archive_tar.cc

   1 /*
   2  * Copyright (c) 2000, 2001, Red Hat, Inc.
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     A copy of the GNU General Public License can be found at
  10  *     http://www.gnu.org/
  11  *
  12  * Written by DJ Delorie <dj@cygnus.com>
  13  *
  14  */
  15
  16 /* Built-in tar functionality.  See tar.h for usage. */
  17
  18 #if 0
  19 static const char *cvsid =
  20   "\n%%% $Id$\n";
  21 #endif
  22
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <sys/types.h>
  26 #include <sys/fcntl.h>
  27 #include <errno.h>
  28
  29 //#include "zlib/zlib.h"
  30 #include "io_stream.h"
  31 //#include "compress.h"
  32 #include "archive.h"
  33 #include "archive_tar.h"
  34 #include "mkdir.h"
  35 #include "LogSingleton.h"
  36 #include "filemanip.h"
  37
  38 #if 0
  39 #undef _WIN32
  40 #include "bzlib.h"
  41
  42 #define FACTOR (0x19db1ded53ea710LL)
  43 #define NSPERSEC 10000000LL
  44 #define SYMLINK_COOKIE "!<symlink>"
  45 #endif
  46 static int err;
  47
  48 //static char file_name[_MAX_PATH+512];
  49 //static char have_longname = 0;
  50 //static int  file_length;
  51
  52 static char buf[512];
  53
  54 int _tar_verbose = 0;
  55 FILE *_tar_vfile = 0;
  56 #define vp if (_tar_verbose) fprintf
  57 #define vp2 if (_tar_verbose>1) fprintf
  58
  59 archive_tar::archive_tar (io_stream * original)
  60 {
  61   archive_children = 0;
  62   if (_tar_vfile == 0)
  63     _tar_vfile = stderr;
  64
  65   vp2 (_tar_vfile, "tar: open `%p'\n", original);
  66
  67   if (!original)
  68     {
  69       state.lasterr = EBADF;
  70       return;
  71     }
  72   state.parent = original;
  73
  74   if (sizeof (state.tar_header) != 512)
  75     {
  76       /* drastic, but important */
  77       log (LOG_TIMESTAMP) << "compilation error: tar header struct not 512"
  78                           << " bytes (it's " << sizeof (state.tar_header)
  79                           << ")" << endLog;
  80       LogSingleton::GetInstance().exit (1);
  81     }
  82 }
  83
  84 ssize_t
  85 archive_tar::read (void *buffer, size_t len)
  86 {
  87   return -1;
  88 }
  89
  90 ssize_t
  91 archive_tar::write (const void *buffer, size_t len)
  92 {
  93   return 0;
  94 }
  95
  96 ssize_t
  97 archive_tar::peek (void *buffer, size_t len)
  98 {
  99   return 0;
 100 }
 101
 102 int
 103 archive_tar::error ()
 104 {
 105   return state.lasterr;
 106 }
 107
 108 long
 109 archive_tar::tell ()
 110 {
 111   return state.file_offset;
 112 }
 113
 114 int
 115 archive_tar::seek (long where, io_stream_seek_t whence)
 116 {
 117   /* seeking in the parent archive doesn't make sense. although we could
 118      map to files ?
 119      Also, seeking might make sense for rewing..??
 120      */
 121   return -1;
 122 }
 123
 124 int
 125 archive_tar::skip_file ()
 126 {
 127   while (state.file_length > state.file_offset)
 128     {
 129       int len = state.parent->read (buf, 512);
 130       state.file_offset += 512;
 131       if (len != 512)
 132         return 1;
 133     }
 134   state.file_length = 0;
 135   state.file_offset = 0;
 136   state.header_read = 0;
 137   return 0;
 138 }
 139
 140 String const
 141 archive_tar::next_file_name ()
 142 {
 143   char *c;
 144
 145   if (state.header_read)
 146     if (strlen (state.filename))
 147       return state.filename;
 148     else
 149       /* End of tar */
 150       return String();
 151
 152   int r = state.parent->read (&state.tar_header, 512);
 153
 154   /* See if we're at end of file */
 155   if (r != 512)
 156     return String();
 157
 158   /* See if the header is all zeros (i.e. last block) */
 159   int n = 0;
 160   for (r = 512 / sizeof (int); r; r--)
 161     n |= ((int *) &state.tar_header)[r - 1];
 162   if (n == 0)
 163     return String();
 164
 165   if (!state.have_longname && state.tar_header.typeflag != 'L')
 166     {
 167       memcpy (state.filename, state.tar_header.name, 100);
 168       state.filename[100] = 0;
 169     }
 170   else if (state.have_longname)
 171     state.have_longname = 0;
 172
 173   sscanf (state.tar_header.size, "%o", &state.file_length);
 174   state.file_offset = 0;
 175
 176 //  vp2 (_tar_vfile, "%c %9d %s\n", state.tar_header.typeflag,
 177 //      state.file_length, state.filename);
 178
 179   switch (state.tar_header.typeflag)
 180     {
 181     case 'L':                   /* GNU tar long name extension */
 182       /* we read the 'file' into the long filename, then call back into here
 183        * to find out if the actual file is a real file, or a special file..
