From patchwork Fri Jan 7 21:54:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= X-Patchwork-Id: 12707095 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EC423C4332F for ; Fri, 7 Jan 2022 21:54:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230205AbiAGVys (ORCPT ); Fri, 7 Jan 2022 16:54:48 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:21105 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230142AbiAGVyr (ORCPT ); Fri, 7 Jan 2022 16:54:47 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1641592486; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=C30WN8dCHLdbfh99BPY5gF72+lpcQTAlFKzrznTegsU=; b=CYJ16vu59XijbLvb5/HxYhzkPwTxPcXNIWElriJXuzxHH+SfuOy839janPwjz6JtD8VKCH +srwUYbER02lU8e4aGNX60vV4eGEBguhSAVHbxoYmfE+vY242kkvsTNUECxQ+t5NDTA3Hh xegCIRaavLPSpGC41pcB3Oj2am2E/YI= Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-418-jnMM7sMrNbCz9AR_jUXUqw-1; Fri, 07 Jan 2022 16:54:45 -0500 X-MC-Unique: jnMM7sMrNbCz9AR_jUXUqw-1 Received: by mail-ed1-f70.google.com with SMTP id ec25-20020a0564020d5900b003fc074c5d21so1390306edb.19 for ; Fri, 07 Jan 2022 13:54:45 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=C30WN8dCHLdbfh99BPY5gF72+lpcQTAlFKzrznTegsU=; b=7HXsjlSERX97LthZ5wzvUrGU1fBN1vB/uJeZXR6sPhoL+wl5FKx7VDNF2RpiS0O7iB /1IBta1W8dab/0IB653I6YapMiimVj1wOMZs68Ue7Q/D8GCzjuUsnAVayC52JqGR6DTN 3W3t5K86cAH+mU+11CEWggkiaxsTlmhqbktMsLOuhRpmaLn4vTDF1jjM7PJaI89Vm+kK Hcd39QmVO5CVTEFPEC+spC7SAUmkCShkc23Mvnks70t4Me6z9dPYUPmdxiPzQ+SXdyhb ZAE8M0V3TP0ihiuf61xNdVlH2zGiNhlYWBws0ivi6+Z5ke/4EqlqfcvAf4RYfA5vG0cP mhVA== X-Gm-Message-State: AOAM532/q7J8zPvjVdNBc7QmNPzjCD0714zkT8s41CVPDtZxdD9zcIXQ G1RZa/tv6Q8iqwE2HPbLlc4+3x+dFO2JeLkLPdD2uCOke/Dx8/lYjdTIR53VlREV7PgHZGHdZ9E qJtzHDCKgbrsBjGeH X-Received: by 2002:aa7:d793:: with SMTP id s19mr5060958edq.85.1641592484341; Fri, 07 Jan 2022 13:54:44 -0800 (PST) X-Google-Smtp-Source: ABdhPJyKsYzPPw6ysf/axAQAzPdvgaSMHYoAKMptNcrAvW7tbLlECwPRB/JBWVW+BKHmSQp02wB0wQ== X-Received: by 2002:aa7:d793:: with SMTP id s19mr5060935edq.85.1641592483930; Fri, 07 Jan 2022 13:54:43 -0800 (PST) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id 16sm1760693ejx.149.2022.01.07.13.54.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Jan 2022 13:54:43 -0800 (PST) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id D7B0E181F2F; Fri, 7 Jan 2022 22:54:42 +0100 (CET) From: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= To: Alexei Starovoitov , Daniel Borkmann , "David S. Miller" , Jakub Kicinski , Jesper Dangaard Brouer , John Fastabend , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , KP Singh Cc: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , Shuah Khan , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH bpf-next v7 3/3] selftests/bpf: Add selftest for XDP_REDIRECT in bpf_prog_run() Date: Fri, 7 Jan 2022 22:54:38 +0100 Message-Id: <20220107215438.321922-4-toke@redhat.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220107215438.321922-1-toke@redhat.com> References: <20220107215438.321922-1-toke@redhat.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net This adds a selftest for the XDP_REDIRECT facility in bpf_prog_run, that redirects packets into a veth and counts them using an XDP program on the other side of the veth pair and a TC program on the local side of the veth. Signed-off-by: Toke Høiland-Jørgensen --- .../bpf/prog_tests/xdp_do_redirect.c | 175 ++++++++++++++++++ .../bpf/progs/test_xdp_do_redirect.c | 85 +++++++++ 2 files changed, 260 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_do_redirect.c diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c b/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c new file mode 100644 index 000000000000..2c17edc3bd5a --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c @@ -0,0 +1,175 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "test_xdp_do_redirect.skel.h" + +#define