2 * linux/drivers/net/netconsole.c
4 * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com>
6 * This file contains the implementation of an IRQ-safe, crash-safe
7 * kernel console implementation that outputs kernel messages to the
10 * Modification history:
12 * 2001-09-17 started by Ingo Molnar.
13 * 2003-08-11 2.6 port by Matt Mackall
17 * 2003-09-07 rewritten with netpoll api
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)
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.
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.
35 ****************************************************************/
38 #include <linux/init.h>
39 #include <linux/module.h>
40 #include <linux/console.h>
41 #include <linux/moduleparam.h>
42 #include <linux/string.h>
43 #include <linux/netpoll.h>
44 #include <linux/inet.h>
45 #include <linux/configfs.h>
47 MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@selenic.com>");
48 MODULE_DESCRIPTION("Console driver for network interfaces");
49 MODULE_LICENSE("GPL");
51 #define MAX_PARAM_LENGTH 256
52 #define MAX_PRINT_CHUNK 1000
54 static char config[MAX_PARAM_LENGTH];
55 module_param_string(netconsole, config, MAX_PARAM_LENGTH, 0);
56 MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]");
59 static int __init option_setup(char *opt)
61 strlcpy(config, opt, MAX_PARAM_LENGTH);
64 __setup("netconsole=", option_setup);
67 /* Linked list of all configured targets */
68 static LIST_HEAD(target_list);
70 /* This needs to be a spinlock because write_msg() cannot sleep */
71 static DEFINE_SPINLOCK(target_list_lock);
74 * struct netconsole_target - Represents a configured netconsole target.
75 * @list: Links this target into the target_list.
76 * @item: Links us into the configfs subsystem hierarchy.
77 * @enabled: On / off knob to enable / disable target.
78 * Visible from userspace (read-write).
79 * We maintain a strict 1:1 correspondence between this and
80 * whether the corresponding netpoll is active or inactive.
81 * Also, other parameters of a target may be modified at
82 * runtime only when it is disabled (enabled == 0).
83 * @np: The netpoll structure for this target.
84 * Contains the other userspace visible parameters:
85 * dev_name (read-write)
86 * local_port (read-write)
87 * remote_port (read-write)
88 * local_ip (read-write)
89 * remote_ip (read-write)
90 * local_mac (read-only)
91 * remote_mac (read-write)
93 struct netconsole_target {
94 struct list_head list;
95 #ifdef CONFIG_NETCONSOLE_DYNAMIC
96 struct config_item item;
102 #ifdef CONFIG_NETCONSOLE_DYNAMIC
104 static struct configfs_subsystem netconsole_subsys;
106 static int __init dynamic_netconsole_init(void)
108 config_group_init(&netconsole_subsys.su_group);
109 mutex_init(&netconsole_subsys.su_mutex);
110 return configfs_register_subsystem(&netconsole_subsys);
113 static void __exit dynamic_netconsole_exit(void)
115 configfs_unregister_subsystem(&netconsole_subsys);
119 * Targets that were created by parsing the boot/module option string
120 * do not exist in the configfs hierarchy (and have NULL names) and will
121 * never go away, so make these a no-op for them.
123 static void netconsole_target_get(struct netconsole_target *nt)
125 if (config_item_name(&nt->item))
126 config_item_get(&nt->item);
129 static void netconsole_target_put(struct netconsole_target *nt)
131 if (config_item_name(&nt->item))
132 config_item_put(&nt->item);
135 #else /* !CONFIG_NETCONSOLE_DYNAMIC */
137 static int __init dynamic_netconsole_init(void)
142 static void __exit dynamic_netconsole_exit(void)
147 * No danger of targets going away from under us when dynamic
148 * reconfigurability is off.
150 static void netconsole_target_get(struct netconsole_target *nt)
154 static void netconsole_target_put(struct netconsole_target *nt)
158 #endif /* CONFIG_NETCONSOLE_DYNAMIC */
160 /* Allocate new target (from boot/module param) and setup netpoll for it */
161 static struct netconsole_target *alloc_param_target(char *target_config)
164 struct netconsole_target *nt;
167 * Allocate and initialize with defaults.
