bsd/sys/namei.h

   1 /*
   2  * Copyright (c) 2000-2007 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 #endif
  74
  75
  76 #ifdef BSD_KERNEL_PRIVATE
  77
  78 /* VFS Supports "/..namedfork/rsrc" access. */
  79 #define NAMEDRSRCFORK           NAMEDSTREAMS
  80
  81
  82 #include <sys/queue.h>
  83 #include <sys/uio.h>
  84 #include <sys/vnode.h>
  85 #include <sys/mount.h>
  86 #include <sys/filedesc.h>
  87
  88 #define PATHBUFLEN      256
  89
  90 /*
  91  * Encapsulation of namei parameters.
  92  */
  93 struct nameidata {
  94         /*
  95          * Arguments to namei/lookup.
  96          */
  97         user_addr_t ni_dirp;            /* pathname pointer */
  98         enum    uio_seg ni_segflg;      /* location of pathname */
  99         /*
 100          * Arguments to lookup.
 101          */
 102         struct  vnode *ni_startdir;     /* starting directory */
 103         struct  vnode *ni_rootdir;      /* logical root directory */
 104         struct  vnode *ni_usedvp;       /* directory passed in via USEDVP */
 105         /*
 106          * Results: returned from/manipulated by lookup
 107          */
 108         struct  vnode *ni_vp;           /* vnode of result */
 109         struct  vnode *ni_dvp;          /* vnode of intermediate directory */
 110         /*
 111          * Shared between namei and lookup/commit routines.
 112          */
 113         u_int   ni_pathlen;             /* remaining chars in path */
 114         char    *ni_next;               /* next location in pathname */
 115         char    ni_pathbuf[PATHBUFLEN];
 116         u_long  ni_loopcnt;             /* count of symlinks encountered */
 117
 118         struct componentname ni_cnd;
 119 };
 120
 121 #ifdef KERNEL
 122 /*
 123  * namei operational modifier flags, stored in ni_cnd.flags
 124  * Also includes LOCKLEAF, LOCKPARENT, and WANTPARENT flags, defined above.
 125  */
 126 #define NOCACHE         0x00000020 /* name must not be left in cache */
 127 #define NOFOLLOW        0x00000000 /* do not follow symbolic links (pseudo) */
 128 /* public FOLLOW        0x00000040    see vnode.h */
 129 #define SHAREDLEAF      0x00000080 /* OK to have shared leaf lock */
 130 /* public NOTRIGGER     0x10000000    see vnode.h */
 131 #define MODMASK         0x100000fc /* mask of operational modifiers */
 132 /*
 133  * Namei parameter descriptors.
 134  *
 135  * SAVESTART is set only by the callers of namei. It implies SAVENAME
 136  * plus the addition of saving the parent directory that contains the
 137  * name in ni_startdir. It allows repeated calls to lookup for the
 138  * name being sought. The caller is responsible for releasing the
 139  * buffer and for vrele'ing ni_startdir.
 140  */
 141 #define SAVENAME        0          /* save pathanme buffer ***obsolete */
 142 #define NOCROSSMOUNT    0x00000100 /* do not cross mount points */
 143 #define RDONLY          0x00000200 /* lookup with read-only semantics */
 144 #define HASBUF          0x00000400 /* has allocated pathname buffer */
 145 #define DONOTAUTH       0x00000800 /* do not authorize during lookup */
 146 #define SAVESTART       0x00001000 /* save starting directory */
 147 /* public ISDOTDOT      0x00002000    see vnode.h */
 148 /* public MAKEENTRY     0x00004000    see vnode.h */
 149 /* public ISLASTCN      0x00008000    see vnode.h */
 150 #define ISSYMLINK       0x00010000 /* symlink needs interpretation */
 151 /* public ISWHITEOUT    0x00020000    see vnode.h */
 152 /* public DOWHITEOUT    0x00040000    see vnode.h */
 153 #define WILLBEDIR       0x00080000 /* new files will be dirs; allow trailing / */
 154 #define AUDITVNPATH1    0x00100000 /* audit the path/vnode info */
 155 #define AUDITVNPATH2    0x00200000 /* audit the path/vnode info */
 156 #define USEDVP          0x00400000 /* start the lookup at ndp.ni_dvp */
 157 #define CN_VOLFSPATH    0x00800000 /* user path was a volfs style path */
 158 #define FSNODELOCKHELD  0x01000000
 159 #define UNIONCREATED    0x02000000 /* union fs creation of vnode */
 160 #if NAMEDRSRCFORK
 161 #define CN_WANTSRSRCFORK 0x04000000
 162 #define CN_ALLOWRSRCFORK 0x08000000
 163 #endif
 164 /* public NOTRIGGER             0x10000000    see vnode.h */
 165 #define CN_NBMOUNTLOOK  0x20000000 /* do not block for cross mount lookups */
 166
 167 /*
 168  * Initialization of an nameidata structure.
