linux/drivers/net/netconsole.c
Linus Torvalds 496322bc91 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:
 "This is a re-do of the net-next pull request for the current merge
  window.  The only difference from the one I made the other day is that
  this has Eliezer's interface renames and the timeout handling changes
  made based upon your feedback, as well as a few bug fixes that have
  trickeled in.

  Highlights:

   1) Low latency device polling, eliminating the cost of interrupt
      handling and context switches.  Allows direct polling of a network
      device from socket operations, such as recvmsg() and poll().

      Currently ixgbe, mlx4, and bnx2x support this feature.

      Full high level description, performance numbers, and design in
      commit 0a4db187a9 ("Merge branch 'll_poll'")

      From Eliezer Tamir.

   2) With the routing cache removed, ip_check_mc_rcu() gets exercised
      more than ever before in the case where we have lots of multicast
      addresses.  Use a hash table instead of a simple linked list, from
      Eric Dumazet.

   3) Add driver for Atheros CQA98xx 802.11ac wireless devices, from
      Bartosz Markowski, Janusz Dziedzic, Kalle Valo, Marek Kwaczynski,
      Marek Puzyniak, Michal Kazior, and Sujith Manoharan.

   4) Support reporting the TUN device persist flag to userspace, from
      Pavel Emelyanov.

   5) Allow controlling network device VF link state using netlink, from
      Rony Efraim.

   6) Support GRE tunneling in openvswitch, from Pravin B Shelar.

   7) Adjust SOCK_MIN_RCVBUF and SOCK_MIN_SNDBUF for modern times, from
      Daniel Borkmann and Eric Dumazet.

   8) Allow controlling of TCP quickack behavior on a per-route basis,
      from Cong Wang.

   9) Several bug fixes and improvements to vxlan from Stephen
      Hemminger, Pravin B Shelar, and Mike Rapoport.  In particular,
      support receiving on multiple UDP ports.

  10) Major cleanups, particular in the area of debugging and cookie
      lifetime handline, to the SCTP protocol code.  From Daniel
      Borkmann.

  11) Allow packets to cross network namespaces when traversing tunnel
      devices.  From Nicolas Dichtel.

  12) Allow monitoring netlink traffic via AF_PACKET sockets, in a
      manner akin to how we monitor real network traffic via ptype_all.
      From Daniel Borkmann.

  13) Several bug fixes and improvements for the new alx device driver,
      from Johannes Berg.

  14) Fix scalability issues in the netem packet scheduler's time queue,
      by using an rbtree.  From Eric Dumazet.

  15) Several bug fixes in TCP loss recovery handling, from Yuchung
      Cheng.

  16) Add support for GSO segmentation of MPLS packets, from Simon
      Horman.

  17) Make network notifiers have a real data type for the opaque
      pointer that's passed into them.  Use this to properly handle
      network device flag changes in arp_netdev_event().  From Jiri
      Pirko and Timo Teräs.

  18) Convert several drivers over to module_pci_driver(), from Peter
      Huewe.

  19) tcp_fixup_rcvbuf() can loop 500 times over loopback, just use a
      O(1) calculation instead.  From Eric Dumazet.

  20) Support setting of explicit tunnel peer addresses in ipv6, just
      like ipv4.  From Nicolas Dichtel.

  21) Protect x86 BPF JIT against spraying attacks, from Eric Dumazet.

  22) Prevent a single high rate flow from overruning an individual cpu
      during RX packet processing via selective flow shedding.  From
      Willem de Bruijn.

  23) Don't use spinlocks in TCP md5 signing fast paths, from Eric
      Dumazet.

  24) Don't just drop GSO packets which are above the TBF scheduler's
      burst limit, chop them up so they are in-bounds instead.  Also
      from Eric Dumazet.

  25) VLAN offloads are missed when configured on top of a bridge, fix
      from Vlad Yasevich.

  26) Support IPV6 in ping sockets.  From Lorenzo Colitti.

  27) Receive flow steering targets should be updated at poll() time
      too, from David Majnemer.

  28) Fix several corner case regressions in PMTU/redirect handling due
      to the routing cache removal, from Timo Teräs.

