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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_flags; /* flags to namei */
50 struct thread *cn_thread;/* thread requesting lookup */
51 struct ucred *cn_cred; /* credentials */
52 enum nameiop cn_nameiop; /* namei operation */
53 int cn_lkflags; /* Lock flags LK_EXCLUSIVE or LK_SHARED */
55 * Shared between lookup and commit routines.
57 char *cn_pnbuf; /* pathname buffer */
58 char *cn_nameptr; /* pointer to looked up name */
59 long cn_namelen; /* length of looked up component */
62 struct nameicap_tracker;
63 TAILQ_HEAD(nameicap_tracker_head, nameicap_tracker);
66 * Encapsulation of namei parameters.
70 * Arguments to namei/lookup.
72 const char *ni_dirp; /* pathname pointer */
73 enum uio_seg ni_segflg; /* location of pathname */
74 cap_rights_t *ni_rightsneeded; /* rights required to look up vnode */
76 * Arguments to lookup.
78 struct vnode *ni_startdir; /* starting directory */
79 struct vnode *ni_rootdir; /* logical root directory */
80 struct vnode *ni_topdir; /* logical top directory */
81 int ni_dirfd; /* starting directory for *at functions */
82 int ni_lcf; /* local call flags */
84 * Results: returned from namei
86 struct filecaps ni_filecaps; /* rights the *at base has */
88 * Results: returned from/manipulated by lookup
90 struct vnode *ni_vp; /* vnode of result */
91 struct vnode *ni_dvp; /* vnode of intermediate directory */
93 * Results: flags returned from namei
97 * Shared between namei and lookup/commit routines.
99 size_t ni_pathlen; /* remaining chars in path */
100 char *ni_next; /* next location in pathname */
101 u_int ni_loopcnt; /* count of symlinks encountered */
103 * Lookup parameters: this structure describes the subset of
104 * information from the nameidata structure that is passed
105 * through the VOP interface.
107 struct componentname ni_cnd;
108 struct nameicap_tracker_head ni_cap_tracker;
109 struct vnode *ni_beneath_latch;
114 enum cache_fpl_status { CACHE_FPL_STATUS_ABORTED, CACHE_FPL_STATUS_PARTIAL,
115 CACHE_FPL_STATUS_HANDLED, CACHE_FPL_STATUS_UNSET };
116 int cache_fplookup(struct nameidata *ndp, enum cache_fpl_status *status,
122 * If modifying the list make sure to check whether NDVALIDATE needs updating.
125 * namei operational modifier flags, stored in ni_cnd.flags
127 #define LOCKLEAF 0x0004 /* lock vnode on return */
128 #define LOCKPARENT 0x0008 /* want parent vnode returned locked */
129 #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */
130 #define NOCACHE 0x0020 /* name must not be left in cache */
131 #define FOLLOW 0x0040 /* follow symbolic links */
132 #define BENEATH 0x0080 /* No escape from the start dir */
133 #define LOCKSHARED 0x0100 /* Shared lock leaf */
134 #define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */
135 #define MODMASK 0x01fc /* mask of operational modifiers */
137 * Namei parameter descriptors.
139 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP.
140 * If the caller of namei sets the flag (for example execve wants to
141 * know the name of the program that is being executed), then it must
142 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must
143 * be freed by either the commit routine or the VOP_ABORT routine.
144 * SAVESTART is set only by the callers of namei. It implies SAVENAME
145 * plus the addition of saving the parent directory that contains the
146 * name in ni_startdir. It allows repeated calls to lookup for the
147 * name being sought. The caller is responsible for releasing the
148 * buffer and for vrele'ing ni_startdir.
150 #define RDONLY 0x00000200 /* lookup with read-only semantics */
151 #define SAVENAME 0x00000400 /* save pathname buffer */
152 #define SAVESTART 0x00000800 /* save starting directory */
153 #define ISWHITEOUT 0x00001000 /* found whiteout */
154 #define DOWHITEOUT 0x00002000 /* do whiteouts */
155 #define WILLBEDIR 0x00004000 /* new files will be dirs; allow trailing / */
156 #define ISOPEN 0x00008000 /* caller is opening; return a real vnode. */
157 #define NOCROSSMOUNT 0x00010000 /* do not cross mount points */
158 #define NOMACCHECK 0x00020000 /* do not perform MAC checks */
159 #define AUDITVNODE1 0x00040000 /* audit the looked up vnode information */
160 #define AUDITVNODE2 0x00080000 /* audit the looked up vnode information */
161 #define NOCAPCHECK 0x00100000 /* do not perform capability checks */
162 /* UNUSED 0x00200000 */
163 /* UNUSED 0x00400000 */
164 /* UNUSED 0x00800000 */
165 #define HASBUF 0x01000000 /* has allocated pathname buffer */
166 #define NOEXECCHECK 0x02000000 /* do not perform exec check on dir */
167 #define MAKEENTRY 0x04000000 /* entry is to be added to name cache */
168 #define ISSYMLINK 0x08000000 /* symlink needs interpretation */
169 #define ISLASTCN 0x10000000 /* this is last component of pathname */
170 #define ISDOTDOT 0x20000000 /* current component name is .. */
171 #define TRAILINGSLASH 0x40000000 /* path ended in a slash */
172 #define PARAMASK 0x7ffffe00 /* mask of parameter descriptors */
175 * Flags which must not be passed in by callers.
