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
|
// 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.
#ifndef CONTENT_ZYGOTE_ZYGOTE_H_
#define CONTENT_ZYGOTE_ZYGOTE_H_
#include <string>
#include <vector>
#include "base/containers/hash_tables.h"
#include "base/process.h"
class Pickle;
class PickleIterator;
namespace content {
class ZygoteForkDelegate;
// This is the object which implements the zygote. The ZygoteMain function,
// which is called from ChromeMain, simply constructs one of these objects and
// runs it.
class Zygote {
public:
Zygote(int sandbox_flags,
ZygoteForkDelegate* helper);
~Zygote();
bool ProcessRequests();
static const int kBrowserDescriptor = 3;
static const int kMagicSandboxIPCDescriptor = 5;
private:
// Returns true if the SUID sandbox is active.
bool UsingSUIDSandbox() const;
// ---------------------------------------------------------------------------
// Requests from the browser...
// Read and process a request from the browser. Returns true if we are in a
// new process and thus need to unwind back into ChromeMain.
bool HandleRequestFromBrowser(int fd);
void HandleReapRequest(int fd, const Pickle& pickle, PickleIterator iter);
void HandleGetTerminationStatus(int fd,
const Pickle& pickle,
PickleIterator iter);
// This is equivalent to fork(), except that, when using the SUID sandbox, it
// returns the real PID of the child process as it appears outside the
// sandbox, rather than returning the PID inside the sandbox. Optionally, it
// fills in uma_name et al with a report the helper wants to make via
// UMA_HISTOGRAM_ENUMERATION.
int ForkWithRealPid(const std::string& process_type,
std::vector<int>& fds,
const std::string& channel_switch,
std::string* uma_name,
int* uma_sample,
int* uma_boundary_value);
// Unpacks process type and arguments from |pickle| and forks a new process.
// Returns -1 on error, otherwise returns twice, returning 0 to the child
// process and the child process ID to the parent process, like fork().
base::ProcessId ReadArgsAndFork(const Pickle& pickle,
PickleIterator iter,
std::vector<int>& fds,
std::string* uma_name,
int* uma_sample,
int* uma_boundary_value);
// Handle a 'fork' request from the browser: this means that the browser
// wishes to start a new renderer. Returns true if we are in a new process,
// otherwise writes the child_pid back to the browser via |fd|. Writes a
// child_pid of -1 on error.
bool HandleForkRequest(int fd,
const Pickle& pickle,
PickleIterator iter,
std::vector<int>& fds);
bool HandleGetSandboxStatus(int fd,
const Pickle& pickle,
PickleIterator iter);
// In the SUID sandbox, we try to use a new PID namespace. Thus the PIDs
// fork() returns are not the real PIDs, so we need to map the Real PIDS
// into the sandbox PID namespace.
typedef base::hash_map<base::ProcessHandle, base::ProcessHandle> ProcessMap;
ProcessMap real_pids_to_sandbox_pids;
const int sandbox_flags_;
ZygoteForkDelegate* helper_;
// These might be set by helper_->InitialUMA. They supply a UMA enumeration
// sample we should report on the first fork.
std::string initial_uma_name_;
int initial_uma_sample_;
int initial_uma_boundary_value_;
};
} // namespace content
#endif // CONTENT_ZYGOTE_ZYGOTE_H_
|
