xref: /openbmc/linux/arch/um/drivers/net_kern.c (revision 93f5715e)
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 	netif_start_queue(dev);
172 
173 	/* clear buffer - it can happen that the host side of the interface
174 	 * is full when we get here.  In this case, new data is never queued,
175 	 * SIGIOs never arrive, and the net never works.
176 	 */
177 	while ((err = uml_net_rx(dev)) > 0) ;
178 
179 	spin_lock(&opened_lock);
180 	list_add(&lp->list, &opened);
181 	spin_unlock(&opened_lock);
182 
183 	return 0;
184 out_close:
185 	if (lp->close != NULL) (*lp->close)(lp->fd, &lp->user);
186 	lp->fd = -1;
187 out:
188 	return err;
189 }
190 
191 static int uml_net_close(struct net_device *dev)
192 {
193 	struct uml_net_private *lp = netdev_priv(dev);
194 
195 	netif_stop_queue(dev);
196 
197 	um_free_irq(dev->irq, dev);
198 	if (lp->close != NULL)
199 		(*lp->close)(lp->fd, &lp->user);
200 	lp->fd = -1;
201 
202 	spin_lock(&opened_lock);
203 	list_del(&lp->list);
204 	spin_unlock(&opened_lock);
205 
206 	return 0;
207 }
208 
209 static int uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
210 {
211 	struct uml_net_private *lp = netdev_priv(dev);
212 	unsigned long flags;
213 	int len;
214 
215 	netif_stop_queue(dev);
216 
217 	spin_lock_irqsave(&lp->lock, flags);
218 
219 	len = (*lp->write)(lp->fd, skb, lp);
220 	skb_tx_timestamp(skb);
221 
222 	if (len == skb->len) {
223 		dev->stats.tx_packets++;
224 		dev->stats.tx_bytes += skb->len;
225 		netif_trans_update(dev);
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_consume_skb_any(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 	netif_trans_update(dev);
255 	netif_wake_queue(dev);
256 }
257 
258 #ifdef CONFIG_NET_POLL_CONTROLLER
259 static void uml_net_poll_controller(struct net_device *dev)
260 {
261 	disable_irq(dev->irq);
262 	uml_net_interrupt(dev->irq, dev);
263 	enable_irq(dev->irq);
264 }
265 #endif
266 
267 static void uml_net_get_drvinfo(struct net_device *dev,
268 				struct ethtool_drvinfo *info)
269 {
270 	strlcpy(info->driver, DRIVER_NAME, sizeof(info->driver));
271 	strlcpy(info->version, "42", sizeof(info->version));
272 }
273 
274 static const struct ethtool_ops uml_net_ethtool_ops = {
275 	.get_drvinfo	= uml_net_get_drvinfo,
276 	.get_link	= ethtool_op_get_link,
277 	.get_ts_info	= ethtool_op_get_ts_info,
278 };
279 
280 static void uml_net_user_timer_expire(struct timer_list *t)
281 {
282 #ifdef undef
283 	struct uml_net_private *lp = from_timer(lp, t, tl);
284 	struct connection *conn = &lp->user;
285 
286 	dprintk(KERN_INFO "uml_net_user_timer_expire [%p]\n", conn);
287 	do_connect(conn);
288 #endif
289 }
290 
291 void uml_net_setup_etheraddr(struct net_device *dev, char *str)
292 {
293 	unsigned char *addr = dev->dev_addr;
294 	char *end;
295 	int i;
296 
297 	if (str == NULL)
298 		goto random;
299 
300 	for (i = 0; i < 6; i++) {
301 		addr[i] = simple_strtoul(str, &end, 16);
302 		if ((end == str) ||
303 		   ((*end != ':') && (*end != ',') && (*end != '\0'))) {
304 			printk(KERN_ERR
305 			       "setup_etheraddr: failed to parse '%s' "
306 			       "as an ethernet address\n", str);
307 			goto random;
308 		}
