add tests which verify packet capture works for tracing of kprobes and raw tracepoints, and for capturing packets from existing skb/xdp programs.
Signed-off-by: Alan Maguire alan.maguire@oracle.com --- tools/testing/selftests/bpf/Makefile | 3 +- .../testing/selftests/bpf/progs/bpftool_pcap_tc.c | 41 +++++++ .../testing/selftests/bpf/progs/bpftool_pcap_xdp.c | 39 ++++++ tools/testing/selftests/bpf/test_bpftool_pcap.sh | 132 +++++++++++++++++++++ 4 files changed, 214 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/progs/bpftool_pcap_tc.c create mode 100644 tools/testing/selftests/bpf/progs/bpftool_pcap_xdp.c create mode 100755 tools/testing/selftests/bpf/test_bpftool_pcap.sh
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 7f3196a..1e8b68d 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -66,7 +66,8 @@ TEST_PROGS := test_kmod.sh \ test_tc_tunnel.sh \ test_tc_edt.sh \ test_xdping.sh \ - test_bpftool_build.sh + test_bpftool_build.sh \ + test_bpftool_pcap.sh
TEST_PROGS_EXTENDED := with_addr.sh \ with_tunnels.sh \ diff --git a/tools/testing/selftests/bpf/progs/bpftool_pcap_tc.c b/tools/testing/selftests/bpf/progs/bpftool_pcap_tc.c new file mode 100644 index 0000000..b51f8fc --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpftool_pcap_tc.c @@ -0,0 +1,41 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. */ + +#include <stddef.h> +#include <linux/ptrace.h> +#include <linux/bpf.h> +#include <linux/pkt_cls.h> + +#include <bpf_helpers.h> + +#define KBUILD_MODNAME "foo" + +struct bpf_map_def SEC("maps") pcap_data_map = { + .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 1024, +}; + +struct bpf_map_def SEC("maps") pcap_conf_map = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(struct bpf_pcap_hdr), + .max_entries = 1, +}; + +SEC("tc_pcap") +int tc_pcap(struct __sk_buff *skb) +{ + struct bpf_pcap_hdr *conf; + int key = 0; + + conf = bpf_map_lookup_elem(&pcap_conf_map, &key); + if (!conf) + return 0; + + bpf_pcap(skb, conf->cap_len, &pcap_data_map, conf->protocol, + conf->flags); + + return TC_ACT_OK; +} diff --git a/tools/testing/selftests/bpf/progs/bpftool_pcap_xdp.c b/tools/testing/selftests/bpf/progs/bpftool_pcap_xdp.c new file mode 100644 index 0000000..a7d6866 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpftool_pcap_xdp.c @@ -0,0 +1,39 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. */ + +#include <stddef.h> +#include <linux/bpf.h> + +#include <bpf_helpers.h> + +#define KBUILD_MODNAME "foo" + +struct bpf_map_def SEC("maps") pcap_data_map = { + .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 1024, +}; + +struct bpf_map_def SEC("maps") pcap_conf_map = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(struct bpf_pcap_hdr), + .max_entries = 1, +}; + +SEC("xdp_pcap") +int xdp_pcap(struct xdp_md *ctx) +{ + struct bpf_pcap_hdr *conf; + int key = 0; + + conf = bpf_map_lookup_elem(&pcap_conf_map, &key); + if (!conf) + return 0; + + bpf_pcap(ctx, conf->cap_len, &pcap_data_map, conf->protocol, + conf->flags); + + return XDP_PASS; +} diff --git a/tools/testing/selftests/bpf/test_bpftool_pcap.sh b/tools/testing/selftests/bpf/test_bpftool_pcap.sh new file mode 100755 index 0000000..92b5438 --- /dev/null +++ b/tools/testing/selftests/bpf/test_bpftool_pcap.sh @@ -0,0 +1,132 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. + +readonly src="../../../../" +readonly bpftool="${src}/tools/bpf/bpftool/bpftool" +readonly capfile="/tmp/cap.