nsDNSService2.cpp
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim: set sw=4 ts=8 et tw=80 : */
/* 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/. */
#include "nsDNSService2.h"
#include "nsIDNSRecord.h"
#include "nsIDNSListener.h"
#include "nsICancelable.h"
#include "nsIPrefService.h"
#include "nsIPrefBranch.h"
#include "nsIServiceManager.h"
#include "nsIXPConnect.h"
#include "nsProxyRelease.h"
#include "nsReadableUtils.h"
#include "nsString.h"
#include "nsAutoPtr.h"
#include "nsNetCID.h"
#include "nsError.h"
#include "nsDNSPrefetch.h"
#include "nsThreadUtils.h"
#include "nsIProtocolProxyService.h"
#include "prsystem.h"
#include "prnetdb.h"
#include "prmon.h"
#include "prio.h"
#include "plstr.h"
#include "nsIOService.h"
#include "nsCharSeparatedTokenizer.h"
#include "nsNetAddr.h"
#include "nsProxyRelease.h"
#include "nsIObserverService.h"
#include "nsINetworkLinkService.h"
#include "mozilla/Attributes.h"
#include "mozilla/VisualEventTracer.h"
#include "mozilla/net/NeckoCommon.h"
#include "mozilla/net/ChildDNSService.h"
#include "mozilla/net/DNSListenerProxy.h"
#include "mozilla/Services.h"
using namespace mozilla;
using namespace mozilla::net;
static const char kPrefDnsCacheEntries[] = "network.dnsCacheEntries";
static const char kPrefDnsCacheExpiration[] = "network.dnsCacheExpiration";
static const char kPrefDnsCacheGrace[] = "network.dnsCacheExpirationGracePeriod";
static const char kPrefIPv4OnlyDomains[] = "network.dns.ipv4OnlyDomains";
static const char kPrefDisableIPv6[] = "network.dns.disableIPv6";
static const char kPrefDisablePrefetch[] = "network.dns.disablePrefetch";
static const char kPrefDnsLocalDomains[] = "network.dns.localDomains";
static const char kPrefDnsNotifyResolution[] = "network.dns.notifyResolution";
//-----------------------------------------------------------------------------
class nsDNSRecord : public nsIDNSRecord
{
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIDNSRECORD
explicit nsDNSRecord(nsHostRecord *hostRecord)
: mHostRecord(hostRecord)
, mIter(nullptr)
, mIterGenCnt(-1)
, mDone(false) {}
private:
virtual ~nsDNSRecord() {}
nsRefPtr<nsHostRecord> mHostRecord;
NetAddrElement *mIter;
int mIterGenCnt; // the generation count of
// mHostRecord->addr_info when we
// start iterating
bool mDone;
};
NS_IMPL_ISUPPORTS(nsDNSRecord, nsIDNSRecord)
NS_IMETHODIMP
nsDNSRecord::GetCanonicalName(nsACString &result)
{
// this method should only be called if we have a CNAME
NS_ENSURE_TRUE(mHostRecord->flags & nsHostResolver::RES_CANON_NAME,
NS_ERROR_NOT_AVAILABLE);
// if the record is for an IP address literal, then the canonical
// host name is the IP address literal.
const char *cname;
{
MutexAutoLock lock(mHostRecord->addr_info_lock);
if (mHostRecord->addr_info)
cname = mHostRecord->addr_info->mCanonicalName ?
mHostRecord->addr_info->mCanonicalName :
mHostRecord->addr_info->mHostName;
else
cname = mHostRecord->host;
result.Assign(cname);
}
return NS_OK;
}
NS_IMETHODIMP
nsDNSRecord::GetNextAddr(uint16_t port, NetAddr *addr)
{
if (mDone) {
return NS_ERROR_NOT_AVAILABLE;
}
mHostRecord->addr_info_lock.Lock();
if (mHostRecord->addr_info) {
if (mIterGenCnt != mHostRecord->addr_info_gencnt) {
// mHostRecord->addr_info has changed, restart the iteration.
mIter = nullptr;
mIterGenCnt = mHostRecord->addr_info_gencnt;
}
bool startedFresh = !mIter;
do {
if (!mIter) {
mIter = mHostRecord->addr_info->mAddresses.getFirst();
} else {
mIter = mIter->getNext();
}
}
while (mIter && mHostRecord->Blacklisted(&mIter->mAddress));
if (!mIter && startedFresh) {
// If everything was blacklisted we want to reset the blacklist (and
// likely relearn it) and return the first address. That is better
// than nothing.
