From: Willem de Bruijn Date: Fri, 22 Mar 2019 18:32:49 +0000 (-0400) Subject: selftests/bpf: bpf tunnel encap test X-Git-Tag: v5.15~6431^2~307^2~5^2~11 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=98cdabcd0798bd9991821493120b928ed0dfab73;p=platform%2Fkernel%2Flinux-starfive.git selftests/bpf: bpf tunnel encap test Validate basic tunnel encapsulation using ipip. Set up two namespaces connected by veth. Connect a client and server. Do this with and without bpf encap. Signed-off-by: Willem de Bruijn Signed-off-by: Alexei Starovoitov --- diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index edd5970..cdcc54d 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -52,7 +52,8 @@ TEST_PROGS := test_kmod.sh \ test_flow_dissector.sh \ test_xdp_vlan.sh \ test_lwt_ip_encap.sh \ - test_tcp_check_syncookie.sh + test_tcp_check_syncookie.sh \ + test_tc_tunnel.sh TEST_PROGS_EXTENDED := with_addr.sh \ with_tunnels.sh \ diff --git a/tools/testing/selftests/bpf/progs/test_tc_tunnel.c b/tools/testing/selftests/bpf/progs/test_tc_tunnel.c new file mode 100644 index 0000000..8223e43 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_tc_tunnel.c @@ -0,0 +1,83 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* In-place tunneling */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "bpf_endian.h" +#include "bpf_helpers.h" + +static const int cfg_port = 8000; + +static __always_inline void set_ipv4_csum(struct iphdr *iph) +{ + __u16 *iph16 = (__u16 *)iph; + __u32 csum; + int i; + + iph->check = 0; + +#pragma clang loop unroll(full) + for (i = 0, csum = 0; i < sizeof(*iph) >> 1; i++) + csum += *iph16++; + + iph->check = ~((csum & 0xffff) + (csum >> 16)); +} + +SEC("encap") +int encap_f(struct __sk_buff *skb) +{ + struct iphdr iph_outer, iph_inner; + struct tcphdr tcph; + + if (skb->protocol != __bpf_constant_htons(ETH_P_IP)) + return TC_ACT_OK; + + if (bpf_skb_load_bytes(skb, ETH_HLEN, &iph_inner, + sizeof(iph_inner)) < 0) + return TC_ACT_OK; + + /* filter only packets we want */ + if (iph_inner.ihl != 5 || iph_inner.protocol != IPPROTO_TCP) + return TC_ACT_OK; + + if (bpf_skb_load_bytes(skb, ETH_HLEN + sizeof(iph_inner), + &tcph, sizeof(tcph)) < 0) + return TC_ACT_OK; + + if (tcph.dest != __bpf_constant_htons(cfg_port)) + return TC_ACT_OK; + + /* add room between mac and network header */ + if (bpf_skb_adjust_room(skb, sizeof(iph_outer), BPF_ADJ_ROOM_NET, 0)) + return TC_ACT_SHOT; + + /* prepare new outer network header */ + iph_outer = iph_inner; + iph_outer.protocol = IPPROTO_IPIP; + iph_outer.tot_len = bpf_htons(sizeof(iph_outer) + + bpf_htons(iph_outer.tot_len)); + set_ipv4_csum(&iph_outer); + + /* store new outer network header */ + if (bpf_skb_store_bytes(skb, ETH_HLEN, &iph_outer, sizeof(iph_outer), + BPF_F_INVALIDATE_HASH) < 0) + return TC_ACT_SHOT; + + /* bpf_skb_adjust_room has moved header to start of room: restore */ + if (bpf_skb_store_bytes(skb, ETH_HLEN + sizeof(iph_outer), + &iph_inner, sizeof(iph_inner), + BPF_F_INVALIDATE_HASH) < 0) + return TC_ACT_SHOT; + + return TC_ACT_OK; +} + +char __license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/test_tc_tunnel.sh b/tools/testing/selftests/bpf/test_tc_tunnel.sh new file mode 100755 index 0000000..6ebb288 --- /dev/null +++ b/tools/testing/selftests/bpf/test_tc_tunnel.sh @@ -0,0 +1,75 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# In-place tunneling + +# must match the port that the bpf program filters on +readonly port=8000 + +readonly ns_prefix="ns-$$-" +readonly ns1="${ns_prefix}1" +readonly ns2="${ns_prefix}2" + +readonly ns1_v4=192.168.1.1 +readonly ns2_v4=192.168.1.2 + +setup() { + ip netns add "${ns1}" + ip netns add "${ns2}" + + ip link add dev veth1 mtu 1500 netns "${ns1}" type veth \ + peer name veth2 mtu 1500 netns "${ns2}" + + ip -netns "${ns1}" link set veth1 up + ip -netns "${ns2}" link set veth2 up + + ip -netns "${ns1}" -4 addr add "${ns1_v4}/24" dev veth1 + ip -netns "${ns2}" -4 addr add "${ns2_v4}/24" dev veth2 + + sleep 1 +} + +cleanup() { + ip netns del "${ns2}" + ip netns del "${ns1}" +} + +server_listen() { + ip netns exec "${ns2}" nc -l -p "${port}" & + sleep 0.2 +} + +client_connect() { + ip netns exec "${ns1}" nc -z -w 1 "${ns2_v4}" "${port}" + echo $? +} + +set -e +trap cleanup EXIT + +setup + +# basic communication works +echo "test basic connectivity" +server_listen +client_connect + +# clientside, insert bpf program to encap all TCP to port ${port} +# client can no longer connect +ip netns exec "${ns1}" tc qdisc add dev veth1 clsact +ip netns exec "${ns1}" tc filter add dev veth1 egress \ + bpf direct-action object-file ./test_tc_tunnel.o section encap +echo "test bpf encap without decap (expect failure)" +server_listen +! client_connect + +# serverside, insert decap module +# server is still running +# client can connect again +ip netns exec "${ns2}" ip link add dev testtun0 type ipip \ + remote "${ns1_v4}" local "${ns2_v4}" +ip netns exec "${ns2}" ip link set dev testtun0 up +echo "test bpf encap with tunnel device decap" +client_connect + +echo OK