master
1/* $NetBSD: namei.h,v 1.115 2021/06/29 22:40:06 dholland Exp $ */
2
3
4/*
5 * WARNING: GENERATED FILE. DO NOT EDIT
6 * (edit namei.src and run make namei in src/sys/sys)
7 * by: NetBSD: gennameih.awk,v 1.5 2009/12/23 14:17:19 pooka Exp
8 * from: NetBSD: namei.src,v 1.60 2021/06/29 22:39:21 dholland Exp
9 */
10
11/*
12 * Copyright (c) 1985, 1989, 1991, 1993
13 * The Regents of the University of California. All rights reserved.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
23 * 3. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 * @(#)namei.h 8.5 (Berkeley) 8/20/94
40 */
41
42#ifndef _SYS_NAMEI_H_
43#define _SYS_NAMEI_H_
44
45#include <sys/queue.h>
46#include <sys/mutex.h>
47
48#if defined(_KERNEL) || defined(_MODULE)
49#include <sys/kauth.h>
50#include <sys/rwlock.h>
51
52/*
53 * Abstraction for a single pathname.
54 *
55 * This contains both the pathname string and (eventually) all
56 * metadata that determines how the path is to be interpreted.
57 * It is an opaque structure; the implementation is in vfs_lookup.c.
58 *
59 * To call namei, first set up a pathbuf with pathbuf_create or
60 * pathbuf_copyin, then do NDINIT(), then call namei, then AFTER THE
61 * STRUCT NAMEIDATA IS DEAD, call pathbuf_destroy. Don't destroy the
62 * pathbuf before you've finished using the nameidata, or mysterious
63 * bad things may happen.
64 *
65 * pathbuf_assimilate is like pathbuf_create but assumes ownership of
66 * the string buffer passed in, which MUST BE of size PATH_MAX and
67 * have been allocated with PNBUF_GET(). This should only be used when
68 * absolutely necessary; e.g. nfsd uses it for loading paths from
69 * mbufs.
70 */
71struct pathbuf;
72
73struct pathbuf *pathbuf_create(const char *path);
74struct pathbuf *pathbuf_assimilate(char *path);
75int pathbuf_copyin(const char *userpath, struct pathbuf **ret);
76void pathbuf_destroy(struct pathbuf *);
77
78/* get a copy of the (current) path string */
79void pathbuf_copystring(const struct pathbuf *, char *buf, size_t maxlen);
80
81/* hold a reference copy of the original path string */
82const char *pathbuf_stringcopy_get(struct pathbuf *);
83void pathbuf_stringcopy_put(struct pathbuf *, const char *);
84
85// XXX remove this
86int pathbuf_maybe_copyin(const char *userpath, enum uio_seg seg, struct pathbuf **ret);
87
88/*
89 * Lookup parameters: this structure describes the subset of
90 * information from the nameidata structure that is passed
91 * through the VOP interface.
92 */
93struct componentname {
94 /*
95 * Arguments to lookup.
96 */
97 uint32_t cn_nameiop; /* namei operation */
98 uint32_t cn_flags; /* flags to namei */
99 kauth_cred_t cn_cred; /* credentials */
100 /*
101 * Shared between lookup and commit routines.
102 */
103 const char *cn_nameptr; /* pointer to looked up name */
104 size_t cn_namelen; /* length of looked up comp */
105};
106
107/*
108 * Encapsulation of namei parameters.
109 */
110struct nameidata {
111 /*
112 * Arguments to namei/lookup.
113 */
114 struct vnode *ni_atdir; /* startup dir, cwd if null */
115 struct pathbuf *ni_pathbuf; /* pathname container */
116 char *ni_pnbuf; /* extra pathname buffer ref (XXX) */
117 /*
118 * Arguments to lookup.
119 */
120 struct vnode *ni_rootdir; /* logical root directory */
121 struct vnode *ni_erootdir; /* emulation root directory */
122 /*
123 * Results: returned from/manipulated by lookup
124 */
125 struct vnode *ni_vp; /* vnode of result */
126 struct vnode *ni_dvp; /* vnode of intermediate directory */
127 /*
128 * Shared between namei and lookup/commit routines.
