selftests/bpf: bpf tunnel test.

The patch migrates the original tests at samples/bpf/tcbpf2_kern.c
and samples/bpf/test_tunnel_bpf.sh to selftests.  There are a couple
changes from the original:
    1) add ipv6 vxlan, ipv6 geneve, ipv6 ipip tests
    2) simplify the original ipip tests (remove iperf tests)
    3) improve documentation
    4) use bpf_ntoh* and bpf_hton* api

In summary, 'test_tunnel_kern.o' contains the following bpf program:
  GRE: gre_set_tunnel, gre_get_tunnel
  IP6GRE: ip6gretap_set_tunnel, ip6gretap_get_tunnel
  ERSPAN: erspan_set_tunnel, erspan_get_tunnel
  IP6ERSPAN: ip4ip6erspan_set_tunnel, ip4ip6erspan_get_tunnel
  VXLAN: vxlan_set_tunnel, vxlan_get_tunnel
  IP6VXLAN: ip6vxlan_set_tunnel, ip6vxlan_get_tunnel
  GENEVE: geneve_set_tunnel, geneve_get_tunnel
  IP6GENEVE: ip6geneve_set_tunnel, ip6geneve_get_tunnel
  IPIP: ipip_set_tunnel, ipip_get_tunnel
  IP6IP: ipip6_set_tunnel, ipip6_get_tunnel,
         ip6ip6_set_tunnel, ip6ip6_get_tunnel
  XFRM: xfrm_get_state

Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools/testing/selftests/bpf/Makefile

@@ -32,7 +32,7 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test
 	test_l4lb_noinline.o test_xdp_noinline.o test_stacktrace_map.o \
 	sample_map_ret0.o test_tcpbpf_kern.o test_stacktrace_build_id.o \
 	sockmap_tcp_msg_prog.o connect4_prog.o connect6_prog.o test_adjust_tail.o \
-	test_btf_haskv.o test_btf_nokv.o test_sockmap_kern.o
+	test_btf_haskv.o test_btf_nokv.o test_sockmap_kern.o test_tunnel_kern.o
 
 # Order correspond to 'make run_tests' order
 TEST_PROGS := test_kmod.sh \
@@ -40,7 +40,8 @@ TEST_PROGS := test_kmod.sh \
 	test_xdp_redirect.sh \
 	test_xdp_meta.sh \
 	test_offload.py \
-	test_sock_addr.sh
+	test_sock_addr.sh \
+	test_tunnel.sh
 
 # Compile but not part of 'make run_tests'
 TEST_GEN_PROGS_EXTENDED = test_libbpf_open test_sock_addr

tools/testing/selftests/bpf/test_tunnel.sh

@@ -0,0 +1,729 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# End-to-end eBPF tunnel test suite
+#   The script tests BPF network tunnel implementation.
+#
+# Topology:
+# ---------
+#     root namespace   |     at_ns0 namespace
+#                      |
+#      -----------     |     -----------
+#      | tnl dev |     |     | tnl dev |  (overlay network)
+#      -----------     |     -----------
+#      metadata-mode   |     native-mode
+#       with bpf       |
+#                      |
+#      ----------      |     ----------
+#      |  veth1  | --------- |  veth0  |  (underlay network)
+#      ----------    peer    ----------
+#
+#
+# Device Configuration
+# --------------------
+# Root namespace with metadata-mode tunnel + BPF
+# Device names and addresses:
+# 	veth1 IP: 172.16.1.200, IPv6: 00::22 (underlay)
+# 	tunnel dev <type>11, ex: gre11, IPv4: 10.1.1.200 (overlay)
+#
+# Namespace at_ns0 with native tunnel
+# Device names and addresses:
+# 	veth0 IPv4: 172.16.1.100, IPv6: 00::11 (underlay)
+# 	tunnel dev <type>00, ex: gre00, IPv4: 10.1.1.100 (overlay)
+#
+#
+# End-to-end ping packet flow
+# ---------------------------
+# Most of the tests start by namespace creation, device configuration,
+# then ping the underlay and overlay network.  When doing 'ping 10.1.1.100'
+# from root namespace, the following operations happen:
+# 1) Route lookup shows 10.1.1.100/24 belongs to tnl dev, fwd to tnl dev.
+# 2) Tnl device's egress BPF program is triggered and set the tunnel metadata,
+#    with remote_ip=172.16.1.200 and others.
