DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (b66b287a2650)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542
// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// This file implements PEImage, a generic class to manipulate PE files.
// This file was adapted from GreenBorder's Code.

#include "base/pe_image.h"

#ifdef _WIN64
#error This code is not tested on x64. Please make sure all the base unit tests\
 pass before doing any real work. The current unit tests don't test the\
 differences between 32- and 64-bits implementations. Bugs may slip through.\
 You need to improve the coverage before continuing.
#endif

// Structure to perform imports enumerations.
struct EnumAllImportsStorage {
  PEImage::EnumImportsFunction callback;
  PVOID cookie;
};

// Callback used to enumerate imports. See EnumImportChunksFunction.
bool ProcessImportChunk(const PEImage &image, LPCSTR module,
                        PIMAGE_THUNK_DATA name_table,
                        PIMAGE_THUNK_DATA iat, PVOID cookie) {
  EnumAllImportsStorage &storage = *reinterpret_cast<EnumAllImportsStorage*>(
                                       cookie);

  return image.EnumOneImportChunk(storage.callback, module, name_table, iat,
                                  storage.cookie);
}

// Callback used to enumerate delay imports. See EnumDelayImportChunksFunction.
bool ProcessDelayImportChunk(const PEImage &image,
                             PImgDelayDescr delay_descriptor,
                             LPCSTR module, PIMAGE_THUNK_DATA name_table,
                             PIMAGE_THUNK_DATA iat, PIMAGE_THUNK_DATA bound_iat,
                             PIMAGE_THUNK_DATA unload_iat, PVOID cookie) {
  EnumAllImportsStorage &storage = *reinterpret_cast<EnumAllImportsStorage*>(
                                       cookie);

  return image.EnumOneDelayImportChunk(storage.callback, delay_descriptor,
                                       module, name_table, iat, bound_iat,
                                       unload_iat, storage.cookie);
}

void PEImage::set_module(HMODULE module) {
  module_ = module;
}

PIMAGE_DOS_HEADER PEImage::GetDosHeader() const {
  return reinterpret_cast<PIMAGE_DOS_HEADER>(module_);
}

PIMAGE_NT_HEADERS PEImage::GetNTHeaders() const {
  PIMAGE_DOS_HEADER dos_header = GetDosHeader();

  return reinterpret_cast<PIMAGE_NT_HEADERS>(
      reinterpret_cast<char*>(dos_header) + dos_header->e_lfanew);
}

PIMAGE_SECTION_HEADER PEImage::GetSectionHeader(UINT section) const {
  PIMAGE_NT_HEADERS nt_headers = GetNTHeaders();
  PIMAGE_SECTION_HEADER first_section = IMAGE_FIRST_SECTION(nt_headers);

  if (section < nt_headers->FileHeader.NumberOfSections)
    return first_section + section;
  else
    return NULL;
}

WORD PEImage::GetNumSections() const {
  return GetNTHeaders()->FileHeader.NumberOfSections;
}

DWORD PEImage::GetImageDirectoryEntrySize(UINT directory) const {
  PIMAGE_NT_HEADERS nt_headers = GetNTHeaders();

  return nt_headers->OptionalHeader.DataDirectory[directory].Size;
}

PVOID PEImage::GetImageDirectoryEntryAddr(UINT directory) const {
  PIMAGE_NT_HEADERS nt_headers = GetNTHeaders();

  return RVAToAddr(
      nt_headers->OptionalHeader.DataDirectory[directory].VirtualAddress);
}

PIMAGE_SECTION_HEADER PEImage::GetImageSectionFromAddr(PVOID address) const {
  PBYTE target = reinterpret_cast<PBYTE>(address);
  PIMAGE_SECTION_HEADER section;

  for (UINT i = 0; NULL != (section = GetSectionHeader(i)); i++) {
    // Don't use the virtual RVAToAddr.
    PBYTE start = reinterpret_cast<PBYTE>(
                      PEImage::RVAToAddr(section->VirtualAddress));

    DWORD size = section->Misc.VirtualSize;

    if ((start <= target) && (start + size > target))
      return section;
  }

  return NULL;
}

PIMAGE_SECTION_HEADER PEImage::GetImageSectionHeaderByName(
    LPCSTR section_name) const {
  if (NULL == section_name)
    return NULL;

