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Blob

Date:: Mon Jan 9 17:32:29 2023 UTC
Message:: use a caller-specified size limit for mapped files in got_object_raw_alloc() Without this we end up being confused about whether a raw object has been mapped into memory, leading to crashes. ok op@
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1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sys/stat.h>
19 #include <sys/queue.h>
20 #include <sys/tree.h>
21 #include <sys/uio.h>
22 #include <sys/mman.h>
23 
24 #include <errno.h>
25 #include <fcntl.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <sha1.h>
30 #include <unistd.h>
31 #include <zlib.h>
32 #include <libgen.h>
33 #include <limits.h>
34 #include <imsg.h>
35 
36 #include "got_error.h"
37 #include "got_object.h"
38 #include "got_repository.h"
39 #include "got_opentemp.h"
40 #include "got_path.h"
41 
42 #include "got_lib_sha1.h"
43 #include "got_lib_delta.h"
44 #include "got_lib_inflate.h"
45 #include "got_lib_object.h"
46 #include "got_lib_object_idcache.h"
47 #include "got_lib_object_cache.h"
48 #include "got_lib_object_parse.h"
49 #include "got_lib_pack.h"
50 #include "got_lib_repository.h"
51 
52 #ifndef MIN
53 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
54 #endif
55 
56 #ifndef nitems
57 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
58 #endif
59 
60 struct got_object_id *
61 got_object_get_id(struct got_object *obj)
62 {
63 	return &obj->id;
64 }
65 
66 const struct got_error *
67 got_object_get_id_str(char **outbuf, struct got_object *obj)
68 {
69 	return got_object_id_str(outbuf, &obj->id);
70 }
71 
72 const struct got_error *
73 got_object_get_type(int *type, struct got_repository *repo,
74     struct got_object_id *id)
75 {
76 	const struct got_error *err = NULL;
77 	struct got_object *obj;
78 
79 	err = got_object_open(&obj, repo, id);
80 	if (err)
81 		return err;
82 
83 	switch (obj->type) {
84 	case GOT_OBJ_TYPE_COMMIT:
85 	case GOT_OBJ_TYPE_TREE:
86 	case GOT_OBJ_TYPE_BLOB:
87 	case GOT_OBJ_TYPE_TAG:
88 		*type = obj->type;
89 		break;
90 	default:
91 		err = got_error(GOT_ERR_OBJ_TYPE);
92 		break;
93 	}
94 
95 	got_object_close(obj);
96 	return err;
97 }
98 
99 const struct got_error *
100 got_object_get_path(char **path, struct got_object_id *id,
101     struct got_repository *repo)
102 {
103 	const struct got_error *err = NULL;
104 	char *hex = NULL;
105 	char *path_objects;
106 
107 	*path = NULL;
108 
109 	path_objects = got_repo_get_path_objects(repo);
110 	if (path_objects == NULL)
111 		return got_error_from_errno("got_repo_get_path_objects");
112 
113 	err = got_object_id_str(&hex, id);
114 	if (err)
115 		goto done;
116 
117 	if (asprintf(path, "%s/%.2x/%s", path_objects,
118 	    id->sha1[0], hex + 2) == -1)
119 		err = got_error_from_errno("asprintf");
120 
121 done:
122 	free(hex);
123 	free(path_objects);
124 	return err;
125 }
126 
127 const struct got_error *
128 got_object_open_loose_fd(int *fd, struct got_object_id *id,
129     struct got_repository *repo)
130 {
131 	const struct got_error *err = NULL;
132 	char *path;
133 
134 	err = got_object_get_path(&path, id, repo);
135 	if (err)
136 		return err;
137 	*fd = open(path, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
138 	if (*fd == -1) {
139 		err = got_error_from_errno2("open", path);
140 		goto done;
141 	}
142 done:
143 	free(path);
144 	return err;
145 }
146 
147 const struct got_error *
