1 /*
2  * Copyright (C) 2015 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 "sysdeps.h"
18 
19 #include <stdio.h>
20 
21 #include <android-base/file.h>
22 #include <android-base/logging.h>
23 #include <android-base/strings.h>
24 #include <cutils/sockets.h>
25 
26 #include "adb.h"
27 #include "adb_client.h"
28 #include "adb_io.h"
29 #include "adb_utils.h"
30 
31 // Return the console authentication command for the emulator, if needed
adb_construct_auth_command()32 static std::string adb_construct_auth_command() {
33     static const char auth_token_filename[] = ".emulator_console_auth_token";
34 
35     std::string auth_token_path = adb_get_homedir_path();
36     auth_token_path += OS_PATH_SEPARATOR;
37     auth_token_path += auth_token_filename;
38 
39     // read the token
40     std::string token;
41     if (!android::base::ReadFileToString(auth_token_path, &token)
42         || token.empty()) {
43         // we either can't read the file, or it doesn't exist, or it's empty -
44         // either way we won't add any authentication command.
45         return {};
46     }
47 
48     // now construct and return the actual command: "auth <token>\n"
49     std::string command = "auth ";
50     command += token;
51     command += '\n';
52     return command;
53 }
54 
55 // Return the console port of the currently connected emulator (if any) or -1 if
56 // there is no emulator, and -2 if there is more than one.
adb_get_emulator_console_port(const char * serial)57 static int adb_get_emulator_console_port(const char* serial) {
58     if (serial) {
59         // The user specified a serial number; is it an emulator?
60         int port;
61         return (sscanf(serial, "emulator-%d", &port) == 1) ? port : -1;
62     }
63 
64     // No specific device was given, so get the list of connected devices and
65     // search for emulators. If there's one, we'll take it. If there are more
66     // than one, that's an error.
67     std::string devices;
68     std::string error;
69     if (!adb_query("host:devices", &devices, &error)) {
70         fprintf(stderr, "error: no emulator connected: %s\n", error.c_str());
71         return -1;
72     }
73 
74     int port;
75     size_t emulator_count = 0;
76     for (const auto& device : android::base::Split(devices, "\n")) {
77         if (sscanf(device.c_str(), "emulator-%d", &port) == 1) {
78             if (++emulator_count > 1) {
79                 fprintf(
80                     stderr, "error: more than one emulator detected; use -s\n");
81                 return -1;
82             }
83         }
84     }
85 
86     if (emulator_count == 0) {
87         fprintf(stderr, "error: no emulator detected\n");
88         return -1;
89     }
90 
91     return port;
92 }
93 
connect_to_console(const char * serial)94 static int connect_to_console(const char* serial) {
95     int port = adb_get_emulator_console_port(serial);
96     if (port == -1) {
97         return -1;
98     }
99 
100     std::string error;
101     int fd = network_loopback_client(port, SOCK_STREAM, &error);
102     if (fd == -1) {
103         fprintf(stderr, "error: could not connect to TCP port %d: %s\n", port,
104                 error.c_str());
105         return -1;
106     }
107     return fd;
108 }
109 
adb_send_emulator_command(int argc,const char ** argv,const char * serial)110 int adb_send_emulator_command(int argc, const char** argv, const char* serial) {
111     int fd = connect_to_console(serial);
112     if (fd == -1) {
113         return 1;
114     }
115 
116     std::string commands = adb_construct_auth_command();
117 
118     for (int i = 1; i < argc; i++) {
119         commands.append(argv[i]);
120         commands.push_back(i == argc - 1 ? '\n' : ' ');
121     }
122 
123     commands.append("quit\n");
124 
125     if (!WriteFdExactly(fd, commands)) {
126         fprintf(stderr, "error: cannot write to emulator: %s\n",
127                 strerror(errno));
128         adb_close(fd);
129         return 1;
130     }
131 
132     // Drain output that the emulator console has sent us to prevent a problem
133     // on Windows where if adb closes the socket without reading all the data,
134     // the emulator's next call to recv() will have an ECONNABORTED error,
135     // preventing the emulator from reading the command that adb has sent.
136     // https://code.google.com/p/android/issues/detail?id=21021
137     int result;
138     do {
139         char buf[BUFSIZ];
140         result = adb_read(fd, buf, sizeof(buf));
141         // Keep reading until zero bytes (orderly/graceful shutdown) or an
142         // error. If 'adb emu kill' is executed, the emulator calls exit() with
143         // the socket open (and shutdown(SD_SEND) was not called), which causes
144         // Windows to send a TCP RST segment which causes adb to get ECONNRESET.
145         // Any other emu command is followed by the quit command that we
146         // appended above, and that causes the emulator to close the socket
147         // which should cause zero bytes (orderly/graceful shutdown) to be
148         // returned.
149     } while (result > 0);
150 
151     adb_close(fd);
152 
153     return 0;
154 }
155