namei.h
1 /* 2 * Copyright (c) 2000-2014 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */ 29 /* 30 * Copyright (c) 1985, 1989, 1991, 1993 31 * The Regents of the University of California. All rights reserved. 32 * 33 * Redistribution and use in source and binary forms, with or without 34 * modification, are permitted provided that the following conditions 35 * are met: 36 * 1. Redistributions of source code must retain the above copyright 37 * notice, this list of conditions and the following disclaimer. 38 * 2. Redistributions in binary form must reproduce the above copyright 39 * notice, this list of conditions and the following disclaimer in the 40 * documentation and/or other materials provided with the distribution. 41 * 3. All advertising materials mentioning features or use of this software 42 * must display the following acknowledgement: 43 * This product includes software developed by the University of 44 * California, Berkeley and its contributors. 45 * 4. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)namei.h 8.4 (Berkeley) 8/20/94 62 */ 63 64 #ifndef _SYS_NAMEI_H_ 65 #define _SYS_NAMEI_H_ 66 67 #include <sys/appleapiopts.h> 68 69 #ifdef KERNEL 70 #define LOCKLEAF 0x0004 /* lock inode on return */ 71 #define LOCKPARENT 0x0008 /* want parent vnode returned */ 72 #define WANTPARENT 0x0010 /* want parent vnode returned */ 73 74 #ifdef KERNEL_PRIVATE 75 #define CN_SECLUDE_RENAME 0x10000000 /*rename iff ￢(hard-linked ∨ opened ∨ mmaped)*/ 76 #define CN_RAW_ENCRYPTED 0x80000000 /* Look-up is for RO raw encrypted access. */ 77 #endif 78 79 #endif // KERNEL 80 81 #ifdef BSD_KERNEL_PRIVATE 82 83 /* VFS Supports "/..namedfork/rsrc" access. */ 84 #define NAMEDRSRCFORK NAMEDSTREAMS 85 86 87 #include <sys/queue.h> 88 #include <sys/uio.h> 89 #include <sys/vnode.h> 90 #include <sys/mount.h> 91 #include <sys/filedesc.h> 92 93 #define PATHBUFLEN 256 94 95 /* 96 * Encapsulation of namei parameters. 97 */ 98 struct nameidata { 99 /* 100 * Arguments to namei/lookup. 101 */ 102 user_addr_t ni_dirp; /* pathname pointer */ 103 enum uio_seg ni_segflg; /* location of pathname */ 104 #if CONFIG_TRIGGERS 105 enum path_operation ni_op; /* intended operation, see enum path_operation in vnode.h */ 106 #endif /* CONFIG_TRIGGERS */ 107 /* 108 * Arguments to lookup. 109 */ 110 struct vnode *ni_startdir; /* starting directory */ 111 struct vnode *ni_rootdir; /* logical root directory */ 112 struct vnode *ni_usedvp; /* directory passed in via USEDVP */ 113 /* 114 * Results: returned from/manipulated by lookup 115 */ 116 struct vnode *ni_vp; /* vnode of result */ 117 struct vnode *ni_dvp; /* vnode of intermediate directory */ 118 /* 119 * Shared between namei and lookup/commit routines. 120 */ 121 u_int ni_pathlen; /* remaining chars in path */ 122 char *ni_next; /* next location in pathname */ 123 char ni_pathbuf[PATHBUFLEN]; 124 u_long ni_loopcnt; /* count of symlinks encountered */ 125 126 struct componentname ni_cnd; 127 int32_t ni_flag; 128 int ni_ncgeneration; /* For a batched vnop, grab generation beforehand */ 129 }; 130 131 #define NAMEI_CONTLOOKUP 0x002 /* Continue processing a lookup which was partially processed in a compound VNOP */ 132 #define NAMEI_TRAILINGSLASH 0x004 /* There was at least one trailing slash after last component */ 133 #define NAMEI_UNFINISHED 0x008 /* We broke off a lookup to do a compound op */ 134 135 /* 136 * XXX Hack: we need to encode the intended VNOP in order to 137 * be able to include information about which operations a filesystem 138 * supports in the decision to break off a lookup early. 