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 "libbb.h"
  29
  30 #define CONFIG_FEATURE_TAR_OLDGNU_COMPATABILITY 1
  31 #define CONFIG_FEATURE_TAR_GNU_EXTENSIONS
  32
  33 #ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
  34 static char *longname = NULL;
  35 static char *linkname = NULL;
  36 #endif
  37
  38 extern void seek_sub_file(FILE *src_stream, const int count);
  39 extern char *extract_archive(FILE *src_stream, FILE *out_stream, const file_header_t *file_entry,
  40                               const int function, const char *prefix);
  41 extern ssize_t seek_by_read(FILE* fd, size_t len);
  42
  43
  44 #ifdef L_archive_offset
  45 off_t archive_offset;
  46 #else
  47 extern off_t archive_offset;
  48 #endif
  49
  50 #ifdef L_seek_sub_file
  51 #define SEEK_BUF 4096
  52 ssize_t seek_by_read(FILE* fd, size_t len)
  53 {
  54         ssize_t cc, total = 0;
  55         char buf[SEEK_BUF];
  56
  57         while (len) {
  58                 cc = fread(buf, sizeof(buf[0]),
  59                                 len > SEEK_BUF ? SEEK_BUF : len,
  60                                 fd);
  61
  62                 total += cc;
  63                 len -= cc;
  64
  65                 if(feof(fd) || ferror(fd))
  66                         break;
  67         }
  68         return total;
  69 }
  70
  71 void seek_sub_file(FILE *src_stream, const int count)
  72 {
  73         /* Try to fseek as faster */
  74         archive_offset += count;
  75         seek_by_read(src_stream, count);
  76         return;
  77 }
  78 #endif
  79
  80
  81
  82 #ifdef L_extract_archive
  83 /* Extract the data postioned at src_stream to either filesystem, stdout or
  84  * buffer depending on the value of 'function' which is defined in libbb.h
  85  *
  86  * prefix doesnt have to be just a directory, it may prefix the filename as well.
  87  *
  88  * e.g. '/var/lib/dpkg/info/dpkg.' will extract all files to the base bath
  89  * '/var/lib/dpkg/info/' and all files/dirs created in that dir will have
  90  * 'dpkg.' as their prefix
  91  *
  92  * For this reason if prefix does point to a dir then it must end with a
  93  * trailing '/' or else the last dir will be assumed to be the file prefix
  94  */
  95 char *extract_archive(FILE *src_stream, FILE *out_stream, const file_header_t *file_entry,
  96  const int function, const char *prefix)
  97 {
  98         FILE *dst_stream = NULL;
  99         char *full_name = NULL;
 100         char *full_link_name = NULL;
 101         char *buffer = NULL;
 102         struct utimbuf t;
 103
 104
 105         /* prefix doesnt have to be a proper path it may prepend
 106          * the filename as well */
 107         if (prefix != NULL) {
 108                 /* strip leading '/' in filename to extract as prefix may not be dir */
 109                 /* Cant use concat_path_file here as prefix might not be a directory */
 110                 char *path = file_entry->name;
 111                 if (strncmp("./", path, 2) == 0) {
 112                         path += 2;
 113                         if (strlen(path) == 0) {
 114                                 return(NULL);
 115                         }
 116                 }
 117                 full_name = xmalloc(strlen(prefix) + strlen(path) + 1);
 118                 strcpy(full_name, prefix);
 119                 strcat(full_name, path);
 120                 if ( file_entry->link_name ){
 121                    full_link_name = xmalloc(strlen(prefix) + strlen(file_entry->link_name) + 1);
 122                    strcpy(full_link_name, prefix);
 123                    strcat(full_link_name, file_entry->link_name);
 124                 }
 125         } else {
 126                 full_name = strdup(file_entry->name);
 127                 if ( file_entry->link_name )
 128                    full_link_name = strdup(file_entry->link_name);
 129         }
 130
 131
 132         if (function & extract_to_stdout) {
 133                 if (S_ISREG(file_entry->mode)) {
 134                         copy_file_chunk(src_stream, out_stream, file_entry->size);
 135                         archive_offset += file_entry->size;
 136                 }
 137         }
 138         else if (function & extract_one_to_buffer) {
 139                 if (S_ISREG(file_entry->mode)) {
 140                         buffer = (char *) xmalloc(file_entry->size + 1);
 141                         fread(buffer, 1, file_entry->size, src_stream);
 142                         buffer[file_entry->size] = '\0';
