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Commit 0fde56e4 authored by Peter Oskolkov's avatar Peter Oskolkov Committed by Alexei Starovoitov
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selftests: bpf: add test_lwt_ip_encap selftest 



This patch adds a bpf self-test to cover BPF_LWT_ENCAP_IP mode
in bpf_lwt_push_encap.

Covered:
- encapping in LWT_IN and LWT_XMIT
- IPv4 and IPv6

A follow-up patch will add GSO and VRF-enabled tests.

Signed-off-by: default avatarPeter Oskolkov <posk@google.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 755db477

tools/testing/selftests/bpf/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -50,7 +50,8 @@ TEST_PROGS := test_kmod.sh \ 
	test_lirc_mode2.sh \

	test_skb_cgroup_id.sh \

	test_flow_dissector.sh \

	test_xdp_vlan.sh

	test_xdp_vlan.sh \

	test_lwt_ip_encap.sh



TEST_PROGS_EXTENDED := with_addr.sh \

	with_tunnels.sh \

tools/testing/selftests/bpf/progs/test_lwt_ip_encap.c

0 → 100644
+85 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#include <stddef.h>

#include <string.h>

#include <linux/bpf.h>

#include <linux/ip.h>

#include <linux/ipv6.h>

#include "bpf_helpers.h"

#include "bpf_endian.h"



struct grehdr {

	__be16 flags;

	__be16 protocol;

};



SEC("encap_gre")

int bpf_lwt_encap_gre(struct __sk_buff *skb)

{

	struct encap_hdr {

		struct iphdr iph;

		struct grehdr greh;

	} hdr;

	int err;



	memset(&hdr, 0, sizeof(struct encap_hdr));



	hdr.iph.ihl = 5;

	hdr.iph.version = 4;

	hdr.iph.ttl = 0x40;

	hdr.iph.protocol = 47;  /* IPPROTO_GRE */

#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__

	hdr.iph.saddr = 0x640110ac;  /* 172.16.1.100 */

	hdr.iph.daddr = 0x641010ac;  /* 172.16.16.100 */

#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__

	hdr.iph.saddr = 0xac100164;  /* 172.16.1.100 */

	hdr.iph.daddr = 0xac101064;  /* 172.16.16.100 */

#else

#error "Fix your compiler's __BYTE_ORDER__?!"

#endif

	hdr.iph.tot_len = bpf_htons(skb->len + sizeof(struct encap_hdr));



	hdr.greh.protocol = skb->protocol;



	err = bpf_lwt_push_encap(skb, BPF_LWT_ENCAP_IP, &hdr,

				 sizeof(struct encap_hdr));

	if (err)

		return BPF_DROP;



	return BPF_LWT_REROUTE;

}



SEC("encap_gre6")

int bpf_lwt_encap_gre6(struct __sk_buff *skb)

{

	struct encap_hdr {

		struct ipv6hdr ip6hdr;

		struct grehdr greh;

	} hdr;

	int err;



	memset(&hdr, 0, sizeof(struct encap_hdr));



	hdr.ip6hdr.version = 6;

	hdr.ip6hdr.payload_len = bpf_htons(skb->len + sizeof(struct grehdr));

	hdr.ip6hdr.nexthdr = 47;  /* IPPROTO_GRE */

	hdr.ip6hdr.hop_limit = 0x40;

	/* fb01::1 */

	hdr.ip6hdr.saddr.s6_addr[0] = 0xfb;

	hdr.ip6hdr.saddr.s6_addr[1] = 1;

	hdr.ip6hdr.saddr.s6_addr[15] = 1;

	/* fb10::1 */

	hdr.ip6hdr.daddr.s6_addr[0] = 0xfb;

	hdr.ip6hdr.daddr.s6_addr[1] = 0x10;

	hdr.ip6hdr.daddr.s6_addr[15] = 1;



	hdr.greh.protocol = skb->protocol;



	err = bpf_lwt_push_encap(skb, BPF_LWT_ENCAP_IP, &hdr,

				 sizeof(struct encap_hdr));

	if (err)

		return BPF_DROP;



	return BPF_LWT_REROUTE;

