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 "win32.h"
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <sys/types.h>
  27 #include <sys/fcntl.h>
  28 #include <errno.h>
  29
  30 //#include "zlib/zlib.h"
  31 #include "io_stream.h"
  32 //#include "compress.h"
  33 #include "archive.h"
  34 #include "archive_tar.h"
  35 #include "mkdir.h"
  36 #include "log.h"
  37 #include "filemanip.h"
  38
  39 #include "port.h"
  40 #if 0
  41 #undef _WIN32
  42 #include "bzlib.h"
  43
  44 #define FACTOR (0x19db1ded53ea710LL)
  45 #define NSPERSEC 10000000LL
  46 #define SYMLINK_COOKIE "!<symlink>"
  47 #endif
  48 static int err;
  49
  50 //static char file_name[_MAX_PATH+512];
  51 //static char have_longname = 0;
  52 //static int  file_length;
  53
  54 static char buf[512];
  55
  56 int _tar_verbose = 0;
  57 FILE *_tar_vfile = 0;
  58 #define vp if (_tar_verbose) fprintf
  59 #define vp2 if (_tar_verbose>1) fprintf
  60
  61 archive_tar::archive_tar (io_stream * original)
  62 {
  63   archive_children = 0;
  64   if (_tar_vfile == 0)
  65     _tar_vfile = stderr;
  66
  67   vp2 (_tar_vfile, "tar: open `%p'\n", original);
  68
  69   if (!original)
  70     {
  71       state.lasterr = EBADF;
  72       return;
  73     }
  74   state.parent = original;
  75
  76   if (sizeof (state.tar_header) != 512)
  77     {
  78       /* drastic, but important */
  79       fprintf (stderr, "compilation error: tar header struct not 512"
  80                " bytes (it's %d)\n", sizeof (state.tar_header));
  81       exit_setup (1);
  82     }
  83 }
  84
  85 ssize_t
  86 archive_tar::read (void *buffer, size_t len)
  87 {
  88   return -1;
  89 }
  90
  91 ssize_t
  92 archive_tar::write (const void *buffer, size_t len)
  93 {
  94   return 0;
  95 }
  96
  97 ssize_t
  98 archive_tar::peek (void *buffer, size_t len)
  99 {
 100   return 0;
 101 }
 102
 103 int
 104 archive_tar::error ()
 105 {
 106   return state.lasterr;
 107 }
 108
 109 long
 110 archive_tar::tell ()
 111 {
 112   return state.file_offset;
 113 }
 114
 115 int
 116 archive_tar::seek (long where, io_stream_seek_t whence)
 117 {
 118   /* seeking in the parent archive doesn't make sense. although we could
 119      map to files ?
 120      Also, seeking might make sense for rewing..??
 121      */
 122   return -1;
 123 }
 124
 125 int
 126 archive_tar::skip_file ()
 127 {
 128   while (state.file_length > state.file_offset)
 129     {
 130       int len = state.parent->read (buf, 512);
 131       state.file_offset += 512;
 132       if (len != 512)
 133         return 1;
 134     }
 135   state.file_length = 0;
 136   state.file_offset = 0;
 137   state.header_read = 0;
 138   return 0;
 139 }
 140
 141 String const
 142 archive_tar::next_file_name ()
 143 {
 144   char *c;
 145
 146   if (state.header_read)
 147     if (strlen (state.filename))
 148       return state.filename;
 149     else
 150       /* End of tar */
 151       return String();
 152
 153   int r = state.parent->read (&state.tar_header, 512);
 154
 155   /* See if we're at end of file */
 156   if (r != 512)
 157     return NULL;
 158
 159   /* See if the header is all zeros (i.e. last block) */
 160   int n = 0;
 161   for (r = 512 / sizeof (int); r; r--)
 162     n |= ((int *) &state.tar_header)[r - 1];
 163   if (n == 0)
 164     return NULL;
 165
 166   if (!state.have_longname && state.tar_header.typeflag != 'L')
 167     {
 168       memcpy (state.filename, state.tar_header.name, 100);
 169       state.filename[100] = 0;
 170     }
 171
 172   sscanf (state.tar_header.size, "%o", &state.file_length);
 173   state.file_offset = 0;
 174
 175 //  vp2 (_tar_vfile, "%c %9d %s\n", state.tar_header.typeflag,
 176 //      state.file_length, state.filename);
 177
 178   switch (state.tar_header.typeflag)
 179     {
 180     case 'L':                   /* GNU tar long name extension */
 181       /* we read the 'file' into the long filename, then call back into here
 182        * to find out if the actual file is a real file, or a special file..
