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-rw-r--r--netwerk/dns/nsHostRecord.h413
1 files changed, 413 insertions, 0 deletions
diff --git a/netwerk/dns/nsHostRecord.h b/netwerk/dns/nsHostRecord.h
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+++ 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__