]> git.proxmox.com Git - mirror_ubuntu-hirsute-kernel.git/blob - drivers/net/netconsole.c
projects / mirror_ubuntu-hirsute-kernel.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
ath11k: put hw to DBS using WMI_PDEV_SET_HW_MODE_CMDID
[mirror_ubuntu-hirsute-kernel.git] / drivers / net / netconsole.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * linux/drivers/net/netconsole.c
4 *
5 * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com>
6 *
7 * This file contains the implementation of an IRQ-safe, crash-safe
8 * kernel console implementation that outputs kernel messages to the
9 * network.
10 *
11 * Modification history:
12 *
13 * 2001-09-17 started by Ingo Molnar.
14 * 2003-08-11 2.6 port by Matt Mackall
15 * simplified options
16 * generic card hooks
17 * works non-modular
18 * 2003-09-07 rewritten with netpoll api
19 */
20
21 /****************************************************************
22 *
23 ****************************************************************/
24
25 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
26
27 #include <linux/mm.h>
28 #include <linux/init.h>
29 #include <linux/module.h>
30 #include <linux/slab.h>
31 #include <linux/console.h>
32 #include <linux/moduleparam.h>
33 #include <linux/kernel.h>
34 #include <linux/string.h>
35 #include <linux/netpoll.h>
36 #include <linux/inet.h>
37 #include <linux/configfs.h>
38 #include <linux/etherdevice.h>
39
40 MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@selenic.com>");
41 MODULE_DESCRIPTION("Console driver for network interfaces");
42 MODULE_LICENSE("GPL");
43
44 #define MAX_PARAM_LENGTH 256
45 #define MAX_PRINT_CHUNK 1000
46
47 static char config[MAX_PARAM_LENGTH];
48 module_param_string(netconsole, config, MAX_PARAM_LENGTH, 0);
49 MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]");
50
51 static bool oops_only = false;
52 module_param(oops_only, bool, 0600);
53 MODULE_PARM_DESC(oops_only, "Only log oops messages");
54
55 #ifndef MODULE
56 static int __init option_setup(char *opt)
57 {
58 strlcpy(config, opt, MAX_PARAM_LENGTH);
59 return 1;
60 }
61 __setup("netconsole=", option_setup);
62 #endif /* MODULE */
63
64 /* Linked list of all configured targets */
65 static LIST_HEAD(target_list);
66
67 /* This needs to be a spinlock because write_msg() cannot sleep */
68 static DEFINE_SPINLOCK(target_list_lock);
69
70 /*
71 * Console driver for extended netconsoles. Registered on the first use to
72 * avoid unnecessarily enabling ext message formatting.
73 */
74 static struct console netconsole_ext;
75
76 /**
77 * struct netconsole_target - Represents a configured netconsole target.
78 * @list: Links this target into the target_list.
79 * @item: Links us into the configfs subsystem hierarchy.
80 * @enabled: On / off knob to enable / disable target.
81 * Visible from userspace (read-write).
82 * We maintain a strict 1:1 correspondence between this and
83 * whether the corresponding netpoll is active or inactive.
84 * Also, other parameters of a target may be modified at
85 * runtime only when it is disabled (enabled == 0).
86 * @extended: Denotes whether console is extended or not.
87 * @np: The netpoll structure for this target.
88 * Contains the other userspace visible parameters:
89 * dev_name (read-write)
90 * local_port (read-write)
91 * remote_port (read-write)
92 * local_ip (read-write)
93 * remote_ip (read-write)
94 * local_mac (read-only)
95 * remote_mac (read-write)
96 */
97 struct netconsole_target {
98 struct list_head list;
99 #ifdef CONFIG_NETCONSOLE_DYNAMIC
100 struct config_item item;
101 #endif
102 bool enabled;
103 bool extended;
104 struct netpoll np;
105 };
106
107 #ifdef CONFIG_NETCONSOLE_DYNAMIC
108
109 static struct configfs_subsystem netconsole_subsys;
110 static DEFINE_MUTEX(dynamic_netconsole_mutex);
111
112 static int __init dynamic_netconsole_init(void)
113 {
114 config_group_init(&netconsole_subsys.su_group);
115 mutex_init(&netconsole_subsys.su_mutex);
116 return configfs_register_subsystem(&netconsole_subsys);
117 }
118
119 static void __exit dynamic_netconsole_exit(void)
120 {
121 configfs_unregister_subsystem(&netconsole_subsys);
122 }
123
124 /*
125 * Targets that were created by parsing the boot/module option string
126 * do not exist in the configfs hierarchy (and have NULL names) and will
127 * never go away, so make these a no-op for them.
