| // Copyright (c) 2014 The Chromium OS Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef UPDATE_ENGINE_UPDATE_MANAGER_CHROMEOS_POLICY_H_ |
| #define UPDATE_ENGINE_UPDATE_MANAGER_CHROMEOS_POLICY_H_ |
| |
| #include <string> |
| |
| #include <base/time/time.h> |
| #include <gtest/gtest_prod.h> // for FRIEND_TEST |
| |
| #include "update_engine/update_manager/policy.h" |
| #include "update_engine/update_manager/prng.h" |
| |
| namespace chromeos_update_manager { |
| |
| // Output information from UpdateBackoffAndDownloadUrl. |
| struct UpdateBackoffAndDownloadUrlResult { |
| // Whether the failed attempt count (maintained by the caller) needs to be |
| // incremented. |
| bool do_increment_failures; |
| // The current backoff expiry. Null if backoff is not in effect. |
| base::Time backoff_expiry; |
| // The new URL index to use and number of download errors associated with it. |
| // Significant iff |do_increment_failures| is false and |backoff_expiry| is |
| // null. Negative value means no usable URL was found. |
| int url_idx; |
| int url_num_errors; |
| }; |
| |
| // Parameters for update scattering, as returned by UpdateScattering. |
| struct UpdateScatteringResult { |
| bool is_scattering; |
| base::TimeDelta wait_period; |
| int check_threshold; |
| }; |
| |
| // ChromeOSPolicy implements the policy-related logic used in ChromeOS. |
| class ChromeOSPolicy : public Policy { |
| public: |
| ChromeOSPolicy() {} |
| virtual ~ChromeOSPolicy() {} |
| |
| // Policy overrides. |
| EvalStatus UpdateCheckAllowed( |
| EvaluationContext* ec, State* state, std::string* error, |
| UpdateCheckParams* result) const override; |
| |
| EvalStatus UpdateCanStart( |
| EvaluationContext* ec, |
| State* state, |
| std::string* error, |
| UpdateDownloadParams* result, |
| UpdateState update_state) const override; |
| |
| EvalStatus UpdateDownloadAllowed( |
| EvaluationContext* ec, |
| State* state, |
| std::string* error, |
| bool* result) const override; |
| |
| protected: |
| // Policy override. |
| std::string PolicyName() const override { return "ChromeOSPolicy"; } |
| |
| private: |
| friend class UmChromeOSPolicyTest; |
| FRIEND_TEST(UmChromeOSPolicyTest, |
| FirstCheckIsAtMostInitialIntervalAfterStart); |
| FRIEND_TEST(UmChromeOSPolicyTest, RecurringCheckBaseIntervalAndFuzz); |
| FRIEND_TEST(UmChromeOSPolicyTest, RecurringCheckBackoffIntervalAndFuzz); |
| FRIEND_TEST(UmChromeOSPolicyTest, RecurringCheckServerDictatedPollInterval); |
| FRIEND_TEST(UmChromeOSPolicyTest, ExponentialBackoffIsCapped); |
| FRIEND_TEST(UmChromeOSPolicyTest, UpdateCheckAllowedWaitsForTheTimeout); |
| FRIEND_TEST(UmChromeOSPolicyTest, UpdateCheckAllowedWaitsForOOBE); |
| FRIEND_TEST(UmChromeOSPolicyTest, |
| UpdateCanStartNotAllowedScatteringNewWaitPeriodApplies); |
| FRIEND_TEST(UmChromeOSPolicyTest, |
| UpdateCanStartNotAllowedScatteringPrevWaitPeriodStillApplies); |
| FRIEND_TEST(UmChromeOSPolicyTest, |
| UpdateCanStartNotAllowedScatteringNewCountThresholdApplies); |
| FRIEND_TEST(UmChromeOSPolicyTest, |
| UpdateCanStartNotAllowedScatteringPrevCountThresholdStillApplies); |
| FRIEND_TEST(UmChromeOSPolicyTest, UpdateCanStartAllowedScatteringSatisfied); |
| FRIEND_TEST(UmChromeOSPolicyTest, |
| UpdateCanStartAllowedInteractivePreventsScattering); |
| FRIEND_TEST(UmChromeOSPolicyTest, |
| UpdateCanStartAllowedP2PDownloadBlockedDueToNumAttempts); |
| FRIEND_TEST(UmChromeOSPolicyTest, |
| UpdateCanStartAllowedP2PDownloadBlockedDueToAttemptsPeriod); |
| |
| // Auxiliary constant (zero by default). |
| const base::TimeDelta kZeroInterval; |
| |
| // Default update check timeout interval/fuzz values used to compute the |
| // NextUpdateCheckTime(), in seconds. Actual fuzz is within +/- half of the |
| // indicated value. |
| static const int kTimeoutInitialInterval; |
| static const int kTimeoutPeriodicInterval; |
| static const int kTimeoutMaxBackoffInterval; |
| static const int kTimeoutRegularFuzz; |
| |
| // Maximum update attempt backoff interval and fuzz. |
