const char *callout_string,
void *aux);
+or:
+
+ struct key *request_key_async(const struct key_type *type,
+ const char *description,
+ const char *callout_string);
+
+or:
+
+ struct key *request_key_async_with_auxdata(const struct key_type *type,
+ const char *description,
+ const char *callout_string,
+ void *aux);
+
Or by userspace invoking the request_key system call:
key_serial_t request_key(const char *type,
destroyed. The kernel interface returns a pointer directly to the key, and
it's up to the caller to destroy the key.
-The request_key_with_auxdata() call is like the in-kernel request_key() call,
-except that it permits auxiliary data to be passed to the upcaller (the default
-is NULL). This is only useful for those key types that define their own upcall
-mechanism rather than using /sbin/request-key.
+The request_key*_with_auxdata() calls are like the in-kernel request_key*()
+calls, except that they permit auxiliary data to be passed to the upcaller (the
+default is NULL). This is only useful for those key types that define their
+own upcall mechanism rather than using /sbin/request-key.
+
+The two async in-kernel calls may return keys that are still in the process of
+being constructed. The two non-async ones will wait for construction to
+complete first.
The userspace interface links the key to a keyring associated with the process
to prevent the key from going away, and returns the serial number of the key to
This service allows cryptographic keys, authentication tokens, cross-domain
user mappings, and similar to be cached in the kernel for the use of
-filesystems other kernel services.
+filesystems and other kernel services.
Keyrings are permitted; these are a special type of key that can hold links to
other keys. Processes each have three standard keyring subscriptions that a
two different users opening the same file is left to the filesystem author to
solve.
+To access the key manager, the following header must be #included:
+
+ <linux/key.h>
+
+Specific key types should have a header file under include/keys/ that should be
+used to access that type. For keys of type "user", for example, that would be:
+
+ <keys/user-type.h>
+
Note that there are two different types of pointers to keys that may be
encountered:
passed to the key_type->request_key() op if it exists.
+(*) A key can be requested asynchronously by calling one of:
+
+ struct key *request_key_async(const struct key_type *type,
+ const char *description,
+ const char *callout_string);
+
+ or:
+
+ struct key *request_key_async_with_auxdata(const struct key_type *type,
+ const char *description,
+ const char *callout_string,
+ void *aux);
+
+ which are asynchronous equivalents of request_key() and
+ request_key_with_auxdata() respectively.
+
+ These two functions return with the key potentially still under
+ construction. To wait for contruction completion, the following should be
+ called:
+
+ int wait_for_key_construction(struct key *key, bool intr);
+
+ The function will wait for the key to finish being constructed and then
+ invokes key_validate() to return an appropriate value to indicate the state
+ of the key (0 indicates the key is usable).
+
+ If intr is true, then the wait can be interrupted by a signal, in which
+ case error ERESTARTSYS will be returned.
+
+
(*) When it is no longer required, the key should be released using:
void key_put(struct key *key);
A kernel service may want to define its own key type. For instance, an AFS
filesystem might want to define a Kerberos 5 ticket key type. To do this, it
-author fills in a struct key_type and registers it with the system.
+author fills in a key_type struct and registers it with the system.
+
+Source files that implement key types should include the following header file:
+
+ <linux/key-type.h>
The structure has a number of fields, some of which are mandatory:
as might happen when the userspace buffer is accessed.
- (*) int (*request_key)(struct key *key, struct key *authkey, const char *op,
+ (*) int (*request_key)(struct key_construction *cons, const char *op,
void *aux);
- This method is optional. If provided, request_key() and
- request_key_with_auxdata() will invoke this function rather than
- upcalling to /sbin/request-key to operate upon a key of this type.
+ This method is optional. If provided, request_key() and friends will
+ invoke this function rather than upcalling to /sbin/request-key to operate
+ upon a key of this type.
+
+ The aux parameter is as passed to request_key_async_with_auxdata() and
+ similar or is NULL otherwise. Also passed are the construction record for
+ the key to be operated upon and the operation type (currently only
+ "create").
+
+ This method is permitted to return before the upcall is complete, but the
+ following function must be called under all circumstances to complete the
+ instantiation process, whether or not it succeeds, whether or not there's
+ an error:
+
+ void complete_request_key(struct key_construction *cons, int error);
+
+ The error parameter should be 0 on success, -ve on error. The
+ construction record is destroyed by this action and the authorisation key
+ will be revoked. If an error is indicated, the key under construction
+ will be negatively instantiated if it wasn't already instantiated.
+
+ If this method returns an error, that error will be returned to the
+ caller of request_key*(). complete_request_key() must be called prior to
+ returning.
+
+ The key under construction and the authorisation key can be found in the
+ key_construction struct pointed to by cons:
+
+ (*) struct key *key;
+
+ The key under construction.
- The aux parameter is as passed to request_key_with_auxdata() or is NULL
- otherwise. Also passed are the key to be operated upon, the
- authorisation key for this operation and the operation type (currently
- only "create").
