inet_timewait_sock.h 6.7 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/kmemcheck.h>
  18. #include <linux/list.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 <linux/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. struct inet_bind_bucket;
  78. /*
  79. * This is a TIME_WAIT sock. It works around the memory consumption
  80. * problems of sockets in such a state on heavily loaded servers, but
  81. * without violating the protocol specification.
  82. */
  83. struct inet_timewait_sock {
  84. /*
  85. * Now struct sock also uses sock_common, so please just
  86. * don't add nothing before this first member (__tw_common) --acme
  87. */
  88. struct sock_common __tw_common;
  89. #define tw_family __tw_common.skc_family
  90. #define tw_state __tw_common.skc_state
  91. #define tw_reuse __tw_common.skc_reuse
  92. #define tw_bound_dev_if __tw_common.skc_bound_dev_if
  93. #define tw_node __tw_common.skc_nulls_node
  94. #define tw_bind_node __tw_common.skc_bind_node
  95. #define tw_refcnt __tw_common.skc_refcnt
  96. #define tw_hash __tw_common.skc_hash
  97. #define tw_prot __tw_common.skc_prot
  98. #define tw_net __tw_common.skc_net
  99. #define tw_daddr __tw_common.skc_daddr
  100. #define tw_rcv_saddr __tw_common.skc_rcv_saddr
  101. int tw_timeout;
  102. volatile unsigned char tw_substate;
  103. unsigned char tw_rcv_wscale;
  104. /* Socket demultiplex comparisons on incoming packets. */
  105. /* these three are in inet_sock */
  106. __be16 tw_sport;
  107. __be16 tw_dport;
  108. __u16 tw_num;
  109. kmemcheck_bitfield_begin(flags);
  110. /* And these are ours. */
  111. unsigned int tw_ipv6only : 1,
  112. tw_transparent : 1,
  113. tw_pad : 6, /* 6 bits hole */
  114. tw_tos : 8,
  115. tw_ipv6_offset : 16;
  116. kmemcheck_bitfield_end(flags);
  117. unsigned long tw_ttd;
  118. struct inet_bind_bucket *tw_tb;
  119. struct hlist_node tw_death_node;
  120. };
  121. #define tw_tclass tw_tos
  122. static inline void inet_twsk_add_node_rcu(struct inet_timewait_sock *tw,
  123. struct hlist_nulls_head *list)
  124. {
  125. hlist_nulls_add_head_rcu(&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_nulls_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 sk_rcv_saddr(const struct sock *sk)
  164. {
  165. /* both inet_sk() and inet_twsk() store rcv_saddr in skc_rcv_saddr */
  166. return sk->__sk_common.skc_rcv_saddr;
  167. }
  168. extern void inet_twsk_put(struct inet_timewait_sock *tw);
  169. extern int inet_twsk_unhash(struct inet_timewait_sock *tw);
  170. extern int inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
  171. struct inet_hashinfo *hashinfo);
  172. extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
  173. const int state);
  174. extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw,
  175. struct sock *sk,
  176. struct inet_hashinfo *hashinfo);
  177. extern void inet_twsk_schedule(struct inet_timewait_sock *tw,
  178. struct inet_timewait_death_row *twdr,
  179. const int timeo, const int timewait_len);
  180. extern void inet_twsk_deschedule(struct inet_timewait_sock *tw,
  181. struct inet_timewait_death_row *twdr);
  182. extern void inet_twsk_purge(struct inet_hashinfo *hashinfo,
  183. struct inet_timewait_death_row *twdr, int family);
  184. static inline
  185. struct net *twsk_net(const struct inet_timewait_sock *twsk)
  186. {
  187. return read_pnet(&twsk->tw_net);
  188. }
  189. static inline
  190. void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net)
  191. {
  192. write_pnet(&twsk->tw_net, net);
  193. }
  194. #endif /* _INET_TIMEWAIT_SOCK_ */