1 /*
2  * Copyright (c) 2018 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/queue.h>
19 #include <sys/uio.h>
20 #include <sys/stat.h>
21 #include <sys/mman.h>
22 #include <sys/syslimits.h>
23 
24 #include <fcntl.h>
25 #include <limits.h>
26 #include <dirent.h>
27 #include <stdlib.h>
28 #include <stdio.h>
29 #include <sha1.h>
30 #include <string.h>
31 #include <zlib.h>
32 #include <errno.h>
33 #include <libgen.h>
34 #include <stdint.h>
35 #include <imsg.h>
36 
37 #include "got_error.h"
38 #include "got_reference.h"
39 #include "got_repository.h"
40 #include "got_worktree.h"
41 #include "got_object.h"
42 
43 #include "got_lib_path.h"
44 #include "got_lib_delta.h"
45 #include "got_lib_inflate.h"
46 #include "got_lib_object.h"
47 #include "got_lib_pack.h"
48 #include "got_lib_privsep.h"
49 #include "got_lib_worktree.h"
50 #include "got_lib_object_cache.h"
51 #include "got_lib_repository.h"
52 
53 #ifndef nitems
54 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
55 #endif
56 
57 #define GOT_GIT_DIR	".git"
58 
59 /* Mandatory files and directories inside the git directory. */
60 #define GOT_OBJECTS_DIR		"objects"
61 #define GOT_REFS_DIR		"refs"
62 #define GOT_HEAD_FILE		"HEAD"
63 
64 /* Other files and directories inside the git directory. */
65 #define GOT_FETCH_HEAD_FILE	"FETCH_HEAD"
66 #define GOT_ORIG_HEAD_FILE	"ORIG_HEAD"
67 #define GOT_OBJECTS_PACK_DIR	"objects/pack"
68 
69 char *
70 got_repo_get_path(struct got_repository *repo)
71 {
72 	return strdup(repo->path);
73 }
74 
75 char *
76 got_repo_get_path_git_dir(struct got_repository *repo)
77 {
78 	return strdup(repo->path_git_dir);
79 }
80 
81 int
82 got_repo_is_bare(struct got_repository *repo)
83 {
84 	return (strcmp(repo->path, repo->path_git_dir) == 0);
85 }
86 
87 static char *
88 get_path_git_child(struct got_repository *repo, const char *basename)
89 {
90 	char *path_child;
91 	
92 	if (asprintf(&path_child, "%s/%s", repo->path_git_dir,
93 	    basename) == -1)
94 		return NULL;
95 
96 	return path_child;
97 }
98 
99 char *
100 got_repo_get_path_objects(struct got_repository *repo)
101 {
102 	return get_path_git_child(repo, GOT_OBJECTS_DIR);
103 }
104 
105 char *
106 got_repo_get_path_objects_pack(struct got_repository *repo)
107 {
108 	return get_path_git_child(repo, GOT_OBJECTS_PACK_DIR);
109 }
110 
111 char *
112 got_repo_get_path_refs(struct got_repository *repo)
113 {
114 	return get_path_git_child(repo, GOT_REFS_DIR);
115 }
116 
117 static char *
118 get_path_head(struct got_repository *repo)
119 {
120 	return get_path_git_child(repo, GOT_HEAD_FILE);
121 }
122 
123 static int
124 is_git_repo(struct got_repository *repo)
125 {
126 	char *path_git = got_repo_get_path_git_dir(repo);
127 	char *path_objects = got_repo_get_path_objects(repo);
128 	char *path_refs = got_repo_get_path_refs(repo);
129 	char *path_head = get_path_head(repo);
130 	int ret = 0;
131 	struct stat sb;
132 	struct got_reference *head_ref;
133 
134 	if (lstat(path_git, &sb) == -1)
135 		goto done;
136 	if (!S_ISDIR(sb.st_mode))
137 		goto done;
138 
139 	if (lstat(path_objects, &sb) == -1)
140 		goto done;
141 	if (!S_ISDIR(sb.st_mode))
142 		goto done;
143 
144 	if (lstat(path_refs, &sb) == -1)
145 		goto done;
146 	if (!S_ISDIR(sb.st_mode))
147 		goto done;
148 
149 	if (lstat(path_head, &sb) == -1)
150 		goto done;
151 	if (!S_ISREG(sb.st_mode))
152 		goto done;
153 
154 	/* Check if the HEAD reference can be opened. */
155 	if (got_ref_open(&head_ref, repo, GOT_REF_HEAD) != NULL)
156 		goto done;
157 	got_ref_close(head_ref);
158 
