1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
/*
* 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;
unsigned long pmtu_expires;
u32 pmtu_orig;
u32 pmtu_learned;
struct inetpeer_addr_base redirect_learned;
union {
struct list_head gc_list;
struct rcu_head gc_rcu;
};
/*
* 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(struct net *net,
const struct inetpeer_addr *daddr,
int create);
static inline struct inet_peer *inet_getpeer_v4(struct net *net,
__be32 v4daddr,
int create)
{
struct inetpeer_addr daddr;
daddr.addr.a4 = v4daddr;
daddr.family = AF_INET;
return inet_getpeer(net, &daddr, create);
}
static inline struct inet_peer *inet_getpeer_v6(struct net *net,
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(net, &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 net *net, 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 */
|