 183        */
 184       if (state.file_length > _MAX_PATH)
 185         {
 186           skip_file ();
 187           fprintf (stderr, "error: long file name exceeds %d characters\n",
 188                    _MAX_PATH);
 189           err++;
 190           state.parent->read (&state.tar_header, 512);
 191           sscanf (state.tar_header.size, "%o", &state.file_length);
 192           state.file_offset = 0;
 193           skip_file ();
 194           return next_file_name ();
 195         }
 196       c = state.filename;
 197       /* FIXME: this should be a single read() call */
 198       while (state.file_length > state.file_offset)
 199         {
 200           int need =
 201             state.file_length - state.file_offset >
 202             512 ? 512 : state.file_length - state.file_offset;
 203           if (state.parent->read (buf, 512) < 512)
 204             return 0;
 205           memcpy (c, buf, need);
 206           c += need;
 207           state.file_offset += need;
 208         }
 209       *c = 0;
 210       state.have_longname = 1;
 211       return next_file_name ();
 212
 213     case '3':                   /* char */
 214     case '4':                   /* block */
 215     case '6':                   /* fifo */
 216       fprintf (stderr, "warning: not extracting special file %s\n",
 217                state.filename);
 218       err++;
 219       return next_file_name ();
 220
 221     case '0':                   /* regular file */
 222     case 0:                     /* regular file also */
 223     case '2':                   /* symbolic link */
 224     case '5':                   /* directory */
 225     case '7':                   /* contiguous file */
 226       state.header_read = 1;
 227       return state.filename;
 228
 229     case '1':                   /* hard link, we just copy */
 230       state.header_read = 1;
 231       return state.filename;
 232
 233     default:
 234       fprintf (stderr, "error: unknown (or unsupported) file type `%c'\n",
 235                state.tar_header.typeflag);
 236       err++;
 237       skip_file ();
 238       return next_file_name ();
 239     }
 240   return NULL;
 241 }
 242
 243 archive_tar::~archive_tar ()
 244 {
 245   if (state.parent)
 246     delete state.parent;
 247   destroyed = 1;
 248 }
 249
 250 # if 0
 251 static void
 252 fix_time_stamp (char *path)
 253 {
 254   int mtime;
 255   long long ftimev;
 256   FILETIME ftime;
 257   HANDLE h;
 258
 259   sscanf (tar_header.mtime, "%o", &mtime);
 260   ftimev = mtime * NSPERSEC + FACTOR;
 261   ftime.dwHighDateTime = ftimev >> 32;
 262   ftime.dwLowDateTime = ftimev;
 263   h = CreateFileA (path, GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE,
 264                    0, OPEN_EXISTING,
 265                    FILE_ATTRIBUTE_NORMAL | FILE_FLAG_BACKUP_SEMANTICS, 0);
 266   if (h)
 267     {
 268       SetFileTime (h, 0, 0, &ftime);
 269       CloseHandle (h);
 270     }
 271 }
 272 #endif
 273 archive_file_t
 274 archive_tar::next_file_type ()
 275 {
 276   switch (state.tar_header.typeflag)
 277     {
 278       /* regular files */
 279     case '0':
 280     case 0:
 281     case '7':
 282       return ARCHIVE_FILE_REGULAR;
 283     case '1':
 284       return ARCHIVE_FILE_HARDLINK;
 285     case '5':
 286       return ARCHIVE_FILE_DIRECTORY;
 287     case '2':
 288       return ARCHIVE_FILE_SYMLINK;
 289     default:
 290       return ARCHIVE_FILE_INVALID;
 291     }
 292 }
 293
 294 String const
 295 archive_tar::linktarget ()
 296 {
 297   /* TODO: consider .. path traversal issues */
 298   if (next_file_type () == ARCHIVE_FILE_SYMLINK ||
 299       next_file_type () == ARCHIVE_FILE_HARDLINK)
 300     return state.tar_header.linkname;
 301   return String();
 302 }
 303
 304 io_stream *
 305 archive_tar::extract_file ()
 306 {
 307   if (archive_children)
 308     return NULL;
 309   archive_tar_file *rv = new archive_tar_file (state);
 310   return rv;
 311 }
 312
 313 int
 314 archive_tar::get_mtime ()
 315 {
 316       if (state.parent)
 317                     return state.parent->get_mtime ();
 318             return 0;
 319 }