dbus/message.cc

   1 // Copyright (c) 2012 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 "dbus/message.h"
   6
   7 #include <string>
   8
   9 #include "base/basictypes.h"
  10 #include "base/format_macros.h"
  11 #include "base/logging.h"
  12 #include "base/strings/string_util.h"
  13 #include "base/strings/stringprintf.h"
  14 #include "dbus/object_path.h"
  15
  16 #if defined(USE_SYSTEM_PROTOBUF)
  17 #include <google/protobuf/message_lite.h>
  18 #else
  19 #include "third_party/protobuf/src/google/protobuf/message_lite.h"
  20 #endif
  21
  22 namespace {
  23
  24 // Appends the header name and the value to |output|, if the value is
  25 // not empty.
  26 void AppendStringHeader(const std::string& header_name,
  27                         const std::string& header_value,
  28                         std::string* output) {
  29   if (!header_value.empty()) {
  30     *output += header_name + ": " + header_value + "\n";
  31   }
  32 }
  33
  34 // Appends the header name and the value to |output|, if the value is
  35 // nonzero.
  36 void AppendUint32Header(const std::string& header_name,
  37                         uint32 header_value,
  38                         std::string* output) {
  39   if (header_value != 0) {
  40     *output += (header_name + ": " + base::StringPrintf("%u", header_value) +
  41                 "\n");
  42   }
  43 }
  44
  45 }  // namespace
  46
  47 namespace dbus {
  48
  49 bool IsDBusTypeUnixFdSupported() {
  50   int major = 0, minor = 0, micro = 0;
  51   dbus_get_version(&major, &minor, &micro);
  52   return major >= 1 && minor >= 4;
  53 }
  54
  55 Message::Message()
  56     : raw_message_(NULL) {
  57 }
  58
  59 Message::~Message() {
  60   if (raw_message_)
  61     dbus_message_unref(raw_message_);
  62 }
  63
  64 void Message::Init(DBusMessage* raw_message) {
  65   DCHECK(!raw_message_);
  66   raw_message_ = raw_message;
  67 }
  68
  69 Message::MessageType Message::GetMessageType() {
  70   if (!raw_message_)
  71     return MESSAGE_INVALID;
  72   const int type = dbus_message_get_type(raw_message_);
  73   return static_cast<Message::MessageType>(type);
  74 }
  75
  76 std::string Message::GetMessageTypeAsString() {
  77   switch (GetMessageType()) {
  78     case MESSAGE_INVALID:
  79       return "MESSAGE_INVALID";
  80     case MESSAGE_METHOD_CALL:
  81       return "MESSAGE_METHOD_CALL";
  82     case MESSAGE_METHOD_RETURN:
  83       return "MESSAGE_METHOD_RETURN";
  84     case MESSAGE_SIGNAL:
  85       return "MESSAGE_SIGNAL";
  86     case MESSAGE_ERROR:
  87       return "MESSAGE_ERROR";
  88   }
  89   NOTREACHED();
  90   return std::string();
  91 }
  92
  93 std::string Message::ToStringInternal(const std::string& indent,
  94                                       MessageReader* reader) {
  95   const char* kBrokenMessage = "[broken message]";
  96   std::string output;
  97   while (reader->HasMoreData()) {
  98     const DataType type = reader->GetDataType();
  99     switch (type) {
 100       case BYTE: {
 101         uint8 value = 0;
 102         if (!reader->PopByte(&value))
 103           return kBrokenMessage;
 104         output += indent + "byte " + base::StringPrintf("%d", value) + "\n";
 105         break;
 106       }
 107       case BOOL: {
 108         bool value = false;
 109         if (!reader->PopBool(&value))
 110           return kBrokenMessage;
 111         output += indent + "bool " + (value ? "true" : "false") + "\n";
 112         break;
 113       }
 114       case INT16: {
 115         int16 value = 0;
 116         if (!reader->PopInt16(&value))
 117           return kBrokenMessage;
 118         output += indent + "int16 " + base::StringPrintf("%d", value) + "\n";
 119         break;
 120       }
 121       case UINT16: {
 122         uint16 value = 0;
 123         if (!reader->PopUint16(&value))
 124           return kBrokenMessage;
 125         output += indent + "uint16 " + base::StringPrintf("%d", value) + "\n";
 126         break;
 127       }
 128       case INT32: {
 129         int32 value = 0;
 130         if (!reader->PopInt32(&value))
 131           return kBrokenMessage;
 132         output += indent + "int32 " + base::StringPrintf("%d", value) + "\n";
 133         break;
 134       }
 135       case UINT32: {
 136         uint32 value = 0;
 137         if (!reader->PopUint32(&value))
 138           return kBrokenMessage;
 139         output += indent + "uint32 " + base::StringPrintf("%u", value) + "\n";
 140         break;
 141       }
 142       case INT64: {
 143         int64 value = 0;
 144         if (!reader->PopInt64(&value))
 145           return kBrokenMessage;
 146         output += (indent + "int64 " +
 147                    base::StringPrintf("%" PRId64, value) + "\n");
 148         break;
 149       }
 150       case UINT64: {
 151         uint64 value = 0;
 152         if (!reader->PopUint64(&value))
 153           return kBrokenMessage;
 154         output += (indent + "uint64 " +
 155                    base::StringPrintf("%" PRIu64, value) + "\n");
 156         break;
 157       }
 158       case DOUBLE: {
 159         double value = 0;
 160         if (!reader->PopDouble(&value))
 161           return kBrokenMessage;
 162         output += indent + "double " + base::StringPrintf("%f", value) + "\n";
 163         break;
 164       }
 165       case STRING: {
 166         std::string value;
 167         if (!reader->PopString(&value))
 168           return kBrokenMessage;
 169         // Truncate if the string is longer than the limit.