mHostRecord->ResetBlacklist();
mIter = mHostRecord->addr_info->mAddresses.getFirst();
}
if (mIter) {
memcpy(addr, &mIter->mAddress, sizeof(NetAddr));
}
mHostRecord->addr_info_lock.Unlock();
if (!mIter) {
mDone = true;
return NS_ERROR_NOT_AVAILABLE;
}
}
else {
mHostRecord->addr_info_lock.Unlock();
if (!mHostRecord->addr) {
// Both mHostRecord->addr_info and mHostRecord->addr are null.
// This can happen if mHostRecord->addr_info expired and the
// attempt to reresolve it failed.
return NS_ERROR_NOT_AVAILABLE;
}
memcpy(addr, mHostRecord->addr, sizeof(NetAddr));
mDone = true;
}
// set given port
port = htons(port);
if (addr->raw.family == AF_INET) {
addr->inet.port = port;
}
else if (addr->raw.family == AF_INET6) {
addr->inet6.port = port;
}
return NS_OK;
}
NS_IMETHODIMP
nsDNSRecord::GetScriptableNextAddr(uint16_t port, nsINetAddr * *result)
{
NetAddr addr;
nsresult rv = GetNextAddr(port, &addr);
if (NS_FAILED(rv)) return rv;
NS_ADDREF(*result = new nsNetAddr(&addr));
return NS_OK;
}
NS_IMETHODIMP
nsDNSRecord::GetNextAddrAsString(nsACString &result)
{
NetAddr addr;
nsresult rv = GetNextAddr(0, &addr);
if (NS_FAILED(rv)) return rv;
char buf[kIPv6CStrBufSize];
if (NetAddrToString(&addr, buf, sizeof(buf))) {
result.Assign(buf);
return NS_OK;
}
NS_ERROR("NetAddrToString failed unexpectedly");
return NS_ERROR_FAILURE; // conversion failed for some reason
}
NS_IMETHODIMP
nsDNSRecord::HasMore(bool *result)
{
if (mDone) {
*result = false;
return NS_OK;
}
NetAddrElement *iterCopy = mIter;
int iterGenCntCopy = mIterGenCnt;
NetAddr addr;
*result = NS_SUCCEEDED(GetNextAddr(0, &addr));
mIter = iterCopy;
mIterGenCnt = iterGenCntCopy;
mDone = false;
return NS_OK;
}
NS_IMETHODIMP
nsDNSRecord::Rewind()
{
mIter = nullptr;
mIterGenCnt = -1;
mDone = false;
return NS_OK;
}
NS_IMETHODIMP
nsDNSRecord::ReportUnusable(uint16_t aPort)
{
// right now we don't use the port in the blacklist
MutexAutoLock lock(mHostRecord->addr_info_lock);
// Check that we are using a real addr_info (as opposed to a single
// constant address), and that the generation count is valid. Otherwise,
// ignore the report.
if (mHostRecord->addr_info &&
mIterGenCnt == mHostRecord->addr_info_gencnt &&
mIter) {
mHostRecord->ReportUnusable(&mIter->mAddress);
}
return NS_OK;
}
//-----------------------------------------------------------------------------
class nsDNSAsyncRequest MOZ_FINAL : public nsResolveHostCallback
, public nsICancelable
{
~nsDNSAsyncRequest() {}
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSICANCELABLE
nsDNSAsyncRequest(nsHostResolver *res,
const nsACString &host,
nsIDNSListener *listener,
uint16_t flags,
uint16_t af)
: mResolver(res)
, mHost(host)
, mListener(listener)
, mFlags(flags)
, mAF(af) {}
void OnLookupComplete(nsHostResolver *, nsHostRecord *, nsresult) MOZ_OVERRIDE;
// Returns TRUE if the DNS listener arg is the same as the member listener
// Used in Cancellations to remove DNS requests associated with a
// particular hostname and nsIDNSListener
bool EqualsAsyncListener(nsIDNSListener *aListener) MOZ_OVERRIDE;
size_t SizeOfIncludingThis(mozilla::MallocSizeOf) const MOZ_OVERRIDE;
nsRefPtr<nsHostResolver> mResolver;
nsCString mHost; // hostname we're resolving
nsCOMPtr<nsIDNSListener> mListener;
uint16_t mFlags;
uint16_t mAF;
};
void
nsDNSAsyncRequest::OnLookupComplete(nsHostResolver *resolver,
nsHostRecord *hostRecord,
nsresult status)
{
// need to have an owning ref when we issue the callback to enable
// the caller to be able to addref/release multiple times without
// destroying the record prematurely.
