return signal_pending(current) ? -ERESTARTSYS : 0;
}
-/*
- * call to complete the construction of a key
+/**
+ * complete_request_key - Complete the construction of a key.
+ * @cons: The key construction record.
+ * @error: The success or failute of the construction.
+ *
+ * Complete the attempt to construct a key. The key will be negated
+ * if an error is indicated. The authorisation key will be revoked
+ * unconditionally.
*/
void complete_request_key(struct key_construction *cons, int error)
{
}
EXPORT_SYMBOL(complete_request_key);
+/*
+ * Initialise a usermode helper that is going to have a specific session
+ * keyring.
+ *
+ * This is called in context of freshly forked kthread before kernel_execve(),
+ * so we can simply install the desired session_keyring at this point.
+ */
static int umh_keys_init(struct subprocess_info *info)
{
struct cred *cred = (struct cred*)current_cred();
struct key *keyring = info->data;
- /*
- * This is called in context of freshly forked kthread before
- * kernel_execve(), we can just change our ->session_keyring.
- */
+
return install_session_keyring_to_cred(cred, keyring);
}
+/*
+ * Clean up a usermode helper with session keyring.
+ */
static void umh_keys_cleanup(struct subprocess_info *info)
{
struct key *keyring = info->data;
key_put(keyring);
}
+/*
+ * Call a usermode helper with a specific session keyring.
+ */
static int call_usermodehelper_keys(char *path, char **argv, char **envp,
struct key *session_keyring, enum umh_wait wait)
{
}
/*
- * request userspace finish the construction of a key
+ * Request userspace finish the construction of a key
* - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>"
*/
static int call_sbin_request_key(struct key_construction *cons,
}
/*
- * call out to userspace for key construction
- * - we ignore program failure and go on key status instead
+ * Call out to userspace for key construction.
+ *
+ * Program failure is ignored in favour of key status.
*/
static int construct_key(struct key *key, const void *callout_info,
size_t callout_len, void *aux,
}
/*
- * get the appropriate destination keyring for the request
- * - we return whatever keyring we select with an extra reference upon it which
- * the caller must release
+ * Get the appropriate destination keyring for the request.
+ *
+ * The keyring selected is returned with an extra reference upon it which the
+ * caller must release.
*/
static void construct_get_dest_keyring(struct key **_dest_keyring)
{
}
/*
- * allocate a new key in under-construction state and attempt to link it in to
- * the requested place
- * - may return a key that's already under construction instead
+ * Allocate a new key in under-construction state and attempt to link it in to
+ * the requested keyring.
+ *
+ * May return a key that's already under construction instead if there was a
+ * race between two thread calling request_key().
*/
static int construct_alloc_key(struct key_type *type,
const char *description,
struct key_user *user,
struct key **_key)
{
- struct keyring_list *prealloc;
const struct cred *cred = current_cred();
+ unsigned long prealloc;
struct key *key;
key_ref_t key_ref;
int ret;
return ret;
link_prealloc_failed:
- up_write(&dest_keyring->sem);
mutex_unlock(&user->cons_lock);
kleave(" = %d [prelink]", ret);
return ret;
}
/*
- * commence key construction
+ * Commence key construction.
*/
static struct key *construct_key_and_link(struct key_type *type,
const char *description,
return ERR_PTR(ret);
}
-/*
- * request a key
- * - search the process's keyrings
- * - check the list of keys being created or updated
- * - call out to userspace for a key if supplementary info was provided
- * - cache the key in an appropriate keyring
+/**
+ * request_key_and_link - Request a key and cache it in a keyring.
+ * @type: The type of key we want.
+ * @description: The searchable description of the key.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ * @callout_len: The length of callout_info.
+ * @aux: Auxiliary data for the upcall.
+ * @dest_keyring: Where to cache the key.
+ * @flags: Flags to key_alloc().
+ *
+ * A key matching the specified criteria is searched for in the process's
+ * keyrings and returned with its usage count incremented if found. Otherwise,
+ * if callout_info is not NULL, a key will be allocated and some service
+ * (probably in userspace) will be asked to instantiate it.
+ *
+ * If successfully found or created, the key will be linked to the destination
+ * keyring if one is provided.
+ *
+ * Returns a pointer to the key if successful; -EACCES, -ENOKEY, -EKEYREVOKED
+ * or -EKEYEXPIRED if an inaccessible, negative, revoked or expired key was
+ * found; -ENOKEY if no key was found and no @callout_info was given; -EDQUOT
+ * if insufficient key quota was available to create a new key; or -ENOMEM if
+ * insufficient memory was available.