 170         const size_t kTruncateLength = 100;
 171         if (value.size() < kTruncateLength) {
 172           output += indent + "string \"" + value + "\"\n";
 173         } else {
 174           std::string truncated;
 175           base::TruncateUTF8ToByteSize(value, kTruncateLength, &truncated);
 176           base::StringAppendF(&truncated, "... (%" PRIuS " bytes in total)",
 177                               value.size());
 178           output += indent + "string \"" + truncated + "\"\n";
 179         }
 180         break;
 181       }
 182       case OBJECT_PATH: {
 183         ObjectPath value;
 184         if (!reader->PopObjectPath(&value))
 185           return kBrokenMessage;
 186         output += indent + "object_path \"" + value.value() + "\"\n";
 187         break;
 188       }
 189       case ARRAY: {
 190         MessageReader sub_reader(this);
 191         if (!reader->PopArray(&sub_reader))
 192           return kBrokenMessage;
 193         output += indent + "array [\n";
 194         output += ToStringInternal(indent + "  ", &sub_reader);
 195         output += indent + "]\n";
 196         break;
 197       }
 198       case STRUCT: {
 199         MessageReader sub_reader(this);
 200         if (!reader->PopStruct(&sub_reader))
 201           return kBrokenMessage;
 202         output += indent + "struct {\n";
 203         output += ToStringInternal(indent + "  ", &sub_reader);
 204         output += indent + "}\n";
 205         break;
 206       }
 207       case DICT_ENTRY: {
 208         MessageReader sub_reader(this);
 209         if (!reader->PopDictEntry(&sub_reader))
 210           return kBrokenMessage;
 211         output += indent + "dict entry {\n";
 212         output += ToStringInternal(indent + "  ", &sub_reader);
 213         output += indent + "}\n";
 214         break;
 215       }
 216       case VARIANT: {
 217         MessageReader sub_reader(this);
 218         if (!reader->PopVariant(&sub_reader))
 219           return kBrokenMessage;
 220         output += indent + "variant ";
 221         output += ToStringInternal(indent + "  ", &sub_reader);
 222         break;
 223       }
 224       case UNIX_FD: {
 225         CHECK(IsDBusTypeUnixFdSupported());
 226
 227         FileDescriptor file_descriptor;
 228         if (!reader->PopFileDescriptor(&file_descriptor))
 229           return kBrokenMessage;
 230         output += indent + "fd#" +
 231                   base::StringPrintf("%d", file_descriptor.value()) + "\n";
 232         break;
 233       }
 234       default:
 235         LOG(FATAL) << "Unknown type: " << type;
 236     }
 237   }
 238   return output;
 239 }
 240
 241 // The returned string consists of message headers such as
 242 // destination if any, followed by a blank line, and the message
 243 // payload. For example, a MethodCall's ToString() will look like:
 244 //
 245 // destination: com.example.Service
 246 // path: /com/example/Object
 247 // interface: com.example.Interface
 248 // member: SomeMethod
 249 //
 250 // string \"payload\"
 251 // ...
 252 std::string Message::ToString() {
 253   if (!raw_message_)
 254     return std::string();
 255
 256   // Generate headers first.
 257   std::string headers;
 258   AppendStringHeader("message_type", GetMessageTypeAsString(), &headers);
 259   AppendStringHeader("destination", GetDestination(), &headers);
 260   AppendStringHeader("path", GetPath().value(), &headers);
 261   AppendStringHeader("interface", GetInterface(), &headers);
 262   AppendStringHeader("member", GetMember(), &headers);
 263   AppendStringHeader("error_name", GetErrorName(), &headers);
 264   AppendStringHeader("sender", GetSender(), &headers);
 265   AppendStringHeader("signature", GetSignature(), &headers);
 266   AppendUint32Header("serial", GetSerial(), &headers);
 267   AppendUint32Header("reply_serial", GetReplySerial(), &headers);
 268
 269   // Generate the payload.
