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 typedef struct file_headers_s {
  31         char *name;
  32         char *link_name;
  33         off_t size;
  34         uid_t uid;
  35         gid_t gid;
  36         mode_t mode;
  37         time_t mtime;
  38         dev_t device;
  39 } file_header_t;
  40
  41
  42 extern void seek_sub_file(FILE *src_stream, const int count);
  43 extern char *extract_archive(FILE *src_stream, FILE *out_stream, const file_header_t *file_entry,
  44  const int function, const char *prefix);
  45
  46
  47 #ifdef L_archive_offset
  48 off_t archive_offset;
  49 #else
  50 extern off_t archive_offset;
  51 #endif
  52
  53 #ifdef L_seek_sub_file
  54 void seek_sub_file(FILE *src_stream, const int count)
  55 {
  56         int i;
  57         /* Try to fseek as faster */
  58         archive_offset += count;
  59         if (fseek(src_stream, count, SEEK_CUR) != 0 && errno == ESPIPE) {
  60         for (i = 0; i < count; i++) {
  61                 fgetc(src_stream);
  62                 }
  63         }
  64         return;
  65 }
  66 #endif
  67
  68
  69
  70 #ifdef L_extract_archive
  71 /* Extract the data postioned at src_stream to either filesystem, stdout or
  72  * buffer depending on the value of 'function' which is defined in libbb.h
  73  *
  74  * prefix doesnt have to be just a directory, it may prefix the filename as well.
  75  *
  76  * e.g. '/var/lib/dpkg/info/dpkg.' will extract all files to the base bath
  77  * '/var/lib/dpkg/info/' and all files/dirs created in that dir will have
  78  * 'dpkg.' as their prefix
  79  *
  80  * For this reason if prefix does point to a dir then it must end with a
  81  * trailing '/' or else the last dir will be assumed to be the file prefix
  82  */
  83 char *extract_archive(FILE *src_stream, FILE *out_stream, const file_header_t *file_entry,
  84  const int function, const char *prefix)
  85 {
  86         FILE *dst_stream = NULL;
  87         char *full_name = NULL;
  88         char *buffer = NULL;
  89         struct utimbuf t;
  90
  91         /* prefix doesnt have to be a proper path it may prepend
  92          * the filename as well */
  93         if (prefix != NULL) {
  94                 /* strip leading '/' in filename to extract as prefix may not be dir */
  95                 /* Cant use concat_path_file here as prefix might not be a directory */
  96                 char *path = file_entry->name;
  97                 if (*path == '/') {
  98                         path++;
  99                 }
 100                 full_name = xmalloc(strlen(prefix) + strlen(path) + 1);
 101                 strcpy(full_name, prefix);
 102                 strcat(full_name, path);
 103         } else {
 104                 full_name = file_entry->name;
 105         }
 106
 107         if (function & extract_to_stdout) {
 108                 if (S_ISREG(file_entry->mode)) {
 109                         copy_file_chunk(src_stream, out_stream, file_entry->size);
 110                         archive_offset += file_entry->size;
 111                 }
 112         }
 113         else if (function & extract_one_to_buffer) {
 114                 if (S_ISREG(file_entry->mode)) {
 115                         buffer = (char *) xmalloc(file_entry->size + 1);
 116                         fread(buffer, 1, file_entry->size, src_stream);
 117                         archive_offset += file_entry->size;
 118                         return(buffer);
 119                 }
 120         }
 121         else if (function & extract_all_to_fs) {
 122                 struct stat oldfile;
 123                 int stat_res;
 124                 stat_res = lstat (full_name, &oldfile);
 125                 if (stat_res == 0) { /* The file already exists */
 126                         if ((function & extract_unconditional) || (oldfile.st_mtime < file_entry->mtime)) {
 127                                 if (!S_ISDIR(oldfile.st_mode)) {
 128                                         unlink(full_name); /* Directories might not be empty etc */
 129                                 }
 130                         } else {
 131                                 error_msg("%s not created: newer or same age file exists", file_entry->name);
 132                                 if (S_ISREG(file_entry->mode)) {
 133                                         seek_sub_file(src_stream, file_entry->size);
 134                                 }
 135                                 return (NULL);
 136                         }
 137                 }
 138                 switch(file_entry->mode & S_IFMT) {
