inet_timewait_sock.h revision 13475a30b66cdb9250a34052c19ac98847373030
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/module.h> 22#include <linux/timer.h> 23#include <linux/types.h> 24#include <linux/workqueue.h> 25 26#include <net/inet_sock.h> 27#include <net/sock.h> 28#include <net/tcp_states.h> 29#include <net/timewait_sock.h> 30 31#include <asm/atomic.h> 32 33struct inet_hashinfo; 34 35#define INET_TWDR_RECYCLE_SLOTS_LOG 5 36#define INET_TWDR_RECYCLE_SLOTS (1 << INET_TWDR_RECYCLE_SLOTS_LOG) 37 38/* 39 * If time > 4sec, it is "slow" path, no recycling is required, 40 * so that we select tick to get range about 4 seconds. 41 */ 42#if HZ <= 16 || HZ > 4096 43# error Unsupported: HZ <= 16 or HZ > 4096 44#elif HZ <= 32 45# define INET_TWDR_RECYCLE_TICK (5 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 46#elif HZ <= 64 47# define INET_TWDR_RECYCLE_TICK (6 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 48#elif HZ <= 128 49# define INET_TWDR_RECYCLE_TICK (7 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 50#elif HZ <= 256 51# define INET_TWDR_RECYCLE_TICK (8 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 52#elif HZ <= 512 53# define INET_TWDR_RECYCLE_TICK (9 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 54#elif HZ <= 1024 55# define INET_TWDR_RECYCLE_TICK (10 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 56#elif HZ <= 2048 57# define INET_TWDR_RECYCLE_TICK (11 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 58#else 59# define INET_TWDR_RECYCLE_TICK (12 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 60#endif 61 62/* TIME_WAIT reaping mechanism. */ 63#define INET_TWDR_TWKILL_SLOTS 8 /* Please keep this a power of 2. */ 64 65#define INET_TWDR_TWKILL_QUOTA 100 66 67struct inet_timewait_death_row { 68 /* Short-time timewait calendar */ 69 int twcal_hand; 70 unsigned long twcal_jiffie; 71 struct timer_list twcal_timer; 72 struct hlist_head twcal_row[INET_TWDR_RECYCLE_SLOTS]; 73 74 spinlock_t death_lock; 75 int tw_count; 76 int period; 77 u32 thread_slots; 78 struct work_struct twkill_work; 79 struct timer_list tw_timer; 80 int slot; 81 struct hlist_head cells[INET_TWDR_TWKILL_SLOTS]; 82 struct inet_hashinfo *hashinfo; 83 int sysctl_tw_recycle; 84 int sysctl_max_tw_buckets; 85}; 86 87extern void inet_twdr_hangman(unsigned long data); 88extern void inet_twdr_twkill_work(struct work_struct *work); 89extern void inet_twdr_twcal_tick(unsigned long data); 90 91#if (BITS_PER_LONG == 64) 92#define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 8 93#else 94#define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 4 95#endif 96 97struct inet_bind_bucket; 98 99/* 100 * This is a TIME_WAIT sock. It works around the memory consumption 101 * problems of sockets in such a state on heavily loaded servers, but 102 * without violating the protocol specification. 103 */ 104struct inet_timewait_sock { 105 /* 106 * Now struct sock also uses sock_common, so please just 107 * don't add nothing before this first member (__tw_common) --acme 108 */ 109 struct sock_common __tw_common; 110#define tw_family __tw_common.skc_family 111#define tw_state __tw_common.skc_state 112#define tw_reuse __tw_common.skc_reuse 113#define tw_bound_dev_if __tw_common.skc_bound_dev_if 114#define tw_node __tw_common.skc_nulls_node 115#define tw_bind_node __tw_common.skc_bind_node 116#define tw_refcnt __tw_common.skc_refcnt 117#define tw_hash __tw_common.skc_hash 118#define tw_prot __tw_common.skc_prot 119#define tw_net __tw_common.skc_net 120 int tw_timeout; 121 volatile unsigned char tw_substate; 122 /* 3 bits hole, try to pack */ 123 unsigned char tw_rcv_wscale; 124 /* Socket demultiplex comparisons on incoming packets. */ 125 /* these five are in inet_sock */ 126 __be16 tw_sport; 127 __be32 tw_daddr __attribute__((aligned(INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES))); 128 __be32 tw_rcv_saddr; 129 __be16 tw_dport; 130 __u16 tw_num; 131 kmemcheck_bitfield_begin(flags); 132 /* And these are ours. */ 133 unsigned int tw_ipv6only : 1, 134 tw_transparent : 1, 135 tw_pad : 14, /* 14 bits hole */ 136 tw_ipv6_offset : 16; 137 kmemcheck_bitfield_end(flags); 138 unsigned long tw_ttd; 139 struct inet_bind_bucket *tw_tb; 140 struct hlist_node tw_death_node; 141}; 142 143static inline void inet_twsk_add_node_rcu(struct inet_timewait_sock *tw, 144 struct hlist_nulls_head *list) 145{ 146 hlist_nulls_add_head_rcu(&tw->tw_node, list); 147} 148 149static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw, 150 struct hlist_head *list) 151{ 152 hlist_add_head(&tw->tw_bind_node, list); 153} 154 155static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw) 156{ 157 return !hlist_unhashed(&tw->tw_death_node); 158} 159 160static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw) 161{ 162 tw->tw_death_node.pprev = NULL; 163} 164 165static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock *tw) 166{ 167 __hlist_del(&tw->tw_death_node); 168 inet_twsk_dead_node_init(tw); 169} 170 171static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw) 172{ 173 if (inet_twsk_dead_hashed(tw)) { 174 __inet_twsk_del_dead_node(tw); 175 return 1; 176 } 177 return 0; 178} 179 180#define inet_twsk_for_each(tw, node, head) \ 181 hlist_nulls_for_each_entry(tw, node, head, tw_node) 182 183#define inet_twsk_for_each_inmate(tw, node, jail) \ 184 hlist_for_each_entry(tw, node, jail, tw_death_node) 185 186#define inet_twsk_for_each_inmate_safe(tw, node, safe, jail) \ 187 hlist_for_each_entry_safe(tw, node, safe, jail, tw_death_node) 188 189static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk) 190{ 191 return (struct inet_timewait_sock *)sk; 192} 193 194static inline __be32 inet_rcv_saddr(const struct sock *sk) 195{ 196 return likely(sk->sk_state != TCP_TIME_WAIT) ? 197 inet_sk(sk)->inet_rcv_saddr : inet_twsk(sk)->tw_rcv_saddr; 198} 199 200extern void inet_twsk_put(struct inet_timewait_sock *tw); 201 202extern int inet_twsk_unhash(struct inet_timewait_sock *tw); 203 204extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, 205 const int state); 206 207extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw, 208 struct sock *sk, 209 struct inet_hashinfo *hashinfo); 210 211extern void inet_twsk_schedule(struct inet_timewait_sock *tw, 212 struct inet_timewait_death_row *twdr, 213 const int timeo, const int timewait_len); 214extern void inet_twsk_deschedule(struct inet_timewait_sock *tw, 215 struct inet_timewait_death_row *twdr); 216 217extern void inet_twsk_purge(struct inet_hashinfo *hashinfo, 218 struct inet_timewait_death_row *twdr, int family); 219 220static inline 221struct net *twsk_net(const struct inet_timewait_sock *twsk) 222{ 223#ifdef CONFIG_NET_NS 224 return rcu_dereference(twsk->tw_net); 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