Botan  2.13.0
Crypto and TLS for C++11
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 #include <botan/exceptn.h>
10 #include <botan/mem_ops.h>
11 #include <chrono>
12 
13 #if defined(BOTAN_HAS_BOOST_ASIO)
14  /*
15  * We don't need serial port support anyway, and asking for it causes
16  * macro conflicts with termios.h when this file is included in the
17  * amalgamation.
18  */
19  #define BOOST_ASIO_DISABLE_SERIAL_PORT
20  #include <boost/asio.hpp>
21  #include <boost/asio/system_timer.hpp>
22 
23 #elif defined(BOTAN_TARGET_OS_HAS_SOCKETS)
24  #include <sys/socket.h>
25  #include <sys/time.h>
26  #include <netinet/in.h>
27  #include <netdb.h>
28  #include <string.h>
29  #include <unistd.h>
30  #include <errno.h>
31  #include <fcntl.h>
32 
33 #elif defined(BOTAN_TARGET_OS_HAS_WINSOCK2)
34  #include <ws2tcpip.h>
35 #endif
36 
37 namespace Botan {
38 
39 namespace {
40 
41 #if defined(BOTAN_HAS_BOOST_ASIO)
42 
43 class Asio_Socket final : public OS::Socket
44  {
45  public:
46  Asio_Socket(const std::string& hostname,
47  const std::string& service,
48  std::chrono::milliseconds timeout) :
49  m_timeout(timeout), m_timer(m_io), m_tcp(m_io)
50  {
51  m_timer.expires_from_now(m_timeout);
52  check_timeout();
53 
54  boost::asio::ip::tcp::resolver resolver(m_io);
55  boost::asio::ip::tcp::resolver::query query(hostname, service);
56  boost::asio::ip::tcp::resolver::iterator dns_iter = resolver.resolve(query);
57 
58  boost::system::error_code ec = boost::asio::error::would_block;
59 
60  auto connect_cb = [&ec](const boost::system::error_code& e,
61  boost::asio::ip::tcp::resolver::iterator) { ec = e; };
62 
63  boost::asio::async_connect(m_tcp, dns_iter, connect_cb);
64 
65  while(ec == boost::asio::error::would_block)
66  {
67  m_io.run_one();
68  }
69 
70  if(ec)
71  throw boost::system::system_error(ec);
72  if(m_tcp.is_open() == false)
73  throw System_Error("Connection to host " + hostname + " failed");
74  }
75 
76  void write(const uint8_t buf[], size_t len) override
77  {
78  m_timer.expires_from_now(m_timeout);
79 
80  boost::system::error_code ec = boost::asio::error::would_block;
81 
82  m_tcp.async_send(boost::asio::buffer(buf, len),
83  [&ec](boost::system::error_code e, size_t) { ec = e; });
84 
85  while(ec == boost::asio::error::would_block) { m_io.run_one(); }
86 
87  if(ec)
88  {
89  throw boost::system::system_error(ec);
90  }
91  }
92 
93  size_t read(uint8_t buf[], size_t len) override
94  {
95  m_timer.expires_from_now(m_timeout);
96 
97  boost::system::error_code ec = boost::asio::error::would_block;
98  size_t got = 0;
99 
100  m_tcp.async_read_some(boost::asio::buffer(buf, len),
101  [&](boost::system::error_code cb_ec, size_t cb_got) { ec = cb_ec; got = cb_got; });
102 
103  while(ec == boost::asio::error::would_block) { m_io.run_one(); }
104 
105  if(ec)
106  {
107  if(ec == boost::asio::error::eof)
108  return 0;
109  throw boost::system::system_error(ec); // Some other error.