129 */
130 size_t ni_pathlen; /* remaining chars in path */
131 const char *ni_next; /* next location in pathname */
132 unsigned int ni_loopcnt; /* count of symlinks encountered */
133 /*
134 * Lookup parameters: this structure describes the subset of
135 * information from the nameidata structure that is passed
136 * through the VOP interface.
137 */
138 struct componentname ni_cnd;
139};
140
141/*
142 * namei operations
143 */
144#define LOOKUP 0 /* perform name lookup only */
145#define CREATE 1 /* setup for file creation */
146#define DELETE 2 /* setup for file deletion */
147#define RENAME 3 /* setup for file renaming */
148#define OPMASK 3 /* mask for operation */
149/*
150 * namei operational modifier flags, stored in ni_cnd.cn_flags
151 */
152#define LOCKLEAF 0x00000004 /* lock inode on return */
153#define LOCKPARENT 0x00000008 /* want parent vnode returned locked */
154#define TRYEMULROOT 0x00000010 /* try relative to emulation root
155 first */
156#define NOCACHE 0x00000020 /* name must not be left in cache */
157#define FOLLOW 0x00000040 /* follow symbolic links */
158#define NOFOLLOW 0x00000000 /* do not follow symbolic links
159 (pseudo) */
160#define EMULROOTSET 0x00000080 /* emulation root already
161 in ni_erootdir */
162#define LOCKSHARED 0x00000100 /* want shared locks if possible */
163#define NOCHROOT 0x01000000 /* no chroot on abs path lookups */
164#define NONEXCLHACK 0x02000000 /* open wwith O_CREAT but not O_EXCL */
165#define MODMASK 0x030001fc /* mask of operational modifiers */
166/*
167 * Namei parameter descriptors.
168 */
169#define NOCROSSMOUNT 0x0000800 /* do not cross mount points */
170#define RDONLY 0x0001000 /* lookup with read-only semantics */
171#define ISDOTDOT 0x0002000 /* current component name is .. */
172#define MAKEENTRY 0x0004000 /* entry is to be added to name cache */
173#define ISLASTCN 0x0008000 /* this is last component of pathname */
174#define WILLBEDIR 0x0010000 /* new files will be dirs */
175#define ISWHITEOUT 0x0020000 /* found whiteout */
176#define DOWHITEOUT 0x0040000 /* do whiteouts */
177#define REQUIREDIR 0x0080000 /* must be a directory */
178#define CREATEDIR 0x0200000 /* trailing slashes are ok */
179#define PARAMASK 0x02ff800 /* mask of parameter descriptors */
180
181/*
182 * Initialization of a nameidata structure.
183 */
184#define NDINIT(ndp, op, flags, pathbuf) { \
185 (ndp)->ni_cnd.cn_nameiop = op; \
186 (ndp)->ni_cnd.cn_flags = flags; \
187 (ndp)->ni_atdir = NULL; \
188 (ndp)->ni_pathbuf = pathbuf; \
189 (ndp)->ni_cnd.cn_cred = kauth_cred_get(); \
190}
191
192/*
193 * Use this to set the start directory for openat()-type operations.
194 */
195#define NDAT(ndp, dir) { \
196 (ndp)->ni_atdir = (dir); \
197}
198
199#endif
200
201#ifdef __NAMECACHE_PRIVATE
202#include <sys/rbtree.h>
203
204/*
205 * For simplicity (and economy of storage), names longer than
206 * a maximum length of NCHNAMLEN are stored in non-pooled storage.
207 */
208#define NCHNAMLEN sizeof(((struct namecache *)NULL)->nc_name)
209
210/*
211 * Namecache entry.
212 *
213 * This structure describes the elements in the cache of recent names looked
214 * up by namei. It's carefully sized to take up 128 bytes on _LP64, to make
215 * good use of space and the CPU caches. Items used during RB tree lookup
216 * (nc_tree, nc_key) are clustered at the start of the structure.
