libbb/unarchive.c

   1 /*
   2  *  Copyright (C) 2000 by Glenn McGrath
   3  *  Copyright (C) 2001 by Laurence Anderson
   4  *
   5  *  Based on previous work by busybox developers and others.
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU Library General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20  */
  21
  22 #include <stdio.h>
  23 #include <errno.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <unistd.h>
  27 #include <utime.h>
  28 #include <libgen.h>
  29
  30 #include "libbb.h"
  31
  32 #define CONFIG_FEATURE_TAR_OLDGNU_COMPATABILITY 1
  33 #define CONFIG_FEATURE_TAR_GNU_EXTENSIONS
  34
  35 #ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
  36 static char *longname = NULL;
  37 static char *linkname = NULL;
  38 #endif
  39
  40 off_t archive_offset;
  41
  42 #define SEEK_BUF 4096
  43 static ssize_t
  44 seek_by_read(FILE* fd, size_t len)
  45 {
  46         ssize_t cc, total = 0;
  47         char buf[SEEK_BUF];
  48
  49         while (len) {
  50                 cc = fread(buf, sizeof(buf[0]),
  51                                 len > SEEK_BUF ? SEEK_BUF : len,
  52                                 fd);
  53
  54                 total += cc;
  55                 len -= cc;
  56
  57                 if(feof(fd) || ferror(fd))
  58                         break;
  59         }
  60         return total;
  61 }
  62
  63 static void
  64 seek_sub_file(FILE *src_stream, const int count)
  65 {
  66         /* Try to fseek as faster */
  67         archive_offset += count;
  68         seek_by_read(src_stream, count);
  69         return;
  70 }
  71
  72
  73 /* Extract the data postioned at src_stream to either filesystem, stdout or
  74  * buffer depending on the value of 'function' which is defined in libbb.h
  75  *
  76  * prefix doesnt have to be just a directory, it may prefix the filename as well.
  77  *
  78  * e.g. '/var/lib/dpkg/info/dpkg.' will extract all files to the base bath
  79  * '/var/lib/dpkg/info/' and all files/dirs created in that dir will have
  80  * 'dpkg.' as their prefix
  81  *
  82  * For this reason if prefix does point to a dir then it must end with a
  83  * trailing '/' or else the last dir will be assumed to be the file prefix
  84  */
  85 static char *
  86 extract_archive(FILE *src_stream, FILE *out_stream,
  87                 const file_header_t *file_entry, const int function,
  88                 const char *prefix,
  89                 int *err)
  90 {
  91         FILE *dst_stream = NULL;
  92         char *full_name = NULL;
  93         char *full_link_name = NULL;
  94         char *buffer = NULL;
  95         struct utimbuf t;
  96
  97         *err = 0;
  98
  99         /* prefix doesnt have to be a proper path it may prepend
 100          * the filename as well */
 101         if (prefix != NULL) {
 102                 /* strip leading '/' in filename to extract as prefix may not be dir */
 103                 /* Cant use concat_path_file here as prefix might not be a directory */
 104                 char *path = file_entry->name;
 105                 if (strncmp("./", path, 2) == 0) {
 106                         path += 2;
 107                         if (strlen(path) == 0)
 108                                 /* Do nothing, current dir already exists. */
 109                                 return NULL;
 110                 }
 111                 full_name = xmalloc(strlen(prefix) + strlen(path) + 1);
 112                 strcpy(full_name, prefix);
 113                 strcat(full_name, path);
 114                 if ( file_entry->link_name ){
 115                    full_link_name = xmalloc(strlen(prefix) + strlen(file_entry->link_name) + 1);
 116                    strcpy(full_link_name, prefix);
 117                    strcat(full_link_name, file_entry->link_name);
 118                 }
 119         } else {
 120                 full_name = xstrdup(file_entry->name);
 121                 if ( file_entry->link_name )
 122                    full_link_name = xstrdup(file_entry->link_name);
 123         }
 124
 125
 126         if (function & extract_to_stream) {
 127                 if (S_ISREG(file_entry->mode)) {
 128                         *err = copy_file_chunk(src_stream, out_stream, file_entry->size);
 129                         archive_offset += file_entry->size;
 130                 }
 131         }
 132         else if (function & extract_one_to_buffer) {
 133                 if (S_ISREG(file_entry->mode)) {
 134                         buffer = (char *) xmalloc(file_entry->size + 1);
 135                         fread(buffer, 1, file_entry->size, src_stream);
 136                         buffer[file_entry->size] = '\0';
 137                         archive_offset += file_entry->size;
 138                         goto cleanup;
 139                 }
 140         }
 141         else if (function & extract_all_to_fs) {
