From: Davide Caratti dcaratti@redhat.com
[ Upstream commit d2126838050ccd1dadf310ffb78b2204f3b032b9 ]
the following command:
# tc filter add dev $h2 ingress protocol ip pref 1 handle 101 flower \ $tcflags dst_ip 192.0.2.2 ip_ttl 63 action drop
doesn't drop all IPv4 packets that match the configured TTL / destination address. In particular, if "fragment offset" or "more fragments" have non zero value in the IPv4 header, setting of FLOW_DISSECTOR_KEY_IP is simply ignored. Fix this dissecting IPv4 TTL and TOS before fragment info; while at it, add a selftest for tc flower's match on 'ip_ttl' that verifies the correct behavior.
Fixes: 518d8a2e9bad ("net/flow_dissector: add support for dissection of misc ip header fields") Reported-by: Shuang Li shuali@redhat.com Signed-off-by: Davide Caratti dcaratti@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/flow_dissector.c | 6 +-- .../selftests/net/forwarding/tc_flower.sh | 38 ++++++++++++++++++- 2 files changed, 40 insertions(+), 4 deletions(-)
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 7a06d4301617..180be5102efc 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -1050,6 +1050,9 @@ proto_again: key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; }
+ __skb_flow_dissect_ipv4(skb, flow_dissector, + target_container, data, iph); + if (ip_is_fragment(iph)) { key_control->flags |= FLOW_DIS_IS_FRAGMENT;
@@ -1066,9 +1069,6 @@ proto_again: } }
- __skb_flow_dissect_ipv4(skb, flow_dissector, - target_container, data, iph); - break; } case htons(ETH_P_IPV6): { diff --git a/tools/testing/selftests/net/forwarding/tc_flower.sh b/tools/testing/selftests/net/forwarding/tc_flower.sh index 058c746ee300..b11d8e6b5bc1 100755 --- a/tools/testing/selftests/net/forwarding/tc_flower.sh +++ b/tools/testing/selftests/net/forwarding/tc_flower.sh @@ -3,7 +3,7 @@
ALL_TESTS="match_dst_mac_test match_src_mac_test match_dst_ip_test \ match_src_ip_test match_ip_flags_test match_pcp_test match_vlan_test \ - match_ip_tos_test match_indev_test" + match_ip_tos_test match_indev_test match_ip_ttl_test" NUM_NETIFS=2 source tc_common.sh source lib.sh @@ -310,6 +310,42 @@ match_ip_tos_test() log_test "ip_tos match ($tcflags)" }
+match_ip_ttl_test() +{ + RET=0 + + tc filter add dev $h2 ingress protocol ip pref 1 handle 101 flower \ + $tcflags dst_ip 192.0.2.2 ip_ttl 63 action drop + tc filter add dev $h2 ingress protocol ip pref 2 handle 102 flower \ + $tcflags dst_ip 192.0.2.2 action drop + + $MZ $h1 -c 1 -p 64 -a $h1mac -b $h2mac -A 192.0.2.1 -B 192.0.2.2 \ + -t ip "ttl=63" -q + + $MZ $h1 -c 1 -p 64 -a $h1mac -b $h2mac -A 192.0.2.1 -B 192.0.2.2 \ + -t ip "ttl=63,mf,frag=256" -q + + tc_check_packets "dev $h2 ingress" 102 1 + check_fail $? "Matched on the wrong filter (no check on ttl)" + + tc_check_packets "dev $h2 ingress" 101 2 + check_err $? "Did not match on correct filter (ttl=63)" + + $MZ $h1 -c 1 -p 64 -a $h1mac -b $h2mac -A 192.0.2.1 -B 192.0.2.2 \ + -t ip "ttl=255" -q + + tc_check_packets "dev $h2 ingress" 101 3 + check_fail $? "Matched on a wrong filter (ttl=63)" + + tc_check_packets "dev $h2 ingress" 102 1 + check_err $? "Did not match on correct filter (no check on ttl)" + + tc filter del dev $h2 ingress protocol ip pref 2 handle 102 flower + tc filter del dev $h2 ingress protocol ip pref 1 handle 101 flower + + log_test "ip_ttl match ($tcflags)" +} + match_indev_test() { RET=0