net_kern.c

linux-2.6.15.6

/*
 * Copyright (C) 2001 Lennert Buytenhek ([e-mail]) and 
 * James Leu ([e-mail]).
 * Copyright (C) 2001 by various other people who didn't put their name here.
 * Licensed under the GPL.
 */

#include "linux/config.h"
#include "linux/kernel.h"
#include "linux/netdevice.h"
#include "linux/rtnetlink.h"
#include "linux/skbuff.h"
#include "linux/socket.h"
#include "linux/spinlock.h"
#include "linux/module.h"
#include "linux/init.h"
#include "linux/etherdevice.h"
#include "linux/list.h"
#include "linux/inetdevice.h"
#include "linux/ctype.h"
#include "linux/bootmem.h"
#include "linux/ethtool.h"
#include "linux/platform_device.h"
#include "asm/uaccess.h"
#include "user_util.h"
#include "kern_util.h"
#include "net_kern.h"
#include "net_user.h"
#include "mconsole_kern.h"
#include "init.h"
#include "irq_user.h"
#include "irq_kern.h"

#define DRIVER_NAME "uml-netdev"

static DEFINE_SPINLOCK(opened_lock);
LIST_HEAD(opened);

static int uml_net_rx(struct net_device *dev)
{
	struct uml_net_private *lp = dev->priv;
	int pkt_len;
	struct sk_buff *skb;

	/* If we can't allocate memory, try again next round. */
	skb = dev_alloc_skb(dev->mtu);
	if (skb == NULL) {
		lp->stats.rx_dropped++;
		return 0;
	}

	skb->dev = dev;
	skb_put(skb, dev->mtu);
	skb->mac.raw = skb->data;
	pkt_len = (*lp->read)(lp->fd, &skb, lp);

	if (pkt_len > 0) {
		skb_trim(skb, pkt_len);
		skb->protocol = (*lp->protocol)(skb);
		netif_rx(skb);

		lp->stats.rx_bytes += skb->len;
		lp->stats.rx_packets++;
		return pkt_len;
	}

	kfree_skb(skb);
	return pkt_len;
}

irqreturn_t uml_net_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct net_device *dev = dev_id;
	struct uml_net_private *lp = dev->priv;
	int err;

	if(!netif_running(dev))
		return(IRQ_NONE);

	spin_lock(&lp->lock);
	while((err = uml_net_rx(dev)) > 0) ;
	if(err < 0) {
		printk(KERN_ERR 
		       "Device '%s' read returned %d, shutting it down\n", 
		       dev->name, err);
		dev_close(dev);
		goto out;
	}
	reactivate_fd(lp->fd, UM_ETH_IRQ);

 out:
	spin_unlock(&lp->lock);
	return(IRQ_HANDLED);
}

static int uml_net_open(struct net_device *dev)
{
	struct uml_net_private *lp = dev->priv;
	int err;

	spin_lock(&lp->lock);

	if(lp->fd >= 0){
		err = -ENXIO;
		goto out;
	}

	if(!lp->have_mac){
 		dev_ip_addr(dev, &lp->mac[2]);
 		set_ether_mac(dev, lp->mac);
	}

	lp->fd = (*lp->open)(&lp->user);
	if(lp->fd < 0){
		err = lp->fd;
		goto out;
	}

	err = um_request_irq(dev->irq, lp->fd, IRQ_READ, uml_net_interrupt,
			     SA_INTERRUPT | SA_SHIRQ, dev->name, dev);
	if(err != 0){
		printk(KERN_ERR "uml_net_open: failed to get irq(%d)\n", err);
		if(lp->close != NULL) (*lp->close)(lp->fd, &lp->user);
		lp->fd = -1;
		err = -ENETUNREACH;
	}

	lp->tl.data = (unsigned long) &lp->user;
	netif_start_queue(dev);

