Implement the PING on a server or the gateway itself

fix #2575

CHANGELOG

+Version 2.0
+- Support PING requests in all directions
+
 Version 1.1                                             2014-16-07
 
  - Fix a segmentation fault when connecting to an IRC server using IPv6

src/bridge/bridge.cpp

@@ -355,6 +355,17 @@ void Bridge::send_irc_participant_ping_request(const Iid& iid, const std::string
   this->send_irc_user_ping_request(iid.get_server(), nick, iq_id, to_jid, from_jid);
 }
 
+void Bridge::on_gateway_ping(const std::string& irc_hostname, const std::string& iq_id, const std::string& to_jid,
+                             const std::string& from_jid)
+{
+  Jid jid(from_jid);
+  if (irc_hostname.empty() || this->get_irc_client(irc_hostname))
+    this->xmpp->send_iq_result(iq_id, to_jid, jid.local);
+  else
+    this->xmpp->send_stanza_error("iq", to_jid, from_jid, iq_id, "cancel", "service-unavailable",
+                                  "", true);
+}
+
 void Bridge::send_irc_version_request(const std::string& irc_hostname, const std::string& target,
                                       const std::string& iq_id, const std::string& to_jid,
                                       const std::string& from_jid)

src/bridge/bridge.hpp

@@ -85,6 +85,12 @@ public:
   void send_irc_participant_ping_request(const Iid& iid, const std::string& nick,
                                          const std::string& iq_id, const std::string& to_jid,
                                          const std::string& from_jid);
+  /**
+   * Directly send back a result if it's a gateway ping or if we are
+   * connected to the given IRC server, an error otherwise.
+   */
+  void on_gateway_ping(const std::string& irc_hostname, const std::string& iq_id, const std::string& to_jid,
+                       const std::string& from_jid);
 
   /***
    **

src/xmpp/xmpp_component.cpp

@@ -568,6 +568,11 @@ void XmppComponent::handle_iq(const Stanza& stanza)
               bridge->send_irc_participant_ping_request(iid,
                                                         to.resource, id, from, to_str);
             }
+          else
+            { // Ping a channel, a server or the gateway itself
+              bridge->on_gateway_ping(iid.get_server(),
+                                     id, from, to_str);
+            }
           stanza_error.disable();
         }
     }