128 */
129 static void netconsole_target_get(struct netconsole_target *nt)
130 {
131 if (config_item_name(&nt->item))
132 config_item_get(&nt->item);
133 }
134
135 static void netconsole_target_put(struct netconsole_target *nt)
136 {
137 if (config_item_name(&nt->item))
138 config_item_put(&nt->item);
139 }
140
141 #else /* !CONFIG_NETCONSOLE_DYNAMIC */
142
143 static int __init dynamic_netconsole_init(void)
144 {
145 return 0;
146 }
147
148 static void __exit dynamic_netconsole_exit(void)
149 {
150 }
151
152 /*
153 * No danger of targets going away from under us when dynamic
154 * reconfigurability is off.
155 */
156 static void netconsole_target_get(struct netconsole_target *nt)
157 {
158 }
159
160 static void netconsole_target_put(struct netconsole_target *nt)
161 {
162 }
163
164 #endif /* CONFIG_NETCONSOLE_DYNAMIC */
165
166 /* Allocate new target (from boot/module param) and setup netpoll for it */
167 static struct netconsole_target *alloc_param_target(char *target_config)
168 {
169 int err = -ENOMEM;
170 struct netconsole_target *nt;
171
172 /*
173 * Allocate and initialize with defaults.
174 * Note that these targets get their config_item fields zeroed-out.
175 */
176 nt = kzalloc(sizeof(*nt), GFP_KERNEL);
177 if (!nt)
178 goto fail;
179
180 nt->np.name = "netconsole";
181 strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
182 nt->np.local_port = 6665;
183 nt->np.remote_port = 6666;
184 eth_broadcast_addr(nt->np.remote_mac);
185
186 if (*target_config == '+') {
187 nt->extended = true;
188 target_config++;
189 }
190
191 /* Parse parameters and setup netpoll */
192 err = netpoll_parse_options(&nt->np, target_config);
193 if (err)
194 goto fail;
195
196 err = netpoll_setup(&nt->np);
197 if (err)
198 goto fail;
199
200 nt->enabled = true;
201
202 return nt;
203
204 fail:
205 kfree(nt);
206 return ERR_PTR(err);
207 }
208
209 /* Cleanup netpoll for given target (from boot/module param) and free it */
210 static void free_param_target(struct netconsole_target *nt)
211 {
212 netpoll_cleanup(&nt->np);
213 kfree(nt);
214 }
215
216 #ifdef CONFIG_NETCONSOLE_DYNAMIC
217
218 /*
219 * Our subsystem hierarchy is:
220 *
221 * /sys/kernel/config/netconsole/
222 * |
223 * <target>/
224 * | enabled
225 * | dev_name
226 * | local_port
227 * | remote_port
228 * | local_ip
229 * | remote_ip
230 * | local_mac
231 * | remote_mac
232 * |
233 * <target>/...
234 */
235
236 static struct netconsole_target *to_target(struct config_item *item)
237 {
238 return item ?
239 container_of(item, struct netconsole_target, item) :
240 NULL;
241 }
242
243 /*
244 * Attribute operations for netconsole_target.
