Rewritten functions for reading and writing resources
[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 Lesser General Public License as published by the Free
15  * Software Foundation; either version 2.1 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 Lesser General Public License for more
21  * details.
22  *
23  * You should have received a copy of the GNU Lesser General Public License
24  * along with wimlib; if not, see http://www.gnu.org/licenses/.
25  */
26
27 #include "wimlib_internal.h"
28 #include "io.h"
29 #include "lookup_table.h"
30 #include "xml.h"
31 #include <stdlib.h>
32
33 static int print_metadata(WIMStruct *w)
34 {
35         print_security_data(wim_security_data(w));
36         return for_dentry_in_tree(wim_root_dentry(w), print_dentry, 
37                                   w->lookup_table);
38 }
39
40
41 static int print_files(WIMStruct *w)
42 {
43         return for_dentry_in_tree(wim_root_dentry(w), print_dentry_full_path, 
44                                   NULL);
45 }
46
47 WIMStruct *new_wim_struct()
48 {
49         return CALLOC(1, sizeof(WIMStruct));
50 }
51
52 /* 
53  * Calls a function on images in the WIM.  If @image is WIM_ALL_IMAGES, @visitor
54  * is called on the WIM once for each image, with each image selected as the
55  * current image in turn.  If @image is a certain image, @visitor is called on
56  * the WIM only once, with that image selected.
57  */
58 int for_image(WIMStruct *w, int image, int (*visitor)(WIMStruct *))
59 {
60         int ret;
61         int i;
62         int end;
63
64         DEBUG("for_image(w = %p, image = %d, visitor = %p)", w, image, visitor);
65
66         if (image == WIM_ALL_IMAGES) {
67                 i = 1;
68                 end = w->hdr.image_count;
69         } else {
70                 if (image < 1 || image > w->hdr.image_count)
71                         return WIMLIB_ERR_INVALID_IMAGE;
72                 i = image;
73                 end = image;
74         }
75         for (; i <= end; i++) {
76                 ret = wimlib_select_image(w, i);
77                 if (ret != 0)
78                         return ret;
79                 ret = visitor(w);
80                 if (ret != 0)
81                         return ret;
82         }
83         return 0;
84 }
85
86 static int sort_image_metadata_by_position(const void *p1, const void *p2)
87 {
88         struct image_metadata *bmd1 = (struct image_metadata*)p1;
89         struct image_metadata *bmd2 = (struct image_metadata*)p2;
90         u64 offset1 = bmd1->metadata_lte->resource_entry.offset;
91         u64 offset2 = bmd2->metadata_lte->resource_entry.offset;
92         if (offset1 < offset2)
93                 return -1;
94         else if (offset1 > offset2)
95                 return 1;
96         else
97                 return 0;
98 }
99
100 /* 
101  * If @lte points to a metadata resource, append it to the list of metadata
102  * resources in the WIMStruct.  Otherwise, do nothing.
103  */
104 static int append_metadata_resource_entry(struct lookup_table_entry *lte, 
105                                           void *wim_p)
106 {
107         WIMStruct *w = wim_p;
108
109         if (lte->resource_entry.flags & WIM_RESHDR_FLAG_METADATA) {
110                 /*fprintf(stderr, "found mlte at %u\n", lte->resource_entry.offset);*/
111                 if (w->current_image == w->hdr.image_count) {
112                         ERROR("Expected only %u images, but found more",
113                               w->hdr.image_count);
114                         return WIMLIB_ERR_IMAGE_COUNT;
115                 } else {
116                         DEBUG("Found metadata resource for image %u at "
117                               "offset %"PRIu64".",
118                               w->current_image + 1, 
119                               lte->resource_entry.offset);
120                         w->image_metadata[
121                                 w->current_image++].metadata_lte = lte;
122                 }
123         }
124         return 0;
125 }
126
127 /* Returns the compression type given in the flags of a WIM header. */
128 int wim_hdr_flags_compression_type(int wim_hdr_flags)
129 {
130         if (wim_hdr_flags & WIM_HDR_FLAG_COMPRESSION) {
131                 if (wim_hdr_flags & WIM_HDR_FLAG_COMPRESS_LZX)
132                         return WIM_COMPRESSION_TYPE_LZX;
133                 else if (wim_hdr_flags & WIM_HDR_FLAG_COMPRESS_XPRESS)
134                         return WIM_COMPRESSION_TYPE_XPRESS;
135                 else
136                         return WIM_COMPRESSION_TYPE_INVALID;
137         } else {
138                 return WIM_COMPRESSION_TYPE_NONE;
139         }
140 }
141
142 /*
143  * Creates a WIMStruct for a new WIM file.
