xref: /linux/arch/um/drivers/net_kern.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 
222 	if (len == skb->len) {
223 		dev->stats.tx_packets++;
224 		dev->stats.tx_bytes += skb->len;
225 		dev->trans_start = jiffies;
226 		netif_start_queue(dev);
227 
228 		/* this is normally done in the interrupt when tx finishes */
229 		netif_wake_queue(dev);
230 	}
231 	else if (len == 0) {
232 		netif_start_queue(dev);
233 		dev->stats.tx_dropped++;
234 	}
235 	else {
236 		netif_start_queue(dev);
237 		printk(KERN_ERR "uml_net_start_xmit: failed(%d)\n", len);
238 	}
239 
240 	spin_unlock_irqrestore(&lp->lock, flags);
241 
242 	dev_kfree_skb(skb);
243 
244 	return NETDEV_TX_OK;
245 }
246 
247 static void uml_net_set_multicast_list(struct net_device *dev)
248 {
249 	return;
250 }
251 
252 static void uml_net_tx_timeout(struct net_device *dev)
253 {
254 	dev->trans_start = jiffies;
255 	netif_wake_queue(dev);
256 }
257 
258 static int uml_net_change_mtu(struct net_device *dev, int new_mtu)
259 {
260 	dev->mtu = new_mtu;
261 
262 	return 0;
263 }
264 
265 #ifdef CONFIG_NET_POLL_CONTROLLER
266 static void uml_net_poll_controller(struct net_device *dev)
267 {
268 	disable_irq(dev->irq);
269 	uml_net_interrupt(dev->irq, dev);
270 	enable_irq(dev->irq);
271 }
272 #endif
273 
274 static void uml_net_get_drvinfo(struct net_device *dev,
275 				struct ethtool_drvinfo *info)
276 {
277 	strcpy(info->driver, DRIVER_NAME);
278 	strcpy(info->version, "42");
279 }
280 
281 static const struct ethtool_ops uml_net_ethtool_ops = {
282 	.get_drvinfo	= uml_net_get_drvinfo,
283 	.get_link	= ethtool_op_get_link,
284 };
285 
286 static void uml_net_user_timer_expire(unsigned long _conn)
287 {
288 #ifdef undef
289 	struct connection *conn = (struct connection *)_conn;
290 
291 	dprintk(KERN_INFO "uml_net_user_timer_expire [%p]\n", conn);
292 	do_connect(conn);
293 #endif
294 }
295 
296 static int setup_etheraddr(char *str, unsigned char *addr, char *name)
297 {
298 	char *end;
299 	int i;
300 
301 	if (str == NULL)
302 		goto random;
303 
304 	for (i = 0; i < 6; i++) {
305 		addr[i] = simple_strtoul(str, &end, 16);
306 		if ((end == str) ||
307 		   ((*end != ':') && (*end != ',') && (*end != '\0'))) {
308 			printk(KERN_ERR
309 			       "setup_etheraddr: failed to parse '%s' "
310 			       "as an ethernet address\n", str);
311 			goto random;
312 		}
313 		str = end + 1;
314 	}
315 	if (is_multicast_ether_addr(addr)) {
316 		printk(KERN_ERR
317 		       "Attempt to assign a multicast ethernet address to a "
318 		       "device disallowed\n");
319 		goto random;
320 	}
321 	if (!is_valid_ether_addr(addr)) {
322 		printk(KERN_ERR
323 		       "Attempt to assign an invalid ethernet address to a "
324 		       "device disallowed\n");
325 		goto random;
326 	}
327 	if (!is_local_ether_addr(addr)) {
328 		printk(KERN_WARNING
329 		       "Warning: Assigning a globally valid ethernet "
330 		       "address to a device\n");
331 		printk(KERN_WARNING "You should set the 2nd rightmost bit in "
332 		       "the first byte of the MAC,\n");
333 		printk(KERN_WARNING "i.e. %02x:%02x:%02x:%02x:%02x:%02x\n",
334 		       addr[0] | 0x02, addr[1], addr[2], addr[3], addr[4],
335 		       addr[5]);
336 	}
337 	return 0;
338 
339 random:
340 	printk(KERN_INFO
341 	       "Choosing a random ethernet address for device %s\n", name);
342 	eth_random_addr(addr);
343 	return 1;
344 }
345 
346 static DEFINE_SPINLOCK(devices_lock);
347 static LIST_HEAD(devices);
348 
349 static struct platform_driver uml_net_driver = {
350 	.driver = {
351 		.name  = DRIVER_NAME,
352 	},
353 };
354 
355 static void net_device_release(struct device *dev)
356 {
357 	struct uml_net *device = dev_get_drvdata(dev);
358 	struct net_device *netdev = device->dev;
359 	struct uml_net_private *lp = netdev_priv(netdev);
360 
361 	if (lp->remove != NULL)
362 		(*lp->remove)(&lp->user);
363 	list_del(&device->list);
364 	kfree(device);
365 	free_netdev(netdev);
366 }
367 
368 static const struct net_device_ops uml_netdev_ops = {
369 	.ndo_open 		= uml_net_open,
370 	.ndo_stop 		= uml_net_close,
371 	.ndo_start_xmit 	= uml_net_start_xmit,
372 	.ndo_set_rx_mode	= uml_net_set_multicast_list,
373 	.ndo_tx_timeout 	= uml_net_tx_timeout,
374 	.ndo_set_mac_address	= eth_mac_addr,
375 	.ndo_change_mtu 	= uml_net_change_mtu,
376 	.ndo_validate_addr	= eth_validate_addr,
377 #ifdef CONFIG_NET_POLL_CONTROLLER
378 	.ndo_poll_controller = uml_net_poll_controller,
379 #endif
380 };
381 
382 /*
383  * Ensures that platform_driver_register is called only once by
384  * eth_configure.  Will be set in an initcall.