139 */ 140 #define NAMEI_COMPOUNDOPEN 0x010 141 #define NAMEI_COMPOUNDREMOVE 0x020 142 #define NAMEI_COMPOUNDMKDIR 0x040 143 #define NAMEI_COMPOUNDRMDIR 0x080 144 #define NAMEI_COMPOUNDRENAME 0x100 145 #define NAMEI_COMPOUND_OP_MASK (NAMEI_COMPOUNDOPEN | NAMEI_COMPOUNDREMOVE | NAMEI_COMPOUNDMKDIR | NAMEI_COMPOUNDRMDIR | NAMEI_COMPOUNDRENAME) 146 147 #define NAMEI_NOFOLLOW_ANY 0x1000 /* no symlinks allowed in the path */ 148 149 #ifdef KERNEL 150 /* 151 * namei operational modifier flags, stored in ni_cnd.flags 152 * Also includes LOCKLEAF, LOCKPARENT, and WANTPARENT flags, defined above. 153 */ 154 #define NOCACHE 0x00000020 /* name must not be left in cache */ 155 #define NOFOLLOW 0x00000000 /* do not follow symbolic links (pseudo) */ 156 /* public FOLLOW 0x00000040 see vnode.h */ 157 #define SHAREDLEAF 0x00000080 /* OK to have shared leaf lock */ 158 #define MODMASK 0x100000fc /* mask of operational modifiers */ 159 /* 160 * Namei parameter descriptors. 161 * 162 * SAVESTART is set only by the callers of namei. It implies SAVENAME 163 * plus the addition of saving the parent directory that contains the 164 * name in ni_startdir. It allows repeated calls to lookup for the 165 * name being sought. The caller is responsible for releasing the 166 * buffer and for vrele'ing ni_startdir. 167 */ 168 #define SAVENAME 0 /* save pathanme buffer ***obsolete */ 169 #define NOCROSSMOUNT 0x00000100 /* do not cross mount points */ 170 #define RDONLY 0x00000200 /* lookup with read-only semantics */ 171 #define HASBUF 0x00000400 /* has allocated pathname buffer */ 172 #define DONOTAUTH 0x00000800 /* do not authorize during lookup */ 173 #define SAVESTART 0x00001000 /* save starting directory */ 174 /* public ISDOTDOT 0x00002000 see vnode.h */ 175 /* public MAKEENTRY 0x00004000 see vnode.h */ 176 /* public ISLASTCN 0x00008000 see vnode.h */ 177 #define ISSYMLINK 0x00010000 /* symlink needs interpretation */ 178 /* public ISWHITEOUT 0x00020000 see vnode.h */ 179 /* public DOWHITEOUT 0x00040000 see vnode.h */ 180 #define WILLBEDIR 0x00080000 /* new files will be dirs; allow trailing / */ 181 #define AUDITVNPATH1 0x00100000 /* audit the path/vnode info */ 182 #define AUDITVNPATH2 0x00200000 /* audit the path/vnode info */ 183 #define USEDVP 0x00400000 /* start the lookup at ndp.ni_dvp */ 184 #define CN_VOLFSPATH 0x00800000 /* user path was a volfs style path */ 185 #define CN_FIRMLINK_NOFOLLOW 0x01000000 /* Do not follow firm links */ 186 #define UNIONCREATED 0x02000000 /* union fs creation of vnode */ 187 #if NAMEDRSRCFORK 188 #define CN_WANTSRSRCFORK 0x04000000 189 #define CN_ALLOWRSRCFORK 0x08000000 190 #endif // NAMEDRSRCFORK 191 // CN_SECLUDE_RENAME is defined above as 0x10000000 (SPI) 192 #define CN_NBMOUNTLOOK 0x20000000 /* do not block for cross mount lookups */ 193 #ifdef BSD_KERNEL_PRIVATE 194 #define CN_SKIPNAMECACHE 0x40000000 /* skip cache during lookup(), allow FS to handle all components */ 195 #endif 196 // CN_RAW_ENCRYPTED is defined above as 0x80000000 (SPI) 197 198 /* 199 * Initialization of an nameidata structure. 