xref: /openbmc/linux/arch/um/drivers/net_kern.c (revision 12eb4683)
1 /*
2  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3  * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
4  * James Leu (jleu@mindspring.net).
5  * Copyright (C) 2001 by various other people who didn't put their name here.
6  * Licensed under the GPL.
7  */
8 
9 #include <linux/bootmem.h>
10 #include <linux/etherdevice.h>
11 #include <linux/ethtool.h>
12 #include <linux/inetdevice.h>
13 #include <linux/init.h>
14 #include <linux/list.h>
15 #include <linux/netdevice.h>
16 #include <linux/platform_device.h>
17 #include <linux/rtnetlink.h>
18 #include <linux/skbuff.h>
19 #include <linux/slab.h>
20 #include <linux/spinlock.h>
21 #include <init.h>
22 #include <irq_kern.h>
23 #include <irq_user.h>
24 #include "mconsole_kern.h"
25 #include <net_kern.h>
26 #include <net_user.h>
27 
28 #define DRIVER_NAME "uml-netdev"
29 
30 static DEFINE_SPINLOCK(opened_lock);
31 static LIST_HEAD(opened);
32 
33 /*
34  * The drop_skb is used when we can't allocate an skb.  The
35  * packet is read into drop_skb in order to get the data off the
36  * connection to the host.
37  * It is reallocated whenever a maximum packet size is seen which is
38  * larger than any seen before.  update_drop_skb is called from
39  * eth_configure when a new interface is added.
40  */
41 static DEFINE_SPINLOCK(drop_lock);
42 static struct sk_buff *drop_skb;
43 static int drop_max;
44 
45 static int update_drop_skb(int max)
46 {
47 	struct sk_buff *new;
48 	unsigned long flags;
49 	int err = 0;
50 
51 	spin_lock_irqsave(&drop_lock, flags);
52 
53 	if (max <= drop_max)
54 		goto out;
55 
56 	err = -ENOMEM;
57 	new = dev_alloc_skb(max);
58 	if (new == NULL)
59 		goto out;
60 
61 	skb_put(new, max);
62 
63 	kfree_skb(drop_skb);
64 	drop_skb = new;
65 	drop_max = max;
66 	err = 0;
67 out:
68 	spin_unlock_irqrestore(&drop_lock, flags);
69 
70 	return err;
71 }
72 
73 static int uml_net_rx(struct net_device *dev)
74 {
75 	struct uml_net_private *lp = netdev_priv(dev);
76 	int pkt_len;
77 	struct sk_buff *skb;
78 
79 	/* If we can't allocate memory, try again next round. */
80 	skb = dev_alloc_skb(lp->max_packet);
81 	if (skb == NULL) {
82 		drop_skb->dev = dev;
83 		/* Read a packet into drop_skb and don't do anything with it. */
84 		(*lp->read)(lp->fd, drop_skb, lp);
85 		dev->stats.rx_dropped++;
86 		return 0;
87 	}
88 
89 	skb->dev = dev;
90 	skb_put(skb, lp->max_packet);
91 	skb_reset_mac_header(skb);
92 	pkt_len = (*lp->read)(lp->fd, skb, lp);
93 
94 	if (pkt_len > 0) {
95 		skb_trim(skb, pkt_len);
96 		skb->protocol = (*lp->protocol)(skb);
97 
98 		dev->stats.rx_bytes += skb->len;
99 		dev->stats.rx_packets++;
100 		netif_rx(skb);
101 		return pkt_len;
102 	}
103 
104 	kfree_skb(skb);
105 	return pkt_len;
106 }
107 
108 static void uml_dev_close(struct work_struct *work)
109 {
110 	struct uml_net_private *lp =
111 		container_of(work, struct uml_net_private, work);
112 	dev_close(lp->dev);
113 }
114 
115 static irqreturn_t uml_net_interrupt(int irq, void *dev_id)
116 {
117 	struct net_device *dev = dev_id;
118 	struct uml_net_private *lp = netdev_priv(dev);
119 	int err;
120 
121 	if (!netif_running(dev))
122 		return IRQ_NONE;
123 
124 	spin_lock(&lp->lock);
125 	while ((err = uml_net_rx(dev)) > 0) ;
126 	if (err < 0) {
127 		printk(KERN_ERR
128 		       "Device '%s' read returned %d, shutting it down\n",
129 		       dev->name, err);
130 		/* dev_close can't be called in interrupt context, and takes
131 		 * again lp->lock.
