1 /* $OpenBSD: symtab.c,v 1.15 2005/06/14 19:46:05 millert 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 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)symtab.c 8.2 (Berkeley) 9/13/94";
36 #else
37 static const char rcsid[] = "$OpenBSD: symtab.c,v 1.15 2005/06/14 19:46:05 millert Exp $";
38 #endif
39 #endif /* not lint */
40
41 /*
42 * These routines maintain the symbol table which tracks the state
43 * of the file system being restored. They provide lookup by either
44 * name or inode number. They also provide for creation, deletion,
45 * and renaming of entries. Because of the dynamic nature of pathnames,
46 * names should not be saved, but always constructed just before they
47 * are needed, by calling "myname".
48 */
49
50 #include <sys/param.h>
51 #include <sys/stat.h>
52
53 #include <ufs/ufs/dinode.h>
54
55 #include <err.h>
56 #include <fcntl.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61
62 #include "restore.h"
63 #include "extern.h"
64
65 /*
66 * The following variables define the inode symbol table.
67 * The primary hash table is dynamically allocated based on
68 * the number of inodes in the file system (maxino), scaled by
69 * HASHFACTOR. The variable "entry" points to the hash table;
70 * the variable "entrytblsize" indicates its size (in entries).
71 */
72 #define HASHFACTOR 5
73 static struct entry **entry;
74 static long entrytblsize;
75
76 static void addino(ino_t, struct entry *);
77 static struct entry *lookupparent(char *);
78 static void removeentry(struct entry *);
79
80 /*
81 * Look up an entry by inode number
82 */
83 struct entry *
lookupino(ino_t inum)84 lookupino(ino_t inum)
85 {
86 struct entry *ep;
87
88 if (inum < ROOTINO || inum >= maxino)
89 return (NULL);
90 for (ep = entry[inum % entrytblsize]; ep != NULL; ep = ep->e_next)
91 if (ep->e_ino == inum)
92 return (ep);
93 return (NULL);
94 }
95
96 /*
97 * Add an entry into the entry table
98 */
99 static void
addino(ino_t inum,struct entry * np)100 addino(ino_t inum, struct entry *np)
101 {
102 struct entry **epp;
103
104 if (inum < ROOTINO || inum >= maxino)
105 panic("addino: out of range %d\n", inum);
106 epp = &entry[inum % entrytblsize];
107 np->e_ino = inum;
108 np->e_next = *epp;
109 *epp = np;
110 if (dflag)
111 for (np = np->e_next; np != NULL; np = np->e_next)
112 if (np->e_ino == inum)
113 badentry(np, "duplicate inum");
114 }
115
116 /*
117 * Delete an entry from the entry table
118 */
119 void
deleteino(ino_t inum)120 deleteino(ino_t inum)
121 {
122 struct entry *next;
123 struct entry **prev;
124
125 if (inum < ROOTINO || inum >= maxino)
126 panic("deleteino: out of range %d\n", inum);
127 prev = &entry[inum % entrytblsize];
128 for (next = *prev; next != NULL; next = next->e_next) {
129 if (next->e_ino == inum) {
130 next->e_ino = 0;
131 *prev = next->e_next;
132 return;
133 }
134 prev = &next->e_next;
135 }
136 panic("deleteino: %d not found\n", inum);
137 }
138
139 /*
140 * Look up an entry by name
141 */
142 struct entry *
lookupname(char * name)143 lookupname(char *name)
144 {
145 struct entry *ep;
146 char *np, *cp;
147 char buf[MAXPATHLEN];
148
149 cp = name;
150 for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) {
151 for (np = buf;
152 *cp != '/' && *cp != '\0' && np < &buf[sizeof(buf)]; )
153 *np++ = *cp++;
154 if (np == &buf[sizeof(buf)])
155 break;
156 *np = '\0';
157 for ( ; ep != NULL; ep = ep->e_sibling)
158 if (strcmp(ep->e_name, buf) == 0)
159 break;
160 if (ep == NULL)
161 break;
162 if (*cp++ == '\0')
163 return (ep);
164 }
165 return (NULL);
166 }
167
168 /*
169 * Look up the parent of a pathname
170 */
171 static struct entry *
lookupparent(char * name)172 lookupparent(char *name)
173 {
174 struct entry *ep;
175 char *tailindex;
176
177 tailindex = strrchr(name, '/');
178 if (tailindex == NULL)
179 return (NULL);
180 *tailindex = '\0';
181 ep = lookupname(name);
182 *tailindex = '/';
183 if (ep == NULL)
184 return (NULL);
185 if (ep->e_type != NODE)
186 panic("%s is not a directory\n", name);
187 return (ep);
188 }
189
190 /*
191 * Determine the current pathname of a node or leaf
192 */
193 char *
myname(struct entry * ep)194 myname(struct entry *ep)
195 {
196 char *cp;
197 static char namebuf[MAXPATHLEN];
198
199 for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) {
200 cp -= ep->e_namlen;
201 memcpy(cp, ep->e_name, (long)ep->e_namlen);
202 if (ep == lookupino(ROOTINO))
203 return (cp);
204 *(--cp) = '/';
205 ep = ep->e_parent;
206 }
207 panic("%s: pathname too long\n", cp);
208 return(cp);
209 }
210
211 /*
212 * Unused symbol table entries are linked together on a freelist
213 * headed by the following pointer.
