xref: /openbmc/linux/include/net/inetpeer.h (revision b96fc2f3)
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->family = AF_INET;
82 }
83 
84 static inline __be32 inetpeer_get_addr_v4(struct inetpeer_addr *iaddr)
85 {
86 	return iaddr->a4.addr;
87 }
88 
89 static inline void inetpeer_set_addr_v6(struct inetpeer_addr *iaddr,
90 					struct in6_addr *in6)
91 {
92 	iaddr->a6 = *in6;
93 	iaddr->family = AF_INET6;
94 }
95 
96 static inline struct in6_addr *inetpeer_get_addr_v6(struct inetpeer_addr *iaddr)
97 {
98 	return &iaddr->a6;
99 }
100 
101 /* can be called with or without local BH being disabled */
102 struct inet_peer *inet_getpeer(struct inet_peer_base *base,
103 			       const struct inetpeer_addr *daddr,
104 			       int create);
105 
106 static inline struct inet_peer *inet_getpeer_v4(struct inet_peer_base *base,
107 						__be32 v4daddr,
108 						int vif, int create)
109 {
110 	struct inetpeer_addr daddr;
111 
112 	daddr.a4.addr = v4daddr;
113 	daddr.a4.vif = vif;
114 	daddr.family = AF_INET;
115 	return inet_getpeer(base, &daddr, create);
116 }
117 
118 static inline struct inet_peer *inet_getpeer_v6(struct inet_peer_base *base,
119 						const struct in6_addr *v6daddr,
120 						int create)
121 {
122 	struct inetpeer_addr daddr;
123 
124 	daddr.a6 = *v6daddr;
125 	daddr.family = AF_INET6;
126 	return inet_getpeer(base, &daddr, create);
127 }
128 
129 static inline int inetpeer_addr_cmp(const struct inetpeer_addr *a,
130 				    const struct inetpeer_addr *b)
131 {
132 	int i, n;
133 
134 	if (a->family == AF_INET)
135 		n = sizeof(a->a4) / sizeof(u32);
136 	else
137 		n = sizeof(a->a6) / sizeof(u32);
138 
139 	for (i = 0; i < n; i++) {
140 		if (a->key[i] == b->key[i])
141 			continue;
142 		if (a->key[i] < b->key[i])
143 			return -1;
144 		return 1;
145 	}
146 
147 	return 0;
148 }
149 
150 /* can be called from BH context or outside */
151 void inet_putpeer(struct inet_peer *p);
152 bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);
153 
154 void inetpeer_invalidate_tree(struct inet_peer_base *);
155 
156 #endif /* _NET_INETPEER_H */
157