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>
45 MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@selenic.com>");
46 MODULE_DESCRIPTION("Console driver for network interfaces");
47 MODULE_LICENSE("GPL");
49 #define MAX_PARAM_LENGTH 256
50 #define MAX_PRINT_CHUNK 1000
52 static char config[MAX_PARAM_LENGTH];
53 module_param_string(netconsole, config, MAX_PARAM_LENGTH, 0);
54 MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]\n");
57 static int __init option_setup(char *opt)
59 strlcpy(config, opt, MAX_PARAM_LENGTH);
62 __setup("netconsole=", option_setup);
65 /* Linked list of all configured targets */
66 static LIST_HEAD(target_list);
68 /* This needs to be a spinlock because write_msg() cannot sleep */
69 static DEFINE_SPINLOCK(target_list_lock);
72 * struct netconsole_target - Represents a configured netconsole target.
73 * @list: Links this target into the target_list.
74 * @np: The netpoll structure for this target.
76 struct netconsole_target {
77 struct list_head list;
81 /* Allocate new target and setup netpoll for it */
82 static struct netconsole_target *alloc_target(char *target_config)
85 struct netconsole_target *nt;
87 /* Allocate and initialize with defaults */
88 nt = kzalloc(sizeof(*nt), GFP_KERNEL);
90 printk(KERN_ERR "netconsole: failed to allocate memory\n");
94 nt->np.name = "netconsole";
95 strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
96 nt->np.local_port = 6665;
97 nt->np.remote_port = 6666;
98 memset(nt->np.remote_mac, 0xff, ETH_ALEN);
100 /* Parse parameters and setup netpoll */
101 err = netpoll_parse_options(&nt->np, target_config);
105 err = netpoll_setup(&nt->np);
116 /* Cleanup netpoll for given target and free it */
117 static void free_target(struct netconsole_target *nt)
119 netpoll_cleanup(&nt->np);
123 /* Handle network interface device notifications */
124 static int netconsole_netdev_event(struct notifier_block *this,
129 struct netconsole_target *nt;
130 struct net_device *dev = ptr;
132 if (!(event == NETDEV_CHANGEADDR || event == NETDEV_CHANGENAME))
135 spin_lock_irqsave(&target_list_lock, flags);
136 list_for_each_entry(nt, &target_list, list) {
137 if (nt->np.dev == dev) {
139 case NETDEV_CHANGEADDR:
140 memcpy(nt->np.local_mac, dev->dev_addr, ETH_ALEN);
143 case NETDEV_CHANGENAME:
144 strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ);
149 spin_unlock_irqrestore(&target_list_lock, flags);
155 static struct notifier_block netconsole_netdev_notifier = {
156 .notifier_call = netconsole_netdev_event,
159 static void write_msg(struct console *con, const char *msg, unsigned int len)
163 struct netconsole_target *nt;
166 /* Avoid taking lock and disabling interrupts unnecessarily */
167 if (list_empty(&target_list))
170 spin_lock_irqsave(&target_list_lock, flags);
171 list_for_each_entry(nt, &target_list, list) {
172 if (netif_running(nt->np.dev)) {
174 * We nest this inside the for-each-target loop above
175 * so that we're able to get as much logging out to
176 * at least one target if we die inside here, instead
177 * of unnecessarily keeping all targets in lock-step.
180 for (left = len; left;) {
181 frag = min(left, MAX_PRINT_CHUNK);
182 netpoll_send_udp(&nt->np, tmp, frag);
188 spin_unlock_irqrestore(&target_list_lock, flags);
191 static struct console netconsole = {
193 .flags = CON_ENABLED | CON_PRINTBUFFER,
197 static int __init init_netconsole(void)
200 struct netconsole_target *nt, *tmp;
203 char *input = config;
205 if (!strnlen(input, MAX_PARAM_LENGTH)) {
206 printk(KERN_INFO "netconsole: not configured, aborting\n");
210 while ((target_config = strsep(&input, ";"))) {
211 nt = alloc_target(target_config);
216 spin_lock_irqsave(&target_list_lock, flags);
217 list_add(&nt->list, &target_list);
218 spin_unlock_irqrestore(&target_list_lock, flags);
221 err = register_netdevice_notifier(&netconsole_netdev_notifier);
225 register_console(&netconsole);
226 printk(KERN_INFO "netconsole: network logging started\n");
232 printk(KERN_ERR "netconsole: cleaning up\n");
235 * Remove all targets and destroy them. Skipping the list
236 * lock is safe here, and netpoll_cleanup() will sleep.
238 list_for_each_entry_safe(nt, tmp, &target_list, list) {
246 static void __exit cleanup_netconsole(void)
248 struct netconsole_target *nt, *tmp;
250 unregister_console(&netconsole);
251 unregister_netdevice_notifier(&netconsole_netdev_notifier);
254 * Remove all targets and destroy them. Skipping the list
255 * lock is safe here, and netpoll_cleanup() will sleep.
257 list_for_each_entry_safe(nt, tmp, &target_list, list) {
263 module_init(init_netconsole);
264 module_exit(cleanup_netconsole);