Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>. This patch introduces support for multiple targets, independent of CONFIG_NETCONSOLE_DYNAMIC -- this is useful even in the default case and (including the infrastructure introduced in previous patches) doesn't really add too many bytes to module text. All the complexity (and size) comes with the dynamic reconfigurability / userspace interface patch, and so it's plausible users may want to keep this enabled but that disabled (say to avoid a dependency on CONFIG_CONFIGFS_FS too). Also update documentation to mention the use of ";" separator to specify multiple logging targets in the boot/module option string. Brief overview: We maintain a target_list (and corresponding lock). Get rid of the static "default_target" and introduce allocation and release functions for our netconsole_target objects (but keeping sure to preserve previous behaviour such as default values). During init_netconsole(), ";" is used as the separator to identify multiple target specifications in the boot/module option string. The target specifications are parsed and netpolls setup. During exit, the target_list is torn down and all items released. Signed-off-by: Satyam Sharma <satyam@infradead.org> Signed-off-by: Keiichi Kii <k-keiichi@bx.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
265 lines
6.7 KiB
C
265 lines
6.7 KiB
C
/*
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* linux/drivers/net/netconsole.c
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*
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* Copyright (C) 2001 Ingo Molnar <mingo@redhat.com>
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*
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* This file contains the implementation of an IRQ-safe, crash-safe
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* kernel console implementation that outputs kernel messages to the
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* network.
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*
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* Modification history:
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*
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* 2001-09-17 started by Ingo Molnar.
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* 2003-08-11 2.6 port by Matt Mackall
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* simplified options
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* generic card hooks
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* works non-modular
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* 2003-09-07 rewritten with netpoll api
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*/
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/****************************************************************
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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****************************************************************/
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#include <linux/mm.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/console.h>
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#include <linux/moduleparam.h>
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#include <linux/string.h>
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#include <linux/netpoll.h>
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MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@selenic.com>");
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MODULE_DESCRIPTION("Console driver for network interfaces");
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MODULE_LICENSE("GPL");
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#define MAX_PARAM_LENGTH 256
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#define MAX_PRINT_CHUNK 1000
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static char config[MAX_PARAM_LENGTH];
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module_param_string(netconsole, config, MAX_PARAM_LENGTH, 0);
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MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]\n");
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#ifndef MODULE
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static int __init option_setup(char *opt)
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{
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strlcpy(config, opt, MAX_PARAM_LENGTH);
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return 1;
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}
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__setup("netconsole=", option_setup);
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#endif /* MODULE */
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/* Linked list of all configured targets */
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static LIST_HEAD(target_list);
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/* This needs to be a spinlock because write_msg() cannot sleep */
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static DEFINE_SPINLOCK(target_list_lock);
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/**
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* struct netconsole_target - Represents a configured netconsole target.
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* @list: Links this target into the target_list.
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* @np: The netpoll structure for this target.
