xref: /openbmc/linux/arch/um/drivers/net_kern.c (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
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/spinlock.h>
20 #include "init.h"
21 #include "irq_kern.h"
22 #include "irq_user.h"
23 #include "mconsole_kern.h"
24 #include "net_kern.h"
25 #include "net_user.h"
26 
27 static inline void set_ether_mac(struct net_device *dev, unsigned char *addr)
28 {
29 	memcpy(dev->dev_addr, addr, ETH_ALEN);
30 }
31 
32 #define DRIVER_NAME "uml-netdev"
33 
34 static DEFINE_SPINLOCK(opened_lock);
35 static LIST_HEAD(opened);
36 
37 /*
38  * The drop_skb is used when we can't allocate an skb.  The
39  * packet is read into drop_skb in order to get the data off the
40  * connection to the host.
41  * It is reallocated whenever a maximum packet size is seen which is
42  * larger than any seen before.  update_drop_skb is called from
43  * eth_configure when a new interface is added.
44  */
45 static DEFINE_SPINLOCK(drop_lock);
46 static struct sk_buff *drop_skb;
47 static int drop_max;
48 
49 static int update_drop_skb(int max)
50 {
51 	struct sk_buff *new;
52 	unsigned long flags;
53 	int err = 0;
54 
55 	spin_lock_irqsave(&drop_lock, flags);
56 
57 	if (max <= drop_max)
58 		goto out;
59 
60 	err = -ENOMEM;
61 	new = dev_alloc_skb(max);
62 	if (new == NULL)
63 		goto out;
64 
65 	skb_put(new, max);
66 
67 	kfree_skb(drop_skb);
68 	drop_skb = new;
69 	drop_max = max;
70 	err = 0;
71 out:
72 	spin_unlock_irqrestore(&drop_lock, flags);
73 
74 	return err;
75 }
76 
77 static int uml_net_rx(struct net_device *dev)
78 {
79 	struct uml_net_private *lp = dev->priv;
80 	int pkt_len;
81 	struct sk_buff *skb;
82 
83 	/* If we can't allocate memory, try again next round. */
84 	skb = dev_alloc_skb(lp->max_packet);
85 	if (skb == NULL) {
86 		drop_skb->dev = dev;
87 		/* Read a packet into drop_skb and don't do anything with it. */
88 		(*lp->read)(lp->fd, drop_skb, lp);
89 		lp->stats.rx_dropped++;
90 		return 0;
91 	}
92 
93 	skb->dev = dev;
94 	skb_put(skb, lp->max_packet);
95 	skb_reset_mac_header(skb);
96 	pkt_len = (*lp->read)(lp->fd, skb, lp);
97 
98 	if (pkt_len > 0) {
99 		skb_trim(skb, pkt_len);
100 		skb->protocol = (*lp->protocol)(skb);
101 
102 		lp->stats.rx_bytes += skb->len;
103 		lp->stats.rx_packets++;
104 		netif_rx(skb);
105 		return pkt_len;
106 	}
107 
108 	kfree_skb(skb);
109 	return pkt_len;
110 }
111 
112 static void uml_dev_close(struct work_struct *work)
113 {
114 	struct uml_net_private *lp =
115 		container_of(work, struct uml_net_private, work);
116 	dev_close(lp->dev);
117 }
118 
119 static irqreturn_t uml_net_interrupt(int irq, void *dev_id)
120 {
121 	struct net_device *dev = dev_id;
122 	struct uml_net_private *lp = dev->priv;
123 	int err;
124 
125 	if (!netif_running(dev))
126 		return IRQ_NONE;
127 
128 	spin_lock(&lp->lock);
129 	while ((err = uml_net_rx(dev)) > 0) ;
130 	if (err < 0) {
131 		printk(KERN_ERR
132 		       "Device '%s' read returned %d, shutting it down\n",
133 		       dev->name, err);
134 		/* dev_close can't be called in interrupt context, and takes
135 		 * again lp->lock.
136 		 * And dev_close() can be safely called multiple times on the
137 		 * same device, since it tests for (dev->flags & IFF_UP). So
138 		 * there's no harm in delaying the device shutdown.
