1 /* $NetBSD: namei.h,v 1.97 2017/03/21 10:20:38 riastradh 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 1.41 2017/03/21 10:20:12 riastradh 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 #ifdef _KERNEL 49 #include <sys/kauth.h> 50 51 /* 52 * Abstraction for a single pathname. 53 * 54 * This contains both the pathname string and (eventually) all 55 * metadata that determines how the path is to be interpreted. 56 * It is an opaque structure; the implementation is in vfs_lookup.c. 57 * 58 * To call namei, first set up a pathbuf with pathbuf_create or 59 * pathbuf_copyin, then do NDINIT(), then call namei, then AFTER THE 60 * STRUCT NAMEIDATA IS DEAD, call pathbuf_destroy. Don't destroy the 61 * pathbuf before you've finished using the nameidata, or mysterious 62 * bad things may happen. 63 * 64 * pathbuf_assimilate is like pathbuf_create but assumes ownership of 65 * the string buffer passed in, which MUST BE of size PATH_MAX and 66 * have been allocated with PNBUF_GET(). This should only be used when 67 * absolutely necessary; e.g. nfsd uses it for loading paths from 68 * mbufs. 69 */ 70 struct pathbuf; 71 72 struct pathbuf *pathbuf_create(const char *path); 73 struct pathbuf *pathbuf_assimilate(char *path); 74 int pathbuf_copyin(const char *userpath, struct pathbuf **ret); 75 void pathbuf_destroy(struct pathbuf *); 76 77 /* get a copy of the (current) path string */ 78 void pathbuf_copystring(const struct pathbuf *, char *buf, size_t maxlen); 79 80 /* hold a reference copy of the original path string */ 81 const char *pathbuf_stringcopy_get(struct pathbuf *); 82 void pathbuf_stringcopy_put(struct pathbuf *, const char *); 83 84 // XXX remove this 85 int pathbuf_maybe_copyin(const char *userpath, enum uio_seg seg, struct pathbuf **ret); 86 87 /* 88 * Lookup parameters: this structure describes the subset of 89 * information from the nameidata structure that is passed 90 * through the VOP interface. 91 */ 92 struct componentname { 93 /* 94 * Arguments to lookup. 95 */ 96 uint32_t cn_nameiop; /* namei operation */ 97 uint32_t cn_flags; /* flags to namei */ 98 kauth_cred_t cn_cred; /* credentials */ 99 /* 100 * Shared between lookup and commit routines. 101 */ 102 const char *cn_nameptr; /* pointer to looked up name */ 103 size_t cn_namelen; /* length of looked up comp */ 104 size_t cn_consume; /* chars to consume in lookup */ 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 NOCHROOT 0x01000000 /* no chroot on abs path lookups */ 163 #define MODMASK 0x010000fc /* mask of operational modifiers */ 164 /* 165 * Namei parameter descriptors. 166 */ 167 #define NOCROSSMOUNT 0x0000100 /* do not cross mount points */ 168 #define RDONLY 0x0000200 /* lookup with read-only semantics */ 169 #define ISDOTDOT 0x0002000 /* current component name is .. */ 170 #define MAKEENTRY 0x0004000 /* entry is to be added to name cache */ 171 #define ISLASTCN 0x0008000 /* this is last component of pathname */ 172 #define ISWHITEOUT 0x0020000 /* found whiteout */ 173 #define DOWHITEOUT 0x0040000 /* do whiteouts */ 174 #define REQUIREDIR 0x0080000 /* must be a directory */ 175 #define CREATEDIR 0x0200000 /* trailing slashes are ok */ 176 #define PARAMASK 0x02ee300 /* mask of parameter descriptors */ 177 178 /* 179 * Initialization of a nameidata structure. 180 */ 181 #define NDINIT(ndp, op, flags, pathbuf) { \ 182 (ndp)->ni_cnd.cn_nameiop = op; \ 183 (ndp)->ni_cnd.cn_flags = flags; \ 184 (ndp)->ni_atdir = NULL; \ 185 (ndp)->ni_pathbuf = pathbuf; \ 186 (ndp)->ni_cnd.cn_cred = kauth_cred_get(); \ 187 } 188 189 /* 190 * Use this to set the start directory for openat()-type operations. 