linux/include/net/dst_ops.h
David S. Miller 6700c2709c net: Pass optional SKB and SK arguments to dst_ops->{update_pmtu,redirect}()
This will be used so that we can compose a full flow key.

Even though we have a route in this context, we need more.  In the
future the routes will be without destination address, source address,
etc. keying.  One ipv4 route will cover entire subnets, etc.

In this environment we have to have a way to possess persistent storage
for redirects and PMTU information.  This persistent storage will exist
in the FIB tables, and that's why we'll need to be able to rebuild a
full lookup flow key here.  Using that flow key will do a fib_lookup()
and create/update the persistent entry.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17 03:29:28 -07:00

74 lines
1.9 KiB
C

#ifndef _NET_DST_OPS_H
#define _NET_DST_OPS_H
#include <linux/types.h>
#include <linux/percpu_counter.h>
#include <linux/cache.h>
struct dst_entry;
struct kmem_cachep;
struct net_device;
struct sk_buff;
struct dst_ops {
unsigned short family;
__be16 protocol;
unsigned int gc_thresh;
int (*gc)(struct dst_ops *ops);
struct dst_entry * (*check)(struct dst_entry *, __u32 cookie);
unsigned int (*default_advmss)(const struct dst_entry *);
unsigned int (*mtu)(const struct dst_entry *);
u32 * (*cow_metrics)(struct dst_entry *, unsigned long);
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, struct sock *sk,
struct sk_buff *skb, u32 mtu);
void (*redirect)(struct dst_entry *dst, struct sock *sk,
struct sk_buff *skb);
int (*local_out)(struct sk_buff *skb);
struct neighbour * (*neigh_lookup)(const struct dst_entry *dst,
struct sk_buff *skb,
const void *daddr);
struct kmem_cache *kmem_cachep;
struct percpu_counter pcpuc_entries ____cacheline_aligned_in_smp;
};
static inline int dst_entries_get_fast(struct dst_ops *dst)
{
return percpu_counter_read_positive(&dst->pcpuc_entries);
}
static inline int dst_entries_get_slow(struct dst_ops *dst)
{
int res;
local_bh_disable();
res = percpu_counter_sum_positive(&dst->pcpuc_entries);
local_bh_enable();
return res;
}
static inline void dst_entries_add(struct dst_ops *dst, int val)
{
local_bh_disable();
percpu_counter_add(&dst->pcpuc_entries, val);
local_bh_enable();
}
static inline int dst_entries_init(struct dst_ops *dst)
{
return percpu_counter_init(&dst->pcpuc_entries, 0);
}
static inline void dst_entries_destroy(struct dst_ops *dst)
{
percpu_counter_destroy(&dst->pcpuc_entries);
}
#endif