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1/*
2 * linux/drivers/net/netconsole.c
3 *
4 * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com>
5 *
6 * This file contains the implementation of an IRQ-safe, crash-safe
7 * kernel console implementation that outputs kernel messages to the
8 * network.
9 *
10 * Modification history:
11 *
12 * 2001-09-17 started by Ingo Molnar.
13 * 2003-08-11 2.6 port by Matt Mackall
14 * simplified options
15 * generic card hooks
16 * works non-modular
17 * 2003-09-07 rewritten with netpoll api
18 */
19
20/****************************************************************
21 * This program is free software; you can redistribute it and/or modify
22 * it under the terms of the GNU General Public License as published by
23 * the Free Software Foundation; either version 2, or (at your option)
24 * any later version.
25 *
26 * This program is distributed in the hope that it will be useful,
27 * but WITHOUT ANY WARRANTY; without even the implied warranty of
28 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
29 * GNU General Public License for more details.
30 *
31 * You should have received a copy of the GNU General Public License
32 * along with this program; if not, write to the Free Software
33 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
34 *
35 ****************************************************************/
36
37#include <linux/mm.h>
38#include <linux/init.h>
39#include <linux/module.h>
40#include <linux/slab.h>
41#include <linux/console.h>
42#include <linux/moduleparam.h>
43#include <linux/string.h>
44#include <linux/netpoll.h>
45#include <linux/inet.h>
46#include <linux/configfs.h>
47
48MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@selenic.com>");
49MODULE_DESCRIPTION("Console driver for network interfaces");
50MODULE_LICENSE("GPL");
51
52#define MAX_PARAM_LENGTH 256
53#define MAX_PRINT_CHUNK 1000
54
55static char config[MAX_PARAM_LENGTH];
56module_param_string(netconsole, config, MAX_PARAM_LENGTH, 0);
57MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]");
58
59#ifndef MODULE
60static int __init option_setup(char *opt)
61{
62 strlcpy(config, opt, MAX_PARAM_LENGTH);
63 return 1;
64}
65__setup("netconsole=", option_setup);
66#endif /* MODULE */
67
68/* Linked list of all configured targets */
69static LIST_HEAD(target_list);
70
71/* This needs to be a spinlock because write_msg() cannot sleep */
72static DEFINE_SPINLOCK(target_list_lock);
73
74/**
75 * struct netconsole_target - Represents a configured netconsole target.
76 * @list: Links this target into the target_list.
77 * @item: Links us into the configfs subsystem hierarchy.
78 * @enabled: On / off knob to enable / disable target.
79 * Visible from userspace (read-write).
80 * We maintain a strict 1:1 correspondence between this and
81 * whether the corresponding netpoll is active or inactive.
82 * Also, other parameters of a target may be modified at
83 * runtime only when it is disabled (enabled == 0).
84 * @np: The netpoll structure for this target.
85 * Contains the other userspace visible parameters:
86 * dev_name (read-write)
87 * local_port (read-write)
88 * remote_port (read-write)
89 * local_ip (read-write)
90 * remote_ip (read-write)
91 * local_mac (read-only)
92 * remote_mac (read-write)
93 */
94struct netconsole_target {
95 struct list_head list;
96#ifdef CONFIG_NETCONSOLE_DYNAMIC
97 struct config_item item;
98#endif
99 int enabled;
100 struct netpoll np;
101};
102
103#ifdef CONFIG_NETCONSOLE_DYNAMIC
104
105static struct configfs_subsystem netconsole_subsys;
106
107static int __init dynamic_netconsole_init(void)
108{
109 config_group_init(&netconsole_subsys.su_group);
110 mutex_init(&netconsole_subsys.su_mutex);
111 return configfs_register_subsystem(&netconsole_subsys);
112}
113
114static void __exit dynamic_netconsole_exit(void)
115{
116 configfs_unregister_subsystem(&netconsole_subsys);
117}
118
119/*
120 * Targets that were created by parsing the boot/module option string
121 * do not exist in the configfs hierarchy (and have NULL names) and will
122 * never go away, so make these a no-op for them.
123 */
124static void netconsole_target_get(struct netconsole_target *nt)
125{
126 if (config_item_name(&nt->item))
127 config_item_get(&nt->item);
128}
129
130static void netconsole_target_put(struct netconsole_target *nt)
131{
132 if (config_item_name(&nt->item))
133 config_item_put(&nt->item);
134}
135
136#else /* !CONFIG_NETCONSOLE_DYNAMIC */
137
138static int __init dynamic_netconsole_init(void)
139{
140 return 0;
141}
142
143static void __exit dynamic_netconsole_exit(void)
144{
145}
146
147/*
148 * No danger of targets going away from under us when dynamic
149 * reconfigurability is off.
150 */
151static void netconsole_target_get(struct netconsole_target *nt)
152{
153}
154
155static void netconsole_target_put(struct netconsole_target *nt)
156{
157}
158
159#endif /* CONFIG_NETCONSOLE_DYNAMIC */
160
161/* Allocate new target (from boot/module param) and setup netpoll for it */
162static struct netconsole_target *alloc_param_target(char *target_config)
163{
164 int err = -ENOMEM;
165 struct netconsole_target *nt;
166
167 /*
168 * Allocate and initialize with defaults.
169 * Note that these targets get their config_item fields zeroed-out.
170 */
171 nt = kzalloc(sizeof(*nt), GFP_KERNEL);
172 if (!nt) {
173 printk(KERN_ERR "netconsole: failed to allocate memory\n");
174 goto fail;
175 }
176
177 nt->np.name = "netconsole";
178 strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
179 nt->np.local_port = 6665;
180 nt->np.remote_port = 6666;
181 memset(nt->np.remote_mac, 0xff, ETH_ALEN);
182
183 /* Parse parameters and setup netpoll */
184 err = netpoll_parse_options(&nt->np, target_config);
185 if (err)
186 goto fail;
187
188 err = netpoll_setup(&nt->np);
189 if (err)
190 goto fail;
191
192 nt->enabled = 1;
193
194 return nt;
195
196fail:
197 kfree(nt);
198 return ERR_PTR(err);
199}
200
201/* Cleanup netpoll for given target (from boot/module param) and free it */
202static void free_param_target(struct netconsole_target *nt)
203{
204 netpoll_cleanup(&nt->np);
205 kfree(nt);
206}
207
208#ifdef CONFIG_NETCONSOLE_DYNAMIC
209
210/*
211 * Our subsystem hierarchy is:
212 *
213 * /sys/kernel/config/netconsole/
214 * |
215 * <target>/
216 * | enabled
217 * | dev_name
218 * | local_port
219 * | remote_port
220 * | local_ip
221 * | remote_ip
222 * | local_mac
223 * | remote_mac
224 * |
225 * <target>/...
