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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;
Eric Dumazet55432d22012-06-05 03:00:18 +000039 union {
40 struct list_head gc_list;
41 struct rcu_head gc_rcu;
42 };
Eric Dumazet317fe0e2010-06-16 04:52:13 +000043 /*
44 * Once inet_peer is queued for deletion (refcnt == -1), following fields
David S. Miller81166dd2012-07-10 03:14:24 -070045 * are not available: rid, ip_id_count
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 */
Eric Dumazet317fe0e2010-06-16 04:52:13 +000052 };
53 struct rcu_head rcu;
Eric Dumazet4b9d9be2011-06-08 13:35:34 +000054 struct inet_peer *gc_next;
Eric Dumazet317fe0e2010-06-16 04:52:13 +000055 };
Eric Dumazet2b77bdd2011-06-08 23:31:27 -070056
57 /* following fields might be frequently dirtied */
58 __u32 dtime; /* the time of last use of not referenced entries */
59 atomic_t refcnt;
Linus Torvalds1da177e2005-04-16 15:20:36 -070060};
61
David S. Millerc3426b42012-06-09 16:27:05 -070062struct inet_peer_base {
63 struct inet_peer __rcu *root;
64 seqlock_t lock;
David S. Millerb48c80ece2012-06-10 00:24:21 -070065 u32 flush_seq;
David S. Millerc3426b42012-06-09 16:27:05 -070066 int total;
67};
68
David S. Miller97bab732012-06-09 22:36:36 -070069#define INETPEER_BASE_BIT 0x1UL
70
71static inline struct inet_peer *inetpeer_ptr(unsigned long val)
72{
73 BUG_ON(val & INETPEER_BASE_BIT);
74 return (struct inet_peer *) val;
75}
76
77static inline struct inet_peer_base *inetpeer_base_ptr(unsigned long val)
78{
79 if (!(val & INETPEER_BASE_BIT))
80 return NULL;
81 val &= ~INETPEER_BASE_BIT;
82 return (struct inet_peer_base *) val;
83}
84
85static inline bool inetpeer_ptr_is_peer(unsigned long val)
86{
87 return !(val & INETPEER_BASE_BIT);
88}
89
90static inline void __inetpeer_ptr_set_peer(unsigned long *val, struct inet_peer *peer)
91{
92 /* This implicitly clears INETPEER_BASE_BIT */
93 *val = (unsigned long) peer;
94}
95
96static inline bool inetpeer_ptr_set_peer(unsigned long *ptr, struct inet_peer *peer)
97{
98 unsigned long val = (unsigned long) peer;
99 unsigned long orig = *ptr;
100
David S. Miller7b34ca22012-06-11 04:13:57 -0700101 if (!(orig & INETPEER_BASE_BIT) ||
David S. Miller97bab732012-06-09 22:36:36 -0700102 cmpxchg(ptr, orig, val) != orig)
103 return false;
104 return true;
105}
106
107static inline void inetpeer_init_ptr(unsigned long *ptr, struct inet_peer_base *base)
108{
109 *ptr = (unsigned long) base | INETPEER_BASE_BIT;
110}
111
112static inline void inetpeer_transfer_peer(unsigned long *to, unsigned long *from)
113{
114 unsigned long val = *from;
115
116 *to = val;
117 if (inetpeer_ptr_is_peer(val)) {
118 struct inet_peer *peer = inetpeer_ptr(val);
119 atomic_inc(&peer->refcnt);
120 }
121}
122
David S. Millerc3426b42012-06-09 16:27:05 -0700123extern void inet_peer_base_init(struct inet_peer_base *);
124
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125void inet_initpeers(void) __init;
126
David S. Miller144001b2011-01-27 13:52:16 -0800127#define INETPEER_METRICS_NEW (~(u32) 0)
128
129static inline bool inet_metrics_new(const struct inet_peer *p)
130{
131 return p->metrics[RTAX_LOCK-1] == INETPEER_METRICS_NEW;
132}
133
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134/* can be called with or without local BH being disabled */
