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/list.h> 20#include <linux/module.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 <asm/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 90#if (BITS_PER_LONG == 64) 91#define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 8 92#else 93#define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 4 94#endif 95 96struct inet_bind_bucket; 97 98/* 99 * This is a TIME_WAIT sock. It works around the memory consumption 100 * problems of sockets in such a state on heavily loaded servers, but 101 * without violating the protocol specification. 102 */ 103struct inet_timewait_sock { 104 /* 105 * Now struct sock also uses sock_common, so please just 106 * don't add nothing before this first member (__tw_common) --acme 107 */ 108 struct sock_common __tw_common; 109#define tw_family __tw_common.skc_family 110#define tw_state __tw_common.skc_state 111#define tw_reuse __tw_common.skc_reuse 112#define tw_bound_dev_if __tw_common.skc_bound_dev_if 113#define tw_node __tw_common.skc_node 114#define tw_bind_node __tw_common.skc_bind_node 115#define tw_refcnt __tw_common.skc_refcnt 116#define tw_hash __tw_common.skc_hash 117#define tw_prot __tw_common.skc_prot 118 volatile unsigned char tw_substate; 119 /* 3 bits hole, try to pack */ 120 unsigned char tw_rcv_wscale; 121 /* Socket demultiplex comparisons on incoming packets. */ 122 /* these five are in inet_sock */ 123 __be16 tw_sport; 124 __be32 tw_daddr __attribute__((aligned(INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES))); 125 __be32 tw_rcv_saddr; 126 __be16 tw_dport; 127 __u16 tw_num; 128 /* And these are ours. */ 129 __u8 tw_ipv6only:1; 130 /* 15 bits hole, try to pack */ 131 __u16 tw_ipv6_offset; 132 int tw_timeout; 133 unsigned long tw_ttd; 134 struct inet_bind_bucket *tw_tb; 135 struct hlist_node tw_death_node; 136}; 137 138static inline void inet_twsk_add_node(struct inet_timewait_sock *tw, 139 struct hlist_head *list) 140{ 141 hlist_add_head(&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_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 inet_rcv_saddr(const struct sock *sk) 190{ 191 return likely(sk->sk_state != TCP_TIME_WAIT) ? 192 inet_sk(sk)->rcv_saddr : inet_twsk(sk)->tw_rcv_saddr; 193} 194 195static inline void inet_twsk_put(struct inet_timewait_sock *tw) 196{ 197 if (atomic_dec_and_test(&tw->tw_refcnt)) { 198 struct module *owner = tw->tw_prot->owner; 199 twsk_destructor((struct sock *)tw); 200#ifdef SOCK_REFCNT_DEBUG 201 printk(KERN_DEBUG "%s timewait_sock %p released\n", 202 tw->tw_prot->name, tw); 203#endif 204 kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw); 205 module_put(owner); 206 } 207} 208 209extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, 210 const int state); 211 212extern void __inet_twsk_kill(struct inet_timewait_sock *tw, 213 struct inet_hashinfo *hashinfo); 214 215extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw, 216 struct sock *sk, 217 struct inet_hashinfo *hashinfo); 218 219extern void inet_twsk_schedule(struct inet_timewait_sock *tw, 220 struct inet_timewait_death_row *twdr, 221 const int timeo, const int timewait_len); 222extern void inet_twsk_deschedule(struct inet_timewait_sock *tw, 223 struct inet_timewait_death_row *twdr); 224#endif /* _INET_TIMEWAIT_SOCK_ */ 225