nsCOMPtr<nsIDNSRecord> rec;
if (NS_SUCCEEDED(status)) {
NS_ASSERTION(hostRecord, "no host record");
rec = new nsDNSRecord(hostRecord);
if (!rec)
status = NS_ERROR_OUT_OF_MEMORY;
}
MOZ_EVENT_TRACER_DONE(this, "net::dns::lookup");
mListener->OnLookupComplete(this, rec, status);
mListener = nullptr;
// release the reference to ourselves that was added before we were
// handed off to the host resolver.
NS_RELEASE_THIS();
}
bool
nsDNSAsyncRequest::EqualsAsyncListener(nsIDNSListener *aListener)
{
nsCOMPtr<nsIDNSListenerProxy> wrapper = do_QueryInterface(mListener);
if (wrapper) {
nsCOMPtr<nsIDNSListener> originalListener;
wrapper->GetOriginalListener(getter_AddRefs(originalListener));
return aListener == originalListener;
}
return (aListener == mListener);
}
size_t
nsDNSAsyncRequest::SizeOfIncludingThis(MallocSizeOf mallocSizeOf) const
{
size_t n = mallocSizeOf(this);
// The following fields aren't measured.
// - mHost, because it's a non-owning pointer
// - mResolver, because it's a non-owning pointer
// - mListener, because it's a non-owning pointer
return n;
}
NS_IMPL_ISUPPORTS(nsDNSAsyncRequest, nsICancelable)
NS_IMETHODIMP
nsDNSAsyncRequest::Cancel(nsresult reason)
{
NS_ENSURE_ARG(NS_FAILED(reason));
mResolver->DetachCallback(mHost.get(), mFlags, mAF, this, reason);
return NS_OK;
}
//-----------------------------------------------------------------------------
class nsDNSSyncRequest : public nsResolveHostCallback
{
public:
explicit nsDNSSyncRequest(PRMonitor *mon)
: mDone(false)
, mStatus(NS_OK)
, mMonitor(mon) {}
virtual ~nsDNSSyncRequest() {}
void OnLookupComplete(nsHostResolver *, nsHostRecord *, nsresult);
bool EqualsAsyncListener(nsIDNSListener *aListener);
size_t SizeOfIncludingThis(mozilla::MallocSizeOf) const;
bool mDone;
nsresult mStatus;
nsRefPtr<nsHostRecord> mHostRecord;
private:
PRMonitor *mMonitor;
};
void
nsDNSSyncRequest::OnLookupComplete(nsHostResolver *resolver,
nsHostRecord *hostRecord,
nsresult status)
{
// store results, and wake up nsDNSService::Resolve to process results.
PR_EnterMonitor(mMonitor);
mDone = true;
mStatus = status;
mHostRecord = hostRecord;
PR_Notify(mMonitor);
PR_ExitMonitor(mMonitor);
}
bool
nsDNSSyncRequest::EqualsAsyncListener(nsIDNSListener *aListener)
{
// Sync request: no listener to compare
return false;
}
size_t
nsDNSSyncRequest::SizeOfIncludingThis(MallocSizeOf mallocSizeOf) const
{
size_t n = mallocSizeOf(this);
// The following fields aren't measured.