214 */
215 static struct entry *freelist = NULL;
216
217 /*
218 * add an entry to the symbol table
219 */
220 struct entry *
addentry(char * name,ino_t inum,int type)221 addentry(char *name, ino_t inum, int type)
222 {
223 struct entry *np, *ep;
224
225 if (freelist != NULL) {
226 np = freelist;
227 freelist = np->e_next;
228 memset(np, 0, (long)sizeof(struct entry));
229 } else {
230 np = (struct entry *)calloc(1, sizeof(struct entry));
231 if (np == NULL)
232 panic("no memory to extend symbol table\n");
233 }
234 np->e_type = type & ~LINK;
235 ep = lookupparent(name);
236 if (ep == NULL) {
237 if (inum != ROOTINO || lookupino(ROOTINO) != NULL)
238 panic("bad name to addentry %s\n", name);
239 np->e_name = savename(name);
240 np->e_namlen = strlen(name);
241 np->e_parent = np;
242 addino(ROOTINO, np);
243 return (np);
244 }
245 np->e_name = savename(strrchr(name, '/') + 1);
246 np->e_namlen = strlen(np->e_name);
247 np->e_parent = ep;
248 np->e_sibling = ep->e_entries;
249 ep->e_entries = np;
250 if (type & LINK) {
251 ep = lookupino(inum);
252 if (ep == NULL)
253 panic("link to non-existent name\n");
254 np->e_ino = inum;
255 np->e_links = ep->e_links;
256 ep->e_links = np;
257 } else if (inum != 0) {
258 if (lookupino(inum) != NULL)
259 panic("duplicate entry\n");
260 addino(inum, np);
261 }
262 return (np);
263 }
264
265 /*
266 * delete an entry from the symbol table
267 */
268 void
freeentry(struct entry * ep)269 freeentry(struct entry *ep)
270 {
271 struct entry *np;
272 ino_t inum;
273
274 if (ep->e_flags != REMOVED)
275 badentry(ep, "not marked REMOVED");
276 if (ep->e_type == NODE) {
277 if (ep->e_links != NULL)
278 badentry(ep, "freeing referenced directory");
279 if (ep->e_entries != NULL)
280 badentry(ep, "freeing non-empty directory");
281 }
282 if (ep->e_ino != 0) {
283 np = lookupino(ep->e_ino);
284 if (np == NULL)
285 badentry(ep, "lookupino failed");
286 if (np == ep) {
287 inum = ep->e_ino;
288 deleteino(inum);
289 if (ep->e_links != NULL)
290 addino(inum, ep->e_links);
291 } else {
292 for (; np != NULL; np = np->e_links) {
293 if (np->e_links == ep) {
294 np->e_links = ep->e_links;
295 break;
296 }
297 }
298 if (np == NULL)
299 badentry(ep, "link not found");
300 }
301 }
302 removeentry(ep);
303 freename(ep->e_name);
304 ep->e_next = freelist;
305 freelist = ep;
306 }
307
308 /*
309 * Relocate an entry in the tree structure
310 */
311 void
moveentry(struct entry * ep,char * newname)312 moveentry(struct entry *ep, char *newname)
313 {
314 struct entry *np;
315 char *cp;
316
317 np = lookupparent(newname);
318 if (np == NULL)
319 badentry(ep, "cannot move ROOT");
320 if (np != ep->e_parent) {
321 removeentry(ep);
322 ep->e_parent = np;
323 ep->e_sibling = np->e_entries;
324 np->e_entries = ep;
325 }
326 cp = strrchr(newname, '/') + 1;
327 freename(ep->e_name);
328 ep->e_name = savename(cp);
329 ep->e_namlen = strlen(cp);
330 if (strcmp(gentempname(ep), ep->e_name) == 0)
331 ep->e_flags |= TMPNAME;
332 else
333 ep->e_flags &= ~TMPNAME;
334 }
335
336 /*
337 * Remove an entry in the tree structure
338 */
339 static void
removeentry(struct entry * ep)340 removeentry(struct entry *ep)
341 {
342 struct entry *np;
343
344 np = ep->e_parent;
345 if (np->e_entries == ep) {
346 np->e_entries = ep->e_sibling;
347 } else {
348 for (np = np->e_entries; np != NULL; np = np->e_sibling) {
349 if (np->e_sibling == ep) {
350 np->e_sibling = ep->e_sibling;
351 break;
352 }
353 }
354 if (np == NULL)
355 badentry(ep, "cannot find entry in parent list");
356 }
357 }
358
359 /*
360 * Table of unused string entries, sorted by length.
