xref: /openbmc/linux/arch/um/drivers/net_kern.c (revision b2765275)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4  * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
5  * James Leu (jleu@mindspring.net).
6  * Copyright (C) 2001 by various other people who didn't put their name here.
7  */
8 
9 #include <linux/memblock.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 out:
141 	spin_unlock(&lp->lock);
142 	return IRQ_HANDLED;
143 }
144 
145 static int uml_net_open(struct net_device *dev)
146 {
147 	struct uml_net_private *lp = netdev_priv(dev);
148 	int err;
149 
150 	if (lp->fd >= 0) {
151 		err = -ENXIO;
152 		goto out;
153 	}
154 
155 	lp->fd = (*lp->open)(&lp->user);
156 	if (lp->fd < 0) {
157 		err = lp->fd;
158 		goto out;
159 	}
160 
161 	err = um_request_irq(dev->irq, lp->fd, IRQ_READ, uml_net_interrupt,
162 			     IRQF_SHARED, dev->name, dev);
163 	if (err != 0) {
164 		printk(KERN_ERR "uml_net_open: failed to get irq(%d)\n", err);
165 		err = -ENETUNREACH;
166 		goto out_close;
167 	}
168 
169 	netif_start_queue(dev);
170 
171 	/* clear buffer - it can happen that the host side of the interface
172 	 * is full when we get here.  In this case, new data is never queued,
173 	 * SIGIOs never arrive, and the net never works.
174 	 */
175 	while ((err = uml_net_rx(dev)) > 0) ;
176 
177 	spin_lock(&opened_lock);
178 	list_add(&lp->list, &opened);
179 	spin_unlock(&opened_lock);
180 
181 	return 0;
182 out_close:
183 	if (lp->close != NULL) (*lp->close)(lp->fd, &lp->user);
184 	lp->fd = -1;
185 out:
186 	return err;
187 }
188 
189 static int uml_net_close(struct net_device *dev)
190 {
191 	struct uml_net_private *lp = netdev_priv(dev);
192 
193 	netif_stop_queue(dev);
194 
195 	um_free_irq(dev->irq, dev);
196 	if (lp->close != NULL)
197 		(*lp->close)(lp->fd, &lp->user);
198 	lp->fd = -1;
199 
200 	spin_lock(&opened_lock);
201 	list_del(&lp->list);
202 	spin_unlock(&opened_lock);
203 
204 	return 0;
205 }
206 
207 static int uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
208 {
209 	struct uml_net_private *lp = netdev_priv(dev);
210 	unsigned long flags;
211 	int len;
212 
213 	netif_stop_queue(dev);
214 
215 	spin_lock_irqsave(&lp->lock, flags);
216 
217 	len = (*lp->write)(lp->fd, skb, lp);
218 	skb_tx_timestamp(skb);
219 
220 	if (len == skb->len) {
221 		dev->stats.tx_packets++;
222 		dev->stats.tx_bytes += skb->len;
223 		netif_trans_update(dev);
224 		netif_start_queue(dev);
225 
226 		/* this is normally done in the interrupt when tx finishes */
227 		netif_wake_queue(dev);
228 	}
229 	else if (len == 0) {
230 		netif_start_queue(dev);
231 		dev->stats.tx_dropped++;
232 	}
233 	else {
234 		netif_start_queue(dev);
235 		printk(KERN_ERR "uml_net_start_xmit: failed(%d)\n", len);
236 	}
237 
238 	spin_unlock_irqrestore(&lp->lock, flags);
239 
240 	dev_consume_skb_any(skb);
241 
242 	return NETDEV_TX_OK;
243 }
244 
245 static void uml_net_set_multicast_list(struct net_device *dev)
246 {
247 	return;
248 }
249 
250 static void uml_net_tx_timeout(struct net_device *dev, unsigned int txqueue)
251 {
252 	netif_trans_update(dev);
253 	netif_wake_queue(dev);
254 }
255 
256 #ifdef CONFIG_NET_POLL_CONTROLLER
257 static void uml_net_poll_controller(struct net_device *dev)
258 {
259 	disable_irq(dev->irq);
260 	uml_net_interrupt(dev->irq, dev);
261 	enable_irq(dev->irq);
262 }
263 #endif
264 
