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 #include <vm/uma.h> 42 43 enum nameiop { LOOKUP, CREATE, DELETE, RENAME }; 44 45 struct componentname { 46 /* 47 * Arguments to lookup. 48 */ 49 u_int64_t cn_flags; /* flags to namei */ 50 struct ucred *cn_cred; /* credentials */ 51 enum nameiop cn_nameiop; /* namei operation */ 52 int cn_lkflags; /* Lock flags LK_EXCLUSIVE or LK_SHARED */ 53 /* 54 * Shared between lookup and commit routines. 55 */ 56 char *cn_pnbuf; /* pathname buffer */ 57 char *cn_nameptr; /* pointer to looked up name */ 58 long cn_namelen; /* length of looked up component */ 59 }; 60 61 struct nameicap_tracker; 62 TAILQ_HEAD(nameicap_tracker_head, nameicap_tracker); 63 64 /* 65 * Encapsulation of namei parameters. 66 */ 67 struct nameidata { 68 /* 69 * Arguments to namei/lookup. 70 */ 71 const char *ni_dirp; /* pathname pointer */ 72 enum uio_seg ni_segflg; /* location of pathname */ 73 cap_rights_t *ni_rightsneeded; /* rights required to look up vnode */ 74 /* 75 * Arguments to lookup. 76 */ 77 struct vnode *ni_startdir; /* starting directory */ 78 struct vnode *ni_rootdir; /* logical root directory */ 79 struct vnode *ni_topdir; /* logical top directory */ 80 int ni_dirfd; /* starting directory for *at functions */ 81 int ni_lcf; /* local call flags */ 82 /* 83 * Results: returned from namei 84 */ 85 struct filecaps ni_filecaps; /* rights the *at base has */ 86 /* 87 * Results: returned from/manipulated by lookup 88 */ 89 struct vnode *ni_vp; /* vnode of result */ 90 struct vnode *ni_dvp; /* vnode of intermediate directory */ 91 /* 92 * Results: flags returned from namei 93 */ 94 u_int ni_resflags; 95 /* 96 * Debug for validating API use by the callers. 97 */ 98 u_short ni_debugflags; 99 /* 100 * Shared between namei and lookup/commit routines. 101 */ 102 u_short ni_loopcnt; /* count of symlinks encountered */ 103 size_t ni_pathlen; /* remaining chars in path */ 104 char *ni_next; /* next location in pathname */ 105 /* 106 * Lookup parameters: this structure describes the subset of 107 * information from the nameidata structure that is passed 108 * through the VOP interface. 109 */ 110 struct componentname ni_cnd; 111 struct nameicap_tracker_head ni_cap_tracker; 112 /* 113 * Private helper data for UFS, must be at the end. See 114 * NDINIT_PREFILL(). 115 */ 116 seqc_t ni_dvp_seqc; 117 seqc_t ni_vp_seqc; 118 }; 119 120 #ifdef _KERNEL 121 122 enum cache_fpl_status { CACHE_FPL_STATUS_DESTROYED, CACHE_FPL_STATUS_ABORTED, 123 CACHE_FPL_STATUS_PARTIAL, CACHE_FPL_STATUS_HANDLED, CACHE_FPL_STATUS_UNSET }; 124 int cache_fplookup(struct nameidata *ndp, enum cache_fpl_status *status, 125 struct pwd **pwdp); 126 127 /* 128 * Flags for namei. 129 * 130 * If modifying the list make sure to check whether NDVALIDATE needs updating. 131 */ 132 133 /* 134 * Debug. 135 */ 136 #define NAMEI_DBG_INITED 0x0001 137 #define NAMEI_DBG_CALLED 0x0002 138 #define NAMEI_DBG_HADSTARTDIR 0x0004 139 140 /* 141 * namei operational modifier flags, stored in ni_cnd.flags 142 */ 143 #define NC_NOMAKEENTRY 0x0001 /* name must not be added to cache */ 144 #define NC_KEEPPOSENTRY 0x0002 /* don't evict a positive entry */ 145 #define NOCACHE NC_NOMAKEENTRY /* for compatibility with older code */ 146 #define LOCKLEAF 0x0004 /* lock vnode on return */ 147 #define LOCKPARENT 0x0008 /* want parent vnode returned locked */ 148 #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */ 149 #define FAILIFEXISTS 0x0020 /* return EEXIST if found */ 150 #define FOLLOW 0x0040 /* follow symbolic links */ 151 #define EMPTYPATH 0x0080 /* Allow empty path for *at */ 152 #define LOCKSHARED 0x0100 /* Shared lock leaf */ 153 #define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */ 154 #define RBENEATH 0x100000000ULL /* No escape, even tmp, from start dir */ 155 #define MODMASK 0xf000001ffULL /* mask of operational modifiers */ 156 157 /* 158 * Namei parameter descriptors. 