+ (*) struct key *authkey;
- This function should return only when the upcall is complete. Upon return
- the authorisation key will be revoked, and the target key will be
- negatively instantiated if it is still uninstantiated. The error will be
- returned to the caller of request_key*().
+ The authorisation key.
============================
This is used to extract the error number from a message indicating either
a local error occurred or a network error occurred.
+
+ (*) Allocate a null key for doing anonymous security.
+
+ struct key *rxrpc_get_null_key(const char *keyname);
+
+ This is used to allocate a null RxRPC key that can be used to indicate
+ anonymous security for a particular domain.
static struct afs_cell *afs_cell_alloc(const char *name, char *vllist)
{
struct afs_cell *cell;
+ struct key *key;
size_t namelen;
char keyname[4 + AFS_MAXCELLNAME + 1], *cp, *dp, *next;
int ret;
do {
*dp++ = toupper(*cp);
} while (*cp++);
- cell->anonymous_key = key_alloc(&key_type_rxrpc, keyname, 0, 0, current,
- KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA);
- if (IS_ERR(cell->anonymous_key)) {
- _debug("no key");
- ret = PTR_ERR(cell->anonymous_key);
- goto error;
- }
- ret = key_instantiate_and_link(cell->anonymous_key, NULL, 0,
- NULL, NULL);
- if (ret < 0) {
- _debug("instantiate failed");
+ key = rxrpc_get_null_key(keyname);
+ if (IS_ERR(key)) {
+ _debug("no key");
+ ret = PTR_ERR(key);
goto error;
}
+ cell->anonymous_key = key;
_debug("anon key %p{%x}",
cell->anonymous_key, key_serial(cell->anonymous_key));
*/
extern struct key_type key_type_rxrpc;
+extern struct key *rxrpc_get_null_key(const char *);
+
#endif /* _KEYS_USER_TYPE_H */
--- /dev/null
+/* Definitions for key type implementations
+ *
+ * Copyright (C) 2007 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 Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_KEY_TYPE_H
+#define _LINUX_KEY_TYPE_H
+
+#include <linux/key.h>
+
+#ifdef CONFIG_KEYS
+
+/*
+ * key under-construction record
+ * - passed to the request_key actor if supplied
+ */
+struct key_construction {
+ struct key *key; /* key being constructed */
+ struct key *authkey;/* authorisation for key being constructed */
+};
+
+typedef int (*request_key_actor_t)(struct key_construction *key,
+ const char *op, void *aux);
+
+/*
+ * kernel managed key type definition
+ */
+struct key_type {
+ /* name of the type */
+ const char *name;
+
+ /* default payload length for quota precalculation (optional)
+ * - this can be used instead of calling key_payload_reserve(), that
+ * function only needs to be called if the real datalen is different
+ */
+ size_t def_datalen;
+
+ /* instantiate a key of this type
+ * - this method should call key_payload_reserve() to determine if the
+ * user's quota will hold the payload
+ */
+ int (*instantiate)(struct key *key, const void *data, size_t datalen);
+
+ /* update a key of this type (optional)
+ * - this method should call key_payload_reserve() to recalculate the
+ * quota consumption
+ * - the key must be locked against read when modifying
+ */
+ int (*update)(struct key *key, const void *data, size_t datalen);
+
+ /* match a key against a description */
+ int (*match)(const struct key *key, const void *desc);
+
+ /* clear some of the data from a key on revokation (optional)
+ * - the key's semaphore will be write-locked by the caller
+ */
+ void (*revoke)(struct key *key);
+
+ /* clear the data from a key (optional) */
+ void (*destroy)(struct key *key);
+
+ /* describe a key */
+ void (*describe)(const struct key *key, struct seq_file *p);
+
+ /* read a key's data (optional)
+ * - permission checks will be done by the caller
+ * - the key's semaphore will be readlocked by the caller
+ * - should return the amount of data that could be read, no matter how
+ * much is copied into the buffer
+ * - shouldn't do the copy if the buffer is NULL
+ */
+ long (*read)(const struct key *key, char __user *buffer, size_t buflen);
+
+ /* handle request_key() for this type instead of invoking
+ * /sbin/request-key (optional)
+ * - key is the key to instantiate
+ * - authkey is the authority to assume when instantiating this key
+ * - op is the operation to be done, usually "create"
+ * - the call must not return until the instantiation process has run
+ * its course
+ */
+ request_key_actor_t request_key;
+
+ /* internal fields */
+ struct list_head link; /* link in types list */
+};
+
+extern struct key_type key_type_keyring;
+
+extern int register_key_type(struct key_type *ktype);
+extern void unregister_key_type(struct key_type *ktype);
+
+extern int key_payload_reserve(struct key *key, size_t datalen);
+extern int key_instantiate_and_link(struct key *key,
+ const void *data,
+ size_t datalen,
+ struct key *keyring,
+ struct key *instkey);
+extern int key_negate_and_link(struct key *key,
+ unsigned timeout,
+ struct key *keyring,
