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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /security/keys/key.c | |
download | kernel_samsung_espresso10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip kernel_samsung_espresso10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz kernel_samsung_espresso10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'security/keys/key.c')
-rw-r--r-- | security/keys/key.c | 1040 |
1 files changed, 1040 insertions, 0 deletions
diff --git a/security/keys/key.c b/security/keys/key.c new file mode 100644 index 0000000..59402c8 --- /dev/null +++ b/security/keys/key.c @@ -0,0 +1,1040 @@ +/* key.c: basic authentication token and access key management + * + * 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/workqueue.h> +#include <linux/err.h> +#include "internal.h" + +static kmem_cache_t *key_jar; +static key_serial_t key_serial_next = 3; +struct rb_root key_serial_tree; /* tree of keys indexed by serial */ +DEFINE_SPINLOCK(key_serial_lock); + +struct rb_root key_user_tree; /* tree of quota records indexed by UID */ +DEFINE_SPINLOCK(key_user_lock); + +static LIST_HEAD(key_types_list); +static DECLARE_RWSEM(key_types_sem); + +static void key_cleanup(void *data); +static DECLARE_WORK(key_cleanup_task, key_cleanup, NULL); + +/* we serialise key instantiation and link */ +DECLARE_RWSEM(key_construction_sem); + +/* any key who's type gets unegistered will be re-typed to this */ +struct key_type key_type_dead = { + .name = "dead", +}; + +#ifdef KEY_DEBUGGING +void __key_check(const struct key *key) +{ + printk("__key_check: key %p {%08x} should be {%08x}\n", + key, key->magic, KEY_DEBUG_MAGIC); + BUG(); +} +#endif + +/*****************************************************************************/ +/* + * get the key quota record for a user, allocating a new record if one doesn't + * already exist + */ +struct key_user *key_user_lookup(uid_t uid) +{ + struct key_user *candidate = NULL, *user; + struct rb_node *parent = NULL; + struct rb_node **p; + + try_again: + p = &key_user_tree.rb_node; + spin_lock(&key_user_lock); + + /* search the tree for a user record with a matching UID */ + while (*p) { + parent = *p; + user = rb_entry(parent, struct key_user, node); + + if (uid < user->uid) + p = &(*p)->rb_left; + else if (uid > user->uid) + p = &(*p)->rb_right; + else + goto found; + } + + /* if we get here, we failed to find a match in the tree */ + if (!candidate) { + /* allocate a candidate user record if we don't already have + * one */ + spin_unlock(&key_user_lock); + + user = NULL; + candidate = kmalloc(sizeof(struct key_user), GFP_KERNEL); + if (unlikely(!candidate)) + goto out; + + /* the allocation may have scheduled, so we need to repeat the + * search lest someone else added the record whilst we were + * asleep */ + goto try_again; + } + + /* if we get here, then the user record still hadn't appeared on the + * second pass - so we use the candidate record */ + atomic_set(&candidate->usage, 1); + atomic_set(&candidate->nkeys, 0); + atomic_set(&candidate->nikeys, 0); + candidate->uid = uid; + candidate->qnkeys = 0; + candidate->qnbytes = 0; + spin_lock_init(&candidate->lock); + INIT_LIST_HEAD(&candidate->consq); + + rb_link_node(&candidate->node, parent, p); + rb_insert_color(&candidate->node, &key_user_tree); + spin_unlock(&key_user_lock); + user = candidate; + goto out; + + /* okay - we found a user record for this UID */ + found: + atomic_inc(&user->usage); + spin_unlock(&key_user_lock); + if (candidate) + kfree(candidate); + out: + return user; + +} /* end key_user_lookup() */ + +/*****************************************************************************/ +/* + * dispose of a user structure + */ +void key_user_put(struct key_user *user) +{ + if (atomic_dec_and_lock(&user->usage, &key_user_lock)) { + rb_erase(&user->node, &key_user_tree); + spin_unlock(&key_user_lock); + + kfree(user); + } + +} /* end key_user_put() */ + +/*****************************************************************************/ +/* + * insert a key with a fixed serial number + */ +static void __init __key_insert_serial(struct key *key) +{ + struct