tar.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini tar implementation for busybox
   4  *
   5  * Note, that as of BusyBox-0.43, tar has been completely rewritten from the
   6  * ground up.  It still has remnents of the old code lying about, but it is
   7  * very different now (i.e. cleaner, less global variables, etc)
   8  *
   9  * Copyright (C) 2000 by Lineo, inc.
  10  * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
  11  *
  12  * Based in part in the tar implementation in sash
  13  *  Copyright (c) 1999 by David I. Bell
  14  *  Permission is granted to use, distribute, or modify this source,
  15  *  provided that this copyright notice remains intact.
  16  *  Permission to distribute sash derived code under the GPL has been granted.
  17  *
  18  * Based in part on the tar implementation from busybox-0.28
  19  *  Copyright (C) 1995 Bruce Perens
  20  *  This is free software under the GNU General Public License.
  21  *
  22  * This program is free software; you can redistribute it and/or modify
  23  * it under the terms of the GNU General Public License as published by
  24  * the Free Software Foundation; either version 2 of the License, or
  25  * (at your option) any later version.
  26  *
  27  * This program is distributed in the hope that it will be useful,
  28  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  29  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  30  * General Public License for more details.
  31  *
  32  * You should have received a copy of the GNU General Public License
  33  * along with this program; if not, write to the Free Software
  34  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  35  *
  36  */
  37
  38
  39 #include "busybox.h"
  40 #define BB_DECLARE_EXTERN
  41 #define bb_need_io_error
  42 #define bb_need_name_longer_than_foo
  43 #include "messages.c"
  44 #include <stdio.h>
  45 #include <dirent.h>
  46 #include <errno.h>
  47 #include <fcntl.h>
  48 #include <signal.h>
  49 #include <time.h>
  50 #include <utime.h>
  51 #include <sys/types.h>
  52 #include <sys/sysmacros.h>
  53 #include <getopt.h>
  54 #include <fnmatch.h>
  55
  56 #ifdef BB_FEATURE_TAR_GZIP
  57 extern int unzip(int in, int out);
  58 extern int gunzip_init();
  59 #endif
  60
  61 /* Tar file constants  */
  62 #ifndef MAJOR
  63 #define MAJOR(dev) (((dev)>>8)&0xff)
  64 #define MINOR(dev) ((dev)&0xff)
  65 #endif
  66
  67 #define NAME_SIZE       100
  68
  69 /* POSIX tar Header Block, from POSIX 1003.1-1990  */
  70 struct TarHeader
  71 {
  72                                 /* byte offset */
  73         char name[NAME_SIZE];         /*   0-99 */
  74         char mode[8];                 /* 100-107 */
  75         char uid[8];                  /* 108-115 */
  76         char gid[8];                  /* 116-123 */
  77         char size[12];                /* 124-135 */
  78         char mtime[12];               /* 136-147 */
  79         char chksum[8];               /* 148-155 */
  80         char typeflag;                /* 156-156 */
  81         char linkname[NAME_SIZE];     /* 157-256 */
  82         char magic[6];                /* 257-262 */
  83         char version[2];              /* 263-264 */
  84         char uname[32];               /* 265-296 */
  85         char gname[32];               /* 297-328 */
  86         char devmajor[8];             /* 329-336 */
  87         char devminor[8];             /* 337-344 */
  88         char prefix[155];             /* 345-499 */
  89         char padding[12];             /* 500-512 (pad to exactly the TAR_BLOCK_SIZE) */
  90 };
  91 typedef struct TarHeader TarHeader;
  92
  93
  94 /* A few useful constants */
  95 #define TAR_MAGIC          "ustar"        /* ustar and a null */
  96 #define TAR_VERSION        "  "           /* Be compatable with GNU tar format */
  97 #define TAR_MAGIC_LEN       6
  98 #define TAR_VERSION_LEN     2
  99 #define TAR_BLOCK_SIZE      512
 100
 101 /* A nice enum with all the possible tar file content types */
 102 enum TarFileType
 103 {
 104         REGTYPE  = '0',            /* regular file */
 105         REGTYPE0 = '\0',           /* regular file (ancient bug compat)*/
 106         LNKTYPE  = '1',            /* hard link */
 107         SYMTYPE  = '2',            /* symbolic link */
 108         CHRTYPE  = '3',            /* character special */
 109         BLKTYPE  = '4',            /* block special */
 110         DIRTYPE  = '5',            /* directory */
 111         FIFOTYPE = '6',            /* FIFO special */
 112         CONTTYPE = '7',            /* reserved */
 113         GNULONGLINK = 'K',         /* GNU long (>100 chars) link name */
 114         GNULONGNAME = 'L',         /* GNU long (>100 chars) file name */
 115 };
 116 typedef enum TarFileType TarFileType;
 117
 118 /* This struct ignores magic, non-numeric user name,
 119  * non-numeric group name, and the checksum, since
 120  * these are all ignored by BusyBox tar. */
 121 struct TarInfo
 122 {
 123         int              tarFd;          /* An open file descriptor for reading from the tarball */
 124         char *           name;           /* File name */
 125         mode_t           mode;           /* Unix mode, including device bits. */
 126         uid_t            uid;            /* Numeric UID */
 127         gid_t            gid;            /* Numeric GID */
 128         size_t           size;           /* Size of file */
 129         time_t           mtime;          /* Last-modified time */
 130         enum TarFileType type;           /* Regular, directory, link, etc */
 131         char *           linkname;       /* Name for symbolic and hard links */
 132         long             devmajor;       /* Major number for special device */
 133         long             devminor;       /* Minor number for special device */
 134 };
 135 typedef struct TarInfo TarInfo;
 136
 137 /* Local procedures to restore files from a tar file.  */
 138 extern int readTarFile(int tarFd, int extractFlag, int listFlag,
 139                 int tostdoutFlag, int verboseFlag, char** extractList,
 140                 char** excludeList);
 141
 142 #ifdef BB_FEATURE_TAR_CREATE
 143 /* Local procedures to save files into a tar file.  */
 144 static int writeTarFile(const char* tarName, int verboseFlag, char **argv,
 145                 char** excludeList);
 146 #endif
 147
 148 #ifdef BB_FEATURE_TAR_GZIP
 149 /* Signal handler for when child gzip process dies...  */
 150 void child_died()
 151 {
 152         fflush(stdout);
 153         fflush(stderr);
 154         exit(EXIT_FAILURE);
 155 }
 156
 157 extern int tar_unzip_init(int tarFd)
 158 {
 159         int child_pid;
 160         static int unzip_pipe[2];
 161         /* Cope if child dies... Otherwise we block forever in read()... */
 162         signal(SIGCHLD, child_died);
 163
 164         if (pipe(unzip_pipe)!=0)
 165                 error_msg_and_die("pipe error\n");
 166
