1 /*
2 * Copyright (C) 2015 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include "socket.h"
30
31 #include <android-base/errors.h>
32 #include <android-base/stringprintf.h>
33
Socket(cutils_socket_t sock)34 Socket::Socket(cutils_socket_t sock) : sock_(sock) {}
35
~Socket()36 Socket::~Socket() {
37 Close();
38 }
39
Close()40 int Socket::Close() {
41 int ret = 0;
42
43 if (sock_ != INVALID_SOCKET) {
44 ret = socket_close(sock_);
45 sock_ = INVALID_SOCKET;
46 }
47
48 return ret;
49 }
50
ReceiveAll(void * data,size_t length,int timeout_ms)51 ssize_t Socket::ReceiveAll(void* data, size_t length, int timeout_ms) {
52 size_t total = 0;
53
54 while (total < length) {
55 ssize_t bytes = Receive(reinterpret_cast<char*>(data) + total, length - total, timeout_ms);
56
57 if (bytes == -1) {
58 if (total == 0) {
59 return -1;
60 }
61 break;
62 }
63 total += bytes;
64 }
65
66 return total;
67 }
68
GetLocalPort()69 int Socket::GetLocalPort() {
70 return socket_get_local_port(sock_);
71 }
72
73 // According to Windows setsockopt() documentation, if a Windows socket times out during send() or
74 // recv() the state is indeterminate and should not be used. Our UDP protocol relies on being able
75 // to re-send after a timeout, so we must use select() rather than SO_RCVTIMEO.
76 // See https://msdn.microsoft.com/en-us/library/windows/desktop/ms740476(v=vs.85).aspx.
WaitForRecv(int timeout_ms)77 bool Socket::WaitForRecv(int timeout_ms) {
78 receive_timed_out_ = false;
79
80 // In our usage |timeout_ms| <= 0 means block forever, so just return true immediately and let
81 // the subsequent recv() do the blocking.
82 if (timeout_ms <= 0) {
83 return true;
84 }
85
86 // select() doesn't always check this case and will block for |timeout_ms| if we let it.
87 if (sock_ == INVALID_SOCKET) {
88 return false;
89 }
90
91 fd_set read_set;
92 FD_ZERO(&read_set);
93 FD_SET(sock_, &read_set);
94
95 timeval timeout;
96 timeout.tv_sec = timeout_ms / 1000;
97 timeout.tv_usec = (timeout_ms % 1000) * 1000;
98
99 int result = TEMP_FAILURE_RETRY(select(sock_ + 1, &read_set, nullptr, nullptr, &timeout));
100
101 if (result == 0) {
102 receive_timed_out_ = true;
103 }
104 return result == 1;
105 }
106
107 // Implements the Socket interface for UDP.
108 class UdpSocket : public Socket {
109 public:
110 enum class Type { kClient, kServer };
111
112 UdpSocket(Type type, cutils_socket_t sock);
113
114 bool Send(const void* data, size_t length) override;
115 bool Send(std::vector<cutils_socket_buffer_t> buffers) override;
116 ssize_t Receive(void* data, size_t length, int timeout_ms) override;
117
118 private:
119 std::unique_ptr<sockaddr_storage> addr_;
120 socklen_t addr_size_ = 0;
121
122 DISALLOW_COPY_AND_ASSIGN(UdpSocket);
123 };
124
UdpSocket(Type type,cutils_socket_t sock)125 UdpSocket::UdpSocket(Type type, cutils_socket_t sock) : Socket(sock) {
126 // Only servers need to remember addresses; clients are connected to a server in NewClient()
127 // so will send to that server without needing to specify the address again.
128 if (type == Type::kServer) {
129 addr_.reset(new sockaddr_storage);
130 addr_size_ = sizeof(*addr_);
131 memset(addr_.get(), 0, addr_size_);
132 }
133 }
134
Send(const void * data,size_t length)135 bool UdpSocket::Send(const void* data, size_t length) {
136 return TEMP_FAILURE_RETRY(sendto(sock_, reinterpret_cast<const char*>(data), length, 0,
137 reinterpret_cast<sockaddr*>(addr_.get()), addr_size_)) ==
138 static_cast<ssize_t>(length);
139 }
140
Send(std::vector<cutils_socket_buffer_t> buffers)141 bool UdpSocket::Send(std::vector<cutils_socket_buffer_t> buffers) {
142 size_t total_length = 0;
143 for (const auto& buffer : buffers) {
144 total_length += buffer.length;
145 }
146
147 return TEMP_FAILURE_RETRY(socket_send_buffers_function_(
148 sock_, buffers.data(), buffers.size())) == static_cast<ssize_t>(total_length);
149 }
150
Receive(void * data,size_t length,int timeout_ms)151 ssize_t UdpSocket::Receive(void* data, size_t length, int timeout_ms) {
152 if (!WaitForRecv(timeout_ms)) {
153 return -1;
154 }
155
156 socklen_t* addr_size_ptr = nullptr;
157 if (addr_ != nullptr) {
158 // Reset addr_size as it may have been modified by previous recvfrom() calls.
