Botan 3.8.1
Crypto and TLS for C&
socket.cpp
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1/*
2* (C) 2015,2016,2017 Jack Lloyd
3* (C) 2016 Daniel Neus
4*
5* Botan is released under the Simplified BSD License (see license.txt)
6*/
7
8#include <botan/internal/socket.h>
9
10#include <botan/exceptn.h>
11#include <botan/mem_ops.h>
12#include <botan/internal/fmt.h>
13#include <botan/internal/target_info.h>
14#include <chrono>
15
16#if defined(BOTAN_HAS_BOOST_ASIO)
17 /*
18 * We don't need serial port support anyway, and asking for it causes
19 * macro conflicts with termios.h when this file is included in the
20 * amalgamation.
21 */
22 #define BOOST_ASIO_DISABLE_SERIAL_PORT
23 #include <boost/asio.hpp>
24 #include <boost/asio/system_timer.hpp>
25
26#elif defined(BOTAN_TARGET_OS_HAS_SOCKETS)
27 #include <errno.h>
28 #include <fcntl.h>
29 #include <netdb.h>
30 #include <netinet/in.h>
31 #include <string.h>
32 #include <sys/socket.h>
33 #include <sys/time.h>
34 #include <unistd.h>
35
36#elif defined(BOTAN_TARGET_OS_HAS_WINSOCK2)
37 #include <ws2tcpip.h>
38#endif
39
40namespace Botan {
41
42namespace {
43
44#if defined(BOTAN_HAS_BOOST_ASIO)
45
46class Asio_Socket final : public OS::Socket {
47 public:
48 Asio_Socket(std::string_view hostname, std::string_view service, std::chrono::milliseconds timeout) :
49 m_timeout(timeout), m_timer(m_io), m_tcp(m_io) {
50 m_timer.expires_after(m_timeout);
51 check_timeout();
52
53 boost::asio::ip::tcp::resolver resolver(m_io);
54 boost::asio::ip::tcp::resolver::results_type dns_iter =
55 resolver.resolve(std::string{hostname}, std::string{service});
56
57 boost::system::error_code ec = boost::asio::error::would_block;
58
59 auto connect_cb = [&ec](const boost::system::error_code& e, const auto&) { ec = e; };
60
61 boost::asio::async_connect(m_tcp, dns_iter.begin(), dns_iter.end(), connect_cb);
62
63 while(ec == boost::asio::error::would_block) {
64 m_io.run_one();
65 }
66
67 if(ec) {
68 throw boost::system::system_error(ec);
69 }
70 if(m_tcp.is_open() == false) {
71 throw System_Error(fmt("Connection to host {} failed", hostname));
72 }
73 }
74
75 void write(const uint8_t buf[], size_t len) override {
76 m_timer.expires_after(m_timeout);
77
78 boost::system::error_code ec = boost::asio::error::would_block;
79
80 m_tcp.async_send(boost::asio::buffer(buf, len), [&ec](boost::system::error_code e, size_t) { ec = e; });
81
82 while(ec == boost::asio::error::would_block) {
83 m_io.run_one();
84 }
85
86 if(ec) {
87 throw boost::system::system_error(ec);
88 }
89 }
90
91 size_t read(uint8_t buf[], size_t len) override {
92 m_timer.expires_after(m_timeout);
93
94 boost::system::error_code ec = boost::asio::error::would_block;
95 size_t got = 0;
96
97 m_tcp.async_read_some(boost::asio::buffer(buf, len), [&](boost::system::error_code cb_ec, size_t cb_got) {
98 ec = cb_ec;
99 got = cb_got;
100 });
101
102 while(ec == boost::asio::error::would_block) {
103 m_io.run_one();
104 }
105
106 if(ec) {
107 if(ec == boost::asio::error::eof) {
108 return 0;
109 }
110 throw boost::system::system_error(ec); // Some other error.