 143                         archive_offset += file_entry->size;
 144                         goto cleanup;
 145                 }
 146         }
 147         else if (function & extract_all_to_fs) {
 148                 struct stat oldfile;
 149                 int stat_res;
 150                 stat_res = lstat (full_name, &oldfile);
 151                 if (stat_res == 0) { /* The file already exists */
 152                         if ((function & extract_unconditional) || (oldfile.st_mtime < file_entry->mtime)) {
 153                                 if (!S_ISDIR(oldfile.st_mode)) {
 154                                         unlink(full_name); /* Directories might not be empty etc */
 155                                 }
 156                         } else {
 157                                 if ((function & extract_quiet) != extract_quiet) {
 158                                         error_msg("%s not created: newer or same age file exists", file_entry->name);
 159                                 }
 160                                 seek_sub_file(src_stream, file_entry->size);
 161                                 goto cleanup;
 162                         }
 163                 }
 164                 if (function & extract_create_leading_dirs) { /* Create leading directories with default umask */
 165                         char *buf, *parent;
 166                         buf = xstrdup(full_name);
 167                         parent = dirname(buf);
 168                         if (make_directory (parent, -1, FILEUTILS_RECUR) != 0) {
 169                                 if ((function & extract_quiet) != extract_quiet) {
 170                                         error_msg("couldn't create leading directories");
 171                                 }
 172                         }
 173                         free (buf);
 174                 }
 175                 switch(file_entry->mode & S_IFMT) {
 176                         case S_IFREG:
 177                                 if (file_entry->link_name) { /* Found a cpio hard link */
 178                                         if (link(full_link_name, full_name) != 0) {
 179                                                 if ((function & extract_quiet) != extract_quiet) {
 180                                                         perror_msg("Cannot link from %s to '%s'",
 181                                                                 file_entry->name, file_entry->link_name);
 182                                                 }
 183                                         }
 184                                 } else {
 185                                         if ((dst_stream = wfopen(full_name, "w")) == NULL) {
 186                                                 seek_sub_file(src_stream, file_entry->size);
 187                                                 goto cleanup;
 188                                         }
 189                                         archive_offset += file_entry->size;
 190                                         copy_file_chunk(src_stream, dst_stream, file_entry->size);
 191                                         fclose(dst_stream);
 192                                 }
 193                                 break;
 194                         case S_IFDIR:
 195                                 if (stat_res != 0) {
 196                                         if (mkdir(full_name, file_entry->mode) < 0) {
 197                                                 if ((function & extract_quiet) != extract_quiet) {
 198                                                         perror_msg("extract_archive: %s", full_name);
 199                                                 }
 200                                         }
 201                                 }
 202                                 break;
 203                         case S_IFLNK:
 204                                 if (symlink(file_entry->link_name, full_name) < 0) {
 205                                         if ((function & extract_quiet) != extract_quiet) {
 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                                                 perror_msg("Cannot create node %s", file_entry->name);
 218                                         }
 219                                         goto cleanup;
 220                                 }
 221                                 break;
 222                          default:
 223                             perror_msg("Don't know how to handle %s", full_name);
 224
 225                 }
 226
