| /* |
| * 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 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 */ |
| int redirect_genid; |
| unsigned long rate_last; |
| unsigned long pmtu_expires; |
| u32 pmtu_orig; |
| u32 pmtu_learned; |
| struct inetpeer_addr_base redirect_learned; |
| struct list_head gc_list; |
| /* |
| * Once inet_peer is queued for deletion (refcnt == -1), following fields |
| * are not available: rid, ip_id_count, tcp_ts, tcp_ts_stamp |
| * We can share memory with rcu_head to help keep inet_peer small. |
| */ |
| union { |
| struct { |
| atomic_t rid; /* Frag reception counter */ |
| atomic_t ip_id_count; /* IP ID for the next packet */ |
| __u32 tcp_ts; |
| __u32 tcp_ts_stamp; |
| }; |
| 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; |
| }; |
| |
| 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(const struct inetpeer_addr *daddr, int create); |
| |
| static inline struct inet_peer *inet_getpeer_v4(__be32 v4daddr, int create) |
| { |
| struct inetpeer_addr daddr; |
| |
| daddr.addr.a4 = v4daddr; |
| daddr.family = AF_INET; |
| return inet_getpeer(&daddr, create); |
| } |
| |
| static inline struct inet_peer *inet_getpeer_v6(const struct in6_addr *v6daddr, int create) |
| { |
| struct inetpeer_addr daddr; |
| |
| *(struct in6_addr *)daddr.addr.a6 = *v6daddr; |
| daddr.family = AF_INET6; |
| return inet_getpeer(&daddr, create); |
| } |
| |
| /* can be called from BH context or outside */ |
| extern void inet_putpeer(struct inet_peer *p); |
| extern bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout); |
| |
| extern void inetpeer_invalidate_tree(int family); |
| |
| /* |
| * temporary check to make sure we dont access rid, ip_id_count, 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); |
| } |
| |
| |
| /* can be called with or without local BH being disabled */ |
| static inline int inet_getid(struct inet_peer *p, int more) |
| { |
| int old, new; |
| more++; |
| inet_peer_refcheck(p); |
| do { |
| old = atomic_read(&p->ip_id_count); |
| new = old + more; |
| if (!new) |
| new = 1; |
| } while (atomic_cmpxchg(&p->ip_id_count, old, new) != old); |
| return new; |
| } |
| |
| #endif /* _NET_INETPEER_H */ |