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
19#include <linux/kmemcheck.h>
20#include <linux/list.h>
21#include <linux/timer.h>
22#include <linux/types.h>
23#include <linux/workqueue.h>
24
25#include <net/inet_sock.h>
26#include <net/sock.h>
27#include <net/tcp_states.h>
28#include <net/timewait_sock.h>
29
30#include <linux/atomic.h>
31
32struct inet_hashinfo;
33
34struct inet_timewait_death_row {
35	atomic_t		tw_count;
36
37	struct inet_hashinfo 	*hashinfo ____cacheline_aligned_in_smp;
38	int			sysctl_tw_recycle;
39	int			sysctl_max_tw_buckets;
40};
41
42struct inet_bind_bucket;
43
44/*
45 * This is a TIME_WAIT sock. It works around the memory consumption
46 * problems of sockets in such a state on heavily loaded servers, but
47 * without violating the protocol specification.
48 */
49struct inet_timewait_sock {
50	/*
51	 * Now struct sock also uses sock_common, so please just
52	 * don't add nothing before this first member (__tw_common) --acme
53	 */
54	struct sock_common	__tw_common;
55#define tw_family		__tw_common.skc_family
56#define tw_state		__tw_common.skc_state
57#define tw_reuse		__tw_common.skc_reuse
58#define tw_ipv6only		__tw_common.skc_ipv6only
59#define tw_bound_dev_if		__tw_common.skc_bound_dev_if
60#define tw_node			__tw_common.skc_nulls_node
61#define tw_bind_node		__tw_common.skc_bind_node
62#define tw_refcnt		__tw_common.skc_refcnt
63#define tw_hash			__tw_common.skc_hash
64#define tw_prot			__tw_common.skc_prot
65#define tw_net			__tw_common.skc_net
66#define tw_daddr        	__tw_common.skc_daddr
67#define tw_v6_daddr		__tw_common.skc_v6_daddr
68#define tw_rcv_saddr    	__tw_common.skc_rcv_saddr
69#define tw_v6_rcv_saddr    	__tw_common.skc_v6_rcv_saddr
70#define tw_dport		__tw_common.skc_dport
71#define tw_num			__tw_common.skc_num
72#define tw_cookie		__tw_common.skc_cookie
73
74	int			tw_timeout;
75	volatile unsigned char	tw_substate;
76	unsigned char		tw_rcv_wscale;
77
78	/* Socket demultiplex comparisons on incoming packets. */
79	/* these three are in inet_sock */
80	__be16			tw_sport;
81	kmemcheck_bitfield_begin(flags);
82	/* And these are ours. */
83	unsigned int		tw_kill		: 1,
84				tw_transparent  : 1,
85				tw_flowlabel	: 20,
86				tw_pad		: 2,	/* 2 bits hole */
87				tw_tos		: 8;
88	kmemcheck_bitfield_end(flags);
89	struct timer_list	tw_timer;
90	struct inet_bind_bucket	*tw_tb;
91	struct inet_timewait_death_row *tw_dr;
92};
93#define tw_tclass tw_tos
94
95static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
96{
97	return (struct inet_timewait_sock *)sk;
98}
99
100void inet_twsk_free(struct inet_timewait_sock *tw);
101void inet_twsk_put(struct inet_timewait_sock *tw);
102
103int inet_twsk_unhash(struct inet_timewait_sock *tw);
104
105int inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
106			  struct inet_hashinfo *hashinfo);
107
108struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
109					   struct inet_timewait_death_row *dr,
110					   const int state);
111
112void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
113			   struct inet_hashinfo *hashinfo);
114
115void __inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo,
116			  bool rearm);
117
118static inline void inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo)
119{
120	__inet_twsk_schedule(tw, timeo, false);
121}
122
123static inline void inet_twsk_reschedule(struct inet_timewait_sock *tw, int timeo)
124{
125	__inet_twsk_schedule(tw, timeo, true);
126}
127
128void inet_twsk_deschedule(struct inet_timewait_sock *tw);
129
130void inet_twsk_purge(struct inet_hashinfo *hashinfo,
131		     struct inet_timewait_death_row *twdr, int family);
132
133static inline
134struct net *twsk_net(const struct inet_timewait_sock *twsk)
135{
136	return read_pnet(&twsk->tw_net);
137}
138
139static inline
140void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net)
141{
142	write_pnet(&twsk->tw_net, net);
143}
144#endif	/* _INET_TIMEWAIT_SOCK_ */
145