 139                         case S_IFREG:
 140                                 if (file_entry->link_name) { /* Found a cpio hard link */
 141                                         if (link(file_entry->link_name, full_name) != 0) {
 142                                                 perror_msg("Cannot link from %s to '%s'",
 143                                                         file_entry->name, file_entry->link_name);
 144                                         }
 145                                 } else {
 146                                         if ((dst_stream = wfopen(full_name, "w")) == NULL) {
 147                                                 seek_sub_file(src_stream, file_entry->size);
 148                                                 return NULL;
 149                                         }
 150                                         archive_offset += file_entry->size;
 151                                         copy_file_chunk(src_stream, dst_stream, file_entry->size);
 152                                         fclose(dst_stream);
 153                                 }
 154                                 break;
 155                         case S_IFDIR:
 156                                 if ((function & extract_create_dirs) && (stat_res != 0)) {
 157                                         /* Make sure the prefix component of full_name was create
 158                                          * in applet before getting here*/
 159                                         if (mkdir(full_name, file_entry->mode) < 0) {
 160                                                 perror_msg("extract_archive: ");
 161                                         }
 162                                 }
 163                                 break;
 164                         case S_IFLNK:
 165                                 if (symlink(file_entry->link_name, full_name) < 0) {
 166                                         perror_msg("Cannot create symlink from %s to '%s'", file_entry->name, file_entry->link_name);
 167                                         return NULL;
 168                                 }
 169                                 break;
 170                         case S_IFSOCK:
 171                         case S_IFBLK:
 172                         case S_IFCHR:
 173                         case S_IFIFO:
 174                                 if (mknod(full_name, file_entry->mode, file_entry->device) == -1) {
 175                                         perror_msg("Cannot create node %s", file_entry->name);
 176                                         return NULL;
 177                                 }
 178                                 break;
 179                 }
 180
 181                 /* Changing a symlink's properties normally changes the properties of the
 182                  * file pointed to, so dont try and change the date or mode, lchown does
 183                  * does the right thing, but isnt available in older versions of libc */
 184                 if (S_ISLNK(file_entry->mode)) {
 185 #if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
 186                         lchown(full_name, file_entry->uid, file_entry->gid);
 187 #endif
 188                 } else {
 189                         if (function & extract_preserve_date) {
 190                                 t.actime = file_entry->mtime;
 191                                 t.modtime = file_entry->mtime;
 192                                 utime(full_name, &t);
 193                         }
 194                         chmod(full_name, file_entry->mode);
 195                         chown(full_name, file_entry->uid, file_entry->gid);
 196                 }
 197         } else {
 198                 /* If we arent extracting data we have to skip it,
 199                  * if data size is 0 then then just do it anyway
 200                  * (saves testing for it) */
 201                 seek_sub_file(src_stream, file_entry->size);
 202         }
 203
 204         /* extract_list and extract_verbose_list can be used in conjunction
 205          * with one of the above four extraction functions, so do this seperately */
 206         if (function & extract_verbose_list) {
 207                 fprintf(out_stream, "%s %d/%d %8d %s ", mode_string(file_entry->mode),
 208                         file_entry->uid, file_entry->gid,
 209                         (int) file_entry->size, time_string(file_entry->mtime));
 210         }
 211         if ((function & extract_list) || (function & extract_verbose_list)){
 212                 /* fputs doesnt add a trailing \n, so use fprintf */
