network.c

linux 内核源代码

	list_for_each(ele, &opened) {
		struct iss_net_private *lp;

		lp = list_entry(ele, struct iss_net_private, opened_list);

		if (!netif_running(lp->dev))
			break;

		spin_lock(&lp->lock);

		while ((err = iss_net_rx(lp->dev)) > 0)
			ret++;

		spin_unlock(&lp->lock);

		if (err < 0) {
			printk(KERN_ERR "Device '%s' read returned %d, "
			       "shutting it down\n", lp->dev->name, err);
			dev_close(lp->dev);
		} else {
			// FIXME reactivate_fd(lp->fd, ISS_ETH_IRQ);
		}
	}

	spin_unlock(&opened_lock);
	return ret;
}


static void iss_net_timer(unsigned long priv)
{
	struct iss_net_private* lp = (struct iss_net_private*) priv;

	spin_lock(&lp->lock);

	iss_net_poll();

	mod_timer(&lp->timer, jiffies + lp->timer_val);

	spin_unlock(&lp->lock);
}


static int iss_net_open(struct net_device *dev)
{
	struct iss_net_private *lp = dev->priv;
	char addr[sizeof "255.255.255.255\0"];
	int err;

	spin_lock(&lp->lock);

	if ((err = lp->tp.open(lp)) < 0)
		goto out;

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

	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 = iss_net_rx(dev)) > 0)
		;

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

	init_timer(&lp->timer);
	lp->timer_val = ISS_NET_TIMER_VALUE;
	lp->timer.data = (unsigned long) lp;
	lp->timer.function = iss_net_timer;
	mod_timer(&lp->timer, jiffies + lp->timer_val);

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

static int iss_net_close(struct net_device *dev)
{
	struct iss_net_private *lp = dev->priv;
printk("iss_net_close!\n");
	netif_stop_queue(dev);
	spin_lock(&lp->lock);

	spin_lock(&opened_lock);
	list_del(&opened);
	spin_unlock(&opened_lock);

	del_timer_sync(&lp->timer);

	lp->tp.close(lp);

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

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

	netif_stop_queue(dev);
	spin_lock_irqsave(&lp->lock, flags);

	len = lp->tp.write(lp, &skb);

	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 "iss_net_start_xmit: failed(%d)\n", len);
	}

	spin_unlock_irqrestore(&lp->lock, flags);

	dev_kfree_skb(skb);
	return 0;
}


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

static void iss_net_set_multicast_list(struct net_device *dev)
{
#if 0
	if (dev->flags & IFF_PROMISC)
		return;
	else if (dev->mc_count)
		dev->flags |= IFF_ALLMULTI;
	else
		dev->flags &= ~IFF_ALLMULTI;
#endif
}

static void iss_net_tx_timeout(struct net_device *dev)
{
#if 0
	dev->trans_start = jiffies;
	netif_wake_queue(dev);
#endif
}

static int iss_net_set_mac(struct net_device *dev, void *addr)
{
#if 0
	struct iss_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);
#endif

	return 0;
}

static int iss_net_change_mtu(struct net_device *dev, int new_mtu)
{
#if 0
	struct iss_net_private *lp = dev->priv;
	int err = 0;

	spin_lock(&lp->lock);

	// FIXME not needed new_mtu = transport_set_mtu(new_mtu, &lp->user);

	if (new_mtu < 0)
		err = new_mtu;
	else
		dev->mtu = new_mtu;

	spin_unlock(&lp->lock);
	return err;
#endif
	return -EINVAL;
}

void iss_net_user_timer_expire(unsigned long _conn)
{
}


static struct platform_driver iss_net_driver = {
	.driver = {
		.name  = DRIVER_NAME,
	},
};

static int driver_registered;

static int iss_net_configure(int index, char *init)
{
	struct net_device *dev;
	struct iss_net_private *lp;
	int err;

	if ((dev = alloc_etherdev(sizeof *lp)) == NULL) {
		printk(KERN_ERR "eth_configure: failed to allocate device\n");
		return 1;
	}

	/* Initialize private element. */

	lp = dev->priv;
	*lp = ((struct iss_net_private) {
		.device_list		= LIST_HEAD_INIT(lp->device_list),
		.opened_list		= LIST_HEAD_INIT(lp->opened_list),
		.lock			= SPIN_LOCK_UNLOCKED,
		.dev			= dev,
		.index			= index,
		//.fd                   = -1,
		.mac			= { 0xfe, 0xfd, 0x0, 0x0, 0x0, 0x0 },
		.have_mac		= 0,
		});

