1//
2// Copyright (C) 2011 The Android Open Source Project
3//
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at
7//
8//      http://www.apache.org/licenses/LICENSE-2.0
9//
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15//
16
17#include "update_engine/omaha_response_handler_action.h"
18
19#include <string>
20
21#include <base/logging.h>
22#include <base/strings/string_util.h>
23#include <policy/device_policy.h>
24
25#include "update_engine/common/constants.h"
26#include "update_engine/common/hardware_interface.h"
27#include "update_engine/common/prefs_interface.h"
28#include "update_engine/common/utils.h"
29#include "update_engine/connection_manager_interface.h"
30#include "update_engine/omaha_request_params.h"
31#include "update_engine/payload_consumer/delta_performer.h"
32#include "update_engine/payload_state_interface.h"
33
34using std::string;
35
36namespace chromeos_update_engine {
37
38OmahaResponseHandlerAction::OmahaResponseHandlerAction(
39    SystemState* system_state)
40    : OmahaResponseHandlerAction(system_state,
41                                 constants::kOmahaResponseDeadlineFile) {}
42
43OmahaResponseHandlerAction::OmahaResponseHandlerAction(
44    SystemState* system_state, const string& deadline_file)
45    : system_state_(system_state),
46      got_no_update_response_(false),
47      key_path_(constants::kUpdatePayloadPublicKeyPath),
48      deadline_file_(deadline_file) {}
49
50void OmahaResponseHandlerAction::PerformAction() {
51  CHECK(HasInputObject());
52  ScopedActionCompleter completer(processor_, this);
53  const OmahaResponse& response = GetInputObject();
54  if (!response.update_exists) {
55    got_no_update_response_ = true;
56    LOG(INFO) << "There are no updates. Aborting.";
57    return;
58  }
59
60  // All decisions as to which URL should be used have already been done. So,
61  // make the current URL as the download URL.
62  string current_url = system_state_->payload_state()->GetCurrentUrl();
63  if (current_url.empty()) {
64    // This shouldn't happen as we should always supply the HTTPS backup URL.
65    // Handling this anyway, just in case.
66    LOG(ERROR) << "There are no suitable URLs in the response to use.";
67    completer.set_code(ErrorCode::kOmahaResponseInvalid);
68    return;
69  }
70
71  install_plan_.download_url = current_url;
72  install_plan_.version = response.version;
73
74  OmahaRequestParams* const params = system_state_->request_params();
75  PayloadStateInterface* const payload_state = system_state_->payload_state();
76
77  // If we're using p2p to download and there is a local peer, use it.
78  if (payload_state->GetUsingP2PForDownloading() &&
79      !payload_state->GetP2PUrl().empty()) {
80    LOG(INFO) << "Replacing URL " << install_plan_.download_url
81              << " with local URL " << payload_state->GetP2PUrl()
82              << " since p2p is enabled.";
83    install_plan_.download_url = payload_state->GetP2PUrl();
84    payload_state->SetUsingP2PForDownloading(true);
85  }
86
87  // Fill up the other properties based on the response.
88  install_plan_.payload_size = response.size;
89  install_plan_.payload_hash = response.hash;
90  install_plan_.metadata_size = response.metadata_size;
91  install_plan_.metadata_signature = response.metadata_signature;
92  install_plan_.public_key_rsa = response.public_key_rsa;
93  install_plan_.hash_checks_mandatory = AreHashChecksMandatory(response);
94  install_plan_.is_resume =
95      DeltaPerformer::CanResumeUpdate(system_state_->prefs(), response.hash);
96  if (install_plan_.is_resume) {
97    payload_state->UpdateResumed();
98  } else {
99    payload_state->UpdateRestarted();
100    LOG_IF(WARNING, !DeltaPerformer::ResetUpdateProgress(
101        system_state_->prefs(), false))
102        << "Unable to reset the update progress.";
103    LOG_IF(WARNING, !system_state_->prefs()->SetString(
104        kPrefsUpdateCheckResponseHash, response.hash))
105        << "Unable to save the update check response hash.";
106  }
107  install_plan_.payload_type = response.is_delta_payload
108                                   ? InstallPayloadType::kDelta
109                                   : InstallPayloadType::kFull;
110
111  install_plan_.source_slot = system_state_->boot_control()->GetCurrentSlot();
112  install_plan_.target_slot = install_plan_.source_slot == 0 ? 1 : 0;
113
114  // The Omaha response doesn't include the channel name for this image, so we
115  // use the download_channel we used during the request to tag the target slot.
