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
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
|
// Copyright 2015 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 "chromeos/binder/command_broker.h"
#include <stddef.h>
#include <stdint.h>
#include "base/bind.h"
#include "base/logging.h"
#include "chromeos/binder/binder_driver_api.h"
#include "chromeos/binder/driver.h"
#include "chromeos/binder/local_object.h"
#include "chromeos/binder/transaction_data.h"
#include "chromeos/binder/transaction_status.h"
namespace binder {
namespace {
// Converts TransactionData to binder_transaction_data struct.
binder_transaction_data ConvertTransactionDataToStruct(
const TransactionData& data) {
binder_transaction_data result = {};
result.code = data.GetCode();
result.flags = TF_ACCEPT_FDS;
if (data.IsOneWay()) {
result.flags |= TF_ONE_WAY;
}
if (data.HasStatus()) {
result.flags |= TF_STATUS_CODE;
}
result.data_size = data.GetDataSize();
result.data.ptr.buffer = reinterpret_cast<binder_uintptr_t>(data.GetData());
result.offsets_size = data.GetNumObjectOffsets() * sizeof(size_t);
result.data.ptr.offsets =
reinterpret_cast<binder_uintptr_t>(data.GetObjectOffsets());
return result;
}
} // namespace
CommandBroker::CommandBroker(Driver* driver)
: command_stream_(driver, this), weak_ptr_factory_(this) {}
CommandBroker::~CommandBroker() {
DCHECK(thread_checker_.CalledOnValidThread());
}
bool CommandBroker::EnterLooper() {
command_stream_.AppendOutgoingCommand(BC_ENTER_LOOPER, nullptr, 0);
return command_stream_.Flush();
}
bool CommandBroker::RegisterLooper() {
command_stream_.AppendOutgoingCommand(BC_REGISTER_LOOPER, nullptr, 0);
return command_stream_.Flush();
}
bool CommandBroker::ExitLooper() {
command_stream_.AppendOutgoingCommand(BC_EXIT_LOOPER, nullptr, 0);
return command_stream_.Flush();
}
bool CommandBroker::PollCommands() {
// Fetch and process commands.
if (!command_stream_.Fetch()) {
LOG(ERROR) << "Failed to fetch commands.";
return false;
}
while (command_stream_.CanProcessIncomingCommand()) {
if (!command_stream_.ProcessIncomingCommand()) {
LOG(ERROR) << "Failed to process command.";
return false;
}
}
// Flush outgoing commands.
if (!command_stream_.Flush()) {
LOG(ERROR) << "Failed to flush commands.";
return false;
}
return true;
}
bool CommandBroker::Transact(int32_t handle,
const TransactionData& request,
scoped_ptr<TransactionData>* reply) {
DCHECK(thread_checker_.CalledOnValidThread());
// Send transaction.
binder_transaction_data tr = ConvertTransactionDataToStruct(request);
tr.target.handle = handle;
command_stream_.AppendOutgoingCommand(BC_TRANSACTION, &tr, sizeof(tr));
if (!command_stream_.Flush()) {
LOG(ERROR) << "Failed to write";
return false;
}
// Wait for response.
scoped_ptr<TransactionData> response_data;
ResponseType response_type = WaitForResponse(&response_data);
if (response_type != RESPONSE_TYPE_TRANSACTION_COMPLETE) {
LOG(ERROR) << "Failed to wait for response: response_type = "
<< response_type;
return false;
}
if (!request.IsOneWay()) {
// Wait for reply.
scoped_ptr<TransactionData> response_data;
ResponseType response_type = WaitForResponse(&response_data);
if (response_type != RESPONSE_TYPE_TRANSACTION_REPLY) {
LOG(ERROR) << "Failed to wait for response: response_type = "
<< response_type;
return false;
}
*reply = std::move(response_data);
}
return true;
}
void CommandBroker::AddReference(int32_t handle) {
// Increment weak reference count.
command_stream_.AppendOutgoingCommand(BC_INCREFS, &handle, sizeof(handle));
// Increment strong reference count.
command_stream_.AppendOutgoingCommand(BC_ACQUIRE, &handle, sizeof(handle));
}
void CommandBroker::ReleaseReference(int32_t handle) {
// Decrement strong reference count.
command_stream_.AppendOutgoingCommand(BC_RELEASE, &handle, sizeof(handle));
// Decrement weak reference count.