 270   MessageReader reader(this);
 271   return headers + "\n" + ToStringInternal(std::string(), &reader);
 272 }
 273
 274 bool Message::SetDestination(const std::string& destination) {
 275   return dbus_message_set_destination(raw_message_, destination.c_str());
 276 }
 277
 278 bool Message::SetPath(const ObjectPath& path) {
 279   return dbus_message_set_path(raw_message_, path.value().c_str());
 280 }
 281
 282 bool Message::SetInterface(const std::string& interface) {
 283   return dbus_message_set_interface(raw_message_, interface.c_str());
 284 }
 285
 286 bool Message::SetMember(const std::string& member) {
 287   return dbus_message_set_member(raw_message_, member.c_str());
 288 }
 289
 290 bool Message::SetErrorName(const std::string& error_name) {
 291   return dbus_message_set_error_name(raw_message_, error_name.c_str());
 292 }
 293
 294 bool Message::SetSender(const std::string& sender) {
 295   return dbus_message_set_sender(raw_message_, sender.c_str());
 296 }
 297
 298 void Message::SetSerial(uint32 serial) {
 299   dbus_message_set_serial(raw_message_, serial);
 300 }
 301
 302 void Message::SetReplySerial(uint32 reply_serial) {
 303   dbus_message_set_reply_serial(raw_message_, reply_serial);
 304 }
 305
 306 std::string Message::GetDestination() {
 307   const char* destination = dbus_message_get_destination(raw_message_);
 308   return destination ? destination : "";
 309 }
 310
 311 ObjectPath Message::GetPath() {
 312   const char* path = dbus_message_get_path(raw_message_);
 313   return ObjectPath(path ? path : "");
 314 }
 315
 316 std::string Message::GetInterface() {
 317   const char* interface = dbus_message_get_interface(raw_message_);
 318   return interface ? interface : "";
 319 }
 320
 321 std::string Message::GetMember() {
 322   const char* member = dbus_message_get_member(raw_message_);
 323   return member ? member : "";
 324 }
 325
 326 std::string Message::GetErrorName() {
 327   const char* error_name = dbus_message_get_error_name(raw_message_);
 328   return error_name ? error_name : "";
 329 }
 330
 331 std::string Message::GetSender() {
 332   const char* sender = dbus_message_get_sender(raw_message_);
 333   return sender ? sender : "";
 334 }
 335
 336 std::string Message::GetSignature() {
 337   const char* signature = dbus_message_get_signature(raw_message_);
 338   return signature ? signature : "";
 339 }
 340
 341 uint32 Message::GetSerial() {
 342   return dbus_message_get_serial(raw_message_);
 343 }
 344
 345 uint32 Message::GetReplySerial() {
 346   return dbus_message_get_reply_serial(raw_message_);
 347 }
 348
 349 //
 350 // MethodCall implementation.
 351 //
 352
 353 MethodCall::MethodCall(const std::string& interface_name,
 354                        const std::string& method_name)
 355     : Message() {
 356   Init(dbus_message_new(DBUS_MESSAGE_TYPE_METHOD_CALL));
 357
 358   CHECK(SetInterface(interface_name));
 359   CHECK(SetMember(method_name));
 360 }
 361
 362 MethodCall::MethodCall() : Message() {
 363 }
 364
 365 MethodCall* MethodCall::FromRawMessage(DBusMessage* raw_message) {
 366   DCHECK_EQ(DBUS_MESSAGE_TYPE_METHOD_CALL, dbus_message_get_type(raw_message));
 367
 368   MethodCall* method_call = new MethodCall;
 369   method_call->Init(raw_message);
 370   return method_call;
 371 }
 372
 373 //
 374 // Signal implementation.
 375 //
 376 Signal::Signal(const std::string& interface_name,
 377                const std::string& method_name)
 378     : Message() {
 379   Init(dbus_message_new(DBUS_MESSAGE_TYPE_SIGNAL));
 380
 381   CHECK(SetInterface(interface_name));
 382   CHECK(SetMember(method_name));
 383 }
 384
 385 Signal::Signal() : Message() {
 386 }
 387
 388 Signal* Signal::FromRawMessage(DBusMessage* raw_message) {
 389   DCHECK_EQ(DBUS_MESSAGE_TYPE_SIGNAL, dbus_message_get_type(raw_message));
 390
 391   Signal* signal = new Signal;
 392   signal->Init(raw_message);
 393   return signal;
 394 }
 395
 396 //
 397 // Response implementation.