	/* clear buffer - it can happen that the host side of the interface
	 * is full when we get here.  In this case, new data is never queued,
	 * SIGIOs never arrive, and the net never works.
	 */
	while((err = uml_net_rx(dev)) > 0) ;

 out:
	spin_unlock(&lp->lock);
	return(err);
}

static int uml_net_close(struct net_device *dev)
{
	struct uml_net_private *lp = dev->priv;
	
	netif_stop_queue(dev);
	spin_lock(&lp->lock);

	free_irq(dev->irq, dev);
	if(lp->close != NULL)
		(*lp->close)(lp->fd, &lp->user);
	lp->fd = -1;

	spin_unlock(&lp->lock);
	return 0;
}

static int uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct uml_net_private *lp = dev->priv;
	unsigned long flags;
	int len;

	netif_stop_queue(dev);

	spin_lock_irqsave(&lp->lock, flags);

	len = (*lp->write)(lp->fd, &skb, lp);

	if(len == skb->len) {
		lp->stats.tx_packets++;
		lp->stats.tx_bytes += skb->len;
		dev->trans_start = jiffies;
		netif_start_queue(dev);

		/* this is normally done in the interrupt when tx finishes */
		netif_wake_queue(dev);
	} 
	else if(len == 0){
		netif_start_queue(dev);
		lp->stats.tx_dropped++;
	}
	else {
		netif_start_queue(dev);
		printk(KERN_ERR "uml_net_start_xmit: failed(%d)\n", len);
	}

	spin_unlock_irqrestore(&lp->lock, flags);

	dev_kfree_skb(skb);

	return 0;
}

static struct net_device_stats *uml_net_get_stats(struct net_device *dev)
{
	struct uml_net_private *lp = dev->priv;
	return &lp->stats;
}

static void uml_net_set_multicast_list(struct net_device *dev)
{
	if (dev->flags & IFF_PROMISC) return;
	else if (dev->mc_count)	dev->flags |= IFF_ALLMULTI;
	else dev->flags &= ~IFF_ALLMULTI;
}

static void uml_net_tx_timeout(struct net_device *dev)
{
	dev->trans_start = jiffies;
	netif_wake_queue(dev);
}

static int uml_net_set_mac(struct net_device *dev, void *addr)
{
	struct uml_net_private *lp = dev->priv;
	struct sockaddr *hwaddr = addr;

	spin_lock(&lp->lock);
	memcpy(dev->dev_addr, hwaddr->sa_data, ETH_ALEN);
	spin_unlock(&lp->lock);

	return(0);
}

static int uml_net_change_mtu(struct net_device *dev, int new_mtu)
{
	struct uml_net_private *lp = dev->priv;
	int err = 0;

	spin_lock(&lp->lock);

	new_mtu = (*lp->set_mtu)(new_mtu, &lp->user);
	if(new_mtu < 0){
		err = new_mtu;
		goto out;
	}

	dev->mtu = new_mtu;

 out:
	spin_unlock(&lp->lock);
	return err;
}

static void uml_net_get_drvinfo(struct net_device *dev,
				struct ethtool_drvinfo *info)
{
	strcpy(info->driver, DRIVER_NAME);
	strcpy(info->version, "42");
}

static struct ethtool_ops uml_net_ethtool_ops = {
	.get_drvinfo	= uml_net_get_drvinfo,
	.get_link	= ethtool_op_get_link,
};

void uml_net_user_timer_expire(unsigned long _conn)
{
#ifdef undef
	struct connection *conn = (struct connection *)_conn;

	dprintk(KERN_INFO "uml_net_user_timer_expire [%p]\n", conn);
	do_connect(conn);
#endif
}

static DEFINE_SPINLOCK(devices_lock);
static struct list_head devices = LIST_HEAD_INIT(devices);

static struct platform_driver uml_net_driver = {
	.driver = {
		.name  = DRIVER_NAME,
	},
};
static int driver_registered;

static int eth_configure(int n, void *init, char *mac,
			 struct transport *transport)
{
	struct uml_net *device;
	struct net_device *dev;
	struct uml_net_private *lp;
	int save, err, size;

	size = transport->private_size + sizeof(struct uml_net_private) + 
		sizeof(((struct uml_net_private *) 0)->user);

	device = kmalloc(sizeof(*device), GFP_KERNEL);
	if (device == NULL) {
		printk(KERN_ERR "eth_configure failed to allocate uml_net\n");
		return(1);
	}

	memset(device, 0, sizeof(*device));
	INIT_LIST_HEAD(&device->list);
	device->index = n;

	spin_lock(&devices_lock);
	list_add(&device->list, &devices);
	spin_unlock(&devices_lock);

	if (setup_etheraddr(mac, device->mac))
		device->have_mac = 1;

	printk(KERN_INFO "Netdevice %d ", n);
	if (device->have_mac)
		printk("(%02x:%02x:%02x:%02x:%02x:%02x) ",
		       device->mac[0], device->mac[1],
		       device->mac[2], device->mac[3],
		       device->mac[4], device->mac[5]);
	printk(": ");
	dev = alloc_etherdev(size);
	if (dev == NULL) {
		printk(KERN_ERR "eth_configure: failed to allocate device\n");
		return 1;
	}

