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 *fd, const int count)
  65 {
  66         archive_offset += count;
  67
  68         /* Do not use fseek() on a pipe. It may fail with ESPIPE, leaving the
  69          * stream at an undefined location.
  70          */
  71         seek_by_read(fd, count);
  72
  73         return;
  74 }
  75
  76
  77 /* Extract the data postioned at src_stream to either filesystem, stdout or
  78  * buffer depending on the value of 'function' which is defined in libbb.h
  79  *
  80  * prefix doesnt have to be just a directory, it may prefix the filename as well.
  81  *
  82  * e.g. '/var/lib/dpkg/info/dpkg.' will extract all files to the base bath
  83  * '/var/lib/dpkg/info/' and all files/dirs created in that dir will have
  84  * 'dpkg.' as their prefix
  85  *
  86  * For this reason if prefix does point to a dir then it must end with a
  87  * trailing '/' or else the last dir will be assumed to be the file prefix
  88  */
  89 static char *
  90 extract_archive(FILE *src_stream, FILE *out_stream,
  91                 const file_header_t *file_entry, const int function,
  92                 const char *prefix,
  93                 int *err)
  94 {
  95         FILE *dst_stream = NULL;
  96         char *full_name = NULL;
  97         char *full_link_name = NULL;
  98         char *buffer = NULL;
  99         struct utimbuf t;
 100
 101         *err = 0;
 102
 103         /* prefix doesnt have to be a proper path it may prepend
 104          * the filename as well */
 105         if (prefix != NULL) {
 106                 /* strip leading '/' in filename to extract as prefix may not be dir */
 107                 /* Cant use concat_path_file here as prefix might not be a directory */
 108                 char *path = file_entry->name;
 109                 if (strncmp("./", path, 2) == 0) {
 110                         path += 2;
 111                         if (strlen(path) == 0)
 112                                 /* Do nothing, current dir already exists. */
 113                                 return NULL;
 114                 }
 115                 full_name = xmalloc(strlen(prefix) + strlen(path) + 1);
 116                 strcpy(full_name, prefix);
 117                 strcat(full_name, path);
 118                 if ( file_entry->link_name ){
 119                    full_link_name = xmalloc(strlen(prefix) + strlen(file_entry->link_name) + 1);
 120                    strcpy(full_link_name, prefix);
 121                    strcat(full_link_name, file_entry->link_name);
 122                 }
 123         } else {
 124                 full_name = xstrdup(file_entry->name);
 125                 if ( file_entry->link_name )
 126                    full_link_name = xstrdup(file_entry->link_name);
 127         }
 128
 129
 130         if (function & extract_to_stream) {
 131                 if (S_ISREG(file_entry->mode)) {
 132                         *err = copy_file_chunk(src_stream, out_stream, file_entry->size);
 133                         archive_offset += file_entry->size;
 134                 }
 135         }
 136         else if (function & extract_one_to_buffer) {
 137                 if (S_ISREG(file_entry->mode)) {
 138                         buffer = (char *) xmalloc(file_entry->size + 1);
 139                         fread(buffer, 1, file_entry->size, src_stream);
 140                         buffer[file_entry->size] = '\0';
 141                         archive_offset += file_entry->size;
 142                         goto cleanup;
 143                 }
 144         }
 145         else if (function & extract_all_to_fs) {
 146                 struct stat oldfile;
 147                 int stat_res;
 148                 stat_res = lstat (full_name, &oldfile);
 149                 if (stat_res == 0) { /* The file already exists */
 150                         if ((function & extract_unconditional) || (oldfile.st_mtime < file_entry->mtime)) {
 151                                 if (!S_ISDIR(oldfile.st_mode)) {
 152                                         unlink(full_name); /* Directories might not be empty etc */
 153                                 }
 154                         } else {
 155                                 if ((function & extract_quiet) != extract_quiet) {
 156                                         *err = -1;
 157                                         error_msg("%s not created: newer or same age file exists", file_entry->name);
 158                                 }
 159                                 seek_sub_file(src_stream, file_entry->size);
 160                                 goto cleanup;
 161                         }
 162                 }
 163                 if (function & extract_create_leading_dirs) { /* Create leading directories with default umask */
 164                         char *buf, *parent;
 165                         buf = xstrdup(full_name);
 166                         parent = dirname(buf);
 167                         if (make_directory (parent, -1, FILEUTILS_RECUR) != 0) {
 168                                 if ((function & extract_quiet) != extract_quiet) {
 169                                         *err = -1;
 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                                                         *err = -1;
 181                                                         perror_msg("Cannot link from %s to '%s'",
