tree 4ce061f9d4f41f4c3508c7c3d499b837f2cf6b14
parent 6093ba47c0b940df7ba60943dfb0ae88de47c323
author Willy Tarreau <w@1wt.eu> 1675779761 +0100
committer Willy Tarreau <w@1wt.eu> 1675851033 +0100
encoding latin1

BUG/MEDIUM: cache: use the correct time reference when comparing dates

The cache makes use of dates advertised by external components, such
as "last-modified" or "date". As such these are wall-clock dates, and
not internal dates. However, all comparisons are mistakenly made based
on the internal monotonic date which is designed to drift from the wall
clock one in order to catch up with stolen time (which can sometimes be
intense in VMs). As such after some run time some objects may fail to
validate or fail to expire depending on the direction of the drift. This
is particularly visible when applying an offset to the internal time to
force it to wrap soon after startup, as it will be shifted up to 49.7
days in the future depending on the current date; what happens in this
case is that the reg-test "cache_expires.vtc" fails on the 3rd test by
returning stale contents from the cache at the date of this commit.

It is really important that all external dates are compared against
"date" and not "now" for this reason.

This fix needs to be backported to all versions.