text: /*	$OpenBSD: uvm_swap_encrypt.h,v 1.9 2009/03/23 22:10:04 oga Exp $	*/
  
  /*
   * Copyright 1999 Niels Provos <provos@citi.umich.edu>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *      This product includes software developed by Niels Provos.
   * 4. The name of the author may not be used to endorse or promote products
   *    derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #ifndef _UVM_SWAP_ENCRYPT_H
  #define _UVM_SWAP_ENCRYPT_H
  
  #define SWPENC_ENABLE	0
  #define SWPENC_CREATED	1
  #define SWPENC_DELETED	2
  #define SWPENC_MAXID	3
  
  #define CTL_SWPENC_NAMES { \
  	{ "enable", CTLTYPE_INT }, \
  	{ "keyscreated", CTLTYPE_INT }, \
  	{ "keysdeleted", CTLTYPE_INT }, \
  }
  
  #define SWAP_KEY_EXPIRE (120 /*60 * 60*/)	/* time after that keys expire */
  #define SWAP_KEY_SIZE	4		/* 128-bit keys */
  
  struct swap_key {
  	u_int32_t key[SWAP_KEY_SIZE];	/* secret key for swap range */
  	u_int16_t refcount;		/* pages that still need it */
  };
  
  int swap_encrypt_ctl(int *, u_int, void *, size_t *, void *, size_t,
  			  struct proc *);
  
  void swap_encrypt(struct swap_key *,caddr_t, caddr_t, u_int64_t, size_t);
  void swap_decrypt(struct swap_key *,caddr_t, caddr_t, u_int64_t, size_t);
  
  void swap_key_cleanup(struct swap_key *);
  void swap_key_prepare(struct swap_key *, int);
  
  extern u_int uvm_swpkeyscreated;
  
  #define SWAP_KEY_GET(s,x)	do {					\
  					if ((x)->refcount == 0) {	\
  						arc4random_buf((x)->key,\
  						    sizeof((x)->key));	\
  						uvm_swpkeyscreated++;	\
  					}				\
  					(x)->refcount++;		\
  				} while(0);
  
  #define SWAP_KEY_PUT(s,x)	do {					\
  					(x)->refcount--;		\
  					if ((x)->refcount == 0) {	\
  						swap_key_delete(x);	\
  					}				\
  				} while(0);
  
  void swap_key_delete(struct swap_key *);
  
  extern int uvm_doswapencrypt;		/* swapencrypt enabled/disabled */
  extern int uvm_swprekeyprint;
  extern u_int uvm_swpkeyexpire;		/* expiry time for keys (tR) */
  extern int swap_encrypt_initialized;
  
  #endif /* _UVM_SWAP_ENCRYPT_H */
  