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 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 63 struct nameicap_tracker; 64 TAILQ_HEAD(nameicap_tracker_head, nameicap_tracker); 65 66 /* 67 * Encapsulation of namei parameters. 68 */ 69 struct 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 * Private helper data for UFS, must be at the end. See 116 * NDINIT_PREFILL(). 117 */ 118 seqc_t ni_dvp_seqc; 119 seqc_t ni_vp_seqc; 120 }; 121 122 #ifdef _KERNEL 123 124 enum cache_fpl_status { CACHE_FPL_STATUS_DESTROYED, CACHE_FPL_STATUS_ABORTED, 125 CACHE_FPL_STATUS_PARTIAL, CACHE_FPL_STATUS_HANDLED, CACHE_FPL_STATUS_UNSET }; 126 int cache_fplookup(struct nameidata *ndp, enum cache_fpl_status *status, 127 struct pwd **pwdp); 128 129 /* 130 * Flags for namei. 131 * 132 * If modifying the list make sure to check whether NDVALIDATE needs updating. 133 */ 134 135 /* 136 * Debug. 137 */ 138 #define NAMEI_DBG_INITED 0x0001 139 #define NAMEI_DBG_CALLED 0x0002 140 #define NAMEI_DBG_HADSTARTDIR 0x0004 141 142 /* 143 * namei operational modifier flags, stored in ni_cnd.flags 144 */ 145 #define NC_NOMAKEENTRY 0x0001 /* name must not be added to cache */ 146 #define NC_KEEPPOSENTRY 0x0002 /* don't evict a positive entry */ 147 #define NOCACHE NC_NOMAKEENTRY /* for compatibility with older code */ 148 #define LOCKLEAF 0x0004 /* lock vnode on return */ 149 #define LOCKPARENT 0x0008 /* want parent vnode returned locked */ 150 #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */ 151 #define FAILIFEXISTS 0x0020 /* return EEXIST if found */ 152 #define FOLLOW 0x0040 /* follow symbolic links */ 153 #define EMPTYPATH 0x0080 /* Allow empty path for *at */ 154 #define LOCKSHARED 0x0100 /* Shared lock leaf */ 155 #define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */ 156 #define RBENEATH 0x100000000ULL /* No escape, even tmp, from start dir */ 157 #define MODMASK 0xf000001ffULL /* mask of operational modifiers */ 158 159 /* 160 * Namei parameter descriptors. 161 * 162 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP. 163 * If the caller of namei sets the flag (for example execve wants to 164 * know the name of the program that is being executed), then it must 165 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must 166 * be freed by either the commit routine or the VOP_ABORT routine. 167 * SAVESTART is set only by the callers of namei. It implies SAVENAME 168 * plus the addition of saving the parent directory that contains the 169 * name in ni_startdir. It allows repeated calls to lookup for the 170 * name being sought. The caller is responsible for releasing the 171 * buffer and for vrele'ing ni_startdir. 172 */ 173 #define RDONLY 0x00000200 /* lookup with read-only semantics */ 174 #define SAVENAME 0x00000400 /* save pathname buffer */ 175 #define SAVESTART 0x00000800 /* save starting directory */ 176 #define ISWHITEOUT 0x00001000 /* found whiteout */ 177 #define DOWHITEOUT 0x00002000 /* do whiteouts */ 178 #define WILLBEDIR 0x00004000 /* new files will be dirs; allow trailing / */ 179 #define ISOPEN 0x00008000 /* caller is opening; return a real vnode. */ 180 #define NOCROSSMOUNT 0x00010000 /* do not cross mount points */ 181 #define NOMACCHECK 0x00020000 /* do not perform MAC checks */ 182 #define AUDITVNODE1 0x00040000 /* audit the looked up vnode information */ 183 #define AUDITVNODE2 0x00080000 /* audit the looked up vnode information */ 184 #define NOCAPCHECK 0x00100000 /* do not perform capability checks */ 185 #define OPENREAD 0x00200000 /* open for reading */ 186 #define OPENWRITE 0x00400000 /* open for writing */ 187 #define WANTIOCTLCAPS 0x00800000 /* leave ioctl caps for the caller */ 188 #define HASBUF 0x01000000 /* has allocated pathname buffer */ 189 #define NOEXECCHECK 0x02000000 /* do not perform exec check on dir */ 190 #define MAKEENTRY 0x04000000 /* entry is to be added to name cache */ 191 #define ISSYMLINK 0x08000000 /* symlink needs interpretation */ 192 #define ISLASTCN 0x10000000 /* this is last component of pathname */ 193 #define ISDOTDOT 0x20000000 /* current component name is .. */ 194 #define TRAILINGSLASH 0x40000000 /* path ended in a slash */ 195 #define PARAMASK 0x7ffffe00 /* mask of parameter descriptors */ 196 197 /* 198 * Flags which must not be passed in by callers. 