1 // 2 // Copyright (C) 2014 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/update_manager/default_policy.h" 18 19 using chromeos_update_engine::ErrorCode; 20 using chromeos_update_engine::InstallPlan; 21 22 namespace { 23 24 // A fixed minimum interval between consecutive allowed update checks. This 25 // needs to be long enough to prevent busywork and/or DDoS attacks on Omaha, but 26 // at the same time short enough to allow the machine to update itself 27 // reasonably soon. 28 const int kCheckIntervalInSeconds = 15 * 60; 29 30 } // namespace 31 32 namespace chromeos_update_manager { 33 34 DefaultPolicy::DefaultPolicy(chromeos_update_engine::ClockInterface* clock) 35 : clock_(clock), aux_state_(new DefaultPolicyState()) {} 36 37 EvalStatus DefaultPolicy::UpdateCheckAllowed(EvaluationContext* ec, 38 State* state, 39 std::string* error, 40 UpdateCheckParams* result) const { 41 result->updates_enabled = true; 42 result->target_channel.clear(); 43 result->target_version_prefix.clear(); 44 result->rollback_allowed = false; 45 result->rollback_allowed_milestones = -1; // No version rolls should happen. 46 result->interactive = false; 47 48 // Ensure that the minimum interval is set. If there's no clock, this defaults 49 // to always allowing the update. 50 if (!aux_state_->IsLastCheckAllowedTimeSet() || 51 ec->IsMonotonicTimeGreaterThan( 52 aux_state_->last_check_allowed_time() + 53 base::TimeDelta::FromSeconds(kCheckIntervalInSeconds))) { 54 if (clock_) 55 aux_state_->set_last_check_allowed_time(clock_->GetMonotonicTime()); 56 return EvalStatus::kSucceeded; 57 } 58 59 return EvalStatus::kAskMeAgainLater; 60 } 61 62 EvalStatus DefaultPolicy::UpdateCanBeApplied(EvaluationContext* ec, 63 State* state, 64 std::string* error, 65 ErrorCode* result, 66 InstallPlan* install_plan) const { 67 *result = ErrorCode::kSuccess; 68 return EvalStatus::kSucceeded; 69 } 70 71 EvalStatus DefaultPolicy::UpdateCanStart(EvaluationContext* ec, 72 State* state, 73 std::string* error, 74 UpdateDownloadParams* result, 75 const UpdateState update_state) const { 76 result->update_can_start = true; 77 result->cannot_start_reason = UpdateCannotStartReason::kUndefined; 78 result->download_url_idx = 0; 79 result->download_url_allowed = true; 80 result->download_url_num_errors = 0; 81 result->p2p_downloading_allowed = false; 82 result->p2p_sharing_allowed = false; 83 result->do_increment_failures = false; 84 result->backoff_expiry = base::Time(); 85 result->scatter_wait_period = base::TimeDelta(); 86 result->scatter_check_threshold = 0; 87 return EvalStatus::kSucceeded; 88 } 89 90 EvalStatus DefaultPolicy::UpdateDownloadAllowed(EvaluationContext* ec, 91 State* state, 92 std::string* error, 93 bool* result) const { 94 *result = true; 95 return EvalStatus::kSucceeded; 96 } 97 98 EvalStatus DefaultPolicy::P2PEnabled(EvaluationContext* ec, 99 State* state, 100 std::string* error, 101 bool* result) const { 102 *result = false; 103 return EvalStatus::kSucceeded; 104 } 105 106 EvalStatus DefaultPolicy::P2PEnabledChanged(EvaluationContext* ec, 107 State* state, 108 std::string* error, 109 bool* result, 110 bool prev_result) const { 111 // This policy will always prohibit P2P, so this is signaling to the caller 112 // that the decision is final (because the current value is the same as the 113 // previous one) and there's no need to issue another call. 114 *result = false; 115 return EvalStatus::kSucceeded; 116 } 117 118 } // namespace chromeos_update_manager 119