  29) We have to be mindful of ipv4 mapped ipv6 sockets in
      upd_v6_push_pending_frames().  From Hannes Frederic Sowa.

  30) Fix L2TP sequence number handling bugs, from James Chapman."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1214 commits)
  drivers/net: caif: fix wrong rtnl_is_locked() usage
  drivers/net: enic: release rtnl_lock on error-path
  vhost-net: fix use-after-free in vhost_net_flush
  net: mv643xx_eth: do not use port number as platform device id
  net: sctp: confirm route during forward progress
  virtio_net: fix race in RX VQ processing
  virtio: support unlocked queue poll
  net/cadence/macb: fix bug/typo in extracting gem_irq_read_clear bit
  Documentation: Fix references to defunct linux-net@vger.kernel.org
  net/fs: change busy poll time accounting
  net: rename low latency sockets functions to busy poll
  bridge: fix some kernel warning in multicast timer
  sfc: Fix memory leak when discarding scattered packets
  sit: fix tunnel update via netlink
  dt:net:stmmac: Add dt specific phy reset callback support.
  dt:net:stmmac: Add support to dwmac version 3.610 and 3.710
  dt:net:stmmac: Allocate platform data only if its NULL.
  net:stmmac: fix memleak in the open method
  ipv6: rt6_check_neigh should successfully verify neigh if no NUD information are available
  net: ipv6: fix wrong ping_v6_sendmsg return value
  ...
2013-07-09 18:24:39 -07:00