159 */ 160 #define RDONLY 0x00000200 /* lookup with read-only semantics */ 161 #define ISRESTARTED 0x00000400 /* restarted namei */ 162 /* UNUSED 0x00000800 */ 163 #define ISWHITEOUT 0x00001000 /* found whiteout */ 164 #define DOWHITEOUT 0x00002000 /* do whiteouts */ 165 #define WILLBEDIR 0x00004000 /* new files will be dirs; allow trailing / */ 166 #define ISOPEN 0x00008000 /* caller is opening; return a real vnode. */ 167 #define NOCROSSMOUNT 0x00010000 /* do not cross mount points */ 168 #define NOMACCHECK 0x00020000 /* do not perform MAC checks */ 169 #define AUDITVNODE1 0x00040000 /* audit the looked up vnode information */ 170 #define AUDITVNODE2 0x00080000 /* audit the looked up vnode information */ 171 #define NOCAPCHECK 0x00100000 /* do not perform capability checks */ 172 #define OPENREAD 0x00200000 /* open for reading */ 173 #define OPENWRITE 0x00400000 /* open for writing */ 174 #define WANTIOCTLCAPS 0x00800000 /* leave ioctl caps for the caller */ 175 /* UNUSED 0x01000000 */ 176 #define NOEXECCHECK 0x02000000 /* do not perform exec check on dir */ 177 #define MAKEENTRY 0x04000000 /* entry is to be added to name cache */ 178 #define ISSYMLINK 0x08000000 /* symlink needs interpretation */ 179 #define ISLASTCN 0x10000000 /* this is last component of pathname */ 180 #define ISDOTDOT 0x20000000 /* current component name is .. */ 181 #define TRAILINGSLASH 0x40000000 /* path ended in a slash */ 182 #define PARAMASK 0x7ffffe00 /* mask of parameter descriptors */ 183 184 /* 185 * Flags which must not be passed in by callers. 186 */ 187 #define NAMEI_INTERNAL_FLAGS \ 188 (NOEXECCHECK | MAKEENTRY | ISSYMLINK | ISLASTCN | ISDOTDOT | \ 189 TRAILINGSLASH | ISRESTARTED) 190 191 /* 192 * Namei results flags 193 */ 194 #define NIRES_ABS 0x00000001 /* Path was absolute */ 195 #define NIRES_STRICTREL 0x00000002 /* Restricted lookup result */ 196 #define NIRES_EMPTYPATH 0x00000004 /* EMPTYPATH used */ 197 198 /* 199 * Flags in ni_lcf, valid for the duration of the namei call. 200 */ 201 #define NI_LCF_STRICTREL 0x0001 /* relative lookup only */ 202 #define NI_LCF_CAP_DOTDOT 0x0002 /* ".." in strictrelative case */ 203 /* Track capability restrictions seperately for violation ktracing. */ 204 #define NI_LCF_STRICTREL_KTR 0x0004 /* trace relative lookups */ 205 #define NI_LCF_CAP_DOTDOT_KTR 0x0008 /* ".." in strictrelative case */ 206 #define NI_LCF_KTR_FLAGS (NI_LCF_STRICTREL_KTR | NI_LCF_CAP_DOTDOT_KTR) 207 208 /* 209 * Initialization of a nameidata structure. 210 */ 211 #define NDINIT(ndp, op, flags, segflg, namep) \ 212 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, &cap_no_rights) 213 #define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd) \ 214 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, &cap_no_rights) 215 #define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp) \ 216 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp) 217 #define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp) \ 218 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, &cap_no_rights) 219 220 /* 221 * Note the constant pattern may *hide* bugs. 222 * Note also that we enable debug checks for non-TIED KLDs 223 * so that they can run on an INVARIANTS kernel without tripping over 224 * assertions on ni_debugflags state. 