command_stream_.AppendOutgoingCommand(BC_DECREFS, &handle, sizeof(handle));
}
base::Closure CommandBroker::GetReleaseReferenceClosure(int32_t handle) {
return base::Bind(&CommandBroker::ReleaseReference,
weak_ptr_factory_.GetWeakPtr(), handle);
}
bool CommandBroker::OnTransaction(const TransactionData& data) {
LocalObject* object = reinterpret_cast<LocalObject*>(data.GetCookie());
scoped_ptr<TransactionData> reply;
if (!object->Transact(this, data, &reply)) {
LOG(ERROR) << "Failed to transact.";
return false;
}
if (!data.IsOneWay()) {
// Send reply.
if (!reply) {
reply.reset(new TransactionStatus(Status::FAILED_TRANSACTION));
}
binder_transaction_data tr = ConvertTransactionDataToStruct(*reply);
tr.target.handle = -1; // This value will be ignored. Set invalid handle.
command_stream_.AppendOutgoingCommand(BC_REPLY, &tr, sizeof(tr));
if (!command_stream_.Flush()) {
LOG(ERROR) << "Failed to write";
return false;
}
scoped_ptr<TransactionData> response_data;
ResponseType response_type = WaitForResponse(&response_data);
// Not returning false for errors here, as doing it can result in letting
// another process abort the loop in PollCommands() (e.g. any process can
// cause a "dead binder" error with crash). We should return false only for
// fundamental errors like binder protocol errors.
LOG_IF(ERROR, response_type != RESPONSE_TYPE_TRANSACTION_COMPLETE)
<< "Error on the other end when sending reply: " << response_type;
}
return true;
}
void CommandBroker::OnReply(scoped_ptr<TransactionData> data) {
DCHECK(thread_checker_.CalledOnValidThread());
DCHECK_EQ(response_type_, RESPONSE_TYPE_NONE);
DCHECK(!response_data_);
response_type_ = RESPONSE_TYPE_TRANSACTION_REPLY;
response_data_ = std::move(data);
}
void CommandBroker::OnDeadReply() {
DCHECK(thread_checker_.CalledOnValidThread());
DCHECK_EQ(response_type_, RESPONSE_TYPE_NONE);
response_type_ = RESPONSE_TYPE_DEAD;
}
void CommandBroker::OnTransactionComplete() {
DCHECK(thread_checker_.CalledOnValidThread());
DCHECK_EQ(response_type_, RESPONSE_TYPE_NONE);
response_type_ = RESPONSE_TYPE_TRANSACTION_COMPLETE;
}
void CommandBroker::OnIncrementWeakReference(void* ptr, void* cookie) {
// Do nothing.
}
void CommandBroker::OnIncrementStrongReference(void* ptr, void* cookie) {
reinterpret_cast<LocalObject*>(cookie)->AddRef();
}
void CommandBroker::OnDecrementStrongReference(void* ptr, void* cookie) {
reinterpret_cast<LocalObject*>(cookie)->Release();
}
void CommandBroker::OnDecrementWeakReference(void* ptr, void* cookie) {
// Do nothing.
}
void CommandBroker::OnFailedReply() {
DCHECK(thread_checker_.CalledOnValidThread());
DCHECK_EQ(response_type_, RESPONSE_TYPE_NONE);
response_type_ = RESPONSE_TYPE_FAILED;
}
CommandBroker::ResponseType CommandBroker::WaitForResponse(
scoped_ptr<TransactionData>* data) {
DCHECK(thread_checker_.CalledOnValidThread());
DCHECK_EQ(response_type_, RESPONSE_TYPE_NONE);
DCHECK(!response_data_);
while (response_type_ == RESPONSE_TYPE_NONE) {
if (command_stream_.CanProcessIncomingCommand()) {
if (!command_stream_.ProcessIncomingCommand()) {
LOG(ERROR) << "Failed to process command.";
return RESPONSE_TYPE_NONE;
}
} else {
// Block until response is received.
if (!command_stream_.FetchBlocking()) {
LOG(ERROR) << "Failed to fetch.";
return RESPONSE_TYPE_NONE;
}
}
}
ResponseType response_type = response_type_;
response_type_ = RESPONSE_TYPE_NONE;
*data = std::move(response_data_);
return response_type;
}
} // namespace binder
|
