Implement a basic webirc support

See https://kiwiirc.com/docs/webirc

fix #3135

doc/biboumi.1.md

@@ -96,6 +96,13 @@ The configuration file uses a simple format of the form
  username of each user will be set to the nick they used to connect to the
  IRC server.
 
+`webirc_password`
+
+ Configure a password to be communicated to the IRC server, as part of the
+ WEBIRC message (see https://kiwiirc.com/docs/webirc).  If this option is
+ set, an additional DNS resolution of the hostname of each XMPP server will
+ be made when connecting to an IRC server.
+
 `log_file`
 
   A filename into which logs are written.  If none is provided, the logs are

src/bridge/bridge.cpp

@@ -56,7 +56,8 @@ void Bridge::clean()
   while (it != this->irc_clients.end())
   {
     IrcClient* client = it->second.get();
-    if (!client->is_connected() && !client->is_connecting())
+    if (!client->is_connected() && !client->is_connecting() &&
+        !client->get_resolver().is_resolving())
       it = this->irc_clients.erase(it);
     else
       ++it;
@@ -94,16 +95,17 @@ IrcClient* Bridge::make_irc_client(const std::string& hostname, const std::strin
     {
       auto username = nickname;
       auto realname = nickname;
+      Jid jid(this->user_jid);
       if (Config::get("realname_from_jid", "false") == "true")
         {
-          Jid jid(this->user_jid);
           username = jid.local;
           realname = this->get_bare_jid();
         }
       this->irc_clients.emplace(hostname,
                                 std::make_shared<IrcClient>(this->poller, hostname,
                                                             nickname, username,
-                                                            realname, this));
+                                                            realname, jid.domain,
+                                                            this));
       std::shared_ptr<IrcClient> irc = this->irc_clients.at(hostname);
       return irc.get();
     }

src/irc/irc_client.cpp

@@ -26,9 +26,11 @@ using namespace std::chrono_literals;
 
 IrcClient::IrcClient(std::shared_ptr<Poller> poller, const std::string& hostname,
                      const std::string& nickname, const std::string& username,
-                     const std::string& realname, Bridge* bridge):
+                     const std::string& realname, const std::string& user_hostname,
+                     Bridge* bridge):
   TCPSocketHandler(poller),
   hostname(hostname),
+  user_hostname(user_hostname),
   username(username),
   realname(realname),
   current_nick(nickname),
@@ -113,6 +115,39 @@ void IrcClient::on_connection_failed(const std::string& reason)
 
 void IrcClient::on_connected()
 {
+  const auto webirc_password = Config::get("webirc_password", "");
+  static std::string resolved_ip;
+
+  if (!webirc_password.empty())
+    {
+      if (!resolved_ip.empty())
+        this->send_webirc_command(webirc_password, resolved_ip);
+      else
+        {  // Start resolving the hostname of the user, and call
+           // on_connected again when it’s done
+          this->dns_resolver.resolve(this->user_hostname, "5222",
+                                     [this](const struct addrinfo* addr)
+                                     {
+                                       resolved_ip = addr_to_string(addr);
+                                       // Only continue the process if we
+                                       // didn’t get connected while we were
+                                       // resolving
+                                       if (this->is_connected())
+                                         this->on_connected();
+                                     },
+                                     [this](const char* error_msg)
+                                     {
+                                       if (this->is_connected())
+                                         {
+                                           this->on_connection_close("Could not resolve hostname "s + this->user_hostname +
+                                                                     ": " + error_msg);
+                                           this->send_quit_command("");
+                                         }
+                                     });
+          return;
+        }
+    }
+
 #ifdef USE_DATABASE
   auto options = Database::get_irc_server_options(this->bridge->get_bare_jid(),
                                                   this->get_hostname());
@@ -253,7 +288,7 @@ void IrcClient::send_raw(const std::string& txt)
 
 void IrcClient::send_user_command(const std::string& username, const std::string& realname)
 {
-  this->send_message(IrcMessage("USER", {username, "ignored", "ignored", realname}));
+  this->send_message(IrcMessage("USER", {username, this->user_hostname, "ignored", realname}));
 }
 
 void IrcClient::send_nick_command(const std::string& nick)
@@ -266,6 +301,11 @@ void IrcClient::send_pass_command(const std::string& password)
   this->send_message(IrcMessage("PASS", {password}));
 }
 
+void IrcClient::send_webirc_command(const std::string& password, const std::string& user_ip)
+{
+  this->send_message(IrcMessage("WEBIRC", {password, "biboumi", this->user_hostname, user_ip}));
+}
+
 void IrcClient::send_kick_command(const std::string& chan_name, const std::string& target, const std::string& reason)
 {
   this->send_message(IrcMessage("KICK", {chan_name, target, reason}));

src/irc/irc_client.hpp

@@ -6,6 +6,7 @@
 #include <irc/iid.hpp>
 
 #include <network/tcp_socket_handler.hpp>
+#include <network/resolver.hpp>
 
 #include <unordered_map>
 #include <utility>
@@ -27,7 +28,8 @@ class IrcClient: public TCPSocketHandler
 public:
   explicit IrcClient(std::shared_ptr<Poller> poller, const std::string& hostname,
                      const std::string& nickname, const std::string& username,
-                     const std::string& realname, Bridge* bridge);
+                     const std::string& realname, const std::string& user_hostname,
+                     Bridge* bridge);
   ~IrcClient();
   /**
    * Connect to the IRC server
@@ -88,6 +90,7 @@ public:
    */
   void send_nick_command(const std::string& username);
   void send_pass_command(const std::string& password);
+  void send_webirc_command(const std::string& password, const std::string& user_ip);
   /**
    * Send the JOIN irc command.
    */
@@ -250,11 +253,18 @@ public:
   std::string get_nick() const { return this->current_nick; }
   bool is_welcomed() const { return this->welcomed; }
 
+  const Resolver& get_resolver() const;
+
 private:
   /**
    * The hostname of the server we are connected to.
    */
   const std::string hostname;
+  /**
+   * The hostname of the user.  This is used in the USER and the WEBIRC
+   * commands, but only the one in WEBIRC will be used by the IRC server.
+   */
+  const std::string user_hostname;
   /**
    * The username used in the USER irc command
    */
@@ -330,6 +340,11 @@ private:
    * A set of (lowercase) nicknames to which we sent a private message.
    */
   std::set<std::string> nicks_to_treat_as_private;
+  /**
+   * DNS resolver, used to resolve the hostname of the user if we are using
+   * the WebIRC protocole.
+   */
+  Resolver dns_resolver;
 
   IrcClient(const IrcClient&) = delete;
   IrcClient(IrcClient&&) = delete;