v4.19.13 snapshot.
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
new file mode 100644
index 0000000..be9aa36
--- /dev/null
+++ b/drivers/net/netconsole.c
@@ -0,0 +1,985 @@
+/*
+ * 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.
+ *
+ ****************************************************************/
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#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>
+#include <linux/etherdevice.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);
+
+/*
+ * Console driver for extended netconsoles. Registered on the first use to
+ * avoid unnecessarily enabling ext message formatting.
+ */
+static struct console netconsole_ext;
+
+/**
+ * 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
+ bool enabled;
+ bool extended;
+ struct netpoll np;
+};
+
+#ifdef CONFIG_NETCONSOLE_DYNAMIC
+
+static struct configfs_subsystem netconsole_subsys;
+static DEFINE_MUTEX(dynamic_netconsole_mutex);
+
+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;
+ eth_broadcast_addr(nt->np.remote_mac);
+
+ if (*target_config == '+') {
+ nt->extended = true;
+ target_config++;
+ }
+
+ /* 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 = true;
+
+ 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>/...
+ */
+
+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 enabled_show(struct config_item *item, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n", to_target(item)->enabled);
+}
+
+static ssize_t extended_show(struct config_item *item, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n", to_target(item)->extended);
+}
+
+static ssize_t dev_name_show(struct config_item *item, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%s\n", to_target(item)->np.dev_name);
+}
+
+static ssize_t local_port_show(struct config_item *item, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n", to_target(item)->np.local_port);
+}
+
+static ssize_t remote_port_show(struct config_item *item, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n", to_target(item)->np.remote_port);
+}
+
+static ssize_t local_ip_show(struct config_item *item, char *buf)
+{
+ struct netconsole_target *nt = to_target(item);
+
+ 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 remote_ip_show(struct config_item *item, char *buf)
+{
+ struct netconsole_target *nt = to_target(item);
+
+ 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 local_mac_show(struct config_item *item, char *buf)
+{
+ struct net_device *dev = to_target(item)->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 remote_mac_show(struct config_item *item, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%pM\n", to_target(item)->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 enabled_store(struct config_item *item,
+ const char *buf, size_t count)
+{
+ struct netconsole_target *nt = to_target(item);
+ unsigned long flags;
+ int enabled;
+ int err;
+
+ mutex_lock(&dynamic_netconsole_mutex);
+ err = kstrtoint(buf, 10, &enabled);
+ if (err < 0)
+ goto out_unlock;
+
+ err = -EINVAL;
+ if (enabled < 0 || enabled > 1)
+ goto out_unlock;
+ if ((bool)enabled == nt->enabled) {
+ pr_info("network logging has already %s\n",
+ nt->enabled ? "started" : "stopped");
+ goto out_unlock;
+ }
+
+ if (enabled) { /* true */
+ if (nt->extended && !(netconsole_ext.flags & CON_ENABLED)) {
+ netconsole_ext.flags |= CON_ENABLED;
+ register_console(&netconsole_ext);
+ }
+
+ /*
+ * 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)
+ goto out_unlock;
+
+ pr_info("network logging started\n");
+ } else { /* false */
+ /* We need to disable the netconsole before cleaning it up
+ * otherwise we might end up in write_msg() with
+ * nt->np.dev == NULL and nt->enabled == true
+ */
+ spin_lock_irqsave(&target_list_lock, flags);
+ nt->enabled = false;
+ spin_unlock_irqrestore(&target_list_lock, flags);
+ netpoll_cleanup(&nt->np);
+ }
+
+ nt->enabled = enabled;
+
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return strnlen(buf, count);
+out_unlock:
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return err;
+}
+
+static ssize_t extended_store(struct config_item *item, const char *buf,
+ size_t count)
+{
+ struct netconsole_target *nt = to_target(item);
+ int extended;
+ int err;
+
+ mutex_lock(&dynamic_netconsole_mutex);
+ if (nt->enabled) {
+ pr_err("target (%s) is enabled, disable to update parameters\n",
+ config_item_name(&nt->item));
+ err = -EINVAL;
+ goto out_unlock;
+ }
+
+ err = kstrtoint(buf, 10, &extended);
+ if (err < 0)
+ goto out_unlock;
+ if (extended < 0 || extended > 1) {
+ err = -EINVAL;
+ goto out_unlock;
+ }
+
+ nt->extended = extended;
+
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return strnlen(buf, count);
