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 * 3. 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/12/sys/sys/namei.h 369500 2021-03-21 17:56:44Z kib $ 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 43 struct 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 60 struct nameicap_tracker; 61 TAILQ_HEAD(nameicap_tracker_head, nameicap_tracker); 62 63 /* 64 * Encapsulation of namei parameters. 65 */ 66 struct 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 * Results: flags returned from namei 92 */ 93 u_int ni_resflags; 94 /* 95 * Shared between namei and lookup/commit routines. 96 */ 97 size_t ni_pathlen; /* remaining chars in path */ 98 char *ni_next; /* next location in pathname */ 99 u_int ni_loopcnt; /* count of symlinks encountered */ 100 /* 101 * Lookup parameters: this structure describes the subset of 102 * information from the nameidata structure that is passed 103 * through the VOP interface. 104 */ 105 struct componentname ni_cnd; 106 struct nameicap_tracker_head ni_cap_tracker; 107 }; 108 109 #ifdef _KERNEL 110 /* 111 * namei operations 112 */ 113 #define LOOKUP 0 /* perform name lookup only */ 114 #define CREATE 1 /* setup for file creation */ 115 #define DELETE 2 /* setup for file deletion */ 116 #define RENAME 3 /* setup for file renaming */ 117 #define OPMASK 3 /* mask for operation */ 118 /* 119 * namei operational modifier flags, stored in ni_cnd.flags 120 */ 121 #define LOCKLEAF 0x0004 /* lock vnode on return */ 122 #define LOCKPARENT 0x0008 /* want parent vnode returned locked */ 123 #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */ 124 #define NOCACHE 0x0020 /* name must not be left in cache */ 125 #define FOLLOW 0x0040 /* follow symbolic links */ 126 #define LOCKSHARED 0x0100 /* Shared lock leaf */ 127 #define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */ 128 #define RBENEATH 0x100000000ULL /* No escape, even tmp, from start dir */ 129 #define MODMASK 0xf000001fcULL /* mask of operational modifiers */ 130 /* 131 * Namei parameter descriptors. 132 * 133 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP. 134 * If the caller of namei sets the flag (for example execve wants to 135 * know the name of the program that is being executed), then it must 136 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must 137 * be freed by either the commit routine or the VOP_ABORT routine. 138 * SAVESTART is set only by the callers of namei. It implies SAVENAME 139 * plus the addition of saving the parent directory that contains the 140 * name in ni_startdir. It allows repeated calls to lookup for the 141 * name being sought. The caller is responsible for releasing the 142 * buffer and for vrele'ing ni_startdir. 143 */ 144 #define RDONLY 0x00000200 /* lookup with read-only semantics */ 145 #define HASBUF 0x00000400 /* has allocated pathname buffer */ 146 #define SAVENAME 0x00000800 /* save pathname buffer */ 147 #define SAVESTART 0x00001000 /* save starting directory */ 148 #define ISDOTDOT 0x00002000 /* current component name is .. */ 149 #define MAKEENTRY 0x00004000 /* entry is to be added to name cache */ 150 #define ISLASTCN 0x00008000 /* this is last component of pathname */ 151 #define ISSYMLINK 0x00010000 /* symlink needs interpretation */ 152 #define ISWHITEOUT 0x00020000 /* found whiteout */ 153 #define DOWHITEOUT 0x00040000 /* do whiteouts */ 154 #define WILLBEDIR 0x00080000 /* new files will be dirs; allow trailing / */ 155 #define ISUNICODE 0x00100000 /* current component name is unicode*/ 156 #define ISOPEN 0x00200000 /* caller is opening; return a real vnode. */ 157 #define NOCROSSMOUNT 0x00400000 /* do not cross mount points */ 158 #define NOMACCHECK 0x00800000 /* do not perform MAC checks */ 159 #define AUDITVNODE1 0x04000000 /* audit the looked up vnode information */ 160 #define AUDITVNODE2 0x08000000 /* audit the looked up vnode information */ 161 #define TRAILINGSLASH 0x10000000 /* path ended in a slash */ 162 #define NOCAPCHECK 0x20000000 /* do not perform capability checks */ 163 #define NOEXECCHECK 0x40000000 /* do not perform exec check on dir */ 164 #define PARAMASK 0x7ffffe00 /* mask of parameter descriptors */ 165 166 /* 167 * Namei results flags 168 */ 169 #define NIRES_ABS 0x00000001 /* Path was absolute */ 170 #define NIRES_STRICTREL 0x00000002 /* Restricted lookup result */ 171 172 /* 173 * Flags in ni_lcf, valid for the duration of the namei call. 174 */ 175 #define NI_LCF_STRICTRELATIVE 0x0001 /* relative lookup only */ 176 #define NI_LCF_CAP_DOTDOT 0x0002 /* ".." in strictrelative case */ 177 178 /* 179 * Initialization of a nameidata structure. 180 */ 181 #define NDINIT(ndp, op, flags, segflg, namep, td) \ 182 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, 0, td) 183 #define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd, td) \ 184 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, 0, td) 185 #define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp, td) \ 186 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp, td) 187 #define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp, td) \ 188 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, 0, td) 189 190 void NDINIT_ALL(struct nameidata *ndp, u_long op, u_long flags, 191 enum uio_seg segflg, const char *namep, int dirfd, struct vnode *startdir, 192 cap_rights_t *rightsp, struct thread *td); 193 194 #define NDF_NO_DVP_RELE 0x00000001 195 #define NDF_NO_DVP_UNLOCK 0x00000002 196 #define NDF_NO_DVP_PUT 0x00000003 197 #define NDF_NO_VP_RELE 0x00000004 198 #define NDF_NO_VP_UNLOCK 0x00000008 199 #define NDF_NO_VP_PUT 0x0000000c 200 #define NDF_NO_STARTDIR_RELE 0x00000010 201 #define NDF_NO_FREE_PNBUF 0x00000020 202 #define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF) 203 204 void NDFREE(struct nameidata *, const u_int); 205 206 int namei(struct nameidata *ndp); 207 int lookup(struct nameidata *ndp); 208 int relookup(struct vnode *dvp, struct vnode **vpp, 209 struct componentname *cnp); 210 #endif 211 212 /* 213 * Stats on usefulness of namei caches. 214 */ 215 struct nchstats { 216 long ncs_goodhits; /* hits that we can really use */ 217 long ncs_neghits; /* negative hits that we can use */ 218 long ncs_badhits; /* hits we must drop */ 219 long ncs_falsehits; /* hits with id mismatch */ 220 long ncs_miss; /* misses */ 221 long ncs_long; /* long names that ignore cache */ 222 long ncs_pass2; /* names found with passes == 2 */ 223 long ncs_2passes; /* number of times we attempt it */ 224 }; 225 226 extern struct nchstats nchstats; 227 228 #endif /* !_SYS_NAMEI_H_ */ 229