lib/object.c

   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 "got_compat.h"
  18
  19 #include <sys/types.h>
  20 #include <sys/stat.h>
  21 #include <sys/queue.h>
  22 #include <sys/uio.h>
  23 #include <sys/mman.h>
  24
  25 #include <errno.h>
  26 #include <fcntl.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.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_hash.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->hash[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                 if (errno == ENOENT)
 140                         err = got_error_no_obj(id);
 141                 else
 142                         err = got_error_from_errno2("open", path);
 143                 goto done;
 144         }
 145 done:
 146         free(path);
 147         return err;
 148 }
 149
 150 const struct got_error *
 151 got_object_open_by_id_str(struct got_object **obj, struct got_repository *repo,
 152     const char *id_str)
 153 {
 154         struct got_object_id id;
 155
 156         if (!got_parse_object_id(&id, id_str, repo->algo))
 157                 return got_error_path(id_str, GOT_ERR_BAD_OBJ_ID_STR);
 158
 159         return got_object_open(obj, repo, &id);
 160 }
 161
 162 const struct got_error *
 163 got_object_resolve_id_str(struct got_object_id **id,
 164     struct got_repository *repo, const char *id_str)
 165 {
 166         const struct got_error *err = NULL;
 167         struct got_object *obj;
 168
 169         err = got_object_open_by_id_str(&obj, repo, id_str);
 170         if (err)
 171                 return err;
 172
 173         *id = got_object_id_dup(got_object_get_id(obj));
 174         got_object_close(obj);
 175         if (*id == NULL)
 176                 return got_error_from_errno("got_object_id_dup");
 177
 178         return NULL;
 179 }
 180
 181 int
 182 got_object_tree_get_nentries(struct got_tree_object *tree)
 183 {
 184         return tree->nentries;
 185 }
 186
 187 struct got_tree_entry *
 188 got_object_tree_get_first_entry(struct got_tree_object *tree)
 189 {
 190         return got_object_tree_get_entry(tree, 0);
 191 }
 192
 193 struct got_tree_entry *
 194 got_object_tree_get_last_entry(struct got_tree_object *tree)
 195 {
 196         return got_object_tree_get_entry(tree, tree->nentries - 1);
 197 }
 198
 199 struct got_tree_entry *
 200 got_object_tree_get_entry(struct got_tree_object *tree, int i)
 201 {
 202         if (i < 0 || i >= tree->nentries)
 203                 return NULL;
 204         return &tree->entries[i];
 205 }
 206
 207 mode_t
 208 got_tree_entry_get_mode(struct got_tree_entry *te)
 209 {
 210         return te->mode;
 211 }
 212
 213 const char *
 214 got_tree_entry_get_name(struct got_tree_entry *te)
 215 {
 216         return &te->name[0];
 217 }
 218
 219 struct got_object_id *
 220 got_tree_entry_get_id(struct got_tree_entry *te)
 221 {
 222         return &te->id;
 223 }
 224
 225 const struct got_error *
 226 got_object_blob_read_to_str(char **s, struct got_blob_object *blob)
 227 {
 228         const struct got_error *err = NULL;
 229         size_t len, totlen, hdrlen, offset;
 230
 231         *s = NULL;
 232
 233         hdrlen = got_object_blob_get_hdrlen(blob);
 234         totlen = 0;
 235         offset = 0;
 236         do {
 237                 char *p;
 238
 239                 err = got_object_blob_read_block(&len, blob);
 240                 if (err)
 241                         return err;
 242
 243                 if (len == 0)
 244                         break;
 245
 246                 totlen += len - hdrlen;
 247                 p = realloc(*s, totlen + 1);
 248                 if (p == NULL) {
 249                         err = got_error_from_errno("realloc");
 250                         free(*s);
 251                         *s = NULL;
 252                         return err;
 253                 }
 254                 *s = p;
 255                 /* Skip blob object header first time around. */
 256                 memcpy(*s + offset,
 257                     got_object_blob_get_read_buf(blob) + hdrlen, len - hdrlen);
 258                 hdrlen = 0;
 259                 offset = totlen;
 260         } while (len > 0);
 261
 262         (*s)[totlen] = '\0';
 263         return NULL;
 264 }
 265
 266 const struct got_error *
 267 got_tree_entry_get_symlink_target(char **link_target, struct got_tree_entry *te,
 268     struct got_repository *repo)
 269 {
 270         const struct got_error *err = NULL;
