*/
#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/kobject.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/user_namespace.h>
#include <linux/socket.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
-#include <linux/string.h>
-#include <linux/kobject.h>
#include <net/sock.h>
+#include <net/net_namespace.h>
-#define BUFFER_SIZE 1024 /* buffer for the hotplug env */
-#define NUM_ENVP 32 /* number of env pointers */
-#if defined(CONFIG_HOTPLUG)
-char hotplug_path[HOTPLUG_PATH_LEN] = "/sbin/hotplug";
-u64 hotplug_seqnum;
+u64 uevent_seqnum;
+char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
static DEFINE_SPINLOCK(sequence_lock);
-
-static char *action_to_string(enum kobject_action action)
-{
- switch (action) {
- case KOBJ_ADD:
- return "add";
- case KOBJ_REMOVE:
- return "remove";
- case KOBJ_CHANGE:
- return "change";
- case KOBJ_OFFLINE:
- return "offline";
- case KOBJ_ONLINE:
- return "online";
- default:
- return NULL;
- }
-}
-
-static struct sock *uevent_sock;
+#ifdef CONFIG_NET
+struct uevent_sock {
+ struct list_head list;
+ struct sock *sk;
+};
+static LIST_HEAD(uevent_sock_list);
+static DEFINE_MUTEX(uevent_sock_mutex);
+#endif
+
+/* the strings here must match the enum in include/linux/kobject.h */
+static const char *kobject_actions[] = {
+ [KOBJ_ADD] = "add",
+ [KOBJ_REMOVE] = "remove",
+ [KOBJ_CHANGE] = "change",
+ [KOBJ_MOVE] = "move",
+ [KOBJ_ONLINE] = "online",
+ [KOBJ_OFFLINE] = "offline",
+};
/**
- * send_uevent - notify userspace by sending event through netlink socket
+ * kobject_action_type - translate action string to numeric type
*
- * @signal: signal name
- * @obj: object path (kobject)
- * @envp: possible hotplug environment to pass with the message
- * @gfp_mask:
+ * @buf: buffer containing the action string, newline is ignored
+ * @len: length of buffer
+ * @type: pointer to the location to store the action type
+ *
+ * Returns 0 if the action string was recognized.
*/
-static int send_uevent(const char *signal, const char *obj,
- char **envp, gfp_t gfp_mask)
+int kobject_action_type(const char *buf, size_t count,
+ enum kobject_action *type)
{
- struct sk_buff *skb;
- char *pos;
- int len;
-
- if (!uevent_sock)
- return -EIO;
-
- len = strlen(signal) + 1;
- len += strlen(obj) + 1;
-
- /* allocate buffer with the maximum possible message size */
- skb = alloc_skb(len + BUFFER_SIZE, gfp_mask);
- if (!skb)
- return -ENOMEM;
-
- pos = skb_put(skb, len);
- sprintf(pos, "%s@%s", signal, obj);
-
- /* copy the environment key by key to our continuous buffer */
- if (envp) {
- int i;
-
- for (i = 2; envp[i]; i++) {
- len = strlen(envp[i]) + 1;
- pos = skb_put(skb, len);
- strcpy(pos, envp[i]);
- }
+ enum kobject_action action;
+ int ret = -EINVAL;
+
+ if (count && (buf[count-1] == '\n' || buf[count-1] == '\0'))
+ count--;
+
+ if (!count)
+ goto out;
+
+ for (action = 0; action < ARRAY_SIZE(kobject_actions); action++) {
+ if (strncmp(kobject_actions[action], buf, count) != 0)
+ continue;
+ if (kobject_actions[action][count] != '\0')
+ continue;
+ *type = action;
+ ret = 0;
+ break;
}
-
- NETLINK_CB(skb).dst_group = 1;
- return netlink_broadcast(uevent_sock, skb, 0, 1, gfp_mask);
+out:
+ return ret;
}
-static int do_kobject_uevent(struct kobject *kobj, enum kobject_action action,
- struct attribute *attr, gfp_t gfp_mask)
+#ifdef CONFIG_NET
+static int kobj_bcast_filter(struct sock *dsk, struct sk_buff *skb, void *data)
{
- char *path;
- char *attrpath;
- char *signal;
- int len;
- int rc = -ENOMEM;
-
- path = kobject_get_path(kobj, gfp_mask);
- if (!path)
- return -ENOMEM;
-
- signal = action_to_string(action);
- if (!signal)
- return -EINVAL;
-
- if (attr) {
- len = strlen(path);
- len += strlen(attr->name) + 2;
- attrpath = kmalloc(len, gfp_mask);
- if (!attrpath)
- goto exit;
