Current File : //backups/router/usr/lib/include/sys/namei.h
/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1985, 1989, 1991, 1993
* The Regents of the University of California. 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. Neither the name of the University 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 REGENTS 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 REGENTS 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.
*
* @(#)namei.h 8.5 (Berkeley) 1/9/95
*/
#ifndef _SYS_NAMEI_H_
#define _SYS_NAMEI_H_
#include <sys/caprights.h>
#include <sys/filedesc.h>
#include <sys/queue.h>
#include <sys/_seqc.h>
#include <sys/_uio.h>
enum nameiop { LOOKUP, CREATE, DELETE, RENAME };
struct componentname {
/*
* Arguments to lookup.
*/
u_int64_t cn_flags; /* flags to namei */
struct ucred *cn_cred; /* credentials */
enum nameiop cn_nameiop; /* namei operation */
int cn_lkflags; /* Lock flags LK_EXCLUSIVE or LK_SHARED */
/*
* Shared between lookup and commit routines.
*/
char *cn_pnbuf; /* pathname buffer */
char *cn_nameptr; /* pointer to looked up name */
long cn_namelen; /* length of looked up component */
};
struct nameicap_tracker;
TAILQ_HEAD(nameicap_tracker_head, nameicap_tracker);
/*
* Encapsulation of namei parameters.
*/
struct nameidata {
/*
* Arguments to namei/lookup.
*/
const char *ni_dirp; /* pathname pointer */
enum uio_seg ni_segflg; /* location of pathname */
cap_rights_t *ni_rightsneeded; /* rights required to look up vnode */
/*
* Arguments to lookup.
*/
struct vnode *ni_startdir; /* starting directory */
struct vnode *ni_rootdir; /* logical root directory */
struct vnode *ni_topdir; /* logical top directory */
int ni_dirfd; /* starting directory for *at functions */
int ni_lcf; /* local call flags */
/*
* Results: returned from namei
*/
struct filecaps ni_filecaps; /* rights the *at base has */
/*
* Results: returned from/manipulated by lookup
*/
struct vnode *ni_vp; /* vnode of result */
struct vnode *ni_dvp; /* vnode of intermediate directory */
/*
* Results: flags returned from namei
*/
u_int ni_resflags;
/*
* Debug for validating API use by the callers.
*/
u_short ni_debugflags;
/*
* Shared between namei and lookup/commit routines.
*/
u_short ni_loopcnt; /* count of symlinks encountered */
size_t ni_pathlen; /* remaining chars in path */
char *ni_next; /* next location in pathname */
/*
* Lookup parameters: this structure describes the subset of
* information from the nameidata structure that is passed
* through the VOP interface.
*/
struct componentname ni_cnd;
struct nameicap_tracker_head ni_cap_tracker;
/*
* Private helper data for UFS, must be at the end. See
* NDINIT_PREFILL().
*/
seqc_t ni_dvp_seqc;
seqc_t ni_vp_seqc;
};
#ifdef _KERNEL
enum cache_fpl_status { CACHE_FPL_STATUS_DESTROYED, CACHE_FPL_STATUS_ABORTED,
CACHE_FPL_STATUS_PARTIAL, CACHE_FPL_STATUS_HANDLED, CACHE_FPL_STATUS_UNSET };
int cache_fplookup(struct nameidata *ndp, enum cache_fpl_status *status,
struct pwd **pwdp);
/*
* Flags for namei.
*
* If modifying the list make sure to check whether NDVALIDATE needs updating.
*/
/*
* Debug.