309 		str = end + 1;
310 	}
311 	if (is_multicast_ether_addr(addr)) {
312 		printk(KERN_ERR
313 		       "Attempt to assign a multicast ethernet address to a "
314 		       "device disallowed\n");
315 		goto random;
316 	}
317 	if (!is_valid_ether_addr(addr)) {
318 		printk(KERN_ERR
319 		       "Attempt to assign an invalid ethernet address to a "
320 		       "device disallowed\n");
321 		goto random;
322 	}
323 	if (!is_local_ether_addr(addr)) {
324 		printk(KERN_WARNING
325 		       "Warning: Assigning a globally valid ethernet "
326 		       "address to a device\n");
327 		printk(KERN_WARNING "You should set the 2nd rightmost bit in "
328 		       "the first byte of the MAC,\n");
329 		printk(KERN_WARNING "i.e. %02x:%02x:%02x:%02x:%02x:%02x\n",
330 		       addr[0] | 0x02, addr[1], addr[2], addr[3], addr[4],
331 		       addr[5]);
332 	}
333 	return;
334 
335 random:
336 	printk(KERN_INFO
337 	       "Choosing a random ethernet address for device %s\n", dev->name);
338 	eth_hw_addr_random(dev);
339 }
340 
341 static DEFINE_SPINLOCK(devices_lock);
342 static LIST_HEAD(devices);
343 
344 static struct platform_driver uml_net_driver = {
345 	.driver = {
346 		.name  = DRIVER_NAME,
347 	},
348 };
349 
350 static void net_device_release(struct device *dev)
351 {
352 	struct uml_net *device = dev_get_drvdata(dev);
353 	struct net_device *netdev = device->dev;
354 	struct uml_net_private *lp = netdev_priv(netdev);
355 
356 	if (lp->remove != NULL)
357 		(*lp->remove)(&lp->user);
358 	list_del(&device->list);
359 	kfree(device);
360 	free_netdev(netdev);
361 }
362 
363 static const struct net_device_ops uml_netdev_ops = {
364 	.ndo_open 		= uml_net_open,
365 	.ndo_stop 		= uml_net_close,
366 	.ndo_start_xmit 	= uml_net_start_xmit,
367 	.ndo_set_rx_mode	= uml_net_set_multicast_list,
368 	.ndo_tx_timeout 	= uml_net_tx_timeout,
369 	.ndo_set_mac_address	= eth_mac_addr,
370 	.ndo_validate_addr	= eth_validate_addr,
371 #ifdef CONFIG_NET_POLL_CONTROLLER
372 	.ndo_poll_controller = uml_net_poll_controller,
373 #endif
374 };
375 
376 /*
377  * Ensures that platform_driver_register is called only once by
378  * eth_configure.  Will be set in an initcall.
379  */
380 static int driver_registered;
381 
382 static void eth_configure(int n, void *init, char *mac,
383 			  struct transport *transport, gfp_t gfp_mask)
384 {
385 	struct uml_net *device;
386 	struct net_device *dev;
387 	struct uml_net_private *lp;
388 	int err, size;
389 
390 	size = transport->private_size + sizeof(struct uml_net_private);
391 
392 	device = kzalloc(sizeof(*device), gfp_mask);
393 	if (device == NULL) {
394 		printk(KERN_ERR "eth_configure failed to allocate struct "
395 		       "uml_net\n");
396 		return;
397 	}
398 
399 	dev = alloc_etherdev(size);
400 	if (dev == NULL) {
401 		printk(KERN_ERR "eth_configure: failed to allocate struct "
402 		       "net_device for eth%d\n", n);
403 		goto out_free_device;
404 	}
405 
406 	INIT_LIST_HEAD(&device->list);
407 	device->index = n;
408 
409 	/* If this name ends up conflicting with an existing registered
410 	 * netdevice, that is OK, register_netdev{,ice}() will notice this
411 	 * and fail.