110  }
111 
112  return got;
113  }
114 
115  private:
116  void check_timeout()
117  {
118  if(m_tcp.is_open() && m_timer.expires_at() < std::chrono::system_clock::now())
119  {
120  boost::system::error_code err;
121  m_tcp.close(err);
122  }
123 
124  m_timer.async_wait(std::bind(&Asio_Socket::check_timeout, this));
125  }
126 
127  const std::chrono::milliseconds m_timeout;
128  boost::asio::io_service m_io;
129  boost::asio::system_timer m_timer;
130  boost::asio::ip::tcp::socket m_tcp;
131  };
132 
133 #elif defined(BOTAN_TARGET_OS_HAS_SOCKETS) || defined(BOTAN_TARGET_OS_HAS_WINSOCK2)
134 
135 class BSD_Socket final : public OS::Socket
136  {
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  static socket_type invalid_socket() { return INVALID_SOCKET; }
144  static void close_socket(socket_type s) { ::closesocket(s); }
145  static std::string get_last_socket_error() { return std::to_string(::WSAGetLastError()); }
146 
147  static bool nonblocking_connect_in_progress()
148  {
149  return (::WSAGetLastError() == WSAEWOULDBLOCK);
150  }
151 
152  static void set_nonblocking(socket_type s)
153  {
154  u_long nonblocking = 1;
155  ::ioctlsocket(s, FIONBIO, &nonblocking);
156  }
157 
158  static void socket_init()
159  {
160  WSAData wsa_data;
161  WORD wsa_version = MAKEWORD(2, 2);
162 
163  if (::WSAStartup(wsa_version, &wsa_data) != 0)
164  {
165  throw System_Error("WSAStartup() failed", WSAGetLastError());
166  }
167 
168  if (LOBYTE(wsa_data.wVersion) != 2 || HIBYTE(wsa_data.wVersion) != 2)
169  {
170  ::WSACleanup();
171  throw System_Error("Could not find a usable version of Winsock.dll");
172  }
173  }
174 
175  static void socket_fini()
176  {
177  ::WSACleanup();
178  }
179 #else
180  typedef int socket_type;
181  typedef ssize_t socket_op_ret_type;
182  typedef socklen_t socklen_type;
183  typedef size_t sendrecv_len_type;
184  static socket_type invalid_socket() { return -1; }
185  static void close_socket(socket_type s) { ::close(s); }
186  static std::string get_last_socket_error() { return ::strerror(errno); }
187  static bool nonblocking_connect_in_progress() { return (errno == EINPROGRESS); }
188  static void set_nonblocking(socket_type s)
189  {
190  if(::fcntl(s, F_SETFL, O_NONBLOCK) < 0)
191  throw System_Error("Setting socket to non-blocking state failed", errno);
192  }
193 
194  static void socket_init() {}
195  static void socket_fini() {}
196 #endif
197 
198  public:
199  BSD_Socket(const std::string& hostname,
200  const std::string& service,
201  std::chrono::microseconds timeout) : m_timeout(timeout)
202  {
203  socket_init();
204 
205  m_socket = invalid_socket();
206 
207  addrinfo hints;
208  clear_mem(&hints, 1);
209  hints.ai_family = AF_UNSPEC;
210  hints.ai_socktype = SOCK_STREAM;
211  addrinfo* res;
212 
213  int rc = ::getaddrinfo(hostname.c_str(), service.c_str(), &hints, &res);
214 
215  if(rc != 0)
216  {
217  throw System_Error("Name resolution failed for " + hostname, rc);
218  }
219 
220  for(addrinfo* rp = res; (m_socket == invalid_socket()) && (rp != nullptr); rp = rp->ai_next)
221  {
222  if(rp->ai_family != AF_INET && rp->ai_family != AF_INET6)
223  continue;
224 
225  m_socket = ::socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
226 
227  if(m_socket == invalid_socket())
228  {
229  // unsupported socket type?
