Commit 2aa349f6 authored by David Howells's avatar David Howells Committed by Linus Torvalds
Browse files

[PATCH] Keys: Export user-defined keyring operations 



Export user-defined key operations so that those who wish to define their
own key type based on the user-defined key operations may do so (as has
been requested).

The header file created has been placed into include/keys/user-type.h, thus
creating a directory where other key types may also be placed.  Any
objections to doing this?

Signed-Off-By: default avatarDavid Howells <dhowells@redhat.com>
Signed-Off-By: default avatarArjan van de Ven <arjan@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 1426d7a8

include/keys/user-type.h

0 → 100644
+47 −0
Original line number Diff line number Diff line 
/* user-type.h: User-defined key type

 *

 * Copyright (C) 2005 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.

 */



#ifndef _KEYS_USER_TYPE_H

#define _KEYS_USER_TYPE_H



#include <linux/key.h>

#include <linux/rcupdate.h>



/*****************************************************************************/

/*

 * the payload for a key of type "user"

 * - once filled in and attached to a key:

 *   - the payload struct is invariant may not be changed, only replaced

 *   - the payload must be read with RCU procedures or with the key semaphore

 *     held

 *   - the payload may only be replaced with the key semaphore write-locked

 * - the key's data length is the size of the actual data, not including the

 *   payload wrapper

 */

struct user_key_payload {

	struct rcu_head	rcu;		/* RCU destructor */

	unsigned short	datalen;	/* length of this data */

	char		data[0];	/* actual data */

};



extern struct key_type key_type_user;



extern int user_instantiate(struct key *key, const void *data, size_t datalen);

extern int user_duplicate(struct key *key, const struct key *source);

extern int user_update(struct key *key, const void *data, size_t datalen);

extern int user_match(const struct key *key, const void *criterion);

extern void user_destroy(struct key *key);

extern void user_describe(const struct key *user, struct seq_file *m);

extern long user_read(const struct key *key,

		      char __user *buffer, size_t buflen);





#endif /* _KEYS_USER_TYPE_H */

security/keys/user_defined.c

+24 −25
Original line number Diff line number Diff line
@@ -15,18 +15,10 @@ 
#include <linux/slab.h>

#include <linux/seq_file.h>

#include <linux/err.h>

#include <keys/user-type.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
@@ -42,19 +34,13 @@ struct key_type key_type_user = { 
	.read		= user_read,

};



struct user_key_payload {

	struct rcu_head	rcu;		/* RCU destructor */

	unsigned short	datalen;	/* length of this data */

	char		data[0];	/* actual data */

};



EXPORT_SYMBOL_GPL(key_type_user);



/*****************************************************************************/

/*

 * instantiate a user defined key

 */

static int user_instantiate(struct key *key, const void *data, size_t datalen)

int user_instantiate(struct key *key, const void *data, size_t datalen)

{

	struct user_key_payload *upayload;

	int ret;
@@ -83,13 +69,15 @@ static int user_instantiate(struct key *key, const void *data, size_t datalen) 


} /* end user_instantiate() */



EXPORT_SYMBOL_GPL(user_instantiate);



/*****************************************************************************/

/*

 * duplicate a user defined key

 * - both keys' semaphores are locked against further modification

 * - the new key cannot yet be accessed

 */

static int user_duplicate(struct key *key, const struct key *source)

int user_duplicate(struct key *key, const struct key *source)

{

	struct user_key_payload *upayload, *spayload;

	int ret;
@@ -112,6 +100,8 @@ static int user_duplicate(struct key *key, const struct key *source) 


} /* end user_duplicate() */



EXPORT_SYMBOL_GPL(user_duplicate);



/*****************************************************************************/

/*

 * dispose of the old data from an updated user defined key
@@ -131,7 +121,7 @@ static void user_update_rcu_disposal(struct rcu_head *rcu) 
 * update a user defined key

 * - the key's semaphore is write-locked

 */

static int user_update(struct key *key, const void *data, size_t datalen)

int user_update(struct key *key, const void *data, size_t datalen)

{

	struct user_key_payload *upayload, *zap;

	int ret;
@@ -168,21 +158,25 @@ static int user_update(struct key *key, const void *data, size_t datalen) 


} /* end user_update() */



EXPORT_SYMBOL_GPL(user_update);



/*****************************************************************************/

/*

 * match users on their name

 */

static int user_match(const struct key *key, const void *description)

int user_match(const struct key *key, const void *description)

{

	return strcmp(key->description, description) == 0;



} /* end user_match() */



EXPORT_SYMBOL_GPL(user_match);



/*****************************************************************************/

/*

 * dispose of the data dangling from the corpse of a user

 */

static void user_destroy(struct key *key)

void user_destroy(struct key *key)

{

	struct user_key_payload *upayload = key->payload.data;
@@ -190,11 +184,13 @@ static void user_destroy(struct key *key) 


} /* end user_destroy() */



EXPORT_SYMBOL_GPL(user_destroy);



/*****************************************************************************/

/*

 * describe the user key

 */

static void user_describe(const struct key *key, struct seq_file *m)

void user_describe(const struct key *key, struct seq_file *m)

{

	seq_puts(m, key->description);
@@ -202,13 +198,14 @@ static void user_describe(const struct key *key, struct seq_file *m) 


} /* end user_describe() */



EXPORT_SYMBOL_GPL(user_describe);



/*****************************************************************************/

/*

 * read the key data

 * - the key's semaphore is read-locked

 */

static long user_read(const struct key *key,

		      char __user *buffer, size_t buflen)

long user_read(const struct key *key, char __user *buffer, size_t buflen)

{

	struct user_key_payload *upayload;

	long ret;
@@ -228,3 +225,5 @@ static long user_read(const struct key *key, 
	return ret;



} /* end user_read() */



EXPORT_SYMBOL_GPL(user_read);

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