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act_mirred: use the backlog for nested calls to mirred ingress
[ Upstream commit ca22da2fbd
]
William reports kernel soft-lockups on some OVS topologies when TC mirred
egress->ingress action is hit by local TCP traffic [1].
The same can also be reproduced with SCTP (thanks Xin for verifying), when
client and server reach themselves through mirred egress to ingress, and
one of the two peers sends a "heartbeat" packet (from within a timer).
Enqueueing to backlog proved to fix this soft lockup; however, as Cong
noticed [2], we should preserve - when possible - the current mirred
behavior that counts as "overlimits" any eventual packet drop subsequent to
the mirred forwarding action [3]. A compromise solution might use the
backlog only when tcf_mirred_act() has a nest level greater than one:
change tcf_mirred_forward() accordingly.
Also, add a kselftest that can reproduce the lockup and verifies TC mirred
ability to account for further packet drops after TC mirred egress->ingress
(when the nest level is 1).
[1] https://lore.kernel.org/netdev/33dc43f587ec1388ba456b4915c75f02a8aae226.1663945716.git.dcaratti@redhat.com/
[2] https://lore.kernel.org/netdev/Y0w%2FWWY60gqrtGLp@pop-os.localdomain/
[3] such behavior is not guaranteed: for example, if RPS or skb RX
timestamping is enabled on the mirred target device, the kernel
can defer receiving the skb and return NET_RX_SUCCESS inside
tcf_mirred_forward().
Reported-by: William Zhao <wizhao@redhat.com>
CC: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
[DP: adjusted context for linux-5.10.y]
Signed-off-by: Dragos-Marian Panait <dragos.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
f5bf8e3ca1
commit
5324510378
2 changed files with 54 additions and 1 deletions
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@ -206,12 +206,19 @@ static int tcf_mirred_init(struct net *net, struct nlattr *nla,
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return err;
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}
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static bool is_mirred_nested(void)
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{
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return unlikely(__this_cpu_read(mirred_nest_level) > 1);
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}
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static int tcf_mirred_forward(bool want_ingress, struct sk_buff *skb)
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{
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int err;
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if (!want_ingress)
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err = dev_queue_xmit(skb);
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else if (is_mirred_nested())
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err = netif_rx(skb);
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else
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err = netif_receive_skb(skb);
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@ -3,7 +3,7 @@
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ALL_TESTS="gact_drop_and_ok_test mirred_egress_redirect_test \
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mirred_egress_mirror_test matchall_mirred_egress_mirror_test \
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gact_trap_test"
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gact_trap_test mirred_egress_to_ingress_tcp_test"
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NUM_NETIFS=4
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source tc_common.sh
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source lib.sh
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@ -153,6 +153,52 @@ gact_trap_test()
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log_test "trap ($tcflags)"
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}
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mirred_egress_to_ingress_tcp_test()
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{
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local tmpfile=$(mktemp) tmpfile1=$(mktemp)
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RET=0
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dd conv=sparse status=none if=/dev/zero bs=1M count=2 of=$tmpfile
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tc filter add dev $h1 protocol ip pref 100 handle 100 egress flower \
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$tcflags ip_proto tcp src_ip 192.0.2.1 dst_ip 192.0.2.2 \
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action ct commit nat src addr 192.0.2.2 pipe \
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action ct clear pipe \
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action ct commit nat dst addr 192.0.2.1 pipe \
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action ct clear pipe \
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action skbedit ptype host pipe \
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action mirred ingress redirect dev $h1
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tc filter add dev $h1 protocol ip pref 101 handle 101 egress flower \
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$tcflags ip_proto icmp \
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action mirred ingress redirect dev $h1
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tc filter add dev $h1 protocol ip pref 102 handle 102 ingress flower \
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ip_proto icmp \
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action drop
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ip vrf exec v$h1 nc --recv-only -w10 -l -p 12345 -o $tmpfile1 &
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local rpid=$!
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ip vrf exec v$h1 nc -w1 --send-only 192.0.2.2 12345 <$tmpfile
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wait -n $rpid
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cmp -s $tmpfile $tmpfile1
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check_err $? "server output check failed"
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$MZ $h1 -c 10 -p 64 -a $h1mac -b $h1mac -A 192.0.2.1 -B 192.0.2.1 \
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-t icmp "ping,id=42,seq=5" -q
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tc_check_packets "dev $h1 egress" 101 10
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check_err $? "didn't mirred redirect ICMP"
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tc_check_packets "dev $h1 ingress" 102 10
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check_err $? "didn't drop mirred ICMP"
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local overlimits=$(tc_rule_stats_get ${h1} 101 egress .overlimits)
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test ${overlimits} = 10
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check_err $? "wrong overlimits, expected 10 got ${overlimits}"
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tc filter del dev $h1 egress protocol ip pref 100 handle 100 flower
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tc filter del dev $h1 egress protocol ip pref 101 handle 101 flower
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tc filter del dev $h1 ingress protocol ip pref 102 handle 102 flower
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rm -f $tmpfile $tmpfile1
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log_test "mirred_egress_to_ingress_tcp ($tcflags)"
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}
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setup_prepare()
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{
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h1=${NETIFS[p1]}
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