diff options
Diffstat (limited to 'security/keys/user_defined.c')
| -rw-r--r-- | security/keys/user_defined.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c new file mode 100644 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() */ |