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>
20 #include <linux/list.h>
21 #include <linux/module.h>
22 #include <linux/timer.h>
23 #include <linux/types.h>
24 #include <linux/workqueue.h>
26 #include <net/inet_sock.h>
28 #include <net/tcp_states.h>
29 #include <net/timewait_sock.h>
31 #include <asm/atomic.h>
35 #define INET_TWDR_RECYCLE_SLOTS_LOG 5
36 #define INET_TWDR_RECYCLE_SLOTS (1 << INET_TWDR_RECYCLE_SLOTS_LOG)
39 * If time > 4sec, it is "slow" path, no recycling is required,
40 * so that we select tick to get range about 4 seconds.
42 #if HZ <= 16 || HZ > 4096
43 # error Unsupported: HZ <= 16 or HZ > 4096
45 # define INET_TWDR_RECYCLE_TICK (5 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
47 # define INET_TWDR_RECYCLE_TICK (6 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
49 # define INET_TWDR_RECYCLE_TICK (7 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
51 # define INET_TWDR_RECYCLE_TICK (8 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
53 # define INET_TWDR_RECYCLE_TICK (9 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
55 # define INET_TWDR_RECYCLE_TICK (10 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
57 # define INET_TWDR_RECYCLE_TICK (11 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
59 # define INET_TWDR_RECYCLE_TICK (12 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
62 /* TIME_WAIT reaping mechanism. */
63 #define INET_TWDR_TWKILL_SLOTS 8 /* Please keep this a power of 2. */
65 #define INET_TWDR_TWKILL_QUOTA 100
67 struct inet_timewait_death_row
{
68 /* Short-time timewait calendar */
71 struct timer_list twcal_timer
;
72 struct hlist_head twcal_row
[INET_TWDR_RECYCLE_SLOTS
];
74 spinlock_t death_lock
;
78 struct work_struct twkill_work
;
79 struct timer_list tw_timer
;
81 struct hlist_head cells
[INET_TWDR_TWKILL_SLOTS
];
82 struct inet_hashinfo
*hashinfo
;
83 int sysctl_tw_recycle
;
84 int sysctl_max_tw_buckets
;
87 extern void inet_twdr_hangman(unsigned long data
);
88 extern void inet_twdr_twkill_work(void *data
);
89 extern void inet_twdr_twcal_tick(unsigned long data
);
91 #if (BITS_PER_LONG == 64)
92 #define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 8
94 #define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 4
97 struct inet_bind_bucket
;
100 * This is a TIME_WAIT sock. It works around the memory consumption
101 * problems of sockets in such a state on heavily loaded servers, but
102 * without violating the protocol specification.
104 struct inet_timewait_sock
{
106 * Now struct sock also uses sock_common, so please just
107 * don't add nothing before this first member (__tw_common) --acme
109 struct sock_common __tw_common
;
110 #define tw_family __tw_common.skc_family
111 #define tw_state __tw_common.skc_state
112 #define tw_reuse __tw_common.skc_reuse
113 #define tw_bound_dev_if __tw_common.skc_bound_dev_if
114 #define tw_node __tw_common.skc_node
115 #define tw_bind_node __tw_common.skc_bind_node
116 #define tw_refcnt __tw_common.skc_refcnt
117 #define tw_hash __tw_common.skc_hash
118 #define tw_prot __tw_common.skc_prot
119 volatile unsigned char tw_substate
;
120 /* 3 bits hole, try to pack */
121 unsigned char tw_rcv_wscale
;
122 /* Socket demultiplex comparisons on incoming packets. */
123 /* these five are in inet_sock */
125 __u32 tw_daddr
__attribute__((aligned(INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES
)));
129 /* And these are ours. */
131 /* 15 bits hole, try to pack */
132 __u16 tw_ipv6_offset
;
134 unsigned long tw_ttd
;
135 struct inet_bind_bucket
*tw_tb
;
136 struct hlist_node tw_death_node
;
139 static inline void inet_twsk_add_node(struct inet_timewait_sock
*tw
,
140 struct hlist_head
*list
)
142 hlist_add_head(&tw
->tw_node
, list
);
145 static inline void inet_twsk_add_bind_node(struct inet_timewait_sock
*tw
,
146 struct hlist_head
*list
)
148 hlist_add_head(&tw
->tw_bind_node
, list
);
151 static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock
*tw
)
153 return !hlist_unhashed(&tw
->tw_death_node
);
156 static inline void inet_twsk_dead_node_init(struct inet_timewait_sock
*tw
)
158 tw
->tw_death_node
.pprev
= NULL
;
161 static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock
*tw
)
163 __hlist_del(&tw
->tw_death_node
);
164 inet_twsk_dead_node_init(tw
);
167 static inline int inet_twsk_del_dead_node(struct inet_timewait_sock
*tw
)
169 if (inet_twsk_dead_hashed(tw
)) {
170 __inet_twsk_del_dead_node(tw
);
176 #define inet_twsk_for_each(tw, node, head) \
177 hlist_for_each_entry(tw, node, head, tw_node)
179 #define inet_twsk_for_each_inmate(tw, node, jail) \
180 hlist_for_each_entry(tw, node, jail, tw_death_node)
182 #define inet_twsk_for_each_inmate_safe(tw, node, safe, jail) \
183 hlist_for_each_entry_safe(tw, node, safe, jail, tw_death_node)
185 static inline struct inet_timewait_sock
*inet_twsk(const struct sock
*sk
)
187 return (struct inet_timewait_sock
*)sk
;
190 static inline u32
inet_rcv_saddr(const struct sock
*sk
)
192 return likely(sk
->sk_state
!= TCP_TIME_WAIT
) ?
193 inet_sk(sk
)->rcv_saddr
: inet_twsk(sk
)->tw_rcv_saddr
;
196 static inline void inet_twsk_put(struct inet_timewait_sock
*tw
)
198 if (atomic_dec_and_test(&tw
->tw_refcnt
)) {
199 struct module
*owner
= tw
->tw_prot
->owner
;
200 #ifdef SOCK_REFCNT_DEBUG
201 printk(KERN_DEBUG
"%s timewait_sock %p released\n",
202 tw
->tw_prot
->name
, tw
);
204 kmem_cache_free(tw
->tw_prot
->twsk_prot
->twsk_slab
, tw
);
209 extern struct inet_timewait_sock
*inet_twsk_alloc(const struct sock
*sk
,
212 extern void __inet_twsk_kill(struct inet_timewait_sock
*tw
,
213 struct inet_hashinfo
*hashinfo
);
215 extern void __inet_twsk_hashdance(struct inet_timewait_sock
*tw
,
217 struct inet_hashinfo
*hashinfo
);
219 extern void inet_twsk_schedule(struct inet_timewait_sock
*tw
,
220 struct inet_timewait_death_row
*twdr
,
221 const int timeo
, const int timewait_len
);
222 extern void inet_twsk_deschedule(struct inet_timewait_sock
*tw
,
223 struct inet_timewait_death_row
*twdr
);
224 #endif /* _INET_TIMEWAIT_SOCK_ */