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/_seqc.h> 42 #include <sys/_uio.h> 43 44 enum nameiop { LOOKUP, CREATE, DELETE, RENAME }; 45 46 struct componentname { 47 /* 48 * Arguments to lookup. 49 */ 50 u_int64_t cn_flags; /* flags to namei */ 51 struct ucred *cn_cred; /* credentials */ 52 enum nameiop cn_nameiop; /* namei operation */ 53 int cn_lkflags; /* Lock flags LK_EXCLUSIVE or LK_SHARED */ 54 /* 55 * Shared between lookup and commit routines. 56 */ 57 char *cn_pnbuf; /* pathname buffer */ 58 char *cn_nameptr; /* pointer to looked up name */ 59 long cn_namelen; /* length of looked up component */ 60 }; 61 62 struct nameicap_tracker; 63 TAILQ_HEAD(nameicap_tracker_head, nameicap_tracker); 64 65 /* 66 * Encapsulation of namei parameters. 67 */ 68 struct nameidata { 69 /* 70 * Arguments to namei/lookup. 71 */ 72 const char *ni_dirp; /* pathname pointer */ 73 enum uio_seg ni_segflg; /* location of pathname */ 74 cap_rights_t *ni_rightsneeded; /* rights required to look up vnode */ 75 /* 76 * Arguments to lookup. 77 */ 78 struct vnode *ni_startdir; /* starting directory */ 79 struct vnode *ni_rootdir; /* logical root directory */ 80 struct vnode *ni_topdir; /* logical top directory */ 81 int ni_dirfd; /* starting directory for *at functions */ 82 int ni_lcf; /* local call flags */ 83 /* 84 * Results: returned from namei 85 */ 86 struct filecaps ni_filecaps; /* rights the *at base has */ 87 /* 88 * Results: returned from/manipulated by lookup 89 */ 90 struct vnode *ni_vp; /* vnode of result */ 91 struct vnode *ni_dvp; /* vnode of intermediate directory */ 92 /* 93 * Results: flags returned from namei 94 */ 95 u_int ni_resflags; 96 /* 97 * Debug for validating API use by the callers. 98 */ 99 u_short ni_debugflags; 100 /* 101 * Shared between namei and lookup/commit routines. 102 */ 103 u_short ni_loopcnt; /* count of symlinks encountered */ 104 size_t ni_pathlen; /* remaining chars in path */ 105 char *ni_next; /* next location in pathname */ 106 /* 107 * Lookup parameters: this structure describes the subset of 108 * information from the nameidata structure that is passed 109 * through the VOP interface. 110 */ 111 struct componentname ni_cnd; 112 struct nameicap_tracker_head ni_cap_tracker; 113 /* 114 * Private helper data for UFS, must be at the end. See 115 * NDINIT_PREFILL(). 116 */ 117 seqc_t ni_dvp_seqc; 118 seqc_t ni_vp_seqc; 119 }; 120 121 #ifdef _KERNEL 122 123 enum cache_fpl_status { CACHE_FPL_STATUS_DESTROYED, CACHE_FPL_STATUS_ABORTED, 124 CACHE_FPL_STATUS_PARTIAL, CACHE_FPL_STATUS_HANDLED, CACHE_FPL_STATUS_UNSET }; 125 int cache_fplookup(struct nameidata *ndp, enum cache_fpl_status *status, 126 struct pwd **pwdp); 127 128 /* 129 * Flags for namei. 130 * 131 * If modifying the list make sure to check whether NDVALIDATE needs updating. 132 */ 133 134 /* 135 * Debug. 136 */ 137 #define NAMEI_DBG_INITED 0x0001 138 #define NAMEI_DBG_CALLED 0x0002 139 #define NAMEI_DBG_HADSTARTDIR 0x0004 140 141 /* 142 * namei operational modifier flags, stored in ni_cnd.flags 143 */ 144 #define NC_NOMAKEENTRY 0x0001 /* name must not be added to cache */ 145 #define NC_KEEPPOSENTRY 0x0002 /* don't evict a positive entry */ 146 #define NOCACHE NC_NOMAKEENTRY /* for compatibility with older code */ 147 #define LOCKLEAF 0x0004 /* lock vnode on return */ 148 #define LOCKPARENT 0x0008 /* want parent vnode returned locked */ 149 #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */ 150 #define FAILIFEXISTS 0x0020 /* return EEXIST if found */ 151 #define FOLLOW 0x0040 /* follow symbolic links */ 152 #define EMPTYPATH 0x0080 /* Allow empty path for *at */ 153 #define LOCKSHARED 0x0100 /* Shared lock leaf */ 154 #define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */ 155 #define RBENEATH 0x100000000ULL /* No escape, even tmp, from start dir */ 156 #define MODMASK 0xf000001ffULL /* mask of operational modifiers */ 157 158 /* 159 * Namei parameter descriptors. 160 */ 161 #define RDONLY 0x00000200 /* lookup with read-only semantics */ 162 /* UNUSED 0x00000400 */ 163 /* UNUSED 0x00000800 */ 164 #define ISWHITEOUT 0x00001000 /* found whiteout */ 165 #define DOWHITEOUT 0x00002000 /* do whiteouts */ 166 #define WILLBEDIR 0x00004000 /* new files will be dirs; allow trailing / */ 167 #define ISOPEN 0x00008000 /* caller is opening; return a real vnode. */ 168 #define NOCROSSMOUNT 0x00010000 /* do not cross mount points */ 169 #define NOMACCHECK 0x00020000 /* do not perform MAC checks */ 170 #define AUDITVNODE1 0x00040000 /* audit the looked up vnode information */ 171 #define AUDITVNODE2 0x00080000 /* audit the looked up vnode information */ 172 #define NOCAPCHECK 0x00100000 /* do not perform capability checks */ 173 #define OPENREAD 0x00200000 /* open for reading */ 174 #define OPENWRITE 0x00400000 /* open for writing */ 175 #define WANTIOCTLCAPS 0x00800000 /* leave ioctl caps for the caller */ 176 /* UNUSED 0x01000000 */ 177 #define NOEXECCHECK 0x02000000 /* do not perform exec check on dir */ 178 #define MAKEENTRY 0x04000000 /* entry is to be added to name cache */ 179 #define ISSYMLINK 0x08000000 /* symlink needs interpretation */ 180 #define ISLASTCN 0x10000000 /* this is last component of pathname */ 181 #define ISDOTDOT 0x20000000 /* current component name is .. */ 182 #define TRAILINGSLASH 0x40000000 /* path ended in a slash */ 183 #define PARAMASK 0x7ffffe00 /* mask of parameter descriptors */ 184 185 /* 186 * Flags which must not be passed in by callers. 187 */ 188 #define NAMEI_INTERNAL_FLAGS \ 189 (NOEXECCHECK | MAKEENTRY | ISSYMLINK | ISLASTCN | ISDOTDOT | \ 190 TRAILINGSLASH) 191 192 /* 193 * Namei results flags 194 */ 195 #define NIRES_ABS 0x00000001 /* Path was absolute */ 196 #define NIRES_STRICTREL 0x00000002 /* Restricted lookup result */ 197 #define NIRES_EMPTYPATH 0x00000004 /* EMPTYPATH used */ 198 199 /* 200 * Flags in ni_lcf, valid for the duration of the namei call. 201 */ 202 #define NI_LCF_STRICTRELATIVE 0x0001 /* relative lookup only */ 203 #define NI_LCF_CAP_DOTDOT 0x0002 /* ".." in strictrelative case */ 204 205 /* 206 * Initialization of a nameidata structure. 207 */ 208 #define NDINIT(ndp, op, flags, segflg, namep) \ 209 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, &cap_no_rights) 210 #define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd) \ 211 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, &cap_no_rights) 212 #define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp) \ 213 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp) 214 #define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp) \ 215 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, &cap_no_rights) 216 217 /* 218 * Note the constant pattern may *hide* bugs. 219 * Note also that we enable debug checks for non-TIED KLDs 220 * so that they can run on an INVARIANTS kernel without tripping over 221 * assertions on ni_debugflags state. 