select_wim_image(): Don't allow selecting WIMLIB_NO_IMAGE
[wimlib] / src / wim.c
1 /*
2  * wim.c
3  */
4
5 /*
6  * Copyright (C) 2010 Carl Thijssen
7  * Copyright (C) 2012 Eric Biggers
8  *
9  * wimlib - Library for working with WIM files
10  *
11  * This file is part of wimlib, a library for working with WIM files.
12  *
13  * wimlib is free software; you can redistribute it and/or modify it under the
14  * terms of the GNU General Public License as published by the Free
15  * Software Foundation; either version 3 of the License, or (at your option)
16  * any later version.
17  *
18  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
19  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
20  * A PARTICULAR PURPOSE. See the GNU General Public License for more
21  * details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with wimlib; if not, see http://www.gnu.org/licenses/.
25  */
26
27 #include "config.h"
28 #include <limits.h>
29 #include <stdlib.h>
30 #include <stdarg.h>
31
32 #include "dentry.h"
33 #include <unistd.h>
34 #include <fcntl.h>
35
36 #ifdef WITH_NTFS_3G
37 #include <time.h>
38 #include <ntfs-3g/volume.h>
39 #endif
40
41 #include "wimlib_internal.h"
42 #include "io.h"
43 #include "lookup_table.h"
44 #include "xml.h"
45
46 static int print_metadata(WIMStruct *w)
47 {
48         DEBUG("Printing metadata for image %d", w->current_image);
49         print_security_data(wim_security_data(w));
50         return for_dentry_in_tree(wim_root_dentry(w), print_dentry,
51                                   w->lookup_table);
52 }
53
54
55 static int print_files(WIMStruct *w)
56 {
57         return for_dentry_in_tree(wim_root_dentry(w), print_dentry_full_path,
58                                   NULL);
59 }
60
61 WIMStruct *new_wim_struct()
62 {
63         WIMStruct *w = CALLOC(1, sizeof(WIMStruct));
64 #ifdef WITH_FUSE
65         if (pthread_mutex_init(&w->fp_tab_mutex, NULL) != 0) {
66                 ERROR_WITH_ERRNO("Failed to initialize mutex");
67                 FREE(w);
68                 w = NULL;
69         }
70 #endif
71         return w;
72
73 }
74
75 /*
76  * Calls a function on images in the WIM.  If @image is WIMLIB_ALL_IMAGES, @visitor
77  * is called on the WIM once for each image, with each image selected as the
78  * current image in turn.  If @image is a certain image, @visitor is called on
79  * the WIM only once, with that image selected.
80  */
81 int for_image(WIMStruct *w, int image, int (*visitor)(WIMStruct *))
82 {
83         int ret;
84         int start;
85         int end;
86         int i;
87
88         if (image == WIMLIB_ALL_IMAGES) {
89                 start = 1;
90                 end = w->hdr.image_count;
91         } else if (image >= 1 && image <= w->hdr.image_count) {
92                 start = image;
93                 end = image;
94         } else {
95                 return WIMLIB_ERR_INVALID_IMAGE;
96         }
97         for (i = start; i <= end; i++) {
98                 ret = select_wim_image(w, i);
99                 if (ret != 0)
100                         return ret;
101                 ret = visitor(w);
102                 if (ret != 0)
103                         return ret;
104         }
105         return 0;
106 }
107
108 static int sort_image_metadata_by_position(const void *p1, const void *p2)
109 {
110         const struct image_metadata *imd1 = p1;
111         const struct image_metadata *imd2 = p2;
112         u64 offset1 = imd1->metadata_lte->resource_entry.offset;
113         u64 offset2 = imd2->metadata_lte->resource_entry.offset;
114         if (offset1 < offset2)
115                 return -1;
116         else if (offset1 > offset2)
117                 return 1;
118         else
119                 return 0;
120 }
121
122 /*
123  * If @lte points to a metadata resource, append it to the list of metadata
124  * resources in the WIMStruct.  Otherwise, do nothing.