- sprintf(attrpath, "%s/%s", path, attr->name);
- rc = send_uevent(signal, attrpath, NULL, gfp_mask);
- kfree(attrpath);
- } else
- rc = send_uevent(signal, path, NULL, gfp_mask);
-
-exit:
- kfree(path);
- return rc;
-}
-
-/**
- * kobject_uevent - notify userspace by sending event through netlink socket
- *
- * @signal: signal name
- * @kobj: struct kobject that the event is happening to
- * @attr: optional struct attribute the event belongs to
- */
-int kobject_uevent(struct kobject *kobj, enum kobject_action action,
- struct attribute *attr)
-{
- return do_kobject_uevent(kobj, action, attr, GFP_KERNEL);
-}
-EXPORT_SYMBOL_GPL(kobject_uevent);
+ struct kobject *kobj = data;
+ const struct kobj_ns_type_operations *ops;
+
+ ops = kobj_ns_ops(kobj);
+ if (ops) {
+ const void *sock_ns, *ns;
+ ns = kobj->ktype->namespace(kobj);
+ sock_ns = ops->netlink_ns(dsk);
+ return sock_ns != ns;
+ }
-int kobject_uevent_atomic(struct kobject *kobj, enum kobject_action action,
- struct attribute *attr)
-{
- return do_kobject_uevent(kobj, action, attr, GFP_ATOMIC);
+ return 0;
}
-EXPORT_SYMBOL_GPL(kobject_uevent_atomic);
+#endif
-static int __init kobject_uevent_init(void)
+static int kobj_usermode_filter(struct kobject *kobj)
{
- uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL,
- THIS_MODULE);
-
- if (!uevent_sock) {
- printk(KERN_ERR
- "kobject_uevent: unable to create netlink socket!\n");
- return -ENODEV;
+ const struct kobj_ns_type_operations *ops;
+
+ ops = kobj_ns_ops(kobj);
+ if (ops) {
+ const void *init_ns, *ns;
+ ns = kobj->ktype->namespace(kobj);
+ init_ns = ops->initial_ns();
+ return ns != init_ns;
}
return 0;
}
-postcore_initcall(kobject_uevent_init);
-
/**
- * kobject_hotplug - notify userspace by executing /sbin/hotplug
+ * kobject_uevent_env - send an uevent with environmental data
*
- * @action: action that is happening (usually "ADD" or "REMOVE")
+ * @action: action that is happening
* @kobj: struct kobject that the action is happening to
+ * @envp_ext: pointer to environmental data
+ *
+ * Returns 0 if kobject_uevent_env() is completed with success or the
+ * corresponding error when it fails.
*/
-void kobject_hotplug(struct kobject *kobj, enum kobject_action action)
+int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
+ char *envp_ext[])
{
- char *argv [3];
- char **envp = NULL;
- char *buffer = NULL;
- char *seq_buff;
- char *scratch;
- int i = 0;
- int retval;
- char *kobj_path = NULL;
- const char *name = NULL;
- char *action_string;
- u64 seq;
- struct kobject *top_kobj = kobj;
+ struct kobj_uevent_env *env;
+ const char *action_string = kobject_actions[action];
+ const char *devpath = NULL;
+ const char *subsystem;
+ struct kobject *top_kobj;
struct kset *kset;
- static struct kset_hotplug_ops null_hotplug_ops;
- struct kset_hotplug_ops *hotplug_ops = &null_hotplug_ops;
-
- /* If this kobj does not belong to a kset,
- try to find a parent that does. */
- if (!top_kobj->kset && top_kobj->parent) {
- do {
- top_kobj = top_kobj->parent;
- } while (!top_kobj->kset && top_kobj->parent);
+ const struct kset_uevent_ops *uevent_ops;
+ u64 seq;
+ int i = 0;
+ int retval = 0;
+#ifdef CONFIG_NET
+ struct uevent_sock *ue_sk;
+#endif
+
+ pr_debug("kobject: '%s' (%p): %s\n",
+ kobject_name(kobj), kobj, __func__);
+
+ /* search the kset we belong to */
+ top_kobj = kobj;
+ while (!top_kobj->kset && top_kobj->parent)
+ top_kobj = top_kobj->parent;
+
+ if (!top_kobj->kset) {
+ pr_debug("kobject: '%s' (%p): %s: attempted to send uevent "
+ "without kset!\n", kobject_name(kobj), kobj,
+ __func__);
+ return -EINVAL;
}
- if (top_kobj->kset)
- kset = top_kobj->kset;
- else
- return;
-
- if (kset->hotplug_ops)
- hotplug_ops = kset->hotplug_ops;
+ kset = top_kobj->kset;
+ uevent_ops = kset->uevent_ops;
- /* If the kset has a filter operation, call it.
