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/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>
48 MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@selenic.com>");
49 MODULE_DESCRIPTION("Console driver for network interfaces");
50 MODULE_LICENSE("GPL");
52 #define MAX_PARAM_LENGTH 256
53 #define MAX_PRINT_CHUNK 1000
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]");
60 static int __init
option_setup(char *opt
)
62 strlcpy(config
, opt
, MAX_PARAM_LENGTH
);
65 __setup("netconsole=", option_setup
);
68 /* Linked list of all configured targets */
69 static LIST_HEAD(target_list
);
71 /* This needs to be a spinlock because write_msg() cannot sleep */
72 static DEFINE_SPINLOCK(target_list_lock
);
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)
94 struct netconsole_target
{
95 struct list_head list
;
96 #ifdef CONFIG_NETCONSOLE_DYNAMIC
97 struct config_item item
;
103 #ifdef CONFIG_NETCONSOLE_DYNAMIC
105 static struct configfs_subsystem netconsole_subsys
;
107 static int __init
dynamic_netconsole_init(void)
109 config_group_init(&netconsole_subsys
.su_group
);
110 mutex_init(&netconsole_subsys
.su_mutex
);
111 return configfs_register_subsystem(&netconsole_subsys
);
114 static void __exit
dynamic_netconsole_exit(void)
116 configfs_unregister_subsystem(&netconsole_subsys
);
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.
124 static void netconsole_target_get(struct netconsole_target
*nt
)
126 if (config_item_name(&nt
->item
))
127 config_item_get(&nt
->item
);
130 static void netconsole_target_put(struct netconsole_target
*nt
)
132 if (config_item_name(&nt
->item
))
133 config_item_put(&nt
->item
);
136 #else /* !CONFIG_NETCONSOLE_DYNAMIC */
138 static int __init
dynamic_netconsole_init(void)
143 static void __exit
dynamic_netconsole_exit(void)
148 * No danger of targets going away from under us when dynamic
149 * reconfigurability is off.
151 static void netconsole_target_get(struct netconsole_target
*nt
)
155 static void netconsole_target_put(struct netconsole_target
*nt
)
159 #endif /* CONFIG_NETCONSOLE_DYNAMIC */
161 /* Allocate new target (from boot/module param) and setup netpoll for it */
162 static struct netconsole_target
*alloc_param_target(char *target_config
)
165 struct netconsole_target
*nt
;
168 * Allocate and initialize with defaults.
169 * Note that these targets get their config_item fields zeroed-out.
171 nt
= kzalloc(sizeof(*nt
), GFP_KERNEL
);
173 printk(KERN_ERR
"netconsole: failed to allocate memory\n");
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
);
183 /* Parse parameters and setup netpoll */
184 err
= netpoll_parse_options(&nt
->np
, target_config
);
188 err
= netpoll_setup(&nt
->np
);
201 /* Cleanup netpoll for given target (from boot/module param) and free it */
202 static void free_param_target(struct netconsole_target
*nt
)
204 netpoll_cleanup(&nt
->np
);
208 #ifdef CONFIG_NETCONSOLE_DYNAMIC
211 * Our subsystem hierarchy is:
213 * /sys/kernel/config/netconsole/
228 struct netconsole_target_attr
{
229 struct configfs_attribute attr
;
230 ssize_t (*show
)(struct netconsole_target
*nt
,
232 ssize_t (*store
)(struct netconsole_target
*nt
,
237 static struct netconsole_target
*to_target(struct config_item
*item
)
240 container_of(item
, struct netconsole_target
, item
) :
245 * Attribute operations for netconsole_target.
248 static ssize_t
show_enabled(struct netconsole_target
*nt
, char *buf
)
250 return snprintf(buf
, PAGE_SIZE
, "%d\n", nt
->enabled
);
253 static ssize_t
show_dev_name(struct netconsole_target
*nt
, char *buf
)
255 return snprintf(buf
, PAGE_SIZE
, "%s\n", nt
->np
.dev_name
);
258 static ssize_t
show_local_port(struct netconsole_target
*nt
, char *buf
)
260 return snprintf(buf
, PAGE_SIZE
, "%d\n", nt
->np
.local_port
);
263 static ssize_t
show_remote_port(struct netconsole_target
*nt
, char *buf
)
265 return snprintf(buf
, PAGE_SIZE
, "%d\n", nt
->np
.remote_port
);
268 static ssize_t
show_local_ip(struct netconsole_target
*nt
, char *buf
)
270 return snprintf(buf
, PAGE_SIZE
, "%pI4\n", &nt
->np
.local_ip
);
273 static ssize_t
show_remote_ip(struct netconsole_target
*nt
, char *buf
)
275 return snprintf(buf
, PAGE_SIZE
, "%pI4\n", &nt
->np
.remote_ip
);
278 static ssize_t
show_local_mac(struct netconsole_target
*nt
, char *buf
)
280 struct net_device
*dev
= nt
->np
.dev
;
281 static const u8 bcast
[ETH_ALEN
] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
283 return snprintf(buf
, PAGE_SIZE
, "%pM\n", dev
? dev
->dev_addr
: bcast
);
286 static ssize_t
show_remote_mac(struct netconsole_target
*nt
, char *buf
)
288 return snprintf(buf
, PAGE_SIZE
, "%pM\n", nt
->np
.remote_mac
);
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).