+ struct key *instkey);
+extern void complete_request_key(struct key_construction *cons, int error);
+
+#endif /* CONFIG_KEYS */
+#endif /* _LINUX_KEY_TYPE_H */
-/* key.h: authentication token and access key management
+/* Authentication token and access key management
*
- * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004, 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
} payload;
};
-/*****************************************************************************/
-/*
- * kernel managed key type definition
- */
-typedef int (*request_key_actor_t)(struct key *key, struct key *authkey,
- const char *op, void *aux);
-
-struct key_type {
- /* name of the type */
- const char *name;
-
- /* default payload length for quota precalculation (optional)
- * - this can be used instead of calling key_payload_reserve(), that
- * function only needs to be called if the real datalen is different
- */
- size_t def_datalen;
-
- /* instantiate a key of this type
- * - this method should call key_payload_reserve() to determine if the
- * user's quota will hold the payload
- */
- int (*instantiate)(struct key *key, const void *data, size_t datalen);
-
- /* update a key of this type (optional)
- * - this method should call key_payload_reserve() to recalculate the
- * quota consumption
- * - the key must be locked against read when modifying
- */
- int (*update)(struct key *key, const void *data, size_t datalen);
-
- /* match a key against a description */
- int (*match)(const struct key *key, const void *desc);
-
- /* clear some of the data from a key on revokation (optional)
- * - the key's semaphore will be write-locked by the caller
- */
- void (*revoke)(struct key *key);
-
- /* clear the data from a key (optional) */
- void (*destroy)(struct key *key);
-
- /* describe a key */
- void (*describe)(const struct key *key, struct seq_file *p);
-
- /* read a key's data (optional)
- * - permission checks will be done by the caller
- * - the key's semaphore will be readlocked by the caller
- * - should return the amount of data that could be read, no matter how
- * much is copied into the buffer
- * - shouldn't do the copy if the buffer is NULL
- */
- long (*read)(const struct key *key, char __user *buffer, size_t buflen);
-
- /* handle request_key() for this type instead of invoking
- * /sbin/request-key (optional)
- * - key is the key to instantiate
- * - authkey is the authority to assume when instantiating this key
- * - op is the operation to be done, usually "create"
- * - the call must not return until the instantiation process has run
- * its course
- */
- request_key_actor_t request_key;
-
- /* internal fields */
- struct list_head link; /* link in types list */
-};
-
-extern struct key_type key_type_keyring;
-
-extern int register_key_type(struct key_type *ktype);
-extern void unregister_key_type(struct key_type *ktype);
-
extern struct key *key_alloc(struct key_type *type,
const char *desc,
uid_t uid, gid_t gid,
#define KEY_ALLOC_QUOTA_OVERRUN 0x0001 /* add to quota, permit even if overrun */
#define KEY_ALLOC_NOT_IN_QUOTA 0x0002 /* not in quota */
-extern int key_payload_reserve(struct key *key, size_t datalen);
-extern int key_instantiate_and_link(struct key *key,
- const void *data,
- size_t datalen,
- struct key *keyring,
- struct key *instkey);
-extern int key_negate_and_link(struct key *key,
- unsigned timeout,
- struct key *keyring,
- struct key *instkey);
extern void key_revoke(struct key *key);
extern void key_put(struct key *key);
const char *callout_info,
void *aux);
+extern struct key *request_key_async(struct key_type *type,
+ const char *description,
+ const char *callout_info);
+
+extern struct key *request_key_async_with_auxdata(struct key_type *type,
+ const char *description,
+ const char *callout_info,
+ void *aux);
+
+extern int wait_for_key_construction(struct key *key, bool intr);
+
extern int key_validate(struct key *key);
extern key_ref_t key_create_or_update(key_ref_t keyring,
extern struct key *key_lookup(key_serial_t id);
-extern void keyring_replace_payload(struct key *key, void *replacement);
-
#define key_serial(key) ((key) ? (key)->serial : 0)
/*
#include <linux/skbuff.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
+#include <linux/key-type.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/skbuff.h>
-#include <linux/key.h>
+#include <linux/key-type.h>
#include <linux/crypto.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
.destroy = rxrpc_destroy,
.describe = rxrpc_describe,
};
-
EXPORT_SYMBOL(key_type_rxrpc);
/*
_leave(" = -ENOMEM [ins %d]", ret);
return -ENOMEM;
}
-
EXPORT_SYMBOL(rxrpc_get_server_data_key);
+
+/**
+ * rxrpc_get_null_key - Generate a null RxRPC key
+ * @keyname: The name to give the key.
+ *
+ * Generate a null RxRPC key that can be used to indicate anonymous security is
+ * required for a particular domain.
