netwerk/base/nsServerSocket.cpp
author Andrew Osmond <aosmond@mozilla.com>
Fri, 17 Nov 2017 06:45:28 -0500
changeset 392351 b9a29d94ccac646c9336fa75e084bbc8581501ad
parent 367749 6a629adbb62a299d7208373d1c6f375149d2afdb
child 412767 d7d2f08e051c3c355d41dc5c1ce1bd3ca55a43b9
permissions -rw-r--r--
Bug 1368776 - Part 15. Cache flags passed to ImageResource::GetImageContainerImpl for consistency. r=tnikkel When FLAG_HIGH_QUALITY_SCALING is used, we need to make sure we continue using that flag when we update the container. We should also use it for comparing whether or not an existing image container is equivalent.

/* vim:set ts=2 sw=2 et cindent: */
/* 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 "nsSocketTransport2.h"
#include "nsServerSocket.h"
#include "nsProxyRelease.h"
#include "nsAutoPtr.h"
#include "nsError.h"
#include "nsNetCID.h"
#include "prnetdb.h"
#include "prio.h"
#include "nsThreadUtils.h"
#include "mozilla/Attributes.h"
#include "mozilla/EndianUtils.h"
#include "mozilla/net/DNS.h"
#include "nsServiceManagerUtils.h"
#include "nsIFile.h"

namespace mozilla { namespace net {

//-----------------------------------------------------------------------------

typedef void (nsServerSocket:: *nsServerSocketFunc)(void);

static nsresult
PostEvent(nsServerSocket *s, nsServerSocketFunc func)
{
  nsCOMPtr<nsIRunnable> ev = NewRunnableMethod("net::PostEvent", s, func);
  if (!gSocketTransportService)
    return NS_ERROR_FAILURE;

  return gSocketTransportService->Dispatch(ev, NS_DISPATCH_NORMAL);
}

//-----------------------------------------------------------------------------
// nsServerSocket
//-----------------------------------------------------------------------------

nsServerSocket::nsServerSocket()
  : mFD(nullptr)
  , mLock("nsServerSocket.mLock")
  , mAttached(false)
  , mKeepWhenOffline(false)
{
  // we want to be able to access the STS directly, and it may not have been
  // constructed yet.  the STS constructor sets gSocketTransportService.
  if (!gSocketTransportService)
  {
    // This call can fail if we're offline, for example.
    nsCOMPtr<nsISocketTransportService> sts =
        do_GetService(NS_SOCKETTRANSPORTSERVICE_CONTRACTID);
  }
  // make sure the STS sticks around as long as we do
  NS_IF_ADDREF(gSocketTransportService);
}

nsServerSocket::~nsServerSocket()
{
  Close(); // just in case :)

  // release our reference to the STS
  nsSocketTransportService *serv = gSocketTransportService;
  NS_IF_RELEASE(serv);
}

void
nsServerSocket::OnMsgClose()
{
  SOCKET_LOG(("nsServerSocket::OnMsgClose [this=%p]\n", this));

  if (NS_FAILED(mCondition))
    return;

  // tear down socket.  this signals the STS to detach our socket handler.
  mCondition = NS_BINDING_ABORTED;

  // if we are attached, then we'll close the socket in our OnSocketDetached.
  // otherwise, call OnSocketDetached from here.
  if (!mAttached)
    OnSocketDetached(mFD);
}

void
nsServerSocket::OnMsgAttach()
{
  SOCKET_LOG(("nsServerSocket::OnMsgAttach [this=%p]\n", this));

  if (NS_FAILED(mCondition))
    return;

  mCondition = TryAttach();

  // if we hit an error while trying to attach then bail...
  if (NS_FAILED(mCondition))
  {
    NS_ASSERTION(!mAttached, "should not be attached already");
    OnSocketDetached(mFD);
  }
}

nsresult
nsServerSocket::TryAttach()
{
  nsresult rv;

  if (!gSocketTransportService)
    return NS_ERROR_FAILURE;

  //
  // find out if it is going to be ok to attach another socket to the STS.
  // if not then we have to wait for the STS to tell us that it is ok.
  // the notification is asynchronous, which means that when we could be
  // in a race to call AttachSocket once notified.  for this reason, when
  // we get notified, we just re-enter this function.  as a result, we are
  // sure to ask again before calling AttachSocket.  in this way we deal
  // with the race condition.  though it isn't the most elegant solution,
  // it is far simpler than trying to build a system that would guarantee
  // FIFO ordering (which wouldn't even be that valuable IMO).  see bug
  // 194402 for more info.
  //
  if (!gSocketTransportService->CanAttachSocket())
  {
    nsCOMPtr<nsIRunnable> event = NewRunnableMethod(
      "net::nsServerSocket::OnMsgAttach", this, &nsServerSocket::OnMsgAttach);
    if (!event)
      return NS_ERROR_OUT_OF_MEMORY;

    nsresult rv = gSocketTransportService->NotifyWhenCanAttachSocket(event);
    if (NS_FAILED(rv))
      return rv;
  }