361 *
362 * Entries are allocated in STRTBLINCR sized pieces so that names
363 * of similar lengths can use the same entry. The value of STRTBLINCR
364 * is chosen so that every entry has at least enough space to hold
365 * a "struct strtbl" header. Thus every entry can be linked onto an
366 * apprpriate free list.
367 *
368 * NB. The macro "allocsize" below assumes that "struct strhdr"
369 * has a size that is a power of two.
370 */
371 struct strhdr {
372 struct strhdr *next;
373 };
374
375 #define STRTBLINCR (sizeof(struct strhdr))
376 #define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1))
377
378 static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR];
379
380 /*
381 * Allocate space for a name. It first looks to see if it already
382 * has an appropriate sized entry, and if not allocates a new one.
383 */
384 char *
savename(char * name)385 savename(char *name)
386 {
387 struct strhdr *np;
388 long len;
389 char *cp;
390
391 if (name == NULL)
392 panic("bad name\n");
393 len = strlen(name);
394 np = strtblhdr[len / STRTBLINCR].next;
395 if (np != NULL) {
396 strtblhdr[len / STRTBLINCR].next = np->next;
397 cp = (char *)np;
398 } else {
399 cp = malloc((unsigned)allocsize(len));
400 if (cp == NULL)
401 panic("no space for string table\n");
402 }
403 (void)strlcpy(cp, name, len + 1);
404 return (cp);
405 }
406
407 /*
408 * Free space for a name. The resulting entry is linked onto the
409 * appropriate free list.
410 */
411 void
freename(char * name)412 freename(char *name)
413 {
414 struct strhdr *tp, *np;
415
416 tp = &strtblhdr[strlen(name) / STRTBLINCR];
417 np = (struct strhdr *)name;
418 np->next = tp->next;
419 tp->next = np;
420 }
421
422 /*
423 * Useful quantities placed at the end of a dumped symbol table.
424 */
425 struct symtableheader {
426 int32_t volno;
427 int32_t stringsize;
428 int32_t entrytblsize;
429 time_t dumptime;
430 time_t dumpdate;
431 ino_t maxino;
432 int32_t ntrec;
433 };
434
435 /*
436 * dump a snapshot of the symbol table
437 */
438 void
dumpsymtable(char * filename,long checkpt)439 dumpsymtable(char *filename, long checkpt)
440 {
441 struct entry *ep, *tep;
442 ino_t i;
443 struct entry temp, *tentry;
444 long mynum = 1, stroff = 0;
445 FILE *fd;
446 struct symtableheader hdr;
447
448 Vprintf(stdout, "Check pointing the restore\n");
449 if (Nflag)
450 return;
451 if ((fd = fopen(filename, "w")) == NULL) {
452 warn("fopen");
453 panic("cannot create save file %s for symbol table\n",
454 filename);
455 }
456 clearerr(fd);
457 /*
458 * Assign indicies to each entry
459 * Write out the string entries
460 */
461 for (i = ROOTINO; i <= maxino; i++) {
462 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
463 ep->e_index = mynum++;
464 (void)fwrite(ep->e_name, sizeof(char),
465 (int)allocsize(ep->e_namlen), fd);
466 }
467 }
468 /*
469 * Convert pointers to indexes, and output
470 */
471 tep = &temp;
472 stroff = 0;
473 for (i = ROOTINO; i <= maxino; i++) {
474 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
475 memcpy(tep, ep, (long)sizeof(struct entry));
476 tep->e_name = (char *)stroff;
477 stroff += allocsize(ep->e_namlen);
478 tep->e_parent = (struct entry *)ep->e_parent->e_index;
479 if (ep->e_links != NULL)
480 tep->e_links =
481 (struct entry *)ep->e_links->e_index;
482 if (ep->e_sibling != NULL)
483 tep->e_sibling =
484 (struct entry *)ep->e_sibling->e_index;
485 if (ep->e_entries != NULL)
486 tep->e_entries =
487 (struct entry *)ep->e_entries->e_index;
488 if (ep->e_next != NULL)
489 tep->e_next =
490 (struct entry *)ep->e_next->e_index;