}



char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/test_lwt_ip_encap.sh

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Original line number Diff line number Diff line 
#!/bin/bash

# SPDX-License-Identifier: GPL-2.0

#

# Setup/topology:

#

#    NS1             NS2             NS3

#   veth1 <---> veth2   veth3 <---> veth4 (the top route)

#   veth5 <---> veth6   veth7 <---> veth8 (the bottom route)

#

#   each vethN gets IPv[4|6]_N address

#

#   IPv*_SRC = IPv*_1

#   IPv*_DST = IPv*_4

#

#   all tests test pings from IPv*_SRC to IPv*_DST

#

#   by default, routes are configured to allow packets to go

#   IP*_1 <=> IP*_2 <=> IP*_3 <=> IP*_4 (the top route)

#

#   a GRE device is installed in NS3 with IPv*_GRE, and

#   NS1/NS2 are configured to route packets to IPv*_GRE via IP*_8

#   (the bottom route)

#

# Tests:

#

#   1. routes NS2->IPv*_DST are brought down, so the only way a ping

#      from IP*_SRC to IP*_DST can work is via IPv*_GRE

#

#   2a. in an egress test, a bpf LWT_XMIT program is installed on veth1

#       that encaps the packets with an IP/GRE header to route to IPv*_GRE

#

#       ping: SRC->[encap at veth1:egress]->GRE:decap->DST

#       ping replies go DST->SRC directly

#

#   2b. in an ingress test, a bpf LWT_IN program is installed on veth2

#       that encaps the packets with an IP/GRE header to route to IPv*_GRE

#

#       ping: SRC->[encap at veth2:ingress]->GRE:decap->DST

#       ping replies go DST->SRC directly



set -e  # exit on error



if [[ $EUID -ne 0 ]]; then

	echo "This script must be run as root"

	echo "FAIL"

	exit 1

fi



readonly NS1="ns1-$(mktemp -u XXXXXX)"

readonly NS2="ns2-$(mktemp -u XXXXXX)"

readonly NS3="ns3-$(mktemp -u XXXXXX)"



readonly IPv4_1="172.16.1.100"

readonly IPv4_2="172.16.2.100"

readonly IPv4_3="172.16.3.100"

readonly IPv4_4="172.16.4.100"

readonly IPv4_5="172.16.5.100"

readonly IPv4_6="172.16.6.100"

readonly IPv4_7="172.16.7.100"

readonly IPv4_8="172.16.8.100"

readonly IPv4_GRE="172.16.16.100"



readonly IPv4_SRC=$IPv4_1

readonly IPv4_DST=$IPv4_4



readonly IPv6_1="fb01::1"

readonly IPv6_2="fb02::1"

readonly IPv6_3="fb03::1"

readonly IPv6_4="fb04::1"

readonly IPv6_5="fb05::1"

readonly IPv6_6="fb06::1"

readonly IPv6_7="fb07::1"

readonly IPv6_8="fb08::1"

readonly IPv6_GRE="fb10::1"



readonly IPv6_SRC=$IPv6_1

readonly IPv6_DST=$IPv6_4



setup() {

set -e  # exit on error

	# create devices and namespaces

	ip netns add "${NS1}"

	ip netns add "${NS2}"

	ip netns add "${NS3}"