 169  */
 170 #define NDINIT(ndp, op, flags, segflg, namep, ctx) { \
 171         (ndp)->ni_cnd.cn_nameiop = op; \
 172         (ndp)->ni_cnd.cn_flags = flags; \
 173         if ((segflg) == UIO_USERSPACE) { \
 174                 (ndp)->ni_segflg = ((IS_64BIT_PROCESS(vfs_context_proc(ctx))) ? UIO_USERSPACE64 : UIO_USERSPACE32); \
 175         } \
 176         else if ((segflg) == UIO_SYSSPACE) { \
 177                 (ndp)->ni_segflg = UIO_SYSSPACE32; \
 178         } \
 179         else { \
 180                 (ndp)->ni_segflg = segflg; \
 181         } \
 182         (ndp)->ni_dirp = namep; \
 183         (ndp)->ni_cnd.cn_context = ctx; \
 184 }
 185 #endif /* KERNEL */
 186
 187 /*
 188  * This structure describes the elements in the cache of recent
 189  * names looked up by namei.
 190  */
 191
 192 #define NCHASHMASK      0x7fffffff
 193
 194 struct  namecache {
 195         TAILQ_ENTRY(namecache)  nc_entry;       /* chain of all entries */
 196         LIST_ENTRY(namecache)   nc_hash;        /* hash chain */
 197         LIST_ENTRY(namecache)   nc_child;       /* chain of ncp's that are children of a vp */
 198         union {
 199           LIST_ENTRY(namecache)  nc_link;       /* chain of ncp's that 'name' a vp */
 200           TAILQ_ENTRY(namecache) nc_negentry;   /* chain of ncp's that 'name' a vp */
 201         } nc_un;
 202         vnode_t                 nc_dvp;         /* vnode of parent of name */
 203         vnode_t                 nc_vp;          /* vnode the name refers to */
 204         unsigned int            nc_whiteout:1,  /* name has whiteout applied */
 205                                 nc_hashval:31;  /* hashval of stringname */
 206         const char              *nc_name;       /* pointer to segment name in string cache */
 207 };
 208
 209
 210 #ifdef KERNEL
 211
 212 int     namei(struct nameidata *ndp);
 213 void    nameidone(struct nameidata *);
 214 int     lookup(struct nameidata *ndp);
 215 int     relookup(struct vnode *dvp, struct vnode **vpp,
 216                 struct componentname *cnp);
 217
 218 /*
 219  * namecache function prototypes
 220  */
 221 void    cache_purgevfs(mount_t mp);
 222 int             cache_lookup_path(struct nameidata *ndp, struct componentname *cnp, vnode_t dp,
 223                           vfs_context_t context, int *trailing_slash, int *dp_authorized, vnode_t last_dp);
 224
 225 void            vnode_cache_authorized_action(vnode_t vp, vfs_context_t context, kauth_action_t action);
 226 void            vnode_uncache_authorized_action(vnode_t vp, kauth_action_t action);
 227 boolean_t       vnode_cache_is_stale(vnode_t vp);
 228 boolean_t       vnode_cache_is_authorized(vnode_t vp, vfs_context_t context, kauth_action_t action);
 229
 230 #endif /* KERNEL */
 231
 232 /*
 233  * Stats on usefulness of namei caches.
 234  */
 235 struct  nchstats {
 236         long    ncs_goodhits;           /* hits that we can really use */
 237         long    ncs_neghits;            /* negative hits that we can use */
 238         long    ncs_badhits;            /* hits we must drop */
 239         long    ncs_miss;               /* misses */
 240         long    ncs_pass2;              /* names found with passes == 2 */
 241         long    ncs_2passes;            /* number of times we attempt it */
 242         long    ncs_stolen;
 243         long    ncs_enters;
 244         long    ncs_deletes;
 245         long    ncs_badvid;
 246 };
 247 #endif /* BSD_KERNEL_PRIVATE */
 248
 249 #endif /* !_SYS_NAMEI_H_ */