rb_node *parent, **p; + struct key *xkey; + + parent = NULL; + p = &key_serial_tree.rb_node; + + while (*p) { + parent = *p; + xkey = rb_entry(parent, struct key, serial_node); + + if (key->serial < xkey->serial) + p = &(*p)->rb_left; + else if (key->serial > xkey->serial) + p = &(*p)->rb_right; + else + BUG(); + } + + /* we've found a suitable hole - arrange for this key to occupy it */ + rb_link_node(&key->serial_node, parent, p); + rb_insert_color(&key->serial_node, &key_serial_tree); + +} /* end __key_insert_serial() */ + +/*****************************************************************************/ +/* + * assign a key the next unique serial number + * - we work through all the serial numbers between 2 and 2^31-1 in turn and + * then wrap + */ +static inline void key_alloc_serial(struct key *key) +{ + struct rb_node *parent, **p; + struct key *xkey; + + spin_lock(&key_serial_lock); + + /* propose a likely serial number and look for a hole for it in the + * serial number tree */ + key->serial = key_serial_next; + if (key->serial < 3) + key->serial = 3; + key_serial_next = key->serial + 1; + + parent = NULL; + p = &key_serial_tree.rb_node; + + while (*p) { + parent = *p; + xkey = rb_entry(parent, struct key, serial_node); + + if (key->serial < xkey->serial) + p = &(*p)->rb_left; + else if (key->serial > xkey->serial) + p = &(*p)->rb_right; + else + goto serial_exists; + } + goto insert_here; + + /* we found a key with the proposed serial number - walk the tree from + * that point looking for the next unused serial number */ + serial_exists: + for (;;) { + key->serial = key_serial_next; + if (key->serial < 2) + key->serial = 2; + key_serial_next = key->serial + 1; + + if (!parent->rb_parent) + p = &key_serial_tree.rb_node; + else if (parent->rb_parent->rb_left == parent) + p = &parent->rb_parent->rb_left; + else + p = &parent->rb_parent->rb_right; + + parent = rb_next(parent); + if (!parent) + break; + + xkey = rb_entry(parent, struct key, serial_node); + if (key->serial < xkey->serial) + goto insert_here; + } + + /* we've found a suitable hole - arrange for this key to occupy it */ + insert_here: + rb_link_node(&key->serial_node, parent, p); + rb_insert_color(&key->serial_node, &key_serial_tree); + + spin_unlock(&key_serial_lock); + +} /* end key_alloc_serial() */ + +/*****************************************************************************/ +/* + * allocate a key of the specified type + * - update the user's quota to reflect the existence of the key + * - called from a key-type operation with key_types_sem read-locked by either + * key_create_or_update() or by key_duplicate(); this prevents unregistration + * of the key type + * - upon return the key is as yet uninstantiated; the caller needs to either + * instantiate the key or discard it before returning + */ +struct key *key_alloc(struct key_type *type, const char *desc, + uid_t uid, gid_t gid, key_perm_t perm, + int not_in_quota) +{ + struct key_user *user = NULL; + struct key *key; + size_t desclen, quotalen; + + key = ERR_PTR(-EINVAL); + if (!desc || !*desc) + goto error; + + desclen = strlen(desc) + 1; + quotalen = desclen + type->def_datalen; + + /* get hold of the key tracking for this user */ + user = key_user_lookup(uid); + if (!user) + goto no_memory_1; + + /* check that the user's quota permits allocation of another key and + * its description */ + if (!not_in_quota) { + spin_lock(&user->lock); + if (user->qnkeys + 1 >= KEYQUOTA_MAX_KEYS && + user->qnbytes + quotalen >= KEYQUOTA_MAX_BYTES + ) + goto no_quota; + + user->qnkeys++; + user->qnbytes += quotalen; + spin_unlock(&user->lock); + } + + /* allocate and initialise the key and its description */ + key = kmem_cache_alloc(key_jar, SLAB_KERNEL); + if (!key) + goto no_memory_2; + + if (desc) { + key->description = kmalloc(desclen, GFP_KERNEL); + if (!key->description) + goto no_memory_3; + + memcpy(key->description, desc, desclen); + } + + atomic_set(&key->usage, 1); + rwlock_init(&key->lock); + init_rwsem(&key->sem); + key->type = type; + key->user = user; + key->quotalen = quotalen; + key->datalen = type->def_datalen; + key->uid = uid; + key->gid = gid; + key->perm = perm; + key->flags = 0; + key->expiry = 0; + key->payload.data = NULL; + + if (!not_in_quota) + key->flags |= KEY_FLAG_IN_QUOTA; + + memset(&key->type_data, 0, sizeof(key->type_data)); + +#ifdef KEY_DEBUGGING + key->magic = KEY_DEBUG_MAGIC; +#endif + + /* publish the key by giving it a serial number */ + atomic_inc(&user->nkeys); + key_alloc_serial(key); + + error: + return key; + + no_memory_3: + kmem_cache_free(key_jar, key); + no_memory_2: + if (!not_in_quota) { + spin_lock(&user->lock); + user->qnkeys--; + user->qnbytes -= quotalen; + spin_unlock(&user->lock); + } + key_user_put(user); + no_memory_1: + key = ERR_PTR(-ENOMEM); + goto error; + + no_quota: + spin_unlock(&user->lock); + key_user_put(user); + key = ERR_PTR(-EDQUOT); + goto error; + +} /* end key_alloc() */ + +EXPORT_SYMBOL(key_alloc); + +/*****************************************************************************/ +/* + * reserve an amount of quota for the key's payload + */ +int key_payload_reserve(struct key *key, size_t datalen) +{ + int delta = (int) datalen - key->datalen; + int ret = 0; + + key_check(key); + + /* contemplate the quota adjustment */ + if (delta != 0 && key->flags & KEY_FLAG_IN_QUOTA) { + spin_lock(&key->user->lock); + + if (delta > 0 && + key->user->qnbytes + delta > KEYQUOTA_MAX_BYTES + ) { + ret = -EDQUOT; + } + else { + key->user->qnbytes += delta; + key->quotalen += delta; + } + spin_unlock(&key->user->lock); + } + + /* change the recorded data length if that didn't generate an error */ + if (ret == 0) + key->datalen = datalen; + + return ret; + +} /* end key_payload_reserve() */ + +EXPORT_SYMBOL(key_payload_reserve); + +/*****************************************************************************/ +/* + * instantiate a key and link it into the target keyring atomically + * - called with the target keyring's semaphore writelocked + */ +static int __key_instantiate_and_link(struct key *key, + const void *data, + size_t datalen, + struct key *keyring) +{ + int ret, awaken; + + key_check(key); + key_check(keyring); + + awaken = 0; + ret = -EBUSY; + + down_write(&key_construction_sem); + + /* can't instantiate twice */ + if (!(key->flags & KEY_FLAG_INSTANTIATED)) { + /* instantiate the key */ + ret = key->type->instantiate(key, data, datalen); + + if (ret == 0) { + /* mark the key as being instantiated */ + write_lock(&key->lock); + + atomic_inc(&key->user->nikeys); + key->flags |= KEY_FLAG_INSTANTIATED; + + if (key->flags & KEY_FLAG_USER_CONSTRUCT) { + key->flags &= ~KEY_FLAG_USER_CONSTRUCT; + awaken = 1; + } + + write_unlock(&key->lock); + + /* and link it into the destination keyring */ + if (keyring) + ret = __key_link(keyring, key); + } + } + + up_write(&key_construction_sem); + + /* wake up anyone waiting for a key to be constructed */ + if (awaken) + wake_up_all(&request_key_conswq); + + return ret; + +} /* end __key_instantiate_and_link() */ + +/*****************************************************************************/ +/* + * instantiate a key and link it into the target keyring atomically + */ +int key_instantiate_and_link(struct key *key, + const void *data, + size_t datalen, + struct key *keyring) +{ + int ret; + + if (keyring) + down_write(&keyring->sem); + + ret = __key_instantiate_and_link(key, data, datalen, keyring); + + if (keyring) + up_write(&keyring->sem); + + return ret; +} /* end key_instantiate_and_link() */ + +EXPORT_SYMBOL(key_instantiate_and_link); + +/*****************************************************************************/ +/* + * negatively instantiate a key and link it into the target keyring atomically + */ +int key_negate_and_link(struct key *key, + unsigned timeout, + struct key *keyring) +{ + struct timespec now; + int ret, awaken; + + key_check(key); + key_check(keyring); + + awaken = 0; + ret = -EBUSY; + + if (keyring) + down_write(&keyring->sem); + + down_write(&key_construction_sem); + + /* can't instantiate twice */ + if (!