 213                 fprintf(out_stream, "%s\n", file_entry->name);
 214         }
 215
 216         free(full_name);
 217
 218         return(NULL); /* Maybe we should say if failed */
 219 }
 220 #endif
 221
 222 #ifdef L_unarchive
 223 char *unarchive(FILE *src_stream, void *(*get_headers)(FILE *),
 224         const int extract_function, const char *prefix, char **extract_names)
 225 {
 226         file_header_t *file_entry;
 227         int found;
 228         int i;
 229         char *buffer = NULL;
 230
 231         archive_offset = 0;
 232         while ((file_entry = (file_header_t *) get_headers(src_stream)) != NULL) {
 233                 found = FALSE;
 234                 if (extract_names[0] != NULL) {
 235                         for(i = 0; extract_names[i] != 0; i++) {
 236                                 if (strcmp(extract_names[i], file_entry->name) == 0) {
 237                                         found = TRUE;
 238                                 }
 239                         }
 240                         if (!found) {
 241                                 /* seek past the data entry */
 242                                 if (!S_ISLNK(file_entry->mode) && file_entry->link_name && file_entry->size == 0) {
 243                                         error_msg("You should extract %s as other files are hardlinked to it", file_entry->name);
 244                                 }
 245                                 seek_sub_file(src_stream, file_entry->size);
 246                                 continue;
 247                         }
 248                 }
 249                 buffer = extract_archive(src_stream, stdout, file_entry, extract_function, prefix);
 250         }
 251         return(buffer);
 252 }
 253 #endif
 254
 255 #ifdef L_get_header_ar
 256 void *get_header_ar(FILE *src_stream)
 257 {
 258         file_header_t *typed;
 259         union {
 260                 char raw[60];
 261                 struct {
 262                         char name[16];
 263                         char date[12];
 264                         char uid[6];
 265                         char gid[6];
 266                         char mode[8];
 267                         char size[10];
 268                         char magic[2];
 269                 } formated;
 270         } ar;
 271         static char *ar_long_names;
 272
 273         if (fread(ar.raw, 1, 60, src_stream) != 60) {
 274                 return(NULL);
 275         }
 276         archive_offset += 60;
 277         /* align the headers based on the header magic */
 278         if ((ar.formated.magic[0] != '`') || (ar.formated.magic[1] != '\n')) {
 279                 /* some version of ar, have an extra '\n' after each data entry,
 280                  * this puts the next header out by 1 */
 281                 if (ar.formated.magic[1] != '`') {
 282                         error_msg("Invalid magic");
 283                         return(NULL);
 284                 }
 285                 /* read the next char out of what would be the data section,
 286                  * if its a '\n' then it is a valid header offset by 1*/
 287                 archive_offset++;
 288                 if (fgetc(src_stream) != '\n') {
 289                         error_msg("Invalid magic");
 290                         return(NULL);
 291                 }
 292                 /* fix up the header, we started reading 1 byte too early */
 293                 /* raw_header[60] wont be '\n' as it should, but it doesnt matter */
 294                 memmove(ar.raw, &ar.raw[1], 59);
 295         }
 296
 297         typed = (file_header_t *) xcalloc(1, sizeof(file_header_t));
 298
 299         typed->size = (size_t) atoi(ar.formated.size);
 300         /* long filenames have '/' as the first character */
 301         if (ar.formated.name[0] == '/') {
 302                 if (ar.formated.name[1] == '/') {
 303                         /* If the second char is a '/' then this entries data section
 304                          * stores long filename for multiple entries, they are stored
 305                          * in static variable long_names for use in future entries */
 306                         ar_long_names = (char *) xrealloc(ar_long_names, typed->size);
 307                         fread(ar_long_names, 1, typed->size, src_stream);
 308                         archive_offset += typed->size;
 309                         /* This ar entries data section only contained filenames for other records
 310                          * they are stored in the static ar_long_names for future reference */
