This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / security / keys / user_defined.c

diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c
new file mode 100644 (file)
index 0000000..8d65b3a
--- /dev/null
+++ b/security/keys/user_defined.c
@@ -0,0 +1,191 @@
+/* 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() */