+ */
+struct key *rxrpc_get_null_key(const char *keyname)
+{
+ struct key *key;
+ int ret;
+
+ key = key_alloc(&key_type_rxrpc, keyname, 0, 0, current,
+ KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA);
+ if (IS_ERR(key))
+ return key;
+
+ ret = key_instantiate_and_link(key, NULL, 0, NULL, NULL);
+ if (ret < 0) {
+ key_revoke(key);
+ key_put(key);
+ return ERR_PTR(ret);
+ }
+
+ return key;
+}
+EXPORT_SYMBOL(rxrpc_get_null_key);
/* internal.h: authentication token and access key management internal defs
*
- * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2003-5, 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
#ifndef _INTERNAL_H
#define _INTERNAL_H
-#include <linux/key.h>
+#include <linux/key-type.h>
#include <linux/key-ui.h>
-#if 0
-#define kenter(FMT, a...) printk("==> %s("FMT")\n",__FUNCTION__ , ## a)
-#define kleave(FMT, a...) printk("<== %s()"FMT"\n",__FUNCTION__ , ## a)
-#define kdebug(FMT, a...) printk(FMT"\n" , ## a)
+static inline __attribute__((format(printf, 1, 2)))
+void no_printk(const char *fmt, ...)
+{
+}
+
+#ifdef __KDEBUG
+#define kenter(FMT, ...) \
+ printk(KERN_DEBUG "==> %s("FMT")\n", __FUNCTION__, ##__VA_ARGS__)
+#define kleave(FMT, ...) \
+ printk(KERN_DEBUG "<== %s()"FMT"\n", __FUNCTION__, ##__VA_ARGS__)
+#define kdebug(FMT, ...) \
+ printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__)
#else
-#define kenter(FMT, a...) do {} while(0)
-#define kleave(FMT, a...) do {} while(0)
-#define kdebug(FMT, a...) do {} while(0)
+#define kenter(FMT, ...) \
+ no_printk(KERN_DEBUG "==> %s("FMT")\n", __FUNCTION__, ##__VA_ARGS__)
+#define kleave(FMT, ...) \
+ no_printk(KERN_DEBUG "<== %s()"FMT"\n", __FUNCTION__, ##__VA_ARGS__)
+#define kdebug(FMT, ...) \
+ no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
#endif
extern struct key_type key_type_user;
*/
struct key_user {
struct rb_node node;
- struct list_head consq; /* construction queue */
+ struct mutex cons_lock; /* construction initiation lock */
spinlock_t lock;
atomic_t usage; /* for accessing qnkeys & qnbytes */
atomic_t nkeys; /* number of keys */
extern struct rb_root key_serial_tree;
extern spinlock_t key_serial_lock;
extern struct semaphore key_alloc_sem;
-extern struct rw_semaphore key_construction_sem;
+extern struct mutex key_construction_mutex;
extern wait_queue_head_t request_key_conswq;
struct request_key_auth {
struct key *target_key;
struct task_struct *context;
- const char *callout_info;
+ char *callout_info;
pid_t pid;
};
-/* key.c: basic authentication token and access key management
+/* Basic authentication token and access key management
*
- * Copyright (C) 2004-6 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
static DECLARE_WORK(key_cleanup_task, key_cleanup);
/* we serialise key instantiation and link */
-DECLARE_RWSEM(key_construction_sem);
+DEFINE_MUTEX(key_construction_mutex);
/* any key who's type gets unegistered will be re-typed to this */
static struct key_type key_type_dead = {
candidate->qnkeys = 0;
candidate->qnbytes = 0;
spin_lock_init(&candidate->lock);
- INIT_LIST_HEAD(&candidate->consq);
+ mutex_init(&candidate->cons_lock);
rb_link_node(&candidate->node, parent, p);
rb_insert_color(&candidate->node, &key_user_tree);
awaken = 0;
ret = -EBUSY;
- down_write(&key_construction_sem);
+ mutex_lock(&key_construction_mutex);
/* can't instantiate twice */
if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
}
}
- up_write(&key_construction_sem);
+ mutex_unlock(&key_construction_mutex);
/* wake up anyone waiting for a key to be constructed */
if (awaken)
- wake_up_all(&request_key_conswq);
+ wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);
return ret;
if (keyring)
down_write(&keyring->sem);
- down_write(&key_construction_sem);
+ mutex_lock(&key_construction_mutex);
/* can't instantiate twice */
if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
key_revoke(instkey);
}
- up_write(&key_construction_sem);
+ mutex_unlock(&key_construction_mutex);
if (keyring)
up_write(&keyring->sem);
/* wake up anyone waiting for a key to be constructed */
if (awaken)
- wake_up_all(&request_key_conswq);
+ wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);
return ret;
{
key_check(key);
- /* make sure no one's trying to change or use the key when we mark
- * it */
- down_write(&key->sem);
- set_bit(KEY_FLAG_REVOKED, &key->flags);
-
- if (key->type->revoke)
+ /* make sure no one's trying to change or use the key when we mark it
