// Copyright 2015 The Crashpad Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "snapshot/win/pe_image_reader.h"
#include <stddef.h>
#include <string.h>
#include <algorithm>
#include <iterator>
#include "base/containers/heap_array.h"
#include "base/logging.h"
#include "base/strings/stringprintf.h"
#include "client/crashpad_info.h"
#include "snapshot/win/pe_image_resource_reader.h"
#include "util/misc/from_pointer_cast.h"
#include "util/misc/pdb_structures.h"
#include "util/win/process_structs.h"
namespace crashpad {
namespace {
// Map from Traits to an IMAGE_NT_HEADERSxx.
template <class Traits>
struct NtHeadersForTraits;
template <>
struct NtHeadersForTraits<process_types::internal::Traits32> {
using type = IMAGE_NT_HEADERS32;
};
template <>
struct NtHeadersForTraits<process_types::internal::Traits64> {
using type = IMAGE_NT_HEADERS64;
};
} // namespace
PEImageReader::PEImageReader()
: module_subrange_reader_(),
initialized_() {
}
PEImageReader::~PEImageReader() {
}
bool PEImageReader::Initialize(ProcessReaderWin* process_reader,
WinVMAddress address,
WinVMSize size,
const std::string& module_name) {
INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
if (!module_subrange_reader_.Initialize(
process_reader, address, size, module_name)) {
return false;
}
INITIALIZATION_STATE_SET_VALID(initialized_);
return true;
}
bool PEImageReader::GetCrashpadInfoSection(WinVMAddress* address,
WinVMSize* size) const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
if (module_subrange_reader_.Is64Bit()) {
return GetCrashpadInfoSectionInternal<process_types::internal::Traits64>(
address, size);
} else {
return GetCrashpadInfoSectionInternal<process_types::internal::Traits32>(
address, size);
}
}
template <class Traits>
bool PEImageReader::GetCrashpadInfo(
process_types::CrashpadInfo<Traits>* crashpad_info) const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
IMAGE_SECTION_HEADER section;
if (!GetSectionByName<typename NtHeadersForTraits<Traits>::type>("CPADinfo",
§ion)) {
return false;
}
if (section.Misc.VirtualSize <
offsetof(process_types::CrashpadInfo<Traits>, size) +
sizeof(crashpad_info->size)) {
LOG(WARNING) << "small crashpad info section size "
<< section.Misc.VirtualSize << ", "
<< module_subrange_reader_.name();
return false;
}
const WinVMAddress crashpad_info_address = Address() + section.VirtualAddress;
const WinVMSize crashpad_info_size =
std::min(static_cast<WinVMSize>(sizeof(*crashpad_info)),
static_cast<WinVMSize>(section.Misc.VirtualSize));
if (!module_subrange_reader_.ReadMemory(
crashpad_info_address, crashpad_info_size, crashpad_info)) {
LOG(WARNING) << "could not read crashpad info from "
<< module_subrange_reader_.name();
return false;
}
if (crashpad_info->size < sizeof(*crashpad_info)) {
// Zero out anything beyond the structure’s declared size.
memset(reinterpret_cast<char*>(crashpad_info) + crashpad_info->size,
0,
sizeof(*crashpad_info) - crashpad_info->size);
}
if (crashpad_info->signature != CrashpadInfo::kSignature ||
crashpad_info->version != 1) {
LOG(WARNING) << base::StringPrintf(
"unexpected crashpad info signature 0x%x, version %u in %s",
crashpad_info->signature,
crashpad_info->version,
module_subrange_reader_.name().c_str());
return false;
}
// Don’t require strict equality, to leave wiggle room for sloppy linkers.
if (crashpad_info->size > section.Misc.VirtualSize) {
LOG(WARNING) << "crashpad info struct size " << crashpad_info->size
<< " large for section size " << section.Misc.VirtualSize
<< " in " << module_subrange_reader_.name();
return false;
}
if (crashpad_info->size > sizeof(*crashpad_info)) {
// This isn’t strictly a problem, because unknown fields will simply be
// ignored, but it may be of diagnostic interest.
