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 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <sys/types.h>
  21 #include <sys/fcntl.h>
  22 #include <errno.h>
  23
  24 //#include "zlib/zlib.h"
  25 #include "io_stream.h"
  26 //#include "compress.h"
  27 #include "win32.h"
  28 #include "archive.h"
  29 #include "archive_tar.h"
  30 #include "mkdir.h"
  31 #include "LogFile.h"
  32 #include "filemanip.h"
  33
  34 #if 0
  35 #undef _WIN32
  36 #include "bzlib.h"
  37
  38 #define SYMLINK_COOKIE "!<symlink>"
  39 #endif
  40 static int err;
  41
  42 static char buf[512];
  43
  44 int _tar_verbose = 0;
  45
  46 archive_tar::archive_tar (io_stream * original)
  47 {
  48   archive_children = 0;
  49
  50   if (_tar_verbose)
  51     LogBabblePrintf("tar: open `%p'\n", original);
  52
  53   if (!original)
  54     {
  55       state.lasterr = EBADF;
  56       return;
  57     }
  58   state.parent = original;
  59
  60   if (sizeof (state.tar_header) != 512)
  61     {
  62       /* drastic, but important */
  63       Log (LOG_TIMESTAMP) << "compilation error: tar header struct not 512"
  64                           << " bytes (it's " << sizeof (state.tar_header)
  65                           << ")" << endLog;
  66       Logger ().exit (1);
  67     }
  68 }
  69
  70 ssize_t
  71 archive_tar::read (void *buffer, size_t len)
  72 {
  73   return -1;
  74 }
  75
  76 ssize_t
  77 archive_tar::write (const void *buffer, size_t len)
  78 {
  79   return 0;
  80 }
  81
  82 ssize_t
  83 archive_tar::peek (void *buffer, size_t len)
  84 {
  85   return 0;
  86 }
  87
  88 int
  89 archive_tar::error ()
  90 {
  91   return state.lasterr;
  92 }
  93
  94 long
  95 archive_tar::tell ()
  96 {
  97   return state.file_offset;
  98 }
  99
 100 int
 101 archive_tar::seek (long where, io_stream_seek_t whence)
 102 {
 103   /* seeking in the parent archive doesn't make sense. although we could
 104      map to files ?
 105      Also, seeking might make sense for rewing..??
 106      */
 107   return -1;
 108 }
 109
 110 int
 111 archive_tar::skip_file ()
 112 {
 113   while (state.file_length > state.file_offset)
 114     {
 115       int len = state.parent->read (buf, 512);
 116       state.file_offset += 512;
 117       if (len != 512)
 118         return 1;
 119     }
 120   state.file_length = 0;
 121   state.file_offset = 0;
 122   state.header_read = 0;
 123   return 0;
 124 }
 125
 126 const std::string
 127 archive_tar::next_file_name ()
 128 {
 129   char *c;
 130
 131   if (state.header_read)
 132     {
 133       if (strlen (state.filename))
 134         return state.filename;
 135       else
 136         /* End of tar */
 137         return std::string();
 138     }
 139
 140   int r = state.parent->read (&state.tar_header, 512);
 141
 142   /* See if we're at end of file */
 143   if (r != 512)
 144     return std::string();
 145
 146   /* See if the header is all zeros (i.e. last block) */
 147   int n = 0;
 148   for (r = 512 / sizeof (int); r; r--)
 149     n |= ((int *) &state.tar_header)[r - 1];
 150   if (n == 0)
 151     return std::string();
 152
 153   if (!state.have_longname && state.tar_header.typeflag != 'L')
 154     {
 155       memcpy (state.filename, state.tar_header.name, 100);
 156       state.filename[100] = 0;
 157     }
 158   else if (state.have_longname)
 159     state.have_longname = 0;
 160
 161   sscanf (state.tar_header.size, "%zo", &state.file_length);
 162   state.file_offset = 0;
 163
 164   if (_tar_verbose)
 165     LogBabblePrintf ("%c %9d %s\n", state.tar_header.typeflag,
 166                      state.file_length, state.filename);
 167
 168   switch (state.tar_header.typeflag)
 169     {
 170     case 'L':                   /* GNU tar long name extension */
 171       /* we read the 'file' into the long filename, then call back into here
 172        * to find out if the actual file is a real file, or a special file..