139 		 * Furthermore, the workqueue will not re-enqueue an already
140 		 * enqueued work item. */
141 		schedule_work(&lp->work);
142 		goto out;
143 	}
144 	reactivate_fd(lp->fd, UM_ETH_IRQ);
145 
146 out:
147 	spin_unlock(&lp->lock);
148 	return IRQ_HANDLED;
149 }
150 
151 static int uml_net_open(struct net_device *dev)
152 {
153 	struct uml_net_private *lp = dev->priv;
154 	int err;
155 
156 	if (lp->fd >= 0) {
157 		err = -ENXIO;
158 		goto out;
159 	}
160 
161 	lp->fd = (*lp->open)(&lp->user);
162 	if (lp->fd < 0) {
163 		err = lp->fd;
164 		goto out;
165 	}
166 
167 	err = um_request_irq(dev->irq, lp->fd, IRQ_READ, uml_net_interrupt,
168 			     IRQF_DISABLED | IRQF_SHARED, dev->name, dev);
169 	if (err != 0) {
170 		printk(KERN_ERR "uml_net_open: failed to get irq(%d)\n", err);
171 		err = -ENETUNREACH;
172 		goto out_close;
173 	}
174 
175 	lp->tl.data = (unsigned long) &lp->user;
176 	netif_start_queue(dev);
177 
178 	/* clear buffer - it can happen that the host side of the interface
179 	 * is full when we get here.  In this case, new data is never queued,
180 	 * SIGIOs never arrive, and the net never works.
181 	 */
182 	while ((err = uml_net_rx(dev)) > 0) ;
183 
184 	spin_lock(&opened_lock);
185 	list_add(&lp->list, &opened);
186 	spin_unlock(&opened_lock);
187 
188 	return 0;
189 out_close:
190 	if (lp->close != NULL) (*lp->close)(lp->fd, &lp->user);
191 	lp->fd = -1;
192 out:
193 	return err;
194 }
195 
196 static int uml_net_close(struct net_device *dev)
197 {
198 	struct uml_net_private *lp = dev->priv;
199 
200 	netif_stop_queue(dev);
201 
202 	free_irq(dev->irq, dev);
203 	if (lp->close != NULL)
204 		(*lp->close)(lp->fd, &lp->user);
205 	lp->fd = -1;
206 
207 	spin_lock(&opened_lock);
208 	list_del(&lp->list);
209 	spin_unlock(&opened_lock);
210 
211 	return 0;
212 }
213 
214 static int uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
215 {
216 	struct uml_net_private *lp = dev->priv;
217 	unsigned long flags;
218 	int len;
219 
220 	netif_stop_queue(dev);
221 
222 	spin_lock_irqsave(&lp->lock, flags);
223 
224 	len = (*lp->write)(lp->fd, skb, lp);
225 
226 	if (len == skb->len) {
227 		lp->stats.tx_packets++;
228 		lp->stats.tx_bytes += skb->len;
229 		dev->trans_start = jiffies;
230 		netif_start_queue(dev);
231 
232 		/* this is normally done in the interrupt when tx finishes */
233 		netif_wake_queue(dev);
234 	}
235 	else if (len == 0) {
236 		netif_start_queue(dev);
237 		lp->stats.tx_dropped++;
238 	}
239 	else {
240 		netif_start_queue(dev);
241 		printk(KERN_ERR "uml_net_start_xmit: failed(%d)\n", len);
242 	}
243 
244 	spin_unlock_irqrestore(&lp->lock, flags);
245 
246 	dev_kfree_skb(skb);
247 
248 	return 0;
249 }
250 
251 static struct net_device_stats *uml_net_get_stats(struct net_device *dev)
252 {
253 	struct uml_net_private *lp = dev->priv;
254 	return &lp->stats;
255 }
256 
257 static void uml_net_set_multicast_list(struct net_device *dev)
258 {
259 	return;
260 }
261 
262 static void uml_net_tx_timeout(struct net_device *dev)
263 {
264 	dev->trans_start = jiffies;
265 	netif_wake_queue(dev);
266 }
267 
268 static int uml_net_set_mac(struct net_device *dev, void *addr)
269 {
270 	struct uml_net_private *lp = dev->priv;
271 	struct sockaddr *hwaddr = addr;
272 
273 	spin_lock_irq(&lp->lock);
274 	set_ether_mac(dev, hwaddr->sa_data);
275 	spin_unlock_irq(&lp->lock);
276 
277 	return 0;
278 }
279 
280 static int uml_net_change_mtu(struct net_device *dev, int new_mtu)
281 {
282 	dev->mtu = new_mtu;
283 
284 	return 0;
285 }
286 
287 static void uml_net_get_drvinfo(struct net_device *dev,
288 				struct ethtool_drvinfo *info)
289 {