- Skip the event, if the filter returns zero. */
- if (hotplug_ops->filter) {
- if (!hotplug_ops->filter(kset, kobj))
- return;
+ /* skip the event, if uevent_suppress is set*/
+ if (kobj->uevent_suppress) {
+ pr_debug("kobject: '%s' (%p): %s: uevent_suppress "
+ "caused the event to drop!\n",
+ kobject_name(kobj), kobj, __func__);
+ return 0;
}
+ /* skip the event, if the filter returns zero. */
+ if (uevent_ops && uevent_ops->filter)
+ if (!uevent_ops->filter(kset, kobj)) {
+ pr_debug("kobject: '%s' (%p): %s: filter function "
+ "caused the event to drop!\n",
+ kobject_name(kobj), kobj, __func__);
+ return 0;
+ }
- pr_debug ("%s\n", __FUNCTION__);
-
- action_string = action_to_string(action);
- if (!action_string)
- return;
+ /* originating subsystem */
+ if (uevent_ops && uevent_ops->name)
+ subsystem = uevent_ops->name(kset, kobj);
+ else
+ subsystem = kobject_name(&kset->kobj);
+ if (!subsystem) {
+ pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the "
+ "event to drop!\n", kobject_name(kobj), kobj,
+ __func__);
+ return 0;
+ }
- envp = kmalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL);
- if (!envp)
- return;
- memset (envp, 0x00, NUM_ENVP * sizeof (char *));
+ /* environment buffer */
+ env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
+ if (!env)
+ return -ENOMEM;
- buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
- if (!buffer)
+ /* complete object path */
+ devpath = kobject_get_path(kobj, GFP_KERNEL);
+ if (!devpath) {
+ retval = -ENOENT;
goto exit;
+ }
- if (hotplug_ops->name)
- name = hotplug_ops->name(kset, kobj);
- if (name == NULL)
- name = kobject_name(&kset->kobj);
-
- argv [0] = hotplug_path;
- argv [1] = (char *)name; /* won't be changed but 'const' has to go */
- argv [2] = NULL;
-
- /* minimal command environment */
- envp [i++] = "HOME=/";
- envp [i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
-
- scratch = buffer;
-
- envp [i++] = scratch;
- scratch += sprintf(scratch, "ACTION=%s", action_string) + 1;
-
- kobj_path = kobject_get_path(kobj, GFP_KERNEL);
- if (!kobj_path)
+ /* default keys */
+ retval = add_uevent_var(env, "ACTION=%s", action_string);
+ if (retval)
+ goto exit;
+ retval = add_uevent_var(env, "DEVPATH=%s", devpath);
+ if (retval)
+ goto exit;
+ retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem);
+ if (retval)
goto exit;
- envp [i++] = scratch;
- scratch += sprintf (scratch, "DEVPATH=%s", kobj_path) + 1;
-
- envp [i++] = scratch;
- scratch += sprintf(scratch, "SUBSYSTEM=%s", name) + 1;
-
- /* reserve space for the sequence,
- * put the real one in after the hotplug call */
- envp[i++] = seq_buff = scratch;
- scratch += strlen("SEQNUM=18446744073709551616") + 1;
+ /* keys passed in from the caller */
+ if (envp_ext) {
+ for (i = 0; envp_ext[i]; i++) {
+ retval = add_uevent_var(env, "%s", envp_ext[i]);
+ if (retval)
+ goto exit;
+ }
+ }
- if (hotplug_ops->hotplug) {
- /* have the kset specific function add its stuff */
- retval = hotplug_ops->hotplug (kset, kobj,
- &envp[i], NUM_ENVP - i, scratch,
- BUFFER_SIZE - (scratch - buffer));
+ /* let the kset specific function add its stuff */
+ if (uevent_ops && uevent_ops->uevent) {
+ retval = uevent_ops->uevent(kset, kobj, env);
if (retval) {
- pr_debug ("%s - hotplug() returned %d\n",
- __FUNCTION__, retval);
+ pr_debug("kobject: '%s' (%p): %s: uevent() returned "
+ "%d\n", kobject_name(kobj), kobj,
+ __func__, retval);
goto exit;
}
}
+ /*
+ * Mark "add" and "remove" events in the object to ensure proper
+ * events to userspace during automatic cleanup. If the object did
+ * send an "add" event, "remove" will automatically generated by
+ * the core, if not already done by the caller.