 227                 /* Changing a symlink's properties normally changes the properties of the
 228                  * file pointed to, so dont try and change the date or mode, lchown does
 229                  * does the right thing, but isnt available in older versions of libc */
 230                 if (S_ISLNK(file_entry->mode)) {
 231 #if (__GLIBC__ > 2) && (__GLIBC_MINOR__ > 1)
 232                         lchown(full_name, file_entry->uid, file_entry->gid);
 233 #endif
 234                 } else {
 235                         if (function & extract_preserve_date) {
 236                                 t.actime = file_entry->mtime;
 237                                 t.modtime = file_entry->mtime;
 238                                 utime(full_name, &t);
 239                         }
 240                         chown(full_name, file_entry->uid, file_entry->gid);
 241                         chmod(full_name, file_entry->mode);
 242                 }
 243         } else {
 244                 /* If we arent extracting data we have to skip it,
 245                  * if data size is 0 then then just do it anyway
 246                  * (saves testing for it) */
 247                 seek_sub_file(src_stream, file_entry->size);
 248         }
 249
 250         /* extract_list and extract_verbose_list can be used in conjunction
 251          * with one of the above four extraction functions, so do this seperately */
 252         if (function & extract_verbose_list) {
 253                 fprintf(out_stream, "%s %d/%d %8d %s ", mode_string(file_entry->mode),
 254                         file_entry->uid, file_entry->gid,
 255                         (int) file_entry->size, time_string(file_entry->mtime));
 256         }
 257         if ((function & extract_list) || (function & extract_verbose_list)){
 258                 /* fputs doesnt add a trailing \n, so use fprintf */
 259                 fprintf(out_stream, "%s\n", file_entry->name);
 260         }
 261
 262 cleanup:
 263         free(full_name);
 264         if ( full_link_name )
 265             free(full_link_name);
 266
 267         return(buffer); /* Maybe we should say if failed */
 268 }
 269 #endif
 270
 271 #ifdef L_unarchive
 272 char *unarchive(FILE *src_stream, FILE *out_stream,
 273                 file_header_t *(*get_headers)(FILE *),
 274                 void (*free_headers)(file_header_t *),
 275                 const int extract_function, const char *prefix, const char **extract_names)
 276 {
 277         file_header_t *file_entry;
 278         int extract_flag;
 279         int i;
 280         char *buffer = NULL;
 281
 282         archive_offset = 0;
 283         while ((file_entry = get_headers(src_stream)) != NULL) {
 284                 extract_flag = TRUE;
 285                 /* fprintf(stderr, __FUNCTION__ " getting headers\n"); */
 286                 if (extract_names != NULL) {
 287                         int found_flag = FALSE;
 288                         for(i = 0; extract_names[i] != 0; i++) {
 289                                 if (strcmp(extract_names[i], file_entry->name) == 0) {
 290                                         found_flag = TRUE;
 291                                         break;
 292                                 }
 293                         }
 294                         if (extract_function & extract_exclude_list) {
 295                                 if (found_flag == TRUE) {
 296                                         extract_flag = FALSE;
 297                                 }
 298                         } else {
 299                                 /* If its not found in the include list dont extract it */
 300                                 if (found_flag == FALSE) {
 301                                         extract_flag = FALSE;
 302                                 }
 303                         }
 304
 305                 }
 306
 307                 if (extract_flag == TRUE) {
 308                         /* fprintf(stderr, __FUNCTION__ " extract?\n"); */
 309                         buffer = extract_archive(src_stream, out_stream, file_entry, extract_function, prefix);
 310                         /* fprintf(stderr, __FUNCTION__ " extracted\n"); */
 311                 } else {
 312                         /* seek past the data entry */
 313                         seek_sub_file(src_stream, file_entry->size);
 314                 }
 315                 free_headers(file_entry);
 316         }
 317         /*fprintf(stderr, __FUNCTION__ " goin home\n");*/
 318
 319         return(buffer);