385  */
386 static int driver_registered;
387 
388 static void eth_configure(int n, void *init, char *mac,
389 			  struct transport *transport)
390 {
391 	struct uml_net *device;
392 	struct net_device *dev;
393 	struct uml_net_private *lp;
394 	int err, size;
395 	int random_mac;
396 
397 	size = transport->private_size + sizeof(struct uml_net_private);
398 
399 	device = kzalloc(sizeof(*device), GFP_KERNEL);
400 	if (device == NULL) {
401 		printk(KERN_ERR "eth_configure failed to allocate struct "
402 		       "uml_net\n");
403 		return;
404 	}
405 
406 	dev = alloc_etherdev(size);
407 	if (dev == NULL) {
408 		printk(KERN_ERR "eth_configure: failed to allocate struct "
409 		       "net_device for eth%d\n", n);
410 		goto out_free_device;
411 	}
412 
413 	INIT_LIST_HEAD(&device->list);
414 	device->index = n;
415 
416 	/* If this name ends up conflicting with an existing registered
417 	 * netdevice, that is OK, register_netdev{,ice}() will notice this
418 	 * and fail.
419 	 */
420 	snprintf(dev->name, sizeof(dev->name), "eth%d", n);
421 
422 	random_mac = setup_etheraddr(mac, device->mac, dev->name);
423 
424 	printk(KERN_INFO "Netdevice %d (%pM) : ", n, device->mac);
425 
426 	lp = netdev_priv(dev);
427 	/* This points to the transport private data. It's still clear, but we
428 	 * must memset it to 0 *now*. Let's help the drivers. */
429 	memset(lp, 0, size);
430 	INIT_WORK(&lp->work, uml_dev_close);
431 
432 	/* sysfs register */
433 	if (!driver_registered) {
434 		platform_driver_register(&uml_net_driver);
435 		driver_registered = 1;
436 	}
437 	device->pdev.id = n;
438 	device->pdev.name = DRIVER_NAME;
439 	device->pdev.dev.release = net_device_release;
440 	dev_set_drvdata(&device->pdev.dev, device);
441 	if (platform_device_register(&device->pdev))
442 		goto out_free_netdev;
443 	SET_NETDEV_DEV(dev,&device->pdev.dev);
444 
445 	device->dev = dev;
446 
447 	/*
448 	 * These just fill in a data structure, so there's no failure
449 	 * to be worried about.
