~singpolyma/biboumi

aa340e1c5e4e28397ef212aa210633e9dcb81f98 — Florent Le Coz 8 years ago 1aa2c2d
Separate the DNS resolution logic from the TCP communication logic

fix #3137
M louloulibs/network/dns_handler.cpp => louloulibs/network/dns_handler.cpp +4 -19
@@ 2,7 2,6 @@
#ifdef CARES_FOUND

#include <network/dns_socket_handler.hpp>
#include <network/tcp_socket_handler.hpp>
#include <network/dns_handler.hpp>
#include <network/poller.hpp>



@@ 14,19 13,6 @@
DNSHandler DNSHandler::instance;

using namespace std::string_literals;

void on_hostname4_resolved(void* arg, int status, int, struct hostent* hostent)
{
  TCPSocketHandler* socket_handler = static_cast<TCPSocketHandler*>(arg);
  socket_handler->on_hostname4_resolved(status, hostent);
}

void on_hostname6_resolved(void* arg, int status, int, struct hostent* hostent)
{
  TCPSocketHandler* socket_handler = static_cast<TCPSocketHandler*>(arg);
  socket_handler->on_hostname6_resolved(status, hostent);
}

DNSHandler::DNSHandler()
{
  int ares_error;


@@ 54,16 40,15 @@ void DNSHandler::destroy()
  ::ares_library_cleanup();
}

void DNSHandler::gethostbyname(const std::string& name,
                               TCPSocketHandler* socket_handler, int family)
void DNSHandler::gethostbyname(const std::string& name, ares_host_callback callback,
                               void* data, int family)
{
  socket_handler->free_cares_addrinfo();
  if (family == AF_INET)
    ::ares_gethostbyname(this->channel, name.data(), family,
                         &::on_hostname4_resolved, socket_handler);
                         callback, data);
  else
    ::ares_gethostbyname(this->channel, name.data(), family,
                         &::on_hostname6_resolved, socket_handler);
                         callback, data);
}

void DNSHandler::watch_dns_sockets(std::shared_ptr<Poller>& poller)

M louloulibs/network/dns_handler.hpp => louloulibs/network/dns_handler.hpp +2 -5
@@ 13,9 13,6 @@ class DNSSocketHandler;
# include <string>
# include <vector>

void on_hostname4_resolved(void* arg, int status, int, struct hostent* hostent);
void on_hostname6_resolved(void* arg, int status, int, struct hostent* hostent);

/**
 * Class managing DNS resolution.  It should only be statically instanciated
 * once in SocketHandler.  It manages ares channel and calls various


@@ 27,8 24,8 @@ class DNSHandler
public:
  DNSHandler();
  ~DNSHandler() = default;
  void gethostbyname(const std::string& name, TCPSocketHandler* socket_handler,
                     int family);
  void gethostbyname(const std::string& name, ares_host_callback callback,
                     void* socket_handler, int family);
  /**
   * Call ares_fds to know what fd needs to be watched by the poller, create
   * or destroy DNSSocketHandlers depending on the result.

A louloulibs/network/resolver.cpp => louloulibs/network/resolver.cpp +219 -0
@@ 0,0 1,219 @@
#include <network/dns_handler.hpp>
#include <network/resolver.hpp>
#include <string.h>
#include <arpa/inet.h>

// remove me
#include <iostream>

using namespace std::string_literals;

Resolver::Resolver():
#ifdef CARES_FOUND
  resolved4(false),
  resolved6(false),
  resolving(false),
  cares_addrinfo(nullptr),
  port{},
#endif
  resolved(false),
  error_msg{}
{
}

void Resolver::resolve(const std::string& hostname, const std::string& port,
                       SuccessCallbackType success_cb, ErrorCallbackType error_cb)
{
  this->error_cb = error_cb;
  this->success_cb = success_cb;
  this->port = port;