298 static ssize_t
store_enabled(struct netconsole_target
*nt
,
305 err
= kstrtoint(buf
, 10, &enabled
);
308 if (enabled
< 0 || enabled
> 1)
311 if (enabled
) { /* 1 */
314 * Skip netpoll_parse_options() -- all the attributes are
315 * already configured via configfs. Just print them out.
317 netpoll_print_options(&nt
->np
);
319 err
= netpoll_setup(&nt
->np
);
323 printk(KERN_INFO
"netconsole: network logging started\n");
326 netpoll_cleanup(&nt
->np
);
329 nt
->enabled
= enabled
;
331 return strnlen(buf
, count
);
334 static ssize_t
store_dev_name(struct netconsole_target
*nt
,
341 printk(KERN_ERR
"netconsole: target (%s) is enabled, "
342 "disable to update parameters\n",
343 config_item_name(&nt
->item
));
347 strlcpy(nt
->np
.dev_name
, buf
, IFNAMSIZ
);
349 /* Get rid of possible trailing newline from echo(1) */
350 len
= strnlen(nt
->np
.dev_name
, IFNAMSIZ
);
351 if (nt
->np
.dev_name
[len
- 1] == '\n')
352 nt
->np
.dev_name
[len
- 1] = '\0';
354 return strnlen(buf
, count
);
357 static ssize_t
store_local_port(struct netconsole_target
*nt
,
364 printk(KERN_ERR
"netconsole: target (%s) is enabled, "
365 "disable to update parameters\n",
366 config_item_name(&nt
->item
));
370 rv
= kstrtou16(buf
, 10, &nt
->np
.local_port
);
373 return strnlen(buf
, count
);
376 static ssize_t
store_remote_port(struct netconsole_target
*nt
,
383 printk(KERN_ERR
"netconsole: target (%s) is enabled, "
384 "disable to update parameters\n",
385 config_item_name(&nt
->item
));
389 rv
= kstrtou16(buf
, 10, &nt
->np
.remote_port
);
392 return strnlen(buf
, count
);
395 static ssize_t
store_local_ip(struct netconsole_target
*nt
,
400 printk(KERN_ERR
"netconsole: target (%s) is enabled, "
401 "disable to update parameters\n",
402 config_item_name(&nt
->item
));
406 nt
->np
.local_ip
= in_aton(buf
);
408 return strnlen(buf
, count
);
411 static ssize_t
store_remote_ip(struct netconsole_target
*nt
,
416 printk(KERN_ERR
"netconsole: target (%s) is enabled, "
417 "disable to update parameters\n",
418 config_item_name(&nt
->item
));
422 nt
->np
.remote_ip
= in_aton(buf
);
424 return strnlen(buf
, count
);
427 static ssize_t
store_remote_mac(struct netconsole_target
*nt
,
431 u8 remote_mac
[ETH_ALEN
];
432 char *p
= (char *) buf
;
436 printk(KERN_ERR
"netconsole: target (%s) is enabled, "
437 "disable to update parameters\n",
438 config_item_name(&nt
->item
));
442 for (i
= 0; i
< ETH_ALEN
- 1; i
++) {
443 remote_mac
[i
] = simple_strtoul(p
, &p
, 16);
448 remote_mac
[ETH_ALEN
- 1] = simple_strtoul(p
, &p
, 16);
449 if (*p
&& (*p
!= '\n'))
452 memcpy(nt
->np
.remote_mac
, remote_mac
, ETH_ALEN
);
454 return strnlen(buf
, count
);
457 printk(KERN_ERR
"netconsole: invalid input\n");
462 * Attribute definitions for netconsole_target.