// - mHostRecord, because it's a non-owning pointer
// Measurement of the following members may be added later if DMD finds it
// is worthwhile:
// - mMonitor
return n;
}
class NotifyDNSResolution: public nsRunnable
{
public:
NotifyDNSResolution(nsMainThreadPtrHandle<nsIObserverService> &aObs,
const nsACString &aHostname)
: mObs(aObs)
, mHostname(aHostname)
{
MOZ_ASSERT(mObs);
}
NS_IMETHOD Run()
{
MOZ_ASSERT(NS_IsMainThread());
mObs->NotifyObservers(nullptr,
"dns-resolution-request",
NS_ConvertUTF8toUTF16(mHostname).get());
return NS_OK;
}
private:
nsMainThreadPtrHandle<nsIObserverService> mObs;
nsCString mHostname;
};
//-----------------------------------------------------------------------------
nsDNSService::nsDNSService()
: mLock("nsDNSServer.mLock")
, mFirstTime(true)
, mOffline(false)
{
}
nsDNSService::~nsDNSService()
{
}
NS_IMPL_ISUPPORTS(nsDNSService, nsIDNSService, nsPIDNSService, nsIObserver,
nsIMemoryReporter)
/******************************************************************************
* nsDNSService impl:
* singleton instance ctor/dtor methods
******************************************************************************/
static nsDNSService *gDNSService;
nsIDNSService*
nsDNSService::GetXPCOMSingleton()
{
if (IsNeckoChild()) {
return ChildDNSService::GetSingleton();
}
return GetSingleton();
}
nsDNSService*
nsDNSService::GetSingleton()
{
NS_ASSERTION(!IsNeckoChild(), "not a parent process");
if (gDNSService) {
NS_ADDREF(gDNSService);
return gDNSService;
}
gDNSService = new nsDNSService();
if (gDNSService) {
NS_ADDREF(gDNSService);
if (NS_FAILED(gDNSService->Init())) {
NS_RELEASE(gDNSService);
}
}
return gDNSService;
}
NS_IMETHODIMP
nsDNSService::Init()
{
if (mResolver)
return NS_OK;
NS_ENSURE_TRUE(!mResolver, NS_ERROR_ALREADY_INITIALIZED);
// prefs
uint32_t maxCacheEntries = 400;
uint32_t defaultCacheLifetime = 120; // seconds
uint32_t defaultGracePeriod = 60; // seconds
bool disableIPv6 = false;
bool disablePrefetch = false;
int proxyType = nsIProtocolProxyService::PROXYCONFIG_DIRECT;
bool notifyResolution = false;
nsAdoptingCString ipv4OnlyDomains;
nsAdoptingCString localDomains;
// read prefs
nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
if (prefs) {
int32_t val;
if (NS_SUCCEEDED(prefs->GetIntPref(kPrefDnsCacheEntries, &val)))
maxCacheEntries = (uint32_t) val;
if (NS_SUCCEEDED(prefs->GetIntPref(kPrefDnsCacheExpiration, &val)))
defaultCacheLifetime = val;
if (NS_SUCCEEDED(prefs->GetIntPref(kPrefDnsCacheGrace, &val)))
defaultGracePeriod = val;
// ASSUMPTION: pref branch does not modify out params on failure
prefs->GetBoolPref(kPrefDisableIPv6, &disableIPv6);
prefs->GetCharPref(kPrefIPv4OnlyDomains, getter_Copies(ipv4OnlyDomains));
prefs->GetCharPref(kPrefDnsLocalDomains, getter_Copies(localDomains));
prefs->GetBoolPref(kPrefDisablePrefetch, &disablePrefetch);
// If a manual proxy is in use, disable prefetch implicitly
prefs->GetIntPref("network.proxy.type", &proxyType);
prefs->GetBoolPref(kPrefDnsNotifyResolution, ¬ifyResolution);
}
if (mFirstTime) {
mFirstTime = false;
// register as prefs observer
if (prefs) {
prefs->AddObserver(kPrefDnsCacheEntries, this, false);
prefs->AddObserver(kPrefDnsCacheExpiration, this, false);
prefs->AddObserver(kPrefDnsCacheGrace, this, false);
prefs->AddObserver(kPrefIPv4OnlyDomains, this, false);
prefs->AddObserver(kPrefDnsLocalDomains, this, false);
prefs->AddObserver(kPrefDisableIPv6, this, false);
prefs->AddObserver(kPrefDisablePrefetch, this, false);
prefs->AddObserver(kPrefDnsNotifyResolution, this, false);
// Monitor these to see if there is a change in proxy configuration
// If a manual proxy is in use, disable prefetch implicitly
prefs->AddObserver("network.proxy.type", this, false);
}
nsCOMPtr<nsIObserverService> observerService =
mozilla::services::GetObserverService();
if (observerService) {
observerService->AddObserver(this, "last-pb-context-exited", false);
observerService->AddObserver(this, NS_NETWORK_LINK_TOPIC, false);
}
}
nsDNSPrefetch::Initialize(this);
// Don't initialize the resolver if we're in offline mode.
