diff options
Diffstat (limited to 'netwerk/dns/nsHostRecord.h')
| -rw-r--r-- | netwerk/dns/nsHostRecord.h | 413 |
1 files changed, 413 insertions, 0 deletions
diff --git a/netwerk/dns/nsHostRecord.h b/netwerk/dns/nsHostRecord.h new file mode 100644 index 0000000000..0064bb9e42 --- /dev/null +++ b/netwerk/dns/nsHostRecord.h @@ -0,0 +1,413 @@ +/* vim:set ts=4 sw=2 sts=2 et cin: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef nsHostRecord_h__ +#define nsHostRecord_h__ + +#include "mozilla/AtomicBitfields.h" +#include "mozilla/DataMutex.h" +#include "mozilla/LinkedList.h" +#include "mozilla/net/HTTPSSVC.h" +#include "nsIDNSService.h" +#include "nsIDNSByTypeRecord.h" +#include "PLDHashTable.h" +#include "nsITRRSkipReason.h" + +class nsHostRecord; +class nsHostResolver; + +namespace mozilla { +namespace net { +class HostRecordQueue; +class TRR; +class TRRQuery; +} // namespace net +} // namespace mozilla + +/** + * This class is used to notify listeners when a ResolveHost operation is + * complete. Classes that derive it must implement threadsafe nsISupports + * to be able to use RefPtr with this class. + */ +class nsResolveHostCallback + : public mozilla::LinkedListElement<RefPtr<nsResolveHostCallback>>, + public nsISupports { + public: + /** + * OnResolveHostComplete + * + * this function is called to complete a host lookup initiated by + * nsHostResolver::ResolveHost. it may be invoked recursively from + * ResolveHost or on an unspecified background thread. + * + * NOTE: it is the responsibility of the implementor of this method + * to handle the callback in a thread safe manner. + * + * @param resolver + * nsHostResolver object associated with this result + * @param record + * the host record containing the results of the lookup + * @param status + * if successful, |record| contains non-null results + */ + virtual void OnResolveHostComplete(nsHostResolver* resolver, + nsHostRecord* record, nsresult status) = 0; + /** + * EqualsAsyncListener + * + * Determines if the listener argument matches the listener member var. + * For subclasses not implementing a member listener, should return false. + * For subclasses having a member listener, the function should check if + * they are the same. Used for cases where a pointer to an object + * implementing nsResolveHostCallback is unknown, but a pointer to + * the original listener is known. + * + * @param aListener + * nsIDNSListener object associated with the original request + */ + virtual bool EqualsAsyncListener(nsIDNSListener* aListener) = 0; + + virtual size_t SizeOfIncludingThis(mozilla::MallocSizeOf) const = 0; + + protected: + virtual ~nsResolveHostCallback() = default; +}; + +struct nsHostKey { + const nsCString host; + const nsCString mTrrServer; + uint16_t type = 0; + nsIDNSService::DNSFlags flags = nsIDNSService::RESOLVE_DEFAULT_FLAGS; + uint16_t af = 0; + bool pb = false; + const nsCString originSuffix; + explicit nsHostKey(const nsACString& host, const nsACString& aTrrServer, + uint16_t type, nsIDNSService::DNSFlags flags, uint16_t af, + bool pb, const nsACString& originSuffix); + bool operator==(const nsHostKey& other) const; + size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const; + PLDHashNumber Hash() const; +}; + +/** + * nsHostRecord - ref counted object type stored in host resolver cache. + */ +class nsHostRecord : public mozilla::LinkedListElement<RefPtr<nsHostRecord>>, + public nsHostKey, + public nsISupports { + using TRRSkippedReason = mozilla::net::TRRSkippedReason; + + public: + NS_DECL_THREADSAFE_ISUPPORTS + + virtual size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const { + return 0; + } + + // Returns the TRR mode encoded by the flags + nsIRequest::TRRMode TRRMode(); + + // Records the first reason that caused TRR to be skipped or to fail. + void RecordReason(TRRSkippedReason reason) { + if (mTRRSkippedReason == TRRSkippedReason::TRR_UNSET) { + mTRRSkippedReason = reason; + } + } + + enum DnsPriority { + DNS_PRIORITY_LOW = nsIDNSService::RESOLVE_PRIORITY_LOW, + DNS_PRIORITY_MEDIUM = nsIDNSService::RESOLVE_PRIORITY_MEDIUM, + DNS_PRIORITY_HIGH, + }; + + protected: + friend class nsHostResolver; + friend class mozilla::net::HostRecordQueue; + friend class mozilla::net::TRR; + friend class mozilla::net::TRRQuery; + + explicit nsHostRecord(const nsHostKey& key); + virtual ~nsHostRecord() = default; + + // Mark hostrecord as not usable + void Invalidate(); + + enum ExpirationStatus { + EXP_VALID, + EXP_GRACE, + EXP_EXPIRED, + }; + + ExpirationStatus CheckExpiration(const mozilla::TimeStamp& now) const; + + // Convenience function for setting the timestamps above (mValidStart, + // mValidEnd, and mGraceStart). valid and grace are durations in seconds. + void SetExpiration(const mozilla::TimeStamp& now, unsigned int valid, + unsigned int grace); + void CopyExpirationTimesAndFlagsFrom(const nsHostRecord* aFromHostRecord); + + // Checks if the record is usable (not expired and has a value) + bool HasUsableResult(const mozilla::TimeStamp& now, + nsIDNSService::DNSFlags queryFlags = + nsIDNSService::RESOLVE_DEFAULT_FLAGS) const; + + static DnsPriority GetPriority(nsIDNSService::DNSFlags aFlags); + + virtual void Cancel(); + virtual bool HasUsableResultInternal( + const mozilla::TimeStamp& now, + nsIDNSService::DNSFlags queryFlags) const = 0; + virtual bool RefreshForNegativeResponse() const { return true; } + + mozilla::LinkedList<RefPtr<nsResolveHostCallback>> mCallbacks; + + bool IsAddrRecord() const { + return type == nsIDNSService::RESOLVE_TYPE_DEFAULT; + } + + virtual void Reset() { + mTRRSkippedReason = TRRSkippedReason::TRR_UNSET; + mFirstTRRSkippedReason = TRRSkippedReason::TRR_UNSET; + mTrrAttempts = 0; + mTRRSuccess = false; + mNativeSuccess = false; + } + + virtual void OnCompleteLookup() {} + + // When the record began being valid. Used mainly for bookkeeping. + mozilla::TimeStamp mValidStart; + + // When the record is no longer valid (it's time of expiration) + mozilla::TimeStamp mValidEnd; + + // When the record enters its grace period. This must be before mValidEnd. + // If a record is in its grace period (and not expired), it will be used + // but a request to refresh it will be made. + mozilla::TimeStamp mGraceStart; + + mozilla::Atomic<uint32_t, mozilla::Relaxed> mTtl{0}; + + // The computed TRR mode that is actually used by the request. + // It is set in nsHostResolver::NameLookup and is based on the mode of the + // default resolver and the TRRMode encoded in the flags. + // The mode into account if the TRR service is disabled, + // parental controls are on, domain matches exclusion list, etc. + mozilla::Atomic<nsIRequest::TRRMode> mEffectiveTRRMode{ + nsIRequest::TRR_DEFAULT_MODE}; + + mozilla::Atomic<TRRSkippedReason> mTRRSkippedReason{ + TRRSkippedReason::TRR_UNSET}; + TRRSkippedReason mFirstTRRSkippedReason = TRRSkippedReason::TRR_UNSET; + + mozilla::DataMutex<RefPtr<mozilla::net::TRRQuery>> mTRRQuery; + + // counter of outstanding resolving calls + mozilla::Atomic<int32_t> mResolving{0}; + + // Number of times