200 */ 201 202 #if CONFIG_TRIGGERS 203 /* Note: vnode triggers require more precise path operation (ni_op) */ 204 205 #define NDINIT(ndp, op, pop, flags, segflg, namep, ctx) { \ 206 (ndp)->ni_cnd.cn_nameiop = op; \ 207 (ndp)->ni_op = pop; \ 208 (ndp)->ni_cnd.cn_flags = flags; \ 209 if ((segflg) == UIO_USERSPACE) { \ 210 (ndp)->ni_segflg = ((IS_64BIT_PROCESS(vfs_context_proc(ctx))) ? UIO_USERSPACE64 : UIO_USERSPACE32); \ 211 } \ 212 else { \ 213 (ndp)->ni_segflg = segflg; \ 214 } \ 215 (ndp)->ni_dirp = namep; \ 216 (ndp)->ni_cnd.cn_context = ctx; \ 217 (ndp)->ni_flag = 0; \ 218 (ndp)->ni_cnd.cn_ndp = (ndp); \ 219 } 220 #else 221 #define NDINIT(ndp, op, _unused_, flags, segflg, namep, ctx) { \ 222 (ndp)->ni_cnd.cn_nameiop = op; \ 223 (ndp)->ni_cnd.cn_flags = flags; \ 224 if ((segflg) == UIO_USERSPACE) { \ 225 (ndp)->ni_segflg = ((IS_64BIT_PROCESS(vfs_context_proc(ctx))) ? UIO_USERSPACE64 : UIO_USERSPACE32); \ 226 } \ 227 else { \ 228 (ndp)->ni_segflg = segflg; \ 229 } \ 230 (ndp)->ni_dirp = namep; \ 231 (ndp)->ni_cnd.cn_context = ctx; \ 232 (ndp)->ni_flag = 0; \ 233 (ndp)->ni_cnd.cn_ndp = (ndp); \ 234 } 235 #endif /* CONFIG_TRIGGERS */ 236 237 #endif /* KERNEL */ 238 239 /* 240 * This structure describes the elements in the cache of recent 241 * names looked up by namei. 242 */ 243 struct namecache { 244 TAILQ_ENTRY(namecache) nc_entry; /* chain of all entries */ 245 TAILQ_ENTRY(namecache) nc_child; /* chain of ncp's that are children of a vp */ 246 union { 247 LIST_ENTRY(namecache) nc_link; /* chain of ncp's that 'name' a vp */ 248 TAILQ_ENTRY(namecache) nc_negentry; /* chain of ncp's that 'name' a vp */ 249 } nc_un; 250 LIST_ENTRY(namecache) nc_hash; /* hash chain */ 251 vnode_t nc_dvp; /* vnode of parent of name */ 252 vnode_t nc_vp; /* vnode the name refers to */ 253 unsigned int nc_hashval; /* hashval of stringname */ 254 const char *nc_name; /* pointer to segment name in string cache */ 255 }; 256 257 258 #ifdef KERNEL 259 260 int namei(struct nameidata *ndp); 261 void nameidone(struct nameidata *); 262 int lookup(struct nameidata *ndp); 263 int relookup(struct vnode *dvp, struct vnode **vpp, 264 struct componentname *cnp); 265 int lookup_traverse_union(vnode_t dvp, vnode_t *new_dvp, vfs_context_t ctx); 266 void lookup_compound_vnop_post_hook(int error, vnode_t dvp, vnode_t vp, struct nameidata *ndp, int did_create); 267 void kdebug_lookup(struct vnode *dp, struct componentname *cnp); 268 269 /* 270 * namecache function prototypes 271 */ 272 void cache_purgevfs(mount_t mp); 273 int cache_lookup_path(struct nameidata *ndp, struct componentname *cnp, vnode_t dp, 274 vfs_context_t context, int *dp_authorized, vnode_t last_dp); 275 276 void vnode_cache_authorized_action(vnode_t vp, vfs_context_t context, kauth_action_t action); 277 void vnode_uncache_authorized_action(vnode_t vp, kauth_action_t action); 278 boolean_t vnode_cache_is_stale(vnode_t vp); 279 boolean_t vnode_cache_is_authorized(vnode_t vp, vfs_context_t context, kauth_action_t action); 280 int lookup_validate_creation_path(struct nameidata *ndp); 281 int namei_compound_available(vnode_t dp, struct nameidata *ndp); 282 283 #endif /* KERNEL */ 284 285 /* 286 * Stats on usefulness of namei caches. 287 */ 288 struct nchstats { 289 long ncs_goodhits; /* hits that we can really use */ 290 long ncs_neghits; /* negative hits that we can use */ 291 long ncs_badhits; /* hits we must drop */ 292 long ncs_miss; /* misses */ 293 long ncs_pass2; /* names found with passes == 2 */ 294 long ncs_2passes; /* number of times we attempt it */ 295 long ncs_stolen; 296 long ncs_enters; 297 long ncs_deletes; 298 long ncs_badvid; 299 }; 300 #endif /* BSD_KERNEL_PRIVATE */ 301 302 #endif /* !_SYS_NAMEI_H_ */