	ip link add veth1 type veth peer name veth2

	ip link add veth3 type veth peer name veth4

	ip link add veth5 type veth peer name veth6

	ip link add veth7 type veth peer name veth8



	ip netns exec ${NS2} sysctl -wq net.ipv4.ip_forward=1

	ip netns exec ${NS2} sysctl -wq net.ipv6.conf.all.forwarding=1



	ip link set veth1 netns ${NS1}

	ip link set veth2 netns ${NS2}

	ip link set veth3 netns ${NS2}

	ip link set veth4 netns ${NS3}

	ip link set veth5 netns ${NS1}

	ip link set veth6 netns ${NS2}

	ip link set veth7 netns ${NS2}

	ip link set veth8 netns ${NS3}



	# configure addesses: the top route (1-2-3-4)

	ip -netns ${NS1}    addr add ${IPv4_1}/24  dev veth1

	ip -netns ${NS2}    addr add ${IPv4_2}/24  dev veth2

	ip -netns ${NS2}    addr add ${IPv4_3}/24  dev veth3

	ip -netns ${NS3}    addr add ${IPv4_4}/24  dev veth4

	ip -netns ${NS1} -6 addr add ${IPv6_1}/128 nodad dev veth1

	ip -netns ${NS2} -6 addr add ${IPv6_2}/128 nodad dev veth2

	ip -netns ${NS2} -6 addr add ${IPv6_3}/128 nodad dev veth3

	ip -netns ${NS3} -6 addr add ${IPv6_4}/128 nodad dev veth4



	# configure addresses: the bottom route (5-6-7-8)

	ip -netns ${NS1}    addr add ${IPv4_5}/24  dev veth5

	ip -netns ${NS2}    addr add ${IPv4_6}/24  dev veth6

	ip -netns ${NS2}    addr add ${IPv4_7}/24  dev veth7

	ip -netns ${NS3}    addr add ${IPv4_8}/24  dev veth8

	ip -netns ${NS1} -6 addr add ${IPv6_5}/128 nodad dev veth5

	ip -netns ${NS2} -6 addr add ${IPv6_6}/128 nodad dev veth6

	ip -netns ${NS2} -6 addr add ${IPv6_7}/128 nodad dev veth7

	ip -netns ${NS3} -6 addr add ${IPv6_8}/128 nodad dev veth8





	ip -netns ${NS1} link set dev veth1 up

	ip -netns ${NS2} link set dev veth2 up

	ip -netns ${NS2} link set dev veth3 up

	ip -netns ${NS3} link set dev veth4 up

	ip -netns ${NS1} link set dev veth5 up

	ip -netns ${NS2} link set dev veth6 up

	ip -netns ${NS2} link set dev veth7 up

	ip -netns ${NS3} link set dev veth8 up



	# configure routes: IP*_SRC -> veth1/IP*_2 (= top route) default;

	# the bottom route to specific bottom addresses



	# NS1

	# top route

	ip -netns ${NS1}    route add ${IPv4_2}/32  dev veth1

	ip -netns ${NS1}    route add default dev veth1 via ${IPv4_2}  # go top by default

	ip -netns ${NS1} -6 route add ${IPv6_2}/128 dev veth1

	ip -netns ${NS1} -6 route add default dev veth1 via ${IPv6_2}  # go top by default