191 */ 192 #define NDAT(ndp, dir) { \ 193 (ndp)->ni_atdir = (dir); \ 194 } 195 196 #endif 197 198 /* 199 * This structure describes the elements in the cache of recent 200 * names looked up by namei. NCHNAMLEN is sized to make structure 201 * size a power of two to optimize allocations. Minimum reasonable 202 * size is 15. 203 */ 204 205 #define NCHNAMLEN 31 /* maximum name segment length we bother with */ 206 207 /* 208 * Namecache entry. This structure is arranged so that frequently 209 * accessed and mostly read-only data is toward the front, with 210 * infrequently accessed data and the lock towards the rear. The 211 * lock is then more likely to be in a seperate cache line. 212 * 213 * Locking rules: 214 * 215 * - stable after initialization 216 * L namecache_lock 217 * C struct nchcpu::cpu_lock 218 * L/C insert needs L, read needs L or any C, 219 * must hold L and all C after (or during) delete before free 220 * N struct namecache::nc_lock 221 */ 222 struct namecache { 223 LIST_ENTRY(namecache) nc_hash; /* L/C hash chain */ 224 LIST_ENTRY(namecache) nc_vhash; /* L directory hash chain */ 225 struct vnode *nc_dvp; /* N vnode of parent of name */ 226 struct vnode *nc_vp; /* N vnode the name refers to */ 227 int nc_flags; /* - copy of componentname ISWHITEOUT */ 228 char nc_nlen; /* - length of name */ 229 char nc_name[NCHNAMLEN]; /* - segment name */ 230 void *nc_gcqueue; /* N queue for garbage collection */ 231 TAILQ_ENTRY(namecache) nc_lru; /* L psuedo-lru chain */ 232 LIST_ENTRY(namecache) nc_dvlist;/* L dvp's list of cache entries */ 233 LIST_ENTRY(namecache) nc_vlist; /* L vp's list of cache entries */ 234 kmutex_t nc_lock; /* lock on this entry */ 235 int nc_hittime; /* N last time scored a hit */ 236 }; 237 238 #ifdef _KERNEL 239 #include <sys/pool.h> 240 241 struct mount; 242 struct cpu_info; 243 244 extern pool_cache_t pnbuf_cache; /* pathname buffer cache */ 245 246 #define PNBUF_GET() ((char *)pool_cache_get(pnbuf_cache, PR_WAITOK)) 247 #define PNBUF_PUT(pnb) pool_cache_put(pnbuf_cache, (void *)(pnb)) 248 249 /* 250 * Typesafe flags for namei_simple/nameiat_simple. 251 * 252 * This encoding is not optimal but serves the important purpose of 253 * not being type-compatible with the regular namei flags. 254 */ 255 struct namei_simple_flags_type; /* Opaque. */ 256 typedef const struct namei_simple_flags_type *namei_simple_flags_t; /* Gross. */ 257 extern const namei_simple_flags_t 258 NSM_NOFOLLOW_NOEMULROOT, 259 NSM_NOFOLLOW_TRYEMULROOT, 260 NSM_FOLLOW_NOEMULROOT, 261 NSM_FOLLOW_TRYEMULROOT; 262 263 /* 264 * namei(at)?_simple_* - the simple cases of namei, with no struct 265 * nameidata involved. 266 * 267 * namei_simple_kernel takes a kernel-space path as the first argument. 268 * namei_simple_user takes a user-space path as the first argument. 269 * The nameiat_simple_* variants handle relative path using the given 270 * directory vnode instead of current directory. 