1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * INET		An implementation of the TCP/IP protocol suite for the LINUX
4 *		operating system.  INET is implemented using the  BSD Socket
5 *		interface as the means of communication with the user level.
6 *
7 *		Definitions for a generic INET TIMEWAIT sock
8 *
9 *		From code originally in net/tcp.h
10 */
11#ifndef _INET_TIMEWAIT_SOCK_
12#define _INET_TIMEWAIT_SOCK_
13
14#include <linux/list.h>
15#include <linux/timer.h>
16#include <linux/types.h>
17#include <linux/workqueue.h>
18
19#include <net/inet_sock.h>
20#include <net/sock.h>
21#include <net/tcp_states.h>
22#include <net/timewait_sock.h>
23
24#include <linux/atomic.h>
25
26struct inet_bind_bucket;
27
28/*
29 * This is a TIME_WAIT sock. It works around the memory consumption
30 * problems of sockets in such a state on heavily loaded servers, but
31 * without violating the protocol specification.
32 */
33struct inet_timewait_sock {
34	/*
35	 * Now struct sock also uses sock_common, so please just
36	 * don't add nothing before this first member (__tw_common) --acme
37	 */
38	struct sock_common	__tw_common;
39#define tw_family		__tw_common.skc_family
40#define tw_state		__tw_common.skc_state
41#define tw_reuse		__tw_common.skc_reuse
42#define tw_reuseport		__tw_common.skc_reuseport
43#define tw_ipv6only		__tw_common.skc_ipv6only
44#define tw_bound_dev_if		__tw_common.skc_bound_dev_if
45#define tw_node			__tw_common.skc_nulls_node
46#define tw_bind_node		__tw_common.skc_bind_node
47#define tw_refcnt		__tw_common.skc_refcnt
48#define tw_hash			__tw_common.skc_hash
49#define tw_prot			__tw_common.skc_prot
50#define tw_net			__tw_common.skc_net
51#define tw_daddr        	__tw_common.skc_daddr
52#define tw_v6_daddr		__tw_common.skc_v6_daddr
53#define tw_rcv_saddr    	__tw_common.skc_rcv_saddr
54#define tw_v6_rcv_saddr    	__tw_common.skc_v6_rcv_saddr
55#define tw_dport		__tw_common.skc_dport
56#define tw_num			__tw_common.skc_num
57#define tw_cookie		__tw_common.skc_cookie
58#define tw_dr			__tw_common.skc_tw_dr
59
60	__u32			tw_mark;
61	volatile unsigned char	tw_substate;
62	unsigned char		tw_rcv_wscale;
63
64	/* Socket demultiplex comparisons on incoming packets. */
65	/* these three are in inet_sock */
66	__be16			tw_sport;
67	/* And these are ours. */
68	unsigned int		tw_kill		: 1,
69				tw_transparent  : 1,
70				tw_flowlabel	: 20,
71				tw_pad		: 2,	/* 2 bits hole */
72				tw_tos		: 8;
73	u32			tw_txhash;
74	u32			tw_priority;
75	struct timer_list	tw_timer;
76	struct inet_bind_bucket	*tw_tb;
77};
78#define tw_tclass tw_tos
79
80static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
81{
82	return (struct inet_timewait_sock *)sk;
83}
84
85void inet_twsk_free(struct inet_timewait_sock *tw);
86void inet_twsk_put(struct inet_timewait_sock *tw);
87
88void inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
89			   struct inet_hashinfo *hashinfo);
90
91struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
92					   struct inet_timewait_death_row *dr,
93					   const int state);
94
95void inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
96			 struct inet_hashinfo *hashinfo);
97
98void __inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo,
99			  bool rearm);
100
101static inline void inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo)
102{
103	__inet_twsk_schedule(tw, timeo, false);
104}
105
106static inline void inet_twsk_reschedule(struct inet_timewait_sock *tw, int timeo)
107{
108	__inet_twsk_schedule(tw, timeo, true);
109}
110
111void inet_twsk_deschedule_put(struct inet_timewait_sock *tw);
112
113void inet_twsk_purge(struct inet_hashinfo *hashinfo, int family);
114
115static inline
116struct net *twsk_net(const struct inet_timewait_sock *twsk)
117{
118	return read_pnet(&twsk->tw_net);
119}
120
121static inline
122void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net)
123{
124	write_pnet(&twsk->tw_net, net);
125}
126#endif	/* _INET_TIMEWAIT_SOCK_ */
127