116  // This will be used in the next boot to know the channel the image was
117  // downloaded from.
118  string current_channel_key =
119      kPrefsChannelOnSlotPrefix + std::to_string(install_plan_.target_slot);
120  system_state_->prefs()->SetString(current_channel_key,
121                                    params->download_channel());
122
123  if (params->to_more_stable_channel() && params->is_powerwash_allowed())
124    install_plan_.powerwash_required = true;
125
126  TEST_AND_RETURN(HasOutputPipe());
127  if (HasOutputPipe())
128    SetOutputObject(install_plan_);
129  LOG(INFO) << "Using this install plan:";
130  install_plan_.Dump();
131
132  // Send the deadline data (if any) to Chrome through a file. This is a pretty
133  // hacky solution but should be OK for now.
134  //
135  // TODO(petkov): Re-architect this to avoid communication through a
136  // file. Ideally, we would include this information in D-Bus's GetStatus
137  // method and UpdateStatus signal. A potential issue is that update_engine may
138  // be unresponsive during an update download.
139  if (!deadline_file_.empty()) {
140    utils::WriteFile(deadline_file_.c_str(),
141                     response.deadline.data(),
142                     response.deadline.size());
143    chmod(deadline_file_.c_str(), S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
144  }
145
146  completer.set_code(ErrorCode::kSuccess);
147}
148
149bool OmahaResponseHandlerAction::AreHashChecksMandatory(
150    const OmahaResponse& response) {
151  // We sometimes need to waive the hash checks in order to download from
152  // sources that don't provide hashes, such as dev server.
153  // At this point UpdateAttempter::IsAnyUpdateSourceAllowed() has already been
154  // checked, so an unofficial update URL won't get this far unless it's OK to
155  // use without a hash. Additionally, we want to always waive hash checks on
156  // unofficial builds (i.e. dev/test images).
157  // The end result is this:
158  //  * Base image:
159  //    - Official URLs require a hash.
160  //    - Unofficial URLs only get this far if the IsAnyUpdateSourceAllowed()
161  //      devmode/debugd checks pass, in which case the hash is waived.
162  //  * Dev/test image:
163  //    - Any URL is allowed through with no hash checking.
164  if (!system_state_->request_params()->IsUpdateUrlOfficial() ||
165      !system_state_->hardware()->IsOfficialBuild()) {
166    // Still do a hash check if a public key is included.
167    if (!response.public_key_rsa.empty()) {
168      // The autoupdate_CatchBadSignatures test checks for this string
169      // in log-files. Keep in sync.
170      LOG(INFO) << "Mandating payload hash checks since Omaha Response "
171                << "for unofficial build includes public RSA key.";
172      return true;
173    } else {
174      LOG(INFO) << "Waiving payload hash checks for unofficial update URL.";
175      return false;
176    }
177  }
178
179  // If we're using p2p, |install_plan_.download_url| may contain a
180  // HTTP URL even if |response.payload_urls| contain only HTTPS URLs.
181  if (!base::StartsWith(install_plan_.download_url, "https://",
182                        base::CompareCase::INSENSITIVE_ASCII)) {
183    LOG(INFO) << "Mandating hash checks since download_url is not HTTPS.";
184    return true;
185  }
186
187  // TODO(jaysri): VALIDATION: For official builds, we currently waive hash
188  // checks for HTTPS until we have rolled out at least once and are confident
189  // nothing breaks. chromium-os:37082 tracks turning this on for HTTPS
190  // eventually.
191
192  // Even if there's a single non-HTTPS URL, make the hash checks as
193  // mandatory because we could be downloading the payload from any URL later
194  // on. It's really hard to do book-keeping based on each byte being
195  // downloaded to see whether we only used HTTPS throughout.
196  for (size_t i = 0; i < response.payload_urls.size(); i++) {
197    if (!base::StartsWith(response.payload_urls[i], "https://",
198                          base::CompareCase::INSENSITIVE_ASCII)) {
199      LOG(INFO) << "Mandating payload hash checks since Omaha response "
200                << "contains non-HTTPS URL(s)";
201      return true;
202    }
203  }
204
205  LOG(INFO) << "Waiving payload hash checks since Omaha response "
206            << "only has HTTPS URL(s)";
207  return false;
208}
209
210}  // namespace chromeos_update_engine
211