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 32 #ifndef _SYS_NAMEI_H_ 33 #define _SYS_NAMEI_H_ 34 35 #include <sys/caprights.h> 36 #include <sys/filedesc.h> 37 #include <sys/queue.h> 38 #include <sys/_seqc.h> 39 #include <sys/_uio.h> 40 41 enum nameiop { LOOKUP, CREATE, DELETE, RENAME }; 42 43 struct componentname { 44 /* 45 * Arguments to lookup. 46 */ 47 u_int64_t cn_flags; /* flags to namei */ 48 struct ucred *cn_cred; /* credentials */ 49 enum nameiop cn_nameiop; /* namei operation */ 50 int cn_lkflags; /* Lock flags LK_EXCLUSIVE or LK_SHARED */ 51 /* 52 * Shared between lookup and commit routines. 53 */ 54 char *cn_pnbuf; /* pathname buffer */ 55 char *cn_nameptr; /* pointer to looked up name */ 56 long cn_namelen; /* length of looked up component */ 57 }; 58 59 struct nameicap_tracker; 60 TAILQ_HEAD(nameicap_tracker_head, nameicap_tracker); 61 62 /* 63 * Encapsulation of namei parameters. 64 */ 65 struct nameidata { 66 /* 67 * Arguments to namei/lookup. 68 */ 69 const char *ni_dirp; /* pathname pointer */ 70 enum uio_seg ni_segflg; /* location of pathname */ 71 cap_rights_t *ni_rightsneeded; /* rights required to look up vnode */ 72 /* 73 * Arguments to lookup. 74 */ 75 struct vnode *ni_startdir; /* starting directory */ 76 struct vnode *ni_rootdir; /* logical root directory */ 77 struct vnode *ni_topdir; /* logical top directory */ 78 int ni_dirfd; /* starting directory for *at functions */ 79 int ni_lcf; /* local call flags */ 80 /* 81 * Results: returned from namei 82 */ 83 struct filecaps ni_filecaps; /* rights the *at base has */ 84 /* 85 * Results: returned from/manipulated by lookup 86 */ 87 struct vnode *ni_vp; /* vnode of result */ 88 struct vnode *ni_dvp; /* vnode of intermediate directory */ 89 /* 90 * Results: flags returned from namei 91 */ 92 u_int ni_resflags; 93 /* 94 * Debug for validating API use by the callers. 95 */ 96 u_short ni_debugflags; 97 /* 98 * Shared between namei and lookup/commit routines. 99 */ 100 u_short ni_loopcnt; /* count of symlinks encountered */ 101 size_t ni_pathlen; /* remaining chars in path */ 102 char *ni_next; /* next location in pathname */ 103 /* 104 * Lookup parameters: this structure describes the subset of 105 * information from the nameidata structure that is passed 106 * through the VOP interface. 107 */ 108 struct componentname ni_cnd; 109 struct nameicap_tracker_head ni_cap_tracker; 110 /* 111 * Private helper data for UFS, must be at the end. See 112 * NDINIT_PREFILL(). 113 */ 114 seqc_t ni_dvp_seqc; 115 seqc_t ni_vp_seqc; 116 }; 117 118 #ifdef _KERNEL 119 120 enum cache_fpl_status { CACHE_FPL_STATUS_DESTROYED, CACHE_FPL_STATUS_ABORTED, 121 CACHE_FPL_STATUS_PARTIAL, CACHE_FPL_STATUS_HANDLED, CACHE_FPL_STATUS_UNSET }; 122 int cache_fplookup(struct nameidata *ndp, enum cache_fpl_status *status, 123 struct pwd **pwdp); 124 125 /* 126 * Flags for namei. 127 * 128 * If modifying the list make sure to check whether NDVALIDATE needs updating. 129 */ 130 131 /* 132 * Debug. 