1 /*
2  * Copyright (C) 2016 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 "socket_spec.h"
18 
19 #include <string>
20 #include <unordered_map>
21 #include <vector>
22 
23 #include <android-base/parseint.h>
24 #include <android-base/parsenetaddress.h>
25 #include <android-base/stringprintf.h>
26 #include <android-base/strings.h>
27 #include <cutils/sockets.h>
28 
29 #include "adb.h"
30 #include "sysdeps.h"
31 
32 using android::base::StartsWith;
33 using android::base::StringPrintf;
34 
35 #if defined(__linux__)
36 #define ADB_LINUX 1
37 #else
38 #define ADB_LINUX 0
39 #endif
40 
41 #if defined(_WIN32)
42 #define ADB_WINDOWS 1
43 #else
44 #define ADB_WINDOWS 0
45 #endif
46 
47 // Not static because it is used in commandline.c.
48 int gListenAll = 0;
49 
50 struct LocalSocketType {
51     int socket_namespace;
52     bool available;
53 };
54 
55 static auto& kLocalSocketTypes = *new std::unordered_map<std::string, LocalSocketType>({
56 #if ADB_HOST
57     { "local", { ANDROID_SOCKET_NAMESPACE_FILESYSTEM, !ADB_WINDOWS } },
58 #else
59     { "local", { ANDROID_SOCKET_NAMESPACE_RESERVED, !ADB_WINDOWS } },
60 #endif
61 
62     { "localreserved", { ANDROID_SOCKET_NAMESPACE_RESERVED, !ADB_HOST } },
63     { "localabstract", { ANDROID_SOCKET_NAMESPACE_ABSTRACT, ADB_LINUX } },
64     { "localfilesystem", { ANDROID_SOCKET_NAMESPACE_FILESYSTEM, !ADB_WINDOWS } },
65 });
66 
parse_tcp_socket_spec(const std::string & spec,std::string * hostname,int * port,std::string * error)67 bool parse_tcp_socket_spec(const std::string& spec, std::string* hostname, int* port,
68                            std::string* error) {
69     if (!StartsWith(spec, "tcp:")) {
70         *error = StringPrintf("specification is not tcp: '%s'", spec.c_str());
71         return false;
72     }
73 
74     std::string hostname_value;
75     int port_value;
76 
77     // If the spec is tcp:<port>, parse it ourselves.
78     // Otherwise, delegate to android::base::ParseNetAddress.
79     if (android::base::ParseInt(&spec[4], &port_value)) {
80         // Do the range checking ourselves, because ParseInt rejects 'tcp:65536' and 'tcp:foo:1234'
81         // identically.
82         if (port_value < 0 || port_value > 65535) {
83             *error = StringPrintf("bad port number '%d'", port_value);
84             return false;
85         }
86     } else {
87         std::string addr = spec.substr(4);
88         port_value = -1;
89 
90         // FIXME: ParseNetAddress rejects port 0. This currently doesn't hurt, because listening
91         //        on an address that isn't 'localhost' is unsupported.
92         if (!android::base::ParseNetAddress(addr, &hostname_value, &port_value, nullptr, error)) {
93             return false;
94         }
95 
96         if (port_value == -1) {
97             *error = StringPrintf("missing port in specification: '%s'", spec.c_str());
98             return false;
99         }
100     }
101 
102     if (hostname) {
103         *hostname = std::move(hostname_value);
104     }
105 
106     if (port) {
107         *port = port_value;
108     }
109 
110     return true;
111 }
112 
tcp_host_is_local(const std::string & hostname)113 static bool tcp_host_is_local(const std::string& hostname) {
114     // FIXME
115     return hostname.empty() || hostname == "localhost";
116 }
117 
is_socket_spec(const std::string & spec)118 bool is_socket_spec(const std::string& spec) {
119     for (const auto& it : kLocalSocketTypes) {
120         std::string prefix = it.first + ":";
121         if (StartsWith(spec, prefix.c_str())) {
122             return true;
123         }
124     }
125     return StartsWith(spec, "tcp:");
126 }
127 
is_local_socket_spec(const std::string & spec)128 bool is_local_socket_spec(const std::string& spec) {
129     for (const auto& it : kLocalSocketTypes) {
130         std::string prefix = it.first + ":";
131         if (StartsWith(spec, prefix.c_str())) {
132             return true;
133         }
134     }
135 
136     std::string error;
137     std::string hostname;
138     if (!parse_tcp_socket_spec(spec, &hostname, nullptr, &error)) {
139         return false;
140     }
141     return tcp_host_is_local(hostname);
142 }
143 
socket_spec_connect(const std::string & spec,std::string * error)144 int socket_spec_connect(const std::string& spec, std::string* error) {
145     if (StartsWith(spec, "tcp:")) {
146         std::string hostname;
147         int port;
148         if (!parse_tcp_socket_spec(spec, &hostname, &port, error)) {
149             return -1;
150         }
151 
152         int result;
153         if (tcp_host_is_local(hostname)) {
154             result = network_loopback_client(port, SOCK_STREAM, error);
155         } else {
156 #if ADB_HOST
157             result = network_connect(hostname, port, SOCK_STREAM, 0, error);
158 #else
159             // Disallow arbitrary connections in adbd.
160             *error = "adbd does not support arbitrary tcp connections";
161             return -1;
162 #endif
163         }
164 
165         if (result >= 0) {
166             disable_tcp_nagle(result);
167         }
168         return result;
169     }
170 
171     for (const auto& it : kLocalSocketTypes) {
172         std::string prefix = it.first + ":";
173         if (StartsWith(spec, prefix.c_str())) {
174             if (!it.second.available) {
175                 *error = StringPrintf("socket type %s is unavailable on this platform",
176                                       it.first.c_str());
177                 return -1;
178             }
179 
180             return network_local_client(&spec[prefix.length()], it.second.socket_namespace,
181                                         SOCK_STREAM, error);
182         }
183     }
184 
185     *error = StringPrintf("unknown socket specification '%s'", spec.c_str());
186     return -1;
187 }
188 
socket_spec_listen(const std::string & spec,std::string * error,int * resolved_tcp_port)189 int socket_spec_listen(const std::string& spec, std::string* error, int* resolved_tcp_port) {
190     if (StartsWith(spec, "tcp:")) {
191         std::string hostname;
192         int port;
193         if (!parse_tcp_socket_spec(spec, &hostname, &port, error)) {
194             return -1;
195         }
196 
197         int result;
198         if (hostname.empty() && gListenAll) {
199             result = network_inaddr_any_server(port, SOCK_STREAM, error);
200         } else if (tcp_host_is_local(hostname)) {
201             result = network_loopback_server(port, SOCK_STREAM, error);
202         } else {
203             // TODO: Implement me.
204             *error = "listening on specified hostname currently unsupported";
205             return -1;
206         }
207 
208         if (result >= 0 && port == 0 && resolved_tcp_port) {
209             *resolved_tcp_port = adb_socket_get_local_port(result);
210         }
211         return result;
212     }
213 
214     for (const auto& it : kLocalSocketTypes) {
215         std::string prefix = it.first + ":";
216         if (StartsWith(spec, prefix.c_str())) {
217             if (!it.second.available) {
218                 *error = StringPrintf("attempted to listen on unavailable socket type: '%s'",
219                                       spec.c_str());
220                 return -1;
221             }
222 
223             return network_local_server(&spec[prefix.length()], it.second.socket_namespace,
224                                         SOCK_STREAM, error);
225         }
226     }
227 
228     *error = StringPrintf("unknown socket specification '%s'", spec.c_str());
229     return -1;
230 }
231