 271         struct got_blob_object *blob = NULL;
 272         int fd = -1;
 273
 274         *link_target = NULL;
 275
 276         if (!got_object_tree_entry_is_symlink(te))
 277                 return got_error(GOT_ERR_TREE_ENTRY_TYPE);
 278
 279         fd = got_opentempfd();
 280         if (fd == -1) {
 281                 err = got_error_from_errno("got_opentempfd");
 282                 goto done;
 283         }
 284
 285         err = got_object_open_as_blob(&blob, repo,
 286             got_tree_entry_get_id(te), PATH_MAX, fd);
 287         if (err)
 288                 goto done;
 289
 290         err = got_object_blob_read_to_str(link_target, blob);
 291 done:
 292         if (fd != -1 && close(fd) == -1 && err == NULL)
 293                 err = got_error_from_errno("close");
 294         if (blob)
 295                 got_object_blob_close(blob);
 296         if (err) {
 297                 free(*link_target);
 298                 *link_target = NULL;
 299         }
 300         return err;
 301 }
 302
 303 int
 304 got_tree_entry_get_index(struct got_tree_entry *te)
 305 {
 306         return te->idx;
 307 }
 308
 309 struct got_tree_entry *
 310 got_tree_entry_get_next(struct got_tree_object *tree,
 311     struct got_tree_entry *te)
 312 {
 313         return got_object_tree_get_entry(tree, te->idx + 1);
 314 }
 315
 316 struct got_tree_entry *
 317 got_tree_entry_get_prev(struct got_tree_object *tree,
 318     struct got_tree_entry *te)
 319 {
 320         return got_object_tree_get_entry(tree, te->idx - 1);
 321 }
 322
 323 const struct got_error *
 324 got_object_blob_close(struct got_blob_object *blob)
 325 {
 326         const struct got_error *err = NULL;
 327         free(blob->read_buf);
 328         if (blob->f && fclose(blob->f) == EOF)
 329                 err = got_error_from_errno("fclose");
 330         free(blob->data);
 331         free(blob);
 332         return err;
 333 }
 334
 335 void
 336 got_object_blob_rewind(struct got_blob_object *blob)
 337 {
 338         if (blob->f)
 339                 rewind(blob->f);
 340 }
 341
 342 char *
 343 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
 344 {
 345         return got_object_id_hex(&blob->id, buf, size);
 346 }
 347
 348 size_t
 349 got_object_blob_get_hdrlen(struct got_blob_object *blob)
 350 {
 351         return blob->hdrlen;
 352 }
 353
 354 const uint8_t *
 355 got_object_blob_get_read_buf(struct got_blob_object *blob)
 356 {
 357         return blob->read_buf;
 358 }
 359
 360 const struct got_error *
 361 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
 362 {
 363         size_t n;
 364
 365         n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
 366         if (n == 0 && ferror(blob->f))
 367                 return got_ferror(blob->f, GOT_ERR_IO);
 368         *outlenp = n;
 369         return NULL;
 370 }
 371
 372 const struct got_error *
 373 got_object_blob_is_binary(int *binary, struct got_blob_object *blob)
 374 {
 375         const struct got_error *err;
 376         size_t hdrlen, len;
 377
 378         *binary = 0;
 379         hdrlen = got_object_blob_get_hdrlen(blob);
 380
 381         if (fseeko(blob->f, hdrlen, SEEK_SET) == -1)
 382                 return got_error_from_errno("fseeko");
 383
 384         err = got_object_blob_read_block(&len, blob);
 385         if (err)
 386                 return err;
 387
 388         *binary = memchr(blob->read_buf, '\0', len) != NULL;
 389
 390         if (fseeko(blob->f, hdrlen, SEEK_SET) == -1)
 391                 return got_error_from_errno("fseeko");
 392         return NULL;
 393 }
 394
 395 const struct got_error *
 396 got_object_blob_getline(char **line, ssize_t *linelen, size_t *linesize,
 397     struct got_blob_object *blob)
 398 {
 399         *linelen = getline(line, linesize, blob->f);
 400         if (*linelen == -1 && !feof(blob->f))
 401                 return got_error_from_errno("getline");
 402         return NULL;
 403 }
 404
 405 const struct got_error *
 406 got_object_blob_dump_to_file(off_t *filesize, int *nlines,
 407     off_t **line_offsets, FILE *outfile, struct got_blob_object *blob)
 408 {
 409         const struct got_error *err = NULL;
 410         size_t n, len, hdrlen;
 411         const uint8_t *buf;
 412         int i;
 413         const int alloc_chunksz = 512;
 414         size_t nalloc = 0;
 415         off_t off = 0, total_len = 0;
 416
 417         if (line_offsets)
 418                 *line_offsets = NULL;