148 got_object_open_by_id_str(struct got_object **obj, struct got_repository *repo,
149     const char *id_str)
150 {
151 	struct got_object_id id;
152 
153 	if (!got_parse_sha1_digest(id.sha1, id_str))
154 		return got_error_path(id_str, GOT_ERR_BAD_OBJ_ID_STR);
155 
156 	return got_object_open(obj, repo, &id);
157 }
158 
159 const struct got_error *
160 got_object_resolve_id_str(struct got_object_id **id,
161     struct got_repository *repo, const char *id_str)
162 {
163 	const struct got_error *err = NULL;
164 	struct got_object *obj;
165 
166 	err = got_object_open_by_id_str(&obj, repo, id_str);
167 	if (err)
168 		return err;
169 
170 	*id = got_object_id_dup(got_object_get_id(obj));
171 	got_object_close(obj);
172 	if (*id == NULL)
173 		return got_error_from_errno("got_object_id_dup");
174 
175 	return NULL;
176 }
177 
178 const struct got_error *
179 got_object_qid_alloc(struct got_object_qid **qid, struct got_object_id *id)
180 {
181 	*qid = calloc(1, sizeof(**qid));
182 	if (*qid == NULL)
183 		return got_error_from_errno("calloc");
184 
185 	memcpy(&(*qid)->id, id, sizeof((*qid)->id));
186 	return NULL;
187 }
188 
189 const struct got_error *
190 got_object_id_queue_copy(const struct got_object_id_queue *src,
191     struct got_object_id_queue *dest)
192 {
193 	const struct got_error *err;
194 	struct got_object_qid *qid;
195 
196 	STAILQ_FOREACH(qid, src, entry) {
197 		struct got_object_qid *new;
198 		/*
199 		 * Deep-copy the object ID only. Let the caller deal
200 		 * with setting up the new->data pointer if needed.
201 		 */
202 		err = got_object_qid_alloc(&new, &qid->id);
203 		if (err) {
204 			got_object_id_queue_free(dest);
205 			return err;
206 		}
207 		STAILQ_INSERT_TAIL(dest, new, entry);
208 	}
209 
210 	return NULL;
211 }
212 
213 int
214 got_object_tree_get_nentries(struct got_tree_object *tree)
215 {
216 	return tree->nentries;
217 }
218 
219 struct got_tree_entry *
220 got_object_tree_get_first_entry(struct got_tree_object *tree)
221 {
222 	return got_object_tree_get_entry(tree, 0);
223 }
224 
225 struct got_tree_entry *
226 got_object_tree_get_last_entry(struct got_tree_object *tree)
227 {
228 	return got_object_tree_get_entry(tree, tree->nentries - 1);
229 }
230 
231 struct got_tree_entry *
232 got_object_tree_get_entry(struct got_tree_object *tree, int i)
233 {
234 	if (i < 0 || i >= tree->nentries)
235 		return NULL;
236 	return &tree->entries[i];
237 }
238 
239 mode_t
240 got_tree_entry_get_mode(struct got_tree_entry *te)
241 {
242 	return te->mode;
243 }
244 
245 const char *
246 got_tree_entry_get_name(struct got_tree_entry *te)
247 {
248 	return &te->name[0];
249 }
250 
251 struct got_object_id *
252 got_tree_entry_get_id(struct got_tree_entry *te)
253 {
254 	return &te->id;
255 }
256 
257 const struct got_error *
258 got_object_blob_read_to_str(char **s, struct got_blob_object *blob)
259 {
260 	const struct got_error *err = NULL;
261 	size_t len, totlen, hdrlen, offset;
262 
263 	*s = NULL;
264 
265 	hdrlen = got_object_blob_get_hdrlen(blob);
266 	totlen = 0;
267 	offset = 0;
268 	do {
269 		char *p;
270 
271 		err = got_object_blob_read_block(&len, blob);
272 		if (err)
273 			return err;
274 
275 		if (len == 0)
276 			break;
277 
278 		totlen += len - hdrlen;
279 		p = realloc(*s, totlen + 1);
280 		if (p == NULL) {
281 			err = got_error_from_errno("realloc");
282 			free(*s);
283 			*s = NULL;
284 			return err;
