inet_timewait_sock.h revision 32aaeffbd4a7457bf2f7448b33b5946ff2a960eb
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 34#define INET_TWDR_RECYCLE_SLOTS_LOG 5 35#define INET_TWDR_RECYCLE_SLOTS (1 << INET_TWDR_RECYCLE_SLOTS_LOG) 36 37/* 38 * If time > 4sec, it is "slow" path, no recycling is required, 39 * so that we select tick to get range about 4 seconds. 40 */ 41#if HZ <= 16 || HZ > 4096 42# error Unsupported: HZ <= 16 or HZ > 4096 43#elif HZ <= 32 44# define INET_TWDR_RECYCLE_TICK (5 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 45#elif HZ <= 64 46# define INET_TWDR_RECYCLE_TICK (6 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 47#elif HZ <= 128 48# define INET_TWDR_RECYCLE_TICK (7 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 49#elif HZ <= 256 50# define INET_TWDR_RECYCLE_TICK (8 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 51#elif HZ <= 512 52# define INET_TWDR_RECYCLE_TICK (9 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 53#elif HZ <= 1024 54# define INET_TWDR_RECYCLE_TICK (10 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 55#elif HZ <= 2048 56# define INET_TWDR_RECYCLE_TICK (11 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 57#else 58# define INET_TWDR_RECYCLE_TICK (12 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 59#endif 60 61/* TIME_WAIT reaping mechanism. */ 62#define INET_TWDR_TWKILL_SLOTS 8 /* Please keep this a power of 2. */ 63 64#define INET_TWDR_TWKILL_QUOTA 100 65 66struct inet_timewait_death_row { 67 /* Short-time timewait calendar */ 68 int twcal_hand; 69 unsigned long twcal_jiffie; 70 struct timer_list twcal_timer; 71 struct hlist_head twcal_row[INET_TWDR_RECYCLE_SLOTS]; 72 73 spinlock_t death_lock; 74 int tw_count; 75 int period; 76 u32 thread_slots; 77 struct work_struct twkill_work; 78 struct timer_list tw_timer; 79 int slot; 80 struct hlist_head cells[INET_TWDR_TWKILL_SLOTS]; 81 struct inet_hashinfo *hashinfo; 82 int sysctl_tw_recycle; 83 int sysctl_max_tw_buckets; 84}; 85 86extern void inet_twdr_hangman(unsigned long data); 87extern void inet_twdr_twkill_work(struct work_struct *work); 88extern void inet_twdr_twcal_tick(unsigned long data); 89 90struct inet_bind_bucket; 91 92/* 93 * This is a TIME_WAIT sock. It works around the memory consumption 94 * problems of sockets in such a state on heavily loaded servers, but 95 * without violating the protocol specification. 96 */ 97struct inet_timewait_sock { 98 /* 99 * Now struct sock also uses sock_common, so please just 100 * don't add nothing before this first member (__tw_common) --acme 101 */ 102 struct sock_common __tw_common; 103#define tw_family __tw_common.skc_family 104#define tw_state __tw_common.skc_state 105#define tw_reuse __tw_common.skc_reuse 106#define tw_bound_dev_if __tw_common.skc_bound_dev_if 107#define tw_node __tw_common.skc_nulls_node 108#define tw_bind_node __tw_common.skc_bind_node 109#define tw_refcnt __tw_common.skc_refcnt 110#define tw_hash __tw_common.skc_hash 111#define tw_prot __tw_common.skc_prot 112#define tw_net __tw_common.skc_net 113#define tw_daddr __tw_common.skc_daddr 114#define tw_rcv_saddr __tw_common.skc_rcv_saddr 115 int tw_timeout; 116 volatile unsigned char tw_substate; 117 unsigned char tw_rcv_wscale; 118 119 /* Socket demultiplex comparisons on incoming packets. */ 120 /* these three are in inet_sock */ 121 __be16 tw_sport; 122 __be16 tw_dport; 123 __u16 tw_num; 124 kmemcheck_bitfield_begin(flags); 125 /* And these are ours. */ 126 unsigned int tw_ipv6only : 1, 127 tw_transparent : 1, 128 tw_pad : 6, /* 6 bits hole */ 129 tw_tos : 8, 130 tw_ipv6_offset : 16; 131 kmemcheck_bitfield_end(flags); 132 unsigned long tw_ttd; 133 struct inet_bind_bucket *tw_tb; 134 struct hlist_node tw_death_node; 135}; 136#define tw_tclass tw_tos 137 138static inline void inet_twsk_add_node_rcu(struct inet_timewait_sock *tw, 139 struct hlist_nulls_head *list) 140{ 141 hlist_nulls_add_head_rcu(&tw->tw_node, list); 142} 143 144static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw, 145 struct hlist_head *list) 146{ 147 hlist_add_head(&tw->tw_bind_node, list); 148} 149 150static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw) 151{ 152 return !hlist_unhashed(&tw->tw_death_node); 153} 154 155static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw) 156{ 157 tw->tw_death_node.pprev = NULL; 158} 159 160static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock *tw) 161{ 162 __hlist_del(&tw->tw_death_node); 163 inet_twsk_dead_node_init(tw); 164} 165 166static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw) 167{ 168 if (inet_twsk_dead_hashed(tw)) { 169 __inet_twsk_del_dead_node(tw); 170 return 1; 171 } 172 return 0; 173} 174 175#define inet_twsk_for_each(tw, node, head) \ 176 hlist_nulls_for_each_entry(tw, node, head, tw_node) 177 178#define inet_twsk_for_each_inmate(tw, node, jail) \ 179 hlist_for_each_entry(tw, node, jail, tw_death_node) 180 181#define inet_twsk_for_each_inmate_safe(tw, node, safe, jail) \ 182 hlist_for_each_entry_safe(tw, node, safe, jail, tw_death_node) 183 184static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk) 185{ 186 return (struct inet_timewait_sock *)sk; 187} 188 189static inline __be32 sk_rcv_saddr(const struct sock *sk) 190{ 191/* both inet_sk() and inet_twsk() store rcv_saddr in skc_rcv_saddr */ 192 return sk->__sk_common.skc_rcv_saddr; 193} 194 195extern void inet_twsk_put(struct inet_timewait_sock *tw); 196 197extern int inet_twsk_unhash(struct inet_timewait_sock *tw); 198 199extern int inet_twsk_bind_unhash(struct inet_timewait_sock *tw, 200 struct inet_hashinfo *hashinfo); 201 202extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, 203 const int state); 204 205extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw, 206 struct sock *sk, 207 struct inet_hashinfo *hashinfo); 208 209extern void inet_twsk_schedule(struct inet_timewait_sock *tw, 210 struct inet_timewait_death_row *twdr, 211 const int timeo, const int timewait_len); 212extern void inet_twsk_deschedule(struct inet_timewait_sock *tw, 213 struct inet_timewait_death_row *twdr); 214 215extern void inet_twsk_purge(struct inet_hashinfo *hashinfo, 216 struct inet_timewait_death_row *twdr, int family); 217 218static inline 219struct net *twsk_net(const struct inet_timewait_sock *twsk) 220{ 221#ifdef CONFIG_NET_NS 222 return rcu_dereference_raw(twsk->tw_net); /* protected by locking, */ 223 /* reference counting, */ 224 /* initialization, or RCU. */ 225#else 226 return &init_net; 227#endif 228} 229 230static inline 231void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net) 232{ 233#ifdef CONFIG_NET_NS 234 rcu_assign_pointer(twsk->tw_net, net); 235#endif 236} 237#endif /* _INET_TIMEWAIT_SOCK_ */ 238