	# bottom route

	ip -netns ${NS1}    route add ${IPv4_6}/32  dev veth5

	ip -netns ${NS1}    route add ${IPv4_7}/32  dev veth5 via ${IPv4_6}

	ip -netns ${NS1}    route add ${IPv4_8}/32  dev veth5 via ${IPv4_6}

	ip -netns ${NS1} -6 route add ${IPv6_6}/128 dev veth5

	ip -netns ${NS1} -6 route add ${IPv6_7}/128 dev veth5 via ${IPv6_6}

	ip -netns ${NS1} -6 route add ${IPv6_8}/128 dev veth5 via ${IPv6_6}



	# NS2

	# top route

	ip -netns ${NS2}    route add ${IPv4_1}/32  dev veth2

	ip -netns ${NS2}    route add ${IPv4_4}/32  dev veth3

	ip -netns ${NS2} -6 route add ${IPv6_1}/128 dev veth2

	ip -netns ${NS2} -6 route add ${IPv6_4}/128 dev veth3

	# bottom route

	ip -netns ${NS2}    route add ${IPv4_5}/32  dev veth6

	ip -netns ${NS2}    route add ${IPv4_8}/32  dev veth7

	ip -netns ${NS2} -6 route add ${IPv6_5}/128 dev veth6

	ip -netns ${NS2} -6 route add ${IPv6_8}/128 dev veth7



	# NS3

	# top route

	ip -netns ${NS3}    route add ${IPv4_3}/32  dev veth4

	ip -netns ${NS3}    route add ${IPv4_1}/32  dev veth4 via ${IPv4_3}

	ip -netns ${NS3}    route add ${IPv4_2}/32  dev veth4 via ${IPv4_3}

	ip -netns ${NS3} -6 route add ${IPv6_3}/128 dev veth4

	ip -netns ${NS3} -6 route add ${IPv6_1}/128 dev veth4 via ${IPv6_3}

	ip -netns ${NS3} -6 route add ${IPv6_2}/128 dev veth4 via ${IPv6_3}

	# bottom route

	ip -netns ${NS3}    route add ${IPv4_7}/32  dev veth8

	ip -netns ${NS3}    route add ${IPv4_5}/32  dev veth8 via ${IPv4_7}

	ip -netns ${NS3}    route add ${IPv4_6}/32  dev veth8 via ${IPv4_7}

	ip -netns ${NS3} -6 route add ${IPv6_7}/128 dev veth8

	ip -netns ${NS3} -6 route add ${IPv6_5}/128 dev veth8 via ${IPv6_7}

	ip -netns ${NS3} -6 route add ${IPv6_6}/128 dev veth8 via ${IPv6_7}



	# configure IPv4 GRE device in NS3, and a route to it via the "bottom" route

	ip -netns ${NS3} tunnel add gre_dev mode gre remote ${IPv4_1} local ${IPv4_GRE} ttl 255

	ip -netns ${NS3} link set gre_dev up

	ip -netns ${NS3} addr add ${IPv4_GRE} dev gre_dev

	ip -netns ${NS1} route add ${IPv4_GRE}/32 dev veth5 via ${IPv4_6}

	ip -netns ${NS2} route add ${IPv4_GRE}/32 dev veth7 via ${IPv4_8}





	# configure IPv6 GRE device in NS3, and a route to it via the "bottom" route

	ip -netns ${NS3} -6 tunnel add name gre6_dev mode ip6gre remote ${IPv6_1} local ${IPv6_GRE} ttl 255

	ip -netns ${NS3} link set gre6_dev up

	ip -netns ${NS3} -6 addr add ${IPv6_GRE} nodad dev gre6_dev

	ip -netns ${NS1} -6 route add ${IPv6_GRE}/128 dev veth5 via ${IPv6_6}

	ip -netns ${NS2} -6 route add ${IPv6_GRE}/128 dev veth7 via ${IPv6_8}



	# rp_filter gets confused by what these tests are doing, so disable it

	ip netns exec ${NS1} sysctl -wq net.ipv4.conf.all.rp_filter=0

	ip netns exec ${NS2} sysctl -wq net.ipv4.conf.all.rp_filter=0

	ip netns exec ${NS3} sysctl -wq net.ipv4.conf.all.rp_filter=0

}



cleanup() {

	ip netns del ${NS1} 2> /dev/null

	ip netns del ${NS2} 2> /dev/null

	ip netns del ${NS3} 2> /dev/null

}



trap cleanup EXIT



test_ping() {

	local readonly PROTO=$1

	local readonly EXPECTED=$2

	local RET=0



	set +e

	if [ "${PROTO}" == "IPv4" ] ; then

		ip netns exec ${NS1} ping  -c 1 -W 1 -I ${IPv4_SRC} ${IPv4_DST} 2>&1 > /dev/null

		RET=$?

