Move all the connect() logic from TCPSocketHandler into a subclass

This way, TCPSocketHandler only deal with the message sending/receiving, not
the connect() or anything else.  This will be used for implementing servers
(because when a client is accepted, we don’t need all the connect() and dns
resolution stuff).

7 files changed, 347 insertions, 290 deletions

diff --git a/louloulibs/network/dns_socket_handler.cpp b/louloulibs/network/dns_socket_handler.cpp
index 403a5be..af39f49 100644
--- a/louloulibs/network/dns_socket_handler.cpp
+++ b/louloulibs/network/dns_socket_handler.cpp
@@ -40,6 +40,11 @@ bool DNSSocketHandler::is_connected() const
   return true;
 }
 
+bool DNSSocketHandler::is_connecting() const
+{
+  return false;
+}
+
 void DNSSocketHandler::remove_from_poller()
 {
   if (this->poller->is_managing_socket(this->socket))
diff --git a/louloulibs/network/dns_socket_handler.hpp b/louloulibs/network/dns_socket_handler.hpp
index 0570196..14ba177 100644
--- a/louloulibs/network/dns_socket_handler.hpp
+++ b/louloulibs/network/dns_socket_handler.hpp
@@ -40,6 +40,7 @@ public:
    * Always true, see the comment for connect()
    */
   bool is_connected() const override final;
+  bool is_connecting() const override final;
   void remove_from_poller();
 
 private:
diff --git a/louloulibs/network/socket_handler.hpp b/louloulibs/network/socket_handler.hpp
index ea79a18..02e3b80 100644
--- a/louloulibs/network/socket_handler.hpp
+++ b/louloulibs/network/socket_handler.hpp
@@ -24,6 +24,7 @@ public:
   virtual void on_send() = 0;
   virtual void connect() = 0;
   virtual bool is_connected() const = 0;
+  virtual bool is_connecting() const = 0;
 
