net_init.c

GNU Mach 微内核源代码, 基于美国卡内基美隆大学的 Mach 研究项目

/* netdrv_init.c: Initialization for network devices. */
/*
	Written 1993,1994,1995 by Donald Becker.

	The author may be reached as [e-mail] or
	C/O Center of Excellence in Space Data and Information Sciences
		Code 930.5, Goddard Space Flight Center, Greenbelt MD 20771

	This file contains the initialization for the "pl14+" style ethernet
	drivers.  It should eventually replace most of drivers/net/Space.c.
	It's primary advantage is that it's able to allocate low-memory buffers.
	A secondary advantage is that the dangerous NE*000 netcards can reserve
	their I/O port region before the SCSI probes start.

	Modifications/additions by Bjorn Ekwall <[e-mail]>:
		ethdev_index[MAX_ETH_CARDS]
		register_netdev() / unregister_netdev()
		
	Modifications by Wolfgang Walter
		Use dev_close cleanly so we always shut things down tidily.
		
	Changed 29/10/95, Alan Cox to pass sockaddr's around for mac addresses.
	
	14/06/96 - Paul Gortmaker:	Add generic eth_change_mtu() function.

	August 12, 1996 - Lawrence V. Stefani: Added fddi_change_mtu() and
					  fddi_setup() functions.
	Sept. 10, 1996  - Lawrence V. Stefani: Increased hard_header_len to
					  include 3 pad bytes.
*/

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/malloc.h>
#include <linux/if_ether.h>
#include <linux/string.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/fddidevice.h>
#include <linux/trdevice.h>
#include <linux/if_arp.h>
#ifdef CONFIG_NET_ALIAS
#include <linux/net_alias.h>
#endif

/* The network devices currently exist only in the socket namespace, so these
   entries are unused.  The only ones that make sense are
    open	start the ethercard
    close	stop  the ethercard
    ioctl	To get statistics, perhaps set the interface port (AUI, BNC, etc.)
   One can also imagine getting raw packets using
    read & write
   but this is probably better handled by a raw packet socket.

   Given that almost all of these functions are handled in the current
   socket-based scheme, putting ethercard devices in /dev/ seems pointless.
   
   [Removed all support for /dev network devices. When someone adds
    streams then by magic we get them, but otherwise they are un-needed
	and a space waste]
*/

/* The list of used and available "eth" slots (for "eth0", "eth1", etc.) */
#define MAX_ETH_CARDS 16 /* same as the number if irq's in irq2dev[] */
static struct device *ethdev_index[MAX_ETH_CARDS];


/* Fill in the fields of the device structure with ethernet-generic values.

   If no device structure is passed, a new one is constructed, complete with
   a SIZEOF_PRIVATE private data area.

   If an empty string area is passed as dev->name, or a new structure is made,
   a new name string is constructed.  The passed string area should be 8 bytes
   long.
 */

struct device *
init_etherdev(struct device *dev, int sizeof_priv)
{
	int new_device = 0;
	int i;

	/* Use an existing correctly named device in Space.c:dev_base. */
	if (dev == NULL) {
		int alloc_size = sizeof(struct device) + sizeof("eth%d  ")
			+ sizeof_priv + 3;
		struct device *cur_dev;
		char pname[8];		/* Putative name for the device.  */

		for (i = 0; i < MAX_ETH_CARDS; ++i)
			if (ethdev_index[i] == NULL) {
				sprintf(pname, "eth%d", i);
				for (cur_dev = dev_base; cur_dev; cur_dev = cur_dev->next)
					if (strcmp(pname, cur_dev->name) == 0) {
						dev = cur_dev;
						dev->init = NULL;
						sizeof_priv = (sizeof_priv + 3) & ~3;
						dev->priv = sizeof_priv
							  ? kmalloc(sizeof_priv, GFP_KERNEL)
							  :	NULL;
						if (dev->priv) memset(dev->priv, 0, sizeof_priv);
						goto found;
					}
			}

		alloc_size &= ~3;		/* Round to dword boundary. */

		dev = (struct device *)kmalloc(alloc_size, GFP_KERNEL);
		memset(dev, 0, alloc_size);
		if (sizeof_priv)
			dev->priv = (void *) (dev + 1);
		dev->name = sizeof_priv + (char *)(dev + 1);
		new_device = 1;
	}

	found:						/* From the double loop above. */

	if (dev->name &&
		((dev->name[0] == '\0') || (dev->name[0] == ' '))) {
		for (i = 0; i < MAX_ETH_CARDS; ++i)
			if (ethdev_index[i] == NULL) {
				sprintf(dev->name, "eth%d", i);
				ethdev_index[i] = dev;
				break;
			}
	}