412 	 */
413 	snprintf(dev->name, sizeof(dev->name), "eth%d", n);
414 
415 	uml_net_setup_etheraddr(dev, mac);
416 
417 	printk(KERN_INFO "Netdevice %d (%pM) : ", n, dev->dev_addr);
418 
419 	lp = netdev_priv(dev);
420 	/* This points to the transport private data. It's still clear, but we
421 	 * must memset it to 0 *now*. Let's help the drivers. */
422 	memset(lp, 0, size);
423 	INIT_WORK(&lp->work, uml_dev_close);
424 
425 	/* sysfs register */
426 	if (!driver_registered) {
427 		platform_driver_register(&uml_net_driver);
428 		driver_registered = 1;
429 	}
430 	device->pdev.id = n;
431 	device->pdev.name = DRIVER_NAME;
432 	device->pdev.dev.release = net_device_release;
433 	dev_set_drvdata(&device->pdev.dev, device);
434 	if (platform_device_register(&device->pdev))
435 		goto out_free_netdev;
436 	SET_NETDEV_DEV(dev,&device->pdev.dev);
437 
438 	device->dev = dev;
439 
440 	/*
441 	 * These just fill in a data structure, so there's no failure
442 	 * to be worried about.
443 	 */
444 	(*transport->kern->init)(dev, init);
445 
446 	*lp = ((struct uml_net_private)
447 		{ .list  		= LIST_HEAD_INIT(lp->list),
448 		  .dev 			= dev,
449 		  .fd 			= -1,
450 		  .mac 			= { 0xfe, 0xfd, 0x0, 0x0, 0x0, 0x0},
451 		  .max_packet		= transport->user->max_packet,
452 		  .protocol 		= transport->kern->protocol,
453 		  .open 		= transport->user->open,
454 		  .close 		= transport->user->close,
455 		  .remove 		= transport->user->remove,
456 		  .read 		= transport->kern->read,
457 		  .write 		= transport->kern->write,
458 		  .add_address 		= transport->user->add_address,
459 		  .delete_address  	= transport->user->delete_address });
460 
461 	timer_setup(&lp->tl, uml_net_user_timer_expire, 0);
462 	spin_lock_init(&lp->lock);
463 	memcpy(lp->mac, dev->dev_addr, sizeof(lp->mac));
464 
465 	if ((transport->user->init != NULL) &&
466 	    ((*transport->user->init)(&lp->user, dev) != 0))
467 		goto out_unregister;
468 
469 	dev->mtu = transport->user->mtu;
470 	dev->netdev_ops = &uml_netdev_ops;
471 	dev->ethtool_ops = &uml_net_ethtool_ops;
472 	dev->watchdog_timeo = (HZ >> 1);
473 	dev->irq = UM_ETH_IRQ;
474 
475 	err = update_drop_skb(lp->max_packet);
476 	if (err)
477 		goto out_undo_user_init;
478 
479 	rtnl_lock();
480 	err = register_netdevice(dev);
481 	rtnl_unlock();
482 	if (err)
483 		goto out_undo_user_init;
484 
485 	spin_lock(&devices_lock);
486 	list_add(&device->list, &devices);
487 	spin_unlock(&devices_lock);
488 
489 	return;
490 
491 out_undo_user_init:
492 	if (transport->user->remove != NULL)
493 		(*transport->user->remove)(&lp->user);
494 out_unregister:
495 	platform_device_unregister(&device->pdev);
496 	return; /* platform_device_unregister frees dev and device */
497 out_free_netdev:
498 	free_netdev(dev);
499 out_free_device:
500 	kfree(device);
501 }
502 
503 static struct uml_net *find_device(int n)
504 {
505 	struct uml_net *device;
506 	struct list_head *ele;
507 
508 	spin_lock(&devices_lock);
509 	list_for_each(ele, &devices) {
510 		device = list_entry(ele, struct uml_net, list);
511 		if (device->index == n)
512 			goto out;
513 	}
514 	device = NULL;
515  out:
516 	spin_unlock(&devices_lock);
517 	return device;
518 }
519 
520 static int eth_parse(char *str, int *index_out, char **str_out,
521 		     char **error_out)
522 {
523 	char *end;
524 	int n, err = -EINVAL;
525 
526 	n = simple_strtoul(str, &end, 0);
527 	if (end == str) {
528 		*error_out = "Bad device number";
529 		return err;
530 	}
531 
