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 * $FreeBSD$ 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 43enum nameiop { LOOKUP, CREATE, DELETE, RENAME }; 44 45struct componentname { 46 /* 47 * Arguments to lookup. 48 */ 49 u_int64_t cn_origflags; /* flags to namei */ 50 u_int64_t cn_flags; /* flags to namei */ 51 struct thread *cn_thread;/* thread requesting lookup */ 52 struct ucred *cn_cred; /* credentials */ 53 enum nameiop cn_nameiop; /* namei operation */ 54 int cn_lkflags; /* Lock flags LK_EXCLUSIVE or LK_SHARED */ 55 /* 56 * Shared between lookup and commit routines. 57 */ 58 char *cn_pnbuf; /* pathname buffer */ 59 char *cn_nameptr; /* pointer to looked up name */ 60 long cn_namelen; /* length of looked up component */ 61}; 62 63struct nameicap_tracker; 64TAILQ_HEAD(nameicap_tracker_head, nameicap_tracker); 65 66/* 67 * Encapsulation of namei parameters. 68 */ 69struct nameidata { 70 /* 71 * Arguments to namei/lookup. 72 */ 73 const char *ni_dirp; /* pathname pointer */ 74 enum uio_seg ni_segflg; /* location of pathname */ 75 cap_rights_t *ni_rightsneeded; /* rights required to look up vnode */ 76 /* 77 * Arguments to lookup. 78 */ 79 struct vnode *ni_startdir; /* starting directory */ 80 struct vnode *ni_rootdir; /* logical root directory */ 81 struct vnode *ni_topdir; /* logical top directory */ 82 int ni_dirfd; /* starting directory for *at functions */ 83 int ni_lcf; /* local call flags */ 84 /* 85 * Results: returned from namei 86 */ 87 struct filecaps ni_filecaps; /* rights the *at base has */ 88 /* 89 * Results: returned from/manipulated by lookup 90 */ 91 struct vnode *ni_vp; /* vnode of result */ 92 struct vnode *ni_dvp; /* vnode of intermediate directory */ 93 /* 94 * Results: flags returned from namei 95 */ 96 u_int ni_resflags; 97 /* 98 * Debug for validating API use by the callers. 99 */ 100 u_short ni_debugflags; 101 /* 102 * Shared between namei and lookup/commit routines. 103 */ 104 u_short ni_loopcnt; /* count of symlinks encountered */ 105 size_t ni_pathlen; /* remaining chars in path */ 106 char *ni_next; /* next location in pathname */ 107 /* 108 * Lookup parameters: this structure describes the subset of 109 * information from the nameidata structure that is passed 110 * through the VOP interface. 111 */ 112 struct componentname ni_cnd; 113 struct nameicap_tracker_head ni_cap_tracker; 114}; 115 116#ifdef _KERNEL 117 118enum cache_fpl_status { CACHE_FPL_STATUS_DESTROYED, CACHE_FPL_STATUS_ABORTED, 119 CACHE_FPL_STATUS_PARTIAL, CACHE_FPL_STATUS_HANDLED, CACHE_FPL_STATUS_UNSET }; 120int cache_fplookup(struct nameidata *ndp, enum cache_fpl_status *status, 121 struct pwd **pwdp); 122 123/* 124 * Flags for namei. 125 * 126 * If modifying the list make sure to check whether NDVALIDATE needs updating. 127 */ 128 129/* 130 * Debug. 131 */ 132#define NAMEI_DBG_INITED 0x0001 133#define NAMEI_DBG_CALLED 0x0002 134#define NAMEI_DBG_HADSTARTDIR 0x0004 135 136/* 137 * namei operational modifier flags, stored in ni_cnd.flags 138 */ 139#define NC_NOMAKEENTRY 0x0001 /* name must not be added to cache */ 140#define NC_KEEPPOSENTRY 0x0002 /* don't evict a positive entry */ 141#define NOCACHE NC_NOMAKEENTRY /* for compatibility with older code */ 142#define LOCKLEAF 0x0004 /* lock vnode on return */ 143#define LOCKPARENT 0x0008 /* want parent vnode returned locked */ 144#define WANTPARENT 0x0010 /* want parent vnode returned unlocked */ 145#define FAILIFEXISTS 0x0020 /* return EEXIST if found */ 146#define FOLLOW 0x0040 /* follow symbolic links */ 147#define EMPTYPATH 0x0080 /* Allow empty path for *at */ 148#define LOCKSHARED 0x0100 /* Shared lock leaf */ 149#define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */ 150#define RBENEATH 0x100000000ULL /* No escape, even tmp, from start dir */ 151#define MODMASK 0xf000001ffULL /* mask of operational modifiers */ 152 153/* 154 * Namei parameter descriptors. 