226 */
227
228struct netconsole_target_attr {
229 struct configfs_attribute attr;
230 ssize_t (*show)(struct netconsole_target *nt,
231 char *buf);
232 ssize_t (*store)(struct netconsole_target *nt,
233 const char *buf,
234 size_t count);
235};
236
237static struct netconsole_target *to_target(struct config_item *item)
238{
239 return item ?
240 container_of(item, struct netconsole_target, item) :
241 NULL;
242}
243
244/*
245 * Attribute operations for netconsole_target.
246 */
247
248static ssize_t show_enabled(struct netconsole_target *nt, char *buf)
249{
250 return snprintf(buf, PAGE_SIZE, "%d\n", nt->enabled);
251}
252
253static ssize_t show_dev_name(struct netconsole_target *nt, char *buf)
254{
255 return snprintf(buf, PAGE_SIZE, "%s\n", nt->np.dev_name);
256}
257
258static ssize_t show_local_port(struct netconsole_target *nt, char *buf)
259{
260 return snprintf(buf, PAGE_SIZE, "%d\n", nt->np.local_port);
261}
262
263static ssize_t show_remote_port(struct netconsole_target *nt, char *buf)
264{
265 return snprintf(buf, PAGE_SIZE, "%d\n", nt->np.remote_port);
266}
267
268static ssize_t show_local_ip(struct netconsole_target *nt, char *buf)
269{
270 return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.local_ip);
271}
272
273static ssize_t show_remote_ip(struct netconsole_target *nt, char *buf)
274{
275 return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.remote_ip);
276}
277
278static ssize_t show_local_mac(struct netconsole_target *nt, char *buf)
279{
280 struct net_device *dev = nt->np.dev;
281 static const u8 bcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
282
283 return snprintf(buf, PAGE_SIZE, "%pM\n", dev ? dev->dev_addr : bcast);
284}
285
286static ssize_t show_remote_mac(struct netconsole_target *nt, char *buf)
287{
288 return snprintf(buf, PAGE_SIZE, "%pM\n", nt->np.remote_mac);
289}
290
291/*
292 * This one is special -- targets created through the configfs interface
293 * are not enabled (and the corresponding netpoll activated) by default.
294 * The user is expected to set the desired parameters first (which
295 * would enable him to dynamically add new netpoll targets for new
296 * network interfaces as and when they come up).
297 */
298static ssize_t store_enabled(struct netconsole_target *nt,
299 const char *buf,
300 size_t count)
301{
302 int enabled;
303 int err;
304
305 err = kstrtoint(buf, 10, &enabled);
306 if (err < 0)
307 return err;
308 if (enabled < 0 || enabled > 1)
309 return -EINVAL;
310 if (enabled == nt->enabled) {
311 printk(KERN_INFO "netconsole: network logging has already %s\n",
312 nt->enabled ? "started" : "stopped");
313 return -EINVAL;
314 }
315
316 if (enabled) { /* 1 */
317
318 /*
319 * Skip netpoll_parse_options() -- all the attributes are
320 * already configured via configfs. Just print them out.
321 */
322 netpoll_print_options(&nt->np);
323
324 err = netpoll_setup(&nt->np);
325 if (err)
326 return err;
327
328 printk(KERN_INFO "netconsole: network logging started\n");
329
330 } else { /* 0 */
331 netpoll_cleanup(&nt->np);
332 }
333
334 nt->enabled = enabled;
335
336 return strnlen(buf, count);
337}
338
339static ssize_t store_dev_name(struct netconsole_target *nt,
340 const char *buf,
341 size_t count)
342{
343 size_t len;
344
345 if (nt->enabled) {
346 printk(KERN_ERR "netconsole: target (%s) is enabled, "
347 "disable to update parameters\n",
348 config_item_name(&nt->item));
349 return -EINVAL;
350 }
351
352 strlcpy(nt->np.dev_name, buf, IFNAMSIZ);
353
354 /* Get rid of possible trailing newline from echo(1) */
355 len = strnlen(nt->np.dev_name, IFNAMSIZ);
356 if (nt->np.dev_name[len - 1] == '\n')
357 nt->np.dev_name[len - 1] = '\0';
358
359 return strnlen(buf, count);
360}
361
362static ssize_t store_local_port(struct netconsole_target *nt,
363 const char *buf,
364 size_t count)
365{
366 int rv;
367
368 if (nt->enabled) {
369 printk(KERN_ERR "netconsole: target (%s) is enabled, "
370 "disable to update parameters\n",
371 config_item_name(&nt->item));
372 return -EINVAL;
373 }
374
375 rv = kstrtou16(buf, 10, &nt->np.local_port);
376 if (rv < 0)
377 return rv;
378 return strnlen(buf, count);
379}
380
381static ssize_t store_remote_port(struct netconsole_target *nt,
382 const char *buf,
383 size_t count)
384{
385 int rv;
386
387 if (nt->enabled) {
388 printk(KERN_ERR "netconsole: target (%s) is enabled, "
389 "disable to update parameters\n",
390 config_item_name(&nt->item));
391 return -EINVAL;
392 }
393
394 rv = kstrtou16(buf, 10, &nt->np.remote_port);
395 if (rv < 0)
396 return rv;
397 return strnlen(buf, count);
398}
399
400static ssize_t store_local_ip(struct netconsole_target *nt,
401 const char *buf,
402 size_t count)
403{
404 if (nt->enabled) {
405 printk(KERN_ERR "netconsole: target (%s) is enabled, "
406 "disable to update parameters\n",
407 config_item_name(&nt->item));
408 return -EINVAL;
409 }
410
411 nt->np.local_ip = in_aton(buf);
412
413 return strnlen(buf, count);
414}
415
416static ssize_t store_remote_ip(struct netconsole_target *nt,
417 const char *buf,
418 size_t count)
419{
420 if (nt->enabled) {
421 printk(KERN_ERR "netconsole: target (%s) is enabled, "
422 "disable to update parameters\n",
423 config_item_name(&nt->item));
424 return -EINVAL;
425 }
426
427 nt->np.remote_ip = in_aton(buf);
428
429 return strnlen(buf, count);
430}
431
432static ssize_t store_remote_mac(struct netconsole_target *nt,
433 const char *buf,
434 size_t count)
435{
436 u8 remote_mac[ETH_ALEN];
437
438 if (nt->enabled) {
439 printk(KERN_ERR "netconsole: target (%s) is enabled, "
440 "disable to update parameters\n",
441 config_item_name(&nt->item));
442 return -EINVAL;
443 }
444
445 if (!mac_pton(buf, remote_mac))
446 return -EINVAL;
447 if (buf[3 * ETH_ALEN - 1] && buf[3 * ETH_ALEN - 1] != '\n')
448 return -EINVAL;
449 memcpy(nt->np.remote_mac, remote_mac, ETH_ALEN);
450
451 return strnlen(buf, count);
452}
453
454/*
455 * Attribute definitions for netconsole_target.