  this->start_resolving(hostname, port);
}

#ifdef CARES_FOUND
void Resolver::start_resolving(const std::string& hostname, const std::string& port)
{
  std::cout << "start_resolving: " << hostname << port << std::endl;
  this->resolving = true;
  this->resolved = false;
  this->resolved4 = false;
  this->resolved6 = false;

  this->error_msg.clear();
  this->cares_addrinfo = nullptr;

  auto hostname4_resolved = [](void* arg, int status, int,
                                  struct hostent* hostent)
    {
      Resolver* resolver = static_cast<Resolver*>(arg);
      resolver->on_hostname4_resolved(status, hostent);
    };
  auto hostname6_resolved = [](void* arg, int status, int,
                                  struct hostent* hostent)
    {
      Resolver* resolver = static_cast<Resolver*>(arg);
      resolver->on_hostname6_resolved(status, hostent);
    };

  DNSHandler::instance.gethostbyname(hostname, hostname6_resolved,
                                     this, AF_INET6);
  DNSHandler::instance.gethostbyname(hostname, hostname4_resolved,
                                     this, AF_INET);
}

void Resolver::on_hostname4_resolved(int status, struct hostent* hostent)
{
  this->resolved4 = true;
  if (status == ARES_SUCCESS)
    this->fill_ares_addrinfo4(hostent);
  else
    this->error_msg = ::ares_strerror(status);

  if (this->resolved4 && this->resolved6)
    this->on_resolved();
}

void Resolver::on_hostname6_resolved(int status, struct hostent* hostent)
{
  this->resolved6 = true;
  if (status == ARES_SUCCESS)
    this->fill_ares_addrinfo6(hostent);
  else
    this->error_msg = ::ares_strerror(status);

  if (this->resolved4 && this->resolved6)
    this->on_resolved();
}

void Resolver::on_resolved()
{
  this->resolved = true;
  this->resolving = false;
  if (!this->cares_addrinfo)
    {
      if (this->error_cb)
        this->error_cb(this->error_msg.data());
    }
  else
    {
      this->addr.reset(this->cares_addrinfo);
      if (this->success_cb)
        this->success_cb(this->addr.get());
    }
}

void Resolver::fill_ares_addrinfo4(const struct hostent* hostent)
{
  std::cout << "fill_ares_addrinfo4" << this->port << std::endl;
  struct addrinfo* prev = this->cares_addrinfo;
  struct in_addr** address = reinterpret_cast<struct in_addr**>(hostent->h_addr_list);

  while (*address)
    {
      // Create a new addrinfo list element, and fill it
      struct addrinfo* current = new struct addrinfo;
      current->ai_flags = 0;
      current->ai_family = hostent->h_addrtype;
      current->ai_socktype = SOCK_STREAM;
      current->ai_protocol = 0;
      current->ai_addrlen = sizeof(struct sockaddr_in);

      struct sockaddr_in* addr = new struct sockaddr_in;
      addr->sin_family = hostent->h_addrtype;
      addr->sin_port = htons(strtoul(this->port.data(), nullptr, 10));
      addr->sin_addr.s_addr = (*address)->s_addr;

      current->ai_addr = reinterpret_cast<struct sockaddr*>(addr);
      current->ai_next = nullptr;
      current->ai_canonname = nullptr;

      current->ai_next = prev;
      this->cares_addrinfo = current;
      prev = current;
      ++address;
    }
}

void Resolver::fill_ares_addrinfo6(const struct hostent* hostent)
{
  std::cout << "fill_ares_addrinfo6" << this->port << std::endl;
  struct addrinfo* prev = this->cares_addrinfo;
  struct in6_addr** address = reinterpret_cast<struct in6_addr**>(hostent->h_addr_list);

  while (*address)
    {
      // Create a new addrinfo list element, and fill it
      struct addrinfo* current = new struct addrinfo;
      current->ai_flags = 0;
      current->ai_family = hostent->h_addrtype;
      current->ai_socktype = SOCK_STREAM;
      current->ai_protocol = 0;
      current->ai_addrlen = sizeof(struct sockaddr_in6);