+out_unlock:
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return err;
+}
+
+static ssize_t dev_name_store(struct config_item *item, const char *buf,
+ size_t count)
+{
+ struct netconsole_target *nt = to_target(item);
+ size_t len;
+
+ mutex_lock(&dynamic_netconsole_mutex);
+ if (nt->enabled) {
+ pr_err("target (%s) is enabled, disable to update parameters\n",
+ config_item_name(&nt->item));
+ mutex_unlock(&dynamic_netconsole_mutex);
+ 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';
+
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return strnlen(buf, count);
+}
+
+static ssize_t local_port_store(struct config_item *item, const char *buf,
+ size_t count)
+{
+ struct netconsole_target *nt = to_target(item);
+ int rv = -EINVAL;
+
+ mutex_lock(&dynamic_netconsole_mutex);
+ if (nt->enabled) {
+ pr_err("target (%s) is enabled, disable to update parameters\n",
+ config_item_name(&nt->item));
+ goto out_unlock;
+ }
+
+ rv = kstrtou16(buf, 10, &nt->np.local_port);
+ if (rv < 0)
+ goto out_unlock;
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return strnlen(buf, count);
+out_unlock:
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return rv;
+}
+
+static ssize_t remote_port_store(struct config_item *item,
+ const char *buf, size_t count)
+{
+ struct netconsole_target *nt = to_target(item);
+ int rv = -EINVAL;
+
+ mutex_lock(&dynamic_netconsole_mutex);
+ if (nt->enabled) {
+ pr_err("target (%s) is enabled, disable to update parameters\n",
+ config_item_name(&nt->item));
+ goto out_unlock;
+ }
+
+ rv = kstrtou16(buf, 10, &nt->np.remote_port);
+ if (rv < 0)
+ goto out_unlock;
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return strnlen(buf, count);
+out_unlock:
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return rv;
+}
+
+static ssize_t local_ip_store(struct config_item *item, const char *buf,
+ size_t count)
+{
+ struct netconsole_target *nt = to_target(item);
+
+ mutex_lock(&dynamic_netconsole_mutex);
+ if (nt->enabled) {
+ pr_err("target (%s) is enabled, disable to update parameters\n",
+ config_item_name(&nt->item));
+ goto out_unlock;
+ }
+
+ 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') {
+ pr_err("invalid IPv6 address at: <%c>\n", *end);
+ goto out_unlock;
+ }
+ nt->np.ipv6 = true;
+ } else
+ goto out_unlock;
+ } else {
+ if (!nt->np.ipv6) {
+ nt->np.local_ip.ip = in_aton(buf);
+ } else
+ goto out_unlock;
+ }
+
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return strnlen(buf, count);
+out_unlock:
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return -EINVAL;
+}
+
+static ssize_t remote_ip_store(struct config_item *item, const char *buf,
+ size_t count)
+{
+ struct netconsole_target *nt = to_target(item);
+
+ mutex_lock(&dynamic_netconsole_mutex);
+ if (nt->enabled) {
+ pr_err("target (%s) is enabled, disable to update parameters\n",
+ config_item_name(&nt->item));
+ goto out_unlock;
+ }
+
+ 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') {
+ pr_err("invalid IPv6 address at: <%c>\n", *end);
+ goto out_unlock;
+ }
+ nt->np.ipv6 = true;
+ } else
+ goto out_unlock;
+ } else {
+ if (!nt->np.ipv6) {
+ nt->np.remote_ip.ip = in_aton(buf);
+ } else
+ goto out_unlock;
+ }
+
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return strnlen(buf, count);
+out_unlock:
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return -EINVAL;
+}
+
+static ssize_t remote_mac_store(struct config_item *item, const char *buf,
+ size_t count)
+{
+ struct netconsole_target *nt = to_target(item);
+ u8 remote_mac[ETH_ALEN];
+
+ mutex_lock(&dynamic_netconsole_mutex);
+ if (nt->enabled) {
+ pr_err("target (%s) is enabled, disable to update parameters\n",
+ config_item_name(&nt->item));
+ goto out_unlock;
+ }
+
+ if (!mac_pton(buf, remote_mac))
+ goto out_unlock;
+ if (buf[3 * ETH_ALEN - 1] && buf[3 * ETH_ALEN - 1] != '\n')
+ goto out_unlock;
+ memcpy(nt->np.remote_mac, remote_mac, ETH_ALEN);
+
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return strnlen(buf, count);
+out_unlock:
+ mutex_unlock(&dynamic_netconsole_mutex);
+ return -EINVAL;
+}
+
+CONFIGFS_ATTR(, enabled);
+CONFIGFS_ATTR(, extended);
+CONFIGFS_ATTR(, dev_name);
+CONFIGFS_ATTR(, local_port);
+CONFIGFS_ATTR(, remote_port);
+CONFIGFS_ATTR(, local_ip);
+CONFIGFS_ATTR(, remote_ip);
+CONFIGFS_ATTR_RO(, local_mac);
+CONFIGFS_ATTR(, remote_mac);
+
+static struct configfs_attribute *netconsole_target_attrs[] = {
+ &attr_enabled,
+ &attr_extended,
+ &attr_dev_name,
+ &attr_local_port,
+ &attr_remote_port,
+ &attr_local_ip,
+ &attr_remote_ip,
+ &attr_local_mac,
+ &attr_remote_mac,
+ NULL,
+};
+
+/*
+ * Item operations and type for netconsole_target.
