diff options
| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2021-10-25 11:26:49 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2021-11-01 09:28:54 +0100 |
| commit | b7b1d02fc43925a4d569ec221715db2dfa1ce4f5 (patch) | |
| tree | 220ebf78bc32a132b45e1634a39a3f7e75ba9539 /net/netfilter | |
| parent | 241eb3f3ee42f6639b31f6e69e7b6ea845e2d182 (diff) | |
netfilter: conntrack: set on IPS_ASSURED if flows enters internal stream state
The internal stream state sets the timeout to 120 seconds 2 seconds
after the creation of the flow, attach this internal stream state to the
IPS_ASSURED flag for consistent event reporting.
Before this patch:
[NEW] udp 17 30 src=10.246.11.13 dst=216.239.35.0 sport=37282 dport=123 [UNREPLIED] src=216.239.35.0 dst=10.246.11.13 sport=123 dport=37282
[UPDATE] udp 17 30 src=10.246.11.13 dst=216.239.35.0 sport=37282 dport=123 src=216.239.35.0 dst=10.246.11.13 sport=123 dport=37282
[UPDATE] udp 17 30 src=10.246.11.13 dst=216.239.35.0 sport=37282 dport=123 src=216.239.35.0 dst=10.246.11.13 sport=123 dport=37282 [ASSURED]
[DESTROY] udp 17 src=10.246.11.13 dst=216.239.35.0 sport=37282 dport=123 src=216.239.35.0 dst=10.246.11.13 sport=123 dport=37282 [ASSURED]
Note IPS_ASSURED for the flow not yet in the internal stream state.
after this update:
[NEW] udp 17 30 src=10.246.11.13 dst=216.239.35.0 sport=37282 dport=123 [UNREPLIED] src=216.239.35.0 dst=10.246.11.13 sport=123 dport=37282
[UPDATE] udp 17 30 src=10.246.11.13 dst=216.239.35.0 sport=37282 dport=123 src=216.239.35.0 dst=10.246.11.13 sport=123 dport=37282
[UPDATE] udp 17 120 src=10.246.11.13 dst=216.239.35.0 sport=37282 dport=123 src=216.239.35.0 dst=10.246.11.13 sport=123 dport=37282 [ASSURED]
[DESTROY] udp 17 src=10.246.11.13 dst=216.239.35.0 sport=37282 dport=123 src=216.239.35.0 dst=10.246.11.13 sport=123 dport=37282 [ASSURED]
Before this patch, short-lived UDP flows never entered IPS_ASSURED, so
they were already candidate flow to be deleted by early_drop under
stress.
Before this patch, IPS_ASSURED is set on regardless the internal stream
state, attach this internal stream state to IPS_ASSURED.
packet #1 (original direction) enters NEW state
packet #2 (reply direction) enters ESTABLISHED state, sets on IPS_SEEN_REPLY
paclet #3 (any direction) sets on IPS_ASSURED (if 2 seconds since the
creation has passed by).
Reported-by: Maciej Żenczykowski <zenczykowski@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter')
| -rw-r--r-- | net/netfilter/nf_conntrack_proto_udp.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/netfilter/nf_conntrack_proto_udp.c b/net/netfilter/nf_conntrack_proto_udp.c index f8e3c0d2602f..3b516cffc779 100644 --- a/net/netfilter/nf_conntrack_proto_udp.c +++ b/net/netfilter/nf_conntrack_proto_udp.c @@ -104,10 +104,13 @@ int nf_conntrack_udp_packet(struct nf_conn *ct, */ if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { unsigned long extra = timeouts[UDP_CT_UNREPLIED]; + bool stream = false; /* Still active after two seconds? Extend timeout. */ - if (time_after(jiffies, ct->proto.udp.stream_ts)) + if (time_after(jiffies, ct->proto.udp.stream_ts)) { extra = timeouts[UDP_CT_REPLIED]; + stream = true; + } nf_ct_refresh_acct(ct, ctinfo, skb, extra); @@ -116,7 +119,7 @@ int nf_conntrack_udp_packet(struct nf_conn *ct, return NF_ACCEPT; /* Also, more likely to be important, and not a probe */ - if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status)) + if (stream && !test_and_set_bit(IPS_ASSURED_BIT, &ct->status)) nf_conntrack_event_cache(IPCT_ASSURED, ct); } else { nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[UDP_CT_UNREPLIED]); |