+ * - we tell lockdep that we might nest because we might be revoking an
+ * authorisation key whilst holding the sem on a key we've just
+ * instantiated
+ */
+ down_write_nested(&key->sem, 1);
+ if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags) &&
+ key->type->revoke)
key->type->revoke(key);
up_write(&key->sem);
/* the root user's tracking struct */
struct key_user root_key_user = {
.usage = ATOMIC_INIT(3),
- .consq = LIST_HEAD_INIT(root_key_user.consq),
+ .cons_lock = __MUTEX_INITIALIZER(root_key_user.cons_lock),
.lock = __SPIN_LOCK_UNLOCKED(root_key_user.lock),
.nkeys = ATOMIC_INIT(2),
.nikeys = ATOMIC_INIT(2),
break;
}
- /* check the status */
- if (perm) {
+ if (!partial) {
+ ret = wait_for_key_construction(key, true);
+ switch (ret) {
+ case -ERESTARTSYS:
+ goto invalid_key;
+ default:
+ if (perm)
+ goto invalid_key;
+ case 0:
+ break;
+ }
+ } else if (perm) {
ret = key_validate(key);
if (ret < 0)
goto invalid_key;
-/* request_key.c: request a key from userspace
+/* Request a key from userspace
*
- * Copyright (C) 2004-6 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
#include <linux/keyctl.h>
#include "internal.h"
-struct key_construction {
- struct list_head link; /* link in construction queue */
- struct key *key; /* key being constructed */
-};
+/*
+ * wait_on_bit() sleep function for uninterruptible waiting
+ */
+static int key_wait_bit(void *flags)
+{
+ schedule();
+ return 0;
+}
+
+/*
+ * wait_on_bit() sleep function for interruptible waiting
+ */
+static int key_wait_bit_intr(void *flags)
+{
+ schedule();
+ return signal_pending(current) ? -ERESTARTSYS : 0;
+}
+
+/*
+ * call to complete the construction of a key
+ */
+void complete_request_key(struct key_construction *cons, int error)
+{
+ kenter("{%d,%d},%d", cons->key->serial, cons->authkey->serial, error);
-/* when waiting for someone else's keys, you get added to this */
-DECLARE_WAIT_QUEUE_HEAD(request_key_conswq);
+ if (error < 0)
+ key_negate_and_link(cons->key, key_negative_timeout, NULL,
+ cons->authkey);
+ else
+ key_revoke(cons->authkey);
+
+ key_put(cons->key);
+ key_put(cons->authkey);
+ kfree(cons);
+}
+EXPORT_SYMBOL(complete_request_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 *key,
- struct key *authkey,
+static int call_sbin_request_key(struct key_construction *cons,
const char *op,
void *aux)
{
struct task_struct *tsk = current;
key_serial_t prkey, sskey;
- struct key *keyring;
+ struct key *key = cons->key, *authkey = cons->authkey, *keyring;
char *argv[9], *envp[3], uid_str[12], gid_str[12];
char key_str[12], keyring_str[3][12];
char desc[20];
rcu_read_lock();
sskey = rcu_dereference(tsk->signal->session_keyring)->serial;
rcu_read_unlock();
- }
- else {
+ } else {
sskey = tsk->user->session_keyring->serial;
}
/* do it */
ret = call_usermodehelper_keys(argv[0], argv, envp, keyring,
UMH_WAIT_PROC);
+ kdebug("usermode -> 0x%x", ret);
+ if (ret >= 0) {
+ /* ret is the exit/wait code */
+ if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) ||
+ key_validate(key) < 0)
+ ret = -ENOKEY;
+ else
+ /* ignore any errors from userspace if the key was
+ * instantiated */
+ ret = 0;
+ }
error_link:
key_put(keyring);
error_alloc:
kleave(" = %d", ret);
+ complete_request_key(cons, ret);
return ret;
+}
-} /* end call_sbin_request_key() */
-
-/*****************************************************************************/
/*
- * call out to userspace for the key
- * - called with the construction sem held, but the sem is dropped here
+ * call out to userspace for key construction
* - we ignore program failure and go on key status instead
*/
-static struct key *__request_key_construction(struct key_type *type,
- const char *description,
- const char *callout_info,
- void *aux,
- unsigned long flags)
+static int construct_key(struct key *key, const char *callout_info, void *aux)
{
+ struct key_construction *cons;
request_key_actor_t actor;
- struct key_construction cons;
- struct timespec now;
- struct key *key, *authkey;
- int ret, negated;
+ struct key *authkey;
+ int ret;
- kenter("%s,%s,%s,%lx", type->name, description, callout_info, flags);
+ kenter("%d,%s,%p", key->serial, callout_info, aux);
- /* create a key and add it to the queue */
- key = key_alloc(type, description,
- current->fsuid, current->fsgid, current, KEY_POS_ALL,
- flags);
- if (IS_ERR(key))
- goto alloc_failed;
-
- set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
-
- cons.key = key;
- list_add_tail(&cons.link, &key->user->consq);
