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/module.h>
23#include <linux/timer.h>
24#include <linux/types.h>
25#include <linux/workqueue.h>
26
27#include <net/sock.h>
28#include <net/tcp_states.h>
29
30#include <asm/atomic.h>
31
32struct 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
86extern 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
90#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
116#define tw_hash __tw_common.skc_hash
117#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 */
123 __u16 tw_sport;
124 __u32 tw_daddr __attribute__((aligned(INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES)));
125 __u32 tw_rcv_saddr;
126 __u16 tw_dport;
127 __u16 tw_num;
128 /* And these are ours. */
129 __u8 tw_ipv6only:1;
130 /* 31 bits hole, try to pack */
131 int tw_timeout;
132 unsigned long tw_ttd;
133 struct inet_bind_bucket *tw_tb;
134 struct hlist_node tw_death_node;
135};
136
137static inline void inet_twsk_add_node(struct inet_timewait_sock *tw,
138 struct hlist_head *list)
139{
140 hlist_add_head(&tw->tw_node, list);
141}
142
143static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw,
144 struct hlist_head *list)
145{
146 hlist_add_head(&tw->tw_bind_node, list);
147}
148
149static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw)
150{
151 return tw->tw_death_node.pprev != NULL;
152}
153
154static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw)
155{
156 tw->tw_death_node.pprev = NULL;
157}
158
159static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
160{
161 __hlist_del(&tw->tw_death_node);
162 inet_twsk_dead_node_init(tw);
163}
164
165static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
166{
167 if (inet_twsk_dead_hashed(tw)) {
168 __inet_twsk_del_dead_node(tw);
169 return 1;
170 }
171 return 0;
172}
173
174#define inet_twsk_for_each(tw, node, head) \
175 hlist_for_each_entry(tw, node, head, tw_node)
176
177#define inet_twsk_for_each_inmate(tw, node, jail) \
178 hlist_for_each_entry(tw, node, jail, tw_death_node)
179
180#define inet_twsk_for_each_inmate_safe(tw, node, safe, jail) \
181 hlist_for_each_entry_safe(tw, node, safe, jail, tw_death_node)
182
183static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
184{
185 return (struct inet_timewait_sock *)sk;
186}
187
188static inline u32 inet_rcv_saddr(const struct sock *sk)
189{
190 return likely(sk->sk_state != TCP_TIME_WAIT) ?
191 inet_sk(sk)->rcv_saddr : inet_twsk(sk)->tw_rcv_saddr;
192}
193
194static inline void inet_twsk_put(struct inet_timewait_sock *tw)
195{
196 if (atomic_dec_and_test(&tw->tw_refcnt)) {
197 struct module *owner = tw->tw_prot->owner;
198#ifdef SOCK_REFCNT_DEBUG
199 printk(KERN_DEBUG "%s timewait_sock %p released\n",
200 tw->tw_prot->name, tw);
201#endif
202 kmem_cache_free(tw->tw_prot->twsk_slab, tw);
203 module_put(owner);
204 }
205}
206
207extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
208 const int state);
209
210extern void __inet_twsk_kill(struct inet_timewait_sock *tw,
211 struct inet_hashinfo *hashinfo);
212
213extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw,
214 struct sock *sk,
215 struct inet_hashinfo *hashinfo);
216
217extern void inet_twsk_schedule(struct inet_timewait_sock *tw,
218 struct inet_timewait_death_row *twdr,
219 const int timeo, const int timewait_len);
220extern void inet_twsk_deschedule(struct inet_timewait_sock *tw,
221 struct inet_timewait_death_row *twdr);
222#endif /* _INET_TIMEWAIT_SOCK_ */