 311                         return(NULL);
 312                 } else {
 313                         /* The number after the '/' indicates the offset in the ar data section
 314                         (saved in variable long_name) that conatains the real filename */
 315                         if (!ar_long_names) {
 316                                 error_msg("Cannot resolve long file name");
 317                                 return (NULL);
 318                         }
 319                         typed->name = xstrdup(ar_long_names + atoi(&ar.formated.name[1]));
 320                 }
 321         } else {
 322                 /* short filenames */
 323                 typed->name = xcalloc(1, 16);
 324                 strncpy(typed->name, ar.formated.name, 16);
 325         }
 326         typed->name[strcspn(typed->name, " /")]='\0';
 327
 328         /* convert the rest of the now valid char header to its typed struct */
 329         parse_mode(ar.formated.mode, &typed->mode);
 330         typed->mtime = atoi(ar.formated.date);
 331         typed->uid = atoi(ar.formated.uid);
 332         typed->gid = atoi(ar.formated.gid);
 333
 334         return(typed);
 335 }
 336 #endif
 337
 338 #ifdef L_get_header_cpio
 339 struct hardlinks {
 340         file_header_t *entry;
 341         int inode;
 342         struct hardlinks *next;
 343 };
 344
 345 void *get_header_cpio(FILE *src_stream)
 346 {
 347         file_header_t *cpio_entry = NULL;
 348         char cpio_header[110];
 349         int namesize;
 350         char dummy[16];
 351         int major, minor, nlink, inode;
 352         static struct hardlinks *saved_hardlinks = NULL;
 353         static int pending_hardlinks = 0;
 354
 355         if (pending_hardlinks) { /* Deal with any pending hardlinks */
 356                 struct hardlinks *tmp = saved_hardlinks, *oldtmp = NULL;
 357                 while (tmp) {
 358                         if (tmp->entry->link_name) { /* Found a hardlink ready to be extracted */
 359                                 cpio_entry = tmp->entry;
 360                                 if (oldtmp) oldtmp->next = tmp->next; /* Remove item from linked list */
 361                                 else saved_hardlinks = tmp->next;
 362                                 free(tmp);
 363                                 return (cpio_entry);
 364                         }
 365                         oldtmp = tmp;
 366                         tmp = tmp->next;
 367                 }
 368                 pending_hardlinks = 0; /* No more pending hardlinks, read next file entry */
 369         }
 370
 371         /* There can be padding before archive header */
 372         seek_sub_file(src_stream, (4 - (archive_offset % 4)) % 4);
 373         if (fread(cpio_header, 1, 110, src_stream) == 110) {
 374                 archive_offset += 110;
 375                 if (strncmp(cpio_header, "07070", 5) != 0) {
 376                         error_msg("Unsupported format or invalid magic");
 377                         return(NULL);
 378                 }
 379                 switch (cpio_header[5]) {
 380                         case '2': /* "crc" header format */
 381                                 /* Doesnt do the crc check yet */
 382                         case '1': /* "newc" header format */
 383                                 cpio_entry = (file_header_t *) xcalloc(1, sizeof(file_header_t));
 384                                 sscanf(cpio_header, "%6c%8x%8x%8x%8x%8x%8lx%8lx%16c%8x%8x%8x%8c",
 385                                         dummy, &inode, &cpio_entry->mode, &cpio_entry->uid, &cpio_entry->gid,
 386                                         &nlink, &cpio_entry->mtime, &cpio_entry->size,
 387                                         dummy, &major, &minor, &namesize, dummy);
 388
 389                                 cpio_entry->name = (char *) xcalloc(1, namesize);
 390                                 fread(cpio_entry->name, 1, namesize, src_stream); /* Read in filename */
 391                                 archive_offset += namesize;
 392                                 /* Skip padding before file contents */
 393                                 seek_sub_file(src_stream, (4 - (archive_offset % 4)) % 4);
 394                                 if (strcmp(cpio_entry->name, "TRAILER!!!") == 0) {
 395                                         printf("%d blocks\n", (int) (archive_offset % 512 ? (archive_offset / 512) + 1 : archive_offset / 512)); /* Always round up */
 396                                         if (saved_hardlinks) { /* Bummer - we still have unresolved hardlinks */