 320 }
 321 #endif
 322
 323 #ifdef L_get_header_ar
 324 file_header_t *get_header_ar(FILE *src_stream)
 325 {
 326         file_header_t *typed;
 327         union {
 328                 char raw[60];
 329                 struct {
 330                         char name[16];
 331                         char date[12];
 332                         char uid[6];
 333                         char gid[6];
 334                         char mode[8];
 335                         char size[10];
 336                         char magic[2];
 337                 } formated;
 338         } ar;
 339         static char *ar_long_names;
 340
 341         if (fread(ar.raw, 1, 60, src_stream) != 60) {
 342                 return(NULL);
 343         }
 344         archive_offset += 60;
 345         /* align the headers based on the header magic */
 346         if ((ar.formated.magic[0] != '`') || (ar.formated.magic[1] != '\n')) {
 347                 /* some version of ar, have an extra '\n' after each data entry,
 348                  * this puts the next header out by 1 */
 349                 if (ar.formated.magic[1] != '`') {
 350                         error_msg("Invalid magic");
 351                         return(NULL);
 352                 }
 353                 /* read the next char out of what would be the data section,
 354                  * if its a '\n' then it is a valid header offset by 1*/
 355                 archive_offset++;
 356                 if (fgetc(src_stream) != '\n') {
 357                         error_msg("Invalid magic");
 358                         return(NULL);
 359                 }
 360                 /* fix up the header, we started reading 1 byte too early */
 361                 /* raw_header[60] wont be '\n' as it should, but it doesnt matter */
 362                 memmove(ar.raw, &ar.raw[1], 59);
 363         }
 364
 365         typed = (file_header_t *) xcalloc(1, sizeof(file_header_t));
 366
 367         typed->size = (size_t) atoi(ar.formated.size);
 368         /* long filenames have '/' as the first character */
 369         if (ar.formated.name[0] == '/') {
 370                 if (ar.formated.name[1] == '/') {
 371                         /* If the second char is a '/' then this entries data section
 372                          * stores long filename for multiple entries, they are stored
 373                          * in static variable long_names for use in future entries */
 374                         ar_long_names = (char *) xrealloc(ar_long_names, typed->size);
 375                         fread(ar_long_names, 1, typed->size, src_stream);
 376                         archive_offset += typed->size;
 377                         /* This ar entries data section only contained filenames for other records
 378                          * they are stored in the static ar_long_names for future reference */
 379                         return (get_header_ar(src_stream)); /* Return next header */
 380                 } else if (ar.formated.name[1] == ' ') {
 381                         /* This is the index of symbols in the file for compilers */
 382                         seek_sub_file(src_stream, typed->size);
 383                         return (get_header_ar(src_stream)); /* Return next header */
 384                 } else {
 385                         /* The number after the '/' indicates the offset in the ar data section
 386                         (saved in variable long_name) that conatains the real filename */
 387                         if (!ar_long_names) {
 388                                 error_msg("Cannot resolve long file name");
 389                                 return (NULL);
 390                         }
 391                         typed->name = xstrdup(ar_long_names + atoi(&ar.formated.name[1]));
 392                 }
 393         } else {
 394                 /* short filenames */
 395                 typed->name = xcalloc(1, 16);
 396                 strncpy(typed->name, ar.formated.name, 16);
 397         }
 398         typed->name[strcspn(typed->name, " /")]='\0';
 399
 400         /* convert the rest of the now valid char header to its typed struct */
 401         parse_mode(ar.formated.mode, &typed->mode);
 402         typed->mtime = atoi(ar.formated.date);
 403         typed->uid = atoi(ar.formated.uid);
 404         typed->gid = atoi(ar.formated.gid);
 405
 406         return(typed);
 407 }
 408
 409 void free_header_ar(file_header_t *ar_entry)
 410 {
 411     if (ar_entry == NULL) {
 412         return;
 413     }
 414