 398 //
 399
 400 Response::Response() : Message() {
 401 }
 402
 403 scoped_ptr<Response> Response::FromRawMessage(DBusMessage* raw_message) {
 404   DCHECK_EQ(DBUS_MESSAGE_TYPE_METHOD_RETURN,
 405             dbus_message_get_type(raw_message));
 406
 407   scoped_ptr<Response> response(new Response);
 408   response->Init(raw_message);
 409   return response.Pass();
 410 }
 411
 412 scoped_ptr<Response> Response::FromMethodCall(MethodCall* method_call) {
 413   scoped_ptr<Response> response(new Response);
 414   response->Init(dbus_message_new_method_return(method_call->raw_message()));
 415   return response.Pass();
 416 }
 417
 418 scoped_ptr<Response> Response::CreateEmpty() {
 419   scoped_ptr<Response> response(new Response);
 420   response->Init(dbus_message_new(DBUS_MESSAGE_TYPE_METHOD_RETURN));
 421   return response.Pass();
 422 }
 423
 424 //
 425 // ErrorResponse implementation.
 426 //
 427
 428 ErrorResponse::ErrorResponse() : Response() {
 429 }
 430
 431 scoped_ptr<ErrorResponse> ErrorResponse::FromRawMessage(
 432     DBusMessage* raw_message) {
 433   DCHECK_EQ(DBUS_MESSAGE_TYPE_ERROR, dbus_message_get_type(raw_message));
 434
 435   scoped_ptr<ErrorResponse> response(new ErrorResponse);
 436   response->Init(raw_message);
 437   return response.Pass();
 438 }
 439
 440 scoped_ptr<ErrorResponse> ErrorResponse::FromMethodCall(
 441     MethodCall* method_call,
 442     const std::string& error_name,
 443     const std::string& error_message) {
 444   scoped_ptr<ErrorResponse> response(new ErrorResponse);
 445   response->Init(dbus_message_new_error(method_call->raw_message(),
 446                                         error_name.c_str(),
 447                                         error_message.c_str()));
 448   return response.Pass();
 449 }
 450
 451 //
 452 // MessageWriter implementation.
 453 //
 454
 455 MessageWriter::MessageWriter(Message* message)
 456     : message_(message),
 457       container_is_open_(false) {
 458   memset(&raw_message_iter_, 0, sizeof(raw_message_iter_));
 459   if (message)
 460     dbus_message_iter_init_append(message_->raw_message(), &raw_message_iter_);
 461 }
 462
 463 MessageWriter::~MessageWriter() {
 464 }
 465
 466 void MessageWriter::AppendByte(uint8 value) {
 467   AppendBasic(DBUS_TYPE_BYTE, &value);
 468 }
 469
 470 void MessageWriter::AppendBool(bool value) {
 471   // The size of dbus_bool_t and the size of bool are different. The
 472   // former is always 4 per dbus-types.h, whereas the latter is usually 1.
 473   // dbus_message_iter_append_basic() used in AppendBasic() expects four
 474   // bytes for DBUS_TYPE_BOOLEAN, so we must pass a dbus_bool_t, instead
 475   // of a bool, to AppendBasic().
 476   dbus_bool_t dbus_value = value;
 477   AppendBasic(DBUS_TYPE_BOOLEAN, &dbus_value);
 478 }
 479
 480 void MessageWriter::AppendInt16(int16 value) {
 481   AppendBasic(DBUS_TYPE_INT16, &value);
 482 }
 483
 484 void MessageWriter::AppendUint16(uint16 value) {
 485   AppendBasic(DBUS_TYPE_UINT16, &value);
 486 }
 487
 488 void MessageWriter::AppendInt32(int32 value) {
 489   AppendBasic(DBUS_TYPE_INT32, &value);
 490 }
 491
 492 void MessageWriter::AppendUint32(uint32 value) {
 493   AppendBasic(DBUS_TYPE_UINT32, &value);
 494 }
 495
 496 void MessageWriter::AppendInt64(int64 value) {
 497   AppendBasic(DBUS_TYPE_INT64, &value);
 498 }
 499
 500 void MessageWriter::AppendUint64(uint64 value) {
 501   AppendBasic(DBUS_TYPE_UINT64, &value);
 502 }
 503
 504 void MessageWriter::AppendDouble(double value) {
 505   AppendBasic(DBUS_TYPE_DOUBLE, &value);
 506 }
 507
 508 void MessageWriter::AppendString(const std::string& value) {
 509   // D-Bus Specification (0.19) says a string "must be valid UTF-8".
 510   CHECK(IsStringUTF8(value));
 511   const char* pointer = value.c_str();
 512   AppendBasic(DBUS_TYPE_STRING, &pointer);
 513   // TODO(satorux): It may make sense to return an error here, as the
 514   // input string can be large. If needed, we could add something like
 515   // bool AppendStringWithErrorChecking().
