1 /* $NetBSD: paths.c,v 1.8 2008/08/12 19:44:39 pooka Exp $ */ 2 3 /* 4 * Copyright (c) 2007 Antti Kantee. All Rights Reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 #if !defined(lint) 30 __RCSID("$NetBSD: paths.c,v 1.8 2008/08/12 19:44:39 pooka Exp $"); 31 #endif /* !lint */ 32 33 #include <sys/hash.h> 34 35 #include <assert.h> 36 #include <errno.h> 37 #include <puffs.h> 38 #include <stdlib.h> 39 40 #include "puffs_priv.h" 41 42 /* 43 * Generic routines for pathbuilding code 44 */ 45 46 int 47 puffs_path_pcnbuild(struct puffs_usermount *pu, struct puffs_cn *pcn, 48 puffs_cookie_t parent) 49 { 50 struct puffs_node *pn_parent = PU_CMAP(pu, parent); 51 struct puffs_cn pcn_orig; 52 struct puffs_pathobj po; 53 int rv; 54 55 assert(pn_parent->pn_po.po_path != NULL); 56 assert(pu->pu_flags & PUFFS_FLAG_BUILDPATH); 57 58 if (pu->pu_pathtransform) { 59 rv = pu->pu_pathtransform(pu, &pn_parent->pn_po, pcn, &po); 60 if (rv) 61 return rv; 62 } else { 63 po.po_path = pcn->pcn_name; 64 po.po_len = pcn->pcn_namelen; 65 } 66 67 if (pu->pu_namemod) { 68 /* XXX: gcc complains if I do assignment */ 69 memcpy(&pcn_orig, pcn, sizeof(pcn_orig)); 70 rv = pu->pu_namemod(pu, &pn_parent->pn_po, pcn); 71 if (rv) 72 return rv; 73 } 74 75 rv = pu->pu_pathbuild(pu, &pn_parent->pn_po, &po, 0, 76 &pcn->pcn_po_full); 77 puffs_path_buildhash(pu, &pcn->pcn_po_full); 78 79 if (pu->pu_pathtransform) 80 pu->pu_pathfree(pu, &po); 81 82 if (pu->pu_namemod && rv) 83 *pcn = pcn_orig; 84 85 return rv; 86 } 87 88 /* 89 * substitute all (child) patch prefixes. called from nodewalk, which 90 * in turn is called from rename 91 */ 92 void * 93 puffs_path_prefixadj(struct puffs_usermount *pu, struct puffs_node *pn, 94 void *arg) 95 { 96 struct puffs_pathinfo *pi = arg; 97 struct puffs_pathobj localpo; 98 struct puffs_pathobj oldpo; 99 int rv; 100 101 /* can't be a path prefix */ 102 if (pn->pn_po.po_len < pi->pi_old->po_len) 103 return NULL; 104 105 if (pu->pu_pathcmp(pu, &pn->pn_po, pi->pi_old, pi->pi_old->po_len, 1)) 106 return NULL; 107 108 /* otherwise we'd have two nodes with an equal path */ 109 assert(pn->pn_po.po_len > pi->pi_old->po_len); 110 111 /* found a matching prefix */ 112 rv = pu->pu_pathbuild(pu, pi->pi_new, &pn->pn_po, 113 pi->pi_old->po_len, &localpo); 114 /* 115 * XXX: technically we shouldn't fail, but this is the only 116 * sensible thing to do here. If the buildpath routine fails, 117 * we will have paths in an inconsistent state. Should fix this, 118 * either by having two separate passes or by doing other tricks 119 * to make an invalid path with BUILDPATHS acceptable. 120 */ 121 if (rv != 0) 122 abort(); 123 124 /* adjust hash sum */ 125 puffs_path_buildhash(pu, &localpo); 126 127 /* out with the old and in with the new */ 128 oldpo = pn->pn_po; 129 pn->pn_po = localpo; 130 pu->pu_pathfree(pu, &oldpo); 131 132 /* continue the walk */ 133 return NULL; 134 } 135 136 /* 137 * called from nodewalk, checks for exact match 138 */ 139 void * 140 puffs_path_walkcmp(struct puffs_usermount *pu, struct puffs_node *pn, void *arg) 141 { 142 struct puffs_pathobj *po = arg; 143 struct puffs_pathobj po2; 144 145 if (po->po_len != PNPLEN(pn)) 146 return NULL; 147 148 /* 149 * If hashing and the hash doesn't match, we know this is 150 * definitely not a match. Otherwise check for collisions. 