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.
6 * Definitions for a generic INET TIMEWAIT sock
8 * From code originally in net/tcp.h
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.
15 #ifndef _INET_TIMEWAIT_SOCK_
16 #define _INET_TIMEWAIT_SOCK_
18 #include <linux/config.h>
20 #include <linux/list.h>
21 #include <linux/types.h>
24 #include <net/tcp_states.h>
26 #include <asm/atomic.h>
28 #if (BITS_PER_LONG == 64)
29 #define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 8
31 #define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 4
34 struct inet_bind_bucket;
37 * This is a TIME_WAIT sock. It works around the memory consumption
38 * problems of sockets in such a state on heavily loaded servers, but
39 * without violating the protocol specification.
41 struct inet_timewait_sock {
43 * Now struct sock also uses sock_common, so please just
44 * don't add nothing before this first member (__tw_common) --acme
46 struct sock_common __tw_common;
47 #define tw_family __tw_common.skc_family
48 #define tw_state __tw_common.skc_state
49 #define tw_reuse __tw_common.skc_reuse
50 #define tw_bound_dev_if __tw_common.skc_bound_dev_if
51 #define tw_node __tw_common.skc_node
52 #define tw_bind_node __tw_common.skc_bind_node
53 #define tw_refcnt __tw_common.skc_refcnt
54 #define tw_prot __tw_common.skc_prot
55 volatile unsigned char tw_substate;
56 /* 3 bits hole, try to pack */
57 unsigned char tw_rcv_wscale;
58 /* Socket demultiplex comparisons on incoming packets. */
59 /* these five are in inet_sock */
61 __u32 tw_daddr __attribute__((aligned(INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES)));
65 /* And these are ours. */
67 /* 31 bits hole, try to pack */
71 struct inet_bind_bucket *tw_tb;
72 struct hlist_node tw_death_node;
75 static inline void inet_twsk_add_node(struct inet_timewait_sock *tw,
76 struct hlist_head *list)
78 hlist_add_head(&tw->tw_node, list);
81 static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw,
82 struct hlist_head *list)
84 hlist_add_head(&tw->tw_bind_node, list);
87 static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw)
89 return tw->tw_death_node.pprev != NULL;
92 static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw)
94 tw->tw_death_node.pprev = NULL;
97 static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
99 __hlist_del(&tw->tw_death_node);
100 inet_twsk_dead_node_init(tw);
103 static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
105 if (inet_twsk_dead_hashed(tw)) {
106 __inet_twsk_del_dead_node(tw);
112 #define inet_twsk_for_each(tw, node, head) \
113 hlist_for_each_entry(tw, node, head, tw_node)
115 #define inet_twsk_for_each_inmate(tw, node, jail) \
116 hlist_for_each_entry(tw, node, jail, tw_death_node)
118 #define inet_twsk_for_each_inmate_safe(tw, node, safe, jail) \
119 hlist_for_each_entry_safe(tw, node, safe, jail, tw_death_node)
121 static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
123 return (struct inet_timewait_sock *)sk;
126 static inline u32 inet_rcv_saddr(const struct sock *sk)
128 return likely(sk->sk_state != TCP_TIME_WAIT) ?
129 inet_sk(sk)->rcv_saddr : inet_twsk(sk)->tw_rcv_saddr;
132 static inline void inet_twsk_put(struct inet_timewait_sock *tw)
134 if (atomic_dec_and_test(&tw->tw_refcnt)) {
135 #ifdef SOCK_REFCNT_DEBUG
136 printk(KERN_DEBUG "%s timewait_sock %p released\n",
137 tw->tw_prot->name, tw);
139 kmem_cache_free(tw->tw_prot->twsk_slab, tw);
142 #endif /* _INET_TIMEWAIT_SOCK_ */