  PIMAGE_SECTION_HEADER ret = NULL;
  int num_sections = GetNumSections();

  for (int i = 0; i < num_sections; i++) {
    PIMAGE_SECTION_HEADER section = GetSectionHeader(i);
    if (0 == _strnicmp(reinterpret_cast<LPCSTR>(section->Name), section_name,
                       sizeof(section->Name))) {
      ret = section;
      break;
    }
  }

  return ret;
}

PDWORD PEImage::GetExportEntry(LPCSTR name) const {
  PIMAGE_EXPORT_DIRECTORY exports = GetExportDirectory();

  if (NULL == exports)
    return NULL;

  WORD ordinal = 0;
  if (!GetProcOrdinal(name, &ordinal))
    return NULL;

  PDWORD functions = reinterpret_cast<PDWORD>(
                         RVAToAddr(exports->AddressOfFunctions));

  return functions + ordinal - exports->Base;
}

FARPROC PEImage::GetProcAddress(LPCSTR function_name) const {
  PDWORD export_entry = GetExportEntry(function_name);
  if (NULL == export_entry)
    return NULL;

  PBYTE function = reinterpret_cast<PBYTE>(RVAToAddr(*export_entry));

  PBYTE exports = reinterpret_cast<PBYTE>(
      GetImageDirectoryEntryAddr(IMAGE_DIRECTORY_ENTRY_EXPORT));
  DWORD size = GetImageDirectoryEntrySize(IMAGE_DIRECTORY_ENTRY_EXPORT);

  // Check for forwarded exports as a special case.
  if (exports <= function && exports + size > function)
#pragma warning(push)
#pragma warning(disable: 4312)
    // This cast generates a warning because it is 32 bit specific.
    return reinterpret_cast<FARPROC>(0xFFFFFFFF);
#pragma warning(pop)

  return reinterpret_cast<FARPROC>(function);
}

bool PEImage::GetProcOrdinal(LPCSTR function_name, WORD *ordinal) const {
  if (NULL == ordinal)
    return false;

  PIMAGE_EXPORT_DIRECTORY exports = GetExportDirectory();

  if (NULL == exports)
    return false;

  if (IsOrdinal(function_name)) {
    *ordinal = ToOrdinal(function_name);
  } else {
    PDWORD names = reinterpret_cast<PDWORD>(RVAToAddr(exports->AddressOfNames));
    PDWORD lower = names;
    PDWORD upper = names + exports->NumberOfNames;
    int cmp = -1;

    // Binary Search for the name.
    while (lower != upper) {
      PDWORD middle = lower + (upper - lower) / 2;
      LPCSTR name = reinterpret_cast<LPCSTR>(RVAToAddr(*middle));

      cmp = strcmp(function_name, name);

      if (cmp == 0) {
        lower = middle;
        break;
      }

      if (cmp > 0)
        lower = middle + 1;
      else
        upper = middle;
    }

    if (cmp != 0)
      return false;


    PWORD ordinals = reinterpret_cast<PWORD>(
                         RVAToAddr(exports->AddressOfNameOrdinals));

    *ordinal = ordinals[lower - names] + static_cast<WORD>(exports->Base);
  }

  return true;
}

bool PEImage::EnumSections(EnumSectionsFunction callback, PVOID cookie) const {
  PIMAGE_NT_HEADERS nt_headers = GetNTHeaders();
  UINT num_sections = nt_headers->FileHeader.NumberOfSections;
  PIMAGE_SECTION_HEADER section = GetSectionHeader(0);

  for (UINT i = 0; i < num_sections; i++, section++) {
    PVOID section_start = RVAToAddr(section->VirtualAddress);
    DWORD size = section->Misc.VirtualSize;

    if (!callback(*this, section, section_start, size, cookie))
      return false;
  }

  return true;
}

bool PEImage::EnumExports(EnumExportsFunction callback, PVOID cookie) const {
  PVOID directory = GetImageDirectoryEntryAddr(IMAGE_DIRECTORY_ENTRY_EXPORT);
  DWORD size = GetImageDirectoryEntrySize(IMAGE_DIRECTORY_ENTRY_EXPORT);