456 */
457
458#define NETCONSOLE_TARGET_ATTR_RO(_name) \
459static struct netconsole_target_attr netconsole_target_##_name = \
460 __CONFIGFS_ATTR(_name, S_IRUGO, show_##_name, NULL)
461
462#define NETCONSOLE_TARGET_ATTR_RW(_name) \
463static struct netconsole_target_attr netconsole_target_##_name = \
464 __CONFIGFS_ATTR(_name, S_IRUGO | S_IWUSR, show_##_name, store_##_name)
465
466NETCONSOLE_TARGET_ATTR_RW(enabled);
467NETCONSOLE_TARGET_ATTR_RW(dev_name);
468NETCONSOLE_TARGET_ATTR_RW(local_port);
469NETCONSOLE_TARGET_ATTR_RW(remote_port);
470NETCONSOLE_TARGET_ATTR_RW(local_ip);
471NETCONSOLE_TARGET_ATTR_RW(remote_ip);
472NETCONSOLE_TARGET_ATTR_RO(local_mac);
473NETCONSOLE_TARGET_ATTR_RW(remote_mac);
474
475static struct configfs_attribute *netconsole_target_attrs[] = {
476 &netconsole_target_enabled.attr,
477 &netconsole_target_dev_name.attr,
478 &netconsole_target_local_port.attr,
479 &netconsole_target_remote_port.attr,
480 &netconsole_target_local_ip.attr,
481 &netconsole_target_remote_ip.attr,
482 &netconsole_target_local_mac.attr,
483 &netconsole_target_remote_mac.attr,
484 NULL,
485};
486
487/*
488 * Item operations and type for netconsole_target.
489 */
490
491static void netconsole_target_release(struct config_item *item)
492{
493 kfree(to_target(item));
494}
495
496static ssize_t netconsole_target_attr_show(struct config_item *item,
497 struct configfs_attribute *attr,
498 char *buf)
499{
500 ssize_t ret = -EINVAL;
501 struct netconsole_target *nt = to_target(item);
502 struct netconsole_target_attr *na =
503 container_of(attr, struct netconsole_target_attr, attr);
504
505 if (na->show)
506 ret = na->show(nt, buf);
507
508 return ret;
509}
510
511static ssize_t netconsole_target_attr_store(struct config_item *item,
512 struct configfs_attribute *attr,
513 const char *buf,
514 size_t count)
515{
516 ssize_t ret = -EINVAL;
517 struct netconsole_target *nt = to_target(item);
518 struct netconsole_target_attr *na =
519 container_of(attr, struct netconsole_target_attr, attr);
520
521 if (na->store)
522 ret = na->store(nt, buf, count);
523
524 return ret;
525}
526
527static struct configfs_item_operations netconsole_target_item_ops = {
528 .release = netconsole_target_release,
529 .show_attribute = netconsole_target_attr_show,
530 .store_attribute = netconsole_target_attr_store,
531};
532
533static struct config_item_type netconsole_target_type = {
534 .ct_attrs = netconsole_target_attrs,
535 .ct_item_ops = &netconsole_target_item_ops,
536 .ct_owner = THIS_MODULE,
537};
538
539/*
540 * Group operations and type for netconsole_subsys.
541 */
542
543static struct config_item *make_netconsole_target(struct config_group *group,
544 const char *name)
545{
546 unsigned long flags;
547 struct netconsole_target *nt;
548
549 /*
550 * Allocate and initialize with defaults.
551 * Target is disabled at creation (enabled == 0).
552 */
553 nt = kzalloc(sizeof(*nt), GFP_KERNEL);
554 if (!nt) {
555 printk(KERN_ERR "netconsole: failed to allocate memory\n");
556 return ERR_PTR(-ENOMEM);
557 }
558
559 nt->np.name = "netconsole";
560 strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
561 nt->np.local_port = 6665;
562 nt->np.remote_port = 6666;
563 memset(nt->np.remote_mac, 0xff, ETH_ALEN);
564
565 /* Initialize the config_item member */
566 config_item_init_type_name(&nt->item, name, &netconsole_target_type);
567
568 /* Adding, but it is disabled */
569 spin_lock_irqsave(&target_list_lock, flags);
570 list_add(&nt->list, &target_list);
571 spin_unlock_irqrestore(&target_list_lock, flags);
572
573 return &nt->item;
574}
575
576static void drop_netconsole_target(struct config_group *group,
577 struct config_item *item)
578{
579 unsigned long flags;
580 struct netconsole_target *nt = to_target(item);
581
582 spin_lock_irqsave(&target_list_lock, flags);
583 list_del(&nt->list);
584 spin_unlock_irqrestore(&target_list_lock, flags);
585
586 /*
587 * The target may have never been enabled, or was manually disabled
588 * before being removed so netpoll may have already been cleaned up.