230  continue;
231  }
232 
233  set_nonblocking(m_socket);
234 
235  int err = ::connect(m_socket, rp->ai_addr, static_cast<socklen_type>(rp->ai_addrlen));
236 
237  if(err == -1)
238  {
239  int active = 0;
240  if(nonblocking_connect_in_progress())
241  {
242  struct timeval timeout_tv = make_timeout_tv();
243  fd_set write_set;
244  FD_ZERO(&write_set);
245  // Weirdly, Winsock uses a SOCKET type but wants FD_SET to get an int instead
246  FD_SET(static_cast<int>(m_socket), &write_set);
247 
248  active = ::select(static_cast<int>(m_socket + 1), nullptr, &write_set, nullptr, &timeout_tv);
249 
250  if(active)
251  {
252  int socket_error = 0;
253  socklen_t len = sizeof(socket_error);
254 
255  if(::getsockopt(m_socket, SOL_SOCKET, SO_ERROR, reinterpret_cast<char*>(&socket_error), &len) < 0)
256  throw System_Error("Error calling getsockopt", errno);
257 
258  if(socket_error != 0)
259  {
260  active = 0;
261  }
262  }
263  }
264 
265  if(active == 0)
266  {
267  close_socket(m_socket);
268  m_socket = invalid_socket();
269  continue;
270  }
271  }
272  }
273 
274  ::freeaddrinfo(res);
275 
276  if(m_socket == invalid_socket())
277  {
278  throw System_Error("Connecting to " + hostname +
279  " for service " + service + " failed", errno);
280  }
281  }
282 
283  ~BSD_Socket()
284  {
285  close_socket(m_socket);
286  m_socket = invalid_socket();
287  socket_fini();
288  }
289 
290  void write(const uint8_t buf[], size_t len) override
291  {
292  fd_set write_set;
293  FD_ZERO(&write_set);
294  FD_SET(m_socket, &write_set);
295 
296  size_t sent_so_far = 0;
297  while(sent_so_far != len)
298  {
299  struct timeval timeout = make_timeout_tv();
300  int active = ::select(static_cast<int>(m_socket + 1), nullptr, &write_set, nullptr, &timeout);
301 
302  if(active == 0)
303  throw System_Error("Timeout during socket write");
304 
305  const size_t left = len - sent_so_far;
306  socket_op_ret_type sent = ::send(m_socket, cast_uint8_ptr_to_char(&buf[sent_so_far]), static_cast<sendrecv_len_type>(left), 0);
307  if(sent < 0)
308  throw System_Error("Socket write failed", errno);
309  else
310  sent_so_far += static_cast<size_t>(sent);
311  }
312  }
313 
314  size_t read(uint8_t buf[], size_t len) override
315  {
316  fd_set read_set;
317  FD_ZERO(&read_set);
318  FD_SET(m_socket, &read_set);
319 
320  struct timeval timeout = make_timeout_tv();
321  int active = ::select(static_cast<int>(m_socket + 1), &read_set, nullptr, nullptr, &timeout);
322 
323  if(active == 0)
324  throw System_Error("Timeout during socket read");
325 
326  socket_op_ret_type got = ::recv(m_socket, cast_uint8_ptr_to_char(buf), static_cast<sendrecv_len_type>(len), 0);
327 
328  if(got < 0)
329  throw System_Error("Socket read failed", errno);
330 
331  return static_cast<size_t>(got);
332  }
333 
334  private:
335  struct timeval make_timeout_tv() const
336  {
337  struct timeval tv;
338  tv.tv_sec = static_cast<decltype(timeval::tv_sec)>(m_timeout.count() / 1000000);
339  tv.tv_usec = static_cast<decltype(timeval::tv_usec)>(m_timeout.count() % 1000000);;
340  return tv;
341  }
342 
343  const std::chrono::microseconds m_timeout;
344  socket_type m_socket;
345  };
346 
347 #endif
348 
349 }
350 
351 std::unique_ptr<OS::Socket>
352 OS::open_socket(const std::string& hostname,
353  const std::string& service,
354  std::chrono::milliseconds timeout)
355  {
356 #if defined(BOTAN_HAS_BOOST_ASIO)
357  return std::unique_ptr<OS::Socket>(new Asio_Socket(hostname, service, timeout));
358 
359 #elif defined(BOTAN_TARGET_OS_HAS_SOCKETS) || defined(BOTAN_TARGET_OS_HAS_WINSOCK2)
360  return std::unique_ptr<OS::Socket>(new BSD_Socket(hostname, service, timeout));
361 
362 #else
363  BOTAN_UNUSED(hostname);
364  BOTAN_UNUSED(service);
365  BOTAN_UNUSED(timeout);
366  // No sockets for you
367  return std::unique_ptr<Socket>();
368 #endif
369  }
370 
371 }
void clear_mem(T *ptr, size_t n)
Definition: mem_ops.h:112
int(* final)(unsigned char *, CTX *)
std::unique_ptr< Socket > BOTAN_TEST_API open_socket(const std::string &hostname, const std::string &service, std::chrono::milliseconds timeout)
Definition: socket.cpp:352
#define O_NONBLOCK
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Definition: asn1_obj.cpp:213
Definition: alg_id.cpp:13
#define BOTAN_UNUSED(...)
Definition: assert.h:142
const char * cast_uint8_ptr_to_char(const uint8_t *b)
Definition: mem_ops.h:194