SYS(fmt, ...) \ + ({ \ + char cmd[1024]; \ + snprintf(cmd, sizeof(cmd), fmt, ##__VA_ARGS__); \ + if (!ASSERT_OK(system(cmd), cmd)) \ + goto out; \ + }) + +struct udp_packet { + struct ethhdr eth; + struct ipv6hdr iph; + struct udphdr udp; + __u8 payload[64 - sizeof(struct udphdr) + - sizeof(struct ethhdr) - sizeof(struct ipv6hdr)]; +} __packed; + +static struct udp_packet pkt_udp = { + .eth.h_proto = __bpf_constant_htons(ETH_P_IPV6), + .eth.h_dest = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55}, + .eth.h_source = {0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb}, + .iph.version = 6, + .iph.nexthdr = IPPROTO_UDP, + .iph.payload_len = bpf_htons(sizeof(struct udp_packet) + - offsetof(struct udp_packet, udp)), + .iph.hop_limit = 2, + .iph.saddr.s6_addr16 = {bpf_htons(0xfc00), 0, 0, 0, 0, 0, 0, bpf_htons(1)}, + .iph.daddr.s6_addr16 = {bpf_htons(0xfc00), 0, 0, 0, 0, 0, 0, bpf_htons(2)}, + .udp.source = bpf_htons(1), + .udp.dest = bpf_htons(1), + .udp.len = bpf_htons(sizeof(struct udp_packet) + - offsetof(struct udp_packet, udp)), + .payload = {0x42}, /* receiver XDP program matches on this */ +}; + +static int attach_tc_prog(struct bpf_tc_hook *hook, int fd) +{ + DECLARE_LIBBPF_OPTS(bpf_tc_opts, opts, .handle = 1, .priority = 1, .prog_fd = fd); + int ret; + + ret = bpf_tc_hook_create(hook); + if (!ASSERT_OK(ret, "create tc hook")) + return ret; + + ret = bpf_tc_attach(hook, &opts); + if (!ASSERT_OK(ret, "bpf_tc_attach")) { + bpf_tc_hook_destroy(hook); + return ret; + } + + return 0; +} + +#define NUM_PKTS 1000000 +void test_xdp_do_redirect(void) +{ + int err, xdp_prog_fd, tc_prog_fd, ifindex_src, ifindex_dst; + char data[sizeof(pkt_udp) + sizeof(__u32)]; + struct test_xdp_do_redirect *skel = NULL; + struct nstoken *nstoken = NULL; + struct bpf_link *link; + + struct xdp_md ctx_in = { .data = sizeof(__u32), + .data_end = sizeof(data) }; + DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts, + .data_in = &data, + .data_size_in = sizeof(data), + .ctx_in = &ctx_in, + .ctx_size_in = sizeof(ctx_in), + .flags = BPF_F_TEST_XDP_LIVE_FRAMES, + .repeat = NUM_PKTS, + ); + DECLARE_LIBBPF_OPTS(bpf_tc_hook, tc_hook, + .attach_point = BPF_TC_INGRESS); + + memcpy(&data[sizeof(__u32)], &pkt_udp, sizeof(pkt_udp)); + *((__u32 *)data) = 0x42; /* metadata test value */ + + skel = test_xdp_do_redirect__open(); + if (!ASSERT_OK_PTR(skel, "skel")) + return; + + /* The XDP program we run with bpf_prog_run() will cycle through all + * three xmit (PASS/TX/REDIRECT) return codes starting from above, and + * ending up with PASS, so we should end up with two packets on the dst + * iface and NUM_PKTS-2 in the TC hook. We match the packets on the UDP + * payload. + */ + SYS("ip netns add testns"); + nstoken = open_netns("testns"); + if (!ASSERT_OK_PTR(nstoken, "setns")) + goto out; + + SYS("ip link add veth_src type veth peer name veth_dst"); + SYS("ip link set dev veth_src address 00:11:22:33:44:55"); + SYS("ip link set dev veth_dst address 66:77:88:99:aa:bb"); + SYS("ip link set dev veth_src up"); + SYS("ip link set dev veth_dst up"); + SYS("ip addr add dev veth_src fc00::1/64"); + SYS("ip addr add dev veth_dst fc00::2/64"); + SYS("ip neigh add fc00::2 dev veth_src lladdr 66:77:88:99:aa:bb"); + + /* We enable forwarding in the test namespace because that will cause + * the packets that go through the kernel stack (with XDP_PASS) to be + * forwarded back out the same interface (because of the packet dst + * combined with the interface addresses). When this happens, the + * regular forwarding path will end up going through the same + * veth_xdp_xmit() call as the XDP_REDIRECT code, which can cause a + * deadlock if it happens on the same CPU. There's a local_bh_disable() + * in the test_run code to prevent this, but an earlier version of the + * code didn't have this, so we keep