111 }
112
113 return got;
114 }
115
116 private:
117 void check_timeout() {
118 if(m_tcp.is_open() && m_timer.expiry() < std::chrono::system_clock::now()) {
119 boost::system::error_code err;
120
121 // NOLINTNEXTLINE(bugprone-unused-return-value,cert-err33-c)
122 m_tcp.close(err);
123 }
124
125 m_timer.async_wait(std::bind(&Asio_Socket::check_timeout, this));
126 }
127
128 const std::chrono::milliseconds m_timeout;
129 boost::asio::io_context m_io;
130 boost::asio::system_timer m_timer;
131 boost::asio::ip::tcp::socket m_tcp;
132};
133
134#elif defined(BOTAN_TARGET_OS_HAS_SOCKETS) || defined(BOTAN_TARGET_OS_HAS_WINSOCK2)
135
136class BSD_Socket final : public OS::Socket {
137 private:
138 #if defined(BOTAN_TARGET_OS_HAS_WINSOCK2)
139 typedef SOCKET socket_type;
140 typedef int socket_op_ret_type;
141 typedef int socklen_type;
142 typedef int sendrecv_len_type;
143
144 static socket_type invalid_socket() { return INVALID_SOCKET; }
145
146 static void close_socket(socket_type s) { ::closesocket(s); }
147
148 static std::string get_last_socket_error() { return std::to_string(::WSAGetLastError()); }
149
150 static bool nonblocking_connect_in_progress() { return (::WSAGetLastError() == WSAEWOULDBLOCK); }
151
152 static void set_nonblocking(socket_type s) {
153 u_long nonblocking = 1;
154 ::ioctlsocket(s, FIONBIO, &nonblocking);
155 }
156
157 static void socket_init() {
158 WSAData wsa_data;
159 WORD wsa_version = MAKEWORD(2, 2);
160
161 if(::WSAStartup(wsa_version, &wsa_data) != 0) {
162 throw System_Error("WSAStartup() failed", WSAGetLastError());
163 }
164
165 if(LOBYTE(wsa_data.wVersion) != 2 || HIBYTE(wsa_data.wVersion) != 2) {
166 ::WSACleanup();
167 throw System_Error("Could not find a usable version of Winsock.dll");
168 }
169 }
170
171 static void socket_fini() { ::WSACleanup(); }
172 #else
173 typedef int socket_type;
174 typedef ssize_t socket_op_ret_type;
175 typedef socklen_t socklen_type;
176 typedef size_t sendrecv_len_type;
177
178 static socket_type invalid_socket() { return -1; }
179
180 static void close_socket(socket_type s) { ::close(s); }
181
182 static std::string get_last_socket_error() { return ::strerror(errno); }
183
184 static bool nonblocking_connect_in_progress() { return (errno == EINPROGRESS); }
185
186 static void set_nonblocking(socket_type s) {
187 if(::fcntl(s, F_SETFL, O_NONBLOCK) < 0) {
188 throw System_Error("Setting socket to non-blocking state failed", errno);
189 }
190 }
191
192 static void socket_init() {}
193
194 static void socket_fini() {}
195 #endif
196
197 public:
198 BSD_Socket(std::string_view hostname, std::string_view service, std::chrono::microseconds timeout) :
199 m_timeout(timeout) {
200 socket_init();
201
202 m_socket = invalid_socket();
203
204 addrinfo hints;
205 clear_mem(&hints, 1);
206 hints.ai_family = AF_UNSPEC;
207 hints.ai_socktype = SOCK_STREAM;
208 addrinfo* res;
209
210 const std::string hostname_str(hostname);
211 const std::string service_str(service);
212
213 int rc = ::getaddrinfo(hostname_str.c_str(), service_str.c_str(), &hints, &res);
214
215 if(rc != 0) {
216 throw System_Error(fmt("Name resolution failed for {}", hostname), rc);
217 }
218
219 for(addrinfo* rp = res; (m_socket == invalid_socket()) && (rp != nullptr); rp = rp->ai_next) {
220 if(rp->ai_family != AF_INET && rp->ai_family != AF_INET6) {
221 continue;
222 }
223
224 m_socket = ::socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
225
226 if(m_socket == invalid_socket()) {
227 // unsupported socket type?