245 */
246
247 static ssize_t enabled_show(struct config_item *item, char *buf)
248 {
249 return snprintf(buf, PAGE_SIZE, "%d\n", to_target(item)->enabled);
250 }
251
252 static ssize_t extended_show(struct config_item *item, char *buf)
253 {
254 return snprintf(buf, PAGE_SIZE, "%d\n", to_target(item)->extended);
255 }
256
257 static ssize_t dev_name_show(struct config_item *item, char *buf)
258 {
259 return snprintf(buf, PAGE_SIZE, "%s\n", to_target(item)->np.dev_name);
260 }
261
262 static ssize_t local_port_show(struct config_item *item, char *buf)
263 {
264 return snprintf(buf, PAGE_SIZE, "%d\n", to_target(item)->np.local_port);
265 }
266
267 static ssize_t remote_port_show(struct config_item *item, char *buf)
268 {
269 return snprintf(buf, PAGE_SIZE, "%d\n", to_target(item)->np.remote_port);
270 }
271
272 static ssize_t local_ip_show(struct config_item *item, char *buf)
273 {
274 struct netconsole_target *nt = to_target(item);
275
276 if (nt->np.ipv6)
277 return snprintf(buf, PAGE_SIZE, "%pI6c\n", &nt->np.local_ip.in6);
278 else
279 return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.local_ip);
280 }
281
282 static ssize_t remote_ip_show(struct config_item *item, char *buf)
283 {
284 struct netconsole_target *nt = to_target(item);
285
286 if (nt->np.ipv6)
287 return snprintf(buf, PAGE_SIZE, "%pI6c\n", &nt->np.remote_ip.in6);
288 else
289 return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.remote_ip);
290 }
291
292 static ssize_t local_mac_show(struct config_item *item, char *buf)
293 {
294 struct net_device *dev = to_target(item)->np.dev;
295 static const u8 bcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
296
297 return snprintf(buf, PAGE_SIZE, "%pM\n", dev ? dev->dev_addr : bcast);
298 }
299
300 static ssize_t remote_mac_show(struct config_item *item, char *buf)
301 {
302 return snprintf(buf, PAGE_SIZE, "%pM\n", to_target(item)->np.remote_mac);
303 }
304
305 /*
306 * This one is special -- targets created through the configfs interface
307 * are not enabled (and the corresponding netpoll activated) by default.
308 * The user is expected to set the desired parameters first (which
309 * would enable him to dynamically add new netpoll targets for new
310 * network interfaces as and when they come up).
311 */
312 static ssize_t enabled_store(struct config_item *item,
313 const char *buf, size_t count)
314 {
315 struct netconsole_target *nt = to_target(item);
316 unsigned long flags;
317 int enabled;
318 int err;
319
320 mutex_lock(&dynamic_netconsole_mutex);
321 err = kstrtoint(buf, 10, &enabled);
322 if (err < 0)
323 goto out_unlock;
324
325 err = -EINVAL;
326 if (enabled < 0 || enabled > 1)
327 goto out_unlock;
328 if ((bool)enabled == nt->enabled) {
329 pr_info("network logging has already %s\n",
330 nt->enabled ? "started" : "stopped");
331 goto out_unlock;
332 }
333
334 if (enabled) { /* true */
335 if (nt->extended && !(netconsole_ext.flags & CON_ENABLED)) {
336 netconsole_ext.flags |= CON_ENABLED;
337 register_console(&netconsole_ext);
338 }
339
340 /*
341 * Skip netpoll_parse_options() -- all the attributes are
342 * already configured via configfs. Just print them out.