the test behaviour to make sure the + * bug doesn't resurface. + */ + SYS("sysctl -qw net.ipv6.conf.all.forwarding=1"); + + ifindex_src = if_nametoindex("veth_src"); + ifindex_dst = if_nametoindex("veth_dst"); + if (!ASSERT_NEQ(ifindex_src, 0, "ifindex_src") || + !ASSERT_NEQ(ifindex_dst, 0, "ifindex_dst")) + goto out; + + memcpy(skel->rodata->expect_dst, &pkt_udp.eth.h_dest, ETH_ALEN); + skel->rodata->ifindex_out = ifindex_src; /* redirect back to the same iface */ + skel->rodata->ifindex_in = ifindex_src; + ctx_in.ingress_ifindex = ifindex_src; + tc_hook.ifindex = ifindex_src; + + if (!ASSERT_OK(test_xdp_do_redirect__load(skel), "load")) + goto out; + + link = bpf_program__attach_xdp(skel->progs.xdp_count_pkts, ifindex_dst); + if (!ASSERT_OK_PTR(link, "prog_attach")) + goto out; + skel->links.xdp_count_pkts = link; + + tc_prog_fd = bpf_program__fd(skel->progs.tc_count_pkts); + if (attach_tc_prog(&tc_hook, tc_prog_fd)) + goto out; + + xdp_prog_fd = bpf_program__fd(skel->progs.xdp_redirect); + err = bpf_prog_test_run_opts(xdp_prog_fd, &opts); + if (!ASSERT_OK(err, "prog_run")) + goto out_tc; + + /* wait for the packets to be flushed */ + kern_sync_rcu(); + + /* There will be one packet sent through XDP_REDIRECT and one through + * XDP_TX; these will show up on the XDP counting program, while the + * rest will be counted at the TC ingress hook (and the counting program + * resets the packet payload so they don't get counted twice even though + * they are re-xmited out the veth device + */ + ASSERT_EQ(skel->bss->pkts_seen_xdp, 2, "pkt_count_xdp"); + ASSERT_EQ(skel->bss->pkts_seen_tc, NUM_PKTS - 2, "pkt_count_tc"); + +out_tc: + bpf_tc_hook_destroy(&tc_hook); +out: + if (nstoken) + close_netns(nstoken); + system("ip netns del testns"); + test_xdp_do_redirect__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_xdp_do_redirect.c b/tools/testing/selftests/bpf/progs/test_xdp_do_redirect.c new file mode 100644 index 000000000000..af3cffccc794 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_xdp_do_redirect.c @@ -0,0 +1,85 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include + +#define ETH_ALEN 6 +const volatile int ifindex_out; +const volatile int ifindex_in; +const volatile __u8 expect_dst[ETH_ALEN]; +volatile int pkts_seen_xdp = 0; +volatile int pkts_seen_tc = 0; +volatile int retcode = XDP_REDIRECT; + +SEC("xdp") +int xdp_redirect(struct xdp_md *xdp) +{ + __u32 *metadata = (void *)(long)xdp->data_meta; + void *data = (void *)(long)xdp->data; + int ret = retcode; + + if (xdp->ingress_ifindex != ifindex_in) + return XDP_ABORTED; + + if (metadata + 1 > data) + return XDP_ABORTED; + + if (*metadata != 0x42) + return XDP_ABORTED; + + if (bpf_xdp_adjust_meta(xdp, 4)) + return XDP_ABORTED; + + if (retcode > XDP_PASS) + retcode--; + + if (ret == XDP_REDIRECT) + return bpf_redirect(ifindex_out, 0); + + return ret; +} + +static bool check_pkt(void *data, void *data_end) +{ + struct ethhdr *eth = data; + struct ipv6hdr *iph = (void *)(eth + 1); + struct udphdr *udp = (void *)(iph + 1); + __u8 *payload = (void *)(udp + 1); + + if (payload + 1 > data_end) + return false; + + if (iph->nexthdr != IPPROTO_UDP || *payload != 0x42) + return false; + + /* reset the payload so the same packet doesn't get counted twice when + * it cycles back through the kernel path and out the dst veth + */ + *payload = 0; + return true; +} + +SEC("xdp") +int xdp_count_pkts(struct xdp_md *xdp) +{ + void *data = (void *)(long)xdp->data; + void *data_end = (void *)(long)xdp->data_end; + + if (check_pkt(data, data_end)) + pkts_seen_xdp++; + + return XDP_PASS; +} + +SEC("tc") +int tc_count_pkts(struct __sk_buff *skb) +{ + void *data = (void *)(long)skb->data; + void *data_end = (void *)(long)skb->data_end; + + if (check_pkt(data, data_end)) + pkts_seen_tc++; + + return 0; +} + +char _license[] SEC("license") = "GPL";