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
|
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "chrome/app/nacl_fork_delegate_linux.h"
#include <signal.h>
#include <stdlib.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <set>
#include "base/basictypes.h"
#include "base/command_line.h"
#include "base/files/file_path.h"
#include "base/logging.h"
#include "base/path_service.h"
#include "base/posix/eintr_wrapper.h"
#include "base/posix/unix_domain_socket_linux.h"
#include "base/process_util.h"
#include "base/third_party/dynamic_annotations/dynamic_annotations.h"
#include "chrome/common/chrome_paths.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/nacl_helper_linux.h"
NaClForkDelegate::NaClForkDelegate()
: status_(kNaClHelperUnused),
fd_(-1) {}
// Note these need to match up with their counterparts in nacl_helper_linux.c
// and nacl_helper_bootstrap_linux.c.
const char kNaClHelperReservedAtZero[] =
"--reserved_at_zero=0xXXXXXXXXXXXXXXXX";
const char kNaClHelperRDebug[] = "--r_debug=0xXXXXXXXXXXXXXXXX";
void NaClForkDelegate::Init(const int sandboxdesc) {
VLOG(1) << "NaClForkDelegate::Init()";
int fds[2];
// Confirm a hard-wired assumption.
// The NaCl constant is from chrome/nacl/nacl_linux_helper.h
DCHECK(kNaClSandboxDescriptor == sandboxdesc);
CHECK(socketpair(PF_UNIX, SOCK_SEQPACKET, 0, fds) == 0);
base::FileHandleMappingVector fds_to_map;
fds_to_map.push_back(std::make_pair(fds[1], kNaClZygoteDescriptor));
fds_to_map.push_back(std::make_pair(sandboxdesc, kNaClSandboxDescriptor));
status_ = kNaClHelperUnused;
base::FilePath helper_exe;
base::FilePath helper_bootstrap_exe;
if (!PathService::Get(chrome::FILE_NACL_HELPER, &helper_exe)) {
status_ = kNaClHelperMissing;
} else if (!PathService::Get(chrome::FILE_NACL_HELPER_BOOTSTRAP,
&helper_bootstrap_exe)) {
status_ = kNaClHelperBootstrapMissing;
} else if (RunningOnValgrind()) {
status_ = kNaClHelperValgrind;
} else {
CommandLine cmd_line(helper_bootstrap_exe);
cmd_line.AppendArgPath(helper_exe);
cmd_line.AppendArgNative(kNaClHelperReservedAtZero);
cmd_line.AppendArgNative(kNaClHelperRDebug);
base::LaunchOptions options;
options.fds_to_remap = &fds_to_map;
options.clone_flags = CLONE_FS | SIGCHLD;
// The NaCl processes spawned may need to exceed the ambient soft limit
// on RLIMIT_AS to allocate the untrusted address space and its guard
// regions. The nacl_helper itself cannot just raise its own limit,
// because the existing limit may prevent the initial exec of
// nacl_helper_bootstrap from succeeding, with its large address space
// reservation.
std::set<int> max_these_limits;
max_these_limits.insert(RLIMIT_AS);
options.maximize_rlimits = &max_these_limits;
if (!base::LaunchProcess(cmd_line.argv(), options, NULL))
status_ = kNaClHelperLaunchFailed;
// parent and error cases are handled below
}
if (HANDLE_EINTR(close(fds[1])) != 0)
LOG(ERROR) << "close(fds[1]) failed";
if (status_ == kNaClHelperUnused) {
const ssize_t kExpectedLength = strlen(kNaClHelperStartupAck);
char buf[kExpectedLength];
// Wait for ack from nacl_helper, indicating it is ready to help
const ssize_t nread = HANDLE_EINTR(read(fds[0], buf, sizeof(buf)));
if (nread == kExpectedLength &&
memcmp(buf, kNaClHelperStartupAck, nread) == 0) {
// all is well
status_ = kNaClHelperSuccess;
fd_ = fds[0];
return;
}
status_ = kNaClHelperAckFailed;
LOG(ERROR) << "Bad NaCl helper startup ack (" << nread << " bytes)";
}
// TODO(bradchen): Make this LOG(ERROR) when the NaCl helper
// becomes the default.
fd_ = -1;
if (HANDLE_EINTR(close(fds[0])) != 0)
LOG(ERROR) << "close(fds[0]) failed";
}
void NaClForkDelegate::InitialUMA(std::string* uma_name,
int* uma_sample,
int* uma_boundary_value) {
*uma_name = "NaCl.Client.Helper.InitState";
*uma_sample = status_;
*uma_boundary_value = kNaClHelperStatusBoundary;
}
NaClForkDelegate::~NaClForkDelegate() {
// side effect of close: delegate process will terminate
if (status_ == kNaClHelperSuccess) {
if (HANDLE_EINTR(close(fd_)) != 0)
LOG(ERROR) << "close(fd_) failed";
}
}
bool NaClForkDelegate::CanHelp(const std::string& process_type,
std::string* uma_name,
int* uma_sample,
int* uma_boundary_value) {
if (process_type != switches::kNaClLoaderProcess)
return false;
*uma_name = "NaCl.Client.Helper.StateOnFork";
*uma_sample = status_;
*uma_boundary_value = kNaClHelperStatusBoundary;
return status_ == kNaClHelperSuccess;
}
pid_t NaClForkDelegate::Fork(const std::vector<int>& fds) {
base::ProcessId naclchild;
VLOG(1) << "NaClForkDelegate::Fork";
DCHECK(fds.size() == kNaClParentFDIndex + 1);
if (!UnixDomainSocket::SendMsg(fd_, kNaClForkRequest,
strlen(kNaClForkRequest), fds)) {
LOG(ERROR) << "NaClForkDelegate::Fork: SendMsg failed";
return -1;
}
int nread = HANDLE_EINTR(read(fd_, &naclchild, sizeof(naclchild)));
if (nread != sizeof(naclchild)) {
LOG(ERROR) << "NaClForkDelegate::Fork: read failed";
return -1;
}
VLOG(1) << "nacl_child is " << naclchild << " (" << nread << " bytes)";
return naclchild;
}
bool NaClForkDelegate::AckChild(const int fd,
const std::string& channel_switch) {
int nwritten = HANDLE_EINTR(write(fd, channel_switch.c_str(),
channel_switch.length()));
if (nwritten != static_cast<int>(channel_switch.length())) {
return false;
}
return true;
}
|