David S. Millerc0efc882012-06-09 19:12:36 -0700135struct inet_peer *inet_getpeer(struct inet_peer_base *base,
Gao fengc8a627e2012-06-08 01:20:41 +0000136 const struct inetpeer_addr *daddr,
137 int create);
David S. Millerb534ecf2010-11-30 11:54:19 -0800138
David S. Millerc0efc882012-06-09 19:12:36 -0700139static inline struct inet_peer *inet_getpeer_v4(struct inet_peer_base *base,
Gao feng54db0cc2012-06-08 01:21:40 +0000140 __be32 v4daddr,
141 int create)
David S. Millerb534ecf2010-11-30 11:54:19 -0800142{
David S. Miller8790ca12010-12-01 17:28:18 -0800143 struct inetpeer_addr daddr;
David S. Millerb534ecf2010-11-30 11:54:19 -0800144
David S. Miller7a71ed82011-02-09 14:30:26 -0800145 daddr.addr.a4 = v4daddr;
David S. Millerb534ecf2010-11-30 11:54:19 -0800146 daddr.family = AF_INET;
David S. Millerc0efc882012-06-09 19:12:36 -0700147 return inet_getpeer(base, &daddr, create);
David S. Millerb534ecf2010-11-30 11:54:19 -0800148}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
David S. Millerc0efc882012-06-09 19:12:36 -0700150static inline struct inet_peer *inet_getpeer_v6(struct inet_peer_base *base,
Gao feng54db0cc2012-06-08 01:21:40 +0000151 const struct in6_addr *v6daddr,
152 int create)
David S. Miller672f0072010-11-30 12:20:00 -0800153{
David S. Miller8790ca12010-12-01 17:28:18 -0800154 struct inetpeer_addr daddr;
David S. Miller672f0072010-11-30 12:20:00 -0800155
Alexey Dobriyan4e3fd7a2011-11-21 03:39:03 +0000156 *(struct in6_addr *)daddr.addr.a6 = *v6daddr;
David S. Miller672f0072010-11-30 12:20:00 -0800157 daddr.family = AF_INET6;
David S. Millerc0efc882012-06-09 19:12:36 -0700158 return inet_getpeer(base, &daddr, create);
David S. Miller672f0072010-11-30 12:20:00 -0800159}
160
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161/* can be called from BH context or outside */
Eric Dumazet4663afe2006-10-12 21:21:06 -0700162extern void inet_putpeer(struct inet_peer *p);
David S. Miller92d86822011-02-04 15:55:25 -0800163extern bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
David S. Miller56a6b242012-06-09 16:32:41 -0700165extern void inetpeer_invalidate_tree(struct inet_peer_base *);
David S. Millerb48c80ece2012-06-10 00:24:21 -0700166extern void inetpeer_invalidate_family(int family);
Steffen Klassert5faa5df2012-03-06 21:20:26 +0000167
Eric Dumazet317fe0e2010-06-16 04:52:13 +0000168/*
169 * temporary check to make sure we dont access rid, ip_id_count, tcp_ts,
170 * tcp_ts_stamp if no refcount is taken on inet_peer
171 */
172static inline void inet_peer_refcheck(const struct inet_peer *p)
173{
174 WARN_ON_ONCE(atomic_read(&p->refcnt) <= 0);
175}
176
177
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178/* can be called with or without local BH being disabled */
Eric Dumazet87c48fa2011-07-21 21:25:58 -0700179static inline int inet_getid(struct inet_peer *p, int more)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180{
Eric Dumazet87c48fa2011-07-21 21:25:58 -0700181 int old, new;
Eric Dumazet2c1409a2009-11-12 09:33:09 +0000182 more++;
Eric Dumazet317fe0e2010-06-16 04:52:13 +0000183 inet_peer_refcheck(p);
Eric Dumazet87c48fa2011-07-21 21:25:58 -0700184 do {
185 old = atomic_read(&p->ip_id_count);
186 new = old + more;
187 if (!new)
188 new = 1;
189 } while (atomic_cmpxchg(&p->ip_id_count, old, new) != old);
190 return new;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191}
192
193#endif /* _NET_INETPEER_H */