  //
  // ok, we can now attach our socket to the STS for polling
  //
  rv = gSocketTransportService->AttachSocket(mFD, this);
  if (NS_FAILED(rv))
    return rv;

  mAttached = true;

  //
  // now, configure our poll flags for listening...
  //
  mPollFlags = (PR_POLL_READ | PR_POLL_EXCEPT);
  return NS_OK;
}

void
nsServerSocket::CreateClientTransport(PRFileDesc* aClientFD,
                                      const NetAddr& aClientAddr)
{
  RefPtr<nsSocketTransport> trans = new nsSocketTransport;
  if (NS_WARN_IF(!trans)) {
    mCondition = NS_ERROR_OUT_OF_MEMORY;
    return;
  }

  nsresult rv = trans->InitWithConnectedSocket(aClientFD, &aClientAddr);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    mCondition = rv;
    return;
  }

  mListener->OnSocketAccepted(this, trans);
}

//-----------------------------------------------------------------------------
// nsServerSocket::nsASocketHandler
//-----------------------------------------------------------------------------

void
nsServerSocket::OnSocketReady(PRFileDesc *fd, int16_t outFlags)
{
  NS_ASSERTION(NS_SUCCEEDED(mCondition), "oops");
  NS_ASSERTION(mFD == fd, "wrong file descriptor");
  NS_ASSERTION(outFlags != -1, "unexpected timeout condition reached");

  if (outFlags & (PR_POLL_ERR | PR_POLL_HUP | PR_POLL_NVAL))
  {
    NS_WARNING("error polling on listening socket");
    mCondition = NS_ERROR_UNEXPECTED;
    return;
  }

  PRFileDesc *clientFD;
  PRNetAddr prClientAddr;
  NetAddr clientAddr;

  // NSPR doesn't tell us the peer address's length (as provided by the
  // 'accept' system call), so we can't distinguish between named,
  // unnamed, and abstract peer addresses. Clear prClientAddr first, so
  // that the path will at least be reliably empty for unnamed and
  // abstract addresses, and not garbage when the peer is unnamed.
  memset(&prClientAddr, 0, sizeof(prClientAddr));

  clientFD = PR_Accept(mFD, &prClientAddr, PR_INTERVAL_NO_WAIT);
  PRNetAddrToNetAddr(&prClientAddr, &clientAddr);
  if (!clientFD) {
    NS_WARNING("PR_Accept failed");
    mCondition = NS_ERROR_UNEXPECTED;
    return;
  }

  // Accept succeeded, create socket transport and notify consumer
  CreateClientTransport(clientFD, clientAddr);
}

void
nsServerSocket::OnSocketDetached(PRFileDesc *fd)
{
  // force a failure condition if none set; maybe the STS is shutting down :-/
  if (NS_SUCCEEDED(mCondition))
    mCondition = NS_ERROR_ABORT;

  if (mFD)
  {
    NS_ASSERTION(mFD == fd, "wrong file descriptor");
    PR_Close(mFD);
    mFD = nullptr;
  }

  if (mListener)
  {
    mListener->OnStopListening(this, mCondition);

    // need to atomically clear mListener.  see our Close() method.
    RefPtr<nsIServerSocketListener> listener = nullptr;
    {
      MutexAutoLock lock(mLock);
      listener = mListener.forget();
    }

    // XXX we need to proxy the release to the listener's target thread to work
    // around bug 337492.
    if (listener) {
      NS_ProxyRelease(
        "nsServerSocket::mListener", mListenerTarget, listener.forget());
    }
  }
}

void
nsServerSocket::IsLocal(bool *aIsLocal)
{
#if defined(XP_UNIX)
  // Unix-domain sockets are always local.
  if (mAddr.raw.family == PR_AF_LOCAL)
  {
    *aIsLocal = true;
    return;
  }
#endif

  // If bound to loopback, this server socket only accepts local connections.
  *aIsLocal = PR_IsNetAddrType(&mAddr, PR_IpAddrLoopback);
}

void
nsServerSocket::KeepWhenOffline(bool *aKeepWhenOffline)
{
  *aKeepWhenOffline = mKeepWhenOffline;
}

//-----------------------------------------------------------------------------
// nsServerSocket::nsISupports
//-----------------------------------------------------------------------------