	ether_setup(dev); 	/* Hmmm, should this be called here? */
	
	if (new_device) {
		/* Append the device to the device queue. */
		struct device **old_devp = &dev_base;
		while ((*old_devp)->next)
			old_devp = & (*old_devp)->next;
		(*old_devp)->next = dev;
		dev->next = 0;
	}
	return dev;
}


static int eth_mac_addr(struct device *dev, void *p)
{
	struct sockaddr *addr=p;
	if(dev->start)
		return -EBUSY;
	memcpy(dev->dev_addr, addr->sa_data,dev->addr_len);
	return 0;
}

static int eth_change_mtu(struct device *dev, int new_mtu)
{
	if ((new_mtu < 68) || (new_mtu > 1500))
		return -EINVAL;
	dev->mtu = new_mtu;
	return 0;
}

#ifdef CONFIG_FDDI

static int fddi_change_mtu(struct device *dev, int new_mtu)
{
	if ((new_mtu < FDDI_K_SNAP_HLEN) || (new_mtu > FDDI_K_SNAP_DLEN))
		return(-EINVAL);
	dev->mtu = new_mtu;
	return(0);
}

#endif

void ether_setup(struct device *dev)
{
	int i;
	/* Fill in the fields of the device structure with ethernet-generic values.
	   This should be in a common file instead of per-driver.  */
	for (i = 0; i < DEV_NUMBUFFS; i++)
		skb_queue_head_init(&dev->buffs[i]);

	/* register boot-defined "eth" devices */
	if (dev->name && (strncmp(dev->name, "eth", 3) == 0)) {
		i = simple_strtoul(dev->name + 3, NULL, 0);
		if (ethdev_index[i] == NULL) {
			ethdev_index[i] = dev;
		}
		else if (dev != ethdev_index[i]) {
			/* Really shouldn't happen! */
#ifdef MACH
			panic("ether_setup: Ouch! Someone else took %s\n",
				dev->name);
#else
			printk("ether_setup: Ouch! Someone else took %s\n",
				dev->name);
#endif
		}
	}

#ifndef MACH
	dev->change_mtu		= eth_change_mtu;
	dev->hard_header	= eth_header;
	dev->rebuild_header 	= eth_rebuild_header;
	dev->set_mac_address 	= eth_mac_addr;
	dev->header_cache_bind 	= eth_header_cache_bind;
	dev->header_cache_update= eth_header_cache_update;
#endif
	
	dev->type		= ARPHRD_ETHER;
	dev->hard_header_len 	= ETH_HLEN;
	dev->mtu		= 1500; /* eth_mtu */
	dev->addr_len		= ETH_ALEN;
	dev->tx_queue_len	= 100;	/* Ethernet wants good queues */	
	
	memset(dev->broadcast,0xFF, ETH_ALEN);

	/* New-style flags. */
	dev->flags		= IFF_BROADCAST|IFF_MULTICAST;
	dev->family		= AF_INET;
	dev->pa_addr	= 0;
	dev->pa_brdaddr = 0;
	dev->pa_mask	= 0;
	dev->pa_alen	= 4;
}

#ifdef CONFIG_TR

void tr_setup(struct device *dev)
{
	int i;
	/* Fill in the fields of the device structure with ethernet-generic values.
	   This should be in a common file instead of per-driver.  */
	for (i = 0; i < DEV_NUMBUFFS; i++)
		skb_queue_head_init(&dev->buffs[i]);

	dev->hard_header	= tr_header;
	dev->rebuild_header 	= tr_rebuild_header;

	dev->type		= ARPHRD_IEEE802;
	dev->hard_header_len 	= TR_HLEN;
	dev->mtu		= 2000; /* bug in fragmenter...*/
	dev->addr_len		= TR_ALEN;
	dev->tx_queue_len	= 100;	/* Long queues on tr */
	
	memset(dev->broadcast,0xFF, TR_ALEN);

	/* New-style flags. */
	dev->flags		= IFF_BROADCAST;
	dev->family		= AF_INET;
	dev->pa_addr	= 0;
	dev->pa_brdaddr = 0;
	dev->pa_mask	= 0;
	dev->pa_alen	= 4;
}

#endif

#ifdef CONFIG_FDDI

void fddi_setup(struct device *dev)
	{
	int i;

	/*
	 * Fill in the fields of the device structure with FDDI-generic values.
	 * This should be in a common file instead of per-driver.
	 */
	for (i=0; i < DEV_NUMBUFFS; i++)
		skb_queue_head_init(&dev->buffs[i]);

	dev->change_mtu			= fddi_change_mtu;
	dev->hard_header		= fddi_header;
	dev->rebuild_header		= fddi_rebuild_header;

	dev->type				= ARPHRD_FDDI;
	dev->hard_header_len	= FDDI_K_SNAP_HLEN+3;	/* Assume 802.2 SNAP hdr len + 3 pad bytes */
	dev->mtu				= FDDI_K_SNAP_DLEN;		/* Assume max payload of 802.2 SNAP frame */
	dev->addr_len			= FDDI_K_ALEN;
	dev->tx_queue_len		= 100;	/* Long queues on FDDI */
	
	memset(dev->broadcast, 0xFF, FDDI_K_ALEN);

