i386/linux-2.3.21/include/net/dst.h

   1 /*
   2  * net/dst.h    Protocol independent destination cache definitions.
   3  *
   4  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   5  *
   6  */
   7
   8 #ifndef _NET_DST_H
   9 #define _NET_DST_H
  10
  11 #include <linux/config.h>
  12 #include <net/neighbour.h>
  13
  14 /*
  15  * 0 - no debugging messages
  16  * 1 - rare events and bugs (default)
  17  * 2 - trace mode.
  18  */
  19 #define RT_CACHE_DEBUG          0
  20
  21 #define DST_GC_MIN      (1*HZ)
  22 #define DST_GC_INC      (5*HZ)
  23 #define DST_GC_MAX      (120*HZ)
  24
  25 struct sk_buff;
  26
  27 struct dst_entry
  28 {
  29         struct dst_entry        *next;
  30         atomic_t                __refcnt;       /* client references    */
  31         int                     __use;
  32         struct net_device               *dev;
  33         int                     obsolete;
  34         unsigned long           lastuse;
  35         unsigned long           expires;
  36         unsigned                mxlock;
  37         unsigned                pmtu;
  38         unsigned                window;
  39         unsigned                rtt;
  40         unsigned                rttvar;
  41         unsigned                ssthresh;
  42         unsigned                cwnd;
  43         unsigned                advmss;
  44         unsigned long           rate_last;      /* rate limiting for ICMP */
  45         unsigned long           rate_tokens;
  46
  47         int                     error;
  48
  49         struct neighbour        *neighbour;
  50         struct hh_cache         *hh;
  51
  52         int                     (*input)(struct sk_buff*);
  53         int                     (*output)(struct sk_buff*);
  54
  55 #ifdef CONFIG_NET_CLS_ROUTE
  56         __u32                   tclassid;
  57 #endif
  58
  59         struct  dst_ops         *ops;
  60
  61         char                    info[0];
  62 };
  63
  64
  65 struct dst_ops
  66 {
  67         unsigned short          family;
  68         unsigned short          protocol;
  69         unsigned                gc_thresh;
  70
  71         int                     (*gc)(void);
  72         struct dst_entry *      (*check)(struct dst_entry *, __u32 cookie);
  73         struct dst_entry *      (*reroute)(struct dst_entry *,
  74                                            struct sk_buff *);
  75         void                    (*destroy)(struct dst_entry *);
  76         struct dst_entry *      (*negative_advice)(struct dst_entry *);
  77         void                    (*link_failure)(struct sk_buff *);
  78         int                     entry_size;
  79
  80         atomic_t                entries;
  81         kmem_cache_t            *kmem_cachep;
  82 };
  83
  84 #ifdef __KERNEL__
  85
  86 extern __inline__ void dst_hold(struct dst_entry * dst)
  87 {
  88         atomic_inc(&dst->__refcnt);
  89 }
  90
  91 extern __inline__
  92 struct dst_entry * dst_clone(struct dst_entry * dst)
  93 {
  94         if (dst)
  95                 atomic_inc(&dst->__refcnt);
  96         return dst;
  97 }
  98
  99 extern __inline__
 100 void dst_release(struct dst_entry * dst)
 101 {
 102         if (dst)
 103                 atomic_dec(&dst->__refcnt);
 104 }
 105
 106 extern void * dst_alloc(struct dst_ops * ops);
 107 extern void __dst_free(struct dst_entry * dst);
 108 extern void dst_destroy(struct dst_entry * dst);
 109
 110 extern __inline__
 111 void dst_free(struct dst_entry * dst)
 112 {
 113         if (dst->obsolete > 1)
 114                 return;
 115         if (!atomic_read(&dst->__refcnt)) {
 116                 dst_destroy(dst);
 117                 return;
 118         }
 119         __dst_free(dst);
 120 }
 121
 122 extern __inline__ void dst_confirm(struct dst_entry *dst)
 123 {
 124         if (dst)
 125                 neigh_confirm(dst->neighbour);
 126 }
 127
 128 extern __inline__ void dst_negative_advice(struct dst_entry **dst_p)
 129 {
 130         struct dst_entry * dst = *dst_p;
 131         if (dst && dst->ops->negative_advice)
 132                 *dst_p = dst->ops->negative_advice(dst);
 133 }
 134
 135 extern __inline__ void dst_link_failure(struct sk_buff *skb)
 136 {
 137         struct dst_entry * dst = skb->dst;
 138         if (dst && dst->ops && dst->ops->link_failure)
 139                 dst->ops->link_failure(skb);
 140 }
 141
 142 extern __inline__ void dst_set_expires(struct dst_entry *dst, int timeout)
 143 {
 144         unsigned long expires = jiffies + timeout;
 145
 146         if (expires == 0)
 147                 expires = 1;
 148
 149         if (dst->expires == 0 || (long)(dst->expires - expires) > 0)
 150                 dst->expires = expires;
 151 }
 152
 153 extern void             dst_init(void);
 154
 155 #endif
 156
 157 #endif /* _NET_DST_H */