144  */
145 WIMLIBAPI int wimlib_create_new_wim(int ctype, WIMStruct **w_ret)
146 {
147         WIMStruct *w;
148         struct lookup_table *table;
149         int ret;
150
151         DEBUG("Creating new WIM with %s compression.",
152               wimlib_get_compression_type_string(ctype));
153
154         /* Allocate the WIMStruct. */
155         w = new_wim_struct();
156         if (!w)
157                 return WIMLIB_ERR_NOMEM;
158
159         ret = init_header(&w->hdr, ctype);
160         if (ret != 0)
161                 goto out_free;
162
163         table = new_lookup_table(9001);
164         if (!table) {
165                 ret = WIMLIB_ERR_NOMEM;
166                 goto out_free;
167         }
168         w->lookup_table = table;
169         *w_ret = w;
170         return 0;
171 out_free:
172         FREE(w);
173         return ret;
174 }
175
176 WIMLIBAPI int wimlib_get_num_images(const WIMStruct *w)
177 {
178         return w->hdr.image_count;
179 }
180
181 int wimlib_select_image(WIMStruct *w, int image)
182 {
183         struct image_metadata *imd;
184
185         DEBUG("Selecting image %d", image);
186
187         if (image == w->current_image)
188                 return 0;
189
190         if (image < 1 || image > w->hdr.image_count) {
191                 ERROR("Cannot select image %d: There are only %u images",
192                       image, w->hdr.image_count);
193                 return WIMLIB_ERR_INVALID_IMAGE;
194         }
195
196
197         /* If a valid image is currently selected, it can be freed if it is not
198          * modified.  */
199         if (w->current_image != WIM_NO_IMAGE) {
200                 imd = wim_get_current_image_metadata(w);
201                 if (!imd->modified) {
202                         DEBUG("Freeing image %u", w->current_image);
203                         destroy_image_metadata(imd, NULL);
204                         imd->root_dentry = NULL;
205                         imd->security_data = NULL;
206                         imd->lgt = NULL;
207                 }
208         }
209
210         w->current_image = image;
211         imd = wim_get_current_image_metadata(w);
212
213         if (imd->root_dentry) {
214                 return 0;
215         } else {
216                 #ifdef ENABLE_DEBUG
217                 DEBUG("Reading metadata resource specified by the following "
218                       "lookup table entry:");
219                 print_lookup_table_entry(imd->metadata_lte);
220                 #endif
221                 return read_metadata_resource(w->fp, 
222                                               wimlib_get_compression_type(w), 
223                                               imd);
224         }
225 }
226
227
228 /* Returns the compression type of the WIM file. */
229 WIMLIBAPI int wimlib_get_compression_type(const WIMStruct *w)
230 {
231         return wim_hdr_flags_compression_type(w->hdr.flags);
232 }
233
234 WIMLIBAPI const char *wimlib_get_compression_type_string(int ctype)
235 {
236         switch (ctype) {
237                 case WIM_COMPRESSION_TYPE_NONE:
238                         return "None";
239                 case WIM_COMPRESSION_TYPE_LZX:
240                         return "LZX";
241                 case WIM_COMPRESSION_TYPE_XPRESS:
242                         return "XPRESS";
243                 default:
244                         return "Invalid";
245         }
246 }
247
248 /*
249  * Returns the number of an image in the WIM file, given a string that is either
250  * the number of the image, or the name of the image.  The images are numbered
251  * starting at 1.