159 	ret = 1;
160 done:
161 	free(path_git);
162 	free(path_objects);
163 	free(path_refs);
164 	free(path_head);
165 	return ret;
166 
167 }
168 
169 const struct got_error *
170 got_repo_cache_object(struct got_repository *repo, struct got_object_id *id,
171     struct got_object *obj)
172 {
173 #ifndef GOT_NO_OBJ_CACHE
174 	const struct got_error *err = NULL;
175 	err = got_object_cache_add(&repo->objcache, id, obj);
176 	if (err)
177 		return err;
178 	obj->refcnt++;
179 #endif
180 	return NULL;
181 }
182 
183 struct got_object *
184 got_repo_get_cached_object(struct got_repository *repo,
185     struct got_object_id *id)
186 {
187 	return (struct got_object *)got_object_cache_get(&repo->objcache, id);
188 }
189 
190 const struct got_error *
191 got_repo_cache_tree(struct got_repository *repo, struct got_object_id *id,
192     struct got_tree_object *tree)
193 {
194 #ifndef GOT_NO_OBJ_CACHE
195 	const struct got_error *err = NULL;
196 	err = got_object_cache_add(&repo->treecache, id, tree);
197 	if (err)
198 		return err;
199 	tree->refcnt++;
200 #endif
201 	return NULL;
202 }
203 
204 struct got_tree_object *
205 got_repo_get_cached_tree(struct got_repository *repo,
206     struct got_object_id *id)
207 {
208 	return (struct got_tree_object *)got_object_cache_get(
209 	    &repo->treecache, id);
210 }
211 
212 const struct got_error *
213 got_repo_cache_commit(struct got_repository *repo, struct got_object_id *id,
214     struct got_commit_object *commit)
215 {
216 #ifndef GOT_NO_OBJ_CACHE
217 	const struct got_error *err = NULL;
218 	err = got_object_cache_add(&repo->commitcache, id, commit);
219 	if (err)
220 		return err;
221 	commit->refcnt++;
222 #endif
223 	return NULL;
224 }
225 
226 struct got_commit_object *
227 got_repo_get_cached_commit(struct got_repository *repo,
228     struct got_object_id *id)
229 {
230 	return (struct got_commit_object *)got_object_cache_get(
231 	    &repo->commitcache, id);
232 }
233 
234 const struct got_error *
235 got_repo_cache_tag(struct got_repository *repo, struct got_object_id *id,
236     struct got_tag_object *tag)
237 {
238 #ifndef GOT_NO_OBJ_CACHE
239 	const struct got_error *err = NULL;
240 	err = got_object_cache_add(&repo->tagcache, id, tag);
241 	if (err)
242 		return err;
243 	tag->refcnt++;
244 #endif
245 	return NULL;
246 }
247 
248 struct got_tag_object *
249 got_repo_get_cached_tag(struct got_repository *repo, struct got_object_id *id)
250 {
251 	return (struct got_tag_object *)got_object_cache_get(
252 	    &repo->tagcache, id);
253 }
254 
255 const struct got_error *
256 open_repo(struct got_repository *repo, const char *path)
257 {
258 	const struct got_error *err = NULL;
259 	struct got_worktree *worktree = NULL;
260 
261 	/* bare git repository? */
262 	repo->path_git_dir = strdup(path);
263 	if (repo->path_git_dir == NULL) {
264 		err = got_error_from_errno();
265 		goto done;
266 	}
267 	if (is_git_repo(repo)) {
268 		repo->path = strdup(repo->path_git_dir);
269 		if (repo->path == NULL) {
270 			err = got_error_from_errno();
271 			goto done;
272 		}
273 		return NULL;
274 	}
275 
276 	/* git repository with working tree? */
277 	free(repo->path_git_dir);
278 	if (asprintf(&repo->path_git_dir, "%s/%s", path, GOT_GIT_DIR) == -1) {
279 		err = got_error_from_errno();
280 		goto done;
281 	}
282 	if (is_git_repo(repo)) {
283 		repo->path = strdup(path);
284 		if (repo->path == NULL) {
285 			err = got_error_from_errno();
286 			goto done;
287 		}
288 		return NULL;
289 	}
290 
291 	/* got work tree checked out from bare git repository? */
