7cdb0b9d82
When renameat(2) is used with: - absolute path for to; - tofd not set to AT_FDCWD; - the target exists kern_renameat() requires CAP_UNLINK capability on tofd, but corresponding namei ni_filecap is not initialized at all because the lookup is absolute. As result, the check was done against empty filecap and syscall fails erronously. Fix it by creating a return flags namei member and reporting if the lookup was absolute, then do not touch to.ni_filecaps at all. PR: 222258 Reviewed by: jilles, ngie Sponsored by: The FreeBSD Foundation MFC after: 1 week X-MFC-note: KBI breakage Differential revision: https://reviews.freebsd.org/D19096
231 lines
8.8 KiB
C
231 lines
8.8 KiB
C
/*-
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright (c) 1985, 1989, 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)namei.h 8.5 (Berkeley) 1/9/95
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* $FreeBSD$
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*/
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#ifndef _SYS_NAMEI_H_
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#define _SYS_NAMEI_H_
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#include <sys/caprights.h>
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#include <sys/filedesc.h>
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#include <sys/queue.h>
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#include <sys/_uio.h>
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struct componentname {
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/*
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* Arguments to lookup.
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*/
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u_long cn_nameiop; /* namei operation */
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u_int64_t cn_flags; /* flags to namei */
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struct thread *cn_thread;/* thread requesting lookup */
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struct ucred *cn_cred; /* credentials */
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int cn_lkflags; /* Lock flags LK_EXCLUSIVE or LK_SHARED */
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/*
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* Shared between lookup and commit routines.
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*/
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char *cn_pnbuf; /* pathname buffer */
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char *cn_nameptr; /* pointer to looked up name */
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long cn_namelen; /* length of looked up component */
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};
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struct nameicap_tracker;
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TAILQ_HEAD(nameicap_tracker_head, nameicap_tracker);
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/*
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* Encapsulation of namei parameters.
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*/
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struct nameidata {
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/*
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* Arguments to namei/lookup.
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*/
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const char *ni_dirp; /* pathname pointer */
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enum uio_seg ni_segflg; /* location of pathname */
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cap_rights_t ni_rightsneeded; /* rights required to look up vnode */
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/*
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* Arguments to lookup.
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*/
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struct vnode *ni_startdir; /* starting directory */
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struct vnode *ni_rootdir; /* logical root directory */
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struct vnode *ni_topdir; /* logical top directory */
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int ni_dirfd; /* starting directory for *at functions */
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int ni_lcf; /* local call flags */
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/*
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* Results: returned from namei
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*/
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struct filecaps ni_filecaps; /* rights the *at base has */
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/*
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* Results: returned from/manipulated by lookup
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*/
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struct vnode *ni_vp; /* vnode of result */
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struct vnode *ni_dvp; /* vnode of intermediate directory */
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/*
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* Results: flags returned from namei
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*/
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u_int ni_resflags;
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/*
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* Shared between namei and lookup/commit routines.
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*/
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size_t ni_pathlen; /* remaining chars in path */
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char *ni_next; /* next location in pathname */
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u_int ni_loopcnt; /* count of symlinks encountered */
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/*
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* Lookup parameters: this structure describes the subset of
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* information from the nameidata structure that is passed
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* through the VOP interface.
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*/
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struct componentname ni_cnd;
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struct nameicap_tracker_head ni_cap_tracker;
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struct vnode *ni_beneath_latch;
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};
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#ifdef _KERNEL
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/*
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* namei operations
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*/
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#define LOOKUP 0 /* perform name lookup only */
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#define CREATE 1 /* setup for file creation */
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#define DELETE 2 /* setup for file deletion */
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#define RENAME 3 /* setup for file renaming */
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#define OPMASK 3 /* mask for operation */
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/*
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* namei operational modifier flags, stored in ni_cnd.flags
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*/
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#define LOCKLEAF 0x0004 /* lock vnode on return */
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#define LOCKPARENT 0x0008 /* want parent vnode returned locked */
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#define WANTPARENT 0x0010 /* want parent vnode returned unlocked */
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#define NOCACHE 0x0020 /* name must not be left in cache */
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#define FOLLOW 0x0040 /* follow symbolic links */
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#define BENEATH 0x0080 /* No escape from the start dir */
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#define LOCKSHARED 0x0100 /* Shared lock leaf */
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#define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */
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#define MODMASK 0x01fc /* mask of operational modifiers */
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/*
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* Namei parameter descriptors.
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*
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* SAVENAME may be set by either the callers of namei or by VOP_LOOKUP.
