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Diffstat (limited to 'sandbox/src/handle_closer.cc')
| -rw-r--r-- | sandbox/src/handle_closer.cc | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/sandbox/src/handle_closer.cc b/sandbox/src/handle_closer.cc new file mode 100644 index 0000000..ee201de --- /dev/null +++ b/sandbox/src/handle_closer.cc @@ -0,0 +1,164 @@ +// Copyright (c) 2011 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/src/handle_closer.h" + +#include "base/logging.h" +#include "base/memory/scoped_ptr.h" +#include "sandbox/src/nt_internals.h" +#include "sandbox/src/win_utils.h" + +namespace sandbox { + +// Memory buffer mapped from the parent, with the list of handles. +SANDBOX_INTERCEPT HandleCloserInfo* g_handles_to_close; + +HandleCloser::HandleCloser() {} + +ResultCode HandleCloser::AddHandle(const char16* handle_type, + const char16* handle_name) { + if (!handle_type) + return SBOX_ERROR_BAD_PARAMS; + + HandleMap::iterator names = handles_to_close_.find(handle_type); + if (names == handles_to_close_.end()) { // We have no entries for this type. + std::pair<HandleMap::iterator, bool> result = handles_to_close_.insert( + HandleMap::value_type(handle_type, HandleMap::mapped_type())); + names = result.first; + if (handle_name) + names->second.insert(handle_name); + } else if (!handle_name) { // Now we need to close all handles of this type. + names->second.clear(); + } else if (!names->second.empty()) { // Add another name for this type. + names->second.insert(handle_name); + } // If we're already closing all handles of type then we're done. + + return SBOX_ALL_OK; +} + +size_t HandleCloser::GetBufferSize() { + size_t bytes_total = offsetof(HandleCloserInfo, handle_entries); + + for (HandleMap::iterator i = handles_to_close_.begin(); + i != handles_to_close_.end(); ++i) { + size_t bytes_entry = offsetof(HandleListEntry, handle_type) + + (i->first.size() + 1) * sizeof(char16); + for (HandleMap::mapped_type::iterator j = i->second.begin(); + j != i->second.end(); ++j) { + bytes_entry += ((*j).size() + 1) * sizeof(char16); + } + + // Round up to the nearest multiple of sizeof(size_t). + if (bytes_entry % sizeof(size_t)) + bytes_entry = (bytes_entry & ~(sizeof(size_t) - 1)) + sizeof(size_t); + + bytes_total += bytes_entry; + } + + return bytes_total; +} + +bool HandleCloser::InitializeTargetHandles(TargetProcess* target) { + // Do nothing on an empty list (global pointer already initialized to NULL). + if (handles_to_close_.empty()) + return true; + + size_t bytes_needed = GetBufferSize(); + scoped_array<size_t> local_buffer( + new size_t[bytes_needed / sizeof(size_t)]); + + if (!SetupHandleList(local_buffer.get(), bytes_needed)) + return false; + + HANDLE child = target->Process(); + + // Allocate memory in the target process without specifying the address + void* remote_data = ::VirtualAllocEx(child, NULL, bytes_needed, + MEM_COMMIT, PAGE_READWRITE); + if (NULL == remote_data) + return false; + + // Copy the handle buffer over. + SIZE_T bytes_written; + BOOL result = ::WriteProcessMemory(child, remote_data, local_buffer.get(), + bytes_needed, &bytes_written); + if (!result || bytes_written != bytes_needed) { + ::VirtualFreeEx(child, remote_data, 0, MEM_RELEASE); + return false; + } + + g_handles_to_close = reinterpret_cast<HandleCloserInfo*>(remote_data); + + ResultCode rc = target->TransferVariable("g_handles_to_close", + &g_handles_to_close, + sizeof(g_handles_to_close)); + + return (SBOX_ALL_OK == rc); +} + +bool HandleCloser::SetupHandleList(void* buffer, size_t buffer_bytes) { + ::ZeroMemory(buffer, buffer_bytes); + HandleCloserInfo* handle_info = reinterpret_cast<HandleCloserInfo*>(buffer); + handle_info->record_bytes = buffer_bytes; + handle_info->num_handle_types = handles_to_close_.size(); + + char16* output = reinterpret_cast<char16*>(&handle_info->handle_entries[0]); + char16* end = reinterpret_cast<char16*>( + reinterpret_cast<char*>(buffer) + buffer_bytes); + for (HandleMap::iterator i = handles_to_close_.begin(); + i != handles_to_close_.end(); ++i) { + if (output >= end) + return false; + HandleListEntry* list_entry = reinterpret_cast<HandleListEntry*>(output); + output = &list_entry->handle_type[0]; + + // Copy the typename and set the offset and count. + i->first._Copy_s(output, i->first.size(), i->first.size()); + *(output += i->first.size()) = L'\0'; + output++; + list_entry->offset_to_names = reinterpret_cast<char*>(output) - + reinterpret_cast<char*>(list_entry); + list_entry->name_count = i->second.size(); + + // Copy the handle names. + for (HandleMap::mapped_type::iterator j = i->second.begin(); + j != i->second.end(); ++j) { + output = std::copy((*j).begin(), (*j).end(), output) + 1; + } + + // Round up to the nearest multiple of sizeof(size_t). + output += (reinterpret_cast<size_t>(output) % sizeof(size_t)) / + sizeof(char16); + list_entry->record_bytes = reinterpret_cast<char*>(output) - + reinterpret_cast<char*>(list_entry); + } + + DCHECK(output == end); + return output <= end; +} + +bool GetHandleName(HANDLE handle, string16* handle_name) { + static NtQueryObject QueryObject = NULL; + if (!QueryObject) + ResolveNTFunctionPtr("NtQueryObject", &QueryObject); + + ULONG size = MAX_PATH; + scoped_ptr<UNICODE_STRING> name; + NTSTATUS result; + + do { + name.reset(reinterpret_cast<UNICODE_STRING*>(new BYTE[size])); + result = QueryObject(handle, ObjectNameInformation, name.get(), + size, &size); + } while (result == STATUS_INFO_LENGTH_MISMATCH); + + if (NT_SUCCESS(result) && name->Buffer && name->Length) + handle_name->assign(name->Buffer, name->Length / sizeof(wchar_t)); + else + handle_name->clear(); + + return NT_SUCCESS(result); +} + +} // namespace sandbox |