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/list.h>
21#include <linux/module.h>
22#include <linux/timer.h>
23#include <linux/types.h>
24#include <linux/workqueue.h>
25
26#include <net/inet_sock.h>
27#include <net/sock.h>
28#include <net/tcp_states.h>
29#include <net/timewait_sock.h>
30
31#include <asm/atomic.h>
32
33struct inet_hashinfo;
34
35#define INET_TWDR_RECYCLE_SLOTS_LOG 5
36#define INET_TWDR_RECYCLE_SLOTS (1 << INET_TWDR_RECYCLE_SLOTS_LOG)
37
38/*
39 * If time > 4sec, it is "slow" path, no recycling is required,
40 * so that we select tick to get range about 4 seconds.
41 */
42#if HZ <= 16 || HZ > 4096
43# error Unsupported: HZ <= 16 or HZ > 4096
44#elif HZ <= 32
45# define INET_TWDR_RECYCLE_TICK (5 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
46#elif HZ <= 64
47# define INET_TWDR_RECYCLE_TICK (6 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
48#elif HZ <= 128
49# define INET_TWDR_RECYCLE_TICK (7 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
50#elif HZ <= 256
51# define INET_TWDR_RECYCLE_TICK (8 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
52#elif HZ <= 512
53# define INET_TWDR_RECYCLE_TICK (9 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
54#elif HZ <= 1024
55# define INET_TWDR_RECYCLE_TICK (10 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
56#elif HZ <= 2048
57# define INET_TWDR_RECYCLE_TICK (11 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
58#else
59# define INET_TWDR_RECYCLE_TICK (12 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
60#endif
61
62/* TIME_WAIT reaping mechanism. */
63#define INET_TWDR_TWKILL_SLOTS 8 /* Please keep this a power of 2. */
64
65#define INET_TWDR_TWKILL_QUOTA 100
66
67struct inet_timewait_death_row {
68 /* Short-time timewait calendar */
69 int twcal_hand;
70 int twcal_jiffie;
71 struct timer_list twcal_timer;
72 struct hlist_head twcal_row[INET_TWDR_RECYCLE_SLOTS];
73
74 spinlock_t death_lock;
75 int tw_count;
76 int period;
77 u32 thread_slots;
78 struct work_struct twkill_work;
79 struct timer_list tw_timer;
80 int slot;
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;
85};
86
87extern void inet_twdr_hangman(unsigned long data);
88extern void inet_twdr_twkill_work(void *data);
89extern void inet_twdr_twcal_tick(unsigned long data);
90
91#if (BITS_PER_LONG == 64)
92#define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 8
93#else
94#define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 4
95#endif
96
97struct inet_bind_bucket;
98
99/*
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.
103 */
104struct inet_timewait_sock {
105 /*
106 * Now struct sock also uses sock_common, so please just
107 * don't add nothing before this first member (__tw_common) --acme
108 */
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 */
124 __u16 tw_sport;
125 __u32 tw_daddr __attribute__((aligned(INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES)));
126 __u32 tw_rcv_saddr;
127 __u16 tw_dport;
128 __u16 tw_num;
129 /* And these are ours. */
130 __u8 tw_ipv6only:1;
131 /* 15 bits hole, try to pack */
132 __u16 tw_ipv6_offset;
133 int tw_timeout;
134 unsigned long tw_ttd;
135 struct inet_bind_bucket *tw_tb;
136 struct hlist_node tw_death_node;
137};
138
139static inline void inet_twsk_add_node(struct inet_timewait_sock *tw,
140 struct hlist_head *list)
141{
142 hlist_add_head(&tw->tw_node, list);
143}
144
145static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw,
146 struct hlist_head *list)
147{
148 hlist_add_head(&tw->tw_bind_node, list);
149}
150
151static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw)
152{
153 return tw->tw_death_node.pprev != NULL;
154}
155
156static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw)
157{
158 tw->tw_death_node.pprev = NULL;
159}
160
161static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
162{
163 __hlist_del(&tw->tw_death_node);
164 inet_twsk_dead_node_init(tw);
165}
166
167static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
168{
169 if (inet_twsk_dead_hashed(tw)) {
170 __inet_twsk_del_dead_node(tw);
171 return 1;
172 }
173 return 0;
174}
175
176#define inet_twsk_for_each(tw, node, head) \
177 hlist_for_each_entry(tw, node, head, tw_node)
178
179#define inet_twsk_for_each_inmate(tw, node, jail) \
180 hlist_for_each_entry(tw, node, jail, tw_death_node)
181
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)
184
185static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
186{
187 return (struct inet_timewait_sock *)sk;
188}
189
190static inline u32 inet_rcv_saddr(const struct sock *sk)
191{
192 return likely(sk->sk_state != TCP_TIME_WAIT) ?
193 inet_sk(sk)->rcv_saddr : inet_twsk(sk)->tw_rcv_saddr;
194}
195
196static inline void inet_twsk_put(struct inet_timewait_sock *tw)
197{
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);
203#endif
204 kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw);
205 module_put(owner);
206 }
207}
208
209extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
210 const int state);
211
212extern void __inet_twsk_kill(struct inet_timewait_sock *tw,
213 struct inet_hashinfo *hashinfo);
214
215extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw,
216 struct sock *sk,
217 struct inet_hashinfo *hashinfo);
218
219extern void inet_twsk_schedule(struct inet_timewait_sock *tw,
220 struct inet_timewait_death_row *twdr,
221 const int timeo, const int timewait_len);
222extern void inet_twsk_deschedule(struct inet_timewait_sock *tw,
223 struct inet_timewait_death_row *twdr);
224#endif /* _INET_TIMEWAIT_SOCK_ */