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/* 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
#ifndef nsHostResolver_h__
#define nsHostResolver_h__
#include "nscore.h"
#include "prnetdb.h"
#include "PLDHashTable.h"
#include "mozilla/CondVar.h"
#include "mozilla/DataMutex.h"
#include "nsISupportsImpl.h"
#include "nsIDNSListener.h"
#include "nsTArray.h"
#include "GetAddrInfo.h"
#include "HostRecordQueue.h"
#include "mozilla/net/DNS.h"
#include "mozilla/net/DashboardTypes.h"
#include "mozilla/Atomics.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/UniquePtr.h"
#include "nsHostRecord.h"
#include "nsRefPtrHashtable.h"
#include "nsIThreadPool.h"
#include "mozilla/net/NetworkConnectivityService.h"
#include "mozilla/net/DNSByTypeRecord.h"
#include "mozilla/Maybe.h"
#include "mozilla/StaticPrefs_network.h"
namespace mozilla {
namespace net {
class TRR;
class TRRQuery;
static inline uint32_t MaxResolverThreadsAnyPriority() {
return StaticPrefs::network_dns_max_any_priority_threads();
}
static inline uint32_t MaxResolverThreadsHighPriority() {
return StaticPrefs::network_dns_max_high_priority_threads();
}
static inline uint32_t MaxResolverThreads() {
return MaxResolverThreadsAnyPriority() + MaxResolverThreadsHighPriority();
}
} // namespace net
} // namespace mozilla
#define TRR_DISABLED(x) \
(((x) == nsIDNSService::MODE_NATIVEONLY) || \
((x) == nsIDNSService::MODE_TRROFF))
extern mozilla::Atomic<bool, mozilla::Relaxed> gNativeIsLocalhost;
#define MAX_NON_PRIORITY_REQUESTS 150
class AHostResolver {
public:
AHostResolver() = default;
virtual ~AHostResolver() = default;
NS_INLINE_DECL_PURE_VIRTUAL_REFCOUNTING
enum LookupStatus {
LOOKUP_OK,
LOOKUP_RESOLVEAGAIN,
};
virtual LookupStatus CompleteLookup(nsHostRecord*, nsresult,
mozilla::net::AddrInfo*, bool pb,
const nsACString& aOriginsuffix,
mozilla::net::TRRSkippedReason aReason,
mozilla::net::TRR*) = 0;
virtual LookupStatus CompleteLookupByType(
nsHostRecord*, nsresult, mozilla::net::TypeRecordResultType& aResult,
mozilla::net::TRRSkippedReason aReason, uint32_t aTtl, bool pb) = 0;
virtual nsresult GetHostRecord(const nsACString& host,
const nsACString& aTrrServer, uint16_t type,
nsIDNSService::DNSFlags flags, uint16_t af,
bool pb, const nsCString& originSuffix,
nsHostRecord** result) {
return NS_ERROR_FAILURE;
}
virtual nsresult TrrLookup_unlocked(nsHostRecord*,
mozilla::net::TRR* pushedTRR = nullptr) {
return NS_ERROR_FAILURE;
}
virtual void MaybeRenewHostRecord(nsHostRecord* aRec) {}
};
/**
* nsHostResolver - an asynchronous host name resolver.
*/
class nsHostResolver : public nsISupports, public AHostResolver {
using CondVar = mozilla::CondVar;
using Mutex = mozilla::Mutex;
public:
NS_DECL_THREADSAFE_ISUPPORTS
/**
* creates an addref'd instance of a nsHostResolver object.
*/
static nsresult Create(uint32_t maxCacheEntries, // zero disables cache
uint32_t defaultCacheEntryLifetime, // seconds
uint32_t defaultGracePeriod, // seconds
nsHostResolver** result);
/**
* Set (new) cache limits.
*/
void SetCacheLimits(uint32_t maxCacheEntries, // zero disables cache
uint32_t defaultCacheEntryLifetime, // seconds
uint32_t defaultGracePeriod); // seconds
/**
* puts the resolver in the shutdown state, which will cause any pending
* callbacks to be detached. any future calls to ResolveHost will fail.
*/
void Shutdown();
/**
* resolve the given hostname and originAttributes asynchronously. the caller
* can synthesize a synchronous host lookup using a lock and a cvar. as noted
* above the callback will occur re-entrantly from an unspecified thread. the
* host lookup cannot be canceled (cancelation can be layered above this by
* having the callback implementation return without doing anything).
*/
nsresult ResolveHost(const nsACString& aHost, const nsACString& trrServer,
int32_t aPort, uint16_t type,
const mozilla::OriginAttributes& aOriginAttributes,
nsIDNSService::DNSFlags flags, uint16_t af,
nsResolveHostCallback* callback);
nsHostRecord* InitRecord(const nsHostKey& key);
mozilla::net::NetworkConnectivityService* GetNCS() {
return mNCS;
} // This is actually a singleton
/**
* return a resolved hard coded loopback dns record for the specified key
*/
already_AddRefed<nsHostRecord> InitLoopbackRecord(const nsHostKey& key,
nsresult* aRv);
/**
* removes the specified callback from the nsHostRecord for the given
* hostname, originAttributes, flags, and address family. these parameters
* should correspond to the parameters passed to ResolveHost. this function
* executes the callback if the callback is still pending with the given
* status.
