Implement PING, user to user only (XMPP and IRC side, using CTCP PING)

ref #2757

src/bridge/bridge.cpp

@@ -7,7 +7,9 @@
 #include <utils/encoding.hpp>
 #include <utils/tolower.hpp>
 #include <logger/logger.hpp>
+#include <utils/revstr.hpp>
 #include <utils/split.hpp>
+#include <xmpp/jid.hpp>
 #include <stdexcept>
 #include <iostream>
 #include <tuple>
@@ -280,6 +282,50 @@ void Bridge::send_xmpp_version_to_irc(const Iid& iid, const std::string& name, c
   this->send_private_message(iid, "\01VERSION "s + result + "\01", "NOTICE");
 }
 
+void Bridge::send_irc_ping_result(const Iid& iid, const std::string& id)
+{
+  this->send_private_message(iid, "\01PING "s + utils::revstr(id), "NOTICE");
+}
+
+void Bridge::send_irc_user_ping_request(const std::string& irc_hostname, const std::string& nick,
+                                        const std::string& iq_id, const std::string& to_jid,
+                                        const std::string& from_jid)
+{
+  Iid iid(nick + "!" + irc_hostname);
+  this->send_private_message(iid, "\01PING " + iq_id + "\01");
+
+  irc_responder_callback_t cb = [this, nick, iq_id, to_jid, irc_hostname, from_jid](const std::string& hostname, const IrcMessage& message) -> bool
+    {
+      if (irc_hostname != hostname)
+        return false;
+      IrcUser user(message.prefix);
+      const std::string body = message.arguments[1];
+      if (message.command == "NOTICE" && user.nick == nick &&
+          message.arguments.size() >= 2 && body.substr(0, 6) == "\01PING ")
+        {
+          const std::string id = body.substr(6, body.size() - 6);
+          if (id != iq_id)
+            return false;
+          Jid jid(from_jid);
+          this->xmpp->send_iq_result(iq_id, to_jid, jid.local);
+          return true;
+        }
+      if (message.command == "401" && message.arguments.size() >= 2
+          && message.arguments[1] == nick)
+        {
+          std::string error_message = "No such nick";
+          if (message.arguments.size() >= 3)
+            error_message = message.arguments[2];
+          this->xmpp->send_stanza_error("iq", to_jid, from_jid, iq_id, "cancel", "service-unavailable",
+                                        error_message, true);
+          return true;
+        }
+
+      return false;
+    };
+  this->add_waiting_irc(std::move(cb));
+}
+
 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)
@@ -437,6 +483,15 @@ void Bridge::send_iq_version_request(const std::string& nick, const std::string&
   this->xmpp->send_iq_version_request(nick + "!" + hostname, this->user_jid);
 }
 
+void Bridge::send_xmpp_ping_request(const std::string& nick, const std::string& hostname,
+                                    const std::string& id)
+{
+  // Use revstr because the forwarded ping to target XMPP user must not be
+  // the same that the request iq, but we also need to get it back easily
+  // (revstr again)
+  this->xmpp->send_ping_request(nick + "!" + hostname, this->user_jid, utils::revstr(id));
+}
+
 void Bridge::set_preferred_from_jid(const std::string& nick, const std::string& full_jid)
 {
   auto it = this->preferred_user_from.find(nick);

src/bridge/bridge.hpp

@@ -68,9 +68,16 @@ public:
   void set_channel_topic(const Iid& iid, const std::string& subject);
   void send_xmpp_version_to_irc(const Iid& iid, const std::string& name, const std::string& version,
                                 const std::string& os);
+  void send_irc_ping_result(const Iid& iid, const std::string& id);
   void 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);
+  /**
+   * Directly send a CTCP PING request to the IRC user
+   */
+  void send_irc_user_ping_request(const std::string& irc_hostname, const std::string& nick,
+                                  const std::string& iq_id, const std::string& to_jid,
+                                  const std::string& from_jid);
 
   /***
    **
@@ -128,7 +135,11 @@ public:
    * Send an iq version request coming from nick!hostname@
    */
   void send_iq_version_request(const std::string& nick, const std::string& hostname);
-
+  /**
+   * Send an iq ping request coming from nick!hostname@
+   */
+  void send_xmpp_ping_request(const std::string& nick, const std::string& hostname,
+                              const std::string& id);
   /**
    * Misc
    */

src/irc/irc_client.cpp

@@ -409,6 +409,9 @@ void IrcClient::on_channel_message(const IrcMessage& message)
                   "/me"s + body.substr(7, body.size() - 8), muc);
       else if (body.substr(1, 8) == "VERSION\01")
         this->bridge->send_iq_version_request(nick, this->hostname);
+      else if (body.substr(1, 5) == "PING ")
+        this->bridge->send_xmpp_ping_request(nick, this->hostname,
+                                             body.substr(6, body.size() - 7));
     }
   else
     this->bridge->send_message(iid, nick, body, muc);

src/xmpp/xmpp_component.cpp

@@ -555,6 +555,16 @@ void XmppComponent::handle_iq(const Stanza& stanza)
               stanza_error.disable();
             }
         }
+      else if ((query = stanza.get_child("ping", PING_NS)))
+        {
+          Iid iid(to.local);
+          if (iid.is_user)
+            { // Ping any user (no check on the nick done ourself)
+              bridge->send_irc_user_ping_request(iid.get_server(),
+                                                 iid.get_local(), id, from, to_str);
+            }
+          stanza_error.disable();
+        }
     }
   else if (type == "result")
     {
@@ -1080,6 +1090,36 @@ void XmppComponent::send_iq_version_request(const std::string& from,
   this->send_stanza(iq);
 }
 
+void XmppComponent::send_ping_request(const std::string& from,
+                                      const std::string& jid_to,
+                                      const std::string& id)
+{
+  Stanza iq("iq");
+  iq["type"] = "get";
+  iq["id"] = id;
+  iq["from"] = from + "@" + this->served_hostname;
+  iq["to"] = jid_to;
+  XmlNode ping("ping");
+  ping["xmlns"] = PING_NS;
+  ping.close();
+  iq.add_child(std::move(ping));
+  iq.close();
+  this->send_stanza(iq);
+
+  auto result_cb = [from, id](Bridge* bridge, const Stanza& stanza)
+    {
+      Jid to(stanza.get_tag("to"));
+      if (to.local != from)
+        {
+          log_error("Received a corresponding ping result, but the 'to' from "
+                    "the response mismatches the 'from' of the request");
+        }
+      else
+        bridge->send_irc_ping_result(from, id);
+    };
+  this->waiting_iq[id] = result_cb;
+}
+
 void XmppComponent::send_iq_result(const std::string& id, const std::string& to_jid, const std::string& from_local_part)
 {
   Stanza iq("iq");

src/xmpp/xmpp_component.hpp

@@ -24,6 +24,8 @@
 #define STREAMS_NS       "urn:ietf:params:xml:ns:xmpp-streams"
 #define VERSION_NS       "jabber:iq:version"
 #define ADHOC_NS         "http://jabber.org/protocol/commands"
+#define PING_NS          "urn:xmpp:ping"
+
 /**
  * A callback called when the waited iq result is received (it is matched
  * against the iq id)
@@ -216,6 +218,12 @@ public:
    */
   void send_iq_version_request(const std::string& from,
                                const std::string& jid_to);
+  /**
+   * Send a ping request
+   */
+  void send_ping_request(const std::string& from,
+                         const std::string& jid_to,
+                         const std::string& id);
   /**
    * Send an empty iq of type result
    */