xref: /linux/include/net/inet_timewait_sock.h (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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 
32 struct inet_bind_bucket;
33 
34 /*
35  * This is a TIME_WAIT sock. It works around the memory consumption
36  * problems of sockets in such a state on heavily loaded servers, but
37  * without violating the protocol specification.
38  */
39 struct inet_timewait_sock {
40 	/*
41 	 * Now struct sock also uses sock_common, so please just
42 	 * don't add nothing before this first member (__tw_common) --acme
43 	 */
44 	struct sock_common	__tw_common;
45 #define tw_family		__tw_common.skc_family
46 #define tw_state		__tw_common.skc_state
47 #define tw_reuse		__tw_common.skc_reuse
48 #define tw_ipv6only		__tw_common.skc_ipv6only
49 #define tw_bound_dev_if		__tw_common.skc_bound_dev_if
50 #define tw_node			__tw_common.skc_nulls_node
51 #define tw_bind_node		__tw_common.skc_bind_node
52 #define tw_refcnt		__tw_common.skc_refcnt
53 #define tw_hash			__tw_common.skc_hash
54 #define tw_prot			__tw_common.skc_prot
55 #define tw_net			__tw_common.skc_net
56 #define tw_daddr        	__tw_common.skc_daddr
57 #define tw_v6_daddr		__tw_common.skc_v6_daddr
58 #define tw_rcv_saddr    	__tw_common.skc_rcv_saddr
59 #define tw_v6_rcv_saddr    	__tw_common.skc_v6_rcv_saddr
60 #define tw_dport		__tw_common.skc_dport
61 #define tw_num			__tw_common.skc_num
62 #define tw_cookie		__tw_common.skc_cookie
63 #define tw_dr			__tw_common.skc_tw_dr
64 
65 	int			tw_timeout;
66 	volatile unsigned char	tw_substate;
67 	unsigned char		tw_rcv_wscale;
68 
69 	/* Socket demultiplex comparisons on incoming packets. */
70 	/* these three are in inet_sock */
71 	__be16			tw_sport;
72 	kmemcheck_bitfield_begin(flags);
73 	/* And these are ours. */
74 	unsigned int		tw_kill		: 1,
75 				tw_transparent  : 1,
76 				tw_flowlabel	: 20,
77 				tw_pad		: 2,	/* 2 bits hole */
78 				tw_tos		: 8;
79 	kmemcheck_bitfield_end(flags);
80 	struct timer_list	tw_timer;
81 	struct inet_bind_bucket	*tw_tb;
82 };
83 #define tw_tclass tw_tos
84 
85 static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
86 {
87 	return (struct inet_timewait_sock *)sk;
88 }
89 
90 void inet_twsk_free(struct inet_timewait_sock *tw);
91 void inet_twsk_put(struct inet_timewait_sock *tw);
92 
93 void inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
94 			   struct inet_hashinfo *hashinfo);
95 
96 struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
97 					   struct inet_timewait_death_row *dr,
98 					   const int state);
99 
100 void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
101 			   struct inet_hashinfo *hashinfo);
102 
103 void __inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo,
104 			  bool rearm);
105 
106 static inline void inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo)
107 {
108 	__inet_twsk_schedule(tw, timeo, false);
109 }
110 
111 static inline void inet_twsk_reschedule(struct inet_timewait_sock *tw, int timeo)
112 {
113 	__inet_twsk_schedule(tw, timeo, true);
114 }
115 
116 void inet_twsk_deschedule_put(struct inet_timewait_sock *tw);
117 
118 void inet_twsk_purge(struct inet_hashinfo *hashinfo, int family);
119 
120 static inline
121 struct net *twsk_net(const struct inet_timewait_sock *twsk)
122 {
123 	return read_pnet(&twsk->tw_net);
124 }
125 
126 static inline
127 void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net)
128 {
129 	write_pnet(&twsk->tw_net, net);
130 }
131 #endif	/* _INET_TIMEWAIT_SOCK_ */
132