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, ULONG_TYPE, ULONG_TYPE, ULONG_TYPE,
  27      ULONG_TYPE, ULONG_TYPE, ULONG_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(
  44     IPCInfo* ipc, base::string16* name, DWORD open_mode, DWORD pipe_mode,
  45     DWORD max_instances, DWORD out_buffer_size, DWORD in_buffer_size,
  46     DWORD default_timeout) {
  47   ipc->return_info.win32_result = ERROR_ACCESS_DENIED;
  48   ipc->return_info.handle = INVALID_HANDLE_VALUE;
  49
  50   std::vector<base::string16> paths;
  51   std::vector<base::string16> innerpaths;
  52   base::SplitString(*name, '/', &paths);
  53
  54   for (std::vector<base::string16>::const_iterator iter = paths.begin();
  55        iter != paths.end(); ++iter) {
  56     base::SplitString(*iter, '\\', &innerpaths);
  57     for (std::vector<base::string16>::const_iterator iter2 = innerpaths.begin();
  58          iter2 != innerpaths.end(); ++iter2) {
  59       if (*iter2 == L"..")
  60         return true;
  61     }
  62   }
  63
  64   const wchar_t* pipe_name = name->c_str();
  65   CountedParameterSet<NameBased> params;
  66   params[NameBased::NAME] = ParamPickerMake(pipe_name);
  67
  68   EvalResult eval = policy_base_->EvalPolicy(IPC_CREATENAMEDPIPEW_TAG,
  69                                              params.GetBase());
  70
  71   // "For file I/O, the "\\?\" prefix to a path string tells the Windows APIs to
  72   // disable all string parsing and to send the string that follows it straight
  73   // to the file system."
  74   // http://msdn.microsoft.com/en-us/library/aa365247(VS.85).aspx
  75   // This ensures even if there is a path traversal in the pipe name, and it is
  76   // able to get past the checks above, it will still not be allowed to escape
  77   // our whitelisted namespace.
  78   if (name->compare(0, 4, L"\\\\.\\") == 0)
  79     name->replace(0, 4, L"\\\\\?\\");
  80
  81   HANDLE pipe;
  82   DWORD ret = NamedPipePolicy::CreateNamedPipeAction(eval, *ipc->client_info,
  83                                                      *name, open_mode,
  84                                                      pipe_mode, max_instances,
  85                                                      out_buffer_size,
  86                                                      in_buffer_size,
  87                                                      default_timeout, &pipe);
  88
  89   ipc->return_info.win32_result = ret;
  90   ipc->return_info.handle = pipe;
  91   return true;
  92 }
  93
  94 }  // namespace sandbox