*/
#define NAMEI_DBG_INITED 0x0001
#define NAMEI_DBG_CALLED 0x0002
#define NAMEI_DBG_HADSTARTDIR 0x0004
/*
* namei operational modifier flags, stored in ni_cnd.flags
*/
#define NC_NOMAKEENTRY 0x0001 /* name must not be added to cache */
#define NC_KEEPPOSENTRY 0x0002 /* don't evict a positive entry */
#define NOCACHE NC_NOMAKEENTRY /* for compatibility with older code */
#define LOCKLEAF 0x0004 /* lock vnode on return */
#define LOCKPARENT 0x0008 /* want parent vnode returned locked */
#define WANTPARENT 0x0010 /* want parent vnode returned unlocked */
#define FAILIFEXISTS 0x0020 /* return EEXIST if found */
#define FOLLOW 0x0040 /* follow symbolic links */
#define EMPTYPATH 0x0080 /* Allow empty path for *at */
#define LOCKSHARED 0x0100 /* Shared lock leaf */
#define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */
#define RBENEATH 0x100000000ULL /* No escape, even tmp, from start dir */
#define MODMASK 0xf000001ffULL /* mask of operational modifiers */
/*
* Namei parameter descriptors.
*/
#define RDONLY 0x00000200 /* lookup with read-only semantics */
#define ISRESTARTED 0x00000400 /* restarted namei */
/* UNUSED 0x00000800 */
#define ISWHITEOUT 0x00001000 /* found whiteout */
#define DOWHITEOUT 0x00002000 /* do whiteouts */
#define WILLBEDIR 0x00004000 /* new files will be dirs; allow trailing / */
#define ISOPEN 0x00008000 /* caller is opening; return a real vnode. */
#define NOCROSSMOUNT 0x00010000 /* do not cross mount points */
#define NOMACCHECK 0x00020000 /* do not perform MAC checks */
#define AUDITVNODE1 0x00040000 /* audit the looked up vnode information */
#define AUDITVNODE2 0x00080000 /* audit the looked up vnode information */
#define NOCAPCHECK 0x00100000 /* do not perform capability checks */
#define OPENREAD 0x00200000 /* open for reading */
#define OPENWRITE 0x00400000 /* open for writing */
#define WANTIOCTLCAPS 0x00800000 /* leave ioctl caps for the caller */
/* UNUSED 0x01000000 */
#define NOEXECCHECK 0x02000000 /* do not perform exec check on dir */
#define MAKEENTRY 0x04000000 /* entry is to be added to name cache */
#define ISSYMLINK 0x08000000 /* symlink needs interpretation */
#define ISLASTCN 0x10000000 /* this is last component of pathname */
#define ISDOTDOT 0x20000000 /* current component name is .. */
#define TRAILINGSLASH 0x40000000 /* path ended in a slash */
#define PARAMASK 0x7ffffe00 /* mask of parameter descriptors */
/*
* Flags which must not be passed in by callers.
*/
#define NAMEI_INTERNAL_FLAGS \
(NOEXECCHECK | MAKEENTRY | ISSYMLINK | ISLASTCN | ISDOTDOT | \
TRAILINGSLASH | ISRESTARTED)
/*
* Namei results flags
*/
#define NIRES_ABS 0x00000001 /* Path was absolute */
#define NIRES_STRICTREL 0x00000002 /* Restricted lookup result */
#define NIRES_EMPTYPATH 0x00000004 /* EMPTYPATH used */
/*
* Flags in ni_lcf, valid for the duration of the namei call.
*/
#define NI_LCF_STRICTREL 0x0001 /* relative lookup only */
#define NI_LCF_CAP_DOTDOT 0x0002 /* ".." in strictrelative case */
/* Track capability restrictions seperately for violation ktracing. */
#define NI_LCF_STRICTREL_KTR 0x0004 /* trace relative lookups */
#define NI_LCF_CAP_DOTDOT_KTR 0x0008 /* ".." in strictrelative case */
#define NI_LCF_KTR_FLAGS (NI_LCF_STRICTREL_KTR | NI_LCF_CAP_DOTDOT_KTR)
/*
* Initialization of a nameidata structure.
*/
#define NDINIT(ndp, op, flags, segflg, namep) \
NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, &cap_no_rights)
#define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd) \
NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, &cap_no_rights)
#define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp) \
NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp)
#define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp) \
NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, &cap_no_rights)
/*
* Note the constant pattern may *hide* bugs.