// Later on, the IO service will reinitialize us when going online.
if (gIOService->IsOffline() && !gIOService->IsComingOnline())
return NS_OK;
nsCOMPtr<nsIIDNService> idn = do_GetService(NS_IDNSERVICE_CONTRACTID);
nsCOMPtr<nsIObserverService> obs =
do_GetService(NS_OBSERVERSERVICE_CONTRACTID);
nsRefPtr<nsHostResolver> res;
nsresult rv = nsHostResolver::Create(maxCacheEntries,
defaultCacheLifetime,
defaultGracePeriod,
getter_AddRefs(res));
if (NS_SUCCEEDED(rv)) {
// now, set all of our member variables while holding the lock
MutexAutoLock lock(mLock);
mResolver = res;
mIDN = idn;
mIPv4OnlyDomains = ipv4OnlyDomains; // exchanges buffer ownership
mDisableIPv6 = disableIPv6;
// Disable prefetching either by explicit preference or if a manual proxy is configured
mDisablePrefetch = disablePrefetch || (proxyType == nsIProtocolProxyService::PROXYCONFIG_MANUAL);
mLocalDomains.Clear();
if (localDomains) {
nsCCharSeparatedTokenizer tokenizer(localDomains, ',',
nsCCharSeparatedTokenizer::SEPARATOR_OPTIONAL);
while (tokenizer.hasMoreTokens()) {
mLocalDomains.PutEntry(tokenizer.nextToken());
}
}
mNotifyResolution = notifyResolution;
if (mNotifyResolution) {
mObserverService =
new nsMainThreadPtrHolder<nsIObserverService>(obs);
}
}
RegisterWeakMemoryReporter(this);
return rv;
}
NS_IMETHODIMP
nsDNSService::Shutdown()
{
UnregisterWeakMemoryReporter(this);
nsRefPtr<nsHostResolver> res;
{
MutexAutoLock lock(mLock);
res = mResolver;
mResolver = nullptr;
}
if (res)
res->Shutdown();
return NS_OK;
}
NS_IMETHODIMP
nsDNSService::GetOffline(bool *offline)
{
*offline = mOffline;
return NS_OK;
}
NS_IMETHODIMP
nsDNSService::SetOffline(bool offline)
{
mOffline = offline;
return NS_OK;
}
NS_IMETHODIMP
nsDNSService::GetPrefetchEnabled(bool *outVal)
{
*outVal = !mDisablePrefetch;
return NS_OK;
}
NS_IMETHODIMP
nsDNSService::SetPrefetchEnabled(bool inVal)
{
mDisablePrefetch = !inVal;
return NS_OK;
}
static inline bool PreprocessHostname(bool aLocalDomain,
const nsACString &aInput,
nsIIDNService *aIDN,
nsACString &aACE)
{
if (aLocalDomain) {
aACE.AssignLiteral("localhost");
return true;
}
if (!aIDN || IsASCII(aInput)) {
aACE = aInput;
return true;
}
return IsUTF8(aInput) && NS_SUCCEEDED(aIDN->ConvertUTF8toACE(aInput, aACE));
}
NS_IMETHODIMP
nsDNSService::AsyncResolve(const nsACString &aHostname,
uint32_t flags,
nsIDNSListener *listener,
nsIEventTarget *target_,
nsICancelable **result)
{
// grab reference to global host resolver and IDN service. beware
// simultaneous shutdown!!
nsRefPtr<nsHostResolver> res;
nsCOMPtr<nsIIDNService> idn;
nsCOMPtr<nsIEventTarget> target = target_;
bool localDomain = false;
{
MutexAutoLock lock(mLock);
if (mDisablePrefetch && (flags & RESOLVE_SPECULATE))
return NS_ERROR_DNS_LOOKUP_QUEUE_FULL;
res = mResolver;
idn = mIDN;
localDomain = mLocalDomains.GetEntry(aHostname);
}
if (mNotifyResolution) {
NS_DispatchToMainThread(new NotifyDNSResolution(mObserverService,
aHostname));
}
if (!res)
return NS_ERROR_OFFLINE;
if (mOffline)
flags |= RESOLVE_OFFLINE;
nsCString hostname;
if (!PreprocessHostname(localDomain, aHostname, idn, hostname))
return NS_ERROR_FAILURE;
// make sure JS callers get notification on the main thread
nsCOMPtr<nsIXPConnectWrappedJS> wrappedListener = do_QueryInterface(listener);
if (wrappedListener && !target) {
nsCOMPtr<nsIThread> mainThread;
NS_GetMainThread(getter_AddRefs(mainThread));
target = do_QueryInterface(mainThread);
}
if (target) {
listener = new DNSListenerProxy(listener, target);
}
uint16_t af = GetAFForLookup(hostname, flags);
nsDNSAsyncRequest *req =
new nsDNSAsyncRequest(res, hostname, listener, flags, af);
if (!req)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(*result = req);
MOZ_EVENT_TRACER_NAME_OBJECT(req, aHostname.BeginReading());
MOZ_EVENT_TRACER_WAIT(req, "net::dns::lookup");
// addref for resolver; will be released when OnLookupComplete is called.
