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_origflags; /* flags to namei */ 51 u_int64_t cn_flags; /* flags to namei */ 52 struct thread *cn_thread;/* thread requesting lookup */ 53 struct ucred *cn_cred; /* credentials */ 54 enum nameiop cn_nameiop; /* namei operation */ 55 int cn_lkflags; /* Lock flags LK_EXCLUSIVE or LK_SHARED */ 56 /* 57 * Shared between lookup and commit routines. 58 */ 59 char *cn_pnbuf; /* pathname buffer */ 60 char *cn_nameptr; /* pointer to looked up name */ 61 long cn_namelen; /* length of looked up component */ 62 }; 63 64 struct nameicap_tracker; 65 TAILQ_HEAD(nameicap_tracker_head, nameicap_tracker); 66 67 /* 68 * Encapsulation of namei parameters. 69 */ 70 struct nameidata { 71 /* 72 * Arguments to namei/lookup. 73 */ 74 const char *ni_dirp; /* pathname pointer */ 75 enum uio_seg ni_segflg; /* location of pathname */ 76 cap_rights_t *ni_rightsneeded; /* rights required to look up vnode */ 77 /* 78 * Arguments to lookup. 79 */ 80 struct vnode *ni_startdir; /* starting directory */ 81 struct vnode *ni_rootdir; /* logical root directory */ 82 struct vnode *ni_topdir; /* logical top directory */ 83 int ni_dirfd; /* starting directory for *at functions */ 84 int ni_lcf; /* local call flags */ 85 /* 86 * Results: returned from namei 87 */ 88 struct filecaps ni_filecaps; /* rights the *at base has */ 89 /* 90 * Results: returned from/manipulated by lookup 91 */ 92 struct vnode *ni_vp; /* vnode of result */ 93 struct vnode *ni_dvp; /* vnode of intermediate directory */ 94 /* 95 * Results: flags returned from namei 96 */ 97 u_int ni_resflags; 98 /* 99 * Debug for validating API use by the callers. 100 */ 101 u_short ni_debugflags; 102 /* 103 * Shared between namei and lookup/commit routines. 104 */ 105 u_short ni_loopcnt; /* count of symlinks encountered */ 106 size_t ni_pathlen; /* remaining chars in path */ 107 char *ni_next; /* next location in pathname */ 108 /* 109 * Lookup parameters: this structure describes the subset of 110 * information from the nameidata structure that is passed 111 * through the VOP interface. 112 */ 113 struct componentname ni_cnd; 114 struct nameicap_tracker_head ni_cap_tracker; 115 /* 116 * Private helper data for UFS, must be at the end. See 117 * NDINIT_PREFILL(). 118 */ 119 seqc_t ni_dvp_seqc; 120 seqc_t ni_vp_seqc; 121 }; 122 123 #ifdef _KERNEL 124 125 enum cache_fpl_status { CACHE_FPL_STATUS_DESTROYED, CACHE_FPL_STATUS_ABORTED, 126 CACHE_FPL_STATUS_PARTIAL, CACHE_FPL_STATUS_HANDLED, CACHE_FPL_STATUS_UNSET }; 127 int cache_fplookup(struct nameidata *ndp, enum cache_fpl_status *status, 128 struct pwd **pwdp); 129 130 /* 131 * Flags for namei. 132 * 133 * If modifying the list make sure to check whether NDVALIDATE needs updating. 134 */ 135 136 /* 137 * Debug. 138 */ 139 #define NAMEI_DBG_INITED 0x0001 140 #define NAMEI_DBG_CALLED 0x0002 141 #define NAMEI_DBG_HADSTARTDIR 0x0004 142 143 /* 144 * namei operational modifier flags, stored in ni_cnd.flags 145 */ 146 #define NC_NOMAKEENTRY 0x0001 /* name must not be added to cache */ 147 #define NC_KEEPPOSENTRY 0x0002 /* don't evict a positive entry */ 148 #define NOCACHE NC_NOMAKEENTRY /* for compatibility with older code */ 149 #define LOCKLEAF 0x0004 /* lock vnode on return */ 150 #define LOCKPARENT 0x0008 /* want parent vnode returned locked */ 151 #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */ 152 #define FAILIFEXISTS 0x0020 /* return EEXIST if found */ 153 #define FOLLOW 0x0040 /* follow symbolic links */ 154 #define EMPTYPATH 0x0080 /* Allow empty path for *at */ 155 #define LOCKSHARED 0x0100 /* Shared lock leaf */ 156 #define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */ 157 #define RBENEATH 0x100000000ULL /* No escape, even tmp, from start dir */ 158 #define MODMASK 0xf000001ffULL /* mask of operational modifiers */ 159 160 /* 161 * Namei parameter descriptors. 