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 <linux/atomic.h> 32 33 struct 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 67 struct 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 87 extern void inet_twdr_hangman(unsigned long data); 88 extern void inet_twdr_twkill_work(struct work_struct *work); 89 extern void inet_twdr_twcal_tick(unsigned long data); 90 91 struct inet_bind_bucket; 92 93 /* 94 * This is a TIME_WAIT sock. It works around the memory consumption 95 * problems of sockets in such a state on heavily loaded servers, but 96 * without violating the protocol specification. 97 */ 98 struct inet_timewait_sock { 99 /* 100 * Now struct sock also uses sock_common, so please just 101 * don't add nothing before this first member (__tw_common) --acme 102 */ 103 struct sock_common __tw_common; 104 #define tw_family __tw_common.skc_family 105 #define tw_state __tw_common.skc_state 106 #define tw_reuse __tw_common.skc_reuse 107 #define tw_bound_dev_if __tw_common.skc_bound_dev_if 108 #define tw_node __tw_common.skc_nulls_node 109 #define tw_bind_node __tw_common.skc_bind_node 110 #define tw_refcnt __tw_common.skc_refcnt 111 #define tw_hash __tw_common.skc_hash 112 #define tw_prot __tw_common.skc_prot 113 #define tw_net __tw_common.skc_net 114 #define tw_daddr __tw_common.skc_daddr 115 #define tw_rcv_saddr __tw_common.skc_rcv_saddr 116 int tw_timeout; 117 volatile unsigned char tw_substate; 118 unsigned char tw_rcv_wscale; 119 120 /* Socket demultiplex comparisons on incoming packets. */ 121 /* these three are in inet_sock */ 122 __be16 tw_sport; 123 __be16 tw_dport; 124 __u16 tw_num; 125 kmemcheck_bitfield_begin(flags); 126 /* And these are ours. */ 127 unsigned int tw_ipv6only : 1, 128 tw_transparent : 1, 129 tw_pad : 6, /* 6 bits hole */ 130 tw_tos : 8, 131 tw_ipv6_offset : 16; 132 kmemcheck_bitfield_end(flags); 133 unsigned long tw_ttd; 134 struct inet_bind_bucket *tw_tb; 135 struct hlist_node tw_death_node; 136 }; 137 138 static 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 } 143 144 static 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 } 149 150 static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw) 151 { 152 return !hlist_unhashed(&tw->tw_death_node); 153 } 154 155 static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw) 156 { 157 tw->tw_death_node.pprev = NULL; 158 } 159 160 static 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 } 165 166 static 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) 183 184 static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk) 185 { 186 return (struct inet_timewait_sock *)sk; 187 } 188 189 static 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 } 194 195 extern void inet_twsk_put(struct inet_timewait_sock *tw); 196 197 extern int inet_twsk_unhash(struct inet_timewait_sock *tw); 198 199 extern int inet_twsk_bind_unhash(struct inet_timewait_sock *tw, 200 struct inet_hashinfo *hashinfo); 201 202 extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, 203 const int state); 204 205 extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw, 206 struct sock *sk, 207 struct inet_hashinfo *hashinfo); 208 209 extern void inet_twsk_schedule(struct inet_timewait_sock *tw, 210 struct inet_timewait_death_row *twdr, 211 const int timeo, const int timewait_len); 212 extern void inet_twsk_deschedule(struct inet_timewait_sock *tw, 213 struct inet_timewait_death_row *twdr); 214 215 extern void inet_twsk_purge(struct inet_hashinfo *hashinfo, 216 struct inet_timewait_death_row *twdr, int family); 217 218 static inline 219 struct 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 } 229 230 static inline 231 void 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