+# 3) Outer tunnel header is prepended and route the packet to veth1's egress
+# 4) veth0's ingress queue receive the tunneled packet at namespace at_ns0
+# 5) Tunnel protocol handler, ex: vxlan_rcv, decap the packet
+# 6) Forward the packet to the overlay tnl dev
+
+PING_ARG="-c 3 -w 10 -q"
+ret=0
+GREEN='\033[0;92m'
+RED='\033[0;31m'
+NC='\033[0m' # No Color
+
+config_device()
+{
+	ip netns add at_ns0
+	ip link add veth0 type veth peer name veth1
+	ip link set veth0 netns at_ns0
+	ip netns exec at_ns0 ip addr add 172.16.1.100/24 dev veth0
+	ip netns exec at_ns0 ip link set dev veth0 up
+	ip link set dev veth1 up mtu 1500
+	ip addr add dev veth1 172.16.1.200/24
+}
+
+add_gre_tunnel()
+{
+	# at_ns0 namespace
+	ip netns exec at_ns0 \
+        ip link add dev $DEV_NS type $TYPE seq key 2 \
+		local 172.16.1.100 remote 172.16.1.200
+	ip netns exec at_ns0 ip link set dev $DEV_NS up
+	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
+
+	# root namespace
+	ip link add dev $DEV type $TYPE key 2 external
+	ip link set dev $DEV up
+	ip addr add dev $DEV 10.1.1.200/24
+}
+
+add_ip6gretap_tunnel()
+{
+
+	# assign ipv6 address
+	ip netns exec at_ns0 ip addr add ::11/96 dev veth0
+	ip netns exec at_ns0 ip link set dev veth0 up
+	ip addr add dev veth1 ::22/96
+	ip link set dev veth1 up
+
+	# at_ns0 namespace
+	ip netns exec at_ns0 \
+		ip link add dev $DEV_NS type $TYPE seq flowlabel 0xbcdef key 2 \
+		local ::11 remote ::22
+
+	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
+	ip netns exec at_ns0 ip addr add dev $DEV_NS fc80::100/96
+	ip netns exec at_ns0 ip link set dev $DEV_NS up
+
+	# root namespace
+	ip link add dev $DEV type $TYPE external
+	ip addr add dev $DEV 10.1.1.200/24
+	ip addr add dev $DEV fc80::200/24
+	ip link set dev $DEV up
+}
+
+add_erspan_tunnel()
+{
+	# at_ns0 namespace
+	if [ "$1" == "v1" ]; then
+		ip netns exec at_ns0 \
+		ip link add dev $DEV_NS type $TYPE seq key 2 \
+		local 172.16.1.100 remote 172.16.1.200 \
+		erspan_ver 1 erspan 123
+	else
+		ip netns exec at_ns0 \
+		ip link add dev $DEV_NS type $TYPE seq key 2 \
+		local 172.16.1.100 remote 172.16.1.200 \
+		erspan_ver 2 erspan_dir egress erspan_hwid 3
+	fi
+	ip netns exec at_ns0 ip link set dev $DEV_NS up
+	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
+
+	# root namespace
+	ip link add dev $DEV type $TYPE external
+	ip link set dev $DEV up
+	ip addr add dev $DEV 10.1.1.200/24
+}
+
+add_ip6erspan_tunnel()
+{
+
+	# assign ipv6 address
+	ip netns exec at_ns0 ip addr add ::11/96 dev veth0
+	ip netns exec at_ns0 ip link set dev veth0 up
+	ip addr add dev veth1 ::22/96
+	ip link set dev veth1 up
+
+	# at_ns0 namespace
+	if [ "$1" == "v1" ]; then
+		ip netns exec at_ns0 \
+		ip link add dev $DEV_NS type $TYPE seq key 2 \
+		local ::11 remote ::22 \
+		erspan_ver 1 erspan 123
+	else
+		ip netns exec at_ns0 \
+		ip link add dev $DEV_NS type $TYPE seq key 2 \
+		local ::11 remote ::22 \
+		erspan_ver 2 erspan_dir egress erspan_hwid 7
+	fi
+	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
+	ip netns exec at_ns0 ip link set dev $DEV_NS up
+
+	# root namespace
+	ip link add dev $DEV type $TYPE external
+	ip addr add dev $DEV 10.1.1.200/24
+	ip link set dev $DEV up
+}
+
+add_vxlan_tunnel()
+{
+	# Set static ARP entry here because iptables set-mark works
+	# on L3 packet, as a result not applying to ARP packets,
+	# causing errors at get_tunnel_{key/opt}.
+
+	# at_ns0 namespace
+	ip netns exec at_ns0 \
+		ip link add dev $DEV_NS type $TYPE \
+		id 2 dstport 4789 gbp remote 172.16.1.200
+	ip netns exec at_ns0 \
+		ip link set dev $DEV_NS address 52:54:00:d9:01:00 up
+	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
+	ip netns exec at_ns0 arp -s 10.1.1.200 52:54:00:d9:02:00
+	ip netns exec at_ns0 iptables -A OUTPUT -j MARK --set-mark 0x800FF
+
+	# root namespace
+	ip link add dev $DEV type $TYPE external gbp dstport 4789
+	ip link set dev $DEV address 52:54:00:d9:02:00 up
+	ip addr add dev $DEV 10.1.1.200/24
+	arp -s 10.1.1.100 52:54:00:d9:01:00
+}
+
+add_ip6vxlan_tunnel()
+{
+	#ip netns exec at_ns0 ip -4 addr del 172.16.1.100 dev veth0
+	ip netns exec at_ns0 ip -6 addr add ::11/96 dev veth0
+	ip netns exec at_ns0 ip link set dev veth0 up
+	#ip -4 addr del 172.16.1.200 dev veth1
+	ip -6 addr add dev veth1 ::22/96
+	ip link set dev veth1 up
+
+	# at_ns0 namespace
+	ip netns exec at_ns0 \
+		ip link add dev $DEV_NS type $TYPE id 22 dstport 4789 \
+		local ::11 remote ::22
+	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
+	ip netns exec at_ns0 ip link set dev $DEV_NS up
+
+	# root namespace
+	ip link add dev $DEV type $TYPE external dstport 4789
+	ip addr add dev $DEV 10.1.1.200/24
+	ip link set dev $DEV up
+}
+
+add_geneve_tunnel()
+{
+	# at_ns0 namespace
+	ip netns exec at_ns0 \
+		ip link add dev $DEV_NS type $TYPE \
+		id 2 dstport 6081 remote 172.16.1.200
+	ip netns exec at_ns0 ip link set dev $DEV_NS up
+	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
+
+	# root namespace
+	ip link add dev $DEV type $TYPE dstport 6081 external
+	ip link set dev $DEV up
+	ip addr add dev $DEV 10.1.1.200/24
+}
+
+add_ip6geneve_tunnel()
+{
+	ip netns exec at_ns0 ip addr add ::11/96 dev veth0
+	ip netns exec at_ns0 ip link set dev veth0 up
+	ip addr add dev veth1 ::22/96
+	ip link set dev veth1 up
+
+	# at_ns0 namespace
+	ip netns exec at_ns0 \
+		ip link add dev $DEV_NS type $TYPE id 22 \
+		remote ::22     # geneve has no local option
+	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
+	ip netns exec at_ns0 ip link set dev $DEV_NS up
+
+	# root namespace
+	ip link add dev $DEV type $TYPE external
+	ip addr add dev $DEV 10.1.1.200/24
+	ip link set dev $DEV up
+}
+
+add_ipip_tunnel()
+{
+	# at_ns0 namespace
+	ip netns exec at_ns0 \
+		ip link add dev $DEV_NS type $TYPE \
+		local 172.16.1.100 remote 172.16.1.200
+	ip netns exec at_ns0 ip link set dev $DEV_NS up
+	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
+
+	# root namespace
+	ip link add dev $DEV type $TYPE external
+	ip link set dev $DEV up
+	ip addr add dev $DEV 10.1.1.200/24
+}
+
+add_ipip6tnl_tunnel()
+{
+	ip netns exec at_ns0 ip addr add ::11/96 dev veth0
+	ip netns exec at_ns0 ip link set dev veth0 up
+	ip addr add dev veth1 ::22/96
+	ip link set dev veth1 up
+
+	# at_ns0 namespace
+	ip netns exec at_ns0 \
+		ip link add dev $DEV_NS type $TYPE \
+		local ::11 remote ::22
+	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
+	ip netns exec at_ns0 ip link set dev $DEV_NS up
+
+	# root namespace
+	ip link add dev $DEV type $TYPE external
+	ip addr add dev $DEV 10.1.1.200/24
+	ip link set dev $DEV up
+}
+
+test_gre()
+{
+	TYPE=gretap
+	DEV_NS=gretap00
+	DEV=gretap11
+	ret=0
+
+	check $TYPE
+	config_device
+	add_gre_tunnel
+	attach_bpf $DEV gre_set_tunnel gre_get_tunnel
+	ping $PING_ARG 10.1.1.100
+	check_err $?