162 * 163 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP. 164 * If the caller of namei sets the flag (for example execve wants to 165 * know the name of the program that is being executed), then it must 166 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must 167 * be freed by either the commit routine or the VOP_ABORT routine. 168 * SAVESTART is set only by the callers of namei. It implies SAVENAME 169 * plus the addition of saving the parent directory that contains the 170 * name in ni_startdir. It allows repeated calls to lookup for the 171 * name being sought. The caller is responsible for releasing the 172 * buffer and for vrele'ing ni_startdir. 173 */ 174 #define RDONLY 0x00000200 /* lookup with read-only semantics */ 175 #define SAVENAME 0x00000400 /* save pathname buffer */ 176 #define SAVESTART 0x00000800 /* save starting directory */ 177 #define ISWHITEOUT 0x00001000 /* found whiteout */ 178 #define DOWHITEOUT 0x00002000 /* do whiteouts */ 179 #define WILLBEDIR 0x00004000 /* new files will be dirs; allow trailing / */ 180 #define ISOPEN 0x00008000 /* caller is opening; return a real vnode. */ 181 #define NOCROSSMOUNT 0x00010000 /* do not cross mount points */ 182 #define NOMACCHECK 0x00020000 /* do not perform MAC checks */ 183 #define AUDITVNODE1 0x00040000 /* audit the looked up vnode information */ 184 #define AUDITVNODE2 0x00080000 /* audit the looked up vnode information */ 185 #define NOCAPCHECK 0x00100000 /* do not perform capability checks */ 186 #define OPENREAD 0x00200000 /* open for reading */ 187 #define OPENWRITE 0x00400000 /* open for writing */ 188 /* UNUSED 0x00800000 */ 189 #define HASBUF 0x01000000 /* has allocated pathname buffer */ 190 #define NOEXECCHECK 0x02000000 /* do not perform exec check on dir */ 191 #define MAKEENTRY 0x04000000 /* entry is to be added to name cache */ 192 #define ISSYMLINK 0x08000000 /* symlink needs interpretation */ 193 #define ISLASTCN 0x10000000 /* this is last component of pathname */ 194 #define ISDOTDOT 0x20000000 /* current component name is .. */ 195 #define TRAILINGSLASH 0x40000000 /* path ended in a slash */ 196 #define PARAMASK 0x7ffffe00 /* mask of parameter descriptors */ 197 198 /* 199 * Flags which must not be passed in by callers. 200 */ 201 #define NAMEI_INTERNAL_FLAGS \ 202 (HASBUF | NOEXECCHECK | MAKEENTRY | ISSYMLINK | ISLASTCN | ISDOTDOT | \ 203 TRAILINGSLASH) 204 205 /* 206 * Namei results flags 207 */ 208 #define NIRES_ABS 0x00000001 /* Path was absolute */ 209 #define NIRES_STRICTREL 0x00000002 /* Restricted lookup result */ 210 #define NIRES_EMPTYPATH 0x00000004 /* EMPTYPATH used */ 211 212 /* 213 * Flags in ni_lcf, valid for the duration of the namei call. 214 */ 215 #define NI_LCF_STRICTRELATIVE 0x0001 /* relative lookup only */ 216 #define NI_LCF_CAP_DOTDOT 0x0002 /* ".." in strictrelative case */ 217 218 /* 219 * Initialization of a nameidata structure. 