 516 }
 517
 518 void MessageWriter::AppendObjectPath(const ObjectPath& value) {
 519   CHECK(value.IsValid());
 520   const char* pointer = value.value().c_str();
 521   AppendBasic(DBUS_TYPE_OBJECT_PATH, &pointer);
 522 }
 523
 524 // Ideally, client shouldn't need to supply the signature string, but
 525 // the underlying D-Bus library requires us to supply this before
 526 // appending contents to array and variant. It's technically possible
 527 // for us to design API that doesn't require the signature but it will
 528 // complicate the implementation so we decided to have the signature
 529 // parameter. Hopefully, variants are less used in request messages from
 530 // client side than response message from server side, so this should
 531 // not be a big issue.
 532 void MessageWriter::OpenArray(const std::string& signature,
 533                               MessageWriter* writer) {
 534   DCHECK(!container_is_open_);
 535
 536   const bool success = dbus_message_iter_open_container(
 537       &raw_message_iter_,
 538       DBUS_TYPE_ARRAY,
 539       signature.c_str(),
 540       &writer->raw_message_iter_);
 541   CHECK(success) << "Unable to allocate memory";
 542   container_is_open_ = true;
 543 }
 544
 545 void MessageWriter::OpenVariant(const std::string& signature,
 546                                 MessageWriter* writer) {
 547   DCHECK(!container_is_open_);
 548
 549   const bool success = dbus_message_iter_open_container(
 550       &raw_message_iter_,
 551       DBUS_TYPE_VARIANT,
 552       signature.c_str(),
 553       &writer->raw_message_iter_);
 554   CHECK(success) << "Unable to allocate memory";
 555   container_is_open_ = true;
 556 }
 557
 558 void MessageWriter::OpenStruct(MessageWriter* writer) {
 559   DCHECK(!container_is_open_);
 560
 561   const bool success = dbus_message_iter_open_container(
 562       &raw_message_iter_,
 563       DBUS_TYPE_STRUCT,
 564       NULL,  // Signature should be NULL.
 565       &writer->raw_message_iter_);
 566   CHECK(success) << "Unable to allocate memory";
 567   container_is_open_ = true;
 568 }
 569
 570 void MessageWriter::OpenDictEntry(MessageWriter* writer) {
 571   DCHECK(!container_is_open_);
 572
 573   const bool success = dbus_message_iter_open_container(
 574       &raw_message_iter_,
 575       DBUS_TYPE_DICT_ENTRY,
 576       NULL,  // Signature should be NULL.
 577       &writer->raw_message_iter_);
 578   CHECK(success) << "Unable to allocate memory";
 579   container_is_open_ = true;
 580 }
 581
 582 void MessageWriter::CloseContainer(MessageWriter* writer) {
 583   DCHECK(container_is_open_);
 584
 585   const bool success = dbus_message_iter_close_container(
 586       &raw_message_iter_, &writer->raw_message_iter_);
 587   CHECK(success) << "Unable to allocate memory";
 588   container_is_open_ = false;
 589 }
 590
 591 void MessageWriter::AppendArrayOfBytes(const uint8* values, size_t length) {
 592   DCHECK(!container_is_open_);
 593   MessageWriter array_writer(message_);
 594   OpenArray("y", &array_writer);
 595   const bool success = dbus_message_iter_append_fixed_array(
 596       &(array_writer.raw_message_iter_),
 597       DBUS_TYPE_BYTE,
 598       &values,
 599       static_cast<int>(length));
 600   CHECK(success) << "Unable to allocate memory";
 601   CloseContainer(&array_writer);
 602 }
 603
 604 void MessageWriter::AppendArrayOfStrings(
 605     const std::vector<std::string>& strings) {
 606   DCHECK(!container_is_open_);
 607   MessageWriter array_writer(message_);
 608   OpenArray("s", &array_writer);
 609   for (size_t i = 0; i < strings.size(); ++i) {
 610     array_writer.AppendString(strings[i]);
 611   }
 612   CloseContainer(&array_writer);
 613 }
 614
 615 void MessageWriter::AppendArrayOfObjectPaths(
 616     const std::vector<ObjectPath>& object_paths) {
 617   DCHECK(!container_is_open_);
 618   MessageWriter array_writer(message_);
 619   OpenArray("o", &array_writer);
 620   for (size_t i = 0; i < object_paths.size(); ++i) {
 621     array_writer.AppendObjectPath(object_paths[i]);
 622   }
 623   CloseContainer(&array_writer);
 624 }
 625
 626 bool MessageWriter::AppendProtoAsArrayOfBytes(
 627     const google::protobuf::MessageLite& protobuf) {
 628   std::string serialized_proto;
 629   if (!protobuf.SerializeToString(&serialized_proto)) {
 630     LOG(ERROR) << "Unable to serialize supplied protocol buffer";
 631     return false;
 632   }
 633   AppendArrayOfBytes(reinterpret_cast<const uint8*>(serialized_proto.data()),
 634                      serialized_proto.size());
 635   return true;
 636 }
 637
 638 void MessageWriter::AppendVariantOfByte(uint8 value) {
 639   AppendVariantOfBasic(DBUS_TYPE_BYTE, &value);
 640 }
 641
 642 void MessageWriter::AppendVariantOfBool(bool value) {
 643   // See the comment at MessageWriter::AppendBool().
