1 /* $OpenBSD: symtab.c,v 1.21 2013/12/30 22:01:23 deraadt Exp $ */ 2 /* $NetBSD: symtab.c,v 1.10 1997/03/19 08:42:54 lukem Exp $ */ 3 4 /* 5 * Copyright (c) 1983, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * These routines maintain the symbol table which tracks the state 35 * of the file system being restored. They provide lookup by either 36 * name or inode number. They also provide for creation, deletion, 37 * and renaming of entries. Because of the dynamic nature of pathnames, 38 * names should not be saved, but always constructed just before they 39 * are needed, by calling "myname". 40 */ 41 42 #include <sys/param.h> 43 #include <sys/stat.h> 44 45 #include <ufs/ufs/dinode.h> 46 47 #include <err.h> 48 #include <fcntl.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 54 #include "restore.h" 55 #include "extern.h" 56 57 /* 58 * The following variables define the inode symbol table. 59 * The primary hash table is dynamically allocated based on 60 * the number of inodes in the file system (maxino), scaled by 61 * HASHFACTOR. The variable "entry" points to the hash table; 62 * the variable "entrytblsize" indicates its size (in entries). 63 */ 64 #define HASHFACTOR 5 65 static struct entry **entry; 66 static long entrytblsize; 67 68 static void addino(ino_t, struct entry *); 69 static struct entry *lookupparent(char *); 70 static void removeentry(struct entry *); 71 72 /* 73 * Look up an entry by inode number 74 */ 75 struct entry * 76 lookupino(ino_t inum) 77 { 78 struct entry *ep; 79 80 if (inum < ROOTINO || inum >= maxino) 81 return (NULL); 82 for (ep = entry[inum % entrytblsize]; ep != NULL; ep = ep->e_next) 83 if (ep->e_ino == inum) 84 return (ep); 85 return (NULL); 86 } 87 88 /* 89 * Add an entry into the entry table 90 */ 91 static void 92 addino(ino_t inum, struct entry *np) 93 { 94 struct entry **epp; 95 96 if (inum < ROOTINO || inum >= maxino) 97 panic("addino: out of range %llu\n", 98 (unsigned long long)inum); 99 epp = &entry[inum % entrytblsize]; 100 np->e_ino = inum; 101 np->e_next = *epp; 102 *epp = np; 103 if (dflag) 104 for (np = np->e_next; np != NULL; np = np->e_next) 105 if (np->e_ino == inum) 106 badentry(np, "duplicate inum"); 107 } 108 109 /* 110 * Delete an entry from the entry table 111 */ 112 void 113 deleteino(ino_t inum) 114 { 115 struct entry *next; 116 struct entry **prev; 117 118 if (inum < ROOTINO || inum >= maxino) 119 panic("deleteino: out of range %llu\n", 120 (unsigned long long)inum); 121 prev = &entry[inum % entrytblsize]; 122 for (next = *prev; next != NULL; next = next->e_next) { 123 if (next->e_ino == inum) { 124 next->e_ino = 0; 125 *prev = next->e_next; 126 return; 127 } 128 prev = &next->e_next; 129 } 130 panic("deleteino: %llu not found\n", (unsigned long long)inum); 131 } 132 133 /* 134 * Look up an entry by name 135 */ 136 struct entry * 137 lookupname(char *name) 138 { 139 struct entry *ep; 140 char *np, *cp; 141 char buf[MAXPATHLEN]; 142 143 cp = name; 144 for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) { 145 for (np = buf; 146 *cp != '/' && *cp != '\0' && np < &buf[sizeof(buf)]; ) 147 *np++ = *cp++; 148 if (np == &buf[sizeof(buf)]) 149 break; 150 *np = '\0'; 151 for ( ; ep != NULL; ep = ep->e_sibling) 152 if (strcmp(ep->e_name, buf) == 0) 153 break; 154 if (ep == NULL) 155 break; 156 if (*cp++ == '\0') 157 return (ep); 158 } 159 return (NULL); 160 } 161 162 /* 163 * Look up the parent of a pathname 164 */ 165 static struct entry * 166 lookupparent(char *name) 167 { 168 struct entry *ep; 169 char *tailindex; 170 171 tailindex = strrchr(name, '/'); 172 if (tailindex == NULL) 173 return (NULL); 174 *tailindex = '\0'; 175 ep = lookupname(name); 176 *tailindex = '/'; 177 if (ep == NULL) 178 return (NULL); 179 if (ep->e_type != NODE) 180 panic("%s is not a directory\n", name); 181 return (ep); 182 } 183 184 /* 185 * Determine the current pathname of a node or leaf 186 */ 187 char * 188 myname(struct entry *ep) 189 { 190 char *cp; 191 static char namebuf[MAXPATHLEN]; 192 193 for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) { 194 cp -= ep->e_namlen; 195 memcpy(cp, ep->e_name, ep->e_namlen); 196 if (ep == lookupino(ROOTINO)) 197 return (cp); 198 *(--cp) = '/'; 199 ep = ep->e_parent; 200 } 201 panic("%s: pathname too long\n", cp); 202 return(cp); 203 } 204 205 /* 206 * Unused symbol table entries are linked together on a freelist 207 * headed by the following pointer. 208 */ 209 static struct entry *freelist = NULL; 210 211 /* 212 * add an entry to the symbol table 213 */ 214 struct entry * 215 addentry(char *name, ino_t inum, int type) 216 { 217 struct entry *np, *ep; 218 219 if (freelist != NULL) { 220 np = freelist; 221 freelist = np->e_next; 222 memset(np, 0, sizeof(struct entry)); 223 } else { 224 np = calloc(1, sizeof(struct entry)); 225 if (np == NULL) 226 panic("no memory to extend symbol table\n"); 227 } 228 np->e_type = type & ~LINK; 229 ep = lookupparent(name); 230 if (ep == NULL) { 231 if (inum != ROOTINO || lookupino(ROOTINO) != NULL) 232 panic("bad name to addentry %s\n", name); 233 np->e_name = savename(name); 234 np->e_namlen = strlen(name); 235 np->e_parent = np; 236 addino(ROOTINO, np); 237 return (np); 238 } 239 np->e_name = savename(strrchr(name, '/') + 1); 240 np->e_namlen = strlen(np->e_name); 241 np->e_parent = ep; 242 np->e_sibling = ep->e_entries; 243 ep->e_entries = np; 244 if (type & LINK) { 245 ep = lookupino(inum); 246 if (ep == NULL) 247 panic("link to non-existent name\n"); 248 np->e_ino = inum; 249 np->e_links = ep->e_links; 250 ep->e_links = np; 251 } else if (inum != 0) { 252 if (lookupino(inum) != NULL) 253 panic("duplicate entry\n"); 254 addino(inum, np); 255 } 256 return (np); 257 } 258 259 /* 260 * delete an entry from the symbol table 261 */ 262 void 263 freeentry(struct entry *ep) 264 { 265 struct entry *np; 266 ino_t inum; 267 268 if (ep->e_flags != REMOVED) 269 badentry(ep, "not marked REMOVED"); 270 if (ep->e_type == NODE) { 271 if (ep->e_links != NULL) 272 badentry(ep, "freeing referenced directory"); 273 if (ep->e_entries != NULL) 274 badentry(ep, "freeing non-empty directory"); 275 } 276 if (ep->e_ino != 0) { 277 np = lookupino(ep->e_ino); 278 if (np == NULL) 279 badentry(ep, "lookupino failed"); 280 if (np == ep) { 281 inum = ep->e_ino; 282 deleteino(inum); 283 if (ep->e_links != NULL) 284 addino(inum, ep->e_links); 285 } else { 286 for (; np != NULL; np = np->e_links) { 287 if (np->e_links == ep) { 288 np->e_links = ep->e_links; 289 break; 290 } 291 } 292 if (np == NULL) 293 badentry(ep, "link not found"); 294 } 295 } 296 removeentry(ep); 297 freename(ep->e_name); 298 ep->e_next = freelist; 299 freelist = ep; 300 } 301 302 /* 303 * Relocate an entry in the tree structure 304 */ 305 void 306 moveentry(struct entry *ep, char *newname) 307 { 308 struct entry *np; 309 char *cp; 310 311 np = lookupparent(newname); 312 if (np == NULL) 313 badentry(ep, "cannot move ROOT"); 314 if (np != ep->e_parent) { 315 removeentry(ep); 316 ep->e_parent = np; 317 ep->e_sibling = np->e_entries; 318 np->e_entries = ep; 319 } 320 cp = strrchr(newname, '/') + 1; 321 freename(ep->e_name); 322 ep->e_name = savename(cp); 323 ep->e_namlen = strlen(cp); 324 if (strcmp(gentempname(ep), ep->e_name) == 0) 325 ep->e_flags |= TMPNAME; 326 else 327 ep->e_flags &= ~TMPNAME; 328 } 329 330 /* 331 * Remove an entry in the tree structure 332 */ 333 static void 334 removeentry(struct entry *ep) 335 { 336 struct entry *np; 337 338 np = ep->e_parent; 339 if (np->e_entries == ep) { 340 np->e_entries = ep->e_sibling; 341 } else { 342 for (np = np->e_entries; np != NULL; np = np->e_sibling) { 343 if (np->e_sibling == ep) { 344 np->e_sibling = ep->e_sibling; 345 break; 346 } 347 } 348 if (np == NULL) 349 badentry(ep, "cannot find entry in parent list"); 350 } 351 } 352 353 /* 354 * Table of unused string entries, sorted by length. 