 142                 struct stat oldfile;
 143                 int stat_res;
 144                 stat_res = lstat (full_name, &oldfile);
 145                 if (stat_res == 0) { /* The file already exists */
 146                         if ((function & extract_unconditional) || (oldfile.st_mtime < file_entry->mtime)) {
 147                                 if (!S_ISDIR(oldfile.st_mode)) {
 148                                         unlink(full_name); /* Directories might not be empty etc */
 149                                 }
 150                         } else {
 151                                 if ((function & extract_quiet) != extract_quiet) {
 152                                         *err = -1;
 153                                         error_msg("%s not created: newer or same age file exists", file_entry->name);
 154                                 }
 155                                 seek_sub_file(src_stream, file_entry->size);
 156                                 goto cleanup;
 157                         }
 158                 }
 159                 if (function & extract_create_leading_dirs) { /* Create leading directories with default umask */
 160                         char *buf, *parent;
 161                         buf = xstrdup(full_name);
 162                         parent = dirname(buf);
 163                         if (make_directory (parent, -1, FILEUTILS_RECUR) != 0) {
 164                                 if ((function & extract_quiet) != extract_quiet) {
 165                                         *err = -1;
 166                                         error_msg("couldn't create leading directories");
 167                                 }
 168                         }
 169                         free (buf);
 170                 }
 171                 switch(file_entry->mode & S_IFMT) {
 172                         case S_IFREG:
 173                                 if (file_entry->link_name) { /* Found a cpio hard link */
 174                                         if (link(full_link_name, full_name) != 0) {
 175                                                 if ((function & extract_quiet) != extract_quiet) {
 176                                                         *err = -1;
 177                                                         perror_msg("Cannot link from %s to '%s'",
 178                                                                 file_entry->name, file_entry->link_name);
 179                                                 }
 180                                         }
 181                                 } else {
 182                                         if ((dst_stream = wfopen(full_name, "w")) == NULL) {
 183                                                 *err = -1;
 184                                                 seek_sub_file(src_stream, file_entry->size);
 185                                                 goto cleanup;
 186                                         }
 187                                         archive_offset += file_entry->size;
 188                                         *err = copy_file_chunk(src_stream, dst_stream, file_entry->size);
 189                                         fclose(dst_stream);
 190                                 }
 191                                 break;
 192                         case S_IFDIR:
 193                                 if (stat_res != 0) {
 194                                         if (mkdir(full_name, file_entry->mode) < 0) {
 195                                                 if ((function & extract_quiet) != extract_quiet) {
 196                                                         *err = -1;
 197                                                         perror_msg("Cannot make dir %s", full_name);
 198                                                 }
 199                                         }
 200                                 }
 201                                 break;
 202                         case S_IFLNK:
 203                                 if (symlink(file_entry->link_name, full_name) < 0) {
 204                                         if ((function & extract_quiet) != extract_quiet) {
 205                                                 *err = -1;
 206                                                 perror_msg("Cannot create symlink from %s to '%s'", file_entry->name, file_entry->link_name);
 207                                         }
 208                                         goto cleanup;
 209                                 }
 210                                 break;
 211                         case S_IFSOCK:
 212                         case S_IFBLK:
 213                         case S_IFCHR:
 214                         case S_IFIFO:
 215                                 if (mknod(full_name, file_entry->mode, file_entry->device) == -1) {
