1 files changed, 369 insertions, 0 deletions
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
new file mode 100644
index 0000000..2a4e767
--- /dev/null
+++ b/lib/kobject_uevent.c
@@ -0,0 +1,369 @@
+/*
+ * kernel userspace event delivery
+ *
+ * Copyright (C) 2004 Red Hat, Inc.  All rights reserved.
+ * Copyright (C) 2004 Novell, Inc.  All rights reserved.
+ * Copyright (C) 2004 IBM, Inc. All rights reserved.
+ *
+ * Licensed under the GNU GPL v2.
+ *
+ * Authors:
+ *	Robert Love		<rml@novell.com>
+ *	Kay Sievers		<kay.sievers@vrfy.org>
+ *	Arjan van de Ven	<arjanv@redhat.com>
+ *	Greg Kroah-Hartman	<greg@kroah.com>
+ */
+
+#include <linux/spinlock.h>
+#include <linux/socket.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/string.h>
+#include <linux/kobject_uevent.h>
+#include <linux/kobject.h>
+#include <net/sock.h>
+
+#define BUFFER_SIZE	1024	/* buffer for the hotplug env */
+#define NUM_ENVP	32	/* number of env pointers */
+
+#if defined(CONFIG_KOBJECT_UEVENT) || defined(CONFIG_HOTPLUG)
+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_MOUNT:
+		return "mount";
+	case KOBJ_UMOUNT:
+		return "umount";
+	case KOBJ_OFFLINE:
+		return "offline";
+	case KOBJ_ONLINE:
+		return "online";
+	default:
+		return NULL;
+	}
+}
+#endif
+
+#ifdef CONFIG_KOBJECT_UEVENT
+static struct sock *uevent_sock;
+
+/**
+ * send_uevent - notify userspace by sending event trough netlink socket
+ *
+ * @signal: signal name
+ * @obj: object path (kobject)
+ * @envp: possible hotplug environment to pass with the message
+ * @gfp_mask:
+ */
+static int send_uevent(const char *signal, const char *obj,
+		       char **envp, int gfp_mask)
+{
+	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]);
+		}
+	}
+
+	return netlink_broadcast(uevent_sock, skb, 0, 1, gfp_mask);
+}
+
+static int do_kobject_uevent(struct kobject *kobj, enum kobject_action action, 
+			     struct attribute *attr, int gfp_mask)
+{
+	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);
+
+int kobject_uevent_atomic(struct kobject *kobj, enum kobject_action action,
+			  struct attribute *attr)
+{
+	return do_kobject_uevent(kobj, action, attr, GFP_ATOMIC);
+}
+EXPORT_SYMBOL_GPL(kobject_uevent_atomic);
+
+static int __init kobject_uevent_init(void)
+{
+	uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, NULL);
+
+	if (!uevent_sock) {
+		printk(KERN_ERR
+		       "kobject_uevent: unable to create netlink socket!\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+postcore_initcall(kobject_uevent_init);
+
+#else
+static inline int send_uevent(const char *signal, const char *obj,
+			      char **envp, int gfp_mask)
+{
+	return 0;
+}
+
+#endif /* CONFIG_KOBJECT_UEVENT */
+
+
+#ifdef CONFIG_HOTPLUG
+char hotplug_path[HOTPLUG_PATH_LEN] = "/sbin/hotplug";
+u64 hotplug_seqnum;
+static DEFINE_SPINLOCK(sequence_lock);
+
+/**
+ * kobject_hotplug - notify userspace by executing /sbin/hotplug
+ *
+ * @action: action that is happening (usually "ADD" or "REMOVE")
+ * @kobj: struct kobject that the action is happening to
+ */
+void kobject_hotplug(struct kobject *kobj, enum kobject_action action)
+{
+	char *argv [3];
+	char **envp = NULL;
+	char *buffer = NULL;
+	char *seq_buff;
+	char *scratch;
+	int i = 0;
+	int retval;
+	char *kobj_path = NULL;
+	char *name = NULL;
+	char *action_string;
+	u64 seq;
+	struct kobject *top_kobj = 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);
+	}
+
+	if (top_kobj->kset)
+		kset = top_kobj->kset;
+	else
+		return;
+
+	if (kset->hotplug_ops)
+		hotplug_ops = kset->hotplug_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;
+	}
+
+	pr_debug ("%s\n", __FUNCTION__);
+
+	action_string = action_to_string(action);
+	if (!action_string)
+		return;
+
+	envp = kmalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL);
+	if (!envp)
+		return;
+	memset (envp, 0x00, NUM_ENVP * sizeof (char *));
+
+	buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
+	if (!buffer)
+		goto exit;
+
+	if (hotplug_ops->name)
+		name = hotplug_ops->name(kset, kobj);
+	if (name == NULL)
+		name = kset->kobj.name;
+
+	argv [0] = hotplug_path;
+	argv [1] = name;
+	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)
+		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;
+
+	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));
+		if (retval) {
+			pr_debug ("%s - hotplug() returned %d\n",
+				  __FUNCTION__, retval);
+			goto exit;
+		}
+	}
+
+	spin_lock(&sequence_lock);
+	seq = ++hotplug_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])
+		goto exit;
+
+	retval = call_usermodehelper (argv[0], argv, envp, 0);
+	if (retval)
+		pr_debug ("%s - call_usermodehelper returned %d\n",
+			  __FUNCTION__, retval);
+
+exit:
+	kfree(kobj_path);
+	kfree(buffer);
+	kfree(envp);
+	return;
+}
+EXPORT_SYMBOL(kobject_hotplug);
+
+/**
+ * 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().
+ *
+ * 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, ...)
+{
+	va_list args;
+
+	/*
+	 * 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)
+		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;
+	va_end(args);
+
+	if (*cur_len > buffer_size)
+		return -ENOMEM;
+
+	(*cur_index)++;
+	return 0;
+}
+EXPORT_SYMBOL(add_hotplug_env_var);
+
+#endif /* CONFIG_HOTPLUG */