225 */ 226 #if defined(INVARIANTS) || (defined(KLD_MODULE) && !defined(KLD_TIED)) 227 #define NDINIT_PREFILL(arg) memset(arg, 0xff, offsetof(struct nameidata, \ 228 ni_dvp_seqc)) 229 #define NDINIT_DBG(arg) { (arg)->ni_debugflags = NAMEI_DBG_INITED; } 230 #define NDREINIT_DBG(arg) { \ 231 if (((arg)->ni_debugflags & NAMEI_DBG_INITED) == 0) \ 232 panic("namei data not inited"); \ 233 if (((arg)->ni_debugflags & NAMEI_DBG_HADSTARTDIR) != 0) \ 234 panic("NDREINIT on namei data with NAMEI_DBG_HADSTARTDIR"); \ 235 (arg)->ni_debugflags = NAMEI_DBG_INITED; \ 236 } 237 #else 238 #define NDINIT_PREFILL(arg) do { } while (0) 239 #define NDINIT_DBG(arg) do { } while (0) 240 #define NDREINIT_DBG(arg) do { } while (0) 241 #endif 242 243 #define NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, startdir, rightsp) \ 244 do { \ 245 struct nameidata *_ndp = (ndp); \ 246 cap_rights_t *_rightsp = (rightsp); \ 247 MPASS(_rightsp != NULL); \ 248 NDINIT_PREFILL(_ndp); \ 249 NDINIT_DBG(_ndp); \ 250 _ndp->ni_cnd.cn_nameiop = op; \ 251 _ndp->ni_cnd.cn_flags = flags; \ 252 _ndp->ni_segflg = segflg; \ 253 _ndp->ni_dirp = namep; \ 254 _ndp->ni_dirfd = dirfd; \ 255 _ndp->ni_startdir = startdir; \ 256 _ndp->ni_resflags = 0; \ 257 filecaps_init(&_ndp->ni_filecaps); \ 258 _ndp->ni_rightsneeded = _rightsp; \ 259 } while (0) 260 261 #define NDREINIT(ndp) do { \ 262 struct nameidata *_ndp = (ndp); \ 263 NDREINIT_DBG(_ndp); \ 264 filecaps_free(&_ndp->ni_filecaps); \ 265 _ndp->ni_resflags = 0; \ 266 _ndp->ni_startdir = NULL; \ 267 } while (0) 268 269 #define NDPREINIT(ndp) do { \ 270 (ndp)->ni_dvp_seqc = SEQC_MOD; \ 271 (ndp)->ni_vp_seqc = SEQC_MOD; \ 272 } while (0) 273 274 #define NDFREE_IOCTLCAPS(ndp) do { \ 275 struct nameidata *_ndp = (ndp); \ 276 filecaps_free(&_ndp->ni_filecaps); \ 277 } while (0) 278 279 #define NDFREE_PNBUF(ndp) do { \ 280 struct nameidata *_ndp = (ndp); \ 281 MPASS(_ndp->ni_cnd.cn_pnbuf != NULL); \ 282 uma_zfree(namei_zone, _ndp->ni_cnd.cn_pnbuf); \ 283 _ndp->ni_cnd.cn_pnbuf = NULL; \ 284 } while (0) 285 286 int namei(struct nameidata *ndp); 287 int vfs_lookup(struct nameidata *ndp); 288 int vfs_relookup(struct vnode *dvp, struct vnode **vpp, 289 struct componentname *cnp, bool refstart); 290 291 #define namei_setup_rootdir(ndp, cnp, pwd) do { \ 292 if (__predict_true((cnp->cn_flags & ISRESTARTED) == 0)) \ 293 ndp->ni_rootdir = pwd->pwd_adir; \ 294 else \ 295 ndp->ni_rootdir = pwd->pwd_rdir; \ 296 } while (0) 297 #endif 298 299 /* 300 * Stats on usefulness of namei caches. 301 */ 302 struct nchstats { 303 long ncs_goodhits; /* hits that we can really use */ 304 long ncs_neghits; /* negative hits that we can use */ 305 long ncs_badhits; /* hits we must drop */ 306 long ncs_falsehits; /* hits with id mismatch */ 307 long ncs_miss; /* misses */ 308 long ncs_long; /* long names that ignore cache */ 309 long ncs_pass2; /* names found with passes == 2 */ 310 long ncs_2passes; /* number of times we attempt it */ 311 }; 312 313 extern struct nchstats nchstats; 314 315 #endif /* !_SYS_NAMEI_H_ */ 316