 173        */
 174       if (state.file_length > CYG_PATH_MAX)
 175         {
 176           skip_file ();
 177           LogPlainPrintf( "error: long file name exceeds %d characters\n",
 178                           CYG_PATH_MAX);
 179           err++;
 180           state.parent->read (&state.tar_header, 512);
 181           sscanf (state.tar_header.size, "%zo", &state.file_length);
 182           state.file_offset = 0;
 183           skip_file ();
 184           return next_file_name ();
 185         }
 186       c = state.filename;
 187       /* FIXME: this should be a single read() call */
 188       while (state.file_length > state.file_offset)
 189         {
 190           int need =
 191             state.file_length - state.file_offset >
 192             512 ? 512 : state.file_length - state.file_offset;
 193           if (state.parent->read (buf, 512) < 512)
 194             // FIXME: What's up with the "0"? It's probably a mistake, and
 195             // should be "". It used to be written as 0, and was subject to a
 196             // bizarre implicit conversion by the unwise String(int)
 197             // constructor.
 198             return "0";
 199           memcpy (c, buf, need);
 200           c += need;
 201           state.file_offset += need;
 202         }
 203       *c = 0;
 204       state.have_longname = 1;
 205       return next_file_name ();
 206
 207     case '3':                   /* char */
 208     case '4':                   /* block */
 209     case '6':                   /* fifo */
 210       LogPlainPrintf ("warning: not extracting special file %s\n",
 211                       state.filename);
 212       err++;
 213       return next_file_name ();
 214
 215     case '0':                   /* regular file */
 216     case 0:                     /* regular file also */
 217     case '2':                   /* symbolic link */
 218     case '5':                   /* directory */
 219     case '7':                   /* contiguous file */
 220       state.header_read = 1;
 221       return state.filename;
 222
 223     case '1':                   /* hard link, we just copy */
 224       state.header_read = 1;
 225       return state.filename;
 226
 227     default:
 228       LogPlainPrintf ("error: unknown (or unsupported) file type `%c'\n",
 229                       state.tar_header.typeflag);
 230       err++;
 231       /* fall through */
 232     case 'g':                   /* POSIX.1-2001 global extended header */
 233     case 'x':                   /* POSIX.1-2001 extended header */
 234       skip_file ();
 235       return next_file_name ();
 236     }
 237   return std::string();
 238 }
 239
 240 archive_tar::~archive_tar ()
 241 {
 242   if (state.parent)
 243     delete state.parent;
 244 }
 245
 246 # if 0
 247 static void
 248 fix_time_stamp (char *path)
 249 {
 250   int mtime;
 251   long long ftimev;
 252   FILETIME ftime;
 253   HANDLE h;
 254
 255   sscanf (tar_header.mtime, "%o", &mtime);
 256   ftimev = mtime * NSPERSEC + FACTOR;
 257   ftime.dwHighDateTime = ftimev >> 32;
 258   ftime.dwLowDateTime = ftimev;
 259   h = CreateFileA (path, GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE,
 260                    0, OPEN_EXISTING,
 261                    FILE_ATTRIBUTE_NORMAL | FILE_FLAG_BACKUP_SEMANTICS, 0);
 262   if (h)
 263     {
 264       SetFileTime (h, 0, 0, &ftime);
 265       CloseHandle (h);
 266     }
 267 }
 268 #endif
 269 archive_file_t
 270 archive_tar::next_file_type ()
 271 {
 272   switch (state.tar_header.typeflag)
 273     {
 274       /* regular files */
 275     case '0':
 276     case 0:
 277     case '7':
 278       return ARCHIVE_FILE_REGULAR;
 279     case '1':
 280       return ARCHIVE_FILE_HARDLINK;
 281     case '5':
 282       return ARCHIVE_FILE_DIRECTORY;
 283     case '2':
 284       return ARCHIVE_FILE_SYMLINK;
 285     default:
 286       return ARCHIVE_FILE_INVALID;
 287     }
 288 }
 289
 290 const std::string
 291 archive_tar::linktarget ()
 292 {
 293   /* TODO: consider .. path traversal issues */
 294   if (next_file_type () == ARCHIVE_FILE_SYMLINK ||
 295       next_file_type () == ARCHIVE_FILE_HARDLINK)
 296     return state.tar_header.linkname;
 297   return std::string();
 298 }
 299
 300 io_stream *
 301 archive_tar::extract_file ()
 302 {
 303   if (archive_children)
 304     return NULL;
 305   archive_tar_file *rv = new archive_tar_file (state);
 306   return rv;
 307 }
 308
 309 time_t
 310 archive_tar::get_mtime ()
 311 {
 312   if (state.parent)
 313     return state.parent->get_mtime ();
 314   return 0;
 315 }
 316
 317 mode_t
 318 archive_tar::get_mode ()
 319 {
 320   if (state.parent)
 321     return state.parent->get_mode ();
 322   return 0;
 323 }