      struct sockaddr_in6* addr = new struct sockaddr_in6;
      addr->sin6_family = hostent->h_addrtype;
      addr->sin6_port = htons(strtoul(this->port.data(), nullptr, 10));
      ::memcpy(addr->sin6_addr.s6_addr, (*address)->s6_addr, 16);
      addr->sin6_flowinfo = 0;
      addr->sin6_scope_id = 0;

      current->ai_addr = reinterpret_cast<struct sockaddr*>(addr);
      current->ai_next = nullptr;
      current->ai_canonname = nullptr;

      current->ai_next = prev;
      this->cares_addrinfo = current;
      prev = current;
      ++address;
    }
}

#else  // ifdef CARES_FOUND

void Resolver::start_resolving(const std::string& hostname, const std::string& port)
{
  // If the resolution fails, the addr will be unset
  this->addr.reset(nullptr);

  struct addrinfo hints;
  memset(&hints, 0, sizeof(struct addrinfo));
  hints.ai_flags = 0;
  hints.ai_family = AF_UNSPEC;
  hints.ai_socktype = SOCK_STREAM;
  hints.ai_protocol = 0;

  struct addrinfo* addr_res = nullptr;
  const int res = ::getaddrinfo(hostname.data(), port.data(),
                                &hints, &addr_res);

  this->resolved = true;

  if (res != 0)
    {
      this->error_msg = gai_strerror(res);
      if (this->error_cb)
        this->error_cb(this->error_msg.data());
    }
  else
    {
      this->addr.reset(addr_res);
      if (this->success_cb)
        this->success_cb(this->addr.get());
    }
}
#endif  // ifdef CARES_FOUND

std::string addr_to_string(const struct addrinfo* rp)
{
  char buf[INET6_ADDRSTRLEN];
  if (rp->ai_family == AF_INET)
    return ::inet_ntop(rp->ai_family,
                       &reinterpret_cast<sockaddr_in*>(rp->ai_addr)->sin_addr,
                       buf, sizeof(buf));
  else if (rp->ai_family == AF_INET6)
    return ::inet_ntop(rp->ai_family,
                       &reinterpret_cast<sockaddr_in6*>(rp->ai_addr)->sin6_addr,
                       buf, sizeof(buf));
  return {};
}

A louloulibs/network/resolver.hpp => louloulibs/network/resolver.hpp +129 -0
@@ 0,0 1,129 @@
#ifndef RESOLVER_HPP_INCLUDED
#define RESOLVER_HPP_INCLUDED

#include "louloulibs.h"

#include <functional>
#include <memory>
#include <string>

#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>

struct AddrinfoDeleter
{
  void operator()(struct addrinfo* addr)
  {
#ifdef CARES_FOUND
    while (addr)
      {
        delete addr->ai_addr;
        auto next = addr->ai_next;
        delete addr;
        addr = next;
      }
#else
    freeaddrinfo(addr);
#endif
  }
};

class Resolver
{
public:
  using ErrorCallbackType = std::function<void(const char*)>;
  using SuccessCallbackType = std::function<void(const struct addrinfo*)>;

  Resolver();
  ~Resolver() = default;

  bool is_resolving() const
  {
#ifdef CARES_FOUND
    return this->resolving;
#else
    return false;
#endif
  }

  bool is_resolved() const
  {
    return this->resolved;
  }

  const auto& get_result() const
  {
    return this->addr;
  }
  std::string get_error_message() const
  {
    return this->error_msg;
  }

  void clear()
  {
#ifdef CARES_FOUND
    this->resolved6 = false;
    this->resolved4 = false;
#endif
    this->resolved = false;
    this->resolving = false;
    this->addr.reset();
    this->cares_addrinfo = nullptr;
    this->port.clear();
    this->error_msg.clear();
  }

  void resolve(const std::string& hostname, const std::string& port,
               SuccessCallbackType success_cb, ErrorCallbackType error_cb);

private:
  void start_resolving(const std::string& hostname, const std::string& port);
#ifdef CARES_FOUND
  void on_hostname4_resolved(int status, struct hostent* hostent);
  void on_hostname6_resolved(int status, struct hostent* hostent);

  void fill_ares_addrinfo4(const struct hostent* hostent);
  void fill_ares_addrinfo6(const struct hostent* hostent);

  void on_resolved();

  bool resolved4;
  bool resolved6;

  bool resolving;