 182                                                                 file_entry->name, file_entry->link_name);
 183                                                 }
 184                                         }
 185                                 } else {
 186                                         if ((dst_stream = wfopen(full_name, "w")) == NULL) {
 187                                                 *err = -1;
 188                                                 seek_sub_file(src_stream, file_entry->size);
 189                                                 goto cleanup;
 190                                         }
 191                                         archive_offset += file_entry->size;
 192                                         *err = copy_file_chunk(src_stream, dst_stream, file_entry->size);
 193                                         fclose(dst_stream);
 194                                 }
 195                                 break;
 196                         case S_IFDIR:
 197                                 if (stat_res != 0) {
 198                                         if (mkdir(full_name, file_entry->mode) < 0) {
 199                                                 if ((function & extract_quiet) != extract_quiet) {
 200                                                         *err = -1;
 201                                                         perror_msg("Cannot make dir %s", full_name);
 202                                                 }
 203                                         }
 204                                 }
 205                                 break;
 206                         case S_IFLNK:
 207                                 if (symlink(file_entry->link_name, full_name) < 0) {
 208                                         if ((function & extract_quiet) != extract_quiet) {
 209                                                 *err = -1;
 210                                                 perror_msg("Cannot create symlink from %s to '%s'", file_entry->name, file_entry->link_name);
 211                                         }
 212                                         goto cleanup;
 213                                 }
 214                                 break;
 215                         case S_IFSOCK:
 216                         case S_IFBLK:
 217                         case S_IFCHR:
 218                         case S_IFIFO:
 219                                 if (mknod(full_name, file_entry->mode, file_entry->device) == -1) {
 220                                         if ((function & extract_quiet) != extract_quiet) {
 221                                                 *err = -1;
 222                                                 perror_msg("Cannot create node %s", file_entry->name);
 223                                         }
 224                                         goto cleanup;
 225                                 }
 226                                 break;
 227                          default:
 228                                 *err = -1;
 229                                 perror_msg("Don't know how to handle %s", full_name);
 230
 231                 }
 232
 233                 /* Changing a symlink's properties normally changes the properties of the
 234                  * file pointed to, so dont try and change the date or mode, lchown does
 235                  * does the right thing, but isnt available in older versions of libc */
 236                 if (S_ISLNK(file_entry->mode)) {
 237 #if (__GLIBC__ > 2) && (__GLIBC_MINOR__ > 1)
 238                         lchown(full_name, file_entry->uid, file_entry->gid);
 239 #endif
 240                 } else {
 241                         if (function & extract_preserve_date) {
 242                                 t.actime = file_entry->mtime;
 243                                 t.modtime = file_entry->mtime;
 244                                 utime(full_name, &t);
 245                         }
 246                         chown(full_name, file_entry->uid, file_entry->gid);
 247                         chmod(full_name, file_entry->mode);
 248                 }
 249         } else {
 250                 /* If we arent extracting data we have to skip it,
 251                  * if data size is 0 then then just do it anyway
 252                  * (saves testing for it) */
 253                 seek_sub_file(src_stream, file_entry->size);
 254         }
 255
 256         /* extract_list and extract_verbose_list can be used in conjunction
 257          * with one of the above four extraction functions, so do this seperately */
 258         if (function & extract_verbose_list) {
 259                 fprintf(out_stream, "%s %d/%d %8d %s ", mode_string(file_entry->mode),
 260                         file_entry->uid, file_entry->gid,
 261                         (int) file_entry->size, time_string(file_entry->mtime));
 262         }
 263         if ((function & extract_list) || (function & extract_verbose_list)){
 264                 /* fputs doesnt add a trailing \n, so use fprintf */
 265                 fprintf(out_stream, "%s\n", file_entry->name);
 266         }
 267
 268 cleanup:
 269         free(full_name);
 270         if ( full_link_name )
 271             free(full_link_name);
 272
 273         return buffer;
 274 }
 275
 276 static char *