285 		}
286 		*s = p;
287 		/* Skip blob object header first time around. */
288 		memcpy(*s + offset,
289 		    got_object_blob_get_read_buf(blob) + hdrlen, len - hdrlen);
290 		hdrlen = 0;
291 		offset = totlen;
292 	} while (len > 0);
293 
294 	(*s)[totlen] = '\0';
295 	return NULL;
296 }
297 
298 const struct got_error *
299 got_tree_entry_get_symlink_target(char **link_target, struct got_tree_entry *te,
300     struct got_repository *repo)
301 {
302 	const struct got_error *err = NULL;
303 	struct got_blob_object *blob = NULL;
304 	int fd = -1;
305 
306 	*link_target = NULL;
307 
308 	if (!got_object_tree_entry_is_symlink(te))
309 		return got_error(GOT_ERR_TREE_ENTRY_TYPE);
310 
311 	fd = got_opentempfd();
312 	if (fd == -1) {
313 		err = got_error_from_errno("got_opentempfd");
314 		goto done;
315 	}
316 
317 	err = got_object_open_as_blob(&blob, repo,
318 	    got_tree_entry_get_id(te), PATH_MAX, fd);
319 	if (err)
320 		goto done;
321 
322 	err = got_object_blob_read_to_str(link_target, blob);
323 done:
324 	if (fd != -1 && close(fd) == -1 && err == NULL)
325 		err = got_error_from_errno("close");
326 	if (blob)
327 		got_object_blob_close(blob);
328 	if (err) {
329 		free(*link_target);
330 		*link_target = NULL;
331 	}
332 	return err;
333 }
334 
335 int
336 got_tree_entry_get_index(struct got_tree_entry *te)
337 {
338 	return te->idx;
339 }
340 
341 struct got_tree_entry *
342 got_tree_entry_get_next(struct got_tree_object *tree,
343     struct got_tree_entry *te)
344 {
345 	return got_object_tree_get_entry(tree, te->idx + 1);
346 }
347 
348 struct got_tree_entry *
349 got_tree_entry_get_prev(struct got_tree_object *tree,
350     struct got_tree_entry *te)
351 {
352 	return got_object_tree_get_entry(tree, te->idx - 1);
353 }
354 
355 const struct got_error *
356 got_object_blob_close(struct got_blob_object *blob)
357 {
358 	const struct got_error *err = NULL;
359 	free(blob->read_buf);
360 	if (blob->f && fclose(blob->f) == EOF)
361 		err = got_error_from_errno("fclose");
362 	free(blob->data);
363 	free(blob);
364 	return err;
365 }
366 
367 void
368 got_object_blob_rewind(struct got_blob_object *blob)
369 {
370 	if (blob->f)
371 		rewind(blob->f);
372 }
373 
374 char *
375 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
376 {
377 	return got_sha1_digest_to_str(blob->id.sha1, buf, size);
378 }
379 
380 size_t
381 got_object_blob_get_hdrlen(struct got_blob_object *blob)
382 {
383 	return blob->hdrlen;
384 }
385 
386 const uint8_t *
387 got_object_blob_get_read_buf(struct got_blob_object *blob)
388 {
389 	return blob->read_buf;
390 }
391 
392 const struct got_error *
393 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
394 {
395 	size_t n;
396 
397 	n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
398 	if (n == 0 && ferror(blob->f))
399 		return got_ferror(blob->f, GOT_ERR_IO);
400 	*outlenp = n;
401 	return NULL;
402 }
403 
404 const struct got_error *
405 got_object_blob_is_binary(int *binary, struct got_blob_object *blob)
406 {
407 	const struct got_error *err;
408 	size_t hdrlen, len;
409 
410 	*binary = 0;
411 	hdrlen = got_object_blob_get_hdrlen(blob);
412 
413 	if (fseeko(blob->f, hdrlen, SEEK_SET) == -1)
414 		return got_error_from_errno("fseeko");
415 
416 	err = got_object_blob_read_block(&len, blob);
417 	if (err)
418 		return err;
419 
420 	*binary = memchr(blob->read_buf, '\0', len) != NULL;
421 
422 	if (fseeko(blob->f, hdrlen, SEEK_SET) == -1)