  // Check if there are any exports at all.
  if (NULL == directory || 0 == size)
    return true;

  PIMAGE_EXPORT_DIRECTORY exports = reinterpret_cast<PIMAGE_EXPORT_DIRECTORY>(
                                        directory);
  UINT ordinal_base = exports->Base;
  UINT num_funcs = exports->NumberOfFunctions;
  UINT num_names = exports->NumberOfNames;
  PDWORD functions  = reinterpret_cast<PDWORD>(RVAToAddr(
                          exports->AddressOfFunctions));
  PDWORD names = reinterpret_cast<PDWORD>(RVAToAddr(exports->AddressOfNames));
  PWORD ordinals = reinterpret_cast<PWORD>(RVAToAddr(
                       exports->AddressOfNameOrdinals));

  for (UINT count = 0; count < num_funcs; count++) {
    PVOID func = RVAToAddr(functions[count]);
    if (NULL == func)
      continue;

    // Check for a name.
    LPCSTR name = NULL;
    UINT hint;
    for (hint = 0; hint < num_names; hint++) {
      if (ordinals[hint] == count) {
        name = reinterpret_cast<LPCSTR>(RVAToAddr(names[hint]));
        break;
      }
    }

    if (name == NULL)
      hint = 0;

    // Check for forwarded exports.
    LPCSTR forward = NULL;
    if (reinterpret_cast<char*>(func) >= reinterpret_cast<char*>(directory) &&
        reinterpret_cast<char*>(func) <= reinterpret_cast<char*>(directory) +
            size) {
      forward = reinterpret_cast<LPCSTR>(func);
      func = 0;
    }

    if (!callback(*this, ordinal_base + count, hint, name, func, forward,
                  cookie))
      return false;
  }

  return true;
}

bool PEImage::EnumRelocs(EnumRelocsFunction callback, PVOID cookie) const {
  PVOID directory = GetImageDirectoryEntryAddr(IMAGE_DIRECTORY_ENTRY_BASERELOC);
  DWORD size = GetImageDirectoryEntrySize(IMAGE_DIRECTORY_ENTRY_BASERELOC);
  PIMAGE_BASE_RELOCATION base = reinterpret_cast<PIMAGE_BASE_RELOCATION>(
      directory);

  if (directory == NULL || size < sizeof(IMAGE_BASE_RELOCATION))
    return true;

  while (base->SizeOfBlock) {
    PWORD reloc = reinterpret_cast<PWORD>(base + 1);
    UINT num_relocs = (base->SizeOfBlock - sizeof(IMAGE_BASE_RELOCATION)) /
        sizeof(WORD);

    for (UINT i = 0; i < num_relocs; i++, reloc++) {
      WORD type = *reloc >> 12;
      PVOID address = RVAToAddr(base->VirtualAddress + (*reloc & 0x0FFF));

      if (!callback(*this, type, address, cookie))
        return false;
    }

    base = reinterpret_cast<PIMAGE_BASE_RELOCATION>(
               reinterpret_cast<char*>(base) + base->SizeOfBlock);
  }

  return true;
}

bool PEImage::EnumImportChunks(EnumImportChunksFunction callback,
                               PVOID cookie) const {
  DWORD size = GetImageDirectoryEntrySize(IMAGE_DIRECTORY_ENTRY_IMPORT);
  PIMAGE_IMPORT_DESCRIPTOR import = GetFirstImportChunk();

  if (import == NULL || size < sizeof(IMAGE_IMPORT_DESCRIPTOR))
    return true;

  for (; import->FirstThunk; import++) {
    LPCSTR module_name = reinterpret_cast<LPCSTR>(RVAToAddr(import->Name));
    PIMAGE_THUNK_DATA name_table = reinterpret_cast<PIMAGE_THUNK_DATA>(
                                       RVAToAddr(import->OriginalFirstThunk));
    PIMAGE_THUNK_DATA iat = reinterpret_cast<PIMAGE_THUNK_DATA>(
                                RVAToAddr(import->FirstThunk));

    if (!callback(*this, module_name, name_table, iat, cookie))
      return false;
  }