290 	strcpy(info->driver, DRIVER_NAME);
291 	strcpy(info->version, "42");
292 }
293 
294 static struct ethtool_ops uml_net_ethtool_ops = {
295 	.get_drvinfo	= uml_net_get_drvinfo,
296 	.get_link	= ethtool_op_get_link,
297 };
298 
299 static void uml_net_user_timer_expire(unsigned long _conn)
300 {
301 #ifdef undef
302 	struct connection *conn = (struct connection *)_conn;
303 
304 	dprintk(KERN_INFO "uml_net_user_timer_expire [%p]\n", conn);
305 	do_connect(conn);
306 #endif
307 }
308 
309 static void setup_etheraddr(char *str, unsigned char *addr, char *name)
310 {
311 	char *end;
312 	int i;
313 
314 	if (str == NULL)
315 		goto random;
316 
317 	for (i = 0; i < 6; i++) {
318 		addr[i] = simple_strtoul(str, &end, 16);
319 		if ((end == str) ||
320 		   ((*end != ':') && (*end != ',') && (*end != '\0'))) {
321 			printk(KERN_ERR
322 			       "setup_etheraddr: failed to parse '%s' "
323 			       "as an ethernet address\n", str);
324 			goto random;
325 		}
326 		str = end + 1;
327 	}
328 	if (is_multicast_ether_addr(addr)) {
329 		printk(KERN_ERR
330 		       "Attempt to assign a multicast ethernet address to a "
331 		       "device disallowed\n");
332 		goto random;
333 	}
334 	if (!is_valid_ether_addr(addr)) {
335 		printk(KERN_ERR
336 		       "Attempt to assign an invalid ethernet address to a "
337 		       "device disallowed\n");
338 		goto random;
339 	}
340 	if (!is_local_ether_addr(addr)) {
341 		printk(KERN_WARNING
342 		       "Warning: Assigning a globally valid ethernet "
343 		       "address to a device\n");
344 		printk(KERN_WARNING "You should set the 2nd rightmost bit in "
345 		       "the first byte of the MAC,\n");
346 		printk(KERN_WARNING "i.e. %02x:%02x:%02x:%02x:%02x:%02x\n",
347 		       addr[0] | 0x02, addr[1], addr[2], addr[3], addr[4],
348 		       addr[5]);
349 	}
350 	return;
351 
352 random:
353 	printk(KERN_INFO
354 	       "Choosing a random ethernet address for device %s\n", name);
355 	random_ether_addr(addr);
356 }
357 
358 static DEFINE_SPINLOCK(devices_lock);
359 static LIST_HEAD(devices);
360 
361 static struct platform_driver uml_net_driver = {
362 	.driver = {
363 		.name  = DRIVER_NAME,
364 	},
365 };
366 
367 static void net_device_release(struct device *dev)
368 {
369 	struct uml_net *device = dev->driver_data;
370 	struct net_device *netdev = device->dev;
371 	struct uml_net_private *lp = netdev->priv;
372 
373 	if (lp->remove != NULL)
374 		(*lp->remove)(&lp->user);
375 	list_del(&device->list);
376 	kfree(device);
377 	free_netdev(netdev);
378 }
379 
380 /*
381  * Ensures that platform_driver_register is called only once by
382  * eth_configure.  Will be set in an initcall.
383  */
384 static int driver_registered;
385 
386 static void eth_configure(int n, void *init, char *mac,
387 			  struct transport *transport)
388 {
389 	struct uml_net *device;
390 	struct net_device *dev;
391 	struct uml_net_private *lp;
392 	int err, size;
393 
394 	size = transport->private_size + sizeof(struct uml_net_private);
395 
396 	device = kzalloc(sizeof(*device), GFP_KERNEL);
397 	if (device == NULL) {
398 		printk(KERN_ERR "eth_configure failed to allocate struct "
399 		       "uml_net\n");
400 		return;
401 	}
402 
403 	dev = alloc_etherdev(size);
404 	if (dev == NULL) {
405 		printk(KERN_ERR "eth_configure: failed to allocate struct "
406 		       "net_device for eth%d\n", n);
407 		goto out_free_device;
408 	}
409 
410 	INIT_LIST_HEAD(&device->list);
411 	device->index = n;
412 
413 	/* If this name ends up conflicting with an existing registered
414 	 * netdevice, that is OK, register_netdev{,ice}() will notice this
415 	 * and fail.
