X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fnet%2Fnetconsole.c;fp=kernel%2Fdrivers%2Fnet%2Fnetconsole.c;h=15731d1db918c32f6dc341800155340c0e62a7a2;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git diff --git a/kernel/drivers/net/netconsole.c b/kernel/drivers/net/netconsole.c new file mode 100644 index 000000000..15731d1db --- /dev/null +++ b/kernel/drivers/net/netconsole.c @@ -0,0 +1,859 @@ +/* + * linux/drivers/net/netconsole.c + * + * Copyright (C) 2001 Ingo Molnar + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +MODULE_AUTHOR("Maintainer: Matt Mackall "); +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-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 mutex mutex; + 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; + mutex_init(&nt->mutex); + eth_broadcast_addr(nt->np.remote_mac); + + /* 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/ + * | + * / + * | enabled + * | dev_name + * | local_port + * | remote_port + * | local_ip + * | remote_ip + * | local_mac + * | remote_mac + * | + * /... + */ + +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) +{ + unsigned long flags; + 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) { + pr_info("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; + + pr_info("netconsole: network logging started\n"); + } else { /* 0 */ + /* 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 == 1 + */ + spin_lock_irqsave(&target_list_lock, flags); + nt->enabled = 0; + spin_unlock_irqrestore(&target_list_lock, flags); + 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) { + pr_err("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) { + pr_err("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) { + pr_err("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) { + pr_err("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') { + pr_err("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) { + pr_err("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') { + pr_err("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) { + pr_err("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); + + mutex_lock(&nt->mutex); + if (na->store) + ret = na->store(nt, buf, count); + mutex_unlock(&nt->mutex); + + 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; + mutex_init(&nt->mutex); + 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 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) { + 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, +}; + +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); + 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); + 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);