423 		return got_error_from_errno("fseeko");
424 	return NULL;
425 }
426 
427 const struct got_error *
428 got_object_blob_getline(char **line, ssize_t *linelen, size_t *linesize,
429     struct got_blob_object *blob)
430 {
431 	*linelen = getline(line, linesize, blob->f);
432 	if (*linelen == -1 && !feof(blob->f))
433 		return got_error_from_errno("getline");
434 	return NULL;
435 }
436 
437 const struct got_error *
438 got_object_blob_dump_to_file(off_t *filesize, int *nlines,
439     off_t **line_offsets, FILE *outfile, struct got_blob_object *blob)
440 {
441 	const struct got_error *err = NULL;
442 	size_t n, len, hdrlen;
443 	const uint8_t *buf;
444 	int i;
445 	const int alloc_chunksz = 512;
446 	size_t nalloc = 0;
447 	off_t off = 0, total_len = 0;
448 
449 	if (line_offsets)
450 		*line_offsets = NULL;
451 	if (filesize)
452 		*filesize = 0;
453 	if (nlines)
454 		*nlines = 0;
455 
456 	hdrlen = got_object_blob_get_hdrlen(blob);
457 	do {
458 		err = got_object_blob_read_block(&len, blob);
459 		if (err)
460 			return err;
461 		if (len == 0)
462 			break;
463 		buf = got_object_blob_get_read_buf(blob);
464 		i = hdrlen;
465 		if (nlines) {
466 			if (line_offsets && *line_offsets == NULL) {
467 				/* Have some data but perhaps no '\n'. */
468 				*nlines = 1;
469 				nalloc = alloc_chunksz;
470 				*line_offsets = calloc(nalloc,
471 				    sizeof(**line_offsets));
472 				if (*line_offsets == NULL)
473 					return got_error_from_errno("calloc");
474 
475 				/* Skip forward over end of first line. */
476 				while (i < len) {
477 					if (buf[i] == '\n')
478 						break;
479 					i++;
480 				}
481 			}
482 			/* Scan '\n' offsets in remaining chunk of data. */
483 			while (i < len) {
484 				if (buf[i] != '\n') {
485 					i++;
486 					continue;
487 				}
488 				(*nlines)++;
489 				if (line_offsets && nalloc < *nlines) {
490 					size_t n = *nlines + alloc_chunksz;
491 					off_t *o = recallocarray(*line_offsets,
492 					    nalloc, n, sizeof(**line_offsets));
493 					if (o == NULL) {
494 						free(*line_offsets);
495 						*line_offsets = NULL;
496 						return got_error_from_errno(
497 						    "recallocarray");
498 					}
499 					*line_offsets = o;
500 					nalloc = n;
501 				}
502 				if (line_offsets) {
503 					off = total_len + i - hdrlen + 1;
504 					(*line_offsets)[*nlines - 1] = off;
505 				}
506 				i++;
507 			}
508 		}
509 		/* Skip blob object header first time around. */
510 		n = fwrite(buf + hdrlen, 1, len - hdrlen, outfile);
511 		if (n != len - hdrlen)
512 			return got_ferror(outfile, GOT_ERR_IO);
513 		total_len += len - hdrlen;
514 		hdrlen = 0;
515 	} while (len != 0);
516 
517 	if (fflush(outfile) != 0)
518 		return got_error_from_errno("fflush");
519 	rewind(outfile);
520 
521 	if (filesize)
522 		*filesize = total_len;
523 
524 	return NULL;
525 }
526 
527 const char *
528 got_object_tag_get_name(struct got_tag_object *tag)
529 {
530 	return tag->tag;
531 }
532 
533 int
534 got_object_tag_get_object_type(struct got_tag_object *tag)
535 {
536 	return tag->obj_type;
537 }
538 
539 struct got_object_id *
540 got_object_tag_get_object_id(struct got_tag_object *tag)
541 {
542 	return &tag->id;
543 }
544 
545 time_t
546 got_object_tag_get_tagger_time(struct got_tag_object *tag)
547 {
548 	return tag->tagger_time;
549 }
550 
551 time_t
552 got_object_tag_get_tagger_gmtoff(struct got_tag_object *tag)
553 {