 415     free(ar_entry->name);
 416     free(ar_entry->link_name);
 417
 418     free(ar_entry);
 419 }
 420 #endif
 421
 422 #ifdef L_get_header_tar
 423 file_header_t *get_header_tar(FILE *tar_stream)
 424 {
 425
 426         union {
 427                 unsigned char raw[512];
 428                 struct {
 429                         char name[100];         /*   0-99 */
 430                         char mode[8];           /* 100-107 */
 431                         char uid[8];            /* 108-115 */
 432                         char gid[8];            /* 116-123 */
 433                         char size[12];          /* 124-135 */
 434                         char mtime[12];         /* 136-147 */
 435                         char chksum[8];         /* 148-155 */
 436                         char typeflag;          /* 156-156 */
 437                         char linkname[100];     /* 157-256 */
 438                         char magic[6];          /* 257-262 */
 439                         char version[2];        /* 263-264 */
 440                         char uname[32];         /* 265-296 */
 441                         char gname[32];         /* 297-328 */
 442                         char devmajor[8];       /* 329-336 */
 443                         char devminor[8];       /* 337-344 */
 444                         char prefix[155];       /* 345-499 */
 445                         char padding[12];       /* 500-512 */
 446                 } formated;
 447         } tar;
 448         file_header_t *tar_entry = NULL;
 449         long i;
 450         long sum = 0;
 451
 452         if (archive_offset % 512 != 0) {
 453                 seek_sub_file(tar_stream, 512 - (archive_offset % 512));
 454         }
 455
 456         if (fread(tar.raw, 1, 512, tar_stream) != 512) {
 457                 /* Unfortunatly its common for tar files to have all sorts of
 458                  * trailing garbage, fail silently */
 459 //              error_msg("Couldnt read header");
 460                 return(NULL);
 461         }
 462         archive_offset += 512;
 463
 464         /* Check header has valid magic, unfortunately some tar files
 465          * have empty (0'ed) tar entries at the end, which will
 466          * cause this to fail, so fail silently for now
 467          */
 468         if (strncmp(tar.formated.magic, "ustar", 5) != 0) {
 469 #ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATABILITY
 470                 if (strncmp(tar.formated.magic, "\0\0\0\0\0", 5) != 0)
 471 #endif
 472                 return(NULL);
 473         }
 474
 475         /* Do checksum on headers */
 476         for (i =  0; i < 148 ; i++) {
 477                 sum += tar.raw[i];
 478         }
 479         sum += ' ' * 8;
 480         for (i =  156; i < 512 ; i++) {
 481                 sum += tar.raw[i];
 482         }
 483         if (sum != strtol(tar.formated.chksum, NULL, 8)) {
 484                 if ( strtol(tar.formated.chksum,NULL,8) != 0 )
 485                         error_msg("Invalid tar header checksum");
 486                 return(NULL);
 487         }
 488
 489         /* convert to type'ed variables */
 490         tar_entry = xcalloc(1, sizeof(file_header_t));
 491
 492 #ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
 493         if (longname) {
 494                 tar_entry->name = longname;
 495                 longname = NULL;
 496         }
 497         else if (linkname) {
 498                 tar_entry->name = linkname;
 499                 linkname = NULL;
 500         } else
 501 #endif
 502         {
 503                 tar_entry->name = xstrndup(tar.formated.name, 100);
 504
 505                 if (tar.formated.prefix[0]) {
 506                         char *temp = tar_entry->name;
 507                         char *prefixTemp = xstrndup(tar.formated.prefix, 155);
 508                         tar_entry->name = concat_path_file(prefixTemp, temp);
 509                         free(temp);
 510                         free(prefixTemp);
 511                 }
 512         }
 513
 514         // tar_entry->name = xstrdup(tar.formated.name);
 515
 516 /*
 517         parse_mode(tar.formated.mode, &tar_entry->mode);
 518 */
 519         tar_entry->mode = 07777 & strtol(tar.formated.mode, NULL, 8);
 520
 521         tar_entry->uid   = strtol(tar.formated.uid, NULL, 8);
 522         tar_entry->gid   = strtol(tar.formated.gid, NULL, 8);
 523         tar_entry->size  = strtol(tar.formated.size, NULL, 8);
 524         tar_entry->mtime = strtol(tar.formated.mtime, NULL, 8);