(key->flags & KEY_FLAG_INSTANTIATED)) { + /* mark the key as being negatively instantiated */ + write_lock(&key->lock); + + atomic_inc(&key->user->nikeys); + key->flags |= KEY_FLAG_INSTANTIATED | KEY_FLAG_NEGATIVE; + now = current_kernel_time(); + key->expiry = now.tv_sec + timeout; + + if (key->flags & KEY_FLAG_USER_CONSTRUCT) { + key->flags &= ~KEY_FLAG_USER_CONSTRUCT; + awaken = 1; + } + + write_unlock(&key->lock); + ret = 0; + + /* and link it into the destination keyring */ + if (keyring) + ret = __key_link(keyring, key); + } + + up_write(&key_construction_sem); + + if (keyring) + up_write(&keyring->sem); + + /* wake up anyone waiting for a key to be constructed */ + if (awaken) + wake_up_all(&request_key_conswq); + + return ret; + +} /* end key_negate_and_link() */ + +EXPORT_SYMBOL(key_negate_and_link); + +/*****************************************************************************/ +/* + * do cleaning up in process context so that we don't have to disable + * interrupts all over the place + */ +static void key_cleanup(void *data) +{ + struct rb_node *_n; + struct key *key; + + go_again: + /* look for a dead key in the tree */ + spin_lock(&key_serial_lock); + + for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { + key = rb_entry(_n, struct key, serial_node); + + if (atomic_read(&key->usage) == 0) + goto found_dead_key; + } + + spin_unlock(&key_serial_lock); + return; + + found_dead_key: + /* we found a dead key - once we've removed it from the tree, we can + * drop the lock */ + rb_erase(&key->serial_node, &key_serial_tree); + spin_unlock(&key_serial_lock); + + /* deal with the user's key tracking and quota */ + if (key->flags & KEY_FLAG_IN_QUOTA) { + spin_lock(&key->user->lock); + key->user->qnkeys--; + key->user->qnbytes -= key->quotalen; + spin_unlock(&key->user->lock); + } + + atomic_dec(&key->user->nkeys); + if (key->flags & KEY_FLAG_INSTANTIATED) + atomic_dec(&key->user->nikeys); + + key_user_put(key->user); + + /* now throw away the key memory */ + if (key->type->destroy) + key->type->destroy(key); + + kfree(key->description); + +#ifdef KEY_DEBUGGING + key->magic = KEY_DEBUG_MAGIC_X; +#endif + kmem_cache_free(key_jar, key); + + /* there may, of course, be more than one key to destroy */ + goto go_again; + +} /* end key_cleanup() */ + +/*****************************************************************************/ +/* + * dispose of a reference to a key + * - when all the references are gone, we schedule the cleanup task to come and + * pull it out of the tree in definite process context + */ +void key_put(struct key *key) +{ + if (key) { + key_check(key); + + if (atomic_dec_and_test(&key->usage)) + schedule_work(&key_cleanup_task); + } + +} /* end key_put() */ + +EXPORT_SYMBOL(key_put); + +/*****************************************************************************/ +/* + * find a key by its serial number + */ +struct key *key_lookup(key_serial_t id) +{ + struct rb_node *n; + struct key *key; + + spin_lock(&key_serial_lock); + + /* search the tree for the specified key */ + n = key_serial_tree.rb_node; + while (n) { + key = rb_entry(n, struct key, serial_node); + + if (id < key->serial) + n = n->rb_left; + else if (id > key->serial) + n = n->rb_right; + else + goto found; + } + + not_found: + key = ERR_PTR(-ENOKEY); + goto error; + + found: + /* pretent doesn't exist if it's dead */ + if (atomic_read(&key->usage) == 0 || + (key->flags & KEY_FLAG_DEAD) || + key->type == &key_type_dead) + goto not_found; + + /* this races with key_put(), but that doesn't matter since key_put() + * doesn't actually change the key + */ + atomic_inc(&key->usage); + + error: + spin_unlock(&key_serial_lock); + return key; + +} /* end key_lookup() */ + +/*****************************************************************************/ +/* + * find and lock the specified key type against removal + * - we return with the sem readlocked + */ +struct key_type *key_type_lookup(const char *type) +{ + struct key_type *ktype; + + down_read(&key_types_sem); + + /* look up the key type to see if it's one of the registered kernel + * types */ + list_for_each_entry(ktype, &key_types_list, link) { + if (strcmp(ktype->name, type) == 0) + goto found_kernel_type; + } + + up_read(&key_types_sem); + ktype = ERR_PTR(-ENOKEY); + + found_kernel_type: + return ktype; + +} /* end key_type_lookup() */ + +/*****************************************************************************/ +/* + * unlock a key type + */ +void key_type_put(struct key_type *ktype) +{ + up_read(&key_types_sem); + +} /* end key_type_put() */ + +/*****************************************************************************/ +/* + * attempt to update an existing key + * - the key has an incremented refcount + * - we need to put the key if we get an error + */ +static inline struct key *__key_update(struct key *key, const void *payload, + size_t plen) +{ + int ret; + + /* need write permission on the key to update it */ + ret = -EACCES; + if (!key_permission(key, KEY_WRITE)) + goto error; + + ret = -EEXIST; + if (!key->type->update) + goto error; + + down_write(&key->sem); + + ret = key->type->update(key, payload, plen); + + if (ret == 0) { + /* updating a negative key instantiates it */ + write_lock(&key->lock); + key->flags &= ~KEY_FLAG_NEGATIVE; + write_unlock(&key->lock); + } + + up_write(&key->sem); + + if (ret < 0) + goto error; + out: + return key; + + error: + key_put(key); + key = ERR_PTR(ret); + goto out; + +} /* end __key_update() */ + +/*****************************************************************************/ +/* + * search the specified keyring for a key of the same description; if one is + * found, update it, otherwise add a new one + */ +struct key *key_create_or_update(struct key *keyring, + const char *type, + const char *description, + const void *payload, + size_t plen, + int not_in_quota) +{ + struct key_type *ktype; + struct key *key = NULL; + key_perm_t perm; + int ret; + + key_check(keyring); + + /* look up the key type to see if it's one of the registered kernel + * types */ + ktype = key_type_lookup(type); + if (IS_ERR(ktype)) { + key = ERR_PTR(-ENODEV); + goto error; + } + + ret = -EINVAL; + if (!ktype->match || !ktype->instantiate) + goto error_2; + + /* search for an existing key of the same type and description in the + * destination keyring + */ + down_write(&keyring->sem); + + key = __keyring_search_one(keyring, ktype, description, 0); + if (!IS_ERR(key)) + goto found_matching_key; + + /* if we're going to allocate a new key, we're going to have to modify + * the keyring */ + ret = -EACCES; + if (!key_permission(keyring, KEY_WRITE)) + goto error_3; + + /* decide on the permissions we want */ + perm = KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK; + + if (ktype->read) + perm |= KEY_USR_READ; + + if (ktype == &key_type_keyring || ktype->update) + perm |= KEY_USR_WRITE; + + /* allocate a new key */ + key = key_alloc(ktype, description, current->fsuid, current->fsgid, + perm, not_in_quota); + if (IS_ERR(key)) { + ret = PTR_ERR(key); + goto error_3; + } + + /* instantiate it and link it into the target keyring */ + ret = __key_instantiate_and_link(key, payload, plen, keyring); + if (ret < 0) { + key_put(key); + key = ERR_PTR(ret); + } + + error_3: + up_write(&keyring->sem); + error_2: + key_type_put(ktype); + error: + return key; + + found_matching_key: + /* we found a matching key, so we're going to try to update it + * - we can drop the locks first as we have the key pinned + */ + up_write(&keyring->sem); + key_type_put(ktype); + + key = __key_update(key, payload, plen); + goto error; + +} /* end key_create_or_update() */ + +EXPORT_SYMBOL(key_create_or_update); + +/*****************************************************************************/ +/* + * update a key + */ +int key_update(struct key *key, const void *payload, size_t plen) +{ + int ret; + + key_check(key); + + /* the key must be writable */ + ret = -EACCES; + if (!key_permission(key, KEY_WRITE)) + goto error; + + /* attempt to update it if supported */ + ret = -EOPNOTSUPP; + if (key->type->update) { + down_write(&key->sem); + ret = key->type->update(key, payload, plen); + + if (ret == 0) { + /* updating a negative key instantiates it */ + write_lock(&key->lock); + key->flags &= ~KEY_FLAG_NEGATIVE; + write_unlock(&key->lock); + } + + up_write(&key->sem); + } + + error: + return ret; + +} /* end key_update() */ + +EXPORT_SYMBOL(key_update); + +/*****************************************************************************/ +/* + * duplicate a key, potentially with a revised description + * - must be supported by the keytype (keyrings for instance can be duplicated) + */ +struct key *key_duplicate(struct key *source, const char *desc) +{ + struct key *key; + int ret; + + key_check(source); + + if (!desc) + desc = source->description; + + down_read(&key_types_sem); + + ret = -EINVAL; + if (!source->type->duplicate) + goto error; + + /* allocate and instantiate a key */ + key = key_alloc(source->type, desc, current->fsuid, current->fsgid, + source->perm, 0); + if (IS_ERR(key)) + goto error_k; + + down_read(&source->sem); + ret = key->type->duplicate(key, source); + up_read(&source->sem); + if (ret < 0) + goto error2; + + atomic_inc(&key->user->nikeys); + + write_lock(&key->lock); + key->flags |= KEY_FLAG_INSTANTIATED; + write_unlock(&key->lock); + + error_k: + up_read(&key_types_sem); + out: + return key; + + error2: + key_put(key); + error: + up_read(&key_types_sem); + key = ERR_PTR(ret); + goto out; + +} /* end key_duplicate() */ + +/*****************************************************************************/ +/* + * revoke a key + */ +void key_revoke(struct key *key) +{ + key_check(key); + + /* make sure no one's trying to change or use the key when we mark + * it */ + down_write(&key->sem); + write_lock(&key->lock); + key->flags |= KEY_FLAG_REVOKED; + write_unlock(&key->lock); + up_write(&key->sem); + +} /* end key_revoke() */ + +EXPORT_SYMBOL(key_revoke); + +/*****************************************************************************/ +/* + * register a type of key + */ +int register_key_type(struct key_type *ktype) +{ + struct key_type *p; + int ret; + + ret = -EEXIST; + down_write(&key_types_sem); + + /* disallow key types with the same name */ + list_for_each_entry(p, &key_types_list, link) { + if (strcmp(p->name, ktype->name) == 0) + goto out; + } + + /* store the type */ + list_add(&ktype->link, &key_types_list); + ret = 0; + + out: + up_write(&key_types_sem); + return ret; + +} /* end register_key_type() */ + +EXPORT_SYMBOL(register_key_type); + +/*****************************************************************************/ +/* + * unregister a type of key + */ +void unregister_key_type(struct key_type *ktype) +{ + struct rb_node *_n; + struct key *key; + + down_write(&key_types_sem); + + /* withdraw the key type */ + list_del_init(&ktype->link); + + /* need to withdraw all keys of this type */ + spin_lock(&key_serial_lock); + + for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { + key = rb_entry(_n, struct key, serial_node); + + if (key->type != ktype) + continue; + + write_lock(&key->lock); + key->type = &key_type_dead; + write_unlock(&key->lock); + + /* there shouldn't be anyone looking at the description or + * payload now */ + if (ktype->destroy) + ktype->destroy(key); + memset(&key->payload, 0xbd, sizeof(key->payload)); + } + + spin_unlock(&key_serial_lock); + up_write(&key_types_sem); + +} /* end unregister_key_type() */ + +EXPORT_SYMBOL(unregister_key_type); + +/*****************************************************************************/ +/* + * initialise the key management stuff + */ +void __init key_init(void) +{ + /* allocate a slab in which we can store keys */ + key_jar = kmem_cache_create("key_jar", sizeof(struct key), + 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL); + + /* add the special key types */ + list_add_tail(&key_type_keyring.link, &key_types_list); + list_add_tail(&key_type_dead.link, &key_types_list); + list_add_tail(&key_type_user.link, &key_types_list); + + /* record the root user tracking */ + rb_link_node(&root_key_user.node, + NULL, + &key_user_tree.rb_node); + + rb_insert_color(&root_key_user.node, + &key_user_tree); + + /* record root's user standard keyrings */ + key_check(&root_user_keyring); + key_check(&root_session_keyring); + + __key_insert_serial(&root_user_keyring); + __key_insert_serial(&root_session_keyring); + + keyring_publish_name(&root_user_keyring); + keyring_publish_name(&root_session_keyring); + + /* link the two root keyrings together */ + key_link(&root_session_keyring, &root_user_keyring); +} /* end key_init() */ |