sandbox/win/src/sync_policy.cc

   1 // Copyright (c) 2006-2008 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 <string>
   6
   7 #include "sandbox/win/src/sync_policy.h"
   8
   9 #include "base/logging.h"
  10 #include "base/strings/stringprintf.h"
  11 #include "sandbox/win/src/ipc_tags.h"
  12 #include "sandbox/win/src/nt_internals.h"
  13 #include "sandbox/win/src/policy_engine_opcodes.h"
  14 #include "sandbox/win/src/policy_params.h"
  15 #include "sandbox/win/src/sandbox_types.h"
  16 #include "sandbox/win/src/sandbox_utils.h"
  17 #include "sandbox/win/src/sync_interception.h"
  18 #include "sandbox/win/src/win_utils.h"
  19
  20 namespace sandbox {
  21
  22 // Provides functionality to resolve a symbolic link within the object
  23 // directory passed in.
  24 NTSTATUS ResolveSymbolicLink(const base::string16& directory_name,
  25                              const base::string16& name,
  26                              base::string16* target) {
  27   NtOpenDirectoryObjectFunction NtOpenDirectoryObject = NULL;
  28   ResolveNTFunctionPtr("NtOpenDirectoryObject", &NtOpenDirectoryObject);
  29
  30   NtQuerySymbolicLinkObjectFunction NtQuerySymbolicLinkObject = NULL;
  31   ResolveNTFunctionPtr("NtQuerySymbolicLinkObject",
  32                        &NtQuerySymbolicLinkObject);
  33
  34   NtOpenSymbolicLinkObjectFunction NtOpenSymbolicLinkObject = NULL;
  35   ResolveNTFunctionPtr("NtOpenSymbolicLinkObject", &NtOpenSymbolicLinkObject);
  36
  37   NtCloseFunction NtClose = NULL;
  38   ResolveNTFunctionPtr("NtClose", &NtClose);
  39
  40   OBJECT_ATTRIBUTES symbolic_link_directory_attributes = {};
  41   UNICODE_STRING symbolic_link_directory_string = {};
  42   InitObjectAttribs(directory_name, OBJ_CASE_INSENSITIVE, NULL,
  43                     &symbolic_link_directory_attributes,
  44                     &symbolic_link_directory_string, NULL);
  45
  46   HANDLE symbolic_link_directory = NULL;
  47   NTSTATUS status = NtOpenDirectoryObject(&symbolic_link_directory,
  48                                           DIRECTORY_QUERY,
  49                                           &symbolic_link_directory_attributes);
  50   if (status != STATUS_SUCCESS) {
  51     DLOG(ERROR) << "Failed to open symbolic link directory. Error: "
  52                 << status;
  53     return status;
  54   }
  55
  56   OBJECT_ATTRIBUTES symbolic_link_attributes = {};
  57   UNICODE_STRING name_string = {};
  58   InitObjectAttribs(name, OBJ_CASE_INSENSITIVE, symbolic_link_directory,
  59                     &symbolic_link_attributes, &name_string, NULL);
  60
  61   HANDLE symbolic_link = NULL;
  62   status = NtOpenSymbolicLinkObject(&symbolic_link, GENERIC_READ,
  63                                     &symbolic_link_attributes);
  64   NtClose(symbolic_link_directory);
  65   if (status != STATUS_SUCCESS) {
  66     DLOG(ERROR) << "Failed to open symbolic link Error: " << status;
  67     return status;
  68   }
  69
  70   UNICODE_STRING target_path = {};
  71   unsigned long target_length = 0;
  72   status = NtQuerySymbolicLinkObject(symbolic_link, &target_path,
  73                                      &target_length);
  74   if (status != STATUS_BUFFER_TOO_SMALL) {
  75     NtClose(symbolic_link);
  76     DLOG(ERROR) << "Failed to get length for symbolic link target. Error: "
  77                 << status;
  78     return status;
  79   }
  80
