namei.h revision 243612
1/*- 2 * Copyright (c) 1985, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)namei.h 8.5 (Berkeley) 1/9/95 30 * $FreeBSD: head/sys/sys/namei.h 243612 2012-11-27 10:32:35Z pjd $ 31 */ 32 33#ifndef _SYS_NAMEI_H_ 34#define _SYS_NAMEI_H_ 35 36#include <sys/queue.h> 37#include <sys/uio.h> 38 39struct componentname { 40 /* 41 * Arguments to lookup. 42 */ 43 u_long cn_nameiop; /* namei operation */ 44 u_int64_t cn_flags; /* flags to namei */ 45 struct thread *cn_thread;/* thread requesting lookup */ 46 struct ucred *cn_cred; /* credentials */ 47 int cn_lkflags; /* Lock flags LK_EXCLUSIVE or LK_SHARED */ 48 /* 49 * Shared between lookup and commit routines. 50 */ 51 char *cn_pnbuf; /* pathname buffer */ 52 char *cn_nameptr; /* pointer to looked up name */ 53 long cn_namelen; /* length of looked up component */ 54 long cn_consume; /* chars to consume in lookup() */ 55}; 56 57/* 58 * Encapsulation of namei parameters. 59 */ 60struct nameidata { 61 /* 62 * Arguments to namei/lookup. 63 */ 64 const char *ni_dirp; /* pathname pointer */ 65 enum uio_seg ni_segflg; /* location of pathname */ 66 cap_rights_t ni_rightsneeded; /* rights required to look up vnode */ 67 /* 68 * Arguments to lookup. 69 */ 70 struct vnode *ni_startdir; /* starting directory */ 71 struct vnode *ni_rootdir; /* logical root directory */ 72 struct vnode *ni_topdir; /* logical top directory */ 73 int ni_dirfd; /* starting directory for *at functions */ 74 int ni_strictrelative; /* relative lookup only; no '..' */ 75 /* 76 * Results: returned from namei 77 */ 78 cap_rights_t ni_baserights; /* rights the *at base has (or -1) */ 79 /* 80 * Results: returned from/manipulated by lookup 81 */ 82 struct vnode *ni_vp; /* vnode of result */ 83 struct vnode *ni_dvp; /* vnode of intermediate directory */ 84 /* 85 * Shared between namei and lookup/commit routines. 86 */ 87 size_t ni_pathlen; /* remaining chars in path */ 88 char *ni_next; /* next location in pathname */ 89 u_int ni_loopcnt; /* count of symlinks encountered */ 90 /* 91 * Lookup parameters: this structure describes the subset of 92 * information from the nameidata structure that is passed 93 * through the VOP interface. 94 */ 95 struct componentname ni_cnd; 96}; 97 98#ifdef _KERNEL 99/* 100 * namei operations 101 */ 102#define LOOKUP 0 /* perform name lookup only */ 103#define CREATE 1 /* setup for file creation */ 104#define DELETE 2 /* setup for file deletion */ 105#define RENAME 3 /* setup for file renaming */ 106#define OPMASK 3 /* mask for operation */ 107/* 108 * namei operational modifier flags, stored in ni_cnd.flags 109 */ 110#define LOCKLEAF 0x0004 /* lock vnode on return */ 111#define LOCKPARENT 0x0008 /* want parent vnode returned locked */ 112#define WANTPARENT 0x0010 /* want parent vnode returned unlocked */ 113#define NOCACHE 0x0020 /* name must not be left in cache */ 114#define FOLLOW 0x0040 /* follow symbolic links */ 115#define LOCKSHARED 0x0100 /* Shared lock leaf */ 116#define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */ 117#define MODMASK 0x01fc /* mask of operational modifiers */ 118/* 119 * Namei parameter descriptors. 120 * 121 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP. 122 * If the caller of namei sets the flag (for example execve wants to 123 * know the name of the program that is being executed), then it must 124 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must 125 * be freed by either the commit routine or the VOP_ABORT routine. 126 * SAVESTART is set only by the callers of namei. It implies SAVENAME 127 * plus the addition of saving the parent directory that contains the 128 * name in ni_startdir. It allows repeated calls to lookup for the 129 * name being sought. The caller is responsible for releasing the 130 * buffer and for vrele'ing ni_startdir. 