 419         if (filesize)
 420                 *filesize = 0;
 421         if (nlines)
 422                 *nlines = 0;
 423
 424         hdrlen = got_object_blob_get_hdrlen(blob);
 425         do {
 426                 err = got_object_blob_read_block(&len, blob);
 427                 if (err)
 428                         return err;
 429                 if (len == 0)
 430                         break;
 431                 buf = got_object_blob_get_read_buf(blob);
 432                 i = hdrlen;
 433                 if (nlines) {
 434                         if (line_offsets && *line_offsets == NULL) {
 435                                 /* Have some data but perhaps no '\n'. */
 436                                 *nlines = 1;
 437                                 nalloc = alloc_chunksz;
 438                                 *line_offsets = calloc(nalloc,
 439                                     sizeof(**line_offsets));
 440                                 if (*line_offsets == NULL)
 441                                         return got_error_from_errno("calloc");
 442
 443                                 /* Skip forward over end of first line. */
 444                                 while (i < len) {
 445                                         if (buf[i] == '\n')
 446                                                 break;
 447                                         i++;
 448                                 }
 449                         }
 450                         /* Scan '\n' offsets in remaining chunk of data. */
 451                         while (i < len) {
 452                                 if (buf[i] != '\n') {
 453                                         i++;
 454                                         continue;
 455                                 }
 456                                 (*nlines)++;
 457                                 if (line_offsets && nalloc < *nlines) {
 458                                         size_t n = *nlines + alloc_chunksz;
 459                                         off_t *o = recallocarray(*line_offsets,
 460                                             nalloc, n, sizeof(**line_offsets));
 461                                         if (o == NULL) {
 462                                                 free(*line_offsets);
 463                                                 *line_offsets = NULL;
 464                                                 return got_error_from_errno(
 465                                                     "recallocarray");
 466                                         }
 467                                         *line_offsets = o;
 468                                         nalloc = n;
 469                                 }
 470                                 if (line_offsets) {
 471                                         off = total_len + i - hdrlen + 1;
 472                                         (*line_offsets)[*nlines - 1] = off;
 473                                 }
 474                                 i++;
 475                         }
 476                 }
 477                 /* Skip blob object header first time around. */
 478                 n = fwrite(buf + hdrlen, 1, len - hdrlen, outfile);
 479                 if (n != len - hdrlen)
 480                         return got_ferror(outfile, GOT_ERR_IO);
 481                 total_len += len - hdrlen;
 482                 hdrlen = 0;
 483         } while (len != 0);
 484
 485         if (fflush(outfile) != 0)
 486                 return got_error_from_errno("fflush");
 487         rewind(outfile);
 488
 489         if (filesize)
 490                 *filesize = total_len;
 491
 492         return NULL;
 493 }
 494
 495 const char *
 496 got_object_tag_get_name(struct got_tag_object *tag)
 497 {
 498         return tag->tag;
 499 }
 500
 501 int
 502 got_object_tag_get_object_type(struct got_tag_object *tag)
 503 {
 504         return tag->obj_type;
 505 }
 506
 507 struct got_object_id *
 508 got_object_tag_get_object_id(struct got_tag_object *tag)
 509 {
 510         return &tag->id;
 511 }
 512
 513 time_t
 514 got_object_tag_get_tagger_time(struct got_tag_object *tag)
 515 {
 516         return tag->tagger_time;
 517 }
 518
 519 time_t
 520 got_object_tag_get_tagger_gmtoff(struct got_tag_object *tag)
 521 {
 522         return tag->tagger_gmtoff;
 523 }
 524
 525 const char *
 526 got_object_tag_get_tagger(struct got_tag_object *tag)
 527 {
 528         return tag->tagger;
 529 }
 530