-
- /* we drop the construction sem here on behalf of the caller */
- up_write(&key_construction_sem);
+ cons = kmalloc(sizeof(*cons), GFP_KERNEL);
+ if (!cons)
+ return -ENOMEM;
/* allocate an authorisation key */
authkey = request_key_auth_new(key, callout_info);
if (IS_ERR(authkey)) {
+ kfree(cons);
ret = PTR_ERR(authkey);
authkey = NULL;
- goto alloc_authkey_failed;
- }
-
- /* make the call */
- actor = call_sbin_request_key;
- if (type->request_key)
- actor = type->request_key;
- ret = actor(key, authkey, "create", aux);
- if (ret < 0)
- goto request_failed;
-
- /* if the key wasn't instantiated, then we want to give an error */
- ret = -ENOKEY;
- if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
- goto request_failed;
-
- key_revoke(authkey);
- key_put(authkey);
-
- down_write(&key_construction_sem);
- list_del(&cons.link);
- up_write(&key_construction_sem);
-
- /* also give an error if the key was negatively instantiated */
-check_not_negative:
- if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) {
- key_put(key);
- key = ERR_PTR(-ENOKEY);
- }
-
-out:
- kleave(" = %p", key);
- return key;
-
-request_failed:
- key_revoke(authkey);
- key_put(authkey);
-
-alloc_authkey_failed:
- /* it wasn't instantiated
- * - remove from construction queue
- * - mark the key as dead
- */
- negated = 0;
- down_write(&key_construction_sem);
-
- list_del(&cons.link);
-
- /* check it didn't get instantiated between the check and the down */
- if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
- set_bit(KEY_FLAG_NEGATIVE, &key->flags);
- set_bit(KEY_FLAG_INSTANTIATED, &key->flags);
- negated = 1;
- }
-
- clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
-
- up_write(&key_construction_sem);
-
- if (!negated)
- goto check_not_negative; /* surprisingly, the key got
- * instantiated */
-
- /* set the timeout and store in the session keyring if we can */
- now = current_kernel_time();
- key->expiry = now.tv_sec + key_negative_timeout;
-
- if (current->signal->session_keyring) {
- struct key *keyring;
-
- rcu_read_lock();
- keyring = rcu_dereference(current->signal->session_keyring);
- atomic_inc(&keyring->usage);
- rcu_read_unlock();
-
- key_link(keyring, key);
- key_put(keyring);
- }
-
- key_put(key);
-
- /* notify anyone who was waiting */
- wake_up_all(&request_key_conswq);
-
- key = ERR_PTR(ret);
- goto out;
-
-alloc_failed:
- up_write(&key_construction_sem);
- goto out;
-
-} /* end __request_key_construction() */
-
-/*****************************************************************************/
-/*
- * call out to userspace to request the key
- * - we check the construction queue first to see if an appropriate key is
- * already being constructed by userspace
- */
-static struct key *request_key_construction(struct key_type *type,
- const char *description,
- const char *callout_info,
- void *aux,
- struct key_user *user,
- unsigned long flags)
-{
- struct key_construction *pcons;
- struct key *key, *ckey;
-
- DECLARE_WAITQUEUE(myself, current);
-
- kenter("%s,%s,{%d},%s,%lx",
- type->name, description, user->uid, callout_info, flags);
-
- /* see if there's such a key under construction already */
- down_write(&key_construction_sem);
-
- list_for_each_entry(pcons, &user->consq, link) {
- ckey = pcons->key;
-
- if (ckey->type != type)
- continue;
-
- if (type->match(ckey, description))
- goto found_key_under_construction;
+ } else {
+ cons->authkey = key_get(authkey);
+ cons->key = key_get(key);
+
+ /* make the call */
+ actor = call_sbin_request_key;
+ if (key->type->request_key)
+ actor = key->type->request_key;
+
+ ret = actor(cons, "create", aux);
+
+ /* check that the actor called complete_request_key() prior to
+ * returning an error */
+ WARN_ON(ret < 0 &&
+ !test_bit(KEY_FLAG_REVOKED, &authkey->flags));
+ key_put(authkey);
}
- /* see about getting userspace to construct the key */
- key = __request_key_construction(type, description, callout_info, aux,
- flags);
- error:
- kleave(" = %p", key);
- return key;
-
- /* someone else has the same key under construction
- * - we want to keep an eye on their key
- */
- found_key_under_construction:
- atomic_inc(&ckey->usage);
- up_write(&key_construction_sem);
-
- /* wait for the key to be completed one way or another */
- add_wait_queue(&request_key_conswq, &myself);
-
- for (;;) {
- set_current_state(TASK_INTERRUPTIBLE);
- if (!test_bit(KEY_FLAG_USER_CONSTRUCT, &ckey->flags))
- break;