we've attempted TRR. Reset when we refresh. + // TRR is attempted at most twice - first attempt and retry. + mozilla::Atomic<int32_t> mTrrAttempts{0}; + + // True if this record is a cache of a failed lookup. Negative cache + // entries are valid just like any other (though never for more than 60 + // seconds), but a use of that negative entry forces an asynchronous refresh. + bool negative = false; + + // Explicitly expired + bool mDoomed = false; + + // Whether this is resolved by TRR successfully or not. + bool mTRRSuccess = false; + + // Whether this is resolved by native resolver successfully or not. + bool mNativeSuccess = false; +}; + +// b020e996-f6ab-45e5-9bf5-1da71dd0053a +#define ADDRHOSTRECORD_IID \ + { \ + 0xb020e996, 0xf6ab, 0x45e5, { \ + 0x9b, 0xf5, 0x1d, 0xa7, 0x1d, 0xd0, 0x05, 0x3a \ + } \ + } + +class AddrHostRecord final : public nsHostRecord { + using Mutex = mozilla::Mutex; + using DNSResolverType = mozilla::net::DNSResolverType; + + public: + NS_DECLARE_STATIC_IID_ACCESSOR(ADDRHOSTRECORD_IID) + NS_DECL_ISUPPORTS_INHERITED + + /* a fully resolved host record has either a non-null |addr_info| or |addr| + * field. if |addr_info| is null, it implies that the |host| is an IP + * address literal. in which case, |addr| contains the parsed address. + * otherwise, if |addr_info| is non-null, then it contains one or many + * IP addresses corresponding to the given host name. if both |addr_info| + * and |addr| are null, then the given host has not yet been fully resolved. + * |af| is the address family of the record we are querying for. + */ + + /* the lock protects |addr_info| and |addr_info_gencnt| because they + * are mutable and accessed by the resolver worker thread and the + * nsDNSService2 class. |addr| doesn't change after it has been + * assigned a value. only the resolver worker thread modifies + * nsHostRecord (and only in nsHostResolver::CompleteLookup); + * the other threads just read it. therefore the resolver worker + * thread doesn't need to lock when reading |addr_info|. + */ + Mutex addr_info_lock MOZ_UNANNOTATED{"AddrHostRecord.addr_info_lock"}; + // generation count of |addr_info| + int addr_info_gencnt = 0; + RefPtr<mozilla::net::AddrInfo> addr_info; + mozilla::UniquePtr<mozilla::net::NetAddr> addr; + + // hold addr_info_lock when calling the blocklist functions + bool Blocklisted(const mozilla::net::NetAddr* query); + void ResetBlocklist(); + void ReportUnusable(const mozilla::net::NetAddr* aAddress); + + size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const override; + + nsIRequest::TRRMode EffectiveTRRMode() const { return mEffectiveTRRMode; } + nsITRRSkipReason::value TrrSkipReason() const { return mTRRSkippedReason; } + + nsresult GetTtl(uint32_t* aResult); + + private: + friend class nsHostResolver; + friend class mozilla::net::HostRecordQueue; + friend class mozilla::net::TRR; + friend class mozilla::net::TRRQuery; + + explicit AddrHostRecord(const nsHostKey& key); + ~AddrHostRecord(); + + // Checks if the record is usable (not expired and has a value) + bool HasUsableResultInternal( + const mozilla::TimeStamp& now, + nsIDNSService::DNSFlags queryFlags) const override; + + bool RemoveOrRefresh(bool aTrrToo); // Mark records currently being resolved + // as needed to resolve again. + + // Saves the skip reason of a first-attempt TRR lookup and clears + // it to prepare for a retry attempt. + void NotifyRetryingTrr(); + void ResolveComplete(); + + static DnsPriority GetPriority(nsIDNSService::DNSFlags aFlags); + + // true