LOG(INFO) << "large crashpad info size " << crashpad_info->size << ", "
<< module_subrange_reader_.name();
}
return true;
}
bool PEImageReader::DebugDirectoryInformation(UUID* uuid,
DWORD* age,
std::string* pdbname) const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
IMAGE_DATA_DIRECTORY data_directory;
if (!ImageDataDirectoryEntry(IMAGE_DIRECTORY_ENTRY_DEBUG, &data_directory))
return false;
IMAGE_DEBUG_DIRECTORY debug_directory;
if (data_directory.Size % sizeof(debug_directory) != 0)
return false;
for (size_t offset = 0; offset < data_directory.Size;
offset += sizeof(debug_directory)) {
if (!module_subrange_reader_.ReadMemory(
Address() + data_directory.VirtualAddress + offset,
sizeof(debug_directory),
&debug_directory)) {
LOG(WARNING) << "could not read data directory from "
<< module_subrange_reader_.name();
return false;
}
if (debug_directory.Type != IMAGE_DEBUG_TYPE_CODEVIEW)
continue;
if (debug_directory.AddressOfRawData) {
if (debug_directory.SizeOfData < sizeof(CodeViewRecordPDB70)) {
LOG(WARNING) << "CodeView debug entry of unexpected size in "
<< module_subrange_reader_.name();
continue;
}
auto data = base::HeapArray<char>::Uninit(debug_directory.SizeOfData);
if (!module_subrange_reader_.ReadMemory(
Address() + debug_directory.AddressOfRawData,
data.size(),
data.data())) {
LOG(WARNING) << "could not read debug directory from "
<< module_subrange_reader_.name();
return false;
}
if (*reinterpret_cast<DWORD*>(data.data()) !=
CodeViewRecordPDB70::kSignature) {
LOG(WARNING) << "encountered non-7.0 CodeView debug record in "
<< module_subrange_reader_.name();
continue;
}
CodeViewRecordPDB70* codeview =
reinterpret_cast<CodeViewRecordPDB70*>(data.data());
*uuid = codeview->uuid;
*age = codeview->age;
// This is a NUL-terminated string encoded in the codepage of the system
// where the binary was linked. We have no idea what that was, so we just
// assume ASCII.
*pdbname = std::string(reinterpret_cast<char*>(&codeview->pdb_name[0]));
return true;
} else if (debug_directory.PointerToRawData) {
// This occurs for non-PDB based debug information. We simply ignore these
// as we don't expect to encounter modules that will be in this format
// for which we'll actually have symbols. See
// https://crashpad.chromium.org/bug/47.
}
}
return false;
}
bool PEImageReader::VSFixedFileInfo(
VS_FIXEDFILEINFO* vs_fixed_file_info) const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
IMAGE_DATA_DIRECTORY data_directory;
if (!ImageDataDirectoryEntry(IMAGE_DIRECTORY_ENTRY_RESOURCE,
&data_directory)) {
return false;
}
PEImageResourceReader resource_reader;
if (!resource_reader.Initialize(module_subrange_reader_, data_directory)) {
return false;
}
WinVMAddress address;
WinVMSize size;
if (!resource_reader.FindResourceByID(
FromPointerCast<uint16_t>(VS_FILE_INFO), // RT_VERSION
VS_VERSION_INFO,
MAKELANGID(LANG_NEUTRAL, SUBLANG_NEUTRAL),
&address,
&size,
nullptr)) {
return false;
}
// This structure is not declared anywhere in the SDK, but is documented at
// https://msdn.microsoft.com/library/ms647001.aspx.
struct VS_VERSIONINFO {
WORD wLength;
WORD wValueLength;
WORD wType;
// The structure documentation on MSDN doesn’t show the [16], but it does
// say that it’s supposed to be L"VS_VERSION_INFO", which is is in fact a
// 16-character string (including its NUL terminator).
WCHAR szKey[16];
WORD Padding1;
VS_FIXEDFILEINFO Value;
// Don’t include Children or the Padding2 that precedes it, because they may
// not be present.
// WORD Padding2;
// WORD Children;
};
VS_VERSIONINFO version_info;
if (size < sizeof(version_info)) {
LOG(WARNING) << "version info size " << size
<< " too small for structure of size " << sizeof(version_info)
<< " in " << module_subrange_reader_.name();
return false;
}
if (!module_subrange_reader_.ReadMemory(
address, sizeof(version_info), &version_info)) {
LOG(WARNING) << "could not read version info from "
<< module_subrange_reader_.name();
return false;
}
if (version_info.wLength < sizeof(version_info) ||
version_info.wValueLength != sizeof(version_info.Value) ||
version_info.wType != 0 ||
wcsncmp(version_info.szKey,
L"VS_VERSION_INFO",
std::size(version_info.szKey)) != 0) {
LOG(WARNING) << "unexpected VS_VERSIONINFO in "
<< module_subrange_reader_.name();
return false;
}
if (version_info.Value.dwSignature != VS_FFI_SIGNATURE ||
version_info.Value.dwStrucVersion != VS_FFI_STRUCVERSION) {