   socket_t get_socket() const
   { return this->socket; }
diff --git a/louloulibs/network/tcp_client_socket_handler.cpp b/louloulibs/network/tcp_client_socket_handler.cpp
new file mode 100644
index 0000000..2de9696
--- /dev/null
+++ b/louloulibs/network/tcp_client_socket_handler.cpp
@@ -0,0 +1,232 @@
+#include <network/tcp_client_socket_handler.hpp>
+#include <utils/timed_events.hpp>
+#include <utils/scopeguard.hpp>
+#include <network/poller.hpp>
+
+#include <logger/logger.hpp>
+
+#include <unistd.h>
+#include <fcntl.h>
+
+using namespace std::string_literals;
+
+TCPClientSocketHandler::TCPClientSocketHandler(std::shared_ptr<Poller> poller):
+   TCPSocketHandler(poller),
+   hostname_resolution_failed(false),
+   connected(false),
+   connecting(false)
+{}
+
+TCPClientSocketHandler::~TCPClientSocketHandler()
+{
+  this->close();
+}
+
+void TCPClientSocketHandler::init_socket(const struct addrinfo* rp)
+{
+  if (this->socket != -1)
+    ::close(this->socket);
+  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));
+  // Bind the socket to a specific address, if specified
+  if (!this->bind_addr.empty())
+    {
+      // Convert the address from string format to a sockaddr that can be
+      // used in bind()
+      struct addrinfo* result;
+      int err = ::getaddrinfo(this->bind_addr.data(), nullptr, nullptr, &result);
+      if (err != 0 || !result)
+        log_error("Failed to bind socket to ", this->bind_addr, ": ",
+                  gai_strerror(err));
+      else
+        {
+          utils::ScopeGuard sg([result](){ freeaddrinfo(result); });
+          struct addrinfo* rp;
+          int bind_error = 0;
+          for (rp = result; rp; rp = rp->ai_next)
+            {
+              if ((bind_error = ::bind(this->socket,
+                         reinterpret_cast<const struct sockaddr*>(rp->ai_addr),
+                         rp->ai_addrlen)) == 0)
+                break;
+            }
+          if (!rp)
+            log_error("Failed to bind socket to ", this->bind_addr, ": ",
+                      strerror(errno));
+          else
+            log_info("Socket successfully bound to ", this->bind_addr);
+        }
+    }
+  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 TCPClientSocketHandler::connect(const std::string& address, const std::string& port, const bool tls)
+{
+  this->address = address;
+  this->port = port;
+  this->use_tls = tls;
+
+  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), TCPClientSocketHandler::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(this->address, this->port);
+#endif
+          this->connection_date = std::chrono::system_clock::now();
+
+          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(&TCPClientSocketHandler::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 TCPClientSocketHandler::on_connection_timeout()
+{
+  this->close();
+  this->on_connection_failed("connection timed out");
+}
+
+void TCPClientSocketHandler::connect()
+{
+  this->connect(this->address, this->port, this->use_tls);
+}
+
+void TCPClientSocketHandler::close()
+{
+  TimedEventsManager::instance().cancel("connection_timeout"s +
+                                        std::to_string(this->socket));
+
+  TCPSocketHandler::close();
+
+  this->connected = false;
+  this->connecting = false;
+  this->port.clear();
+  this->resolver.clear();
+}
+
+void TCPClientSocketHandler::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));
+}
+
+bool TCPClientSocketHandler::is_connected() const
+{
+  return this->connected;
+}
+
+bool TCPClientSocketHandler::is_connecting() const
+{
+  return this->connecting || this->resolver.is_resolving();
+}
+
+std::string TCPClientSocketHandler::get_port() const
+{
+  return this->port;
+}
diff --git a/louloulibs/network/tcp_client_socket_handler.hpp b/louloulibs/network/tcp_client_socket_handler.hpp
new file mode 100644
index 0000000..7dd476c
--- /dev/null
+++ b/louloulibs/network/tcp_client_socket_handler.hpp
@@ -0,0 +1,75 @@
+#pragma once
+
+#include <network/tcp_socket_handler.hpp>
+
+class TCPClientSocketHandler: public TCPSocketHandler
+{
+ public:
+  TCPClientSocketHandler(std::shared_ptr<Poller> poller);
+  ~TCPClientSocketHandler();
+  /**
+   * Connect to the remote server, and call on_connected() if this
+   * succeeds. If tls is true, we set use_tls to true and will also call
+   * start_tls() when the connection succeeds.
+   */
+  void connect(const std::string& address, const std::string& port, const bool tls);
+  void connect() override final;
+  /**
+   * Called by a TimedEvent, when the connection did not succeed or fail
+   * after a given time.
+   */
+  void on_connection_timeout();
+  /**
+   * Called when the connection is successful.
+   */
+  virtual void on_connected() = 0;
+  bool is_connected() const override;
+  bool is_connecting() const;
+
+  std::string get_port() const;
+
+  void close() override final;
+  std::chrono::system_clock::time_point connection_date;
+
+ protected:
+  bool hostname_resolution_failed;
+  /**
+   * Address to bind the socket to, before calling connect().
+   * If empty, it’s equivalent to binding to INADDR_ANY.
+   */
+  std::string bind_addr;
+  /**
+   * Display the resolved IP, just for information purpose.
+   */
+  void display_resolved_ip(struct addrinfo* rp) const;
+ private:
+  /**
+   * Initialize the socket with the parameters contained in the given
+   * addrinfo structure.
+   */
+  void init_socket(const struct addrinfo* rp);
+  /**
+   * DNS resolver
+   */
+  Resolver resolver;
+  /**
+   * Keep the details of the addrinfo returned by the resolver that
+   * triggered a EINPROGRESS error when connect()ing to it, to reuse it
+   * directly when connect() is called again.
+   */
+  struct addrinfo addrinfo;
+  struct sockaddr_in6 ai_addr;
+  socklen_t ai_addrlen;
+
+  /**
+   * Hostname we are connected/connecting to
+   */
+  std::string address;
+  /**
+   * Port we are connected/connecting to
+   */
+  std::string port;
+
+  bool connected;
+  bool connecting;
+};
diff --git a/louloulibs/network/tcp_socket_handler.cpp b/louloulibs/network/tcp_socket_handler.cpp
index 1dddde5..5782f66 100644
--- a/louloulibs/network/tcp_socket_handler.cpp
+++ b/louloulibs/network/tcp_socket_handler.cpp
@@ -1,8 +1,6 @@
 #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>
@@ -12,7 +10,6 @@
 #include <unistd.h>
 #include <errno.h>
 #include <cstring>
-#include <fcntl.h>
 
 #ifdef BOTAN_FOUND
 # include <botan/hex.h>
@@ -35,10 +32,7 @@ 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)
+  use_tls(false)
 #ifdef BOTAN_FOUND
   ,credential_manager(this)
 #endif
@@ -46,181 +40,13 @@ TCPSocketHandler::TCPSocketHandler(std::shared_ptr<Poller> poller):
 