 277 unarchive(FILE *src_stream, FILE *out_stream,
 278                 file_header_t *(*get_headers)(FILE *),
 279                 void (*free_headers)(file_header_t *),
 280                 const int extract_function,
 281                 const char *prefix,
 282                 const char **extract_names,
 283                 int *err)
 284 {
 285         file_header_t *file_entry;
 286         int extract_flag;
 287         int i;
 288         char *buffer = NULL;
 289
 290         *err = 0;
 291
 292         archive_offset = 0;
 293         while ((file_entry = get_headers(src_stream)) != NULL) {
 294                 extract_flag = TRUE;
 295
 296                 if (extract_names != NULL) {
 297                         int found_flag = FALSE;
 298                         for(i = 0; extract_names[i] != 0; i++) {
 299                                 if (strcmp(extract_names[i], file_entry->name) == 0) {
 300                                         found_flag = TRUE;
 301                                         break;
 302                                 }
 303                         }
 304                         if (extract_function & extract_exclude_list) {
 305                                 if (found_flag == TRUE) {
 306                                         extract_flag = FALSE;
 307                                 }
 308                         } else {
 309                                 /* If its not found in the include list dont extract it */
 310                                 if (found_flag == FALSE) {
 311                                         extract_flag = FALSE;
 312                                 }
 313                         }
 314                 }
 315
 316                 if (extract_flag == TRUE) {
 317                         buffer = extract_archive(src_stream, out_stream,
 318                                         file_entry, extract_function,
 319                                         prefix, err);
 320                         *err = 0; /* XXX: ignore extraction errors */
 321                         if (*err) {
 322                                 free_headers(file_entry);
 323                                 break;
 324                         }
 325                 } else {
 326                         /* seek past the data entry */
 327                         seek_sub_file(src_stream, file_entry->size);
 328                 }
 329                 free_headers(file_entry);
 330         }
 331
 332         return buffer;
 333 }
 334
 335 static file_header_t *
 336 get_header_ar(FILE *src_stream)
 337 {
 338         file_header_t *typed;
 339         union {
 340                 char raw[60];
 341                 struct {
 342                         char name[16];
 343                         char date[12];
 344                         char uid[6];
 345                         char gid[6];
 346                         char mode[8];
 347                         char size[10];
 348                         char magic[2];
 349                 } formated;
 350         } ar;
 351         static char *ar_long_names;
 352
 353         if (fread(ar.raw, 1, 60, src_stream) != 60) {
 354                 return(NULL);
 355         }
 356         archive_offset += 60;
 357         /* align the headers based on the header magic */
 358         if ((ar.formated.magic[0] != '`') || (ar.formated.magic[1] != '\n')) {
 359                 /* some version of ar, have an extra '\n' after each data entry,
 360                  * this puts the next header out by 1 */
 361                 if (ar.formated.magic[1] != '`') {
 362                         error_msg("Invalid magic");
 363                         return(NULL);
 364                 }
 365                 /* read the next char out of what would be the data section,
 366                  * if its a '\n' then it is a valid header offset by 1*/
 367                 archive_offset++;
 368                 if (fgetc(src_stream) != '\n') {
 369                         error_msg("Invalid magic");
 370                         return(NULL);
 371                 }
 372                 /* fix up the header, we started reading 1 byte too early */
 373                 /* raw_header[60] wont be '\n' as it should, but it doesnt matter */
 374                 memmove(ar.raw, &ar.raw[1], 59);
 375         }
 376
 377         typed = (file_header_t *) xcalloc(1, sizeof(file_header_t));
 378
 379         typed->size = (size_t) atoi(ar.formated.size);
 380         /* long filenames have '/' as the first character */
 381         if (ar.formated.name[0] == '/') {
 382                 if (ar.formated.name[1] == '/') {
 383                         /* If the second char is a '/' then this entries data section
 384                          * stores long filename for multiple entries, they are stored
 385                          * in static variable long_names for use in future entries */
 386                         ar_long_names = (char *) xrealloc(ar_long_names, typed->size);
 387                         fread(ar_long_names, 1, typed->size, src_stream);
 388                         archive_offset += typed->size;
 389                         /* This ar entries data section only contained filenames for other records
 390                          * they are stored in the static ar_long_names for future reference */
 391                         return (get_header_ar(src_stream)); /* Return next header */
