Quoting Stefan Hanreich (2024-05-29 15:25:26)
> When disabling the nftables firewall again, there is a race condition
> where the nftables ruleset never gets flushed and persists after
> disabling. In practice this almost never happens due to pve-firewall
> running every 10 seconds, and proxmox-firewall running every 5
> seconds, so the proxmox-firewall main loop almost always runs at least
> once before the force disable file gets created and flushes the
> ruleset.
so if I understand this correctly, it should handle the following case:
proxmox-firewall runs and sets up NFT rules
user disables NFT
pve-firewall runs and sets up legacy rules and force disable file
proxmox-firewall runs and disables NFT rules
as opposed to the following sequence
proxmox-firewall runs and sets up NFT rules
user disables NFT
proxmox-firewall runs and disables NFT rules
pve-firewall runs and sets up legacy rules and force disable file
which is already handled..
I don't see why the first cast should "almost never happen", just because the
loops have a different period - it all comes down to alignment of the periods
and timing of the user action?
in other words, you have a sequence
0: N
5: N
5+X: L
10: N
15: N
15+X: L
20: N
25: N
25+X: L
where the gap between N and N is 5 seconds, and the gap between N and L and L
and N together is also 5 seconds. on average (assuming random alignment of the
periods), there's an X=2.5s window (out of 10) that the user action must hit to
trigger the issue (in the gap between L and N, since X can be between 0 and
5s)?
FWIW, the change itself looks good to me, but the commit message might need
some adaptation ;)
>
> Reported-by: Hannes Laimer <h.lai...@proxmox.com>
> Signed-off-by: Stefan Hanreich <s.hanre...@proxmox.com>
> ---
> proxmox-firewall/src/bin/proxmox-firewall.rs | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/proxmox-firewall/src/bin/proxmox-firewall.rs
> b/proxmox-firewall/src/bin/proxmox-firewall.rs
> index f7e816e..5133cbf 100644
> --- a/proxmox-firewall/src/bin/proxmox-firewall.rs
> +++ b/proxmox-firewall/src/bin/proxmox-firewall.rs
> @@ -91,6 +91,10 @@ fn main() -> Result<(), std::io::Error> {
>
> while !term.load(Ordering::Relaxed) {
> if force_disable_flag.exists() {
> + if let Err(error) = remove_firewall() {
> + log::error!("unable to disable firewall: {error:#}");
> + }
> +
> std::thread::sleep(Duration::from_secs(5));
> continue;
> }
> --
> 2.39.2
>
>
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>
>
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