217 *
218 * Field markings and their corresponding locks:
219 *
220 * - stable throughout the lifetime of the namecache entry
221 * d protected by nc_dvp->vi_nc_lock
222 * v protected by nc_vp->vi_nc_listlock
223 * l protected by cache_lru_lock
224 */
225struct namecache {
226 struct rb_node nc_tree; /* d red-black tree, must be first */
227 uint64_t nc_key; /* - hashed key value */
228 TAILQ_ENTRY(namecache) nc_list; /* v nc_vp's list of cache entries */
229 TAILQ_ENTRY(namecache) nc_lru; /* l pseudo-lru chain */
230 struct vnode *nc_dvp; /* - vnode of parent of name */
231 struct vnode *nc_vp; /* - vnode the name refers to */
232 int nc_lrulist; /* l which LRU list it's on */
233 u_short nc_nlen; /* - length of the name */
234 char nc_whiteout; /* - true if a whiteout */
235 char nc_name[41]; /* - segment name */
236};
237#endif
238
239#ifdef _KERNEL
240#include <sys/pool.h>
241
242struct mount;
243struct cpu_info;
244
245extern pool_cache_t pnbuf_cache; /* pathname buffer cache */
246
247#define PNBUF_GET() ((char *)pool_cache_get(pnbuf_cache, PR_WAITOK))
248#define PNBUF_PUT(pnb) pool_cache_put(pnbuf_cache, (void *)(pnb))
249
250/*
251 * Typesafe flags for namei_simple/nameiat_simple.
252 *
253 * This encoding is not optimal but serves the important purpose of
254 * not being type-compatible with the regular namei flags.
255 */
256struct namei_simple_flags_type; /* Opaque. */
257typedef const struct namei_simple_flags_type *namei_simple_flags_t; /* Gross. */
258extern const namei_simple_flags_t
259 NSM_NOFOLLOW_NOEMULROOT,
260 NSM_NOFOLLOW_TRYEMULROOT,
261 NSM_FOLLOW_NOEMULROOT,
262 NSM_FOLLOW_TRYEMULROOT;
263
264/*
265 * namei(at)?_simple_* - the simple cases of namei, with no struct
266 * nameidata involved.
267 *
268 * namei_simple_kernel takes a kernel-space path as the first argument.
269 * namei_simple_user takes a user-space path as the first argument.
270 * The nameiat_simple_* variants handle relative path using the given
271 * directory vnode instead of current directory.
272 *
273 * A namei call can be converted to namei_simple_* if:
274 * - the second arg to NDINIT is LOOKUP;
275 * - it does not need the parent vnode, nd.ni_dvp;
276 * - the only flags it uses are (NO)FOLLOW and TRYEMULROOT;
277 * - it does not do anything else gross with the contents of nd.
278 */
279int namei_simple_kernel(const char *, namei_simple_flags_t, struct vnode **);
280int namei_simple_user(const char *, namei_simple_flags_t, struct vnode **);
281int nameiat_simple_kernel(struct vnode *, const char *, namei_simple_flags_t,
282 struct vnode **);
283int nameiat_simple_user(struct vnode *, const char *, namei_simple_flags_t,
284 struct vnode **);
285
286int namei(struct nameidata *);
287uint32_t namei_hash(const char *, const char **);
288int lookup_for_nfsd(struct nameidata *, struct vnode *, int neverfollow);
289int lookup_for_nfsd_index(struct nameidata *, struct vnode *);
290int relookup(struct vnode *, struct vnode **, struct componentname *, int);
291void cache_purge1(struct vnode *, const char *, size_t, int);
292#define PURGE_PARENTS 1
293#define PURGE_CHILDREN 2
294#define cache_purge(vp) cache_purge1((vp),NULL,0,PURGE_PARENTS|PURGE_CHILDREN)
295bool cache_lookup(struct vnode *, const char *, size_t, uint32_t, uint32_t,
296 int *, struct vnode **);
297bool cache_lookup_raw(struct vnode *, const char *, size_t, uint32_t,
298 int *, struct vnode **);
299bool cache_lookup_linked(struct vnode *, const char *, size_t,
300 struct vnode **, krwlock_t **, kauth_cred_t);
301int cache_revlookup(struct vnode *, struct vnode **, char **, char *,
302 bool, accmode_t);
303int cache_diraccess(struct vnode *, int);
304void cache_enter(struct vnode *, struct vnode *,
305 const char *, size_t, uint32_t);
306void cache_enter_id(struct vnode *, mode_t, uid_t, gid_t, bool);
307bool cache_have_id(struct vnode *);
308void cache_vnode_init(struct vnode * );
309void cache_vnode_fini(struct vnode * );
310void cache_cpu_init(struct cpu_info *);
311void cache_enter_mount(struct vnode *, struct vnode *);
312bool cache_cross_mount(struct vnode **, krwlock_t **);
313bool cache_lookup_mount(struct vnode *, struct vnode **);
314
315void nchinit(void);
316void namecache_count_pass2(void);
317void namecache_count_2passes(void);
318void cache_purgevfs(struct mount *);
319void namecache_print(struct vnode *, void (*)(const char *, ...)