125  */
126 static int append_metadata_resource_entry(struct lookup_table_entry *lte,
127                                           void *wim_p)
128 {
129         WIMStruct *w = wim_p;
130         int ret = 0;
131
132         if (lte->resource_entry.flags & WIM_RESHDR_FLAG_METADATA) {
133                 if (w->current_image == w->hdr.image_count) {
134                         ERROR("The WIM header says there are %u images in the WIM,\n"
135                               "        but we found more metadata resources than this",
136                               w->hdr.image_count);
137                         ret = WIMLIB_ERR_IMAGE_COUNT;
138                 } else {
139                         DEBUG("Found metadata resource for image %u at "
140                               "offset %"PRIu64".",
141                               w->current_image + 1,
142                               lte->resource_entry.offset);
143                         w->image_metadata[
144                                 w->current_image++].metadata_lte = lte;
145                 }
146         }
147         return ret;
148 }
149
150 /* Returns the compression type given in the flags of a WIM header. */
151 int wim_hdr_flags_compression_type(int wim_hdr_flags)
152 {
153         if (wim_hdr_flags & WIM_HDR_FLAG_COMPRESSION) {
154                 if (wim_hdr_flags & WIM_HDR_FLAG_COMPRESS_LZX)
155                         return WIMLIB_COMPRESSION_TYPE_LZX;
156                 else if (wim_hdr_flags & WIM_HDR_FLAG_COMPRESS_XPRESS)
157                         return WIMLIB_COMPRESSION_TYPE_XPRESS;
158                 else
159                         return WIMLIB_COMPRESSION_TYPE_INVALID;
160         } else {
161                 return WIMLIB_COMPRESSION_TYPE_NONE;
162         }
163 }
164
165 /*
166  * Creates a WIMStruct for a new WIM file.
167  */
168 WIMLIBAPI int wimlib_create_new_wim(int ctype, WIMStruct **w_ret)
169 {
170         WIMStruct *w;
171         struct lookup_table *table;
172         int ret;
173
174         DEBUG("Creating new WIM with %s compression.",
175               wimlib_get_compression_type_string(ctype));
176
177         /* Allocate the WIMStruct. */
178         w = new_wim_struct();
179         if (!w)
180                 return WIMLIB_ERR_NOMEM;
181
182         ret = init_header(&w->hdr, ctype);
183         if (ret != 0)
184                 goto out_free;
185
186         table = new_lookup_table(9001);
187         if (!table) {
188                 ret = WIMLIB_ERR_NOMEM;
189                 goto out_free;
190         }
191         w->lookup_table = table;
192         *w_ret = w;
193         return 0;
194 out_free:
195         FREE(w);
196         return ret;
197 }
198
199 WIMLIBAPI int wimlib_get_num_images(const WIMStruct *w)
200 {
201         return w->hdr.image_count;
202 }
203
204 int select_wim_image(WIMStruct *w, int image)
205 {
206         struct image_metadata *imd;
207
208         DEBUG("Selecting image %d", image);
209
210         if (image == WIMLIB_NO_IMAGE) {
211                 ERROR("Invalid image: %d", WIMLIB_NO_IMAGE);
212                 return WIMLIB_ERR_INVALID_IMAGE;
213         }
214
215         if (image == w->current_image)
216                 return 0;
217
218         if (image < 1 || image > w->hdr.image_count) {
219                 ERROR("Cannot select image %d: There are only %u images",
220                       image, w->hdr.image_count);
221                 return WIMLIB_ERR_INVALID_IMAGE;
222         }
223
224         /* If a valid image is currently selected, it can be freed if it is not
225          * modified.  */
226         if (w->current_image != WIMLIB_NO_IMAGE) {
227                 imd = wim_get_current_image_metadata(w);
228                 if (!imd->modified) {
229                         DEBUG("Freeing image %u", w->current_image);
230                         destroy_image_metadata(imd, NULL);
231                         imd->root_dentry = NULL;
232                         imd->security_data = NULL;
233                         INIT_HLIST_HEAD(&imd->inode_list);
234                 }
235         }
236
237         w->current_image = image;
