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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 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 "ForkServiceChild.h"
#include "ForkServer.h"
#include "mozilla/ipc/IPDLParamTraits.h"
#include "mozilla/Logging.h"
#include "mozilla/ipc/GeckoChildProcessHost.h"
#include "mozilla/ipc/ProtocolMessageUtils.h"
#include "mozilla/StaticPrefs_dom.h"
#include "mozilla/Services.h"
#include "ipc/IPCMessageUtilsSpecializations.h"
#include "nsIObserverService.h"
#include <unistd.h>
#include <fcntl.h>
namespace mozilla {
namespace ipc {
extern LazyLogModule gForkServiceLog;
mozilla::UniquePtr<ForkServiceChild> ForkServiceChild::sForkServiceChild;
void ForkServiceChild::StartForkServer() {
std::vector<std::string> extraArgs;
GeckoChildProcessHost* subprocess =
new GeckoChildProcessHost(GeckoProcessType_ForkServer, false);
subprocess->LaunchAndWaitForProcessHandle(std::move(extraArgs));
int fd = subprocess->GetChannel()->GetFileDescriptor();
fd = dup(fd); // Dup it because the channel will close it.
int fs_flags = fcntl(fd, F_GETFL, 0);
fcntl(fd, F_SETFL, fs_flags & ~O_NONBLOCK);
int fd_flags = fcntl(fd, F_GETFD, 0);
fcntl(fd, F_SETFD, fd_flags | FD_CLOEXEC);
sForkServiceChild = mozilla::MakeUnique<ForkServiceChild>(fd, subprocess);
// Without doing this, IO thread may intercept messages since the
// IPC::Channel created by it is still open.
subprocess->GetChannel()->Close();
}
void ForkServiceChild::StopForkServer() { sForkServiceChild = nullptr; }
ForkServiceChild::ForkServiceChild(int aFd, GeckoChildProcessHost* aProcess)
: mWaitForHello(true), mFailed(false), mProcess(aProcess) {
mTcver = MakeUnique<MiniTransceiver>(aFd);
}
ForkServiceChild::~ForkServiceChild() {
mProcess->Destroy();
close(mTcver->GetFD());
}
bool ForkServiceChild::SendForkNewSubprocess(
const nsTArray<nsCString>& aArgv, const nsTArray<EnvVar>& aEnvMap,
const nsTArray<FdMapping>& aFdsRemap, pid_t* aPid) {
if (mWaitForHello) {
// IPC::Channel created by the GeckoChildProcessHost has
// already send a HELLO. It is expected to receive a hello
// message from the fork server too.
IPC::Message hello;
mTcver->RecvInfallible(hello, "Fail to receive HELLO message");
MOZ_ASSERT(hello.type() == ForkServer::kHELLO_MESSAGE_TYPE);
mWaitForHello = false;
}
mRecvPid = -1;
IPC::Message msg(MSG_ROUTING_CONTROL, Msg_ForkNewSubprocess__ID);
WriteIPDLParam(&msg, nullptr, aArgv);
WriteIPDLParam(&msg, nullptr, aEnvMap);
WriteIPDLParam(&msg, nullptr, aFdsRemap);
if (!mTcver->Send(msg)) {
MOZ_LOG(gForkServiceLog, LogLevel::Verbose,
("the pipe to the fork server is closed or having errors"));
OnError();
return false;
}
IPC::Message reply;
if (!mTcver->Recv(reply)) {
MOZ_LOG(gForkServiceLog, LogLevel::Verbose,
("the pipe to the fork server is closed or having errors"));
OnError();
return false;
}
OnMessageReceived(std::move(reply));
MOZ_ASSERT(mRecvPid != -1);
*aPid = mRecvPid;
return true;
}
void ForkServiceChild::OnMessageReceived(IPC::Message&& message) {
if (message.type() != Reply_ForkNewSubprocess__ID) {
MOZ_LOG(gForkServiceLog, LogLevel::Verbose,
("unknown reply type %d", message.type()));
return;
}
PickleIterator iter__(message);
if (!ReadIPDLParam(&message, &iter__, nullptr, &mRecvPid)) {
MOZ_CRASH("Error deserializing 'pid_t'");
}
message.EndRead(iter__, message.type());
}
void ForkServiceChild::OnError() {
mFailed = true;
ForkServerLauncher::RestartForkServer();
}
NS_IMPL_ISUPPORTS(ForkServerLauncher, nsIObserver)
bool ForkServerLauncher::mHaveStartedClient = false;
StaticRefPtr<ForkServerLauncher> ForkServerLauncher::mSingleton;
ForkServerLauncher::ForkServerLauncher() {}
ForkServerLauncher::~ForkServerLauncher() {}
already_AddRefed<ForkServerLauncher> ForkServerLauncher::Create() {
if (mSingleton == nullptr) {
mSingleton = new ForkServerLauncher();
}
RefPtr<ForkServerLauncher> launcher = mSingleton;
return launcher.forget();
}
NS_IMETHODIMP
ForkServerLauncher::Observe(nsISupports* aSubject, const char* aTopic,
const char16_t* aData) {
if (strcmp(aTopic, NS_XPCOM_STARTUP_CATEGORY) == 0) {
nsCOMPtr<nsIObserverService> obsSvc =
mozilla::services::GetObserverService();
MOZ_ASSERT(obsSvc != nullptr);
// preferences are not available until final-ui-startup
obsSvc->AddObserver(this, "final-ui-startup", false);
} else if (!mHaveStartedClient && strcmp(aTopic, "final-ui-startup") == 0) {
if (StaticPrefs::dom_ipc_forkserver_enable_AtStartup()) {
mHaveStartedClient = true;
ForkServiceChild::StartForkServer();
nsCOMPtr<nsIObserverService> obsSvc =
mozilla::services::GetObserverService();
MOZ_ASSERT(obsSvc != nullptr);
obsSvc->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
} else {
mSingleton = nullptr;
}
}
if (strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
if (mHaveStartedClient) {
mHaveStartedClient = false;
ForkServiceChild::StopForkServer();
}
// To make leak checker happy!
mSingleton = nullptr;
}
return NS_OK;
}
void ForkServerLauncher::RestartForkServer() {
// Restart fork server
NS_SUCCEEDED(NS_DispatchToMainThreadQueue(
NS_NewRunnableFunction("OnForkServerError",
[] {
if (mSingleton) {
ForkServiceChild::StopForkServer();
ForkServiceChild::StartForkServer();
}
}),
EventQueuePriority::Idle));
}
} // namespace ipc
} // namespace mozilla