- if (signal_pending(current))
- break;
- schedule();
- }
-
- set_current_state(TASK_RUNNING);
- remove_wait_queue(&request_key_conswq, &myself);
-
- /* we'll need to search this process's keyrings to see if the key is
- * now there since we can't automatically assume it's also available
- * there */
- key_put(ckey);
- ckey = NULL;
-
- key = NULL; /* request a retry */
- goto error;
-
-} /* end request_key_construction() */
+ kleave(" = %d", ret);
+ return ret;
+}
-/*****************************************************************************/
/*
- * link a freshly minted key to an appropriate destination keyring
+ * link a key to the appropriate destination keyring
+ * - the caller must hold a write lock on the destination keyring
*/
-static void request_key_link(struct key *key, struct key *dest_keyring)
+static void construct_key_make_link(struct key *key, struct key *dest_keyring)
{
struct task_struct *tsk = current;
struct key *drop = NULL;
break;
case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
- dest_keyring = current->user->session_keyring;
+ dest_keyring = tsk->user->session_keyring;
break;
case KEY_REQKEY_DEFL_USER_KEYRING:
- dest_keyring = current->user->uid_keyring;
+ dest_keyring = tsk->user->uid_keyring;
break;
case KEY_REQKEY_DEFL_GROUP_KEYRING:
}
/* and attach the key to it */
- key_link(dest_keyring, key);
-
+ __key_link(dest_keyring, key);
key_put(drop);
-
kleave("");
+}
-} /* end request_key_link() */
+/*
+ * 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
+ */
+static int construct_alloc_key(struct key_type *type,
+ const char *description,
+ struct key *dest_keyring,
+ unsigned long flags,
+ struct key_user *user,
+ struct key **_key)
+{
+ struct key *key;
+ key_ref_t key_ref;
+
+ kenter("%s,%s,,,", type->name, description);
+
+ mutex_lock(&user->cons_lock);
+
+ key = key_alloc(type, description,
+ current->fsuid, current->fsgid, current, KEY_POS_ALL,
+ flags);
+ if (IS_ERR(key))
+ goto alloc_failed;
+
+ set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
+
+ if (dest_keyring)
+ down_write(&dest_keyring->sem);
+
+ /* attach the key to the destination keyring under lock, but we do need
+ * to do another check just in case someone beat us to it whilst we
+ * waited for locks */
+ mutex_lock(&key_construction_mutex);
+
+ key_ref = search_process_keyrings(type, description, type->match,
+ current);
+ if (!IS_ERR(key_ref))
+ goto key_already_present;
+
+ if (dest_keyring)
+ construct_key_make_link(key, dest_keyring);
+
+ mutex_unlock(&key_construction_mutex);
+ if (dest_keyring)
+ up_write(&dest_keyring->sem);
+ mutex_unlock(&user->cons_lock);
+ *_key = key;
+ kleave(" = 0 [%d]", key_serial(key));
+ return 0;
+
+key_already_present:
+ mutex_unlock(&key_construction_mutex);
+ if (dest_keyring)
+ up_write(&dest_keyring->sem);
+ mutex_unlock(&user->cons_lock);
+ key_put(key);
+ *_key = key = key_ref_to_ptr(key_ref);
+ kleave(" = -EINPROGRESS [%d]", key_serial(key));
+ return -EINPROGRESS;
+
+alloc_failed:
+ mutex_unlock(&user->cons_lock);
+ *_key = NULL;
+ kleave(" = %ld", PTR_ERR(key));
+ return PTR_ERR(key);
+}
+
+/*
+ * commence key construction
+ */
+static struct key *construct_key_and_link(struct key_type *type,
+ const char *description,
+ const char *callout_info,
+ void *aux,
+ struct key *dest_keyring,
+ unsigned long flags)
+{
+ struct key_user *user;
+ struct key *key;
+ int ret;
+
+ user = key_user_lookup(current->fsuid);
+ if (!user)
+ return ERR_PTR(-ENOMEM);
+
+ ret = construct_alloc_key(type, description, dest_keyring, flags, user,
+ &key);
+ key_user_put(user);
+
+ if (ret == 0) {
+ ret = construct_key(key, callout_info, aux);
+ if (ret < 0)
+ goto construction_failed;
+ }
+
+ return key;
+
+construction_failed:
+ key_negate_and_link(key, key_negative_timeout, NULL, NULL);
+ key_put(key);
+ return ERR_PTR(ret);
+}
-/*****************************************************************************/
/*
* request a key
* - search the process's keyrings
struct key *dest_keyring,
unsigned long flags)
{
- struct key_user *user;
struct key *key;
key_ref_t key_ref;
key_ref = search_process_keyrings(type, description, type->match,
current);
- kdebug("search 1: %p", key_ref);
-
if (!IS_ERR(key_ref)) {
key = key_ref_to_ptr(key_ref);
- }
- else if (PTR_ERR(key_ref) != -EAGAIN) {
+ } else if (PTR_ERR(key_ref) != -EAGAIN) {
key = ERR_PTR(PTR_ERR(key_ref));
- }
- else {
+ } else {
/* the search failed, but the keyrings were searchable, so we