	/* New-style flags */
	dev->flags		= IFF_BROADCAST | IFF_MULTICAST;
	dev->family		= AF_INET;
	dev->pa_addr	= 0;
	dev->pa_brdaddr = 0;
	dev->pa_mask	= 0;
	dev->pa_alen	= 4;
	return;
	}

#endif

int ether_config(struct device *dev, struct ifmap *map)
{
	if (map->mem_start != (u_long)(-1))
		dev->mem_start = map->mem_start;
	if (map->mem_end != (u_long)(-1))
		dev->mem_end = map->mem_end;
	if (map->base_addr != (u_short)(-1))
		dev->base_addr = map->base_addr;
	if (map->irq != (u_char)(-1))
		dev->irq = map->irq;
	if (map->dma != (u_char)(-1))
		dev->dma = map->dma;
	if (map->port != (u_char)(-1))
		dev->if_port = map->port;
	return 0;
}

int register_netdev(struct device *dev)
{
	struct device *d = dev_base;
	unsigned long flags;
	int i=MAX_ETH_CARDS;

	save_flags(flags);
	cli();

	if (dev && dev->init) {
		if (dev->name &&
			((dev->name[0] == '\0') || (dev->name[0] == ' '))) {
			for (i = 0; i < MAX_ETH_CARDS; ++i)
				if (ethdev_index[i] == NULL) {
					sprintf(dev->name, "eth%d", i);
					printk("loading device '%s'...\n", dev->name);
					ethdev_index[i] = dev;
					break;
				}
		}

		sti();	/* device probes assume interrupts enabled */
		if (dev->init(dev) != 0) {
		    if (i < MAX_ETH_CARDS) ethdev_index[i] = NULL;
			restore_flags(flags);
			return -EIO;
		}
		cli();

		/* Add device to end of chain */
		if (dev_base) {
			while (d->next)
				d = d->next;
			d->next = dev;
		}
		else
			dev_base = dev;
		dev->next = NULL;
	}
	restore_flags(flags);
	return 0;
}

void unregister_netdev(struct device *dev)
{
	struct device *d = dev_base;
	unsigned long flags;
	int i;

	save_flags(flags);
	cli();

	if (dev == NULL) 
	{
		printk("was NULL\n");
		restore_flags(flags);
		return;
	}
	/* else */
	if (dev->start)
		printk("ERROR '%s' busy and not MOD_IN_USE.\n", dev->name);

	/*
	 * 	must jump over main_device+aliases
	 * 	avoid alias devices unregistration so that only
	 * 	net_alias module manages them
	 */
#ifdef CONFIG_NET_ALIAS		
	if (dev_base == dev)
		dev_base = net_alias_nextdev(dev);
	else
	{
		while(d && (net_alias_nextdev(d) != dev)) /* skip aliases */
			d = net_alias_nextdev(d);
	  
		if (d && (net_alias_nextdev(d) == dev))
		{
			/*
			 * 	Critical: Bypass by consider devices as blocks (maindev+aliases)
			 */
			net_alias_nextdev_set(d, net_alias_nextdev(dev)); 
		}
#else
	if (dev_base == dev)
		dev_base = dev->next;
	else 
	{
		while (d && (d->next != dev))
			d = d->next;
		
		if (d && (d->next == dev)) 
		{
			d->next = dev->next;
		}
#endif
		else 
		{
			printk("unregister_netdev: '%s' not found\n", dev->name);
			restore_flags(flags);
			return;
		}
	}
	for (i = 0; i < MAX_ETH_CARDS; ++i) 
	{
		if (ethdev_index[i] == dev) 
		{
			ethdev_index[i] = NULL;
			break;
		}
	}

	restore_flags(flags);

	/*
	 *	You can i.e use a interfaces in a route though it is not up.
	 *	We call close_dev (which is changed: it will down a device even if
	 *	dev->flags==0 (but it will not call dev->stop if IFF_UP
	 *	is not set).
	 *	This will call notifier_call_chain(&netdev_chain, NETDEV_DOWN, dev),
	 *	dev_mc_discard(dev), ....
	 */
	 
	dev_close(dev);
}


/*
 * Local variables:
 *  compile-command: "gcc -D__KERNEL__ -I/usr/src/linux/net/inet -Wall -Wstrict-prototypes -O6 -m486 -c net_init.c"
 *  version-control: t
 *  kept-new-versions: 5
 *  tab-width: 4
 * End:
 */