1 /* $OpenBSD: walk.c,v 1.9 2016/12/17 16:12:15 krw Exp $ */ 2 /* $NetBSD: walk.c,v 1.29 2015/11/25 00:48:49 christos Exp $ */ 3 4 /* 5 * Copyright (c) 2001 Wasabi Systems, Inc. 6 * All rights reserved. 7 * 8 * Written by Luke Mewburn for Wasabi Systems, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed for the NetBSD Project by 21 * Wasabi Systems, Inc. 22 * 4. The name of Wasabi Systems, Inc. may not be used to endorse 23 * or promote products derived from this software without specific prior 24 * written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <sys/param.h> 40 #include <sys/stat.h> 41 42 #include <assert.h> 43 #include <stdio.h> 44 #include <dirent.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <unistd.h> 48 49 #include "makefs.h" 50 51 static fsnode *create_fsnode(const char *, const char *, const char *, 52 struct stat *); 53 static fsinode *link_check(fsinode *); 54 55 56 /* 57 * walk_dir -- 58 * build a tree of fsnodes from `root' and `dir', with a parent 59 * fsnode of `parent' (which may be NULL for the root of the tree). 60 * append the tree to a fsnode of `join' if it is not NULL. 61 * each "level" is a directory, with the "." entry guaranteed to be 62 * at the start of the list, and without ".." entries. 63 */ 64 fsnode * 65 walk_dir(const char *root, const char *dir, fsnode *parent, fsnode *join) 66 { 67 fsnode *first, *cur, *prev, *last; 68 DIR *dirp; 69 struct dirent *dent; 70 char path[MAXPATHLEN + 1]; 71 struct stat stbuf; 72 char *name, *rp; 73 int dot, len; 74 75 assert(root != NULL); 76 assert(dir != NULL); 77 78 len = snprintf(path, sizeof(path), "%s/%s", root, dir); 79 if (len >= (int)sizeof(path)) 80 errx(1, "Pathname too long."); 81 if ((dirp = opendir(path)) == NULL) 82 err(1, "Can't opendir `%s'", path); 83 rp = path + strlen(root) + 1; 84 if (join != NULL) { 85 first = cur = join; 86 while (cur->next != NULL) 87 cur = cur->next; 88 prev = last = cur; 89 } else 90 last = first = prev = NULL; 91 while ((dent = readdir(dirp)) != NULL) { 92 name = dent->d_name; 93 dot = 0; 94 if (name[0] == '.') 95 switch (name[1]) { 96 case '\0': /* "." */ 97 if (join != NULL) 98 continue; 99 dot = 1; 100 break; 101 case '.': /* ".." */ 102 if (name[2] == '\0') 103 continue; 104 /* FALLTHROUGH */ 105 default: 106 dot = 0; 107 } 108 if (snprintf(path + len, sizeof(path) - len, "/%s", name) >= 109 (int)sizeof(path) - len) 110 errx(1, "Pathname too long."); 111 if (lstat(path, &stbuf) == -1) 112 err(1, "Can't lstat `%s'", path); 113 if (S_ISSOCK(stbuf.st_mode & S_IFMT)) 114 continue; 115 116 if (join != NULL) { 117 cur = join->next; 118 for (;;) { 119 if (cur == NULL || strcmp(cur->name, name) == 0) 120 break; 121 if (cur == last) { 122 cur = NULL; 123 break; 124 } 125 cur = cur->next; 126 } 127 if (cur != NULL) { 128 if (S_ISDIR(cur->type) && 129 S_ISDIR(stbuf.st_mode)) { 130 cur->child = walk_dir(root, rp, cur, 131 cur->child); 132 continue; 133 } 134 errx(1, "Can't merge %s `%s' with " 135 "existing %s", 136 inode_type(stbuf.st_mode), path, 137 inode_type(cur->type)); 138 } 139 } 140 141 cur = create_fsnode(root, dir, name, &stbuf); 142 cur->parent = parent; 143 if (dot) { 144 /* ensure "." is at the start of the list */ 145 cur->next = first; 146 first = cur; 147 if (! prev) 148 prev = cur; 149 cur->first = first; 150 } else { /* not "." */ 151 if (prev) 152 prev->next = cur; 153 prev = cur; 154 if (!first) 155 first = cur; 156 cur->first = first; 157 if (S_ISDIR(cur->type)) { 158 cur->child = walk_dir(root, rp, cur, NULL); 159 continue; 160 } 161 } 162 if (stbuf.st_nlink > 1) { 163 fsinode *curino; 164 165 curino = link_check(cur->inode); 166 if (curino != NULL) { 167 free(cur->inode); 168 cur->inode = curino; 169 cur->inode->nlink++; 170 } 171 } 172 if (S_ISLNK(cur->type)) { 173 char slink[PATH_MAX+1]; 174 int llen; 175 176 llen = readlink(path, slink, sizeof(slink) - 1); 177 if (llen == -1) 178 err(1, "Readlink `%s'", path); 179 slink[llen] = '\0'; 180 cur->symlink = estrdup(slink); 181 } 182 } 183 assert(first != NULL); 184 if (join == NULL) 185 for (cur = first->next; cur != NULL; cur = cur->next) 186 cur->first = first; 187 if (closedir(dirp) == -1) 188 err(1, "Can't closedir `%s/%s'", root, dir); 189 return (first); 190 } 191 192 static fsnode * 193 create_fsnode(const char *root, const