From patchwork Tue Jan 12 17:45:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jesper Dangaard Brouer X-Patchwork-Id: 12014253 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 X-Spam-Level: X-Spam-Status: No, score=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CBFF2C4332E for ; Tue, 12 Jan 2021 17:47:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 93AE823123 for ; Tue, 12 Jan 2021 17:47:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404284AbhALRrF (ORCPT ); Tue, 12 Jan 2021 12:47:05 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:33938 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404144AbhALRrF (ORCPT ); Tue, 12 Jan 2021 12:47:05 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610473538; 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=iFs5YuS+UQBHxuk28XB6kdJ0sgDe9yXGAPFUS7xIqxM=; b=Nq+q6L6Llvl3PQ9ny1TDAJyccEWOhneyI3jDBSJmF4FGdNp+7EpOl9IB63NlQawpM+VawB /fl+BpVKzMl9XMRsD8l2RTcMI3XEkmMCyisetIcQ2dfn+/6GUOA0ZHN5cZoxoDyTG/yZUR xTFL9SxUX5cKmT5bFM4DJqsOZ1xrzHM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-331-WGLDVq_oMV2wbAXbWQJt1Q-1; Tue, 12 Jan 2021 12:45:34 -0500 X-MC-Unique: WGLDVq_oMV2wbAXbWQJt1Q-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 571BA8144E0; Tue, 12 Jan 2021 17:45:32 +0000 (UTC) Received: from firesoul.localdomain (unknown [10.40.208.19]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0BC005D762; Tue, 12 Jan 2021 17:45:32 +0000 (UTC) Received: from [192.168.42.3] (localhost [IPv6:::1]) by firesoul.localdomain (Postfix) with ESMTP id 164D232138454; Tue, 12 Jan 2021 18:45:31 +0100 (CET) Subject: [PATCH bpf-next V11 6/7] selftests/bpf: use bpf_check_mtu in selftest test_cls_redirect From: Jesper Dangaard Brouer To: bpf@vger.kernel.org Cc: Jesper Dangaard Brouer , netdev@vger.kernel.org, Daniel Borkmann , Alexei Starovoitov , maze@google.com, lmb@cloudflare.com, shaun@tigera.io, Lorenzo Bianconi , marek@cloudflare.com, John Fastabend , Jakub Kicinski , eyal.birger@gmail.com, colrack@gmail.com Date: Tue, 12 Jan 2021 18:45:31 +0100 Message-ID: <161047353102.4003084.16408050677931166544.stgit@firesoul> In-Reply-To: <161047346644.4003084.2653117664787086168.stgit@firesoul> References: <161047346644.4003084.2653117664787086168.stgit@firesoul> User-Agent: StGit/0.19 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net This demonstrate how bpf_check_mtu() helper can easily be used together with bpf_skb_adjust_room() helper, prior to doing size adjustment, as delta argument is already setup. Hint: This specific test can be selected like this: ./test_progs -t cls_redirect Signed-off-by: Jesper Dangaard Brouer --- .../selftests/bpf/progs/test_cls_redirect.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/tools/testing/selftests/bpf/progs/test_cls_redirect.c b/tools/testing/selftests/bpf/progs/test_cls_redirect.c index c9f8464996ea..3c1e042962e6 100644 --- a/tools/testing/selftests/bpf/progs/test_cls_redirect.c +++ b/tools/testing/selftests/bpf/progs/test_cls_redirect.c @@ -70,6 +70,7 @@ typedef struct { uint64_t errors_total_encap_adjust_failed; uint64_t errors_total_encap_buffer_too_small; uint64_t errors_total_redirect_loop; + uint64_t errors_total_encap_mtu_violate; } metrics_t; typedef enum { @@ -407,6 +408,7 @@ static INLINING ret_t forward_with_gre(struct __sk_buff *skb, encap_headers_t *e payload_off - sizeof(struct ethhdr) - sizeof(struct iphdr); int32_t delta = sizeof(struct gre_base_hdr) - encap_overhead; uint16_t proto = ETH_P_IP; + uint32_t mtu_len = 0; /* Loop protection: the inner packet's TTL is decremented as a safeguard * against any forwarding loop. As the only interesting field is the TTL @@ -479,6 +481,11 @@ static INLINING ret_t forward_with_gre(struct __sk_buff *skb, encap_headers_t *e } } + if (bpf_check_mtu(skb, skb->ifindex, &mtu_len, delta, 0)) { + metrics->errors_total_encap_mtu_violate++; + return TC_ACT_SHOT; + } + if (bpf_skb_adjust_room(skb, delta, BPF_ADJ_ROOM_NET, BPF_F_ADJ_ROOM_FIXED_GSO | BPF_F_ADJ_ROOM_NO_CSUM_RESET) ||