132 		 * And dev_close() can be safely called multiple times on the
133 		 * same device, since it tests for (dev->flags & IFF_UP). So
134 		 * there's no harm in delaying the device shutdown.
135 		 * Furthermore, the workqueue will not re-enqueue an already
136 		 * enqueued work item. */
137 		schedule_work(&lp->work);
138 		goto out;
139 	}
140 	reactivate_fd(lp->fd, UM_ETH_IRQ);
141 
142 out:
143 	spin_unlock(&lp->lock);
144 	return IRQ_HANDLED;
145 }
146 
147 static int uml_net_open(struct net_device *dev)
148 {
149 	struct uml_net_private *lp = netdev_priv(dev);
150 	int err;
151 
152 	if (lp->fd >= 0) {
153 		err = -ENXIO;
154 		goto out;
155 	}
156 
157 	lp->fd = (*lp->open)(&lp->user);
158 	if (lp->fd < 0) {
159 		err = lp->fd;
160 		goto out;
161 	}
162 
163 	err = um_request_irq(dev->irq, lp->fd, IRQ_READ, uml_net_interrupt,
164 			     IRQF_SHARED, dev->name, dev);
165 	if (err != 0) {
166 		printk(KERN_ERR "uml_net_open: failed to get irq(%d)\n", err);
167 		err = -ENETUNREACH;
168 		goto out_close;
169 	}
170 
171 	lp->tl.data = (unsigned long) &lp->user;
172 	netif_start_queue(dev);
173 
174 	/* clear buffer - it can happen that the host side of the interface
175 	 * is full when we get here.  In this case, new data is never queued,
176 	 * SIGIOs never arrive, and the net never works.
177 	 */
178 	while ((err = uml_net_rx(dev)) > 0) ;
179 
180 	spin_lock(&opened_lock);
181 	list_add(&lp->list, &opened);
182 	spin_unlock(&opened_lock);
183 
184 	return 0;
185 out_close:
186 	if (lp->close != NULL) (*lp->close)(lp->fd, &lp->user);
187 	lp->fd = -1;
188 out:
189 	return err;
190 }
191 
192 static int uml_net_close(struct net_device *dev)
193 {
194 	struct uml_net_private *lp = netdev_priv(dev);
195 
196 	netif_stop_queue(dev);
197 
198 	um_free_irq(dev->irq, dev);
199 	if (lp->close != NULL)
200 		(*lp->close)(lp->fd, &lp->user);
201 	lp->fd = -1;
202 
203 	spin_lock(&opened_lock);
204 	list_del(&lp->list);
205 	spin_unlock(&opened_lock);
206 
207 	return 0;
208 }
209 
210 static int uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
211 {
212 	struct uml_net_private *lp = netdev_priv(dev);
213 	unsigned long flags;
214 	int len;
215 
216 	netif_stop_queue(dev);
217 
218 	spin_lock_irqsave(&lp->lock, flags);
219 
220 	len = (*lp->write)(lp->fd, skb, lp);
221 	skb_tx_timestamp(skb);
222 
223 	if (len == skb->len) {
224 		dev->stats.tx_packets++;
225 		dev->stats.tx_bytes += skb->len;
226 		dev->trans_start = jiffies;
227 		netif_start_queue(dev);
228 
229 		/* this is normally done in the interrupt when tx finishes */
230 		netif_wake_queue(dev);
231 	}
232 	else if (len == 0) {
233 		netif_start_queue(dev);
234 		dev->stats.tx_dropped++;
235 	}
236 	else {
237 		netif_start_queue(dev);
238 		printk(KERN_ERR "uml_net_start_xmit: failed(%d)\n", len);
239 	}
240 
241 	spin_unlock_irqrestore(&lp->lock, flags);
242 
243 	dev_kfree_skb(skb);
244 
245 	return NETDEV_TX_OK;
246 }
247 
248 static void uml_net_set_multicast_list(struct net_device *dev)
249 {
250 	return;
251 }
252 
253 static void uml_net_tx_timeout(struct net_device *dev)
254 {
255 	dev->trans_start = jiffies;
256 	netif_wake_queue(dev);
257 }
258 
259 static int uml_net_change_mtu(struct net_device *dev, int new_mtu)
260 {
261 	dev->mtu = new_mtu;
262 
263 	return 0;
264 }
265 
266 #ifdef CONFIG_NET_POLL_CONTROLLER
267 static void uml_net_poll_controller(struct net_device *dev)
268 {
269 	disable_irq(dev->irq);
270 	uml_net_interrupt(dev->irq, dev);