850 lines
21 KiB
C

/*
* 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/slab.h>
#include <linux/console.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/netpoll.h>
#include <linux/inet.h>
#include <linux/configfs.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]");
static bool oops_only = false;
module_param(oops_only, bool, 0600);
MODULE_PARM_DESC(oops_only, "Only log oops messages");
#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.
* @item: Links us into the configfs subsystem hierarchy.
* @enabled: On / off knob to enable / disable target.
* Visible from userspace (read-write).
* We maintain a strict 1:1 correspondence between this and
* whether the corresponding netpoll is active or inactive.
* Also, other parameters of a target may be modified at
* runtime only when it is disabled (enabled == 0).
* @np: The netpoll structure for this target.
* Contains the other userspace visible parameters:
* dev_name (read-write)
* local_port (read-write)
* remote_port (read-write)
* local_ip (read-write)
* remote_ip (read-write)
* local_mac (read-only)
* remote_mac (read-write)
*/
struct netconsole_target {
struct list_head list;
#ifdef CONFIG_NETCONSOLE_DYNAMIC
struct config_item item;
#endif
int enabled;
struct netpoll np;
};
#ifdef CONFIG_NETCONSOLE_DYNAMIC
static struct configfs_subsystem netconsole_subsys;
static int __init dynamic_netconsole_init(void)
{
config_group_init(&netconsole_subsys.su_group);
mutex_init(&netconsole_subsys.su_mutex);
return configfs_register_subsystem(&netconsole_subsys);
}
static void __exit dynamic_netconsole_exit(void)
{
configfs_unregister_subsystem(&netconsole_subsys);
}
/*
* Targets that were created by parsing the boot/module option string
* do not exist in the configfs hierarchy (and have NULL names) and will
* never go away, so make these a no-op for them.
*/
static void netconsole_target_get(struct netconsole_target *nt)
{
if (config_item_name(&nt->item))
config_item_get(&nt->item);
}
static void netconsole_target_put(struct netconsole_target *nt)
{
if (config_item_name(&nt->item))
config_item_put(&nt->item);
}
#else /* !CONFIG_NETCONSOLE_DYNAMIC */
static int __init dynamic_netconsole_init(void)
{
return 0;
}
static void __exit dynamic_netconsole_exit(void)
{
}
/*
* No danger of targets going away from under us when dynamic
* reconfigurability is off.
*/
static void netconsole_target_get(struct netconsole_target *nt)
{
}
static void netconsole_target_put(struct netconsole_target *nt)
{
}
#endif /* CONFIG_NETCONSOLE_DYNAMIC */
/* Allocate new target (from boot/module param) and setup netpoll for it */
static struct netconsole_target *alloc_param_target(char *target_config)
{
int err = -ENOMEM;
struct netconsole_target *nt;
/*
* Allocate and initialize with defaults.
* Note that these targets get their config_item fields zeroed-out.
*/
nt = kzalloc(sizeof(*nt), GFP_KERNEL);
if (!nt)
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;
nt->enabled = 1;
return nt;
fail:
kfree(nt);
return ERR_PTR(err);
}
/* Cleanup netpoll for given target (from boot/module param) and free it */
static void free_param_target(struct netconsole_target *nt)
{
netpoll_cleanup(&nt->np);
kfree(nt);
}
#ifdef CONFIG_NETCONSOLE_DYNAMIC
/*
* Our subsystem hierarchy is:
*
* /sys/kernel/config/netconsole/
* |
* <target>/
* | enabled
* | dev_name
* | local_port
* | remote_port
* | local_ip
* | remote_ip
* | local_mac
* | remote_mac
* |
* <target>/...
*/
struct netconsole_target_attr {
struct configfs_attribute attr;
ssize_t (*show)(struct netconsole_target *nt,
char *buf);
ssize_t (*store)(struct netconsole_target *nt,
const char *buf,
size_t count);
};
static struct netconsole_target *to_target(struct config_item *item)
{
return item ?
container_of(item, struct netconsole_target, item) :
NULL;
}
/*
* Attribute operations for netconsole_target.
*/
static ssize_t show_enabled(struct netconsole_target *nt, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%d\n", nt->enabled);
}
static ssize_t show_dev_name(struct netconsole_target *nt, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%s\n", nt->np.dev_name);
}
static ssize_t show_local_port(struct netconsole_target *nt, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%d\n", nt->np.local_port);
