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->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 */