133 */ 134 #define NAMEI_DBG_INITED 0x0001 135 #define NAMEI_DBG_CALLED 0x0002 136 #define NAMEI_DBG_HADSTARTDIR 0x0004 137 138 /* 139 * namei operational modifier flags, stored in ni_cnd.flags 140 */ 141 #define NC_NOMAKEENTRY 0x0001 /* name must not be added to cache */ 142 #define NC_KEEPPOSENTRY 0x0002 /* don't evict a positive entry */ 143 #define NOCACHE NC_NOMAKEENTRY /* for compatibility with older code */ 144 #define LOCKLEAF 0x0004 /* lock vnode on return */ 145 #define LOCKPARENT 0x0008 /* want parent vnode returned locked */ 146 #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */ 147 #define FAILIFEXISTS 0x0020 /* return EEXIST if found */ 148 #define FOLLOW 0x0040 /* follow symbolic links */ 149 #define EMPTYPATH 0x0080 /* Allow empty path for *at */ 150 #define LOCKSHARED 0x0100 /* Shared lock leaf */ 151 #define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */ 152 #define RBENEATH 0x100000000ULL /* No escape, even tmp, from start dir */ 153 #define MODMASK 0xf000001ffULL /* mask of operational modifiers */ 154 155 /* 156 * Namei parameter descriptors. 157 */ 158 #define RDONLY 0x00000200 /* lookup with read-only semantics */ 159 #define ISRESTARTED 0x00000400 /* restarted namei */ 160 /* UNUSED 0x00000800 */ 161 #define ISWHITEOUT 0x00001000 /* found whiteout */ 162 #define DOWHITEOUT 0x00002000 /* do whiteouts */ 163 #define WILLBEDIR 0x00004000 /* new files will be dirs; allow trailing / */ 164 #define ISOPEN 0x00008000 /* caller is opening; return a real vnode. */ 165 #define NOCROSSMOUNT 0x00010000 /* do not cross mount points */ 166 #define NOMACCHECK 0x00020000 /* do not perform MAC checks */ 167 #define AUDITVNODE1 0x00040000 /* audit the looked up vnode information */ 168 #define AUDITVNODE2 0x00080000 /* audit the looked up vnode information */ 169 #define NOCAPCHECK 0x00100000 /* do not perform capability checks */ 170 #define OPENREAD 0x00200000 /* open for reading */ 171 #define OPENWRITE 0x00400000 /* open for writing */ 172 #define WANTIOCTLCAPS 0x00800000 /* leave ioctl caps for the caller */ 173 /* UNUSED 0x01000000 */ 174 #define NOEXECCHECK 0x02000000 /* do not perform exec check on dir */ 175 #define MAKEENTRY 0x04000000 /* entry is to be added to name cache */ 176 #define ISSYMLINK 0x08000000 /* symlink needs interpretation */ 177 #define ISLASTCN 0x10000000 /* this is last component of pathname */ 178 #define ISDOTDOT 0x20000000 /* current component name is .. */ 179 #define TRAILINGSLASH 0x40000000 /* path ended in a slash */ 180 #define PARAMASK 0x7ffffe00 /* mask of parameter descriptors */ 181 182 /* 183 * Flags which must not be passed in by callers. 184 */ 185 #define NAMEI_INTERNAL_FLAGS \ 186 (NOEXECCHECK | MAKEENTRY | ISSYMLINK | ISLASTCN | ISDOTDOT | \ 187 TRAILINGSLASH | ISRESTARTED) 188 189 /* 190 * Namei results flags 191 */ 192 #define NIRES_ABS 0x00000001 /* Path was absolute */ 193 #define NIRES_STRICTREL 0x00000002 /* Restricted lookup result */ 194 #define NIRES_EMPTYPATH 0x00000004 /* EMPTYPATH used */ 195 196 /* 197 * Flags in ni_lcf, valid for the duration of the namei call. 198 */ 199 #define NI_LCF_STRICTRELATIVE 0x0001 /* relative lookup only */ 200 #define NI_LCF_CAP_DOTDOT 0x0002 /* ".." in strictrelative case */ 201 202 /* 203 * Initialization of a nameidata structure. 204 */ 205 #define NDINIT(ndp, op, flags, segflg, namep) \ 206 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, &cap_no_rights) 207 #define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd) \ 208 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, &cap_no_rights) 209 #define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp) \ 210 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp) 211 #define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp) \ 212 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, &cap_no_rights) 213 214 /* 215 * Note the constant pattern may *hide* bugs. 216 * Note also that we enable debug checks for non-TIED KLDs 217 * so that they can run on an INVARIANTS kernel without tripping over 218 * assertions on ni_debugflags state. 