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Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001/*
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
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -070018
19#include <linux/list.h>
Arnaldo Carvalho de Meloeeb2b852005-10-10 21:25:23 -070020#include <linux/module.h>
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -070021#include <linux/timer.h>
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -070022#include <linux/types.h>
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -070023#include <linux/workqueue.h>
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -070024
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020025#include <net/inet_sock.h>
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -070026#include <net/sock.h>
27#include <net/tcp_states.h>
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -080028#include <net/timewait_sock.h>
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -070029
30#include <asm/atomic.h>
31
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -070032struct inet_hashinfo;
33
34#define INET_TWDR_RECYCLE_SLOTS_LOG 5
35#define INET_TWDR_RECYCLE_SLOTS (1 << INET_TWDR_RECYCLE_SLOTS_LOG)
36
37/*
38 * If time > 4sec, it is "slow" path, no recycling is required,
39 * so that we select tick to get range about 4 seconds.
40 */
41#if HZ <= 16 || HZ > 4096
42# error Unsupported: HZ <= 16 or HZ > 4096
43#elif HZ <= 32
44# define INET_TWDR_RECYCLE_TICK (5 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
45#elif HZ <= 64
46# define INET_TWDR_RECYCLE_TICK (6 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
47#elif HZ <= 128
48# define INET_TWDR_RECYCLE_TICK (7 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
49#elif HZ <= 256
50# define INET_TWDR_RECYCLE_TICK (8 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
51#elif HZ <= 512
52# define INET_TWDR_RECYCLE_TICK (9 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
53#elif HZ <= 1024
54# define INET_TWDR_RECYCLE_TICK (10 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
55#elif HZ <= 2048
56# define INET_TWDR_RECYCLE_TICK (11 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
57#else
58# define INET_TWDR_RECYCLE_TICK (12 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
59#endif
60
61/* TIME_WAIT reaping mechanism. */
62#define INET_TWDR_TWKILL_SLOTS 8 /* Please keep this a power of 2. */
63
64#define INET_TWDR_TWKILL_QUOTA 100
65
66struct inet_timewait_death_row {
67 /* Short-time timewait calendar */
68 int twcal_hand;
69 int twcal_jiffie;
70 struct timer_list twcal_timer;
71 struct hlist_head twcal_row[INET_TWDR_RECYCLE_SLOTS];
72
73 spinlock_t death_lock;
74 int tw_count;
75 int period;
76 u32 thread_slots;
77 struct work_struct twkill_work;
78 struct timer_list tw_timer;
79 int slot;
80 struct hlist_head cells[INET_TWDR_TWKILL_SLOTS];
81 struct inet_hashinfo *hashinfo;
82 int sysctl_tw_recycle;
83 int sysctl_max_tw_buckets;
84};
85
Arnaldo Carvalho de Melo696ab2d2005-08-09 20:45:03 -070086extern void inet_twdr_hangman(unsigned long data);
87extern void inet_twdr_twkill_work(void *data);
88extern void inet_twdr_twcal_tick(unsigned long data);
89
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -070090#if (BITS_PER_LONG == 64)
91#define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 8
92#else
93#define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 4
94#endif
95
96struct inet_bind_bucket;
97
98/*
99 * This is a TIME_WAIT sock. It works around the memory consumption
100 * problems of sockets in such a state on heavily loaded servers, but
101 * without violating the protocol specification.