 TCPSocketHandler::~TCPSocketHandler()
 {
-  this->close();
-}
-
-
-void TCPSocketHandler::init_socket(const struct addrinfo* rp)
-{
+  if (this->poller->is_managing_socket(this->get_socket()))
+    this->poller->remove_socket_handler(this->get_socket());
   if (this->socket != -1)
-    ::close(this->socket);
-  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));
-  // Bind the socket to a specific address, if specified
-  if (!this->bind_addr.empty())
     {
-      // Convert the address from string format to a sockaddr that can be
-      // used in bind()
-      struct addrinfo* result;
-      int err = ::getaddrinfo(this->bind_addr.data(), nullptr, nullptr, &result);
-      if (err != 0 || !result)
-        log_error("Failed to bind socket to ", this->bind_addr, ": ",
-                  gai_strerror(err));
-      else
-        {
-          utils::ScopeGuard sg([result](){ freeaddrinfo(result); });
-          struct addrinfo* rp;
-          int bind_error = 0;
-          for (rp = result; rp; rp = rp->ai_next)
-            {
-              if ((bind_error = ::bind(this->socket,
-                         reinterpret_cast<const struct sockaddr*>(rp->ai_addr),
-                         rp->ai_addrlen)) == 0)
-                break;
-            }
-          if (!rp)
-            log_error("Failed to bind socket to ", this->bind_addr, ": ",
-                      strerror(errno));
-          else
-            log_info("Socket successfully bound to ", this->bind_addr);
-        }
-    }
-  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;
-
-  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->connection_date = std::chrono::system_clock::now();
-
-          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));
+      ::close(this->socket);
+      this->socket = -1;
     }
-  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()
@@ -267,13 +93,13 @@ ssize_t TCPSocketHandler::do_recv(void* recv_buf, const size_t buf_size)
     }
   else if (-1 == size)
     {
-      if (this->connecting)
+      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->connecting;
+      const auto were_connecting = this->is_connecting();
       this->close();
       if (were_connecting)
         this->on_connection_failed(strerror(errno));
@@ -333,29 +159,15 @@ void TCPSocketHandler::on_send()
 
 void TCPSocketHandler::close()
 {
-  TimedEventsManager::instance().cancel("connection_timeout"s +
-                                        std::to_string(this->socket));
-  if (this->connected || this->connecting)
+  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->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)
@@ -379,45 +191,35 @@ void TCPSocketHandler::raw_send(std::string&& data)
   if (data.empty())
     return ;
   this->out_buf.emplace_back(std::move(data));
-  if (this->connected)
+  if (this->is_connected())
     this->poller->watch_send_events(this);
 }
 
 void TCPSocketHandler::send_pending_data()
 {
-  if (this->connected && !this->out_buf.empty())
+  if (this->is_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();
-}
-
 bool TCPSocketHandler::is_using_tls() const
 {
   return this->use_tls;
 }
 
-std::string TCPSocketHandler::get_port() const
+void* TCPSocketHandler::get_receive_buffer(const size_t) const
 {
-  return this->port;
+  return nullptr;
 }
 
-void* TCPSocketHandler::get_receive_buffer(const size_t) const
+void TCPSocketHandler::consume_in_buffer(const std::size_t size)
 {
-  return nullptr;
+  this->in_buf = this->in_buf.substr(size, std::string::npos);
 }
 
 #ifdef BOTAN_FOUND
-void TCPSocketHandler::start_tls()
+void TCPSocketHandler::start_tls(const std::string& address, const std::string& port)
 {
-  Botan::TLS::Server_Information server_info(this->address, "irc", std::stoul(this->port));
+  Botan::TLS::Server_Information server_info(address, "irc", std::stoul(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),
diff --git a/louloulibs/network/tcp_socket_handler.hpp b/louloulibs/network/tcp_socket_handler.hpp
index 20a3e5a..d5e24ee 100644
--- a/louloulibs/network/tcp_socket_handler.hpp
+++ b/louloulibs/network/tcp_socket_handler.hpp
@@ -20,10 +20,8 @@
 #include <list>
 
 /**
- * An interface, with a series of callbacks that should be implemented in
- * subclasses that deal with a socket. These callbacks are called on various events
- * (read/write/timeout, etc) when they are notified to a poller
- * (select/poll/epoll etc)
+ * Does all the read/write, buffering etc. With optional tls.
+ * But doesn’t do any connect() or accept() or anything else.
  */
 class TCPSocketHandler: public SocketHandler
 {
@@ -37,13 +35,6 @@ public:
   TCPSocketHandler& operator=(TCPSocketHandler&&) = delete;
 
