MantisBT - Zandronum
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IDProjectCategoryView StatusDate SubmittedLast Update
0001638Zandronum[All Projects] Suggestionpublic2014-01-02 22:242014-03-30 20:38
ReporterAlienOverlord 
Assigned To 
PrioritylowSeveritytweakReproducibilityalways
StatusclosedResolutionnot fixable 
PlatformMicrosoftOSWindowsOS VersionXP/Vista/7
Product Version1.2 
Target Version1.3Fixed in Version 
Summary0001638: Rejection of invalid client pong responses
DescriptionSince the server is sending it's current millisecond time to the client, the client can then alter this time and send it back to the server, thus altering it's displayed ping. Although that doesn't really change anything gameplay-wise (other than teleportation reaction time, of course) I highly doubt that it's a valid approach to allow clients to manipulate anything at random will.

The suggestion itself: keep the log of last 30 ping requests, compare pong that comes from the client with what the server has sent, reject invalid responses.
Steps To Reproduce
Additional Information
TagsNo tags attached.
Relationships
related to 0001705closed Watermelon Gametic-based unlagged 
Attached Files
Issue History
Date ModifiedUsernameFieldChange
2014-01-02 22:24AlienOverlordNew Issue
2014-01-14 20:22LlewellynNote Added: 0008006
2014-01-14 21:31Konar6Note Added: 0008008
2014-02-10 22:41Jen0vaNote Added: 0008187
2014-02-10 22:43DuskAssigned To => Dusk
2014-02-10 22:43DuskStatusnew => assigned
2014-02-10 22:44DuskTarget Version => 1.3
2014-02-10 22:56Jen0vaNote Edited: 0008187bug_revision_view_page.php?bugnote_id=8187#r4487
2014-02-11 00:34DuskStatusassigned => needs review
2014-02-18 15:03DuskRelationship addedrelated to 0001705
2014-03-30 20:35DuskNote Added: 0008466
2014-03-30 20:35DuskStatusneeds review => closed
2014-03-30 20:35DuskAssigned ToDusk =>
2014-03-30 20:35DuskResolutionopen => not fixable
2014-03-30 20:38DuskNote Edited: 0008466bug_revision_view_page.php?bugnote_id=8466#r4591

Notes
(0008006)
Llewellyn   
2014-01-14 20:22   
So the server is supposed to ignore your responses if your ping spikes?
(0008008)
Konar6   
2014-01-14 21:31   
The server should calculate pings on its own by subtracting the client's pong reply delay. I thought this was the case. :o
(0008187)
Jen0va   
2014-02-10 22:41   
(edited on: 2014-02-10 22:56)
Setting my ping to 200 using a custom client gave me a pretty large advantage and let me almost land any shot (even ones that missed).

Just throwing this in there.

I should probably elaborate that I think around 200ms is kind of a sweet spot where you have a wider target because of unlagged.
(0008466)
Dusk   
2014-03-30 20:35   
(edited on: 2014-03-30 20:38)
The client can just spoof the ping anyway by delaying the ping response. Not much we can do here.