1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *		INETPEER - A storage for permanent information about peers
4  *
5  *  Authors:	Andrey V. Savochkin <saw@msu.ru>
6  */
7 
8 #ifndef _NET_INETPEER_H
9 #define _NET_INETPEER_H
10 
11 #include <linux/types.h>
12 #include <linux/init.h>
13 #include <linux/jiffies.h>
14 #include <linux/spinlock.h>
15 #include <linux/rtnetlink.h>
16 #include <net/ipv6.h>
17 #include <linux/atomic.h>
18 
19 /* IPv4 address key for cache lookups */
20 struct ipv4_addr_key {
21 	__be32	addr;
22 	int	vif;
23 };
24 
25 #define INETPEER_MAXKEYSZ   (sizeof(struct in6_addr) / sizeof(u32))
26 
27 struct inetpeer_addr {
28 	union {
29 		struct ipv4_addr_key	a4;
30 		struct in6_addr		a6;
31 		u32			key[INETPEER_MAXKEYSZ];
32 	};
33 	__u16				family;
34 };
35 
36 struct inet_peer {
37 	struct rb_node		rb_node;
38 	struct inetpeer_addr	daddr;
39 
40 	u32			metrics[RTAX_MAX];
41 	u32			rate_tokens;	/* rate limiting for ICMP */
42 	u32			n_redirects;
43 	unsigned long		rate_last;
44 	/*
45 	 * Once inet_peer is queued for deletion (refcnt == 0), following field
46 	 * is not available: rid
47 	 * We can share memory with rcu_head to help keep inet_peer small.
48 	 */
49 	union {
50 		struct {
51 			atomic_t			rid;		/* Frag reception counter */
52 		};
53 		struct rcu_head         rcu;
54 	};
55 
56 	/* following fields might be frequently dirtied */
57 	__u32			dtime;	/* the time of last use of not referenced entries */
58 	refcount_t		refcnt;
59 };
60 
61 struct inet_peer_base {
62 	struct rb_root		rb_root;
63 	seqlock_t		lock;
64 	int			total;
65 };
66 
67 void inet_peer_base_init(struct inet_peer_base *);
68 
69 void inet_initpeers(void) __init;
70 
71 #define INETPEER_METRICS_NEW	(~(u32) 0)
72 
inetpeer_set_addr_v4(struct inetpeer_addr * iaddr,__be32 ip)73 static inline void inetpeer_set_addr_v4(struct inetpeer_addr *iaddr, __be32 ip)
74 {
75 	iaddr->a4.addr = ip;
76 	iaddr->a4.vif = 0;
77 	iaddr->family = AF_INET;
78 }
79 
inetpeer_get_addr_v4(struct inetpeer_addr * iaddr)80 static inline __be32 inetpeer_get_addr_v4(struct inetpeer_addr *iaddr)
81 {
82 	return iaddr->a4.addr;
83 }
84 
inetpeer_set_addr_v6(struct inetpeer_addr * iaddr,struct in6_addr * in6)85 static inline void inetpeer_set_addr_v6(struct inetpeer_addr *iaddr,
86 					struct in6_addr *in6)
87 {
88 	iaddr->a6 = *in6;
89 	iaddr->family = AF_INET6;
90 }
91 
inetpeer_get_addr_v6(struct inetpeer_addr * iaddr)92 static inline struct in6_addr *inetpeer_get_addr_v6(struct inetpeer_addr *iaddr)
93 {
94 	return &iaddr->a6;
95 }
96 
97 /* can be called with or without local BH being disabled */
98 struct inet_peer *inet_getpeer(struct inet_peer_base *base,
99 			       const struct inetpeer_addr *daddr,
100 			       int create);
101 
inet_getpeer_v4(struct inet_peer_base * base,__be32 v4daddr,int vif,int create)102 static inline struct inet_peer *inet_getpeer_v4(struct inet_peer_base *base,
103 						__be32 v4daddr,
104 						int vif, int create)
105 {
106 	struct inetpeer_addr daddr;
107 
108 	daddr.a4.addr = v4daddr;
109 	daddr.a4.vif = vif;
110 	daddr.family = AF_INET;
111 	return inet_getpeer(base, &daddr, create);
112 }
113 
inet_getpeer_v6(struct inet_peer_base * base,const struct in6_addr * v6daddr,int create)114 static inline struct inet_peer *inet_getpeer_v6(struct inet_peer_base *base,
115 						const struct in6_addr *v6daddr,
116 						int create)
117 {
118 	struct inetpeer_addr daddr;
119 
120 	daddr.a6 = *v6daddr;
121 	daddr.family = AF_INET6;
122 	return inet_getpeer(base, &daddr, create);
123 }
124 
inetpeer_addr_cmp(const struct inetpeer_addr * a,const struct inetpeer_addr * b)125 static inline int inetpeer_addr_cmp(const struct inetpeer_addr *a,
126 				    const struct inetpeer_addr *b)
127 {
128 	int i, n;
129 
130 	if (a->family == AF_INET)
131 		n = sizeof(a->a4) / sizeof(u32);
132 	else
133 		n = sizeof(a->a6) / sizeof(u32);
134 
135 	for (i = 0; i < n; i++) {
136 		if (a->key[i] == b->key[i])
137 			continue;
138 		if (a->key[i] < b->key[i])
139 			return -1;
140 		return 1;
141 	}
142 
143 	return 0;
144 }
145 
146 /* can be called from BH context or outside */
147 void inet_putpeer(struct inet_peer *p);
148 bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);
149 
150 void inetpeer_invalidate_tree(struct inet_peer_base *);
151 
152 #endif /* _NET_INETPEER_H */
153