+ */
+ if (action == KOBJ_ADD)
+ kobj->state_add_uevent_sent = 1;
+ else if (action == KOBJ_REMOVE)
+ kobj->state_remove_uevent_sent = 1;
+
+ /* we will send an event, so request a new sequence number */
spin_lock(&sequence_lock);
- seq = ++hotplug_seqnum;
+ seq = ++uevent_seqnum;
spin_unlock(&sequence_lock);
- sprintf(seq_buff, "SEQNUM=%llu", (unsigned long long)seq);
-
- pr_debug ("%s: %s %s seq=%llu %s %s %s %s %s\n",
- __FUNCTION__, argv[0], argv[1], (unsigned long long)seq,
- envp[0], envp[1], envp[2], envp[3], envp[4]);
-
- send_uevent(action_string, kobj_path, envp, GFP_KERNEL);
-
- if (!hotplug_path[0])
+ retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)seq);
+ if (retval)
goto exit;
- retval = call_usermodehelper (argv[0], argv, envp, 0);
- if (retval)
- pr_debug ("%s - call_usermodehelper returned %d\n",
- __FUNCTION__, retval);
+#if defined(CONFIG_NET)
+ /* send netlink message */
+ mutex_lock(&uevent_sock_mutex);
+ list_for_each_entry(ue_sk, &uevent_sock_list, list) {
+ struct sock *uevent_sock = ue_sk->sk;
+ struct sk_buff *skb;
+ size_t len;
+
+ /* allocate message with the maximum possible size */
+ len = strlen(action_string) + strlen(devpath) + 2;
+ skb = alloc_skb(len + env->buflen, GFP_KERNEL);
+ if (skb) {
+ char *scratch;
+
+ /* add header */
+ scratch = skb_put(skb, len);
+ sprintf(scratch, "%s@%s", action_string, devpath);
+
+ /* copy keys to our continuous event payload buffer */
+ for (i = 0; i < env->envp_idx; i++) {
+ len = strlen(env->envp[i]) + 1;
+ scratch = skb_put(skb, len);
+ strcpy(scratch, env->envp[i]);
+ }
+
+ NETLINK_CB(skb).dst_group = 1;
+ retval = netlink_broadcast_filtered(uevent_sock, skb,
+ 0, 1, GFP_KERNEL,
+ kobj_bcast_filter,
+ kobj);
+ /* ENOBUFS should be handled in userspace */
+ if (retval == -ENOBUFS)
+ retval = 0;
+ } else
+ retval = -ENOMEM;
+ }
+ mutex_unlock(&uevent_sock_mutex);
+#endif
+
+ /* call uevent_helper, usually only enabled during early boot */
+ if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
+ char *argv [3];
+
+ argv [0] = uevent_helper;
+ argv [1] = (char *)subsystem;
+ argv [2] = NULL;
+ retval = add_uevent_var(env, "HOME=/");
+ if (retval)
+ goto exit;
+ retval = add_uevent_var(env,
+ "PATH=/sbin:/bin:/usr/sbin:/usr/bin");
+ if (retval)
+ goto exit;
+
+ retval = call_usermodehelper(argv[0], argv,
+ env->envp, UMH_WAIT_EXEC);
+ }
exit:
- kfree(kobj_path);
- kfree(buffer);
- kfree(envp);
- return;
+ kfree(devpath);
+ kfree(env);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(kobject_uevent_env);
+
+/**
+ * kobject_uevent - notify userspace by sending an uevent
+ *
+ * @action: action that is happening
+ * @kobj: struct kobject that the action is happening to
+ *
+ * Returns 0 if kobject_uevent() is completed with success or the
+ * corresponding error when it fails.