292 	free(repo->path_git_dir);
293 	repo->path_git_dir = NULL;
294 	err = got_worktree_open(&worktree, path);
295 	if (err) {
296 		if (err->code == GOT_ERR_ERRNO && errno == ENOENT)
297 			err = got_error(GOT_ERR_NOT_GIT_REPO);
298 		goto done;
299 	}
300 	repo->path_git_dir = strdup(worktree->repo_path);
301 	if (repo->path_git_dir == NULL) {
302 		err = got_error_from_errno();
303 		goto done;
304 	}
305 
306 	/* got work tree checked out from git repository with working tree? */
307 	if (!is_git_repo(repo)) {
308 		free(repo->path_git_dir);
309 		if (asprintf(&repo->path_git_dir, "%s/%s", worktree->repo_path,
310 		    GOT_GIT_DIR) == -1) {
311 			err = got_error_from_errno();
312 			repo->path_git_dir = NULL;
313 			goto done;
314 		}
315 		if (!is_git_repo(repo)) {
316 			err = got_error(GOT_ERR_NOT_GIT_REPO);
317 			goto done;
318 		}
319 		repo->path = strdup(worktree->repo_path);
320 		if (repo->path == NULL) {
321 			err = got_error_from_errno();
322 			goto done;
323 		}
324 	} else {
325 		repo->path = strdup(repo->path_git_dir);
326 		if (repo->path == NULL) {
327 			err = got_error_from_errno();
328 			goto done;
329 		}
330 	}
331 done:
332 	if (worktree)
333 		got_worktree_close(worktree);
334 	return err;
335 }
336 
337 const struct got_error *
338 got_repo_open(struct got_repository **repop, const char *path)
339 {
340 	struct got_repository *repo = NULL;
341 	const struct got_error *err = NULL;
342 	char *abspath, *normpath = NULL;
343 	int i, tried_root = 0;
344 
345 	*repop = NULL;
346 
347 	if (got_path_is_absolute(path))
348 		abspath = strdup(path);
349 	else
350 		abspath = got_path_get_absolute(path);
351 	if (abspath == NULL)
352 		return got_error(GOT_ERR_BAD_PATH);
353 
354 	repo = calloc(1, sizeof(*repo));
355 	if (repo == NULL) {
356 		err = got_error_from_errno();
357 		goto done;
358 	}
359 
360 	for (i = 0; i < nitems(repo->privsep_children); i++) {
361 		memset(&repo->privsep_children[i], 0,
362 		    sizeof(repo->privsep_children[0]));
363 		repo->privsep_children[i].imsg_fd = -1;
364 	}
365 
366 	err = got_object_cache_init(&repo->objcache,
367 	    GOT_OBJECT_CACHE_TYPE_OBJ);
368 	if (err)
369 		goto done;
370 	err = got_object_cache_init(&repo->treecache,
371 	    GOT_OBJECT_CACHE_TYPE_TREE);
372 	if (err)
373 		goto done;
374 	err = got_object_cache_init(&repo->commitcache,
375 	    GOT_OBJECT_CACHE_TYPE_COMMIT);
376 	if (err)
377 		goto done;
378 	err = got_object_cache_init(&repo->tagcache,
379 	    GOT_OBJECT_CACHE_TYPE_TAG);
380 	if (err)
381 		goto done;
382 
383 	normpath = got_path_normalize(abspath);
384 	if (normpath == NULL) {
385 		err = got_error(GOT_ERR_BAD_PATH);
386 		goto done;
387 	}
388 
389 	path = normpath;
390 	do {
391 		err = open_repo(repo, path);
392 		if (err == NULL)
393 			break;
394 		if (err->code != GOT_ERR_NOT_GIT_REPO)
395 			break;
396 		if (path[0] == '/' && path[1] == '\0') {
397 			if (tried_root) {
398 				err = got_error(GOT_ERR_NOT_GIT_REPO);
399 				break;
400 			}
401 			tried_root = 1;
402 		}
403 		path = dirname(path);
404 		if (path == NULL)
405 			err = got_error_from_errno();
406 	} while (path);
407 done:
408 	if (err)
409 		got_repo_close(repo);
410 	else
411 		*repop = repo;
412 	free(abspath);
413 	free(normpath);
414 	return err;
415 }
416 
417 const struct got_error *
418 got_repo_close(struct got_repository *repo)
419 {
420 	const struct got_error *err = NULL, *child_err;
421 	int i;
422 
423 	for (i = 0; i < nitems(repo->packidx_cache); i++) {