589 */
590 if (nt->enabled)
591 netpoll_cleanup(&nt->np);
592
593 config_item_put(&nt->item);
594}
595
596static struct configfs_group_operations netconsole_subsys_group_ops = {
597 .make_item = make_netconsole_target,
598 .drop_item = drop_netconsole_target,
599};
600
601static struct config_item_type netconsole_subsys_type = {
602 .ct_group_ops = &netconsole_subsys_group_ops,
603 .ct_owner = THIS_MODULE,
604};
605
606/* The netconsole configfs subsystem */
607static struct configfs_subsystem netconsole_subsys = {
608 .su_group = {
609 .cg_item = {
610 .ci_namebuf = "netconsole",
611 .ci_type = &netconsole_subsys_type,
612 },
613 },
614};
615
616#endif /* CONFIG_NETCONSOLE_DYNAMIC */
617
618/* Handle network interface device notifications */
619static int netconsole_netdev_event(struct notifier_block *this,
620 unsigned long event,
621 void *ptr)
622{
623 unsigned long flags;
624 struct netconsole_target *nt;
625 struct net_device *dev = ptr;
626 bool stopped = false;
627
628 if (!(event == NETDEV_CHANGENAME || event == NETDEV_UNREGISTER ||
629 event == NETDEV_RELEASE || event == NETDEV_JOIN))
630 goto done;
631
632 spin_lock_irqsave(&target_list_lock, flags);
633 list_for_each_entry(nt, &target_list, list) {
634 netconsole_target_get(nt);
635 if (nt->np.dev == dev) {
636 switch (event) {
637 case NETDEV_CHANGENAME:
638 strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ);
639 break;
640 case NETDEV_RELEASE:
641 case NETDEV_JOIN:
642 case NETDEV_UNREGISTER:
643 /*
644 * rtnl_lock already held
645 */
646 if (nt->np.dev) {
647 spin_unlock_irqrestore(
648 &target_list_lock,
649 flags);
650 __netpoll_cleanup(&nt->np);
651 spin_lock_irqsave(&target_list_lock,
652 flags);
653 dev_put(nt->np.dev);
654 nt->np.dev = NULL;
655 netconsole_target_put(nt);
656 }
657 nt->enabled = 0;
658 stopped = true;
659 break;
660 }
661 }
662 netconsole_target_put(nt);
663 }
664 spin_unlock_irqrestore(&target_list_lock, flags);
665 if (stopped) {
666 printk(KERN_INFO "netconsole: network logging stopped on "
667 "interface %s as it ", dev->name);
668 switch (event) {
669 case NETDEV_UNREGISTER:
670 printk(KERN_CONT "unregistered\n");
671 break;
672 case NETDEV_RELEASE:
673 printk(KERN_CONT "released slaves\n");
674 break;
675 case NETDEV_JOIN:
676 printk(KERN_CONT "is joining a master device\n");
677 break;
678 }
679 }
680
681done:
682 return NOTIFY_DONE;
683}
684
685static struct notifier_block netconsole_netdev_notifier = {
686 .notifier_call = netconsole_netdev_event,
687};
688
689static void write_msg(struct console *con, const char *msg, unsigned int len)
690{
691 int frag, left;
692 unsigned long flags;
693 struct netconsole_target *nt;
694 const char *tmp;
695
696 /* Avoid taking lock and disabling interrupts unnecessarily */
697 if (list_empty(&target_list))
698 return;
699
700 spin_lock_irqsave(&target_list_lock, flags);
701 list_for_each_entry(nt, &target_list, list) {
702 netconsole_target_get(nt);
703 if (nt->enabled && netif_running(nt->np.dev)) {
704 /*
705 * We nest this inside the for-each-target loop above
706 * so that we're able to get as much logging out to
707 * at least one target if we die inside here, instead
708 * of unnecessarily keeping all targets in lock-step.
709 */
710 tmp = msg;
711 for (left = len; left;) {
712 frag = min(left, MAX_PRINT_CHUNK);
713 netpoll_send_udp(&nt->np, tmp, frag);
714 tmp += frag;
715 left -= frag;
716 }
717 }
718 netconsole_target_put(nt);
719 }
720 spin_unlock_irqrestore(&target_list_lock, flags);
721}
722
723static struct console netconsole = {
724 .name = "netcon",
725 .flags = CON_ENABLED,
726 .write = write_msg,
727};
728
729static int __init init_netconsole(void)
730{
731 int err;
732 struct netconsole_target *nt, *tmp;
733 unsigned long flags;
734 char *target_config;
735 char *input = config;
736
737 if (strnlen(input, MAX_PARAM_LENGTH)) {
738 while ((target_config = strsep(&input, ";"))) {
739 nt = alloc_param_target(target_config);
740 if (IS_ERR(nt)) {
741 err = PTR_ERR(nt);
742 goto fail;
743 }
744 /* Dump existing printks when we register */
745 netconsole.flags |= CON_PRINTBUFFER;
746
747 spin_lock_irqsave(&target_list_lock, flags);
748 list_add(&nt->list, &target_list);
749 spin_unlock_irqrestore(&target_list_lock, flags);
750 }
751 }
752
753 err = register_netdevice_notifier(&netconsole_netdev_notifier);
754 if (err)
755 goto fail;
756
757 err = dynamic_netconsole_init();
758 if (err)
759 goto undonotifier;
760
761 register_console(&netconsole);
762 printk(KERN_INFO "netconsole: network logging started\n");
763
764 return err;
765
766undonotifier:
767 unregister_netdevice_notifier(&netconsole_netdev_notifier);
768
769fail:
770 printk(KERN_ERR "netconsole: cleaning up\n");
771
772 /*
773 * Remove all targets and destroy them (only targets created
774 * from the boot/module option exist here). Skipping the list
775 * lock is safe here, and netpoll_cleanup() will sleep.
776 */
777 list_for_each_entry_safe(nt, tmp, &target_list, list) {
778 list_del(&nt->list);
779 free_param_target(nt);
780 }
781
782 return err;
783}
784
785static void __exit cleanup_netconsole(void)
786{
787 struct netconsole_target *nt, *tmp;
788
789 unregister_console(&netconsole);
790 dynamic_netconsole_exit();
791 unregister_netdevice_notifier(&netconsole_netdev_notifier);
792
793 /*
794 * Targets created via configfs pin references on our module
795 * and would first be rmdir(2)'ed from userspace. We reach
796 * here only when they are already destroyed, and only those
797 * created from the boot/module option are left, so remove and
798 * destroy them. Skipping the list lock is safe here, and
799 * netpoll_cleanup() will sleep.
800 */
801 list_for_each_entry_safe(nt, tmp, &target_list, list) {
802 list_del(&nt->list);
803 free_param_target(nt);
804 }
805}
806
807/*
808 * Use late_initcall to ensure netconsole is
809 * initialized after network device driver if built-in.
810 *
811 * late_initcall() and module_init() are identical if built as module.