+ */
+int kobject_uevent(struct kobject *kobj, enum kobject_action action)
+{
+ return kobject_uevent_env(kobj, action, NULL);
}
-EXPORT_SYMBOL(kobject_hotplug);
+EXPORT_SYMBOL_GPL(kobject_uevent);
/**
- * add_hotplug_env_var - helper for creating hotplug environment variables
- * @envp: Pointer to table of environment variables, as passed into
- * hotplug() method.
- * @num_envp: Number of environment variable slots available, as
- * passed into hotplug() method.
- * @cur_index: Pointer to current index into @envp. It should be
- * initialized to 0 before the first call to add_hotplug_env_var(),
- * and will be incremented on success.
- * @buffer: Pointer to buffer for environment variables, as passed
- * into hotplug() method.
- * @buffer_size: Length of @buffer, as passed into hotplug() method.
- * @cur_len: Pointer to current length of space used in @buffer.
- * Should be initialized to 0 before the first call to
- * add_hotplug_env_var(), and will be incremented on success.
- * @format: Format for creating environment variable (of the form
- * "XXX=%x") for snprintf().
+ * add_uevent_var - add key value string to the environment buffer
+ * @env: environment buffer structure
+ * @format: printf format for the key=value pair
*
* Returns 0 if environment variable was added successfully or -ENOMEM
* if no space was available.
*/
-int add_hotplug_env_var(char **envp, int num_envp, int *cur_index,
- char *buffer, int buffer_size, int *cur_len,
- const char *format, ...)
+int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
{
va_list args;
+ int len;
- /*
- * We check against num_envp - 1 to make sure there is at
- * least one slot left after we return, since the hotplug
- * method needs to set the last slot to NULL.
- */
- if (*cur_index >= num_envp - 1)
+ if (env->envp_idx >= ARRAY_SIZE(env->envp)) {
+ WARN(1, KERN_ERR "add_uevent_var: too many keys\n");
return -ENOMEM;
-
- envp[*cur_index] = buffer + *cur_len;
+ }
va_start(args, format);
- *cur_len += vsnprintf(envp[*cur_index],
- max(buffer_size - *cur_len, 0),
- format, args) + 1;
+ len = vsnprintf(&env->buf[env->buflen],
+ sizeof(env->buf) - env->buflen,
+ format, args);
va_end(args);
- if (*cur_len > buffer_size)
+ if (len >= (sizeof(env->buf) - env->buflen)) {
+ WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n");
+ return -ENOMEM;
+ }
+
+ env->envp[env->envp_idx++] = &env->buf[env->buflen];
+ env->buflen += len + 1;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(add_uevent_var);
+
+#if defined(CONFIG_NET)
+static int uevent_net_init(struct net *net)
+{
+ struct uevent_sock *ue_sk;
+
+ ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL);
+ if (!ue_sk)
return -ENOMEM;
- (*cur_index)++;
+ ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT,
+ 1, NULL, NULL, THIS_MODULE);
+ if (!ue_sk->sk) {
+ printk(KERN_ERR
+ "kobject_uevent: unable to create netlink socket!\n");
+ kfree(ue_sk);
+ return -ENODEV;
+ }
+ mutex_lock(&uevent_sock_mutex);
+ list_add_tail(&ue_sk->list, &uevent_sock_list);
+ mutex_unlock(&uevent_sock_mutex);
return 0;
}
-EXPORT_SYMBOL(add_hotplug_env_var);
-#endif /* CONFIG_HOTPLUG */
+static void uevent_net_exit(struct net *net)
+{
+ struct uevent_sock *ue_sk;
+
+ mutex_lock(&uevent_sock_mutex);
+ list_for_each_entry(ue_sk, &uevent_sock_list, list) {
+ if (sock_net(ue_sk->sk) == net)
+ goto found;
+ }
+ mutex_unlock(&uevent_sock_mutex);
+ return;
+
+found:
+ list_del(&ue_sk->list);
+ mutex_unlock(&uevent_sock_mutex);
+
+ netlink_kernel_release(ue_sk->sk);
+ kfree(ue_sk);
+}
+
+static struct pernet_operations uevent_net_ops = {
+ .init = uevent_net_init,
+ .exit = uevent_net_exit,
+};
+
+static int __init kobject_uevent_init(void)
+{
+ netlink_set_nonroot(NETLINK_KOBJECT_UEVENT, NL_NONROOT_RECV);
+ return register_pernet_subsys(&uevent_net_ops);
+}
+
+
+postcore_initcall(kobject_uevent_init);
+#endif
Code Review / linux-2.6.git / blobdiff