paths.c revision 1.4
1 /* $NetBSD: paths.c,v 1.4 2007/02/15 17:04:46 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 * 3. The name of the company nor the name of the author may be used to 15 * endorse or promote products derived from this software without specific 16 * prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 19 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 21 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 24 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/cdefs.h> 32 #if !defined(lint) 33 __RCSID("$NetBSD: paths.c,v 1.4 2007/02/15 17:04:46 pooka Exp $"); 34 #endif /* !lint */ 35 36 #include <assert.h> 37 #include <errno.h> 38 #include <puffs.h> 39 #include <stdlib.h> 40 41 #include "puffs_priv.h" 42 43 /* 44 * Generic routines for pathbuilding code 45 */ 46 47 int 48 puffs_path_pcnbuild(struct puffs_usermount *pu, struct puffs_cn *pcn, 49 void *parent) 50 { 51 struct puffs_node *pn_parent = PU_CMAP(pu, parent); 52 struct puffs_cn pcn_orig; 53 struct puffs_pathobj po; 54 int rv; 55 56 assert(pn_parent->pn_po.po_path != NULL); 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 78 if (pu->pu_pathtransform) 79 pu->pu_pathfree(pu, &po); 80 81 if (pu->pu_namemod && rv) 82 *pcn = pcn_orig; 83 84 return rv; 85 } 86 87 /* 88 * substitute all (child) patch prefixes. called from nodewalk, which 89 * in turn is called from rename 90 */ 91 void * 92 puffs_path_prefixadj(struct puffs_usermount *pu, struct puffs_node *pn, 93 void *arg) 94 { 95 struct puffs_pathinfo *pi = arg; 96 struct puffs_pathobj localpo; 97 struct puffs_pathobj oldpo; 98 int rv; 99 100 /* can't be a path prefix */ 101 if (pn->pn_po.po_len < pi->pi_old->po_len) 102 return NULL; 103 104 if (pu->pu_pathcmp(pu, &pn->pn_po, pi->pi_old, pi->pi_old->po_len, 1)) 105 return NULL; 106 107 /* otherwise we'd have two nodes with an equal path */ 108 assert(pn->pn_po.po_len > pi->pi_old->po_len); 109 110 /* found a matching prefix */ 111 rv = pu->pu_pathbuild(pu, pi->pi_new, &pn->pn_po, 112 pi->pi_old->po_len, &localpo); 113 /* 114 * XXX: technically we shouldn't fail, but this is the only 115 * sensible thing to do here. If the buildpath routine fails, 116 * we will have paths in an inconsistent state. Should fix this, 117 * either by having two separate passes or by doing other tricks 118 * to make an invalid path with BUILDPATHS acceptable. 119 */ 120 if (rv != 0) 121 abort(); 122 123 /* out with the old and in with the new */ 124 oldpo = pn->pn_po; 125 pn->pn_po = localpo; 126 pu->pu_pathfree(pu, &oldpo); 127 128 /* continue the walk */ 129 return NULL; 130 } 131 132 /* 133 * called from nodewalk, checks for exact match 134 */ 135 void * 136 puffs_path_walkcmp(struct puffs_usermount *pu, struct puffs_node *pn, void *arg) 137 { 138 struct puffs_pathobj *po = arg; 139 struct puffs_pathobj po2; 140 141 if (po->po_len != PNPLEN(pn)) 142 return NULL; 143 144 po2.po_path = PNPATH(pn); 145 po2.po_len = PNPLEN(pn); 146 147 if (pu->pu_pathcmp(pu, po, &po2, PNPLEN(pn), 0) == 0) 148 return pn; 149 return NULL; 150 } 151 152 /* 153 * Routines provided to file systems which consider a path a tuple of 154 * strings and / the component separator. 155 */ 156 157 /*ARGSUSED*/ 158 int 159 puffs_stdpath_cmppath(struct puffs_usermount *pu, struct puffs_pathobj *c1, 160 struct puffs_pathobj *c2, size_t clen, int checkprefix) 161 { 162 char *p; 163 int rv; 164 165 rv = strncmp(c1->po_path, c2->po_path, clen); 166 if (rv) 167 return 1; 168 169 if (checkprefix == 0) 170 return 0; 171 172 /* sanity for next step */ 173 if (!(c1->po_len > c2->po_len)) 174 return 1; 175 176 /* check if it's really a complete path prefix */ 177 p = c1->po_path; 178 if ((*(p + clen)) != '/') 179 return 1; 180 181 return 0; 182 } 183 184 /*ARGSUSED*/ 185 int 186 puffs_stdpath_buildpath(struct puffs_usermount *pu, 187 const struct puffs_pathobj *po_pre, const struct puffs_pathobj *po_comp, 188 size_t offset, struct puffs_pathobj *newpath) 189 { 190 char *path, *pcomp; 191 size_t plen, complen; 192 size_t prelen; 193 int isdotdot; 194 195 complen = po_comp->po_len - offset; 196 197 /* seek to correct place & remove all leading '/' from component */ 198 pcomp = po_comp->po_path; 199 pcomp += offset; 200 while (*pcomp == '/') { 201 pcomp++; 202 complen--; 203 } 204 205 /* todotdot or nottodotdot */ 206 if (complen == 2 && strcmp(pcomp, "..") == 0) 207 isdotdot = 1; 208 else 209 isdotdot = 0; 210 211 /* 212 * Strip trailing components from the preceending component. 213 * This is an issue only for the root node, which we might want 214 * to be at path "/" for some file systems. 215 */ 216 prelen = po_pre->po_len; 217 while (prelen > 0 && *((char *)po_pre->po_path + (prelen-1)) == '/') { 218 assert(isdotdot == 0); 219 prelen--; 220 } 221 222 if (isdotdot) { 223 char *slash; /* sweet char of mine */ 224 225 slash = strrchr(po_pre->po_path, '/'); 226 assert(slash != NULL); 227 228 plen = slash - (char *)po_pre->po_path; 229 path = malloc(plen + 1); 230 if (path == NULL) 231 return errno; 232 233 strlcpy(path, po_pre->po_path, plen+1); 234 } else { 235 /* + '/' + '\0' */ 236 plen = prelen + 1 + complen; 237 path = malloc(plen + 1); 238 if (path == NULL) 239 return errno; 240 241 strlcpy(path, po_pre->po_path, prelen+1); 242 strcat(path, "/"); 243 strncat(path, pcomp, complen); 244 } 245 246 newpath->po_path = path; 247 newpath->po_len = plen; 248 249 return 0; 250 } 251 252 /*ARGSUSED*/ 253 void 254 puffs_stdpath_freepath(struct puffs_usermount *pu, struct puffs_pathobj *po) 255 { 256 257 free(po->po_path); 258 } 259
Indexes created Fri Oct 03 02:09:57 GMT 2025