~singpolyma/biboumi

ref: e8386bd14e9783f0bef39bdf577545522e33e719 biboumi/louloulibs/network/tcp_socket_handler.cpp -rw-r--r-- 14.1 KiB
e8386bd1 — Florent Le Coz Provide an adhoc option to let user pass the cert verif for some IRC servers 7 years ago
                                                                                
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
#include <network/tcp_socket_handler.hpp>
#include <network/dns_handler.hpp>

#include <utils/timed_events.hpp>
#include <utils/scopeguard.hpp>
#include <network/poller.hpp>

#include <logger/logger.hpp>
#include <sys/socket.h>
#include <sys/types.h>
#include <stdexcept>
#include <unistd.h>
#include <errno.h>
#include <cstring>
#include <fcntl.h>

#ifdef BOTAN_FOUND
# include <botan/hex.h>
# include <botan/tls_exceptn.h>

Botan::AutoSeeded_RNG TCPSocketHandler::rng;
Botan::TLS::Policy TCPSocketHandler::policy;
Botan::TLS::Session_Manager_In_Memory TCPSocketHandler::session_manager(TCPSocketHandler::rng);

#endif

#ifndef UIO_FASTIOV
# define UIO_FASTIOV 8
#endif

using namespace std::string_literals;
using namespace std::chrono_literals;

namespace ph = std::placeholders;

TCPSocketHandler::TCPSocketHandler(std::shared_ptr<Poller> poller):
  SocketHandler(poller, -1),
  use_tls(false),
  connected(false),
  connecting(false),
  hostname_resolution_failed(false)
#ifdef BOTAN_FOUND
  ,credential_manager(this)
#endif
{}

void TCPSocketHandler::init_socket(const struct addrinfo* rp)
{
  if ((this->socket = ::socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol)) == -1)
    throw std::runtime_error("Could not create socket: "s + strerror(errno));
  int optval = 1;
  if (::setsockopt(this->socket, SOL_SOCKET, SO_KEEPALIVE, &optval, sizeof(optval)) == -1)
    log_warning("Failed to enable TCP keepalive on socket: " << strerror(errno));
  // Set the socket on non-blocking mode.  This is useful to receive a EAGAIN
  // error when connect() would block, to not block the whole process if a
  // remote is not responsive.
  const int existing_flags = ::fcntl(this->socket, F_GETFL, 0);
  if ((existing_flags == -1) ||
      (::fcntl(this->socket, F_SETFL, existing_flags | O_NONBLOCK) == -1))
    throw std::runtime_error("Could not initialize socket: "s + strerror(errno));
}

void TCPSocketHandler::connect(const std::string& address, const std::string& port, const bool tls)
{
  this->address = address;
  this->port = port;
  this->use_tls = tls;

  utils::ScopeGuard sg;

  struct addrinfo* addr_res;

  if (!this->connecting)
    {
      // Get the addrinfo from getaddrinfo (or ares_gethostbyname), only if
      // this is the first call of this function.
      if (!this->resolver.is_resolved())
        {
          log_info("Trying to connect to " << address << ":" << port);
          // Start the asynchronous process of resolving the hostname. Once
          // the addresses have been found and `resolved` has been set to true
          // (but connecting will still be false), TCPSocketHandler::connect()
          // needs to be called, again.
          this->resolver.resolve(address, port,
                                 [this](const struct addrinfo*)
                                 {
                                   log_debug("Resolution success, calling connect() again");
                                   this->connect();
                                 },
                                 [this](const char*)
                                 {
                                   log_debug("Resolution failed, calling connect() again");
                                   this->connect();
                                 });
          return;
        }
      else
        {
          // The c-ares resolved the hostname and the available addresses
          // where saved in the cares_addrinfo linked list. Now, just use
          // this list to try to connect.
          addr_res = this->resolver.get_result().get();
          if (!addr_res)
            {
              this->hostname_resolution_failed = true;
              const auto msg = this->resolver.get_error_message();
              this->close();
              this->on_connection_failed(msg);
              return ;
            }
        }
    }
  else
    { // This function is called again, use the saved addrinfo structure,
      // instead of re-doing the whole getaddrinfo process.
      addr_res = &this->addrinfo;
    }

  for (struct addrinfo* rp = addr_res; rp; rp = rp->ai_next)
    {
      if (!this->connecting)
        {
          try {
            this->init_socket(rp);
          }
          catch (const std::runtime_error& error) {
            log_error("Failed to init socket: " << error.what());
            break;
          }
        }

      this->display_resolved_ip(rp);