228 continue;
229 }
230
231 set_nonblocking(m_socket);
232
233 int err = ::connect(m_socket, rp->ai_addr, static_cast<socklen_type>(rp->ai_addrlen));
234
235 if(err == -1) {
236 int active = 0;
237 if(nonblocking_connect_in_progress()) {
238 struct timeval timeout_tv = make_timeout_tv();
239 fd_set write_set;
240 FD_ZERO(&write_set);
241 // Weirdly, Winsock uses a SOCKET type but wants FD_SET to get an int instead
242 FD_SET(static_cast<int>(m_socket), &write_set);
243
244 active = ::select(static_cast<int>(m_socket + 1), nullptr, &write_set, nullptr, &timeout_tv);
245
246 if(active) {
247 int socket_error = 0;
248 socklen_t len = sizeof(socket_error);
249
250 if(::getsockopt(m_socket, SOL_SOCKET, SO_ERROR, reinterpret_cast<char*>(&socket_error), &len) <
251 0) {
252 throw System_Error("Error calling getsockopt", errno);
253 }
254
255 if(socket_error != 0) {
256 active = 0;
257 }
258 }
259 }
260
261 if(active == 0) {
262 close_socket(m_socket);
263 m_socket = invalid_socket();
264 continue;
265 }
266 }
267 }
268
269 ::freeaddrinfo(res);
270
271 if(m_socket == invalid_socket()) {
272 throw System_Error(fmt("Connecting to {} for service {} failed with errno {}", hostname, service, errno),
273 errno);
274 }
275 }
276
277 ~BSD_Socket() override {
278 close_socket(m_socket);
279 m_socket = invalid_socket();
280 socket_fini();
281 }
282
283 BSD_Socket(const BSD_Socket& other) = delete;
284 BSD_Socket(BSD_Socket&& other) = delete;
285 BSD_Socket& operator=(const BSD_Socket& other) = delete;
286 BSD_Socket& operator=(BSD_Socket&& other) = delete;
287
288 void write(const uint8_t buf[], size_t len) override {
289 fd_set write_set;
290 FD_ZERO(&write_set);
291 FD_SET(m_socket, &write_set);
292
293 size_t sent_so_far = 0;
294 while(sent_so_far != len) {
295 struct timeval timeout = make_timeout_tv();
296 int active = ::select(static_cast<int>(m_socket + 1), nullptr, &write_set, nullptr, &timeout);
297
298 if(active == 0) {
299 throw System_Error("Timeout during socket write");
300 }
301
302 const size_t left = len - sent_so_far;
303 socket_op_ret_type sent =
304 ::send(m_socket, cast_uint8_ptr_to_char(&buf[sent_so_far]), static_cast<sendrecv_len_type>(left), 0);
305 if(sent < 0) {
306 throw System_Error("Socket write failed", errno);
307 } else {
308 sent_so_far += static_cast<size_t>(sent);
309 }
310 }
311 }
312
313 size_t read(uint8_t buf[], size_t len) override {
314 fd_set read_set;
315 FD_ZERO(&read_set);
316 FD_SET(m_socket, &read_set);
317
318 struct timeval timeout = make_timeout_tv();
319 int active = ::select(static_cast<int>(m_socket + 1), &read_set, nullptr, nullptr, &timeout);
320
321 if(active == 0) {
322 throw System_Error("Timeout during socket read");
323 }
324
325 socket_op_ret_type got = ::recv(m_socket, cast_uint8_ptr_to_char(buf), static_cast<sendrecv_len_type>(len), 0);
326
327 if(got < 0) {
328 throw System_Error("Socket read failed", errno);
329 }
330
331 return static_cast<size_t>(got);
332 }
333
334 private:
335 struct timeval make_timeout_tv() const {
336 struct timeval tv;
337 tv.tv_sec = static_cast<decltype(timeval::tv_sec)>(m_timeout.count() / 1000000);
338 tv.tv_usec = static_cast<decltype(timeval::tv_usec)>(m_timeout.count() % 1000000);
339 return tv;
340 }
341
342 const std::chrono::microseconds m_timeout;
343 socket_type m_socket;
344};
345
346#endif
347
348} // namespace
349
350std::unique_ptr<OS::Socket> OS::open_socket(std::string_view hostname,
351 std::string_view service,
352 std::chrono::milliseconds timeout) {
353#if defined(BOTAN_HAS_BOOST_ASIO)
354 return std::make_unique<Asio_Socket>(hostname, service, timeout);
355
356#elif defined(BOTAN_TARGET_OS_HAS_SOCKETS) || defined(BOTAN_TARGET_OS_HAS_WINSOCK2)
357 return std::make_unique<BSD_Socket>(hostname, service, timeout);
358
359#else
360 BOTAN_UNUSED(hostname, service, timeout);
361 // No sockets for you
362 return std::unique_ptr<Socket>();
363#endif
364}
365
366} // namespace Botan
#define BOTAN_UNUSED
Definition assert.h:120
std::unique_ptr< Socket > BOTAN_TEST_API open_socket(std::string_view hostname, std::string_view service, std::chrono::milliseconds timeout)
Definition socket.cpp:350
std::string fmt(std::string_view format, const T &... args)
Definition fmt.h:53