+	ip netns exec at_ns0 ping $PING_ARG 10.1.1.200
+	check_err $?
+	cleanup
+
+        if [ $ret -ne 0 ]; then
+                echo -e ${RED}"FAIL: $TYPE"${NC}
+                return 1
+        fi
+        echo -e ${GREEN}"PASS: $TYPE"${NC}
+}
+
+test_ip6gre()
+{
+	TYPE=ip6gre
+	DEV_NS=ip6gre00
+	DEV=ip6gre11
+	ret=0
+
+	check $TYPE
+	config_device
+	# reuse the ip6gretap function
+	add_ip6gretap_tunnel
+	attach_bpf $DEV ip6gretap_set_tunnel ip6gretap_get_tunnel
+	# underlay
+	ping6 $PING_ARG ::11
+	# overlay: ipv4 over ipv6
+	ip netns exec at_ns0 ping $PING_ARG 10.1.1.200
+	ping $PING_ARG 10.1.1.100
+	check_err $?
+	# overlay: ipv6 over ipv6
+	ip netns exec at_ns0 ping6 $PING_ARG fc80::200
+	check_err $?
+	cleanup
+
+        if [ $ret -ne 0 ]; then
+                echo -e ${RED}"FAIL: $TYPE"${NC}
+                return 1
+        fi
+        echo -e ${GREEN}"PASS: $TYPE"${NC}
+}
+
+test_ip6gretap()
+{
+	TYPE=ip6gretap
+	DEV_NS=ip6gretap00
+	DEV=ip6gretap11
+	ret=0
+
+	check $TYPE
+	config_device
+	add_ip6gretap_tunnel
+	attach_bpf $DEV ip6gretap_set_tunnel ip6gretap_get_tunnel
+	# underlay
+	ping6 $PING_ARG ::11
+	# overlay: ipv4 over ipv6
+	ip netns exec at_ns0 ping $PING_ARG 10.1.1.200
+	ping $PING_ARG 10.1.1.100
+	check_err $?
+	# overlay: ipv6 over ipv6
+	ip netns exec at_ns0 ping6 $PING_ARG fc80::200
+	check_err $?
+	cleanup
+
+	if [ $ret -ne 0 ]; then
+                echo -e ${RED}"FAIL: $TYPE"${NC}
+                return 1
+        fi
+        echo -e ${GREEN}"PASS: $TYPE"${NC}
+}
+
+test_erspan()
+{
+	TYPE=erspan
+	DEV_NS=erspan00
+	DEV=erspan11
+	ret=0
+
+	check $TYPE
+	config_device
+	add_erspan_tunnel $1
+	attach_bpf $DEV erspan_set_tunnel erspan_get_tunnel
+	ping $PING_ARG 10.1.1.100
+	check_err $?
+	ip netns exec at_ns0 ping $PING_ARG 10.1.1.200
+	check_err $?
+	cleanup
+
+	if [ $ret -ne 0 ]; then
+                echo -e ${RED}"FAIL: $TYPE"${NC}
+                return 1
+        fi
+        echo -e ${GREEN}"PASS: $TYPE"${NC}
+}
+
+test_ip6erspan()
+{
+	TYPE=ip6erspan
+	DEV_NS=ip6erspan00
+	DEV=ip6erspan11
+	ret=0
+
+	check $TYPE
+	config_device
+	add_ip6erspan_tunnel $1
+	attach_bpf $DEV ip4ip6erspan_set_tunnel ip4ip6erspan_get_tunnel
+	ping6 $PING_ARG ::11
+	ip netns exec at_ns0 ping $PING_ARG 10.1.1.200
+	check_err $?
+	cleanup
+
+	if [ $ret -ne 0 ]; then
+                echo -e ${RED}"FAIL: $TYPE"${NC}
+                return 1
+        fi
+        echo -e ${GREEN}"PASS: $TYPE"${NC}
+}
+
+test_vxlan()
+{
+	TYPE=vxlan
+	DEV_NS=vxlan00
+	DEV=vxlan11
+	ret=0
+
+	check $TYPE
+	config_device
+	add_vxlan_tunnel
+	attach_bpf $DEV vxlan_set_tunnel vxlan_get_tunnel
+	ping $PING_ARG 10.1.1.100
+	check_err $?
+	ip netns exec at_ns0 ping $PING_ARG 10.1.1.200
+	check_err $?