343 */
344 netpoll_print_options(&nt->np);
345
346 err = netpoll_setup(&nt->np);
347 if (err)
348 goto out_unlock;
349
350 pr_info("network logging started\n");
351 } else { /* false */
352 /* We need to disable the netconsole before cleaning it up
353 * otherwise we might end up in write_msg() with
354 * nt->np.dev == NULL and nt->enabled == true
355 */
356 spin_lock_irqsave(&target_list_lock, flags);
357 nt->enabled = false;
358 spin_unlock_irqrestore(&target_list_lock, flags);
359 netpoll_cleanup(&nt->np);
360 }
361
362 nt->enabled = enabled;
363
364 mutex_unlock(&dynamic_netconsole_mutex);
365 return strnlen(buf, count);
366 out_unlock:
367 mutex_unlock(&dynamic_netconsole_mutex);
368 return err;
369 }
370
371 static ssize_t extended_store(struct config_item *item, const char *buf,
372 size_t count)
373 {
374 struct netconsole_target *nt = to_target(item);
375 int extended;
376 int err;
377
378 mutex_lock(&dynamic_netconsole_mutex);
379 if (nt->enabled) {
380 pr_err("target (%s) is enabled, disable to update parameters\n",
381 config_item_name(&nt->item));
382 err = -EINVAL;
383 goto out_unlock;
384 }
385
386 err = kstrtoint(buf, 10, &extended);
387 if (err < 0)
388 goto out_unlock;
389 if (extended < 0 || extended > 1) {
390 err = -EINVAL;
391 goto out_unlock;
392 }
393
394 nt->extended = extended;
395
396 mutex_unlock(&dynamic_netconsole_mutex);
397 return strnlen(buf, count);
398 out_unlock:
399 mutex_unlock(&dynamic_netconsole_mutex);
400 return err;
401 }
402
403 static ssize_t dev_name_store(struct config_item *item, const char *buf,
404 size_t count)
405 {
406 struct netconsole_target *nt = to_target(item);
407 size_t len;
408
409 mutex_lock(&dynamic_netconsole_mutex);
410 if (nt->enabled) {
411 pr_err("target (%s) is enabled, disable to update parameters\n",
412 config_item_name(&nt->item));
413 mutex_unlock(&dynamic_netconsole_mutex);
414 return -EINVAL;
415 }
416
417 strlcpy(nt->np.dev_name, buf, IFNAMSIZ);
418
419 /* Get rid of possible trailing newline from echo(1) */
420 len = strnlen(nt->np.dev_name, IFNAMSIZ);
421 if (nt->np.dev_name[len - 1] == '\n')
422 nt->np.dev_name[len - 1] = '\0';
423
424 mutex_unlock(&dynamic_netconsole_mutex);
425 return strnlen(buf, count);
426 }
427
428 static ssize_t local_port_store(struct config_item *item, const char *buf,
429 size_t count)
430 {
431 struct netconsole_target *nt = to_target(item);
432 int rv = -EINVAL;
433
434 mutex_lock(&dynamic_netconsole_mutex);
435 if (nt->enabled) {
436 pr_err("target (%s) is enabled, disable to update parameters\n",
437 config_item_name(&nt->item));
438 goto out_unlock;
439 }
440
441 rv = kstrtou16(buf, 10, &nt->np.local_port);
442 if (rv < 0)
443 goto out_unlock;
444 mutex_unlock(&dynamic_netconsole_mutex);
445 return strnlen(buf, count);
446 out_unlock:
447 mutex_unlock(&dynamic_netconsole_mutex);
448 return rv;
449 }
450
451 static ssize_t remote_port_store(struct config_item *item,
452 const char *buf, size_t count)
453 {
454 struct netconsole_target *nt = to_target(item);
455 int rv = -EINVAL;
456
457 mutex_lock(&dynamic_netconsole_mutex);
458 if (nt->enabled) {
459 pr_err("target (%s) is enabled, disable to update parameters\n",
460 config_item_name(&nt->item));
461 goto out_unlock;
462 }
463
464 rv = kstrtou16(buf, 10, &nt->np.remote_port);
465 if (rv < 0)
466 goto out_unlock;
467 mutex_unlock(&dynamic_netconsole_mutex);