  81   target_path.Length = 0;
  82   target_path.MaximumLength = static_cast<USHORT>(target_length);
  83   target_path.Buffer = new wchar_t[target_path.MaximumLength + 1];
  84   status = NtQuerySymbolicLinkObject(symbolic_link, &target_path,
  85                                      &target_length);
  86   if (status == STATUS_SUCCESS) {
  87     target->assign(target_path.Buffer, target_length);
  88   } else {
  89     DLOG(ERROR) << "Failed to resolve symbolic link. Error: " << status;
  90   }
  91
  92   NtClose(symbolic_link);
  93   delete[] target_path.Buffer;
  94   return status;
  95 }
  96
  97 NTSTATUS GetBaseNamedObjectsDirectory(HANDLE* directory) {
  98   static HANDLE base_named_objects_handle = NULL;
  99   if (base_named_objects_handle) {
 100     *directory = base_named_objects_handle;
 101     return STATUS_SUCCESS;
 102   }
 103
 104   NtOpenDirectoryObjectFunction NtOpenDirectoryObject = NULL;
 105   ResolveNTFunctionPtr("NtOpenDirectoryObject", &NtOpenDirectoryObject);
 106
 107   DWORD session_id = 0;
 108   ProcessIdToSessionId(::GetCurrentProcessId(), &session_id);
 109
 110   base::string16 base_named_objects_path;
 111
 112   NTSTATUS status = ResolveSymbolicLink(L"\\Sessions\\BNOLINKS",
 113                                         base::StringPrintf(L"%d", session_id),
 114                                         &base_named_objects_path);
 115   if (status != STATUS_SUCCESS) {
 116     DLOG(ERROR) << "Failed to resolve BaseNamedObjects path. Error: "
 117                 << status;
 118     return status;
 119   }
 120
 121   UNICODE_STRING directory_name = {};
 122   OBJECT_ATTRIBUTES object_attributes = {};
 123   InitObjectAttribs(base_named_objects_path, OBJ_CASE_INSENSITIVE, NULL,
 124                     &object_attributes, &directory_name, NULL);
 125   status = NtOpenDirectoryObject(&base_named_objects_handle,
 126                                  DIRECTORY_ALL_ACCESS,
 127                                  &object_attributes);
 128   if (status == STATUS_SUCCESS)
 129     *directory = base_named_objects_handle;
 130   return status;
 131 }
 132
 133 bool SyncPolicy::GenerateRules(const wchar_t* name,
 134                                TargetPolicy::Semantics semantics,
 135                                LowLevelPolicy* policy) {
 136   base::string16 mod_name(name);
 137   if (mod_name.empty()) {
 138     return false;
 139   }
 140
 141   if (TargetPolicy::EVENTS_ALLOW_ANY != semantics &&
 142       TargetPolicy::EVENTS_ALLOW_READONLY != semantics) {
 143     // Other flags are not valid for sync policy yet.
 144     NOTREACHED();
 145     return false;
 146   }
 147
 148   // Add the open rule.
 149   EvalResult result = ASK_BROKER;
 150   PolicyRule open(result);
 151
 152   if (!open.AddStringMatch(IF, OpenEventParams::NAME, name, CASE_INSENSITIVE))
 153     return false;
 154
 155   if (TargetPolicy::EVENTS_ALLOW_READONLY == semantics) {
 156     // We consider all flags that are not known to be readonly as potentially
 157     // used for write.
 158     uint32 allowed_flags = SYNCHRONIZE | GENERIC_READ | READ_CONTROL;
 159     uint32 restricted_flags = ~allowed_flags;
 160     open.AddNumberMatch(IF_NOT, OpenEventParams::ACCESS, restricted_flags, AND);
 161   }
 162
 163   if (!policy->AddRule(IPC_OPENEVENT_TAG, &open))
 164     return false;
 165
 166   // If it's not a read only, add the create rule.