450 	 */
451 	(*transport->kern->init)(dev, init);
452 
453 	*lp = ((struct uml_net_private)
454 		{ .list  		= LIST_HEAD_INIT(lp->list),
455 		  .dev 			= dev,
456 		  .fd 			= -1,
457 		  .mac 			= { 0xfe, 0xfd, 0x0, 0x0, 0x0, 0x0},
458 		  .max_packet		= transport->user->max_packet,
459 		  .protocol 		= transport->kern->protocol,
460 		  .open 		= transport->user->open,
461 		  .close 		= transport->user->close,
462 		  .remove 		= transport->user->remove,
463 		  .read 		= transport->kern->read,
464 		  .write 		= transport->kern->write,
465 		  .add_address 		= transport->user->add_address,
466 		  .delete_address  	= transport->user->delete_address });
467 
468 	init_timer(&lp->tl);
469 	spin_lock_init(&lp->lock);
470 	lp->tl.function = uml_net_user_timer_expire;
471 	memcpy(lp->mac, device->mac, sizeof(lp->mac));
472 
473 	if ((transport->user->init != NULL) &&
474 	    ((*transport->user->init)(&lp->user, dev) != 0))
475 		goto out_unregister;
476 
477 	/* don't use eth_mac_addr, it will not work here */
478 	memcpy(dev->dev_addr, device->mac, ETH_ALEN);
479 	if (random_mac)
480 		dev->addr_assign_type |= NET_ADDR_RANDOM;
481 
482 	dev->mtu = transport->user->mtu;
483 	dev->netdev_ops = &uml_netdev_ops;
484 	dev->ethtool_ops = &uml_net_ethtool_ops;
485 	dev->watchdog_timeo = (HZ >> 1);
486 	dev->irq = UM_ETH_IRQ;
487 
488 	err = update_drop_skb(lp->max_packet);
489 	if (err)
490 		goto out_undo_user_init;
491 
492 	rtnl_lock();
493 	err = register_netdevice(dev);
494 	rtnl_unlock();
495 	if (err)
496 		goto out_undo_user_init;
497 
498 	spin_lock(&devices_lock);
499 	list_add(&device->list, &devices);
500 	spin_unlock(&devices_lock);
501 
502 	return;
503 
504 out_undo_user_init:
505 	if (transport->user->remove != NULL)
506 		(*transport->user->remove)(&lp->user);
507 out_unregister:
508 	platform_device_unregister(&device->pdev);
509 	return; /* platform_device_unregister frees dev and device */
510 out_free_netdev:
511 	free_netdev(dev);
512 out_free_device:
513 	kfree(device);
514 }
515 
516 static struct uml_net *find_device(int n)
517 {
518 	struct uml_net *device;
519 	struct list_head *ele;
520 
521 	spin_lock(&devices_lock);
522 	list_for_each(ele, &devices) {
523 		device = list_entry(ele, struct uml_net, list);
524 		if (device->index == n)
525 			goto out;
526 	}
527 	device = NULL;
528  out:
529 	spin_unlock(&devices_lock);
530 	return device;
531 }
532 
533 static int eth_parse(char *str, int *index_out, char **str_out,
534 		     char **error_out)
535 {
536 	char *end;
537 	int n, err = -EINVAL;
538 
539 	n = simple_strtoul(str, &end, 0);
540 	if (end == str) {
541 		*error_out = "Bad device number";
542 		return err;
543 	}
544 
545 	str = end;
546 	if (*str != '=') {
547 		*error_out = "Expected '=' after device number";
548 		return err;
549 	}
550 
551 	str++;
552 	if (find_device(n)) {
553 		*error_out = "Device already configured";
554 		return err;
555 	}
556 
557 	*index_out = n;
558 	*str_out = str;
559 	return 0;
560 }
561 
562 struct eth_init {
563 	struct list_head list;
564 	char *init;
565 	int index;
566 };
567 
568 static DEFINE_SPINLOCK(transports_lock);
569 static LIST_HEAD(transports);
570 
571 /* Filled in during early boot */
572 static LIST_HEAD(eth_cmd_line);
573 
574 static int check_transport(struct transport *transport, char *eth, int n,
575 			   void **init_out, char **mac_out)
576 {
577 	int len;
578 
579 	len = strlen(transport->name);
580 	if (strncmp(eth, transport->name, len))
581 		return 0;
582 
583 	eth += len;
584 	if (*eth == ',')
585 		eth++;
586 	else if (*eth != '\0')
587 		return 0;
588 
589 	*init_out = kmalloc(transport->setup_size, GFP_KERNEL);
590 	if (*init_out == NULL)
591 		return 1;
592 
593 	if (!transport->setup(eth, mac_out, *init_out)) {
594 		kfree(*init_out);
595 		*init_out = NULL;
596 	}
597 	return 1;
598 }
599 
600 void register_transport(struct transport *new)
601 {
602 	struct list_head *ele, *next;
603 	struct eth_init *eth;
604 	void *init;
605 	char *mac = NULL;
606 	int match;
607 
608 	spin_lock(&transports_lock);
609 	BUG_ON(!list_empty(&new->list));
610 	list_add(&new->list, &transports);
611 	spin_unlock(&transports_lock);
612 
613 	list_for_each_safe(ele, next, &eth_cmd_line) {
614 		eth = list_entry(ele, struct eth_init, list);
615 		match = check_transport(new, eth->init, eth->index, &init,
616 					&mac);
617 		if (!match)
618 			continue;
619 		else if (init != NULL) {
620 			eth_configure(eth->index, init, mac, new);