}
static ssize_t show_remote_port(struct netconsole_target *nt, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%d\n", nt->np.remote_port);
}
static ssize_t show_local_ip(struct netconsole_target *nt, char *buf)
{
if (nt->np.ipv6)
return snprintf(buf, PAGE_SIZE, "%pI6c\n", &nt->np.local_ip.in6);
else
return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.local_ip);
}
static ssize_t show_remote_ip(struct netconsole_target *nt, char *buf)
{
if (nt->np.ipv6)
return snprintf(buf, PAGE_SIZE, "%pI6c\n", &nt->np.remote_ip.in6);
else
return snprintf(buf, PAGE_SIZE, "%pI4\n", &nt->np.remote_ip);
}
static ssize_t show_local_mac(struct netconsole_target *nt, char *buf)
{
struct net_device *dev = nt->np.dev;
static const u8 bcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
return snprintf(buf, PAGE_SIZE, "%pM\n", dev ? dev->dev_addr : bcast);
}
static ssize_t show_remote_mac(struct netconsole_target *nt, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%pM\n", nt->np.remote_mac);
}
/*
* This one is special -- targets created through the configfs interface
* are not enabled (and the corresponding netpoll activated) by default.
* The user is expected to set the desired parameters first (which
* would enable him to dynamically add new netpoll targets for new
* network interfaces as and when they come up).
*/
static ssize_t store_enabled(struct netconsole_target *nt,
const char *buf,
size_t count)
{
int enabled;
int err;
err = kstrtoint(buf, 10, &enabled);
if (err < 0)
return err;
if (enabled < 0 || enabled > 1)
return -EINVAL;
if (enabled == nt->enabled) {
printk(KERN_INFO "netconsole: network logging has already %s\n",
nt->enabled ? "started" : "stopped");
return -EINVAL;
}
if (enabled) { /* 1 */
/*
* Skip netpoll_parse_options() -- all the attributes are
* already configured via configfs. Just print them out.
*/
netpoll_print_options(&nt->np);
err = netpoll_setup(&nt->np);
if (err)
return err;
printk(KERN_INFO "netconsole: network logging started\n");
} else { /* 0 */
netpoll_cleanup(&nt->np);
}
nt->enabled = enabled;
return strnlen(buf, count);
}
static ssize_t store_dev_name(struct netconsole_target *nt,
const char *buf,
size_t count)
{
size_t len;
if (nt->enabled) {
printk(KERN_ERR "netconsole: target (%s) is enabled, "
"disable to update parameters\n",
config_item_name(&nt->item));
return -EINVAL;
}
strlcpy(nt->np.dev_name, buf, IFNAMSIZ);
/* Get rid of possible trailing newline from echo(1) */
len = strnlen(nt->np.dev_name, IFNAMSIZ);
if (nt->np.dev_name[len - 1] == '\n')
nt->np.dev_name[len - 1] = '\0';
return strnlen(buf, count);
}
static ssize_t store_local_port(struct netconsole_target *nt,
const char *buf,
size_t count)
{
int rv;
if (nt->enabled) {
printk(KERN_ERR "netconsole: target (%s) is enabled, "
"disable to update parameters\n",
config_item_name(&nt->item));
return -EINVAL;
}
rv = kstrtou16(buf, 10, &nt->np.local_port);
if (rv < 0)
return rv;
return strnlen(buf, count);
}
static ssize_t store_remote_port(struct netconsole_target *nt,
const char *buf,
size_t count)
{
int rv;
if (nt->enabled) {
printk(KERN_ERR "netconsole: target (%s) is enabled, "
"disable to update parameters\n",
config_item_name(&nt->item));
return -EINVAL;
}
rv = kstrtou16(buf, 10, &nt->np.remote_port);
if (rv < 0)
return rv;
return strnlen(buf, count);
}
static ssize_t store_local_ip(struct netconsole_target *nt,
const char *buf,
size_t count)
{
if (nt->enabled) {
printk(KERN_ERR "netconsole: target (%s) is enabled, "
"disable to update parameters\n",
config_item_name(&nt->item));
return -EINVAL;
}
if (strnchr(buf, count, ':')) {
const char *end;
if (in6_pton(buf, count, nt->np.local_ip.in6.s6_addr, -1, &end) > 0) {
if (*end && *end != '\n') {
printk(KERN_ERR "netconsole: invalid IPv6 address at: <%c>\n", *end);
return -EINVAL;
}
nt->np.ipv6 = true;
} else
return -EINVAL;
} else {
if (!nt->np.ipv6) {
nt->np.local_ip.ip = in_aton(buf);
} else
return -EINVAL;
}
return strnlen(buf, count);
}
static ssize_t store_remote_ip(struct netconsole_target *nt,
const char *buf,
size_t count)
{
if (nt->enabled) {
printk(KERN_ERR "netconsole: target (%s) is enabled, "