238         imd = wim_get_current_image_metadata(w);
239
240         if (imd->root_dentry) {
241                 return 0;
242         } else {
243                 #ifdef ENABLE_DEBUG
244                 DEBUG("Reading metadata resource specified by the following "
245                       "lookup table entry:");
246                 print_lookup_table_entry(imd->metadata_lte);
247                 #endif
248                 return read_metadata_resource(w, imd);
249         }
250 }
251
252
253 /* Returns the compression type of the WIM file. */
254 WIMLIBAPI int wimlib_get_compression_type(const WIMStruct *w)
255 {
256         return wim_hdr_flags_compression_type(w->hdr.flags);
257 }
258
259 WIMLIBAPI const char *wimlib_get_compression_type_string(int ctype)
260 {
261         switch (ctype) {
262                 case WIMLIB_COMPRESSION_TYPE_NONE:
263                         return "None";
264                 case WIMLIB_COMPRESSION_TYPE_LZX:
265                         return "LZX";
266                 case WIMLIB_COMPRESSION_TYPE_XPRESS:
267                         return "XPRESS";
268                 default:
269                         return "Invalid";
270         }
271 }
272
273 /*
274  * Returns the number of an image in the WIM file, given a string that is either
275  * the number of the image, or the name of the image.  The images are numbered
276  * starting at 1.
277  */
278 WIMLIBAPI int wimlib_resolve_image(WIMStruct *w, const char *image_name_or_num)
279 {
280         char *p;
281         int image;
282         int i;
283
284         if (!image_name_or_num || !*image_name_or_num)
285                 return WIMLIB_NO_IMAGE;
286
287         if (strcmp(image_name_or_num, "all") == 0
288             || strcmp(image_name_or_num, "*") == 0)
289                 return WIMLIB_ALL_IMAGES;
290         image = strtol(image_name_or_num, &p, 10);
291         if (p != image_name_or_num && *p == '\0' && image > 0) {
292                 if (image > w->hdr.image_count)
293                         return WIMLIB_NO_IMAGE;
294                 return image;
295         } else {
296                 for (i = 1; i <= w->hdr.image_count; i++) {
297                         if (strcmp(image_name_or_num,
298                                    wimlib_get_image_name(w, i)) == 0)
299                                 return i;
300                 }
301                 return WIMLIB_NO_IMAGE;
302         }
303 }
304
305
306 /* Prints some basic information about a WIM file. */
307 WIMLIBAPI void wimlib_print_wim_information(const WIMStruct *w)
308 {
309         const struct wim_header *hdr;
310
311         hdr = &w->hdr;
312         puts("WIM Information:");
313         puts("----------------");
314         printf("Path:           %s\n", w->filename);
315         fputs ("GUID:           0x", stdout);
316         print_byte_field(hdr->guid, WIM_GID_LEN);
317         putchar('\n');
318         printf("Image Count:    %d\n", hdr->image_count);
319         printf("Compression:    %s\n", wimlib_get_compression_type_string(
320                                                 wimlib_get_compression_type(w)));
321         printf("Part Number:    %d/%d\n", hdr->part_number, hdr->total_parts);
322         printf("Boot Index:     %d\n", hdr->boot_idx);
323         printf("Size:           %"PRIu64" bytes\n",
324                                 wim_info_get_total_bytes(w->wim_info));
325         printf("Integrity Info: %s\n", (w->hdr.integrity.size != 0) ? "yes" : "no");
326         putchar('\n');
327 }
328
329 WIMLIBAPI bool wimlib_has_integrity_table(const WIMStruct *w)
330 {
331         return w->hdr.integrity.size != 0;
332 }
333
334 WIMLIBAPI void wimlib_print_available_images(const WIMStruct *w, int image)
335 {
336         int first;
337         int last;
338         int i;
339         int n;
340         if (image == WIMLIB_ALL_IMAGES) {
341                 n = printf("Available Images:\n");
342                 first = 1;
343                 last = w->hdr.image_count;
344         } else if (image >= 1 && image <= w->hdr.image_count) {
345                 n = printf("Information for Image %d\n", image);
