192 lines
4.5 KiB
C
192 lines
4.5 KiB
C
/* user_defined.c: user defined key type
|
|
*
|
|
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/seq_file.h>
|
|
#include <linux/err.h>
|
|
#include <asm/uaccess.h>
|
|
#include "internal.h"
|
|
|
|
static int user_instantiate(struct key *key, const void *data, size_t datalen);
|
|
static int user_duplicate(struct key *key, const struct key *source);
|
|
static int user_update(struct key *key, const void *data, size_t datalen);
|
|
static int user_match(const struct key *key, const void *criterion);
|
|
static void user_destroy(struct key *key);
|
|
static void user_describe(const struct key *user, struct seq_file *m);
|
|
static long user_read(const struct key *key,
|
|
char __user *buffer, size_t buflen);
|
|
|
|
/*
|
|
* user defined keys take an arbitrary string as the description and an
|
|
* arbitrary blob of data as the payload
|
|
*/
|
|
struct key_type key_type_user = {
|
|
.name = "user",
|
|
.instantiate = user_instantiate,
|
|
.duplicate = user_duplicate,
|
|
.update = user_update,
|
|
.match = user_match,
|
|
.destroy = user_destroy,
|
|
.describe = user_describe,
|
|
.read = user_read,
|
|
};
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* instantiate a user defined key
|
|
*/
|
|
static int user_instantiate(struct key *key, const void *data, size_t datalen)
|
|
{
|
|
int ret;
|
|
|
|
ret = -EINVAL;
|
|
if (datalen <= 0 || datalen > 32767 || !data)
|
|
goto error;
|
|
|
|
ret = key_payload_reserve(key, datalen);
|
|
if (ret < 0)
|
|
goto error;
|
|
|
|
/* attach the data */
|
|
ret = -ENOMEM;
|
|
key->payload.data = kmalloc(datalen, GFP_KERNEL);
|
|
if (!key->payload.data)
|
|
goto error;
|
|
|
|
memcpy(key->payload.data, data, datalen);
|
|
ret = 0;
|
|
|
|
error:
|
|
return ret;
|
|
|
|
} /* end user_instantiate() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* duplicate a user defined key
|
|
*/
|
|
static int user_duplicate(struct key *key, const struct key *source)
|
|
{
|
|
int ret;
|
|
|
|
/* just copy the payload */
|
|
ret = -ENOMEM;
|
|
key->payload.data = kmalloc(source->datalen, GFP_KERNEL);
|
|
|
|
if (key->payload.data) {
|
|
key->datalen = source->datalen;
|
|
memcpy(key->payload.data, source->payload.data, source->datalen);
|
|
ret = 0;
|
|
}
|
|
|
|
return ret;
|
|
|
|
} /* end user_duplicate() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* update a user defined key
|
|
*/
|
|
static int user_update(struct key *key, const void *data, size_t datalen)
|
|
{
|
|
void *new, *zap;
|
|
int ret;
|
|
|
|
ret = -EINVAL;
|
|
if (datalen <= 0 || datalen > 32767 || !data)
|
|
goto error;
|
|
|
|
/* copy the data */
|
|
ret = -ENOMEM;
|
|
new = kmalloc(datalen, GFP_KERNEL);
|
|
if (!new)
|
|
goto error;
|
|
|
|
memcpy(new, data, datalen);
|
|
|
|
/* check the quota and attach the new data */
|
|
zap = new;
|
|
write_lock(&key->lock);
|
|
|
|
ret = key_payload_reserve(key, datalen);
|
|
|
|
if (ret == 0) {
|
|
/* attach the new data, displacing the old */
|
|
zap = key->payload.data;
|
|
key->payload.data = new;
|
|
key->expiry = 0;
|
|
}
|
|
|
|
write_unlock(&key->lock);
|
|
kfree(zap);
|
|
|
|
error:
|
|
return ret;
|
|
|
|
} /* end user_update() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* match users on their name
|
|
*/
|
|
static int user_match(const struct key *key, const void *description)
|
|
{
|
|
return strcmp(key->description, description) == 0;
|
|
|
|
} /* end user_match() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* dispose of the data dangling from the corpse of a user
|
|
*/
|
|
static void user_destroy(struct key *key)
|
|
{
|
|
kfree(key->payload.data);
|
|
|
|
} /* end user_destroy() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* describe the user
|
|
*/
|
|
static void user_describe(const struct key *key, struct seq_file *m)
|
|
{
|
|
seq_puts(m, key->description);
|
|
|
|
seq_printf(m, ": %u", key->datalen);
|
|
|
|
} /* end user_describe() */
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* read the key data
|
|
*/
|
|
static long user_read(const struct key *key,
|
|
char __user *buffer, size_t buflen)
|
|
{
|
|
long ret = key->datalen;
|
|
|
|
/* we can return the data as is */
|
|
if (buffer && buflen > 0) {
|
|
if (buflen > key->datalen)
|
|
buflen = key->datalen;
|
|
|
|
if (copy_to_user(buffer, key->payload.data, buflen) != 0)
|
|
ret = -EFAULT;
|
|
}
|
|
|
|
return ret;
|
|
|
|
} /* end user_read() */
|