355 * 356 * Entries are allocated in STRTBLINCR sized pieces so that names 357 * of similar lengths can use the same entry. The value of STRTBLINCR 358 * is chosen so that every entry has at least enough space to hold 359 * a "struct strtbl" header. Thus every entry can be linked onto an 360 * apprpriate free list. 361 * 362 * NB. The macro "allocsize" below assumes that "struct strhdr" 363 * has a size that is a power of two. 364 */ 365 struct strhdr { 366 struct strhdr *next; 367 }; 368 369 #define STRTBLINCR (sizeof(struct strhdr)) 370 #define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1)) 371 372 static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR]; 373 374 /* 375 * Allocate space for a name. It first looks to see if it already 376 * has an appropriate sized entry, and if not allocates a new one. 377 */ 378 char * 379 savename(char *name) 380 { 381 struct strhdr *np; 382 long len; 383 char *cp; 384 385 if (name == NULL) 386 panic("bad name\n"); 387 len = strlen(name); 388 np = strtblhdr[len / STRTBLINCR].next; 389 if (np != NULL) { 390 strtblhdr[len / STRTBLINCR].next = np->next; 391 cp = (char *)np; 392 } else { 393 cp = malloc(allocsize(len)); 394 if (cp == NULL) 395 panic("no space for string table\n"); 396 } 397 (void)strlcpy(cp, name, len + 1); 398 return (cp); 399 } 400 401 /* 402 * Free space for a name. The resulting entry is linked onto the 403 * appropriate free list. 404 */ 405 void 406 freename(char *name) 407 { 408 struct strhdr *tp, *np; 409 410 tp = &strtblhdr[strlen(name) / STRTBLINCR]; 411 np = (struct strhdr *)name; 412 np->next = tp->next; 413 tp->next = np; 414 } 415 416 /* 417 * Useful quantities placed at the end of a dumped symbol table. 418 */ 419 struct symtableheader { 420 int32_t volno; 421 int32_t stringsize; 422 int32_t entrytblsize; 423 time_t dumptime; 424 time_t dumpdate; 425 ino_t maxino; 426 int32_t ntrec; 427 }; 428 429 /* 430 * dump a snapshot of the symbol table 431 */ 432 void 433 dumpsymtable(char *filename, long checkpt) 434 { 435 struct entry *ep, *tep; 436 ino_t i; 437 struct entry temp, *tentry; 438 long mynum = 1, stroff = 0; 439 FILE *fp; 440 struct symtableheader hdr; 441 442 Vprintf(stdout, "Check pointing the restore\n"); 443 if (Nflag) 444 return; 445 if ((fp = fopen(filename, "w")) == NULL) { 446 warn("fopen"); 447 panic("cannot create save file %s for symbol table\n", 448 filename); 449 } 450 clearerr(fp); 451 /* 452 * Assign indices to each entry 453 * Write out the string entries 454 */ 455 for (i = ROOTINO; i <= maxino; i++) { 456 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) { 457 ep->e_index = mynum++; 458 (void)fwrite(ep->e_name, sizeof(char), 459 (int)allocsize(ep->e_namlen), fp); 460 } 461 } 462 /* 463 * Convert pointers to indexes, and output 464 */ 465 tep = &temp; 466 stroff = 0; 467 for (i = ROOTINO; i <= maxino; i++) { 468 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) { 469 memcpy(tep, ep, sizeof(struct entry)); 470 tep->e_name = (char *)stroff; 471 stroff += allocsize(ep->e_namlen); 472 tep->e_parent = (struct entry *)ep->e_parent->e_index; 473 if (ep->e_links != NULL) 474 tep->e_links = 475 (struct entry *)ep->e_links->e_index; 476 if (ep->e_sibling != NULL) 477 