 167         if ( (child_pid = fork()) == -1)
 168                 error_msg_and_die("fork failure\n");
 169
 170         if (child_pid==0) {
 171                 /* child process */
 172                 close(unzip_pipe[0]);
 173                 gunzip_init();
 174                 unzip(tarFd, unzip_pipe[1]);
 175                 exit(EXIT_SUCCESS);
 176         }
 177         else {
 178                 /* return fd of uncompressed data to parent process */
 179                 close(unzip_pipe[1]);
 180                 return(unzip_pipe[0]);
 181         }
 182 }
 183 #endif
 184
 185 extern int tar_main(int argc, char **argv)
 186 {
 187         char** excludeList=NULL;
 188         char** extractList=NULL;
 189         const char *tarName="-";
 190 #if defined BB_FEATURE_TAR_EXCLUDE
 191         int excludeListSize=0;
 192         char *excludeFileName ="-";
 193         FILE *fileList;
 194         char file[256];
 195 #endif
 196 #if defined BB_FEATURE_TAR_GZIP
 197         int unzipFlag    = FALSE;
 198 #endif
 199         int listFlag     = FALSE;
 200         int extractFlag  = FALSE;
 201         int createFlag   = FALSE;
 202         int verboseFlag  = FALSE;
 203         int tostdoutFlag = FALSE;
 204         int status       = FALSE;
 205         int firstOpt     = TRUE;
 206         int stopIt;
 207
 208         if (argc <= 1)
 209                 usage(tar_usage);
 210
 211         while (*(++argv) && (**argv == '-' || firstOpt == TRUE)) {
 212                 firstOpt=FALSE;
 213                 stopIt=FALSE;
 214                 while (stopIt==FALSE && **argv) {
 215                         switch (*((*argv)++)) {
 216                                 case 'c':
 217                                         if (extractFlag == TRUE || listFlag == TRUE)
 218                                                 goto flagError;
 219                                         createFlag = TRUE;
 220                                         break;
 221                                 case 'x':
 222                                         if (listFlag == TRUE || createFlag == TRUE)
 223                                                 goto flagError;
 224                                         extractFlag = TRUE;
 225                                         break;
 226                                 case 't':
 227                                         if (extractFlag == TRUE || createFlag == TRUE)
 228                                                 goto flagError;
 229                                         listFlag = TRUE;
 230                                         break;
 231 #ifdef BB_FEATURE_TAR_GZIP
 232                                 case 'z':
 233                                         unzipFlag = TRUE;
 234                                         break;
 235 #endif
 236                                 case 'v':
 237                                         verboseFlag = TRUE;
 238                                         break;
 239                                 case 'O':
 240                                         tostdoutFlag = TRUE;
 241                                         break;
 242                                 case 'f':
 243                                         if (*tarName != '-')
 244                                                 error_msg_and_die( "Only one 'f' option allowed\n");
 245                                         tarName = *(++argv);
 246                                         if (tarName == NULL)
 247                                                 error_msg_and_die( "Option requires an argument: No file specified\n");
 248                                         stopIt=TRUE;
 249                                         break;
 250 #if defined BB_FEATURE_TAR_EXCLUDE
 251                                 case 'e':
 252                                         if (strcmp(*argv, "xclude")==0) {
 253                                                 excludeList=xrealloc( excludeList,
 254                                                                 sizeof(char *) * (excludeListSize+2));
 255                                                 excludeList[excludeListSize] = *(++argv);
 256                                                 if (excludeList[excludeListSize] == NULL)
 257                                                         error_msg_and_die( "Option requires an argument: No file specified\n");
 258                                                 /* Tack a NULL onto the end of the list */
 259                                                 excludeList[++excludeListSize] = NULL;
 260                                                 stopIt=TRUE;
 261                                                 break;
 262                                         }
 263                                 case 'X':
 264                                         if (*excludeFileName != '-')
 265                                                 error_msg_and_die("Only one 'X' option allowed\n");
 266                                         excludeFileName = *(++argv);
 267                                         if (excludeFileName == NULL)
 268                                                 error_msg_and_die("Option requires an argument: No file specified\n");
 269                                         fileList = fopen (excludeFileName, "r");
 270                                         if (! fileList)
 271                                                 error_msg_and_die("Exclude file: file not found\n");
 272                                         while (fgets(file, sizeof(file), fileList) != NULL) {
 273                                                 excludeList = xrealloc(excludeList,
 274                                                                 sizeof(char *) * (excludeListSize+2));
 275                                                 if (file[strlen(file)-1] == '\n')
 276                                                         file[strlen(file)-1] = '\0';
 277                                                 excludeList[excludeListSize] = xstrdup(file);
 278                                                 /* Tack a NULL onto the end of the list */
 279                                                 excludeList[++excludeListSize] = NULL;
 280                                         }
 281                                         fclose(fileList);
 282                                         stopIt=TRUE;
 283                                         break;
 284 #endif
 285                                 case '-':
 286                                                 break;
 287                                 default:
 288                                         usage(tar_usage);
 289                         }
 290                 }
 291         }
 292
 293         /*
 294          * Do the correct type of action supplying the rest of the
 295          * command line arguments as the list of files to process.