 531 const char *
 532 got_object_tag_get_message(struct got_tag_object *tag)
 533 {
 534         return tag->tagmsg;
 535 }
 536
 537 static struct got_tree_entry *
 538 find_entry_by_name(struct got_tree_object *tree, const char *name, size_t len)
 539 {
 540         int i;
 541
 542         /* Note that tree entries are sorted in strncmp() order. */
 543         for (i = 0; i < tree->nentries; i++) {
 544                 struct got_tree_entry *te = &tree->entries[i];
 545                 int cmp = strncmp(te->name, name, len);
 546                 if (cmp < 0)
 547                         continue;
 548                 if (cmp > 0)
 549                         break;
 550                 if (te->name[len] == '\0')
 551                         return te;
 552         }
 553         return NULL;
 554 }
 555
 556 struct got_tree_entry *
 557 got_object_tree_find_entry(struct got_tree_object *tree, const char *name)
 558 {
 559         return find_entry_by_name(tree, name, strlen(name));
 560 }
 561
 562 const struct got_error *
 563 got_object_tree_find_path(struct got_object_id **id, mode_t *mode,
 564     struct got_repository *repo, struct got_tree_object *tree,
 565     const char *path)
 566 {
 567         const struct got_error *err = NULL;
 568         struct got_tree_object *subtree = NULL;
 569         struct got_tree_entry *te = NULL;
 570         const char *seg, *s;
 571         size_t seglen;
 572
 573         *id = NULL;
 574
 575         s = path;
 576         while (s[0] == '/')
 577                 s++;
 578         seg = s;
 579         seglen = 0;
 580         subtree = tree;
 581         while (*s) {
 582                 struct got_tree_object *next_tree;
 583
 584                 if (*s != '/') {
 585                         s++;
 586                         seglen++;
 587                         if (*s)
 588                                 continue;
 589                 }
 590
 591                 te = find_entry_by_name(subtree, seg, seglen);
 592                 if (te == NULL) {
 593                         err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
 594                         goto done;
 595                 }
 596
 597                 if (*s == '\0')
 598                         break;
 599
 600                 seg = s + 1;
 601                 seglen = 0;
 602                 s++;
 603                 if (*s) {
 604                         err = got_object_open_as_tree(&next_tree, repo,
 605                             &te->id);
 606                         te = NULL;
 607                         if (err)
 608                                 goto done;
 609                         if (subtree != tree)
 610                                 got_object_tree_close(subtree);
 611                         subtree = next_tree;
 612                 }
 613         }
 614
 615         if (te) {
 616                 *id = got_object_id_dup(&te->id);
 617                 if (*id == NULL)
 618                         return got_error_from_errno("got_object_id_dup");
 619                 if (mode)
 620                         *mode = te->mode;
 621         } else
 622                 err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
 623 done:
 624         if (subtree && subtree != tree)
 625                 got_object_tree_close(subtree);
 626         return err;
 627 }
 628
 629 const struct got_error *
 630 got_object_id_by_path(struct got_object_id **id, struct got_repository *repo,
 631     struct got_commit_object *commit, const char *path)
 632 {
 633         const struct got_error *err = NULL;
 634         struct got_tree_object *tree = NULL;
 635
 636         *id = NULL;
 637
 638         /* Handle opening of root of commit's tree. */
 639         if (got_path_is_root_dir(path)) {
 640                 *id = got_object_id_dup(commit->tree_id);
 641                 if (*id == NULL)
 642                         err = got_error_from_errno("got_object_id_dup");
 643         } else {
 644                 err = got_object_open_as_tree(&tree, repo, commit->tree_id);
 645                 if (err)
 646                         goto done;
 647                 err = got_object_tree_find_path(id, NULL, repo, tree, path);
 648         }
 649 done:
 650         if (tree)
 651                 got_object_tree_close(tree);
 652         return err;
 653 }
 654
 655 /*
 656  * Normalize file mode bits to avoid false positive tree entry differences
 657  * in case tree entries have unexpected mode bits set.