 397                                                 struct hardlinks *tmp = saved_hardlinks, *oldtmp = NULL;
 398                                                 while (tmp) {
 399                                                         error_msg("%s not created: cannot resolve hardlink", tmp->entry->name);
 400                                                         oldtmp = tmp;
 401                                                         tmp = tmp->next;
 402                                                         free (oldtmp->entry->name);
 403                                                         free (oldtmp->entry);
 404                                                         free (oldtmp);
 405                                                 }
 406                                                 saved_hardlinks = NULL;
 407                                                 pending_hardlinks = 0;
 408                                         }
 409                                         return(NULL);
 410                                 }
 411
 412                                 if (S_ISLNK(cpio_entry->mode)) {
 413                                         cpio_entry->link_name = (char *) xcalloc(1, cpio_entry->size + 1);
 414                                         fread(cpio_entry->link_name, 1, cpio_entry->size, src_stream);
 415                                         archive_offset += cpio_entry->size;
 416                                 }
 417                                 if (nlink > 1 && !S_ISDIR(cpio_entry->mode)) {
 418                                         if (cpio_entry->size == 0) { /* Put file on a linked list for later */
 419                                                 struct hardlinks *new = xmalloc(sizeof(struct hardlinks));
 420                                                 new->next = saved_hardlinks;
 421                                                 new->inode = inode;
 422                                                 new->entry = cpio_entry;
 423                                                 saved_hardlinks = new;
 424                                         return(get_header_cpio(src_stream)); /* Recurse to next file */
 425                                         } else { /* Found the file with data in */
 426                                                 struct hardlinks *tmp = saved_hardlinks;
 427                                                 pending_hardlinks = 1;
 428                                                 while (tmp) {
 429                                                         if (tmp->inode == inode) {
 430                                                                 tmp->entry->link_name = xstrdup(cpio_entry->name);
 431                                                                 nlink--;
 432                                                         }
 433                                                         tmp = tmp->next;
 434                                                 }
 435                                                 if (nlink > 1) error_msg("error resolving hardlink: did you create the archive with GNU cpio 2.0-2.2?");
 436                                         }
 437                                 }
 438                                 cpio_entry->device = (major << 8) | minor;
 439                                 break;
 440                         default:
 441                                 error_msg("Unsupported format");
 442                                 return(NULL);
 443                 }
 444                 if (ferror(src_stream) || feof(src_stream)) {
 445                         perror_msg("Stream error");
 446                         return(NULL);
 447                 }
 448         }
 449         return(cpio_entry);
 450 }
 451 #endif
 452
 453 #ifdef L_get_header_tar
 454 void *get_header_tar(FILE *tar_stream)
 455 {
 456         union {
 457                 unsigned char raw[512];
 458                 struct {
 459                         char name[100];         /*   0-99 */
 460                         char mode[8];           /* 100-107 */
 461                         char uid[8];            /* 108-115 */
 462                         char gid[8];            /* 116-123 */
 463                         char size[12];          /* 124-135 */
 464                         char mtime[12];         /* 136-147 */
 465                         char chksum[8];         /* 148-155 */
 466                         char typeflag;          /* 156-156 */
 467                         char linkname[100];     /* 157-256 */
 468                         char magic[6];          /* 257-262 */
