linux/include/net/dst.h
Arnaldo Carvalho de Melo 14c850212e [INET_SOCK]: Move struct inet_sock & helper functions to net/inet_sock.h
To help in reducing the number of include dependencies, several files were
touched as they were getting needed headers indirectly for stuff they use.

Thanks also to Alan Menegotto for pointing out that net/dccp/proto.c had
linux/dccp.h include twice.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03 13:11:21 -08:00

279 lines
5.8 KiB
C

/*
* net/dst.h Protocol independent destination cache definitions.
*
* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
*
*/
#ifndef _NET_DST_H
#define _NET_DST_H
#include <linux/config.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <linux/rcupdate.h>
#include <linux/jiffies.h>
#include <net/neighbour.h>
#include <asm/processor.h>
/*
* 0 - no debugging messages
* 1 - rare events and bugs (default)
* 2 - trace mode.
*/
#define RT_CACHE_DEBUG 0
#define DST_GC_MIN (HZ/10)
#define DST_GC_INC (HZ/2)
#define DST_GC_MAX (120*HZ)
/* Each dst_entry has reference count and sits in some parent list(s).
* When it is removed from parent list, it is "freed" (dst_free).
* After this it enters dead state (dst->obsolete > 0) and if its refcnt
* is zero, it can be destroyed immediately, otherwise it is added
* to gc list and garbage collector periodically checks the refcnt.
*/
struct sk_buff;
struct dst_entry
{
struct dst_entry *next;
atomic_t __refcnt; /* client references */
int __use;
struct dst_entry *child;
struct net_device *dev;
short error;
short obsolete;
int flags;
#define DST_HOST 1
#define DST_NOXFRM 2
#define DST_NOPOLICY 4
#define DST_NOHASH 8
#define DST_BALANCED 0x10
unsigned long lastuse;
unsigned long expires;
unsigned short header_len; /* more space at head required */
unsigned short trailer_len; /* space to reserve at tail */
u32 metrics[RTAX_MAX];
struct dst_entry *path;
unsigned long rate_last; /* rate limiting for ICMP */
unsigned long rate_tokens;
struct neighbour *neighbour;
struct hh_cache *hh;
struct xfrm_state *xfrm;
int (*input)(struct sk_buff*);
int (*output)(struct sk_buff*);
#ifdef CONFIG_NET_CLS_ROUTE
__u32 tclassid;
#endif
struct dst_ops *ops;
struct rcu_head rcu_head;
char info[0];
};
struct dst_ops
{
unsigned short family;
unsigned short protocol;
unsigned gc_thresh;
int (*gc)(void);
struct dst_entry * (*check)(struct dst_entry *, __u32 cookie);
void (*destroy)(struct dst_entry *);
void (*ifdown)(struct dst_entry *,
struct net_device *dev, int how);
struct dst_entry * (*negative_advice)(struct dst_entry *);
void (*link_failure)(struct sk_buff *);
void (*update_pmtu)(struct dst_entry *dst, u32 mtu);
int entry_size;
atomic_t entries;
kmem_cache_t *kmem_cachep;
};
#ifdef __KERNEL__
static inline u32
dst_metric(const struct dst_entry *dst, int metric)
{
return dst->metrics[metric-1];
}
static inline u32 dst_mtu(const struct dst_entry *dst)
{
u32 mtu = dst_metric(dst, RTAX_MTU);
/*
* Alexey put it here, so ask him about it :)
*/
barrier();
return mtu;
}
static inline u32
dst_allfrag(const struct dst_entry *dst)
{
int ret = dst_metric(dst, RTAX_FEATURES) & RTAX_FEATURE_ALLFRAG;
/* Yes, _exactly_. This is paranoia. */
barrier();
return ret;
}
static inline int
dst_metric_locked(struct dst_entry *dst, int metric)
{
return dst_metric(dst, RTAX_LOCK) & (1<<metric);
}
static inline void dst_hold(struct dst_entry * dst)
{
atomic_inc(&dst->__refcnt);
}
static inline
struct dst_entry * dst_clone(struct dst_entry * dst)
{
if (dst)
atomic_inc(&dst->__refcnt);
return dst;
}
static inline
void dst_release(struct dst_entry * dst)
{
if (dst) {
WARN_ON(atomic_read(&dst->__refcnt) < 1);
smp_mb__before_atomic_dec();
atomic_dec(&dst->__refcnt);
}
}
/* Children define the path of the packet through the
* Linux networking. Thus, destinations are stackable.
*/
static inline struct dst_entry *dst_pop(struct dst_entry *dst)
{
struct dst_entry *child = dst_clone(dst->child);
dst_release(dst);
return child;
}
extern void * dst_alloc(struct dst_ops * ops);
extern void __dst_free(struct dst_entry * dst);
extern struct dst_entry *dst_destroy(struct dst_entry * dst);
static inline void dst_free(struct dst_entry * dst)
{
if (dst->obsolete > 1)
return;
if (!atomic_read(&dst->__refcnt)) {
dst = dst_destroy(dst);
if (!dst)
return;
}
__dst_free(dst);
}
static inline void dst_rcu_free(struct rcu_head *head)
{
struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
dst_free(dst);
}
static inline void dst_confirm(struct dst_entry *dst)
{
if (dst)
neigh_confirm(dst->neighbour);
}
static inline void dst_negative_advice(struct dst_entry **dst_p)
{
struct dst_entry * dst = *dst_p;
if (dst && dst->ops->negative_advice)
*dst_p = dst->ops->negative_advice(dst);
}
static inline void dst_link_failure(struct sk_buff *skb)
{
struct dst_entry * dst = skb->dst;
if (dst && dst->ops && dst->ops->link_failure)
dst->ops->link_failure(skb);
}
static inline void dst_set_expires(struct dst_entry *dst, int timeout)
{
unsigned long expires = jiffies + timeout;
if (expires == 0)
expires = 1;
if (dst->expires == 0 || time_before(expires, dst->expires))
dst->expires = expires;
}
/* Output packet to network from transport. */
static inline int dst_output(struct sk_buff *skb)
{
int err;
for (;;) {
err = skb->dst->output(skb);
if (likely(err == 0))
return err;
if (unlikely(err != NET_XMIT_BYPASS))
return err;
}
}
/* Input packet from network to transport. */
static inline int dst_input(struct sk_buff *skb)
{
int err;
for (;;) {
err = skb->dst->input(skb);
if (likely(err == 0))
return err;
/* Oh, Jamal... Seems, I will not forgive you this mess. :-) */
if (unlikely(err != NET_XMIT_BYPASS))
return err;
}
}
static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
{
if (dst->obsolete)
dst = dst->ops->check(dst, cookie);
return dst;
}
extern void dst_init(void);
struct flowi;
#ifndef CONFIG_XFRM
static inline int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
struct sock *sk, int flags)
{
return 0;
}
#else
extern int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl,
struct sock *sk, int flags);
#endif
#endif
#endif /* _NET_DST_H */