271 * 272 * A namei call can be converted to namei_simple_* if: 273 * - the second arg to NDINIT is LOOKUP; 274 * - it does not need the parent vnode, nd.ni_dvp; 275 * - the only flags it uses are (NO)FOLLOW and TRYEMULROOT; 276 * - it does not do anything else gross with the contents of nd. 277 */ 278 int namei_simple_kernel(const char *, namei_simple_flags_t, struct vnode **); 279 int namei_simple_user(const char *, namei_simple_flags_t, struct vnode **); 280 int nameiat_simple_kernel(struct vnode *, const char *, namei_simple_flags_t, 281 struct vnode **); 282 int nameiat_simple_user(struct vnode *, const char *, namei_simple_flags_t, 283 struct vnode **); 284 285 int namei(struct nameidata *); 286 uint32_t namei_hash(const char *, const char **); 287 int lookup_for_nfsd(struct nameidata *, struct vnode *, int neverfollow); 288 int lookup_for_nfsd_index(struct nameidata *, struct vnode *); 289 int relookup(struct vnode *, struct vnode **, struct componentname *, int); 290 void cache_purge1(struct vnode *, const char *, size_t, int); 291 #define PURGE_PARENTS 1 292 #define PURGE_CHILDREN 2 293 #define cache_purge(vp) cache_purge1((vp),NULL,0,PURGE_PARENTS|PURGE_CHILDREN) 294 bool cache_lookup(struct vnode *, const char *, size_t, uint32_t, uint32_t, 295 int *, struct vnode **); 296 bool cache_lookup_raw(struct vnode *, const char *, size_t, uint32_t, 297 int *, struct vnode **); 298 int cache_revlookup(struct vnode *, struct vnode **, char **, char *); 299 void cache_enter(struct vnode *, struct vnode *, 300 const char *, size_t, uint32_t); 301 void nchinit(void); 302 void nchreinit(void); 303 void namecache_count_pass2(void); 304 void namecache_count_2passes(void); 305 void cache_cpu_init(struct cpu_info *); 306 void cache_purgevfs(struct mount *); 307 void namecache_print(struct vnode *, void (*)(const char *, ...) 308 __printflike(1, 2)); 309 310 #endif 311 312 /* 313 * Stats on usefulness of namei caches. A couple of structures are 314 * used for counting, with members having the same names but different 315 * types. Containerize member names with the preprocessor to avoid 316 * cut-'n'-paste. A (U) in the comment documents values that are 317 * incremented unlocked; we may treat these specially. 318 */ 319 #define _NAMEI_CACHE_STATS(type) { \ 320 type ncs_goodhits; /* hits that we can really use (U) */ \ 321 type ncs_neghits; /* negative hits that we can use */ \ 322 type ncs_badhits; /* hits we must drop */ \ 323 type ncs_falsehits; /* hits with id mismatch (U) */ \ 324 type ncs_miss; /* misses */ \ 325 type ncs_long; /* long names that ignore cache */ \ 326 type ncs_pass2; /* names found with passes == 2 (U) */ \ 327 type ncs_2passes; /* number of times we attempt it (U) */ \ 328 type ncs_revhits; /* reverse-cache hits */ \ 329 type ncs_revmiss; /* reverse-cache misses */ \ 330 } 331 332 /* 333 * Sysctl deals with a uint64_t version of the stats and summary 334 * totals are kept that way. 335 */ 336 struct nchstats _NAMEI_CACHE_STATS(uint64_t); 337 338 /* #endif !_SYS_NAMEI_H_ (generated by gennameih.awk) */ 339 340 /* Definitions match above, but with NAMEI_ prefix */ 341 #define NAMEI_LOOKUP 0 342 #define NAMEI_CREATE 1 343 #define NAMEI_DELETE 2 344 #define NAMEI_RENAME 3 345 #define NAMEI_OPMASK 3 346 #define NAMEI_LOCKLEAF 0x00000004 347 #define NAMEI_LOCKPARENT 0x00000008 348 #define NAMEI_TRYEMULROOT 0x00000010 349 #define NAMEI_NOCACHE 0x00000020 350 #define NAMEI_FOLLOW 0x00000040 351 #define NAMEI_NOFOLLOW 0x00000000 352 #define NAMEI_EMULROOTSET 0x00000080 353 #define NAMEI_NOCHROOT 0x01000000 354 #define NAMEI_MODMASK 0x010000fc 355 #define NAMEI_NOCROSSMOUNT 0x0000100 356 #define NAMEI_RDONLY 0x0000200 357 #define NAMEI_ISDOTDOT 0x0002000 358 #define NAMEI_MAKEENTRY 0x0004000 359 #define NAMEI_ISLASTCN 0x0008000 360 #define NAMEI_ISWHITEOUT 0x0020000 361 #define NAMEI_DOWHITEOUT 0x0040000 362 #define NAMEI_REQUIREDIR 0x0080000 363 #define NAMEI_CREATEDIR 0x0200000 364 #define NAMEI_PARAMASK 0x02ee300 365 366 #endif /* !_SYS_NAMEI_H_ */ 367