416 	 */
417 	snprintf(dev->name, sizeof(dev->name), "eth%d", n);
418 
419 	setup_etheraddr(mac, device->mac, dev->name);
420 
421 	printk(KERN_INFO "Netdevice %d ", n);
422 	printk("(%02x:%02x:%02x:%02x:%02x:%02x) ",
423 	       device->mac[0], device->mac[1],
424 	       device->mac[2], device->mac[3],
425 	       device->mac[4], device->mac[5]);
426 	printk(": ");
427 
428 	lp = dev->priv;
429 	/* This points to the transport private data. It's still clear, but we
430 	 * must memset it to 0 *now*. Let's help the drivers. */
431 	memset(lp, 0, size);
432 	INIT_WORK(&lp->work, uml_dev_close);
433 
434 	/* sysfs register */
435 	if (!driver_registered) {
436 		platform_driver_register(&uml_net_driver);
437 		driver_registered = 1;
438 	}
439 	device->pdev.id = n;
440 	device->pdev.name = DRIVER_NAME;
441 	device->pdev.dev.release = net_device_release;
442 	device->pdev.dev.driver_data = device;
443 	if (platform_device_register(&device->pdev))
444 		goto out_free_netdev;
445 	SET_NETDEV_DEV(dev,&device->pdev.dev);
446 
447 	device->dev = dev;
448 
449 	/*
450 	 * These just fill in a data structure, so there's no failure
451 	 * to be worried about.
452 	 */
453 	(*transport->kern->init)(dev, init);
454 
455 	*lp = ((struct uml_net_private)
456 		{ .list  		= LIST_HEAD_INIT(lp->list),
457 		  .dev 			= dev,
458 		  .fd 			= -1,
459 		  .mac 			= { 0xfe, 0xfd, 0x0, 0x0, 0x0, 0x0},
460 		  .max_packet		= transport->user->max_packet,
461 		  .protocol 		= transport->kern->protocol,
462 		  .open 		= transport->user->open,
463 		  .close 		= transport->user->close,
464 		  .remove 		= transport->user->remove,
465 		  .read 		= transport->kern->read,
466 		  .write 		= transport->kern->write,
467 		  .add_address 		= transport->user->add_address,
468 		  .delete_address  	= transport->user->delete_address });
469 
470 	init_timer(&lp->tl);
471 	spin_lock_init(&lp->lock);
472 	lp->tl.function = uml_net_user_timer_expire;
473 	memcpy(lp->mac, device->mac, sizeof(lp->mac));
474 
475 	if ((transport->user->init != NULL) &&
476 	    ((*transport->user->init)(&lp->user, dev) != 0))
477 		goto out_unregister;
478 
479 	set_ether_mac(dev, device->mac);
480 	dev->mtu = transport->user->mtu;
481 	dev->open = uml_net_open;
482 	dev->hard_start_xmit = uml_net_start_xmit;
483 	dev->stop = uml_net_close;
484 	dev->get_stats = uml_net_get_stats;
485 	dev->set_multicast_list = uml_net_set_multicast_list;
486 	dev->tx_timeout = uml_net_tx_timeout;
487 	dev->set_mac_address = uml_net_set_mac;
488 	dev->change_mtu = uml_net_change_mtu;
489 	dev->ethtool_ops = &uml_net_ethtool_ops;
490 	dev->watchdog_timeo = (HZ >> 1);
491 	dev->irq = UM_ETH_IRQ;
492 
493 	err = update_drop_skb(lp->max_packet);
494 	if (err)
495 		goto out_undo_user_init;
496 
497 	rtnl_lock();
498 	err = register_netdevice(dev);
499 	rtnl_unlock();
500 	if (err)
501 		goto out_undo_user_init;
502 
503 	spin_lock(&devices_lock);
504 	list_add(&device->list, &devices);
505 	spin_unlock(&devices_lock);
506 
507 	return;
508 
509 out_undo_user_init:
510 	if (transport->user->remove != NULL)
511 		(*transport->user->remove)(&lp->user);
512 out_unregister:
513 	platform_device_unregister(&device->pdev);
514 	return; /* platform_device_unregister frees dev and device */
515 out_free_netdev:
516 	free_netdev(dev);
517 out_free_device:
518 	kfree(device);
519 }
520 
521 static struct uml_net *find_device(int n)
522 {
