xref: /linux/include/net/inetpeer.h (revision 8c749ce93ee69e789e46b3be98de9e0cbfcf8ed8)
1 /*
2  *		INETPEER - A storage for permanent information about peers
3  *
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 <linux/rtnetlink.h>
15 #include <net/ipv6.h>
16 #include <linux/atomic.h>
17 
18 /* IPv4 address key for cache lookups */
19 struct ipv4_addr_key {
20 	__be32	addr;
21 	int	vif;
22 };
23 
24 #define INETPEER_MAXKEYSZ   (sizeof(struct in6_addr) / sizeof(u32))
25 
26 struct inetpeer_addr {
27 	union {
28 		struct ipv4_addr_key	a4;
29 		struct in6_addr		a6;
30 		u32			key[INETPEER_MAXKEYSZ];
31 	};
32 	__u16				family;
33 };
34 
35 struct inet_peer {
36 	/* group together avl_left,avl_right,v4daddr to speedup lookups */
37 	struct inet_peer __rcu	*avl_left, *avl_right;
38 	struct inetpeer_addr	daddr;
39 	__u32			avl_height;
40 
41 	u32			metrics[RTAX_MAX];
42 	u32			rate_tokens;	/* rate limiting for ICMP */
43 	unsigned long		rate_last;
44 	union {
45 		struct list_head	gc_list;
46 		struct rcu_head     gc_rcu;
47 	};
48 	/*
49 	 * Once inet_peer is queued for deletion (refcnt == -1), following field
50 	 * is not available: rid
51 	 * We can share memory with rcu_head to help keep inet_peer small.
52 	 */
53 	union {
54 		struct {
55 			atomic_t			rid;		/* Frag reception counter */
56 		};
57 		struct rcu_head         rcu;
58 		struct inet_peer	*gc_next;
59 	};
60 
61 	/* following fields might be frequently dirtied */
62 	__u32			dtime;	/* the time of last use of not referenced entries */
63 	atomic_t		refcnt;
64 };
65 
66 struct inet_peer_base {
67 	struct inet_peer __rcu	*root;
68 	seqlock_t		lock;
69 	int			total;
70 };
71 
72 void inet_peer_base_init(struct inet_peer_base *);
73 
74 void inet_initpeers(void) __init;
75 
76 #define INETPEER_METRICS_NEW	(~(u32) 0)
77 
78 static inline void inetpeer_set_addr_v4(struct inetpeer_addr *iaddr, __be32 ip)
79 {
80 	iaddr->a4.addr = ip;
81 	iaddr->a4.vif = 0;
82 	iaddr->family = AF_INET;
83 }
84 
85 static inline __be32 inetpeer_get_addr_v4(struct inetpeer_addr *iaddr)
86 {
87 	return iaddr->a4.addr;
88 }
89 
90 static inline void inetpeer_set_addr_v6(struct inetpeer_addr *iaddr,
91 					struct in6_addr *in6)
92 {
93 	iaddr->a6 = *in6;
94 	iaddr->family = AF_INET6;
95 }
96 
97 static inline struct in6_addr *inetpeer_get_addr_v6(struct inetpeer_addr *iaddr)
98 {
99 	return &iaddr->a6;
100 }
101 
102 /* can be called with or without local BH being disabled */
103 struct inet_peer *inet_getpeer(struct inet_peer_base *base,
104 			       const struct inetpeer_addr *daddr,
105 			       int create);
106 
107 static inline struct inet_peer *inet_getpeer_v4(struct inet_peer_base *base,
108 						__be32 v4daddr,
109 						int vif, int create)
110 {
111 	struct inetpeer_addr daddr;
112 
113 	daddr.a4.addr = v4daddr;
114 	daddr.a4.vif = vif;
115 	daddr.family = AF_INET;
116 	return inet_getpeer(base, &daddr, create);
117 }
118 
119 static inline struct inet_peer *inet_getpeer_v6(struct inet_peer_base *base,
120 						const struct in6_addr *v6daddr,
121 						int create)
122 {
123 	struct inetpeer_addr daddr;
124 
125 	daddr.a6 = *v6daddr;
126 	daddr.family = AF_INET6;
127 	return inet_getpeer(base, &daddr, create);
128 }
129 
130 static inline int inetpeer_addr_cmp(const struct inetpeer_addr *a,
131 				    const struct inetpeer_addr *b)
132 {
133 	int i, n;
134 
135 	if (a->family == AF_INET)
136 		n = sizeof(a->a4) / sizeof(u32);
137 	else
138 		n = sizeof(a->a6) / sizeof(u32);
139 
140 	for (i = 0; i < n; i++) {
141 		if (a->key[i] == b->key[i])
142 			continue;
143 		if (a->key[i] < b->key[i])
144 			return -1;
145 		return 1;
146 	}
147 
148 	return 0;
149 }
150 
151 /* can be called from BH context or outside */
152 void inet_putpeer(struct inet_peer *p);
153 bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);
154 
155 void inetpeer_invalidate_tree(struct inet_peer_base *);
156 
157 #endif /* _NET_INETPEER_H */
158