199 */ 200 #define NAMEI_INTERNAL_FLAGS \ 201 (HASBUF | NOEXECCHECK | MAKEENTRY | ISSYMLINK | ISLASTCN | ISDOTDOT | \ 202 TRAILINGSLASH) 203 204 /* 205 * Namei results flags 206 */ 207 #define NIRES_ABS 0x00000001 /* Path was absolute */ 208 #define NIRES_STRICTREL 0x00000002 /* Restricted lookup result */ 209 #define NIRES_EMPTYPATH 0x00000004 /* EMPTYPATH used */ 210 211 /* 212 * Flags in ni_lcf, valid for the duration of the namei call. 213 */ 214 #define NI_LCF_STRICTRELATIVE 0x0001 /* relative lookup only */ 215 #define NI_LCF_CAP_DOTDOT 0x0002 /* ".." in strictrelative case */ 216 217 /* 218 * Initialization of a nameidata structure. 219 */ 220 #define NDINIT(ndp, op, flags, segflg, namep) \ 221 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, &cap_no_rights) 222 #define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd) \ 223 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, &cap_no_rights) 224 #define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp) \ 225 NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp) 226 #define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp) \ 227 NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, &cap_no_rights) 228 229 /* 230 * Note the constant pattern may *hide* bugs. 231 * Note also that we enable debug checks for non-TIED KLDs 232 * so that they can run on an INVARIANTS kernel without tripping over 233 * assertions on ni_debugflags state. 234 */ 235 #if defined(INVARIANTS) || (defined(KLD_MODULE) && !defined(KLD_TIED)) 236 #define NDINIT_PREFILL(arg) memset(arg, 0xff, offsetof(struct nameidata, \ 237 ni_dvp_seqc)) 238 #define NDINIT_DBG(arg) { (arg)->ni_debugflags = NAMEI_DBG_INITED; } 239 #define NDREINIT_DBG(arg) { \ 240 if (((arg)->ni_debugflags & NAMEI_DBG_INITED) == 0) \ 241 panic("namei data not inited"); \ 242 if (((arg)->ni_debugflags & NAMEI_DBG_HADSTARTDIR) != 0) \ 243 panic("NDREINIT on namei data with NAMEI_DBG_HADSTARTDIR"); \ 244 (arg)->ni_debugflags = NAMEI_DBG_INITED; \ 245 } 246 #else 247 #define NDINIT_PREFILL(arg) do { } while (0) 248 #define NDINIT_DBG(arg) do { } while (0) 249 #define NDREINIT_DBG(arg) do { } while (0) 250 #endif 251 252 #define NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, startdir, rightsp) \ 253 do { \ 254 struct nameidata *_ndp = (ndp); \ 255 cap_rights_t *_rightsp = (rightsp); \ 256 MPASS(_rightsp != NULL); \ 257 NDINIT_PREFILL(_ndp); \ 258 NDINIT_DBG(_ndp); \ 259 _ndp->ni_cnd.cn_nameiop = op; \ 260 _ndp->ni_cnd.cn_flags = flags; \ 261 _ndp->ni_segflg = segflg; \ 262 _ndp->ni_dirp = namep; \ 263 _ndp->ni_dirfd = dirfd; \ 264 _ndp->ni_startdir = startdir; \ 265 _ndp->ni_resflags = 0; \ 266 filecaps_init(&_ndp->ni_filecaps); \ 267 _ndp->ni_rightsneeded = _rightsp; \ 268 } while (0) 269 270 #define NDREINIT(ndp) do { \ 271 struct nameidata *_ndp = (ndp); \ 272 NDREINIT_DBG(_ndp); \ 273 filecaps_free(&_ndp->ni_filecaps); \ 274 _ndp->ni_resflags = 0; \ 275 _ndp->ni_startdir = NULL; \ 276 } while (0) 277 278 #define NDPREINIT(ndp) do { \ 279 (ndp)->ni_dvp_seqc = SEQC_MOD; \ 280 (ndp)->ni_vp_seqc = SEQC_MOD; \ 281 } while (0) 282 283 #define NDF_NO_DVP_RELE 0x00000001 284 #define NDF_NO_DVP_UNLOCK 0x00000002 285 #define NDF_NO_DVP_PUT 0x00000003 286 #define NDF_NO_VP_RELE 0x00000004 287 #define NDF_NO_VP_UNLOCK 0x00000008 288 #define NDF_NO_VP_PUT 0x0000000c 289 #define NDF_NO_STARTDIR_RELE 0x00000010 290 #define NDF_NO_FREE_PNBUF 0x00000020 291 292 #define NDFREE_IOCTLCAPS(ndp) do { \ 293 struct nameidata *_ndp = (ndp); \ 294 filecaps_free(&_ndp->ni_filecaps); \ 295 } while (0) 296 void NDFREE_PNBUF(struct nameidata *); 297 void NDFREE(struct nameidata *, const u_int); 298 299 #ifdef INVARIANTS 300 void NDFREE_NOTHING(struct nameidata *); 301 void NDVALIDATE(struct nameidata *); 302 #else 303 #define NDFREE_NOTHING(ndp) do { } while (0) 304 #define NDVALIDATE(ndp) do { } while (0) 305 #endif 306 307 int namei(struct nameidata *ndp); 308 int vfs_lookup(struct nameidata *ndp); 309 int vfs_relookup(struct vnode *dvp, struct vnode **vpp, 310 struct componentname *cnp); 311 #endif 312 313 /* 314 * Stats on usefulness of namei caches. 315 */ 316 struct nchstats { 317 long ncs_goodhits; /* hits that we can really use */ 318 long ncs_neghits; /* negative hits that we can use */ 319 long ncs_badhits; /* hits we must drop */ 320 long ncs_falsehits; /* hits with id mismatch */ 321 long ncs_miss; /* misses */ 322 long ncs_long; /* long names that ignore cache */ 323 long ncs_pass2; /* names found with passes == 2 */ 324 long ncs_2passes; /* number of times we attempt it */ 325 }; 326 327 extern struct nchstats nchstats; 328 329 #endif /* !_SYS_NAMEI_H_ */ 330