1 /*-
2 * Copyright (c) 1985, 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)namei.h 8.5 (Berkeley) 1/9/95
30 * $FreeBSD: stable/9/sys/sys/namei.h 224810 2011-08-13 09:21:16Z jonathan $
31 */
32
33 #ifndef _SYS_NAMEI_H_
34 #define _SYS_NAMEI_H_
35
36 #include <sys/queue.h>
37 #include <sys/uio.h>
38
39 struct componentname {
40 /*
41 * Arguments to lookup.
42 */
43 u_long cn_nameiop; /* namei operation */
44 u_int64_t cn_flags; /* flags to namei */
45 struct thread *cn_thread;/* thread requesting lookup */
46 struct ucred *cn_cred; /* credentials */
47 int cn_lkflags; /* Lock flags LK_EXCLUSIVE or LK_SHARED */
48 /*
49 * Shared between lookup and commit routines.
50 */
51 char *cn_pnbuf; /* pathname buffer */
52 char *cn_nameptr; /* pointer to looked up name */
53 long cn_namelen; /* length of looked up component */
54 long cn_consume; /* chars to consume in lookup() */
55 };
56
57 /*
58 * Encapsulation of namei parameters.
59 */
60 struct nameidata {
61 /*
62 * Arguments to namei/lookup.
63 */
64 const char *ni_dirp; /* pathname pointer */
65 enum uio_seg ni_segflg; /* location of pathname */
66 cap_rights_t ni_rightsneeded; /* rights required to look up vnode */
67 /*
68 * Arguments to lookup.
69 */
70 struct vnode *ni_startdir; /* starting directory */
71 struct vnode *ni_rootdir; /* logical root directory */
72 struct vnode *ni_topdir; /* logical top directory */
73 int ni_dirfd; /* starting directory for *at functions */
74 int ni_strictrelative; /* relative lookup only; no '..' */
75 /*
76 * Results: returned from namei
77 */
78 cap_rights_t ni_baserights; /* rights the *at base has (or -1) */
79 /*
80 * Results: returned from/manipulated by lookup
81 */
82 struct vnode *ni_vp; /* vnode of result */
83 struct vnode *ni_dvp; /* vnode of intermediate directory */
84 /*
85 * Shared between namei and lookup/commit routines.
86 */
87 size_t ni_pathlen; /* remaining chars in path */
88 char *ni_next; /* next location in pathname */
89 u_int ni_loopcnt; /* count of symlinks encountered */
90 /*
91 * Lookup parameters: this structure describes the subset of
92 * information from the nameidata structure that is passed
93 * through the VOP interface.
94 */
95 struct componentname ni_cnd;
96 };
97
98 #ifdef _KERNEL
99 /*
100 * namei operations
101 */
102 #define LOOKUP 0 /* perform name lookup only */
103 #define CREATE 1 /* setup for file creation */
104 #define DELETE 2 /* setup for file deletion */
105 #define RENAME 3 /* setup for file renaming */
106 #define OPMASK 3 /* mask for operation */
107 /*
108 * namei operational modifier flags, stored in ni_cnd.flags
109 */
110 #define LOCKLEAF 0x0004 /* lock inode on return */
111 #define LOCKPARENT 0x0008 /* want parent vnode returned locked */
112 #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */
113 #define NOCACHE 0x0020 /* name must not be left in cache */
114 #define FOLLOW 0x0040 /* follow symbolic links */
115 #define LOCKSHARED 0x0100 /* Shared lock leaf */
116 #define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */
117 #define MODMASK 0x01fc /* mask of operational modifiers */
118 /*
119 * Namei parameter descriptors.
120 *
121 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP.
122 * If the caller of namei sets the flag (for example execve wants to
123 * know the name of the program that is being executed), then it must
124 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must
125 * be freed by either the commit routine or the VOP_ABORT routine.
126 * SAVESTART is set only by the callers of namei. It implies SAVENAME
127 * plus the addition of saving the parent directory that contains the
128 * name in ni_startdir. It allows repeated calls to lookup for the
129 * name being sought. The caller is responsible for releasing the
130 * buffer and for vrele'ing ni_startdir.
