2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1985, 1989, 1991, 1993
5 * The Regents of the University of California. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * @(#)namei.h 8.5 (Berkeley) 1/9/95
38 #include <sys/caprights.h>
39 #include <sys/filedesc.h>
40 #include <sys/queue.h>
43 enum nameiop { LOOKUP, CREATE, DELETE, RENAME };
45 struct componentname {
47 * Arguments to lookup.
49 u_int64_t cn_origflags; /* flags to namei */
50 u_int64_t cn_flags; /* flags to namei */
51 struct thread *cn_thread;/* thread requesting lookup */
52 struct ucred *cn_cred; /* credentials */
53 enum nameiop cn_nameiop; /* namei operation */
54 int cn_lkflags; /* Lock flags LK_EXCLUSIVE or LK_SHARED */
56 * Shared between lookup and commit routines.
58 char *cn_pnbuf; /* pathname buffer */
59 char *cn_nameptr; /* pointer to looked up name */
60 long cn_namelen; /* length of looked up component */
63 struct nameicap_tracker;
64 TAILQ_HEAD(nameicap_tracker_head, nameicap_tracker);
67 * Encapsulation of namei parameters.
71 * Arguments to namei/lookup.
73 const char *ni_dirp; /* pathname pointer */
74 enum uio_seg ni_segflg; /* location of pathname */
75 cap_rights_t *ni_rightsneeded; /* rights required to look up vnode */
77 * Arguments to lookup.
79 struct vnode *ni_startdir; /* starting directory */
80 struct vnode *ni_rootdir; /* logical root directory */
81 struct vnode *ni_topdir; /* logical top directory */
82 int ni_dirfd; /* starting directory for *at functions */
83 int ni_lcf; /* local call flags */
85 * Results: returned from namei
87 struct filecaps ni_filecaps; /* rights the *at base has */
89 * Results: returned from/manipulated by lookup
91 struct vnode *ni_vp; /* vnode of result */
92 struct vnode *ni_dvp; /* vnode of intermediate directory */
94 * Results: flags returned from namei
98 * Shared between namei and lookup/commit routines.
100 size_t ni_pathlen; /* remaining chars in path */
101 char *ni_next; /* next location in pathname */
102 u_int ni_loopcnt; /* count of symlinks encountered */
104 * Lookup parameters: this structure describes the subset of
105 * information from the nameidata structure that is passed
106 * through the VOP interface.
108 struct componentname ni_cnd;
109 struct nameicap_tracker_head ni_cap_tracker;
110 struct vnode *ni_beneath_latch;
115 enum cache_fpl_status { CACHE_FPL_STATUS_ABORTED, CACHE_FPL_STATUS_PARTIAL,
116 CACHE_FPL_STATUS_HANDLED, CACHE_FPL_STATUS_UNSET };
117 int cache_fplookup(struct nameidata *ndp, enum cache_fpl_status *status,
123 * If modifying the list make sure to check whether NDVALIDATE needs updating.
126 * namei operational modifier flags, stored in ni_cnd.flags
128 #define NC_NOMAKEENTRY 0x0001 /* name must not be added to cache */
129 #define NC_KEEPPOSENTRY 0x0002 /* don't evict a positive entry */
130 #define NOCACHE NC_NOMAKEENTRY /* for compatibility with older code */
131 #define LOCKLEAF 0x0004 /* lock vnode on return */
132 #define LOCKPARENT 0x0008 /* want parent vnode returned locked */
133 #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */
135 #define FOLLOW 0x0040 /* follow symbolic links */
136 #define BENEATH 0x0080 /* No escape from the start dir */
137 #define LOCKSHARED 0x0100 /* Shared lock leaf */
138 #define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */
139 #define RBENEATH 0x100000000ULL /* No escape, even tmp, from start dir */
140 #define MODMASK 0xf000001ffULL /* mask of operational modifiers */
142 * Namei parameter descriptors.
144 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP.
145 * If the caller of namei sets the flag (for example execve wants to
146 * know the name of the program that is being executed), then it must
147 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must
148 * be freed by either the commit routine or the VOP_ABORT routine.
149 * SAVESTART is set only by the callers of namei. It implies SAVENAME
150 * plus the addition of saving the parent directory that contains the
151 * name in ni_startdir. It allows repeated calls to lookup for the
152 * name being sought. The caller is responsible for releasing the
153 * buffer and for vrele'ing ni_startdir.