271 	enable_irq(dev->irq);
272 }
273 #endif
274 
275 static void uml_net_get_drvinfo(struct net_device *dev,
276 				struct ethtool_drvinfo *info)
277 {
278 	strlcpy(info->driver, DRIVER_NAME, sizeof(info->driver));
279 	strlcpy(info->version, "42", sizeof(info->version));
280 }
281 
282 static const struct ethtool_ops uml_net_ethtool_ops = {
283 	.get_drvinfo	= uml_net_get_drvinfo,
284 	.get_link	= ethtool_op_get_link,
285 	.get_ts_info	= ethtool_op_get_ts_info,
286 };
287 
288 static void uml_net_user_timer_expire(unsigned long _conn)
289 {
290 #ifdef undef
291 	struct connection *conn = (struct connection *)_conn;
292 
293 	dprintk(KERN_INFO "uml_net_user_timer_expire [%p]\n", conn);
294 	do_connect(conn);
295 #endif
296 }
297 
298 static void setup_etheraddr(struct net_device *dev, char *str)
299 {
300 	unsigned char *addr = dev->dev_addr;
301 	char *end;
302 	int i;
303 
304 	if (str == NULL)
305 		goto random;
306 
307 	for (i = 0; i < 6; i++) {
308 		addr[i] = simple_strtoul(str, &end, 16);
309 		if ((end == str) ||
310 		   ((*end != ':') && (*end != ',') && (*end != '\0'))) {
311 			printk(KERN_ERR
312 			       "setup_etheraddr: failed to parse '%s' "
313 			       "as an ethernet address\n", str);
314 			goto random;
315 		}
316 		str = end + 1;
317 	}
318 	if (is_multicast_ether_addr(addr)) {
319 		printk(KERN_ERR
320 		       "Attempt to assign a multicast ethernet address to a "
321 		       "device disallowed\n");
322 		goto random;
323 	}
324 	if (!is_valid_ether_addr(addr)) {
325 		printk(KERN_ERR
326 		       "Attempt to assign an invalid ethernet address to a "
327 		       "device disallowed\n");
328 		goto random;
329 	}
330 	if (!is_local_ether_addr(addr)) {
331 		printk(KERN_WARNING
332 		       "Warning: Assigning a globally valid ethernet "
333 		       "address to a device\n");
334 		printk(KERN_WARNING "You should set the 2nd rightmost bit in "
335 		       "the first byte of the MAC,\n");
336 		printk(KERN_WARNING "i.e. %02x:%02x:%02x:%02x:%02x:%02x\n",
337 		       addr[0] | 0x02, addr[1], addr[2], addr[3], addr[4],
338 		       addr[5]);
339 	}
340 	return;
341 
342 random:
343 	printk(KERN_INFO
344 	       "Choosing a random ethernet address for device %s\n", dev->name);
345 	eth_hw_addr_random(dev);
346 }
347 
348 static DEFINE_SPINLOCK(devices_lock);
349 static LIST_HEAD(devices);
350 
351 static struct platform_driver uml_net_driver = {
352 	.driver = {
353 		.name  = DRIVER_NAME,
354 	},
355 };
356 
357 static void net_device_release(struct device *dev)
358 {
359 	struct uml_net *device = dev_get_drvdata(dev);
360 	struct net_device *netdev = device->dev;
361 	struct uml_net_private *lp = netdev_priv(netdev);
362 
363 	if (lp->remove != NULL)
364 		(*lp->remove)(&lp->user);
365 	list_del(&device->list);
366 	kfree(device);
367 	free_netdev(netdev);
368 }
369 
370 static const struct net_device_ops uml_netdev_ops = {
371 	.ndo_open 		= uml_net_open,
372 	.ndo_stop 		= uml_net_close,
373 	.ndo_start_xmit 	= uml_net_start_xmit,
374 	.ndo_set_rx_mode	= uml_net_set_multicast_list,
375 	.ndo_tx_timeout 	= uml_net_tx_timeout,
376 	.ndo_set_mac_address	= eth_mac_addr,
377 	.ndo_change_mtu 	= uml_net_change_mtu,
378 	.ndo_validate_addr	= eth_validate_addr,
379 #ifdef CONFIG_NET_POLL_CONTROLLER
380 	.ndo_poll_controller = uml_net_poll_controller,
381 #endif
382 };
383 
384 /*
385  * Ensures that platform_driver_register is called only once by
386  * eth_configure.  Will be set in an initcall.
