1 /* $OpenBSD: symtab.c,v 1.24 2021/10/24 21:24:22 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/stat.h>
43
44 #include <ufs/ufs/dinode.h>
45
46 #include <err.h>
47 #include <fcntl.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include <limits.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 *
lookupino(ino_t inum)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
addino(ino_t inum,struct entry * np)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
deleteino(ino_t inum)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 *
lookupname(char * name)137 lookupname(char *name)
138 {
139 struct entry *ep;
140 char *np, *cp;
141 char buf[PATH_MAX];
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 *
lookupparent(char * name)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 *
myname(struct entry * ep)188 myname(struct entry *ep)
189 {
190 char *cp;
191 static char namebuf[PATH_MAX];
192
193 for (cp = &namebuf[PATH_MAX - 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 *
addentry(char * name,ino_t inum,int type)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
freeentry(struct entry * ep)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
moveentry(struct entry * ep,char * newname)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
removeentry(struct entry * ep)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 *
savename(char * name)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
freename(char * name)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
dumpsymtable(char * filename,long checkpt)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
initsymtable(char * filename)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)) == -1) {
540 warn("open");
541 panic("cannot open symbol table file %s\n", filename);
542 }
543 if (fstat(fd, &stbuf) == -1) {
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) == -1 ||
552 read(fd, &hdr, sizeof(struct symtableheader)) == -1) {
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