namei.h revision 330897
1/*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1985, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 4. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)namei.h 8.5 (Berkeley) 1/9/95 32 * $FreeBSD: stable/11/sys/sys/namei.h 330897 2018-03-14 03:19:51Z eadler $ 33 */ 34 35#ifndef _SYS_NAMEI_H_ 36#define _SYS_NAMEI_H_ 37 38#include <sys/caprights.h> 39#include <sys/filedesc.h> 40#include <sys/queue.h> 41#include <sys/uio.h> 42 43struct componentname { 44 /* 45 * Arguments to lookup. 46 */ 47 u_long cn_nameiop; /* namei operation */ 48 u_int64_t cn_flags; /* flags to namei */ 49 struct thread *cn_thread;/* thread requesting lookup */ 50 struct ucred *cn_cred; /* credentials */ 51 int cn_lkflags; /* Lock flags LK_EXCLUSIVE or LK_SHARED */ 52 /* 53 * Shared between lookup and commit routines. 54 */ 55 char *cn_pnbuf; /* pathname buffer */ 56 char *cn_nameptr; /* pointer to looked up name */ 57 long cn_namelen; /* length of looked up component */ 58}; 59 60struct nameicap_tracker; 61TAILQ_HEAD(nameicap_tracker_head, nameicap_tracker); 62 63/* 64 * Encapsulation of namei parameters. 65 */ 66struct nameidata { 67 /* 68 * Arguments to namei/lookup. 69 */ 70 const char *ni_dirp; /* pathname pointer */ 71 enum uio_seg ni_segflg; /* location of pathname */ 72 cap_rights_t ni_rightsneeded; /* rights required to look up vnode */ 73 /* 74 * Arguments to lookup. 75 */ 76 struct vnode *ni_startdir; /* starting directory */ 77 struct vnode *ni_rootdir; /* logical root directory */ 78 struct vnode *ni_topdir; /* logical top directory */ 79 int ni_dirfd; /* starting directory for *at functions */ 80 int ni_lcf; /* local call flags */ 81 /* 82 * Results: returned from namei 83 */ 84 struct filecaps ni_filecaps; /* rights the *at base has */ 85 /* 86 * Results: returned from/manipulated by lookup 87 */ 88 struct vnode *ni_vp; /* vnode of result */ 89 struct vnode *ni_dvp; /* vnode of intermediate directory */ 90 /* 91 * Shared between namei and lookup/commit routines. 92 */ 93 size_t ni_pathlen; /* remaining chars in path */ 94 char *ni_next; /* next location in pathname */ 95 u_int ni_loopcnt; /* count of symlinks encountered */ 96 /* 97 * Lookup parameters: this structure describes the subset of 98 * information from the nameidata structure that is passed 99 * through the VOP interface. 100 */ 101 struct componentname ni_cnd; 102 struct nameicap_tracker_head ni_cap_tracker; 103}; 104 105#ifdef _KERNEL 106/* 107 * namei operations 108 */ 109#define LOOKUP 0 /* perform name lookup only */ 110#define CREATE 1 /* setup for file creation */ 111#define DELETE 2 /* setup for file deletion */ 112#define RENAME 3 /* setup for file renaming */ 113#define OPMASK 3 /* mask for operation */ 114/* 115 * namei operational modifier flags, stored in ni_cnd.flags 116 */ 117#define LOCKLEAF 0x0004 /* lock vnode on return */ 118#define LOCKPARENT 0x0008 /* want parent vnode returned locked */ 119#define WANTPARENT 0x0010 /* want parent vnode returned unlocked */ 120#define NOCACHE 0x0020 /* name must not be left in cache */ 121#define FOLLOW 0x0040 /* follow symbolic links */ 122#define LOCKSHARED 0x0100 /* Shared lock leaf */ 123#define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */ 124#define MODMASK 0x01fc /* mask of operational modifiers */ 125/* 126 * Namei parameter descriptors. 127 * 128 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP. 129 * If the caller of namei sets the flag (for example execve wants to 130 * know the name of the program that is being executed), then it must 131 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must 132 * be freed by either the commit routine or the VOP_ABORT routine. 