387  */
388 static int driver_registered;
389 
390 static void eth_configure(int n, void *init, char *mac,
391 			  struct transport *transport)
392 {
393 	struct uml_net *device;
394 	struct net_device *dev;
395 	struct uml_net_private *lp;
396 	int err, size;
397 
398 	size = transport->private_size + sizeof(struct uml_net_private);
399 
400 	device = kzalloc(sizeof(*device), GFP_KERNEL);
401 	if (device == NULL) {
402 		printk(KERN_ERR "eth_configure failed to allocate struct "
403 		       "uml_net\n");
404 		return;
405 	}
406 
407 	dev = alloc_etherdev(size);
408 	if (dev == NULL) {
409 		printk(KERN_ERR "eth_configure: failed to allocate struct "
410 		       "net_device for eth%d\n", n);
411 		goto out_free_device;
412 	}
413 
414 	INIT_LIST_HEAD(&device->list);
415 	device->index = n;
416 
417 	/* If this name ends up conflicting with an existing registered
418 	 * netdevice, that is OK, register_netdev{,ice}() will notice this
419 	 * and fail.
420 	 */
421 	snprintf(dev->name, sizeof(dev->name), "eth%d", n);
422 
423 	setup_etheraddr(dev, mac);
424 
425 	printk(KERN_INFO "Netdevice %d (%pM) : ", n, dev->dev_addr);
426 
427 	lp = netdev_priv(dev);
428 	/* This points to the transport private data. It's still clear, but we
429 	 * must memset it to 0 *now*. Let's help the drivers. */
430 	memset(lp, 0, size);
431 	INIT_WORK(&lp->work, uml_dev_close);
432 
433 	/* sysfs register */
434 	if (!driver_registered) {
435 		platform_driver_register(&uml_net_driver);
436 		driver_registered = 1;
437 	}
438 	device->pdev.id = n;
439 	device->pdev.name = DRIVER_NAME;
440 	device->pdev.dev.release = net_device_release;
441 	dev_set_drvdata(&device->pdev.dev, device);
442 	if (platform_device_register(&device->pdev))
443 		goto out_free_netdev;
444 	SET_NETDEV_DEV(dev,&device->pdev.dev);
445 
446 	device->dev = dev;
447 
448 	/*
449 	 * These just fill in a data structure, so there's no failure
450 	 * to be worried about.
451 	 */
452 	(*transport->kern->init)(dev, init);
453 
454 	*lp = ((struct uml_net_private)
455 		{ .list  		= LIST_HEAD_INIT(lp->list),
456 		  .dev 			= dev,
457 		  .fd 			= -1,
458 		  .mac 			= { 0xfe, 0xfd, 0x0, 0x0, 0x0, 0x0},
459 		  .max_packet		= transport->user->max_packet,
460 		  .protocol 		= transport->kern->protocol,
461 		  .open 		= transport->user->open,
462 		  .close 		= transport->user->close,
463 		  .remove 		= transport->user->remove,
464 		  .read 		= transport->kern->read,
465 		  .write 		= transport->kern->write,
466 		  .add_address 		= transport->user->add_address,
467 		  .delete_address  	= transport->user->delete_address });
468 
469 	init_timer(&lp->tl);
470 	spin_lock_init(&lp->lock);
471 	lp->tl.function = uml_net_user_timer_expire;
472 	memcpy(lp->mac, dev->dev_addr, sizeof(lp->mac));
473 
474 	if ((transport->user->init != NULL) &&
475 	    ((*transport->user->init)(&lp->user, dev) != 0))
476 		goto out_unregister;
477 
478 	dev->mtu = transport->user->mtu;
479 	dev->netdev_ops = &uml_netdev_ops;
480 	dev->ethtool_ops = &uml_net_ethtool_ops;
481 	dev->watchdog_timeo = (HZ >> 1);
482 	dev->irq = UM_ETH_IRQ;
483 
484 	err = update_drop_skb(lp->max_packet);
485 	if (err)
486 		goto out_undo_user_init;
487 
488 	rtnl_lock();
489 	err = register_netdevice(dev);
490 	rtnl_unlock();
491 	if (err)
492 		goto out_undo_user_init;
493 
494 	spin_lock(&devices_lock);
495 	list_add(&device->list, &devices);
496 	spin_unlock(&devices_lock);
497 
498 	return;
499 
500 out_undo_user_init:
501 	if (transport->user->remove != NULL)
502 		(*transport->user->remove)(&lp->user);
