. inet_twsk_dead_node_init(tw);
  144. }
  145. static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
  146. {
  147. if (inet_twsk_dead_hashed(tw)) {
  148. __inet_twsk_del_dead_node(tw);
  149. return 1;
  150. }
  151. return 0;
  152. }
  153. #define inet_twsk_for_each(tw, node, head) \
  154. hlist_for_each_entry(tw, node, head, tw_node)
  155. #define inet_twsk_for_each_inmate(tw, node, jail) \
  156. hlist_for_each_entry(tw, node, jail, tw_death_node)
  157. #define inet_twsk_for_each_inmate_safe(tw, node, safe, jail) \
  158. hlist_for_each_entry_safe(tw, node, safe, jail, tw_death_node)
  159. static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
  160. {
  161. return (struct inet_timewait_sock *)sk;
  162. }
  163. static inline __be32 inet_rcv_saddr(const struct sock *sk)
  164. {
  165. return likely(sk->sk_state != TCP_TIME_WAIT) ?
  166. inet_sk(sk)->rcv_saddr : inet_twsk(sk)->tw_rcv_saddr;
  167. }
  168. static inline void inet_twsk_put(struct inet_timewait_sock *tw)
  169. {
  170. if (atomic_dec_and_test(&tw->tw_refcnt)) {
  171. struct module *owner = tw->tw_prot->owner;
  172. twsk_destructor((struct sock *)tw);
  173. #ifdef SOCK_REFCNT_DEBUG
  174. printk(KERN_DEBUG "%s timewait_sock %p released\n",
  175. tw->tw_prot->name, tw);
  176. #endif
  177. kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw);
  178. module_put(owner);
  179. }
  180. }
  181. extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
  182. const int state);
  183. extern void __inet_twsk_kill(struct inet_timewait_sock *tw,
  184. struct inet_hashinfo *hashinfo);
  185. extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw,
  186. struct sock *sk,
  187. struct inet_hashinfo *hashinfo);
  188. extern void inet_twsk_schedule(struct inet_timewait_sock *tw,
  189. struct inet_timewait_death_row *twdr,
  190. const int timeo, const int timewait_len);
  191. extern void inet_twsk_deschedule(struct inet_timewait_sock *tw,
  192. struct inet_timewait_death_row *twdr);
  193. #endif /* _INET_TIMEWAIT_SOCK_ */