346                 first = image;
347                 last = image;
348         } else {
349                 printf("wimlib_print_available_images(): Invalid image %d",
350                        image);
351                 return;
352         }
353         for (i = 0; i < n - 1; i++)
354                 putchar('-');
355         putchar('\n');
356         for (i = first; i <= last; i++)
357                 print_image_info(w->wim_info, i);
358 }
359
360
361 /* Prints the metadata for the specified image, which may be WIMLIB_ALL_IMAGES, but
362  * not WIMLIB_NO_IMAGE. */
363 WIMLIBAPI int wimlib_print_metadata(WIMStruct *w, int image)
364 {
365         if (!w)
366                 return WIMLIB_ERR_INVALID_PARAM;
367         if (w->hdr.part_number != 1) {
368                 ERROR("Cannot show the metadata from part %hu of a %hu-part split WIM!",
369                        w->hdr.part_number, w->hdr.total_parts);
370                 ERROR("Select the first part of the split WIM to see the metadata.");
371                 return WIMLIB_ERR_SPLIT_UNSUPPORTED;
372         }
373         return for_image(w, image, print_metadata);
374 }
375
376 WIMLIBAPI int wimlib_print_files(WIMStruct *w, int image)
377 {
378         if (!w)
379                 return WIMLIB_ERR_INVALID_PARAM;
380         if (w->hdr.part_number != 1) {
381                 ERROR("Cannot list the files from part %hu of a %hu-part split WIM!",
382                        w->hdr.part_number, w->hdr.total_parts);
383                 ERROR("Select the first part of the split WIM if you'd like to list the files.");
384                 return WIMLIB_ERR_SPLIT_UNSUPPORTED;
385         }
386         return for_image(w, image, print_files);
387 }
388
389 /* Sets the index of the bootable image. */
390 WIMLIBAPI int wimlib_set_boot_idx(WIMStruct *w, int boot_idx)
391 {
392         if (!w)
393                 return WIMLIB_ERR_INVALID_PARAM;
394         if (w->hdr.total_parts != 1) {
395                 ERROR("Cannot modify the boot index of a split WIM!");
396                 return WIMLIB_ERR_SPLIT_UNSUPPORTED;
397         }
398         if (boot_idx < 0 || boot_idx > w->hdr.image_count)
399                 return WIMLIB_ERR_INVALID_IMAGE;
400         w->hdr.boot_idx = boot_idx;
401
402         if (boot_idx == 0) {
403                 memset(&w->hdr.boot_metadata_res_entry, 0,
404                        sizeof(struct resource_entry));
405         } else {
406                 memcpy(&w->hdr.boot_metadata_res_entry,
407                        &w->image_metadata[
408                           boot_idx - 1].metadata_lte->resource_entry,
409                        sizeof(struct resource_entry));
410         }
411
412         return 0;
413 }
414
415 WIMLIBAPI int wimlib_get_part_number(const WIMStruct *w, int *total_parts_ret)
416 {
417         if (total_parts_ret)
418                 *total_parts_ret = w->hdr.total_parts;
419         return w->hdr.part_number;
420 }
421
422
423 WIMLIBAPI int wimlib_get_boot_idx(const WIMStruct *w)
424 {
425         return w->hdr.boot_idx;
426 }
427
428 /*
429  * Begins the reading of a WIM file; opens the file and reads its header and
430  * lookup table, and optionally checks the integrity.
431  */
432 static int begin_read(WIMStruct *w, const char *in_wim_path, int open_flags,
433                       wimlib_progress_func_t progress_func)
434 {
435         int ret;
436         uint xml_num_images;
437
438         DEBUG("Reading the WIM file `%s'", in_wim_path);
439
440         w->fp = fopen(in_wim_path, "rb");
441         if (!w->fp) {
442                 ERROR_WITH_ERRNO("Failed to open `%s' for reading",
443                                  in_wim_path);
444                 return WIMLIB_ERR_OPEN;
445         }
446
447         /* The absolute path to the WIM is requested so that wimlib_overwrite()
448          * still works even if the process changes its working directory.  This
449          * actually happens if a WIM is mounted read-write, since the FUSE
450          * thread changes directory to "/", and it needs to be able to find the
451          * WIM file again.