  /**
   * When using c-ares to resolve the host asynchronously, we need the
   * c-ares callbacks to fill a structure (a struct addrinfo, for
   * compatibility with getaddrinfo and the rest of the code that works when
   * c-ares is not used) with all returned values (for example an IPv6 and
   * an IPv4). The pointer is given to the unique_ptr to manage its lifetime.
   */
  struct addrinfo* cares_addrinfo;
  std::string port;

#endif
 /**
  * Tells if we finished the resolution process. It doesn't indicate if it
  * was successful (it is true even if the result is an error).
  */
  bool resolved;
  std::string error_msg;


  std::unique_ptr<struct addrinfo, AddrinfoDeleter> addr;

  ErrorCallbackType error_cb;
  SuccessCallbackType success_cb;

  Resolver(const Resolver&) = delete;
  Resolver(Resolver&&) = delete;
  Resolver& operator=(const Resolver&) = delete;
  Resolver& operator=(Resolver&&) = delete;
};

std::string addr_to_string(const struct addrinfo* rp);

#endif /* RESOLVER_HPP_INCLUDED */

M louloulibs/network/tcp_socket_handler.cpp => louloulibs/network/tcp_socket_handler.cpp +20 -182
@@ 11,13 11,9 @@
#include <stdexcept>
#include <unistd.h>
#include <errno.h>
#include <netdb.h>
#include <cstring>
#include <fcntl.h>

#include <iostream>
#include <arpa/inet.h>

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


@@ 43,24 39,9 @@ TCPSocketHandler::TCPSocketHandler(std::shared_ptr<Poller> poller):
  use_tls(false),
  connected(false),
  connecting(false),
#ifdef CARES_FOUND
  resolving(false),
  resolved(false),
  resolved4(false),
  resolved6(false),
  cares_addrinfo(nullptr),
  cares_error(),
#endif
  hostname_resolution_failed(false)
{}

TCPSocketHandler::~TCPSocketHandler()
{
#ifdef CARES_FOUND
  this->free_cares_addrinfo();
#endif
}

void TCPSocketHandler::init_socket(const struct addrinfo* rp)
{
  if ((this->socket = ::socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol)) == -1)


@@ 91,17 72,24 @@ void TCPSocketHandler::connect(const std::string& address, const std::string& po
    {
      // Get the addrinfo from getaddrinfo (or ares_gethostbyname), only if
      // this is the first call of this function.
#ifdef CARES_FOUND
      if (!this->resolved)
      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->resolving = true;
          DNSHandler::instance.gethostbyname(address, this, AF_INET6);
          DNSHandler::instance.gethostbyname(address, this, AF_INET);
          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


@@ 109,39 97,16 @@ void TCPSocketHandler::connect(const std::string& address, const std::string& po
          // 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->cares_addrinfo;
          addr_res = this->resolver.get_result().get();
          if (!addr_res)
            {
              this->hostname_resolution_failed = true;
              const auto msg = this->cares_error;
              const auto msg = this->resolver.get_error_message();
              this->close();
              this->on_connection_failed(msg);
              return ;
            }
        }
#else
      log_info("Trying to connect to " << address << ":" << port);
      struct addrinfo hints;
      memset(&hints, 0, sizeof(struct addrinfo));
      hints.ai_flags = 0;
      hints.ai_family = AF_UNSPEC;
      hints.ai_socktype = SOCK_STREAM;
      hints.ai_protocol = 0;

      const int res = ::getaddrinfo(address.c_str(), port.c_str(), &hints, &addr_res);

      if (res != 0)
        {
          log_warning("getaddrinfo failed: "s + gai_strerror(res));
          this->hostname_resolution_failed = true;
          this->close();
          this->on_connection_failed(gai_strerror(res));
          return ;
        }
      // Make sure the alloced structure is always freed at the end of the
      // function
      sg.add_callback([&addr_res](){ freeaddrinfo(addr_res); });
#endif
    }
  else
    { // This function is called again, use the saved addrinfo structure,