if pending and on the queue (not yet given to getaddrinfo()) + bool onQueue() { return LoadNative() && isInList(); } + + virtual void Reset() override { + nsHostRecord::Reset(); + StoreNativeUsed(false); + mResolverType = DNSResolverType::Native; + } + + virtual void OnCompleteLookup() override { + nsHostRecord::OnCompleteLookup(); + // This should always be cleared when a request is completed. + StoreNative(false); + } + + // When the lookups of this record started and their durations + mozilla::TimeStamp mNativeStart; + mozilla::TimeDuration mTrrDuration; + mozilla::TimeDuration mNativeDuration; + + // TRR was used on this record + mozilla::Atomic<DNSResolverType> mResolverType{DNSResolverType::Native}; + + // clang-format off + MOZ_ATOMIC_BITFIELDS(mAtomicBitfields, 8, ( + // true if this record is being resolved "natively", which means that + // it is either on the pending queue or owned by one of the worker threads. + (uint16_t, Native, 1), + (uint16_t, NativeUsed, 1), + // true if off queue and contributing to mActiveAnyThreadCount + (uint16_t, UsingAnyThread, 1), + (uint16_t, GetTtl, 1), + (uint16_t, ResolveAgain, 1) + )) + // clang-format on + + // The number of times ReportUnusable() has been called in the record's + // lifetime. + uint32_t mUnusableCount = 0; + + // a list of addresses associated with this record that have been reported + // as unusable. the list is kept as a set of strings to make it independent + // of gencnt. + nsTArray<nsCString> mUnusableItems; +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(AddrHostRecord, ADDRHOSTRECORD_IID) + +// 77b786a7-04be-44f2-987c-ab8aa96676e0 +#define TYPEHOSTRECORD_IID \ + { \ + 0x77b786a7, 0x04be, 0x44f2, { \ + 0x98, 0x7c, 0xab, 0x8a, 0xa9, 0x66, 0x76, 0xe0 \ + } \ + } + +class TypeHostRecord final : public nsHostRecord, + public nsIDNSTXTRecord, + public nsIDNSHTTPSSVCRecord, + public mozilla::net::DNSHTTPSSVCRecordBase { + public: + NS_DECLARE_STATIC_IID_ACCESSOR(TYPEHOSTRECORD_IID) + NS_DECL_ISUPPORTS_INHERITED + NS_DECL_NSIDNSTXTRECORD + NS_DECL_NSIDNSHTTPSSVCRECORD + + size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const override; + uint32_t GetType(); + mozilla::net::TypeRecordResultType GetResults(); + + private: + friend class nsHostResolver; + friend class mozilla::net::TRR; + friend class mozilla::net::TRRQuery; + + explicit TypeHostRecord(const nsHostKey& key); + ~TypeHostRecord(); + + // Checks if the record is usable (not expired and has a value) + bool HasUsableResultInternal( + const mozilla::TimeStamp& now, + nsIDNSService::DNSFlags queryFlags) const override; + bool RefreshForNegativeResponse() const override; + + mozilla::net::TypeRecordResultType mResults = AsVariant(mozilla::Nothing()); + mozilla::Mutex mResultsLock MOZ_UNANNOTATED{"TypeHostRecord.mResultsLock"}; + + mozilla::Maybe<nsCString> mOriginHost; + + // When the lookups of this record started (for telemetry). + mozilla::TimeStamp mStart; + bool mAllRecordsExcluded = false; +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(TypeHostRecord, TYPEHOSTRECORD_IID) + +static inline bool IsHighPriority(nsIDNSService::DNSFlags flags) { + return !(flags & (nsHostRecord::DNS_PRIORITY_LOW | + nsHostRecord::DNS_PRIORITY_MEDIUM)); +} + +static inline bool IsMediumPriority(nsIDNSService::DNSFlags flags) { + return flags & nsHostRecord::DNS_PRIORITY_MEDIUM; +} + +static inline bool IsLowPriority(nsIDNSService::DNSFlags flags) { + return flags & nsHostRecord::DNS_PRIORITY_LOW; +} + +#endif // nsHostRecord_h__ |