sandbox/win/src/named_pipe_dispatcher.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "sandbox/win/src/named_pipe_dispatcher.h"
   6
   7 #include "base/basictypes.h"
   8 #include "base/strings/string_split.h"
   9
  10 #include "sandbox/win/src/crosscall_client.h"
  11 #include "sandbox/win/src/interception.h"
  12 #include "sandbox/win/src/interceptors.h"
  13 #include "sandbox/win/src/ipc_tags.h"
  14 #include "sandbox/win/src/named_pipe_interception.h"
  15 #include "sandbox/win/src/named_pipe_policy.h"
  16 #include "sandbox/win/src/policy_broker.h"
  17 #include "sandbox/win/src/policy_params.h"
  18 #include "sandbox/win/src/sandbox.h"
  19
  20
  21 namespace sandbox {
  22
  23 NamedPipeDispatcher::NamedPipeDispatcher(PolicyBase* policy_base)
  24     : policy_base_(policy_base) {
  25   static const IPCCall create_params = {
  26     {IPC_CREATENAMEDPIPEW_TAG, WCHAR_TYPE, UINT32_TYPE, UINT32_TYPE,
  27      UINT32_TYPE, UINT32_TYPE, UINT32_TYPE, UINT32_TYPE},
  28     reinterpret_cast<CallbackGeneric>(&NamedPipeDispatcher::CreateNamedPipe)
  29   };
  30
  31   ipc_calls_.push_back(create_params);
  32 }
  33
  34 bool NamedPipeDispatcher::SetupService(InterceptionManager* manager,
  35                                        int service) {
  36   if (IPC_CREATENAMEDPIPEW_TAG == service)
  37     return INTERCEPT_EAT(manager, kKerneldllName, CreateNamedPipeW,
  38                          CREATE_NAMED_PIPE_ID, 36);
  39
  40   return false;
  41 }
  42
  43 bool NamedPipeDispatcher::CreateNamedPipe(IPCInfo* ipc,
  44                                           base::string16* name,
  45                                           uint32 open_mode,
  46                                           uint32 pipe_mode,
  47                                           uint32 max_instances,
  48                                           uint32 out_buffer_size,
  49                                           uint32 in_buffer_size,
  50                                           uint32 default_timeout) {
  51   ipc->return_info.win32_result = ERROR_ACCESS_DENIED;
  52   ipc->return_info.handle = INVALID_HANDLE_VALUE;
  53
  54   std::vector<base::string16> paths;
  55   std::vector<base::string16> innerpaths;
  56   base::SplitString(*name, '/', &paths);
  57
  58   for (std::vector<base::string16>::const_iterator iter = paths.begin();
  59        iter != paths.end(); ++iter) {
  60     base::SplitString(*iter, '\\', &innerpaths);
  61     for (std::vector<base::string16>::const_iterator iter2 = innerpaths.begin();
  62          iter2 != innerpaths.end(); ++iter2) {
  63       if (*iter2 == L"..")
  64         return true;
  65     }
  66   }
  67
  68   const wchar_t* pipe_name = name->c_str();
  69   CountedParameterSet<NameBased> params;
  70   params[NameBased::NAME] = ParamPickerMake(pipe_name);
  71
  72   EvalResult eval = policy_base_->EvalPolicy(IPC_CREATENAMEDPIPEW_TAG,
  73                                              params.GetBase());
  74
  75   // "For file I/O, the "\\?\" prefix to a path string tells the Windows APIs to
  76   // disable all string parsing and to send the string that follows it straight
  77   // to the file system."
  78   // http://msdn.microsoft.com/en-us/library/aa365247(VS.85).aspx
  79   // This ensures even if there is a path traversal in the pipe name, and it is
  80   // able to get past the checks above, it will still not be allowed to escape
  81   // our whitelisted namespace.
  82   if (name->compare(0, 4, L"\\\\.\\") == 0)
  83     name->replace(0, 4, L"\\\\\?\\");
  84
  85   HANDLE pipe;
  86   DWORD ret = NamedPipePolicy::CreateNamedPipeAction(eval, *ipc->client_info,
  87                                                      *name, open_mode,
  88                                                      pipe_mode, max_instances,
  89                                                      out_buffer_size,
  90                                                      in_buffer_size,
  91                                                      default_timeout, &pipe);
  92
  93   ipc->return_info.win32_result = ret;
  94   ipc->return_info.handle = pipe;
  95   return true;
  96 }
  97
  98 }  // namespace sandbox