 296          */
 297         if (createFlag == TRUE) {
 298 #ifndef BB_FEATURE_TAR_CREATE
 299                 error_msg_and_die( "This version of tar was not compiled with tar creation support.\n");
 300 #else
 301 #ifdef BB_FEATURE_TAR_GZIP
 302                 if (unzipFlag==TRUE)
 303                         error_msg_and_die("Creation of compressed not internally support by tar, pipe to busybox gunzip\n");
 304 #endif
 305                 status = writeTarFile(tarName, verboseFlag, argv, excludeList);
 306 #endif
 307         }
 308         if (listFlag == TRUE || extractFlag == TRUE) {
 309                 int tarFd;
 310                 if (*argv)
 311                         extractList = argv;
 312                 /* Open the tar file for reading.  */
 313                 if (!strcmp(tarName, "-"))
 314                         tarFd = fileno(stdin);
 315                 else
 316                         tarFd = open(tarName, O_RDONLY);
 317                 if (tarFd < 0)
 318                         perror_msg_and_die("Error opening '%s'", tarName);
 319
 320 #ifdef BB_FEATURE_TAR_GZIP
 321                 /* unzip tarFd in a seperate process */
 322                 if (unzipFlag == TRUE)
 323                         tarFd = tar_unzip_init(tarFd);
 324 #endif
 325                 status = readTarFile(tarFd, extractFlag, listFlag, tostdoutFlag,
 326                                         verboseFlag, extractList, excludeList);
 327         }
 328
 329         if (status == TRUE)
 330                 return EXIT_SUCCESS;
 331         else
 332                 return EXIT_FAILURE;
 333
 334   flagError:
 335         error_msg_and_die( "Exactly one of 'c', 'x' or 't' must be specified\n");
 336 }
 337
 338 static void
 339 fixUpPermissions(TarInfo *header)
 340 {
 341         struct utimbuf t;
 342         /* Now set permissions etc for the new file */
 343         chown(header->name, header->uid, header->gid);
 344         chmod(header->name, header->mode);
 345         /* Reset the time */
 346         t.actime = time(0);
 347         t.modtime = header->mtime;
 348         utime(header->name, &t);
 349 }
 350
 351 static int
 352 tarExtractRegularFile(TarInfo *header, int extractFlag, int tostdoutFlag)
 353 {
 354         size_t  writeSize;
 355         size_t  readSize;
 356         size_t  actualWriteSz;
 357         char    buffer[BUFSIZ];
 358         size_t  size = header->size;
 359         int outFd=fileno(stdout);
 360
 361         /* Open the file to be written, if a file is supposed to be written */
 362         if (extractFlag==TRUE && tostdoutFlag==FALSE) {
 363                 /* Create the path to the file, just in case it isn't there...
 364                  * This should not screw up path permissions or anything. */
 365                 create_path(header->name, 0777);
 366                 if ((outFd=open(header->name, O_CREAT|O_TRUNC|O_WRONLY,
 367                                                 header->mode & ~S_IFMT)) < 0) {
 368                         error_msg(io_error, header->name, strerror(errno));
 369                         return( FALSE);
 370                 }
 371         }
 372
 373         /* Write out the file, if we are supposed to be doing that */
 374         while ( size > 0 ) {
 375                 actualWriteSz=0;
 376                 if ( size > sizeof(buffer) )
 377                         writeSize = readSize = sizeof(buffer);
 378                 else {
 379                         int mod = size % 512;
 380                         if ( mod != 0 )
 381                                 readSize = size + (512 - mod);
 382                         else
 383                                 readSize = size;
 384                         writeSize = size;
 385                 }
 386                 if ( (readSize = full_read(header->tarFd, buffer, readSize)) <= 0 ) {
 387                         /* Tarball seems to have a problem */
 388                         error_msg("Unexpected EOF in archive\n");
 389                         return( FALSE);
 390                 }
 391                 if ( readSize < writeSize )
 392                         writeSize = readSize;
 393
 394                 /* Write out the file, if we are supposed to be doing that */
 395                 if (extractFlag==TRUE) {
 396
 397                         if ((actualWriteSz=full_write(outFd, buffer, writeSize)) != writeSize ) {
 398                                 /* Output file seems to have a problem */
 399                                 error_msg(io_error, header->name, strerror(errno));
 400                                 return( FALSE);
 401                         }
 402                 } else {
 403                         actualWriteSz=writeSize;
 404                 }
 405
 406                 size -= actualWriteSz;
 407         }
 408
 409         /* Now we are done writing the file out, so try
 410          * and fix up the permissions and whatnot */
 411         if (extractFlag==TRUE && tostdoutFlag==FALSE) {
 412                 close(outFd);
 413                 fixUpPermissions(header);
 414         }
 415         return( TRUE);
 416 }
 417
 418 static int
 419 tarExtractDirectory(TarInfo *header, int extractFlag, int tostdoutFlag)
 420 {
 421
 422         if (extractFlag==FALSE || tostdoutFlag==TRUE)
 423                 return( TRUE);
 424
 425         if (create_path(header->name, header->mode) != TRUE) {
 426                 perror_msg("%s: Cannot mkdir", header->name);
 427                 return( FALSE);
 428         }
 429         /* make the final component, just in case it was
 430          * omitted by create_path() (which will skip the
 431          * directory if it doesn't have a terminating '/') */
 432         if (mkdir(header->name, header->mode) < 0 && errno != EEXIST) {
 433                 perror_msg("%s", header->name);
 434                 return FALSE;
 435         }
 436
 437         fixUpPermissions(header);
 438         return( TRUE);
 439 }
 440
 441 static int
 442 tarExtractHardLink(TarInfo *header, int extractFlag, int tostdoutFlag)
 443 {
 444         if (extractFlag==FALSE || tostdoutFlag==TRUE)
 445                 return( TRUE);
 446
 447         if (link(header->linkname, header->name) < 0) {
 448                 perror_msg("%s: Cannot create hard link to '%s'", header->name,
 449                                 header->linkname);
 450                 return( FALSE);
 451         }
 452
 453         /* Now set permissions etc for the new directory */
 454         fixUpPermissions(header);
 455         return( TRUE);
 456 }
 457
 458 static int
 459 tarExtractSymLink(TarInfo *header, int extractFlag, int tostdoutFlag)
 460 {
 461         if (extractFlag==FALSE || tostdoutFlag==TRUE)
 462                 return( TRUE);
 463
 464 #ifdef  S_ISLNK
 465         if (symlink(header->linkname, header->name) < 0) {
 466                 perror_msg("%s: Cannot create symlink to '%s'", header->name,
 467                                 header->linkname);
 468                 return( FALSE);
 469         }
 470         /* Try to change ownership of the symlink.
