include/net/inetpeer.h

   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         unsigned long           rate_last;
  43         /*
  44          * Once inet_peer is queued for deletion (refcnt == 0), following field
  45          * is not available: rid
  46          * We can share memory with rcu_head to help keep inet_peer small.
  47          */
  48         union {
  49                 struct {
  50                         atomic_t                        rid;            /* Frag reception counter */
  51                 };
  52                 struct rcu_head         rcu;
  53         };
  54
  55         /* following fields might be frequently dirtied */
  56         __u32                   dtime;  /* the time of last use of not referenced entries */
  57         refcount_t              refcnt;
  58 };
  59
  60 struct inet_peer_base {
  61         struct rb_root          rb_root;
  62         seqlock_t               lock;
  63         int                     total;
  64 };
  65
  66 void inet_peer_base_init(struct inet_peer_base *);
  67
  68 void inet_initpeers(void) __init;
  69
  70 #define INETPEER_METRICS_NEW    (~(u32) 0)
  71
  72 static inline void inetpeer_set_addr_v4(struct inetpeer_addr *iaddr, __be32 ip)
  73 {
  74         iaddr->a4.addr = ip;
  75         iaddr->a4.vif = 0;
  76         iaddr->family = AF_INET;
  77 }
  78
  79 static inline __be32 inetpeer_get_addr_v4(struct inetpeer_addr *iaddr)
  80 {
  81         return iaddr->a4.addr;
  82 }
  83
  84 static inline void inetpeer_set_addr_v6(struct inetpeer_addr *iaddr,
  85                                         struct in6_addr *in6)
  86 {
  87         iaddr->a6 = *in6;
  88         iaddr->family = AF_INET6;
  89 }
  90
  91 static inline struct in6_addr *inetpeer_get_addr_v6(struct inetpeer_addr *iaddr)
  92 {
  93         return &iaddr->a6;
  94 }
  95
  96 /* can be called with or without local BH being disabled */
  97 struct inet_peer *inet_getpeer(struct inet_peer_base *base,
  98                                const struct inetpeer_addr *daddr,
  99                                int create);
 100
 101 static inline struct inet_peer *inet_getpeer_v4(struct inet_peer_base *base,
 102                                                 __be32 v4daddr,
 103                                                 int vif, int create)
 104 {
 105         struct inetpeer_addr daddr;
 106
 107         daddr.a4.addr = v4daddr;
 108         daddr.a4.vif = vif;
 109         daddr.family = AF_INET;
 110         return inet_getpeer(base, &daddr, create);
 111 }
 112
 113 static inline struct inet_peer *inet_getpeer_v6(struct inet_peer_base *base,
 114                                                 const struct in6_addr *v6daddr,
 115                                                 int create)
 116 {
 117         struct inetpeer_addr daddr;
 118
 119         daddr.a6 = *v6daddr;
 120         daddr.family = AF_INET6;
 121         return inet_getpeer(base, &daddr, create);
 122 }
 123
 124 static inline int inetpeer_addr_cmp(const struct inetpeer_addr *a,
 125                                     const struct inetpeer_addr *b)
 126 {
 127         int i, n;
 128
 129         if (a->family == AF_INET)
 130                 n = sizeof(a->a4) / sizeof(u32);
 131         else
 132                 n = sizeof(a->a6) / sizeof(u32);
 133
 134         for (i = 0; i < n; i++) {
 135                 if (a->key[i] == b->key[i])
 136                         continue;
 137                 if (a->key[i] < b->key[i])
 138                         return -1;
 139                 return 1;
 140         }
 141
 142         return 0;
 143 }
 144
 145 /* can be called from BH context or outside */
 146 void inet_putpeer(struct inet_peer *p);
 147 bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);
 148
 149 void inetpeer_invalidate_tree(struct inet_peer_base *);
 150
 151 #endif /* _NET_INETPEER_H */