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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
#include "ForkServiceChild.h"
#include "ForkServer.h"
#include "mozilla/Atomics.h"
#include "mozilla/Logging.h"
#include "mozilla/ipc/GeckoChildProcessHost.h"
#include "mozilla/ipc/IPDLParamTraits.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;
Atomic<bool> ForkServiceChild::sForkServiceUsed;
static bool ConfigurePipeFd(int aFd) {
int flags = fcntl(aFd, F_GETFD, 0);
return flags != -1 && fcntl(aFd, F_SETFD, flags | FD_CLOEXEC) != -1;
}
void ForkServiceChild::StartForkServer() {
// Create the socket to use for communication, and mark both ends as
// FD_CLOEXEC.
int fds[2];
if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) < 0) {
MOZ_LOG(gForkServiceLog, LogLevel::Error,
("failed to create fork server socket"));
return;
}
UniqueFileHandle server(fds[0]);
UniqueFileHandle client(fds[1]);
if (!ConfigurePipeFd(server.get()) || !ConfigurePipeFd(client.get())) {
MOZ_LOG(gForkServiceLog, LogLevel::Error,
("failed to configure fork server socket"));
return;
}
GeckoChildProcessHost* subprocess =
new GeckoChildProcessHost(GeckoProcessType_ForkServer, false);
subprocess->AddFdToRemap(client.get(), ForkServer::kClientPipeFd);
if (!subprocess->LaunchAndWaitForProcessHandle(std::vector<std::string>{})) {
MOZ_LOG(gForkServiceLog, LogLevel::Error, ("failed to launch fork server"));
return;
}
sForkServiceUsed = true;
sForkServiceChild =
mozilla::MakeUnique<ForkServiceChild>(server.release(), subprocess);
}
void ForkServiceChild::StopForkServer() { sForkServiceChild = nullptr; }
ForkServiceChild::ForkServiceChild(int aFd, GeckoChildProcessHost* aProcess)
: mFailed(false), mProcess(aProcess) {
mTcver = MakeUnique<MiniTransceiver>(aFd);
}
ForkServiceChild::~ForkServiceChild() {
mProcess->Destroy();
close(mTcver->GetFD());
}
Result<Ok, LaunchError> ForkServiceChild::SendForkNewSubprocess(
const Args& aArgs, pid_t* aPid) {
mRecvPid = -1;
IPC::Message msg(MSG_ROUTING_CONTROL, Msg_ForkNewSubprocess__ID);
IPC::MessageWriter writer(msg);
#if defined(XP_LINUX) && defined(MOZ_SANDBOX)
WriteIPDLParam(&writer, nullptr, aArgs.mForkFlags);
WriteIPDLParam(&writer, nullptr, aArgs.mChroot);
#endif
WriteIPDLParam(&writer, nullptr, aArgs.mArgv);
WriteIPDLParam(&writer, nullptr, aArgs.mEnv);
WriteIPDLParam(&writer, nullptr, aArgs.mFdsRemap);
if (!mTcver->Send(msg)) {
MOZ_LOG(gForkServiceLog, LogLevel::Verbose,
("the pipe to the fork server is closed or having errors"));
OnError();
return Err(LaunchError("FSC::SFNS::Send"));
}
UniquePtr<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 Err(LaunchError("FSC::SFNS::Recv"));
}
OnMessageReceived(std::move(reply));
MOZ_ASSERT(mRecvPid != -1);
*aPid = mRecvPid;
return Ok();
}
void ForkServiceChild::OnMessageReceived(UniquePtr<IPC::Message> message) {
if (message->type() != Reply_ForkNewSubprocess__ID) {
MOZ_LOG(gForkServiceLog, LogLevel::Verbose,
("unknown reply type %d", message->type()));
return;
}
IPC::MessageReader reader(*message);
if (!ReadIPDLParam(&reader, nullptr, &mRecvPid)) {
MOZ_CRASH("Error deserializing 'pid_t'");
}
reader.EndRead();
}
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