"disable to update parameters\n",
config_item_name(&nt->item));
return -EINVAL;
}
if (strnchr(buf, count, ':')) {
const char *end;
if (in6_pton(buf, count, nt->np.remote_ip.in6.s6_addr, -1, &end) > 0) {
if (*end && *end != '\n') {
printk(KERN_ERR "netconsole: invalid IPv6 address at: <%c>\n", *end);
return -EINVAL;
}
nt->np.ipv6 = true;
} else
return -EINVAL;
} else {
if (!nt->np.ipv6) {
nt->np.remote_ip.ip = in_aton(buf);
} else
return -EINVAL;
}
return strnlen(buf, count);
}
static ssize_t store_remote_mac(struct netconsole_target *nt,
const char *buf,
size_t count)
{
u8 remote_mac[ETH_ALEN];
if (nt->enabled) {
printk(KERN_ERR "netconsole: target (%s) is enabled, "
"disable to update parameters\n",
config_item_name(&nt->item));
return -EINVAL;
}
if (!mac_pton(buf, remote_mac))
return -EINVAL;
if (buf[3 * ETH_ALEN - 1] && buf[3 * ETH_ALEN - 1] != '\n')
return -EINVAL;
memcpy(nt->np.remote_mac, remote_mac, ETH_ALEN);
return strnlen(buf, count);
}
/*
* Attribute definitions for netconsole_target.
*/
#define NETCONSOLE_TARGET_ATTR_RO(_name) \
static struct netconsole_target_attr netconsole_target_##_name = \
__CONFIGFS_ATTR(_name, S_IRUGO, show_##_name, NULL)
#define NETCONSOLE_TARGET_ATTR_RW(_name) \
static struct netconsole_target_attr netconsole_target_##_name = \
__CONFIGFS_ATTR(_name, S_IRUGO | S_IWUSR, show_##_name, store_##_name)
NETCONSOLE_TARGET_ATTR_RW(enabled);
NETCONSOLE_TARGET_ATTR_RW(dev_name);
NETCONSOLE_TARGET_ATTR_RW(local_port);
NETCONSOLE_TARGET_ATTR_RW(remote_port);
NETCONSOLE_TARGET_ATTR_RW(local_ip);
NETCONSOLE_TARGET_ATTR_RW(remote_ip);
NETCONSOLE_TARGET_ATTR_RO(local_mac);
NETCONSOLE_TARGET_ATTR_RW(remote_mac);
static struct configfs_attribute *netconsole_target_attrs[] = {
&netconsole_target_enabled.attr,
&netconsole_target_dev_name.attr,
&netconsole_target_local_port.attr,
&netconsole_target_remote_port.attr,
&netconsole_target_local_ip.attr,
&netconsole_target_remote_ip.attr,
&netconsole_target_local_mac.attr,
&netconsole_target_remote_mac.attr,
NULL,
};
/*
* Item operations and type for netconsole_target.
*/
static void netconsole_target_release(struct config_item *item)
{
kfree(to_target(item));
}
static ssize_t netconsole_target_attr_show(struct config_item *item,
struct configfs_attribute *attr,
char *buf)
{
ssize_t ret = -EINVAL;
struct netconsole_target *nt = to_target(item);
struct netconsole_target_attr *na =
container_of(attr, struct netconsole_target_attr, attr);
if (na->show)
ret = na->show(nt, buf);
return ret;
}
static ssize_t netconsole_target_attr_store(struct config_item *item,
struct configfs_attribute *attr,
const char *buf,
size_t count)
{
ssize_t ret = -EINVAL;
struct netconsole_target *nt = to_target(item);
struct netconsole_target_attr *na =
container_of(attr, struct netconsole_target_attr, attr);
if (na->store)
ret = na->store(nt, buf, count);
return ret;
}
static struct configfs_item_operations netconsole_target_item_ops = {
.release = netconsole_target_release,
.show_attribute = netconsole_target_attr_show,
.store_attribute = netconsole_target_attr_store,
};
static struct config_item_type netconsole_target_type = {
.ct_attrs = netconsole_target_attrs,
.ct_item_ops = &netconsole_target_item_ops,
.ct_owner = THIS_MODULE,
};
/*
* Group operations and type for netconsole_subsys.
*/
static struct config_item *make_netconsole_target(struct config_group *group,
const char *name)
{
unsigned long flags;
struct netconsole_target *nt;
/*
* Allocate and initialize with defaults.
* Target is disabled at creation (enabled == 0).
*/
nt = kzalloc(sizeof(*nt), GFP_KERNEL);
if (!nt)
return ERR_PTR(-ENOMEM);
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);
/* Initialize the config_item member */
config_item_init_type_name(&nt->item, name, &netconsole_target_type);
/* Adding, but it is disabled */
spin_lock_irqsave(&target_list_lock, flags);
list_add(&nt->list, &target_list);
spin_unlock_irqrestore(&target_list_lock, flags);
return &nt->item;
}
static void drop_netconsole_target(struct config_group *group,
struct config_item *item)
{
unsigned long flags;
struct netconsole_target *nt = to_target(item);
spin_lock_irqsave(&target_list_lock, flags);
list_del(&nt->list);
spin_unlock_irqrestore(&target_list_lock, flags);
