A backfill runs for minutes or hours inside a queue worker, where none
of it is visible. The third tab polls every four seconds and says what
is happening: whether anything is running, how many uploads are held,
how deep the queue is, how many files were checked in the last hour,
and the last twenty verdicts with what each one was. When nothing is
running, that same list is the record of the last run, which is what
somebody opening the tab after the fact came for.
Two things the live screen found that the tests had not:
**A backfill read as "nothing is being scanned."** Re-scanning a file
that already went out unchecked deliberately leaves it available, so it
is never "pending" — and the screen counted only pending files. It
counts the scans queue too, and the two are shown separately, because
"an upload nobody can download yet" and "work the scanner has not
reached" are different facts.
**A file whose bytes are missing was recorded as "the scanner could not
be reached."** Wrong on screen, and worse than wrong in behaviour: that
is the one reason the hourly sweep re-queues, so every orphaned row
would have been rescanned every hour forever. It has its own reason
now, and goes through the same policy as a file the scanner could not
open.
Both tabs also gained the header shortcut to Quarantine, and Quarantine
one back to the settings, each shown only to somebody the destination
will actually let in.
Sharing a file that is still being checked writes the assignment and
says nothing. The announcement goes out when the file becomes
available — a clean scan, a file let through while the scanner was
down, or an administrator releasing it from quarantine — so nobody is
ever sent to a page that refuses them, and a file about to be
quarantined is not announced to everyone before anybody knows.
Recipients are derived from the assignments as they stand at that
moment, not remembered from the moment of sharing: a share taken back
in the meantime produces no email, and one added does. New-version
notices ride the same path, which they had to anyway — the audience
rule re-checks visibility, and a file being scanned is not visible.
Two bugs found while writing the tests, both in the hourly command:
Re-queuing a file marked it pending first. Pending means withheld, so
running --existing over a library that predates scanning would have
hidden every file in it from every client for as long as the backfill
ran, and then announced each one to its recipients a second time when
it came back. The job now knows which state it expects instead, and a
rescan leaves the file downloadable until a verdict actually arrives.
Every upload now starts as "being checked" and is not served to anyone
until a scanner has looked at it. Infected files are quarantined: kept
on disk, unreachable, waiting for an administrator.
The scanner is ClamAV, reached over a socket, streaming the file
wherever it is stored — no temporary copy for an S3 or GCS disk. What
the scanner answers is a fact; what it means for the file is this
installation's setting, so ClamAvScanner knows nothing about settings
and ScanPolicy knows nothing about sockets. Three of clamd's own alert
options are what make a file it could not open come back as an answer
rather than as "OK"; the client maps those to "too large" and
"encrypted" instead of to a threat.
Both policies default to letting files through, marked "not scanned",
which is the product owner's decision: a scanner that cannot answer must
not stop people working. Every such file is logged, and the screens that
say so come with the rest of this work.
Withholding is two rules. A file that is not available drops out of the
scopes that answer "what may this person see" — recipients and the
public listings, never the uploader's own copy. And every route that
puts bytes on the wire asks FileAvailability first: download, thumbnail,
preview, share link, the four public routes and both ends of a zip
build. A share link minted before the scan finishes says the file is
still being checked rather than 404ing.
Not yet here, and coming next: the quarantine screen and its permission,
the notifications, the settings screen, the hourly retry, the backfill
for existing libraries, and the Docker service.
ignacionelson