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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>
41 #include <sys/_seqc.h>
44 enum nameiop { LOOKUP, CREATE, DELETE, RENAME };
46 struct componentname {
48 * Arguments to lookup.
50 u_int64_t cn_origflags; /* flags to namei */
51 u_int64_t cn_flags; /* flags to namei */
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 * Debug for validating API use by the callers.
100 u_short ni_debugflags;
102 * Shared between namei and lookup/commit routines.
104 u_short ni_loopcnt; /* count of symlinks encountered */
105 size_t ni_pathlen; /* remaining chars in path */
106 char *ni_next; /* next location in pathname */
108 * Lookup parameters: this structure describes the subset of
109 * information from the nameidata structure that is passed
110 * through the VOP interface.
112 struct componentname ni_cnd;
113 struct nameicap_tracker_head ni_cap_tracker;
115 * Private helper data for UFS, must be at the end. See
124 enum cache_fpl_status { CACHE_FPL_STATUS_DESTROYED, CACHE_FPL_STATUS_ABORTED,
125 CACHE_FPL_STATUS_PARTIAL, CACHE_FPL_STATUS_HANDLED, CACHE_FPL_STATUS_UNSET };
126 int cache_fplookup(struct nameidata *ndp, enum cache_fpl_status *status,
132 * If modifying the list make sure to check whether NDVALIDATE needs updating.
138 #define NAMEI_DBG_INITED 0x0001
139 #define NAMEI_DBG_CALLED 0x0002
140 #define NAMEI_DBG_HADSTARTDIR 0x0004
143 * namei operational modifier flags, stored in ni_cnd.flags
145 #define NC_NOMAKEENTRY 0x0001 /* name must not be added to cache */
146 #define NC_KEEPPOSENTRY 0x0002 /* don't evict a positive entry */
147 #define NOCACHE NC_NOMAKEENTRY /* for compatibility with older code */
148 #define LOCKLEAF 0x0004 /* lock vnode on return */
149 #define LOCKPARENT 0x0008 /* want parent vnode returned locked */
150 #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */
151 #define FAILIFEXISTS 0x0020 /* return EEXIST if found */
152 #define FOLLOW 0x0040 /* follow symbolic links */
153 #define EMPTYPATH 0x0080 /* Allow empty path for *at */
154 #define LOCKSHARED 0x0100 /* Shared lock leaf */
155 #define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */
156 #define RBENEATH 0x100000000ULL /* No escape, even tmp, from start dir */
157 #define MODMASK 0xf000001ffULL /* mask of operational modifiers */
160 * Namei parameter descriptors.
162 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP.
163 * If the caller of namei sets the flag (for example execve wants to
164 * know the name of the program that is being executed), then it must
165 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must
166 * be freed by either the commit routine or the VOP_ABORT routine.
167 * SAVESTART is set only by the callers of namei. It implies SAVENAME
168 * plus the addition of saving the parent directory that contains the
169 * name in ni_startdir. It allows repeated calls to lookup for the
170 * name being sought. The caller is responsible for releasing the
171 * buffer and for vrele'ing ni_startdir.
173 #define RDONLY 0x00000200 /* lookup with read-only semantics */
174 #define SAVENAME 0x00000400 /* save pathname buffer */
175 #define SAVESTART 0x00000800 /* save starting directory */
176 #define ISWHITEOUT 0x00001000 /* found whiteout */
177 #define DOWHITEOUT 0x00002000 /* do whiteouts */
178 #define WILLBEDIR 0x00004000 /* new files will be dirs; allow trailing / */
179 #define ISOPEN 0x00008000 /* caller is opening; return a real vnode. */
180 #define NOCROSSMOUNT 0x00010000 /* do not cross mount points */
181 #define NOMACCHECK 0x00020000 /* do not perform MAC checks */
182 #define AUDITVNODE1 0x00040000 /* audit the looked up vnode information */
183 #define AUDITVNODE2 0x00080000 /* audit the looked up vnode information */
184 #define NOCAPCHECK 0x00100000 /* do not perform capability checks */
185 #define OPENREAD 0x00200000 /* open for reading */
186 #define OPENWRITE 0x00400000 /* open for writing */
187 #define WANTIOCTLCAPS 0x00800000 /* leave ioctl caps for the caller */
188 #define HASBUF 0x01000000 /* has allocated pathname buffer */
189 #define NOEXECCHECK 0x02000000 /* do not perform exec check on dir */
190 #define MAKEENTRY 0x04000000 /* entry is to be added to name cache */
191 #define ISSYMLINK 0x08000000 /* symlink needs interpretation */
192 #define ISLASTCN 0x10000000 /* this is last component of pathname */
193 #define ISDOTDOT 0x20000000 /* current component name is .. */
194 #define TRAILINGSLASH 0x40000000 /* path ended in a slash */
195 #define PARAMASK 0x7ffffe00 /* mask of parameter descriptors */
198 * Flags which must not be passed in by callers.