532 	str = end;
533 	if (*str != '=') {
534 		*error_out = "Expected '=' after device number";
535 		return err;
536 	}
537 
538 	str++;
539 	if (find_device(n)) {
540 		*error_out = "Device already configured";
541 		return err;
542 	}
543 
544 	*index_out = n;
545 	*str_out = str;
546 	return 0;
547 }
548 
549 struct eth_init {
550 	struct list_head list;
551 	char *init;
552 	int index;
553 };
554 
555 static DEFINE_SPINLOCK(transports_lock);
556 static LIST_HEAD(transports);
557 
558 /* Filled in during early boot */
559 static LIST_HEAD(eth_cmd_line);
560 
561 static int check_transport(struct transport *transport, char *eth, int n,
562 			   void **init_out, char **mac_out, gfp_t gfp_mask)
563 {
564 	int len;
565 
566 	len = strlen(transport->name);
567 	if (strncmp(eth, transport->name, len))
568 		return 0;
569 
570 	eth += len;
571 	if (*eth == ',')
572 		eth++;
573 	else if (*eth != '\0')
574 		return 0;
575 
576 	*init_out = kmalloc(transport->setup_size, gfp_mask);
577 	if (*init_out == NULL)
578 		return 1;
579 
580 	if (!transport->setup(eth, mac_out, *init_out)) {
581 		kfree(*init_out);
582 		*init_out = NULL;
583 	}
584 	return 1;
585 }
586 
587 void register_transport(struct transport *new)
588 {
589 	struct list_head *ele, *next;
590 	struct eth_init *eth;
591 	void *init;
592 	char *mac = NULL;
593 	int match;
594 
595 	spin_lock(&transports_lock);
596 	BUG_ON(!list_empty(&new->list));
597 	list_add(&new->list, &transports);
598 	spin_unlock(&transports_lock);
599 
600 	list_for_each_safe(ele, next, &eth_cmd_line) {
601 		eth = list_entry(ele, struct eth_init, list);
602 		match = check_transport(new, eth->init, eth->index, &init,
603 					&mac, GFP_KERNEL);
604 		if (!match)
605 			continue;
606 		else if (init != NULL) {
607 			eth_configure(eth->index, init, mac, new, GFP_KERNEL);
608 			kfree(init);
609 		}
610 		list_del(&eth->list);
611 	}
612 }
613 
614 static int eth_setup_common(char *str, int index)
615 {
616 	struct list_head *ele;
617 	struct transport *transport;
618 	void *init;
619 	char *mac = NULL;
620 	int found = 0;
621 
622 	spin_lock(&transports_lock);
623 	list_for_each(ele, &transports) {
624 		transport = list_entry(ele, struct transport, list);
625 	        if (!check_transport(transport, str, index, &init,
626 					&mac, GFP_ATOMIC))
627 			continue;
628 		if (init != NULL) {
629 			eth_configure(index, init, mac, transport, GFP_ATOMIC);
630 			kfree(init);
631 		}
632 		found = 1;
633 		break;
634 	}
635 
636 	spin_unlock(&transports_lock);
637 	return found;
638 }
639 
640 static int __init eth_setup(char *str)
641 {
642 	struct eth_init *new;
643 	char *error;
644 	int n, err;
645 
646 	err = eth_parse(str, &n, &str, &error);
647 	if (err) {
648 		printk(KERN_ERR "eth_setup - Couldn't parse '%s' : %s\n",
649 		       str, error);
650 		return 1;
651 	}
652 
653 	new = alloc_bootmem(sizeof(*new));
654 
655 	INIT_LIST_HEAD(&new->list);
656 	new->index = n;
657 	new->init = str;
658 
659 	list_add_tail(&new->list, &eth_cmd_line);
660 	return 1;
661 }
662 
663 __setup("eth", eth_setup);
664 __uml_help(eth_setup,
665 "eth[0-9]+=<transport>,<options>\n"
666 "    Configure a network device.\n\n"
667 );
668 
669 static int net_config(char *str, char **error_out)
670 {
671 	int n, err;
672 
673 	err = eth_parse(str, &n, &str, error_out);
674 	if (err)
675 		return err;
676 
677 	/* This string is broken up and the pieces used by the underlying
678 	 * driver.  So, it is freed only if eth_setup_common fails.
