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 <asm/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 struct list_head unused; 36 __u32 dtime; /* the time of last use of not 37 * referenced entries */ 38 atomic_t refcnt; 39 /* 40 * Once inet_peer is queued for deletion (refcnt == -1), following fields 41 * are not available: rid, ip_id_count, tcp_ts, tcp_ts_stamp, metrics 42 * We can share memory with rcu_head to help keep inet_peer small. 43 */ 44 union { 45 struct { 46 atomic_t rid; /* Frag reception counter */ 47 atomic_t ip_id_count; /* IP ID for the next packet */ 48 __u32 tcp_ts; 49 __u32 tcp_ts_stamp; 50 u32 metrics[RTAX_MAX]; 51 u32 rate_tokens; /* rate limiting for ICMP */ 52 unsigned long rate_last; 53 unsigned long pmtu_expires; 54 u32 pmtu_orig; 55 u32 pmtu_learned; 56 struct inetpeer_addr_base redirect_learned; 57 }; 58 struct rcu_head rcu; 59 }; 60 }; 61 62 void inet_initpeers(void) __init; 63 64 #define INETPEER_METRICS_NEW (~(u32) 0) 65 66 static inline bool inet_metrics_new(const struct inet_peer *p) 67 { 68 return p->metrics[RTAX_LOCK-1] == INETPEER_METRICS_NEW; 69 } 70 71 /* can be called with or without local BH being disabled */ 72 struct inet_peer *inet_getpeer(struct inetpeer_addr *daddr, int create); 73 74 static inline struct inet_peer *inet_getpeer_v4(__be32 v4daddr, int create) 75 { 76 struct inetpeer_addr daddr; 77 78 daddr.addr.a4 = v4daddr; 79 daddr.family = AF_INET; 80 return inet_getpeer(&daddr, create); 81 } 82 83 static inline struct inet_peer *inet_getpeer_v6(struct in6_addr *v6daddr, int create) 84 { 85 struct inetpeer_addr daddr; 86 87 ipv6_addr_copy((struct in6_addr *)daddr.addr.a6, v6daddr); 88 daddr.family = AF_INET6; 89 return inet_getpeer(&daddr, create); 90 } 91 92 /* can be called from BH context or outside */ 93 extern void inet_putpeer(struct inet_peer *p); 94 extern bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout); 95 96 /* 97 * temporary check to make sure we dont access rid, ip_id_count, tcp_ts, 98 * tcp_ts_stamp if no refcount is taken on inet_peer 99 */ 100 static inline void inet_peer_refcheck(const struct inet_peer *p) 101 { 102 WARN_ON_ONCE(atomic_read(&p->refcnt) <= 0); 103 } 104 105 106 /* can be called with or without local BH being disabled */ 107 static inline __u16 inet_getid(struct inet_peer *p, int more) 108 { 109 more++; 110 inet_peer_refcheck(p); 111 return atomic_add_return(more, &p->ip_id_count) - more; 112 } 113 114 #endif /* _NET_INETPEER_H */ 115