  return true;
}

bool PEImage::EnumOneImportChunk(EnumImportsFunction callback,
                                 LPCSTR module_name,
                                 PIMAGE_THUNK_DATA name_table,
                                 PIMAGE_THUNK_DATA iat, PVOID cookie) const {
  if (NULL == name_table)
    return false;

  for (; name_table && name_table->u1.Ordinal; name_table++, iat++) {
    LPCSTR name = NULL;
    WORD ordinal = 0;
    WORD hint = 0;

    if (IMAGE_SNAP_BY_ORDINAL(name_table->u1.Ordinal)) {
      ordinal = static_cast<WORD>(IMAGE_ORDINAL32(name_table->u1.Ordinal));
    } else {
      PIMAGE_IMPORT_BY_NAME import = reinterpret_cast<PIMAGE_IMPORT_BY_NAME>(
          RVAToAddr(name_table->u1.ForwarderString));

      hint = import->Hint;
      name = reinterpret_cast<LPCSTR>(&import->Name);
    }

    if (!callback(*this, module_name, ordinal, name, hint, iat, cookie))
      return false;
  }

  return true;
}

bool PEImage::EnumAllImports(EnumImportsFunction callback, PVOID cookie) const {
  EnumAllImportsStorage temp = { callback, cookie };
  return EnumImportChunks(ProcessImportChunk, &temp);
}

bool PEImage::EnumDelayImportChunks(EnumDelayImportChunksFunction callback,
                                    PVOID cookie) const {
  PVOID directory = GetImageDirectoryEntryAddr(
                        IMAGE_DIRECTORY_ENTRY_DELAY_IMPORT);
  DWORD size = GetImageDirectoryEntrySize(IMAGE_DIRECTORY_ENTRY_DELAY_IMPORT);
  PImgDelayDescr delay_descriptor = reinterpret_cast<PImgDelayDescr>(directory);

  if (directory == NULL || size == 0)
    return true;

  for (; delay_descriptor->rvaHmod; delay_descriptor++) {
    PIMAGE_THUNK_DATA name_table;
    PIMAGE_THUNK_DATA iat;
    PIMAGE_THUNK_DATA bound_iat;    // address of the optional bound IAT
    PIMAGE_THUNK_DATA unload_iat;   // address of optional copy of original IAT
    LPCSTR module_name;

    // check if VC7-style imports, using RVAs instead of
    // VC6-style addresses.
    bool rvas = (delay_descriptor->grAttrs & dlattrRva) != 0;

    if (rvas) {
      module_name = reinterpret_cast<LPCSTR>(
                        RVAToAddr(delay_descriptor->rvaDLLName));
      name_table = reinterpret_cast<PIMAGE_THUNK_DATA>(
                       RVAToAddr(delay_descriptor->rvaINT));
      iat = reinterpret_cast<PIMAGE_THUNK_DATA>(
                RVAToAddr(delay_descriptor->rvaIAT));
      bound_iat = reinterpret_cast<PIMAGE_THUNK_DATA>(
                      RVAToAddr(delay_descriptor->rvaBoundIAT));
      unload_iat = reinterpret_cast<PIMAGE_THUNK_DATA>(
                       RVAToAddr(delay_descriptor->rvaUnloadIAT));
    } else {
#pragma warning(push)
#pragma warning(disable: 4312)
      // These casts generate warnings because they are 32 bit specific.
      module_name = reinterpret_cast<LPCSTR>(delay_descriptor->rvaDLLName);
      name_table = reinterpret_cast<PIMAGE_THUNK_DATA>(
                       delay_descriptor->rvaINT);
      iat = reinterpret_cast<PIMAGE_THUNK_DATA>(delay_descriptor->rvaIAT);
      bound_iat = reinterpret_cast<PIMAGE_THUNK_DATA>(
                      delay_descriptor->rvaBoundIAT);
      unload_iat = reinterpret_cast<PIMAGE_THUNK_DATA>(
                       delay_descriptor->rvaUnloadIAT);
#pragma warning(pop)
    }

    if (!callback(*this, delay_descriptor, module_name, name_table, iat,
                  bound_iat, unload_iat, cookie))
      return false;
  }

