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( 38 EvaluationContext* ec, State* state, std::string* error, 39 UpdateCheckParams* result) const { 40 result->updates_enabled = true; 41 result->target_channel.clear(); 42 result->target_version_prefix.clear(); 43 result->is_interactive = false; 44 45 // Ensure that the minimum interval is set. If there's no clock, this defaults 46 // to always allowing the update. 47 if (!aux_state_->IsLastCheckAllowedTimeSet() || 48 ec->IsMonotonicTimeGreaterThan( 49 aux_state_->last_check_allowed_time() + 50 base::TimeDelta::FromSeconds(kCheckIntervalInSeconds))) { 51 if (clock_) 52 aux_state_->set_last_check_allowed_time(clock_->GetMonotonicTime()); 53 return EvalStatus::kSucceeded; 54 } 55 56 return EvalStatus::kAskMeAgainLater; 57 } 58 59 EvalStatus DefaultPolicy::UpdateCanBeApplied(EvaluationContext* ec, 60 State* state, 61 std::string* error, 62 ErrorCode* result, 63 InstallPlan* install_plan) const { 64 *result = ErrorCode::kSuccess; 65 return EvalStatus::kSucceeded; 66 } 67 68 EvalStatus DefaultPolicy::UpdateCanStart( 69 EvaluationContext* ec, 70 State* state, 71 std::string* error, 72 UpdateDownloadParams* result, 73 const UpdateState update_state) const { 74 result->update_can_start = true; 75 result->cannot_start_reason = UpdateCannotStartReason::kUndefined; 76 result->download_url_idx = 0; 77 result->download_url_allowed = true; 78 result->download_url_num_errors = 0; 79 result->p2p_downloading_allowed = false; 80 result->p2p_sharing_allowed = false; 81 result->do_increment_failures = false; 82 result->backoff_expiry = base::Time(); 83 result->scatter_wait_period = base::TimeDelta(); 84 result->scatter_check_threshold = 0; 85 return EvalStatus::kSucceeded; 86 } 87 88 EvalStatus DefaultPolicy::UpdateDownloadAllowed( 89 EvaluationContext* ec, 90 State* state, 91 std::string* error, 92 bool* result) const { 93 *result = true; 94 return EvalStatus::kSucceeded; 95 } 96 97 EvalStatus DefaultPolicy::P2PEnabled( 98 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( 107 EvaluationContext* ec, 108 State* state, 109 std::string* error, 110 bool* result, 111 bool prev_result) const { 112 // This policy will always prohibit P2P, so this is signaling to the caller 113 // that the decision is final (because the current value is the same as the 114 // previous one) and there's no need to issue another call. 115 *result = false; 116 return EvalStatus::kSucceeded; 117 } 118 119 } // namespace chromeos_update_manager 120
