diff options
Diffstat (limited to 'drivers/mmc/core/lock.c')
| -rw-r--r-- | drivers/mmc/core/lock.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/drivers/mmc/core/lock.c b/drivers/mmc/core/lock.c new file mode 100644 index 000000000000..cc22cc204962 --- /dev/null +++ b/drivers/mmc/core/lock.c @@ -0,0 +1,193 @@ +/* + * linux/drivers/mmc/core/lock.h + * + * Copyright 2006 Instituto Nokia de Tecnologia (INdT), All Rights Reserved. + * Copyright 2007 Pierre Ossman + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * MMC password key handling. + */ + +#include <linux/device.h> +#include <linux/key-type.h> +#include <linux/err.h> + +#include <linux/mmc/card.h> +#include <linux/mmc/host.h> +#include <linux/mmc/mmc.h> + +#include "mmc_ops.h" +#include "lock.h" + +#define MMC_KEYLEN_MAXBYTES 32 + +#define dev_to_mmc_card(d) container_of(d, struct mmc_card, dev) + +static int mmc_key_instantiate(struct key *key, const void *data, size_t datalen) +{ + struct mmc_key_payload *mpayload; + int ret; + + ret = -EINVAL; + if (datalen <= 0 || datalen > MMC_KEYLEN_MAXBYTES || !data) { + pr_debug("Invalid data\n"); + goto error; + } + + ret = key_payload_reserve(key, datalen); + if (ret < 0) { + pr_debug("ret = %d\n", ret); + goto error; + } + + ret = -ENOMEM; + mpayload = kmalloc(sizeof(*mpayload) + datalen, GFP_KERNEL); + if (!mpayload) { + pr_debug("Unable to allocate mpayload structure\n"); + goto error; + } + mpayload->datalen = datalen; + memcpy(mpayload->data, data, datalen); + + rcu_assign_pointer(key->payload.data, mpayload); + + /* ret = 0 if there is no error */ + ret = 0; + +error: + return ret; +} + +static int mmc_key_match(const struct key *key, const void *description) +{ + return strcmp(key->description, description) == 0; +} + +/* + * dispose of the data dangling from the corpse of a mmc key + */ +static void mmc_key_destroy(struct key *key) +{ + struct mmc_key_payload *mpayload = key->payload.data; + + kfree(mpayload); +} + +static struct key_type mmc_key_type = { + .name = "mmc", + .def_datalen = MMC_KEYLEN_MAXBYTES, + .instantiate = mmc_key_instantiate, + .match = mmc_key_match, + .destroy = mmc_key_destroy, +}; + +int mmc_register_key_type(void) +{ + return register_key_type(&mmc_key_type); +} + +void mmc_unregister_key_type(void) +{ + unregister_key_type(&mmc_key_type); +} + +static ssize_t +mmc_lockable_show(struct device *dev, struct device_attribute *att, char *buf) +{ + struct mmc_card *card = dev_to_mmc_card(dev); + + return sprintf(buf, "%slocked\n", mmc_card_locked(card) ? "" : "un"); +} + +/* + * implement MMC password functions: force erase, remove password, change + * password, unlock card and assign password. + */ +static ssize_t +mmc_lockable_store(struct device *dev, struct device_attribute *att, + const char *data, size_t len) +{ + struct mmc_card *card = dev_to_mmc_card(dev); + int ret; + struct key *mmc_key; + + WARN_ON(card->type != MMC_TYPE_MMC); + WARN_ON(!(card->csd.cmdclass & CCC_LOCK_CARD)); + + if(card->type != MMC_TYPE_MMC) + return -EINVAL; + if(!(card->csd.cmdclass & CCC_LOCK_CARD)) + return -EINVAL; + + mmc_claim_host(card->host); + + ret = -EINVAL; + if (mmc_card_locked(card) && !strncmp(data, "erase", 5)) { + /* forced erase only works while card is locked */ + mmc_lock_unlock(card, NULL, MMC_LOCK_MODE_ERASE); + ret = len; + } else if (!mmc_card_locked(card) && !strncmp(data, "remove", 6)) { + /* remove password only works while card is unlocked */ + mmc_key = request_key(&mmc_key_type, "mmc:key", "remove"); + + if (!IS_ERR(mmc_key)) { + ret = mmc_lock_unlock(card, mmc_key, MMC_LOCK_MODE_CLR_PWD); + if (!ret) + ret = len; + } else + dev_dbg(&card->dev, "request_key returned error %ld\n", PTR_ERR(mmc_key)); + } else if (!mmc_card_locked(card) && ((!strncmp(data, "assign", 6)) || + (!strncmp(data, "change", 6)))) { + /* assign or change */ + if(!(strncmp(data, "assign", 6))) + mmc_key = request_key(&mmc_key_type, "mmc:key", "assign"); + else + mmc_key = request_key(&mmc_key_type, "mmc:key", "change"); + + if (!IS_ERR(mmc_key)) { + ret = mmc_lock_unlock(card, mmc_key, MMC_LOCK_MODE_SET_PWD); + if (!ret) + ret = len; + } else + dev_dbg(&card->dev, "request_key returned error %ld\n", PTR_ERR(mmc_key)); + } else if (mmc_card_locked(card) && !strncmp(data, "unlock", 6)) { + /* unlock */ + mmc_key = request_key(&mmc_key_type, "mmc:key", "unlock"); + if (!IS_ERR(mmc_key)) { + ret = mmc_lock_unlock(card, mmc_key, MMC_LOCK_MODE_UNLOCK); + if (ret) { + dev_dbg(&card->dev, "Wrong password\n"); + ret = -EINVAL; + } + else { + mmc_release_host(card->host); + device_release_driver(dev); + ret = device_attach(dev); + if(!ret) + return -EINVAL; + else + return len; + } + } else + dev_dbg(&card->dev, "request_key returned error %ld\n", PTR_ERR(mmc_key)); + } + + mmc_release_host(card->host); + return ret; +} + +static DEVICE_ATTR(lockable, S_IWUSR | S_IRUGO, + mmc_lockable_show, mmc_lockable_store); + +static struct attribute *mmc_lock_attrs[] = { + &dev_attr_lockable.attr, + NULL, +}; + +struct attribute_group mmc_lock_attr_group = { + .attrs = mmc_lock_attrs, +}; + |