      if (::connect(this->socket, rp->ai_addr, rp->ai_addrlen) == 0
          || errno == EISCONN)
        {
          log_info("Connection success.");
          TimedEventsManager::instance().cancel("connection_timeout"s +
                                                std::to_string(this->socket));
          this->poller->add_socket_handler(this);
          this->connected = true;
          this->connecting = false;
#ifdef BOTAN_FOUND
          if (this->use_tls)
            this->start_tls();
#endif
          this->on_connected();
          return ;
        }
      else if (errno == EINPROGRESS || errno == EALREADY)
        {   // retry this process later, when the socket
            // is ready to be written on.
          this->connecting = true;
          this->poller->add_socket_handler(this);
          this->poller->watch_send_events(this);
          // Save the addrinfo structure, to use it on the next call
          this->ai_addrlen = rp->ai_addrlen;
          memcpy(&this->ai_addr, rp->ai_addr, this->ai_addrlen);
          memcpy(&this->addrinfo, rp, sizeof(struct addrinfo));
          this->addrinfo.ai_addr = reinterpret_cast<struct sockaddr*>(&this->ai_addr);
          this->addrinfo.ai_next = nullptr;
          // If the connection has not succeeded or failed in 5s, we consider
          // it to have failed
          TimedEventsManager::instance().add_event(
                                                   TimedEvent(std::chrono::steady_clock::now() + 5s,
                                                              std::bind(&TCPSocketHandler::on_connection_timeout, this),
                                                              "connection_timeout"s + std::to_string(this->socket)));
          return ;
        }
      log_info("Connection failed:" << strerror(errno));
    }
  log_error("All connection attempts failed.");
  this->close();
  this->on_connection_failed(strerror(errno));
  return ;
}

void TCPSocketHandler::on_connection_timeout()
{
  this->close();
  this->on_connection_failed("connection timed out");
}

void TCPSocketHandler::connect()
{
  this->connect(this->address, this->port, this->use_tls);
}

void TCPSocketHandler::on_recv()
{
#ifdef BOTAN_FOUND
  if (this->use_tls)
    this->tls_recv();
  else
#endif
    this->plain_recv();
}

void TCPSocketHandler::plain_recv()
{
  static constexpr size_t buf_size = 4096;
  char buf[buf_size];
  void* recv_buf = this->get_receive_buffer(buf_size);

  if (recv_buf == nullptr)
    recv_buf = buf;

  const ssize_t size = this->do_recv(recv_buf, buf_size);

  if (size > 0)
    {
      if (buf == recv_buf)
        {
          // data needs to be placed in the in_buf string, because no buffer
          // was provided to receive that data directly. The in_buf buffer
          // will be handled in parse_in_buffer()
          this->in_buf += std::string(buf, size);
        }
      this->parse_in_buffer(size);
    }
}

ssize_t TCPSocketHandler::do_recv(void* recv_buf, const size_t buf_size)
{
  ssize_t size = ::recv(this->socket, recv_buf, buf_size, 0);
  if (0 == size)
    {
      this->on_connection_close("");
      this->close();
    }
  else if (-1 == size)
    {
      log_warning("Error while reading from socket: " << strerror(errno));
      // Remember if we were connecting, or already connected when this
      // happened, because close() sets this->connecting to false
      const auto were_connecting = this->connecting;
      this->close();
      if (were_connecting)
        this->on_connection_failed(strerror(errno));
      else
        this->on_connection_close(strerror(errno));
    }
  return size;
}

void TCPSocketHandler::on_send()
{
  struct iovec msg_iov[UIO_FASTIOV] = {};
  struct msghdr msg{nullptr, 0,
      msg_iov,
      0, nullptr, 0, 0};
  for (const std::string& s: this->out_buf)
    {
      // unconsting the content of s is ok, sendmsg will never modify it
      msg_iov[msg.msg_iovlen].iov_base = const_cast<char*>(s.data());
      msg_iov[msg.msg_iovlen].iov_len = s.size();
      if (++msg.msg_iovlen == UIO_FASTIOV)
        break;
    }
  ssize_t res = ::sendmsg(this->socket, &msg, MSG_NOSIGNAL);
  if (res < 0)
    {
      log_error("sendmsg failed: " << strerror(errno));
      this->on_connection_close(strerror(errno));
      this->close();
    }
  else
    {
      // remove all the strings that were successfully sent.
      for (auto it = this->out_buf.begin();
           it != this->out_buf.end();)
        {
          if (static_cast<size_t>(res) >= (*it).size())
            {
              res -= (*it).size();
              it = this->out_buf.erase(it);
            }
          else
            {
              // If one string has partially been sent, we use substr to
              // crop it
              if (res > 0)
                (*it) = (*it).substr(res, std::string::npos);
              break;
            }
        }
      if (this->out_buf.empty())
        this->poller->stop_watching_send_events(this);
    }
}

void TCPSocketHandler::close()
{
  TimedEventsManager::instance().cancel("connection_timeout"s +
                                        std::to_string(this->socket));
  if (this->connected || this->connecting)
    this->poller->remove_socket_handler(this->get_socket());
  if (this->socket != -1)
    {
      ::close(this->socket);
      this->socket = -1;
    }
  this->connected = false;
  this->connecting = false;
  this->in_buf.clear();
  this->out_buf.clear();
  this->port.clear();
  this->resolver.clear();
}