@@ 335,30 300,18 @@ void TCPSocketHandler::close()
    }
  this->connected = false;
  this->connecting = false;
#ifdef CARES_FOUND
  this->resolving = false;
  this->resolved = false;
  this->resolved4 = false;
  this->resolved6 = false;
  this->free_cares_addrinfo();
  this->cares_error.clear();
#endif
  this->in_buf.clear();
  this->out_buf.clear();
  this->port.clear();
  this->resolver.clear();
}

void TCPSocketHandler::display_resolved_ip(struct addrinfo* rp) const
{
  char buf[INET6_ADDRSTRLEN];
  if (rp->ai_family == AF_INET)
    log_debug("Connecting to IP address " << ::inet_ntop(rp->ai_family,
              &reinterpret_cast<sockaddr_in*>(rp->ai_addr)->sin_addr,
                                                         buf, sizeof(buf)));
    log_debug("Trying IPv4 address " << addr_to_string(rp));
  else if (rp->ai_family == AF_INET6)
    log_debug("Connecting to IPv6 address " << ::inet_ntop(rp->ai_family,
              &reinterpret_cast<sockaddr_in6*>(rp->ai_addr)->sin6_addr,
                                                           buf, sizeof(buf)));
    log_debug("Trying IPv6 address " << addr_to_string(rp));
}

void TCPSocketHandler::send_data(std::string&& data)


@@ 399,11 352,7 @@ bool TCPSocketHandler::is_connected() const

bool TCPSocketHandler::is_connecting() const
{
#ifdef CARES_FOUND
  return this->connecting || this->resolving;
#else
  return this->connecting;
#endif
  return this->connecting || this->resolver.is_resolving();
}

void* TCPSocketHandler::get_receive_buffer(const size_t) const


@@ 506,122 455,11 @@ void TCPSocketHandler::on_tls_activated()
}

void Permissive_Credentials_Manager::verify_certificate_chain(const std::string& type,
                                                const std::string& purported_hostname,
                                                const std::vector<Botan::X509_Certificate>&)
                                                              const std::string& purported_hostname,
                                                              const std::vector<Botan::X509_Certificate>&)
{ // TODO: Offer the admin to disallow connection on untrusted
  // certificates
  log_debug("Checking remote certificate (" << type << ") for hostname " << purported_hostname);
}

#endif // BOTAN_FOUND

#ifdef CARES_FOUND

void TCPSocketHandler::on_hostname4_resolved(int status, struct hostent* hostent)
{
  this->resolved4 = true;
  if (status == ARES_SUCCESS)
    this->fill_ares_addrinfo4(hostent);
  else
    this->cares_error = ::ares_strerror(status);

  if (this->resolved4 && this->resolved6)
    {
      this->resolved = true;
      this->resolving = false;
      this->connect();
    }
}

void TCPSocketHandler::on_hostname6_resolved(int status, struct hostent* hostent)
{
  this->resolved6 = true;
  if (status == ARES_SUCCESS)
    this->fill_ares_addrinfo6(hostent);
  else
    this->cares_error = ::ares_strerror(status);

  if (this->resolved4 && this->resolved6)
    {
      this->resolved = true;
      this->resolving = false;
      this->connect();
    }
}

void TCPSocketHandler::fill_ares_addrinfo4(const struct hostent* hostent)
{
  struct addrinfo* prev = this->cares_addrinfo;
  struct in_addr** address = reinterpret_cast<struct in_addr**>(hostent->h_addr_list);