 392                 } else if (ar.formated.name[1] == ' ') {
 393                         /* This is the index of symbols in the file for compilers */
 394                         seek_sub_file(src_stream, typed->size);
 395                         return (get_header_ar(src_stream)); /* Return next header */
 396                 } else {
 397                         /* The number after the '/' indicates the offset in the ar data section
 398                         (saved in variable long_name) that conatains the real filename */
 399                         if (!ar_long_names) {
 400                                 error_msg("Cannot resolve long file name");
 401                                 return (NULL);
 402                         }
 403                         typed->name = xstrdup(ar_long_names + atoi(&ar.formated.name[1]));
 404                 }
 405         } else {
 406                 /* short filenames */
 407                 typed->name = xcalloc(1, 16);
 408                 strncpy(typed->name, ar.formated.name, 16);
 409         }
 410         typed->name[strcspn(typed->name, " /")]='\0';
 411
 412         /* convert the rest of the now valid char header to its typed struct */
 413         parse_mode(ar.formated.mode, &typed->mode);
 414         typed->mtime = atoi(ar.formated.date);
 415         typed->uid = atoi(ar.formated.uid);
 416         typed->gid = atoi(ar.formated.gid);
 417
 418         return(typed);
 419 }
 420
 421 static void
 422 free_header_ar(file_header_t *ar_entry)
 423 {
 424         if (ar_entry == NULL)
 425                 return;
 426
 427         free(ar_entry->name);
 428         if (ar_entry->link_name)
 429                 free(ar_entry->link_name);
 430
 431         free(ar_entry);
 432 }
 433
 434
 435 static file_header_t *
 436 get_header_tar(FILE *tar_stream)
 437 {
 438         union {
 439                 unsigned char raw[512];
 440                 struct {
 441                         char name[100];         /*   0-99 */
 442                         char mode[8];           /* 100-107 */
 443                         char uid[8];            /* 108-115 */
 444                         char gid[8];            /* 116-123 */
 445                         char size[12];          /* 124-135 */
 446                         char mtime[12];         /* 136-147 */
 447                         char chksum[8];         /* 148-155 */
 448                         char typeflag;          /* 156-156 */
 449                         char linkname[100];     /* 157-256 */
 450                         char magic[6];          /* 257-262 */
 451                         char version[2];        /* 263-264 */
 452                         char uname[32];         /* 265-296 */
 453                         char gname[32];         /* 297-328 */
 454                         char devmajor[8];       /* 329-336 */
 455                         char devminor[8];       /* 337-344 */
 456                         char prefix[155];       /* 345-499 */
 457                         char padding[12];       /* 500-512 */
 458                 } formated;
 459         } tar;
 460         file_header_t *tar_entry = NULL;
 461         long i;
 462         long sum = 0;
 463
 464         if (archive_offset % 512 != 0) {
 465                 seek_sub_file(tar_stream, 512 - (archive_offset % 512));
 466         }
 467
 468         if (fread(tar.raw, 1, 512, tar_stream) != 512) {
 469                 /* Unfortunately its common for tar files to have all sorts of
 470                  * trailing garbage, fail silently */
 471 //              error_msg("Couldnt read header");
 472                 return(NULL);
 473         }
 474         archive_offset += 512;
 475
 476         /* Check header has valid magic, unfortunately some tar files
 477          * have empty (0'ed) tar entries at the end, which will
 478          * cause this to fail, so fail silently for now
 479          */
 480         if (strncmp(tar.formated.magic, "ustar", 5) != 0) {
 481 #ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATABILITY
 482                 if (strncmp(tar.formated.magic, "\0\0\0\0\0", 5) != 0)
 483 #endif
 484                 return(NULL);
 485         }
 486
 487         /* Do checksum on headers */
 488         for (i =  0; i < 148 ; i++) {
 489                 sum += tar.raw[i];
 490         }
 491         sum += ' ' * 8;
 492         for (i =  156; i < 512 ; i++) {
 493                 sum += tar.raw[i];
 494         }
 495         if (sum != strtol(tar.formated.chksum, NULL, 8)) {
 496                 if ( strtol(tar.formated.chksum,NULL,8) != 0 )
 497                         error_msg("Invalid tar header checksum");
 498                 return(NULL);
 499         }
 500
 501         /* convert to type'ed variables */
 502         tar_entry = xcalloc(1, sizeof(file_header_t));
 503
 504 #ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
 505         if (longname) {
 506                 tar_entry->name = longname;
 507                 longname = 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 #ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
 534         if (linkname) {
 535                 tar_entry->link_name = linkname;
 536                 linkname = NULL;
 537         } else
 538 #endif
 539         {
 540                 tar_entry->link_name = *tar.formated.linkname != '\0' ?