+	cleanup
+
+	if [ $ret -ne 0 ]; then
+                echo -e ${RED}"FAIL: $TYPE"${NC}
+                return 1
+        fi
+        echo -e ${GREEN}"PASS: $TYPE"${NC}
+}
+
+test_ip6vxlan()
+{
+	TYPE=vxlan
+	DEV_NS=ip6vxlan00
+	DEV=ip6vxlan11
+	ret=0
+
+	check $TYPE
+	config_device
+	add_ip6vxlan_tunnel
+	ip link set dev veth1 mtu 1500
+	attach_bpf $DEV ip6vxlan_set_tunnel ip6vxlan_get_tunnel
+	# underlay
+	ping6 $PING_ARG ::11
+	# ip4 over ip6
+	ping $PING_ARG 10.1.1.100
+	check_err $?
+	ip netns exec at_ns0 ping $PING_ARG 10.1.1.200
+	check_err $?
+	cleanup
+
+	if [ $ret -ne 0 ]; then
+                echo -e ${RED}"FAIL: ip6$TYPE"${NC}
+                return 1
+        fi
+        echo -e ${GREEN}"PASS: ip6$TYPE"${NC}
+}
+
+test_geneve()
+{
+	TYPE=geneve
+	DEV_NS=geneve00
+	DEV=geneve11
+	ret=0
+
+	check $TYPE
+	config_device
+	add_geneve_tunnel
+	attach_bpf $DEV geneve_set_tunnel geneve_get_tunnel
+	ping $PING_ARG 10.1.1.100
+	check_err $?
+	ip netns exec at_ns0 ping $PING_ARG 10.1.1.200
+	check_err $?
+	cleanup
+
+	if [ $ret -ne 0 ]; then
+                echo -e ${RED}"FAIL: $TYPE"${NC}
+                return 1
+        fi
+        echo -e ${GREEN}"PASS: $TYPE"${NC}
+}
+
+test_ip6geneve()
+{
+	TYPE=geneve
+	DEV_NS=ip6geneve00
+	DEV=ip6geneve11
+	ret=0
+
+	check $TYPE
+	config_device
+	add_ip6geneve_tunnel
+	attach_bpf $DEV ip6geneve_set_tunnel ip6geneve_get_tunnel
+	ping $PING_ARG 10.1.1.100
+	check_err $?
+	ip netns exec at_ns0 ping $PING_ARG 10.1.1.200
+	check_err $?
+	cleanup
+
+	if [ $ret -ne 0 ]; then
+                echo -e ${RED}"FAIL: ip6$TYPE"${NC}
+                return 1
+        fi
+        echo -e ${GREEN}"PASS: ip6$TYPE"${NC}
+}
+
+test_ipip()
+{
+	TYPE=ipip
+	DEV_NS=ipip00
+	DEV=ipip11
+	ret=0
+
+	check $TYPE
+	config_device
+	add_ipip_tunnel
+	ip link set dev veth1 mtu 1500
+	attach_bpf $DEV ipip_set_tunnel ipip_get_tunnel
+	ping $PING_ARG 10.1.1.100
+	check_err $?
+	ip netns exec at_ns0 ping $PING_ARG 10.1.1.200
+	check_err $?
+	cleanup
+
+	if [ $ret -ne 0 ]; then
+                echo -e ${RED}"FAIL: $TYPE"${NC}
+                return 1
+        fi
+        echo -e ${GREEN}"PASS: $TYPE"${NC}
+}
+
+test_ipip6()
+{
+	TYPE=ip6tnl
+	DEV_NS=ipip6tnl00
+	DEV=ipip6tnl11
+	ret=0
+
+	check $TYPE
+	config_device
+	add_ipip6tnl_tunnel
+	ip link set dev veth1 mtu 1500
+	attach_bpf $DEV ipip6_set_tunnel ipip6_get_tunnel
+	# underlay
+	ping6 $PING_ARG ::11
+	# ip4 over ip6
+	ping $PING_ARG 10.1.1.100
+	check_err $?
+	ip netns exec at_ns0 ping $PING_ARG 10.1.1.200
+	check_err $?
+	cleanup
+
+	if [ $ret -ne 0 ]; then
+                echo -e ${RED}"FAIL: $TYPE"${NC}
+                return 1
+        fi
+        echo -e ${GREEN}"PASS: $TYPE"${NC}
+}
+
+setup_xfrm_tunnel()
+{
+	auth=0x$(printf '1%.0s' {1..40})
+	enc=0x$(printf '2%.0s' {1..32})
+	spi_in_to_out=0x1
+	spi_out_to_in=0x2
+	# at_ns0 namespace
+	# at_ns0 -> root
+	ip netns exec at_ns0 \
+		ip xfrm state add src 172.16.1.100 dst 172.16.1.200 proto esp \
+			spi $spi_in_to_out reqid 1 mode tunnel \
+			auth-trunc 'hmac(sha1)' $auth 96 enc 'cbc(aes)' $enc
+	ip netns exec at_ns0 \
+		ip xfrm policy add src 10.1.1.100/32 dst 10.1.1.200/32 dir out \
+		tmpl src 172.16.1.100 dst 172.16.1.200 proto esp reqid 1 \
+		mode tunnel
+	# root -> at_ns0
+	ip netns exec at_ns0 \
+		ip xfrm state add src 172.16.1.200 dst 172.16.1.100 proto esp \
+			spi $spi_out_to_in reqid 2 mode tunnel \
+			auth-trunc 'hmac(sha1)' $auth 96 enc 'cbc(aes)' $enc
+	ip netns exec at_ns0 \
+		ip xfrm policy add src 10.1.1.200/32 dst 10.1.1.100/32 dir in \
+		tmpl src 172.16.1.200 dst 172.16.1.100 proto esp reqid 2 \
+		mode tunnel
+	# address & route
+	ip netns exec at_ns0 \
+		ip addr add dev veth0 10.1.1.100/32
+	ip netns exec at_ns0 \
+		ip route add 10.1.1.200 dev veth0 via 172.16.1.200 \
+			src 10.1.1.100
+
+	# root namespace
+	# at_ns0 -> root
+	ip xfrm state add src 172.16.1.100 dst 172.16.1.200 proto esp \
+		spi $spi_in_to_out reqid 1 mode tunnel \
+		auth-trunc 'hmac(sha1)' $auth 96  enc 'cbc(aes)' $enc
+	ip xfrm policy add src 10.1.1.100/32 dst 10.1.1.200/32 dir in \
+		tmpl src 172.16.1.100 dst 172.16.1.200 proto esp reqid 1 \
+		mode tunnel
+	# root -> at_ns0
+	ip xfrm state add src 172.16.1.200 dst 172.16.1.100 proto esp \
+		spi $spi_out_to_in reqid 2 mode tunnel \
+		auth-trunc 'hmac(sha1)' $auth 96  enc 'cbc(aes)' $enc
+	ip xfrm policy add src 10.1.1.200/32 dst 10.1.1.100/32 dir out \
+		tmpl src 172.16.1.200 dst 172.16.1.100 proto esp reqid 2 \
+		mode tunnel
+	# address & route
+	ip addr add dev veth1 10.1.1.200/32
+	ip route add 10.1.1.100 dev veth1 via 172.16.1.100 src 10.1.1.200
+}
+
+test_xfrm_tunnel()
+{
+	config_device
+        #tcpdump -nei veth1 ip &
+	output=$(mktemp)
+	cat /sys/kernel/debug/tracing/trace_pipe | tee $output &
+        setup_xfrm_tunnel
+	tc qdisc add dev veth1 clsact
+	tc filter add dev veth1 proto ip ingress bpf da obj test_tunnel_kern.o \
+		sec xfrm_get_state
+	ip netns exec at_ns0 ping $PING_ARG 10.1.1.200
+	sleep 1
+	grep "reqid 1" $output
+	check_err $?