* should consult userspace if we can */
key = ERR_PTR(-ENOKEY);
if (!callout_info)
goto error;
- /* - get hold of the user's construction queue */
- user = key_user_lookup(current->fsuid);
- if (!user)
- goto nomem;
-
- for (;;) {
- if (signal_pending(current))
- goto interrupted;
-
- /* ask userspace (returns NULL if it waited on a key
- * being constructed) */
- key = request_key_construction(type, description,
- callout_info, aux,
- user, flags);
- if (key)
- break;
-
- /* someone else made the key we want, so we need to
- * search again as it might now be available to us */
- key_ref = search_process_keyrings(type, description,
- type->match,
- current);
-
- kdebug("search 2: %p", key_ref);
-
- if (!IS_ERR(key_ref)) {
- key = key_ref_to_ptr(key_ref);
- break;
- }
-
- if (PTR_ERR(key_ref) != -EAGAIN) {
- key = ERR_PTR(PTR_ERR(key_ref));
- break;
- }
- }
-
- key_user_put(user);
-
- /* link the new key into the appropriate keyring */
- if (!IS_ERR(key))
- request_key_link(key, dest_keyring);
+ key = construct_key_and_link(type, description, callout_info,
+ aux, dest_keyring, flags);
}
error:
kleave(" = %p", key);
return key;
+}
-nomem:
- key = ERR_PTR(-ENOMEM);
- goto error;
-
-interrupted:
- key_user_put(user);
- key = ERR_PTR(-EINTR);
- goto error;
+/*
+ * wait for construction of a key to complete
+ */
+int wait_for_key_construction(struct key *key, bool intr)
+{
+ int ret;
-} /* end request_key_and_link() */
+ ret = wait_on_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT,
+ intr ? key_wait_bit_intr : key_wait_bit,
+ intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
+ if (ret < 0)
+ return ret;
+ 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
*/
struct key *request_key(struct key_type *type,
const char *description,
const char *callout_info)
{
- return request_key_and_link(type, description, callout_info, NULL,
- NULL, KEY_ALLOC_IN_QUOTA);
-
-} /* end request_key() */
-
+ struct key *key;
+ int ret;
+
+ key = request_key_and_link(type, description, callout_info, NULL,
+ NULL, KEY_ALLOC_IN_QUOTA);
+ if (!IS_ERR(key)) {
+ ret = wait_for_key_construction(key, false);
+ if (ret < 0) {
+ key_put(key);
+ return ERR_PTR(ret);
+ }
+ }
+ return key;
+}
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
*/
struct key *request_key_with_auxdata(struct key_type *type,
const char *description,
const char *callout_info,
void *aux)
{
- return request_key_and_link(type, description, callout_info, aux,
- NULL, KEY_ALLOC_IN_QUOTA);
+ struct key *key;
+ int ret;
+
+ key = request_key_and_link(type, description, callout_info, aux,
+ NULL, KEY_ALLOC_IN_QUOTA);
+ if (!IS_ERR(key)) {
+ ret = wait_for_key_construction(key, false);
+ if (ret < 0) {
+ key_put(key);
+ return ERR_PTR(ret);
+ }
+ }
+ return key;
+}
+EXPORT_SYMBOL(request_key_with_auxdata);
-} /* end 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
+ */
+struct key *request_key_async(struct key_type *type,
+ const char *description,
+ const char *callout_info)
+{
+ return request_key_and_link(type, description, callout_info, NULL,
+ NULL, KEY_ALLOC_IN_QUOTA);
+}
+EXPORT_SYMBOL(request_key_async);
-EXPORT_SYMBOL(request_key_with_auxdata);
+/*
+ * 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
+ */
+struct key *request_key_async_with_auxdata(struct key_type *type,
+ const char *description,
+ const char *callout_info,
+ void *aux)
+{
+ return request_key_and_link(type, description, callout_info, aux,
+ NULL, KEY_ALLOC_IN_QUOTA);
+}
+EXPORT_SYMBOL(request_key_async_with_auxdata);
}
key_put(rka->target_key);
+ kfree(rka->callout_info);
kfree(rka);
} /* end request_key_auth_destroy() */
kleave(" = -ENOMEM");
return ERR_PTR(-ENOMEM);
}
+ rka->callout_info = kmalloc(strlen(callout_info) + 1, GFP_KERNEL);
+ if (!rka->callout_info) {
+ kleave(" = -ENOMEM");
+ kfree(rka);
+ return ERR_PTR(-ENOMEM);
+ }
/* see if the calling process is already servicing the key request of
* another process */
}
rka->target_key = key_get(target);
- rka->callout_info = callout_info;
+ strcpy(rka->callout_info, callout_info);
/* allocate the auth key */
sprintf(desc, "%x", target->serial);
auth_key_revoked:
up_read(¤t->request_key_auth->sem);
+ kfree(rka->callout_info);
kfree(rka);
kleave("= -EKEYREVOKED");
return ERR_PTR(-EKEYREVOKED);
key_put(authkey);
error_alloc:
key_put(rka->target_key);
+ kfree(rka->callout_info);
kfree(rka);
kleave("= %d", ret);
return ERR_PTR(ret);
projects / users / hch / xfs.git / commitdiff