311 строки
6.8 KiB
C
311 строки
6.8 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 <net/dst_ops.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 rcu_head rcu_head;
|
|
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
|
|
unsigned long expires;
|
|
|
|
unsigned short header_len; /* more space at head required */
|
|
unsigned short trailer_len; /* space to reserve at tail */
|
|
|
|
unsigned int rate_tokens;
|
|
unsigned long rate_last; /* rate limiting for ICMP */
|
|
|
|
struct dst_entry *path;
|
|
|
|
struct neighbour *neighbour;
|
|
struct hh_cache *hh;
|
|
#ifdef CONFIG_XFRM
|
|
struct xfrm_state *xfrm;
|
|
#else
|
|
void *__pad1;
|
|
#endif
|
|
int (*input)(struct sk_buff*);
|
|
int (*output)(struct sk_buff*);
|
|
|
|
struct dst_ops *ops;
|
|
|
|
u32 metrics[RTAX_MAX];
|
|
|
|
#ifdef CONFIG_NET_CLS_ROUTE
|
|
__u32 tclassid;
|
|
#else
|
|
__u32 __pad2;
|
|
#endif
|
|
|
|
|
|
/*
|
|
* Align __refcnt to a 64 bytes alignment
|
|
* (L1_CACHE_SIZE would be too much)
|
|
*/
|
|
#ifdef CONFIG_64BIT
|
|
long __pad_to_align_refcnt[2];
|
|
#else
|
|
long __pad_to_align_refcnt[1];
|
|
#endif
|
|
/*
|
|
* __refcnt wants to be on a different cache line from
|
|
* input/output/ops or performance tanks badly
|
|
*/
|
|
atomic_t __refcnt; /* client references */
|
|
int __use;
|
|
unsigned long lastuse;
|
|
union {
|
|
struct dst_entry *next;
|
|
struct rtable *rt_next;
|
|
struct rt6_info *rt6_next;
|
|
struct dn_route *dn_next;
|
|
};
|
|
};
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
static inline u32
|
|
dst_metric(const struct dst_entry *dst, int metric)
|
|
{
|
|
return dst->metrics[metric-1];
|
|
}
|
|
|
|
static inline u32
|
|
dst_feature(const struct dst_entry *dst, u32 feature)
|
|
{
|
|
return dst_metric(dst, RTAX_FEATURES) & feature;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
|
|
static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
|
|
{
|
|
return msecs_to_jiffies(dst_metric(dst, metric));
|
|
}
|
|
|
|
static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric,
|
|
unsigned long rtt)
|
|
{
|
|
dst->metrics[metric-1] = jiffies_to_msecs(rtt);
|
|
}
|
|
|
|
static inline u32
|
|
dst_allfrag(const struct dst_entry *dst)
|
|
{
|
|
int ret = dst_feature(dst, 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)
|
|
{
|
|
/*
|
|
* If your kernel compilation stops here, please check
|
|
* __pad_to_align_refcnt declaration in struct dst_entry
|
|
*/
|
|
BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
|
|
atomic_inc(&dst->__refcnt);
|
|
}
|
|
|
|
static inline void dst_use(struct dst_entry *dst, unsigned long time)
|
|
{
|
|
dst_hold(dst);
|
|
dst->__use++;
|
|
dst->lastuse = time;
|
|
}
|
|
|
|
static inline
|
|
struct dst_entry * dst_clone(struct dst_entry * dst)
|
|
{
|
|
if (dst)
|
|
atomic_inc(&dst->__refcnt);
|
|
return dst;
|
|
}
|
|
|
|
extern void dst_release(struct dst_entry *dst);
|
|
static inline void skb_dst_drop(struct sk_buff *skb)
|
|
{
|
|
if (skb->_skb_dst)
|
|
dst_release(skb_dst(skb));
|
|
skb->_skb_dst = 0UL;
|
|
}
|
|
|
|
/* 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 int dst_discard(struct sk_buff *skb);
|
|
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 sock *sk)
|
|
{
|
|
struct dst_entry * dst = *dst_p;
|
|
if (dst && dst->ops->negative_advice) {
|
|
*dst_p = dst->ops->negative_advice(dst);
|
|
|
|
if (dst != *dst_p) {
|
|
extern void sk_reset_txq(struct sock *sk);
|
|
|
|
sk_reset_txq(sk);
|
|
}
|
|
}
|
|
}
|
|
|
|
static inline void dst_link_failure(struct sk_buff *skb)
|
|
{
|
|
struct dst_entry *dst = skb_dst(skb);
|
|
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)
|
|
{
|
|
return skb_dst(skb)->output(skb);
|
|
}
|
|
|
|
/* Input packet from network to transport. */
|
|
static inline int dst_input(struct sk_buff *skb)
|
|
{
|
|
return skb_dst(skb)->input(skb);
|
|
}
|
|
|
|
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);
|
|
|
|
/* Flags for xfrm_lookup flags argument. */
|
|
enum {
|
|
XFRM_LOOKUP_WAIT = 1 << 0,
|
|
XFRM_LOOKUP_ICMP = 1 << 1,
|
|
};
|
|
|
|
struct flowi;
|
|
#ifndef CONFIG_XFRM
|
|
static inline int xfrm_lookup(struct net *net, struct dst_entry **dst_p,
|
|
struct flowi *fl, struct sock *sk, int flags)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int __xfrm_lookup(struct net *net, struct dst_entry **dst_p,
|
|
struct flowi *fl, struct sock *sk, int flags)
|
|
{
|
|
return 0;
|
|
}
|
|
#else
|
|
extern int xfrm_lookup(struct net *net, struct dst_entry **dst_p,
|
|
struct flowi *fl, struct sock *sk, int flags);
|
|
extern int __xfrm_lookup(struct net *net, struct dst_entry **dst_p,
|
|
struct flowi *fl, struct sock *sk, int flags);
|
|
#endif
|
|
#endif
|
|
|
|
#endif /* _NET_DST_H */
|