 216                                         if ((function & extract_quiet) != extract_quiet) {
 217                                                 *err = -1;
 218                                                 perror_msg("Cannot create node %s", file_entry->name);
 219                                         }
 220                                         goto cleanup;
 221                                 }
 222                                 break;
 223                          default:
 224                                 *err = -1;
 225                                 perror_msg("Don't know how to handle %s", full_name);
 226
 227                 }
 228
 229                 /* Changing a symlink's properties normally changes the properties of the
 230                  * file pointed to, so dont try and change the date or mode, lchown does
 231                  * does the right thing, but isnt available in older versions of libc */
 232                 if (S_ISLNK(file_entry->mode)) {
 233 #if (__GLIBC__ > 2) && (__GLIBC_MINOR__ > 1)
 234                         lchown(full_name, file_entry->uid, file_entry->gid);
 235 #endif
 236                 } else {
 237                         if (function & extract_preserve_date) {
 238                                 t.actime = file_entry->mtime;
 239                                 t.modtime = file_entry->mtime;
 240                                 utime(full_name, &t);
 241                         }
 242                         chown(full_name, file_entry->uid, file_entry->gid);
 243                         chmod(full_name, file_entry->mode);
 244                 }
 245         } else {
 246                 /* If we arent extracting data we have to skip it,
 247                  * if data size is 0 then then just do it anyway
 248                  * (saves testing for it) */
 249                 seek_sub_file(src_stream, file_entry->size);
 250         }
 251
 252         /* extract_list and extract_verbose_list can be used in conjunction
 253          * with one of the above four extraction functions, so do this seperately */
 254         if (function & extract_verbose_list) {
 255                 fprintf(out_stream, "%s %d/%d %8d %s ", mode_string(file_entry->mode),
 256                         file_entry->uid, file_entry->gid,
 257                         (int) file_entry->size, time_string(file_entry->mtime));
 258         }
 259         if ((function & extract_list) || (function & extract_verbose_list)){
 260                 /* fputs doesnt add a trailing \n, so use fprintf */
 261                 fprintf(out_stream, "%s\n", file_entry->name);
 262         }
 263
 264 cleanup:
 265         free(full_name);
 266         if ( full_link_name )
 267             free(full_link_name);
 268
 269         return buffer;
 270 }
 271
 272 static char *
 273 unarchive(FILE *src_stream, FILE *out_stream,
 274                 file_header_t *(*get_headers)(FILE *),
 275                 void (*free_headers)(file_header_t *),
 276                 const int extract_function,
 277                 const char *prefix,
 278                 const char **extract_names,
 279                 int *err)
 280 {
 281         file_header_t *file_entry;
 282         int extract_flag;
 283         int i;
 284         char *buffer = NULL;
 285
 286         *err = 0;
 287
 288         archive_offset = 0;
 289         while ((file_entry = get_headers(src_stream)) != NULL) {
 290                 extract_flag = TRUE;
 291
 292                 if (extract_names != NULL) {
 293                         int found_flag = FALSE;
 294                         for(i = 0; extract_names[i] != 0; i++) {
 295                                 if (strcmp(extract_names[i], file_entry->name) == 0) {
 296                                         found_flag = TRUE;
 297                                         break;
 298                                 }
 299                         }
 300                         if (extract_function & extract_exclude_list) {
 301                                 if (found_flag == TRUE) {
 302                                         extract_flag = FALSE;
 303                                 }
 304                         } else {
 305                                 /* If its not found in the include list dont extract it */
 306                                 if (found_flag == FALSE) {
 307                                         extract_flag = FALSE;
 308                                 }
 309                         }
 310                 }
 311
 312                 if (extract_flag == TRUE) {
 313                         buffer = extract_archive(src_stream, out_stream,
 314                                         file_entry, extract_function,
 315                                         prefix, err);
 316                         *err = 0; /* XXX: ignore extraction errors */