*/
void DetachCallback(const nsACString& hostname, const nsACString& trrServer,
uint16_t type,
const mozilla::OriginAttributes& aOriginAttributes,
nsIDNSService::DNSFlags flags, uint16_t af,
nsResolveHostCallback* callback, nsresult status);
/**
* Cancels an async request associated with the hostname, originAttributes,
* flags, address family and listener. Cancels first callback found which
* matches these criteria. These parameters should correspond to the
* parameters passed to ResolveHost. If this is the last callback associated
* with the host record, it is removed from any request queues it might be on.
*/
void CancelAsyncRequest(const nsACString& host, const nsACString& trrServer,
uint16_t type,
const mozilla::OriginAttributes& aOriginAttributes,
nsIDNSService::DNSFlags flags, uint16_t af,
nsIDNSListener* aListener, nsresult status);
/**
* values for the flags parameter passed to ResolveHost and DetachCallback
* that may be bitwise OR'd together.
*
* NOTE: in this implementation, these flags correspond exactly in value
* to the flags defined on nsIDNSService.
*/
enum {
RES_BYPASS_CACHE = nsIDNSService::RESOLVE_BYPASS_CACHE,
RES_CANON_NAME = nsIDNSService::RESOLVE_CANONICAL_NAME,
RES_PRIORITY_MEDIUM = nsHostRecord::DNS_PRIORITY_MEDIUM,
RES_PRIORITY_LOW = nsHostRecord::DNS_PRIORITY_LOW,
RES_SPECULATE = nsIDNSService::RESOLVE_SPECULATE,
// RES_DISABLE_IPV6 = nsIDNSService::RESOLVE_DISABLE_IPV6, // Not used
RES_OFFLINE = nsIDNSService::RESOLVE_OFFLINE,
// RES_DISABLE_IPv4 = nsIDNSService::RESOLVE_DISABLE_IPV4, // Not Used
RES_ALLOW_NAME_COLLISION = nsIDNSService::RESOLVE_ALLOW_NAME_COLLISION,
RES_DISABLE_TRR = nsIDNSService::RESOLVE_DISABLE_TRR,
RES_REFRESH_CACHE = nsIDNSService::RESOLVE_REFRESH_CACHE,
RES_IP_HINT = nsIDNSService::RESOLVE_IP_HINT
};
size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
/**
* Flush the DNS cache.
*/
void FlushCache(bool aTrrToo);
LookupStatus CompleteLookup(nsHostRecord*, nsresult, mozilla::net::AddrInfo*,
bool pb, const nsACString& aOriginsuffix,
mozilla::net::TRRSkippedReason aReason,
mozilla::net::TRR* aTRRRequest) override;
LookupStatus CompleteLookupByType(nsHostRecord*, nsresult,
mozilla::net::TypeRecordResultType& aResult,
mozilla::net::TRRSkippedReason aReason,
uint32_t aTtl, bool pb) override;
nsresult GetHostRecord(const nsACString& host, const nsACString& trrServer,
uint16_t type, nsIDNSService::DNSFlags flags,
uint16_t af, bool pb, const nsCString& originSuffix,
nsHostRecord** result) override;
nsresult TrrLookup_unlocked(nsHostRecord*,
mozilla::net::TRR* pushedTRR = nullptr) override;
static nsIDNSService::ResolverMode Mode();
virtual void MaybeRenewHostRecord(nsHostRecord* aRec) override;
// Records true if the TRR service is enabled for the record's effective
// TRR mode. Also records the TRRSkipReason when the TRR service is not
// available/enabled.
bool TRRServiceEnabledForRecord(nsHostRecord* aRec) MOZ_REQUIRES(mLock);
private:
explicit nsHostResolver(uint32_t maxCacheEntries,
uint32_t defaultCacheEntryLifetime,
uint32_t defaultGracePeriod);
virtual ~nsHostResolver();
bool DoRetryTRR(AddrHostRecord* aAddrRec,
const mozilla::MutexAutoLock& aLock);
bool MaybeRetryTRRLookup(
AddrHostRecord* aAddrRec, nsresult aFirstAttemptStatus,
mozilla::net::TRRSkippedReason aFirstAttemptSkipReason,
nsresult aChannelStatus, const mozilla::MutexAutoLock& aLock);
LookupStatus CompleteLookupLocked(nsHostRecord*, nsresult,
mozilla::net::AddrInfo*, bool pb,
const nsACString& aOriginsuffix,
mozilla::net::TRRSkippedReason aReason,
mozilla::net::TRR* aTRRRequest,
const mozilla::MutexAutoLock& aLock)
MOZ_REQUIRES(mLock);
LookupStatus CompleteLookupByTypeLocked(
nsHostRecord*, nsresult, mozilla::net::TypeRecordResultType& aResult,
mozilla::net::TRRSkippedReason aReason, uint32_t aTtl, bool pb,
const mozilla::MutexAutoLock& aLock) MOZ_REQUIRES(mLock);
nsresult Init();
static void ComputeEffectiveTRRMode(nsHostRecord* aRec);
nsresult NativeLookup(nsHostRecord* aRec,
const mozilla::MutexAutoLock& aLock);
nsresult TrrLookup(nsHostRecord*, const mozilla::MutexAutoLock& aLock,
mozilla::net::TRR* pushedTRR = nullptr);
// Kick-off a name resolve operation, using native resolver and/or TRR
nsresult NameLookup(nsHostRecord* aRec, const mozilla::MutexAutoLock& aLock);
bool GetHostToLookup(nsHostRecord** result);
void MaybeRenewHostRecordLocked(nsHostRecord* aRec,
const mozilla::MutexAutoLock& aLock)
MOZ_REQUIRES(mLock);
// Cancels host records in the pending queue and also
// calls CompleteLookup with the NS_ERROR_ABORT result code.