265 static void uml_net_get_drvinfo(struct net_device *dev,
266 				struct ethtool_drvinfo *info)
267 {
268 	strlcpy(info->driver, DRIVER_NAME, sizeof(info->driver));
269 	strlcpy(info->version, "42", sizeof(info->version));
270 }
271 
272 static const struct ethtool_ops uml_net_ethtool_ops = {
273 	.get_drvinfo	= uml_net_get_drvinfo,
274 	.get_link	= ethtool_op_get_link,
275 	.get_ts_info	= ethtool_op_get_ts_info,
276 };
277 
278 static void uml_net_user_timer_expire(struct timer_list *t)
279 {
280 #ifdef undef
281 	struct uml_net_private *lp = from_timer(lp, t, tl);
282 	struct connection *conn = &lp->user;
283 
284 	dprintk(KERN_INFO "uml_net_user_timer_expire [%p]\n", conn);
285 	do_connect(conn);
286 #endif
287 }
288 
289 void uml_net_setup_etheraddr(struct net_device *dev, char *str)
290 {
291 	unsigned char *addr = dev->dev_addr;
292 	char *end;
293 	int i;
294 
295 	if (str == NULL)
296 		goto random;
297 
298 	for (i = 0; i < 6; i++) {
299 		addr[i] = simple_strtoul(str, &end, 16);
300 		if ((end == str) ||
301 		   ((*end != ':') && (*end != ',') && (*end != '\0'))) {
302 			printk(KERN_ERR
303 			       "setup_etheraddr: failed to parse '%s' "
304 			       "as an ethernet address\n", str);
305 			goto random;
306 		}
307 		str = end + 1;
308 	}
309 	if (is_multicast_ether_addr(addr)) {
310 		printk(KERN_ERR
311 		       "Attempt to assign a multicast ethernet address to a "
312 		       "device disallowed\n");
313 		goto random;
314 	}
315 	if (!is_valid_ether_addr(addr)) {
316 		printk(KERN_ERR
317 		       "Attempt to assign an invalid ethernet address to a "
318 		       "device disallowed\n");
319 		goto random;
320 	}
321 	if (!is_local_ether_addr(addr)) {
322 		printk(KERN_WARNING
323 		       "Warning: Assigning a globally valid ethernet "
324 		       "address to a device\n");
325 		printk(KERN_WARNING "You should set the 2nd rightmost bit in "
326 		       "the first byte of the MAC,\n");
327 		printk(KERN_WARNING "i.e. %02x:%02x:%02x:%02x:%02x:%02x\n",
328 		       addr[0] | 0x02, addr[1], addr[2], addr[3], addr[4],
329 		       addr[5]);
330 	}
331 	return;
332 
333 random:
334 	printk(KERN_INFO
335 	       "Choosing a random ethernet address for device %s\n", dev->name);
336 	eth_hw_addr_random(dev);
337 }
338 
339 static DEFINE_SPINLOCK(devices_lock);
340 static LIST_HEAD(devices);
341 
342 static struct platform_driver uml_net_driver = {
343 	.driver = {
344 		.name  = DRIVER_NAME,
345 	},
346 };
347 
348 static void net_device_release(struct device *dev)
349 {
350 	struct uml_net *device = dev_get_drvdata(dev);
351 	struct net_device *netdev = device->dev;
352 	struct uml_net_private *lp = netdev_priv(netdev);
353 
354 	if (lp->remove != NULL)
355 		(*lp->remove)(&lp->user);
356 	list_del(&device->list);
357 	kfree(device);
358 	free_netdev(netdev);
359 }
360 
361 static const struct net_device_ops uml_netdev_ops = {
362 	.ndo_open 		= uml_net_open,
363 	.ndo_stop 		= uml_net_close,
364 	.ndo_start_xmit 	= uml_net_start_xmit,
365 	.ndo_set_rx_mode	= uml_net_set_multicast_list,
366 	.ndo_tx_timeout 	= uml_net_tx_timeout,
367 	.ndo_set_mac_address	= eth_mac_addr,
368 	.ndo_validate_addr	= eth_validate_addr,
369 #ifdef CONFIG_NET_POLL_CONTROLLER
370 	.ndo_poll_controller = uml_net_poll_controller,
371 #endif
372 };
373 
374 /*
375  * Ensures that platform_driver_register is called only once by
376  * eth_configure.  Will be set in an initcall.