 184        */
 185       if (state.file_length > _MAX_PATH)
 186         {
 187           skip_file ();
 188           fprintf (stderr, "error: long file name exceeds %d characters\n",
 189                    _MAX_PATH);
 190           err++;
 191           state.parent->read (&state.tar_header, 512);
 192           sscanf (state.tar_header.size, "%o", &state.file_length);
 193           state.file_offset = 0;
 194           skip_file ();
 195           return next_file_name ();
 196         }
 197       c = state.filename;
 198       /* FIXME: this should be a single read() call */
 199       while (state.file_length > state.file_offset)
 200         {
 201           int need =
 202             state.file_length - state.file_offset >
 203             512 ? 512 : state.file_length - state.file_offset;
 204           if (state.parent->read (buf, 512) < 512)
 205             return 0;
 206           memcpy (c, buf, need);
 207           c += need;
 208           state.file_offset += need;
 209         }
 210       *c = 0;
 211       state.have_longname = 1;
 212       return next_file_name ();
 213
 214     case '3':                   /* char */
 215     case '4':                   /* block */
 216     case '6':                   /* fifo */
 217       fprintf (stderr, "warning: not extracting special file %s\n",
 218                state.filename);
 219       err++;
 220       return next_file_name ();
 221
 222     case '0':                   /* regular file */
 223     case 0:                     /* regular file also */
 224     case '2':                   /* symbolic link */
 225     case '5':                   /* directory */
 226     case '7':                   /* contiguous file */
 227       state.header_read = 1;
 228       return state.filename;
 229
 230     case '1':                   /* hard link, we just copy */
 231       state.header_read = 1;
 232       return state.filename;
 233
 234     default:
 235       fprintf (stderr, "error: unknown (or unsupported) file type `%c'\n",
 236                state.tar_header.typeflag);
 237       err++;
 238       skip_file ();
 239       return next_file_name ();
 240     }
 241   return String();
 242 }
 243
 244 archive_tar::~archive_tar ()
 245 {
 246   if (state.parent)
 247     delete state.parent;
 248   destroyed = 1;
 249 }
 250
 251 # if 0
 252 static void
 253 fix_time_stamp (char *path)
 254 {
 255   int mtime;
 256   long long ftimev;
 257   FILETIME ftime;
 258   HANDLE h;
 259
 260   sscanf (tar_header.mtime, "%o", &mtime);
 261   ftimev = mtime * NSPERSEC + FACTOR;
 262   ftime.dwHighDateTime = ftimev >> 32;
 263   ftime.dwLowDateTime = ftimev;
 264   h = CreateFileA (path, GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE,
 265                    0, OPEN_EXISTING,
 266                    FILE_ATTRIBUTE_NORMAL | FILE_FLAG_BACKUP_SEMANTICS, 0);
 267   if (h)
 268     {
 269       SetFileTime (h, 0, 0, &ftime);
 270       CloseHandle (h);
 271     }
 272 }
 273 #endif
 274 archive_file_t
 275 archive_tar::next_file_type ()
 276 {
 277   switch (state.tar_header.typeflag)
 278     {
 279       /* regular files */
 280     case '0':
 281     case 0:
 282     case '7':
 283       return ARCHIVE_FILE_REGULAR;
 284     case '1':
 285       return ARCHIVE_FILE_HARDLINK;
 286     case '5':
 287       return ARCHIVE_FILE_DIRECTORY;
 288     case '2':
 289       return ARCHIVE_FILE_SYMLINK;
 290     default:
 291       return ARCHIVE_FILE_INVALID;
 292     }
 293 }
 294
 295 String const
 296 archive_tar::linktarget ()
 297 {
 298   /* TODO: consider .. path traversal issues */
 299   if (next_file_type () == ARCHIVE_FILE_SYMLINK ||
 300       next_file_type () == ARCHIVE_FILE_HARDLINK)
 301     return state.tar_header.linkname;
 302   return String();
 303 }
 304
 305 io_stream *
 306 archive_tar::extract_file ()
 307 {
 308   if (archive_children)
 309     return NULL;
 310   archive_tar_file *rv = new archive_tar_file (state);
 311   return rv;
 312 }
 313
 314 int
 315 archive_tar::get_mtime ()
 316 {
 317       if (state.parent)
 318                     return state.parent->get_mtime ();
 319             return 0;
 320 }