465 #define NETCONSOLE_TARGET_ATTR_RO(_name) \
466 static struct netconsole_target_attr netconsole_target_##_name = \
467 __CONFIGFS_ATTR(_name, S_IRUGO, show_##_name, NULL)
469 #define NETCONSOLE_TARGET_ATTR_RW(_name) \
470 static struct netconsole_target_attr netconsole_target_##_name = \
471 __CONFIGFS_ATTR(_name, S_IRUGO | S_IWUSR, show_##_name, store_##_name)
473 NETCONSOLE_TARGET_ATTR_RW(enabled
);
474 NETCONSOLE_TARGET_ATTR_RW(dev_name
);
475 NETCONSOLE_TARGET_ATTR_RW(local_port
);
476 NETCONSOLE_TARGET_ATTR_RW(remote_port
);
477 NETCONSOLE_TARGET_ATTR_RW(local_ip
);
478 NETCONSOLE_TARGET_ATTR_RW(remote_ip
);
479 NETCONSOLE_TARGET_ATTR_RO(local_mac
);
480 NETCONSOLE_TARGET_ATTR_RW(remote_mac
);
482 static struct configfs_attribute
*netconsole_target_attrs
[] = {
483 &netconsole_target_enabled
.attr
,
484 &netconsole_target_dev_name
.attr
,
485 &netconsole_target_local_port
.attr
,
486 &netconsole_target_remote_port
.attr
,
487 &netconsole_target_local_ip
.attr
,
488 &netconsole_target_remote_ip
.attr
,
489 &netconsole_target_local_mac
.attr
,
490 &netconsole_target_remote_mac
.attr
,
495 * Item operations and type for netconsole_target.
498 static void netconsole_target_release(struct config_item
*item
)
500 kfree(to_target(item
));
503 static ssize_t
netconsole_target_attr_show(struct config_item
*item
,
504 struct configfs_attribute
*attr
,
507 ssize_t ret
= -EINVAL
;
508 struct netconsole_target
*nt
= to_target(item
);
509 struct netconsole_target_attr
*na
=
510 container_of(attr
, struct netconsole_target_attr
, attr
);
513 ret
= na
->show(nt
, buf
);
518 static ssize_t
netconsole_target_attr_store(struct config_item
*item
,
519 struct configfs_attribute
*attr
,
523 ssize_t ret
= -EINVAL
;
524 struct netconsole_target
*nt
= to_target(item
);
525 struct netconsole_target_attr
*na
=
526 container_of(attr
, struct netconsole_target_attr
, attr
);
529 ret
= na
->store(nt
, buf
, count
);
534 static struct configfs_item_operations netconsole_target_item_ops
= {
535 .release
= netconsole_target_release
,
536 .show_attribute
= netconsole_target_attr_show
,
537 .store_attribute
= netconsole_target_attr_store
,
540 static struct config_item_type netconsole_target_type
= {
541 .ct_attrs
= netconsole_target_attrs
,
542 .ct_item_ops
= &netconsole_target_item_ops
,
543 .ct_owner
= THIS_MODULE
,
547 * Group operations and type for netconsole_subsys.
550 static struct config_item
*make_netconsole_target(struct config_group
*group
,
554 struct netconsole_target
*nt
;
557 * Allocate and initialize with defaults.
558 * Target is disabled at creation (enabled == 0).
560 nt
= kzalloc(sizeof(*nt
), GFP_KERNEL
);
562 printk(KERN_ERR
"netconsole: failed to allocate memory\n");
563 return ERR_PTR(-ENOMEM
);
566 nt
->np
.name
= "netconsole";
567 strlcpy(nt
->np
.dev_name
, "eth0", IFNAMSIZ
);
568 nt
->np
.local_port
= 6665;
569 nt
->np
.remote_port
= 6666;
570 memset(nt
->np
.remote_mac
, 0xff, ETH_ALEN
);
572 /* Initialize the config_item member */
573 config_item_init_type_name(&nt
->item
, name
, &netconsole_target_type
);
575 /* Adding, but it is disabled */
576 spin_lock_irqsave(&target_list_lock
, flags
);
577 list_add(&nt
->list
, &target_list
);
578 spin_unlock_irqrestore(&target_list_lock
, flags
);
583 static void drop_netconsole_target(struct config_group
*group
,
584 struct config_item
*item
)
587 struct netconsole_target
*nt
= to_target(item
);
589 spin_lock_irqsave(&target_list_lock
, flags
);
591 spin_unlock_irqrestore(&target_list_lock
, flags
);
594 * The target may have never been enabled, or was manually disabled
595 * before being removed so netpoll may have already been cleaned up.