252  */
253 WIMLIBAPI int wimlib_resolve_image(WIMStruct *w, const char *image_name_or_num)
254 {
255         char *p;
256         int image;
257         int i;
258
259         if (!image_name_or_num)
260                 return WIM_NO_IMAGE;
261
262         if (strcmp(image_name_or_num, "all") == 0)
263                 return WIM_ALL_IMAGES;
264         image = strtol(image_name_or_num, &p, 10);
265         if (p != image_name_or_num && *p == '\0') {
266                 if (image < 1 || image > w->hdr.image_count)
267                         return WIM_NO_IMAGE;
268                 return image;
269         } else {
270                 for (i = 1; i <= w->hdr.image_count; i++) {
271                         if (strcmp(image_name_or_num,
272                                    wimlib_get_image_name(w, i)) == 0)
273                                 return i;
274                 }
275                 return WIM_NO_IMAGE;
276         }
277 }
278
279
280 /* Prints some basic information about a WIM file. */
281 WIMLIBAPI void wimlib_print_wim_information(const WIMStruct *w)
282 {
283         const struct wim_header *hdr;
284         
285         hdr = &w->hdr;
286         puts("WIM Information:");
287         puts("----------------");
288         printf("Path:           %s\n", w->filename);
289         fputs ("GUID:           0x", stdout);
290         print_byte_field(hdr->guid, WIM_GID_LEN);
291         putchar('\n');
292         printf("Image Count:    %d\n", hdr->image_count);
293         printf("Compression:    %s\n", wimlib_get_compression_type_string(
294                                                 wimlib_get_compression_type(w)));
295         printf("Part Number:    %d/%d\n", hdr->part_number, hdr->total_parts);
296         printf("Boot Index:     %d\n", hdr->boot_idx);
297         printf("Size:           %"PRIu64" bytes\n", 
298                                 wim_info_get_total_bytes(w->wim_info));
299         printf("Integrity Info: %s\n", (w->hdr.integrity.size != 0) ? "yes" : "no");
300         putchar('\n');
301 }
302
303 WIMLIBAPI bool wimlib_has_integrity_table(const WIMStruct *w)
304 {
305         return w->hdr.integrity.size != 0;
306 }
307
308 WIMLIBAPI void wimlib_print_available_images(const WIMStruct *w, int image)
309 {
310         if (image == WIM_ALL_IMAGES) {
311                 puts("Available Images:");
312                 puts("-----------------");
313         } else {
314                 int n;
315                 int i;
316
317                 n = printf("Information for Image %d\n", image);
318                 for (i = 0; i < n - 1; i++)
319                         putchar('-');
320                 putchar('\n');
321
322         }
323         print_image_info(w->wim_info, image);
324 }
325
326
327 /* Prints the metadata for the specified image, which may be WIM_ALL_IMAGES, but
328  * not WIM_NO_IMAGE. */
329 WIMLIBAPI int wimlib_print_metadata(WIMStruct *w, int image)
330 {
331         return for_image(w, image, print_metadata);
332 }
333
334 WIMLIBAPI int wimlib_print_files(WIMStruct *w, int image)
335 {
336         return for_image(w, image, print_files);
337 }
338
339 /* Sets the index of the bootable image. */
340 WIMLIBAPI int wimlib_set_boot_idx(WIMStruct *w, int boot_idx)
341 {
342         if (boot_idx < 0 || boot_idx > w->hdr.image_count)
343                 return WIMLIB_ERR_INVALID_IMAGE;
344         w->hdr.boot_idx = boot_idx;
345         if (boot_idx == 0) {
346                 memset(&w->hdr.boot_metadata_res_entry, 0, 
347                        sizeof(struct resource_entry));
348         } else {
349                 memcpy(&w->hdr.boot_metadata_res_entry,
350                        &w->image_metadata[
351                                 boot_idx - 1].metadata_lte->resource_entry, 
352                        sizeof(struct resource_entry));
353         }
354         return 0;
355 }
356
357 WIMLIBAPI int wimlib_get_part_number(const WIMStruct *w, int *total_parts_ret)
358 {
359         if (total_parts_ret)
360                 *total_parts_ret = w->hdr.total_parts;
361         return w->hdr.part_number;
362 }
363                                     
364
365 WIMLIBAPI int wimlib_get_boot_idx(const WIMStruct *w)
366 {
367         return w->hdr.boot_idx;
368 }
369
370 /* 
371  * Begins the reading of a WIM file; opens the file and reads its header and
372  * lookup table, and optionally checks the integrity.