+	grep "spi 0x1" $output
+	check_err $?
+	grep "remote ip 0xac100164" $output
+	check_err $?
+	cleanup
+
+	if [ $ret -ne 0 ]; then
+                echo -e ${RED}"FAIL: xfrm tunnel"${NC}
+                return 1
+        fi
+        echo -e ${GREEN}"PASS: xfrm tunnel"${NC}
+}
+
+attach_bpf()
+{
+	DEV=$1
+	SET=$2
+	GET=$3
+	tc qdisc add dev $DEV clsact
+	tc filter add dev $DEV egress bpf da obj test_tunnel_kern.o sec $SET
+	tc filter add dev $DEV ingress bpf da obj test_tunnel_kern.o sec $GET
+}
+
+cleanup()
+{
+	ip netns delete at_ns0 2> /dev/null
+	ip link del veth1 2> /dev/null
+	ip link del ipip11 2> /dev/null
+	ip link del ipip6tnl11 2> /dev/null
+	ip link del gretap11 2> /dev/null
+	ip link del ip6gre11 2> /dev/null
+	ip link del ip6gretap11 2> /dev/null
+	ip link del vxlan11 2> /dev/null
+	ip link del ip6vxlan11 2> /dev/null
+	ip link del geneve11 2> /dev/null
+	ip link del ip6geneve11 2> /dev/null
+	ip link del erspan11 2> /dev/null
+	ip link del ip6erspan11 2> /dev/null
+}
+
+cleanup_exit()
+{
+	echo "CATCH SIGKILL or SIGINT, cleanup and exit"
+	cleanup
+	exit 0
+}
+
+check()
+{
+	ip link help $1 2>&1 | grep -q "^Usage:"
+	if [ $? -ne 0 ];then
+		echo "SKIP $1: iproute2 not support"
+	cleanup
+	return 1
+	fi
+}
+
+enable_debug()
+{
+	echo 'file ip_gre.c +p' > /sys/kernel/debug/dynamic_debug/control
+	echo 'file ip6_gre.c +p' > /sys/kernel/debug/dynamic_debug/control
+	echo 'file vxlan.c +p' > /sys/kernel/debug/dynamic_debug/control
+	echo 'file geneve.c +p' > /sys/kernel/debug/dynamic_debug/control
+	echo 'file ipip.c +p' > /sys/kernel/debug/dynamic_debug/control
+}
+
+check_err()
+{
+	if [ $ret -eq 0 ]; then
+		ret=$1
+	fi
+}
+
+bpf_tunnel_test()
+{
+	echo "Testing GRE tunnel..."
+	test_gre
+	echo "Testing IP6GRE tunnel..."
+	test_ip6gre
+	echo "Testing IP6GRETAP tunnel..."
+	test_ip6gretap
+	echo "Testing ERSPAN tunnel..."
+	test_erspan v2
+	echo "Testing IP6ERSPAN tunnel..."
+	test_ip6erspan v2
+	echo "Testing VXLAN tunnel..."
+	test_vxlan
+	echo "Testing IP6VXLAN tunnel..."
+	test_ip6vxlan
+	echo "Testing GENEVE tunnel..."
+	test_geneve
+	echo "Testing IP6GENEVE tunnel..."
+	test_ip6geneve
+	echo "Testing IPIP tunnel..."
+	test_ipip
+	echo "Testing IPIP6 tunnel..."
+	test_ipip6
+	echo "Testing IPSec tunnel..."
