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.
6 * Definitions for a generic INET TIMEWAIT sock
8 * From code originally in net/tcp.h
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.
15 #ifndef _INET_TIMEWAIT_SOCK_
16 #define _INET_TIMEWAIT_SOCK_
18 #include <linux/config.h>
21 #include <linux/list.h>
22 #include <linux/timer.h>
23 #include <linux/types.h>
24 #include <linux/workqueue.h>
27 #include <net/tcp_states.h>
29 #include <asm/atomic.h>
33 #define INET_TWDR_RECYCLE_SLOTS_LOG 5
34 #define INET_TWDR_RECYCLE_SLOTS (1 << INET_TWDR_RECYCLE_SLOTS_LOG)
37 * If time > 4sec, it is "slow" path, no recycling is required,
38 * so that we select tick to get range about 4 seconds.
40 #if HZ <= 16 || HZ > 4096
41 # error Unsupported: HZ <= 16 or HZ > 4096
43 # define INET_TWDR_RECYCLE_TICK (5 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
45 # define INET_TWDR_RECYCLE_TICK (6 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
47 # define INET_TWDR_RECYCLE_TICK (7 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
49 # define INET_TWDR_RECYCLE_TICK (8 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
51 # define INET_TWDR_RECYCLE_TICK (9 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
53 # define INET_TWDR_RECYCLE_TICK (10 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
55 # define INET_TWDR_RECYCLE_TICK (11 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
57 # define INET_TWDR_RECYCLE_TICK (12 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
60 /* TIME_WAIT reaping mechanism. */
61 #define INET_TWDR_TWKILL_SLOTS 8 /* Please keep this a power of 2. */
63 #define INET_TWDR_TWKILL_QUOTA 100
65 struct inet_timewait_death_row
{
66 /* Short-time timewait calendar */
69 struct timer_list twcal_timer
;
70 struct hlist_head twcal_row
[INET_TWDR_RECYCLE_SLOTS
];
72 spinlock_t death_lock
;
76 struct work_struct twkill_work
;
77 struct timer_list tw_timer
;
79 struct hlist_head cells
[INET_TWDR_TWKILL_SLOTS
];
80 struct inet_hashinfo
*hashinfo
;
81 int sysctl_tw_recycle
;
82 int sysctl_max_tw_buckets
;
85 extern void inet_twdr_hangman(unsigned long data
);
86 extern void inet_twdr_twkill_work(void *data
);
87 extern void inet_twdr_twcal_tick(unsigned long data
);
89 #if (BITS_PER_LONG == 64)
90 #define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 8
92 #define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 4
95 struct inet_bind_bucket
;
98 * This is a TIME_WAIT sock. It works around the memory consumption
99 * problems of sockets in such a state on heavily loaded servers, but
100 * without violating the protocol specification.
102 struct inet_timewait_sock
{
104 * Now struct sock also uses sock_common, so please just
105 * don't add nothing before this first member (__tw_common) --acme
107 struct sock_common __tw_common
;
108 #define tw_family __tw_common.skc_family
109 #define tw_state __tw_common.skc_state
110 #define tw_reuse __tw_common.skc_reuse
111 #define tw_bound_dev_if __tw_common.skc_bound_dev_if
112 #define tw_node __tw_common.skc_node
113 #define tw_bind_node __tw_common.skc_bind_node
114 #define tw_refcnt __tw_common.skc_refcnt
115 #define tw_prot __tw_common.skc_prot
116 volatile unsigned char tw_substate
;
117 /* 3 bits hole, try to pack */
118 unsigned char tw_rcv_wscale
;
119 /* Socket demultiplex comparisons on incoming packets. */
120 /* these five are in inet_sock */
122 __u32 tw_daddr
__attribute__((aligned(INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES
)));
126 /* And these are ours. */
128 /* 31 bits hole, try to pack */
131 unsigned long tw_ttd
;
132 struct inet_bind_bucket
*tw_tb
;
133 struct hlist_node tw_death_node
;
136 static inline void inet_twsk_add_node(struct inet_timewait_sock
*tw
,
137 struct hlist_head
*list
)
139 hlist_add_head(&tw
->tw_node
, list
);
142 static inline void inet_twsk_add_bind_node(struct inet_timewait_sock
*tw
,
143 struct hlist_head
*list
)
145 hlist_add_head(&tw
->tw_bind_node
, list
);
148 static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock
*tw
)
150 return tw
->tw_death_node
.pprev
!= NULL
;
153 static inline void inet_twsk_dead_node_init(struct inet_timewait_sock
*tw
)
155 tw
->tw_death_node
.pprev
= NULL
;
158 static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock
*tw
)
160 __hlist_del(&tw
->tw_death_node
);
161 inet_twsk_dead_node_init(tw
);
164 static inline int inet_twsk_del_dead_node(struct inet_timewait_sock
*tw
)
166 if (inet_twsk_dead_hashed(tw
)) {
167 __inet_twsk_del_dead_node(tw
);
173 #define inet_twsk_for_each(tw, node, head) \
174 hlist_for_each_entry(tw, node, head, tw_node)
176 #define inet_twsk_for_each_inmate(tw, node, jail) \
177 hlist_for_each_entry(tw, node, jail, tw_death_node)
179 #define inet_twsk_for_each_inmate_safe(tw, node, safe, jail) \
180 hlist_for_each_entry_safe(tw, node, safe, jail, tw_death_node)
182 static inline struct inet_timewait_sock
*inet_twsk(const struct sock
*sk
)
184 return (struct inet_timewait_sock
*)sk
;
187 static inline u32
inet_rcv_saddr(const struct sock
*sk
)
189 return likely(sk
->sk_state
!= TCP_TIME_WAIT
) ?
190 inet_sk(sk
)->rcv_saddr
: inet_twsk(sk
)->tw_rcv_saddr
;
193 static inline void inet_twsk_put(struct inet_timewait_sock
*tw
)
195 if (atomic_dec_and_test(&tw
->tw_refcnt
)) {
196 #ifdef SOCK_REFCNT_DEBUG
197 printk(KERN_DEBUG
"%s timewait_sock %p released\n",
198 tw
->tw_prot
->name
, tw
);
200 kmem_cache_free(tw
->tw_prot
->twsk_slab
, tw
);
204 extern struct inet_timewait_sock
*inet_twsk_alloc(const struct sock
*sk
,
207 extern void __inet_twsk_kill(struct inet_timewait_sock
*tw
,
208 struct inet_hashinfo
*hashinfo
);
210 extern void __inet_twsk_hashdance(struct inet_timewait_sock
*tw
,
212 struct inet_hashinfo
*hashinfo
);
214 extern void inet_twsk_schedule(struct inet_timewait_sock
*tw
,
215 struct inet_timewait_death_row
*twdr
,
216 const int timeo
, const int timewait_len
);
217 extern void inet_twsk_deschedule(struct inet_timewait_sock
*tw
,
218 struct inet_timewait_death_row
*twdr
);
219 #endif /* _INET_TIMEWAIT_SOCK_ */