 658  */
 659 static mode_t
 660 normalize_mode_for_comparison(mode_t mode)
 661 {
 662         /*
 663          * For directories, the only relevant bit is the IFDIR bit.
 664          * This allows us to detect paths changing from a directory
 665          * to a file and vice versa.
 666          */
 667         if (S_ISDIR(mode))
 668                 return mode & S_IFDIR;
 669
 670         /*
 671          * For symlinks, the only relevant bit is the IFLNK bit.
 672          * This allows us to detect paths changing from a symlinks
 673          * to a file or directory and vice versa.
 674          */
 675         if (S_ISLNK(mode))
 676                 return mode & S_IFLNK;
 677
 678         /* For files, the only change we care about is the executable bit. */
 679         return mode & S_IXUSR;
 680 }
 681
 682 const struct got_error *
 683 got_object_tree_path_changed(int *changed,
 684     struct got_tree_object *tree01, struct got_tree_object *tree02,
 685     const char *path, struct got_repository *repo)
 686 {
 687         const struct got_error *err = NULL;
 688         struct got_tree_object *tree1 = NULL, *tree2 = NULL;
 689         struct got_tree_entry *te1 = NULL, *te2 = NULL;
 690         const char *seg, *s;
 691         size_t seglen;
 692
 693         *changed = 0;
 694
 695         /* We not do support comparing the root path. */
 696         if (got_path_is_root_dir(path))
 697                 return got_error_path(path, GOT_ERR_BAD_PATH);
 698
 699         tree1 = tree01;
 700         tree2 = tree02;
 701         s = path;
 702         while (*s == '/')
 703                 s++;
 704         seg = s;
 705         seglen = 0;
 706         while (*s) {
 707                 struct got_tree_object *next_tree1, *next_tree2;
 708                 mode_t mode1, mode2;
 709
 710                 if (*s != '/') {
 711                         s++;
 712                         seglen++;
 713                         if (*s)
 714                                 continue;
 715                 }
 716
 717                 te1 = find_entry_by_name(tree1, seg, seglen);
 718                 if (te1 == NULL) {
 719                         err = got_error(GOT_ERR_NO_OBJ);
 720                         goto done;
 721                 }
 722
 723                 if (tree2)
 724                         te2 = find_entry_by_name(tree2, seg, seglen);
 725
 726                 if (te2) {
 727                         mode1 = normalize_mode_for_comparison(te1->mode);
 728                         mode2 = normalize_mode_for_comparison(te2->mode);
 729                         if (mode1 != mode2) {
 730                                 *changed = 1;
 731                                 goto done;
 732                         }
 733
 734                         if (got_object_id_cmp(&te1->id, &te2->id) == 0) {
 735                                 *changed = 0;
 736                                 goto done;
 737                         }
 738                 }
 739
 740                 if (*s == '\0') { /* final path element */
 741                         *changed = 1;
 742                         goto done;
 743                 }
 744
 745                 seg = s + 1;
 746                 s++;
 747                 seglen = 0;
 748                 if (*s) {
 749                         err = got_object_open_as_tree(&next_tree1, repo,
 750                             &te1->id);
 751                         te1 = NULL;
 752                         if (err)
 753                                 goto done;
 754                         if (tree1 != tree01)
 755                                 got_object_tree_close(tree1);
 756                         tree1 = next_tree1;
 757
 758                         if (te2) {
 759                                 err = got_object_open_as_tree(&next_tree2, repo,
 760                                     &te2->id);
 761                                 te2 = NULL;
 762                                 if (err)
 763                                         goto done;
 764                                 if (tree2 != tree02)
 765                                         got_object_tree_close(tree2);
 766                                 tree2 = next_tree2;