424 		if (repo->packidx_cache[i] == NULL)
425 			break;
426 		got_packidx_close(repo->packidx_cache[i]);
427 	}
428 
429 	for (i = 0; i < nitems(repo->packs); i++) {
430 		if (repo->packs[i].path_packfile == NULL)
431 			break;
432 		got_pack_close(&repo->packs[i]);
433 	}
434 
435 	free(repo->path);
436 	free(repo->path_git_dir);
437 
438 	got_object_cache_close(&repo->objcache);
439 	got_object_cache_close(&repo->treecache);
440 	got_object_cache_close(&repo->commitcache);
441 	got_object_cache_close(&repo->tagcache);
442 
443 	for (i = 0; i < nitems(repo->privsep_children); i++) {
444 		if (repo->privsep_children[i].imsg_fd == -1)
445 			continue;
446 		imsg_clear(repo->privsep_children[i].ibuf);
447 		free(repo->privsep_children[i].ibuf);
448 		err = got_privsep_send_stop(repo->privsep_children[i].imsg_fd);
449 		child_err = got_privsep_wait_for_child(
450 		    repo->privsep_children[i].pid);
451 		if (child_err && err == NULL)
452 			err = child_err;
453 		close(repo->privsep_children[i].imsg_fd);
454 	}
455 	free(repo);
456 
457 	return err;
458 }
459 
460 const struct got_error *
461 got_repo_map_path(char **in_repo_path, struct got_repository *repo,
462     const char *input_path, int check_disk)
463 {
464 	const struct got_error *err = NULL;
465 	char *repo_abspath = NULL, *cwd = NULL;
466 	struct stat sb;
467 	size_t repolen, cwdlen, len;
468 	char *canonpath, *path = NULL;
469 
470 	*in_repo_path = NULL;
471 
472 	cwd = getcwd(NULL, 0);
473 	if (cwd == NULL)
474 		return got_error_from_errno();
475 
476 	canonpath = strdup(input_path);
477 	if (canonpath == NULL) {
478 		err = got_error_from_errno();
479 		goto done;
480 	}
481 	err = got_canonpath(input_path, canonpath, strlen(canonpath) + 1);
482 	if (err)
483 		goto done;
484 
485 	repo_abspath = got_repo_get_path(repo);
486 	if (repo_abspath == NULL) {
487 		err = got_error_from_errno();
488 		goto done;
489 	}
490 
491 	/* TODO: Call "get in-repository path of work-tree node" API. */
492 
493 	if (!check_disk)
494 		path = strdup(canonpath);
495 	else if (lstat(canonpath, &sb) != 0) {
496 		if (errno != ENOENT) {
497 			err = got_error_from_errno();
498 			goto done;
499 		}
500 		/*
501 		 * Path is not on disk.
502 		 * Assume it is already relative to repository root.
503 		 */
504 		path = strdup(canonpath);
505 	} else {
506 		int is_repo_child = 0, is_cwd_child = 0;
507 
508 		path = realpath(canonpath, NULL);
509 		if (path == NULL) {
510 			err = got_error_from_errno();
511 			goto done;
512 		}
513 
514 		repolen = strlen(repo_abspath);
515 		cwdlen = strlen(cwd);
516 		len = strlen(path);
517 
518 		if (len > repolen && strncmp(path, repo_abspath, repolen) == 0)
519 			is_repo_child = 1;
520 		if (len > cwdlen && strncmp(path, cwd, cwdlen) == 0)
521 			is_cwd_child = 1;
522 
523 		if (strcmp(path, repo_abspath) == 0) {
524 			free(path);
525 			path = strdup("");
526 			if (path == NULL) {
527 				err = got_error_from_errno();
528 				goto done;
529 			}
530 		} else if (is_repo_child && is_cwd_child) {
531 			char *child;
532 			/* TODO: Is path inside a got worktree? */
533 			/* Strip common prefix with repository path. */
534 			err = got_path_skip_common_ancestor(&child,
535 			    repo_abspath, path);
536 			if (err)
537 				goto done;
538 			free(path);
539 			path = child;
540 		} else if (is_repo_child) {
541 			/* Matched an on-disk path inside repository. */
542 			if (got_repo_is_bare(repo)) {
543 				/*
544 				 * Matched an on-disk path inside repository
545 				 * database. Treat as repository-relative.