320 __printflike(1, 2));
321
322#endif
323
324/*
325 * Stats on usefulness of namei caches. A couple of structures are
326 * used for counting, with members having the same names but different
327 * types. Containerize member names with the preprocessor to avoid
328 * cut-'n'-paste.
329 */
330#define _NAMEI_CACHE_STATS(type) { \
331 type ncs_goodhits; /* hits that we can really use */ \
332 type ncs_neghits; /* negative hits that we can use */ \
333 type ncs_badhits; /* hits we must drop */ \
334 type ncs_falsehits; /* hits with id mismatch */ \
335 type ncs_miss; /* misses */ \
336 type ncs_long; /* long names that ignore cache */ \
337 type ncs_pass2; /* names found with passes == 2 */ \
338 type ncs_2passes; /* number of times we attempt it */ \
339 type ncs_revhits; /* reverse-cache hits */ \
340 type ncs_revmiss; /* reverse-cache misses */ \
341 type ncs_denied; /* access denied */ \
342}
343
344/*
345 * Sysctl deals with a uint64_t version of the stats and summary
346 * totals are kept that way.
347 */
348struct nchstats _NAMEI_CACHE_STATS(uint64_t);
349
350/* #endif !_SYS_NAMEI_H_ (generated by gennameih.awk) */
351
352/* Definitions match above, but with NAMEI_ prefix */
353#define NAMEI_LOOKUP 0
354#define NAMEI_CREATE 1
355#define NAMEI_DELETE 2
356#define NAMEI_RENAME 3
357#define NAMEI_OPMASK 3
358#define NAMEI_LOCKLEAF 0x00000004
359#define NAMEI_LOCKPARENT 0x00000008
360#define NAMEI_TRYEMULROOT 0x00000010
361#define NAMEI_NOCACHE 0x00000020
362#define NAMEI_FOLLOW 0x00000040
363#define NAMEI_NOFOLLOW 0x00000000
364#define NAMEI_EMULROOTSET 0x00000080
365#define NAMEI_LOCKSHARED 0x00000100
366#define NAMEI_NOCHROOT 0x01000000
367#define NAMEI_NONEXCLHACK 0x02000000
368#define NAMEI_MODMASK 0x030001fc
369#define NAMEI_NOCROSSMOUNT 0x0000800
370#define NAMEI_RDONLY 0x0001000
371#define NAMEI_ISDOTDOT 0x0002000
372#define NAMEI_MAKEENTRY 0x0004000
373#define NAMEI_ISLASTCN 0x0008000
374#define NAMEI_WILLBEDIR 0x0010000
375#define NAMEI_ISWHITEOUT 0x0020000
376#define NAMEI_DOWHITEOUT 0x0040000
377#define NAMEI_REQUIREDIR 0x0080000
378#define NAMEI_CREATEDIR 0x0200000
379#define NAMEI_PARAMASK 0x02ff800
380
381#endif /* !_SYS_NAMEI_H_ */