 767                         } else if (tree2) {
 768                                 if (tree2 != tree02)
 769                                         got_object_tree_close(tree2);
 770                                 tree2 = NULL;
 771                         }
 772                 }
 773         }
 774 done:
 775         if (tree1 && tree1 != tree01)
 776                 got_object_tree_close(tree1);
 777         if (tree2 && tree2 != tree02)
 778                 got_object_tree_close(tree2);
 779         return err;
 780 }
 781
 782 const struct got_error *
 783 got_object_tree_entry_dup(struct got_tree_entry **new_te,
 784     struct got_tree_entry *te)
 785 {
 786         const struct got_error *err = NULL;
 787
 788         *new_te = calloc(1, sizeof(**new_te));
 789         if (*new_te == NULL)
 790                 return got_error_from_errno("calloc");
 791
 792         (*new_te)->mode = te->mode;
 793         memcpy((*new_te)->name, te->name, sizeof((*new_te)->name));
 794         memcpy(&(*new_te)->id, &te->id, sizeof((*new_te)->id));
 795         return err;
 796 }
 797
 798 int
 799 got_object_tree_entry_is_submodule(struct got_tree_entry *te)
 800 {
 801         return (te->mode & S_IFMT) == (S_IFDIR | S_IFLNK);
 802 }
 803
 804 int
 805 got_object_tree_entry_is_symlink(struct got_tree_entry *te)
 806 {
 807         /* S_IFDIR check avoids confusing symlinks with submodules. */
 808         return ((te->mode & (S_IFDIR | S_IFLNK)) == S_IFLNK);
 809 }
 810
 811 static const struct got_error *
 812 resolve_symlink(char **link_target, const char *path,
 813     struct got_commit_object *commit, struct got_repository *repo)
 814 {
 815         const struct got_error *err = NULL;
 816         char buf[PATH_MAX];
 817         char *name, *parent_path = NULL;
 818         struct got_object_id *tree_obj_id = NULL;
 819         struct got_tree_object *tree = NULL;
 820         struct got_tree_entry *te = NULL;
 821
 822         *link_target = NULL;
 823
 824         if (strlcpy(buf, path, sizeof(buf)) >= sizeof(buf))
 825                 return got_error(GOT_ERR_NO_SPACE);
 826
 827         name = basename(buf);
 828         if (name == NULL)
 829                 return got_error_from_errno2("basename", path);
 830
 831         err = got_path_dirname(&parent_path, path);
 832         if (err)
 833                 return err;
 834
 835         err = got_object_id_by_path(&tree_obj_id, repo, commit,
 836             parent_path);
 837         if (err) {
 838                 if (err->code == GOT_ERR_NO_TREE_ENTRY) {
 839                         /* Display the complete path in error message. */
 840                         err = got_error_path(path, err->code);
 841                 }
 842                 goto done;
 843         }
 844
 845         err = got_object_open_as_tree(&tree, repo, tree_obj_id);
 846         if (err)
 847                 goto done;
 848
 849         te = got_object_tree_find_entry(tree, name);
 850         if (te == NULL) {
 851                 err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
 852                 goto done;
 853         }
 854
 855         if (got_object_tree_entry_is_symlink(te)) {
 856                 err = got_tree_entry_get_symlink_target(link_target, te, repo);
 857                 if (err)
 858                         goto done;
 859                 if (!got_path_is_absolute(*link_target)) {
 860                         char *abspath;
 861                         if (asprintf(&abspath, "%s/%s", parent_path,
 862                             *link_target) == -1) {
 863                                 err = got_error_from_errno("asprintf");
 864                                 goto done;
 865                         }
 866                         free(*link_target);
 867                         *link_target = malloc(PATH_MAX);
 868                         if (*link_target == NULL) {
 869                                 err = got_error_from_errno("malloc");
 870                                 goto done;
 871                         }
 872                         err = got_canonpath(abspath, *link_target, PATH_MAX);
 873                         free(abspath);
 874                         if (err)
 875                                 goto done;