546 				 */
547 			} else {
548 				char *child;
549 				/* Strip common prefix with repository path. */
550 				err = got_path_skip_common_ancestor(&child,
551 				    repo_abspath, path);
552 				if (err)
553 					goto done;
554 				free(path);
555 				path = child;
556 			}
557 		} else if (is_cwd_child) {
558 			char *child;
559 			/* TODO: Is path inside a got worktree? */
560 			/* Strip common prefix with cwd. */
561 			err = got_path_skip_common_ancestor(&child, cwd,
562 			    path);
563 			if (err)
564 				goto done;
565 			free(path);
566 			path = child;
567 		} else {
568 			/*
569 			 * Matched unrelated on-disk path.
570 			 * Treat it as repository-relative.
571 			 */
572 		}
573 	}
574 
575 	/* Make in-repository path absolute */
576 	if (path[0] != '/') {
577 		char *abspath;
578 		if (asprintf(&abspath, "/%s", path) == -1) {
579 			err = got_error_from_errno();
580 			goto done;
581 		}
582 		free(path);
583 		path = abspath;
584 	}
585 
586 done:
587 	free(repo_abspath);
588 	free(cwd);
589 	free(canonpath);
590 	if (err)
591 		free(path);
592 	else
593 		*in_repo_path = path;
594 	return err;
595 }
596 
597 const struct got_error *
598 got_repo_cache_packidx(struct got_repository *repo, struct got_packidx *packidx)
599 {
600 	const struct got_error *err = NULL;
601 	int i;
602 
603 	for (i = 0; i < nitems(repo->packidx_cache); i++) {
604 		if (repo->packidx_cache[i] == NULL)
605 			break;
606 	}
607 	if (i == nitems(repo->packidx_cache)) {
608 		err = got_packidx_close(repo->packidx_cache[i - 1]);
609 		if (err)
610 			return err;
611 	}
612 
613 	/*
614 	 * Insert the new pack index at the front so it will
615 	 * be searched first in the future.
616 	 */
617 	memmove(&repo->packidx_cache[1], &repo->packidx_cache[0],
618 	    sizeof(repo->packidx_cache) -
619 	    sizeof(repo->packidx_cache[0]));
620 	repo->packidx_cache[0] = packidx;
621 
622 	return NULL;
623 }
624 
625 static int
626 is_packidx_filename(const char *name, size_t len)
627 {
628 	if (len != GOT_PACKIDX_NAMELEN)
629 		return 0;
630 
631 	if (strncmp(name, GOT_PACK_PREFIX, strlen(GOT_PACK_PREFIX)) != 0)
632 		return 0;
633 
634 	if (strcmp(name + strlen(GOT_PACK_PREFIX) +
635 	    SHA1_DIGEST_STRING_LENGTH - 1, GOT_PACKIDX_SUFFIX) != 0)
636 		return 0;
637 
638 	return 1;
639 }
640 
641 const struct got_error *
642 got_repo_search_packidx(struct got_packidx **packidx, int *idx,
643     struct got_repository *repo, struct got_object_id *id)
644 {
645 	const struct got_error *err;
646 	char *path_packdir;
647 	DIR *packdir;
648 	struct dirent *dent;
649 	char *path_packidx;
650 	int i;
651 
652 	/* Search pack index cache. */
653 	for (i = 0; i < nitems(repo->packidx_cache); i++) {
654 		if (repo->packidx_cache[i] == NULL)
655 			break;
656 		*idx = got_packidx_get_object_idx(repo->packidx_cache[i], id);
657 		if (*idx != -1) {
658 			*packidx = repo->packidx_cache[i];
659 			return NULL;
660 		}
661 	}
662 	/* No luck. Search the filesystem. */
663 
664 	path_packdir = got_repo_get_path_objects_pack(repo);
665 	if (path_packdir == NULL)
666 		return got_error_from_errno();
667 
668 	packdir = opendir(path_packdir);
669 	if (packdir == NULL) {
670 		err = got_error_from_errno();
671 		goto done;
672 	}
673 
674 	while ((dent = readdir(packdir)) != NULL) {
675 		if (!is_packidx_filename(dent->d_name, dent->d_namlen))
676 			continue;
677 
678 		if (asprintf(&path_packidx, "%s/%s", path_packdir,
679 		    dent->d_name) == -1) {
680 			err = got_error_from_errno();
681 			goto done;
682 		}
683 
684 		err = got_packidx_open(packidx, path_packidx, 0);
685 		free(path_packidx);
686 		if (err)
687 			goto done;
688 