503 out_unregister:
504 	platform_device_unregister(&device->pdev);
505 	return; /* platform_device_unregister frees dev and device */
506 out_free_netdev:
507 	free_netdev(dev);
508 out_free_device:
509 	kfree(device);
510 }
511 
512 static struct uml_net *find_device(int n)
513 {
514 	struct uml_net *device;
515 	struct list_head *ele;
516 
517 	spin_lock(&devices_lock);
518 	list_for_each(ele, &devices) {
519 		device = list_entry(ele, struct uml_net, list);
520 		if (device->index == n)
521 			goto out;
522 	}
523 	device = NULL;
524  out:
525 	spin_unlock(&devices_lock);
526 	return device;
527 }
528 
529 static int eth_parse(char *str, int *index_out, char **str_out,
530 		     char **error_out)
531 {
532 	char *end;
533 	int n, err = -EINVAL;
534 
535 	n = simple_strtoul(str, &end, 0);
536 	if (end == str) {
537 		*error_out = "Bad device number";
538 		return err;
539 	}
540 
541 	str = end;
542 	if (*str != '=') {
543 		*error_out = "Expected '=' after device number";
544 		return err;
545 	}
546 
547 	str++;
548 	if (find_device(n)) {
549 		*error_out = "Device already configured";
550 		return err;
551 	}
552 
553 	*index_out = n;
554 	*str_out = str;
555 	return 0;
556 }
557 
558 struct eth_init {
559 	struct list_head list;
560 	char *init;
561 	int index;
562 };
563 
564 static DEFINE_SPINLOCK(transports_lock);
565 static LIST_HEAD(transports);
566 
567 /* Filled in during early boot */
568 static LIST_HEAD(eth_cmd_line);
569 
570 static int check_transport(struct transport *transport, char *eth, int n,
571 			   void **init_out, char **mac_out)
572 {
573 	int len;
574 
575 	len = strlen(transport->name);
576 	if (strncmp(eth, transport->name, len))
577 		return 0;
578 
579 	eth += len;
580 	if (*eth == ',')
581 		eth++;
582 	else if (*eth != '\0')
583 		return 0;
584 
585 	*init_out = kmalloc(transport->setup_size, GFP_KERNEL);
586 	if (*init_out == NULL)
587 		return 1;
588 
589 	if (!transport->setup(eth, mac_out, *init_out)) {
590 		kfree(*init_out);
591 		*init_out = NULL;
592 	}
593 	return 1;
594 }
595 
596 void register_transport(struct transport *new)
597 {
598 	struct list_head *ele, *next;
599 	struct eth_init *eth;
600 	void *init;
601 	char *mac = NULL;
602 	int match;
603 
604 	spin_lock(&transports_lock);
605 	BUG_ON(!list_empty(&new->list));
606 	list_add(&new->list, &transports);
607 	spin_unlock(&transports_lock);
608 
609 	list_for_each_safe(ele, next, &eth_cmd_line) {
610 		eth = list_entry(ele, struct eth_init, list);
611 		match = check_transport(new, eth->init, eth->index, &init,
612 					&mac);
613 		if (!match)
614 			continue;
615 		else if (init != NULL) {
616 			eth_configure(eth->index, init, mac, new);
617 			kfree(init);
618 		}
619 		list_del(&eth->list);
620 	}
621 }
622 
623 static int eth_setup_common(char *str, int index)
624 {
625 	struct list_head *ele;
626 	struct transport *transport;
627 	void *init;
628 	char *mac = NULL;
629 	int found = 0;
630 
631 	spin_lock(&transports_lock);
632 	list_for_each(ele, &transports) {
633 		transport = list_entry(ele, struct transport, list);
634 	        if (!check_transport(transport, str, index, &init, &mac))
635 			continue;
636 		if (init != NULL) {
637 			eth_configure(index, init, mac, transport);
638 			kfree(init);
639 		}
640 		found = 1;
641 		break;
642 	}
643 
644 	spin_unlock(&transports_lock);
645 	return found;
646 }
647 
648 static int __init eth_setup(char *str)
649 {
650 	struct eth_init *new;
651 	char *error;
652 	int n, err;
653 
654 	err = eth_parse(str, &n, &str, &error);
655 	if (err) {