151 */ 152 if (pu->pu_flags & PUFFS_FLAG_HASHPATH) 153 if (pn->pn_po.po_hash != po->po_hash) 154 return NULL; 155 156 po2.po_path = PNPATH(pn); 157 po2.po_len = PNPLEN(pn); 158 159 if (pu->pu_pathcmp(pu, po, &po2, PNPLEN(pn), 0) == 0) 160 return pn; 161 return NULL; 162 } 163 164 /* 165 * Hash sum building routine. Use string hash if the buildpath routine 166 * is the standard one, otherwise use binary hashes. A bit whimsical 167 * way to choose the routine, but the binary works for strings also, 168 * so don't sweat it. 169 */ 170 void 171 puffs_path_buildhash(struct puffs_usermount *pu, struct puffs_pathobj *po) 172 { 173 174 if ((pu->pu_flags & PUFFS_FLAG_HASHPATH) == 0) 175 return; 176 177 if (pu->pu_pathbuild == puffs_stdpath_buildpath) 178 po->po_hash = hash32_strn(po->po_path, po->po_len, 179 HASH32_STR_INIT); 180 else 181 po->po_hash = hash32_buf(po->po_path, po->po_len, 182 HASH32_BUF_INIT); 183 } 184 185 /* 186 * Routines provided to file systems which consider a path a tuple of 187 * strings and / the component separator. 188 */ 189 190 /*ARGSUSED*/ 191 int 192 puffs_stdpath_cmppath(struct puffs_usermount *pu, struct puffs_pathobj *c1, 193 struct puffs_pathobj *c2, size_t clen, int checkprefix) 194 { 195 char *p; 196 int rv; 197 198 rv = strncmp(c1->po_path, c2->po_path, clen); 199 if (rv) 200 return 1; 201 202 if (checkprefix == 0) 203 return 0; 204 205 /* sanity for next step */ 206 if (!(c1->po_len > c2->po_len)) 207 return 1; 208 209 /* check if it's really a complete path prefix */ 210 p = c1->po_path; 211 if ((*(p + clen)) != '/') 212 return 1; 213 214 return 0; 215 } 216 217 /*ARGSUSED*/ 218 int 219 puffs_stdpath_buildpath(struct puffs_usermount *pu, 220 const struct puffs_pathobj *po_pre, const struct puffs_pathobj *po_comp, 221 size_t offset, struct puffs_pathobj *newpath) 222 { 223 char *path, *pcomp; 224 size_t plen, complen; 225 size_t prelen; 226 int isdotdot; 227 228 complen = po_comp->po_len - offset; 229 230 /* seek to correct place & remove all leading '/' from component */ 231 pcomp = po_comp->po_path; 232 pcomp += offset; 233 while (*pcomp == '/') { 234 pcomp++; 235 complen--; 236 } 237 238 /* todotdot or nottodotdot */ 239 if (complen == 2 && strcmp(pcomp, "..") == 0) 240 isdotdot = 1; 241 else 242 isdotdot = 0; 243 244 /* 245 * Strip trailing components from the preceending component. 246 * This is an issue only for the root node, which we might want 247 * to be at path "/" for some file systems. 248 */ 249 prelen = po_pre->po_len; 250 while (prelen > 0 && *((char *)po_pre->po_path + (prelen-1)) == '/') { 251 assert(isdotdot == 0); 252 prelen--; 253 } 254 255 if (isdotdot) { 256 char *slash; /* sweet char of mine */ 257 258 slash = strrchr(po_pre->po_path, '/'); 259 assert(slash != NULL); 260 261 plen = slash - (char *)po_pre->po_path; 262 263 /* 264 * As the converse to not stripping the initial "/" above, 265 * don't nuke it here either. 266 */ 267 if (plen == 0) 268 plen++; 269 270 path = malloc(plen + 1); 271 if (path == NULL) 272 return errno; 273 274 strlcpy(path, po_pre->po_path, plen+1); 275 } else { 276 /* + '/' + '\0' */ 277 plen = prelen + 1 + complen; 278 path = malloc(plen + 1); 279 if (path == NULL) 280 return errno; 281 282 strlcpy(path, po_pre->po_path, prelen+1); 283 strcat(path, "/"); 284 strncat(path, pcomp, complen); 285 } 286 287 newpath->po_path = path; 288 newpath->po_len = plen; 289 290 return 0; 291 } 292 293 /*ARGSUSED*/ 294 void 295 puffs_stdpath_freepath(struct puffs_usermount *pu, struct puffs_pathobj *po) 296 { 297 298 free(po->po_path); 299 } 300
Indexes created Sat Sep 20 22:09:52 GMT 2025