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*/
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struct netconsole_target {
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struct list_head list;
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struct netpoll np;
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};
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/* Allocate new target and setup netpoll for it */
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static struct netconsole_target *alloc_target(char *target_config)
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{
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int err = -ENOMEM;
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struct netconsole_target *nt;
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/* Allocate and initialize with defaults */
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nt = kzalloc(sizeof(*nt), GFP_KERNEL);
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if (!nt) {
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printk(KERN_ERR "netconsole: failed to allocate memory\n");
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goto fail;
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}
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nt->np.name = "netconsole";
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strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
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nt->np.local_port = 6665;
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nt->np.remote_port = 6666;
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memset(nt->np.remote_mac, 0xff, ETH_ALEN);
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/* Parse parameters and setup netpoll */
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err = netpoll_parse_options(&nt->np, target_config);
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if (err)
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goto fail;
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err = netpoll_setup(&nt->np);
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if (err)
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goto fail;
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return nt;
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fail:
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kfree(nt);
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return ERR_PTR(err);
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}
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/* Cleanup netpoll for given target and free it */
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static void free_target(struct netconsole_target *nt)
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{
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netpoll_cleanup(&nt->np);
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kfree(nt);
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}
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/* Handle network interface device notifications */
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static int netconsole_netdev_event(struct notifier_block *this,
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unsigned long event,
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void *ptr)
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{
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unsigned long flags;
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struct netconsole_target *nt;
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struct net_device *dev = ptr;
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if (!(event == NETDEV_CHANGEADDR || event == NETDEV_CHANGENAME))
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goto done;
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spin_lock_irqsave(&target_list_lock, flags);
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list_for_each_entry(nt, &target_list, list) {
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if (nt->np.dev == dev) {
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switch (event) {
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case NETDEV_CHANGEADDR:
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memcpy(nt->np.local_mac, dev->dev_addr, ETH_ALEN);
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break;
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case NETDEV_CHANGENAME:
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strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ);
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break;
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}
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}
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}
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spin_unlock_irqrestore(&target_list_lock, flags);
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done:
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return NOTIFY_DONE;
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}
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static struct notifier_block netconsole_netdev_notifier = {
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.notifier_call = netconsole_netdev_event,
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};
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static void write_msg(struct console *con, const char *msg, unsigned int len)
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{
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int frag, left;
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unsigned long flags;
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struct netconsole_target *nt;
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const char *tmp;
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/* Avoid taking lock and disabling interrupts unnecessarily */
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if (list_empty(&target_list))
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return;
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spin_lock_irqsave(&target_list_lock, flags);
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list_for_each_entry(nt, &target_list, list) {
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if (netif_running(nt->np.dev)) {
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/*
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* We nest this inside the for-each-target loop above
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* so that we're able to get as much logging out to
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* at least one target if we die inside here, instead
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* of unnecessarily keeping all targets in lock-step.
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*/
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tmp = msg;
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for (left = len; left;) {
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frag = min(left, MAX_PRINT_CHUNK);
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netpoll_send_udp(&nt->np, tmp, frag);
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tmp += frag;
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left -= frag;
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}
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}
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}
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spin_unlock_irqrestore(&target_list_lock, flags);
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}
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static struct console netconsole = {
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.name = "netcon",
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.flags = CON_ENABLED | CON_PRINTBUFFER,
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.write = write_msg,
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};
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static int __init init_netconsole(void)
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{
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int err = 0;
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struct netconsole_target *nt, *tmp;
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unsigned long flags;
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char *target_config;
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char *input = config;
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if (!strnlen(input, MAX_PARAM_LENGTH)) {
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printk(KERN_INFO "netconsole: not configured, aborting\n");
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goto out;
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}
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while ((target_config = strsep(&input, ";"))) {
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nt = alloc_target(target_config);
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if (IS_ERR(nt)) {
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err = PTR_ERR(nt);
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goto fail;
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}
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spin_lock_irqsave(&target_list_lock, flags);
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list_add(&nt->list, &target_list);
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spin_unlock_irqrestore(&target_list_lock, flags);
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}
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err = register_netdevice_notifier(&netconsole_netdev_notifier);
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if (err)
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goto fail;
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register_console(&netconsole);
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printk(KERN_INFO "netconsole: network logging started\n");
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out:
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return err;
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fail:
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printk(KERN_ERR "netconsole: cleaning up\n");
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/*
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* Remove all targets and destroy them. Skipping the list
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* lock is safe here, and netpoll_cleanup() will sleep.
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*/
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list_for_each_entry_safe(nt, tmp, &target_list, list) {
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list_del(&nt->list);
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free_target(nt);
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}
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return err;
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}
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static void __exit cleanup_netconsole(void)
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{
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struct netconsole_target *nt, *tmp;
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unregister_console(&netconsole);
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unregister_netdevice_notifier(&netconsole_netdev_notifier);
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/*
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* Remove all targets and destroy them. Skipping the list
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* lock is safe here, and netpoll_cleanup() will sleep.
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*/
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list_for_each_entry_safe(nt, tmp, &target_list, list) {
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list_del(&nt->list);
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free_target(nt);
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}
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}
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module_init(init_netconsole);
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module_exit(cleanup_netconsole);
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