168 * Note that these targets get their config_item fields zeroed-out.
170 nt = kzalloc(sizeof(*nt), GFP_KERNEL);
172 printk(KERN_ERR "netconsole: failed to allocate memory\n");
176 nt->np.name = "netconsole";
177 strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
178 nt->np.local_port = 6665;
179 nt->np.remote_port = 6666;
180 memset(nt->np.remote_mac, 0xff, ETH_ALEN);
182 /* Parse parameters and setup netpoll */
183 err = netpoll_parse_options(&nt->np, target_config);
187 err = netpoll_setup(&nt->np);
200 /* Cleanup netpoll for given target (from boot/module param) and free it */
201 static void free_param_target(struct netconsole_target *nt)
203 netpoll_cleanup(&nt->np);
207 #ifdef CONFIG_NETCONSOLE_DYNAMIC
210 * Our subsystem hierarchy is:
212 * /sys/kernel/config/netconsole/
227 struct netconsole_target_attr {
228 struct configfs_attribute attr;
229 ssize_t (*show)(struct netconsole_target *nt,
231 ssize_t (*store)(struct netconsole_target *nt,
236 static struct netconsole_target *to_target(struct config_item *item)
239 container_of(item, struct netconsole_target, item) :
244 * Wrapper over simple_strtol (base 10) with sanity and range checking.
245 * We return (signed) long only because we may want to return errors.
246 * Do not use this to convert numbers that are allowed to be negative.
248 static long strtol10_check_range(const char *cp, long min, long max)
251 char *p = (char *) cp;
256 ret = simple_strtol(p, &p, 10);
258 if (*p && (*p != '\n')) {
259 printk(KERN_ERR "netconsole: invalid input\n");
262 if ((ret < min) || (ret > max)) {
263 printk(KERN_ERR "netconsole: input %ld must be between "
264 "%ld and %ld\n", ret, min, max);
272 * Attribute operations for netconsole_target.
275 static ssize_t show_enabled(struct netconsole_target *nt, char *buf)
277 return snprintf(buf, PAGE_SIZE, "%d\n", nt->enabled);
280 static ssize_t show_dev_name(struct netconsole_target *nt, char *buf)
282 return snprintf(buf, PAGE_SIZE, "%s\n", nt->np.dev_name);
285 static ssize_t show_local_port(struct netconsole_target *nt, char *buf)
287 return snprintf(buf, PAGE_SIZE, "%d\n", nt->np.local_port);
290 static ssize_t show_remote_port(struct netconsole_target *nt, char *buf)
292 return snprintf(buf, PAGE_SIZE, "%d\n", nt->np.remote_port);
295 static ssize_t show_local_ip(struct netconsole_target *nt, char *buf)
297 return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.local_ip);
300 static ssize_t show_remote_ip(struct netconsole_target *nt, char *buf)
302 return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.remote_ip);
305 static ssize_t show_local_mac(struct netconsole_target *nt, char *buf)
307 struct net_device *dev = nt->np.dev;
308 static const u8 bcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
310 return snprintf(buf, PAGE_SIZE, "%pM\n", dev ? dev->dev_addr : bcast);
313 static ssize_t show_remote_mac(struct netconsole_target *nt, char *buf)
315 return snprintf(buf, PAGE_SIZE, "%pM\n", nt->np.remote_mac);
319 * This one is special -- targets created through the configfs interface
320 * are not enabled (and the corresponding netpoll activated) by default.
321 * The user is expected to set the desired parameters first (which
322 * would enable him to dynamically add new netpoll targets for new
323 * network interfaces as and when they come up).
325 static ssize_t store_enabled(struct netconsole_target *nt,
332 enabled = strtol10_check_range(buf, 0, 1);
336 if (enabled) { /* 1 */
339 * Skip netpoll_parse_options() -- all the attributes are
340 * already configured via configfs. Just print them out.
