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 #include <linux/config.h> 19 20 #include <linux/ip.h> 21 #include <linux/list.h> 22 #include <linux/timer.h> 23 #include <linux/types.h> 24 #include <linux/workqueue.h> 25 26 #include <net/sock.h> 27 #include <net/tcp_states.h> 28 29 #include <asm/atomic.h> 30 31 struct inet_hashinfo; 32 33 #define INET_TWDR_RECYCLE_SLOTS_LOG 5 34 #define INET_TWDR_RECYCLE_SLOTS (1 << INET_TWDR_RECYCLE_SLOTS_LOG) 35 36 /* 37 * If time > 4sec, it is "slow" path, no recycling is required, 38 * so that we select tick to get range about 4 seconds. 39 */ 40 #if HZ <= 16 || HZ > 4096 41 # error Unsupported: HZ <= 16 or HZ > 4096 42 #elif HZ <= 32 43 # define INET_TWDR_RECYCLE_TICK (5 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 44 #elif HZ <= 64 45 # define INET_TWDR_RECYCLE_TICK (6 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 46 #elif HZ <= 128 47 # define INET_TWDR_RECYCLE_TICK (7 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 48 #elif HZ <= 256 49 # define INET_TWDR_RECYCLE_TICK (8 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 50 #elif HZ <= 512 51 # define INET_TWDR_RECYCLE_TICK (9 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 52 #elif HZ <= 1024 53 # define INET_TWDR_RECYCLE_TICK (10 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 54 #elif HZ <= 2048 55 # define INET_TWDR_RECYCLE_TICK (11 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 56 #else 57 # define INET_TWDR_RECYCLE_TICK (12 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG) 58 #endif 59 60 /* TIME_WAIT reaping mechanism. */ 61 #define INET_TWDR_TWKILL_SLOTS 8 /* Please keep this a power of 2. */ 62 63 #define INET_TWDR_TWKILL_QUOTA 100 64 65 struct inet_timewait_death_row { 66 /* Short-time timewait calendar */ 67 int twcal_hand; 68 int twcal_jiffie; 69 struct timer_list twcal_timer; 70 struct hlist_head twcal_row[INET_TWDR_RECYCLE_SLOTS]; 71 72 spinlock_t death_lock; 73 int tw_count; 74 int period; 75 u32 thread_slots; 76 struct work_struct twkill_work; 77 struct timer_list tw_timer; 78 int slot; 79 struct hlist_head cells[INET_TWDR_TWKILL_SLOTS]; 80 struct inet_hashinfo *hashinfo; 81 int sysctl_tw_recycle; 82 int sysctl_max_tw_buckets; 83 }; 84 85 extern void inet_twdr_hangman(unsigned long data); 86 extern void inet_twdr_twkill_work(void *data); 87 extern void inet_twdr_twcal_tick(unsigned long data); 88 89 #if (BITS_PER_LONG == 64) 90 #define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 8 91 #else 92 #define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 4 93 #endif 94 95 struct inet_bind_bucket; 96 97 /* 98 * This is a TIME_WAIT sock. It works around the memory consumption 99 * problems of sockets in such a state on heavily loaded servers, but 100 * without violating the protocol specification. 101 */ 102 struct inet_timewait_sock { 103 /* 104 * Now struct sock also uses sock_common, so please just 105 * don't add nothing before this first member (__tw_common) --acme 106 */ 107 struct sock_common __tw_common; 108 #define tw_family __tw_common.skc_family 109 #define tw_state __tw_common.skc_state 110 #define tw_reuse __tw_common.skc_reuse 111 #define tw_bound_dev_if __tw_common.skc_bound_dev_if 112 #define tw_node __tw_common.skc_node 113 #define tw_bind_node __tw_common.skc_bind_node 114 #define tw_refcnt __tw_common.skc_refcnt 115 #define tw_hash __tw_common.skc_hash 116 #define tw_prot __tw_common.skc_prot 117 volatile unsigned char tw_substate; 118 /* 3 bits hole, try to pack */ 119 unsigned char tw_rcv_wscale; 120 /* Socket demultiplex comparisons on incoming packets. */ 121 /* these five are in inet_sock */ 122 __u16 tw_sport; 123 __u32 tw_daddr __attribute__((aligned(INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES))); 124 __u32 tw_rcv_saddr; 125 __u16 tw_dport; 126 __u16 tw_num; 127 /* And these are ours. */ 128 __u8 tw_ipv6only:1; 129 /* 31 bits hole, try to pack */ 130 int tw_timeout; 131 unsigned long tw_ttd; 132 struct inet_bind_bucket *tw_tb; 133 struct hlist_node tw_death_node; 134 }; 135 136 static inline void inet_twsk_add_node(struct inet_timewait_sock *tw, 137 struct hlist_head *list) 138 { 139 hlist_add_head(&tw->tw_node, list); 140 } 141 142 static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw, 143 struct hlist_head *list) 144 { 145 hlist_add_head(&tw->tw_bind_node, list); 146 } 147 148 static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw) 149 { 150 return tw->tw_death_node.pprev != NULL; 151 } 152 153 static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw) 154 { 155 tw->tw_death_node.pprev = NULL; 156 } 157 158 static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock *tw) 159 { 160 __hlist_del(&tw->tw_death_node); 161 inet_twsk_dead_node_init(tw); 162 } 163 164 static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw) 165 { 166 if (inet_twsk_dead_hashed(tw)) { 167 __inet_twsk_del_dead_node(tw); 168 return 1; 169 } 170 return 0; 171 } 172 173 #define inet_twsk_for_each(tw, node, head) \ 174 hlist_for_each_entry(tw, node, head, tw_node) 175 176 #define inet_twsk_for_each_inmate(tw, node, jail) \ 177 hlist_for_each_entry(tw, node, jail, tw_death_node) 178 179 #define inet_twsk_for_each_inmate_safe(tw, node, safe, jail) \ 180 hlist_for_each_entry_safe(tw, node, safe, jail, tw_death_node) 181 182 static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk) 183 { 184 return (struct inet_timewait_sock *)sk; 185 } 186 187 static inline u32 inet_rcv_saddr(const struct sock *sk) 188 { 189 return likely(sk->sk_state != TCP_TIME_WAIT) ? 190 inet_sk(sk)->rcv_saddr : inet_twsk(sk)->tw_rcv_saddr; 191 } 192 193 static inline void inet_twsk_put(struct inet_timewait_sock *tw) 194 { 195 if (atomic_dec_and_test(&tw->tw_refcnt)) { 196 #ifdef SOCK_REFCNT_DEBUG 197 printk(KERN_DEBUG "%s timewait_sock %p released\n", 198 tw->tw_prot->name, tw); 199 #endif 200 kmem_cache_free(tw->tw_prot->twsk_slab, tw); 201 } 202 } 203 204 extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, 205 const int state); 206 207 extern void __inet_twsk_kill(struct inet_timewait_sock *tw, 208 struct inet_hashinfo *hashinfo); 209 210 extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw, 211 struct sock *sk, 212 struct inet_hashinfo *hashinfo); 213 214 extern void inet_twsk_schedule(struct inet_timewait_sock *tw, 215 struct inet_timewait_death_row *twdr, 216 const int timeo, const int timewait_len); 217 extern void inet_twsk_deschedule(struct inet_timewait_sock *tw, 218 struct inet_timewait_death_row *twdr); 219 #endif /* _INET_TIMEWAIT_SOCK_ */ 220