  while (*address)
    {
       // Create a new addrinfo list element, and fill it
      struct addrinfo* current = new struct addrinfo;
      current->ai_flags = 0;
      current->ai_family = hostent->h_addrtype;
      current->ai_socktype = SOCK_STREAM;
      current->ai_protocol = 0;
      current->ai_addrlen = sizeof(struct sockaddr_in);

      struct sockaddr_in* addr = new struct sockaddr_in;
      addr->sin_family = hostent->h_addrtype;
      addr->sin_port = htons(strtoul(this->port.data(), nullptr, 10));
      addr->sin_addr.s_addr = (*address)->s_addr;

      current->ai_addr = reinterpret_cast<struct sockaddr*>(addr);
      current->ai_next = nullptr;
      current->ai_canonname = nullptr;

      current->ai_next = prev;
      this->cares_addrinfo = current;
      prev = current;
      ++address;
    }
}

void TCPSocketHandler::fill_ares_addrinfo6(const struct hostent* hostent)
{
  struct addrinfo* prev = this->cares_addrinfo;
  struct in6_addr** address = reinterpret_cast<struct in6_addr**>(hostent->h_addr_list);

  while (*address)
    {
       // Create a new addrinfo list element, and fill it
      struct addrinfo* current = new struct addrinfo;
      current->ai_flags = 0;
      current->ai_family = hostent->h_addrtype;
      current->ai_socktype = SOCK_STREAM;
      current->ai_protocol = 0;
      current->ai_addrlen = sizeof(struct sockaddr_in6);

      struct sockaddr_in6* addr = new struct sockaddr_in6;
      addr->sin6_family = hostent->h_addrtype;
      addr->sin6_port = htons(strtoul(this->port.data(), nullptr, 10));
      ::memcpy(addr->sin6_addr.s6_addr, (*address)->s6_addr, 16);
      addr->sin6_flowinfo = 0;
      addr->sin6_scope_id = 0;

      current->ai_addr = reinterpret_cast<struct sockaddr*>(addr);
      current->ai_next = nullptr;
      current->ai_canonname = nullptr;

      current->ai_next = prev;
      this->cares_addrinfo = current;
      prev = current;
      ++address;
    }
}

void TCPSocketHandler::free_cares_addrinfo()
{
  while (this->cares_addrinfo)
    {
      delete this->cares_addrinfo->ai_addr;
      auto next = this->cares_addrinfo->ai_next;
      delete this->cares_addrinfo;
      this->cares_addrinfo = next;
    }
}

#endif  // CARES_FOUND

M louloulibs/network/tcp_socket_handler.hpp => louloulibs/network/tcp_socket_handler.hpp +9 -40
@@ 2,6 2,7 @@
# define SOCKET_HANDLER_INCLUDED

#include <network/socket_handler.hpp>
#include <network/resolver.hpp>

#include <sys/types.h>
#include <sys/socket.h>


@@ 14,10 15,6 @@

#include "louloulibs.h"

#ifdef CARES_FOUND
# include <ares.h>
#endif

#ifdef BOTAN_FOUND
# include <botan/botan.h>
# include <botan/tls_client.h>


@@ 43,7 40,7 @@ public:
class TCPSocketHandler: public SocketHandler
{
protected:
  ~TCPSocketHandler();
  ~TCPSocketHandler() = default;

public:
  explicit TCPSocketHandler(std::shared_ptr<Poller> poller);


@@ 109,16 106,6 @@ public:
  bool is_connected() const override final;
  bool is_connecting() const;

#ifdef CARES_FOUND
  void on_hostname4_resolved(int status, struct hostent* hostent);
  void on_hostname6_resolved(int status, struct hostent* hostent);

  void free_cares_addrinfo();

  void fill_ares_addrinfo4(const struct hostent* hostent);
  void fill_ares_addrinfo6(const struct hostent* hostent);
#endif

private:
  /**
   * Initialize the socket with the parameters contained in the given