 317                         if (*err) {
 318                                 free_headers(file_entry);
 319                                 break;
 320                         }
 321                 } else {
 322                         /* seek past the data entry */
 323                         seek_sub_file(src_stream, file_entry->size);
 324                 }
 325                 free_headers(file_entry);
 326         }
 327
 328         return buffer;
 329 }
 330
 331 static file_header_t *
 332 get_header_ar(FILE *src_stream)
 333 {
 334         file_header_t *typed;
 335         union {
 336                 char raw[60];
 337                 struct {
 338                         char name[16];
 339                         char date[12];
 340                         char uid[6];
 341                         char gid[6];
 342                         char mode[8];
 343                         char size[10];
 344                         char magic[2];
 345                 } formated;
 346         } ar;
 347         static char *ar_long_names;
 348
 349         if (fread(ar.raw, 1, 60, src_stream) != 60) {
 350                 return(NULL);
 351         }
 352         archive_offset += 60;
 353         /* align the headers based on the header magic */
 354         if ((ar.formated.magic[0] != '`') || (ar.formated.magic[1] != '\n')) {
 355                 /* some version of ar, have an extra '\n' after each data entry,
 356                  * this puts the next header out by 1 */
 357                 if (ar.formated.magic[1] != '`') {
 358                         error_msg("Invalid magic");
 359                         return(NULL);
 360                 }
 361                 /* read the next char out of what would be the data section,
 362                  * if its a '\n' then it is a valid header offset by 1*/
 363                 archive_offset++;
 364                 if (fgetc(src_stream) != '\n') {
 365                         error_msg("Invalid magic");
 366                         return(NULL);
 367                 }
 368                 /* fix up the header, we started reading 1 byte too early */
 369                 /* raw_header[60] wont be '\n' as it should, but it doesnt matter */
 370                 memmove(ar.raw, &ar.raw[1], 59);
 371         }
 372
 373         typed = (file_header_t *) xcalloc(1, sizeof(file_header_t));
 374
 375         typed->size = (size_t) atoi(ar.formated.size);
 376         /* long filenames have '/' as the first character */
 377         if (ar.formated.name[0] == '/') {
 378                 if (ar.formated.name[1] == '/') {
 379                         /* If the second char is a '/' then this entries data section
 380                          * stores long filename for multiple entries, they are stored
 381                          * in static variable long_names for use in future entries */
 382                         ar_long_names = (char *) xrealloc(ar_long_names, typed->size);
 383                         fread(ar_long_names, 1, typed->size, src_stream);
 384                         archive_offset += typed->size;
 385                         /* This ar entries data section only contained filenames for other records
 386                          * they are stored in the static ar_long_names for future reference */
 387                         return (get_header_ar(src_stream)); /* Return next header */
 388                 } else if (ar.formated.name[1] == ' ') {
 389                         /* This is the index of symbols in the file for compilers */
 390                         seek_sub_file(src_stream, typed->size);
 391                         return (get_header_ar(src_stream)); /* Return next header */
 392                 } else {
 393                         /* The number after the '/' indicates the offset in the ar data section
 394                         (saved in variable long_name) that conatains the real filename */
 395                         if (!ar_long_names) {
 396                                 error_msg("Cannot resolve long file name");
 397                                 return (NULL);
 398                         }
 399                         typed->name = xstrdup(ar_long_names + atoi(&ar.formated.name[1]));
 400                 }
 401         } else {
 402                 /* short filenames */
 403                 typed->name = xcalloc(1, 16);
 404                 strncpy(typed->name, ar.formated.name, 16);
 405         }
 406         typed->name[strcspn(typed->name, " /")]='\0';
 407
 408         /* convert the rest of the now valid char header to its typed struct */
 409         parse_mode(ar.formated.mode, &typed->mode);
 410         typed->mtime = atoi(ar.formated.date);
 411         typed->uid = atoi(ar.formated.uid);
 412         typed->gid = atoi(ar.formated.gid);
 413
 414         return(typed);
 415 }
 416
 417 static void
