1// Copyright 2014 The Chromium OS 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 <brillo/dbus/utils.h>
6
7#include <tuple>
8#include <vector>
9
10#include <base/bind.h>
11#include <brillo/errors/error_codes.h>
12#include <brillo/strings/string_utils.h>
13
14namespace brillo {
15namespace dbus_utils {
16
17std::unique_ptr<dbus::Response> CreateDBusErrorResponse(
18    dbus::MethodCall* method_call,
19    const std::string& error_name,
20    const std::string& error_message) {
21  return dbus::ErrorResponse::FromMethodCall(method_call, error_name,
22                                             error_message);
23}
24
25std::unique_ptr<dbus::Response> GetDBusError(dbus::MethodCall* method_call,
26                                             const brillo::Error* error) {
27  CHECK(error) << "Error object must be specified";
28  std::string error_name = DBUS_ERROR_FAILED;  // Default error code.
29  std::string error_message;
30
31  // Special case for "dbus" error domain.
32  // Pop the error code and message from the error chain and use them as the
33  // actual D-Bus error message.
34  if (error->GetDomain() == errors::dbus::kDomain) {
35    error_name = error->GetCode();
36    error_message = error->GetMessage();
37    error = error->GetInnerError();
38  }
39
40  // Append any inner errors to the error message.
41  while (error) {
42    // Format error string as "domain/code:message".
43    if (!error_message.empty())
44      error_message += ';';
45    error_message +=
46        error->GetDomain() + '/' + error->GetCode() + ':' + error->GetMessage();
47    error = error->GetInnerError();
48  }
49  return CreateDBusErrorResponse(method_call, error_name, error_message);
50}
51
52void AddDBusError(brillo::ErrorPtr* error,
53                  const std::string& dbus_error_name,
54                  const std::string& dbus_error_message) {
55  std::vector<std::string> parts = string_utils::Split(dbus_error_message, ";");
56  std::vector<std::tuple<std::string, std::string, std::string>> errors;
57  for (const std::string& part : parts) {
58    // Each part should be in format of "domain/code:message"
59    size_t slash_pos = part.find('/');
60    size_t colon_pos = part.find(':');
61    if (slash_pos != std::string::npos && colon_pos != std::string::npos &&
62        slash_pos < colon_pos) {
63      // If we have both '/' and ':' and in proper order, then we have a
64      // correctly encoded error object.
65      std::string domain = part.substr(0, slash_pos);
66      std::string code = part.substr(slash_pos + 1, colon_pos - slash_pos - 1);
67      std::string message = part.substr(colon_pos + 1);
68      errors.emplace_back(domain, code, message);
69    } else if (slash_pos == std::string::npos &&
70               colon_pos == std::string::npos && errors.empty()) {
71      // If we don't have both '/' and ':' and this is the first error object,
72      // then we had a D-Bus error at the top of the error chain.
73      errors.emplace_back(errors::dbus::kDomain, dbus_error_name, part);
74    } else {
75      // We have a malformed part. The whole D-Bus error was most likely
76      // not generated by GetDBusError(). To be safe, stop parsing it
77      // and return the error as received from D-Bus.
78      errors.clear();  // Remove any errors accumulated so far.
79      errors.emplace_back(
80          errors::dbus::kDomain, dbus_error_name, dbus_error_message);
81      break;
82    }
83  }
84
85  // Go backwards and add the parsed errors to the error chain.
86  for (auto it = errors.crbegin(); it != errors.crend(); ++it) {
87    Error::AddTo(
88        error, FROM_HERE, std::get<0>(*it), std::get<1>(*it), std::get<2>(*it));
89  }
90}
91
92}  // namespace dbus_utils
93}  // namespace brillo
94