NS_IMPL_ISUPPORTS(nsServerSocket, nsIServerSocket)


//-----------------------------------------------------------------------------
// nsServerSocket::nsIServerSocket
//-----------------------------------------------------------------------------

NS_IMETHODIMP
nsServerSocket::Init(int32_t aPort, bool aLoopbackOnly, int32_t aBackLog)
{
  return InitSpecialConnection(aPort, aLoopbackOnly ? LoopbackOnly : 0, aBackLog);
}

NS_IMETHODIMP
nsServerSocket::InitWithFilename(nsIFile *aPath, uint32_t aPermissions, int32_t aBacklog)
{
#if defined(XP_UNIX)
  nsresult rv;

  nsAutoCString path;
  rv = aPath->GetNativePath(path);
  if (NS_FAILED(rv))
    return rv;

  // Create a Unix domain PRNetAddr referring to the given path.
  PRNetAddr addr;
  if (path.Length() > sizeof(addr.local.path) - 1)
    return NS_ERROR_FILE_NAME_TOO_LONG;
  addr.local.family = PR_AF_LOCAL;
  memcpy(addr.local.path, path.get(), path.Length());
  addr.local.path[path.Length()] = '\0';

  rv = InitWithAddress(&addr, aBacklog);
  if (NS_FAILED(rv))
    return rv;

  return aPath->SetPermissions(aPermissions);
#else
  return NS_ERROR_SOCKET_ADDRESS_NOT_SUPPORTED;
#endif
}

NS_IMETHODIMP
nsServerSocket::InitSpecialConnection(int32_t aPort, nsServerSocketFlag aFlags,
                                      int32_t aBackLog)
{
  PRNetAddrValue val;
  PRNetAddr addr;

  if (aPort < 0)
    aPort = 0;
  if (aFlags & nsIServerSocket::LoopbackOnly)
    val = PR_IpAddrLoopback;
  else
    val = PR_IpAddrAny;
  PR_SetNetAddr(val, PR_AF_INET, aPort, &addr);

  mKeepWhenOffline = ((aFlags & nsIServerSocket::KeepWhenOffline) != 0);
  return InitWithAddress(&addr, aBackLog);
}

NS_IMETHODIMP
nsServerSocket::InitWithAddress(const PRNetAddr *aAddr, int32_t aBackLog)
{
  NS_ENSURE_TRUE(mFD == nullptr, NS_ERROR_ALREADY_INITIALIZED);
  nsresult rv;

  //
  // configure listening socket...
  //

  mFD = PR_OpenTCPSocket(aAddr->raw.family);
  if (!mFD)
  {
    NS_WARNING("unable to create server socket");
    return ErrorAccordingToNSPR(PR_GetError());
  }

  PRSocketOptionData opt;

  opt.option = PR_SockOpt_Reuseaddr;
  opt.value.reuse_addr = true;
  PR_SetSocketOption(mFD, &opt);

  opt.option = PR_SockOpt_Nonblocking;
  opt.value.non_blocking = true;
  PR_SetSocketOption(mFD, &opt);

  if (PR_Bind(mFD, aAddr) != PR_SUCCESS)
  {
    NS_WARNING("failed to bind socket");
    goto fail;
  }

  if (aBackLog < 0)
    aBackLog = 5; // seems like a reasonable default

  if (PR_Listen(mFD, aBackLog) != PR_SUCCESS)
  {
    NS_WARNING("cannot listen on socket");
    goto fail;
  }

  // get the resulting socket address, which may be different than what
  // we passed to bind.
  if (PR_GetSockName(mFD, &mAddr) != PR_SUCCESS)
  {
    NS_WARNING("cannot get socket name");
    goto fail;
  }

  // Set any additional socket defaults needed by child classes
  rv = SetSocketDefaults();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    goto fail;
  }

  // wait until AsyncListen is called before polling the socket for
  // client connections.
  return NS_OK;

fail:
  rv = ErrorAccordingToNSPR(PR_GetError());
  Close();
  return rv;
}

NS_IMETHODIMP
nsServerSocket::Close()
{
  {
    MutexAutoLock lock(mLock);
    // we want to proxy the close operation to the socket thread if a listener
    // has been set.  otherwise, we should just close the socket here...
    if (!mListener)
    {
      if (mFD)
      {
        PR_Close(mFD);
        mFD = nullptr;
      }
      return NS_OK;
    }
  }
  return PostEvent(this, &nsServerSocket::OnMsgClose);
}

namespace {

class ServerSocketListenerProxy final : public nsIServerSocketListener
{
  ~ServerSocketListenerProxy() {}

public:
  explicit ServerSocketListenerProxy(nsIServerSocketListener* aListener)
    : mListener(new nsMainThreadPtrHolder<nsIServerSocketListener>(
        "ServerSocketListenerProxy::mListener", aListener))
    , mTarget(GetCurrentThreadEventTarget())
  { }

