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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 LOCKLEAF 0x0004 /* lock vnode on return */
129 #define LOCKPARENT 0x0008 /* want parent vnode returned locked */
130 #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */
131 #define NOCACHE 0x0020 /* name must not be left in cache */
132 #define FOLLOW 0x0040 /* follow symbolic links */
133 #define BENEATH 0x0080 /* No escape from the start dir */
134 #define LOCKSHARED 0x0100 /* Shared lock leaf */
135 #define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */
136 #define MODMASK 0x01fc /* mask of operational modifiers */
138 * Namei parameter descriptors.
140 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP.
141 * If the caller of namei sets the flag (for example execve wants to
142 * know the name of the program that is being executed), then it must
143 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must
144 * be freed by either the commit routine or the VOP_ABORT routine.
145 * SAVESTART is set only by the callers of namei. It implies SAVENAME
146 * plus the addition of saving the parent directory that contains the
147 * name in ni_startdir. It allows repeated calls to lookup for the
148 * name being sought. The caller is responsible for releasing the
149 * buffer and for vrele'ing ni_startdir.
151 #define RDONLY 0x00000200 /* lookup with read-only semantics */
152 #define SAVENAME 0x00000400 /* save pathname buffer */
153 #define SAVESTART 0x00000800 /* save starting directory */
154 #define ISWHITEOUT 0x00001000 /* found whiteout */
155 #define DOWHITEOUT 0x00002000 /* do whiteouts */
156 #define WILLBEDIR 0x00004000 /* new files will be dirs; allow trailing / */
157 #define ISOPEN 0x00008000 /* caller is opening; return a real vnode. */
158 #define NOCROSSMOUNT 0x00010000 /* do not cross mount points */
159 #define NOMACCHECK 0x00020000 /* do not perform MAC checks */
160 #define AUDITVNODE1 0x00040000 /* audit the looked up vnode information */
161 #define AUDITVNODE2 0x00080000 /* audit the looked up vnode information */
162 #define NOCAPCHECK 0x00100000 /* do not perform capability checks */
163 /* UNUSED 0x00200000 */
164 /* UNUSED 0x00400000 */
165 /* UNUSED 0x00800000 */
166 #define HASBUF 0x01000000 /* has allocated pathname buffer */
167 #define NOEXECCHECK 0x02000000 /* do not perform exec check on dir */
168 #define MAKEENTRY 0x04000000 /* entry is to be added to name cache */
169 #define ISSYMLINK 0x08000000 /* symlink needs interpretation */
170 #define ISLASTCN 0x10000000 /* this is last component of pathname */
171 #define ISDOTDOT 0x20000000 /* current component name is .. */
172 #define TRAILINGSLASH 0x40000000 /* path ended in a slash */
173 #define PARAMASK 0x7ffffe00 /* mask of parameter descriptors */
176 * Flags which must not be passed in by callers.
178 #define NAMEI_INTERNAL_FLAGS \
179 (HASBUF | NOEXECCHECK | MAKEENTRY | ISSYMLINK | ISLASTCN | ISDOTDOT | \
183 * Namei results flags
185 #define NIRES_ABS 0x00000001 /* Path was absolute */
188 * Flags in ni_lcf, valid for the duration of the namei call.
190 #define NI_LCF_STRICTRELATIVE 0x0001 /* relative lookup only */
191 #define NI_LCF_CAP_DOTDOT 0x0002 /* ".." in strictrelative case */
192 #define NI_LCF_BENEATH_ABS 0x0004 /* BENEATH with absolute path */
193 #define NI_LCF_BENEATH_LATCHED 0x0008 /* BENEATH_ABS traversed starting dir */
194 #define NI_LCF_LATCH 0x0010 /* ni_beneath_latch valid */
197 * Initialization of a nameidata structure.
199 #define NDINIT(ndp, op, flags, segflg, namep, td) \
200 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, &cap_no_rights, td)
201 #define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd, td) \
202 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, &cap_no_rights, td)
203 #define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp, td) \
204 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp, td)
205 #define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp, td) \
206 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, &cap_no_rights, td)
209 * Note the constant pattern may *hide* bugs.
212 #define NDINIT_PREFILL(arg) memset(arg, 0xff, sizeof(*arg))
214 #define NDINIT_PREFILL(arg) do { } while (0)
217 #define NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, startdir, rightsp, td) \
219 struct nameidata *_ndp = (ndp); \
220 cap_rights_t *_rightsp = (rightsp); \
221 MPASS(_rightsp != NULL); \
222 NDINIT_PREFILL(_ndp); \
223 _ndp->ni_cnd.cn_nameiop = op; \
224 _ndp->ni_cnd.cn_flags = flags; \
225 _ndp->ni_segflg = segflg; \
226 _ndp->ni_dirp = namep; \
227 _ndp->ni_dirfd = dirfd; \
228 _ndp->ni_startdir = startdir; \
229 _ndp->ni_resflags = 0; \
230 filecaps_init(&_ndp->ni_filecaps); \
231 _ndp->ni_cnd.cn_thread = td; \
232 _ndp->ni_rightsneeded = _rightsp; \
235 #define NDF_NO_DVP_RELE 0x00000001
236 #define NDF_NO_DVP_UNLOCK 0x00000002
237 #define NDF_NO_DVP_PUT 0x00000003
238 #define NDF_NO_VP_RELE 0x00000004
239 #define NDF_NO_VP_UNLOCK 0x00000008
240 #define NDF_NO_VP_PUT 0x0000000c
241 #define NDF_NO_STARTDIR_RELE 0x00000010
242 #define NDF_NO_FREE_PNBUF 0x00000020
243 #define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF)
245 void NDFREE_PNBUF(struct nameidata *);
246 void NDFREE(struct nameidata *, const u_int);
247 #define NDFREE(ndp, flags) do { \
248 struct nameidata *_ndp = (ndp); \
249 if (__builtin_constant_p(flags) && flags == NDF_ONLY_PNBUF) \
250 NDFREE_PNBUF(_ndp); \
252 NDFREE(_ndp, flags); \
256 void NDVALIDATE(struct nameidata *);
258 #define NDVALIDATE(ndp) do { } while (0)
261 int namei(struct nameidata *ndp);
262 int lookup(struct nameidata *ndp);
263 int relookup(struct vnode *dvp, struct vnode **vpp,
264 struct componentname *cnp);
268 * Stats on usefulness of namei caches.
271 long ncs_goodhits; /* hits that we can really use */
272 long ncs_neghits; /* negative hits that we can use */
273 long ncs_badhits; /* hits we must drop */
274 long ncs_falsehits; /* hits with id mismatch */
275 long ncs_miss; /* misses */
276 long ncs_long; /* long names that ignore cache */
277 long ncs_pass2; /* names found with passes == 2 */
278 long ncs_2passes; /* number of times we attempt it */
281 extern struct nchstats nchstats;
283 #endif /* !_SYS_NAMEI_H_ */