452          *
453          * This will break if the full path to the WIM changes in the
454          * intervening time...
455          */
456         w->filename = realpath(in_wim_path, NULL);
457         if (!w->filename) {
458                 ERROR_WITH_ERRNO("Failed to resolve WIM filename");
459                 ret = WIMLIB_ERR_NOMEM;
460                 goto out_close;
461         }
462
463         ret = read_header(w->fp, &w->hdr, open_flags);
464         if (ret != 0)
465                 goto out_close;
466
467         DEBUG("Wim file contains %u images", w->hdr.image_count);
468
469         /* If the boot index is invalid, print a warning and set it to 0 */
470         if (w->hdr.boot_idx > w->hdr.image_count) {
471                 WARNING("In `%s', image %u is marked as bootable, "
472                         "but there are only %u images in the WIM",
473                         in_wim_path, w->hdr.boot_idx, w->hdr.image_count);
474                 w->hdr.boot_idx = 0;
475         }
476
477         if (wimlib_get_compression_type(w) == WIMLIB_COMPRESSION_TYPE_INVALID) {
478                 ERROR("Invalid compression type (WIM header flags = %x)",
479                       w->hdr.flags);
480                 ret = WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
481                 goto out_close;
482         }
483
484         if (open_flags & WIMLIB_OPEN_FLAG_CHECK_INTEGRITY) {
485                 ret = check_wim_integrity(w, progress_func);
486                 if (ret == WIM_INTEGRITY_NONEXISTENT) {
487                         WARNING("No integrity information for `%s'; skipping "
488                                 "integrity check.", w->filename);
489                 } else if (ret == WIM_INTEGRITY_NOT_OK) {
490                         ERROR("WIM is not intact! (Failed integrity check)");
491                         ret = WIMLIB_ERR_INTEGRITY;
492                         goto out_close;
493                 } else if (ret != 0) {
494                         goto out_close;
495                 }
496         }
497
498         if (resource_is_compressed(&w->hdr.lookup_table_res_entry)) {
499                 ERROR("Didn't expect a compressed lookup table!");
500                 ERROR("Ask the author to implement support for this.");
501                 ret = WIMLIB_ERR_COMPRESSED_LOOKUP_TABLE;
502                 goto out_close;
503         }
504
505         ret = read_lookup_table(w);
506         if (ret != 0)
507                 goto out_close;
508
509         w->image_metadata = CALLOC(w->hdr.image_count,
510                                    sizeof(struct image_metadata));
511
512         if (!w->image_metadata) {
513                 ERROR("Failed to allocate memory for %u metadata structures",
514                       w->hdr.image_count);
515                 ret = WIMLIB_ERR_NOMEM;
516                 goto out_free_lookup_table;
517         }
518         w->current_image = 0;
519
520         DEBUG("Looking for metadata resources in the lookup table.");
521
522         /* Find the images in the WIM by searching the lookup table. */
523         ret = for_lookup_table_entry(w->lookup_table,
524                                      append_metadata_resource_entry, w);
525
526         if (ret != 0)
527                 goto out_free_image_metadata;
528
529         /* Make sure all the expected images were found.  (We already have
530          * returned false if *extra* images were found) */
531         if (w->current_image != w->hdr.image_count &&
532             w->hdr.part_number == 1)
533         {
534                 ERROR("Only found %u images in WIM, but expected %u",
535                       w->current_image, w->hdr.image_count);
536                 ret = WIMLIB_ERR_IMAGE_COUNT;
537                 goto out_free_image_metadata;
538         }
539
540         /* Sort images by the position of their metadata resources.  I'm
541          * assuming that is what determines the other of the images in the WIM
542          * file, rather than their order in the lookup table, which is random
543          * because of hashing. */
544         qsort(w->image_metadata, w->current_image,
545               sizeof(struct image_metadata), sort_image_metadata_by_position);
546
547         w->current_image = WIMLIB_NO_IMAGE;
548
549         /* Read the XML data. */
550         ret = read_xml_data(w->fp, &w->hdr.xml_res_entry,
551                             &w->xml_data, &w->wim_info);
552
553         if (ret != 0)
554                 goto out_free_image_metadata;
555
556         xml_num_images = wim_info_get_num_images(w->wim_info);
557         if (xml_num_images != w->hdr.image_count) {
558                 ERROR("In the file `%s', there are %u <IMAGE> elements "
559                       "in the XML data,", in_wim_path, xml_num_images);
560                 ERROR("but %u images in the WIM!  There must be exactly one "
561                       "<IMAGE> element per image.", w->hdr.image_count);
562                 ret = WIMLIB_ERR_IMAGE_COUNT;
563                 goto out_free_xml_data;
564         }
565
566         DEBUG("Done beginning read of WIM file `%s'.", in_wim_path);
567         return 0;
568
569         //
570         // Everything is freed in wimlib_free() anyway, so no need to roll back
571         // changes here.
