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