tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
18#include <linux/config.h>
19
20#include <linux/ip.h>
21#include <linux/list.h>
22#include <linux/timer.h>
23#include <linux/types.h>
24#include <linux/workqueue.h>
25
26#include <net/sock.h>
27#include <net/tcp_states.h>
28
29#include <asm/atomic.h>
30
31struct inet_hashinfo;
32
33#define INET_TWDR_RECYCLE_SLOTS_LOG 5
34#define INET_TWDR_RECYCLE_SLOTS (1 << INET_TWDR_RECYCLE_SLOTS_LOG)
35
36/*
37 * If time > 4sec, it is "slow" path, no recycling is required,
38 * so that we select tick to get range about 4 seconds.
39 */
40#if HZ <= 16 || HZ > 4096
41# error Unsupported: HZ <= 16 or HZ > 4096
42#elif HZ <= 32
43# define INET_TWDR_RECYCLE_TICK (5 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
44#elif HZ <= 64
45# define INET_TWDR_RECYCLE_TICK (6 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
46#elif HZ <= 128
47# define INET_TWDR_RECYCLE_TICK (7 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
48#elif HZ <= 256
49# define INET_TWDR_RECYCLE_TICK (8 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
50#elif HZ <= 512
51# define INET_TWDR_RECYCLE_TICK (9 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
52#elif HZ <= 1024
53# define INET_TWDR_RECYCLE_TICK (10 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
54#elif HZ <= 2048
55# define INET_TWDR_RECYCLE_TICK (11 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
56#else
57# define INET_TWDR_RECYCLE_TICK (12 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
58#endif
59
60/* TIME_WAIT reaping mechanism. */
61#define INET_TWDR_TWKILL_SLOTS 8 /* Please keep this a power of 2. */
62
63#define INET_TWDR_TWKILL_QUOTA 100
64
65struct inet_timewait_death_row {
66 /* Short-time timewait calendar */
67 int twcal_hand;
68 int twcal_jiffie;
69 struct timer_list twcal_timer;
70 struct hlist_head twcal_row[INET_TWDR_RECYCLE_SLOTS];
71
72 spinlock_t death_lock;
73 int tw_count;
74 int period;
75 u32 thread_slots;
76 struct work_struct twkill_work;
77 struct timer_list tw_timer;
78 int slot;
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;
83};
84
85extern void inet_twdr_hangman(unsigned long data);
86extern void inet_twdr_twkill_work(void *data);
87extern void inet_twdr_twcal_tick(unsigned long data);
88
89#if (BITS_PER_LONG == 64)
90#define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 8
91#else
92#define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 4
93#endif
94
95struct inet_bind_bucket;
96
97/*
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.
101 */
102struct inet_timewait_sock {
103 /*
104 * Now struct sock also uses sock_common, so please just
105 * don't add nothing before this first member (__tw_common) --acme
106 */
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 */
121 __u16 tw_sport;
122 __u32 tw_daddr __attribute__((aligned(INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES)));
123 __u32 tw_rcv_saddr;
124 __u16 tw_dport;
125 __u16 tw_num;
126 /* And these are ours. */
127 __u8 tw_ipv6only:1;
128 /* 31 bits hole, try to pack */
129 int tw_hashent;
130 int tw_timeout;
131 unsigned long tw_ttd;
132 struct inet_bind_bucket *tw_tb;
133 struct hlist_node tw_death_node;
134};
135
136static inline void inet_twsk_add_node(struct inet_timewait_sock *tw,
137 struct hlist_head *list)
138{
139 hlist_add_head(&tw->tw_node, list);
140}
141
142static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw,
143 struct hlist_head *list)
144{
145 hlist_add_head(&tw->tw_bind_node, list);
146}
147
148static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw)
149{
150 return tw->tw_death_node.pprev != NULL;
151}
152
153static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw)
154{
155 tw->tw_death_node.pprev = NULL;
156}
157
158static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
159{
160 __hlist_del(&tw->tw_death_node);
161 inet_twsk_dead_node_init(tw);
162}
163
164static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
165{
166 if (inet_twsk_dead_hashed(tw)) {
167 __inet_twsk_del_dead_node(tw);
168 return 1;
169 }
170 return 0;
171}
172
173#define inet_twsk_for_each(tw, node, head) \
174 hlist_for_each_entry(tw, node, head, tw_node)
175
176#define inet_twsk_for_each_inmate(tw, node, jail) \
177 hlist_for_each_entry(tw, node, jail, tw_death_node)
178
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)
181
182static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
183{
184 return (struct inet_timewait_sock *)sk;
185}
186
187static inline u32 inet_rcv_saddr(const struct sock *sk)
188{
189 return likely(sk->sk_state != TCP_TIME_WAIT) ?
190 inet_sk(sk)->rcv_saddr : inet_twsk(sk)->tw_rcv_saddr;
191}
192
193static inline void inet_twsk_put(struct inet_timewait_sock *tw)
194{
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);
199#endif
200 kmem_cache_free(tw->tw_prot->twsk_slab, tw);
201 }
202}
203
204extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
205 const int state);
206
207extern void __inet_twsk_kill(struct inet_timewait_sock *tw,
208 struct inet_hashinfo *hashinfo);
209
210extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw,
211 struct sock *sk,
212 struct inet_hashinfo *hashinfo);
213
214extern void inet_twsk_schedule(struct inet_timewait_sock *tw,
215 struct inet_timewait_death_row *twdr,
216 const int timeo, const int timewait_len);
217extern void inet_twsk_deschedule(struct inet_timewait_sock *tw,
218 struct inet_timewait_death_row *twdr);
219#endif /* _INET_TIMEWAIT_SOCK_ */