   /**
-   * Connect to the remote server, and call on_connected() if this
-   * succeeds. If tls is true, we set use_tls to true and will also call
-   * start_tls() when the connection succeeds.
-   */
-  void connect(const std::string& address, const std::string& port, const bool tls);
-  void connect() override final;
-  /**
    * Reads raw data from the socket. And pass it to parse_in_buffer()
    * If we are using TLS on this connection, we call tls_recv()
    */
@@ -67,25 +58,7 @@ public:
   /**
    * Close the connection, remove us from the poller
    */
-  void close();
-  /**
-   * Called by a TimedEvent, when the connection did not succeed or fail
-   * after a given time.
-   */
-  void on_connection_timeout();
-  /**
-   * Called when the connection is successful.
-   */
-  virtual void on_connected() = 0;
-  /**
-   * Called when the connection fails. Not when it is closed later, just at
-   * the connect() call.
-   */
-  virtual void on_connection_failed(const std::string& reason) = 0;
-  /**
-   * Called when we detect a disconnection from the remote host.
-   */
-  virtual void on_connection_close(const std::string& error) = 0;
+  virtual void close();
   /**
    * Handle/consume (some of) the data received so far.  The data to handle
    * may be in the in_buf buffer, or somewhere else, depending on what
@@ -93,6 +66,9 @@ public:
    * should be truncated, only the unused data should be left untouched.
    *
    * The size argument is the size of the last chunk of data that was added to the buffer.
+   *
+   * The function should call consume_in_buffer, with the size that was consumed by the
+   * “parsing”, and thus to be removed from the input buffer.
    */
   virtual void parse_in_buffer(const size_t size) = 0;
 #ifdef BOTAN_FOUND
@@ -105,19 +81,10 @@ public:
     return true;
   }
 #endif
-  bool is_connected() const override final;
-  bool is_connecting() const;
   bool is_using_tls() const;
-  std::string get_port() const;
-  std::chrono::system_clock::time_point connection_date;
 
 private:
   /**
-   * Initialize the socket with the parameters contained in the given
-   * addrinfo structure.
-   */
-  void init_socket(const struct addrinfo* rp);
-  /**
    * Reads from the socket into the provided buffer.  If an error occurs
    * (read returns <= 0), the handling of the error is done here (close the
    * connection, log a message, etc).
@@ -137,12 +104,14 @@ private:
   void raw_send(std::string&& data);
 
 #ifdef BOTAN_FOUND
+ protected:
   /**
    * Create the TLS::Client object, with all the callbacks etc. This must be
    * called only when we know we are able to send TLS-encrypted data over
    * the socket.
    */
-  void start_tls();
+  void start_tls(const std::string& address, const std::string& port);
+ private:
   /**
    * An additional step to pass the data into our tls object to decrypt it
    * before passing it to parse_in_buffer.
@@ -185,20 +154,11 @@ private:
    * Where data is added, when we want to send something to the client.
    */
   std::vector<std::string> out_buf;
+protected:
   /**
-   * DNS resolver
-   */
-  Resolver resolver;
-  /**
-   * Keep the details of the addrinfo returned by the resolver that
-   * triggered a EINPROGRESS error when connect()ing to it, to reuse it
-   * directly when connect() is called again.
+   * Whether we are using TLS on this connection or not.
    */
-  struct addrinfo addrinfo;
-  struct sockaddr_in6 ai_addr;
-  socklen_t ai_addrlen;
-
-protected:
+  bool use_tls;
   /**
    * Where data read from the socket is added until we can extract a full
    * and meaningful “message” from it.
@@ -207,9 +167,9 @@ protected:
    */
   std::string in_buf;
   /**
-   * Whether we are using TLS on this connection or not.
+   * Remove the given “size” first bytes from our in_buf.
    */
-  bool use_tls;
+  void consume_in_buffer(const std::size_t size);
   /**
    * Provide a buffer in which data can be directly received. This can be
    * used to avoid copying data into in_buf before using it. If no buffer
@@ -219,31 +179,12 @@ protected:
    */
   virtual void* get_receive_buffer(const size_t size) const;
   /**
-   * Hostname we are connected/connecting to
-   */
-  std::string address;
-  /**
-   * Port we are connected/connecting to
-   */
-  std::string port;
-
-  bool connected;
-  bool connecting;
-
-  bool hostname_resolution_failed;
-
-  /**
-   * Address to bind the socket to, before calling connect().
-   * If empty, it’s equivalent to binding to INADDR_ANY.
+   * Called when we detect a disconnection from the remote host.
    */
-  std::string bind_addr;
+  virtual void on_connection_close(const std::string& error) = 0;
+  virtual void on_connection_failed(const std::string& error) = 0;
 
 private:
-  /**
-   * Display the resolved IP, just for information purpose.
-   */
-  void display_resolved_ip(struct addrinfo* rp) const;
-
 #ifdef BOTAN_FOUND
   /**
    * Botan stuff to manipulate a TLS session.