523 	struct uml_net *device;
524 	struct list_head *ele;
525 
526 	spin_lock(&devices_lock);
527 	list_for_each(ele, &devices) {
528 		device = list_entry(ele, struct uml_net, list);
529 		if (device->index == n)
530 			goto out;
531 	}
532 	device = NULL;
533  out:
534 	spin_unlock(&devices_lock);
535 	return device;
536 }
537 
538 static int eth_parse(char *str, int *index_out, char **str_out,
539 		     char **error_out)
540 {
541 	char *end;
542 	int n, err = -EINVAL;;
543 
544 	n = simple_strtoul(str, &end, 0);
545 	if (end == str) {
546 		*error_out = "Bad device number";
547 		return err;
548 	}
549 
550 	str = end;
551 	if (*str != '=') {
552 		*error_out = "Expected '=' after device number";
553 		return err;
554 	}
555 
556 	str++;
557 	if (find_device(n)) {
558 		*error_out = "Device already configured";
559 		return err;
560 	}
561 
562 	*index_out = n;
563 	*str_out = str;
564 	return 0;
565 }
566 
567 struct eth_init {
568 	struct list_head list;
569 	char *init;
570 	int index;
571 };
572 
573 static DEFINE_SPINLOCK(transports_lock);
574 static LIST_HEAD(transports);
575 
576 /* Filled in during early boot */
577 static LIST_HEAD(eth_cmd_line);
578 
579 static int check_transport(struct transport *transport, char *eth, int n,
580 			   void **init_out, char **mac_out)
581 {
582 	int len;
583 
584 	len = strlen(transport->name);
585 	if (strncmp(eth, transport->name, len))
586 		return 0;
587 
588 	eth += len;
589 	if (*eth == ',')
590 		eth++;
591 	else if (*eth != '\0')
592 		return 0;
593 
594 	*init_out = kmalloc(transport->setup_size, GFP_KERNEL);
595 	if (*init_out == NULL)
596 		return 1;
597 
598 	if (!transport->setup(eth, mac_out, *init_out)) {
599 		kfree(*init_out);
600 		*init_out = NULL;
601 	}
602 	return 1;
603 }
604 
605 void register_transport(struct transport *new)
606 {
607 	struct list_head *ele, *next;
608 	struct eth_init *eth;
609 	void *init;
610 	char *mac = NULL;
611 	int match;
612 
613 	spin_lock(&transports_lock);
614 	BUG_ON(!list_empty(&new->list));
615 	list_add(&new->list, &transports);
616 	spin_unlock(&transports_lock);
617 
618 	list_for_each_safe(ele, next, &eth_cmd_line) {
619 		eth = list_entry(ele, struct eth_init, list);
620 		match = check_transport(new, eth->init, eth->index, &init,
621 					&mac);
622 		if (!match)
623 			continue;
624 		else if (init != NULL) {
625 			eth_configure(eth->index, init, mac, new);
626 			kfree(init);
627 		}
628 		list_del(&eth->list);
629 	}
630 }
631 
632 static int eth_setup_common(char *str, int index)
633 {
634 	struct list_head *ele;
635 	struct transport *transport;
636 	void *init;
637 	char *mac = NULL;
638 	int found = 0;
639 
640 	spin_lock(&transports_lock);
641 	list_for_each(ele, &transports) {
642 		transport = list_entry(ele, struct transport, list);
643 	        if (!check_transport(transport, str, index, &init, &mac))
644 			continue;
645 		if (init != NULL) {
646 			eth_configure(index, init, mac, transport);
647 			kfree(init);
648 		}
649 		found = 1;
650 		break;
651 	}
652 
653 	spin_unlock(&transports_lock);
654 	return found;
655 }
656 
657 static int __init eth_setup(char *str)
658 {
659 	struct eth_init *new;
660 	char *error;
661 	int n, err;
662 
663 	err = eth_parse(str, &n, &str, &error);
664 	if (err) {
665 		printk(KERN_ERR "eth_setup - Couldn't parse '%s' : %s\n",
666 		       str, error);
667 		return 1;
668 	}
669 
670 	new = alloc_bootmem(sizeof(*new));
