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