 541                         xstrndup(tar.formated.linkname, 100) : NULL;
 542         }
 543         tar_entry->device = (strtol(tar.formated.devmajor, NULL, 8) << 8) +
 544                 strtol(tar.formated.devminor, NULL, 8);
 545
 546         /* Fix mode, used by the old format */
 547         switch (tar.formated.typeflag) {
 548         /* hard links are detected as regular files with 0 size and a link name */
 549         case '1':
 550                 tar_entry->mode |= S_IFREG ;
 551                 break;
 552         case 0:
 553         case '0':
 554
 555 # ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATABILITY
 556                 if (last_char_is(tar_entry->name, '/')) {
 557                         tar_entry->mode |= S_IFDIR;
 558                 } else
 559 # endif
 560                         tar_entry->mode |= S_IFREG;
 561                 break;
 562         case '2':
 563                 tar_entry->mode |= S_IFLNK;
 564                 break;
 565         case '3':
 566                 tar_entry->mode |= S_IFCHR;
 567                 break;
 568         case '4':
 569                 tar_entry->mode |= S_IFBLK;
 570                 break;
 571         case '5':
 572                 tar_entry->mode |= S_IFDIR;
 573                 break;
 574         case '6':
 575                 tar_entry->mode |= S_IFIFO;
 576                 break;
 577 # ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
 578         case 'L': {
 579                         longname = xmalloc(tar_entry->size + 1);
 580                         if(fread(longname, tar_entry->size, 1, tar_stream) != 1)
 581                                 return NULL;
 582                         longname[tar_entry->size] = '\0';
 583                         archive_offset += tar_entry->size;
 584
 585                         return(get_header_tar(tar_stream));
 586                 }
 587         case 'K': {
 588                         linkname = xmalloc(tar_entry->size + 1);
 589                         if(fread(linkname, tar_entry->size, 1, tar_stream) != 1)
 590                                 return NULL;
 591                         linkname[tar_entry->size] = '\0';
 592                         archive_offset += tar_entry->size;
 593
 594                         return(get_header_tar(tar_stream));
 595                 }
 596         case 'D':
 597         case 'M':
 598         case 'N':
 599         case 'S':
 600         case 'V':
 601                 perror_msg("Ignoring GNU extension type %c", tar.formated.typeflag);
 602 # endif
 603         default:
 604                 perror_msg("Unknown typeflag: 0x%x", tar.formated.typeflag);
 605                 break;
 606
 607         }
 608
 609         return(tar_entry);
 610 }
 611
 612 static void
 613 free_header_tar(file_header_t *tar_entry)
 614 {
 615         if (tar_entry == NULL)
 616                 return;
 617
 618         free(tar_entry->name);
 619         if (tar_entry->link_name);
 620                 free(tar_entry->link_name);
 621
 622         free(tar_entry);
 623 }
 624
 625 char *
 626 deb_extract(const char *package_filename, FILE *out_stream,
 627         const int extract_function, const char *prefix,
 628         const char *filename, int *err)
 629 {
 630         FILE *deb_stream = NULL;
 631         file_header_t *ar_header = NULL;
 632         const char **file_list = NULL;
 633         char *output_buffer = NULL;
 634         char *ared_file = NULL;
 635         char ar_magic[8];
 636         int gz_err;
 637
 638         *err = 0;
 639
 640         if (filename != NULL) {
 641                 file_list = xmalloc(sizeof(char *) * 2);
 642                 file_list[0] = filename;
 643                 file_list[1] = NULL;
 644         }
 645
 646         if (extract_function & extract_control_tar_gz) {
 647                 ared_file = "control.tar.gz";
 648         }
 649         else if (extract_function & extract_data_tar_gz) {
 650                 ared_file = "data.tar.gz";
 651         } else {
 652                 opkg_msg(ERROR, "Internal error: extract_function=%x\n",
 653                                 extract_function);
 654                 *err = -1;
 655                 goto cleanup;
 656         }
 657
 658         /* open the debian package to be worked on */
 659         deb_stream = wfopen(package_filename, "r");
 660         if (deb_stream == NULL) {
 661                 *err = -1;
 662                 goto cleanup;
 663         }
 664         /* set the buffer size */
 665         setvbuf(deb_stream, NULL, _IOFBF, 0x8000);
 666
 667         /* check ar magic */
 668         fread(ar_magic, 1, 8, deb_stream);
 669
 670         if (strncmp(ar_magic,"!<arch>",7) == 0) {
 671                 archive_offset = 8;
 672
 673                 while ((ar_header = get_header_ar(deb_stream)) != NULL) {
 674                         if (strcmp(ared_file, ar_header->name) == 0) {
 675                                 int gunzip_pid = 0;
 676                                 FILE *uncompressed_stream;
 677                                 /* open a stream of decompressed data */
