xref: /linux/include/net/inet_timewait_sock.h (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
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 
26 struct 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  */
33 struct 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_tx_queue_mapping	__tw_common.skc_tx_queue_mapping
49 #define tw_rx_queue_mapping	__tw_common.skc_rx_queue_mapping
50 #define tw_hash			__tw_common.skc_hash
51 #define tw_prot			__tw_common.skc_prot
52 #define tw_net			__tw_common.skc_net
53 #define tw_daddr        	__tw_common.skc_daddr
54 #define tw_v6_daddr		__tw_common.skc_v6_daddr
55 #define tw_rcv_saddr    	__tw_common.skc_rcv_saddr
56 #define tw_v6_rcv_saddr    	__tw_common.skc_v6_rcv_saddr
57 #define tw_dport		__tw_common.skc_dport
58 #define tw_num			__tw_common.skc_num
59 #define tw_cookie		__tw_common.skc_cookie
60 #define tw_dr			__tw_common.skc_tw_dr
61 
62 	__u32			tw_mark;
63 	unsigned char		tw_substate;
64 	unsigned char		tw_rcv_wscale;
65 
66 	/* Socket demultiplex comparisons on incoming packets. */
67 	/* these three are in inet_sock */
68 	__be16			tw_sport;
69 	/* And these are ours. */
70 	unsigned int		tw_transparent  : 1,
71 				tw_flowlabel	: 20,
72 				tw_usec_ts	: 1,
73 				tw_connect_bind	: 1,
74 				tw_pad		: 1,	/* 1 bit hole */
75 				tw_tos		: 8;
76 	u32			tw_txhash;
77 	u32			tw_priority;
78 	/**
79 	 * @tw_reuse_stamp: Time of entry into %TCP_TIME_WAIT state in msec.
80 	 */
81 	u32			tw_entry_stamp;
82 	struct timer_list	tw_timer;
83 	struct inet_bind_bucket	*tw_tb;
84 	struct inet_bind2_bucket	*tw_tb2;
85 #if IS_ENABLED(CONFIG_INET_PSP)
86 	struct psp_assoc __rcu	  *psp_assoc;
87 #endif
88 #ifdef CONFIG_SOCK_VALIDATE_XMIT
89 	struct sk_buff*		(*tw_validate_xmit_skb)(struct sock *sk,
90 							struct net_device *dev,
91 							struct sk_buff *skb);
92 #endif
93 };
94 #define tw_tclass tw_tos
95 
96 static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
97 {
98 	return (struct inet_timewait_sock *)sk;
99 }
100 
101 void inet_twsk_free(struct inet_timewait_sock *tw);
102 void inet_twsk_put(struct inet_timewait_sock *tw);
103 
104 void inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
105 			   struct inet_hashinfo *hashinfo);
106 
107 struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
108 					   struct inet_timewait_death_row *dr,
109 					   const int state);
110 
111 void inet_twsk_hashdance_schedule(struct inet_timewait_sock *tw,
112 				  struct sock *sk,
113 				  struct inet_hashinfo *hashinfo,
114 				  int timeo);
115 
116 void __inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo,
117 			  bool rearm);
118 
119 static inline void inet_twsk_reschedule(struct inet_timewait_sock *tw, int timeo)
120 {
121 	__inet_twsk_schedule(tw, timeo, true);
122 }
123 
124 void inet_twsk_deschedule_put(struct inet_timewait_sock *tw);
125 
126 void inet_twsk_purge(struct inet_hashinfo *hashinfo);
127 
128 static inline
129 struct net *twsk_net(const struct inet_timewait_sock *twsk)
130 {
131 	return read_pnet(&twsk->tw_net);
132 }
133 
134 static inline
135 void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net)
136 {
137 	write_pnet(&twsk->tw_net, net);
138 }
139 #endif	/* _INET_TIMEWAIT_SOCK_ */
140