468 return strnlen(buf, count);
469 out_unlock:
470 mutex_unlock(&dynamic_netconsole_mutex);
471 return rv;
472 }
473
474 static ssize_t local_ip_store(struct config_item *item, const char *buf,
475 size_t count)
476 {
477 struct netconsole_target *nt = to_target(item);
478
479 mutex_lock(&dynamic_netconsole_mutex);
480 if (nt->enabled) {
481 pr_err("target (%s) is enabled, disable to update parameters\n",
482 config_item_name(&nt->item));
483 goto out_unlock;
484 }
485
486 if (strnchr(buf, count, ':')) {
487 const char *end;
488 if (in6_pton(buf, count, nt->np.local_ip.in6.s6_addr, -1, &end) > 0) {
489 if (*end && *end != '\n') {
490 pr_err("invalid IPv6 address at: <%c>\n", *end);
491 goto out_unlock;
492 }
493 nt->np.ipv6 = true;
494 } else
495 goto out_unlock;
496 } else {
497 if (!nt->np.ipv6) {
498 nt->np.local_ip.ip = in_aton(buf);
499 } else
500 goto out_unlock;
501 }
502
503 mutex_unlock(&dynamic_netconsole_mutex);
504 return strnlen(buf, count);
505 out_unlock:
506 mutex_unlock(&dynamic_netconsole_mutex);
507 return -EINVAL;
508 }
509
510 static ssize_t remote_ip_store(struct config_item *item, const char *buf,
511 size_t count)
512 {
513 struct netconsole_target *nt = to_target(item);
514
515 mutex_lock(&dynamic_netconsole_mutex);
516 if (nt->enabled) {
517 pr_err("target (%s) is enabled, disable to update parameters\n",
518 config_item_name(&nt->item));
519 goto out_unlock;
520 }
521
522 if (strnchr(buf, count, ':')) {
523 const char *end;
524 if (in6_pton(buf, count, nt->np.remote_ip.in6.s6_addr, -1, &end) > 0) {
525 if (*end && *end != '\n') {
526 pr_err("invalid IPv6 address at: <%c>\n", *end);
527 goto out_unlock;
528 }
529 nt->np.ipv6 = true;
530 } else
531 goto out_unlock;
532 } else {
533 if (!nt->np.ipv6) {
534 nt->np.remote_ip.ip = in_aton(buf);
535 } else
536 goto out_unlock;
537 }
538
539 mutex_unlock(&dynamic_netconsole_mutex);
540 return strnlen(buf, count);
541 out_unlock:
542 mutex_unlock(&dynamic_netconsole_mutex);
543 return -EINVAL;
544 }
545
546 static ssize_t remote_mac_store(struct config_item *item, const char *buf,
547 size_t count)
548 {
549 struct netconsole_target *nt = to_target(item);
550 u8 remote_mac[ETH_ALEN];
551
552 mutex_lock(&dynamic_netconsole_mutex);
553 if (nt->enabled) {
554 pr_err("target (%s) is enabled, disable to update parameters\n",
555 config_item_name(&nt->item));
556 goto out_unlock;
557 }
558
559 if (!mac_pton(buf, remote_mac))
560 goto out_unlock;
561 if (buf[3 * ETH_ALEN - 1] && buf[3 * ETH_ALEN - 1] != '\n')
562 goto out_unlock;
563 memcpy(nt->np.remote_mac, remote_mac, ETH_ALEN);
564
565 mutex_unlock(&dynamic_netconsole_mutex);
566 return strnlen(buf, count);
567 out_unlock:
568 mutex_unlock(&dynamic_netconsole_mutex);
569 return -EINVAL;
570 }
571
572 CONFIGFS_ATTR(, enabled);
573 CONFIGFS_ATTR(, extended);
574 CONFIGFS_ATTR(, dev_name);
575 CONFIGFS_ATTR(, local_port);
576 CONFIGFS_ATTR(, remote_port);
577 CONFIGFS_ATTR(, local_ip);
578 CONFIGFS_ATTR(, remote_ip);
579 CONFIGFS_ATTR_RO(, local_mac);
580 CONFIGFS_ATTR(, remote_mac);
581
582 static struct configfs_attribute *netconsole_target_attrs[] = {
583 &attr_enabled,
584 &attr_extended,
585 &attr_dev_name,
586 &attr_local_port,
587 &attr_remote_port,
588 &attr_local_ip,
589 &attr_remote_ip,
590 &attr_local_mac,
591 &attr_remote_mac,
592 NULL,
593 };
594
595 /*
596 * Item operations and type for netconsole_target.