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* If the caller of namei sets the flag (for example execve wants to
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* know the name of the program that is being executed), then it must
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* free the buffer. If VOP_LOOKUP sets the flag, then the buffer must
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* be freed by either the commit routine or the VOP_ABORT routine.
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* SAVESTART is set only by the callers of namei. It implies SAVENAME
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* plus the addition of saving the parent directory that contains the
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* name in ni_startdir. It allows repeated calls to lookup for the
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* name being sought. The caller is responsible for releasing the
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* buffer and for vrele'ing ni_startdir.
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*/
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#define RDONLY 0x00000200 /* lookup with read-only semantics */
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#define HASBUF 0x00000400 /* has allocated pathname buffer */
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#define SAVENAME 0x00000800 /* save pathname buffer */
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#define SAVESTART 0x00001000 /* save starting directory */
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#define ISDOTDOT 0x00002000 /* current component name is .. */
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#define MAKEENTRY 0x00004000 /* entry is to be added to name cache */
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#define ISLASTCN 0x00008000 /* this is last component of pathname */
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#define ISSYMLINK 0x00010000 /* symlink needs interpretation */
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#define ISWHITEOUT 0x00020000 /* found whiteout */
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#define DOWHITEOUT 0x00040000 /* do whiteouts */
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#define WILLBEDIR 0x00080000 /* new files will be dirs; allow trailing / */
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#define ISUNICODE 0x00100000 /* current component name is unicode*/
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#define ISOPEN 0x00200000 /* caller is opening; return a real vnode. */
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#define NOCROSSMOUNT 0x00400000 /* do not cross mount points */
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#define NOMACCHECK 0x00800000 /* do not perform MAC checks */
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#define AUDITVNODE1 0x04000000 /* audit the looked up vnode information */
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#define AUDITVNODE2 0x08000000 /* audit the looked up vnode information */
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#define TRAILINGSLASH 0x10000000 /* path ended in a slash */
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#define NOCAPCHECK 0x20000000 /* do not perform capability checks */
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#define PARAMASK 0x3ffffe00 /* mask of parameter descriptors */
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/*
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* Namei results flags
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*/
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#define NIRES_ABS 0x00000001 /* Path was absolute */
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/*
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* Flags in ni_lcf, valid for the duration of the namei call.
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*/
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#define NI_LCF_STRICTRELATIVE 0x0001 /* relative lookup only */
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#define NI_LCF_CAP_DOTDOT 0x0002 /* ".." in strictrelative case */
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#define NI_LCF_BENEATH_ABS 0x0004 /* BENEATH with absolute path */
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#define NI_LCF_BENEATH_LATCHED 0x0008 /* BENEATH_ABS traversed starting dir */
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#define NI_LCF_LATCH 0x0010 /* ni_beneath_latch valid */
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/*
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* Initialization of a nameidata structure.
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*/
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#define NDINIT(ndp, op, flags, segflg, namep, td) \
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NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, 0, td)
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#define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd, td) \
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NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, 0, td)
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#define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp, td) \
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NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp, td)
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#define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp, td) \
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NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, 0, td)
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void NDINIT_ALL(struct nameidata *ndp, u_long op, u_long flags,
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enum uio_seg segflg, const char *namep, int dirfd, struct vnode *startdir,
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cap_rights_t *rightsp, struct thread *td);
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#define NDF_NO_DVP_RELE 0x00000001
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#define NDF_NO_DVP_UNLOCK 0x00000002
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#define NDF_NO_DVP_PUT 0x00000003
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#define NDF_NO_VP_RELE 0x00000004
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#define NDF_NO_VP_UNLOCK 0x00000008
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#define NDF_NO_VP_PUT 0x0000000c
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#define NDF_NO_STARTDIR_RELE 0x00000010
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#define NDF_NO_FREE_PNBUF 0x00000020
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#define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF)
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void NDFREE(struct nameidata *, const u_int);
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int namei(struct nameidata *ndp);
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int lookup(struct nameidata *ndp);
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int relookup(struct vnode *dvp, struct vnode **vpp,
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struct componentname *cnp);
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#endif
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/*
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* Stats on usefulness of namei caches.
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*/
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struct nchstats {
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long ncs_goodhits; /* hits that we can really use */
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long ncs_neghits; /* negative hits that we can use */
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long ncs_badhits; /* hits we must drop */
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long ncs_falsehits; /* hits with id mismatch */
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long ncs_miss; /* misses */
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long ncs_long; /* long names that ignore cache */
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long ncs_pass2; /* names found with passes == 2 */
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long ncs_2passes; /* number of times we attempt it */
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};
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extern struct nchstats nchstats;
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#endif /* !_SYS_NAMEI_H_ */
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