+	test_xfrm_tunnel
+}
+
+trap cleanup 0 3 6
+trap cleanup_exit 2 9
+
+cleanup
+bpf_tunnel_test
+
+exit 0

tools/testing/selftests/bpf/test_tunnel_kern.c

@@ -0,0 +1,713 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2016 VMware
+ * Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <stddef.h>
+#include <string.h>
+#include <arpa/inet.h>
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/types.h>
+#include <linux/tcp.h>
+#include <linux/socket.h>
+#include <linux/pkt_cls.h>
+#include <linux/erspan.h>
+#include "bpf_helpers.h"
+#include "bpf_endian.h"
+
+#define ERROR(ret) do {\
+		char fmt[] = "ERROR line:%d ret:%d\n";\
+		bpf_trace_printk(fmt, sizeof(fmt), __LINE__, ret); \
+	} while (0)
+
+int _version SEC("version") = 1;
+
+struct geneve_opt {
+	__be16	opt_class;
+	__u8	type;
+	__u8	length:5;
+	__u8	r3:1;
+	__u8	r2:1;
+	__u8	r1:1;
+	__u8	opt_data[8]; /* hard-coded to 8 byte */
+};
+
+struct vxlan_metadata {
+	__u32     gbp;
+};
+
+SEC("gre_set_tunnel")
+int _gre_set_tunnel(struct __sk_buff *skb)
+{
+	int ret;
+	struct bpf_tunnel_key key;
+
+	__builtin_memset(&key, 0x0, sizeof(key));
+	key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
+	key.tunnel_id = 2;
+	key.tunnel_tos = 0;
+	key.tunnel_ttl = 64;
+
+	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_ZERO_CSUM_TX | BPF_F_SEQ_NUMBER);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("gre_get_tunnel")
+int _gre_get_tunnel(struct __sk_buff *skb)
+{
+	int ret;
+	struct bpf_tunnel_key key;
+	char fmt[] = "key %d remote ip 0x%x\n";
+
+	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	bpf_trace_printk(fmt, sizeof(fmt), key.tunnel_id, key.remote_ipv4);
+	return TC_ACT_OK;
+}
+
+SEC("ip6gretap_set_tunnel")
+int _ip6gretap_set_tunnel(struct __sk_buff *skb)
+{
+	struct bpf_tunnel_key key;
+	int ret;
+
+	__builtin_memset(&key, 0x0, sizeof(key));
+	key.remote_ipv6[3] = bpf_htonl(0x11); /* ::11 */
+	key.tunnel_id = 2;
+	key.tunnel_tos = 0;
+	key.tunnel_ttl = 64;
+	key.tunnel_label = 0xabcde;
+
+	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_TUNINFO_IPV6 | BPF_F_ZERO_CSUM_TX |
+				     BPF_F_SEQ_NUMBER);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("ip6gretap_get_tunnel")
+int _ip6gretap_get_tunnel(struct __sk_buff *skb)
+{
+	char fmt[] = "key %d remote ip6 ::%x label %x\n";
+	struct bpf_tunnel_key key;
+	int ret;
+
+	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_TUNINFO_IPV6);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	bpf_trace_printk(fmt, sizeof(fmt),
+			 key.tunnel_id, key.remote_ipv6[3], key.tunnel_label);
+
+	return TC_ACT_OK;
+}
+
+SEC("erspan_set_tunnel")
+int _erspan_set_tunnel(struct __sk_buff *skb)
+{
+	struct bpf_tunnel_key key;
+	struct erspan_metadata md;
+	int ret;
+
+	__builtin_memset(&key, 0x0, sizeof(key));
+	key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
+	key.tunnel_id = 2;
+	key.tunnel_tos = 0;
+	key.tunnel_ttl = 64;
+
+	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_ZERO_CSUM_TX);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	__builtin_memset(&md, 0, sizeof(md));
+#ifdef ERSPAN_V1
+	md.version = 1;
+	md.u.index = bpf_htonl(123);
+#else
+	__u8 direction = 1;
+	__u8 hwid = 7;
+
+	md.version = 2;
+	md.u.md2.dir = direction;
+	md.u.md2.hwid = hwid & 0xf;
+	md.u.md2.hwid_upper = (hwid >> 4) & 0x3;
+#endif
+
+	ret = bpf_skb_set_tunnel_opt(skb, &md, sizeof(md));
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("erspan_get_tunnel")
+int _erspan_get_tunnel(struct __sk_buff *skb)
+{
+	char fmt[] = "key %d remote ip 0x%x erspan version %d\n";
+	struct bpf_tunnel_key key;
+	struct erspan_metadata md;
+	__u32 index;
+	int ret;
+
+	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	ret = bpf_skb_get_tunnel_opt(skb, &md, sizeof(md));
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	bpf_trace_printk(fmt, sizeof(fmt),
+			key.tunnel_id, key.remote_ipv4, md.version);
+
+#ifdef ERSPAN_V1
+	char fmt2[] = "\tindex %x\n";
+
+	index = bpf_ntohl(md.u.index);
+	bpf_trace_printk(fmt2, sizeof(fmt2), index);
+#else
+	char fmt2[] = "\tdirection %d hwid %x timestamp %u\n";
+
+	bpf_trace_printk(fmt2, sizeof(fmt2),
+			 md.u.md2.dir,
+			 (md.u.md2.hwid_upper << 4) + md.u.md2.hwid,
+			 bpf_ntohl(md.u.md2.timestamp));
+#endif
+
+	return TC_ACT_OK;
+}
+
+SEC("ip4ip6erspan_set_tunnel")
+int _ip4ip6erspan_set_tunnel(struct __sk_buff *skb)
+{
+	struct bpf_tunnel_key key;
+	struct erspan_metadata md;
+	int ret;
+
+	__builtin_memset(&key, 0x0, sizeof(key));
+	key.remote_ipv6[3] = bpf_htonl(0x11);
+	key.tunnel_id = 2;
+	key.tunnel_tos = 0;
+	key.tunnel_ttl = 64;
+
+	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_TUNINFO_IPV6);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	__builtin_memset(&md, 0, sizeof(md));
+
+#ifdef ERSPAN_V1
+	md.u.index = bpf_htonl(123);
+	md.version = 1;
+#else
+	__u8 direction = 0;
+	__u8 hwid = 17;
+
+	md.version = 2;
+	md.u.md2.dir = direction;
+	md.u.md2.hwid = hwid & 0xf;
