On 02/13, Peter Oskolkov wrote:
> 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: Peter Oskolkov <p...@google.com>
> ---
> tools/testing/selftests/bpf/Makefile | 3 +-
> .../selftests/bpf/progs/test_lwt_ip_encap.c | 85 +++++
> .../selftests/bpf/test_lwt_ip_encap.sh | 311 ++++++++++++++++++
> 3 files changed, 398 insertions(+), 1 deletion(-)
> create mode 100644 tools/testing/selftests/bpf/progs/test_lwt_ip_encap.c
> create mode 100755 tools/testing/selftests/bpf/test_lwt_ip_encap.sh
>
> diff --git a/tools/testing/selftests/bpf/Makefile
> b/tools/testing/selftests/bpf/Makefile
> index c3edf47da05d..ccffaa0a0787 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -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 \
> diff --git a/tools/testing/selftests/bpf/progs/test_lwt_ip_encap.c
> b/tools/testing/selftests/bpf/progs/test_lwt_ip_encap.c
> new file mode 100644
> index 000000000000..c957d6dfe6d7
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/test_lwt_ip_encap.c
> @@ -0,0 +1,85 @@
> +// 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
Nit, why not just:
hdr.iph.saddr = bpf_htonl(0xac100164); /* 172.16.1.100 */
hdr.iph.daddr = bpf_htonl(0xac101064); /* 172.16.16.100 */
?
> + 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";
> diff --git a/tools/testing/selftests/bpf/test_lwt_ip_encap.sh
> b/tools/testing/selftests/bpf/test_lwt_ip_encap.sh
> new file mode 100755
> index 000000000000..4ca714e23ab0
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/test_lwt_ip_encap.sh
> @@ -0,0 +1,311 @@
> +#!/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"
> --
> 2.20.1.791.gb4d0f1c61a-goog
>