 525         tar_entry->link_name  = *tar.formated.linkname != '\0' ? xstrndup(tar.formated.linkname, 100) : NULL;
 526         tar_entry->device = (strtol(tar.formated.devmajor, NULL, 8) << 8) +
 527                 strtol(tar.formated.devminor, NULL, 8);
 528
 529         /* Fix mode, used by the old format */
 530         switch (tar.formated.typeflag) {
 531         /* hard links are detected as regular files with 0 size and a link name */
 532         case '1':
 533                 tar_entry->mode |= S_IFREG ;
 534                 break;
 535         case 0:
 536         case '0':
 537
 538 # ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATABILITY
 539                 if (last_char_is(tar_entry->name, '/')) {
 540                         tar_entry->mode |= S_IFDIR;
 541                 } else
 542 # endif
 543                         tar_entry->mode |= S_IFREG;
 544                 break;
 545         case '2':
 546                 tar_entry->mode |= S_IFLNK;
 547                 break;
 548         case '3':
 549                 tar_entry->mode |= S_IFCHR;
 550                 break;
 551         case '4':
 552                 tar_entry->mode |= S_IFBLK;
 553                 break;
 554         case '5':
 555                 tar_entry->mode |= S_IFDIR;
 556                 break;
 557         case '6':
 558                 tar_entry->mode |= S_IFIFO;
 559                 break;
 560 # ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
 561         case 'L': {
 562                         longname = xmalloc(tar_entry->size + 1);
 563                         if(fread(longname, tar_entry->size, 1, tar_stream) != 1)
 564                                 return NULL;
 565                         longname[tar_entry->size] = '\0';
 566                         archive_offset += tar_entry->size;
 567
 568                         return(get_header_tar(tar_stream));
 569                 }
 570         case 'K': {
 571                         linkname = xmalloc(tar_entry->size + 1);
 572                         if(fread(linkname, tar_entry->size, 1, tar_stream) != 1)
 573                                 return NULL;
 574                         linkname[tar_entry->size] = '\0';
 575                         archive_offset += tar_entry->size;
 576
 577                         tar_entry->name = linkname;
 578                         return(get_header_tar(tar_stream));
 579                 }
 580         case 'D':
 581         case 'M':
 582         case 'N':
 583         case 'S':
 584         case 'V':
 585                 perror_msg("Ignoring GNU extension type %c", tar.formated.typeflag);
 586 # endif
 587         default:
 588                 perror_msg("Unknown typeflag: 0x%x", tar.formated.typeflag);
 589                 break;
 590
 591         }
 592
 593         return(tar_entry);
 594 }
 595
 596 void free_header_tar(file_header_t *tar_entry)
 597 {
 598     if (tar_entry == NULL) {
 599         return;
 600     }
 601
 602     free(tar_entry->name);
 603     free(tar_entry->link_name);
 604
 605     free(tar_entry);
 606 }
 607
 608 #endif
 609
 610 #ifdef L_deb_extract
 611 char *deb_extract(const char *package_filename, FILE *out_stream,
 612                   const int extract_function, const char *prefix, const char *filename)
 613 {
 614         FILE *deb_stream = NULL;
 615         FILE *uncompressed_stream = NULL;
 616         file_header_t *ar_header = NULL;
 617         const char **file_list = NULL;
 618         char *output_buffer = NULL;
 619         char *ared_file = NULL;
 620         char ar_magic[8];
 621         int gunzip_pid = 0;
 622
 623         if (filename != NULL) {
 624                 file_list = xmalloc(sizeof(char *) * 2);
 625                 file_list[0] = filename;
 626                 file_list[1] = NULL;
 627         }
 628
 629         if (extract_function & extract_control_tar_gz) {
 630                 ared_file = "control.tar.gz";
 631         }
 632         else if (extract_function & extract_data_tar_gz) {
 633                 ared_file = "data.tar.gz";
 634         } else {
 635                 fprintf(stderr, "no file specified to extract -- extract_function=%x\n", extract_function);
 636                 goto cleanup;
 637         }
 638
 639         /* open the debian package to be worked on */
 640         deb_stream = wfopen(package_filename, "r");
 641         if (deb_stream == NULL) {
 642                 goto cleanup;
 643         }
 644         /* set the buffer size */
 645         setvbuf(deb_stream, NULL, _IOFBF, 0x8000);
 646
 647         /* check ar magic */