/*
* The target may have never been enabled, or was manually disabled
* before being removed so netpoll may have already been cleaned up.
*/
if (nt->enabled)
netpoll_cleanup(&nt->np);
config_item_put(&nt->item);
}
static struct configfs_group_operations netconsole_subsys_group_ops = {
.make_item = make_netconsole_target,
.drop_item = drop_netconsole_target,
};
static struct config_item_type netconsole_subsys_type = {
.ct_group_ops = &netconsole_subsys_group_ops,
.ct_owner = THIS_MODULE,
};
/* The netconsole configfs subsystem */
static struct configfs_subsystem netconsole_subsys = {
.su_group = {
.cg_item = {
.ci_namebuf = "netconsole",
.ci_type = &netconsole_subsys_type,
},
},
};
#endif /* CONFIG_NETCONSOLE_DYNAMIC */
/* 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 = netdev_notifier_info_to_dev(ptr);
bool stopped = false;
if (!(event == NETDEV_CHANGENAME || event == NETDEV_UNREGISTER ||
event == NETDEV_RELEASE || event == NETDEV_JOIN))
goto done;
spin_lock_irqsave(&target_list_lock, flags);
restart:
list_for_each_entry(nt, &target_list, list) {
netconsole_target_get(nt);
if (nt->np.dev == dev) {
switch (event) {
case NETDEV_CHANGENAME:
strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ);
break;
case NETDEV_RELEASE:
case NETDEV_JOIN:
case NETDEV_UNREGISTER:
/*
* rtnl_lock already held
* we might sleep in __netpoll_cleanup()
*/
spin_unlock_irqrestore(&target_list_lock, flags);
__netpoll_cleanup(&nt->np);
spin_lock_irqsave(&target_list_lock, flags);
dev_put(nt->np.dev);
nt->np.dev = NULL;
nt->enabled = 0;
stopped = true;
netconsole_target_put(nt);
goto restart;
}
}
netconsole_target_put(nt);
}
spin_unlock_irqrestore(&target_list_lock, flags);
if (stopped) {
printk(KERN_INFO "netconsole: network logging stopped on "
"interface %s as it ", dev->name);
switch (event) {
case NETDEV_UNREGISTER:
printk(KERN_CONT "unregistered\n");
break;
case NETDEV_RELEASE:
printk(KERN_CONT "released slaves\n");
break;
case NETDEV_JOIN:
printk(KERN_CONT "is joining a master device\n");
break;
}
}
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;
if (oops_only && !oops_in_progress)
return;
/* 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) {
netconsole_target_get(nt);
if (nt->enabled && 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;
}
}
netconsole_target_put(nt);
}
spin_unlock_irqrestore(&target_list_lock, flags);
}
static struct console netconsole = {
.name = "netcon",
.flags = CON_ENABLED,
.write = write_msg,
};
static int __init init_netconsole(void)
{
int err;
struct netconsole_target *nt, *tmp;
unsigned long flags;
char *target_config;
char *input = config;
if (strnlen(input, MAX_PARAM_LENGTH)) {
while ((target_config = strsep(&input, ";"))) {
nt = alloc_param_target(target_config);
if (IS_ERR(nt)) {
err = PTR_ERR(nt);
goto fail;
}
/* Dump existing printks when we register */
netconsole.flags |= CON_PRINTBUFFER;
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;
err = dynamic_netconsole_init();
if (err)
goto undonotifier;
register_console(&netconsole);
printk(KERN_INFO "netconsole: network logging started\n");
return err;
undonotifier:
unregister_netdevice_notifier(&netconsole_netdev_notifier);
fail:
printk(KERN_ERR "netconsole: cleaning up\n");
/*
* Remove all targets and destroy them (only targets created
* from the boot/module option exist here). 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_param_target(nt);
}
return err;
}
static void __exit cleanup_netconsole(void)
{
struct netconsole_target *nt, *tmp;
unregister_console(&netconsole);
dynamic_netconsole_exit();
unregister_netdevice_notifier(&netconsole_netdev_notifier);
/*
* Targets created via configfs pin references on our module
* and would first be rmdir(2)'ed from userspace. We reach
* here only when they are already destroyed, and only those
* created from the boot/module option are left, so remove 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_param_target(nt);
}
}
/*
* Use late_initcall to ensure netconsole is
* initialized after network device driver if built-in.
*
* late_initcall() and module_init() are identical if built as module.
*/
late_initcall(init_netconsole);
module_exit(cleanup_netconsole);