155 * 156 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP. 157 * If the caller of namei sets the flag (for example execve wants to 158 * know the name of the program that is being executed), then it must 159 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must 160 * be freed by either the commit routine or the VOP_ABORT routine. 161 * SAVESTART is set only by the callers of namei. It implies SAVENAME 162 * plus the addition of saving the parent directory that contains the 163 * name in ni_startdir. It allows repeated calls to lookup for the 164 * name being sought. The caller is responsible for releasing the 165 * buffer and for vrele'ing ni_startdir. 166 */ 167#define RDONLY 0x00000200 /* lookup with read-only semantics */ 168#define SAVENAME 0x00000400 /* save pathname buffer */ 169#define SAVESTART 0x00000800 /* save starting directory */ 170#define ISWHITEOUT 0x00001000 /* found whiteout */ 171#define DOWHITEOUT 0x00002000 /* do whiteouts */ 172#define WILLBEDIR 0x00004000 /* new files will be dirs; allow trailing / */ 173#define ISOPEN 0x00008000 /* caller is opening; return a real vnode. */ 174#define NOCROSSMOUNT 0x00010000 /* do not cross mount points */ 175#define NOMACCHECK 0x00020000 /* do not perform MAC checks */ 176#define AUDITVNODE1 0x00040000 /* audit the looked up vnode information */ 177#define AUDITVNODE2 0x00080000 /* audit the looked up vnode information */ 178#define NOCAPCHECK 0x00100000 /* do not perform capability checks */ 179/* UNUSED 0x00200000 */ 180/* UNUSED 0x00400000 */ 181/* UNUSED 0x00800000 */ 182#define HASBUF 0x01000000 /* has allocated pathname buffer */ 183#define NOEXECCHECK 0x02000000 /* do not perform exec check on dir */ 184#define MAKEENTRY 0x04000000 /* entry is to be added to name cache */ 185#define ISSYMLINK 0x08000000 /* symlink needs interpretation */ 186#define ISLASTCN 0x10000000 /* this is last component of pathname */ 187#define ISDOTDOT 0x20000000 /* current component name is .. */ 188#define TRAILINGSLASH 0x40000000 /* path ended in a slash */ 189#define PARAMASK 0x7ffffe00 /* mask of parameter descriptors */ 190 191/* 192 * Flags which must not be passed in by callers. 193 */ 194#define NAMEI_INTERNAL_FLAGS \ 195 (HASBUF | NOEXECCHECK | MAKEENTRY | ISSYMLINK | ISLASTCN | ISDOTDOT | \ 196 TRAILINGSLASH) 197 198/* 199 * Namei results flags 200 */ 201#define NIRES_ABS 0x00000001 /* Path was absolute */ 202#define NIRES_STRICTREL 0x00000002 /* Restricted lookup result */ 203#define NIRES_EMPTYPATH 0x00000004 /* EMPTYPATH used */ 204 205/* 206 * Flags in ni_lcf, valid for the duration of the namei call. 207 */ 208#define NI_LCF_STRICTRELATIVE 0x0001 /* relative lookup only */ 209#define NI_LCF_CAP_DOTDOT 0x0002 /* ".." in strictrelative case */ 210 211/* 212 * Initialization of a nameidata structure. 