812 */
813late_initcall(init_netconsole);
814module_exit(cleanup_netconsole);
1/*
2 * linux/drivers/net/netconsole.c
3 *
4 * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com>
5 *
6 * This file contains the implementation of an IRQ-safe, crash-safe
7 * kernel console implementation that outputs kernel messages to the
8 * network.
9 *
10 * Modification history:
11 *
12 * 2001-09-17 started by Ingo Molnar.
13 * 2003-08-11 2.6 port by Matt Mackall
14 * simplified options
15 * generic card hooks
16 * works non-modular
17 * 2003-09-07 rewritten with netpoll api
18 */
19
20/****************************************************************
21 * This program is free software; you can redistribute it and/or modify
22 * it under the terms of the GNU General Public License as published by
23 * the Free Software Foundation; either version 2, or (at your option)
24 * any later version.
25 *
26 * This program is distributed in the hope that it will be useful,
27 * but WITHOUT ANY WARRANTY; without even the implied warranty of
28 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
29 * GNU General Public License for more details.
30 *
31 * You should have received a copy of the GNU General Public License
32 * along with this program; if not, write to the Free Software
33 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
34 *
35 ****************************************************************/
36
37#include <linux/mm.h>
38#include <linux/init.h>
39#include <linux/module.h>
40#include <linux/slab.h>
41#include <linux/console.h>
42#include <linux/moduleparam.h>
43#include <linux/string.h>
44#include <linux/netpoll.h>
45#include <linux/inet.h>
46#include <linux/configfs.h>
47
48MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@selenic.com>");
49MODULE_DESCRIPTION("Console driver for network interfaces");
50MODULE_LICENSE("GPL");
51
52#define MAX_PARAM_LENGTH 256
53#define MAX_PRINT_CHUNK 1000
54
55static char config[MAX_PARAM_LENGTH];
56module_param_string(netconsole, config, MAX_PARAM_LENGTH, 0);
57MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]");
58
59#ifndef MODULE
60static int __init option_setup(char *opt)
61{
62 strlcpy(config, opt, MAX_PARAM_LENGTH);
63 return 1;
64}
65__setup("netconsole=", option_setup);
66#endif /* MODULE */
67
68/* Linked list of all configured targets */
69static LIST_HEAD(target_list);
70
71/* This needs to be a spinlock because write_msg() cannot sleep */
72static DEFINE_SPINLOCK(target_list_lock);
73
74/**
75 * struct netconsole_target - Represents a configured netconsole target.
76 * @list: Links this target into the target_list.
77 * @item: Links us into the configfs subsystem hierarchy.
78 * @enabled: On / off knob to enable / disable target.
79 * Visible from userspace (read-write).
80 * We maintain a strict 1:1 correspondence between this and
81 * whether the corresponding netpoll is active or inactive.
82 * Also, other parameters of a target may be modified at
83 * runtime only when it is disabled (enabled == 0).
84 * @np: The netpoll structure for this target.
85 * Contains the other userspace visible parameters:
86 * dev_name (read-write)
87 * local_port (read-write)
88 * remote_port (read-write)
89 * local_ip (read-write)
90 * remote_ip (read-write)
91 * local_mac (read-only)
92 * remote_mac (read-write)
93 */
94struct netconsole_target {
95 struct list_head list;
96#ifdef CONFIG_NETCONSOLE_DYNAMIC
97 struct config_item item;
98#endif
99 int enabled;
100 struct netpoll np;
101};
102
103#ifdef CONFIG_NETCONSOLE_DYNAMIC
104
105static struct configfs_subsystem netconsole_subsys;
106
107static int __init dynamic_netconsole_init(void)
108{
109 config_group_init(&netconsole_subsys.su_group);
110 mutex_init(&netconsole_subsys.su_mutex);
111 return configfs_register_subsystem(&netconsole_subsys);
112}
113
114static void __exit dynamic_netconsole_exit(void)
115{
116 configfs_unregister_subsystem(&netconsole_subsys);
117}
118
119/*
120 * Targets that were created by parsing the boot/module option string
121 * do not exist in the configfs hierarchy (and have NULL names) and will
122 * never go away, so make these a no-op for them.
123 */
124static void netconsole_target_get(struct netconsole_target *nt)
125{
126 if (config_item_name(&nt->item))
127 config_item_get(&nt->item);
128}
129
130static void netconsole_target_put(struct netconsole_target *nt)
131{
132 if (config_item_name(&nt->item))
133 config_item_put(&nt->item);
134}
135
136#else /* !CONFIG_NETCONSOLE_DYNAMIC */
137
138static int __init dynamic_netconsole_init(void)
139{
140 return 0;
141}
142
143static void __exit dynamic_netconsole_exit(void)
144{
145}
146
147/*
148 * No danger of targets going away from under us when dynamic
149 * reconfigurability is off.
150 */
151static void netconsole_target_get(struct netconsole_target *nt)
152{
153}
154
155static void netconsole_target_put(struct netconsole_target *nt)
156{
157}
158
159#endif /* CONFIG_NETCONSOLE_DYNAMIC */
160
161/* Allocate new target (from boot/module param) and setup netpoll for it */
162static struct netconsole_target *alloc_param_target(char *target_config)
163{
164 int err = -ENOMEM;
165 struct netconsole_target *nt;
166
167 /*
168 * Allocate and initialize with defaults.
169 * Note that these targets get their config_item fields zeroed-out.
170 */
171 nt = kzalloc(sizeof(*nt), GFP_KERNEL);
172 if (!nt)
173 goto fail;
174
175 nt->np.name = "netconsole";
176 strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
177 nt->np.local_port = 6665;
178 nt->np.remote_port = 6666;
179 memset(nt->np.remote_mac, 0xff, ETH_ALEN);
180
181 /* Parse parameters and setup netpoll */
182 err = netpoll_parse_options(&nt->np, target_config);
183 if (err)
184 goto fail;
185
186 err = netpoll_setup(&nt->np);
187 if (err)
188 goto fail;
189
190 nt->enabled = 1;
191
192 return nt;
193
194fail:
195 kfree(nt);
196 return ERR_PTR(err);
197}
198
199/* Cleanup netpoll for given target (from boot/module param) and free it */
200static void free_param_target(struct netconsole_target *nt)
201{
202 netpoll_cleanup(&nt->np);
203 kfree(nt);
204}
205
206#ifdef CONFIG_NETCONSOLE_DYNAMIC
207
208/*
209 * Our subsystem hierarchy is:
210 *
211 * /sys/kernel/config/netconsole/
212 * |
213 * <target>/
214 * | enabled
215 * | dev_name
216 * | local_port
217 * | remote_port
218 * | local_ip
219 * | remote_ip
220 * | local_mac
221 * | remote_mac
222 * |
223 * <target>/...