 876                 }
 877         }
 878 done:
 879         free(parent_path);
 880         free(tree_obj_id);
 881         if (tree)
 882                 got_object_tree_close(tree);
 883         if (err) {
 884                 free(*link_target);
 885                 *link_target = NULL;
 886         }
 887         return err;
 888 }
 889
 890 const struct got_error *
 891 got_object_resolve_symlinks(char **link_target, const char *path,
 892     struct got_commit_object *commit, struct got_repository *repo)
 893 {
 894         const struct got_error *err = NULL;
 895         char *next_target = NULL;
 896         int max_recursion = 40; /* matches Git */
 897
 898         *link_target = NULL;
 899
 900         do {
 901                 err = resolve_symlink(&next_target,
 902                     *link_target ? *link_target : path, commit, repo);
 903                 if (err)
 904                         break;
 905                 if (next_target) {
 906                         free(*link_target);
 907                         if (--max_recursion == 0) {
 908                                 err = got_error_path(path, GOT_ERR_RECURSION);
 909                                 *link_target = NULL;
 910                                 break;
 911                         }
 912                         *link_target = next_target;
 913                 }
 914         } while (next_target);
 915
 916         return err;
 917 }
 918
 919 void
 920 got_object_commit_retain(struct got_commit_object *commit)
 921 {
 922         commit->refcnt++;
 923 }
 924
 925 const struct got_error *
 926 got_object_raw_alloc(struct got_raw_object **obj, uint8_t *outbuf, int *outfd,
 927     size_t max_in_mem_size, size_t hdrlen, off_t size)
 928 {
 929         const struct got_error *err = NULL;
 930         off_t tot;
 931
 932         tot = hdrlen + size;
 933
 934         *obj = calloc(1, sizeof(**obj));
 935         if (*obj == NULL) {
 936                 err = got_error_from_errno("calloc");
 937                 goto done;
 938         }
 939         (*obj)->fd = -1;
 940         (*obj)->tempfile_idx = -1;
 941
 942         if (outbuf) {
 943                 (*obj)->data = outbuf;
 944         } else {
 945                 struct stat sb;
 946                 if (fstat(*outfd, &sb) == -1) {
 947                         err = got_error_from_errno("fstat");
 948                         goto done;
 949                 }
 950
 951                 if (sb.st_size != tot) {
 952                         err = got_error_msg(GOT_ERR_BAD_OBJ_HDR,
 953                             "raw object has unexpected size");
 954                         goto done;
 955                 }
 956 #ifndef GOT_PACK_NO_MMAP
 957                 if (tot > 0 && tot <= max_in_mem_size) {
 958                         (*obj)->data = mmap(NULL, tot, PROT_READ,
 959                             MAP_PRIVATE, *outfd, 0);
 960                         if ((*obj)->data == MAP_FAILED) {
 961                                 if (errno != ENOMEM) {
 962                                         err = got_error_from_errno("mmap");
 963                                         goto done;
 964                                 }
 965                                 (*obj)->data = NULL;
 966                         } else {
 967                                 (*obj)->fd = *outfd;
 968                                 *outfd = -1;
 969                         }
 970                 }
 971 #endif
 972                 if (*outfd != -1) {
 973                         (*obj)->f = fdopen(*outfd, "r");
 974                         if ((*obj)->f == NULL) {
 975                                 err = got_error_from_errno("fdopen");
 976                                 goto done;
 977                         }
 978                         *outfd = -1;
 979                 }
 980         }
 981         (*obj)->hdrlen = hdrlen;
 982         (*obj)->size = size;
 983 done:
 984         if (err) {
 985                 if (*obj) {
 986                         got_object_raw_close(*obj);
 987                         *obj = NULL;
 988                 }
 989         } else
 990                 (*obj)->refcnt++;
 991         return err;
 992 }