@@ 194,9 181,13 @@ private:
   */
  std::list<std::string> out_buf;
  /**
   * Keep the details of the addrinfo that triggered a EINPROGRESS error when
   * connect()ing to it, to reuse it directly when connect() is called
   * again.
   * 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;


@@ 234,28 225,6 @@ protected:
  bool connected;
  bool connecting;

#ifdef CARES_FOUND
  bool resolving;
  /**
   * Whether or not the DNS resolution was successfully done
   */
  bool resolved;
  bool resolved4;
  bool resolved6;
  /**
   * When using c-ares to resolve the host asynchronously, we need the
   * c-ares callback to fill a structure (a struct addrinfo, for
   * compatibility with getaddrinfo and the rest of the code that works when
   * c-ares is not used) with all returned values (for example an IPv6 and
   * an IPv4). The next call of connect() will then try all these values
   * (exactly like we do with the result of getaddrinfo) and save the one
   * that worked (or returned EINPROGRESS) in the other struct addrinfo (see
   * the members addrinfo, ai_addrlen, and ai_addr).
   */
  struct addrinfo* cares_addrinfo;
  std::string cares_error;
#endif  // CARES_FOUND

  bool hostname_resolution_failed;

private:

M src/test.cpp => src/test.cpp +80 -0
@@ 3,10 3,13 @@
 */

#include <xmpp/xmpp_component.hpp>
#include <network/dns_handler.hpp>
#include <utils/timed_events.hpp>
#include <database/database.hpp>
#include <xmpp/xmpp_parser.hpp>
#include <network/resolver.hpp>
#include <utils/encoding.hpp>
#include <network/poller.hpp>
#include <logger/logger.hpp>
#include <config/config.hpp>
#include <bridge/colors.hpp>


@@ 462,7 465,84 @@ int main()
    res = xdg_data_path("bonjour.txt");
    std::cout << res << std::endl;
    assert(res == "/datadir/biboumi/bonjour.txt");
  }


  {
    std::cout << color << "Testing the DNS resolver…" << reset << std::endl;

    Resolver resolver;

    /**
     * If we are using cares, we need to run a poller loop until each
     * resolution is finished. Without cares we get the result before
     * resolve() returns because it’s blocking.
     */
#ifdef CARES_FOUND
    auto p = std::make_shared<Poller>();

    const auto loop = [&p]()
      {
        do
          {
            DNSHandler::instance.watch_dns_sockets(p);
          }
        while (p->poll(utils::no_timeout) != -1);
      };
#else
    // We don’t need to do anything if we are not using cares.
    const auto loop = [](){};
#endif

    std::string hostname;
    std::string port = "6667";

    bool success = true;

    auto error_cb = [&success, &hostname, &port](const char* msg)
      {
        std::cout << "Failed to resolve " << hostname << ":" << port << ": " << msg << std::endl;
        success = false;
      };
    auto success_cb = [&success, &hostname, &port](const struct addrinfo* addr)
      {
        std::cout << "Successfully resolved " << hostname << ":" << port << ": " << addr_to_string(addr) << std::endl;
        success = true;
      };

    hostname = "example.com";
    resolver.resolve(hostname, port,
                     success_cb, error_cb);
    loop();
    assert(success);

    hostname = "this.should.fail.because.it.is..misformatted";
    resolver.resolve(hostname, port,
                     success_cb, error_cb);
    loop();
    assert(!success);

    hostname = "this.should.fail.because.it.is.does.not.exist.invalid";
    resolver.resolve(hostname, port,
                     success_cb, error_cb);
    loop();
    assert(!success);

    hostname = "localhost6";
    resolver.resolve(hostname, port,
                     success_cb, error_cb);
    loop();
    assert(success);

    hostname = "localhost";
    resolver.resolve(hostname, port,
                     success_cb, error_cb);
    loop();
    assert(success);

#ifdef CARES_FOUND
    DNSHandler::instance.destroy();
#endif
  }

  return 0;