	elif [ "${PROTO}" == "IPv6" ] ; then

		ip netns exec ${NS1} ping6 -c 1 -W 6 -I ${IPv6_SRC} ${IPv6_DST} 2>&1 > /dev/null

		RET=$?

	else

		echo "test_ping: unknown PROTO: ${PROTO}"

		exit 1

	fi

	set -e



	if [ "0" != "${RET}" ]; then

		RET=1

	fi



	if [ "${EXPECTED}" != "${RET}" ] ; then

		echo "FAIL: test_ping: ${RET}"

		exit 1

	fi

}



test_egress() {

	local readonly ENCAP=$1

	echo "starting egress ${ENCAP} encap test"

	setup



	# need to wait a bit for IPv6 to autoconf, otherwise

	# ping6 sometimes fails with "unable to bind to address"



	# by default, pings work

	test_ping IPv4 0

	test_ping IPv6 0



	# remove NS2->DST routes, ping fails

	ip -netns ${NS2}    route del ${IPv4_DST}/32  dev veth3

	ip -netns ${NS2} -6 route del ${IPv6_DST}/128 dev veth3

	test_ping IPv4 1

	test_ping IPv6 1



	# install replacement routes (LWT/eBPF), pings succeed

	if [ "${ENCAP}" == "IPv4" ] ; then

		ip -netns ${NS1} route add ${IPv4_DST} encap bpf xmit obj test_lwt_ip_encap.o sec encap_gre dev veth1

		ip -netns ${NS1} -6 route add ${IPv6_DST} encap bpf xmit obj test_lwt_ip_encap.o sec encap_gre dev veth1

	elif [ "${ENCAP}" == "IPv6" ] ; then

		ip -netns ${NS1} route add ${IPv4_DST} encap bpf xmit obj test_lwt_ip_encap.o sec encap_gre6 dev veth1

		ip -netns ${NS1} -6 route add ${IPv6_DST} encap bpf xmit obj test_lwt_ip_encap.o sec encap_gre6 dev veth1

	else

		echo "FAIL: unknown encap ${ENCAP}"

	fi

	test_ping IPv4 0

	test_ping IPv6 0



	cleanup

	echo "PASS"

}



test_ingress() {

	local readonly ENCAP=$1

	echo "starting ingress ${ENCAP} encap test"

	setup



	# need to wait a bit for IPv6 to autoconf, otherwise

	# ping6 sometimes fails with "unable to bind to address"



	# by default, pings work

	test_ping IPv4 0

	test_ping IPv6 0



	# remove NS2->DST routes, pings fail

	ip -netns ${NS2}    route del ${IPv4_DST}/32  dev veth3

	ip -netns ${NS2} -6 route del ${IPv6_DST}/128 dev veth3

	test_ping IPv4 1

	test_ping IPv6 1



	# install replacement routes (LWT/eBPF), pings succeed

	if [ "${ENCAP}" == "IPv4" ] ; then

		ip -netns ${NS2} route add ${IPv4_DST} encap bpf in obj test_lwt_ip_encap.o sec encap_gre dev veth2

		ip -netns ${NS2} -6 route add ${IPv6_DST} encap bpf in obj test_lwt_ip_encap.o sec encap_gre dev veth2

	elif [ "${ENCAP}" == "IPv6" ] ; then

		ip -netns ${NS2} route add ${IPv4_DST} encap bpf in obj test_lwt_ip_encap.o sec encap_gre6 dev veth2

		ip -netns ${NS2} -6 route add ${IPv6_DST} encap bpf in obj test_lwt_ip_encap.o sec encap_gre6 dev veth2

	else

		echo "FAIL: unknown encap ${ENCAP}"

	fi

	test_ping IPv4 0

	test_ping IPv6 0



	cleanup

	echo "PASS"

}



test_egress IPv4

test_egress IPv6



test_ingress IPv4

test_ingress IPv6



echo "all tests passed"