554 	return tag->tagger_gmtoff;
555 }
556 
557 const char *
558 got_object_tag_get_tagger(struct got_tag_object *tag)
559 {
560 	return tag->tagger;
561 }
562 
563 const char *
564 got_object_tag_get_message(struct got_tag_object *tag)
565 {
566 	return tag->tagmsg;
567 }
568 
569 static struct got_tree_entry *
570 find_entry_by_name(struct got_tree_object *tree, const char *name, size_t len)
571 {
572 	int i;
573 
574 	/* Note that tree entries are sorted in strncmp() order. */
575 	for (i = 0; i < tree->nentries; i++) {
576 		struct got_tree_entry *te = &tree->entries[i];
577 		int cmp = strncmp(te->name, name, len);
578 		if (cmp < 0)
579 			continue;
580 		if (cmp > 0)
581 			break;
582 		if (te->name[len] == '\0')
583 			return te;
584 	}
585 	return NULL;
586 }
587 
588 struct got_tree_entry *
589 got_object_tree_find_entry(struct got_tree_object *tree, const char *name)
590 {
591 	return find_entry_by_name(tree, name, strlen(name));
592 }
593 
594 const struct got_error *
595 got_object_tree_find_path(struct got_object_id **id, mode_t *mode,
596     struct got_repository *repo, struct got_tree_object *tree,
597     const char *path)
598 {
599 	const struct got_error *err = NULL;
600 	struct got_tree_object *subtree = NULL;
601 	struct got_tree_entry *te = NULL;
602 	const char *seg, *s;
603 	size_t seglen;
604 
605 	*id = NULL;
606 
607 	s = path;
608 	while (s[0] == '/')
609 		s++;
610 	seg = s;
611 	seglen = 0;
612 	subtree = tree;
613 	while (*s) {
614 		struct got_tree_object *next_tree;
615 
616 		if (*s != '/') {
617 			s++;
618 			seglen++;
619 			if (*s)
620 				continue;
621 		}
622 
623 		te = find_entry_by_name(subtree, seg, seglen);
624 		if (te == NULL) {
625 			err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
626 			goto done;
627 		}
628 
629 		if (*s == '\0')
630 			break;
631 
632 		seg = s + 1;
633 		seglen = 0;
634 		s++;
635 		if (*s) {
636 			err = got_object_open_as_tree(&next_tree, repo,
637 			    &te->id);
638 			te = NULL;
639 			if (err)
640 				goto done;
641 			if (subtree != tree)
642 				got_object_tree_close(subtree);
643 			subtree = next_tree;
644 		}
645 	}
646 
647 	if (te) {
648 		*id = got_object_id_dup(&te->id);
649 		if (*id == NULL)
650 			return got_error_from_errno("got_object_id_dup");
651 		if (mode)
652 			*mode = te->mode;
653 	} else
654 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
655 done:
656 	if (subtree && subtree != tree)
657 		got_object_tree_close(subtree);
658 	return err;
659 }
660 
661 const struct got_error *
662 got_object_id_by_path(struct got_object_id **id, struct got_repository *repo,
663     struct got_commit_object *commit, const char *path)
664 {
665 	const struct got_error *err = NULL;
666 	struct got_tree_object *tree = NULL;
667 
668 	*id = NULL;
669 
670 	/* Handle opening of root of commit's tree. */
671 	if (got_path_is_root_dir(path)) {
672 		*id = got_object_id_dup(commit->tree_id);
673 		if (*id == NULL)
674 			err = got_error_from_errno("got_object_id_dup");
675 	} else {
676 		err = got_object_open_as_tree(&tree, repo, commit->tree_id);
677 		if (err)
678 			goto done;
679 		err = got_object_tree_find_path(id, NULL, repo, tree, path);
680 	}
681 done:
682 	if (tree)
683 		got_object_tree_close(tree);
684 	return err;
685 }
686 
687 /*
688  * Normalize file mode bits to avoid false positive tree entry differences
689  * in case tree entries have unexpected mode bits set.