LOG(WARNING) << "unexpected VS_FIXEDFILEINFO in "
<< module_subrange_reader_.name();
return false;
}
*vs_fixed_file_info = version_info.Value;
vs_fixed_file_info->dwFileFlags &= vs_fixed_file_info->dwFileFlagsMask;
return true;
}
template <class Traits>
bool PEImageReader::GetCrashpadInfoSectionInternal(WinVMAddress* address,
WinVMSize* size) const {
IMAGE_SECTION_HEADER section;
if (!GetSectionByName<typename NtHeadersForTraits<Traits>::type>("CPADinfo",
§ion)) {
return false;
}
process_types::CrashpadInfo<Traits> crashpad_info;
if (section.Misc.VirtualSize <
offsetof(process_types::CrashpadInfo<Traits>, size) +
sizeof(crashpad_info.size)) {
LOG(WARNING) << "small crashpad info section size "
<< section.Misc.VirtualSize << ", "
<< module_subrange_reader_.name();
return false;
}
*address = Address() + section.VirtualAddress;
*size = std::min<WinVMSize>(sizeof(crashpad_info), section.Misc.VirtualSize);
return true;
}
template <class NtHeadersType>
bool PEImageReader::ReadNtHeaders(NtHeadersType* nt_headers,
WinVMAddress* nt_headers_address) const {
IMAGE_DOS_HEADER dos_header;
if (!module_subrange_reader_.ReadMemory(
Address(), sizeof(IMAGE_DOS_HEADER), &dos_header)) {
LOG(WARNING) << "could not read dos header from "
<< module_subrange_reader_.name();
return false;
}
if (dos_header.e_magic != IMAGE_DOS_SIGNATURE) {
LOG(WARNING) << "invalid e_magic in dos header of "
<< module_subrange_reader_.name();
return false;
}
WinVMAddress local_nt_headers_address = Address() + dos_header.e_lfanew;
if (!module_subrange_reader_.ReadMemory(
local_nt_headers_address, sizeof(NtHeadersType), nt_headers)) {
LOG(WARNING) << "could not read nt headers from "
<< module_subrange_reader_.name();
return false;
}
if (nt_headers->Signature != IMAGE_NT_SIGNATURE) {
LOG(WARNING) << "invalid signature in nt headers of "
<< module_subrange_reader_.name();
return false;
}
if (nt_headers_address)
*nt_headers_address = local_nt_headers_address;
return true;
}
template <class NtHeadersType>
bool PEImageReader::GetSectionByName(const std::string& name,
IMAGE_SECTION_HEADER* section) const {
if (name.size() > sizeof(section->Name)) {
LOG(WARNING) << "supplied section name too long " << name;
return false;
}
NtHeadersType nt_headers;
WinVMAddress nt_headers_address;
if (!ReadNtHeaders(&nt_headers, &nt_headers_address))
return false;
WinVMAddress first_section_address =
nt_headers_address + offsetof(NtHeadersType, OptionalHeader) +
nt_headers.FileHeader.SizeOfOptionalHeader;
for (DWORD i = 0; i < nt_headers.FileHeader.NumberOfSections; ++i) {
WinVMAddress section_address =
first_section_address + sizeof(IMAGE_SECTION_HEADER) * i;
if (!module_subrange_reader_.ReadMemory(
section_address, sizeof(IMAGE_SECTION_HEADER), section)) {
LOG(WARNING) << "could not read section " << i << " from "
<< module_subrange_reader_.name();
return false;
}
if (strncmp(reinterpret_cast<const char*>(section->Name),
name.c_str(),
sizeof(section->Name)) == 0) {
return true;
}
}
return false;
}
bool PEImageReader::ImageDataDirectoryEntry(size_t index,
IMAGE_DATA_DIRECTORY* entry) const {
bool rv;
if (module_subrange_reader_.Is64Bit()) {
rv = ImageDataDirectoryEntryT<IMAGE_NT_HEADERS64>(index, entry);
} else {
rv = ImageDataDirectoryEntryT<IMAGE_NT_HEADERS32>(index, entry);
}
return rv && entry->VirtualAddress != 0 && entry->Size != 0;
}
template <class NtHeadersType>
bool PEImageReader::ImageDataDirectoryEntryT(
size_t index,
IMAGE_DATA_DIRECTORY* entry) const {
NtHeadersType nt_headers;
if (!ReadNtHeaders(&nt_headers, nullptr)) {
return false;
}
if (nt_headers.FileHeader.SizeOfOptionalHeader <
offsetof(decltype(nt_headers.OptionalHeader), DataDirectory[index]) +
sizeof(nt_headers.OptionalHeader.DataDirectory[index]) ||
nt_headers.OptionalHeader.NumberOfRvaAndSizes <= index) {
return false;
}
*entry = nt_headers.OptionalHeader.DataDirectory[index];
return true;
}
// Explicit instantiations with the only 2 valid template arguments to avoid
// putting the body of the function in the header.
template bool PEImageReader::GetCrashpadInfo<process_types::internal::Traits32>(
process_types::CrashpadInfo<process_types::internal::Traits32>*
crashpad_info) const;
template bool PEImageReader::GetCrashpadInfo<process_types::internal::Traits64>(
process_types::CrashpadInfo<process_types::internal::Traits64>*
crashpad_info) const;
} // namespace crashpad
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