Tweak freshclam ReceiveTimeout value for slow internet connections

apt install clamav on eoan brings in:
clamav clamav-base clamav-freshclam libclamav9 libltdl7 libtfm1

The freshclam daemon tries to download the databases right away:
Tue Mar 3 20:01:42 2020 -> freshclam daemon 0.102.2 (OS: linux-gnu, ARCH: x86_64, CPU: x86_64)
Tue Mar 3 20:01:42 2020 -> ClamAV update process started at Tue Mar 3 20:01:42 2020
Tue Mar 3 20:01:42 2020 -> daily database available for download (remote version: 25740)
Tue Mar 3 20:02:12 2020 -> WARNING: Download failed (28) Tue Mar 3 20:02:12 2020 -> WARNING: Message: Timeout was reached
Tue Mar 3 20:02:12 2020 -> WARNING: getcvd: Can't download daily.cvd from https://database.clamav.net/daily.cvd
Tue Mar 3 20:02:12 2020 -> Trying again in 5 secs...

While that is happening, clamscan won't work:
root@e1:~# clamcsc^C
root@e1:~# clamscan
LibClamAV Error: cli_loaddbdir(): No supported database files found in /var/lib/clamav
ERROR: Can't open file or directory

Which is expected.

It will keep trying. In my case, now it managed to download daily:
Tue Mar 3 20:03:11 2020 -> Testing database: '/var/lib/clamav/tmp.3f047/clamav-323978c4ffb272b6b680262710a2e099.tmp-daily.cvd' ...
Tue Mar 3 20:03:16 2020 -> Database test passed.
Tue Mar 3 20:03:16 2020 -> daily.cvd updated (version: 25740, sigs: 2204413, f-level: 63, builder: raynman)

And it's trying main again. That's a big file, over 100Mb in size. I believe that's why I'm getting timeouts, as I can't receive such a big file in 30s, which is the default ReceiveTimeout in /etc/clamav/freshclam.conf:

ReceiveTimeout 30

Once I updated that to 300s, and restarted the freshclam daemon, it fetched the main database just fine:

Tue Mar 3 20:08:15 2020 -> main database available for download (remote version: 59)
Tue Mar 3 20:10:09 2020 -> Testing database: '/var/lib/clamav/tmp.393b2/clamav-bcd674e3559e38c5a502dfe72b8bf48c.tmp-main.cvd' ...
Tue Mar 3 20:10:13 2020 -> Database test passed.
Tue Mar 3 20:10:13 2020 -> main.cvd updated (version: 59, sigs: 4564902, f-level: 60, builder: sigmgr)
Tue Mar 3 20:10:13 2020 -> bytecode database available for download (remote version: 331)
Tue Mar 3 20:10:15 2020 -> Testing database: '/var/lib/clamav/tmp.393b2/clamav-99166262d870f9b5d36574c18189bea1.tmp-bytecode.cvd' ...
Tue Mar 3 20:10:15 2020 -> Database test passed.
Tue Mar 3 20:10:15 2020 -> bytecode.cvd updated (version: 331, sigs: 94, f-level: 63, builder: anvilleg)
Tue Mar 3 20:10:15 2020 -> ERROR: NotifyClamd: Can't find or parse configuration file /etc/clamav/clamd.conf

The last error about NotifyClamd is also expected, since I didn't install the clamd daemon.

clamscan now works:
root@e1:~# clamscan
/root/.viminfo: OK
/root/.profile: OK
/root/.lesshst: OK
/root/.bashrc: OK

----------- SCAN SUMMARY -----------
Known viruses: 6759121
Engine version: 0.102.2
Scanned directories: 1
Scanned files: 4
Infected files: 0
Data scanned: 0.00 MB
Data read: 0.00 MB (ratio 0.00:1)
Time: 12.184 sec (0 m 12 s)

Regarding this bug then:
1) clamav-data should no longer be mentioned in d/control indeed, as this package doesn't exist anymore.
2) clamav-freshclam could be made a bit better by increasing the ReceiveTimeout, but by how much I'm...

Actually, looks like this was fixed already. The 30s ReceiveTimeout default value was being set in eoan's clamav-freshclam.postinst:

  [ -z "$ReceiveTimeout" ] && ReceiveTimeout=30

This was later changed to 0 in the package version 0.102.2+dfsg-1:
clamav (0.102.2+dfsg-1) unstable; urgency=medium

  * Import 0.102.2
    - CVE-2020-3123 (DoS may occur in the optional DLP feature)
      (Closes: 950944).
  * Update symbol file.
  * Set ReceiveTimeout to 0 which is upstream default.

Which is in Ubuntu Focal. Therefore, this bug is fixed in that upcoming release.

Would this be worth an SRU for eoan? Or is there one already planned? Looks like eoan-security has:

    0.102.2+dfsg-0ubuntu0.19.10.1