572         //
573 out_free_xml_data:
574         /*FREE(w->xml_data);*/
575         /*w->xml_data = NULL;*/
576         /*free_wim_info(w->wim_info);*/
577         /*w->wim_info = NULL;*/
578 out_free_image_metadata:
579         /*FREE(w->image_metadata);*/
580         /*w->image_metadata = NULL;*/
581         /*w->current_image = WIMLIB_NO_IMAGE;*/
582 out_free_lookup_table:
583         /*free_lookup_table(w->lookup_table);*/
584         /*w->lookup_table = NULL;*/
585 out_close:
586         /*fclose(w->fp);*/
587         /*w->fp = NULL;*/
588 out:
589         return ret;
590 }
591
592
593 /*
594  * Opens a WIM file and creates a WIMStruct for it.
595  */
596 WIMLIBAPI int wimlib_open_wim(const char *wim_file, int open_flags,
597                               WIMStruct **w_ret,
598                               wimlib_progress_func_t progress_func)
599 {
600         WIMStruct *w;
601         int ret;
602
603         if (!wim_file || !w_ret)
604                 return WIMLIB_ERR_INVALID_PARAM;
605         w = new_wim_struct();
606         if (!w) {
607                 ERROR("Failed to allocate memory for WIMStruct");
608                 return WIMLIB_ERR_NOMEM;
609         }
610
611         ret = begin_read(w, wim_file, open_flags, progress_func);
612         if (ret == 0) {
613                 *w_ret = w;
614         } else {
615                 DEBUG("Could not begin reading the WIM file `%s'", wim_file);
616                 wimlib_free(w);
617         }
618         return ret;
619 }
620
621 /* Frees the memory for the WIMStruct, including all internal memory; also
622  * closes all files associated with the WIMStruct.  */
623 WIMLIBAPI void wimlib_free(WIMStruct *w)
624 {
625         DEBUG2("Freeing WIMStruct");
626
627         if (!w)
628                 return;
629         if (w->fp)
630                 fclose(w->fp);
631         if (w->out_fp)
632                 fclose(w->out_fp);
633
634 #ifdef WITH_FUSE
635         if (w->fp_tab) {
636                 for (size_t i = 0; i < w->num_allocated_fps; i++)
637                         if (w->fp_tab[i])
638                                 fclose(w->fp_tab[i]);
639                 FREE(w->fp_tab);
640         }
641         pthread_mutex_destroy(&w->fp_tab_mutex);
642 #endif
643
644         free_lookup_table(w->lookup_table);
645
646         FREE(w->filename);
647         FREE(w->xml_data);
648         free_wim_info(w->wim_info);
649         if (w->image_metadata) {
650                 for (uint i = 0; i < w->hdr.image_count; i++)
651                         destroy_image_metadata(&w->image_metadata[i], NULL);
652                 FREE(w->image_metadata);
653         }
654 #ifdef WITH_NTFS_3G
655         if (w->ntfs_vol) {
656                 DEBUG("Unmounting NTFS volume");
657                 ntfs_umount(w->ntfs_vol, FALSE);
658         }
659 #endif
660         FREE(w);
661 }