 471          * If libs doesn't support that, don't bother.
 472          * Changing the pointed-to-file is the Wrong Thing(tm).
 473          */
 474 #if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
 475         lchown(header->name, header->uid, header->gid);
 476 #endif
 477
 478         /* Do not change permissions or date on symlink,
 479          * since it changes the pointed to file instead.  duh. */
 480 #else
 481         error_msg("%s: Cannot create symlink to '%s': %s\n",
 482                         header->name, header->linkname,
 483                         "symlinks not supported");
 484 #endif
 485         return( TRUE);
 486 }
 487
 488 static int
 489 tarExtractSpecial(TarInfo *header, int extractFlag, int tostdoutFlag)
 490 {
 491         if (extractFlag==FALSE || tostdoutFlag==TRUE)
 492                 return( TRUE);
 493
 494         if (S_ISCHR(header->mode) || S_ISBLK(header->mode) || S_ISSOCK(header->mode)) {
 495                 if (mknod(header->name, header->mode, makedev(header->devmajor, header->devminor)) < 0) {
 496                         perror_msg("%s: Cannot mknod", header->name);
 497                         return( FALSE);
 498                 }
 499         } else if (S_ISFIFO(header->mode)) {
 500                 if (mkfifo(header->name, header->mode) < 0) {
 501                         perror_msg("%s: Cannot mkfifo", header->name);
 502                         return( FALSE);
 503                 }
 504         }
 505
 506         /* Now set permissions etc for the new directory */
 507         fixUpPermissions(header);
 508         return( TRUE);
 509 }
 510
 511 /* Read an octal value in a field of the specified width, with optional
 512  * spaces on both sides of the number and with an optional null character
 513  * at the end.  Returns -1 on an illegal format.  */
 514 static long getOctal(const char *cp, int size)
 515 {
 516         long val = 0;
 517
 518         for(;(size > 0) && (*cp == ' '); cp++, size--);
 519         if ((size == 0) || !is_octal(*cp))
 520                 return -1;
 521         for(; (size > 0) && is_octal(*cp); size--) {
 522                 val = val * 8 + *cp++ - '0';
 523         }
 524         for (;(size > 0) && (*cp == ' '); cp++, size--);
 525         if ((size > 0) && *cp)
 526                 return -1;
 527         return val;
 528 }
 529
 530
 531 /* Parse the tar header and fill in the nice struct with the details */
 532 static int
 533 readTarHeader(struct TarHeader *rawHeader, struct TarInfo *header)
 534 {
 535         int i;
 536         long chksum, sum=0;
 537         unsigned char *s = (unsigned char *)rawHeader;
 538
 539         header->name  = rawHeader->name;
 540         /* Check for and relativify any absolute paths */
 541         if ( *(header->name) == '/' ) {
 542                 static int alreadyWarned=FALSE;
 543
 544                 while (*(header->name) == '/')
 545                         ++*(header->name);
 546
 547                 if (alreadyWarned == FALSE) {
 548                         error_msg("Removing leading '/' from member names\n");
 549                         alreadyWarned = TRUE;
 550                 }
 551         }
 552
 553         header->mode  = getOctal(rawHeader->mode, sizeof(rawHeader->mode));
 554         header->uid   =  getOctal(rawHeader->uid, sizeof(rawHeader->uid));
 555         header->gid   =  getOctal(rawHeader->gid, sizeof(rawHeader->gid));
 556         header->size  = getOctal(rawHeader->size, sizeof(rawHeader->size));
 557         header->mtime = getOctal(rawHeader->mtime, sizeof(rawHeader->mtime));
 558         chksum = getOctal(rawHeader->chksum, sizeof(rawHeader->chksum));
 559         header->type  = rawHeader->typeflag;
 560         header->linkname  = rawHeader->linkname;
 561         header->devmajor  = getOctal(rawHeader->devmajor, sizeof(rawHeader->devmajor));
 562         header->devminor  = getOctal(rawHeader->devminor, sizeof(rawHeader->devminor));
 563
 564         /* Check the checksum */
 565         for (i = sizeof(*rawHeader); i-- != 0;) {
 566                 sum += *s++;
 567         }
 568         /* Remove the effects of the checksum field (replace
 569          * with blanks for the purposes of the checksum) */
 570         s = rawHeader->chksum;
 571         for (i = sizeof(rawHeader->chksum) ; i-- != 0;) {
 572                 sum -= *s++;
 573         }
 574         sum += ' ' * sizeof(rawHeader->chksum);
 575         if (sum == chksum )
 576                 return ( TRUE);
 577         return( FALSE);
 578 }
 579
 580 int exclude_file(char **excluded_files, const char *file)
 581 {
 582         int i;
 583
 584         if (excluded_files == NULL)
 585                 return 0;
 586
 587         for (i = 0; excluded_files[i] != NULL; i++) {
 588                 if (excluded_files[i][0] == '/') {
 589                         if (fnmatch(excluded_files[i], file,
 590                                                 FNM_PATHNAME | FNM_LEADING_DIR) == 0)
 591                                 return 1;
 592                 } else {
 593                         const char *p;
 594
 595                         for (p = file; p[0] != '\0'; p++) {
 596                                 if ((p == file || p[-1] == '/') && p[0] != '/' &&
 597                                                 fnmatch(excluded_files[i], p,
 598                                                         FNM_PATHNAME | FNM_LEADING_DIR) == 0)
 599                                         return 1;
 600                         }
 601                 }
 602         }
 603
 604         return 0;
 605 }
 606
 607 int extract_file(char **extract_files, const char *file)
 608 {
 609         int i;
 610
 611         if (extract_files == NULL)
 612                 return 1;
 613
 614         for (i = 0; extract_files[i] != NULL; i++) {
 615                 if (fnmatch(extract_files[i], file, FNM_LEADING_DIR) == 0)
 616                         return 1;
 617         }
 618
 619         return 0;
 620 }
 621
 622 /*
 623  * Read a tar file and extract or list the specified files within it.
 624  * If the list is empty than all files are extracted or listed.