219 */ 220 #if defined(INVARIANTS) || (defined(KLD_MODULE) && !defined(KLD_TIED)) 221 #define NDINIT_PREFILL(arg) memset(arg, 0xff, offsetof(struct nameidata, \ 222 ni_dvp_seqc)) 223 #define NDINIT_DBG(arg) { (arg)->ni_debugflags = NAMEI_DBG_INITED; } 224 #define NDREINIT_DBG(arg) { \ 225 if (((arg)->ni_debugflags & NAMEI_DBG_INITED) == 0) \ 226 panic("namei data not inited"); \ 227 if (((arg)->ni_debugflags & NAMEI_DBG_HADSTARTDIR) != 0) \ 228 panic("NDREINIT on namei data with NAMEI_DBG_HADSTARTDIR"); \ 229 (arg)->ni_debugflags = NAMEI_DBG_INITED; \ 230 } 231 #else 232 #define NDINIT_PREFILL(arg) do { } while (0) 233 #define NDINIT_DBG(arg) do { } while (0) 234 #define NDREINIT_DBG(arg) do { } while (0) 235 #endif 236 237 #define NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, startdir, rightsp) \ 238 do { \ 239 struct nameidata *_ndp = (ndp); \ 240 cap_rights_t *_rightsp = (rightsp); \ 241 MPASS(_rightsp != NULL); \ 242 NDINIT_PREFILL(_ndp); \ 243 NDINIT_DBG(_ndp); \ 244 _ndp->ni_cnd.cn_nameiop = op; \ 245 _ndp->ni_cnd.cn_flags = flags; \ 246 _ndp->ni_segflg = segflg; \ 247 _ndp->ni_dirp = namep; \ 248 _ndp->ni_dirfd = dirfd; \ 249 _ndp->ni_startdir = startdir; \ 250 _ndp->ni_resflags = 0; \ 251 filecaps_init(&_ndp->ni_filecaps); \ 252 _ndp->ni_rightsneeded = _rightsp; \ 253 } while (0) 254 255 #define NDREINIT(ndp) do { \ 256 struct nameidata *_ndp = (ndp); \ 257 NDREINIT_DBG(_ndp); \ 258 filecaps_free(&_ndp->ni_filecaps); \ 259 _ndp->ni_resflags = 0; \ 260 _ndp->ni_startdir = NULL; \ 261 } while (0) 262 263 #define NDPREINIT(ndp) do { \ 264 (ndp)->ni_dvp_seqc = SEQC_MOD; \ 265 (ndp)->ni_vp_seqc = SEQC_MOD; \ 266 } while (0) 267 268 #define NDFREE_IOCTLCAPS(ndp) do { \ 269 struct nameidata *_ndp = (ndp); \ 270 filecaps_free(&_ndp->ni_filecaps); \ 271 } while (0) 272 273 #define NDFREE_PNBUF(ndp) do { \ 274 struct nameidata *_ndp = (ndp); \ 275 MPASS(_ndp->ni_cnd.cn_pnbuf != NULL); \ 276 uma_zfree(namei_zone, _ndp->ni_cnd.cn_pnbuf); \ 277 _ndp->ni_cnd.cn_pnbuf = NULL; \ 278 } while (0) 279 280 int namei(struct nameidata *ndp); 281 int vfs_lookup(struct nameidata *ndp); 282 int vfs_relookup(struct vnode *dvp, struct vnode **vpp, 283 struct componentname *cnp, bool refstart); 284 285 #define namei_setup_rootdir(ndp, cnp, pwd) do { \ 286 if (__predict_true((cnp->cn_flags & ISRESTARTED) == 0)) \ 287 ndp->ni_rootdir = pwd->pwd_adir; \ 288 else \ 289 ndp->ni_rootdir = pwd->pwd_rdir; \ 290 } while (0) 291 #endif 292 293 /* 294 * Stats on usefulness of namei caches. 295 */ 296 struct nchstats { 297 long ncs_goodhits; /* hits that we can really use */ 298 long ncs_neghits; /* negative hits that we can use */ 299 long ncs_badhits; /* hits we must drop */ 300 long ncs_falsehits; /* hits with id mismatch */ 301 long ncs_miss; /* misses */ 302 long ncs_long; /* long names that ignore cache */ 303 long ncs_pass2; /* names found with passes == 2 */ 304 long ncs_2passes; /* number of times we attempt it */ 305 }; 306 307 extern struct nchstats nchstats; 308 309 #endif /* !_SYS_NAMEI_H_ */ 310