1 /* $NetBSD: namei.h,v 1.120 2024/07/01 00:58:43 christos 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 1.65 2024/07/01 00:58:05 christos 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 */ 71 struct pathbuf; 72 73 struct pathbuf *pathbuf_create(const char *path); 74 struct pathbuf *pathbuf_assimilate(char *path); 75 int pathbuf_copyin(const char *userpath, struct pathbuf **ret); 76 void pathbuf_destroy(struct pathbuf *); 77 78 /* get a copy of the (current) path string */ 79 void pathbuf_copystring(const struct pathbuf *, char *buf, size_t maxlen); 80 81 /* hold a reference copy of the original path string */ 82 const char *pathbuf_stringcopy_get(struct pathbuf *); 83 void pathbuf_stringcopy_put(struct pathbuf *, const char *); 84 85 // XXX remove this 86 int 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 */ 93 struct 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 */ 110 struct 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 * The uintptr_t-sized key value computed for each name consists of name 212 * length and a hash value. On 32-bit platforms the top NC_NLEN_BITS of 213 * the 32-bit hash value is lobbed off. 214 */ 215 216 #define NC_NLEN_BITS 11 217 #define NC_NLEN_MASK ((1 << NC_NLEN_BITS) - 1) 218 #define NC_NLEN(ncp) ((ncp)->nc_key & NC_NLEN_MASK) 219 220 /* 221 * Namecache entry. 222 * 223 * This structure describes the elements in the cache of recent names looked 224 * up by namei. It's carefully sized to take up 128 bytes on _LP64 and 64 225 * bytes on 32-bit machines, to make good use of space and the CPU caches. 226 * 227 * Items used during RB tree lookup (nc_tree, nc_key) are clustered at the 228 * start of the structure to minimise cache misses during lookup. 229 * 230 * Field markings and their corresponding locks: 231 * 232 * - stable throughout the lifetime of the namecache entry 233 * d protected by nc_dvp->vi_nc_lock 234 * v protected by nc_vp->vi_nc_listlock 235 * l protected by cache_lru_lock 236 */ 237 struct namecache { 238 struct rb_node nc_tree; /* d red-black tree, must be first */ 239 uintptr_t nc_key; /* - hashed key value */ 240 TAILQ_ENTRY(namecache) nc_list; /* v nc_vp's list of cache entries */ 241 TAILQ_ENTRY(namecache) nc_lru; /* l pseudo-lru chain */ 242 struct vnode *nc_dvp; /* - vnode of parent of name */ 243 struct vnode *nc_vp; /* - vnode the name refers to */ 244 u_char nc_lrulist; /* l LRU list entry is on */ 245 u_char nc_whiteout; /* - whiteout indicator */ 246 #ifdef _LP64 247 char nc_name[46]; /* - segment name */ 248 #else 249 char nc_name[22]; /* - segment name */ 250 #endif 251 }; 252 #endif /* __NAMECACHE_PRIVATE */ 253 254 #ifdef _KERNEL 255 #include <sys/kmem.h> 256 257 struct mount; 258 struct cpu_info; 259 260 #define PNBUF_GET() ((char *)kmem_alloc(MAXPATHLEN, KM_SLEEP)) 261 #define PNBUF_PUT(pnb) kmem_free((pnb), MAXPATHLEN) 262 263 /* 264 * Typesafe flags for namei_simple/nameiat_simple. 265 * 266 * This encoding is not optimal but serves the important purpose of 267 * not being type-compatible with the regular namei flags. 268 */ 269 struct namei_simple_flags_type; /* Opaque. */ 270 typedef const struct namei_simple_flags_type *namei_simple_flags_t; /* Gross. */ 271 extern const namei_simple_flags_t 272 NSM_NOFOLLOW_NOEMULROOT, 273 NSM_NOFOLLOW_TRYEMULROOT, 274 NSM_FOLLOW_NOEMULROOT, 275 NSM_FOLLOW_TRYEMULROOT; 276 277 /* 278 * namei(at)?_simple_* - the simple cases of namei, with no struct 279 * nameidata involved. 280 * 281 * namei_simple_kernel takes a kernel-space path as the first argument. 282 * namei_simple_user takes a user-space path as the first argument. 283 * The nameiat_simple* variants handle relative path using the given 284 * directory vnode instead of current directory. 