dst.c

一个基于linux的TCP/IP协议栈的实现

/* dst.c
 * [e-mail]
 * 2006-11-13
 */

#include "dst.h"

#if RT_CACHE_DEBUG >= 2 
static atomic_t		mydst_total = ATOMIC_INIT(0);
#endif

static int mydst_discard_in(struct sk_buff *skb)
{
	kfree_skb(skb);
	return 0;
}

static int mydst_discard_out(struct sk_buff *skb)
{
	kfree_skb(skb);
	return 0;
}

void * mydst_alloc( struct dst_ops * ops )
{
	struct dst_entry * dst;

	if( ops->gc && atomic_read(&ops->entries) > ops->gc_thresh ){
		if( ops->gc() )
			return NULL;
	}
	dst = kmem_cache_alloc( ops->kmem_cachep, SLAB_ATOMIC );
	if( !dst )
		return NULL;
	memset( dst, 0, ops->entry_size );
	atomic_set(&dst->__refcnt, 0);
	dst->ops = ops;
	dst->lastuse = jiffies;
	dst->path = dst;
	dst->input = mydst_discard_in;
	dst->output = mydst_discard_out;
#if RT_CACHE_DEBUG >= 2 
	atomic_inc( &mydst_total );
#endif
	atomic_inc( &ops->entries );
	return dst;
}

EXPORT_SYMBOL_GPL( mydst_alloc );