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    revision 983 by niro, Fri Apr 24 18:33:46 2009 UTC revision 984 by niro, Sun May 30 11:32:42 2010 UTC
    # Line 14  Line 14 
    14  #include "libbb.h"  #include "libbb.h"
    15  #include "unarchive.h"  #include "unarchive.h"
    16    
    17    /*
    18     * GNU tar uses "base-256 encoding" for very large numbers (>8 billion).
    19     * Encoding is binary, with highest bit always set as a marker
    20     * and sign in next-highest bit:
    21     * 80 00 .. 00 - zero
    22     * bf ff .. ff - largest positive number
    23     * ff ff .. ff - minus 1
    24     * c0 00 .. 00 - smallest negative number
    25     *
    26     * We expect it only in size field, where negative numbers don't make sense.
    27     */
    28    static off_t getBase256_len12(const char *str)
    29    {
    30     off_t value;
    31     int len;
    32    
    33     /* if (*str & 0x40) error; - caller prevents this */
    34    
    35     if (sizeof(off_t) >= 12) {
    36     /* Probably 128-bit (16 byte) off_t. Can be optimized. */
    37     len = 12;
    38     value = *str++ & 0x3f;
    39     while (--len)
    40     value = (value << 8) + (unsigned char) *str++;
    41     return value;
    42     }
    43    
    44    #ifdef CHECK_FOR_OVERFLOW
    45     /* Can be optimized to eat 32-bit chunks */
    46     char c = *str++ & 0x3f;
    47     len = 12;
    48     while (1) {
    49     if (c)
    50     bb_error_msg_and_die("overflow in base-256 encoded file size");
    51     if (--len == sizeof(off_t))
    52     break;
    53     c = *str++;
    54     }
    55    #else
    56     str += (12 - sizeof(off_t));
    57    #endif
    58    
    59    /* Now str points to sizeof(off_t) least significant bytes.
    60     *
    61     * Example of tar file with 8914993153 (0x213600001) byte file.
    62     * Field starts at offset 7c:
    63     * 00070  30 30 30 00 30 30 30 30  30 30 30 00 80 00 00 00  |000.0000000.....|
    64     * 00080  00 00 00 02 13 60 00 01  31 31 31 32 30 33 33 36  |.....`..11120336|
    65     *
    66     * str is at offset 80 or 84 now (64-bit or 32-bit off_t).
    67     * We (ab)use the fact that value happens to be aligned,
    68     * and fetch it in one go:
    69     */
    70     if (sizeof(off_t) == 8) {
    71     value = *(off_t*)str;
    72     value = SWAP_BE64(value);
    73     } else if (sizeof(off_t) == 4) {
    74     value = *(off_t*)str;
    75     value = SWAP_BE32(value);
    76     } else {
    77     value = 0;
    78     len = sizeof(off_t);
    79     while (--len)
    80     value = (value << 8) + (unsigned char) *str++;
    81     }
    82     return value;
    83    }
    84    
    85  /* NB: _DESTROYS_ str[len] character! */  /* NB: _DESTROYS_ str[len] character! */
    86  static unsigned long long getOctal(char *str, int len)  static unsigned long long getOctal(char *str, int len)
    87  {  {
    88   unsigned long long v;   unsigned long long v;
    89   /* NB: leading spaces are allowed. Using strtoull to handle that.   /* NB: leading spaces are allowed. Using strtoull to handle that.