597 */
598
599 static void netconsole_target_release(struct config_item *item)
600 {
601 kfree(to_target(item));
602 }
603
604 static struct configfs_item_operations netconsole_target_item_ops = {
605 .release = netconsole_target_release,
606 };
607
608 static const struct config_item_type netconsole_target_type = {
609 .ct_attrs = netconsole_target_attrs,
610 .ct_item_ops = &netconsole_target_item_ops,
611 .ct_owner = THIS_MODULE,
612 };
613
614 /*
615 * Group operations and type for netconsole_subsys.
616 */
617
618 static struct config_item *make_netconsole_target(struct config_group *group,
619 const char *name)
620 {
621 unsigned long flags;
622 struct netconsole_target *nt;
623
624 /*
625 * Allocate and initialize with defaults.
626 * Target is disabled at creation (!enabled).
627 */
628 nt = kzalloc(sizeof(*nt), GFP_KERNEL);
629 if (!nt)
630 return ERR_PTR(-ENOMEM);
631
632 nt->np.name = "netconsole";
633 strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
634 nt->np.local_port = 6665;
635 nt->np.remote_port = 6666;
636 eth_broadcast_addr(nt->np.remote_mac);
637
638 /* Initialize the config_item member */
639 config_item_init_type_name(&nt->item, name, &netconsole_target_type);
640
641 /* Adding, but it is disabled */
642 spin_lock_irqsave(&target_list_lock, flags);
643 list_add(&nt->list, &target_list);
644 spin_unlock_irqrestore(&target_list_lock, flags);
645
646 return &nt->item;
647 }
648
649 static void drop_netconsole_target(struct config_group *group,
650 struct config_item *item)
651 {
652 unsigned long flags;
653 struct netconsole_target *nt = to_target(item);
654
655 spin_lock_irqsave(&target_list_lock, flags);
656 list_del(&nt->list);
657 spin_unlock_irqrestore(&target_list_lock, flags);
658
659 /*
660 * The target may have never been enabled, or was manually disabled
661 * before being removed so netpoll may have already been cleaned up.
662 */
663 if (nt->enabled)
664 netpoll_cleanup(&nt->np);
665
666 config_item_put(&nt->item);
667 }
668
669 static struct configfs_group_operations netconsole_subsys_group_ops = {
670 .make_item = make_netconsole_target,
671 .drop_item = drop_netconsole_target,
672 };
673
674 static const struct config_item_type netconsole_subsys_type = {
675 .ct_group_ops = &netconsole_subsys_group_ops,
676 .ct_owner = THIS_MODULE,
677 };
678
679 /* The netconsole configfs subsystem */
680 static struct configfs_subsystem netconsole_subsys = {
681 .su_group = {
682 .cg_item = {
683 .ci_namebuf = "netconsole",
684 .ci_type = &netconsole_subsys_type,
685 },
686 },
687 };
688
689 #endif /* CONFIG_NETCONSOLE_DYNAMIC */
690
691 /* Handle network interface device notifications */
692 static int netconsole_netdev_event(struct notifier_block *this,
693 unsigned long event, void *ptr)
694 {
695 unsigned long flags;
696 struct netconsole_target *nt;
697 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
698 bool stopped = false;
699
700 if (!(event == NETDEV_CHANGENAME || event == NETDEV_UNREGISTER ||
701 event == NETDEV_RELEASE || event == NETDEV_JOIN))
702 goto done;
703
704 spin_lock_irqsave(&target_list_lock, flags);
705 restart:
706 list_for_each_entry(nt, &target_list, list) {
707 netconsole_target_get(nt);
708 if (nt->np.dev == dev) {
709 switch (event) {
710 case NETDEV_CHANGENAME:
711 strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ);
712 break;
713 case NETDEV_RELEASE:
714 case NETDEV_JOIN:
715 case NETDEV_UNREGISTER:
716 /* rtnl_lock already held
717 * we might sleep in __netpoll_cleanup()
718 */
719 spin_unlock_irqrestore(&target_list_lock, flags);
720
721 __netpoll_cleanup(&nt->np);
722
723 spin_lock_irqsave(&target_list_lock, flags);
724 dev_put(nt->np.dev);
725 nt->np.dev = NULL;