679 	 */
680 	str = kstrdup(str, GFP_KERNEL);
681 	if (str == NULL) {
682 	        *error_out = "net_config failed to strdup string";
683 		return -ENOMEM;
684 	}
685 	err = !eth_setup_common(str, n);
686 	if (err)
687 		kfree(str);
688 	return err;
689 }
690 
691 static int net_id(char **str, int *start_out, int *end_out)
692 {
693 	char *end;
694 	int n;
695 
696 	n = simple_strtoul(*str, &end, 0);
697 	if ((*end != '\0') || (end == *str))
698 		return -1;
699 
700 	*start_out = n;
701 	*end_out = n;
702 	*str = end;
703 	return n;
704 }
705 
706 static int net_remove(int n, char **error_out)
707 {
708 	struct uml_net *device;
709 	struct net_device *dev;
710 	struct uml_net_private *lp;
711 
712 	device = find_device(n);
713 	if (device == NULL)
714 		return -ENODEV;
715 
716 	dev = device->dev;
717 	lp = netdev_priv(dev);
718 	if (lp->fd > 0)
719 		return -EBUSY;
720 	unregister_netdev(dev);
721 	platform_device_unregister(&device->pdev);
722 
723 	return 0;
724 }
725 
726 static struct mc_device net_mc = {
727 	.list		= LIST_HEAD_INIT(net_mc.list),
728 	.name		= "eth",
729 	.config		= net_config,
730 	.get_config	= NULL,
731 	.id		= net_id,
732 	.remove		= net_remove,
733 };
734 
735 #ifdef CONFIG_INET
736 static int uml_inetaddr_event(struct notifier_block *this, unsigned long event,
737 			      void *ptr)
738 {
739 	struct in_ifaddr *ifa = ptr;
740 	struct net_device *dev = ifa->ifa_dev->dev;
741 	struct uml_net_private *lp;
742 	void (*proc)(unsigned char *, unsigned char *, void *);
743 	unsigned char addr_buf[4], netmask_buf[4];
744 
745 	if (dev->netdev_ops->ndo_open != uml_net_open)
746 		return NOTIFY_DONE;
747 
748 	lp = netdev_priv(dev);
749 
750 	proc = NULL;
751 	switch (event) {
752 	case NETDEV_UP:
753 		proc = lp->add_address;
754 		break;
755 	case NETDEV_DOWN:
756 		proc = lp->delete_address;
757 		break;
758 	}
759 	if (proc != NULL) {
760 		memcpy(addr_buf, &ifa->ifa_address, sizeof(addr_buf));
761 		memcpy(netmask_buf, &ifa->ifa_mask, sizeof(netmask_buf));
762 		(*proc)(addr_buf, netmask_buf, &lp->user);
763 	}
764 	return NOTIFY_DONE;
765 }
766 
767 /* uml_net_init shouldn't be called twice on two CPUs at the same time */
768 static struct notifier_block uml_inetaddr_notifier = {
769 	.notifier_call		= uml_inetaddr_event,
770 };
771 
772 static void inet_register(void)
773 {
774 	struct list_head *ele;
775 	struct uml_net_private *lp;
776 	struct in_device *ip;
777 	struct in_ifaddr *in;
778 
779 	register_inetaddr_notifier(&uml_inetaddr_notifier);
780 
781 	/* Devices may have been opened already, so the uml_inetaddr_notifier
782 	 * didn't get a chance to run for them.  This fakes it so that
783 	 * addresses which have already been set up get handled properly.