689 		*idx = got_packidx_get_object_idx(*packidx, id);
690 		if (*idx != -1) {
691 			err = NULL; /* found the object */
692 			err = got_repo_cache_packidx(repo, *packidx);
693 			goto done;
694 		}
695 
696 		err = got_packidx_close(*packidx);
697 		*packidx = NULL;
698 		if (err)
699 			goto done;
700 	}
701 
702 	err = got_error_no_obj(id);
703 done:
704 	free(path_packdir);
705 	if (packdir && closedir(packdir) != 0 && err == 0)
706 		err = got_error_from_errno();
707 	return err;
708 }
709 
710 static const struct got_error *
711 read_packfile_hdr(int fd, struct got_packidx *packidx)
712 {
713 	const struct got_error *err = NULL;
714 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
715 	struct got_packfile_hdr hdr;
716 	ssize_t n;
717 
718 	n = read(fd, &hdr, sizeof(hdr));
719 	if (n < 0)
720 		return got_error_from_errno();
721 	if (n != sizeof(hdr))
722 		return got_error(GOT_ERR_BAD_PACKFILE);
723 
724 	if (betoh32(hdr.signature) != GOT_PACKFILE_SIGNATURE ||
725 	    betoh32(hdr.version) != GOT_PACKFILE_VERSION ||
726 	    betoh32(hdr.nobjects) != totobj)
727 		err = got_error(GOT_ERR_BAD_PACKFILE);
728 
729 	return err;
730 }
731 
732 static const struct got_error *
733 open_packfile(int *fd, const char *path_packfile, struct got_packidx *packidx)
734 {
735 	const struct got_error *err = NULL;
736 
737 	*fd = open(path_packfile, O_RDONLY | O_NOFOLLOW, GOT_DEFAULT_FILE_MODE);
738 	if (*fd == -1)
739 		return got_error_from_errno();
740 
741 	if (packidx) {
742 		err = read_packfile_hdr(*fd, packidx);
743 		if (err) {
744 			close(*fd);
745 			*fd = -1;
746 		}
747 	}
748 
749 	return err;
750 }
751 
752 const struct got_error *
753 got_repo_cache_pack(struct got_pack **packp, struct got_repository *repo,
754     const char *path_packfile, struct got_packidx *packidx)
755 {
756 	const struct got_error *err = NULL;
757 	struct got_pack *pack = NULL;
758 	int i;
759 
760 	if (packp)
761 		*packp = NULL;
762 
763 	for (i = 0; i < nitems(repo->packs); i++) {
764 		pack = &repo->packs[i];
765 		if (pack->path_packfile == NULL)
766 			break;
767 		if (strcmp(pack->path_packfile, path_packfile) == 0)
768 			return NULL;
769 	}
770 
771 	if (i == nitems(repo->packs) - 1) {
772 		err = got_pack_close(&repo->packs[i - 1]);
773 		if (err)
774 			return err;
775 		memmove(&repo->packs[1], &repo->packs[0],
776 		    sizeof(repo->packs) - sizeof(repo->packs[0]));
777 		i = 0;
778 	}
779 
780 	pack = &repo->packs[i];
781 
782 	pack->path_packfile = strdup(path_packfile);
783 	if (pack->path_packfile == NULL) {
784 		err = got_error_from_errno();
785 		goto done;
786 	}
787 
788 	err = open_packfile(&pack->fd, path_packfile, packidx);
789 	if (err)
790 		goto done;
791 
792 	err = got_pack_get_packfile_size(&pack->filesize, path_packfile);
793 	if (err)
794 		goto done;
795 
796 	pack->privsep_child = NULL;
797 
798 #ifndef GOT_PACK_NO_MMAP
799 	pack->map = mmap(NULL, pack->filesize, PROT_READ, MAP_PRIVATE,
800 	    pack->fd, 0);
801 	if (pack->map == MAP_FAILED)
802 		pack->map = NULL; /* fall back to read(2) */
803 #endif
804 done:
805 	if (err) {
806 		if (pack) {
807 			free(pack->path_packfile);
808 			memset(pack, 0, sizeof(*pack));
809 		}
810 	} else if (packp)
811 		*packp = pack;
812 	return err;
813 }
814 
815 struct got_pack *
816 got_repo_get_cached_pack(struct got_repository *repo, const char *path_packfile)
817 {
818 	struct got_pack *pack = NULL;
819 	int i;
820 
821 	for (i = 0; i < nitems(repo->packs); i++) {
822 		pack = &repo->packs[i];
823 		if (pack->path_packfile == NULL)
824 			break;
825 		if (strcmp(pack->path_packfile, path_packfile) == 0)
826 			return pack;
827 	}
828 
829 	return NULL;
830 }