Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * INETPEER - A storage for permanent information about peers |
| 3 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 <asm/atomic.h> |
| 15 | |
Eric Dumazet | fd2c3ef | 2009-11-03 03:26:03 +0000 | [diff] [blame] | 16 | struct inet_peer { |
Eric Dumazet | 78d7942 | 2006-10-20 00:28:35 -0700 | [diff] [blame] | 17 | /* group together avl_left,avl_right,v4daddr to speedup lookups */ |
Eric Dumazet | b914c4e | 2010-10-25 23:55:38 +0000 | [diff] [blame] | 18 | struct inet_peer __rcu *avl_left, *avl_right; |
Eric Dumazet | 78d7942 | 2006-10-20 00:28:35 -0700 | [diff] [blame] | 19 | __be32 v4daddr; /* peer's address */ |
Eric Dumazet | 2c1409a | 2009-11-12 09:33:09 +0000 | [diff] [blame] | 20 | __u32 avl_height; |
Pavel Emelyanov | d71209d | 2007-11-12 21:27:28 -0800 | [diff] [blame] | 21 | struct list_head unused; |
Eric Dumazet | 4663afe | 2006-10-12 21:21:06 -0700 | [diff] [blame] | 22 | __u32 dtime; /* the time of last use of not |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | * referenced entries */ |
| 24 | atomic_t refcnt; |
Eric Dumazet | 317fe0e | 2010-06-16 04:52:13 +0000 | [diff] [blame] | 25 | /* |
| 26 | * Once inet_peer is queued for deletion (refcnt == -1), following fields |
| 27 | * are not available: rid, ip_id_count, tcp_ts, tcp_ts_stamp |
| 28 | * We can share memory with rcu_head to keep inet_peer small |
| 29 | * (less then 64 bytes) |
| 30 | */ |
| 31 | union { |
| 32 | struct { |
| 33 | atomic_t rid; /* Frag reception counter */ |
| 34 | atomic_t ip_id_count; /* IP ID for the next packet */ |
| 35 | __u32 tcp_ts; |
| 36 | __u32 tcp_ts_stamp; |
| 37 | }; |
| 38 | struct rcu_head rcu; |
| 39 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | }; |
| 41 | |
| 42 | void inet_initpeers(void) __init; |
| 43 | |
| 44 | /* can be called with or without local BH being disabled */ |
Al Viro | 53576d9 | 2006-09-26 22:18:43 -0700 | [diff] [blame] | 45 | struct inet_peer *inet_getpeer(__be32 daddr, int create); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | /* can be called from BH context or outside */ |
Eric Dumazet | 4663afe | 2006-10-12 21:21:06 -0700 | [diff] [blame] | 48 | extern void inet_putpeer(struct inet_peer *p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | |
Eric Dumazet | 317fe0e | 2010-06-16 04:52:13 +0000 | [diff] [blame] | 50 | /* |
| 51 | * temporary check to make sure we dont access rid, ip_id_count, tcp_ts, |
| 52 | * tcp_ts_stamp if no refcount is taken on inet_peer |
| 53 | */ |
| 54 | static inline void inet_peer_refcheck(const struct inet_peer *p) |
| 55 | { |
| 56 | WARN_ON_ONCE(atomic_read(&p->refcnt) <= 0); |
| 57 | } |
| 58 | |
| 59 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | /* can be called with or without local BH being disabled */ |
| 61 | static inline __u16 inet_getid(struct inet_peer *p, int more) |
| 62 | { |
Eric Dumazet | 2c1409a | 2009-11-12 09:33:09 +0000 | [diff] [blame] | 63 | more++; |
Eric Dumazet | 317fe0e | 2010-06-16 04:52:13 +0000 | [diff] [blame] | 64 | inet_peer_refcheck(p); |
Eric Dumazet | 2c1409a | 2009-11-12 09:33:09 +0000 | [diff] [blame] | 65 | return atomic_add_return(more, &p->ip_id_count) - more; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | } |
| 67 | |
| 68 | #endif /* _NET_INETPEER_H */ |