 678                                 uncompressed_stream = gz_open(deb_stream, &gunzip_pid);
 679                                 if (uncompressed_stream == NULL) {
 680                                         *err = -1;
 681                                         goto cleanup;
 682                                 }
 683
 684                                 archive_offset = 0;
 685                                 output_buffer = unarchive(uncompressed_stream,
 686                                                 out_stream, get_header_tar,
 687                                                 free_header_tar,
 688                                                 extract_function, prefix,
 689                                                 file_list, err);
 690                                 fclose(uncompressed_stream);
 691                                 gz_err = gz_close(gunzip_pid);
 692                                 if (gz_err)
 693                                         *err = -1;
 694                                 free_header_ar(ar_header);
 695                                 break;
 696                         }
 697                         if (fseek(deb_stream, ar_header->size, SEEK_CUR) == -1) {
 698                                 opkg_perror(ERROR, "Couldn't fseek into %s", package_filename);
 699                                 *err = -1;
 700                                 free_header_ar(ar_header);
 701                                 goto cleanup;
 702                         }
 703                         free_header_ar(ar_header);
 704                 }
 705                 goto cleanup;
 706         } else if (strncmp(ar_magic, "\037\213", 2) == 0) {
 707                 /* it's a gz file, let's assume it's an opkg */
 708                 int unzipped_opkg_pid;
 709                 FILE *unzipped_opkg_stream;
 710                 file_header_t *tar_header;
 711                 archive_offset = 0;
 712                 if (fseek(deb_stream, 0, SEEK_SET) == -1) {
 713                         opkg_perror(ERROR, "Couldn't fseek into %s", package_filename);
 714                         *err = -1;
 715                         goto cleanup;
 716                 }
 717                 unzipped_opkg_stream = gz_open(deb_stream, &unzipped_opkg_pid);
 718                 if (unzipped_opkg_stream == NULL) {
 719                         *err = -1;
 720                         goto cleanup;
 721                 }
 722
 723                 /* walk through outer tar file to find ared_file */
 724                 while ((tar_header = get_header_tar(unzipped_opkg_stream)) != NULL) {
 725                         int name_offset = 0;
 726                         if (strncmp(tar_header->name, "./", 2) == 0)
 727                                 name_offset = 2;
 728                         if (strcmp(ared_file, tar_header->name+name_offset) == 0) {
 729                                 int gunzip_pid = 0;
 730                                 FILE *uncompressed_stream;
 731                                 /* open a stream of decompressed data */
 732                                 uncompressed_stream = gz_open(unzipped_opkg_stream, &gunzip_pid);
 733                                 if (uncompressed_stream == NULL) {
 734                                         *err = -1;
 735                                         goto cleanup;
 736                                 }
 737                                 archive_offset = 0;
 738
 739                                 output_buffer = unarchive(uncompressed_stream,
 740                                                           out_stream,
 741                                                           get_header_tar,
 742                                                           free_header_tar,
 743                                                           extract_function,
 744                                                           prefix,
 745                                                           file_list,
 746                                                           err);
 747
 748                                 free_header_tar(tar_header);
 749                                 fclose(uncompressed_stream);
 750                                 gz_err = gz_close(gunzip_pid);
 751                                 if (gz_err)
 752                                         *err = -1;
 753                                 break;
 754                         }
 755                         seek_sub_file(unzipped_opkg_stream, tar_header->size);
 756                         free_header_tar(tar_header);
 757                 }
 758                 fclose(unzipped_opkg_stream);
 759                 gz_err = gz_close(unzipped_opkg_pid);
 760                 if (gz_err)
 761                         *err = -1;
 762
 763                 goto cleanup;
 764         } else {
 765                 *err = -1;
 766                 error_msg("%s: invalid magic", package_filename);
 767         }
 768
 769 cleanup:
 770         if (deb_stream)
 771                 fclose(deb_stream);
 772         if (file_list)
 773                 free(file_list);
 774
 775         return output_buffer;
 776 }