  return true;
}

bool PEImage::EnumOneDelayImportChunk(EnumImportsFunction callback,
                                      PImgDelayDescr delay_descriptor,
                                      LPCSTR module_name,
                                      PIMAGE_THUNK_DATA name_table,
                                      PIMAGE_THUNK_DATA iat,
                                      PIMAGE_THUNK_DATA bound_iat,
                                      PIMAGE_THUNK_DATA unload_iat,
                                      PVOID cookie) const {
  UNREFERENCED_PARAMETER(bound_iat);
  UNREFERENCED_PARAMETER(unload_iat);

  for (; name_table->u1.Ordinal; name_table++, iat++) {
    LPCSTR name = NULL;
    WORD ordinal = 0;
    WORD hint = 0;

    if (IMAGE_SNAP_BY_ORDINAL(name_table->u1.Ordinal)) {
      ordinal = static_cast<WORD>(IMAGE_ORDINAL32(name_table->u1.Ordinal));
    } else {
      PIMAGE_IMPORT_BY_NAME import;
      bool rvas = (delay_descriptor->grAttrs & dlattrRva) != 0;

      if (rvas) {
        import = reinterpret_cast<PIMAGE_IMPORT_BY_NAME>(
                     RVAToAddr(name_table->u1.ForwarderString));
      } else {
#pragma warning(push)
#pragma warning(disable: 4312)
        // This cast generates a warning because it is 32 bit specific.
        import = reinterpret_cast<PIMAGE_IMPORT_BY_NAME>(
                     name_table->u1.ForwarderString);
#pragma warning(pop)
      }

      hint = import->Hint;
      name = reinterpret_cast<LPCSTR>(&import->Name);
    }

    if (!callback(*this, module_name, ordinal, name, hint, iat, cookie))
      return false;
  }

  return true;
}

bool PEImage::EnumAllDelayImports(EnumImportsFunction callback,
                                  PVOID cookie) const {
  EnumAllImportsStorage temp = { callback, cookie };
  return EnumDelayImportChunks(ProcessDelayImportChunk, &temp);
}

bool PEImage::VerifyMagic() const {
  PIMAGE_DOS_HEADER dos_header = GetDosHeader();

  if (dos_header->e_magic != IMAGE_DOS_SIGNATURE)
    return false;

  PIMAGE_NT_HEADERS nt_headers = GetNTHeaders();

  if (nt_headers->Signature != IMAGE_NT_SIGNATURE)
    return false;

  if (nt_headers->FileHeader.SizeOfOptionalHeader !=
      sizeof(IMAGE_OPTIONAL_HEADER))
    return false;

  if (nt_headers->OptionalHeader.Magic != IMAGE_NT_OPTIONAL_HDR_MAGIC)
    return false;

  return true;
}

bool PEImage::ImageRVAToOnDiskOffset(DWORD rva, DWORD *on_disk_offset) const {
  LPVOID address = RVAToAddr(rva);
  return ImageAddrToOnDiskOffset(address, on_disk_offset);
}

bool PEImage::ImageAddrToOnDiskOffset(LPVOID address,
                                      DWORD *on_disk_offset) const {
  if (NULL == address)
    return false;

  // Get the section that this address belongs to.
  PIMAGE_SECTION_HEADER section_header = GetImageSectionFromAddr(address);
  if (NULL == section_header)
    return false;

#pragma warning(push)
#pragma warning(disable: 4311)
  // These casts generate warnings because they are 32 bit specific.
  // Don't follow the virtual RVAToAddr, use the one on the base.
  DWORD offset_within_section = reinterpret_cast<DWORD>(address) -
                                    reinterpret_cast<DWORD>(PEImage::RVAToAddr(
                                        section_header->VirtualAddress));
#pragma warning(pop)

  *on_disk_offset = section_header->PointerToRawData + offset_within_section;
  return true;
}

PVOID PEImage::RVAToAddr(DWORD_PTR rva) const {
  if (rva == 0)
    return NULL;

  return reinterpret_cast<char*>(module_) + rva;
}

PVOID PEImageAsData::RVAToAddr(DWORD_PTR rva) const {
  if (rva == 0)
    return NULL;

  PVOID in_memory = PEImage::RVAToAddr(rva);
  DWORD dummy;

  if (!ImageAddrToOnDiskOffset(in_memory, &dummy))
    return NULL;

  return in_memory;
}