void ClearPendingQueue(mozilla::LinkedList<RefPtr<nsHostRecord>>& aPendingQ);
nsresult ConditionallyCreateThread(nsHostRecord* rec) MOZ_REQUIRES(mLock);
/**
* Starts a new lookup in the background for entries that are in the grace
* period with a failed connect or all cached entries are negative.
*/
nsresult ConditionallyRefreshRecord(nsHostRecord* rec, const nsACString& host,
const mozilla::MutexAutoLock& aLock)
MOZ_REQUIRES(mLock);
void OnResolveComplete(nsHostRecord* aRec,
const mozilla::MutexAutoLock& aLock)
MOZ_REQUIRES(mLock);
void AddToEvictionQ(nsHostRecord* rec, const mozilla::MutexAutoLock& aLock)
MOZ_REQUIRES(mLock);
void ThreadFunc();
// Resolve the host from the DNS cache.
already_AddRefed<nsHostRecord> FromCache(nsHostRecord* aRec,
const nsACString& aHost,
uint16_t aType, nsresult& aStatus,
const mozilla::MutexAutoLock& aLock)
MOZ_REQUIRES(mLock);
// Called when the host name is an IP address and has been passed.
already_AddRefed<nsHostRecord> FromCachedIPLiteral(nsHostRecord* aRec);
// Like the above function, but the host name is not parsed to NetAddr yet.
already_AddRefed<nsHostRecord> FromIPLiteral(
AddrHostRecord* aAddrRec, const mozilla::net::NetAddr& aAddr);
// Called to check if we have an AF_UNSPEC entry in the cache.
already_AddRefed<nsHostRecord> FromUnspecEntry(
nsHostRecord* aRec, const nsACString& aHost, const nsACString& aTrrServer,
const nsACString& aOriginSuffix, uint16_t aType,
nsIDNSService::DNSFlags aFlags, uint16_t af, bool aPb, nsresult& aStatus)
MOZ_REQUIRES(mLock);
enum {
METHOD_HIT = 1,
METHOD_RENEWAL = 2,
METHOD_NEGATIVE_HIT = 3,
METHOD_LITERAL = 4,
METHOD_OVERFLOW = 5,
METHOD_NETWORK_FIRST = 6,
METHOD_NETWORK_SHARED = 7
};
uint32_t mMaxCacheEntries = 0;
uint32_t mDefaultCacheLifetime = 0; // granularity seconds
uint32_t mDefaultGracePeriod = 0; // granularity seconds
// mutable so SizeOfIncludingThis can be const
mutable Mutex mLock{"nsHostResolver.mLock"};
CondVar mIdleTaskCV;
nsRefPtrHashtable<nsGenericHashKey<nsHostKey>, nsHostRecord> mRecordDB
MOZ_GUARDED_BY(mLock);
PRTime mCreationTime;
mozilla::TimeDuration mLongIdleTimeout;
mozilla::TimeDuration mShortIdleTimeout;
RefPtr<nsIThreadPool> mResolverThreads;
RefPtr<mozilla::net::NetworkConnectivityService>
mNCS; // reference to a singleton
mozilla::net::HostRecordQueue mQueue MOZ_GUARDED_BY(mLock);
mozilla::Atomic<bool> mShutdown MOZ_GUARDED_BY(mLock){true};
mozilla::Atomic<uint32_t> mNumIdleTasks MOZ_GUARDED_BY(mLock){0};
mozilla::Atomic<uint32_t> mActiveTaskCount MOZ_GUARDED_BY(mLock){0};
mozilla::Atomic<uint32_t> mActiveAnyThreadCount MOZ_GUARDED_BY(mLock){0};
// Set the expiration time stamps appropriately.
void PrepareRecordExpirationAddrRecord(AddrHostRecord* rec) const;
public:
/*
* Called by the networking dashboard via the DnsService2
*/
void GetDNSCacheEntries(nsTArray<mozilla::net::DNSCacheEntries>*);
};
#endif // nsHostResolver_h__