1 /*
2  * Copyright (C) 2018 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "adb.h"
18 #include "adb_io.h"
19 #include "adb_unique_fd.h"
20 #include "adb_utils.h"
21 #include "shell_service.h"
22 
23 #include <android-base/cmsg.h>
24 
25 namespace {
26 
27 struct AbbProcess {
28     unique_fd sendCommand(std::string_view command);
29 
30   private:
31     static unique_fd startAbbProcess(unique_fd* error_fd);
32 
33     static constexpr auto kRetries = 2;
34     static constexpr auto kErrorProtocol = SubprocessProtocol::kShell;
35 
36     std::mutex locker_;
37     unique_fd socket_fd_;
38 };
39 
sendCommand(std::string_view command)40 unique_fd AbbProcess::sendCommand(std::string_view command) {
41     std::unique_lock lock{locker_};
42 
43     for (int i = 0; i < kRetries; ++i) {
44         unique_fd error_fd;
45         if (socket_fd_ == -1) {
46             socket_fd_ = startAbbProcess(&error_fd);
47         }
48         if (socket_fd_ == -1) {
49             LOG(ERROR) << "failed to start abb process";
50             return error_fd;
51         }
52 
53         if (!SendProtocolString(socket_fd_, command)) {
54             PLOG(ERROR) << "failed to send command to abb";
55             socket_fd_.reset();
56             continue;
57         }
58 
59         unique_fd fd;
60         char buf;
61         if (android::base::ReceiveFileDescriptors(socket_fd_, &buf, 1, &fd) != 1) {
62             PLOG(ERROR) << "failed to receive FD from abb";
63             socket_fd_.reset();
64             continue;
65         }
66 
67         return fd;
68     }
69 
70     LOG(ERROR) << "abb is unavailable";
71     socket_fd_.reset();
72     return ReportError(kErrorProtocol, "abb is unavailable");
73 }
74 
startAbbProcess(unique_fd * error_fd)75 unique_fd AbbProcess::startAbbProcess(unique_fd* error_fd) {
76     constexpr auto abb_process_type = SubprocessType::kRaw;
77     constexpr auto abb_protocol = SubprocessProtocol::kNone;
78     constexpr auto make_pty_raw = false;
79     return StartSubprocess("abb", "dumb", abb_process_type, abb_protocol, make_pty_raw,
80                            kErrorProtocol, error_fd);
81 }
82 
83 static auto& abbp = *new AbbProcess;
84 
85 }  // namespace
86 
execute_abb_command(std::string_view command)87 unique_fd execute_abb_command(std::string_view command) {
88     return abbp.sendCommand(command);
89 }
90