690  */
691 static mode_t
692 normalize_mode_for_comparison(mode_t mode)
693 {
694 	/*
695 	 * For directories, the only relevant bit is the IFDIR bit.
696 	 * This allows us to detect paths changing from a directory
697 	 * to a file and vice versa.
698 	 */
699 	if (S_ISDIR(mode))
700 		return mode & S_IFDIR;
701 
702 	/*
703 	 * For symlinks, the only relevant bit is the IFLNK bit.
704 	 * This allows us to detect paths changing from a symlinks
705 	 * to a file or directory and vice versa.
706 	 */
707 	if (S_ISLNK(mode))
708 		return mode & S_IFLNK;
709 
710 	/* For files, the only change we care about is the executable bit. */
711 	return mode & S_IXUSR;
712 }
713 
714 const struct got_error *
715 got_object_tree_path_changed(int *changed,
716     struct got_tree_object *tree01, struct got_tree_object *tree02,
717     const char *path, struct got_repository *repo)
718 {
719 	const struct got_error *err = NULL;
720 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
721 	struct got_tree_entry *te1 = NULL, *te2 = NULL;
722 	const char *seg, *s;
723 	size_t seglen;
724 
725 	*changed = 0;
726 
727 	/* We not do support comparing the root path. */
728 	if (got_path_is_root_dir(path))
729 		return got_error_path(path, GOT_ERR_BAD_PATH);
730 
731 	tree1 = tree01;
732 	tree2 = tree02;
733 	s = path;
734 	while (*s == '/')
735 		s++;
736 	seg = s;
737 	seglen = 0;
738 	while (*s) {
739 		struct got_tree_object *next_tree1, *next_tree2;
740 		mode_t mode1, mode2;
741 
742 		if (*s != '/') {
743 			s++;
744 			seglen++;
745 			if (*s)
746 				continue;
747 		}
748 
749 		te1 = find_entry_by_name(tree1, seg, seglen);
750 		if (te1 == NULL) {
751 			err = got_error(GOT_ERR_NO_OBJ);
752 			goto done;
753 		}
754 
755 		if (tree2)
756 			te2 = find_entry_by_name(tree2, seg, seglen);
757 
758 		if (te2) {
759 			mode1 = normalize_mode_for_comparison(te1->mode);
760 			mode2 = normalize_mode_for_comparison(te2->mode);
761 			if (mode1 != mode2) {
762 				*changed = 1;
763 				goto done;
764 			}
765 
766 			if (got_object_id_cmp(&te1->id, &te2->id) == 0) {
767 				*changed = 0;
768 				goto done;
769 			}
770 		}
771 
772 		if (*s == '\0') { /* final path element */
773 			*changed = 1;
774 			goto done;
775 		}
776 
777 		seg = s + 1;
778 		s++;
779 		seglen = 0;
780 		if (*s) {
781 			err = got_object_open_as_tree(&next_tree1, repo,
782 			    &te1->id);
783 			te1 = NULL;
784 			if (err)
785 				goto done;
786 			if (tree1 != tree01)
787 				got_object_tree_close(tree1);
788 			tree1 = next_tree1;
789 
790 			if (te2) {
791 				err = got_object_open_as_tree(&next_tree2, repo,
792 				    &te2->id);
793 				te2 = NULL;
794 				if (err)
795 					goto done;
796 				if (tree2 != tree02)
797 					got_object_tree_close(tree2);
798 				tree2 = next_tree2;
799 			} else if (tree2) {
800 				if (tree2 != tree02)
801 					got_object_tree_close(tree2);
802 				tree2 = NULL;