 418 free_header_ar(file_header_t *ar_entry)
 419 {
 420         if (ar_entry == NULL)
 421                 return;
 422
 423         free(ar_entry->name);
 424         if (ar_entry->link_name)
 425                 free(ar_entry->link_name);
 426
 427         free(ar_entry);
 428 }
 429
 430
 431 static file_header_t *
 432 get_header_tar(FILE *tar_stream)
 433 {
 434         union {
 435                 unsigned char raw[512];
 436                 struct {
 437                         char name[100];         /*   0-99 */
 438                         char mode[8];           /* 100-107 */
 439                         char uid[8];            /* 108-115 */
 440                         char gid[8];            /* 116-123 */
 441                         char size[12];          /* 124-135 */
 442                         char mtime[12];         /* 136-147 */
 443                         char chksum[8];         /* 148-155 */
 444                         char typeflag;          /* 156-156 */
 445                         char linkname[100];     /* 157-256 */
 446                         char magic[6];          /* 257-262 */
 447                         char version[2];        /* 263-264 */
 448                         char uname[32];         /* 265-296 */
 449                         char gname[32];         /* 297-328 */
 450                         char devmajor[8];       /* 329-336 */
 451                         char devminor[8];       /* 337-344 */
 452                         char prefix[155];       /* 345-499 */
 453                         char padding[12];       /* 500-512 */
 454                 } formated;
 455         } tar;
 456         file_header_t *tar_entry = NULL;
 457         long i;
 458         long sum = 0;
 459
 460         if (archive_offset % 512 != 0) {
 461                 seek_sub_file(tar_stream, 512 - (archive_offset % 512));
 462         }
 463
 464         if (fread(tar.raw, 1, 512, tar_stream) != 512) {
 465                 /* Unfortunatly its common for tar files to have all sorts of
 466                  * trailing garbage, fail silently */
 467 //              error_msg("Couldnt read header");
 468                 return(NULL);
 469         }
 470         archive_offset += 512;
 471
 472         /* Check header has valid magic, unfortunately some tar files
 473          * have empty (0'ed) tar entries at the end, which will
 474          * cause this to fail, so fail silently for now
 475          */
 476         if (strncmp(tar.formated.magic, "ustar", 5) != 0) {
 477 #ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATABILITY
 478                 if (strncmp(tar.formated.magic, "\0\0\0\0\0", 5) != 0)
 479 #endif
 480                 return(NULL);
 481         }
 482
 483         /* Do checksum on headers */
 484         for (i =  0; i < 148 ; i++) {
 485                 sum += tar.raw[i];
 486         }
 487         sum += ' ' * 8;
 488         for (i =  156; i < 512 ; i++) {
 489                 sum += tar.raw[i];
 490         }
 491         if (sum != strtol(tar.formated.chksum, NULL, 8)) {
 492                 if ( strtol(tar.formated.chksum,NULL,8) != 0 )
 493                         error_msg("Invalid tar header checksum");
 494                 return(NULL);
 495         }
 496
 497         /* convert to type'ed variables */
 498         tar_entry = xcalloc(1, sizeof(file_header_t));
 499
 500 #ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
 501         if (longname) {
 502                 tar_entry->name = longname;
 503                 longname = NULL;
 504         }
 505         else if (linkname) {
 506                 tar_entry->name = linkname;
 507                 linkname = NULL;
 508         } else
 509 #endif
 510         {
 511                 tar_entry->name = xstrndup(tar.formated.name, 100);
 512
 513                 if (tar.formated.prefix[0]) {
 514                         char *temp = tar_entry->name;
 515                         char *prefixTemp = xstrndup(tar.formated.prefix, 155);
 516                         tar_entry->name = concat_path_file(prefixTemp, temp);
 517                         free(temp);
 518                         free(prefixTemp);
 519                 }
 520         }
 521
 522         // tar_entry->name = xstrdup(tar.formated.name);
 523
 524 /*
 525         parse_mode(tar.formated.mode, &tar_entry->mode);
 526 */
 527         tar_entry->mode = 07777 & strtol(tar.formated.mode, NULL, 8);
 528
 529         tar_entry->uid   = strtol(tar.formated.uid, NULL, 8);
 530         tar_entry->gid   = strtol(tar.formated.gid, NULL, 8);
 531         tar_entry->size  = strtol(tar.formated.size, NULL, 8);
 532         tar_entry->mtime = strtol(tar.formated.mtime, NULL, 8);
 533         tar_entry->link_name  = *tar.formated.linkname != '\0' ? xstrndup(tar.formated.linkname, 100) : NULL;
 534         tar_entry->device = (strtol(tar.formated.devmajor, NULL, 8) << 8) +