373  */
374 static int begin_read(WIMStruct *w, const char *in_wim_path, int flags)
375 {
376         int ret;
377         uint xml_num_images;
378
379         DEBUG("Reading the WIM file `%s'", in_wim_path);
380
381         w->filename = STRDUP(in_wim_path);
382         if (!w->filename) {
383                 ERROR("Failed to allocate memory for WIM filename");
384                 return WIMLIB_ERR_NOMEM;
385         }
386
387         w->fp = fopen(in_wim_path, "rb");
388
389         if (!w->fp) {
390                 ERROR_WITH_ERRNO("Failed to open the file `%s' for reading",
391                                  in_wim_path);
392                 return WIMLIB_ERR_OPEN;
393         }
394
395         ret = read_header(w->fp, &w->hdr, flags & WIMLIB_OPEN_FLAG_SPLIT_OK);
396         if (ret != 0)
397                 return ret;
398
399         DEBUG("Wim file contains %u images", w->hdr.image_count);
400
401         /* If the boot index is invalid, print a warning and set it to 0 */
402         if (w->hdr.boot_idx > w->hdr.image_count) {
403                 WARNING("In `%s', image %u is marked as bootable, "
404                         "but there are only %u images",
405                          in_wim_path, w->hdr.boot_idx, w->hdr.image_count);
406                 w->hdr.boot_idx = 0;
407         }
408
409         if (wimlib_get_compression_type(w) == WIM_COMPRESSION_TYPE_INVALID) {
410                 ERROR("Invalid compression type (WIM header flags = %x)",
411                       w->hdr.flags);
412                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
413         }
414
415
416         if (flags & WIMLIB_OPEN_FLAG_CHECK_INTEGRITY) {
417                 int integrity_status;
418                 ret = check_wim_integrity(w, 
419                                           flags & WIMLIB_OPEN_FLAG_SHOW_PROGRESS, 
420                                           &integrity_status);
421                 if (ret != 0) {
422                         ERROR("Error in check_wim_integrity()");
423                         return ret;
424                 }
425                 if (integrity_status == WIM_INTEGRITY_NONEXISTENT) {
426                         WARNING("No integrity information for `%s'; skipping "
427                                 "integrity check.", w->filename);
428                 } else if (integrity_status == WIM_INTEGRITY_NOT_OK) {
429                         ERROR("WIM is not intact! (Failed integrity check)");
430                         return WIMLIB_ERR_INTEGRITY;
431                 }
432         }
433
434         if (resource_is_compressed(&w->hdr.lookup_table_res_entry)) {
435                 ERROR("Didn't expect a compressed lookup table!");
436                 ERROR("Ask the author to implement support for this.");
437                 return WIMLIB_ERR_COMPRESSED_LOOKUP_TABLE;
438         }
439
440         ret = read_lookup_table(w);
441         if (ret != 0)
442                 return ret;
443
444         w->image_metadata = CALLOC(w->hdr.image_count, 
445                                    sizeof(struct image_metadata));
446
447         if (!w->image_metadata) {
448                 ERROR("Failed to allocate memory for %u metadata structures",
449                       w->hdr.image_count);
450                 return WIMLIB_ERR_NOMEM;
451         }
452         w->current_image = 0;
453
454         DEBUG("Looking for metadata resources in the lookup table.");
455
456         /* Find the images in the WIM by searching the lookup table. */
457         ret = for_lookup_table_entry(w->lookup_table, 
