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 <sys/wait.h>
18 
19 #include <android-base/cmsg.h>
20 #include <android-base/strings.h>
21 #include <cmd.h>
22 
23 #include "adb.h"
24 #include "adb_io.h"
25 #include "adb_utils.h"
26 #include "shell_service.h"
27 #include "sysdeps.h"
28 
29 namespace {
30 
31 class AdbFdTextOutput : public android::TextOutput {
32   public:
33     explicit AdbFdTextOutput(borrowed_fd fd) : fd_(fd) {}
34 
35   private:
36     android::status_t print(const char* txt, size_t len) override {
37         return WriteFdExactly(fd_, txt, len) ? android::OK : -errno;
38     }
39     void moveIndent(int delta) override { /*not implemented*/
40     }
41 
42     void pushBundle() override { /*not implemented*/
43     }
44     void popBundle() override { /*not implemented*/
45     }
46 
47   private:
48     borrowed_fd fd_;
49 };
50 
51 std::vector<std::string_view> parseCmdArgs(std::string_view args) {
52     std::vector<std::string_view> argv;
53 
54     char delim = ABB_ARG_DELIMETER;
55     size_t size = args.size();
56     size_t base = 0;
57     while (base < size) {
58         size_t found;
59         for (found = base; found < size && args[found] && args[found] != delim; ++found)
60             ;
61         if (found > base) {
62             argv.emplace_back(args.substr(base, found - base));
63         }
64         base = found + 1;
65     }
66 
67     return argv;
68 }
69 
70 }  // namespace
71 
72 static int execCmd(std::string_view args, borrowed_fd in, borrowed_fd out, borrowed_fd err) {
73     int max_buf = LINUX_MAX_SOCKET_SIZE;
74     adb_setsockopt(in, SOL_SOCKET, SO_SNDBUF, &max_buf, sizeof(max_buf));
75     adb_setsockopt(out, SOL_SOCKET, SO_SNDBUF, &max_buf, sizeof(max_buf));
76     adb_setsockopt(err, SOL_SOCKET, SO_SNDBUF, &max_buf, sizeof(max_buf));
77 
78     AdbFdTextOutput oin(out);
79     AdbFdTextOutput oerr(err);
80     return cmdMain(parseCmdArgs(args), oin, oerr, in.get(), out.get(), err.get(),
81                    RunMode::kLibrary);
82 }
83 
84 int main(int argc, char* const argv[]) {
85     signal(SIGPIPE, SIG_IGN);
86 
87     int fd = STDIN_FILENO;
88     std::string data;
89     while (true) {
90         std::string error;
91         if (!ReadProtocolString(fd, &data, &error)) {
92             PLOG(ERROR) << "Failed to read message: " << error;
93             break;
94         }
95 
96         std::string_view name = data;
97         auto protocol = SubprocessProtocol::kShell;
98         if (android::base::ConsumePrefix(&name, "abb:")) {
99             protocol = SubprocessProtocol::kShell;
100         } else if (android::base::ConsumePrefix(&name, "abb_exec:")) {
101             protocol = SubprocessProtocol::kNone;
102         } else {
103             LOG(FATAL) << "Unknown command prefix for abb: " << data;
104         }
105 
106         unique_fd result = StartCommandInProcess(std::string(name), &execCmd, protocol);
107         int max_buf = LINUX_MAX_SOCKET_SIZE;
108         adb_setsockopt(result, SOL_SOCKET, SO_SNDBUF, &max_buf, sizeof(max_buf));
109         if (android::base::SendFileDescriptors(fd, "", 1, result.get()) != 1) {
110             PLOG(ERROR) << "Failed to send an inprocess fd for command: " << data;
111             break;
112         }
113     }
114 }
115