200 #define NAMEI_INTERNAL_FLAGS \
201 (HASBUF | NOEXECCHECK | MAKEENTRY | ISSYMLINK | ISLASTCN | ISDOTDOT | \
205 * Namei results flags
207 #define NIRES_ABS 0x00000001 /* Path was absolute */
208 #define NIRES_STRICTREL 0x00000002 /* Restricted lookup result */
209 #define NIRES_EMPTYPATH 0x00000004 /* EMPTYPATH used */
212 * Flags in ni_lcf, valid for the duration of the namei call.
214 #define NI_LCF_STRICTRELATIVE 0x0001 /* relative lookup only */
215 #define NI_LCF_CAP_DOTDOT 0x0002 /* ".." in strictrelative case */
218 * Initialization of a nameidata structure.
220 #define NDINIT(ndp, op, flags, segflg, namep) \
221 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, &cap_no_rights)
222 #define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd) \
223 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, &cap_no_rights)
224 #define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp) \
225 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp)
226 #define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp) \
227 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, &cap_no_rights)
230 * Note the constant pattern may *hide* bugs.
231 * Note also that we enable debug checks for non-TIED KLDs
232 * so that they can run on an INVARIANTS kernel without tripping over
233 * assertions on ni_debugflags state.
235 #if defined(INVARIANTS) || (defined(KLD_MODULE) && !defined(KLD_TIED))
236 #define NDINIT_PREFILL(arg) memset(arg, 0xff, offsetof(struct nameidata, \
238 #define NDINIT_DBG(arg) { (arg)->ni_debugflags = NAMEI_DBG_INITED; }
239 #define NDREINIT_DBG(arg) { \
240 if (((arg)->ni_debugflags & NAMEI_DBG_INITED) == 0) \
241 panic("namei data not inited"); \
242 if (((arg)->ni_debugflags & NAMEI_DBG_HADSTARTDIR) != 0) \
243 panic("NDREINIT on namei data with NAMEI_DBG_HADSTARTDIR"); \
244 (arg)->ni_debugflags = NAMEI_DBG_INITED; \
247 #define NDINIT_PREFILL(arg) do { } while (0)
248 #define NDINIT_DBG(arg) do { } while (0)
249 #define NDREINIT_DBG(arg) do { } while (0)
252 #define NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, startdir, rightsp) \
254 struct nameidata *_ndp = (ndp); \
255 cap_rights_t *_rightsp = (rightsp); \
256 MPASS(_rightsp != NULL); \
257 NDINIT_PREFILL(_ndp); \
259 _ndp->ni_cnd.cn_nameiop = op; \
260 _ndp->ni_cnd.cn_flags = flags; \
261 _ndp->ni_segflg = segflg; \
262 _ndp->ni_dirp = namep; \
263 _ndp->ni_dirfd = dirfd; \
264 _ndp->ni_startdir = startdir; \
265 _ndp->ni_resflags = 0; \
266 filecaps_init(&_ndp->ni_filecaps); \
267 _ndp->ni_rightsneeded = _rightsp; \
270 #define NDREINIT(ndp) do { \
271 struct nameidata *_ndp = (ndp); \
272 NDREINIT_DBG(_ndp); \
273 filecaps_free(&_ndp->ni_filecaps); \
274 _ndp->ni_resflags = 0; \
275 _ndp->ni_startdir = NULL; \
278 #define NDPREINIT(ndp) do { \
279 (ndp)->ni_dvp_seqc = SEQC_MOD; \
280 (ndp)->ni_vp_seqc = SEQC_MOD; \
283 #define NDF_NO_DVP_RELE 0x00000001
284 #define NDF_NO_DVP_UNLOCK 0x00000002
285 #define NDF_NO_DVP_PUT 0x00000003
286 #define NDF_NO_VP_RELE 0x00000004
287 #define NDF_NO_VP_UNLOCK 0x00000008
288 #define NDF_NO_VP_PUT 0x0000000c
289 #define NDF_NO_STARTDIR_RELE 0x00000010
290 #define NDF_NO_FREE_PNBUF 0x00000020
292 #define NDFREE_IOCTLCAPS(ndp) do { \
293 struct nameidata *_ndp = (ndp); \
294 filecaps_free(&_ndp->ni_filecaps); \
296 void NDFREE_PNBUF(struct nameidata *);
297 void NDFREE(struct nameidata *, const u_int);
300 void NDFREE_NOTHING(struct nameidata *);
301 void NDVALIDATE(struct nameidata *);
303 #define NDFREE_NOTHING(ndp) do { } while (0)
304 #define NDVALIDATE(ndp) do { } while (0)
307 int namei(struct nameidata *ndp);
308 int vfs_lookup(struct nameidata *ndp);
309 int vfs_relookup(struct vnode *dvp, struct vnode **vpp,
310 struct componentname *cnp);
314 * Stats on usefulness of namei caches.
317 long ncs_goodhits; /* hits that we can really use */
318 long ncs_neghits; /* negative hits that we can use */
319 long ncs_badhits; /* hits we must drop */
320 long ncs_falsehits; /* hits with id mismatch */
321 long ncs_miss; /* misses */
322 long ncs_long; /* long names that ignore cache */
323 long ncs_pass2; /* names found with passes == 2 */
324 long ncs_2passes; /* number of times we attempt it */
327 extern struct nchstats nchstats;
329 #endif /* !_SYS_NAMEI_H_ */