224 */
225
226struct netconsole_target_attr {
227 struct configfs_attribute attr;
228 ssize_t (*show)(struct netconsole_target *nt,
229 char *buf);
230 ssize_t (*store)(struct netconsole_target *nt,
231 const char *buf,
232 size_t count);
233};
234
235static struct netconsole_target *to_target(struct config_item *item)
236{
237 return item ?
238 container_of(item, struct netconsole_target, item) :
239 NULL;
240}
241
242/*
243 * Attribute operations for netconsole_target.
244 */
245
246static ssize_t show_enabled(struct netconsole_target *nt, char *buf)
247{
248 return snprintf(buf, PAGE_SIZE, "%d\n", nt->enabled);
249}
250
251static ssize_t show_dev_name(struct netconsole_target *nt, char *buf)
252{
253 return snprintf(buf, PAGE_SIZE, "%s\n", nt->np.dev_name);
254}
255
256static ssize_t show_local_port(struct netconsole_target *nt, char *buf)
257{
258 return snprintf(buf, PAGE_SIZE, "%d\n", nt->np.local_port);
259}
260
261static ssize_t show_remote_port(struct netconsole_target *nt, char *buf)
262{
263 return snprintf(buf, PAGE_SIZE, "%d\n", nt->np.remote_port);
264}
265
266static ssize_t show_local_ip(struct netconsole_target *nt, char *buf)
267{
268 return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.local_ip);
269}
270
271static ssize_t show_remote_ip(struct netconsole_target *nt, char *buf)
272{
273 return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.remote_ip);
274}
275
276static ssize_t show_local_mac(struct netconsole_target *nt, char *buf)
277{
278 struct net_device *dev = nt->np.dev;
279 static const u8 bcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
280
281 return snprintf(buf, PAGE_SIZE, "%pM\n", dev ? dev->dev_addr : bcast);
282}
283
284static ssize_t show_remote_mac(struct netconsole_target *nt, char *buf)
285{
286 return snprintf(buf, PAGE_SIZE, "%pM\n", nt->np.remote_mac);
287}
288
289/*
290 * This one is special -- targets created through the configfs interface
291 * are not enabled (and the corresponding netpoll activated) by default.
292 * The user is expected to set the desired parameters first (which
293 * would enable him to dynamically add new netpoll targets for new
294 * network interfaces as and when they come up).
295 */
296static ssize_t store_enabled(struct netconsole_target *nt,
297 const char *buf,
298 size_t count)
299{
300 int enabled;
301 int err;
302
303 err = kstrtoint(buf, 10, &enabled);
304 if (err < 0)
305 return err;
306 if (enabled < 0 || enabled > 1)
307 return -EINVAL;
308 if (enabled == nt->enabled) {
309 printk(KERN_INFO "netconsole: network logging has already %s\n",
310 nt->enabled ? "started" : "stopped");
311 return -EINVAL;
312 }
313
314 if (enabled) { /* 1 */
315
316 /*
317 * Skip netpoll_parse_options() -- all the attributes are
318 * already configured via configfs. Just print them out.
319 */
320 netpoll_print_options(&nt->np);
321
322 err = netpoll_setup(&nt->np);
323 if (err)
324 return err;
325
326 printk(KERN_INFO "netconsole: network logging started\n");
327
328 } else { /* 0 */
329 netpoll_cleanup(&nt->np);
330 }
331
332 nt->enabled = enabled;
333
334 return strnlen(buf, count);
335}
336
337static ssize_t store_dev_name(struct netconsole_target *nt,
338 const char *buf,
339 size_t count)
340{
341 size_t len;
342
343 if (nt->enabled) {
344 printk(KERN_ERR "netconsole: target (%s) is enabled, "
345 "disable to update parameters\n",
346 config_item_name(&nt->item));
347 return -EINVAL;
348 }
349
350 strlcpy(nt->np.dev_name, buf, IFNAMSIZ);
351
352 /* Get rid of possible trailing newline from echo(1) */
353 len = strnlen(nt->np.dev_name, IFNAMSIZ);
354 if (nt->np.dev_name[len - 1] == '\n')
355 nt->np.dev_name[len - 1] = '\0';
356
357 return strnlen(buf, count);
358}
359
360static ssize_t store_local_port(struct netconsole_target *nt,
361 const char *buf,
362 size_t count)
363{
364 int rv;
365
366 if (nt->enabled) {
367 printk(KERN_ERR "netconsole: target (%s) is enabled, "
368 "disable to update parameters\n",
369 config_item_name(&nt->item));
370 return -EINVAL;
371 }
372
373 rv = kstrtou16(buf, 10, &nt->np.local_port);
374 if (rv < 0)
375 return rv;
376 return strnlen(buf, count);
377}
378
379static ssize_t store_remote_port(struct netconsole_target *nt,
380 const char *buf,
381 size_t count)
382{
383 int rv;
384
385 if (nt->enabled) {
386 printk(KERN_ERR "netconsole: target (%s) is enabled, "
387 "disable to update parameters\n",
388 config_item_name(&nt->item));
389 return -EINVAL;
390 }
391
392 rv = kstrtou16(buf, 10, &nt->np.remote_port);
393 if (rv < 0)
394 return rv;
395 return strnlen(buf, count);
396}
397
398static ssize_t store_local_ip(struct netconsole_target *nt,
399 const char *buf,
400 size_t count)
401{
402 if (nt->enabled) {
403 printk(KERN_ERR "netconsole: target (%s) is enabled, "
404 "disable to update parameters\n",
405 config_item_name(&nt->item));
406 return -EINVAL;
407 }
408
409 nt->np.local_ip = in_aton(buf);
410
411 return strnlen(buf, count);
412}
413
414static ssize_t store_remote_ip(struct netconsole_target *nt,
415 const char *buf,
416 size_t count)
417{
418 if (nt->enabled) {
419 printk(KERN_ERR "netconsole: target (%s) is enabled, "
420 "disable to update parameters\n",
421 config_item_name(&nt->item));
422 return -EINVAL;
423 }
424
425 nt->np.remote_ip = in_aton(buf);
426
427 return strnlen(buf, count);
428}
429
430static ssize_t store_remote_mac(struct netconsole_target *nt,
431 const char *buf,
432 size_t count)
433{
434 u8 remote_mac[ETH_ALEN];
435
436 if (nt->enabled) {
437 printk(KERN_ERR "netconsole: target (%s) is enabled, "
438 "disable to update parameters\n",
439 config_item_name(&nt->item));
440 return -EINVAL;
441 }
442
443 if (!mac_pton(buf, remote_mac))
444 return -EINVAL;
445 if (buf[3 * ETH_ALEN - 1] && buf[3 * ETH_ALEN - 1] != '\n')
446 return -EINVAL;
447 memcpy(nt->np.remote_mac, remote_mac, ETH_ALEN);
448
449 return strnlen(buf, count);
450}
451
452/*
453 * Attribute definitions for netconsole_target.