784 	 */
785 	spin_lock(&opened_lock);
786 	list_for_each(ele, &opened) {
787 		lp = list_entry(ele, struct uml_net_private, list);
788 		ip = lp->dev->ip_ptr;
789 		if (ip == NULL)
790 			continue;
791 		in = ip->ifa_list;
792 		while (in != NULL) {
793 			uml_inetaddr_event(NULL, NETDEV_UP, in);
794 			in = in->ifa_next;
795 		}
796 	}
797 	spin_unlock(&opened_lock);
798 }
799 #else
800 static inline void inet_register(void)
801 {
802 }
803 #endif
804 
805 static int uml_net_init(void)
806 {
807 	mconsole_register_dev(&net_mc);
808 	inet_register();
809 	return 0;
810 }
811 
812 __initcall(uml_net_init);
813 
814 static void close_devices(void)
815 {
816 	struct list_head *ele;
817 	struct uml_net_private *lp;
818 
819 	spin_lock(&opened_lock);
820 	list_for_each(ele, &opened) {
821 		lp = list_entry(ele, struct uml_net_private, list);
822 		um_free_irq(lp->dev->irq, lp->dev);
823 		if ((lp->close != NULL) && (lp->fd >= 0))
824 			(*lp->close)(lp->fd, &lp->user);
825 		if (lp->remove != NULL)
826 			(*lp->remove)(&lp->user);
827 	}
828 	spin_unlock(&opened_lock);
829 }
830 
831 __uml_exitcall(close_devices);
832 
833 void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *,
834 					void *),
835 		    void *arg)
836 {
837 	struct net_device *dev = d;
838 	struct in_device *ip = dev->ip_ptr;
839 	struct in_ifaddr *in;
840 	unsigned char address[4], netmask[4];
841 
842 	if (ip == NULL) return;
843 	in = ip->ifa_list;
844 	while (in != NULL) {
845 		memcpy(address, &in->ifa_address, sizeof(address));
846 		memcpy(netmask, &in->ifa_mask, sizeof(netmask));
847 		(*cb)(address, netmask, arg);
848 		in = in->ifa_next;
849 	}
850 }
851 
852 int dev_netmask(void *d, void *m)
853 {
854 	struct net_device *dev = d;
855 	struct in_device *ip = dev->ip_ptr;
856 	struct in_ifaddr *in;
857 	__be32 *mask_out = m;
858 
859 	if (ip == NULL)
860 		return 1;
861 
862 	in = ip->ifa_list;
863 	if (in == NULL)
864 		return 1;
865 
866 	*mask_out = in->ifa_mask;
867 	return 0;
868 }
869 
870 void *get_output_buffer(int *len_out)
871 {
872 	void *ret;
873 
874 	ret = (void *) __get_free_pages(GFP_KERNEL, 0);
875 	if (ret) *len_out = PAGE_SIZE;
876 	else *len_out = 0;
877 	return ret;
878 }
879 
880 void free_output_buffer(void *buffer)
881 {
882 	free_pages((unsigned long) buffer, 0);
883 }
884 
885 int tap_setup_common(char *str, char *type, char **dev_name, char **mac_out,
886 		     char **gate_addr)
887 {
888 	char *remain;
889 
890 	remain = split_if_spec(str, dev_name, mac_out, gate_addr, NULL);
891 	if (remain != NULL) {
892 		printk(KERN_ERR "tap_setup_common - Extra garbage on "
893 		       "specification : '%s'\n", remain);
894 		return 1;
895 	}
896 
897 	return 0;
898 }
899 
900 unsigned short eth_protocol(struct sk_buff *skb)
901 {
902 	return eth_type_trans(skb, skb->dev);
903 }
904