    90   * The downside is that we accept e.g. "-123" too :)   * The downside is that we accept e.g. "-123" too :(
    91   */   */
    92   str[len] = '\0';   str[len] = '\0';
    93   v = strtoull(str, &str, 8);   v = strtoull(str, &str, 8);
    94   if (*str && (!ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY || *str != ' '))   /* std: "Each numeric field is terminated by one or more
    95     * <space> or NUL characters". We must support ' '! */
    96     if (*str != '\0' && *str != ' ')
    97   bb_error_msg_and_die("corrupted octal value in tar header");   bb_error_msg_and_die("corrupted octal value in tar header");
    98   return v;   return v;
    99  }  }
    # Line 65  char FAST_FUNC get_header_tar(archive_ha Line 135  char FAST_FUNC get_header_tar(archive_ha
    135   int parse_names;   int parse_names;
    136    
    137   /* Our "private data" */   /* Our "private data" */
     #define p_end (*(smallint *)(&archive_handle->ah_priv[0]))  
    138  #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS  #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
    139  #define p_longname (*(char* *)(&archive_handle->ah_priv[1]))  # define p_longname (archive_handle->tar__longname)
    140  #define p_linkname (*(char* *)(&archive_handle->ah_priv[2]))  # define p_linkname (archive_handle->tar__linkname)
    141  #else  #else
    142  #define p_longname 0  # define p_longname 0
    143  #define p_linkname 0  # define p_linkname 0
    144  #endif  #endif
     // if (!archive_handle->ah_priv_inited) {  
     // archive_handle->ah_priv_inited = 1;  
     // p_end = 0;  
     // USE_FEATURE_TAR_GNU_EXTENSIONS(p_longname = NULL;)  
     // USE_FEATURE_TAR_GNU_EXTENSIONS(p_linkname = NULL;)  
     // }  
    145    
    146   if (sizeof(tar) != 512)   if (sizeof(tar) != 512)
    147   BUG_tar_header_size();   BUG_tar_header_size();
    # Line 108  char FAST_FUNC get_header_tar(archive_ha Line 171  char FAST_FUNC get_header_tar(archive_ha
    171   bb_error_msg_and_die("short read");   bb_error_msg_and_die("short read");
    172   }   }
    173   if (i != 512) {   if (i != 512) {
    174   USE_FEATURE_TAR_AUTODETECT(goto autodetect;)   IF_FEATURE_TAR_AUTODETECT(goto autodetect;)
    175   goto short_read;   goto short_read;
    176   }   }
    177    
    # Line 120  char FAST_FUNC get_header_tar(archive_ha Line 183  char FAST_FUNC get_header_tar(archive_ha
    183    
    184   /* If there is no filename its an empty header */   /* If there is no filename its an empty header */
    185   if (tar.name[0] == 0 && tar.prefix[0] == 0) {   if (tar.name[0] == 0 && tar.prefix[0] == 0) {
    186   if (p_end) {   if (archive_handle->tar__end) {
    187   /* Second consecutive empty header - end of archive.   /* Second consecutive empty header - end of archive.
    188   * Read until the end to empty the pipe from gz or bz2   * Read until the end to empty the pipe from gz or bz2
    189   */   */
    # Line 128  char FAST_FUNC get_header_tar(archive_ha Line 191  char FAST_FUNC get_header_tar(archive_ha
    191   continue;   continue;
    192   return EXIT_FAILURE;   return EXIT_FAILURE;
    193   }   }
    194   p_end = 1;   archive_handle->tar__end = 1;
    195   return EXIT_SUCCESS;   return EXIT_SUCCESS;
    196   }   }
    197   p_end = 0;   archive_handle->tar__end = 0;
    198    
    199   /* Check header has valid magic, "ustar" is for the proper tar,   /* Check header has valid magic, "ustar" is for the proper tar,
    200   * five NULs are for the old tar format  */   * five NULs are for the old tar format  */
    # Line 194  char FAST_FUNC get_header_tar(archive_ha Line 257  char FAST_FUNC get_header_tar(archive_ha
    257   sum_s += ((signed char*)&tar)[i];   sum_s += ((signed char*)&tar)[i];
    258  #endif  #endif
    259   }   }
     #if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY  
      sum = strtoul(tar.chksum, &cp, 8);  
      if ((*cp && *cp != ' ')  
      || (sum_u != sum USE_FEATURE_TAR_OLDSUN_COMPATIBILITY(&& sum_s != sum))  