131 */ 132#define RDONLY 0x00000200 /* lookup with read-only semantics */ 133#define HASBUF 0x00000400 /* has allocated pathname buffer */ 134#define SAVENAME 0x00000800 /* save pathname buffer */ 135#define SAVESTART 0x00001000 /* save starting directory */ 136#define ISDOTDOT 0x00002000 /* current component name is .. */ 137#define MAKEENTRY 0x00004000 /* entry is to be added to name cache */ 138#define ISLASTCN 0x00008000 /* this is last component of pathname */ 139#define ISSYMLINK 0x00010000 /* symlink needs interpretation */ 140#define ISWHITEOUT 0x00020000 /* found whiteout */ 141#define DOWHITEOUT 0x00040000 /* do whiteouts */ 142#define WILLBEDIR 0x00080000 /* new files will be dirs; allow trailing / */ 143#define ISUNICODE 0x00100000 /* current component name is unicode*/ 144#define ISOPEN 0x00200000 /* caller is opening; return a real vnode. */ 145#define NOCROSSMOUNT 0x00400000 /* do not cross mount points */ 146#define NOMACCHECK 0x00800000 /* do not perform MAC checks */ 147#define AUDITVNODE1 0x04000000 /* audit the looked up vnode information */ 148#define AUDITVNODE2 0x08000000 /* audit the looked up vnode information */ 149#define TRAILINGSLASH 0x10000000 /* path ended in a slash */ 150#define NOCAPCHECK 0x20000000 /* do not perform capability checks */ 151#define PARAMASK 0x3ffffe00 /* mask of parameter descriptors */ 152 153/* 154 * Initialization of a nameidata structure. 155 */ 156#define NDINIT(ndp, op, flags, segflg, namep, td) \ 157 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, 0, td) 158#define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd, td) \ 159 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, 0, td) 160#define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rights, td) \ 161 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rights, td) 162#define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp, td) \ 163 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, 0, td) 164 165static __inline void 166NDINIT_ALL(struct nameidata *ndp, 167 u_long op, u_long flags, 168 enum uio_seg segflg, 169 const char *namep, 170 int dirfd, 171 struct vnode *startdir, 172 cap_rights_t rights, 173 struct thread *td) 174{ 175 ndp->ni_cnd.cn_nameiop = op; 176 ndp->ni_cnd.cn_flags = flags; 177 ndp->ni_segflg = segflg; 178 ndp->ni_dirp = namep; 179 ndp->ni_dirfd = dirfd; 180 ndp->ni_startdir = startdir; 181 ndp->ni_strictrelative = 0; 182 ndp->ni_rightsneeded = rights; 183 ndp->ni_baserights = 0; 184 ndp->ni_cnd.cn_thread = td; 185} 186 187#define NDF_NO_DVP_RELE 0x00000001 188#define NDF_NO_DVP_UNLOCK 0x00000002 189#define NDF_NO_DVP_PUT 0x00000003 190#define NDF_NO_VP_RELE 0x00000004 191#define NDF_NO_VP_UNLOCK 0x00000008 192#define NDF_NO_VP_PUT 0x0000000c 193#define NDF_NO_STARTDIR_RELE 0x00000010 194#define NDF_NO_FREE_PNBUF 0x00000020 195#define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF) 196 197void NDFREE(struct nameidata *, const u_int); 198 199int namei(struct nameidata *ndp); 200int lookup(struct nameidata *ndp); 201int relookup(struct vnode *dvp, struct vnode **vpp, 202 struct componentname *cnp); 203#endif 204 205/* 206 * Stats on usefulness of namei caches. 207 */ 208struct nchstats { 209 long ncs_goodhits; /* hits that we can really use */ 210 long ncs_neghits; /* negative hits that we can use */ 211 long ncs_badhits; /* hits we must drop */ 212 long ncs_falsehits; /* hits with id mismatch */ 213 long ncs_miss; /* misses */ 214 long ncs_long; /* long names that ignore cache */ 215 long ncs_pass2; /* names found with passes == 2 */ 216 long ncs_2passes; /* number of times we attempt it */ 217}; 218 219extern struct nchstats nchstats; 220 221#endif /* !_SYS_NAMEI_H_ */ 222