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/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 <linux/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 static inline u32 inet_tw_time_stamp(void) 62 { 63 return jiffies; 64 } 65 66 /* TIME_WAIT reaping mechanism. */ 67 #define INET_TWDR_TWKILL_SLOTS 8 /* Please keep this a power of 2. */ 68 69 #define INET_TWDR_TWKILL_QUOTA 100 70 71 struct inet_timewait_death_row { 72 /* Short-time timewait calendar */ 73 int twcal_hand; 74 unsigned long twcal_jiffie; 75 struct timer_list twcal_timer; 76 struct hlist_head twcal_row[INET_TWDR_RECYCLE_SLOTS]; 77 78 spinlock_t death_lock; 79 int tw_count; 80 int period; 81 u32 thread_slots; 82 struct work_struct twkill_work; 83 struct timer_list tw_timer; 84 int slot; 85 struct hlist_head cells[INET_TWDR_TWKILL_SLOTS]; 86 struct inet_hashinfo *hashinfo; 87 int sysctl_tw_recycle; 88 int sysctl_max_tw_buckets; 89 }; 90 91 void inet_twdr_hangman(unsigned long data); 92 void inet_twdr_twkill_work(struct work_struct *work); 93 void inet_twdr_twcal_tick(unsigned long data); 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_nulls_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 #define tw_net __tw_common.skc_net 118 #define tw_daddr __tw_common.skc_daddr 119 #define tw_rcv_saddr __tw_common.skc_rcv_saddr 120 #define tw_dport __tw_common.skc_dport 121 #define tw_num __tw_common.skc_num 122 123 int tw_timeout; 124 volatile unsigned char tw_substate; 125 unsigned char tw_rcv_wscale; 126 127 /* Socket demultiplex comparisons on incoming packets. */ 128 /* these three are in inet_sock */ 129 __be16 tw_sport; 130 kmemcheck_bitfield_begin(flags); 131 /* And these are ours. */ 132 unsigned int tw_ipv6only : 1, 133 tw_transparent : 1, 134 tw_pad : 6, /* 6 bits hole */ 135 tw_tos : 8, 136 tw_ipv6_offset : 16; 137 kmemcheck_bitfield_end(flags); 138 u32 tw_ttd; 139 struct inet_bind_bucket *tw_tb; 140 struct hlist_node tw_death_node; 141 }; 142 #define tw_tclass tw_tos 143 144 static inline void inet_twsk_add_node_rcu(struct inet_timewait_sock *tw, 145 struct hlist_nulls_head *list) 146 { 147 hlist_nulls_add_head_rcu(&tw->tw_node, list); 148 } 149 150 static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw, 151 struct hlist_head *list) 152 { 153 hlist_add_head(&tw->tw_bind_node, list); 154 } 155 156 static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw) 157 { 158 return !hlist_unhashed(&tw->tw_death_node); 159 } 160 161 static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw) 162 { 163 tw->tw_death_node.pprev = NULL; 164 } 165 166 static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock *tw) 167 { 168 __hlist_del(&tw->tw_death_node); 169 inet_twsk_dead_node_init(tw); 170 } 171 172 static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw) 173 { 174 if (inet_twsk_dead_hashed(tw)) { 175 __inet_twsk_del_dead_node(tw); 176 return 1; 177 } 178 return 0; 179 } 180 181 #define inet_twsk_for_each(tw, node, head) \ 182 hlist_nulls_for_each_entry(tw, node, head, tw_node) 183 184 #define inet_twsk_for_each_inmate(tw, jail) \ 185 hlist_for_each_entry(tw, jail, tw_death_node) 186 187 #define inet_twsk_for_each_inmate_safe(tw, safe, jail) \ 188 hlist_for_each_entry_safe(tw, safe, jail, tw_death_node) 189 190 static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk) 191 { 192 return (struct inet_timewait_sock *)sk; 193 } 194 195 void inet_twsk_put(struct inet_timewait_sock *tw); 196 197 int inet_twsk_unhash(struct inet_timewait_sock *tw); 198 199 int inet_twsk_bind_unhash(struct inet_timewait_sock *tw, 200 struct inet_hashinfo *hashinfo); 201 202 struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, 203 const int state); 204 205 void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk, 206 struct inet_hashinfo *hashinfo); 207 208 void inet_twsk_schedule(struct inet_timewait_sock *tw, 209 struct inet_timewait_death_row *twdr, 210 const int timeo, const int timewait_len); 211 void inet_twsk_deschedule(struct inet_timewait_sock *tw, 212 struct inet_timewait_death_row *twdr); 213 214 void inet_twsk_purge(struct inet_hashinfo *hashinfo, 215 struct inet_timewait_death_row *twdr, int family); 216 217 static inline 218 struct net *twsk_net(const struct inet_timewait_sock *twsk) 219 { 220 return read_pnet(&twsk->tw_net); 221 } 222 223 static inline 224 void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net) 225 { 226 write_pnet(&twsk->tw_net, net); 227 } 228 #endif /* _INET_TIMEWAIT_SOCK_ */ 229