671 	if (new == NULL) {
672 		printk(KERN_ERR "eth_init : alloc_bootmem failed\n");
673 		return 1;
674 	}
675 
676 	INIT_LIST_HEAD(&new->list);
677 	new->index = n;
678 	new->init = str;
679 
680 	list_add_tail(&new->list, &eth_cmd_line);
681 	return 1;
682 }
683 
684 __setup("eth", eth_setup);
685 __uml_help(eth_setup,
686 "eth[0-9]+=<transport>,<options>\n"
687 "    Configure a network device.\n\n"
688 );
689 
690 static int net_config(char *str, char **error_out)
691 {
692 	int n, err;
693 
694 	err = eth_parse(str, &n, &str, error_out);
695 	if (err)
696 		return err;
697 
698 	/* This string is broken up and the pieces used by the underlying
699 	 * driver.  So, it is freed only if eth_setup_common fails.
700 	 */
701 	str = kstrdup(str, GFP_KERNEL);
702 	if (str == NULL) {
703 	        *error_out = "net_config failed to strdup string";
704 		return -ENOMEM;
705 	}
706 	err = !eth_setup_common(str, n);
707 	if (err)
708 		kfree(str);
709 	return err;
710 }
711 
712 static int net_id(char **str, int *start_out, int *end_out)
713 {
714 	char *end;
715 	int n;
716 
717 	n = simple_strtoul(*str, &end, 0);
718 	if ((*end != '\0') || (end == *str))
719 		return -1;
720 
721 	*start_out = n;
722 	*end_out = n;
723 	*str = end;
724 	return n;
725 }
726 
727 static int net_remove(int n, char **error_out)
728 {
729 	struct uml_net *device;
730 	struct net_device *dev;
731 	struct uml_net_private *lp;
732 
733 	device = find_device(n);
734 	if (device == NULL)
735 		return -ENODEV;
736 
737 	dev = device->dev;
738 	lp = dev->priv;
739 	if (lp->fd > 0)
740 		return -EBUSY;
741 	unregister_netdev(dev);
742 	platform_device_unregister(&device->pdev);
743 
744 	return 0;
745 }
746 
747 static struct mc_device net_mc = {
748 	.list		= LIST_HEAD_INIT(net_mc.list),
749 	.name		= "eth",
750 	.config		= net_config,
751 	.get_config	= NULL,
752 	.id		= net_id,
753 	.remove		= net_remove,
754 };
755 
756 #ifdef CONFIG_INET
757 static int uml_inetaddr_event(struct notifier_block *this, unsigned long event,
758 			      void *ptr)
759 {
760 	struct in_ifaddr *ifa = ptr;
761 	struct net_device *dev = ifa->ifa_dev->dev;
762 	struct uml_net_private *lp;
763 	void (*proc)(unsigned char *, unsigned char *, void *);
764 	unsigned char addr_buf[4], netmask_buf[4];
765 
766 	if (dev->open != uml_net_open)
767 		return NOTIFY_DONE;
768 
769 	lp = dev->priv;
770 
771 	proc = NULL;
772 	switch (event) {
773 	case NETDEV_UP:
774 		proc = lp->add_address;
775 		break;
776 	case NETDEV_DOWN:
777 		proc = lp->delete_address;
778 		break;
779 	}
780 	if (proc != NULL) {
781 		memcpy(addr_buf, &ifa->ifa_address, sizeof(addr_buf));
782 		memcpy(netmask_buf, &ifa->ifa_mask, sizeof(netmask_buf));
783 		(*proc)(addr_buf, netmask_buf, &lp->user);
784 	}
785 	return NOTIFY_DONE;
786 }
787 
788 /* uml_net_init shouldn't be called twice on two CPUs at the same time */
789 static struct notifier_block uml_inetaddr_notifier = {
790 	.notifier_call		= uml_inetaddr_event,
791 };
792 
793 static void inet_register(void)
794 {
795 	struct list_head *ele;
796 	struct uml_net_private *lp;
797 	struct in_device *ip;
798 	struct in_ifaddr *in;
799 
800 	register_inetaddr_notifier(&uml_inetaddr_notifier);
801 
802 	/* Devices may have been opened already, so the uml_inetaddr_notifier
803 	 * didn't get a chance to run for them.  This fakes it so that
804 	 * addresses which have already been set up get handled properly.
