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Packet delay not respected in qscan.nse #1038
Description
There is a defect in how script qscan.nse implements script parameter qscan.delay. Specifically, it compares its value (which is in seconds) against an observed round-trip time (which is in microseconds).
The following patch remediates the issue. It also incidentally resolves #1037.
--- a/scripts/qscan.nse
+++ b/scripts/qscan.nse
@@ -484,12 +484,9 @@
-- Unlike qscan.cc which loops around while waiting for
-- the delay, I just sleep here (depending on rtt)
- if rtt < (3 * delay) / 2 then
- if rtt < (delay / 2) then
- stdnse.sleep(((delay / 2) + math.random(0, delay) - rtt))
- else
- stdnse.sleep(math.random((3 * delay) / 2 - rtt))
- end
+ local sleep = delay * (0.5 + math.random()) - rtt / 1000000
+ if sleep > 0 then
+ stdnse.sleep(sleep)
end
end
endPlease let me know if you have any questions or concerns. Otherwise I will commit the patch in a few weeks.
Activity
u0m3 commentedon Oct 17, 2017
An elegant solution! I am a bit curious as to why the original implementation was so convoluted, though...