621 			kfree(init);
622 		}
623 		list_del(&eth->list);
624 	}
625 }
626 
627 static int eth_setup_common(char *str, int index)
628 {
629 	struct list_head *ele;
630 	struct transport *transport;
631 	void *init;
632 	char *mac = NULL;
633 	int found = 0;
634 
635 	spin_lock(&transports_lock);
636 	list_for_each(ele, &transports) {
637 		transport = list_entry(ele, struct transport, list);
638 	        if (!check_transport(transport, str, index, &init, &mac))
639 			continue;
640 		if (init != NULL) {
641 			eth_configure(index, init, mac, transport);
642 			kfree(init);
643 		}
644 		found = 1;
645 		break;
646 	}
647 
648 	spin_unlock(&transports_lock);
649 	return found;
650 }
651 
652 static int __init eth_setup(char *str)
653 {
654 	struct eth_init *new;
655 	char *error;
656 	int n, err;
657 
658 	err = eth_parse(str, &n, &str, &error);
659 	if (err) {
660 		printk(KERN_ERR "eth_setup - Couldn't parse '%s' : %s\n",
661 		       str, error);
662 		return 1;
663 	}
664 
665 	new = alloc_bootmem(sizeof(*new));
666 	if (new == NULL) {
667 		printk(KERN_ERR "eth_init : alloc_bootmem failed\n");
668 		return 1;
669 	}
670 
671 	INIT_LIST_HEAD(&new->list);
672 	new->index = n;
673 	new->init = str;
674 
675 	list_add_tail(&new->list, &eth_cmd_line);
676 	return 1;
677 }
678 
679 __setup("eth", eth_setup);
680 __uml_help(eth_setup,
681 "eth[0-9]+=<transport>,<options>\n"
682 "    Configure a network device.\n\n"
683 );
684 
685 static int net_config(char *str, char **error_out)
686 {
687 	int n, err;
688 
689 	err = eth_parse(str, &n, &str, error_out);
690 	if (err)
691 		return err;
692 
693 	/* This string is broken up and the pieces used by the underlying
694 	 * driver.  So, it is freed only if eth_setup_common fails.
695 	 */
696 	str = kstrdup(str, GFP_KERNEL);
697 	if (str == NULL) {
698 	        *error_out = "net_config failed to strdup string";
699 		return -ENOMEM;
700 	}
701 	err = !eth_setup_common(str, n);
702 	if (err)
703 		kfree(str);
704 	return err;
705 }
706 
707 static int net_id(char **str, int *start_out, int *end_out)
708 {
709 	char *end;
710 	int n;
711 
712 	n = simple_strtoul(*str, &end, 0);
713 	if ((*end != '\0') || (end == *str))
714 		return -1;
715 
716 	*start_out = n;
717 	*end_out = n;
718 	*str = end;
719 	return n;
720 }
721 
722 static int net_remove(int n, char **error_out)
723 {
724 	struct uml_net *device;
725 	struct net_device *dev;
726 	struct uml_net_private *lp;
727 
728 	device = find_device(n);
729 	if (device == NULL)
730 		return -ENODEV;
731 
732 	dev = device->dev;
733 	lp = netdev_priv(dev);
734 	if (lp->fd > 0)
735 		return -EBUSY;
736 	unregister_netdev(dev);
737 	platform_device_unregister(&device->pdev);
738 
739 	return 0;
740 }
741 
742 static struct mc_device net_mc = {
743 	.list		= LIST_HEAD_INIT(net_mc.list),
744 	.name		= "eth",
745 	.config		= net_config,
746 	.get_config	= NULL,
747 	.id		= net_id,
748 	.remove		= net_remove,
749 };
750 
751 #ifdef CONFIG_INET
752 static int uml_inetaddr_event(struct notifier_block *this, unsigned long event,
753 			      void *ptr)
754 {
755 	struct in_ifaddr *ifa = ptr;
756 	struct net_device *dev = ifa->ifa_dev->dev;
757 	struct uml_net_private *lp;
758 	void (*proc)(unsigned char *, unsigned char *, void *);
759 	unsigned char addr_buf[4], netmask_buf[4];
760 
761 	if (dev->netdev_ops->ndo_open != uml_net_open)
762 		return NOTIFY_DONE;
763 
764 	lp = netdev_priv(dev);
765 
766 	proc = NULL;
767 	switch (event) {
768 	case NETDEV_UP:
769 		proc = lp->add_address;
770 		break;
771 	case NETDEV_DOWN:
772 		proc = lp->delete_address;
773 		break;
774 	}
775 	if (proc != NULL) {
776 		memcpy(addr_buf, &ifa->ifa_address, sizeof(addr_buf));
777 		memcpy(netmask_buf, &ifa->ifa_mask, sizeof(netmask_buf));
778 		(*proc)(addr_buf, netmask_buf, &lp->user);
779 	}
780 	return NOTIFY_DONE;
781 }
782 
783 /* uml_net_init shouldn't be called twice on two CPUs at the same time */
784 static struct notifier_block uml_inetaddr_notifier = {
785 	.notifier_call		= uml_inetaddr_event,
786 };
787 
788 static void inet_register(void)
789 {
790 	struct list_head *ele;
791 	struct uml_net_private *lp;
792 	struct in_device *ip;
793 	struct in_ifaddr *in;
794 
795 	register_inetaddr_notifier(&uml_inetaddr_notifier);
796 
797 	/* Devices may have been opened already, so the uml_inetaddr_notifier
798 	 * didn't get a chance to run for them.  This fakes it so that
799 	 * addresses which have already been set up get handled properly.