285 * 286 * A namei call can be converted to namei_simple_* if: 287 * - the second arg to NDINIT is LOOKUP; 288 * - it does not need the parent vnode, nd.ni_dvp; 289 * - the only flags it uses are (NO)FOLLOW and TRYEMULROOT; 290 * - it does not do anything else gross with the contents of nd. 291 */ 292 int namei_simple_kernel(const char *, namei_simple_flags_t, struct vnode **); 293 int namei_simple_user(const char *, namei_simple_flags_t, struct vnode **); 294 int nameiat_simple(struct vnode *, struct pathbuf *, namei_simple_flags_t, 295 struct vnode **); 296 int nameiat_simple_kernel(struct vnode *, const char *, namei_simple_flags_t, 297 struct vnode **); 298 int nameiat_simple_user(struct vnode *, const char *, namei_simple_flags_t, 299 struct vnode **); 300 301 int namei(struct nameidata *); 302 uint32_t namei_hash(const char *, const char **); 303 int lookup_for_nfsd(struct nameidata *, struct vnode *, int neverfollow); 304 int lookup_for_nfsd_index(struct nameidata *, struct vnode *); 305 int relookup(struct vnode *, struct vnode **, struct componentname *, int); 306 void cache_purge1(struct vnode *, const char *, size_t, int); 307 #define PURGE_PARENTS 1 308 #define PURGE_CHILDREN 2 309 #define cache_purge(vp) cache_purge1((vp),NULL,0,PURGE_PARENTS|PURGE_CHILDREN) 310 bool cache_lookup(struct vnode *, const char *, size_t, uint32_t, uint32_t, 311 int *, struct vnode **); 312 bool cache_lookup_raw(struct vnode *, const char *, size_t, uint32_t, 313 int *, struct vnode **); 314 bool cache_lookup_linked(struct vnode *, const char *, size_t, 315 struct vnode **, krwlock_t **, kauth_cred_t); 316 int cache_revlookup(struct vnode *, struct vnode **, char **, char *, 317 bool, accmode_t); 318 int cache_diraccess(struct vnode *, int); 319 void cache_enter(struct vnode *, struct vnode *, 320 const char *, size_t, uint32_t); 321 void cache_enter_id(struct vnode *, mode_t, uid_t, gid_t, bool); 322 bool cache_have_id(struct vnode *); 323 void cache_vnode_init(struct vnode * ); 324 void cache_vnode_fini(struct vnode * ); 325 void cache_cpu_init(struct cpu_info *); 326 void cache_enter_mount(struct vnode *, struct vnode *); 327 bool cache_cross_mount(struct vnode **, krwlock_t **); 328 bool cache_lookup_mount(struct vnode *, struct vnode **); 329 330 void nchinit(void); 331 void namecache_count_pass2(void); 332 void namecache_count_2passes(void); 333 void cache_purgevfs(struct mount *); 334 void namecache_print(struct vnode *, void (*)(const char *, ...) 335 __printflike(1, 2)); 336 337 #endif 338 339 /* 340 * Stats on usefulness of namei caches. A couple of structures are 341 * used for counting, with members having the same names but different 342 * types. Containerize member names with the preprocessor to avoid 343 * cut-'n'-paste. 344 */ 345 #define _NAMEI_CACHE_STATS(type) { \ 346 type ncs_goodhits; /* hits that we can really use */ \ 347 type ncs_neghits; /* negative hits that we can use */ \ 348 type ncs_badhits; /* hits we must drop */ \ 349 type ncs_falsehits; /* hits with id mismatch */ \ 350 type ncs_miss; /* misses */ \ 351 type ncs_long; /* long names that ignore cache */ \ 352 type ncs_pass2; /* names found with passes == 2 */ \ 353 type ncs_2passes; /* number of times we attempt it */ \ 354 type ncs_revhits; /* reverse-cache hits */ \ 355 type ncs_revmiss; /* reverse-cache misses */ \ 356 type ncs_denied; /* access denied */ \ 357 } 358 359 /* 360 * Sysctl deals with a uint64_t version of the stats and summary 361 * totals are kept that way. 362 */ 363 struct nchstats _NAMEI_CACHE_STATS(uint64_t); 364 365 /* #endif !_SYS_NAMEI_H_ (generated by gennameih.awk) */ 366 367 /* Definitions match above, but with NAMEI_ prefix */ 368 #define NAMEI_LOOKUP 0 369 #define NAMEI_CREATE 1 370 #define NAMEI_DELETE 2 371 #define NAMEI_RENAME 3 372 #define NAMEI_OPMASK 3 373 #define NAMEI_LOCKLEAF 0x00000004 374 #define NAMEI_LOCKPARENT 0x00000008 375 #define NAMEI_TRYEMULROOT 0x00000010 376 #define NAMEI_NOCACHE 0x00000020 377 #define NAMEI_FOLLOW 0x00000040 378 #define NAMEI_NOFOLLOW 0x00000000 379 #define NAMEI_EMULROOTSET 0x00000080 380 #define NAMEI_LOCKSHARED 0x00000100 381 #define NAMEI_NOCHROOT 0x01000000 382 #define NAMEI_NONEXCLHACK 0x02000000 383 #define NAMEI_MODMASK 0x030001fc 384 #define NAMEI_NOCROSSMOUNT 0x0000800 385 #define NAMEI_RDONLY 0x0001000 386 #define NAMEI_ISDOTDOT 0x0002000 387 #define NAMEI_MAKEENTRY 0x0004000 388 #define NAMEI_ISLASTCN 0x0008000 389 #define NAMEI_WILLBEDIR 0x0010000 390 #define NAMEI_ISWHITEOUT 0x0020000 391 #define NAMEI_DOWHITEOUT 0x0040000 392 #define NAMEI_REQUIREDIR 0x0080000 393 #define NAMEI_CREATEDIR 0x0200000 394 #define NAMEI_PARAMASK 0x02ff800 395 396 #endif /* !_SYS_NAMEI_H_ */ 397