From patchwork Tue Dec 20 23:13:44 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin KaFai Lau X-Patchwork-Id: 13078240 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 6EA10C3DA6E for ; Tue, 20 Dec 2022 23:14:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232195AbiLTXN6 (ORCPT ); Tue, 20 Dec 2022 18:13:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57916 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229944AbiLTXN4 (ORCPT ); Tue, 20 Dec 2022 18:13:56 -0500 Received: from out-240.mta0.migadu.com (out-240.mta0.migadu.com [91.218.175.240]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF4711F62E for ; Tue, 20 Dec 2022 15:13:54 -0800 (PST) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1671578032; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Cz2KXS/INUjALXR4cbN+Pplq/L9eWXpKY50+u9kBeY0=; b=ua9UNlr8yjJeIb/A/HxZ5EDx2EJ6SaXTNw0wxty/yGox7eN33Hl8VzuEJUoOFNY7vFg0/q jjc3s5H6ENS5bkvmhTX/wQllkUV4bLSzpWzX+mYeamNDJt2k+vsmh7g4ypjzBd/NOYPTnu SJ6cU/hbJ9xaDu3TOH52PQMAUhPEknY= From: Martin KaFai Lau To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , netdev@vger.kernel.org, kernel-team@meta.com Subject: [PATCH bpf] selftests/bpf: Test bpf_skb_adjust_room on CHECKSUM_PARTIAL Date: Tue, 20 Dec 2022 15:13:44 -0800 Message-Id: <20221220231344.2262134-1-martin.lau@linux.dev> In-Reply-To: <20221220004701.402165-2-kuba@kernel.org> References: <20221220004701.402165-2-kuba@kernel.org> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Martin KaFai Lau When the bpf_skb_adjust_room() shrinks the skb such that its csum_start is invalid, the skb->ip_summed should be reset from CHECKSUM_PARTIAL to CHECKSUM_NONE. This patch adds a test to ensure the skb->ip_summed changed from CHECKSUM_PARTIAL to CHECKSUM_NONE after bpf_skb_adjust_room(). Signed-off-by: Martin KaFai Lau --- .../selftests/bpf/prog_tests/decap_sanity.c | 83 +++++++++++++++++++ .../selftests/bpf/progs/bpf_tracing_net.h | 6 ++ .../selftests/bpf/progs/decap_sanity.c | 68 +++++++++++++++ 3 files changed, 157 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/decap_sanity.c create mode 100644 tools/testing/selftests/bpf/progs/decap_sanity.c diff --git a/tools/testing/selftests/bpf/prog_tests/decap_sanity.c b/tools/testing/selftests/bpf/prog_tests/decap_sanity.c new file mode 100644 index 000000000000..2fbb3017b740 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/decap_sanity.c @@ -0,0 +1,83 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include +#include + +#include "test_progs.h" +#include "network_helpers.h" +#include "decap_sanity.skel.h" + +#define SYS(fmt, ...) \ + ({ \ + char cmd[1024]; \ + snprintf(cmd, sizeof(cmd), fmt, ##__VA_ARGS__); \ + if (!ASSERT_OK(system(cmd), cmd)) \ + goto fail; \ + }) + +#define NS_TEST "decap_sanity_ns" +#define IPV6_IFACE_ADDR "face::1" +#define UDP_TEST_PORT 7777 + +void test_decap_sanity(void) +{ + LIBBPF_OPTS(bpf_tc_hook, qdisc_hook, .attach_point = BPF_TC_EGRESS); + LIBBPF_OPTS(bpf_tc_opts, tc_attach); + struct nstoken *nstoken = NULL; + struct decap_sanity *skel; + struct sockaddr_in6 addr; + socklen_t addrlen; + char buf[128] = {}; + int sockfd, err; + + skel = decap_sanity__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel open_and_load")) + return; + + SYS("ip netns add %s", NS_TEST); + SYS("ip -net %s -6 addr add %s/128 dev lo nodad", NS_TEST, IPV6_IFACE_ADDR); + SYS("ip -net %s link set dev lo up", NS_TEST); + + nstoken = open_netns(NS_TEST); + if (!ASSERT_OK_PTR(nstoken, "open_netns")) + goto