      ) {  
      bb_error_msg_and_die("invalid tar header checksum");  
      }  
     #else  
    260   /* This field does not need special treatment (getOctal) */   /* This field does not need special treatment (getOctal) */
    261   sum = xstrtoul(tar.chksum, 8);   {
    262   if (sum_u != sum USE_FEATURE_TAR_OLDSUN_COMPATIBILITY(&& sum_s != sum)) {   char *endp; /* gcc likes temp var for &endp */
    263     sum = strtoul(tar.chksum, &endp, 8);
    264     if ((*endp != '\0' && *endp != ' ')
    265     || (sum_u != sum IF_FEATURE_TAR_OLDSUN_COMPATIBILITY(&& sum_s != sum))
    266     ) {
    267     bb_error_msg_and_die("invalid tar header checksum");
    268     }
    269     }
    270     /* don't use xstrtoul, tar.chksum may have leading spaces */
    271     sum = strtoul(tar.chksum, NULL, 8);
    272     if (sum_u != sum IF_FEATURE_TAR_OLDSUN_COMPATIBILITY(&& sum_s != sum)) {
    273   bb_error_msg_and_die("invalid tar header checksum");   bb_error_msg_and_die("invalid tar header checksum");
    274   }   }
     #endif  
    275    
    276   /* 0 is reserved for high perf file, treat as normal file */   /* 0 is reserved for high perf file, treat as normal file */
    277   if (!tar.typeflag) tar.typeflag = '0';   if (!tar.typeflag) tar.typeflag = '0';
    # Line 230  char FAST_FUNC get_header_tar(archive_ha Line 294  char FAST_FUNC get_header_tar(archive_ha
    294   /* Will link_target be free()ed? */   /* Will link_target be free()ed? */
    295   }   }
    296  #if ENABLE_FEATURE_TAR_UNAME_GNAME  #if ENABLE_FEATURE_TAR_UNAME_GNAME
    297   file_header->uname = tar.uname[0] ? xstrndup(tar.uname, sizeof(tar.uname)) : NULL;   file_header->tar__uname = tar.uname[0] ? xstrndup(tar.uname, sizeof(tar.uname)) : NULL;
    298   file_header->gname = tar.gname[0] ? xstrndup(tar.gname, sizeof(tar.gname)) : NULL;   file_header->tar__gname = tar.gname[0] ? xstrndup(tar.gname, sizeof(tar.gname)) : NULL;
    299  #endif  #endif
    300   file_header->mtime = GET_OCTAL(tar.mtime);   /* mtime: rudimentally handle GNU tar's "base256 encoding"
    301   file_header->size = GET_OCTAL(tar.size);   * People report tarballs with NEGATIVE unix times encoded that way */
    302     file_header->mtime = (tar.mtime[0] & 0x80) /* base256? */
    303     ? 0 /* bogus */
    304     : GET_OCTAL(tar.mtime);
    305     /* size: handle GNU tar's "base256 encoding" */
    306     file_header->size = (tar.size[0] & 0xc0) == 0x80 /* positive base256? */
    307     ? getBase256_len12(tar.size)
    308     : GET_OCTAL(tar.size);
    309   file_header->gid = GET_OCTAL(tar.gid);   file_header->gid = GET_OCTAL(tar.gid);
    310   file_header->uid = GET_OCTAL(tar.uid);   file_header->uid = GET_OCTAL(tar.uid);
    311   /* Set bits 0-11 of the files mode */   /* Set bits 0-11 of the files mode */
    # Line 285  char FAST_FUNC get_header_tar(archive_ha Line 356  char FAST_FUNC get_header_tar(archive_ha
    356   file_header->mode |= S_IFBLK;   file_header->mode |= S_IFBLK;
    357   goto size0;   goto size0;
    358   case '5':   case '5':
    359   USE_FEATURE_TAR_OLDGNU_COMPATIBILITY(set_dir:)   IF_FEATURE_TAR_OLDGNU_COMPATIBILITY(set_dir:)
    360   file_header->mode |= S_IFDIR;   file_header->mode |= S_IFDIR;
    361   goto size0;   goto size0;
    362   case '6':   case '6':
    # Line 371  char FAST_FUNC get_header_tar(archive_ha Line 442  char FAST_FUNC get_header_tar(archive_ha
    442   free(file_header->link_target);   free(file_header->link_target);
    443   /* Do not free(file_header->name)! (why?) */   /* Do not free(file_header->name)! (why?) */
    444  #if ENABLE_FEATURE_TAR_UNAME_GNAME  #if ENABLE_FEATURE_TAR_UNAME_GNAME
    445   free(file_header->uname);   free(file_header->tar__uname);
    446   free(file_header->gname);   free(file_header->tar__gname);
    447  #endif  #endif
    448   return EXIT_SUCCESS;   return EXIT_SUCCESS;
    449  }  }
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