800 	 */
801 	spin_lock(&opened_lock);
802 	list_for_each(ele, &opened) {
803 		lp = list_entry(ele, struct uml_net_private, list);
804 		ip = lp->dev->ip_ptr;
805 		if (ip == NULL)
806 			continue;
807 		in = ip->ifa_list;
808 		while (in != NULL) {
809 			uml_inetaddr_event(NULL, NETDEV_UP, in);
810 			in = in->ifa_next;
811 		}
812 	}
813 	spin_unlock(&opened_lock);
814 }
815 #else
816 static inline void inet_register(void)
817 {
818 }
819 #endif
820 
821 static int uml_net_init(void)
822 {
823 	mconsole_register_dev(&net_mc);
824 	inet_register();
825 	return 0;
826 }
827 
828 __initcall(uml_net_init);
829 
830 static void close_devices(void)
831 {
832 	struct list_head *ele;
833 	struct uml_net_private *lp;
834 
835 	spin_lock(&opened_lock);
836 	list_for_each(ele, &opened) {
837 		lp = list_entry(ele, struct uml_net_private, list);
838 		um_free_irq(lp->dev->irq, lp->dev);
839 		if ((lp->close != NULL) && (lp->fd >= 0))
840 			(*lp->close)(lp->fd, &lp->user);
841 		if (lp->remove != NULL)
842 			(*lp->remove)(&lp->user);
843 	}
844 	spin_unlock(&opened_lock);
845 }
846 
847 __uml_exitcall(close_devices);
848 
849 void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *,
850 					void *),
851 		    void *arg)
852 {
853 	struct net_device *dev = d;
854 	struct in_device *ip = dev->ip_ptr;
855 	struct in_ifaddr *in;
856 	unsigned char address[4], netmask[4];
857 
858 	if (ip == NULL) return;
859 	in = ip->ifa_list;
860 	while (in != NULL) {
861 		memcpy(address, &in->ifa_address, sizeof(address));
862 		memcpy(netmask, &in->ifa_mask, sizeof(netmask));
863 		(*cb)(address, netmask, arg);
864 		in = in->ifa_next;
865 	}
866 }
867 
868 int dev_netmask(void *d, void *m)
869 {
870 	struct net_device *dev = d;
871 	struct in_device *ip = dev->ip_ptr;
872 	struct in_ifaddr *in;
873 	__be32 *mask_out = m;
874 
875 	if (ip == NULL)
876 		return 1;
877 
878 	in = ip->ifa_list;
879 	if (in == NULL)
880 		return 1;
881 
882 	*mask_out = in->ifa_mask;
883 	return 0;
884 }
885 
886 void *get_output_buffer(int *len_out)
887 {
888 	void *ret;
889 
890 	ret = (void *) __get_free_pages(GFP_KERNEL, 0);
891 	if (ret) *len_out = PAGE_SIZE;
892 	else *len_out = 0;
893 	return ret;
894 }
895 
896 void free_output_buffer(void *buffer)
897 {
898 	free_pages((unsigned long) buffer, 0);
899 }
900 
901 int tap_setup_common(char *str, char *type, char **dev_name, char **mac_out,
902 		     char **gate_addr)
903 {
904 	char *remain;
905 
906 	remain = split_if_spec(str, dev_name, mac_out, gate_addr, NULL);
907 	if (remain != NULL) {
908 		printk(KERN_ERR "tap_setup_common - Extra garbage on "
909 		       "specification : '%s'\n", remain);
910 		return 1;
911 	}
912 
913 	return 0;
914 }
915 
916 unsigned short eth_protocol(struct sk_buff *skb)
917 {
918 	return eth_type_trans(skb, skb->dev);
919 }
920