	/* sysfs register */
	if (!driver_registered) {
		platform_driver_register(&uml_net_driver);
		driver_registered = 1;
	}
	device->pdev.id = n;
	device->pdev.name = DRIVER_NAME;
	platform_device_register(&device->pdev);
	SET_NETDEV_DEV(dev,&device->pdev.dev);

	/* If this name ends up conflicting with an existing registered
	 * netdevice, that is OK, register_netdev{,ice}() will notice this
	 * and fail.
	 */
	snprintf(dev->name, sizeof(dev->name), "eth%d", n);
	device->dev = dev;

	(*transport->kern->init)(dev, init);

	dev->mtu = transport->user->max_packet;
	dev->open = uml_net_open;
	dev->hard_start_xmit = uml_net_start_xmit;
	dev->stop = uml_net_close;
	dev->get_stats = uml_net_get_stats;
	dev->set_multicast_list = uml_net_set_multicast_list;
	dev->tx_timeout = uml_net_tx_timeout;
	dev->set_mac_address = uml_net_set_mac;
	dev->change_mtu = uml_net_change_mtu;
	dev->ethtool_ops = &uml_net_ethtool_ops;
	dev->watchdog_timeo = (HZ >> 1);
	dev->irq = UM_ETH_IRQ;

	rtnl_lock();
	err = register_netdevice(dev);
	rtnl_unlock();
	if (err) {
		device->dev = NULL;
		/* XXX: should we call ->remove() here? */
		free_netdev(dev);
		return 1;
	}
	lp = dev->priv;

	/* lp.user is the first four bytes of the transport data, which
	 * has already been initialized.  This structure assignment will
	 * overwrite that, so we make sure that .user gets overwritten with
	 * what it already has.
	 */
	save = lp->user[0];
	*lp = ((struct uml_net_private)
		{ .list  		= LIST_HEAD_INIT(lp->list),
		  .dev 			= dev,
		  .fd 			= -1,
		  .mac 			= { 0xfe, 0xfd, 0x0, 0x0, 0x0, 0x0},
		  .have_mac 		= device->have_mac,
		  .protocol 		= transport->kern->protocol,
		  .open 		= transport->user->open,
		  .close 		= transport->user->close,
		  .remove 		= transport->user->remove,
		  .read 		= transport->kern->read,
		  .write 		= transport->kern->write,
		  .add_address 		= transport->user->add_address,
		  .delete_address  	= transport->user->delete_address,
		  .set_mtu 		= transport->user->set_mtu,
		  .user  		= { save } });

	init_timer(&lp->tl);
	spin_lock_init(&lp->lock);
	lp->tl.function = uml_net_user_timer_expire;
	if (lp->have_mac)
		memcpy(lp->mac, device->mac, sizeof(lp->mac));

	if (transport->user->init) 
		(*transport->user->init)(&lp->user, dev);

	if (device->have_mac)
		set_ether_mac(dev, device->mac);

	spin_lock(&opened_lock);
	list_add(&lp->list, &opened);
	spin_unlock(&opened_lock);

	return(0);
}

static struct uml_net *find_device(int n)
{
	struct uml_net *device;
	struct list_head *ele;

	spin_lock(&devices_lock);
	list_for_each(ele, &devices){
		device = list_entry(ele, struct uml_net, list);
		if(device->index == n)
			goto out;
	}
	device = NULL;
 out:
	spin_unlock(&devices_lock);
	return(device);
}

static int eth_parse(char *str, int *index_out, char **str_out)
{
	char *end;
	int n;

	n = simple_strtoul(str, &end, 0);
	if(end == str){
		printk(KERN_ERR "eth_setup: Failed to parse '%s'\n", str);
		return(1);
	}
	if(n < 0){
		printk(KERN_ERR "eth_setup: device %d is negative\n", n);
		return(1);
	}
	str = end;