 535                 strtol(tar.formated.devminor, NULL, 8);
 536
 537         /* Fix mode, used by the old format */
 538         switch (tar.formated.typeflag) {
 539         /* hard links are detected as regular files with 0 size and a link name */
 540         case '1':
 541                 tar_entry->mode |= S_IFREG ;
 542                 break;
 543         case 0:
 544         case '0':
 545
 546 # ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATABILITY
 547                 if (last_char_is(tar_entry->name, '/')) {
 548                         tar_entry->mode |= S_IFDIR;
 549                 } else
 550 # endif
 551                         tar_entry->mode |= S_IFREG;
 552                 break;
 553         case '2':
 554                 tar_entry->mode |= S_IFLNK;
 555                 break;
 556         case '3':
 557                 tar_entry->mode |= S_IFCHR;
 558                 break;
 559         case '4':
 560                 tar_entry->mode |= S_IFBLK;
 561                 break;
 562         case '5':
 563                 tar_entry->mode |= S_IFDIR;
 564                 break;
 565         case '6':
 566                 tar_entry->mode |= S_IFIFO;
 567                 break;
 568 # ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
 569         case 'L': {
 570                         longname = xmalloc(tar_entry->size + 1);
 571                         if(fread(longname, tar_entry->size, 1, tar_stream) != 1)
 572                                 return NULL;
 573                         longname[tar_entry->size] = '\0';
 574                         archive_offset += tar_entry->size;
 575
 576                         return(get_header_tar(tar_stream));
 577                 }
 578         case 'K': {
 579                         linkname = xmalloc(tar_entry->size + 1);
 580                         if(fread(linkname, tar_entry->size, 1, tar_stream) != 1)
 581                                 return NULL;
 582                         linkname[tar_entry->size] = '\0';
 583                         archive_offset += tar_entry->size;
 584
 585                         tar_entry->name = linkname;
 586                         return(get_header_tar(tar_stream));
 587                 }
 588         case 'D':
 589         case 'M':
 590         case 'N':
 591         case 'S':
 592         case 'V':
 593                 perror_msg("Ignoring GNU extension type %c", tar.formated.typeflag);
 594 # endif
 595         default:
 596                 perror_msg("Unknown typeflag: 0x%x", tar.formated.typeflag);
 597                 break;
 598
 599         }
 600
 601         return(tar_entry);
 602 }
 603
 604 static void
 605 free_header_tar(file_header_t *tar_entry)
 606 {
 607         if (tar_entry == NULL)
 608                 return;
 609
 610         free(tar_entry->name);
 611         if (tar_entry->link_name);
 612                 free(tar_entry->link_name);
 613
 614         free(tar_entry);
 615 }
 616
 617 char *
 618 deb_extract(const char *package_filename, FILE *out_stream,
 619         const int extract_function, const char *prefix,
 620         const char *filename, int *err)
 621 {
 622         FILE *deb_stream = NULL;
 623         file_header_t *ar_header = NULL;
 624         const char **file_list = NULL;
 625         char *output_buffer = NULL;
 626         char *ared_file = NULL;
 627         char ar_magic[8];
 628         int gz_err;
 629
 630         *err = 0;
 631
 632         if (filename != NULL) {
 633                 file_list = xmalloc(sizeof(char *) * 2);
 634                 file_list[0] = filename;
 635                 file_list[1] = NULL;
 636         }
 637
 638         if (extract_function & extract_control_tar_gz) {
 639                 ared_file = "control.tar.gz";
 640         }
 641         else if (extract_function & extract_data_tar_gz) {
 642                 ared_file = "data.tar.gz";
 643         } else {
 644                 opkg_msg(ERROR, "Internal error: extract_function=%x\n",
 645                                 extract_function);
 646                 *err = -1;
 647                 goto cleanup;
 648         }
 649
 650         /* open the debian package to be worked on */
 651         deb_stream = wfopen(package_filename, "r");
 652         if (deb_stream == NULL) {
 653                 *err = -1;
 654                 goto cleanup;
 655         }
 656         /* set the buffer size */
 657         setvbuf(deb_stream, NULL, _IOFBF, 0x8000);
 658
 659         /* check ar magic */
 660         fread(ar_magic, 1, 8, deb_stream);
 661
 662         if (strncmp(ar_magic,"!<arch>",7) == 0) {
 663                 archive_offset = 8;
 664
 665                 while ((ar_header = get_header_ar(deb_stream)) != NULL) {
 666                         if (strcmp(ared_file, ar_header->name) == 0) {
 667                                 int gunzip_pid = 0;
