1 /* $OpenBSD: namei.h,v 1.16 2005/07/20 17:01:14 miod Exp $ */ 2 /* $NetBSD: namei.h,v 1.11 1996/02/09 18:25:20 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1985, 1989, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)namei.h 8.4 (Berkeley) 8/20/94 33 */ 34 35 #ifndef _SYS_NAMEI_H_ 36 #define _SYS_NAMEI_H_ 37 38 #include <sys/queue.h> 39 40 /* 41 * Encapsulation of namei parameters. 42 */ 43 struct nameidata { 44 /* 45 * Arguments to namei/lookup. 46 */ 47 const char *ni_dirp; /* pathname pointer */ 48 enum uio_seg ni_segflg; /* location of pathname */ 49 /* u_long ni_nameiop; namei operation */ 50 /* u_long ni_flags; flags to namei */ 51 /* struct proc *ni_proc; process requesting lookup */ 52 /* 53 * Arguments to lookup. 54 */ 55 /* struct ucred *ni_cred; credentials */ 56 struct vnode *ni_startdir; /* starting directory */ 57 struct vnode *ni_rootdir; /* logical root directory */ 58 /* 59 * Results: returned from/manipulated by lookup 60 */ 61 struct vnode *ni_vp; /* vnode of result */ 62 struct vnode *ni_dvp; /* vnode of intermediate directory */ 63 /* 64 * Shared between namei and lookup/commit routines. 65 */ 66 size_t ni_pathlen; /* remaining chars in path */ 67 char *ni_next; /* next location in pathname */ 68 u_long ni_loopcnt; /* count of symlinks encountered */ 69 /* 70 * Lookup parameters: this structure describes the subset of 71 * information from the nameidata structure that is passed 72 * through the VOP interface. 73 */ 74 struct componentname { 75 /* 76 * Arguments to lookup. 77 */ 78 u_long cn_nameiop; /* namei operation */ 79 u_long cn_flags; /* flags to namei */ 80 struct proc *cn_proc; /* process requesting lookup */ 81 struct ucred *cn_cred; /* credentials */ 82 /* 83 * Shared between lookup and commit routines. 84 */ 85 char *cn_pnbuf; /* pathname buffer */ 86 char *cn_nameptr; /* pointer to looked up name */ 87 long cn_namelen; /* length of looked up component */ 88 u_long cn_hash; /* hash value of looked up name */ 89 long cn_consume; /* chars to consume in lookup() */ 90 } ni_cnd; 91 }; 92 93 #ifdef _KERNEL 94 /* 95 * namei operations 96 */ 97 #define LOOKUP 0 /* perform name lookup only */ 98 #define CREATE 1 /* setup for file creation */ 99 #define DELETE 2 /* setup for file deletion */ 100 #define RENAME 3 /* setup for file renaming */ 101 #define OPMASK 3 /* mask for operation */ 102 /* 103 * namei operational modifier flags, stored in ni_cnd.flags 104 */ 105 #define LOCKLEAF 0x0004 /* lock inode on return */ 106 #define LOCKPARENT 0x0008 /* want parent vnode returned locked */ 107 #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */ 108 #define NOCACHE 0x0020 /* name must not be left in cache */ 109 #define FOLLOW 0x0040 /* follow symbolic links */ 110 #define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */ 111 #define MODMASK 0x00fc /* mask of operational modifiers */ 112 /* 113 * Namei parameter descriptors. 114 * 115 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP. 116 * If the caller of namei sets the flag (for example execve wants to 117 * know the name of the program that is being executed), then it must 118 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must 119 * be freed by either the commit routine or the VOP_ABORT routine. 120 * SAVESTART is set only by the callers of namei. It implies SAVENAME 121 * plus the addition of saving the parent directory that contains the 122 * name in ni_startdir. It allows repeated calls to lookup for the 123 * name being sought. The caller is responsible for releasing the 124 * buffer and for vrele'ing ni_startdir. 