726 nt->enabled = false;
727 stopped = true;
728 netconsole_target_put(nt);
729 goto restart;
730 }
731 }
732 netconsole_target_put(nt);
733 }
734 spin_unlock_irqrestore(&target_list_lock, flags);
735 if (stopped) {
736 const char *msg = "had an event";
737 switch (event) {
738 case NETDEV_UNREGISTER:
739 msg = "unregistered";
740 break;
741 case NETDEV_RELEASE:
742 msg = "released slaves";
743 break;
744 case NETDEV_JOIN:
745 msg = "is joining a master device";
746 break;
747 }
748 pr_info("network logging stopped on interface %s as it %s\n",
749 dev->name, msg);
750 }
751
752 done:
753 return NOTIFY_DONE;
754 }
755
756 static struct notifier_block netconsole_netdev_notifier = {
757 .notifier_call = netconsole_netdev_event,
758 };
759
760 /**
761 * send_ext_msg_udp - send extended log message to target
762 * @nt: target to send message to
763 * @msg: extended log message to send
764 * @msg_len: length of message
765 *
766 * Transfer extended log @msg to @nt. If @msg is longer than
767 * MAX_PRINT_CHUNK, it'll be split and transmitted in multiple chunks with
768 * ncfrag header field added to identify them.
769 */
770 static void send_ext_msg_udp(struct netconsole_target *nt, const char *msg,
771 int msg_len)
772 {
773 static char buf[MAX_PRINT_CHUNK]; /* protected by target_list_lock */
774 const char *header, *body;
775 int offset = 0;
776 int header_len, body_len;
777
778 if (msg_len <= MAX_PRINT_CHUNK) {
779 netpoll_send_udp(&nt->np, msg, msg_len);
780 return;
781 }
782
783 /* need to insert extra header fields, detect header and body */
784 header = msg;
785 body = memchr(msg, ';', msg_len);
786 if (WARN_ON_ONCE(!body))
787 return;
788
789 header_len = body - header;
790 body_len = msg_len - header_len - 1;
791 body++;
792
793 /*
794 * Transfer multiple chunks with the following extra header.
795 * "ncfrag=<byte-offset>/<total-bytes>"
796 */
797 memcpy(buf, header, header_len);
798
799 while (offset < body_len) {
800 int this_header = header_len;
801 int this_chunk;
802
803 this_header += scnprintf(buf + this_header,
804 sizeof(buf) - this_header,
805 ",ncfrag=%d/%d;", offset, body_len);
806
807 this_chunk = min(body_len - offset,
808 MAX_PRINT_CHUNK - this_header);
809 if (WARN_ON_ONCE(this_chunk <= 0))
810 return;
811
812 memcpy(buf + this_header, body + offset, this_chunk);
813
814 netpoll_send_udp(&nt->np, buf, this_header + this_chunk);
815
816 offset += this_chunk;
817 }
818 }
819
820 static void write_ext_msg(struct console *con, const char *msg,
821 unsigned int len)
822 {
823 struct netconsole_target *nt;
824 unsigned long flags;
825
826 if ((oops_only && !oops_in_progress) || list_empty(&target_list))
827 return;
828
829 spin_lock_irqsave(&target_list_lock, flags);
830 list_for_each_entry(nt, &target_list, list)
831 if (nt->extended && nt->enabled && netif_running(nt->np.dev))
832 send_ext_msg_udp(nt, msg, len);
833 spin_unlock_irqrestore(&target_list_lock, flags);
834 }
835
836 static void write_msg(struct console *con, const char *msg, unsigned int len)
837 {
838 int frag, left;
839 unsigned long flags;
840 struct netconsole_target *nt;
841 const char *tmp;
842
843 if (oops_only && !oops_in_progress)
844 return;
845 /* Avoid taking lock and disabling interrupts unnecessarily */
846 if (list_empty(&target_list))
847 return;
848
849 spin_lock_irqsave(&target_list_lock, flags);
850 list_for_each_entry(nt, &target_list, list) {
851 if (!nt->extended && nt->enabled && netif_running(nt->np.dev)) {
852 /*
853 * We nest this inside the for-each-target loop above
854 * so that we're able to get as much logging out to
855 * at least one target if we die inside here, instead
856 * of unnecessarily keeping all targets in lock-step.