char *path, const char *name, 194 struct stat *stbuf) 195 { 196 fsnode *cur; 197 198 cur = ecalloc(1, sizeof(*cur)); 199 cur->path = estrdup(path); 200 cur->name = estrdup(name); 201 cur->inode = ecalloc(1, sizeof(*cur->inode)); 202 cur->root = root; 203 cur->type = stbuf->st_mode & S_IFMT; 204 cur->inode->nlink = 1; 205 cur->inode->st = *stbuf; 206 if (Tflag) { 207 cur->inode->st.st_atime = stampts; 208 cur->inode->st.st_mtime = stampts; 209 cur->inode->st.st_ctime = stampts; 210 cur->inode->st.st_atimensec = 0; 211 cur->inode->st.st_mtimensec = 0; 212 cur->inode->st.st_ctimensec = 0; 213 } 214 return (cur); 215 } 216 217 /* 218 * free_fsnodes -- 219 * Removes node from tree and frees it and all of 220 * its decendents. 221 */ 222 void 223 free_fsnodes(fsnode *node) 224 { 225 fsnode *cur, *next; 226 227 assert(node != NULL); 228 229 /* for ".", start with actual parent node */ 230 if (node->first == node) { 231 assert(node->name[0] == '.' && node->name[1] == '\0'); 232 if (node->parent) { 233 assert(node->parent->child == node); 234 node = node->parent; 235 } 236 } 237 238 /* Find ourselves in our sibling list and unlink */ 239 if (node->first != node) { 240 for (cur = node->first; cur->next; cur = cur->next) { 241 if (cur->next == node) { 242 cur->next = node->next; 243 node->next = NULL; 244 break; 245 } 246 } 247 } 248 249 for (cur = node; cur != NULL; cur = next) { 250 next = cur->next; 251 if (cur->child) { 252 cur->child->parent = NULL; 253 free_fsnodes(cur->child); 254 } 255 if (cur->inode->nlink-- == 1) 256 free(cur->inode); 257 if (cur->symlink) 258 free(cur->symlink); 259 free(cur->path); 260 free(cur->name); 261 free(cur); 262 } 263 } 264 265 266 /* 267 * inode_type -- 268 * for a given inode type `mode', return a descriptive string. 269 * for most cases, uses inotype() from mtree/misc.c 270 */ 271 const char * 272 inode_type(mode_t mode) 273 { 274 switch (mode & S_IFMT) { 275 case S_IFBLK: 276 return ("block"); 277 case S_IFCHR: 278 return ("char"); 279 case S_IFDIR: 280 return ("dir"); 281 case S_IFIFO: 282 return ("fifo"); 283 case S_IFREG: 284 return ("file"); 285 case S_IFLNK: 286 return ("symlink"); 287 case S_IFSOCK: 288 return ("socket"); 289 default: 290 return ("unknown"); 291 } 292 } 293 294 295 /* 296 * link_check -- 297 * return pointer to fsinode matching `entry's st_ino & st_dev if it exists, 298 * otherwise add `entry' to table and return NULL 299 */ 300 /* This was borrowed from du.c and tweaked to keep an fsnode 301 * pointer instead. -- dbj@netbsd.org 302 */ 303 static fsinode * 304 link_check(fsinode *entry) 305 { 306 static struct entry { 307 fsinode *data; 308 } *htable; 309 static int htshift; /* log(allocated size) */ 310 static int htmask; /* allocated size - 1 */ 311 static int htused; /* 2*number of insertions */ 312 int h, h2; 313 uint64_t tmp; 314 /* this constant is (1<<64)/((1+sqrt(5))/2) 315 * aka (word size)/(golden ratio) 316 */ 317 const uint64_t HTCONST = 11400714819323198485ULL; 318 const int HTBITS = 64; 319 320 /* Never store zero in hashtable */ 321 assert(entry); 322 323 /* Extend hash table if necessary, keep load under 0.5 */ 324 if (htused<<1 >= htmask) { 325 struct entry *ohtable; 326 327 if (!htable) 328 htshift = 10; /* starting hashtable size */ 329 else 330 htshift++; /* exponential hashtable growth */ 331 332 htmask = (1 << htshift) - 1; 333 htused = 0; 334 335 ohtable = htable; 336 htable = ecalloc(htmask+1, sizeof(*htable)); 337 /* populate newly allocated hashtable */ 338 if (ohtable) { 339 int i; 340 for (i = 0; i <= htmask>>1; i++) 341 if (ohtable[i].data) 342 link_check(ohtable[i].data); 343 free(ohtable); 344 } 345 } 346 347 /* multiplicative hashing */ 348 tmp = entry->st.st_dev; 349 tmp <<= HTBITS>>1; 350 tmp |= entry->st.st_ino; 351 tmp *= HTCONST; 352 h = tmp >> (HTBITS - htshift); 353 h2 = 1 | ( tmp >> (HTBITS - (htshift<<1) - 1)); /* must be odd */ 354 355 /* open address hashtable search with double hash probing */ 356 while (htable[h].data) { 357 if ((htable[h].data->st.st_ino == entry->st.st_ino) && 358 (htable[h].data->st.st_dev == entry->st.st_dev)) { 359 return htable[h].data; 360 } 361 h = (h + h2) & htmask; 362 } 363 364 /* Insert the current entry into hashtable */ 365 htable[h].data = entry; 366 htused++; 367 return NULL; 368 } 369