+ */
+
+static void netconsole_target_release(struct config_item *item)
+{
+ kfree(to_target(item));
+}
+
+static struct configfs_item_operations netconsole_target_item_ops = {
+ .release = netconsole_target_release,
+};
+
+static const 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).
+ */
+ 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;
+ eth_broadcast_addr(nt->np.remote_mac);
+
+ /* 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 const 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 = false;
+ stopped = true;
+ netconsole_target_put(nt);
+ goto restart;
+ }
+ }
+ netconsole_target_put(nt);
+ }
+ spin_unlock_irqrestore(&target_list_lock, flags);
+ if (stopped) {
+ const char *msg = "had an event";
+ switch (event) {
+ case NETDEV_UNREGISTER:
+ msg = "unregistered";
+ break;
+ case NETDEV_RELEASE:
+ msg = "released slaves";
+ break;
+ case NETDEV_JOIN:
+ msg = "is joining a master device";
+ break;
+ }
+ pr_info("network logging stopped on interface %s as it %s\n",
+ dev->name, msg);
+ }
+
+done:
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block netconsole_netdev_notifier = {
+ .notifier_call = netconsole_netdev_event,
+};
+
+/**
+ * send_ext_msg_udp - send extended log message to target
+ * @nt: target to send message to
+ * @msg: extended log message to send
+ * @msg_len: length of message
+ *
+ * Transfer extended log @msg to @nt. If @msg is longer than
+ * MAX_PRINT_CHUNK, it'll be split and transmitted in multiple chunks with
+ * ncfrag header field added to identify them.
+ */
+static void send_ext_msg_udp(struct netconsole_target *nt, const char *msg,
+ int msg_len)
+{
+ static char buf[MAX_PRINT_CHUNK]; /* protected by target_list_lock */
+ const char *header, *body;
+ int offset = 0;
+ int header_len, body_len;
+
+ if (msg_len <= MAX_PRINT_CHUNK) {
+ netpoll_send_udp(&nt->np, msg, msg_len);
+ return;
+ }
+
+ /* need to insert extra header fields, detect header and body */
+ header = msg;
+ body = memchr(msg, ';', msg_len);
+ if (WARN_ON_ONCE(!body))
+ return;
+
+ header_len = body - header;
+ body_len = msg_len - header_len - 1;
+ body++;
+
+ /*
+ * Transfer multiple chunks with the following extra header.
+ * "ncfrag=<byte-offset>/<total-bytes>"
+ */
+ memcpy(buf, header, header_len);
+
+ while (offset < body_len) {
+ int this_header = header_len;
+ int this_chunk;
+
+ this_header += scnprintf(buf + this_header,
+ sizeof(buf) - this_header,
+ ",ncfrag=%d/%d;", offset, body_len);
+
+ this_chunk = min(body_len - offset,
+ MAX_PRINT_CHUNK - this_header);
+ if (WARN_ON_ONCE(this_chunk <= 0))
+ return;
+
+ memcpy(buf + this_header, body + offset, this_chunk);
+
+ netpoll_send_udp(&nt->np, buf, this_header + this_chunk);
+
+ offset += this_chunk;
+ }
+}
+
+static void write_ext_msg(struct console *con, const char *msg,
+ unsigned int len)
+{
+ struct netconsole_target *nt;
+ unsigned long flags;
+
+ if ((oops_only && !oops_in_progress) || list_empty(&target_list))
+ return;
+
+ spin_lock_irqsave(&target_list_lock, flags);
+ list_for_each_entry(nt, &target_list, list)
+ if (nt->extended && nt->enabled && netif_running(nt->np.dev))
+ send_ext_msg_udp(nt, msg, len);
+ spin_unlock_irqrestore(&target_list_lock, flags);
+}
+
+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) {
+ if (!nt->extended && 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;
+ }
+ }
+ }
+ spin_unlock_irqrestore(&target_list_lock, flags);
+}
+
+static struct console netconsole_ext = {
+ .name = "netcon_ext",
+ .flags = CON_EXTENDED, /* starts disabled, registered on first use */
+ .write = write_ext_msg,
+};
+
+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 */
+ if (nt->extended)
+ netconsole_ext.flags |= CON_PRINTBUFFER |
+ CON_ENABLED;
+ else
+ 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;
+
+ if (netconsole_ext.flags & CON_ENABLED)
+ register_console(&netconsole_ext);
+ register_console(&netconsole);
+ pr_info("network logging started\n");
+
+ return err;
+
+undonotifier:
+ unregister_netdevice_notifier(&netconsole_netdev_notifier);
+
+fail:
+ pr_err("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_ext);
+ 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);