+	md.u.md2.hwid_upper = (hwid >> 4) & 0x3;
+#endif
+
+	ret = bpf_skb_set_tunnel_opt(skb, &md, sizeof(md));
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("ip4ip6erspan_get_tunnel")
+int _ip4ip6erspan_get_tunnel(struct __sk_buff *skb)
+{
+	char fmt[] = "ip6erspan get key %d remote ip6 ::%x erspan version %d\n";
+	struct bpf_tunnel_key key;
+	struct erspan_metadata md;
+	__u32 index;
+	int ret;
+
+	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_TUNINFO_IPV6);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	ret = bpf_skb_get_tunnel_opt(skb, &md, sizeof(md));
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	bpf_trace_printk(fmt, sizeof(fmt),
+			key.tunnel_id, key.remote_ipv4, md.version);
+
+#ifdef ERSPAN_V1
+	char fmt2[] = "\tindex %x\n";
+
+	index = bpf_ntohl(md.u.index);
+	bpf_trace_printk(fmt2, sizeof(fmt2), index);
+#else
+	char fmt2[] = "\tdirection %d hwid %x timestamp %u\n";
+
+	bpf_trace_printk(fmt2, sizeof(fmt2),
+			 md.u.md2.dir,
+			 (md.u.md2.hwid_upper << 4) + md.u.md2.hwid,
+			 bpf_ntohl(md.u.md2.timestamp));
+#endif
+
+	return TC_ACT_OK;
+}
+
+SEC("vxlan_set_tunnel")
+int _vxlan_set_tunnel(struct __sk_buff *skb)
+{
+	int ret;
+	struct bpf_tunnel_key key;
+	struct vxlan_metadata md;
+
+	__builtin_memset(&key, 0x0, sizeof(key));
+	key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
+	key.tunnel_id = 2;
+	key.tunnel_tos = 0;
+	key.tunnel_ttl = 64;
+
+	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_ZERO_CSUM_TX);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	md.gbp = 0x800FF; /* Set VXLAN Group Policy extension */
+	ret = bpf_skb_set_tunnel_opt(skb, &md, sizeof(md));
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("vxlan_get_tunnel")
+int _vxlan_get_tunnel(struct __sk_buff *skb)
+{
+	int ret;
+	struct bpf_tunnel_key key;
+	struct vxlan_metadata md;
+	char fmt[] = "key %d remote ip 0x%x vxlan gbp 0x%x\n";
+
+	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	ret = bpf_skb_get_tunnel_opt(skb, &md, sizeof(md));
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	bpf_trace_printk(fmt, sizeof(fmt),
+			key.tunnel_id, key.remote_ipv4, md.gbp);
+
+	return TC_ACT_OK;
+}
+
+SEC("ip6vxlan_set_tunnel")
+int _ip6vxlan_set_tunnel(struct __sk_buff *skb)
+{
+	struct bpf_tunnel_key key;
+	int ret;
+
+	__builtin_memset(&key, 0x0, sizeof(key));
+	key.remote_ipv6[3] = bpf_htonl(0x11); /* ::11 */
+	key.tunnel_id = 22;
+	key.tunnel_tos = 0;
+	key.tunnel_ttl = 64;
+
+	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_TUNINFO_IPV6);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("ip6vxlan_get_tunnel")
+int _ip6vxlan_get_tunnel(struct __sk_buff *skb)
+{
+	char fmt[] = "key %d remote ip6 ::%x label %x\n";
+	struct bpf_tunnel_key key;
+	int ret;
+
+	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_TUNINFO_IPV6);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	bpf_trace_printk(fmt, sizeof(fmt),
+			 key.tunnel_id, key.remote_ipv6[3], key.tunnel_label);
+
+	return TC_ACT_OK;
+}
+
+SEC("geneve_set_tunnel")
+int _geneve_set_tunnel(struct __sk_buff *skb)
+{
+	int ret, ret2;
+	struct bpf_tunnel_key key;
+	struct geneve_opt gopt;
+
+	__builtin_memset(&key, 0x0, sizeof(key));
+	key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
+	key.tunnel_id = 2;
+	key.tunnel_tos = 0;
+	key.tunnel_ttl = 64;
+
+	__builtin_memset(&gopt, 0x0, sizeof(gopt));
+	gopt.opt_class = bpf_htons(0x102); /* Open Virtual Networking (OVN) */
+	gopt.type = 0x08;
+	gopt.r1 = 0;
+	gopt.r2 = 0;
+	gopt.r3 = 0;
+	gopt.length = 2; /* 4-byte multiple */
+	*(int *) &gopt.opt_data = bpf_htonl(0xdeadbeef);
+
+	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_ZERO_CSUM_TX);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	ret = bpf_skb_set_tunnel_opt(skb, &gopt, sizeof(gopt));
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("geneve_get_tunnel")
+int _geneve_get_tunnel(struct __sk_buff *skb)
+{
+	int ret;
+	struct bpf_tunnel_key key;
+	struct geneve_opt gopt;
+	char fmt[] = "key %d remote ip 0x%x geneve class 0x%x\n";
+
+	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	ret = bpf_skb_get_tunnel_opt(skb, &gopt, sizeof(gopt));
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	bpf_trace_printk(fmt, sizeof(fmt),
+			key.tunnel_id, key.remote_ipv4, gopt.opt_class);
+	return TC_ACT_OK;
+}
+
+SEC("ip6geneve_set_tunnel")
+int _ip6geneve_set_tunnel(struct __sk_buff *skb)
+{
+	struct bpf_tunnel_key key;
+	struct geneve_opt gopt;
+	int ret;
+
+	__builtin_memset(&key, 0x0, sizeof(key));
+	key.remote_ipv6[3] = bpf_htonl(0x11); /* ::11 */
+	key.tunnel_id = 22;
+	key.tunnel_tos = 0;
+	key.tunnel_ttl = 64;
+
+	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_TUNINFO_IPV6);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	__builtin_memset(&gopt, 0x0, sizeof(gopt));
+	gopt.opt_class = bpf_htons(0x102); /* Open Virtual Networking (OVN) */
+	gopt.type = 0x08;
+	gopt.r1 = 0;
+	gopt.r2 = 0;
+	gopt.r3 = 0;
