[Kde-games-devel] KBattleship network protocol reveals ship types

[Stephen McCamant]

>>>>> "AAC" == Albert Astals Cid <aacid at kde.org> writes:

AAC> A Dijous 16 Març 2006 00:05, Stephen McCamant va escriure:

SMcC> While looking at the protocol that KBattleship uses for network
SMcC> games, I noticed an unexpected feature: in the ANSWER_SHOOT
SMcC> message that tells the opponent whether their shot was a hit or
SMcC> a miss, the client actually reveals some extra
SMcC> information. Because the "fieldstate" field of the message is
SMcC> taken directly from the return value of the shipTypeAt() method,
SMcC> it also reveals the type of ship that the shot hit. [...]

AAC> It would be nice if you could provide that patch yes.

I've appended a patch against the latest 3.5-branch version from SVN
to the end of this message.

AAC> P.S: I hope you are not trying to donwload SVN trunk (that will
AAC> be KDE 4.0 but branches/3.5) so we can fix that for KDE 3.5.3 and
AAC> so on.

I actually did try the trunk first, but had some trouble compiling
because of the klistview -> k3listview transition. That's fixed now,
though, and kbattleship doesn't appear to have changed too much in the
trunk, so I could also supply a patch against that pretty easily as
well.

 -- Stephen

Index: kbattleship/kbattleship/kbattleship.cpp
===================================================================
--- kbattleship/kbattleship/kbattleship.cpp	(revision 521181)
+++ kbattleship/kbattleship/kbattleship.cpp	(working copy)
@@ -922,7 +922,7 @@
 void KBattleshipWindow::slotSendEnemyFieldState(int fieldx, int fieldy)
 {
 	int data, showstate;
-	bool xokay = false, yokay = false;
+	bool xokay = false, yokay = false, is_kill = false;
 	typedef QValueList<int> DeathValueList;
 	DeathValueList deathList;
 
@@ -987,12 +987,12 @@
 			msg->addField(QString("ystart"), QString::number(fieldy));
 			msg->addField(QString("ystop"), QString::number(fieldy));
 			msg->addField(QString("death"), QString("true"));
+			is_kill = true;
 		}
 	}
 
 	msg->addField(QString("fieldx"), QString::number(fieldx));
 	msg->addField(QString("fieldy"), QString::number(fieldy));
-	msg->addField(QString("fieldstate"), QString::number(data));
 
 	if(xokay)
 	{
@@ -1001,6 +1001,7 @@
 		msg->addField(QString("ystart"), QString::number(fieldy));
 		msg->addField(QString("ystop"), QString::number(fieldy));
 		msg->addField(QString("death"), QString("true"));
+		is_kill = true;
 	}
 	else if(yokay)
 	{
@@ -1009,8 +1010,19 @@
 		msg->addField(QString("ystart"), QString::number(deathList.first()));
 		msg->addField(QString("ystop"), QString::number(deathList.last()));
 		msg->addField(QString("death"), QString("true"));
+		is_kill = true;
 	}
 
+	if(is_kill)
+		// If sunk, reveal ship type
+		msg->addField(QString("fieldstate"), QString::number(data));
+	else if(showstate == KBattleField::HIT)
+		// On non-fatal hit, keep ship type secret
+		msg->addField(QString("fieldstate"), QString::number(1));
+	else /* showstate == KBattleField::WATER */
+		// Miss
+		msg->addField(QString("fieldstate"), QString::number(99));
+
 	if(m_connection->type() == KonnectionHandling::SERVER)
 		m_kbserver->sendMessage(msg);
 	else