act_mirred: clear skb->tstamp on redirect

If sch_fq is used at ingress, skbs that might have been
timestamped by net_timestamp_set() if a packet capture
is requesting timestamps could be delayed by arbitrary
amount of time, since sch_fq time base is MONOTONIC.

Fix this problem by moving code from sch_netem.c to act_mirred.c.

Fixes: fb420d5d91c1 ("tcp/fq: move back to CLOCK_MONOTONIC")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 2 insertions, 10 deletions

diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c
index 1dae5f2b358f..c8cf4d10c435 100644
--- a/net/sched/act_mirred.c
+++ b/net/sched/act_mirred.c
@@ -258,7 +258,8 @@ static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a,
         if (is_redirect) {
                 skb2->tc_redirected = 1;
                 skb2->tc_from_ingress = skb2->tc_at_ingress;
-
+                if (skb2->tc_from_ingress)
+                        skb2->tstamp = 0;
                 /* let's the caller reinsert the packet, if possible */
                 if (use_reinsert) {
                         res->ingress = want_ingress;
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 57b3ad9394ad..2c38e3d07924 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -648,15 +648,6 @@ deliver:
                          */
                         skb->dev = qdisc_dev(sch);
 
-#ifdef CONFIG_NET_CLS_ACT
-                        /*
-                         * If it's at ingress let's pretend the delay is
-                         * from the network (tstamp will be updated).
-                         */
-                        if (skb->tc_redirected && skb->tc_from_ingress)
-                                skb->tstamp = 0;
-#endif
-
                         if (q->slot.slot_next) {
                                 q->slot.packets_left--;
                                 q->slot.bytes_left -= qdisc_pkt_len(skb);