| static const int kAttemptBackoffMaxIntervalInDays; |
| static const int kAttemptBackoffFuzzInHours; |
| |
| // Maximum number of times we'll allow using P2P for the same update payload. |
| static const int kMaxP2PAttempts; |
| // Maximum period of time allowed for download a payload via P2P, in seconds. |
| static const int kMaxP2PAttemptsPeriodInSeconds; |
| |
| // A private policy implementation returning the wallclock timestamp when |
| // the next update check should happen. |
| // TODO(garnold) We should probably change that to infer a monotonic |
| // timestamp, which will make the update check intervals more resilient to |
| // clock skews. Might require switching some of the variables exported by the |
| // UpdaterProvider to report monotonic time, as well. |
| EvalStatus NextUpdateCheckTime(EvaluationContext* ec, State* state, |
| std::string* error, |
| base::Time* next_update_check) const; |
| |
| // Returns a TimeDelta based on the provided |interval| seconds +/- half |
| // |fuzz| seconds. The return value is guaranteed to be a non-negative |
| // TimeDelta. |
| static base::TimeDelta FuzzedInterval(PRNG* prng, int interval, int fuzz); |
| |
| // A private policy for determining backoff and the download URL to use. |
| // Within |update_state|, |backoff_expiry| and |is_backoff_disabled| are used |
| // for determining whether backoff is still in effect; if not, |
| // |download_errors| is scanned past |failures_last_updated|, and a new |
| // download URL from |download_urls| is found and written to |result->url_idx| |
| // (-1 means no usable URL exists); |download_errors_max| determines the |
| // maximum number of attempts per URL, according to the Omaha response. If an |
| // update failure is identified then |result->do_increment_failures| is set to |
| // true; if backoff is enabled, a new backoff period is computed (from the |
| // time of failure) based on |num_failures|. Otherwise, backoff expiry is |
| // nullified, indicating that no backoff is in effect. |
| // |
| // If backing off but the previous backoff expiry is unchanged, returns |
| // |EvalStatus::kAskMeAgainLater|. Otherwise: |
| // |
| // * If backing off with a new expiry time, then |result->backoff_expiry| is |
| // set to this time. |
| // |
| // * Else, |result->backoff_expiry| is set to null, indicating that no backoff |
| // is in effect. |
| // |
| // In any of these cases, returns |EvalStatus::kSucceeded|. If an error |
| // occurred, returns |EvalStatus::kFailed|. |
| EvalStatus UpdateBackoffAndDownloadUrl( |
| EvaluationContext* ec, State* state, std::string* error, |
| UpdateBackoffAndDownloadUrlResult* result, |
| const UpdateState& update_state) const; |
| |
| // A private policy for checking whether scattering is due. Writes in |result| |
| // the decision as to whether or not to scatter; a wallclock-based scatter |
| // wait period, which ranges from zero (do not wait) and no greater than the |
| // current scatter factor provided by the device policy (if available) or the |
| // maximum wait period determined by Omaha; and an update check-based |
| // threshold between zero (no threshold) and the maximum number determined by |
| // the update engine. Within |update_state|, |scatter_wait_period| should |
| // contain the last scattering period returned by this function, or zero if no |
| // wait period is known; |scatter_check_threshold| is the last update check |
| // threshold, or zero if no such threshold is known. If not scattering, or if |
| // any of the scattering values has changed, returns |EvalStatus::kSucceeded|; |
| // otherwise, |EvalStatus::kAskMeAgainLater|. |
| EvalStatus UpdateScattering(EvaluationContext* ec, State* state, |
| std::string* error, |
| UpdateScatteringResult* result, |
| const UpdateState& update_state) const; |
| |
| DISALLOW_COPY_AND_ASSIGN(ChromeOSPolicy); |
| }; |
| |
| } // namespace chromeos_update_manager |
| |
| #endif // UPDATE_ENGINE_UPDATE_MANAGER_CHROMEOS_POLICY_H_ |