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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 	u32			n_redirects;
44 	unsigned long		rate_last;
45 	union {
46 		struct list_head	gc_list;
47 		struct rcu_head     gc_rcu;
48 	};
49 	/*
50 	 * Once inet_peer is queued for deletion (refcnt == -1), following field
51 	 * is not available: rid
52 	 * We can share memory with rcu_head to help keep inet_peer small.
53 	 */
54 	union {
55 		struct {
56 			atomic_t			rid;		/* Frag reception counter */
57 		};
58 		struct rcu_head         rcu;
59 		struct inet_peer	*gc_next;
60 	};
61 
62 	/* following fields might be frequently dirtied */
63 	__u32			dtime;	/* the time of last use of not referenced entries */
64 	atomic_t		refcnt;
65 };
66 
67 struct inet_peer_base {
68 	struct inet_peer __rcu	*root;
69 	seqlock_t		lock;
70 	int			total;
71 };
72 
73 void inet_peer_base_init(struct inet_peer_base *);
74 
75 void inet_initpeers(void) __init;
76 
77 #define INETPEER_METRICS_NEW	(~(u32) 0)
78 
inetpeer_set_addr_v4(struct inetpeer_addr * iaddr,__be32 ip)79 static inline void inetpeer_set_addr_v4(struct inetpeer_addr *iaddr, __be32 ip)
80 {
81 	iaddr->a4.addr = ip;
82 	iaddr->a4.vif = 0;
83 	iaddr->family = AF_INET;
84 }
85 
inetpeer_get_addr_v4(struct inetpeer_addr * iaddr)86 static inline __be32 inetpeer_get_addr_v4(struct inetpeer_addr *iaddr)
87 {
88 	return iaddr->a4.addr;
89 }
90 
inetpeer_set_addr_v6(struct inetpeer_addr * iaddr,struct in6_addr * in6)91 static inline void inetpeer_set_addr_v6(struct inetpeer_addr *iaddr,
92 					struct in6_addr *in6)
93 {
94 	iaddr->a6 = *in6;
95 	iaddr->family = AF_INET6;
96 }
97 
inetpeer_get_addr_v6(struct inetpeer_addr * iaddr)98 static inline struct in6_addr *inetpeer_get_addr_v6(struct inetpeer_addr *iaddr)
99 {
100 	return &iaddr->a6;
101 }
102 
103 /* can be called with or without local BH being disabled */
104 struct inet_peer *inet_getpeer(struct inet_peer_base *base,
105 			       const struct inetpeer_addr *daddr,
106 			       int create);
107 
inet_getpeer_v4(struct inet_peer_base * base,__be32 v4daddr,int vif,int create)108 static inline struct inet_peer *inet_getpeer_v4(struct inet_peer_base *base,
109 						__be32 v4daddr,
110 						int vif, int create)
111 {
112 	struct inetpeer_addr daddr;
113 
114 	daddr.a4.addr = v4daddr;
115 	daddr.a4.vif = vif;
116 	daddr.family = AF_INET;
117 	return inet_getpeer(base, &daddr, create);
118 }
119 
inet_getpeer_v6(struct inet_peer_base * base,const struct in6_addr * v6daddr,int create)120 static inline struct inet_peer *inet_getpeer_v6(struct inet_peer_base *base,
121 						const struct in6_addr *v6daddr,
122 						int create)
123 {
124 	struct inetpeer_addr daddr;
125 
126 	daddr.a6 = *v6daddr;
127 	daddr.family = AF_INET6;
128 	return inet_getpeer(base, &daddr, create);
129 }
130 
inetpeer_addr_cmp(const struct inetpeer_addr * a,const struct inetpeer_addr * b)131 static inline int inetpeer_addr_cmp(const struct inetpeer_addr *a,
132 				    const struct inetpeer_addr *b)
133 {
134 	int i, n;
135 
136 	if (a->family == AF_INET)
137 		n = sizeof(a->a4) / sizeof(u32);
138 	else
139 		n = sizeof(a->a6) / sizeof(u32);
140 
141 	for (i = 0; i < n; i++) {
142 		if (a->key[i] == b->key[i])
143 			continue;
144 		if (a->key[i] < b->key[i])
145 			return -1;
146 		return 1;
147 	}
148 
149 	return 0;
150 }
151 
152 /* can be called from BH context or outside */
153 void inet_putpeer(struct inet_peer *p);
154 bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);
155 
156 void inetpeer_invalidate_tree(struct inet_peer_base *);
157 
158 #endif /* _NET_INETPEER_H */
159