377  */
378 static int driver_registered;
379 
380 static void eth_configure(int n, void *init, char *mac,
381 			  struct transport *transport, gfp_t gfp_mask)
382 {
383 	struct uml_net *device;
384 	struct net_device *dev;
385 	struct uml_net_private *lp;
386 	int err, size;
387 
388 	size = transport->private_size + sizeof(struct uml_net_private);
389 
390 	device = kzalloc(sizeof(*device), gfp_mask);
391 	if (device == NULL) {
392 		printk(KERN_ERR "eth_configure failed to allocate struct "
393 		       "uml_net\n");
394 		return;
395 	}
396 
397 	dev = alloc_etherdev(size);
398 	if (dev == NULL) {
399 		printk(KERN_ERR "eth_configure: failed to allocate struct "
400 		       "net_device for eth%d\n", n);
401 		goto out_free_device;
402 	}
403 
404 	INIT_LIST_HEAD(&device->list);
405 	device->index = n;
406 
407 	/* If this name ends up conflicting with an existing registered
408 	 * netdevice, that is OK, register_netdev{,ice}() will notice this
409 	 * and fail.
410 	 */
411 	snprintf(dev->name, sizeof(dev->name), "eth%d", n);
412 
413 	uml_net_setup_etheraddr(dev, mac);
414 
415 	printk(KERN_INFO "Netdevice %d (%pM) : ", n, dev->dev_addr);
416 
417 	lp = netdev_priv(dev);
418 	/* This points to the transport private data. It's still clear, but we
419 	 * must memset it to 0 *now*. Let's help the drivers. */
420 	memset(lp, 0, size);
421 	INIT_WORK(&lp->work, uml_dev_close);
422 
423 	/* sysfs register */
424 	if (!driver_registered) {
425 		platform_driver_register(&uml_net_driver);
426 		driver_registered = 1;
427 	}
428 	device->pdev.id = n;
429 	device->pdev.name = DRIVER_NAME;
430 	device->pdev.dev.release = net_device_release;
431 	dev_set_drvdata(&device->pdev.dev, device);
432 	if (platform_device_register(&device->pdev))
433 		goto out_free_netdev;
434 	SET_NETDEV_DEV(dev,&device->pdev.dev);
435 
436 	device->dev = dev;
437 
438 	/*
439 	 * These just fill in a data structure, so there's no failure
440 	 * to be worried about.
441 	 */
442 	(*transport->kern->init)(dev, init);
443 
444 	*lp = ((struct uml_net_private)
445 		{ .list  		= LIST_HEAD_INIT(lp->list),
446 		  .dev 			= dev,
447 		  .fd 			= -1,
448 		  .mac 			= { 0xfe, 0xfd, 0x0, 0x0, 0x0, 0x0},
449 		  .max_packet		= transport->user->max_packet,
450 		  .protocol 		= transport->kern->protocol,
451 		  .open 		= transport->user->open,
452 		  .close 		= transport->user->close,
453 		  .remove 		= transport->user->remove,
454 		  .read 		= transport->kern->read,
455 		  .write 		= transport->kern->write,
456 		  .add_address 		= transport->user->add_address,
457 		  .delete_address  	= transport->user->delete_address });
458 
459 	timer_setup(&lp->tl, uml_net_user_timer_expire, 0);
460 	spin_lock_init(&lp->lock);
461 	memcpy(lp->mac, dev->dev_addr, sizeof(lp->mac));
462 
463 	if ((transport->user->init != NULL) &&
464 	    ((*transport->user->init)(&lp->user, dev) != 0))
465 		goto out_unregister;
466 
467 	dev->mtu = transport->user->mtu;
468 	dev->netdev_ops = &uml_netdev_ops;
469 	dev->ethtool_ops = &uml_net_ethtool_ops;
470 	dev->watchdog_timeo = (HZ >> 1);
471 	dev->irq = UM_ETH_IRQ;
472 
473 	err = update_drop_skb(lp->max_packet);
474 	if (err)
475 		goto out_undo_user_init;
476 
477 	rtnl_lock();
478 	err = register_netdevice(dev);
479 	rtnl_unlock();
480 	if (err)
481 		goto out_undo_user_init;
482 
483 	spin_lock(&devices_lock);
484 	list_add(&device->list, &devices);
485 	spin_unlock(&devices_lock);
486 
487 	return;
488 
489 out_undo_user_init:
490 	if (transport->user->remove != NULL)
491 		(*transport->user->remove)(&lp->user);
492 out_unregister:
493 	platform_device_unregister(&device->pdev);
494 	return; /* platform_device_unregister frees dev and device */
495 out_free_netdev:
496 	free_netdev(dev);
497 out_free_device:
498 	kfree(device);
499 }
500 
501 static struct uml_net *find_device(int n)
502 {
503 	struct uml_net *device;
504 	struct list_head *ele;
505 
506 	spin_lock(&devices_lock);
507 	list_for_each(ele, &devices) {
508 		device = list_entry(ele, struct uml_net, list);
509 		if (device->index == n)
510 			goto out;
511 	}
512 	device = NULL;
513  out:
514 	spin_unlock(&devices_lock);
515 	return device;
516 }
517 
518 static int eth_parse(char *str, int *index_out, char **str_out,
519 		     char **error_out)
520 {
521 	char *end;
522 	int n, err = -EINVAL;
523 
524 	n = simple_strtoul(str, &end, 0);
525 	if (end == str) {
526 		*error_out = "Bad device number";
527 		return err;
528 	}
529 
530 	str = end;
531 	if (*str != '=') {
532 		*error_out = "Expected '=' after device number";
533 		return err;
534 	}
535 
536 	str++;
537 	if (find_device(n)) {
538 		*error_out = "Device already configured";
539 		return err;
540 	}
541 
542 	*index_out = n;
543 	*str_out = str;
544 	return 0;
545 }
546 
547 struct eth_init {
548 	struct list_head list;
549 	char *init;
550 	int index;
551 };
552 
553 static DEFINE_SPINLOCK(transports_lock);
554 static LIST_HEAD(transports);
555 
556 /* Filled in during early boot */
557 static LIST_HEAD(eth_cmd_line);
558 
559 static int check_transport(struct transport *transport, char *eth, int n,
560 			   void **init_out, char **mac_out, gfp_t gfp_mask)
561 {
562 	int len;
563 
564 	len = strlen(transport->name);
565 	if (strncmp(eth, transport->name, len))
566 		return 0;
567 
568 	eth += len;
569 	if (*eth == ',')
570 		eth++;
571 	else if (*eth != '\0')
572 		return 0;
573 
574 	*init_out = kmalloc(transport->setup_size, gfp_mask);
575 	if (*init_out == NULL)
576 		return 1;
577 
578 	if (!transport->setup(eth, mac_out, *init_out)) {
579 		kfree(*init_out);
580 		*init_out = NULL;
581 	}
582 	return 1;
583 }
584 
585 void register_transport(struct transport *new)
586 {
587 	struct list_head *ele, *next;
588 	struct eth_init *eth;
589 	void *init;
590 	char *mac = NULL;
591 	int match;
592 
593 	spin_lock(&transports_lock);
594 	BUG_ON(!list_empty(&new->list));
595 	list_add(&new->list, &transports);
596 	spin_unlock(&transports_lock);
597 
598 	list_for_each_safe(ele, next, &eth_cmd_line) {
599 		eth = list_entry(ele, struct eth_init, list);
600 		match = check_transport(new, eth->init, eth->index, &init,
601 					&mac, GFP_KERNEL);
602 		if (!match)
603 			continue;
604 		else if (init != NULL) {
605 			eth_configure(eth->index, init, mac, new, GFP_KERNEL);
606 			kfree(init);
607 		}
608 		list_del(&eth->list);
609 	}
610 }
611 
612 static int eth_setup_common(char *str, int index)
613 {
614 	struct list_head *ele;
615 	struct transport *transport;
616 	void *init;
617 	char *mac = NULL;
618 	int found = 0;
619 
620 	spin_lock(&transports_lock);
621 	list_for_each(ele, &transports) {
622 		transport = list_entry(ele, struct transport, list);
623 	        if (!check_transport(transport, str, index, &init,
624 					&mac, GFP_ATOMIC))
625 			continue;
626 		if (init != NULL) {
627 			eth_configure(index, init, mac, transport, GFP_ATOMIC);
628 			kfree(init);
629 		}
630 		found = 1;
631 		break;
632 	}
633 
634 	spin_unlock(&transports_lock);
635 	return found;
636 }
637 
638 static int __init eth_setup(char *str)
639 {
640 	struct eth_init *new;
641 	char *error;
642 	int n, err;
643 
644 	err = eth_parse(str, &n, &str, &error);
645 	if (err) {
