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 /* 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 struct inet_bind_bucket; 91 92 /* 93 * This is a TIME_WAIT sock. It works around the memory consumption 94 * problems of sockets in such a state on heavily loaded servers, but 95 * without violating the protocol specification. 96 */ 97 struct inet_timewait_sock { 98 /* 99 * Now struct sock also uses sock_common, so please just 100 * don't add nothing before this first member (__tw_common) --acme 101 */ 102 struct sock_common __tw_common; 103 #define tw_family __tw_common.skc_family 104 #define tw_state __tw_common.skc_state 105 #define tw_reuse __tw_common.skc_reuse 106 #define tw_bound_dev_if __tw_common.skc_bound_dev_if 107 #define tw_node __tw_common.skc_nulls_node 108 #define tw_bind_node __tw_common.skc_bind_node 109 #define tw_refcnt __tw_common.skc_refcnt 110 #define tw_hash __tw_common.skc_hash 111 #define tw_prot __tw_common.skc_prot 112 #define tw_net __tw_common.skc_net 113 #define tw_daddr __tw_common.skc_daddr 114 #define tw_rcv_saddr __tw_common.skc_rcv_saddr 115 #define tw_addrpair __tw_common.skc_addrpair 116 #define tw_dport __tw_common.skc_dport 117 #define tw_num __tw_common.skc_num 118 #define tw_portpair __tw_common.skc_portpair 119 120 int tw_timeout; 121 volatile unsigned char tw_substate; 122 unsigned char tw_rcv_wscale; 123 124 /* Socket demultiplex comparisons on incoming packets. */ 125 /* these three are in inet_sock */ 126 __be16 tw_sport; 127 kmemcheck_bitfield_begin(flags); 128 /* And these are ours. */ 129 unsigned int tw_ipv6only : 1, 130 tw_transparent : 1, 131 tw_pad : 6, /* 6 bits hole */ 132 tw_tos : 8, 133 tw_ipv6_offset : 16; 134 kmemcheck_bitfield_end(flags); 135 unsigned long tw_ttd; 136 struct inet_bind_bucket *tw_tb; 137 struct hlist_node tw_death_node; 138 }; 139 #define tw_tclass tw_tos 140 141 static inline void inet_twsk_add_node_rcu(struct inet_timewait_sock *tw, 142 struct hlist_nulls_head *list) 143 { 144 hlist_nulls_add_head_rcu(&tw->tw_node, list); 145 } 146 147 static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw, 148 struct hlist_head *list) 149 { 150 hlist_add_head(&tw->tw_bind_node, list); 151 } 152 153 static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw) 154 { 155 return !hlist_unhashed(&tw->tw_death_node); 156 } 157 158 static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw) 159 { 160 tw->tw_death_node.pprev = NULL; 161 } 162 163 static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock *tw) 164 { 165 __hlist_del(&tw->tw_death_node); 166 inet_twsk_dead_node_init(tw); 167 } 168 169 static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw) 170 { 171 if (inet_twsk_dead_hashed(tw)) { 172 __inet_twsk_del_dead_node(tw); 173 return 1; 174 } 175 return 0; 176 } 177 178 #define inet_twsk_for_each(tw, node, head) \ 179 hlist_nulls_for_each_entry(tw, node, head, tw_node) 180 181 #define inet_twsk_for_each_inmate(tw, node, jail) \ 182 hlist_for_each_entry(tw, node, jail, tw_death_node) 183 184 #define inet_twsk_for_each_inmate_safe(tw, node, safe, jail) \ 185 hlist_for_each_entry_safe(tw, node, safe, jail, tw_death_node) 186 187 static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk) 188 { 189 return (struct inet_timewait_sock *)sk; 190 } 191 192 static inline __be32 sk_rcv_saddr(const struct sock *sk) 193 { 194 /* both inet_sk() and inet_twsk() store rcv_saddr in skc_rcv_saddr */ 195 return sk->__sk_common.skc_rcv_saddr; 196 } 197 198 extern void inet_twsk_put(struct inet_timewait_sock *tw); 199 200 extern int inet_twsk_unhash(struct inet_timewait_sock *tw); 201 202 extern int inet_twsk_bind_unhash(struct inet_timewait_sock *tw, 203 struct inet_hashinfo *hashinfo); 204 205 extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, 206 const int state); 207 208 extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw, 209 struct sock *sk, 210 struct inet_hashinfo *hashinfo); 211 212 extern void inet_twsk_schedule(struct inet_timewait_sock *tw, 213 struct inet_timewait_death_row *twdr, 214 const int timeo, const int timewait_len); 215 extern void inet_twsk_deschedule(struct inet_timewait_sock *tw, 216 struct inet_timewait_death_row *twdr); 217 218 extern void inet_twsk_purge(struct inet_hashinfo *hashinfo, 219 struct inet_timewait_death_row *twdr, int family); 220 221 static inline 222 struct net *twsk_net(const struct inet_timewait_sock *twsk) 223 { 224 return read_pnet(&twsk->tw_net); 225 } 226 227 static inline 228 void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net) 229 { 230 write_pnet(&twsk->tw_net, net); 231 } 232 #endif /* _INET_TIMEWAIT_SOCK_ */ 233