* Note also that we enable debug checks for non-TIED KLDs
* so that they can run on an INVARIANTS kernel without tripping over
* assertions on ni_debugflags state.
*/
#if defined(INVARIANTS) || (defined(KLD_MODULE) && !defined(KLD_TIED))
#define NDINIT_PREFILL(arg) memset(arg, 0xff, offsetof(struct nameidata, \
ni_dvp_seqc))
#define NDINIT_DBG(arg) { (arg)->ni_debugflags = NAMEI_DBG_INITED; }
#define NDREINIT_DBG(arg) { \
if (((arg)->ni_debugflags & NAMEI_DBG_INITED) == 0) \
panic("namei data not inited"); \
if (((arg)->ni_debugflags & NAMEI_DBG_HADSTARTDIR) != 0) \
panic("NDREINIT on namei data with NAMEI_DBG_HADSTARTDIR"); \
(arg)->ni_debugflags = NAMEI_DBG_INITED; \
}
#else
#define NDINIT_PREFILL(arg) do { } while (0)
#define NDINIT_DBG(arg) do { } while (0)
#define NDREINIT_DBG(arg) do { } while (0)
#endif
#define NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, startdir, rightsp) \
do { \
struct nameidata *_ndp = (ndp); \
cap_rights_t *_rightsp = (rightsp); \
MPASS(_rightsp != NULL); \
NDINIT_PREFILL(_ndp); \
NDINIT_DBG(_ndp); \
_ndp->ni_cnd.cn_nameiop = op; \
_ndp->ni_cnd.cn_flags = flags; \
_ndp->ni_segflg = segflg; \
_ndp->ni_dirp = namep; \
_ndp->ni_dirfd = dirfd; \
_ndp->ni_startdir = startdir; \
_ndp->ni_resflags = 0; \
filecaps_init(&_ndp->ni_filecaps); \
_ndp->ni_rightsneeded = _rightsp; \
} while (0)
#define NDREINIT(ndp) do { \
struct nameidata *_ndp = (ndp); \
NDREINIT_DBG(_ndp); \
filecaps_free(&_ndp->ni_filecaps); \
_ndp->ni_resflags = 0; \
_ndp->ni_startdir = NULL; \
} while (0)
#define NDPREINIT(ndp) do { \
(ndp)->ni_dvp_seqc = SEQC_MOD; \
(ndp)->ni_vp_seqc = SEQC_MOD; \
} while (0)
#define NDFREE_IOCTLCAPS(ndp) do { \
struct nameidata *_ndp = (ndp); \
filecaps_free(&_ndp->ni_filecaps); \
} while (0)
#define NDFREE_PNBUF(ndp) do { \
struct nameidata *_ndp = (ndp); \
MPASS(_ndp->ni_cnd.cn_pnbuf != NULL); \
uma_zfree(namei_zone, _ndp->ni_cnd.cn_pnbuf); \
_ndp->ni_cnd.cn_pnbuf = NULL; \
} while (0)
int namei(struct nameidata *ndp);
int vfs_lookup(struct nameidata *ndp);
int vfs_relookup(struct vnode *dvp, struct vnode **vpp,
struct componentname *cnp, bool refstart);
#define namei_setup_rootdir(ndp, cnp, pwd) do { \
if (__predict_true((cnp->cn_flags & ISRESTARTED) == 0)) \
ndp->ni_rootdir = pwd->pwd_adir; \
else \
ndp->ni_rootdir = pwd->pwd_rdir; \
} while (0)
#endif
/*
* Stats on usefulness of namei caches.
*/
struct nchstats {
long ncs_goodhits; /* hits that we can really use */
long ncs_neghits; /* negative hits that we can use */
long ncs_badhits; /* hits we must drop */
long ncs_falsehits; /* hits with id mismatch */
long ncs_miss; /* misses */
long ncs_long; /* long names that ignore cache */
long ncs_pass2; /* names found with passes == 2 */
long ncs_2passes; /* number of times we attempt it */
};
extern struct nchstats nchstats;
#endif /* !_SYS_NAMEI_H_ */
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