diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/net/netconsole.c | 605 |
2 files changed, 589 insertions, 26 deletions
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig index 40ff9a5269a..10ed28ef356 100644 --- a/drivers/net/Kconfig +++ b/drivers/net/Kconfig @@ -3082,6 +3082,16 @@ config NETCONSOLE If you want to log kernel messages over the network, enable this. See <file:Documentation/networking/netconsole.txt> for details. +config NETCONSOLE_DYNAMIC + bool "Dynamic reconfiguration of logging targets (EXPERIMENTAL)" + depends on NETCONSOLE && SYSFS && EXPERIMENTAL + select CONFIGFS_FS + help + This option enables the ability to dynamically reconfigure target + parameters (interface, IP addresses, port numbers, MAC addresses) + at runtime through a userspace interface exported using configfs. + See <file:Documentation/networking/netconsole.txt> for details. + config NETPOLL def_bool NETCONSOLE diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index 458c4d674a9..69ef1eb03be 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -41,6 +41,8 @@ #include <linux/moduleparam.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"); @@ -71,20 +73,100 @@ 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; }; -/* Allocate new target and setup netpoll for it */ -static struct netconsole_target *alloc_target(char *target_config) +#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 */ + /* + * Allocate and initialize with defaults. + * Note that these targets get their config_item fields zeroed-out. + */ nt = kzalloc(sizeof(*nt), GFP_KERNEL); if (!nt) { printk(KERN_ERR "netconsole: failed to allocate memory\n"); @@ -106,6 +188,8 @@ static struct netconsole_target *alloc_target(char *target_config) if (err) goto fail; + nt->enabled = 1; + return nt; fail: @@ -113,13 +197,469 @@ fail: return ERR_PTR(err); } -/* Cleanup netpoll for given target and free it */ -static void free_target(struct netconsole_target *nt) +/* 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; +} + +/* + * Wrapper over simple_strtol (base 10) with sanity and range checking. + * We return (signed) long only because we may want to return errors. + * Do not use this to convert numbers that are allowed to be negative. + */ +static long strtol10_check_range(const char *cp, long min, long max) +{ + long ret; + char *p = (char *) cp; + + WARN_ON(min < 0); + WARN_ON(max < min); + + ret = simple_strtol(p, &p, 10); + + if (*p && (*p != '\n')) { + printk(KERN_ERR "netconsole: invalid input\n"); + return -EINVAL; + } + if ((ret < min) || (ret > max)) { + printk(KERN_ERR "netconsole: input %ld must be between " + "%ld and %ld\n", ret, min, max); + return -EINVAL; + } + + return ret; +} + +/* + * 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) +{ + return snprintf(buf, PAGE_SIZE, "%d.%d.%d.%d\n", + HIPQUAD(nt->np.local_ip)); +} + +static ssize_t show_remote_ip(struct netconsole_target *nt, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%d.%d.%d.%d\n", + HIPQUAD(nt->np.remote_ip)); +} + +static ssize_t show_local_mac(struct netconsole_target *nt, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%02x:%02x:%02x:%02x:%02x:%02x\n", + nt->np.local_mac[0], nt->np.local_mac[1], + nt->np.local_mac[2], nt->np.local_mac[3], + nt->np.local_mac[4], nt->np.local_mac[5]); +} + +static ssize_t show_remote_mac(struct netconsole_target *nt, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%02x:%02x:%02x:%02x:%02x:%02x\n", + nt->np.remote_mac[0], nt->np.remote_mac[1], + nt->np.remote_mac[2], nt->np.remote_mac[3], + nt->np.remote_mac[4], nt->np.remote_mac[5]); +} + +/* + * 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 err; + long enabled; + + enabled = strtol10_check_range(buf, 0, 1); + if (enabled < 0) + return enabled; + + 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) +{ + long local_port; +#define __U16_MAX ((__u16) ~0U) + + if (nt->enabled) { + printk(KERN_ERR "netconsole: target (%s) is enabled, " + "disable to update parameters\n", + config_item_name(&nt->item)); + return -EINVAL; + } + + local_port = strtol10_check_range(buf, 