 625  */
 626 extern int readTarFile(int tarFd, int extractFlag, int listFlag,
 627                 int tostdoutFlag, int verboseFlag, char** extractList,
 628                 char** excludeList)
 629 {
 630         int status;
 631         int errorFlag=FALSE;
 632         int skipNextHeaderFlag=FALSE;
 633         TarHeader rawHeader;
 634         TarInfo header;
 635
 636         /* Set the umask for this process so it doesn't
 637          * screw up permission setting for us later. */
 638         umask(0);
 639
 640         /* Read the tar file, and iterate over it one file at a time */
 641         while ( (status = full_read(tarFd, (char*)&rawHeader, TAR_BLOCK_SIZE)) == TAR_BLOCK_SIZE ) {
 642
 643                 /* Try to read the header */
 644                 if ( readTarHeader(&rawHeader, &header) == FALSE ) {
 645                         if ( *(header.name) == '\0' ) {
 646                                 goto endgame;
 647                         } else {
 648                                 errorFlag=TRUE;
 649                                 error_msg("Bad tar header, skipping\n");
 650                                 continue;
 651                         }
 652                 }
 653                 if ( *(header.name) == '\0' )
 654                                 goto endgame;
 655                 header.tarFd = tarFd;
 656
 657                 /* Skip funky extra GNU headers that precede long files */
 658                 if ( (header.type == GNULONGNAME) || (header.type == GNULONGLINK) ) {
 659                         skipNextHeaderFlag=TRUE;
 660                         if (tarExtractRegularFile(&header, FALSE, FALSE) == FALSE)
 661                                 errorFlag = TRUE;
 662                         continue;
 663                 }
 664                 if ( skipNextHeaderFlag == TRUE ) {
 665                         skipNextHeaderFlag=FALSE;
 666                         error_msg(name_longer_than_foo, NAME_SIZE);
 667                         if (tarExtractRegularFile(&header, FALSE, FALSE) == FALSE)
 668                                 errorFlag = TRUE;
 669                         continue;
 670                 }
 671
 672 #if defined BB_FEATURE_TAR_EXCLUDE
 673                 if (exclude_file(excludeList, header.name)) {
 674                         /* There are not the droids you're looking for, move along */
 675                         /* If it is a regular file, pretend to extract it with
 676                          * the extractFlag set to FALSE, so the junk in the tarball
 677                          * is properly skipped over */
 678                         if ( header.type==REGTYPE || header.type==REGTYPE0 ) {
 679                                 if (tarExtractRegularFile(&header, FALSE, FALSE) == FALSE)
 680                                         errorFlag = TRUE;
 681                         }
 682                         continue;
 683                 }
 684 #endif
 685
 686                 if (!extract_file(extractList, header.name)) {
 687                         /* There are not the droids you're looking for, move along */
 688                         /* If it is a regular file, pretend to extract it with
 689                          * the extractFlag set to FALSE, so the junk in the tarball
 690                          * is properly skipped over */
 691                         if ( header.type==REGTYPE || header.type==REGTYPE0 ) {
 692                                 if (tarExtractRegularFile(&header, FALSE, FALSE) == FALSE)
 693                                         errorFlag = TRUE;
 694                         }
 695                         continue;
 696                 }
 697
 698                 if (listFlag == TRUE) {
 699                         /* Special treatment if the list (-t) flag is on */
 700                         if (verboseFlag == TRUE) {
 701                                 int len, len1;
 702                                 char buf[35];
 703                                 struct tm *tm = localtime (&(header.mtime));
 704
 705                                 len=printf("%s ", mode_string(header.mode));
 706                                 my_getpwuid(buf, header.uid);
 707                                 if (! *buf)
 708                                         len+=printf("%d", header.uid);
 709                                 else
 710                                         len+=printf("%s", buf);
 711                                 my_getgrgid(buf, header.gid);
 712                                 if (! *buf)
 713                                         len+=printf("/%-d ", header.gid);
 714                                 else
 715                                         len+=printf("/%-s ", buf);
 716
 717                                 if (header.type==CHRTYPE || header.type==BLKTYPE) {
 718                                         len1=snprintf(buf, sizeof(buf), "%ld,%-ld ",
 719                                                         header.devmajor, header.devminor);
 720                                 } else {
 721                                         len1=snprintf(buf, sizeof(buf), "%lu ", (long)header.size);
 722                                 }
 723                                 /* Jump through some hoops to make the columns match up */
 724                                 for(;(len+len1)<31;len++)
 725                                         printf(" ");
 726                                 printf(buf);
 727
 728                                 /* Use ISO 8610 time format */
 729                                 if (tm) {
 730                                         printf ("%04d-%02d-%02d %02d:%02d:%02d ",
 731                                                         tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
 732                                                         tm->tm_hour, tm->tm_min, tm->tm_sec);
 733                                 }
 734                         }
 735                         printf("%s", header.name);
 736                         if (verboseFlag == TRUE) {
 737                                 if (header.type==LNKTYPE)       /* If this is a link, say so */
 738                                         printf(" link to %s", header.linkname);
 739                                 else if (header.type==SYMTYPE)
 740                                         printf(" -> %s", header.linkname);
 741                         }
 742                         printf("\n");
 743                 }
 744
 745                 /* List contents if we are supposed to do that */
 746                 if (verboseFlag == TRUE && extractFlag == TRUE) {
 747                         /* Now the normal listing */
 748                         FILE *vbFd = stdout;
 749                         if (tostdoutFlag == TRUE)       // If the archive goes to stdout, verbose to stderr
 750                                 vbFd = stderr;
 751                         fprintf(vbFd, "%s\n", header.name);
 752                 }
 753
 754                 /* Remove files if we would overwrite them */