NS_ADDREF(req);
nsresult rv = res->ResolveHost(req->mHost.get(), flags, af, req);
if (NS_FAILED(rv)) {
NS_RELEASE(req);
NS_RELEASE(*result);
}
return rv;
}
NS_IMETHODIMP
nsDNSService::CancelAsyncResolve(const nsACString &aHostname,
uint32_t aFlags,
nsIDNSListener *aListener,
nsresult aReason)
{
// grab reference to global host resolver and IDN service. beware
// simultaneous shutdown!!
nsRefPtr<nsHostResolver> res;
nsCOMPtr<nsIIDNService> idn;
bool localDomain = false;
{
MutexAutoLock lock(mLock);
if (mDisablePrefetch && (aFlags & RESOLVE_SPECULATE))
return NS_ERROR_DNS_LOOKUP_QUEUE_FULL;
res = mResolver;
idn = mIDN;
localDomain = mLocalDomains.GetEntry(aHostname);
}
if (!res)
return NS_ERROR_OFFLINE;
nsCString hostname;
if (!PreprocessHostname(localDomain, aHostname, idn, hostname))
return NS_ERROR_FAILURE;
uint16_t af = GetAFForLookup(hostname, aFlags);
res->CancelAsyncRequest(hostname.get(), aFlags, af, aListener, aReason);
return NS_OK;
}
NS_IMETHODIMP
nsDNSService::Resolve(const nsACString &aHostname,
uint32_t flags,
nsIDNSRecord **result)
{
// grab reference to global host resolver and IDN service. beware
// simultaneous shutdown!!
nsRefPtr<nsHostResolver> res;
nsCOMPtr<nsIIDNService> idn;
bool localDomain = false;
{
MutexAutoLock lock(mLock);
res = mResolver;
idn = mIDN;
localDomain = mLocalDomains.GetEntry(aHostname);
}
if (mNotifyResolution) {
NS_DispatchToMainThread(new NotifyDNSResolution(mObserverService,
aHostname));
}
NS_ENSURE_TRUE(res, NS_ERROR_OFFLINE);
if (mOffline)
flags |= RESOLVE_OFFLINE;
nsCString hostname;
if (!PreprocessHostname(localDomain, aHostname, idn, hostname))
return NS_ERROR_FAILURE;
//
// sync resolve: since the host resolver only works asynchronously, we need
// to use a mutex and a condvar to wait for the result. however, since the
// result may be in the resolvers cache, we might get called back recursively
// on the same thread. so, our mutex needs to be re-entrant. in other words,
// we need to use a monitor! ;-)
//
PRMonitor *mon = PR_NewMonitor();
if (!mon)
return NS_ERROR_OUT_OF_MEMORY;
PR_EnterMonitor(mon);
nsDNSSyncRequest syncReq(mon);
uint16_t af = GetAFForLookup(hostname, flags);
nsresult rv = res->ResolveHost(hostname.get(), flags, af, &syncReq);
if (NS_SUCCEEDED(rv)) {
// wait for result
while (!syncReq.mDone)
PR_Wait(mon, PR_INTERVAL_NO_TIMEOUT);
if (NS_FAILED(syncReq.mStatus))
rv = syncReq.mStatus;
else {
NS_ASSERTION(syncReq.mHostRecord, "no host record");
nsDNSRecord *rec = new nsDNSRecord(syncReq.mHostRecord);
if (!rec)
rv = NS_ERROR_OUT_OF_MEMORY;
else
NS_ADDREF(*result = rec);
}
}
PR_ExitMonitor(mon);
PR_DestroyMonitor(mon);
return rv;
}
NS_IMETHODIMP
nsDNSService::GetMyHostName(nsACString &result)
{
char name[100];
if (PR_GetSystemInfo(PR_SI_HOSTNAME, name, sizeof(name)) == PR_SUCCESS) {
result = name;
return NS_OK;
}
return NS_ERROR_FAILURE;
}
NS_IMETHODIMP
nsDNSService::Observe(nsISupports *subject, const char *topic, const char16_t *data)
{
// We are only getting called if a preference has changed or there's a
// network link event.