656 		printk(KERN_ERR "eth_setup - Couldn't parse '%s' : %s\n",
657 		       str, error);
658 		return 1;
659 	}
660 
661 	new = alloc_bootmem(sizeof(*new));
662 	if (new == NULL) {
663 		printk(KERN_ERR "eth_init : alloc_bootmem failed\n");
664 		return 1;
665 	}
666 
667 	INIT_LIST_HEAD(&new->list);
668 	new->index = n;
669 	new->init = str;
670 
671 	list_add_tail(&new->list, &eth_cmd_line);
672 	return 1;
673 }
674 
675 __setup("eth", eth_setup);
676 __uml_help(eth_setup,
677 "eth[0-9]+=<transport>,<options>\n"
678 "    Configure a network device.\n\n"
679 );
680 
681 static int net_config(char *str, char **error_out)
682 {
683 	int n, err;
684 
685 	err = eth_parse(str, &n, &str, error_out);
686 	if (err)
687 		return err;
688 
689 	/* This string is broken up and the pieces used by the underlying
690 	 * driver.  So, it is freed only if eth_setup_common fails.
691 	 */
692 	str = kstrdup(str, GFP_KERNEL);
693 	if (str == NULL) {
694 	        *error_out = "net_config failed to strdup string";
695 		return -ENOMEM;
696 	}
697 	err = !eth_setup_common(str, n);
698 	if (err)
699 		kfree(str);
700 	return err;
701 }
702 
703 static int net_id(char **str, int *start_out, int *end_out)
704 {
705 	char *end;
706 	int n;
707 
708 	n = simple_strtoul(*str, &end, 0);
709 	if ((*end != '\0') || (end == *str))
710 		return -1;
711 
712 	*start_out = n;
713 	*end_out = n;
714 	*str = end;
715 	return n;
716 }
717 
718 static int net_remove(int n, char **error_out)
719 {
720 	struct uml_net *device;
721 	struct net_device *dev;
722 	struct uml_net_private *lp;
723 
724 	device = find_device(n);
725 	if (device == NULL)
726 		return -ENODEV;
727 
728 	dev = device->dev;
729 	lp = netdev_priv(dev);
730 	if (lp->fd > 0)
731 		return -EBUSY;
732 	unregister_netdev(dev);
733 	platform_device_unregister(&device->pdev);
734 
735 	return 0;
736 }
737 
738 static struct mc_device net_mc = {
739 	.list		= LIST_HEAD_INIT(net_mc.list),
740 	.name		= "eth",
741 	.config		= net_config,
742 	.get_config	= NULL,
743 	.id		= net_id,
744 	.remove		= net_remove,
745 };
746 
747 #ifdef CONFIG_INET
748 static int uml_inetaddr_event(struct notifier_block *this, unsigned long event,
749 			      void *ptr)
750 {
751 	struct in_ifaddr *ifa = ptr;
752 	struct net_device *dev = ifa->ifa_dev->dev;
753 	struct uml_net_private *lp;
754 	void (*proc)(unsigned char *, unsigned char *, void *);
755 	unsigned char addr_buf[4], netmask_buf[4];
756 
757 	if (dev->netdev_ops->ndo_open != uml_net_open)
758 		return NOTIFY_DONE;
759 
760 	lp = netdev_priv(dev);
761 
762 	proc = NULL;
763 	switch (event) {
764 	case NETDEV_UP:
765 		proc = lp->add_address;
766 		break;
767 	case NETDEV_DOWN:
768 		proc = lp->delete_address;
769 		break;
770 	}
771 	if (proc != NULL) {
772 		memcpy(addr_buf, &ifa->ifa_address, sizeof(addr_buf));
773 		memcpy(netmask_buf, &ifa->ifa_mask, sizeof(netmask_buf));
774 		(*proc)(addr_buf, netmask_buf, &lp->user);
775 	}
776 	return NOTIFY_DONE;
777 }
778 
779 /* uml_net_init shouldn't be called twice on two CPUs at the same time */
780 static struct notifier_block uml_inetaddr_notifier = {
781 	.notifier_call		= uml_inetaddr_event,
782 };
783 
784 static void inet_register(void)
785 {
786 	struct list_head *ele;
787 	struct uml_net_private *lp;
788 	struct in_device *ip;
789 	struct in_ifaddr *in;
790 
791 	register_inetaddr_notifier(&uml_inetaddr_notifier);
792 
793 	/* Devices may have been opened already, so the uml_inetaddr_notifier
794 	 * didn't get a chance to run for them.  This fakes it so that
795 	 * addresses which have already been set up get handled properly.