0, __U16_MAX); + if (local_port < 0) + return local_port; + + nt->np.local_port = local_port; + + return strnlen(buf, count); +} + +static ssize_t store_remote_port(struct netconsole_target *nt, + const char *buf, + size_t count) +{ + long remote_port; +#define __U16_MAX ((__u16) ~0U) + + if (nt->enabled) { + printk(KERN_ERR "netconsole: target (%s) is enabled, " + "disable to update parameters\n", + config_item_name(&nt->item)); + return -EINVAL; + } + + remote_port = strtol10_check_range(buf, 0, __U16_MAX); + if (remote_port < 0) + return remote_port; + + nt->np.remote_port = remote_port; + + 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; + } + + nt->np.local_ip = ntohl(in_aton(buf)); + + 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; + } + + nt->np.remote_ip = ntohl(in_aton(buf)); + + 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]; + char *p = (char *) buf; + int i; + + if (nt->enabled) { + printk(KERN_ERR "netconsole: target (%s) is enabled, " + "disable to update parameters\n", + config_item_name(&nt->item)); + return -EINVAL; + } + + for (i = 0; i < ETH_ALEN - 1; i++) { + remote_mac[i] = simple_strtoul(p, &p, 16); + if (*p != ':') + goto invalid; + p++; + } + remote_mac[ETH_ALEN - 1] = simple_strtoul(p, &p, 16); + if (*p && (*p != '\n')) + goto invalid; + + memcpy(nt->np.remote_mac, remote_mac, ETH_ALEN); + + return strnlen(buf, count); + +invalid: + printk(KERN_ERR "netconsole: invalid input\n"); + return -EINVAL; +} + +/* + * 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) { + printk(KERN_ERR "netconsole: failed to allocate memory\n"); + return NULL; + } + + 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, @@ -134,6 +674,7 @@ static int netconsole_netdev_event(struct notifier_block *this, spin_lock_irqsave(&target_list_lock, flags); list_for_each_entry(nt, &target_list, list) { + netconsole_target_get(nt); if (nt->np.dev == dev) { switch (event) { case NETDEV_CHANGEADDR: @@ -145,6 +686,7 @@ static int netconsole_netdev_event(struct notifier_block *this, break; } } + netconsole_target_put(nt); } spin_unlock_irqrestore(&target_list_lock, flags); @@ -169,7 +711,8 @@ static void write_msg(struct console *con, const char *msg, unsigned int len) spin_lock_irqsave(&target_list_lock, flags); list_for_each_entry(nt, &target_list, list) { - if (netif_running(nt->np.dev)) { + 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 @@ -184,6 +727,7 @@ static void write_msg(struct console *con, const char *msg, unsigned int len) left -= frag; } } + netconsole_target_put(nt); } spin_unlock_irqrestore(&target_list_lock, flags); } @@ -196,48 +740,52 @@ static struct console netconsole = { static int __init init_netconsole(void) { - int err = 0; + int err; struct netconsole_target *nt, *tmp; unsigned long flags; char *target_config; char *input = config; - if (!strnlen(input, MAX_PARAM_LENGTH)) { - printk(KERN_INFO "netconsole: not configured, aborting\n"); - goto out; - } - - while ((target_config = strsep(&input, ";"))) { - nt = alloc_target(target_config); - if (IS_ERR(nt)) { - err = PTR_ERR(nt); - goto fail; + 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; + } + spin_lock_irqsave(&target_list_lock, flags); + list_add(&nt->list, &target_list); + spin_unlock_irqrestore(&target_list_lock, flags); } - 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"); -out: return err; +undonotifier: + unregister_netdevice_notifier(&netconsole_netdev_notifier); + fail: printk(KERN_ERR "netconsole: cleaning up\n"); /* - * Remove all targets and destroy them. Skipping the list + * 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_target(nt); + free_param_target(nt); } return err; @@ -248,15 +796,20 @@ static void __exit cleanup_netconsole(void) struct netconsole_target *nt, *tmp; unregister_console(&netconsole); + dynamic_netconsole_exit(); unregister_netdevice_notifier(&netconsole_netdev_notifier); /* - * Remove all targets and destroy them. Skipping the list - * lock is safe here, and netpoll_cleanup() will sleep. + * 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_target(nt); + free_param_target(nt); } } |