| /* |
| * 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 */ |
| 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; |
| u32 flush_seq; |
| 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); |
| } |
| } |
| |
| extern 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; |
| |
| *(struct in6_addr *)daddr.addr.a6 = *v6daddr; |
| daddr.family = AF_INET6; |
| return inet_getpeer(base, &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(struct inet_peer_base *); |
| extern void inetpeer_invalidate_family(int family); |
| |
| /* |
| * 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 */ |