LXR linux/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 */
  20struct ipv4_addr_key {
  21        __be32  addr;
  22        int     vif;
  23};
  24
  25#define INETPEER_MAXKEYSZ   (sizeof(struct in6_addr) / sizeof(u32))
  26
  27struct 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
  36struct 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
  61struct inet_peer_base {
  62        struct rb_root          rb_root;
  63        seqlock_t               lock;
  64        int                     total;
  65};
  66
  67void inet_peer_base_init(struct inet_peer_base *);
  68
  69void inet_initpeers(void) __init;
  70
  71#define INETPEER_METRICS_NEW    (~(u32) 0)
  72
  73static 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
  80static inline __be32 inetpeer_get_addr_v4(struct inetpeer_addr *iaddr)
  81{
  82        return iaddr->a4.addr;
  83}
  84
  85static 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
  92static 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 */
  98struct inet_peer *inet_getpeer(struct inet_peer_base *base,
  99                               const struct inetpeer_addr *daddr,
 100                               int create);
 101
 102static 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
 114static 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
 125static 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 */
 147void inet_putpeer(struct inet_peer *p);
 148bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);
 149
 150void inetpeer_invalidate_tree(struct inet_peer_base *);
 151
 152#endif /* _NET_INETPEER_H */
 153