 469                         char version[2];        /* 263-264 */
 470                         char uname[32];         /* 265-296 */
 471                         char gname[32];         /* 297-328 */
 472                         char devmajor[8];       /* 329-336 */
 473                         char devminor[8];       /* 337-344 */
 474                         char prefix[155];       /* 345-499 */
 475                         char padding[12];       /* 500-512 */
 476                 } formated;
 477         } tar;
 478         file_header_t *tar_entry = NULL;
 479         long i;
 480         long sum = 0;
 481
 482         if (archive_offset % 512 != 0) {
 483                 seek_sub_file(tar_stream, 512 - (archive_offset % 512));
 484         }
 485
 486         if (fread(tar.raw, 1, 512, tar_stream) != 512) {
 487                 error_msg("Couldnt read header");
 488                 return(NULL);
 489         }
 490         archive_offset += 512;
 491
 492         /* Check header has valid magic, unfortunately some tar files
 493          * have empty (0'ed) tar entries at the end, which will
 494          * cause this to fail, so fail silently for now
 495          */
 496         if (strncmp(tar.formated.magic, "ustar", 5) != 0) {
 497                 return(NULL);
 498         }
 499
 500         /* Do checksum on headers */
 501         for (i =  0; i < 148 ; i++) {
 502                 sum += tar.raw[i];
 503         }
 504         sum += ' ' * 8;
 505         for (i =  156; i < 512 ; i++) {
 506                 sum += tar.raw[i];
 507         }
 508         if (sum != strtol(tar.formated.chksum, NULL, 8)) {
 509                 error_msg("Invalid tar header checksum");
 510                 return(NULL);
 511         }
 512
 513         /* convert to type'ed variables */
 514         tar_entry = xcalloc(1, sizeof(file_header_t));
 515         tar_entry->name = xstrdup(tar.formated.name);
 516
 517         parse_mode(tar.formated.mode, &tar_entry->mode);
 518         tar_entry->uid   = strtol(tar.formated.uid, NULL, 8);
 519         tar_entry->gid   = strtol(tar.formated.gid, NULL, 8);
 520         tar_entry->size  = strtol(tar.formated.size, NULL, 8);
 521         tar_entry->mtime = strtol(tar.formated.mtime, NULL, 8);
 522         tar_entry->link_name  = strlen(tar.formated.linkname) ? xstrdup(tar.formated.linkname) : NULL;
 523         tar_entry->device = (strtol(tar.formated.devmajor, NULL, 8) << 8) +
 524                 strtol(tar.formated.devminor, NULL, 8);
 525
 526         return(tar_entry);
 527 }
 528 #endif
 529
 530 #ifdef L_deb_extract
 531 char *deb_extract(const char *package_filename, FILE *out_stream, const int extract_function,
 532         const char *prefix, const char *filename)
 533 {
 534         FILE *deb_stream;
 535         FILE *uncompressed_stream = NULL;
 536         file_header_t *ar_header = NULL;
 537         char *output_buffer = NULL;
 538         char *ared_file = NULL;
 539         char ar_magic[8];
 540         char **file_list;
 541         int gunzip_pid;
 542
 543         file_list = malloc(sizeof(char *));
 544         file_list[0] = xstrdup(filename);
 545         file_list[1] = NULL;
 546
 547         if (extract_function & extract_control_tar_gz) {
 548                 ared_file = xstrdup("control.tar.gz");
 549         }
 550         else if (extract_function & extract_data_tar_gz) {
 551                 ared_file = xstrdup("data.tar.gz");
 552         }
 553
 554         /* open the debian package to be worked on */
 555         deb_stream = wfopen(package_filename, "r");
 556
 557         /* check ar magic */
 558         fread(ar_magic, 1, 8, deb_stream);
 559         if (strncmp(ar_magic,"!<arch>",7) != 0) {
 560                 error_msg_and_die("invalid magic");
 561         }
 562         archive_offset = 8;
 563
 564         while ((ar_header = get_header_ar(deb_stream)) != NULL) {
 565                 if (strcmp(ared_file, ar_header->name) == 0) {
 566                         /* open a stream of decompressed data */
 567                         uncompressed_stream = gz_open(deb_stream, &gunzip_pid);
 568                         archive_offset = 0;
 569                         output_buffer = unarchive(uncompressed_stream, get_header_tar, extract_function, prefix, file_list);
 570                 }
 571                 seek_sub_file(deb_stream, ar_header->size);
 572         }
 573         gz_close(gunzip_pid);
 574         fclose(deb_stream);
 575         fclose(uncompressed_stream);
 576         free(ared_file);
 577         return(output_buffer);
 578 }
 579 #endif