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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /lib/kobject_uevent.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'lib/kobject_uevent.c')
-rw-r--r--lib/kobject_uevent.c369
1 files changed, 369 insertions, 0 deletions
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
new file mode 100644
index 000000000000..2a4e7671eaf4
--- /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 */

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