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