805 	 */
806 	spin_lock(&opened_lock);
807 	list_for_each(ele, &opened) {
808 		lp = list_entry(ele, struct uml_net_private, list);
809 		ip = lp->dev->ip_ptr;
810 		if (ip == NULL)
811 			continue;
812 		in = ip->ifa_list;
813 		while (in != NULL) {
814 			uml_inetaddr_event(NULL, NETDEV_UP, in);
815 			in = in->ifa_next;
816 		}
817 	}
818 	spin_unlock(&opened_lock);
819 }
820 #else
821 static inline void inet_register(void)
822 {
823 }
824 #endif
825 
826 static int uml_net_init(void)
827 {
828 	mconsole_register_dev(&net_mc);
829 	inet_register();
830 	return 0;
831 }
832 
833 __initcall(uml_net_init);
834 
835 static void close_devices(void)
836 {
837 	struct list_head *ele;
838 	struct uml_net_private *lp;
839 
840 	spin_lock(&opened_lock);
841 	list_for_each(ele, &opened) {
842 		lp = list_entry(ele, struct uml_net_private, list);
843 		free_irq(lp->dev->irq, lp->dev);
844 		if ((lp->close != NULL) && (lp->fd >= 0))
845 			(*lp->close)(lp->fd, &lp->user);
846 		if (lp->remove != NULL)
847 			(*lp->remove)(&lp->user);
848 	}
849 	spin_unlock(&opened_lock);
850 }
851 
852 __uml_exitcall(close_devices);
853 
854 void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *,
855 					void *),
856 		    void *arg)
857 {
858 	struct net_device *dev = d;
859 	struct in_device *ip = dev->ip_ptr;
860 	struct in_ifaddr *in;
861 	unsigned char address[4], netmask[4];
862 
863 	if (ip == NULL) return;
864 	in = ip->ifa_list;
865 	while (in != NULL) {
866 		memcpy(address, &in->ifa_address, sizeof(address));
867 		memcpy(netmask, &in->ifa_mask, sizeof(netmask));
868 		(*cb)(address, netmask, arg);
869 		in = in->ifa_next;
870 	}
871 }
872 
873 int dev_netmask(void *d, void *m)
874 {
875 	struct net_device *dev = d;
876 	struct in_device *ip = dev->ip_ptr;
877 	struct in_ifaddr *in;
878 	__be32 *mask_out = m;
879 
880 	if (ip == NULL)
881 		return 1;
882 
883 	in = ip->ifa_list;
884 	if (in == NULL)
885 		return 1;
886 
887 	*mask_out = in->ifa_mask;
888 	return 0;
889 }
890 
891 void *get_output_buffer(int *len_out)
892 {
893 	void *ret;
894 
895 	ret = (void *) __get_free_pages(GFP_KERNEL, 0);
896 	if (ret) *len_out = PAGE_SIZE;
897 	else *len_out = 0;
898 	return ret;
899 }
900 
901 void free_output_buffer(void *buffer)
902 {
903 	free_pages((unsigned long) buffer, 0);
904 }
905 
906 int tap_setup_common(char *str, char *type, char **dev_name, char **mac_out,
907 		     char **gate_addr)
908 {
909 	char *remain;
910 
911 	remain = split_if_spec(str, dev_name, mac_out, gate_addr, NULL);
912 	if (remain != NULL) {
913 		printk(KERN_ERR "tap_setup_common - Extra garbage on "
914 		       "specification : '%s'\n", remain);
915 		return 1;
916 	}
917 
918 	return 0;
919 }
920 
921 unsigned short eth_protocol(struct sk_buff *skb)
922 {
923 	return eth_type_trans(skb, skb->dev);
924 }
925