125 */ 126 #define NOCROSSMOUNT 0x000100 /* do not cross mount points */ 127 #define RDONLY 0x000200 /* lookup with read-only semantics */ 128 #define HASBUF 0x000400 /* has allocated pathname buffer */ 129 #define SAVENAME 0x000800 /* save pathanme buffer */ 130 #define SAVESTART 0x001000 /* save starting directory */ 131 #define ISDOTDOT 0x002000 /* current component name is .. */ 132 #define MAKEENTRY 0x004000 /* entry is to be added to name cache */ 133 #define ISLASTCN 0x008000 /* this is last component of pathname */ 134 #define ISSYMLINK 0x010000 /* symlink needs interpretation */ 135 #define REQUIREDIR 0x080000 /* must be a directory */ 136 #define STRIPSLASHES 0x100000 /* strip trailing slashes */ 137 #define PDIRUNLOCK 0x200000 /* vfs_lookup() unlocked parent dir */ 138 139 /* 140 * Initialization of an nameidata structure. 141 */ 142 #define NDINIT(ndp, op, flags, segflg, namep, p) { \ 143 (ndp)->ni_cnd.cn_nameiop = op; \ 144 (ndp)->ni_cnd.cn_flags = flags; \ 145 (ndp)->ni_segflg = segflg; \ 146 (ndp)->ni_dirp = namep; \ 147 (ndp)->ni_cnd.cn_proc = p; \ 148 } 149 #endif 150 151 /* 152 * This structure describes the elements in the cache of recent 153 * names looked up by namei. NCHNAMLEN is sized to make structure 154 * size a power of two to optimize malloc's. Minimum reasonable 155 * size is 15. 156 */ 157 158 #define NCHNAMLEN 31 /* maximum name segment length we bother with */ 159 160 struct namecache { 161 LIST_ENTRY(namecache) nc_hash; /* hash chain */ 162 LIST_ENTRY(namecache) nc_vhash; /* (reverse) directory hash chain */ 163 TAILQ_ENTRY(namecache) nc_lru; /* LRU chain */ 164 struct vnode *nc_dvp; /* vnode of parent of name */ 165 u_long nc_dvpid; /* capability number of nc_dvp */ 166 struct vnode *nc_vp; /* vnode the name refers to */ 167 u_long nc_vpid; /* capability number of nc_vp */ 168 char nc_nlen; /* length of name */ 169 char nc_name[NCHNAMLEN]; /* segment name */ 170 }; 171 172 #ifdef _KERNEL 173 extern u_long nextvnodeid; 174 int namei(struct nameidata *ndp); 175 int lookup(struct nameidata *ndp); 176 int relookup(struct vnode *dvp, struct vnode **vpp, 177 struct componentname *cnp); 178 void cache_purge(struct vnode *); 179 int cache_lookup(struct vnode *, struct vnode **, struct componentname *); 180 void cache_enter(struct vnode *, struct vnode *, struct componentname *); 181 int cache_revlookup(struct vnode *, struct vnode **, char **, char *); 182 void nchinit(void); 183 struct mount; 184 void cache_purgevfs(struct mount *); 185 186 extern struct pool namei_pool; 187 188 #endif 189 190 /* 191 * Stats on usefulness of namei caches. 192 */ 193 struct nchstats { 194 long ncs_goodhits; /* hits that we can really use */ 195 long ncs_neghits; /* negative hits that we can use */ 196 long ncs_badhits; /* hits we must drop */ 197 long ncs_falsehits; /* hits with id mismatch */ 198 long ncs_miss; /* misses */ 199 long ncs_long; /* long names that ignore cache */ 200 long ncs_pass2; /* names found with passes == 2 */ 201 long ncs_2passes; /* number of times we attempt it */ 202 long ncs_revhits; /* reverse-cache hits */ 203 long ncs_revmiss; /* reverse-cache misses */ 204 }; 205 206 /* These sysctl names are only really used by sysctl(8) */ 207 #define KERN_NCHSTATS_GOODHITS 1 208 #define KERN_NCHSTATS_NEGHITS 2 209 #define KERN_NCHSTATS_BADHITS 3 210 #define KERN_NCHSTATS_FALSEHITS 4 211 #define KERN_NCHSTATS_MISS 5 212 #define KERN_NCHSTATS_LONG 6 213 #define KERN_NCHSTATS_PASS2 7 214 #define KERN_NCHSTATS_2PASSES 8 215 #define KERN_NCHSTATS_REVHITS 9 216 #define KERN_NCHSTATS_REVMISS 10 217 #define KERN_NCHSTATS_MAXID 11 218 219 #define CTL_KERN_NCHSTATS_NAMES { \ 220 { 0, 0 }, \ 221 { "good_hits", CTLTYPE_INT }, \ 222 { "negative_hits", CTLTYPE_INT }, \ 223 { "bad_hits", CTLTYPE_INT }, \ 224 { "false_hits", CTLTYPE_INT }, \ 225 { "misses", CTLTYPE_INT }, \ 226 { "long_names", CTLTYPE_INT }, \ 227 { "pass2", CTLTYPE_INT }, \ 228 { "2passes", CTLTYPE_INT }, \ 229 { "ncs_revhits", CTLTYPE_INT }, \ 230 { "ncs_revmiss", CTLTYPE_INT }, \ 231 } 232 #endif /* !_SYS_NAMEI_H_ */ 233