598 netpoll_cleanup(&nt
->np
);
600 config_item_put(&nt
->item
);
603 static struct configfs_group_operations netconsole_subsys_group_ops
= {
604 .make_item
= make_netconsole_target
,
605 .drop_item
= drop_netconsole_target
,
608 static struct config_item_type netconsole_subsys_type
= {
609 .ct_group_ops
= &netconsole_subsys_group_ops
,
610 .ct_owner
= THIS_MODULE
,
613 /* The netconsole configfs subsystem */
614 static struct configfs_subsystem netconsole_subsys
= {
617 .ci_namebuf
= "netconsole",
618 .ci_type
= &netconsole_subsys_type
,
623 #endif /* CONFIG_NETCONSOLE_DYNAMIC */
625 /* Handle network interface device notifications */
626 static int netconsole_netdev_event(struct notifier_block
*this,
631 struct netconsole_target
*nt
;
632 struct net_device
*dev
= ptr
;
633 bool stopped
= false;
635 if (!(event
== NETDEV_CHANGENAME
|| event
== NETDEV_UNREGISTER
||
636 event
== NETDEV_BONDING_DESLAVE
|| event
== NETDEV_GOING_DOWN
))
639 spin_lock_irqsave(&target_list_lock
, flags
);
641 list_for_each_entry(nt
, &target_list
, list
) {
642 netconsole_target_get(nt
);
643 if (nt
->np
.dev
== dev
) {
645 case NETDEV_CHANGENAME
:
646 strlcpy(nt
->np
.dev_name
, dev
->name
, IFNAMSIZ
);
648 case NETDEV_UNREGISTER
:
650 * rtnl_lock already held
653 spin_unlock_irqrestore(
656 __netpoll_cleanup(&nt
->np
);
657 spin_lock_irqsave(&target_list_lock
,
661 netconsole_target_put(nt
);
665 case NETDEV_GOING_DOWN
:
666 case NETDEV_BONDING_DESLAVE
:
672 netconsole_target_put(nt
);
674 spin_unlock_irqrestore(&target_list_lock
, flags
);
675 if (stopped
&& (event
== NETDEV_UNREGISTER
|| event
== NETDEV_BONDING_DESLAVE
))
676 printk(KERN_INFO
"netconsole: network logging stopped on "
677 "interface %s as it %s\n", dev
->name
,
678 event
== NETDEV_UNREGISTER
? "unregistered" : "released slaves");
684 static struct notifier_block netconsole_netdev_notifier
= {
685 .notifier_call
= netconsole_netdev_event
,
688 static void write_msg(struct console
*con
, const char *msg
, unsigned int len
)
692 struct netconsole_target
*nt
;
695 /* Avoid taking lock and disabling interrupts unnecessarily */
696 if (list_empty(&target_list
))
699 spin_lock_irqsave(&target_list_lock
, flags
);
700 list_for_each_entry(nt
, &target_list
, list
) {
701 netconsole_target_get(nt
);
702 if (nt
->enabled
&& netif_running(nt
->np
.dev
)) {
704 * We nest this inside the for-each-target loop above
705 * so that we're able to get as much logging out to
706 * at least one target if we die inside here, instead
707 * of unnecessarily keeping all targets in lock-step.
710 for (left
= len
; left
;) {
711 frag
= min(left
, MAX_PRINT_CHUNK
);
712 netpoll_send_udp(&nt
->np
, tmp
, frag
);
717 netconsole_target_put(nt
);
719 spin_unlock_irqrestore(&target_list_lock
, flags
);
722 static struct console netconsole
= {
724 .flags
= CON_ENABLED
,
728 static int __init
init_netconsole(void)
731 struct netconsole_target
*nt
, *tmp
;
734 char *input
= config
;
736 if (strnlen(input
, MAX_PARAM_LENGTH
)) {
737 while ((target_config
= strsep(&input
, ";"))) {
738 nt
= alloc_param_target(target_config
);
743 /* Dump existing printks when we register */
744 netconsole
.flags
|= CON_PRINTBUFFER
;
746 spin_lock_irqsave(&target_list_lock
, flags
);
747 list_add(&nt
->list
, &target_list
);
748 spin_unlock_irqrestore(&target_list_lock
, flags
);
752 err
= register_netdevice_notifier(&netconsole_netdev_notifier
);
756 err
= dynamic_netconsole_init();
760 register_console(&netconsole
);
761 printk(KERN_INFO
"netconsole: network logging started\n");
766 unregister_netdevice_notifier(&netconsole_netdev_notifier
);
769 printk(KERN_ERR
"netconsole: cleaning up\n");
772 * Remove all targets and destroy them (only targets created
773 * from the boot/module option exist here). Skipping the list
774 * lock is safe here, and netpoll_cleanup() will sleep.
776 list_for_each_entry_safe(nt
, tmp
, &target_list
, list
) {
778 free_param_target(nt
);
784 static void __exit
cleanup_netconsole(void)
786 struct netconsole_target
*nt
, *tmp
;
788 unregister_console(&netconsole
);
789 dynamic_netconsole_exit();
790 unregister_netdevice_notifier(&netconsole_netdev_notifier
);
793 * Targets created via configfs pin references on our module
794 * and would first be rmdir(2)'ed from userspace. We reach
795 * here only when they are already destroyed, and only those
796 * created from the boot/module option are left, so remove and
797 * destroy them. Skipping the list lock is safe here, and
798 * netpoll_cleanup() will sleep.
800 list_for_each_entry_safe(nt
, tmp
, &target_list
, list
) {
802 free_param_target(nt
);
806 module_init(init_netconsole
);
807 module_exit(cleanup_netconsole
);