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// Copyright (c) 2006-2010 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.
#include "sandbox/win/src/process_thread_dispatcher.h"
#include "base/basictypes.h"
#include "base/logging.h"
#include "sandbox/win/src/crosscall_client.h"
#include "sandbox/win/src/interception.h"
#include "sandbox/win/src/interceptors.h"
#include "sandbox/win/src/ipc_tags.h"
#include "sandbox/win/src/policy_broker.h"
#include "sandbox/win/src/policy_params.h"
#include "sandbox/win/src/process_thread_interception.h"
#include "sandbox/win/src/process_thread_policy.h"
#include "sandbox/win/src/sandbox.h"
namespace {
// Extracts the application name from a command line.
//
// The application name is the first element of the command line. If
// there is no quotes, the first element is delimited by the first space.
// If there are quotes, the first element is delimited by the quotes.
//
// The create process call is smarter than us. It tries really hard to launch
// the process even if the command line is wrong. For example:
// "c:\program files\test param" will first try to launch c:\program.exe then
// c:\program files\test.exe. We don't do that, we stop after at the first
// space when there is no quotes.
std::wstring GetPathFromCmdLine(const std::wstring &cmd_line) {
std::wstring exe_name;
// Check if it starts with '"'.
if (cmd_line[0] == L'\"') {
// Find the position of the second '"', this terminates the path.
std::wstring::size_type pos = cmd_line.find(L'\"', 1);
if (std::wstring::npos == pos)
return cmd_line;
exe_name = cmd_line.substr(1, pos - 1);
} else {
// There is no '"', that means that the appname is terminated at the
// first space.
std::wstring::size_type pos = cmd_line.find(L' ');
if (std::wstring::npos == pos) {
// There is no space, the cmd_line contains only the app_name
exe_name = cmd_line;
} else {
exe_name = cmd_line.substr(0, pos);
}
}
return exe_name;
}
// Returns true is the path in parameter is relative. False if it's
// absolute.
bool IsPathRelative(const std::wstring &path) {
// A path is Relative if it's not a UNC path beginnning with \\ or a
// path beginning with a drive. (i.e. X:\)
if (path.find(L"\\\\") == 0 || path.find(L":\\") == 1)
return false;
return true;
}
// Converts a relative path to an absolute path.
bool ConvertToAbsolutePath(const std::wstring& child_current_directory,
bool use_env_path, std::wstring *path) {
wchar_t file_buffer[MAX_PATH];
wchar_t *file_part = NULL;
// Here we should start by looking at the path where the child application was
// started. We don't have this information yet.
DWORD result = 0;
if (use_env_path) {
// Try with the complete path
result = ::SearchPath(NULL, path->c_str(), NULL, MAX_PATH, file_buffer,
&file_part);
}
if (0 == result) {
// Try with the current directory of the child
result = ::SearchPath(child_current_directory.c_str(), path->c_str(), NULL,
MAX_PATH, file_buffer, &file_part);
}
if (0 == result || result >= MAX_PATH)
return false;
*path = file_buffer;
return true;
}
} // namespace
namespace sandbox {
ThreadProcessDispatcher::ThreadProcessDispatcher(PolicyBase* policy_base)
: policy_base_(policy_base) {
static const IPCCall open_thread = {
{IPC_NTOPENTHREAD_TAG, ULONG_TYPE, ULONG_TYPE},
reinterpret_cast<CallbackGeneric>(
&ThreadProcessDispatcher::NtOpenThread)
};
static const IPCCall open_process = {
{IPC_NTOPENPROCESS_TAG, ULONG_TYPE, ULONG_TYPE},
reinterpret_cast<CallbackGeneric>(
&ThreadProcessDispatcher::NtOpenProcess)
};
static const IPCCall process_token = {
{IPC_NTOPENPROCESSTOKEN_TAG, VOIDPTR_TYPE, ULONG_TYPE},
reinterpret_cast<CallbackGeneric>(
&ThreadProcessDispatcher::NtOpenProcessToken)
};
static const IPCCall process_tokenex = {
{IPC_NTOPENPROCESSTOKENEX_TAG, VOIDPTR_TYPE, ULONG_TYPE, ULONG_TYPE},
reinterpret_cast<CallbackGeneric>(
&ThreadProcessDispatcher::NtOpenProcessTokenEx)
};
static const IPCCall create_params = {
{IPC_CREATEPROCESSW_TAG, WCHAR_TYPE, WCHAR_TYPE, WCHAR_TYPE, INOUTPTR_TYPE},
reinterpret_cast<CallbackGeneric>(
&ThreadProcessDispatcher::CreateProcessW)
};
ipc_calls_.push_back(open_thread);
ipc_calls_.push_back(open_process);
ipc_calls_.push_back(process_token);
ipc_calls_.push_back(process_tokenex);
ipc_calls_.push_back(create_params);
}
bool ThreadProcessDispatcher::SetupService(InterceptionManager* manager,
int service) {
switch (service) {
case IPC_NTOPENTHREAD_TAG:
case IPC_NTOPENPROCESS_TAG:
case IPC_NTOPENPROCESSTOKEN_TAG:
case IPC_NTOPENPROCESSTOKENEX_TAG:
// There is no explicit policy for these services.