 644   dbus_bool_t dbus_value = value;
 645   AppendVariantOfBasic(DBUS_TYPE_BOOLEAN, &dbus_value);
 646 }
 647
 648 void MessageWriter::AppendVariantOfInt16(int16 value) {
 649   AppendVariantOfBasic(DBUS_TYPE_INT16, &value);
 650 }
 651
 652 void MessageWriter::AppendVariantOfUint16(uint16 value) {
 653   AppendVariantOfBasic(DBUS_TYPE_UINT16, &value);
 654 }
 655
 656 void MessageWriter::AppendVariantOfInt32(int32 value) {
 657   AppendVariantOfBasic(DBUS_TYPE_INT32, &value);
 658 }
 659
 660 void MessageWriter::AppendVariantOfUint32(uint32 value) {
 661   AppendVariantOfBasic(DBUS_TYPE_UINT32, &value);
 662 }
 663
 664 void MessageWriter::AppendVariantOfInt64(int64 value) {
 665   AppendVariantOfBasic(DBUS_TYPE_INT64, &value);
 666 }
 667
 668 void MessageWriter::AppendVariantOfUint64(uint64 value) {
 669   AppendVariantOfBasic(DBUS_TYPE_UINT64, &value);
 670 }
 671
 672 void MessageWriter::AppendVariantOfDouble(double value) {
 673   AppendVariantOfBasic(DBUS_TYPE_DOUBLE, &value);
 674 }
 675
 676 void MessageWriter::AppendVariantOfString(const std::string& value) {
 677   const char* pointer = value.c_str();
 678   AppendVariantOfBasic(DBUS_TYPE_STRING, &pointer);
 679 }
 680
 681 void MessageWriter::AppendVariantOfObjectPath(const ObjectPath& value) {
 682   const char* pointer = value.value().c_str();
 683   AppendVariantOfBasic(DBUS_TYPE_OBJECT_PATH, &pointer);
 684 }
 685
 686 void MessageWriter::AppendBasic(int dbus_type, const void* value) {
 687   DCHECK(!container_is_open_);
 688
 689   const bool success = dbus_message_iter_append_basic(
 690       &raw_message_iter_, dbus_type, value);
 691   // dbus_message_iter_append_basic() fails only when there is not enough
 692   // memory. We don't return this error as there is nothing we can do when
 693   // it fails to allocate memory for a byte etc.
 694   CHECK(success) << "Unable to allocate memory";
 695 }
 696
 697 void MessageWriter::AppendVariantOfBasic(int dbus_type, const void* value) {
 698   const std::string signature = base::StringPrintf("%c", dbus_type);
 699   MessageWriter variant_writer(message_);
 700   OpenVariant(signature, &variant_writer);
 701   variant_writer.AppendBasic(dbus_type, value);
 702   CloseContainer(&variant_writer);
 703 }
 704
 705 void MessageWriter::AppendFileDescriptor(const FileDescriptor& value) {
 706   CHECK(IsDBusTypeUnixFdSupported());
 707
 708   if (!value.is_valid()) {
 709     // NB: sending a directory potentially enables sandbox escape
 710     LOG(FATAL) << "Attempt to pass invalid file descriptor";
 711   }
 712   int fd = value.value();
 713   AppendBasic(DBUS_TYPE_UNIX_FD, &fd);
 714 }
 715
 716 //
 717 // MessageReader implementation.
 718 //
 719
 720 MessageReader::MessageReader(Message* message)
 721     : message_(message) {
 722   memset(&raw_message_iter_, 0, sizeof(raw_message_iter_));
 723   if (message)
 724     dbus_message_iter_init(message_->raw_message(), &raw_message_iter_);
 725 }
 726
 727
 728 MessageReader::~MessageReader() {
 729 }
 730
 731 bool MessageReader::HasMoreData() {
 732   const int dbus_type = dbus_message_iter_get_arg_type(&raw_message_iter_);
 733   return dbus_type != DBUS_TYPE_INVALID;
 734 }
 735
 736 bool MessageReader::PopByte(uint8* value) {
 737   return PopBasic(DBUS_TYPE_BYTE, value);
 738 }
 739
 740 bool MessageReader::PopBool(bool* value) {
 741   // Like MessageWriter::AppendBool(), we should copy |value| to
 742   // dbus_bool_t, as dbus_message_iter_get_basic() used in PopBasic()
 743   // expects four bytes for DBUS_TYPE_BOOLEAN.
