net: wireless: bcmdhd: Fix filtering setting in case of P2P
[linux-2.6.git] / drivers / net / netconsole.c
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
48 MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@selenic.com>");
49 MODULE_DESCRIPTION("Console driver for network interfaces");
50 MODULE_LICENSE("GPL");
51
52 #define MAX_PARAM_LENGTH        256
53 #define MAX_PRINT_CHUNK         1000
54
55 static char config[MAX_PARAM_LENGTH];
56 module_param_string(netconsole, config, MAX_PARAM_LENGTH, 0);
57 MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]");
58
59 #ifndef MODULE
60 static 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 */
69 static LIST_HEAD(target_list);
70
71 /* This needs to be a spinlock because write_msg() cannot sleep */
72 static 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  */
94 struct 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
105 static struct configfs_subsystem netconsole_subsys;
106
107 static 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
114 static 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  */
124 static void netconsole_target_get(struct netconsole_target *nt)
125 {
126         if (config_item_name(&nt->item))
127                 config_item_get(&nt->item);
128 }
129
130 static 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
138 static int __init dynamic_netconsole_init(void)
139 {
140         return 0;
141 }
142
143 static 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  */
151 static void netconsole_target_get(struct netconsole_target *nt)
152 {
153 }
154
155 static 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 */
162 static 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
196 fail:
197         kfree(nt);
198         return ERR_PTR(err);
199 }
200
201 /* Cleanup netpoll for given target (from boot/module param) and free it */
202 static 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
228 struct 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
237 static 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
248 static ssize_t show_enabled(struct netconsole_target *nt, char *buf)
249 {
250         return snprintf(buf, PAGE_SIZE, "%d\n", nt->enabled);
251 }
252
253 static 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
258 static 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
263 static 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
268 static 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
273 static 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
278 static 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
286 static 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  */
298 static 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
339 static 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
362 static 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
381 static 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
400 static 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
416 static 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
432 static 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)                                \
459 static struct netconsole_target_attr netconsole_target_##_name =        \
460         __CONFIGFS_ATTR(_name, S_IRUGO, show_##_name, NULL)
461
462 #define NETCONSOLE_TARGET_ATTR_RW(_name)                                \
463 static struct netconsole_target_attr netconsole_target_##_name =        \
464         __CONFIGFS_ATTR(_name, S_IRUGO | S_IWUSR, show_##_name, store_##_name)
465
466 NETCONSOLE_TARGET_ATTR_RW(enabled);
467 NETCONSOLE_TARGET_ATTR_RW(dev_name);
468 NETCONSOLE_TARGET_ATTR_RW(local_port);
469 NETCONSOLE_TARGET_ATTR_RW(remote_port);
470 NETCONSOLE_TARGET_ATTR_RW(local_ip);
471 NETCONSOLE_TARGET_ATTR_RW(remote_ip);
472 NETCONSOLE_TARGET_ATTR_RO(local_mac);
473 NETCONSOLE_TARGET_ATTR_RW(remote_mac);
474
475 static 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
491 static void netconsole_target_release(struct config_item *item)
492 {
493         kfree(to_target(item));
494 }
495
496 static 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
511 static 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
527 static 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
533 static 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
543 static 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
576 static 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
596 static struct configfs_group_operations netconsole_subsys_group_ops = {
597         .make_item      = make_netconsole_target,
598         .drop_item      = drop_netconsole_target,
599 };
600
601 static 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 */
607 static 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 */
619 static 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
681 done:
682         return NOTIFY_DONE;
683 }
684
685 static struct notifier_block netconsole_netdev_notifier = {
686         .notifier_call  = netconsole_netdev_event,
687 };
688
689 static 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
723 static struct console netconsole = {
724         .name   = "netcon",
725         .flags  = CON_ENABLED,
726         .write  = write_msg,
727 };
728
729 static 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
766 undonotifier:
767         unregister_netdevice_notifier(&netconsole_netdev_notifier);
768
769 fail:
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
785 static 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  */
813 late_initcall(init_netconsole);
814 module_exit(cleanup_netconsole);