213 */ 214#define NDINIT(ndp, op, flags, segflg, namep, td) \ 215 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, &cap_no_rights, td) 216#define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd, td) \ 217 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, &cap_no_rights, td) 218#define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp, td) \ 219 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp, td) 220#define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp, td) \ 221 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, &cap_no_rights, td) 222 223/* 224 * Note the constant pattern may *hide* bugs. 225 */ 226#ifdef INVARIANTS 227#define NDINIT_PREFILL(arg) memset(arg, 0xff, sizeof(*arg)) 228#define NDINIT_DBG(arg) { (arg)->ni_debugflags = NAMEI_DBG_INITED; } 229#define NDREINIT_DBG(arg) { \ 230 if (((arg)->ni_debugflags & NAMEI_DBG_INITED) == 0) \ 231 panic("namei data not inited"); \ 232 if (((arg)->ni_debugflags & NAMEI_DBG_HADSTARTDIR) != 0) \ 233 panic("NDREINIT on namei data with NAMEI_DBG_HADSTARTDIR"); \ 234 (arg)->ni_debugflags = NAMEI_DBG_INITED; \ 235} 236#else 237#define NDINIT_PREFILL(arg) do { } while (0) 238#define NDINIT_DBG(arg) do { } while (0) 239#define NDREINIT_DBG(arg) do { } while (0) 240#endif 241 242#define NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, startdir, rightsp, td) \ 243do { \ 244 struct nameidata *_ndp = (ndp); \ 245 cap_rights_t *_rightsp = (rightsp); \ 246 MPASS(_rightsp != NULL); \ 247 NDINIT_PREFILL(_ndp); \ 248 NDINIT_DBG(_ndp); \ 249 _ndp->ni_cnd.cn_nameiop = op; \ 250 _ndp->ni_cnd.cn_flags = flags; \ 251 _ndp->ni_segflg = segflg; \ 252 _ndp->ni_dirp = namep; \ 253 _ndp->ni_dirfd = dirfd; \ 254 _ndp->ni_startdir = startdir; \ 255 _ndp->ni_resflags = 0; \ 256 filecaps_init(&_ndp->ni_filecaps); \ 257 _ndp->ni_cnd.cn_thread = td; \ 258 _ndp->ni_rightsneeded = _rightsp; \ 259} while (0) 260 261#define NDREINIT(ndp) do { \ 262 struct nameidata *_ndp = (ndp); \ 263 NDREINIT_DBG(_ndp); \ 264 _ndp->ni_resflags = 0; \ 265 _ndp->ni_startdir = NULL; \ 266} while (0) 267 268#define NDF_NO_DVP_RELE 0x00000001 269#define NDF_NO_DVP_UNLOCK 0x00000002 270#define NDF_NO_DVP_PUT 0x00000003 271#define NDF_NO_VP_RELE 0x00000004 272#define NDF_NO_VP_UNLOCK 0x00000008 273#define NDF_NO_VP_PUT 0x0000000c 274#define NDF_NO_STARTDIR_RELE 0x00000010 275#define NDF_NO_FREE_PNBUF 0x00000020 276#define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF) 277 278void NDFREE_PNBUF(struct nameidata *); 279void NDFREE(struct nameidata *, const u_int); 280#define NDFREE(ndp, flags) do { \ 281 struct nameidata *_ndp = (ndp); \ 282 if (__builtin_constant_p(flags) && flags == NDF_ONLY_PNBUF) \ 283 NDFREE_PNBUF(_ndp); \ 284 else \ 285 NDFREE(_ndp, flags); \ 286} while (0) 287 288#ifdef INVARIANTS 289void NDFREE_NOTHING(struct nameidata *); 290void NDVALIDATE(struct nameidata *); 291#else 292#define NDFREE_NOTHING(ndp) do { } while (0) 293#define NDVALIDATE(ndp) do { } while (0) 294#endif 295 296int namei(struct nameidata *ndp); 297int lookup(struct nameidata *ndp); 298int relookup(struct vnode *dvp, struct vnode **vpp, 299 struct componentname *cnp); 300#endif 301 302/* 303 * Stats on usefulness of namei caches. 304 */ 305struct nchstats { 306 long ncs_goodhits; /* hits that we can really use */ 307 long ncs_neghits; /* negative hits that we can use */ 308 long ncs_badhits; /* hits we must drop */ 309 long ncs_falsehits; /* hits with id mismatch */ 310 long ncs_miss; /* misses */ 311 long ncs_long; /* long names that ignore cache */ 312 long ncs_pass2; /* names found with passes == 2 */ 313 long ncs_2passes; /* number of times we attempt it */ 314}; 315 316extern struct nchstats nchstats; 317 318#endif /* !_SYS_NAMEI_H_ */ 319