454 */
455
456#define NETCONSOLE_TARGET_ATTR_RO(_name) \
457static struct netconsole_target_attr netconsole_target_##_name = \
458 __CONFIGFS_ATTR(_name, S_IRUGO, show_##_name, NULL)
459
460#define NETCONSOLE_TARGET_ATTR_RW(_name) \
461static struct netconsole_target_attr netconsole_target_##_name = \
462 __CONFIGFS_ATTR(_name, S_IRUGO | S_IWUSR, show_##_name, store_##_name)
463
464NETCONSOLE_TARGET_ATTR_RW(enabled);
465NETCONSOLE_TARGET_ATTR_RW(dev_name);
466NETCONSOLE_TARGET_ATTR_RW(local_port);
467NETCONSOLE_TARGET_ATTR_RW(remote_port);
468NETCONSOLE_TARGET_ATTR_RW(local_ip);
469NETCONSOLE_TARGET_ATTR_RW(remote_ip);
470NETCONSOLE_TARGET_ATTR_RO(local_mac);
471NETCONSOLE_TARGET_ATTR_RW(remote_mac);
472
473static struct configfs_attribute *netconsole_target_attrs[] = {
474 &netconsole_target_enabled.attr,
475 &netconsole_target_dev_name.attr,
476 &netconsole_target_local_port.attr,
477 &netconsole_target_remote_port.attr,
478 &netconsole_target_local_ip.attr,
479 &netconsole_target_remote_ip.attr,
480 &netconsole_target_local_mac.attr,
481 &netconsole_target_remote_mac.attr,
482 NULL,
483};
484
485/*
486 * Item operations and type for netconsole_target.
487 */
488
489static void netconsole_target_release(struct config_item *item)
490{
491 kfree(to_target(item));
492}
493
494static ssize_t netconsole_target_attr_show(struct config_item *item,
495 struct configfs_attribute *attr,
496 char *buf)
497{
498 ssize_t ret = -EINVAL;
499 struct netconsole_target *nt = to_target(item);
500 struct netconsole_target_attr *na =
501 container_of(attr, struct netconsole_target_attr, attr);
502
503 if (na->show)
504 ret = na->show(nt, buf);
505
506 return ret;
507}
508
509static ssize_t netconsole_target_attr_store(struct config_item *item,
510 struct configfs_attribute *attr,
511 const char *buf,
512 size_t count)
513{
514 ssize_t ret = -EINVAL;
515 struct netconsole_target *nt = to_target(item);
516 struct netconsole_target_attr *na =
517 container_of(attr, struct netconsole_target_attr, attr);
518
519 if (na->store)
520 ret = na->store(nt, buf, count);
521
522 return ret;
523}
524
525static struct configfs_item_operations netconsole_target_item_ops = {
526 .release = netconsole_target_release,
527 .show_attribute = netconsole_target_attr_show,
528 .store_attribute = netconsole_target_attr_store,
529};
530
531static struct config_item_type netconsole_target_type = {
532 .ct_attrs = netconsole_target_attrs,
533 .ct_item_ops = &netconsole_target_item_ops,
534 .ct_owner = THIS_MODULE,
535};
536
537/*
538 * Group operations and type for netconsole_subsys.
539 */
540
541static struct config_item *make_netconsole_target(struct config_group *group,
542 const char *name)
543{
544 unsigned long flags;
545 struct netconsole_target *nt;
546
547 /*
548 * Allocate and initialize with defaults.
549 * Target is disabled at creation (enabled == 0).
550 */
551 nt = kzalloc(sizeof(*nt), GFP_KERNEL);
552 if (!nt)
553 return ERR_PTR(-ENOMEM);
554
555 nt->np.name = "netconsole";
556 strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
557 nt->np.local_port = 6665;
558 nt->np.remote_port = 6666;
559 memset(nt->np.remote_mac, 0xff, ETH_ALEN);
560
561 /* Initialize the config_item member */
562 config_item_init_type_name(&nt->item, name, &netconsole_target_type);
563
564 /* Adding, but it is disabled */
565 spin_lock_irqsave(&target_list_lock, flags);
566 list_add(&nt->list, &target_list);
567 spin_unlock_irqrestore(&target_list_lock, flags);
568
569 return &nt->item;
570}
571
572static void drop_netconsole_target(struct config_group *group,
573 struct config_item *item)
574{
575 unsigned long flags;
576 struct netconsole_target *nt = to_target(item);
577
578 spin_lock_irqsave(&target_list_lock, flags);
579 list_del(&nt->list);
580 spin_unlock_irqrestore(&target_list_lock, flags);
581
582 /*
583 * The target may have never been enabled, or was manually disabled
584 * before being removed so netpoll may have already been cleaned up.
