Subversion Repositories test_project

/*

 * 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.h>

#include <net/sock.h>

u64 uevent_seqnum;

char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;

static DEFINE_SPINLOCK(sequence_lock);

#if defined(CONFIG_NET)

static struct sock *uevent_sock;

#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",

};

/**

 * kobject_action_type - translate action string to numeric type

 *

 * @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.

 */

int kobject_action_type(const char *buf, size_t count,

                        enum kobject_action *type)

{

        enum kobject_action action;

        int ret = -EINVAL;

        if (count && buf[count-1] == '\n')

                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;

        }

out:

        return ret;

}

/**

 * kobject_uevent_env - send an uevent with environmental data

 *

 * @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() is completed with success or the

 * corresponding error when it fails.

 */

int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,

                       char *envp_ext[])

{

        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;

        struct kset_uevent_ops *uevent_ops;

        u64 seq;

        int i = 0;

        int retval = 0;

        pr_debug("%s\n", __FUNCTION__);

        /* 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 attempted to send uevent without kset!\n");

                return -EINVAL;

        }

        kset = top_kobj->kset;

        uevent_ops = kset->uevent_ops;

        /* skip the event, if the filter returns zero. */

        if (uevent_ops && uevent_ops->filter)

                if (!uevent_ops->filter(kset, kobj)) {

                        pr_debug("kobject filter function caused the event to drop!\n");

                        return 0;

                }

        /* originating subsystem */

        if (uevent_ops && uevent_ops->name)

                subsystem = uevent_ops->name(kset, kobj);

        else

                subsystem = kobject_name(&kset->kobj);

        if (!subsystem) {

                pr_debug("unset subsystem caused the event to drop!\n");

                return 0;

        }

        /* environment buffer */

        env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);

        if (!env)

                return -ENOMEM;

        /* complete object path */

        devpath = kobject_get_path(kobj, GFP_KERNEL);

        if (!devpath) {

                retval = -ENOENT;

                goto exit;

        }

        /* 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;

        /* keys passed in from the caller */

        if (envp_ext) {

                for (i = 0; envp_ext[i]; i++) {

                        retval = add_uevent_var(env, envp_ext[i]);

                        if (retval)

                                goto exit;

                }

        }

        /* 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 - uevent() returned %d\n",

                                  __FUNCTION__, retval);

                        goto exit;

                }

        }

        /* we will send an event, so request a new sequence number */

        spin_lock(&sequence_lock);

        seq = ++uevent_seqnum;

        spin_unlock(&sequence_lock);

        retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)seq);

        if (retval)

                goto exit;

#if defined(CONFIG_NET)

        /* send netlink message */

        if (uevent_sock) {

                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;

                        netlink_broadcast(uevent_sock, skb, 0, 1, GFP_KERNEL);

                }

        }

#endif

        /* call uevent_helper, usually only enabled during early boot */

        if (uevent_helper[0]) {

                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;

                call_usermodehelper (argv[0], argv, env->envp, UMH_WAIT_EXEC);

        }

exit:

        kfree(devpath);

        kfree(env);

        return retval;

}

EXPORT_SYMBOL_GPL(kobject_uevent_env);

/**

 * kobject_uevent - notify userspace by ending 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_GPL(kobject_uevent);

/**

 * 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_uevent_var(struct kobj_uevent_env *env, const char *format, ...)

{

        va_list args;

        int len;

        if (env->envp_idx >= ARRAY_SIZE(env->envp)) {

                printk(KERN_ERR "add_uevent_var: too many keys\n");

                WARN_ON(1);

                return -ENOMEM;

        }

        va_start(args, format);

        len = vsnprintf(&env->buf[env->buflen],

                        sizeof(env->buf) - env->buflen,

                        format, args);

        va_end(args);

        if (len >= (sizeof(env->buf) - env->buflen)) {

                printk(KERN_ERR "add_uevent_var: buffer size too small\n");

                WARN_ON(1);

                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 __init kobject_uevent_init(void)

{

        uevent_sock = netlink_kernel_create(&init_net, NETLINK_KOBJECT_UEVENT,

                                            1, NULL, NULL, THIS_MODULE);

        if (!uevent_sock) {

                printk(KERN_ERR

                       "kobject_uevent: unable to create netlink socket!\n");

                return -ENODEV;

        }

        return 0;

}

postcore_initcall(kobject_uevent_init);

#endif