342 netpoll_print_options(&nt->np);
344 err = netpoll_setup(&nt->np);
348 printk(KERN_INFO "netconsole: network logging started\n");
351 netpoll_cleanup(&nt->np);
354 nt->enabled = enabled;
356 return strnlen(buf, count);
359 static ssize_t store_dev_name(struct netconsole_target *nt,
366 printk(KERN_ERR "netconsole: target (%s) is enabled, "
367 "disable to update parameters\n",
368 config_item_name(&nt->item));
372 strlcpy(nt->np.dev_name, buf, IFNAMSIZ);
374 /* Get rid of possible trailing newline from echo(1) */
375 len = strnlen(nt->np.dev_name, IFNAMSIZ);
376 if (nt->np.dev_name[len - 1] == '\n')
377 nt->np.dev_name[len - 1] = '\0';
379 return strnlen(buf, count);
382 static ssize_t store_local_port(struct netconsole_target *nt,
387 #define __U16_MAX ((__u16) ~0U)
390 printk(KERN_ERR "netconsole: target (%s) is enabled, "
391 "disable to update parameters\n",
392 config_item_name(&nt->item));
396 local_port = strtol10_check_range(buf, 0, __U16_MAX);
400 nt->np.local_port = local_port;
402 return strnlen(buf, count);
405 static ssize_t store_remote_port(struct netconsole_target *nt,
410 #define __U16_MAX ((__u16) ~0U)
413 printk(KERN_ERR "netconsole: target (%s) is enabled, "
414 "disable to update parameters\n",
415 config_item_name(&nt->item));
419 remote_port = strtol10_check_range(buf, 0, __U16_MAX);
423 nt->np.remote_port = remote_port;
425 return strnlen(buf, count);
428 static ssize_t store_local_ip(struct netconsole_target *nt,
433 printk(KERN_ERR "netconsole: target (%s) is enabled, "
434 "disable to update parameters\n",
435 config_item_name(&nt->item));
439 nt->np.local_ip = in_aton(buf);
441 return strnlen(buf, count);
444 static ssize_t store_remote_ip(struct netconsole_target *nt,
449 printk(KERN_ERR "netconsole: target (%s) is enabled, "
450 "disable to update parameters\n",
451 config_item_name(&nt->item));
455 nt->np.remote_ip = in_aton(buf);
457 return strnlen(buf, count);
460 static ssize_t store_remote_mac(struct netconsole_target *nt,
464 u8 remote_mac[ETH_ALEN];
465 char *p = (char *) buf;
469 printk(KERN_ERR "netconsole: target (%s) is enabled, "
470 "disable to update parameters\n",
471 config_item_name(&nt->item));
475 for (i = 0; i < ETH_ALEN - 1; i++) {
476 remote_mac[i] = simple_strtoul(p, &p, 16);
481 remote_mac[ETH_ALEN - 1] = simple_strtoul(p, &p, 16);
482 if (*p && (*p != '\n'))
485 memcpy(nt->np.remote_mac, remote_mac, ETH_ALEN);
487 return strnlen(buf, count);
490 printk(KERN_ERR "netconsole: invalid input\n");
495 * Attribute definitions for netconsole_target.
498 #define NETCONSOLE_TARGET_ATTR_RO(_name) \
499 static struct netconsole_target_attr netconsole_target_##_name = \
500 __CONFIGFS_ATTR(_name, S_IRUGO, show_##_name, NULL)
502 #define NETCONSOLE_TARGET_ATTR_RW(_name) \
503 static struct netconsole_target_attr netconsole_target_##_name = \
504 __CONFIGFS_ATTR(_name, S_IRUGO | S_IWUSR, show_##_name, store_##_name)
506 NETCONSOLE_TARGET_ATTR_RW(enabled);
507 NETCONSOLE_TARGET_ATTR_RW(dev_name);
508 NETCONSOLE_TARGET_ATTR_RW(local_port);
509 NETCONSOLE_TARGET_ATTR_RW(remote_port);
510 NETCONSOLE_TARGET_ATTR_RW(local_ip);
511 NETCONSOLE_TARGET_ATTR_RW(remote_ip);
512 NETCONSOLE_TARGET_ATTR_RO(local_mac);
513 NETCONSOLE_TARGET_ATTR_RW(remote_mac);
515 static struct configfs_attribute *netconsole_target_attrs[] = {
516 &netconsole_target_enabled.attr,
517 &netconsole_target_dev_name.attr,
518 &netconsole_target_local_port.attr,
519 &netconsole_target_remote_port.attr,
520 &netconsole_target_local_ip.attr,
521 &netconsole_target_remote_ip.attr,
522 &netconsole_target_local_mac.attr,
523 &netconsole_target_remote_mac.attr,
528 * Item operations and type for netconsole_target.