646 		printk(KERN_ERR "eth_setup - Couldn't parse '%s' : %s\n",
647 		       str, error);
648 		return 1;
649 	}
650 
651 	new = memblock_alloc(sizeof(*new), SMP_CACHE_BYTES);
652 	if (!new)
653 		panic("%s: Failed to allocate %zu bytes\n", __func__,
654 		      sizeof(*new));
655 
656 	INIT_LIST_HEAD(&new->list);
657 	new->index = n;
658 	new->init = str;
659 
660 	list_add_tail(&new->list, &eth_cmd_line);
661 	return 1;
662 }
663 
664 __setup("eth", eth_setup);
665 __uml_help(eth_setup,
666 "eth[0-9]+=<transport>,<options>\n"
667 "    Configure a network device.\n\n"
668 );
669 
670 static int net_config(char *str, char **error_out)
671 {
672 	int n, err;
673 
674 	err = eth_parse(str, &n, &str, error_out);
675 	if (err)
676 		return err;
677 
678 	/* This string is broken up and the pieces used by the underlying
679 	 * driver.  So, it is freed only if eth_setup_common fails.
680 	 */
681 	str = kstrdup(str, GFP_KERNEL);
682 	if (str == NULL) {
683 	        *error_out = "net_config failed to strdup string";
684 		return -ENOMEM;
685 	}
686 	err = !eth_setup_common(str, n);
687 	if (err)
688 		kfree(str);
689 	return err;
690 }
691 
692 static int net_id(char **str, int *start_out, int *end_out)
693 {
694 	char *end;
695 	int n;
696 
697 	n = simple_strtoul(*str, &end, 0);
698 	if ((*end != '\0') || (end == *str))
699 		return -1;
700 
701 	*start_out = n;
702 	*end_out = n;
703 	*str = end;
704 	return n;
705 }
706 
707 static int net_remove(int n, char **error_out)
708 {
709 	struct uml_net *device;
710 	struct net_device *dev;
711 	struct uml_net_private *lp;
712 
713 	device = find_device(n);
714 	if (device == NULL)
715 		return -ENODEV;
716 
717 	dev = device->dev;
718 	lp = netdev_priv(dev);
719 	if (lp->fd > 0)
720 		return -EBUSY;
721 	unregister_netdev(dev);
722 	platform_device_unregister(&device->pdev);
723 
724 	return 0;
725 }
726 
727 static struct mc_device net_mc = {
728 	.list		= LIST_HEAD_INIT(net_mc.list),
729 	.name		= "eth",
730 	.config		= net_config,
731 	.get_config	= NULL,
732 	.id		= net_id,
733 	.remove		= net_remove,
734 };
735 
736 #ifdef CONFIG_INET
737 static int uml_inetaddr_event(struct notifier_block *this, unsigned long event,
738 			      void *ptr)
739 {
740 	struct in_ifaddr *ifa = ptr;
741 	struct net_device *dev = ifa->ifa_dev->dev;
742 	struct uml_net_private *lp;
743 	void (*proc)(unsigned char *, unsigned char *, void *);
744 	unsigned char addr_buf[4], netmask_buf[4];
745 
746 	if (dev->netdev_ops->ndo_open != uml_net_open)
747 		return NOTIFY_DONE;
748 
749 	lp = netdev_priv(dev);
750 
751 	proc = NULL;
752 	switch (event) {
753 	case NETDEV_UP:
754 		proc = lp->add_address;
755 		break;
756 	case NETDEV_DOWN:
757 		proc = lp->delete_address;
758 		break;
759 	}
760 	if (proc != NULL) {
761 		memcpy(addr_buf, &ifa->ifa_address, sizeof(addr_buf));
762 		memcpy(netmask_buf, &ifa->ifa_mask, sizeof(netmask_buf));
763 		(*proc)(addr_buf, netmask_buf, &lp->user);
764 	}
765 	return NOTIFY_DONE;
766 }
767 
768 /* uml_net_init shouldn't be called twice on two CPUs at the same time */
769 static struct notifier_block uml_inetaddr_notifier = {
770 	.notifier_call		= uml_inetaddr_event,
771 };
772 
773 static void inet_register(void)
774 {
775 	struct list_head *ele;
776 	struct uml_net_private *lp;
777 	struct in_device *ip;
778 	struct in_ifaddr *in;
779 
780 	register_inetaddr_notifier(&uml_inetaddr_notifier);
781 
782 	/* Devices may have been opened already, so the uml_inetaddr_notifier
783 	 * didn't get a chance to run for them.  This fakes it so that
784 	 * addresses which have already been set up get handled properly.
