1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
/* -*- 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/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
|