531 static void netconsole_target_release(struct config_item *item)
533 kfree(to_target(item));
536 static ssize_t netconsole_target_attr_show(struct config_item *item,
537 struct configfs_attribute *attr,
540 ssize_t ret = -EINVAL;
541 struct netconsole_target *nt = to_target(item);
542 struct netconsole_target_attr *na =
543 container_of(attr, struct netconsole_target_attr, attr);
546 ret = na->show(nt, buf);
551 static ssize_t netconsole_target_attr_store(struct config_item *item,
552 struct configfs_attribute *attr,
556 ssize_t ret = -EINVAL;
557 struct netconsole_target *nt = to_target(item);
558 struct netconsole_target_attr *na =
559 container_of(attr, struct netconsole_target_attr, attr);
562 ret = na->store(nt, buf, count);
567 static struct configfs_item_operations netconsole_target_item_ops = {
568 .release = netconsole_target_release,
569 .show_attribute = netconsole_target_attr_show,
570 .store_attribute = netconsole_target_attr_store,
573 static struct config_item_type netconsole_target_type = {
574 .ct_attrs = netconsole_target_attrs,
575 .ct_item_ops = &netconsole_target_item_ops,
576 .ct_owner = THIS_MODULE,
580 * Group operations and type for netconsole_subsys.
583 static struct config_item *make_netconsole_target(struct config_group *group,
587 struct netconsole_target *nt;
590 * Allocate and initialize with defaults.
591 * Target is disabled at creation (enabled == 0).
593 nt = kzalloc(sizeof(*nt), GFP_KERNEL);
595 printk(KERN_ERR "netconsole: failed to allocate memory\n");
596 return ERR_PTR(-ENOMEM);
599 nt->np.name = "netconsole";
600 strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
601 nt->np.local_port = 6665;
602 nt->np.remote_port = 6666;
603 memset(nt->np.remote_mac, 0xff, ETH_ALEN);
605 /* Initialize the config_item member */
606 config_item_init_type_name(&nt->item, name, &netconsole_target_type);
608 /* Adding, but it is disabled */
609 spin_lock_irqsave(&target_list_lock, flags);
610 list_add(&nt->list, &target_list);
611 spin_unlock_irqrestore(&target_list_lock, flags);
616 static void drop_netconsole_target(struct config_group *group,
617 struct config_item *item)
620 struct netconsole_target *nt = to_target(item);
622 spin_lock_irqsave(&target_list_lock, flags);
624 spin_unlock_irqrestore(&target_list_lock, flags);
627 * The target may have never been enabled, or was manually disabled
628 * before being removed so netpoll may have already been cleaned up.
