From 916f6efae62305796e012e7c3a7884a267cbacbf Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Wed, 17 Apr 2019 02:17:23 +0200 Subject: netfilter: never get/set skb->tstamp setting net.netfilter.nf_conntrack_timestamp=1 breaks xmit with fq scheduler. skb->tstamp might be "refreshed" using ktime_get_real(), but fq expects CLOCK_MONOTONIC. This patch removes all places in netfilter that check/set skb->tstamp: 1. To fix the bogus "start" time seen with conntrack timestamping for outgoing packets, never use skb->tstamp and always use current time. 2. In nfqueue and nflog, only use skb->tstamp for incoming packets, as determined by current hook (prerouting, input, forward). 3. xt_time has to use system clock as well rather than skb->tstamp. We could still use skb->tstamp for prerouting/input/foward, but I see no advantage to make this conditional. Fixes: fb420d5d91c1 ("tcp/fq: move back to CLOCK_MONOTONIC") Cc: Eric Dumazet Reported-by: Michal Soltys Signed-off-by: Florian Westphal Acked-by: Eric Dumazet Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_core.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'net/netfilter/nf_conntrack_core.c') diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 3c48d44d6fff..2a714527cde1 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1017,12 +1017,9 @@ __nf_conntrack_confirm(struct sk_buff *skb) /* set conntrack timestamp, if enabled. */ tstamp = nf_conn_tstamp_find(ct); - if (tstamp) { - if (skb->tstamp == 0) - __net_timestamp(skb); + if (tstamp) + tstamp->start = ktime_get_real_ns(); - tstamp->start = ktime_to_ns(skb->tstamp); - } /* Since the lookup is lockless, hash insertion must be done after * starting the timer and setting the CONFIRMED bit. The RCU barriers * guarantee that no other CPU can find the conntrack before the above -- cgit v1.2.3-55-g7522