585 */
586 if (nt->enabled)
587 netpoll_cleanup(&nt->np);
588
589 config_item_put(&nt->item);
590}
591
592static struct configfs_group_operations netconsole_subsys_group_ops = {
593 .make_item = make_netconsole_target,
594 .drop_item = drop_netconsole_target,
595};
596
597static struct config_item_type netconsole_subsys_type = {
598 .ct_group_ops = &netconsole_subsys_group_ops,
599 .ct_owner = THIS_MODULE,
600};
601
602/* The netconsole configfs subsystem */
603static struct configfs_subsystem netconsole_subsys = {
604 .su_group = {
605 .cg_item = {
606 .ci_namebuf = "netconsole",
607 .ci_type = &netconsole_subsys_type,
608 },
609 },
610};
611
612#endif /* CONFIG_NETCONSOLE_DYNAMIC */
613
614/* Handle network interface device notifications */
615static int netconsole_netdev_event(struct notifier_block *this,
616 unsigned long event,
617 void *ptr)
618{
619 unsigned long flags;
620 struct netconsole_target *nt;
621 struct net_device *dev = ptr;
622 bool stopped = false;
623
624 if (!(event == NETDEV_CHANGENAME || event == NETDEV_UNREGISTER ||
625 event == NETDEV_RELEASE || event == NETDEV_JOIN))
626 goto done;
627
628 spin_lock_irqsave(&target_list_lock, flags);
629 list_for_each_entry(nt, &target_list, list) {
630 netconsole_target_get(nt);
631 if (nt->np.dev == dev) {
632 switch (event) {
633 case NETDEV_CHANGENAME:
634 strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ);
635 break;
636 case NETDEV_RELEASE:
637 case NETDEV_JOIN:
638 case NETDEV_UNREGISTER:
639 /*
640 * rtnl_lock already held
641 */
642 if (nt->np.dev) {
643 spin_unlock_irqrestore(
644 &target_list_lock,
645 flags);
646 __netpoll_cleanup(&nt->np);
647 spin_lock_irqsave(&target_list_lock,
648 flags);
649 dev_put(nt->np.dev);
650 nt->np.dev = NULL;
651 }
652 nt->enabled = 0;
653 stopped = true;
654 break;
655 }
656 }
657 netconsole_target_put(nt);
658 }
659 spin_unlock_irqrestore(&target_list_lock, flags);
660 if (stopped) {
661 printk(KERN_INFO "netconsole: network logging stopped on "
662 "interface %s as it ", dev->name);
663 switch (event) {
664 case NETDEV_UNREGISTER:
665 printk(KERN_CONT "unregistered\n");
666 break;
667 case NETDEV_RELEASE:
668 printk(KERN_CONT "released slaves\n");
669 break;
670 case NETDEV_JOIN:
671 printk(KERN_CONT "is joining a master device\n");
672 break;
673 }
674 }
675
676done:
677 return NOTIFY_DONE;
678}
679
680static struct notifier_block netconsole_netdev_notifier = {
681 .notifier_call = netconsole_netdev_event,
682};
683
684static void write_msg(struct console *con, const char *msg, unsigned int len)
685{
686 int frag, left;
687 unsigned long flags;
688 struct netconsole_target *nt;
689 const char *tmp;
690
691 /* Avoid taking lock and disabling interrupts unnecessarily */
692 if (list_empty(&target_list))
693 return;
694
695 spin_lock_irqsave(&target_list_lock, flags);
696 list_for_each_entry(nt, &target_list, list) {
697 netconsole_target_get(nt);
698 if (nt->enabled && netif_running(nt->np.dev)) {
699 /*
700 * We nest this inside the for-each-target loop above
701 * so that we're able to get as much logging out to
702 * at least one target if we die inside here, instead
703 * of unnecessarily keeping all targets in lock-step.
704 */
705 tmp = msg;
706 for (left = len; left;) {
707 frag = min(left, MAX_PRINT_CHUNK);
708 netpoll_send_udp(&nt->np, tmp, frag);
709 tmp += frag;
710 left -= frag;
711 }
712 }
713 netconsole_target_put(nt);
714 }
715 spin_unlock_irqrestore(&target_list_lock, flags);
716}
717
718static struct console netconsole = {
719 .name = "netcon",
720 .flags = CON_ENABLED,
721 .write = write_msg,
722};
723
724static int __init init_netconsole(void)
725{
726 int err;
727 struct netconsole_target *nt, *tmp;
728 unsigned long flags;
729 char *target_config;
730 char *input = config;
731
732 if (strnlen(input, MAX_PARAM_LENGTH)) {
733 while ((target_config = strsep(&input, ";"))) {
734 nt = alloc_param_target(target_config);
735 if (IS_ERR(nt)) {
736 err = PTR_ERR(nt);
737 goto fail;
738 }
739 /* Dump existing printks when we register */
740 netconsole.flags |= CON_PRINTBUFFER;
741
742 spin_lock_irqsave(&target_list_lock, flags);
743 list_add(&nt->list, &target_list);
744 spin_unlock_irqrestore(&target_list_lock, flags);
745 }
746 }
747
748 err = register_netdevice_notifier(&netconsole_netdev_notifier);
749 if (err)
750 goto fail;
751
752 err = dynamic_netconsole_init();
753 if (err)
754 goto undonotifier;
755
756 register_console(&netconsole);
757 printk(KERN_INFO "netconsole: network logging started\n");
758
759 return err;
760
761undonotifier:
762 unregister_netdevice_notifier(&netconsole_netdev_notifier);
763
764fail:
765 printk(KERN_ERR "netconsole: cleaning up\n");
766
767 /*
768 * Remove all targets and destroy them (only targets created
769 * from the boot/module option exist here). Skipping the list
770 * lock is safe here, and netpoll_cleanup() will sleep.
771 */
772 list_for_each_entry_safe(nt, tmp, &target_list, list) {
773 list_del(&nt->list);
774 free_param_target(nt);
775 }
776
777 return err;
778}
779
780static void __exit cleanup_netconsole(void)
781{
782 struct netconsole_target *nt, *tmp;
783
784 unregister_console(&netconsole);
785 dynamic_netconsole_exit();
786 unregister_netdevice_notifier(&netconsole_netdev_notifier);
787
788 /*
789 * Targets created via configfs pin references on our module
790 * and would first be rmdir(2)'ed from userspace. We reach
791 * here only when they are already destroyed, and only those
792 * created from the boot/module option are left, so remove and
793 * destroy them. Skipping the list lock is safe here, and
794 * netpoll_cleanup() will sleep.
795 */
796 list_for_each_entry_safe(nt, tmp, &target_list, list) {
797 list_del(&nt->list);
798 free_param_target(nt);
799 }
800}
801
802/*
803 * Use late_initcall to ensure netconsole is
804 * initialized after network device driver if built-in.
805 *
806 * late_initcall() and module_init() are identical if built as module.
807 */
808late_initcall(init_netconsole);
809module_exit(cleanup_netconsole);