796 	 */
797 	spin_lock(&opened_lock);
798 	list_for_each(ele, &opened) {
799 		lp = list_entry(ele, struct uml_net_private, list);
800 		ip = lp->dev->ip_ptr;
801 		if (ip == NULL)
802 			continue;
803 		in = ip->ifa_list;
804 		while (in != NULL) {
805 			uml_inetaddr_event(NULL, NETDEV_UP, in);
806 			in = in->ifa_next;
807 		}
808 	}
809 	spin_unlock(&opened_lock);
810 }
811 #else
812 static inline void inet_register(void)
813 {
814 }
815 #endif
816 
817 static int uml_net_init(void)
818 {
819 	mconsole_register_dev(&net_mc);
820 	inet_register();
821 	return 0;
822 }
823 
824 __initcall(uml_net_init);
825 
826 static void close_devices(void)
827 {
828 	struct list_head *ele;
829 	struct uml_net_private *lp;
830 
831 	spin_lock(&opened_lock);
832 	list_for_each(ele, &opened) {
833 		lp = list_entry(ele, struct uml_net_private, list);
834 		um_free_irq(lp->dev->irq, lp->dev);
835 		if ((lp->close != NULL) && (lp->fd >= 0))
836 			(*lp->close)(lp->fd, &lp->user);
837 		if (lp->remove != NULL)
838 			(*lp->remove)(&lp->user);
839 	}
840 	spin_unlock(&opened_lock);
841 }
842 
843 __uml_exitcall(close_devices);
844 
845 void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *,
846 					void *),
847 		    void *arg)
848 {
849 	struct net_device *dev = d;
850 	struct in_device *ip = dev->ip_ptr;
851 	struct in_ifaddr *in;
852 	unsigned char address[4], netmask[4];
853 
854 	if (ip == NULL) return;
855 	in = ip->ifa_list;
856 	while (in != NULL) {
857 		memcpy(address, &in->ifa_address, sizeof(address));
858 		memcpy(netmask, &in->ifa_mask, sizeof(netmask));
859 		(*cb)(address, netmask, arg);
860 		in = in->ifa_next;
861 	}
862 }
863 
864 int dev_netmask(void *d, void *m)
865 {
866 	struct net_device *dev = d;
867 	struct in_device *ip = dev->ip_ptr;
868 	struct in_ifaddr *in;
869 	__be32 *mask_out = m;
870 
871 	if (ip == NULL)
872 		return 1;
873 
874 	in = ip->ifa_list;
875 	if (in == NULL)
876 		return 1;
877 
878 	*mask_out = in->ifa_mask;
879 	return 0;
880 }
881 
882 void *get_output_buffer(int *len_out)
883 {
884 	void *ret;
885 
886 	ret = (void *) __get_free_pages(GFP_KERNEL, 0);
887 	if (ret) *len_out = PAGE_SIZE;
888 	else *len_out = 0;
889 	return ret;
890 }
891 
892 void free_output_buffer(void *buffer)
893 {
894 	free_pages((unsigned long) buffer, 0);
895 }
896 
897 int tap_setup_common(char *str, char *type, char **dev_name, char **mac_out,
898 		     char **gate_addr)
899 {
900 	char *remain;
901 
902 	remain = split_if_spec(str, dev_name, mac_out, gate_addr, NULL);
903 	if (remain != NULL) {
904 		printk(KERN_ERR "tap_setup_common - Extra garbage on "
905 		       "specification : '%s'\n", remain);
906 		return 1;
907 	}
908 
909 	return 0;
910 }
911 
912 unsigned short eth_protocol(struct sk_buff *skb)
913 {
914 	return eth_type_trans(skb, skb->dev);
915 }
916