 755                 if (extractFlag == TRUE && tostdoutFlag == FALSE)
 756                         unlink(header.name);
 757
 758                 /* If we got here, we can be certain we have a legitimate
 759                  * header to work with.  So work with it.  */
 760                 switch ( header.type ) {
 761                         case REGTYPE:
 762                         case REGTYPE0:
 763                                 /* If the name ends in a '/' then assume it is
 764                                  * supposed to be a directory, and fall through */
 765                                 if (header.name[strlen(header.name)-1] != '/') {
 766                                         if (tarExtractRegularFile(&header, extractFlag, tostdoutFlag)==FALSE)
 767                                                 errorFlag=TRUE;
 768                                         break;
 769                                 }
 770                         case DIRTYPE:
 771                                 if (tarExtractDirectory( &header, extractFlag, tostdoutFlag)==FALSE)
 772                                         errorFlag=TRUE;
 773                                 break;
 774                         case LNKTYPE:
 775                                 if (tarExtractHardLink( &header, extractFlag, tostdoutFlag)==FALSE)
 776                                         errorFlag=TRUE;
 777                                 break;
 778                         case SYMTYPE:
 779                                 if (tarExtractSymLink( &header, extractFlag, tostdoutFlag)==FALSE)
 780                                         errorFlag=TRUE;
 781                                 break;
 782                         case CHRTYPE:
 783                         case BLKTYPE:
 784                         case FIFOTYPE:
 785                                 if (tarExtractSpecial( &header, extractFlag, tostdoutFlag)==FALSE)
 786                                         errorFlag=TRUE;
 787                                 break;
 788 #if 0
 789                         /* Handled earlier */
 790                         case GNULONGNAME:
 791                         case GNULONGLINK:
 792                                 skipNextHeaderFlag=TRUE;
 793                                 break;
 794 #endif
 795                         default:
 796                                 error_msg("Unknown file type '%c' in tar file\n", header.type);
 797                                 close( tarFd);
 798                                 return( FALSE);
 799                 }
 800         }
 801         close(tarFd);
 802         if (status > 0) {
 803                 /* Bummer - we read a partial header */
 804                 perror_msg("Error reading tar file");
 805                 return ( FALSE);
 806         }
 807         else if (errorFlag==TRUE) {
 808                 error_msg( "Error exit delayed from previous errors\n");
 809                 return( FALSE);
 810         } else
 811                 return( status);
 812
 813         /* Stuff to do when we are done */
 814 endgame:
 815         close( tarFd);
 816         if ( *(header.name) == '\0' ) {
 817                 if (errorFlag==TRUE)
 818                         error_msg( "Error exit delayed from previous errors\n");
 819                 else
 820                         return( TRUE);
 821         }
 822         return( FALSE);
 823 }
 824
 825
 826 #ifdef BB_FEATURE_TAR_CREATE
 827
 828 /*
 829 ** writeTarFile(),  writeFileToTarball(), and writeTarHeader() are
 830 ** the only functions that deal with the HardLinkInfo structure.
 831 ** Even these functions use the xxxHardLinkInfo() functions.
 832 */
 833 typedef struct HardLinkInfo HardLinkInfo;
 834 struct HardLinkInfo
 835 {
 836         HardLinkInfo *next;           /* Next entry in list */
 837         dev_t dev;                    /* Device number */
 838         ino_t ino;                    /* Inode number */
 839         short linkCount;              /* (Hard) Link Count */
 840         char name[1];                 /* Start of filename (must be last) */
 841 };
 842
 843 /* Some info to be carried along when creating a new tarball */
 844 struct TarBallInfo
 845 {
 846         char* fileName;               /* File name of the tarball */
 847         int tarFd;                    /* Open-for-write file descriptor
 848                                                                          for the tarball */
 849         struct stat statBuf;          /* Stat info for the tarball, letting
 850                                                                          us know the inode and device that the
 851                                                                          tarball lives, so we can avoid trying
 852                                                                          to include the tarball into itself */
 853         int verboseFlag;              /* Whether to print extra stuff or not */
 854         char** excludeList;           /* List of files to not include */
 855         HardLinkInfo *hlInfoHead;     /* Hard Link Tracking Information */
 856         HardLinkInfo *hlInfo;         /* Hard Link Info for the current file */
 857 };
 858 typedef struct TarBallInfo TarBallInfo;
 859
 860
 861 /* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
 862 static void
 863 addHardLinkInfo (HardLinkInfo **hlInfoHeadPtr, dev_t dev, ino_t ino,
 864                 short linkCount, const char *name)
 865 {
 866         /* Note: hlInfoHeadPtr can never be NULL! */
 867         HardLinkInfo *hlInfo;
 868
 869         hlInfo = (HardLinkInfo *)xmalloc(sizeof(HardLinkInfo)+strlen(name)+1);
 870         if (hlInfo) {
 871                 hlInfo->next = *hlInfoHeadPtr;
 872                 *hlInfoHeadPtr = hlInfo;
 873                 hlInfo->dev = dev;
 874                 hlInfo->ino = ino;
 875                 hlInfo->linkCount = linkCount;
 876                 strcpy(hlInfo->name, name);
 877         }
 878         return;
 879 }
 880
 881 static void
 882 freeHardLinkInfo (HardLinkInfo **hlInfoHeadPtr)
 883 {
 884         HardLinkInfo *hlInfo = NULL;
 885         HardLinkInfo *hlInfoNext = NULL;
 886
 887         if (hlInfoHeadPtr) {
 888                 hlInfo = *hlInfoHeadPtr;
 889                 while (hlInfo) {
 890                         hlInfoNext = hlInfo->next;
 891                         free(hlInfo);
 892                         hlInfo = hlInfoNext;
 893                 }
 894                 *hlInfoHeadPtr = NULL;
 895         }
 896         return;
 897 }
 898
 899 /* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
 900 static HardLinkInfo *
 901 findHardLinkInfo (HardLinkInfo *hlInfo, dev_t dev, ino_t ino)
 902 {
 903         while(hlInfo) {
 904                 if ((ino == hlInfo->ino) && (dev == hlInfo->dev))
 905                         break;
 906                 hlInfo = hlInfo->next;
 907         }
 908         return(hlInfo);
 909 }
 910
 911 /* Put an octal string into the specified buffer.
 912  * The number is zero and space padded and possibly null padded.