 648         fread(ar_magic, 1, 8, deb_stream);
 649         /*fprintf(stderr, "deb_extract ar_magic=%08x\n", *(long *)ar_magic);*/
 650         if (strncmp(ar_magic,"!<arch>",7) == 0) {
 651                 archive_offset = 8;
 652
 653                 while ((ar_header = get_header_ar(deb_stream)) != NULL) {
 654                         if (strcmp(ared_file, ar_header->name) == 0) {
 655                                 /* open a stream of decompressed data */
 656                                 uncompressed_stream = gz_open(deb_stream, &gunzip_pid);
 657                                 if (uncompressed_stream == NULL) {
 658                                         goto cleanup;
 659                                 }
 660
 661                                 archive_offset = 0;
 662                                 output_buffer = unarchive(uncompressed_stream, out_stream, get_header_tar, free_header_tar, extract_function, prefix, file_list);
 663                         }
 664                         seek_sub_file(deb_stream, ar_header->size);
 665                         free (ar_header->name);
 666                         free (ar_header);
 667                 }
 668                 gz_close(gunzip_pid);
 669                 fclose(uncompressed_stream);
 670                 goto cleanup;
 671         } else if (strncmp(ar_magic, "\037\213", 2) == 0) {
 672                 /* it's a gz file, let's assume it's an opkg */
 673                 int unzipped_opkg_pid;
 674                 FILE *unzipped_opkg_stream;
 675                 file_header_t *tar_header;
 676                 archive_offset = 0;
 677                 fseek(deb_stream, 0, SEEK_SET);
 678                 unzipped_opkg_stream = gz_open(deb_stream, &unzipped_opkg_pid);
 679                 if (unzipped_opkg_stream == NULL) {
 680                         goto cleanup;
 681                 }
 682
 683                 /*fprintf(stderr, __FUNCTION__ ": processing opkg %s -- ared_file=%s\n", package_filename, ared_file);*/
 684                 /* walk through outer tar file to find ared_file */
 685                 while ((tar_header = get_header_tar(unzipped_opkg_stream)) != NULL) {
 686                         int name_offset = 0;
 687                         if (strncmp(tar_header->name, "./", 2) == 0)
 688                                 name_offset = 2;
 689                         if (strcmp(ared_file, tar_header->name+name_offset) == 0) {
 690                                 /* open a stream of decompressed data */
 691                                 uncompressed_stream = gz_open(unzipped_opkg_stream, &gunzip_pid);
 692                                 if (uncompressed_stream == NULL) {
 693                                         goto cleanup;
 694                                 }
 695                                 archive_offset = 0;
 696                                 /*fprintf(stderr, __FUNCTION__ ":%d: here -- found file\n", __LINE__);*/
 697                                 output_buffer = unarchive(uncompressed_stream,
 698                                                           out_stream,
 699                                                           get_header_tar,
 700                                                           free_header_tar,
 701                                                           extract_function,
 702                                                           prefix,
 703                                                           file_list);
 704                                 /*fprintf(stderr, __FUNCTION__ ":%d: unarchive complete\n", __LINE__);*/
 705                                 free_header_tar(tar_header);
 706                                 gz_close(gunzip_pid);
 707                                 fclose(uncompressed_stream);
 708                                 break;
 709                         }
 710                         seek_sub_file(unzipped_opkg_stream, tar_header->size);
 711                         free_header_tar(tar_header);
 712                 }
 713                 gz_close(unzipped_opkg_pid);
 714                 fclose(unzipped_opkg_stream);
 715                 /*fprintf(stderr, __FUNCTION__ ":%d: done\n", __LINE__);*/
 716                 goto cleanup;
 717         } else {
 718                 error_msg_and_die("invalid magic");
 719         }
 720
 721 cleanup:
 722         if (deb_stream)
 723                 fclose(deb_stream);
 724         if (file_list)
 725                 free(file_list);
 726
 727         return output_buffer;
 728 }
 729 #endif