void TCPSocketHandler::display_resolved_ip(struct addrinfo* rp) const
{
  if (rp->ai_family == AF_INET)
    log_debug("Trying IPv4 address " << addr_to_string(rp));
  else if (rp->ai_family == AF_INET6)
    log_debug("Trying IPv6 address " << addr_to_string(rp));
}

void TCPSocketHandler::send_data(std::string&& data)
{
#ifdef BOTAN_FOUND
  if (this->use_tls)
    try {
      this->tls_send(std::move(data));
    } catch (const Botan::TLS::TLS_Exception& e) {
      this->on_connection_close("TLS error: "s + e.what());
      this->close();
      return ;
    }
  else
#endif
    this->raw_send(std::move(data));
}

void TCPSocketHandler::raw_send(std::string&& data)
{
  if (data.empty())
    return ;
  this->out_buf.emplace_back(std::move(data));
  if (this->connected)
    this->poller->watch_send_events(this);
}

void TCPSocketHandler::send_pending_data()
{
  if (this->connected && !this->out_buf.empty())
    this->poller->watch_send_events(this);
}

bool TCPSocketHandler::is_connected() const
{
  return this->connected;
}

bool TCPSocketHandler::is_connecting() const
{
  return this->connecting || this->resolver.is_resolving();
}

void* TCPSocketHandler::get_receive_buffer(const size_t) const
{
  return nullptr;
}

#ifdef BOTAN_FOUND
void TCPSocketHandler::start_tls()
{
  Botan::TLS::Server_Information server_info(this->address, "irc", std::stoul(this->port));
  this->tls = std::make_unique<Botan::TLS::Client>(
      std::bind(&TCPSocketHandler::tls_output_fn, this, ph::_1, ph::_2),
      std::bind(&TCPSocketHandler::tls_data_cb, this, ph::_1, ph::_2),
      std::bind(&TCPSocketHandler::tls_alert_cb, this, ph::_1, ph::_2, ph::_3),
      std::bind(&TCPSocketHandler::tls_handshake_cb, this, ph::_1),
      session_manager, this->credential_manager, policy,
      rng, server_info, Botan::TLS::Protocol_Version::latest_tls_version());
}

void TCPSocketHandler::tls_recv()
{
  static constexpr size_t buf_size = 4096;
  char recv_buf[buf_size];

  const ssize_t size = this->do_recv(recv_buf, buf_size);
  if (size > 0)
    {
      const bool was_active = this->tls->is_active();
      try {
        this->tls->received_data(reinterpret_cast<const Botan::byte*>(recv_buf),
                                 static_cast<size_t>(size));
      } catch (const Botan::TLS::TLS_Exception& e) {
        // May happen if the server sends malformed TLS data (buggy server,
        // or more probably we are just connected to a server that sends
        // plain-text)
        this->on_connection_close("TLS error: "s + e.what());
        this->close();
        return ;
      }
      if (!was_active && this->tls->is_active())
        this->on_tls_activated();
    }
}

void TCPSocketHandler::tls_send(std::string&& data)
{
  if (this->tls->is_active())
    {
      const bool was_active = this->tls->is_active();
      if (!this->pre_buf.empty())
        {
          this->tls->send(reinterpret_cast<const Botan::byte*>(this->pre_buf.data()),
                          this->pre_buf.size());
          this->pre_buf = "";
        }
      if (!data.empty())
        this->tls->send(reinterpret_cast<const Botan::byte*>(data.data()),
                       data.size());
      if (!was_active && this->tls->is_active())
        this->on_tls_activated();
    }
  else
    this->pre_buf += data;
}

void TCPSocketHandler::tls_data_cb(const Botan::byte* data, size_t size)
{
  this->in_buf += std::string(reinterpret_cast<const char*>(data),
                              size);
  if (!this->in_buf.empty())
    this->parse_in_buffer(size);
}

void TCPSocketHandler::tls_output_fn(const Botan::byte* data, size_t size)
{
  this->raw_send(std::string(reinterpret_cast<const char*>(data), size));
}

void TCPSocketHandler::tls_alert_cb(Botan::TLS::Alert alert, const Botan::byte*, size_t)
{
  log_debug("tls_alert: " << alert.type_string());
}

bool TCPSocketHandler::tls_handshake_cb(const Botan::TLS::Session& session)
{
  log_debug("Handshake with " << session.server_info().hostname() << " complete."
            << " Version: " << session.version().to_string()
            << " using " << session.ciphersuite().to_string());
  if (!session.session_id().empty())
    log_debug("Session ID " << Botan::hex_encode(session.session_id()));
  if (!session.session_ticket().empty())
    log_debug("Session ticket " << Botan::hex_encode(session.session_ticket()));
  return true;
}

void TCPSocketHandler::on_tls_activated()
{
  this->send_data({});
}

#endif // BOTAN_FOUND