fail; + + qdisc_hook.ifindex = if_nametoindex("lo"); + if (!ASSERT_GT(qdisc_hook.ifindex, 0, "if_nametoindex lo")) + goto fail; + + err = bpf_tc_hook_create(&qdisc_hook); + if (!ASSERT_OK(err, "create qdisc hook")) + goto fail; + + tc_attach.prog_fd = bpf_program__fd(skel->progs.decap_sanity); + err = bpf_tc_attach(&qdisc_hook, &tc_attach); + if (!ASSERT_OK(err, "attach filter")) + goto fail; + + addrlen = sizeof(addr); + err = make_sockaddr(AF_INET6, IPV6_IFACE_ADDR, UDP_TEST_PORT, + (void *)&addr, &addrlen); + if (!ASSERT_OK(err, "make_sockaddr")) + goto fail; + sockfd = socket(AF_INET6, SOCK_DGRAM, 0); + if (!ASSERT_NEQ(sockfd, -1, "socket")) + goto fail; + err = sendto(sockfd, buf, sizeof(buf), 0, (void *)&addr, addrlen); + close(sockfd); + if (!ASSERT_EQ(err, sizeof(buf), "send")) + goto fail; + + ASSERT_EQ(skel->bss->init_csum_partial, true, "init_csum_partial"); + ASSERT_EQ(skel->bss->final_csum_none, true, "final_csum_none"); + ASSERT_EQ(skel->bss->broken_csum_start, false, "broken_csum_start"); + +fail: + if (nstoken) + close_netns(nstoken); + system("ip netns del " NS_TEST " >& /dev/null"); + decap_sanity__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h index b394817126cf..cfed4df490f3 100644 --- a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h +++ b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h @@ -50,6 +50,12 @@ #define ICSK_TIME_LOSS_PROBE 5 #define ICSK_TIME_REO_TIMEOUT 6 +#define ETH_HLEN 14 +#define ETH_P_IPV6 0x86DD + +#define CHECKSUM_NONE 0 +#define CHECKSUM_PARTIAL 3 + #define IFNAMSIZ 16 #define RTF_GATEWAY 0x0002 diff --git a/tools/testing/selftests/bpf/progs/decap_sanity.c b/tools/testing/selftests/bpf/progs/decap_sanity.c new file mode 100644 index 000000000000..b85113554cbf --- /dev/null +++ b/tools/testing/selftests/bpf/progs/decap_sanity.c @@ -0,0 +1,68 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ + +#include "vmlinux.h" +#include "bpf_tracing_net.h" +#include +#include + +#define UDP_TEST_PORT 7777 + +void *bpf_cast_to_kern_ctx(void *) __ksym; +bool init_csum_partial = false; +bool final_csum_none = false; +bool broken_csum_start = false; + +static inline unsigned int skb_headlen(const struct sk_buff *skb) +{ + return skb->len - skb->data_len; +} + +static unsigned int skb_headroom(const struct sk_buff *skb) +{ + return skb->data - skb->head; +} + +static int skb_checksum_start_offset(const struct sk_buff *skb) +{ + return skb->csum_start - skb_headroom(skb); +} + +SEC("tc") +int decap_sanity(struct __sk_buff *skb) +{ + struct sk_buff *kskb; + struct ipv6hdr ip6h; + struct udphdr udph; + int err; + + if (skb->protocol != __bpf_constant_htons(ETH_P_IPV6)) + return TC_ACT_SHOT; + + if (bpf_skb_load_bytes(skb, ETH_HLEN, &ip6h, sizeof(ip6h))) + return TC_ACT_SHOT; + + if (ip6h.nexthdr != IPPROTO_UDP) + return TC_ACT_SHOT; + + if (bpf_skb_load_bytes(skb, ETH_HLEN + sizeof(ip6h), &udph, sizeof(udph))) + return TC_ACT_SHOT; + + if (udph.dest != __bpf_constant_htons(UDP_TEST_PORT)) + return TC_ACT_SHOT; + + kskb = bpf_cast_to_kern_ctx(skb); + init_csum_partial = (kskb->ip_summed == CHECKSUM_PARTIAL); + err = bpf_skb_adjust_room(skb, -(s32)(ETH_HLEN + sizeof(ip6h) + sizeof(udph)), + 1, BPF_F_ADJ_ROOM_FIXED_GSO); + if (err) + return TC_ACT_SHOT; + final_csum_none = (kskb->ip_summed == CHECKSUM_NONE); + if (kskb->ip_summed == CHECKSUM_PARTIAL && + (unsigned int)skb_checksum_start_offset(kskb) >= skb_headlen(kskb)) + broken_csum_start = true; + + return TC_ACT_SHOT; +} + +char __license[] SEC("license") = "GPL";