Allow to override the addresses used to connect to an IRC network

fix #3273

CHANGELOG.rst

@@ -4,6 +4,9 @@ Version 8.0
 - Add a complete='true' in MAM’s iq result when appropriate
 - The “virtual” channel with an empty name (for example
   %irc.freenode.net@biboumi) has been entirely removed.
+- Add an “Address” field in the servers’ configure form. This lets
+  the user customize the address to use when connecting to a server.
+  See https://lab.louiz.org/louiz/biboumi/issues/3273 for more details.
 
 Version 7.2 - 2018-01-24
 ========================

doc/biboumi.1.rst

@@ -621,6 +621,17 @@ On a server JID (e.g on the JID chat.freenode.org@biboumi.example.com)
 - configure: Lets each user configure some options that applies to the
   concerned IRC server.  The provided configuration form contains these
   fields:
+
+    * Address: This address (IPv4, IPv6 or hostname) will be used, when
+      biboumi connects to this server. This is a very handy way to have a
+      custom name for a network, and be able to edit the address to use
+      if one endpoint for that server is dead, but continue using the same
+      JID. For example, a user could configure the server
+      “freenode@biboumi.example.com”, set “chat.freenode.net” in its
+      “Address” field, and then they would be able to user “freenode” as
+      the network name forever: if “chat.freenode.net” breaks for some
+      reason, it can be changed to “irc.freenode.org” instead, and the user
+      would not need to change all their bookmarks and settings.
     * Realname: The customized “real name” as it will appear on the
       user’s whois. This option is not available if biboumi is configured
       with realname_customization to false.

src/database/database.hpp

@@ -84,6 +84,7 @@ class Database
 
   struct RemoteJid: Column<std::string> { static constexpr auto name = "remote"; };
 
+  struct Address: Column<std::string> { static constexpr auto name = "hostname_"; };
 
   using MucLogLineTable = Table<Id, Uuid, Owner, IrcChanName, IrcServerName, Date, Body, Nick>;
   using MucLogLine = MucLogLineTable::RowType;
@@ -91,7 +92,7 @@ class Database
   using GlobalOptionsTable = Table<Id, Owner, MaxHistoryLength, RecordHistory, GlobalPersistent>;
   using GlobalOptions = GlobalOptionsTable::RowType;
 
-  using IrcServerOptionsTable = Table<Id, Owner, Server, Pass, AfterConnectionCommand, TlsPorts, Ports, Username, Realname, VerifyCert, TrustedFingerprint, EncodingOut, EncodingIn, MaxHistoryLength>;
+  using IrcServerOptionsTable = Table<Id, Owner, Server, Pass, AfterConnectionCommand, TlsPorts, Ports, Username, Realname, VerifyCert, TrustedFingerprint, EncodingOut, EncodingIn, MaxHistoryLength, Address>;
   using IrcServerOptions = IrcServerOptionsTable::RowType;
 
   using IrcChannelOptionsTable = Table<Id, Owner, Server, Channel, EncodingOut, EncodingIn, MaxHistoryLength, Persistent, RecordHistoryOptional>;

src/irc/irc_client.cpp

@@ -186,20 +186,22 @@ void IrcClient::start()
   bool tls;
   std::tie(port, tls) = this->ports_to_try.top();
   this->ports_to_try.pop();
-  this->bridge.send_xmpp_message(this->hostname, "", "Connecting to " +
-                                  this->hostname + ":" + port + " (" +
-                                  (tls ? "encrypted" : "not encrypted") + ")");
-
   this->bind_addr = Config::get("outgoing_bind", "");
+  std::string address = this->hostname;
 
-#ifdef BOTAN_FOUND
 #ifdef USE_DATABASE
   auto options = Database::get_irc_server_options(this->bridge.get_bare_jid(),
                                                   this->get_hostname());
+# ifdef BOTAN_FOUND
   this->credential_manager.set_trusted_fingerprint(options.col<Database::TrustedFingerprint>());
 # endif
+  if (!options.col<Database::Address>().empty())
+    address = options.col<Database::Address>();
 #endif
-  this->connect(this->hostname, port, tls);
+  this->bridge.send_xmpp_message(this->hostname, "", "Connecting to " +
+                                  address + ":" + port + " (" +
+                                  (tls ? "encrypted" : "not encrypted") + ")");
+  this->connect(address, port, tls);
 }
 
 void IrcClient::on_connection_failed(const std::string& reason)

src/xmpp/biboumi_adhoc_commands.cpp

@@ -227,6 +227,19 @@ void ConfigureIrcServerStep1(XmppComponent&, AdhocSession& session, XmlNode& com
   XmlSubNode instructions(x, "instructions");
   instructions.set_inner("Edit the form, to configure the settings of the IRC server " + server_domain);
 
+  {
+    XmlSubNode hostname(x, "field");
+    hostname["var"] = "hostname";
+    hostname["type"] = "text-single";
+    hostname["label"] = "Address";
+    hostname["desc"] = "The hostname (or IP) to connect to.";
+    XmlSubNode value(hostname, "value");
+    if (options.col<Database::Address>().empty())
+      value.set_inner(server_domain);
+    else
+      value.set_inner(options.col<Database::Address>());
+  }
+
   {
     XmlSubNode ports(x, "field");
     ports["var"] = "ports";
@@ -375,6 +388,11 @@ void ConfigureIrcServerStep2(XmppComponent&, AdhocSession& session, XmlNode& com
         {
           const XmlNode* value = field->get_child("value", "jabber:x:data");
           const std::vector<const XmlNode*> values = field->get_children("value", "jabber:x:data");
+
+          if (field->get_tag("var") == "hostname")
+            {
+              options.col<Database::Address>() = value->get_inner();
+            }
           if (field->get_tag("var") == "ports")
             {
               std::string ports;