 744   dbus_bool_t dbus_value = FALSE;
 745   const bool success = PopBasic(DBUS_TYPE_BOOLEAN, &dbus_value);
 746   *value = static_cast<bool>(dbus_value);
 747   return success;
 748 }
 749
 750 bool MessageReader::PopInt16(int16* value) {
 751   return PopBasic(DBUS_TYPE_INT16, value);
 752 }
 753
 754 bool MessageReader::PopUint16(uint16* value) {
 755   return PopBasic(DBUS_TYPE_UINT16, value);
 756 }
 757
 758 bool MessageReader::PopInt32(int32* value) {
 759   return PopBasic(DBUS_TYPE_INT32, value);
 760 }
 761
 762 bool MessageReader::PopUint32(uint32* value) {
 763   return PopBasic(DBUS_TYPE_UINT32, value);
 764 }
 765
 766 bool MessageReader::PopInt64(int64* value) {
 767   return PopBasic(DBUS_TYPE_INT64, value);
 768 }
 769
 770 bool MessageReader::PopUint64(uint64* value) {
 771   return PopBasic(DBUS_TYPE_UINT64, value);
 772 }
 773
 774 bool MessageReader::PopDouble(double* value) {
 775   return PopBasic(DBUS_TYPE_DOUBLE, value);
 776 }
 777
 778 bool MessageReader::PopString(std::string* value) {
 779   char* tmp_value = NULL;
 780   const bool success = PopBasic(DBUS_TYPE_STRING, &tmp_value);
 781   if (success)
 782     value->assign(tmp_value);
 783   return success;
 784 }
 785
 786 bool MessageReader::PopObjectPath(ObjectPath* value) {
 787   char* tmp_value = NULL;
 788   const bool success = PopBasic(DBUS_TYPE_OBJECT_PATH, &tmp_value);
 789   if (success)
 790     *value = ObjectPath(tmp_value);
 791   return success;
 792 }
 793
 794 bool MessageReader::PopArray(MessageReader* sub_reader) {
 795   return PopContainer(DBUS_TYPE_ARRAY, sub_reader);
 796 }
 797
 798 bool MessageReader::PopStruct(MessageReader* sub_reader) {
 799   return PopContainer(DBUS_TYPE_STRUCT, sub_reader);
 800 }
 801
 802 bool MessageReader::PopDictEntry(MessageReader* sub_reader) {
 803   return PopContainer(DBUS_TYPE_DICT_ENTRY, sub_reader);
 804 }
 805
 806 bool MessageReader::PopVariant(MessageReader* sub_reader) {
 807   return PopContainer(DBUS_TYPE_VARIANT, sub_reader);
 808 }
 809
 810 bool MessageReader::PopArrayOfBytes(uint8** bytes, size_t* length) {
 811   MessageReader array_reader(message_);
 812   if (!PopArray(&array_reader))
 813       return false;
 814   // An empty array is allowed.
 815   if (!array_reader.HasMoreData()) {
 816     *length = 0;
 817     *bytes = NULL;
 818     return true;
 819   }
 820   if (!array_reader.CheckDataType(DBUS_TYPE_BYTE))
 821     return false;
 822   int int_length = 0;
 823   dbus_message_iter_get_fixed_array(&array_reader.raw_message_iter_,
 824                                     bytes,
 825                                     &int_length);
 826   *length = static_cast<int>(int_length);
 827   return true;
 828 }
 829
 830 bool MessageReader::PopArrayOfStrings(
 831     std::vector<std::string> *strings) {
 832   MessageReader array_reader(message_);
 833   if (!PopArray(&array_reader))
 834       return false;
 835   while (array_reader.HasMoreData()) {
 836     std::string string;
 837     if (!array_reader.PopString(&string))
 838       return false;
 839     strings->push_back(string);
 840   }
 841   return true;
 842 }
 843
 844 bool MessageReader::PopArrayOfObjectPaths(
 845     std::vector<ObjectPath> *object_paths) {
 846   MessageReader array_reader(message_);
 847   if (!PopArray(&array_reader))
 848       return false;
 849   while (array_reader.HasMoreData()) {
 850     ObjectPath object_path;
 851     if (!array_reader.PopObjectPath(&object_path))
 852       return false;
 853     object_paths->push_back(object_path);
 854   }
 855   return true;
 856 }
 857
 858 bool MessageReader::PopArrayOfBytesAsProto(
 859     google::protobuf::MessageLite* protobuf) {
 860   DCHECK(protobuf != NULL);
 861   char* serialized_buf = NULL;
 862   size_t buf_size = 0;
 863   if (!PopArrayOfBytes(reinterpret_cast<uint8**>(&serialized_buf), &buf_size)) {
 864     LOG(ERROR) << "Error reading array of bytes";
 865     return false;
 866   }
 867   if (!protobuf->ParseFromArray(serialized_buf, buf_size)) {
 868     LOG(ERROR) << "Failed to parse protocol buffer from array";
 869     return false;
 870   }
 871   return true;
 872 }
 873
 874 bool MessageReader::PopVariantOfByte(uint8* value) {
 875   return PopVariantOfBasic(DBUS_TYPE_BYTE, value);
 876 }
 877
 878 bool MessageReader::PopVariantOfBool(bool* value) {
 879   // See the comment at MessageReader::PopBool().