133 * SAVESTART is set only by the callers of namei. It implies SAVENAME 134 * plus the addition of saving the parent directory that contains the 135 * name in ni_startdir. It allows repeated calls to lookup for the 136 * name being sought. The caller is responsible for releasing the 137 * buffer and for vrele'ing ni_startdir. 138 */ 139#define RDONLY 0x00000200 /* lookup with read-only semantics */ 140#define HASBUF 0x00000400 /* has allocated pathname buffer */ 141#define SAVENAME 0x00000800 /* save pathname buffer */ 142#define SAVESTART 0x00001000 /* save starting directory */ 143#define ISDOTDOT 0x00002000 /* current component name is .. */ 144#define MAKEENTRY 0x00004000 /* entry is to be added to name cache */ 145#define ISLASTCN 0x00008000 /* this is last component of pathname */ 146#define ISSYMLINK 0x00010000 /* symlink needs interpretation */ 147#define ISWHITEOUT 0x00020000 /* found whiteout */ 148#define DOWHITEOUT 0x00040000 /* do whiteouts */ 149#define WILLBEDIR 0x00080000 /* new files will be dirs; allow trailing / */ 150#define ISUNICODE 0x00100000 /* current component name is unicode*/ 151#define ISOPEN 0x00200000 /* caller is opening; return a real vnode. */ 152#define NOCROSSMOUNT 0x00400000 /* do not cross mount points */ 153#define NOMACCHECK 0x00800000 /* do not perform MAC checks */ 154#define AUDITVNODE1 0x04000000 /* audit the looked up vnode information */ 155#define AUDITVNODE2 0x08000000 /* audit the looked up vnode information */ 156#define TRAILINGSLASH 0x10000000 /* path ended in a slash */ 157#define NOCAPCHECK 0x20000000 /* do not perform capability checks */ 158#define PARAMASK 0x3ffffe00 /* mask of parameter descriptors */ 159 160/* 161 * Flags in ni_lcf, valid for the duration of the namei call. 162 */ 163#define NI_LCF_STRICTRELATIVE 0x0001 /* relative lookup only */ 164#define NI_LCF_CAP_DOTDOT 0x0002 /* ".." in strictrelative case */ 165 166/* 167 * Initialization of a nameidata structure. 168 */ 169#define NDINIT(ndp, op, flags, segflg, namep, td) \ 170 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, 0, td) 171#define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd, td) \ 172 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, 0, td) 173#define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp, td) \ 174 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp, td) 175#define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp, td) \ 176 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, 0, td) 177 178void NDINIT_ALL(struct nameidata *ndp, u_long op, u_long flags, 179 enum uio_seg segflg, const char *namep, int dirfd, struct vnode *startdir, 180 cap_rights_t *rightsp, struct thread *td); 181 182#define NDF_NO_DVP_RELE 0x00000001 183#define NDF_NO_DVP_UNLOCK 0x00000002 184#define NDF_NO_DVP_PUT 0x00000003 185#define NDF_NO_VP_RELE 0x00000004 186#define NDF_NO_VP_UNLOCK 0x00000008 187#define NDF_NO_VP_PUT 0x0000000c 188#define NDF_NO_STARTDIR_RELE 0x00000010 189#define NDF_NO_FREE_PNBUF 0x00000020 190#define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF) 191 192void NDFREE(struct nameidata *, const u_int); 193 194int namei(struct nameidata *ndp); 195int lookup(struct nameidata *ndp); 196int relookup(struct vnode *dvp, struct vnode **vpp, 197 struct componentname *cnp); 198#endif 199 200/* 201 * Stats on usefulness of namei caches. 202 */ 203struct nchstats { 204 long ncs_goodhits; /* hits that we can really use */ 205 long ncs_neghits; /* negative hits that we can use */ 206 long ncs_badhits; /* hits we must drop */ 207 long ncs_falsehits; /* hits with id mismatch */ 208 long ncs_miss; /* misses */ 209 long ncs_long; /* long names that ignore cache */ 210 long ncs_pass2; /* names found with passes == 2 */ 211 long ncs_2passes; /* number of times we attempt it */ 212}; 213 214extern struct nchstats nchstats; 215 216#endif /* !_SYS_NAMEI_H_ */ 217