NOTREACHED();
return false;
case IPC_CREATEPROCESSW_TAG:
return INTERCEPT_EAT(manager, L"kernel32.dll", CreateProcessW,
CREATE_PROCESSW_ID, 44) &&
INTERCEPT_EAT(manager, L"kernel32.dll", CreateProcessA,
CREATE_PROCESSA_ID, 44);
default:
return false;
}
}
bool ThreadProcessDispatcher::NtOpenThread(IPCInfo* ipc, DWORD desired_access,
DWORD thread_id) {
HANDLE handle;
NTSTATUS ret = ProcessPolicy::OpenThreadAction(*ipc->client_info,
desired_access, thread_id,
&handle);
ipc->return_info.nt_status = ret;
ipc->return_info.handle = handle;
return true;
}
bool ThreadProcessDispatcher::NtOpenProcess(IPCInfo* ipc, DWORD desired_access,
DWORD process_id) {
HANDLE handle;
NTSTATUS ret = ProcessPolicy::OpenProcessAction(*ipc->client_info,
desired_access, process_id,
&handle);
ipc->return_info.nt_status = ret;
ipc->return_info.handle = handle;
return true;
}
bool ThreadProcessDispatcher::NtOpenProcessToken(IPCInfo* ipc, HANDLE process,
DWORD desired_access) {
HANDLE handle;
NTSTATUS ret = ProcessPolicy::OpenProcessTokenAction(*ipc->client_info,
process, desired_access,
&handle);
ipc->return_info.nt_status = ret;
ipc->return_info.handle = handle;
return true;
}
bool ThreadProcessDispatcher::NtOpenProcessTokenEx(IPCInfo* ipc, HANDLE process,
DWORD desired_access,
DWORD attributes) {
HANDLE handle;
NTSTATUS ret = ProcessPolicy::OpenProcessTokenExAction(*ipc->client_info,
process,
desired_access,
attributes, &handle);
ipc->return_info.nt_status = ret;
ipc->return_info.handle = handle;
return true;
}
bool ThreadProcessDispatcher::CreateProcessW(IPCInfo* ipc, std::wstring* name,
std::wstring* cmd_line,
std::wstring* cur_dir,
CountedBuffer* info) {
if (sizeof(PROCESS_INFORMATION) != info->Size())
return false;
// Check if there is an application name.
std::wstring exe_name;
if (!name->empty())
exe_name = *name;
else
exe_name = GetPathFromCmdLine(*cmd_line);
if (IsPathRelative(exe_name)) {
if (!ConvertToAbsolutePath(*cur_dir, name->empty(), &exe_name)) {
// Cannot find the path. Maybe the file does not exist.
ipc->return_info.win32_result = ERROR_FILE_NOT_FOUND;
return true;
}
}
const wchar_t* const_exe_name = exe_name.c_str();
CountedParameterSet<NameBased> params;
params[NameBased::NAME] = ParamPickerMake(const_exe_name);
EvalResult eval = policy_base_->EvalPolicy(IPC_CREATEPROCESSW_TAG,
params.GetBase());
PROCESS_INFORMATION* proc_info =
reinterpret_cast<PROCESS_INFORMATION*>(info->Buffer());
// Here we force the app_name to be the one we used for the policy lookup.
// If our logic was wrong, at least we wont allow create a random process.
DWORD ret = ProcessPolicy::CreateProcessWAction(eval, *ipc->client_info,
exe_name, *cmd_line,
proc_info);
ipc->return_info.win32_result = ret;
return true;
}
} // namespace sandbox
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