102 */
103struct inet_timewait_sock {
104 /*
105 * Now struct sock also uses sock_common, so please just
106 * don't add nothing before this first member (__tw_common) --acme
107 */
108 struct sock_common __tw_common;
109#define tw_family __tw_common.skc_family
110#define tw_state __tw_common.skc_state
111#define tw_reuse __tw_common.skc_reuse
112#define tw_bound_dev_if __tw_common.skc_bound_dev_if
113#define tw_node __tw_common.skc_node
114#define tw_bind_node __tw_common.skc_bind_node
115#define tw_refcnt __tw_common.skc_refcnt
Eric Dumazet81c3d542005-10-03 14:13:38 -0700116#define tw_hash __tw_common.skc_hash
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700117#define tw_prot __tw_common.skc_prot
118 volatile unsigned char tw_substate;
119 /* 3 bits hole, try to pack */
120 unsigned char tw_rcv_wscale;
121 /* Socket demultiplex comparisons on incoming packets. */
122 /* these five are in inet_sock */
Al Viro23f33c22006-09-27 18:43:50 -0700123 __be16 tw_sport;
124 __be32 tw_daddr __attribute__((aligned(INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES)));
125 __be32 tw_rcv_saddr;
126 __be16 tw_dport;
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700127 __u16 tw_num;
128 /* And these are ours. */
129 __u8 tw_ipv6only:1;
Arnaldo Carvalho de Melo0fa1a532005-12-13 23:23:09 -0800130 /* 15 bits hole, try to pack */
131 __u16 tw_ipv6_offset;
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700132 int tw_timeout;
133 unsigned long tw_ttd;
134 struct inet_bind_bucket *tw_tb;
135 struct hlist_node tw_death_node;
136};
137
138static inline void inet_twsk_add_node(struct inet_timewait_sock *tw,
139 struct hlist_head *list)
140{
141 hlist_add_head(&tw->tw_node, list);
142}
143
144static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw,
145 struct hlist_head *list)
146{
147 hlist_add_head(&tw->tw_bind_node, list);
148}
149
150static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw)
151{
Akinobu Mitada753be2006-04-28 15:21:23 -0700152 return !hlist_unhashed(&tw->tw_death_node);
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700153}
154
155static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw)
156{
157 tw->tw_death_node.pprev = NULL;
158}
159
160static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
161{
162 __hlist_del(&tw->tw_death_node);
163 inet_twsk_dead_node_init(tw);
164}
165
166static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
167{
168 if (inet_twsk_dead_hashed(tw)) {
169 __inet_twsk_del_dead_node(tw);
170 return 1;
171 }
172 return 0;
173}
174
175#define inet_twsk_for_each(tw, node, head) \
176 hlist_for_each_entry(tw, node, head, tw_node)
177
178#define inet_twsk_for_each_inmate(tw, node, jail) \
179 hlist_for_each_entry(tw, node, jail, tw_death_node)
180
181#define inet_twsk_for_each_inmate_safe(tw, node, safe, jail) \
182 hlist_for_each_entry_safe(tw, node, safe, jail, tw_death_node)
183
184static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
185{
186 return (struct inet_timewait_sock *)sk;
187}
188
Al Viro82103232006-09-27 18:44:10 -0700189static inline __be32 inet_rcv_saddr(const struct sock *sk)
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700190{
191 return likely(sk->sk_state != TCP_TIME_WAIT) ?
192 inet_sk(sk)->rcv_saddr : inet_twsk(sk)->tw_rcv_saddr;
193}
194
195static inline void inet_twsk_put(struct inet_timewait_sock *tw)
196{
197 if (atomic_dec_and_test(&tw->tw_refcnt)) {
Arnaldo Carvalho de Meloeeb2b852005-10-10 21:25:23 -0700198 struct module *owner = tw->tw_prot->owner;
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700199#ifdef SOCK_REFCNT_DEBUG
200 printk(KERN_DEBUG "%s timewait_sock %p released\n",
201 tw->tw_prot->name, tw);
202#endif
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800203 kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw);
Arnaldo Carvalho de Meloeeb2b852005-10-10 21:25:23 -0700204 module_put(owner);
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700205 }
206}
Arnaldo Carvalho de Meloe48c4142005-08-09 20:09:46 -0700207
Arnaldo Carvalho de Meloc6762702005-08-09 20:09:59 -0700208extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
209 const int state);
210
Arnaldo Carvalho de Meloe48c4142005-08-09 20:09:46 -0700211extern void __inet_twsk_kill(struct inet_timewait_sock *tw,
212 struct inet_hashinfo *hashinfo);
213
214extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw,
215 struct sock *sk,
216 struct inet_hashinfo *hashinfo);
Arnaldo Carvalho de Melo696ab2d2005-08-09 20:45:03 -0700217
218extern void inet_twsk_schedule(struct inet_timewait_sock *tw,
219 struct inet_timewait_death_row *twdr,
220 const int timeo, const int timewait_len);
221extern void inet_twsk_deschedule(struct inet_timewait_sock *tw,
222 struct inet_timewait_death_row *twdr);
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700223#endif /* _INET_TIMEWAIT_SOCK_ */