 913  * Returns TRUE if successful.  */
 914 static int putOctal (char *cp, int len, long value)
 915 {
 916         int tempLength;
 917         char tempBuffer[32];
 918         char *tempString = tempBuffer;
 919
 920         /* Create a string of the specified length with an initial space,
 921          * leading zeroes and the octal number, and a trailing null.  */
 922         sprintf (tempString, "%0*lo", len - 1, value);
 923
 924         /* If the string is too large, suppress the leading space.  */
 925         tempLength = strlen (tempString) + 1;
 926         if (tempLength > len) {
 927                 tempLength--;
 928                 tempString++;
 929         }
 930
 931         /* If the string is still too large, suppress the trailing null.  */
 932         if (tempLength > len)
 933                 tempLength--;
 934
 935         /* If the string is still too large, fail.  */
 936         if (tempLength > len)
 937                 return FALSE;
 938
 939         /* Copy the string to the field.  */
 940         memcpy (cp, tempString, len);
 941
 942         return TRUE;
 943 }
 944
 945 /* Write out a tar header for the specified file/directory/whatever */
 946 static int
 947 writeTarHeader(struct TarBallInfo *tbInfo, const char *header_name,
 948                 const char *real_name, struct stat *statbuf)
 949 {
 950         long chksum=0;
 951         struct TarHeader header;
 952         const unsigned char *cp = (const unsigned char *) &header;
 953         ssize_t size = sizeof(struct TarHeader);
 954
 955         memset( &header, 0, size);
 956
 957         strncpy(header.name, header_name, sizeof(header.name));
 958
 959         putOctal(header.mode, sizeof(header.mode), statbuf->st_mode);
 960         putOctal(header.uid, sizeof(header.uid), statbuf->st_uid);
 961         putOctal(header.gid, sizeof(header.gid), statbuf->st_gid);
 962         putOctal(header.size, sizeof(header.size), 0); /* Regular file size is handled later */
 963         putOctal(header.mtime, sizeof(header.mtime), statbuf->st_mtime);
 964         strncpy(header.magic, TAR_MAGIC TAR_VERSION,
 965                         TAR_MAGIC_LEN + TAR_VERSION_LEN );
 966
 967         /* Enter the user and group names (default to root if it fails) */
 968         my_getpwuid(header.uname, statbuf->st_uid);
 969         if (! *header.uname)
 970                 strcpy(header.uname, "root");
 971         my_getgrgid(header.gname, statbuf->st_gid);
 972         if (! *header.uname)
 973                 strcpy(header.uname, "root");
 974
 975         if (tbInfo->hlInfo) {
 976                 /* This is a hard link */
 977                 header.typeflag = LNKTYPE;
 978                 strncpy(header.linkname, tbInfo->hlInfo->name, sizeof(header.linkname));
 979         } else if (S_ISLNK(statbuf->st_mode)) {
 980                 int link_size=0;
 981                 char buffer[BUFSIZ];
 982                 header.typeflag  = SYMTYPE;
 983                 link_size = readlink(real_name, buffer, sizeof(buffer) - 1);
 984                 if ( link_size < 0) {
 985                         perror_msg("Error reading symlink '%s'", header.name);
 986                         return ( FALSE);
 987                 }
 988                 buffer[link_size] = '\0';
 989                 strncpy(header.linkname, buffer, sizeof(header.linkname));
 990         } else if (S_ISDIR(statbuf->st_mode)) {
 991                 header.typeflag  = DIRTYPE;
 992                 strncat(header.name, "/", sizeof(header.name));
 993         } else if (S_ISCHR(statbuf->st_mode)) {
 994                 header.typeflag  = CHRTYPE;
 995                 putOctal(header.devmajor, sizeof(header.devmajor), MAJOR(statbuf->st_rdev));
 996                 putOctal(header.devminor, sizeof(header.devminor), MINOR(statbuf->st_rdev));
 997         } else if (S_ISBLK(statbuf->st_mode)) {
 998                 header.typeflag  = BLKTYPE;
 999                 putOctal(header.devmajor, sizeof(header.devmajor), MAJOR(statbuf->st_rdev));
1000                 putOctal(header.devminor, sizeof(header.devminor), MINOR(statbuf->st_rdev));
1001         } else if (S_ISFIFO(statbuf->st_mode)) {
1002                 header.typeflag  = FIFOTYPE;
1003         } else if (S_ISREG(statbuf->st_mode)) {
1004                 header.typeflag  = REGTYPE;
1005                 putOctal(header.size, sizeof(header.size), statbuf->st_size);
1006         } else {
1007                 error_msg("%s: Unknown file type\n", real_name);
1008                 return ( FALSE);
1009         }
1010
1011         /* Calculate and store the checksum (i.e. the sum of all of the bytes of
1012          * the header).  The checksum field must be filled with blanks for the
1013          * calculation.  The checksum field is formatted differently from the
1014          * other fields: it has [6] digits, a null, then a space -- rather than
1015          * digits, followed by a null like the other fields... */
1016         memset(header.chksum, ' ', sizeof(header.chksum));
1017         cp = (const unsigned char *) &header;
1018         while (size-- > 0)
1019                 chksum += *cp++;
1020         putOctal(header.chksum, 7, chksum);
1021
1022         /* Now write the header out to disk */
1023         if ((size=full_write(tbInfo->tarFd, (char*)&header, sizeof(struct TarHeader))) < 0) {
1024                 error_msg(io_error, real_name, strerror(errno));
1025                 return ( FALSE);
1026         }
1027         /* Pad the header up to the tar block size */
1028         for (; size<TAR_BLOCK_SIZE; size++) {
1029                 write(tbInfo->tarFd, "\0", 1);
1030         }
1031         /* Now do the verbose thing (or not) */
1032         if (tbInfo->verboseFlag==TRUE) {
1033                 FILE *vbFd = stdout;
1034                 if (tbInfo->tarFd == fileno(stdout))    // If the archive goes to stdout, verbose to stderr
1035                         vbFd = stderr;
1036                 fprintf(vbFd, "%s\n", header.name);
1037         }
1038
1039         return ( TRUE);
1040 }
1041
1042
1043 static int writeFileToTarball(const char *fileName, struct stat *statbuf, void* userData)
1044 {
1045         struct TarBallInfo *tbInfo = (struct TarBallInfo *)userData;
1046         const char *header_name;
1047
1048         /*
1049         ** Check to see if we are dealing with a hard link.
1050         ** If so -
1051         ** Treat the first occurance of a given dev/inode as a file while
1052         ** treating any additional occurances as hard links.  This is done
1053         ** by adding the file information to the HardLinkInfo linked list.