803 			}
804 		}
805 	}
806 done:
807 	if (tree1 && tree1 != tree01)
808 		got_object_tree_close(tree1);
809 	if (tree2 && tree2 != tree02)
810 		got_object_tree_close(tree2);
811 	return err;
812 }
813 
814 const struct got_error *
815 got_object_tree_entry_dup(struct got_tree_entry **new_te,
816     struct got_tree_entry *te)
817 {
818 	const struct got_error *err = NULL;
819 
820 	*new_te = calloc(1, sizeof(**new_te));
821 	if (*new_te == NULL)
822 		return got_error_from_errno("calloc");
823 
824 	(*new_te)->mode = te->mode;
825 	memcpy((*new_te)->name, te->name, sizeof((*new_te)->name));
826 	memcpy(&(*new_te)->id, &te->id, sizeof((*new_te)->id));
827 	return err;
828 }
829 
830 int
831 got_object_tree_entry_is_submodule(struct got_tree_entry *te)
832 {
833 	return (te->mode & S_IFMT) == (S_IFDIR | S_IFLNK);
834 }
835 
836 int
837 got_object_tree_entry_is_symlink(struct got_tree_entry *te)
838 {
839 	/* S_IFDIR check avoids confusing symlinks with submodules. */
840 	return ((te->mode & (S_IFDIR | S_IFLNK)) == S_IFLNK);
841 }
842 
843 static const struct got_error *
844 resolve_symlink(char **link_target, const char *path,
845     struct got_commit_object *commit, struct got_repository *repo)
846 {
847 	const struct got_error *err = NULL;
848 	char buf[PATH_MAX];
849 	char *name, *parent_path = NULL;
850 	struct got_object_id *tree_obj_id = NULL;
851 	struct got_tree_object *tree = NULL;
852 	struct got_tree_entry *te = NULL;
853 
854 	*link_target = NULL;
855 
856 	if (strlcpy(buf, path, sizeof(buf)) >= sizeof(buf))
857 		return got_error(GOT_ERR_NO_SPACE);
858 
859 	name = basename(buf);
860 	if (name == NULL)
861 		return got_error_from_errno2("basename", path);
862 
863 	err = got_path_dirname(&parent_path, path);
864 	if (err)
865 		return err;
866 
867 	err = got_object_id_by_path(&tree_obj_id, repo, commit,
868 	    parent_path);
869 	if (err) {
870 		if (err->code == GOT_ERR_NO_TREE_ENTRY) {
871 			/* Display the complete path in error message. */
872 			err = got_error_path(path, err->code);
873 		}
874 		goto done;
875 	}
876 
877 	err = got_object_open_as_tree(&tree, repo, tree_obj_id);
878 	if (err)
879 		goto done;
880 
881 	te = got_object_tree_find_entry(tree, name);
882 	if (te == NULL) {
883 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
884 		goto done;
885 	}
886 
887 	if (got_object_tree_entry_is_symlink(te)) {
888 		err = got_tree_entry_get_symlink_target(link_target, te, repo);
889 		if (err)
890 			goto done;
891 		if (!got_path_is_absolute(*link_target)) {
892 			char *abspath;
893 			if (asprintf(&abspath, "%s/%s", parent_path,
894 			    *link_target) == -1) {
895 				err = got_error_from_errno("asprintf");
896 				goto done;
897 			}
898 			free(*link_target);
899 			*link_target = malloc(PATH_MAX);
900 			if (*link_target == NULL) {
901 				err = got_error_from_errno("malloc");
902 				goto done;
903 			}