 668                                 FILE *uncompressed_stream;
 669                                 /* open a stream of decompressed data */
 670                                 uncompressed_stream = gz_open(deb_stream, &gunzip_pid);
 671                                 if (uncompressed_stream == NULL) {
 672                                         *err = -1;
 673                                         goto cleanup;
 674                                 }
 675
 676                                 archive_offset = 0;
 677                                 output_buffer = unarchive(uncompressed_stream,
 678                                                 out_stream, get_header_tar,
 679                                                 free_header_tar,
 680                                                 extract_function, prefix,
 681                                                 file_list, err);
 682                                 fclose(uncompressed_stream);
 683                                 gz_err = gz_close(gunzip_pid);
 684                                 if (gz_err)
 685                                         *err = -1;
 686                                 free_header_ar(ar_header);
 687                                 break;
 688                         }
 689                         seek_sub_file(deb_stream, ar_header->size);
 690                         free_header_ar(ar_header);
 691                 }
 692                 goto cleanup;
 693         } else if (strncmp(ar_magic, "\037\213", 2) == 0) {
 694                 /* it's a gz file, let's assume it's an opkg */
 695                 int unzipped_opkg_pid;
 696                 FILE *unzipped_opkg_stream;
 697                 file_header_t *tar_header;
 698                 archive_offset = 0;
 699                 fseek(deb_stream, 0, SEEK_SET);
 700                 unzipped_opkg_stream = gz_open(deb_stream, &unzipped_opkg_pid);
 701                 if (unzipped_opkg_stream == NULL) {
 702                         *err = -1;
 703                         goto cleanup;
 704                 }
 705
 706                 /* walk through outer tar file to find ared_file */
 707                 while ((tar_header = get_header_tar(unzipped_opkg_stream)) != NULL) {
 708                         int name_offset = 0;
 709                         if (strncmp(tar_header->name, "./", 2) == 0)
 710                                 name_offset = 2;
 711                         if (strcmp(ared_file, tar_header->name+name_offset) == 0) {
 712                                 int gunzip_pid = 0;
 713                                 FILE *uncompressed_stream;
 714                                 /* open a stream of decompressed data */
 715                                 uncompressed_stream = gz_open(unzipped_opkg_stream, &gunzip_pid);
 716                                 if (uncompressed_stream == NULL) {
 717                                         *err = -1;
 718                                         goto cleanup;
 719                                 }
 720                                 archive_offset = 0;
 721
 722                                 output_buffer = unarchive(uncompressed_stream,
 723                                                           out_stream,
 724                                                           get_header_tar,
 725                                                           free_header_tar,
 726                                                           extract_function,
 727                                                           prefix,
 728                                                           file_list,
 729                                                           err);
 730
 731                                 free_header_tar(tar_header);
 732                                 fclose(uncompressed_stream);
 733                                 gz_err = gz_close(gunzip_pid);
 734                                 if (gz_err)
 735                                         *err = -1;
 736                                 free_header_tar(tar_header);
 737                                 break;
 738                         }
 739                         seek_sub_file(unzipped_opkg_stream, tar_header->size);
 740                         free_header_tar(tar_header);
 741                 }
 742                 fclose(unzipped_opkg_stream);
 743                 gz_err = gz_close(unzipped_opkg_pid);
 744                 if (gz_err)
 745                         *err = -1;
 746
 747                 goto cleanup;
 748         } else {
 749                 *err = -1;
 750                 error_msg("%s: invalid magic", package_filename);
 751         }
 752
 753 cleanup:
 754         if (deb_stream)
 755                 fclose(deb_stream);
 756         if (file_list)
 757                 free(file_list);
 758
 759         return output_buffer;
 760 }