1054         */
1055         tbInfo->hlInfo = NULL;
1056         if (statbuf->st_nlink > 1) {
1057                 tbInfo->hlInfo = findHardLinkInfo(tbInfo->hlInfoHead, statbuf->st_dev,
1058                                 statbuf->st_ino);
1059                 if (tbInfo->hlInfo == NULL)
1060                         addHardLinkInfo (&tbInfo->hlInfoHead, statbuf->st_dev,
1061                                         statbuf->st_ino, statbuf->st_nlink, fileName);
1062         }
1063
1064         /* It is against the rules to archive a socket */
1065         if (S_ISSOCK(statbuf->st_mode)) {
1066                 error_msg("%s: socket ignored\n", fileName);
1067                 return( TRUE);
1068         }
1069
1070         /* It is a bad idea to store the archive we are in the process of creating,
1071          * so check the device and inode to be sure that this particular file isn't
1072          * the new tarball */
1073         if (tbInfo->statBuf.st_dev == statbuf->st_dev &&
1074                         tbInfo->statBuf.st_ino == statbuf->st_ino) {
1075                 error_msg("%s: file is the archive; skipping\n", fileName);
1076                 return( TRUE);
1077         }
1078
1079         header_name = fileName;
1080         while (header_name[0] == '/') {
1081                 static int alreadyWarned=FALSE;
1082                 if (alreadyWarned==FALSE) {
1083                         error_msg("Removing leading '/' from member names\n");
1084                         alreadyWarned=TRUE;
1085                 }
1086                 header_name++;
1087         }
1088
1089         if (strlen(fileName) >= NAME_SIZE) {
1090                 error_msg(name_longer_than_foo, NAME_SIZE);
1091                 return ( TRUE);
1092         }
1093
1094         if (header_name[0] == '\0')
1095                 return TRUE;
1096
1097 #if defined BB_FEATURE_TAR_EXCLUDE
1098         if (exclude_file(tbInfo->excludeList, header_name)) {
1099                 return SKIP;
1100         }
1101 #endif
1102
1103         if (writeTarHeader(tbInfo, header_name, fileName, statbuf)==FALSE) {
1104                 return( FALSE);
1105         }
1106
1107         /* Now, if the file is a regular file, copy it out to the tarball */
1108         if ((tbInfo->hlInfo == NULL)
1109         &&  (S_ISREG(statbuf->st_mode))) {
1110                 int  inputFileFd;
1111                 char buffer[BUFSIZ];
1112                 ssize_t size=0, readSize=0;
1113
1114                 /* open the file we want to archive, and make sure all is well */
1115                 if ((inputFileFd = open(fileName, O_RDONLY)) < 0) {
1116                         error_msg("%s: Cannot open: %s\n", fileName, strerror(errno));
1117                         return( FALSE);
1118                 }
1119
1120                 /* write the file to the archive */
1121                 while ( (size = full_read(inputFileFd, buffer, sizeof(buffer))) > 0 ) {
1122                         if (full_write(tbInfo->tarFd, buffer, size) != size ) {
1123                                 /* Output file seems to have a problem */
1124                                 error_msg(io_error, fileName, strerror(errno));
1125                                 return( FALSE);
1126                         }
1127                         readSize+=size;
1128                 }
1129                 if (size == -1) {
1130                         error_msg(io_error, fileName, strerror(errno));
1131                         return( FALSE);
1132                 }
1133                 /* Pad the file up to the tar block size */
1134                 for (; (readSize%TAR_BLOCK_SIZE) != 0; readSize++) {
1135                         write(tbInfo->tarFd, "\0", 1);
1136                 }
1137                 close( inputFileFd);
1138         }
1139
1140         return( TRUE);
1141 }
1142
1143 static int writeTarFile(const char* tarName, int verboseFlag, char **argv,
1144                 char** excludeList)
1145 {
1146         int tarFd=-1;
1147         int errorFlag=FALSE;
1148         ssize_t size;
1149         struct TarBallInfo tbInfo;
1150         tbInfo.verboseFlag = verboseFlag;
1151         tbInfo.hlInfoHead = NULL;
1152
1153         /* Make sure there is at least one file to tar up.  */
1154         if (*argv == NULL)
1155                 error_msg_and_die("Cowardly refusing to create an empty archive\n");
1156
1157         /* Open the tar file for writing.  */
1158         if (!strcmp(tarName, "-"))
1159                 tbInfo.tarFd = fileno(stdout);
1160         else
1161                 tbInfo.tarFd = open (tarName, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1162         if (tbInfo.tarFd < 0) {
1163                 perror_msg( "Error opening '%s'", tarName);
1164                 freeHardLinkInfo(&tbInfo.hlInfoHead);
1165                 return ( FALSE);
1166         }
1167         tbInfo.excludeList=excludeList;
1168         /* Store the stat info for the tarball's file, so
1169          * can avoid including the tarball into itself....  */
1170         if (fstat(tbInfo.tarFd, &tbInfo.statBuf) < 0)
1171                 error_msg_and_die(io_error, tarName, strerror(errno));
1172
1173         /* Set the umask for this process so it doesn't
1174          * screw up permission setting for us later. */
1175         umask(0);
1176
1177         /* Read the directory/files and iterate over them one at a time */
1178         while (*argv != NULL) {
1179                 if (recursive_action(*argv++, TRUE, FALSE, FALSE,
1180                                         writeFileToTarball, writeFileToTarball,
1181                                         (void*) &tbInfo) == FALSE) {
1182                         errorFlag = TRUE;
1183                 }
1184         }
1185         /* Write two empty blocks to the end of the archive */
1186         for (size=0; size<(2*TAR_BLOCK_SIZE); size++) {
1187                 write(tbInfo.tarFd, "\0", 1);
1188         }
1189
1190         /* To be pedantically correct, we would check if the tarball
1191          * is smaller than 20 tar blocks, and pad it if it was smaller,
1192          * but that isn't necessary for GNU tar interoperability, and
1193          * so is considered a waste of space */
1194
1195         /* Hang up the tools, close up shop, head home */
1196         close(tarFd);
1197         if (errorFlag == TRUE) {
1198                 error_msg("Error exit delayed from previous errors\n");
1199                 freeHardLinkInfo(&tbInfo.hlInfoHead);
1200                 return(FALSE);
1201         }
1202         freeHardLinkInfo(&tbInfo.hlInfoHead);
1203         return( TRUE);
1204 }
1205
1206
1207 #endif
1208