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/* Loopback "device" for pfinet
Copyright (C) 1996,98,2000 Free Software Foundation, Inc.
This file is part of the GNU Hurd.
The GNU Hurd is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2, or (at
your option) any later version.
The GNU Hurd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
#include "pfinet.h"
#include <netinet/in.h>
#include <arpa/inet.h>
#include <linux/socket.h>
#include <linux/net.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <linux/if_ether.h> /* For the statistics structure. */
#include <linux/if_arp.h> /* For ARPHRD_ETHER */
#define LOOPBACK_MTU (vm_page_size - 172)
/*
* The higher levels take care of making this non-reentrant (it's
* called with bh's disabled).
*/
static int loopback_xmit(struct sk_buff *skb, struct device *dev)
{
struct net_device_stats *stats = (struct net_device_stats *)dev->priv;
/*
* Take this out if the debug says its ok
*/
if (skb == NULL || dev == NULL)
printk(KERN_DEBUG "loopback fed NULL data - splat\n");
/*
* Optimise so buffers with skb->free=1 are not copied but
* instead are lobbed from tx queue to rx queue
*/
if(atomic_read(&skb->users) != 1)
{
struct sk_buff *skb2=skb;
skb=skb_clone(skb, GFP_ATOMIC); /* Clone the buffer */
if(skb==NULL) {
kfree_skb(skb2);
return 0;
}
kfree_skb(skb2);
}
else
skb_orphan(skb);
skb->protocol=eth_type_trans(skb,dev);
skb->dev=dev;
#ifndef LOOPBACK_MUST_CHECKSUM
skb->ip_summed = CHECKSUM_UNNECESSARY;
#endif
/*
* Calling netif_rx() requires locking net_bh_lock, which
* has already been done since this function is called by
* the net_bh worker thread.
*/
netif_rx(skb);
stats->rx_bytes+=skb->len;
stats->tx_bytes+=skb->len;
stats->rx_packets++;
stats->tx_packets++;
return(0);
}
static struct net_device_stats *get_stats(struct device *dev)
{
return (struct net_device_stats *)dev->priv;
}
static int loopback_open(struct device *dev)
{
dev->flags|=IFF_LOOPBACK;
return 0;
}
/* Initialize the rest of the LOOPBACK device. */
static int loopback_init(struct device *dev)
{
dev->mtu = LOOPBACK_MTU;
dev->tbusy = 0;
dev->hard_start_xmit = loopback_xmit;
dev->hard_header = eth_header;
dev->hard_header_cache = eth_header_cache;
dev->header_cache_update= eth_header_cache_update;
dev->hard_header_len = ETH_HLEN; /* 14 */
dev->addr_len = ETH_ALEN; /* 6 */
dev->tx_queue_len = 0;
dev->type = ARPHRD_LOOPBACK; /* 0x0001 */
dev->rebuild_header = eth_rebuild_header;
dev->open = loopback_open;
dev->flags = IFF_LOOPBACK;
dev->priv = kmalloc(sizeof(struct net_device_stats), GFP_KERNEL);
if (dev->priv == NULL)
return -ENOMEM;
memset(dev->priv, 0, sizeof(struct net_device_stats));
dev->get_stats = get_stats;
/*
* Fill in the generic fields of the device structure.
*/
dev_init_buffers(dev);
return(0);
}
struct device loopback_dev = { name: "lo", init: &loopback_init, };
/* It is important magic that this is the first thing on the list. */
struct device *dev_base = &loopback_dev;
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