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 32 struct 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 66 struct 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 86 extern void inet_twdr_hangman(unsigned long data); 87 extern void inet_twdr_twkill_work(struct work_struct *work); 88 extern 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 96 struct 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 */ 103 struct 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 #define tw_net __tw_common.skc_net 119 int tw_timeout; 120 volatile unsigned char tw_substate; 121 /* 3 bits hole, try to pack */ 122 unsigned char tw_rcv_wscale; 123 /* Socket demultiplex comparisons on incoming packets. */ 124 /* these five are in inet_sock */ 125 __be16 tw_sport; 126 __be32 tw_daddr __attribute__((aligned(INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES))); 127 __be32 tw_rcv_saddr; 128 __be16 tw_dport; 129 __u16 tw_num; 130 /* And these are ours. */ 131 __u8 tw_ipv6only:1, 132 tw_transparent:1; 133 /* 15 bits hole, try to pack */ 134 __u16 tw_ipv6_offset; 135 unsigned long tw_ttd; 136 struct inet_bind_bucket *tw_tb; 137 struct hlist_node tw_death_node; 138 }; 139 140 static inline void inet_twsk_add_node(struct inet_timewait_sock *tw, 141 struct hlist_head *list) 142 { 143 hlist_add_head(&tw->tw_node, list); 144 } 145 146 static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw, 147 struct hlist_head *list) 148 { 149 hlist_add_head(&tw->tw_bind_node, list); 150 } 151 152 static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw) 153 { 154 return !hlist_unhashed(&tw->tw_death_node); 155 } 156 157 static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw) 158 { 159 tw->tw_death_node.pprev = NULL; 160 } 161 162 static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock *tw) 163 { 164 __hlist_del(&tw->tw_death_node); 165 inet_twsk_dead_node_init(tw); 166 } 167 168 static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw) 169 { 170 if (inet_twsk_dead_hashed(tw)) { 171 __inet_twsk_del_dead_node(tw); 172 return 1; 173 } 174 return 0; 175 } 176 177 #define inet_twsk_for_each(tw, node, head) \ 178 hlist_for_each_entry(tw, node, head, tw_node) 179 180 #define inet_twsk_for_each_inmate(tw, node, jail) \ 181 hlist_for_each_entry(tw, node, jail, tw_death_node) 182 183 #define inet_twsk_for_each_inmate_safe(tw, node, safe, jail) \ 184 hlist_for_each_entry_safe(tw, node, safe, jail, tw_death_node) 185 186 static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk) 187 { 188 return (struct inet_timewait_sock *)sk; 189 } 190 191 static inline __be32 inet_rcv_saddr(const struct sock *sk) 192 { 193 return likely(sk->sk_state != TCP_TIME_WAIT) ? 194 inet_sk(sk)->rcv_saddr : inet_twsk(sk)->tw_rcv_saddr; 195 } 196 197 extern void inet_twsk_put(struct inet_timewait_sock *tw); 198 199 extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, 200 const int state); 201 202 extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw, 203 struct sock *sk, 204 struct inet_hashinfo *hashinfo); 205 206 extern void inet_twsk_schedule(struct inet_timewait_sock *tw, 207 struct inet_timewait_death_row *twdr, 208 const int timeo, const int timewait_len); 209 extern void inet_twsk_deschedule(struct inet_timewait_sock *tw, 210 struct inet_timewait_death_row *twdr); 211 212 extern void inet_twsk_purge(struct net *net, struct inet_hashinfo *hashinfo, 213 struct inet_timewait_death_row *twdr, int family); 214 215 static inline 216 struct net *twsk_net(const struct inet_timewait_sock *twsk) 217 { 218 #ifdef CONFIG_NET_NS 219 return twsk->tw_net; 220 #else 221 return &init_net; 222 #endif 223 } 224 225 static inline 226 void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net) 227 { 228 #ifdef CONFIG_NET_NS 229 twsk->tw_net = net; 230 #endif 231 } 232 #endif /* _INET_TIMEWAIT_SOCK_ */ 233