summaryrefslogtreecommitdiff
path: root/src/network/tcp_socket_handler.cpp
blob: 1bd5315b4260e1c22e5b1d7e121ae34d171d8b51 (plain)
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
#include <network/tcp_socket_handler.hpp>
#include <network/dns_handler.hpp>

#include <network/poller.hpp>

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

#ifdef BOTAN_FOUND
# include <botan/hex.h>
# include <botan/tls_exceptn.h>
# include <config/config.hpp>
# include <utils/dirname.hpp>

namespace
{
    Botan::AutoSeeded_RNG& get_rng()
    {
      static Botan::AutoSeeded_RNG rng{};
      return rng;
    }
    Botan::TLS::Session_Manager_In_Memory& get_session_manager()
    {
      static Botan::TLS::Session_Manager_In_Memory session_manager{get_rng()};
      return session_manager;
    }
}
#endif

#ifndef UIO_FASTIOV
# define UIO_FASTIOV 8
#endif

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


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

TCPSocketHandler::~TCPSocketHandler()
{
  if (this->poller->is_managing_socket(this->get_socket()))
    this->poller->remove_socket_handler(this->get_socket());
  if (this->socket != -1)
    {
      ::close(this->socket);
      this->socket = -1;
    }
}

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)
    {
      if (this->is_connecting())
        log_warning("Error connecting: ", strerror(errno));
      else
        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->is_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{};
  msg.msg_iov = msg_iov;
  msg.msg_iovlen = 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();
      msg.msg_iovlen++;
      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.
      auto it = this->out_buf.begin();
      while (it != this->out_buf.end())
        {
          if (static_cast<size_t>(res) >= it->size())
            {
              res -= it->size();
              ++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;
            }
        }
      this->out_buf.erase(this->out_buf.begin(), it);
      if (this->out_buf.empty())
        this->poller->stop_watching_send_events(this);
    }
}

void TCPSocketHandler::close()
{
  if (this->is_connected() || this->is_connecting())
    this->poller->remove_socket_handler(this->get_socket());
  if (this->socket != -1)
    {
      ::close(this->socket);
      this->socket = -1;
    }
  this->in_buf.clear();
  this->out_buf.clear();
}

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->is_connected())
    this->poller->watch_send_events(this);
}

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

bool TCPSocketHandler::is_using_tls() const
{
  return this->use_tls;
}

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

void TCPSocketHandler::consume_in_buffer(const std::size_t size)
{
  this->in_buf = this->in_buf.substr(size, std::string::npos);
}

#ifdef BOTAN_FOUND
void TCPSocketHandler::start_tls(const std::string& address, const std::string& port)
{
  Botan::TLS::Server_Information server_info(address, "irc", std::stoul(port));
  auto policy_directory = Config::get("policy_directory", utils::dirname(Config::get_filename()));
  if (!policy_directory.empty() && policy_directory[policy_directory.size()-1] != '/')
    policy_directory += '/';
  this->policy.load(policy_directory + "policy.txt");
  this->policy.load(policy_directory + address + ".policy.txt");
  this->tls = std::make_unique<Botan::TLS::Client>(
# if BOTAN_VERSION_CODE >= BOTAN_VERSION_CODE_FOR(1,11,32)
      *this,
# else
      [this](const Botan::byte* data, size_t size) { this->tls_emit_data(data, size); },
      [this](const Botan::byte* data, size_t size) { this->tls_record_received(0, data, size); },
      [this](Botan::TLS::Alert alert, const Botan::byte*, size_t) { this->tls_alert(alert); },
      [this](const Botan::TLS::Session& session) { return this->tls_session_established(session); },
# endif
      get_session_manager(), this->credential_manager, this->policy,
      get_rng(), server_info, Botan::TLS::Protocol_Version::latest_tls_version());
}

void TCPSocketHandler::tls_recv()
{
  static constexpr size_t buf_size = 4096;
  Botan::byte 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(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)
{
  // We may not be connected yet, or the tls session has
  // not yet been negociated
  if (this->tls && this->tls->is_active())
    {
      const bool was_active = this->tls->is_active();
      if (!this->pre_buf.empty())
        {
          this->tls->send(this->pre_buf.data(), this->pre_buf.size());
          this->pre_buf.clear();
        }
      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.insert(this->pre_buf.end(),
                         std::make_move_iterator(data.begin()),
                         std::make_move_iterator(data.end()));
}

void TCPSocketHandler::tls_record_received(uint64_t, 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_emit_data(const Botan::byte *data, size_t size)
{
  this->raw_send(std::string(reinterpret_cast<const char*>(data), size));
}

void TCPSocketHandler::tls_alert(Botan::TLS::Alert alert)
{
  log_debug("tls_alert: ", alert.type_string());
}

bool TCPSocketHandler::tls_session_established(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;
}

#if BOTAN_VERSION_CODE >= BOTAN_VERSION_CODE_FOR(1,11,34)
void TCPSocketHandler::tls_verify_cert_chain(const std::vector<Botan::X509_Certificate>& cert_chain,
                                             const std::vector<std::shared_ptr<const Botan::OCSP::Response>>& ocsp_responses,
                                             const std::vector<Botan::Certificate_Store*>& trusted_roots,
                                             Botan::Usage_Type usage, const std::string& hostname,
                                             const Botan::TLS::Policy& policy)
{
  log_debug("Checking remote certificate for hostname ", hostname);
  try
    {
      Botan::TLS::Callbacks::tls_verify_cert_chain(cert_chain, ocsp_responses, trusted_roots, usage, hostname, policy);
      log_debug("Certificate is valid");
    }
  catch (const std::exception& tls_exception)
    {
      log_warning("TLS certificate check failed: ", tls_exception.what());
      std::exception_ptr exception_ptr{};
      if (this->abort_on_invalid_cert())
        exception_ptr = std::current_exception();

      check_tls_certificate(cert_chain, hostname, this->credential_manager.get_trusted_fingerprint(), exception_ptr);
    }
}
#endif

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

#endif // BOTAN_FOUND