text: /*
   * Copyright (c) 2004 The DragonFly Project.  All rights reserved.
   * 
   * This code is derived from software contributed to The DragonFly Project
   * by Matthew Dillon <dillon@backplane.com>
   * 
   * 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. Neither the name of The DragonFly Project nor the names of its
   *    contributors may be used to endorse or promote products derived
   *    from this software without specific, prior written permission.
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * ``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
   * COPYRIGHT HOLDERS OR CONTRIBUTORS 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.
   *
   * $DragonFly: src/sys/sys/nlookup.h,v 1.6 2008/05/09 17:52:18 dillon Exp $
   */
  
  #ifndef _SYS_NLOOKUP_H_
  #define	_SYS_NLOOKUP_H_
  
  #ifndef _SYS_UIO_H_
  #include <sys/uio.h>
  #endif
  #ifndef _SYS_NAMECACHE_H_
  #include <sys/namecache.h>
  #endif
  #ifndef _SYS_FILE_H_
  #include <sys/file.h>
  #endif
  
  struct vnode;
  struct vattr;
  struct mount;
  struct thread;
  struct ucred;
  
  /*
   * nlookup component
   */
  struct nlcomponent {
  	char 		*nlc_nameptr;
  	int		nlc_namelen;
  };
  
  /*
   * Encapsulation of nlookup parameters.
   *
   * Note on nl_flags and nl_op: nl_flags supports a simplified subset of 
   * namei's original CNP flags.  nl_op (e.g. NAMEI_*) does no in any way
   * effect the state of the returned namecache and is only used to enforce
   * access checks.
   */
  struct nlookupdata {
  	/*
  	 * These fields are setup by nlookup_init() with nl_nch set to
  	 * the current directory if a process or the root directory if
  	 * a pure thread.  The result from nlookup() will be returned in
  	 * nl_nch.
  	 */
  	struct nchandle nl_nch;		/* start-point and result */
  	struct nchandle nl_rootnch;	/* root directory */
  	struct nchandle nl_jailnch;	/* jail directory */
  
  	char 		*nl_path;	/* path buffer */
  	struct thread	*nl_td;		/* thread requesting the nlookup */
  	struct ucred	*nl_cred;	/* credentials for nlookup */
  	struct vnode	*nl_dvp;	/* NLC_REFDVP */
  
  	int		nl_flags;	/* operations flags */
  	int		nl_loopcnt;	/* symlinks encountered */
  
  	/*
  	 * These fields are populated by vn_open().  nlookup_done() will
  	 * vn_close() a non-NULL vp so if you extract it be sure to NULL out
  	 * nl_open_vp.
  	 */
  	struct  vnode	*nl_open_vp;	
  	int		nl_vp_fmode;
  };
  
  /*
   * NOTE: nlookup() flags related to open checks do not actually perform
   *	 any modifying operation.  e.g. the file isn't created, truncated,
   *	 etc.  vn_open() handles that.
   */
  #define NLC_FOLLOW		0x00000001	/* follow leaf symlink */
  #define NLC_NOCROSSMOUNT	0x00000002	/* do not cross mount points */
  #define NLC_HASBUF		0x00000004	/* nl_path is allocated */
  #define NLC_ISWHITEOUT		0x00000008
  #define NLC_WILLBEDIR		0x00000010
  #define NLC_NCPISLOCKED		0x00000020
  #define NLC_LOCKVP		0x00000040	/* nl_open_vp from vn_open */
  #define NLC_CREATE		0x00000080	/* do create checks */
  #define NLC_DELETE		0x00000100	/* do delete checks */
  #define NLC_RENAME_DST		0x00000200	/* do rename checks (target) */
  #define NLC_OPEN		0x00000400	/* do open checks */
  #define NLC_TRUNCATE		0x00000800	/* do truncation checks */
  #define NLC_HLINK		0x00001000	/* do hardlink checks */
  #define NLC_RENAME_SRC		0x00002000	/* do rename checks (source) */
  #define NLC_SHAREDLOCK		0x00004000	/* allow shared ncp & vp lock */
  #define NLC_UNUSED00008000	0x00008000
  #define NLC_NFS_RDONLY		0x00010000	/* set by nfs_namei() only */
  #define NLC_NFS_NOSOFTLINKTRAV	0x00020000	/* do not traverse softlnks */
  #define NLC_REFDVP		0x00040000	/* set ref'd/unlocked nl_dvp */
  
  #define NLC_APPEND		0x00100000	/* open check: append */
  #define NLC_NCDIR		0x00200000	/* nd->nl_nch is ncdir */
  
  #define NLC_READ		0x00400000	/* require read access */
  #define NLC_WRITE		0x00800000	/* require write access */
  #define NLC_EXEC		0x01000000	/* require execute access */
  #define NLC_EXCL		0x02000000	/* open check: exclusive */
  #define NLC_OWN			0x04000000	/* open check: owner override */
  #define NLC_BORROWCRED		0x08000000	/* cred ref borrowed */
  #define NLC_STICKY		0x10000000	/* indicate sticky case */
  #define NLC_APPENDONLY		0x20000000	/* indicate append-only */
  #define NLC_IMMUTABLE		0x40000000	/* indicate immutable set */
  #define NLC_WRITABLE		0x80000000	/* indicate writeable */
  
  /*
   * All checks.  If any of these bits are set general user/group/world
   * permission checks will be done by nlookup().
   */
  #define NLC_ALLCHKS		(NLC_CREATE | NLC_DELETE | NLC_RENAME_DST | \
  				 NLC_OPEN | NLC_TRUNCATE | NLC_RENAME_SRC | \
  				 NLC_READ | NLC_WRITE | NLC_EXEC | NLC_OWN)
  
  #ifdef _KERNEL
  
  int nlookup_init(struct nlookupdata *, const char *, enum uio_seg, int);
  int nlookup_init_at(struct nlookupdata *, struct file **, int, const char *, 
  		enum uio_seg, int);
  int nlookup_init_raw(struct nlookupdata *, const char *, enum uio_seg, int, struct ucred *, struct nchandle *);
  int nlookup_init_root(struct nlookupdata *, const char *, enum uio_seg, int, struct ucred *, struct nchandle *, struct nchandle *);
  void nlookup_zero(struct nlookupdata *);
  void nlookup_done(struct nlookupdata *);
  void nlookup_done_at(struct nlookupdata *, struct file *);
  struct nchandle nlookup_simple(const char *str, enum uio_seg seg, 
  				int niflags, int *error);
  int nlookup_mp(struct mount *mp, struct nchandle *nch);
  int nlookup(struct nlookupdata *);
  int nreadsymlink(struct nlookupdata *nd, struct nchandle *nch, 
  				struct nlcomponent *nlc);
  int naccess_va(struct vattr *va, int nflags, struct ucred *cred);
  
  #endif
  
  #endif /* !_SYS_NAMEI_H_ */
  