1 /* 2 * INETPEER - A storage for permanent information about peers 3 * 4 * Authors: Andrey V. Savochkin <[email protected]> 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 unsigned long pmtu_expires; 40 u32 pmtu_orig; 41 u32 pmtu_learned; 42 struct inetpeer_addr_base redirect_learned; 43 union { 44 struct list_head gc_list; 45 struct rcu_head gc_rcu; 46 }; 47 /* 48 * Once inet_peer is queued for deletion (refcnt == -1), following fields 49 * are not available: rid, ip_id_count, tcp_ts, tcp_ts_stamp 50 * We can share memory with rcu_head to help keep inet_peer small. 51 */ 52 union { 53 struct { 54 atomic_t rid; /* Frag reception counter */ 55 atomic_t ip_id_count; /* IP ID for the next packet */ 56 __u32 tcp_ts; 57 __u32 tcp_ts_stamp; 58 }; 59 struct rcu_head rcu; 60 struct inet_peer *gc_next; 61 }; 62 63 /* following fields might be frequently dirtied */ 64 __u32 dtime; /* the time of last use of not referenced entries */ 65 atomic_t refcnt; 66 }; 67 68 struct inet_peer_base { 69 struct inet_peer __rcu *root; 70 seqlock_t lock; 71 u32 flush_seq; 72 int total; 73 }; 74 75 #define INETPEER_BASE_BIT 0x1UL 76 77 static inline struct inet_peer *inetpeer_ptr(unsigned long val) 78 { 79 BUG_ON(val & INETPEER_BASE_BIT); 80 return (struct inet_peer *) val; 81 } 82 83 static inline struct inet_peer_base *inetpeer_base_ptr(unsigned long val) 84 { 85 if (!(val & INETPEER_BASE_BIT)) 86 return NULL; 87 val &= ~INETPEER_BASE_BIT; 88 return (struct inet_peer_base *) val; 89 } 90 91 static inline bool inetpeer_ptr_is_peer(unsigned long val) 92 { 93 return !(val & INETPEER_BASE_BIT); 94 } 95 96 static inline void __inetpeer_ptr_set_peer(unsigned long *val, struct inet_peer *peer) 97 { 98 /* This implicitly clears INETPEER_BASE_BIT */ 99 *val = (unsigned long) peer; 100 } 101 102 static inline bool inetpeer_ptr_set_peer(unsigned long *ptr, struct inet_peer *peer) 103 { 104 unsigned long val = (unsigned long) peer; 105 unsigned long orig = *ptr; 106 107 if (!(orig & INETPEER_BASE_BIT) || 108 cmpxchg(ptr, orig, val) != orig) 109 return false; 110 return true; 111 } 112 113 static inline void inetpeer_init_ptr(unsigned long *ptr, struct inet_peer_base *base) 114 { 115 *ptr = (unsigned long) base | INETPEER_BASE_BIT; 116 } 117 118 static inline void inetpeer_transfer_peer(unsigned long *to, unsigned long *from) 119 { 120 unsigned long val = *from; 121 122 *to = val; 123 if (inetpeer_ptr_is_peer(val)) { 124 struct inet_peer *peer = inetpeer_ptr(val); 125 atomic_inc(&peer->refcnt); 126 } 127 } 128 129 extern void inet_peer_base_init(struct inet_peer_base *); 130 131 void inet_initpeers(void) __init; 132 133 #define INETPEER_METRICS_NEW (~(u32) 0) 134 135 static inline bool inet_metrics_new(const struct inet_peer *p) 136 { 137 return p->metrics[RTAX_LOCK-1] == INETPEER_METRICS_NEW; 138 } 139 140 /* can be called with or without local BH being disabled */ 141 struct inet_peer *inet_getpeer(struct inet_peer_base *base, 142 const struct inetpeer_addr *daddr, 143 int create); 144 145 static inline struct inet_peer *inet_getpeer_v4(struct inet_peer_base *base, 146 __be32 v4daddr, 147 int create) 148 { 149 struct inetpeer_addr daddr; 150 151 daddr.addr.a4 = v4daddr; 152 daddr.family = AF_INET; 153 return inet_getpeer(base, &daddr, create); 154 } 155 156 static inline struct inet_peer *inet_getpeer_v6(struct inet_peer_base *base, 157 const struct in6_addr *v6daddr, 158 int create) 159 { 160 struct inetpeer_addr daddr; 161 162 *(struct in6_addr *)daddr.addr.a6 = *v6daddr; 163 daddr.family = AF_INET6; 164 return inet_getpeer(base, &daddr, create); 165 } 166 167 /* can be called from BH context or outside */ 168 extern void inet_putpeer(struct inet_peer *p); 169 extern bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout); 170 171 extern void inetpeer_invalidate_tree(struct inet_peer_base *); 172 extern void inetpeer_invalidate_family(int family); 173 174 /* 175 * temporary check to make sure we dont access rid, ip_id_count, tcp_ts, 176 * tcp_ts_stamp if no refcount is taken on inet_peer 177 */ 178 static inline void inet_peer_refcheck(const struct inet_peer *p) 179 { 180 WARN_ON_ONCE(atomic_read(&p->refcnt) <= 0); 181 } 182 183 184 /* can be called with or without local BH being disabled */ 185 static inline int inet_getid(struct inet_peer *p, int more) 186 { 187 int old, new; 188 more++; 189 inet_peer_refcheck(p); 190 do { 191 old = atomic_read(&p->ip_id_count); 192 new = old + more; 193 if (!new) 194 new = 1; 195 } while (atomic_cmpxchg(&p->ip_id_count, old, new) != old); 196 return new; 197 } 198 199 #endif /* _NET_INETPEER_H */ 200