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 <net/ipv6.h> 15 #include <asm/atomic.h> 16 17 struct inetpeer_addr { 18 union { 19 __be32 a4; 20 __be32 a6[4]; 21 }; 22 __u16 family; 23 }; 24 25 struct inet_peer { 26 /* group together avl_left,avl_right,v4daddr to speedup lookups */ 27 struct inet_peer __rcu *avl_left, *avl_right; 28 struct inetpeer_addr daddr; 29 __u32 avl_height; 30 struct list_head unused; 31 __u32 dtime; /* the time of last use of not 32 * referenced entries */ 33 atomic_t refcnt; 34 /* 35 * Once inet_peer is queued for deletion (refcnt == -1), following fields 36 * are not available: rid, ip_id_count, tcp_ts, tcp_ts_stamp 37 * We can share memory with rcu_head to keep inet_peer small 38 */ 39 union { 40 struct { 41 atomic_t rid; /* Frag reception counter */ 42 atomic_t ip_id_count; /* IP ID for the next packet */ 43 __u32 tcp_ts; 44 __u32 tcp_ts_stamp; 45 }; 46 struct rcu_head rcu; 47 }; 48 }; 49 50 void inet_initpeers(void) __init; 51 52 /* can be called with or without local BH being disabled */ 53 struct inet_peer *inet_getpeer(struct inetpeer_addr *daddr, int create); 54 55 static inline struct inet_peer *inet_getpeer_v4(__be32 v4daddr, int create) 56 { 57 struct inetpeer_addr daddr; 58 59 daddr.a4 = v4daddr; 60 daddr.family = AF_INET; 61 return inet_getpeer(&daddr, create); 62 } 63 64 static inline struct inet_peer *inet_getpeer_v6(struct in6_addr *v6daddr, int create) 65 { 66 struct inetpeer_addr daddr; 67 68 ipv6_addr_copy((struct in6_addr *)daddr.a6, v6daddr); 69 daddr.family = AF_INET6; 70 return inet_getpeer(&daddr, create); 71 } 72 73 /* can be called from BH context or outside */ 74 extern void inet_putpeer(struct inet_peer *p); 75 76 /* 77 * temporary check to make sure we dont access rid, ip_id_count, tcp_ts, 78 * tcp_ts_stamp if no refcount is taken on inet_peer 79 */ 80 static inline void inet_peer_refcheck(const struct inet_peer *p) 81 { 82 WARN_ON_ONCE(atomic_read(&p->refcnt) <= 0); 83 } 84 85 86 /* can be called with or without local BH being disabled */ 87 static inline __u16 inet_getid(struct inet_peer *p, int more) 88 { 89 more++; 90 inet_peer_refcheck(p); 91 return atomic_add_return(more, &p->ip_id_count) - more; 92 } 93 94 #endif /* _NET_INETPEER_H */ 95