 167   if (TargetPolicy::EVENTS_ALLOW_READONLY != semantics) {
 168     PolicyRule create(result);
 169     if (!create.AddStringMatch(IF, NameBased::NAME, name, CASE_INSENSITIVE))
 170       return false;
 171
 172     if (!policy->AddRule(IPC_CREATEEVENT_TAG, &create))
 173       return false;
 174   }
 175
 176   return true;
 177 }
 178
 179 NTSTATUS SyncPolicy::CreateEventAction(EvalResult eval_result,
 180                                        const ClientInfo& client_info,
 181                                        const base::string16 &event_name,
 182                                        uint32 event_type,
 183                                        uint32 initial_state,
 184                                        HANDLE *handle) {
 185   NtCreateEventFunction NtCreateEvent = NULL;
 186   ResolveNTFunctionPtr("NtCreateEvent", &NtCreateEvent);
 187
 188   // The only action supported is ASK_BROKER which means create the requested
 189   // file as specified.
 190   if (ASK_BROKER != eval_result)
 191     return false;
 192
 193   HANDLE object_directory = NULL;
 194   NTSTATUS status = GetBaseNamedObjectsDirectory(&object_directory);
 195   if (status != STATUS_SUCCESS)
 196     return status;
 197
 198   UNICODE_STRING unicode_event_name = {};
 199   OBJECT_ATTRIBUTES object_attributes = {};
 200   InitObjectAttribs(event_name, OBJ_CASE_INSENSITIVE, object_directory,
 201                     &object_attributes, &unicode_event_name, NULL);
 202
 203   HANDLE local_handle = NULL;
 204   status = NtCreateEvent(&local_handle, EVENT_ALL_ACCESS, &object_attributes,
 205                          static_cast<EVENT_TYPE>(event_type),
 206                          static_cast<BOOLEAN>(initial_state));
 207   if (NULL == local_handle)
 208     return status;
 209
 210   if (!::DuplicateHandle(::GetCurrentProcess(), local_handle,
 211                          client_info.process, handle, 0, FALSE,
 212                          DUPLICATE_CLOSE_SOURCE | DUPLICATE_SAME_ACCESS)) {
 213     return STATUS_ACCESS_DENIED;
 214   }
 215   return status;
 216 }
 217
 218 NTSTATUS SyncPolicy::OpenEventAction(EvalResult eval_result,
 219                                      const ClientInfo& client_info,
 220                                      const base::string16 &event_name,
 221                                      uint32 desired_access,
 222                                      HANDLE *handle) {
 223   NtOpenEventFunction NtOpenEvent = NULL;
 224   ResolveNTFunctionPtr("NtOpenEvent", &NtOpenEvent);
 225
 226   // The only action supported is ASK_BROKER which means create the requested
 227   // event as specified.
 228   if (ASK_BROKER != eval_result)
 229     return false;
 230
 231   HANDLE object_directory = NULL;
 232   NTSTATUS status = GetBaseNamedObjectsDirectory(&object_directory);
 233   if (status != STATUS_SUCCESS)
 234     return status;
 235
 236   UNICODE_STRING unicode_event_name = {};
 237   OBJECT_ATTRIBUTES object_attributes = {};
 238   InitObjectAttribs(event_name, OBJ_CASE_INSENSITIVE, object_directory,
 239                     &object_attributes, &unicode_event_name, NULL);
 240
 241   HANDLE local_handle = NULL;
 242   status = NtOpenEvent(&local_handle, desired_access, &object_attributes);
 243   if (NULL == local_handle)
 244     return status;
 245
 246   if (!::DuplicateHandle(::GetCurrentProcess(), local_handle,
 247                          client_info.process, handle, 0, FALSE,
 248                          DUPLICATE_CLOSE_SOURCE | DUPLICATE_SAME_ACCESS)) {
 249     return STATUS_ACCESS_DENIED;
 250   }
 251   return status;
 252 }
 253
 254 }  // namespace sandbox