458                                      append_metadata_resource_entry, w);
459
460         if (ret != 0)
461                 return ret;
462
463         /* Make sure all the expected images were found.  (We already have
464          * returned false if *extra* images were found) */
465         if (w->current_image != w->hdr.image_count && w->hdr.part_number == 1) {
466                 ERROR("Only found %u images in WIM, but expected %u",
467                       w->current_image, w->hdr.image_count);
468                 return WIMLIB_ERR_IMAGE_COUNT;
469         }
470
471
472         /* Sort images by the position of their metadata resources.  I'm
473          * assuming that is what determines the other of the images in the WIM
474          * file, rather than their order in the lookup table, which is random
475          * because of hashing. */
476         qsort(w->image_metadata, w->current_image,
477               sizeof(struct image_metadata), sort_image_metadata_by_position);
478
479         w->current_image = WIM_NO_IMAGE;
480
481         /* Read the XML data. */
482         ret = read_xml_data(w->fp, &w->hdr.xml_res_entry, 
483                             &w->xml_data, &w->wim_info);
484
485         if (ret != 0) {
486                 ERROR("Missing or invalid XML data");
487                 return ret;
488         }
489
490         xml_num_images = wim_info_get_num_images(w->wim_info);
491         if (xml_num_images != w->hdr.image_count) {
492                 ERROR("In the file `%s', there are %u <IMAGE> elements "
493                       "in the XML data,", in_wim_path, xml_num_images);
494                 ERROR("but %u images in the WIM!  There must be exactly one "
495                       "<IMAGE> element per image.", w->hdr.image_count);
496                 return WIMLIB_ERR_IMAGE_COUNT;
497         }
498
499         DEBUG("Done beginning read of WIM file `%s'.", in_wim_path);
500         return 0;
501 }
502
503
504 /*
505  * Opens a WIM file and creates a WIMStruct for it.
506  */
507 WIMLIBAPI int wimlib_open_wim(const char *wim_file, int flags, 
508                               WIMStruct **w_ret)
509 {
510         WIMStruct *w;
511         int ret;
512
513         DEBUG("wim_file = `%s', flags = %#x", wim_file, flags);
514         w = new_wim_struct();
515         if (!w) {
516                 ERROR("Failed to allocate memory for WIMStruct");
517                 return WIMLIB_ERR_NOMEM;
518         }
519
520         ret = begin_read(w, wim_file, flags);
521         if (ret != 0) {
522                 DEBUG("Could not begin reading the WIM file `%s'", wim_file);
523                 wimlib_free(w);
524                 return ret;
525         }
526         *w_ret = w;
527         return 0;
528 }
529
530 /* Frees the memory for the WIMStruct, including all internal memory; also
531  * closes all files associated with the WIMStruct.  */
532 WIMLIBAPI void wimlib_free(WIMStruct *w)
533 {
534         DEBUG("Freeing WIMStruct");
535
536         if (!w)
537                 return;
538         if (w->fp)
539                 fclose(w->fp);
540         if (w->out_fp)
541                 fclose(w->out_fp);
542
543         free_lookup_table(w->lookup_table);
544
545         FREE(w->filename);
546         FREE(w->xml_data);
547         free_wim_info(w->wim_info);
548         if (w->image_metadata) {
549                 for (uint i = 0; i < w->hdr.image_count; i++)
550                         destroy_image_metadata(&w->image_metadata[i], NULL);
551                 FREE(w->image_metadata);
552         }
553         FREE(w);
554 }
555