$$" +readonly ns="ns-$$" +readonly badport="5555" +readonly addr1="192.168.1.1" +readonly addr2="192.168.1.2" +readonly pinpath="/sys/fs/bpf/" +readonly veth1="${ns}-veth1" +readonly veth2="${ns}-veth2" +# 24 bytes for the pcap header +readonly cap_minsize=24 +readonly caplens="0 8192" +readonly addrs="127.0.0.1 ::1" +readonly devs="none lo" + +cleanup() { + iptables -D INPUT -p tcp --dport $badport -j DROP + ip6tables -D INPUT -p tcp --dport $badport -j DROP + ip netns del $ns 2>/dev/null + rm -f $capfile +} + +verify_capture() { + capsize=$(stat -c '%s' $capfile) + if [[ $capsize -le $cap_minsize ]]; then + exit 1 + fi + if [[ $no_tcpdump == 0 ]]; then + count=$(tcpdump -lnr $capfile $1 2>/dev/null) + if [[ -z "$count" ]]; then + exit 1 + fi + fi +} + +which tcpdump 2>&1 > /dev/null +no_tcpdump=$? + +pcap_supported=$(bpftool pcap help >/dev/null 2>&1) +if [[ $? -ne 0 ]]; then + echo "no pcap support in bpftool, cannot test feature." + exit 0 +fi + +set -e + +trap cleanup EXIT + +iptables -A INPUT -p tcp --dport $badport -j DROP +ip6tables -A INPUT -p tcp --dport $badport -j DROP + +# Test "bpftool pcap trace" - kprobe, tracepoint tracing +for probe in kprobe tracepoint; do + for dev in $devs; do + devarg= + if [[ $dev != "none" ]]; then + devarg="dev $dev" + fi + args="$probe:kfree_skb proto ip data_out $capfile $devarg" + echo "Test trace $args" + for caplen in $caplens ; do + for progname in none $probe ; do + progpath= + if [[ $progname != "none" ]]; then + progpath=${bpftool}_pcap_${probe}.o + fi + allargs="$progpath $args len $caplen" + for addr in $addrs ; do + $bpftool pcap trace $allargs & + bpftool_pid=$! + set +e + timeout 2 nc $addr $badport 2>/dev/null + kill -TERM $bpftool_pid + set -e + sleep 1 + verify_capture "host $addr and port $badport" + rm -f $capfile + done + done + done + echo "Test trace $args: PASS" + done +done + +# Test "bpftool pcap prog" - skb, xdp program tracing +ip netns add $ns +ip link add dev $veth2 netns $ns type veth peer name $veth1 +ip link set $veth1 up +ip addr add ${addr1}/24 dev $veth1 +ip -netns $ns link set $veth2 up +ip netns exec $ns ip addr add ${addr2}/24 dev $veth2 + +for prog in tc xdp ; do + if [[ $prog == tc ]]; then + ip netns exec $ns tc qdisc add dev $veth2 clsact + ip netns exec $ns tc filter add dev $veth2 ingress bpf da \ + obj bpftool_pcap_${prog}.o sec ${prog}_pcap + id=$(ip netns exec $ns tc filter show dev $veth2 ingress | \ + awk '/direct-action/ { for(i=1;i<=NF;i++)if($i=="id")print $(i+1)}') + else + ip netns exec $ns ip link set dev $veth2 xdp obj bpftool_pcap_${prog}.o \ + sec ${prog}_pcap + id=$(ip netns exec $ns ip link show $veth2 | awk '/prog/xdp/ { print $3 }') + sleep 5 + fi + args="id $id data_out $capfile" + echo "Test prog $args" + for caplen in $caplens ; do + allargs="$args len $caplen" + $bpftool pcap prog $allargs & + bpftool_pid=$! + set +e + ping -q -c 5 $addr2 1>/dev/null + kill -TERM $bpftool_pid + set -e + sleep 1 + verify_capture "host $addr1" + rm -f $capfile + done + if [[ $prog == tc ]]; then + ip netns exec $ns tc qdisc del dev $veth2 clsact + sleep 1 + else + ip netns exec $ns ip link set dev $veth2 xdp off + fi + echo "Test trace $args: PASS" +done