904 			err = got_canonpath(abspath, *link_target, PATH_MAX);
905 			free(abspath);
906 			if (err)
907 				goto done;
908 		}
909 	}
910 done:
911 	free(parent_path);
912 	free(tree_obj_id);
913 	if (tree)
914 		got_object_tree_close(tree);
915 	if (err) {
916 		free(*link_target);
917 		*link_target = NULL;
918 	}
919 	return err;
920 }
921 
922 const struct got_error *
923 got_object_resolve_symlinks(char **link_target, const char *path,
924     struct got_commit_object *commit, struct got_repository *repo)
925 {
926 	const struct got_error *err = NULL;
927 	char *next_target = NULL;
928 	int max_recursion = 40; /* matches Git */
929 
930 	*link_target = NULL;
931 
932 	do {
933 		err = resolve_symlink(&next_target,
934 		    *link_target ? *link_target : path, commit, repo);
935 		if (err)
936 			break;
937 		if (next_target) {
938 			free(*link_target);
939 			if (--max_recursion == 0) {
940 				err = got_error_path(path, GOT_ERR_RECURSION);
941 				*link_target = NULL;
942 				break;
943 			}
944 			*link_target = next_target;
945 		}
946 	} while (next_target);
947 
948 	return err;
949 }
950 
951 void
952 got_object_commit_retain(struct got_commit_object *commit)
953 {
954 	commit->refcnt++;
955 }
956 
957 const struct got_error *
958 got_object_raw_alloc(struct got_raw_object **obj, uint8_t *outbuf, int *outfd,
959     size_t max_in_mem_size, size_t hdrlen, off_t size)
960 {
961 	const struct got_error *err = NULL;
962 	off_t tot;
963 
964 	tot = hdrlen + size;
965 
966 	*obj = calloc(1, sizeof(**obj));
967 	if (*obj == NULL) {
968 		err = got_error_from_errno("calloc");
969 		goto done;
970 	}
971 	(*obj)->fd = -1;
972 	(*obj)->tempfile_idx = -1;
973 
974 	if (outbuf) {
975 		(*obj)->data = outbuf;
976 	} else {
977 		struct stat sb;
978 		if (fstat(*outfd, &sb) == -1) {
979 			err = got_error_from_errno("fstat");
980 			goto done;
981 		}
982 
983 		if (sb.st_size != tot) {
984 			err = got_error_msg(GOT_ERR_BAD_OBJ_HDR,
985 			    "raw object has unexpected size");
986 			goto done;
987 		}
988 #ifndef GOT_PACK_NO_MMAP
989 		if (tot > 0 && tot <= max_in_mem_size) {
990 			(*obj)->data = mmap(NULL, tot, PROT_READ,
991 			    MAP_PRIVATE, *outfd, 0);
992 			if ((*obj)->data == MAP_FAILED) {
993 				if (errno != ENOMEM) {
994 					err = got_error_from_errno("mmap");
995 					goto done;
996 				}
997 				(*obj)->data = NULL;
998 			} else {
999 				(*obj)->fd = *outfd;
1000 				*outfd = -1;
1001 			}
1002 		}
1003 #endif
1004 		if (*outfd != -1) {
1005 			(*obj)->f = fdopen(*outfd, "r");
1006 			if ((*obj)->f == NULL) {
1007 				err = got_error_from_errno("fdopen");
1008 				goto done;
1009 			}
1010 			*outfd = -1;
1011 		}
1012 	}
1013 	(*obj)->hdrlen = hdrlen;
1014 	(*obj)->size = size;
1015 done:
1016 	if (err) {
1017 		if (*obj) {
1018 			got_object_raw_close(*obj);
1019 			*obj = NULL;
1020 		}
1021 	} else
1022 		(*obj)->refcnt++;
1023 	return err;
1024 }