michael@0: // Copyright (c) 2006-2010 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #include "sandbox/win/src/eat_resolver.h"
michael@0: 
michael@0: #include "base/win/pe_image.h"
michael@0: #include "sandbox/win/src/sandbox_nt_util.h"
michael@0: 
michael@0: namespace sandbox {
michael@0: 
michael@0: NTSTATUS EatResolverThunk::Setup(const void* target_module,
michael@0:                                  const void* interceptor_module,
michael@0:                                  const char* target_name,
michael@0:                                  const char* interceptor_name,
michael@0:                                  const void* interceptor_entry_point,
michael@0:                                  void* thunk_storage,
michael@0:                                  size_t storage_bytes,
michael@0:                                  size_t* storage_used) {
michael@0:   NTSTATUS ret = Init(target_module, interceptor_module, target_name,
michael@0:                       interceptor_name, interceptor_entry_point,
michael@0:                       thunk_storage, storage_bytes);
michael@0:   if (!NT_SUCCESS(ret))
michael@0:     return ret;
michael@0: 
michael@0:   if (!eat_entry_)
michael@0:     return STATUS_INVALID_PARAMETER;
michael@0: 
michael@0:   size_t thunk_bytes = GetInternalThunkSize();
michael@0: 
michael@0: #if defined(_WIN64)
michael@0:   // We have two thunks, in order: the return path and the forward path.
michael@0:   if (!SetInternalThunk(thunk_storage, storage_bytes, NULL, target_))
michael@0:     return STATUS_BUFFER_TOO_SMALL;
michael@0: 
michael@0:   storage_bytes -= thunk_bytes;
michael@0:   thunk_storage = reinterpret_cast<char*>(thunk_storage) + thunk_bytes;
michael@0: #endif
michael@0: 
michael@0:   if (!SetInternalThunk(thunk_storage, storage_bytes, target_, interceptor_))
michael@0:     return STATUS_BUFFER_TOO_SMALL;
michael@0: 
michael@0:   AutoProtectMemory memory;
michael@0:   ret = memory.ChangeProtection(eat_entry_, sizeof(DWORD), PAGE_READWRITE);
michael@0:   if (!NT_SUCCESS(ret))
michael@0:     return ret;
michael@0: 
michael@0:   // Perform the patch.
michael@0: #pragma warning(push)
michael@0: #pragma warning(disable: 4311)
michael@0:   // These casts generate warnings because they are 32 bit specific.
michael@0:   *eat_entry_ = reinterpret_cast<DWORD>(thunk_storage) -
michael@0:                 reinterpret_cast<DWORD>(target_module);
michael@0: #pragma warning(pop)
michael@0: 
michael@0:   if (NULL != storage_used)
michael@0:     *storage_used = GetThunkSize();
michael@0: 
michael@0:   return ret;
michael@0: }
michael@0: 
michael@0: NTSTATUS EatResolverThunk::ResolveTarget(const void* module,
michael@0:                                          const char* function_name,
michael@0:                                          void** address) {
michael@0:   DCHECK_NT(address);
michael@0:   if (!module)
michael@0:     return STATUS_INVALID_PARAMETER;
michael@0: 
michael@0:   base::win::PEImage pe(module);
michael@0:   if (!pe.VerifyMagic())
michael@0:     return STATUS_INVALID_IMAGE_FORMAT;
michael@0: 
michael@0:   eat_entry_ = pe.GetExportEntry(function_name);
michael@0: 
michael@0:   if (!eat_entry_)
michael@0:     return STATUS_PROCEDURE_NOT_FOUND;
michael@0: 
michael@0:   *address = pe.RVAToAddr(*eat_entry_);
michael@0: 
michael@0:   return STATUS_SUCCESS;
michael@0: }
michael@0: 
michael@0: size_t EatResolverThunk::GetThunkSize() const {
michael@0: #if defined(_WIN64)
michael@0:   return GetInternalThunkSize() * 2;
michael@0: #else
michael@0:   return GetInternalThunkSize();
michael@0: #endif
michael@0: }
michael@0: 
michael@0: }  // namespace sandbox