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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * INETPEER - A storage for permanent information about peers
3 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 * 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>
David S. Miller60659822011-01-26 20:55:53 -080014#include <linux/rtnetlink.h>
David S. Miller672f0072010-11-30 12:20:00 -080015#include <net/ipv6.h>
Arun Sharma600634972011-07-26 16:09:06 -070016#include <linux/atomic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017
David S. Miller7a71ed82011-02-09 14:30:26 -080018struct inetpeer_addr_base {
David S. Miller582a72d2010-11-30 11:53:55 -080019 union {
David S. Miller7a71ed82011-02-09 14:30:26 -080020 __be32 a4;
21 __be32 a6[4];
David S. Miller582a72d2010-11-30 11:53:55 -080022 };
David S. Miller7a71ed82011-02-09 14:30:26 -080023};
24
25struct inetpeer_addr {
26 struct inetpeer_addr_base addr;
27 __u16 family;
David S. Miller8790ca12010-12-01 17:28:18 -080028};
David S. Miller582a72d2010-11-30 11:53:55 -080029
Eric Dumazetfd2c3ef2009-11-03 03:26:03 +000030struct inet_peer {
Eric Dumazet78d79422006-10-20 00:28:35 -070031 /* group together avl_left,avl_right,v4daddr to speedup lookups */
Eric Dumazetb914c4e2010-10-25 23:55:38 +000032 struct inet_peer __rcu *avl_left, *avl_right;
David S. Miller8790ca12010-12-01 17:28:18 -080033 struct inetpeer_addr daddr;
Eric Dumazet2c1409a2009-11-12 09:33:09 +000034 __u32 avl_height;
Eric Dumazet2b77bdd2011-06-08 23:31:27 -070035
36 u32 metrics[RTAX_MAX];
37 u32 rate_tokens; /* rate limiting for ICMP */
38 unsigned long rate_last;
39 unsigned long pmtu_expires;
40 u32 pmtu_orig;
41 u32 pmtu_learned;
42 struct inetpeer_addr_base redirect_learned;
Eric Dumazet317fe0e2010-06-16 04:52:13 +000043 /*
44 * Once inet_peer is queued for deletion (refcnt == -1), following fields
Eric Dumazet2b77bdd2011-06-08 23:31:27 -070045 * are not available: rid, ip_id_count, tcp_ts, tcp_ts_stamp
David S. Miller60659822011-01-26 20:55:53 -080046 * We can share memory with rcu_head to help keep inet_peer small.
Eric Dumazet317fe0e2010-06-16 04:52:13 +000047 */
48 union {
49 struct {
David S. Millerddd4aa42011-02-09 15:36:47 -080050 atomic_t rid; /* Frag reception counter */
51 atomic_t ip_id_count; /* IP ID for the next packet */
52 __u32 tcp_ts;
53 __u32 tcp_ts_stamp;
Eric Dumazet317fe0e2010-06-16 04:52:13 +000054 };
55 struct rcu_head rcu;
Eric Dumazet4b9d9be2011-06-08 13:35:34 +000056 struct inet_peer *gc_next;
Eric Dumazet317fe0e2010-06-16 04:52:13 +000057 };
Eric Dumazet2b77bdd2011-06-08 23:31:27 -070058
59 /* following fields might be frequently dirtied */
60 __u32 dtime; /* the time of last use of not referenced entries */
61 atomic_t refcnt;
Linus Torvalds1da177e2005-04-16 15:20:36 -070062};
63
64void inet_initpeers(void) __init;
65
David S. Miller144001b2011-01-27 13:52:16 -080066#define INETPEER_METRICS_NEW (~(u32) 0)
67
68static inline bool inet_metrics_new(const struct inet_peer *p)
69{
70 return p->metrics[RTAX_LOCK-1] == INETPEER_METRICS_NEW;
71}
72
Linus Torvalds1da177e2005-04-16 15:20:36 -070073/* can be called with or without local BH being disabled */
Eric Dumazet87c48fa2011-07-21 21:25:58 -070074struct inet_peer *inet_getpeer(const struct inetpeer_addr *daddr, int create);
David S. Millerb534ecf2010-11-30 11:54:19 -080075
76static inline struct inet_peer *inet_getpeer_v4(__be32 v4daddr, int create)
77{
David S. Miller8790ca12010-12-01 17:28:18 -080078 struct inetpeer_addr daddr;
David S. Millerb534ecf2010-11-30 11:54:19 -080079
David S. Miller7a71ed82011-02-09 14:30:26 -080080 daddr.addr.a4 = v4daddr;
David S. Millerb534ecf2010-11-30 11:54:19 -080081 daddr.family = AF_INET;
82 return inet_getpeer(&daddr, create);
83}
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
Eric Dumazetb71d1d42011-04-22 04:53:02 +000085static inline struct inet_peer *inet_getpeer_v6(const struct in6_addr *v6daddr, int create)
David S. Miller672f0072010-11-30 12:20:00 -080086{
David S. Miller8790ca12010-12-01 17:28:18 -080087 struct inetpeer_addr daddr;
David S. Miller672f0072010-11-30 12:20:00 -080088
David S. Miller7a71ed82011-02-09 14:30:26 -080089 ipv6_addr_copy((struct in6_addr *)daddr.addr.a6, v6daddr);
David S. Miller672f0072010-11-30 12:20:00 -080090 daddr.family = AF_INET6;
91 return inet_getpeer(&daddr, create);
92}
93
Linus Torvalds1da177e2005-04-16 15:20:36 -070094/* can be called from BH context or outside */
Eric Dumazet4663afe2006-10-12 21:21:06 -070095extern void inet_putpeer(struct inet_peer *p);
David S. Miller92d86822011-02-04 15:55:25 -080096extern bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
Eric Dumazet317fe0e2010-06-16 04:52:13 +000098/*
99 * temporary check to make sure we dont access rid, ip_id_count, tcp_ts,
100 * tcp_ts_stamp if no refcount is taken on inet_peer
101 */
102static inline void inet_peer_refcheck(const struct inet_peer *p)
103{
104 WARN_ON_ONCE(atomic_read(&p->refcnt) <= 0);
105}
106
107
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108/* can be called with or without local BH being disabled */
Eric Dumazet87c48fa2011-07-21 21:25:58 -0700109static inline int inet_getid(struct inet_peer *p, int more)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110{
Eric Dumazet87c48fa2011-07-21 21:25:58 -0700111 int old, new;
Eric Dumazet2c1409a2009-11-12 09:33:09 +0000112 more++;
Eric Dumazet317fe0e2010-06-16 04:52:13 +0000113 inet_peer_refcheck(p);
Eric Dumazet87c48fa2011-07-21 21:25:58 -0700114 do {
115 old = atomic_read(&p->ip_id_count);
116 new = old + more;
117 if (!new)
118 new = 1;
119 } while (atomic_cmpxchg(&p->ip_id_count, old, new) != old);
120 return new;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121}
122
123#endif /* _NET_INETPEER_H */