	/*
	 * Try all transport protocols.
	 * Note: more protocols can be added by adding '&& !X_init(lp, eth)'.
	 */

	if (!tuntap_probe(lp, index, init)) {
		printk("Invalid arguments. Skipping device!\n");
		goto errout;
	}

	printk(KERN_INFO "Netdevice %d ", index);
	if (lp->have_mac)
		printk("(%02x:%02x:%02x:%02x:%02x:%02x) ",
				lp->mac[0], lp->mac[1],
				lp->mac[2], lp->mac[3],
				lp->mac[4], lp->mac[5]);
	printk(": ");

	/* sysfs register */

	if (!driver_registered) {
		platform_driver_register(&iss_net_driver);
		driver_registered = 1;
	}

	spin_lock(&devices_lock);
	list_add(&lp->device_list, &devices);
	spin_unlock(&devices_lock);

	lp->pdev.id = index;
	lp->pdev.name = DRIVER_NAME;
	platform_device_register(&lp->pdev);
	SET_NETDEV_DEV(dev,&lp->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", index);

	dev->mtu = lp->mtu;
	dev->open = iss_net_open;
	dev->hard_start_xmit = iss_net_start_xmit;
	dev->stop = iss_net_close;
	dev->get_stats = iss_net_get_stats;
	dev->set_multicast_list = iss_net_set_multicast_list;
	dev->tx_timeout = iss_net_tx_timeout;
	dev->set_mac_address = iss_net_set_mac;
	dev->change_mtu = iss_net_change_mtu;
	dev->watchdog_timeo = (HZ >> 1);
	dev->irq = -1;

	rtnl_lock();
	err = register_netdevice(dev);
	rtnl_unlock();

	if (err) {
		printk("Error registering net device!\n");
		/* XXX: should we call ->remove() here? */
		free_netdev(dev);
		return 1;
	}

	init_timer(&lp->tl);
	lp->tl.function = iss_net_user_timer_expire;

#if 0
	if (lp->have_mac)
		set_ether_mac(dev, lp->mac);
#endif
	return 0;

errout:
	// FIXME: unregister; free, etc..
	return -EIO;

}

/* ------------------------------------------------------------------------- */

/* Filled in during early boot */

struct list_head eth_cmd_line = LIST_HEAD_INIT(eth_cmd_line);

struct iss_net_init {
	struct list_head list;
	char *init;		/* init string */
	int index;
};

/*
 * Parse the command line and look for 'ethX=...' fields, and register all
 * those fields. They will be later initialized in iss_net_init.
 */

#define ERR KERN_ERR "iss_net_setup: "

static int iss_net_setup(char *str)
{
	struct iss_net_private *device = NULL;
	struct iss_net_init *new;
	struct list_head *ele;
	char *end;
	int n;

	n = simple_strtoul(str, &end, 0);
	if (end == str) {
		printk(ERR "Failed to parse '%s'\n", str);
		return 1;
	}
	if (n < 0) {
		printk(ERR "Device %d is negative\n", n);
		return 1;
	}
	if (*(str = end) != '=') {
		printk(ERR "Expected '=' after device number\n");
		return 1;
	}

	spin_lock(&devices_lock);

	list_for_each(ele, &devices) {
		device = list_entry(ele, struct iss_net_private, device_list);
		if (device->index == n)
			break;
	}

	spin_unlock(&devices_lock);

	if (device && device->index == n) {
		printk(ERR "Device %d already configured\n", n);
		return 1;
	}

	if ((new = alloc_bootmem(sizeof new)) == NULL) {
		printk("Alloc_bootmem failed\n");
		return 1;
	}

	INIT_LIST_HEAD(&new->list);
	new->index = n;
	new->init = str + 1;

	list_add_tail(&new->list, &eth_cmd_line);
	return 1;
}

#undef ERR

__setup("eth=", iss_net_setup);

/*
 * Initialize all ISS Ethernet devices previously registered in iss_net_setup.
 */

static int iss_net_init(void)
{
	struct list_head *ele, *next;

	/* Walk through all Ethernet devices specified in the command line. */

	list_for_each_safe(ele, next, &eth_cmd_line) {
		struct iss_net_init *eth;
		eth = list_entry(ele, struct iss_net_init, list);
		iss_net_configure(eth->index, eth->init);
	}

	return 1;
}

module_init(iss_net_init);