NS_ASSERTION(strcmp(topic, NS_PREFBRANCH_PREFCHANGE_TOPIC_ID) == 0 ||
strcmp(topic, "last-pb-context-exited") == 0 ||
strcmp(topic, NS_NETWORK_LINK_TOPIC) == 0,
"unexpected observe call");
if (!strcmp(topic, NS_NETWORK_LINK_TOPIC)) {
nsAutoCString converted = NS_ConvertUTF16toUTF8(data);
if (mResolver && !strcmp(converted.get(), NS_NETWORK_LINK_DATA_CHANGED)) {
mResolver->FlushCache();
}
return NS_OK;
}
//
// Shutdown and this function are both only called on the UI thread, so we don't
// have to worry about mResolver being cleared out from under us.
//
// NOTE Shutting down and reinitializing the service like this is obviously
// suboptimal if Observe gets called several times in a row, but we don't
// expect that to be the case.
//
if (mResolver) {
Shutdown();
}
Init();
return NS_OK;
}
uint16_t
nsDNSService::GetAFForLookup(const nsACString &host, uint32_t flags)
{
if (mDisableIPv6 || (flags & RESOLVE_DISABLE_IPV6))
return PR_AF_INET;
MutexAutoLock lock(mLock);
uint16_t af = PR_AF_UNSPEC;
if (!mIPv4OnlyDomains.IsEmpty()) {
const char *domain, *domainEnd, *end;
uint32_t hostLen, domainLen;
// see if host is in one of the IPv4-only domains
domain = mIPv4OnlyDomains.BeginReading();
domainEnd = mIPv4OnlyDomains.EndReading();
nsACString::const_iterator hostStart;
host.BeginReading(hostStart);
hostLen = host.Length();
do {
// skip any whitespace
while (*domain == ' ' || *domain == '\t')
++domain;
// find end of this domain in the string
end = strchr(domain, ',');
if (!end)
end = domainEnd;
// to see if the hostname is in the domain, check if the domain
// matches the end of the hostname.
domainLen = end - domain;
if (domainLen && hostLen >= domainLen) {
const char *hostTail = hostStart.get() + hostLen - domainLen;
if (PL_strncasecmp(domain, hostTail, domainLen) == 0) {
// now, make sure either that the hostname is a direct match or
// that the hostname begins with a dot.
if (hostLen == domainLen ||
*hostTail == '.' || *(hostTail - 1) == '.') {
af = PR_AF_INET;
break;
}
}
}
domain = end + 1;
} while (*end);
}
if ((af != PR_AF_INET) && (flags & RESOLVE_DISABLE_IPV4))
af = PR_AF_INET6;
return af;
}
NS_IMETHODIMP
nsDNSService::GetDNSCacheEntries(nsTArray<mozilla::net::DNSCacheEntries> *args)
{
NS_ENSURE_TRUE(mResolver, NS_ERROR_NOT_INITIALIZED);
mResolver->GetDNSCacheEntries(args);
return NS_OK;
}
size_t
nsDNSService::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
{
// Measurement of the following members may be added later if DMD finds it
// is worthwhile:
// - mIDN
// - mLock
size_t n = mallocSizeOf(this);
n += mResolver->SizeOfIncludingThis(mallocSizeOf);
n += mIPv4OnlyDomains.SizeOfExcludingThisMustBeUnshared(mallocSizeOf);
n += mLocalDomains.SizeOfExcludingThis(mallocSizeOf);
return n;
}
MOZ_DEFINE_MALLOC_SIZE_OF(DNSServiceMallocSizeOf)
NS_IMETHODIMP
nsDNSService::CollectReports(nsIHandleReportCallback* aHandleReport,
nsISupports* aData, bool aAnonymize)
{
return MOZ_COLLECT_REPORT(
"explicit/network/dns-service", KIND_HEAP, UNITS_BYTES,
SizeOfIncludingThis(DNSServiceMallocSizeOf),
"Memory used for the DNS service.");
}