631 netpoll_cleanup(&nt->np);
633 config_item_put(&nt->item);
636 static struct configfs_group_operations netconsole_subsys_group_ops = {
637 .make_item = make_netconsole_target,
638 .drop_item = drop_netconsole_target,
641 static struct config_item_type netconsole_subsys_type = {
642 .ct_group_ops = &netconsole_subsys_group_ops,
643 .ct_owner = THIS_MODULE,
646 /* The netconsole configfs subsystem */
647 static struct configfs_subsystem netconsole_subsys = {
650 .ci_namebuf = "netconsole",
651 .ci_type = &netconsole_subsys_type,
656 #endif /* CONFIG_NETCONSOLE_DYNAMIC */
658 /* Handle network interface device notifications */
659 static int netconsole_netdev_event(struct notifier_block *this,
664 struct netconsole_target *nt;
665 struct net_device *dev = ptr;
667 if (!(event == NETDEV_CHANGENAME || event == NETDEV_UNREGISTER))
670 spin_lock_irqsave(&target_list_lock, flags);
671 list_for_each_entry(nt, &target_list, list) {
672 netconsole_target_get(nt);
673 if (nt->np.dev == dev) {
675 case NETDEV_CHANGENAME:
676 strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ);
678 case NETDEV_UNREGISTER:
681 netpoll_cleanup(&nt->np);
683 printk(KERN_INFO "netconsole: network logging stopped"
684 ", interface %s unregistered\n",
689 netconsole_target_put(nt);
691 spin_unlock_irqrestore(&target_list_lock, flags);
697 static struct notifier_block netconsole_netdev_notifier = {
698 .notifier_call = netconsole_netdev_event,
701 static void write_msg(struct console *con, const char *msg, unsigned int len)
705 struct netconsole_target *nt;
708 /* Avoid taking lock and disabling interrupts unnecessarily */
709 if (list_empty(&target_list))
712 spin_lock_irqsave(&target_list_lock, flags);
713 list_for_each_entry(nt, &target_list, list) {
714 netconsole_target_get(nt);
715 if (nt->enabled && netif_running(nt->np.dev)) {
717 * We nest this inside the for-each-target loop above
718 * so that we're able to get as much logging out to
719 * at least one target if we die inside here, instead
720 * of unnecessarily keeping all targets in lock-step.
723 for (left = len; left;) {
724 frag = min(left, MAX_PRINT_CHUNK);
725 netpoll_send_udp(&nt->np, tmp, frag);
730 netconsole_target_put(nt);
732 spin_unlock_irqrestore(&target_list_lock, flags);
735 static struct console netconsole = {
737 .flags = CON_ENABLED,
741 static int __init init_netconsole(void)
744 struct netconsole_target *nt, *tmp;
747 char *input = config;
749 if (strnlen(input, MAX_PARAM_LENGTH)) {
750 while ((target_config = strsep(&input, ";"))) {
751 nt = alloc_param_target(target_config);
756 /* Dump existing printks when we register */
757 netconsole.flags |= CON_PRINTBUFFER;
759 spin_lock_irqsave(&target_list_lock, flags);
760 list_add(&nt->list, &target_list);
761 spin_unlock_irqrestore(&target_list_lock, flags);
765 err = register_netdevice_notifier(&netconsole_netdev_notifier);
769 err = dynamic_netconsole_init();
773 register_console(&netconsole);
774 printk(KERN_INFO "netconsole: network logging started\n");
779 unregister_netdevice_notifier(&netconsole_netdev_notifier);
782 printk(KERN_ERR "netconsole: cleaning up\n");
785 * Remove all targets and destroy them (only targets created
786 * from the boot/module option exist here). Skipping the list
787 * lock is safe here, and netpoll_cleanup() will sleep.
789 list_for_each_entry_safe(nt, tmp, &target_list, list) {
791 free_param_target(nt);
797 static void __exit cleanup_netconsole(void)
799 struct netconsole_target *nt, *tmp;
801 unregister_console(&netconsole);
802 dynamic_netconsole_exit();
803 unregister_netdevice_notifier(&netconsole_netdev_notifier);
806 * Targets created via configfs pin references on our module
807 * and would first be rmdir(2)'ed from userspace. We reach
808 * here only when they are already destroyed, and only those
809 * created from the boot/module option are left, so remove and
810 * destroy them. Skipping the list lock is safe here, and
811 * netpoll_cleanup() will sleep.
813 list_for_each_entry_safe(nt, tmp, &target_list, list) {
815 free_param_target(nt);
819 module_init(init_netconsole);
820 module_exit(cleanup_netconsole);