177 #define NAMEI_INTERNAL_FLAGS \
178 (HASBUF | NOEXECCHECK | MAKEENTRY | ISSYMLINK | ISLASTCN | ISDOTDOT | \
182 * Namei results flags
184 #define NIRES_ABS 0x00000001 /* Path was absolute */
187 * Flags in ni_lcf, valid for the duration of the namei call.
189 #define NI_LCF_STRICTRELATIVE 0x0001 /* relative lookup only */
190 #define NI_LCF_CAP_DOTDOT 0x0002 /* ".." in strictrelative case */
191 #define NI_LCF_BENEATH_ABS 0x0004 /* BENEATH with absolute path */
192 #define NI_LCF_BENEATH_LATCHED 0x0008 /* BENEATH_ABS traversed starting dir */
193 #define NI_LCF_LATCH 0x0010 /* ni_beneath_latch valid */
196 * Initialization of a nameidata structure.
198 #define NDINIT(ndp, op, flags, segflg, namep, td) \
199 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, &cap_no_rights, td)
200 #define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd, td) \
201 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, &cap_no_rights, td)
202 #define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp, td) \
203 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp, td)
204 #define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp, td) \
205 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, &cap_no_rights, td)
208 * Note the constant pattern may *hide* bugs.
211 #define NDINIT_PREFILL(arg) memset(arg, 0xff, sizeof(*arg))
213 #define NDINIT_PREFILL(arg) do { } while (0)
216 #define NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, startdir, rightsp, td) \
218 struct nameidata *_ndp = (ndp); \
219 cap_rights_t *_rightsp = (rightsp); \
220 MPASS(_rightsp != NULL); \
221 NDINIT_PREFILL(_ndp); \
222 _ndp->ni_cnd.cn_nameiop = op; \
223 _ndp->ni_cnd.cn_flags = flags; \
224 _ndp->ni_segflg = segflg; \
225 _ndp->ni_dirp = namep; \
226 _ndp->ni_dirfd = dirfd; \
227 _ndp->ni_startdir = startdir; \
228 _ndp->ni_resflags = 0; \
229 filecaps_init(&_ndp->ni_filecaps); \
230 _ndp->ni_cnd.cn_thread = td; \
231 _ndp->ni_rightsneeded = _rightsp; \
234 #define NDF_NO_DVP_RELE 0x00000001
235 #define NDF_NO_DVP_UNLOCK 0x00000002
236 #define NDF_NO_DVP_PUT 0x00000003
237 #define NDF_NO_VP_RELE 0x00000004
238 #define NDF_NO_VP_UNLOCK 0x00000008
239 #define NDF_NO_VP_PUT 0x0000000c
240 #define NDF_NO_STARTDIR_RELE 0x00000010
241 #define NDF_NO_FREE_PNBUF 0x00000020
242 #define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF)
244 void NDFREE_PNBUF(struct nameidata *);
245 void NDFREE(struct nameidata *, const u_int);
246 #define NDFREE(ndp, flags) do { \
247 struct nameidata *_ndp = (ndp); \
248 if (__builtin_constant_p(flags) && flags == NDF_ONLY_PNBUF) \
249 NDFREE_PNBUF(_ndp); \
251 NDFREE(_ndp, flags); \
254 int namei(struct nameidata *ndp);
255 int lookup(struct nameidata *ndp);
256 int relookup(struct vnode *dvp, struct vnode **vpp,
257 struct componentname *cnp);
261 * Stats on usefulness of namei caches.
264 long ncs_goodhits; /* hits that we can really use */
265 long ncs_neghits; /* negative hits that we can use */
266 long ncs_badhits; /* hits we must drop */
267 long ncs_falsehits; /* hits with id mismatch */
268 long ncs_miss; /* misses */
269 long ncs_long; /* long names that ignore cache */
270 long ncs_pass2; /* names found with passes == 2 */
271 long ncs_2passes; /* number of times we attempt it */
274 extern struct nchstats nchstats;
276 #endif /* !_SYS_NAMEI_H_ */