857 */
858 tmp = msg;
859 for (left = len; left;) {
860 frag = min(left, MAX_PRINT_CHUNK);
861 netpoll_send_udp(&nt->np, tmp, frag);
862 tmp += frag;
863 left -= frag;
864 }
865 }
866 }
867 spin_unlock_irqrestore(&target_list_lock, flags);
868 }
869
870 static struct console netconsole_ext = {
871 .name = "netcon_ext",
872 .flags = CON_EXTENDED, /* starts disabled, registered on first use */
873 .write = write_ext_msg,
874 };
875
876 static struct console netconsole = {
877 .name = "netcon",
878 .flags = CON_ENABLED,
879 .write = write_msg,
880 };
881
882 static int __init init_netconsole(void)
883 {
884 int err;
885 struct netconsole_target *nt, *tmp;
886 unsigned long flags;
887 char *target_config;
888 char *input = config;
889
890 if (strnlen(input, MAX_PARAM_LENGTH)) {
891 while ((target_config = strsep(&input, ";"))) {
892 nt = alloc_param_target(target_config);
893 if (IS_ERR(nt)) {
894 err = PTR_ERR(nt);
895 goto fail;
896 }
897 /* Dump existing printks when we register */
898 if (nt->extended)
899 netconsole_ext.flags |= CON_PRINTBUFFER |
900 CON_ENABLED;
901 else
902 netconsole.flags |= CON_PRINTBUFFER;
903
904 spin_lock_irqsave(&target_list_lock, flags);
905 list_add(&nt->list, &target_list);
906 spin_unlock_irqrestore(&target_list_lock, flags);
907 }
908 }
909
910 err = register_netdevice_notifier(&netconsole_netdev_notifier);
911 if (err)
912 goto fail;
913
914 err = dynamic_netconsole_init();
915 if (err)
916 goto undonotifier;
917
918 if (netconsole_ext.flags & CON_ENABLED)
919 register_console(&netconsole_ext);
920 register_console(&netconsole);
921 pr_info("network logging started\n");
922
923 return err;
924
925 undonotifier:
926 unregister_netdevice_notifier(&netconsole_netdev_notifier);
927
928 fail:
929 pr_err("cleaning up\n");
930
931 /*
932 * Remove all targets and destroy them (only targets created
933 * from the boot/module option exist here). Skipping the list
934 * lock is safe here, and netpoll_cleanup() will sleep.
935 */
936 list_for_each_entry_safe(nt, tmp, &target_list, list) {
937 list_del(&nt->list);
938 free_param_target(nt);
939 }
940
941 return err;
942 }
943
944 static void __exit cleanup_netconsole(void)
945 {
946 struct netconsole_target *nt, *tmp;
947
948 unregister_console(&netconsole_ext);
949 unregister_console(&netconsole);
950 dynamic_netconsole_exit();
951 unregister_netdevice_notifier(&netconsole_netdev_notifier);
952
953 /*
954 * Targets created via configfs pin references on our module
955 * and would first be rmdir(2)'ed from userspace. We reach
956 * here only when they are already destroyed, and only those
957 * created from the boot/module option are left, so remove and
958 * destroy them. Skipping the list lock is safe here, and
959 * netpoll_cleanup() will sleep.
960 */
961 list_for_each_entry_safe(nt, tmp, &target_list, list) {
962 list_del(&nt->list);
963 free_param_target(nt);
964 }
965 }
966
967 /*
968 * Use late_initcall to ensure netconsole is
969 * initialized after network device driver if built-in.
970 *
971 * late_initcall() and module_init() are identical if built as module.
972 */
973 late_initcall(init_netconsole);
974 module_exit(cleanup_netconsole);
Ubuntu Hirsute Linux kernel mirror