 880   dbus_bool_t dbus_value = FALSE;
 881   const bool success = PopVariantOfBasic(DBUS_TYPE_BOOLEAN, &dbus_value);
 882   *value = static_cast<bool>(dbus_value);
 883   return success;
 884 }
 885
 886 bool MessageReader::PopVariantOfInt16(int16* value) {
 887   return PopVariantOfBasic(DBUS_TYPE_INT16, value);
 888 }
 889
 890 bool MessageReader::PopVariantOfUint16(uint16* value) {
 891   return PopVariantOfBasic(DBUS_TYPE_UINT16, value);
 892 }
 893
 894 bool MessageReader::PopVariantOfInt32(int32* value) {
 895   return PopVariantOfBasic(DBUS_TYPE_INT32, value);
 896 }
 897
 898 bool MessageReader::PopVariantOfUint32(uint32* value) {
 899   return PopVariantOfBasic(DBUS_TYPE_UINT32, value);
 900 }
 901
 902 bool MessageReader::PopVariantOfInt64(int64* value) {
 903   return PopVariantOfBasic(DBUS_TYPE_INT64, value);
 904 }
 905
 906 bool MessageReader::PopVariantOfUint64(uint64* value) {
 907   return PopVariantOfBasic(DBUS_TYPE_UINT64, value);
 908 }
 909
 910 bool MessageReader::PopVariantOfDouble(double* value) {
 911   return PopVariantOfBasic(DBUS_TYPE_DOUBLE, value);
 912 }
 913
 914 bool MessageReader::PopVariantOfString(std::string* value) {
 915   char* tmp_value = NULL;
 916   const bool success = PopVariantOfBasic(DBUS_TYPE_STRING, &tmp_value);
 917   if (success)
 918     value->assign(tmp_value);
 919   return success;
 920 }
 921
 922 bool MessageReader::PopVariantOfObjectPath(ObjectPath* value) {
 923   char* tmp_value = NULL;
 924   const bool success = PopVariantOfBasic(DBUS_TYPE_OBJECT_PATH, &tmp_value);
 925   if (success)
 926     *value = ObjectPath(tmp_value);
 927   return success;
 928 }
 929
 930 Message::DataType MessageReader::GetDataType() {
 931   const int dbus_type = dbus_message_iter_get_arg_type(&raw_message_iter_);
 932   return static_cast<Message::DataType>(dbus_type);
 933 }
 934
 935 bool MessageReader::CheckDataType(int dbus_type) {
 936   const int actual_type = dbus_message_iter_get_arg_type(&raw_message_iter_);
 937   if (actual_type != dbus_type) {
 938     VLOG(1) << "Type " << dbus_type  << " is expected but got "
 939             << actual_type;
 940     return false;
 941   }
 942   return true;
 943 }
 944
 945 bool MessageReader::PopBasic(int dbus_type, void* value) {
 946   if (!CheckDataType(dbus_type))
 947     return false;
 948   // dbus_message_iter_get_basic() here should always work, as we have
 949   // already checked the next item's data type in CheckDataType(). Note
 950   // that dbus_message_iter_get_basic() is a void function.
 951   dbus_message_iter_get_basic(&raw_message_iter_, value);
 952   DCHECK(value);
 953   dbus_message_iter_next(&raw_message_iter_);
 954   return true;
 955 }
 956
 957 bool MessageReader::PopContainer(int dbus_type, MessageReader* sub_reader) {
 958   DCHECK_NE(this, sub_reader);
 959
 960   if (!CheckDataType(dbus_type))
 961     return false;
 962   dbus_message_iter_recurse(&raw_message_iter_,
 963                             &sub_reader->raw_message_iter_);
 964   dbus_message_iter_next(&raw_message_iter_);
 965   return true;
 966 }
 967
 968 bool MessageReader::PopVariantOfBasic(int dbus_type, void* value) {
 969   MessageReader variant_reader(message_);
 970   if (!PopVariant(&variant_reader))
 971     return false;
 972   return variant_reader.PopBasic(dbus_type, value);
 973 }
 974
 975 bool MessageReader::PopFileDescriptor(FileDescriptor* value) {
 976   CHECK(IsDBusTypeUnixFdSupported());
 977
 978   int fd = -1;
 979   const bool success = PopBasic(DBUS_TYPE_UNIX_FD, &fd);
 980   if (!success)
 981     return false;
 982
 983   value->PutValue(fd);
 984   // NB: the caller must check validity before using the value
 985   return true;
 986 }
 987
 988 }  // namespace dbus