155 #define RDONLY 0x00000200 /* lookup with read-only semantics */
156 #define SAVENAME 0x00000400 /* save pathname buffer */
157 #define SAVESTART 0x00000800 /* save starting directory */
158 #define ISWHITEOUT 0x00001000 /* found whiteout */
159 #define DOWHITEOUT 0x00002000 /* do whiteouts */
160 #define WILLBEDIR 0x00004000 /* new files will be dirs; allow trailing / */
161 #define ISOPEN 0x00008000 /* caller is opening; return a real vnode. */
162 #define NOCROSSMOUNT 0x00010000 /* do not cross mount points */
163 #define NOMACCHECK 0x00020000 /* do not perform MAC checks */
164 #define AUDITVNODE1 0x00040000 /* audit the looked up vnode information */
165 #define AUDITVNODE2 0x00080000 /* audit the looked up vnode information */
166 #define NOCAPCHECK 0x00100000 /* do not perform capability checks */
167 /* UNUSED 0x00200000 */
168 /* UNUSED 0x00400000 */
169 /* UNUSED 0x00800000 */
170 #define HASBUF 0x01000000 /* has allocated pathname buffer */
171 #define NOEXECCHECK 0x02000000 /* do not perform exec check on dir */
172 #define MAKEENTRY 0x04000000 /* entry is to be added to name cache */
173 #define ISSYMLINK 0x08000000 /* symlink needs interpretation */
174 #define ISLASTCN 0x10000000 /* this is last component of pathname */
175 #define ISDOTDOT 0x20000000 /* current component name is .. */
176 #define TRAILINGSLASH 0x40000000 /* path ended in a slash */
177 #define PARAMASK 0x7ffffe00 /* mask of parameter descriptors */
180 * Flags which must not be passed in by callers.
182 #define NAMEI_INTERNAL_FLAGS \
183 (HASBUF | NOEXECCHECK | MAKEENTRY | ISSYMLINK | ISLASTCN | ISDOTDOT | \
187 * Namei results flags
189 #define NIRES_ABS 0x00000001 /* Path was absolute */
190 #define NIRES_STRICTREL 0x00000002 /* Restricted lookup result */
193 * Flags in ni_lcf, valid for the duration of the namei call.
195 #define NI_LCF_STRICTRELATIVE 0x0001 /* relative lookup only */
196 #define NI_LCF_CAP_DOTDOT 0x0002 /* ".." in strictrelative case */
197 #define NI_LCF_BENEATH_ABS 0x0004 /* BENEATH with absolute path */
198 #define NI_LCF_BENEATH_LATCHED 0x0008 /* BENEATH_ABS traversed starting dir */
199 #define NI_LCF_LATCH 0x0010 /* ni_beneath_latch valid */
202 * Initialization of a nameidata structure.
204 #define NDINIT(ndp, op, flags, segflg, namep, td) \
205 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, &cap_no_rights, td)
206 #define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd, td) \
207 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, &cap_no_rights, td)
208 #define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp, td) \
209 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp, td)
210 #define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp, td) \
211 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, &cap_no_rights, td)
214 * Note the constant pattern may *hide* bugs.
217 #define NDINIT_PREFILL(arg) memset(arg, 0xff, sizeof(*arg))
219 #define NDINIT_PREFILL(arg) do { } while (0)
222 #define NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, startdir, rightsp, td) \
224 struct nameidata *_ndp = (ndp); \
225 cap_rights_t *_rightsp = (rightsp); \
226 MPASS(_rightsp != NULL); \
227 NDINIT_PREFILL(_ndp); \
228 _ndp->ni_cnd.cn_nameiop = op; \
229 _ndp->ni_cnd.cn_flags = flags; \
230 _ndp->ni_segflg = segflg; \
231 _ndp->ni_dirp = namep; \
232 _ndp->ni_dirfd = dirfd; \
233 _ndp->ni_startdir = startdir; \
234 _ndp->ni_resflags = 0; \
235 filecaps_init(&_ndp->ni_filecaps); \
236 _ndp->ni_cnd.cn_thread = td; \
237 _ndp->ni_rightsneeded = _rightsp; \
240 #define NDF_NO_DVP_RELE 0x00000001
241 #define NDF_NO_DVP_UNLOCK 0x00000002
242 #define NDF_NO_DVP_PUT 0x00000003
243 #define NDF_NO_VP_RELE 0x00000004
244 #define NDF_NO_VP_UNLOCK 0x00000008
245 #define NDF_NO_VP_PUT 0x0000000c
246 #define NDF_NO_STARTDIR_RELE 0x00000010
247 #define NDF_NO_FREE_PNBUF 0x00000020
248 #define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF)
250 void NDFREE_PNBUF(struct nameidata *);
251 void NDFREE(struct nameidata *, const u_int);
252 #define NDFREE(ndp, flags) do { \
253 struct nameidata *_ndp = (ndp); \
254 if (__builtin_constant_p(flags) && flags == NDF_ONLY_PNBUF) \
255 NDFREE_PNBUF(_ndp); \
257 NDFREE(_ndp, flags); \
261 void NDVALIDATE(struct nameidata *);
263 #define NDVALIDATE(ndp) do { } while (0)
266 int namei(struct nameidata *ndp);
267 int lookup(struct nameidata *ndp);
268 int relookup(struct vnode *dvp, struct vnode **vpp,
269 struct componentname *cnp);
273 * Stats on usefulness of namei caches.
276 long ncs_goodhits; /* hits that we can really use */
277 long ncs_neghits; /* negative hits that we can use */
278 long ncs_badhits; /* hits we must drop */
279 long ncs_falsehits; /* hits with id mismatch */
280 long ncs_miss; /* misses */
281 long ncs_long; /* long names that ignore cache */
282 long ncs_pass2; /* names found with passes == 2 */
283 long ncs_2passes; /* number of times we attempt it */
286 extern struct nchstats nchstats;
288 #endif /* !_SYS_NAMEI_H_ */