+ *
+ * If the returned key was created, then it may still be under construction,
+ * and wait_for_key_construction() should be used to wait for that to complete.
*/
struct key *request_key_and_link(struct key_type *type,
const char *description,
dest_keyring, flags);
/* search all the process keyrings for a key */
- key_ref = search_process_keyrings(type, description, type->match,
- cred);
+ key_ref = search_process_keyrings(type, description, type->match, cred);
if (!IS_ERR(key_ref)) {
key = key_ref_to_ptr(key_ref);
return key;
}
-/*
- * wait for construction of a key to complete
+/**
+ * wait_for_key_construction - Wait for construction of a key to complete
+ * @key: The key being waited for.
+ * @intr: Whether to wait interruptibly.
+ *
+ * Wait for a key to finish being constructed.
+ *
+ * Returns 0 if successful; -ERESTARTSYS if the wait was interrupted; -ENOKEY
+ * if the key was negated; or -EKEYREVOKED or -EKEYEXPIRED if the key was
+ * revoked or expired.
*/
int wait_for_key_construction(struct key *key, bool intr)
{
if (ret < 0)
return ret;
if (test_bit(KEY_FLAG_NEGATIVE, &key->flags))
- return -ENOKEY;
+ return key->type_data.reject_error;
return key_validate(key);
}
EXPORT_SYMBOL(wait_for_key_construction);
-/*
- * request a key
- * - search the process's keyrings
- * - check the list of keys being created or updated
- * - call out to userspace for a key if supplementary info was provided
- * - waits uninterruptible for creation to complete
+/**
+ * request_key - Request a key and wait for construction
+ * @type: Type of key.
+ * @description: The searchable description of the key.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ *
+ * As for request_key_and_link() except that it does not add the returned key
+ * to a keyring if found, new keys are always allocated in the user's quota,
+ * the callout_info must be a NUL-terminated string and no auxiliary data can
+ * be passed.
+ *
+ * Furthermore, it then works as wait_for_key_construction() to wait for the
+ * completion of keys undergoing construction with a non-interruptible wait.
*/
struct key *request_key(struct key_type *type,
const char *description,
}
EXPORT_SYMBOL(request_key);
-/*
- * request a key with auxiliary data for the upcaller
- * - search the process's keyrings
- * - check the list of keys being created or updated
- * - call out to userspace for a key if supplementary info was provided
- * - waits uninterruptible for creation to complete
+/**
+ * request_key_with_auxdata - Request a key with auxiliary data for the upcaller
+ * @type: The type of key we want.
+ * @description: The searchable description of the key.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ * @callout_len: The length of callout_info.
+ * @aux: Auxiliary data for the upcall.
+ *
+ * As for request_key_and_link() except that it does not add the returned key
+ * to a keyring if found and new keys are always allocated in the user's quota.
+ *
+ * Furthermore, it then works as wait_for_key_construction() to wait for the
+ * completion of keys undergoing construction with a non-interruptible wait.
*/
struct key *request_key_with_auxdata(struct key_type *type,
const char *description,
EXPORT_SYMBOL(request_key_with_auxdata);
/*
- * request a key (allow async construction)
- * - search the process's keyrings
- * - check the list of keys being created or updated
- * - call out to userspace for a key if supplementary info was provided
+ * request_key_async - Request a key (allow async construction)
+ * @type: Type of key.
+ * @description: The searchable description of the key.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ * @callout_len: The length of callout_info.
+ *
+ * As for request_key_and_link() except that it does not add the returned key
+ * to a keyring if found, new keys are always allocated in the user's quota and
+ * no auxiliary data can be passed.
+ *
+ * The caller should call wait_for_key_construction() to wait for the
+ * completion of the returned key if it is still undergoing construction.
*/
struct key *request_key_async(struct key_type *type,
const char *description,
/*
* request a key with auxiliary data for the upcaller (allow async construction)
- * - search the process's keyrings
- * - check the list of keys being created or updated
- * - call out to userspace for a key if supplementary info was provided
+ * @type: Type of key.
+ * @description: The searchable description of the key.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ * @callout_len: The length of callout_info.
+ * @aux: Auxiliary data for the upcall.
+ *
+ * As for request_key_and_link() except that it does not add the returned key
+ * to a keyring if found and new keys are always allocated in the user's quota.
+ *
+ * The caller should call wait_for_key_construction() to wait for the
+ * completion of the returned key if it is still undergoing construction.
*/
struct key *request_key_async_with_auxdata(struct key_type *type,
const char *description,
Code Review / linux-3.10.git / blobdiff