include/net/inetpeer.h

   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         struct rb_node          rb_node;
  37         struct inetpeer_addr    daddr;
  38
  39         u32                     metrics[RTAX_MAX];
  40         u32                     rate_tokens;    /* rate limiting for ICMP */
  41         unsigned long           rate_last;
  42         /*
  43          * Once inet_peer is queued for deletion (refcnt == 0), following field
  44          * is not available: rid
  45          * We can share memory with rcu_head to help keep inet_peer small.
  46          */
  47         union {
  48                 struct {
  49                         atomic_t                        rid;            /* Frag reception counter */
  50                 };
  51                 struct rcu_head         rcu;
  52         };
  53
  54         /* following fields might be frequently dirtied */
  55         __u32                   dtime;  /* the time of last use of not referenced entries */
  56         refcount_t              refcnt;
  57 };
  58
  59 struct inet_peer_base {
  60         struct rb_root          rb_root;
  61         seqlock_t               lock;
  62         int                     total;
  63 };
  64
  65 void inet_peer_base_init(struct inet_peer_base *);
  66
  67 void inet_initpeers(void) __init;
  68
  69 #define INETPEER_METRICS_NEW    (~(u32) 0)
  70
  71 static inline void inetpeer_set_addr_v4(struct inetpeer_addr *iaddr, __be32 ip)
  72 {
  73         iaddr->a4.addr = ip;
  74         iaddr->a4.vif = 0;
  75         iaddr->family = AF_INET;
  76 }
  77
  78 static inline __be32 inetpeer_get_addr_v4(struct inetpeer_addr *iaddr)
  79 {
  80         return iaddr->a4.addr;
  81 }
  82
  83 static inline void inetpeer_set_addr_v6(struct inetpeer_addr *iaddr,
  84                                         struct in6_addr *in6)
  85 {
  86         iaddr->a6 = *in6;
  87         iaddr->family = AF_INET6;
  88 }
  89
  90 static inline struct in6_addr *inetpeer_get_addr_v6(struct inetpeer_addr *iaddr)
  91 {
  92         return &iaddr->a6;
  93 }
  94
  95 /* can be called with or without local BH being disabled */
  96 struct inet_peer *inet_getpeer(struct inet_peer_base *base,
  97                                const struct inetpeer_addr *daddr,
  98                                int create);
  99
 100 static inline struct inet_peer *inet_getpeer_v4(struct inet_peer_base *base,
 101                                                 __be32 v4daddr,
 102                                                 int vif, int create)
 103 {
 104         struct inetpeer_addr daddr;
 105
 106         daddr.a4.addr = v4daddr;
 107         daddr.a4.vif = vif;
 108         daddr.family = AF_INET;
 109         return inet_getpeer(base, &daddr, create);
 110 }
 111
 112 static inline struct inet_peer *inet_getpeer_v6(struct inet_peer_base *base,
 113                                                 const struct in6_addr *v6daddr,
 114                                                 int create)
 115 {
 116         struct inetpeer_addr daddr;
 117
 118         daddr.a6 = *v6daddr;
 119         daddr.family = AF_INET6;
 120         return inet_getpeer(base, &daddr, create);
 121 }
 122
 123 static inline int inetpeer_addr_cmp(const struct inetpeer_addr *a,
 124                                     const struct inetpeer_addr *b)
 125 {
 126         int i, n;
 127
 128         if (a->family == AF_INET)
 129                 n = sizeof(a->a4) / sizeof(u32);
 130         else
 131                 n = sizeof(a->a6) / sizeof(u32);
 132
 133         for (i = 0; i < n; i++) {
 134                 if (a->key[i] == b->key[i])
 135                         continue;
 136                 if (a->key[i] < b->key[i])
 137                         return -1;
 138                 return 1;
 139         }
 140
 141         return 0;
 142 }
 143
 144 /* can be called from BH context or outside */
 145 void inet_putpeer(struct inet_peer *p);
 146 bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);
 147
 148 void inetpeer_invalidate_tree(struct inet_peer_base *);
 149
 150 #endif /* _NET_INETPEER_H */