/*
* linux/drivers/net/netconsole.c
*
* Copyright (C) 2001 Ingo Molnar <mingo@redhat.com>
*
* This file contains the implementation of an IRQ-safe, crash-safe
* kernel console implementation that outputs kernel messages to the
* network.
*
* Modification history:
*
* 2001-09-17 started by Ingo Molnar.
* 2003-08-11 2.6 port by Matt Mackall
* simplified options
* generic card hooks
* works non-modular
* 2003-09-07 rewritten with netpoll api
*/
/****************************************************************
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
****************************************************************/
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/console.h>
#include <linux/moduleparam.h>
#include <linux/string.h>
#include <linux/netpoll.h>
MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@selenic.com>");
MODULE_DESCRIPTION("Console driver for network interfaces");
MODULE_LICENSE("GPL");
#define MAX_PARAM_LENGTH 256
#define MAX_PRINT_CHUNK 1000
static char config[MAX_PARAM_LENGTH];
module_param_string(netconsole, config, MAX_PARAM_LENGTH, 0);
MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]\n");
#ifndef MODULE
static int __init option_setup(char *opt)
{
strlcpy(config, opt, MAX_PARAM_LENGTH);
return 1;
}
__setup("netconsole=", option_setup);
#endif /* MODULE */
/* Linked list of all configured targets */
static LIST_HEAD(target_list);
/* This needs to be a spinlock because write_msg() cannot sleep */
static DEFINE_SPINLOCK(target_list_lock);
/**
* struct netconsole_target - Represents a configured netconsole target.
* @list: Links this target into the target_list.
* @np: The netpoll structure for this target.
*/
struct netconsole_target {
struct list_head list;
struct netpoll np;
};
/* Allocate new target and setup netpoll for it */
static struct netconsole_target *alloc_target(char *target_config)
{
int err = -ENOMEM;
struct netconsole_target *nt;
/* Allocate and initialize with defaults */
nt = kzalloc(sizeof(*nt), GFP_KERNEL);
if (!nt) {
printk(KERN_ERR "netconsole: failed to allocate memory\n");
goto fail;
}
nt->np.name = "netconsole";
strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
nt->np.local_port = 6665;
nt->np.remote_port = 6666;
memset(nt->np.remote_mac, 0xff, ETH_ALEN);
/* Parse parameters and setup netpoll */
err = netpoll_parse_options(&nt->np, target_config);
if (err)
goto fail;
err = netpoll_setup(&nt->np);
if (err)
goto fail;
return nt;
fail:
kfree(nt);
return ERR_PTR(err);
}
/* Cleanup netpoll for given target and free it */
static void free_target(struct netconsole_target *nt)
{
netpoll_cleanup(&nt->np);
kfree(nt);
}
/* Handle network interface device notifications */
static int netconsole_netdev_event(struct notifier_block *this,
unsigned long event,
void *ptr)
{
unsigned long flags;
struct netconsole_target *nt;
struct net_device *dev = ptr;
if (!(event == NETDEV_CHANGEADDR || event == NETDEV_CHANGENAME))
goto done;
spin_lock_irqsave(&target_list_lock, flags);
list_for_each_entry(nt, &target_list, list) {
if (nt->np.dev == dev) {
switch (event) {
case NETDEV_CHANGEADDR:
memcpy(nt->np.local_mac, dev->dev_addr, ETH_ALEN);
break;
case NETDEV_CHANGENAME:
strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ);
break;
}
}
}
spin_unlock_irqrestore(&target_list_lock, flags);
done:
return NOTIFY_DONE;
}
static struct notifier_block netconsole_netdev_notifier = {
.notifier_call = netconsole_netdev_event,
};
static void write_msg(struct console *con, const char *msg, unsigned int len)
{
int frag, left;
unsigned long flags;
struct netconsole_target *nt;
const char *tmp;
/* Avoid taking lock and disabling interrupts unnecessarily */
if (list_empty(&target_list))
return;
spin_lock_irqsave(&target_list_lock, flags);
list_for_each_entry(nt, &target_list, list) {
if (netif_running(nt->np.dev)) {
/*
* We nest this inside the for-each-target loop above
* so that we're able to get as much logging out to
* at least one target if we die inside here, instead
* of unnecessarily keeping all targets in lock-step.
*/
tmp = msg;
for (left = len; left;) {
frag = min(left, MAX_PRINT_CHUNK);
netpoll_send_udp(&nt->np, tmp, frag);
tmp += frag;
left -= frag;
}
}
}
spin_unlock_irqrestore(&target_list_lock, flags);
}
static struct console netconsole = {
.name = "netcon",
.flags = CON_ENABLED | CON_PRINTBUFFER,
.write = write_msg,
};
static int __init init_netconsole(void)
{
int err = 0;
struct netconsole_target *nt, *tmp;
unsigned long flags;
char *target_config;
char *input = config;
if (!strnlen(input, MAX_PARAM_LENGTH)) {
printk(KERN_INFO "netconsole: not configured, aborting\n");
goto out;
}
while ((target_config = strsep(&input, ";"))) {
nt = alloc_target(target_config);
if (IS_ERR(nt)) {
err = PTR_ERR(nt);
goto fail;
}
spin_lock_irqsave(&target_list_lock, flags);
list_add(&nt->list, &target_list);
spin_unlock_irqrestore(&target_list_lock, flags);
}
err = register_netdevice_notifier(&netconsole_netdev_notifier);
if (err)
goto fail;
register_console(&netconsole);
printk(KERN_INFO "netconsole: network logging started\n");
out:
return err;
fail:
printk(KERN_ERR "netconsole: cleaning up\n");
/*
* Remove all targets and destroy them. Skipping the list
* lock is safe here, and netpoll_cleanup() will sleep.
*/
list_for_each_entry_safe(nt, tmp, &target_list, list) {
list_del(&nt->list);
free_target(nt);
}
return err;
}
static void __exit cleanup_netconsole(void)
{
struct netconsole_target *nt, *tmp;
unregister_console(&netconsole);
unregister_netdevice_notifier(&netconsole_netdev_notifier);
/*
* Remove all targets and destroy them. Skipping the list
* lock is safe here, and netpoll_cleanup() will sleep.
*/
list_for_each_entry_safe(nt, tmp, &target_list, list) {
list_del(&nt->list);
free_target(nt);
}
}
module_init(init_netconsole);
module_exit(cleanup_netconsole);