131 */
132 #define RDONLY 0x00000200 /* lookup with read-only semantics */
133 #define HASBUF 0x00000400 /* has allocated pathname buffer */
134 #define SAVENAME 0x00000800 /* save pathname buffer */
135 #define SAVESTART 0x00001000 /* save starting directory */
136 #define ISDOTDOT 0x00002000 /* current component name is .. */
137 #define MAKEENTRY 0x00004000 /* entry is to be added to name cache */
138 #define ISLASTCN 0x00008000 /* this is last component of pathname */
139 #define ISSYMLINK 0x00010000 /* symlink needs interpretation */
140 #define ISWHITEOUT 0x00020000 /* found whiteout */
141 #define DOWHITEOUT 0x00040000 /* do whiteouts */
142 #define WILLBEDIR 0x00080000 /* new files will be dirs; allow trailing / */
143 #define ISUNICODE 0x00100000 /* current component name is unicode*/
144 #define ISOPEN 0x00200000 /* caller is opening; return a real vnode. */
145 #define NOCROSSMOUNT 0x00400000 /* do not cross mount points */
146 #define NOMACCHECK 0x00800000 /* do not perform MAC checks */
147 #define MPSAFE 0x01000000 /* namei() must acquire Giant if needed. */
148 #define GIANTHELD 0x02000000 /* namei() is holding giant. */
149 #define AUDITVNODE1 0x04000000 /* audit the looked up vnode information */
150 #define AUDITVNODE2 0x08000000 /* audit the looked up vnode information */
151 #define TRAILINGSLASH 0x10000000 /* path ended in a slash */
152 #define PARAMASK 0x1ffffe00 /* mask of parameter descriptors */
153
154 #define NDHASGIANT(NDP) (((NDP)->ni_cnd.cn_flags & GIANTHELD) != 0)
155
156 /*
157 * Initialization of a nameidata structure.
158 */
159 #define NDINIT(ndp, op, flags, segflg, namep, td) \
160 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, 0, td)
161 #define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd, td) \
162 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, 0, td)
163 #define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rights, td) \
164 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rights, td)
165 #define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp, td) \
166 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, 0, td)
167
168 static __inline void
NDINIT_ALL(struct nameidata * ndp,u_long op,u_long flags,enum uio_seg segflg,const char * namep,int dirfd,struct vnode * startdir,cap_rights_t rights,struct thread * td)169 NDINIT_ALL(struct nameidata *ndp,
170 u_long op, u_long flags,
171 enum uio_seg segflg,
172 const char *namep,
173 int dirfd,
174 struct vnode *startdir,
175 cap_rights_t rights,
176 struct thread *td)
177 {
178 ndp->ni_cnd.cn_nameiop = op;
179 ndp->ni_cnd.cn_flags = flags;
180 ndp->ni_segflg = segflg;
181 ndp->ni_dirp = namep;
182 ndp->ni_dirfd = dirfd;
183 ndp->ni_startdir = startdir;
184 ndp->ni_strictrelative = 0;
185 ndp->ni_rightsneeded = rights;
186 ndp->ni_baserights = 0;
187 ndp->ni_cnd.cn_thread = td;
188 }
189
190 #define NDF_NO_DVP_RELE 0x00000001
191 #define NDF_NO_DVP_UNLOCK 0x00000002
192 #define NDF_NO_DVP_PUT 0x00000003
193 #define NDF_NO_VP_RELE 0x00000004
194 #define NDF_NO_VP_UNLOCK 0x00000008
195 #define NDF_NO_VP_PUT 0x0000000c
196 #define NDF_NO_STARTDIR_RELE 0x00000010
197 #define NDF_NO_FREE_PNBUF 0x00000020
198 #define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF)
199
200 void NDFREE(struct nameidata *, const u_int);
201
202 int namei(struct nameidata *ndp);
203 int lookup(struct nameidata *ndp);
204 int relookup(struct vnode *dvp, struct vnode **vpp,
205 struct componentname *cnp);
206 #endif
207
208 /*
209 * Stats on usefulness of namei caches.
210 */
211 struct nchstats {
212 long ncs_goodhits; /* hits that we can really use */
213 long ncs_neghits; /* negative hits that we can use */
214 long ncs_badhits; /* hits we must drop */
215 long ncs_falsehits; /* hits with id mismatch */
216 long ncs_miss; /* misses */
217 long ncs_long; /* long names that ignore cache */
218 long ncs_pass2; /* names found with passes == 2 */
219 long ncs_2passes; /* number of times we attempt it */
220 };
221
222 extern struct nchstats nchstats;
223
224 #endif /* !_SYS_NAMEI_H_ */
225