220 */ 221 #define NDINIT(ndp, op, flags, segflg, namep, td) \ 222 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, &cap_no_rights, td) 223 #define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd, td) \ 224 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, &cap_no_rights, td) 225 #define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp, td) \ 226 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp, td) 227 #define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp, td) \ 228 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, &cap_no_rights, td) 229 230 /* 231 * Note the constant pattern may *hide* bugs. 232 */ 233 #ifdef INVARIANTS 234 #define NDINIT_PREFILL(arg) memset(arg, 0xff, offsetof(struct nameidata, \ 235 ni_dvp_seqc)) 236 #define NDINIT_DBG(arg) { (arg)->ni_debugflags = NAMEI_DBG_INITED; } 237 #define NDREINIT_DBG(arg) { \ 238 if (((arg)->ni_debugflags & NAMEI_DBG_INITED) == 0) \ 239 panic("namei data not inited"); \ 240 if (((arg)->ni_debugflags & NAMEI_DBG_HADSTARTDIR) != 0) \ 241 panic("NDREINIT on namei data with NAMEI_DBG_HADSTARTDIR"); \ 242 (arg)->ni_debugflags = NAMEI_DBG_INITED; \ 243 } 244 #else 245 #define NDINIT_PREFILL(arg) do { } while (0) 246 #define NDINIT_DBG(arg) do { } while (0) 247 #define NDREINIT_DBG(arg) do { } while (0) 248 #endif 249 250 #define NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, startdir, rightsp, td) \ 251 do { \ 252 struct nameidata *_ndp = (ndp); \ 253 cap_rights_t *_rightsp = (rightsp); \ 254 MPASS(_rightsp != NULL); \ 255 NDINIT_PREFILL(_ndp); \ 256 NDINIT_DBG(_ndp); \ 257 _ndp->ni_cnd.cn_nameiop = op; \ 258 _ndp->ni_cnd.cn_flags = flags; \ 259 _ndp->ni_segflg = segflg; \ 260 _ndp->ni_dirp = namep; \ 261 _ndp->ni_dirfd = dirfd; \ 262 _ndp->ni_startdir = startdir; \ 263 _ndp->ni_resflags = 0; \ 264 filecaps_init(&_ndp->ni_filecaps); \ 265 _ndp->ni_cnd.cn_thread = td; \ 266 _ndp->ni_rightsneeded = _rightsp; \ 267 } while (0) 268 269 #define NDREINIT(ndp) do { \ 270 struct nameidata *_ndp = (ndp); \ 271 NDREINIT_DBG(_ndp); \ 272 _ndp->ni_resflags = 0; \ 273 _ndp->ni_startdir = NULL; \ 274 } while (0) 275 276 #define NDPREINIT(ndp) do { \ 277 (ndp)->ni_dvp_seqc = SEQC_MOD; \ 278 (ndp)->ni_vp_seqc = SEQC_MOD; \ 279 } while (0) 280 281 #define NDF_NO_DVP_RELE 0x00000001 282 #define NDF_NO_DVP_UNLOCK 0x00000002 283 #define NDF_NO_DVP_PUT 0x00000003 284 #define NDF_NO_VP_RELE 0x00000004 285 #define NDF_NO_VP_UNLOCK 0x00000008 286 #define NDF_NO_VP_PUT 0x0000000c 287 #define NDF_NO_STARTDIR_RELE 0x00000010 288 #define NDF_NO_FREE_PNBUF 0x00000020 289 #define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF) 290 291 void NDFREE_PNBUF(struct nameidata *); 292 void NDFREE(struct nameidata *, const u_int); 293 #define NDFREE(ndp, flags) do { \ 294 struct nameidata *_ndp = (ndp); \ 295 if (__builtin_constant_p(flags) && flags == NDF_ONLY_PNBUF) \ 296 NDFREE_PNBUF(_ndp); \ 297 else \ 298 NDFREE(_ndp, flags); \ 299 } while (0) 300 301 #ifdef INVARIANTS 302 void NDFREE_NOTHING(struct nameidata *); 303 void NDVALIDATE(struct nameidata *); 304 #else 305 #define NDFREE_NOTHING(ndp) do { } while (0) 306 #define NDVALIDATE(ndp) do { } while (0) 307 #endif 308 309 int namei(struct nameidata *ndp); 310 int lookup(struct nameidata *ndp); 311 int relookup(struct vnode *dvp, struct vnode **vpp, 312 struct componentname *cnp); 313 #endif 314 315 /* 316 * Stats on usefulness of namei caches. 317 */ 318 struct nchstats { 319 long ncs_goodhits; /* hits that we can really use */ 320 long ncs_neghits; /* negative hits that we can use */ 321 long ncs_badhits; /* hits we must drop */ 322 long ncs_falsehits; /* hits with id mismatch */ 323 long ncs_miss; /* misses */ 324 long ncs_long; /* long names that ignore cache */ 325 long ncs_pass2; /* names found with passes == 2 */ 326 long ncs_2passes; /* number of times we attempt it */ 327 }; 328 329 extern struct nchstats nchstats; 330 331 #endif /* !_SYS_NAMEI_H_ */ 332