+	gopt.length = 2; /* 4-byte multiple */
+	*(int *) &gopt.opt_data = bpf_htonl(0xfeedbeef);
+
+	ret = bpf_skb_set_tunnel_opt(skb, &gopt, sizeof(gopt));
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("ip6geneve_get_tunnel")
+int _ip6geneve_get_tunnel(struct __sk_buff *skb)
+{
+	char fmt[] = "key %d remote ip 0x%x geneve class 0x%x\n";
+	struct bpf_tunnel_key key;
+	struct geneve_opt gopt;
+	int ret;
+
+	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_TUNINFO_IPV6);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	ret = bpf_skb_get_tunnel_opt(skb, &gopt, sizeof(gopt));
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	bpf_trace_printk(fmt, sizeof(fmt),
+			key.tunnel_id, key.remote_ipv4, gopt.opt_class);
+
+	return TC_ACT_OK;
+}
+
+SEC("ipip_set_tunnel")
+int _ipip_set_tunnel(struct __sk_buff *skb)
+{
+	struct bpf_tunnel_key key = {};
+	void *data = (void *)(long)skb->data;
+	struct iphdr *iph = data;
+	struct tcphdr *tcp = data + sizeof(*iph);
+	void *data_end = (void *)(long)skb->data_end;
+	int ret;
+
+	/* single length check */
+	if (data + sizeof(*iph) + sizeof(*tcp) > data_end) {
+		ERROR(1);
+		return TC_ACT_SHOT;
+	}
+
+	key.tunnel_ttl = 64;
+	if (iph->protocol == IPPROTO_ICMP) {
+		key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
+	} else {
+		if (iph->protocol != IPPROTO_TCP || iph->ihl != 5)
+			return TC_ACT_SHOT;
+
+		if (tcp->dest == bpf_htons(5200))
+			key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
+		else if (tcp->dest == bpf_htons(5201))
+			key.remote_ipv4 = 0xac100165; /* 172.16.1.101 */
+		else
+			return TC_ACT_SHOT;
+	}
+
+	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key), 0);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("ipip_get_tunnel")
+int _ipip_get_tunnel(struct __sk_buff *skb)
+{
+	int ret;
+	struct bpf_tunnel_key key;
+	char fmt[] = "remote ip 0x%x\n";
+
+	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	bpf_trace_printk(fmt, sizeof(fmt), key.remote_ipv4);
+	return TC_ACT_OK;
+}
+
+SEC("ipip6_set_tunnel")
+int _ipip6_set_tunnel(struct __sk_buff *skb)
+{
+	struct bpf_tunnel_key key = {};
+	void *data = (void *)(long)skb->data;
+	struct iphdr *iph = data;
+	struct tcphdr *tcp = data + sizeof(*iph);
+	void *data_end = (void *)(long)skb->data_end;
+	int ret;
+
+	/* single length check */
+	if (data + sizeof(*iph) + sizeof(*tcp) > data_end) {
+		ERROR(1);
+		return TC_ACT_SHOT;
+	}
+
+	__builtin_memset(&key, 0x0, sizeof(key));
+	key.remote_ipv6[3] = bpf_htonl(0x11); /* ::11 */
+	key.tunnel_ttl = 64;
+
+	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_TUNINFO_IPV6);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("ipip6_get_tunnel")
+int _ipip6_get_tunnel(struct __sk_buff *skb)
+{
+	int ret;
+	struct bpf_tunnel_key key;
+	char fmt[] = "remote ip6 %x::%x\n";
+
+	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_TUNINFO_IPV6);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	bpf_trace_printk(fmt, sizeof(fmt), bpf_htonl(key.remote_ipv6[0]),
+			 bpf_htonl(key.remote_ipv6[3]));
+	return TC_ACT_OK;
+}
+
+SEC("ip6ip6_set_tunnel")
+int _ip6ip6_set_tunnel(struct __sk_buff *skb)
+{
+	struct bpf_tunnel_key key = {};
+	void *data = (void *)(long)skb->data;
+	struct ipv6hdr *iph = data;
+	struct tcphdr *tcp = data + sizeof(*iph);
+	void *data_end = (void *)(long)skb->data_end;
+	int ret;
+
+	/* single length check */
+	if (data + sizeof(*iph) + sizeof(*tcp) > data_end) {
+		ERROR(1);
+		return TC_ACT_SHOT;
+	}
+
+	key.remote_ipv6[0] = bpf_htonl(0x2401db00);
+	key.tunnel_ttl = 64;
+
+	if (iph->nexthdr == 58 /* NEXTHDR_ICMP */) {
+		key.remote_ipv6[3] = bpf_htonl(1);
+	} else {
+		if (iph->nexthdr != 6 /* NEXTHDR_TCP */) {
+			ERROR(iph->nexthdr);
+			return TC_ACT_SHOT;
+		}
+
+		if (tcp->dest == bpf_htons(5200)) {
+			key.remote_ipv6[3] = bpf_htonl(1);
+		} else if (tcp->dest == bpf_htons(5201)) {
+			key.remote_ipv6[3] = bpf_htonl(2);
+		} else {
+			ERROR(tcp->dest);
+			return TC_ACT_SHOT;
+		}
+	}
+
+	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_TUNINFO_IPV6);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("ip6ip6_get_tunnel")
+int _ip6ip6_get_tunnel(struct __sk_buff *skb)
+{
+	int ret;
+	struct bpf_tunnel_key key;
+	char fmt[] = "remote ip6 %x::%x\n";
+
+	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key),
+				     BPF_F_TUNINFO_IPV6);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	bpf_trace_printk(fmt, sizeof(fmt), bpf_htonl(key.remote_ipv6[0]),
+			 bpf_htonl(key.remote_ipv6[3]));
+	return TC_ACT_OK;
+}
+
+SEC("xfrm_get_state")
+int _xfrm_get_state(struct __sk_buff *skb)
+{
+	struct bpf_xfrm_state x;
+	char fmt[] = "reqid %d spi 0x%x remote ip 0x%x\n";
+	int ret;
+
+	ret = bpf_skb_get_xfrm_state(skb, 0, &x, sizeof(x), 0);
+	if (ret < 0)
+		return TC_ACT_OK;
+
+	bpf_trace_printk(fmt, sizeof(fmt), x.reqid, bpf_ntohl(x.spi),
+			 bpf_ntohl(x.remote_ipv4));
+	return TC_ACT_OK;
+}
+
+char _license[] SEC("license") = "GPL";