  NS_DECL_THREADSAFE_ISUPPORTS
  NS_DECL_NSISERVERSOCKETLISTENER

  class OnSocketAcceptedRunnable : public Runnable
  {
  public:
    OnSocketAcceptedRunnable(
      const nsMainThreadPtrHandle<nsIServerSocketListener>& aListener,
      nsIServerSocket* aServ,
      nsISocketTransport* aTransport)
      : Runnable("net::ServerSocketListenerProxy::OnSocketAcceptedRunnable")
      , mListener(aListener)
      , mServ(aServ)
      , mTransport(aTransport)
    { }

    NS_DECL_NSIRUNNABLE

  private:
    nsMainThreadPtrHandle<nsIServerSocketListener> mListener;
    nsCOMPtr<nsIServerSocket> mServ;
    nsCOMPtr<nsISocketTransport> mTransport;
  };

  class OnStopListeningRunnable : public Runnable
  {
  public:
    OnStopListeningRunnable(
      const nsMainThreadPtrHandle<nsIServerSocketListener>& aListener,
      nsIServerSocket* aServ,
      nsresult aStatus)
      : Runnable("net::ServerSocketListenerProxy::OnStopListeningRunnable")
      , mListener(aListener)
      , mServ(aServ)
      , mStatus(aStatus)
    { }

    NS_DECL_NSIRUNNABLE

  private:
    nsMainThreadPtrHandle<nsIServerSocketListener> mListener;
    nsCOMPtr<nsIServerSocket> mServ;
    nsresult mStatus;
  };

private:
  nsMainThreadPtrHandle<nsIServerSocketListener> mListener;
  nsCOMPtr<nsIEventTarget> mTarget;
};

NS_IMPL_ISUPPORTS(ServerSocketListenerProxy,
                  nsIServerSocketListener)

NS_IMETHODIMP
ServerSocketListenerProxy::OnSocketAccepted(nsIServerSocket* aServ,
                                            nsISocketTransport* aTransport)
{
  RefPtr<OnSocketAcceptedRunnable> r =
    new OnSocketAcceptedRunnable(mListener, aServ, aTransport);
  return mTarget->Dispatch(r, NS_DISPATCH_NORMAL);
}

NS_IMETHODIMP
ServerSocketListenerProxy::OnStopListening(nsIServerSocket* aServ,
                                           nsresult aStatus)
{
  RefPtr<OnStopListeningRunnable> r =
    new OnStopListeningRunnable(mListener, aServ, aStatus);
  return mTarget->Dispatch(r, NS_DISPATCH_NORMAL);
}

NS_IMETHODIMP
ServerSocketListenerProxy::OnSocketAcceptedRunnable::Run()
{
  mListener->OnSocketAccepted(mServ, mTransport);
  return NS_OK;
}

NS_IMETHODIMP
ServerSocketListenerProxy::OnStopListeningRunnable::Run()
{
  mListener->OnStopListening(mServ, mStatus);
  return NS_OK;
}

} // namespace

NS_IMETHODIMP
nsServerSocket::AsyncListen(nsIServerSocketListener *aListener)
{
  // ensuring mFD implies ensuring mLock
  NS_ENSURE_TRUE(mFD, NS_ERROR_NOT_INITIALIZED);
  NS_ENSURE_TRUE(mListener == nullptr, NS_ERROR_IN_PROGRESS);
  {
    MutexAutoLock lock(mLock);
    mListener = new ServerSocketListenerProxy(aListener);
    mListenerTarget = GetCurrentThreadEventTarget();
  }

  // Child classes may need to do additional setup just before listening begins
  nsresult rv = OnSocketListen();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  return PostEvent(this, &nsServerSocket::OnMsgAttach);
}

NS_IMETHODIMP
nsServerSocket::GetPort(int32_t *aResult)
{
  // no need to enter the lock here
  uint16_t port;
  if (mAddr.raw.family == PR_AF_INET)
    port = mAddr.inet.port;
  else if (mAddr.raw.family == PR_AF_INET6)
    port = mAddr.ipv6.port;
  else
    return NS_ERROR_FAILURE;

  *aResult = static_cast<int32_t>(NetworkEndian::readUint16(&port));
  return NS_OK;
}

NS_IMETHODIMP
nsServerSocket::GetAddress(PRNetAddr *aResult)
{
  // no need to enter the lock here
  memcpy(aResult, &mAddr, sizeof(mAddr));
  return NS_OK;
}

} // namespace net
} // namespace mozilla