From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/net/netconsole.c | 1048 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1048 insertions(+) create mode 100644 drivers/net/netconsole.c (limited to 'drivers/net/netconsole.c') diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c new file mode 100644 index 0000000000..3111e16485 --- /dev/null +++ b/drivers/net/netconsole.c @@ -0,0 +1,1048 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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 + */ + +/**************************************************************** + * + ****************************************************************/ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#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) +{ + strscpy(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). + * @extended: Denotes whether console is extended or not. + * @release: Denotes whether kernel release version should be prepended + * to the message. Depends on extended console. + * @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; + bool release; + 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 and initialize with defaults. + * Note that these targets get their config_item fields zeroed-out. + */ +static struct netconsole_target *alloc_and_init(void) +{ + struct netconsole_target *nt; + + nt = kzalloc(sizeof(*nt), GFP_KERNEL); + if (!nt) + return nt; + + if (IS_ENABLED(CONFIG_NETCONSOLE_EXTENDED_LOG)) + nt->extended = true; + if (IS_ENABLED(CONFIG_NETCONSOLE_PREPEND_RELEASE)) + nt->release = true; + + nt->np.name = "netconsole"; + strscpy(nt->np.dev_name, "eth0", IFNAMSIZ); + nt->np.local_port = 6665; + nt->np.remote_port = 6666; + eth_broadcast_addr(nt->np.remote_mac); + + return nt; +} + +/* Allocate new target (from boot/module param) and setup netpoll for it */ +static struct netconsole_target *alloc_param_target(char *target_config) +{ + struct netconsole_target *nt; + int err; + + nt = alloc_and_init(); + if (!nt) { + err = -ENOMEM; + goto fail; + } + + if (*target_config == '+') { + nt->extended = true; + target_config++; + } + + if (*target_config == 'r') { + if (!nt->extended) { + pr_err("Netconsole configuration error. Release feature requires extended log message"); + err = -EINVAL; + goto fail; + } + nt->release = 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/ + * | + * / + * | enabled + * | release + * | dev_name + * | local_port + * | remote_port + * | local_ip + * | remote_ip + * | local_mac + * | remote_mac + * | + * /... + */ + +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 sysfs_emit(buf, "%d\n", to_target(item)->enabled); +} + +static ssize_t extended_show(struct config_item *item, char *buf) +{ + return sysfs_emit(buf, "%d\n", to_target(item)->extended); +} + +static ssize_t release_show(struct config_item *item, char *buf) +{ + return sysfs_emit(buf, "%d\n", to_target(item)->release); +} + +static ssize_t dev_name_show(struct config_item *item, char *buf) +{ + return sysfs_emit(buf, "%s\n", to_target(item)->np.dev_name); +} + +static ssize_t local_port_show(struct config_item *item, char *buf) +{ + return sysfs_emit(buf, "%d\n", to_target(item)->np.local_port); +} + +static ssize_t remote_port_show(struct config_item *item, char *buf) +{ + return sysfs_emit(buf, "%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 sysfs_emit(buf, "%pI6c\n", &nt->np.local_ip.in6); + else + return sysfs_emit(buf, "%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 sysfs_emit(buf, "%pI6c\n", &nt->np.remote_ip.in6); + else + return sysfs_emit(buf, "%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 sysfs_emit(buf, "%pM\n", dev ? dev->dev_addr : bcast); +} + +static ssize_t remote_mac_show(struct config_item *item, char *buf) +{ + return sysfs_emit(buf, "%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; + bool enabled; + int err; + + mutex_lock(&dynamic_netconsole_mutex); + err = kstrtobool(buf, &enabled); + if (err) + goto out_unlock; + + err = -EINVAL; + 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->release && !nt->extended) { + pr_err("Not enabling netconsole. Release feature requires extended log message"); + goto out_unlock; + } + + if (nt->extended && !console_is_registered(&netconsole_ext)) + 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 release_store(struct config_item *item, const char *buf, + size_t count) +{ + struct netconsole_target *nt = to_target(item); + bool release; + 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 = kstrtobool(buf, &release); + if (err) + goto out_unlock; + + nt->release = release; + + 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); + bool 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 = kstrtobool(buf, &extended); + if (err) + 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; + } + + strscpy(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); +CONFIGFS_ATTR(, release); + +static struct configfs_attribute *netconsole_target_attrs[] = { + &attr_enabled, + &attr_extended, + &attr_release, + &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) +{ + struct netconsole_target *nt; + unsigned long flags; + + nt = alloc_and_init(); + if (!nt) + return ERR_PTR(-ENOMEM); + + /* 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: + strscpy(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); + netdev_put(nt->np.dev, &nt->np.dev_tracker); + 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; + const char *msg_ready = msg; + const char *release; + int release_len = 0; + + if (nt->release) { + release = init_utsname()->release; + release_len = strlen(release) + 1; + } + + if (msg_len + release_len <= MAX_PRINT_CHUNK) { + /* No fragmentation needed */ + if (nt->release) { + scnprintf(buf, MAX_PRINT_CHUNK, "%s,%s", release, msg); + msg_len += release_len; + msg_ready = buf; + } + netpoll_send_udp(&nt->np, msg_ready, 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=/" + */ + if (nt->release) + scnprintf(buf, MAX_PRINT_CHUNK, "%s,", release); + memcpy(buf + release_len, header, header_len); + header_len += release_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_ENABLED | CON_EXTENDED, + .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; + bool extended = false; + 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) { + extended = true; + netconsole_ext.flags |= CON_PRINTBUFFER; + } 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 (extended) + 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; + + if (console_is_registered(&netconsole_ext)) + 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); -- cgit v1.2.3