1 /* 2 * INETPEER - A storage for permanent information about peers 3 * 4 * Authors: Andrey V. Savochkin <saw@msu.ru> 5 */ 6 7 #ifndef _NET_INETPEER_H 8 #define _NET_INETPEER_H 9 10 #include <linux/types.h> 11 #include <linux/init.h> 12 #include <linux/jiffies.h> 13 #include <linux/spinlock.h> 14 #include <linux/rtnetlink.h> 15 #include <net/ipv6.h> 16 #include <linux/atomic.h> 17 18 struct inetpeer_addr_base { 19 union { 20 __be32 a4; 21 __be32 a6[4]; 22 struct in6_addr in6; 23 }; 24 }; 25 26 struct inetpeer_addr { 27 struct inetpeer_addr_base addr; 28 __u16 family; 29 }; 30 31 struct inet_peer { 32 /* group together avl_left,avl_right,v4daddr to speedup lookups */ 33 struct inet_peer __rcu *avl_left, *avl_right; 34 struct inetpeer_addr daddr; 35 __u32 avl_height; 36 37 u32 metrics[RTAX_MAX]; 38 u32 rate_tokens; /* rate limiting for ICMP */ 39 unsigned long rate_last; 40 union { 41 struct list_head gc_list; 42 struct rcu_head gc_rcu; 43 }; 44 /* 45 * Once inet_peer is queued for deletion (refcnt == -1), following field 46 * is not available: rid 47 * We can share memory with rcu_head to help keep inet_peer small. 48 */ 49 union { 50 struct { 51 atomic_t rid; /* Frag reception counter */ 52 }; 53 struct rcu_head rcu; 54 struct inet_peer *gc_next; 55 }; 56 57 /* following fields might be frequently dirtied */ 58 __u32 dtime; /* the time of last use of not referenced entries */ 59 atomic_t refcnt; 60 }; 61 62 struct inet_peer_base { 63 struct inet_peer __rcu *root; 64 seqlock_t lock; 65 int total; 66 }; 67 68 #define INETPEER_BASE_BIT 0x1UL 69 70 static inline struct inet_peer *inetpeer_ptr(unsigned long val) 71 { 72 BUG_ON(val & INETPEER_BASE_BIT); 73 return (struct inet_peer *) val; 74 } 75 76 static inline struct inet_peer_base *inetpeer_base_ptr(unsigned long val) 77 { 78 if (!(val & INETPEER_BASE_BIT)) 79 return NULL; 80 val &= ~INETPEER_BASE_BIT; 81 return (struct inet_peer_base *) val; 82 } 83 84 static inline bool inetpeer_ptr_is_peer(unsigned long val) 85 { 86 return !(val & INETPEER_BASE_BIT); 87 } 88 89 static inline void __inetpeer_ptr_set_peer(unsigned long *val, struct inet_peer *peer) 90 { 91 /* This implicitly clears INETPEER_BASE_BIT */ 92 *val = (unsigned long) peer; 93 } 94 95 static inline bool inetpeer_ptr_set_peer(unsigned long *ptr, struct inet_peer *peer) 96 { 97 unsigned long val = (unsigned long) peer; 98 unsigned long orig = *ptr; 99 100 if (!(orig & INETPEER_BASE_BIT) || 101 cmpxchg(ptr, orig, val) != orig) 102 return false; 103 return true; 104 } 105 106 static inline void inetpeer_init_ptr(unsigned long *ptr, struct inet_peer_base *base) 107 { 108 *ptr = (unsigned long) base | INETPEER_BASE_BIT; 109 } 110 111 static inline void inetpeer_transfer_peer(unsigned long *to, unsigned long *from) 112 { 113 unsigned long val = *from; 114 115 *to = val; 116 if (inetpeer_ptr_is_peer(val)) { 117 struct inet_peer *peer = inetpeer_ptr(val); 118 atomic_inc(&peer->refcnt); 119 } 120 } 121 122 void inet_peer_base_init(struct inet_peer_base *); 123 124 void inet_initpeers(void) __init; 125 126 #define INETPEER_METRICS_NEW (~(u32) 0) 127 128 static inline bool inet_metrics_new(const struct inet_peer *p) 129 { 130 return p->metrics[RTAX_LOCK-1] == INETPEER_METRICS_NEW; 131 } 132 133 /* can be called with or without local BH being disabled */ 134 struct inet_peer *inet_getpeer(struct inet_peer_base *base, 135 const struct inetpeer_addr *daddr, 136 int create); 137 138 static inline struct inet_peer *inet_getpeer_v4(struct inet_peer_base *base, 139 __be32 v4daddr, 140 int create) 141 { 142 struct inetpeer_addr daddr; 143 144 daddr.addr.a4 = v4daddr; 145 daddr.family = AF_INET; 146 return inet_getpeer(base, &daddr, create); 147 } 148 149 static inline struct inet_peer *inet_getpeer_v6(struct inet_peer_base *base, 150 const struct in6_addr *v6daddr, 151 int create) 152 { 153 struct inetpeer_addr daddr; 154 155 daddr.addr.in6 = *v6daddr; 156 daddr.family = AF_INET6; 157 return inet_getpeer(base, &daddr, create); 158 } 159 160 /* can be called from BH context or outside */ 161 void inet_putpeer(struct inet_peer *p); 162 bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout); 163 164 void inetpeer_invalidate_tree(struct inet_peer_base *); 165 166 /* 167 * temporary check to make sure we dont access rid, tcp_ts, 168 * tcp_ts_stamp if no refcount is taken on inet_peer 169 */ 170 static inline void inet_peer_refcheck(const struct inet_peer *p) 171 { 172 WARN_ON_ONCE(atomic_read(&p->refcnt) <= 0); 173 } 174 #endif /* _NET_INETPEER_H */ 175