222 */ 223 #if defined(INVARIANTS) || (defined(KLD_MODULE) && !defined(KLD_TIED)) 224 #define NDINIT_PREFILL(arg) memset(arg, 0xff, offsetof(struct nameidata, \ 225 ni_dvp_seqc)) 226 #define NDINIT_DBG(arg) { (arg)->ni_debugflags = NAMEI_DBG_INITED; } 227 #define NDREINIT_DBG(arg) { \ 228 if (((arg)->ni_debugflags & NAMEI_DBG_INITED) == 0) \ 229 panic("namei data not inited"); \ 230 if (((arg)->ni_debugflags & NAMEI_DBG_HADSTARTDIR) != 0) \ 231 panic("NDREINIT on namei data with NAMEI_DBG_HADSTARTDIR"); \ 232 (arg)->ni_debugflags = NAMEI_DBG_INITED; \ 233 } 234 #else 235 #define NDINIT_PREFILL(arg) do { } while (0) 236 #define NDINIT_DBG(arg) do { } while (0) 237 #define NDREINIT_DBG(arg) do { } while (0) 238 #endif 239 240 #define NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, startdir, rightsp) \ 241 do { \ 242 struct nameidata *_ndp = (ndp); \ 243 cap_rights_t *_rightsp = (rightsp); \ 244 MPASS(_rightsp != NULL); \ 245 NDINIT_PREFILL(_ndp); \ 246 NDINIT_DBG(_ndp); \ 247 _ndp->ni_cnd.cn_nameiop = op; \ 248 _ndp->ni_cnd.cn_flags = flags; \ 249 _ndp->ni_segflg = segflg; \ 250 _ndp->ni_dirp = namep; \ 251 _ndp->ni_dirfd = dirfd; \ 252 _ndp->ni_startdir = startdir; \ 253 _ndp->ni_resflags = 0; \ 254 filecaps_init(&_ndp->ni_filecaps); \ 255 _ndp->ni_rightsneeded = _rightsp; \ 256 } while (0) 257 258 #define NDREINIT(ndp) do { \ 259 struct nameidata *_ndp = (ndp); \ 260 NDREINIT_DBG(_ndp); \ 261 filecaps_free(&_ndp->ni_filecaps); \ 262 _ndp->ni_resflags = 0; \ 263 _ndp->ni_startdir = NULL; \ 264 } while (0) 265 266 #define NDPREINIT(ndp) do { \ 267 (ndp)->ni_dvp_seqc = SEQC_MOD; \ 268 (ndp)->ni_vp_seqc = SEQC_MOD; \ 269 } while (0) 270 271 #define NDF_NO_DVP_RELE 0x00000001 272 #define NDF_NO_DVP_UNLOCK 0x00000002 273 #define NDF_NO_DVP_PUT 0x00000003 274 #define NDF_NO_VP_RELE 0x00000004 275 #define NDF_NO_VP_UNLOCK 0x00000008 276 #define NDF_NO_VP_PUT 0x0000000c 277 #define NDF_NO_STARTDIR_RELE 0x00000010 278 #define NDF_NO_FREE_PNBUF 0x00000020 279 280 #define NDFREE_IOCTLCAPS(ndp) do { \ 281 struct nameidata *_ndp = (ndp); \ 282 filecaps_free(&_ndp->ni_filecaps); \ 283 } while (0) 284 285 #define NDFREE_PNBUF(ndp) do { \ 286 struct nameidata *_ndp = (ndp); \ 287 MPASS(_ndp->ni_cnd.cn_pnbuf != NULL); \ 288 uma_zfree(namei_zone, _ndp->ni_cnd.cn_pnbuf); \ 289 _ndp->ni_cnd.cn_pnbuf = NULL; \ 290 } while (0) 291 292 int namei(struct nameidata *ndp); 293 int vfs_lookup(struct nameidata *ndp); 294 int vfs_relookup(struct vnode *dvp, struct vnode **vpp, 295 struct componentname *cnp, bool refstart); 296 #endif 297 298 /* 299 * Stats on usefulness of namei caches. 300 */ 301 struct nchstats { 302 long ncs_goodhits; /* hits that we can really use */ 303 long ncs_neghits; /* negative hits that we can use */ 304 long ncs_badhits; /* hits we must drop */ 305 long ncs_falsehits; /* hits with id mismatch */ 306 long ncs_miss; /* misses */ 307 long ncs_long; /* long names that ignore cache */ 308 long ncs_pass2; /* names found with passes == 2 */ 309 long ncs_2passes; /* number of times we attempt it */ 310 }; 311 312 extern struct nchstats nchstats; 313 314 #endif /* !_SYS_NAMEI_H_ */ 315