tep->e_sibling = 478 (struct entry *)ep->e_sibling->e_index; 479 if (ep->e_entries != NULL) 480 tep->e_entries = 481 (struct entry *)ep->e_entries->e_index; 482 if (ep->e_next != NULL) 483 tep->e_next = 484 (struct entry *)ep->e_next->e_index; 485 (void)fwrite((char *)tep, sizeof(struct entry), 1, fp); 486 } 487 } 488 /* 489 * Convert entry pointers to indexes, and output 490 */ 491 for (i = 0; i < entrytblsize; i++) { 492 if (entry[i] == NULL) 493 tentry = NULL; 494 else 495 tentry = (struct entry *)entry[i]->e_index; 496 (void)fwrite((char *)&tentry, sizeof(struct entry *), 1, fp); 497 } 498 hdr.volno = checkpt; 499 hdr.maxino = maxino; 500 hdr.entrytblsize = entrytblsize; 501 hdr.stringsize = stroff; 502 hdr.dumptime = dumptime; 503 hdr.dumpdate = dumpdate; 504 hdr.ntrec = ntrec; 505 (void)fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fp); 506 if (ferror(fp)) { 507 warn("fwrite"); 508 panic("output error to file %s writing symbol table\n", 509 filename); 510 } 511 (void)fclose(fp); 512 } 513 514 /* 515 * Initialize a symbol table from a file 516 */ 517 void 518 initsymtable(char *filename) 519 { 520 char *base; 521 long tblsize; 522 struct entry *ep; 523 struct entry *baseep, *lep; 524 struct symtableheader hdr; 525 struct stat stbuf; 526 long i; 527 int fd; 528 529 Vprintf(stdout, "Initialize symbol table.\n"); 530 if (filename == NULL) { 531 entrytblsize = maxino / HASHFACTOR; 532 entry = calloc(entrytblsize, sizeof(struct entry *)); 533 if (entry == NULL) 534 panic("no memory for entry table\n"); 535 ep = addentry(".", ROOTINO, NODE); 536 ep->e_flags |= NEW; 537 return; 538 } 539 if ((fd = open(filename, O_RDONLY, 0)) < 0) { 540 warn("open"); 541 panic("cannot open symbol table file %s\n", filename); 542 } 543 if (fstat(fd, &stbuf) < 0) { 544 warn("stat"); 545 panic("cannot stat symbol table file %s\n", filename); 546 } 547 tblsize = stbuf.st_size - sizeof(struct symtableheader); 548 base = calloc(tblsize, sizeof(char)); 549 if (base == NULL) 550 panic("cannot allocate space for symbol table\n"); 551 if (read(fd, base, tblsize) < 0 || 552 read(fd, &hdr, sizeof(struct symtableheader)) < 0) { 553 warn("read"); 554 panic("cannot read symbol table file %s\n", filename); 555 } 556 close(fd); 557 switch (command) { 558 case 'r': 559 /* 560 * For normal continuation, insure that we are using 561 * the next incremental tape 562 */ 563 if (hdr.dumpdate != dumptime) 564 errx(1, "Incremental tape too %s", 565 (hdr.dumpdate < dumptime) ? "low" : "high"); 566 break; 567 case 'R': 568 /* 569 * For restart, insure that we are using the same tape 570 */ 571 curfile.action = SKIP; 572 dumptime = hdr.dumptime; 573 dumpdate = hdr.dumpdate; 574 if (!bflag) 575 newtapebuf(hdr.ntrec); 576 getvol(hdr.volno); 577 break; 578 default: 579 panic("initsymtable called from command %c\n", command); 580 break; 581 } 582 maxino = hdr.maxino; 583 entrytblsize = hdr.entrytblsize; 584 entry = (struct entry **) 585 (base + tblsize - (entrytblsize * sizeof(struct entry *))); 586 baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry)); 587 lep = (struct entry *)entry; 588 for (i = 0; i < entrytblsize; i++) { 589 if (entry[i] == NULL) 590 continue; 591 entry[i] = &baseep[(long)entry[i]]; 592 } 593 for (ep = &baseep[1]; ep < lep; ep++) { 594 ep->e_name = base + (long)ep->e_name; 595 ep->e_parent = &baseep[(long)ep->e_parent]; 596 if (ep->e_sibling != NULL) 597 ep->e_sibling = &baseep[(long)ep->e_sibling]; 598 if (ep->e_links != NULL) 599 ep->e_links = &baseep[(long)ep->e_links]; 600 if (ep->e_entries != NULL) 601 ep->e_entries = &baseep[(long)ep->e_entries]; 602 if (ep->e_next != NULL) 603 ep->e_next = &baseep[(long)ep->e_next]; 604 } 605 } 606