491 (void)fwrite((char *)tep, sizeof(struct entry), 1, fd);
492 }
493 }
494 /*
495 * Convert entry pointers to indexes, and output
496 */
497 for (i = 0; i < entrytblsize; i++) {
498 if (entry[i] == NULL)
499 tentry = NULL;
500 else
501 tentry = (struct entry *)entry[i]->e_index;
502 (void)fwrite((char *)&tentry, sizeof(struct entry *), 1, fd);
503 }
504 hdr.volno = checkpt;
505 hdr.maxino = maxino;
506 hdr.entrytblsize = entrytblsize;
507 hdr.stringsize = stroff;
508 hdr.dumptime = dumptime;
509 hdr.dumpdate = dumpdate;
510 hdr.ntrec = ntrec;
511 (void)fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd);
512 if (ferror(fd)) {
513 warn("fwrite");
514 panic("output error to file %s writing symbol table\n",
515 filename);
516 }
517 (void)fclose(fd);
518 }
519
520 /*
521 * Initialize a symbol table from a file
522 */
523 void
initsymtable(char * filename)524 initsymtable(char *filename)
525 {
526 char *base;
527 long tblsize;
528 struct entry *ep;
529 struct entry *baseep, *lep;
530 struct symtableheader hdr;
531 struct stat stbuf;
532 long i;
533 int fd;
534
535 Vprintf(stdout, "Initialize symbol table.\n");
536 if (filename == NULL) {
537 entrytblsize = maxino / HASHFACTOR;
538 entry = (struct entry **)
539 calloc((unsigned)entrytblsize, sizeof(struct entry *));
540 if (entry == (struct entry **)NULL)
541 panic("no memory for entry table\n");
542 ep = addentry(".", ROOTINO, NODE);
543 ep->e_flags |= NEW;
544 return;
545 }
546 if ((fd = open(filename, O_RDONLY, 0)) < 0) {
547 warn("open");
548 panic("cannot open symbol table file %s\n", filename);
549 }
550 if (fstat(fd, &stbuf) < 0) {
551 warn("stat");
552 panic("cannot stat symbol table file %s\n", filename);
553 }
554 tblsize = stbuf.st_size - sizeof(struct symtableheader);
555 base = calloc((unsigned)tblsize, sizeof(char));
556 if (base == NULL)
557 panic("cannot allocate space for symbol table\n");
558 if (read(fd, base, (int)tblsize) < 0 ||
559 read(fd, (char *)&hdr, sizeof(struct symtableheader)) < 0) {
560 warn("read");
561 panic("cannot read symbol table file %s\n", filename);
562 }
563 switch (command) {
564 case 'r':
565 /*
566 * For normal continuation, insure that we are using
567 * the next incremental tape
568 */
569 if (hdr.dumpdate != dumptime)
570 errx(1, "Incremental tape too %s",
571 (hdr.dumpdate < dumptime) ? "low" : "high");
572 break;
573 case 'R':
574 /*
575 * For restart, insure that we are using the same tape
576 */
577 curfile.action = SKIP;
578 dumptime = hdr.dumptime;
579 dumpdate = hdr.dumpdate;
580 if (!bflag)
581 newtapebuf(hdr.ntrec);
582 getvol(hdr.volno);
583 break;
584 default:
585 panic("initsymtable called from command %c\n", command);
586 break;
587 }
588 maxino = hdr.maxino;
589 entrytblsize = hdr.entrytblsize;
590 entry = (struct entry **)
591 (base + tblsize - (entrytblsize * sizeof(struct entry *)));
592 baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry));
593 lep = (struct entry *)entry;
594 for (i = 0; i < entrytblsize; i++) {
595 if (entry[i] == NULL)
596 continue;
597 entry[i] = &baseep[(long)entry[i]];
598 }
599 for (ep = &baseep[1]; ep < lep; ep++) {
600 ep->e_name = base + (long)ep->e_name;
601 ep->e_parent = &baseep[(long)ep->e_parent];
602 if (ep->e_sibling != NULL)
603 ep->e_sibling = &baseep[(long)ep->e_sibling];
604 if (ep->e_links != NULL)
605 ep->e_links = &baseep[(long)ep->e_links];
606 if (ep->e_entries != NULL)
607 ep->e_entries = &baseep[(long)ep->e_entries];
608 if (ep->e_next != NULL)
609 ep->e_next = &baseep[(long)ep->e_next];
610 }
611 }
612