785 	 */
786 	spin_lock(&opened_lock);
787 	list_for_each(ele, &opened) {
788 		lp = list_entry(ele, struct uml_net_private, list);
789 		ip = lp->dev->ip_ptr;
790 		if (ip == NULL)
791 			continue;
792 		in = ip->ifa_list;
793 		while (in != NULL) {
794 			uml_inetaddr_event(NULL, NETDEV_UP, in);
795 			in = in->ifa_next;
796 		}
797 	}
798 	spin_unlock(&opened_lock);
799 }
800 #else
801 static inline void inet_register(void)
802 {
803 }
804 #endif
805 
806 static int uml_net_init(void)
807 {
808 	mconsole_register_dev(&net_mc);
809 	inet_register();
810 	return 0;
811 }
812 
813 __initcall(uml_net_init);
814 
815 static void close_devices(void)
816 {
817 	struct list_head *ele;
818 	struct uml_net_private *lp;
819 
820 	spin_lock(&opened_lock);
821 	list_for_each(ele, &opened) {
822 		lp = list_entry(ele, struct uml_net_private, list);
823 		um_free_irq(lp->dev->irq, lp->dev);
824 		if ((lp->close != NULL) && (lp->fd >= 0))
825 			(*lp->close)(lp->fd, &lp->user);
826 		if (lp->remove != NULL)
827 			(*lp->remove)(&lp->user);
828 	}
829 	spin_unlock(&opened_lock);
830 }
831 
832 __uml_exitcall(close_devices);
833 
834 void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *,
835 					void *),
836 		    void *arg)
837 {
838 	struct net_device *dev = d;
839 	struct in_device *ip = dev->ip_ptr;
840 	struct in_ifaddr *in;
841 	unsigned char address[4], netmask[4];
842 
843 	if (ip == NULL) return;
844 	in = ip->ifa_list;
845 	while (in != NULL) {
846 		memcpy(address, &in->ifa_address, sizeof(address));
847 		memcpy(netmask, &in->ifa_mask, sizeof(netmask));
848 		(*cb)(address, netmask, arg);
849 		in = in->ifa_next;
850 	}
851 }
852 
853 int dev_netmask(void *d, void *m)
854 {
855 	struct net_device *dev = d;
856 	struct in_device *ip = dev->ip_ptr;
857 	struct in_ifaddr *in;
858 	__be32 *mask_out = m;
859 
860 	if (ip == NULL)
861 		return 1;
862 
863 	in = ip->ifa_list;
864 	if (in == NULL)
865 		return 1;
866 
867 	*mask_out = in->ifa_mask;
868 	return 0;
869 }
870 
871 void *get_output_buffer(int *len_out)
872 {
873 	void *ret;
874 
875 	ret = (void *) __get_free_pages(GFP_KERNEL, 0);
876 	if (ret) *len_out = PAGE_SIZE;
877 	else *len_out = 0;
878 	return ret;
879 }
880 
881 void free_output_buffer(void *buffer)
882 {
883 	free_pages((unsigned long) buffer, 0);
884 }
885 
886 int tap_setup_common(char *str, char *type, char **dev_name, char **mac_out,
887 		     char **gate_addr)
888 {
889 	char *remain;
890 
891 	remain = split_if_spec(str, dev_name, mac_out, gate_addr, NULL);
892 	if (remain != NULL) {
893 		printk(KERN_ERR "tap_setup_common - Extra garbage on "
894 		       "specification : '%s'\n", remain);
895 		return 1;
896 	}
897 
898 	return 0;
899 }
900 
901 unsigned short eth_protocol(struct sk_buff *skb)
902 {
903 	return eth_type_trans(skb, skb->dev);
904 }
905