159 addr_size_ = sizeof(*addr_);
160 addr_size_ptr = &addr_size_;
161 }
162
163 return TEMP_FAILURE_RETRY(recvfrom(sock_, reinterpret_cast<char*>(data), length, 0,
164 reinterpret_cast<sockaddr*>(addr_.get()), addr_size_ptr));
165 }
166
167 // Implements the Socket interface for TCP.
168 class TcpSocket : public Socket {
169 public:
TcpSocket(cutils_socket_t sock)170 TcpSocket(cutils_socket_t sock) : Socket(sock) {}
171
172 bool Send(const void* data, size_t length) override;
173 bool Send(std::vector<cutils_socket_buffer_t> buffers) override;
174 ssize_t Receive(void* data, size_t length, int timeout_ms) override;
175
176 std::unique_ptr<Socket> Accept() override;
177
178 private:
179 DISALLOW_COPY_AND_ASSIGN(TcpSocket);
180 };
181
Send(const void * data,size_t length)182 bool TcpSocket::Send(const void* data, size_t length) {
183 while (length > 0) {
184 ssize_t sent =
185 TEMP_FAILURE_RETRY(send(sock_, reinterpret_cast<const char*>(data), length, 0));
186
187 if (sent == -1) {
188 return false;
189 }
190 length -= sent;
191 }
192
193 return true;
194 }
195
Send(std::vector<cutils_socket_buffer_t> buffers)196 bool TcpSocket::Send(std::vector<cutils_socket_buffer_t> buffers) {
197 while (!buffers.empty()) {
198 ssize_t sent = TEMP_FAILURE_RETRY(
199 socket_send_buffers_function_(sock_, buffers.data(), buffers.size()));
200
201 if (sent == -1) {
202 return false;
203 }
204
205 // Adjust the buffers to skip past the bytes we've just sent.
206 auto iter = buffers.begin();
207 while (sent > 0) {
208 if (iter->length > static_cast<size_t>(sent)) {
209 // Incomplete buffer write; adjust the buffer to point to the next byte to send.
210 iter->length -= sent;
211 iter->data = reinterpret_cast<const char*>(iter->data) + sent;
212 break;
213 }
214
215 // Complete buffer write; move on to the next buffer.
216 sent -= iter->length;
217 ++iter;
218 }
219
220 // Shortcut the common case: we've written everything remaining.
221 if (iter == buffers.end()) {
222 break;
223 }
224 buffers.erase(buffers.begin(), iter);
225 }
226
227 return true;
228 }
229
Receive(void * data,size_t length,int timeout_ms)230 ssize_t TcpSocket::Receive(void* data, size_t length, int timeout_ms) {
231 if (!WaitForRecv(timeout_ms)) {
232 return -1;
233 }
234
235 return TEMP_FAILURE_RETRY(recv(sock_, reinterpret_cast<char*>(data), length, 0));
236 }
237
Accept()238 std::unique_ptr<Socket> TcpSocket::Accept() {
239 cutils_socket_t handler = accept(sock_, nullptr, nullptr);
240 if (handler == INVALID_SOCKET) {
241 return nullptr;
242 }
243 return std::unique_ptr<TcpSocket>(new TcpSocket(handler));
244 }
245
NewClient(Protocol protocol,const std::string & host,int port,std::string * error)246 std::unique_ptr<Socket> Socket::NewClient(Protocol protocol, const std::string& host, int port,
247 std::string* error) {
248 if (protocol == Protocol::kUdp) {
249 cutils_socket_t sock = socket_network_client(host.c_str(), port, SOCK_DGRAM);
250 if (sock != INVALID_SOCKET) {
251 return std::unique_ptr<UdpSocket>(new UdpSocket(UdpSocket::Type::kClient, sock));
252 }
253 } else {
254 cutils_socket_t sock = socket_network_client(host.c_str(), port, SOCK_STREAM);
255 if (sock != INVALID_SOCKET) {
256 return std::unique_ptr<TcpSocket>(new TcpSocket(sock));
257 }
258 }
259
260 if (error) {
261 *error = android::base::StringPrintf("Failed to connect to %s:%d", host.c_str(), port);
262 }
263 return nullptr;
264 }
265
266 // This functionality is currently only used by tests so we don't need any error messages.
NewServer(Protocol protocol,int port)267 std::unique_ptr<Socket> Socket::NewServer(Protocol protocol, int port) {
268 if (protocol == Protocol::kUdp) {
269 cutils_socket_t sock = socket_inaddr_any_server(port, SOCK_DGRAM);
270 if (sock != INVALID_SOCKET) {
271 return std::unique_ptr<UdpSocket>(new UdpSocket(UdpSocket::Type::kServer, sock));
272 }
273 } else {
274 cutils_socket_t sock = socket_inaddr_any_server(port, SOCK_STREAM);
275 if (sock != INVALID_SOCKET) {
276 return std::unique_ptr<TcpSocket>(new TcpSocket(sock));
277 }
278 }
279
280 return nullptr;
281 }
282
GetErrorMessage()283 std::string Socket::GetErrorMessage() {
284 #if defined(_WIN32)
285 DWORD error_code = WSAGetLastError();
286 #else
287 int error_code = errno;
288 #endif
289 return android::base::SystemErrorCodeToString(error_code);
290 }
291