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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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* Definitions for a generic INET TIMEWAIT sock
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* From code originally in net/tcp.h
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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#ifndef _INET_TIMEWAIT_SOCK_
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#define _INET_TIMEWAIT_SOCK_
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#include <linux/kmemcheck.h>
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#include <linux/list.h>
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#include <linux/timer.h>
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#include <linux/types.h>
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#include <linux/workqueue.h>
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#include <net/inet_sock.h>
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#include <net/tcp_states.h>
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#include <net/timewait_sock.h>
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#include <linux/atomic.h>
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#define INET_TWDR_RECYCLE_SLOTS_LOG 5
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#define INET_TWDR_RECYCLE_SLOTS (1 << INET_TWDR_RECYCLE_SLOTS_LOG)
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* If time > 4sec, it is "slow" path, no recycling is required,
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* so that we select tick to get range about 4 seconds.
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#if HZ <= 16 || HZ > 4096
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# error Unsupported: HZ <= 16 or HZ > 4096
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# define INET_TWDR_RECYCLE_TICK (5 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
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# define INET_TWDR_RECYCLE_TICK (6 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
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# define INET_TWDR_RECYCLE_TICK (7 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
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# define INET_TWDR_RECYCLE_TICK (8 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
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# define INET_TWDR_RECYCLE_TICK (9 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
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# define INET_TWDR_RECYCLE_TICK (10 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
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# define INET_TWDR_RECYCLE_TICK (11 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
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# define INET_TWDR_RECYCLE_TICK (12 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
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/* TIME_WAIT reaping mechanism. */
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#define INET_TWDR_TWKILL_SLOTS 8 /* Please keep this a power of 2. */
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#define INET_TWDR_TWKILL_QUOTA 100
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struct inet_timewait_death_row {
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/* Short-time timewait calendar */
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unsigned long twcal_jiffie;
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struct timer_list twcal_timer;
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struct hlist_head twcal_row[INET_TWDR_RECYCLE_SLOTS];
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spinlock_t death_lock;
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struct work_struct twkill_work;
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struct timer_list tw_timer;
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struct hlist_head cells[INET_TWDR_TWKILL_SLOTS];
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struct inet_hashinfo *hashinfo;
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int sysctl_tw_recycle;
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int sysctl_max_tw_buckets;
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extern void inet_twdr_hangman(unsigned long data);
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extern void inet_twdr_twkill_work(struct work_struct *work);
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extern void inet_twdr_twcal_tick(unsigned long data);
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struct inet_bind_bucket;
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* This is a TIME_WAIT sock. It works around the memory consumption
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* problems of sockets in such a state on heavily loaded servers, but
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* without violating the protocol specification.
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struct inet_timewait_sock {
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* Now struct sock also uses sock_common, so please just
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* don't add nothing before this first member (__tw_common) --acme
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struct sock_common __tw_common;
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#define tw_family __tw_common.skc_family
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#define tw_state __tw_common.skc_state
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#define tw_reuse __tw_common.skc_reuse
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#define tw_bound_dev_if __tw_common.skc_bound_dev_if
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#define tw_node __tw_common.skc_nulls_node
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#define tw_bind_node __tw_common.skc_bind_node
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#define tw_refcnt __tw_common.skc_refcnt
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#define tw_hash __tw_common.skc_hash
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#define tw_prot __tw_common.skc_prot
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#define tw_net __tw_common.skc_net
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#define tw_daddr __tw_common.skc_daddr
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#define tw_rcv_saddr __tw_common.skc_rcv_saddr
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volatile unsigned char tw_substate;
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unsigned char tw_rcv_wscale;
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/* Socket demultiplex comparisons on incoming packets. */
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/* these three are in inet_sock */
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kmemcheck_bitfield_begin(flags);
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/* And these are ours. */
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unsigned int tw_ipv6only : 1,
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tw_pad : 6, /* 6 bits hole */
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kmemcheck_bitfield_end(flags);
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unsigned long tw_ttd;
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struct inet_bind_bucket *tw_tb;
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struct hlist_node tw_death_node;
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#define tw_tclass tw_tos
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static inline void inet_twsk_add_node_rcu(struct inet_timewait_sock *tw,
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struct hlist_nulls_head *list)
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hlist_nulls_add_head_rcu(&tw->tw_node, list);
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static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw,
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struct hlist_head *list)
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hlist_add_head(&tw->tw_bind_node, list);
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static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw)
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return !hlist_unhashed(&tw->tw_death_node);
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static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw)
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tw->tw_death_node.pprev = NULL;
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static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
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__hlist_del(&tw->tw_death_node);
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inet_twsk_dead_node_init(tw);
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static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
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if (inet_twsk_dead_hashed(tw)) {
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__inet_twsk_del_dead_node(tw);
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#define inet_twsk_for_each(tw, node, head) \
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hlist_nulls_for_each_entry(tw, node, head, tw_node)
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#define inet_twsk_for_each_inmate(tw, node, jail) \
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hlist_for_each_entry(tw, node, jail, tw_death_node)
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#define inet_twsk_for_each_inmate_safe(tw, node, safe, jail) \
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hlist_for_each_entry_safe(tw, node, safe, jail, tw_death_node)
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static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
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return (struct inet_timewait_sock *)sk;
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static inline __be32 sk_rcv_saddr(const struct sock *sk)
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/* both inet_sk() and inet_twsk() store rcv_saddr in skc_rcv_saddr */
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return sk->__sk_common.skc_rcv_saddr;
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extern void inet_twsk_put(struct inet_timewait_sock *tw);
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extern int inet_twsk_unhash(struct inet_timewait_sock *tw);
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extern int inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
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struct inet_hashinfo *hashinfo);
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extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
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extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw,
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struct inet_hashinfo *hashinfo);
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extern void inet_twsk_schedule(struct inet_timewait_sock *tw,
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struct inet_timewait_death_row *twdr,
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const int timeo, const int timewait_len);
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extern void inet_twsk_deschedule(struct inet_timewait_sock *tw,
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struct inet_timewait_death_row *twdr);
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extern void inet_twsk_purge(struct inet_hashinfo *hashinfo,
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struct inet_timewait_death_row *twdr, int family);
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struct net *twsk_net(const struct inet_timewait_sock *twsk)
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return rcu_dereference_raw(twsk->tw_net); /* protected by locking, */
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/* reference counting, */
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/* initialization, or RCU. */
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void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net)
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rcu_assign_pointer(twsk->tw_net, net);
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#endif /* _INET_TIMEWAIT_SOCK_ */