From patchwork Thu Jul 1 00:27:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 469448 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 71744C11F66 for ; Thu, 1 Jul 2021 00:30:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 566666146D for ; Thu, 1 Jul 2021 00:30:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238177AbhGAAcq (ORCPT ); Wed, 30 Jun 2021 20:32:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46576 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238224AbhGAAcl (ORCPT ); Wed, 30 Jun 2021 20:32:41 -0400 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CEF98C061756; Wed, 30 Jun 2021 17:30:10 -0700 (PDT) Received: by mail-pg1-x541.google.com with SMTP id t9so4436451pgn.4; Wed, 30 Jun 2021 17:30:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=SkgpkHwukme+s+DiUo/QAxq3uuNb0i0Ju9uiWH1fc9E=; b=qTYnPkb90Gwe6s1eVuvrmLmrqyjctqLVk/ta1z+WXptREFN1taVF4hgAcWFEKYHNZr 9m58rW4DyOPBx8xpghN3M75vJzs5lrHysQa2HZhyEf+i3IcMx1n9Alz3qYizNFiDGllr W+jPMsgs3qccxiL72n81muAa7LHo+UasIFU3Xts1zqGWMSx+aPKq0+R7S77Ccn8wX74m MwJyBQA8rknZdMbBRpBeJX78YhDJxzB4mzJdy2aNFEOwQDN2ZUdChagKRqeJ74k0ixhp aeafsxnBLAJVnn4gEaeO+PHLrh3nEH1lC3pjpak5Fkz4f6D14c6pLupbo5coZcBwJZbK xoKA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=SkgpkHwukme+s+DiUo/QAxq3uuNb0i0Ju9uiWH1fc9E=; b=UdvaqkIDypuR4hTg2xu2oYTmbGFwGX7zYyfcTYsoYp8BUDxazoqYSsuC/KLFSsGaZD Yv6YJeu9rMNFsoI2mr6XcwOZ/RHQCCActDHmMczFrOOE/dOMnt7FRmNbOyFocsWYDiHI qM0+gjVetzxQlAk3cmCC2tyd/r4pG63xHE6zRHNCzfq4iYbTV+yoS1kHd99fQChpbti+ W/abW4dWMOzBj/fZfMH+kfBEcs/rb8ocUuNSofKs4SVRnorbD/pXHe5GJH84wcVaO3uc 4kc5WfJkDH+OlcFiQ1vGypMXuVwTImfCbLaldTwTyuSlo0BsvMuz/9uPFPEgabtgs7t3 TIfw== X-Gm-Message-State: AOAM532xv9PRmMDtHEVRp3Lq71QvLqPQNSZkGXQddj52MCfsQGu2ioXd rkrpqMQ4okUr6gsg8p0+AyOsR1wXhuk= X-Google-Smtp-Source: ABdhPJx1oPfh3CMSQbayS4D1qA8/l8j41gvWPRcV9+uKl/GEIaXnR09ZRYSmwcKQ1n98dEivdTEopQ== X-Received: by 2002:a63:f10:: with SMTP id e16mr6243928pgl.163.1625099410254; Wed, 30 Jun 2021 17:30:10 -0700 (PDT) Received: from localhost ([2402:3a80:11db:6f6:e6a8:37a6:1da7:fbc7]) by smtp.gmail.com with ESMTPSA id na7sm7467224pjb.36.2021.06.30.17.30.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Jun 2021 17:30:09 -0700 (PDT) From: Kumar Kartikeya Dwivedi To: netdev@vger.kernel.org Cc: Kumar Kartikeya Dwivedi , =?utf-8?q?Toke_H=C3=B8ilan?= =?utf-8?q?d-J=C3=B8rgensen?= , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Jesper Dangaard Brouer , "David S. Miller" , Jakub Kicinski , John Fastabend , Martin KaFai Lau , bpf@vger.kernel.org Subject: [PATCH net-next v5 4/5] bpf: devmap: implement devmap prog execution for generic XDP Date: Thu, 1 Jul 2021 05:57:58 +0530 Message-Id: <20210701002759.381983-5-memxor@gmail.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210701002759.381983-1-memxor@gmail.com> References: <20210701002759.381983-1-memxor@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This lifts the restriction on running devmap BPF progs in generic redirect mode. To match native XDP behavior, it is invoked right before generic_xdp_tx is called, and only supports XDP_PASS/XDP_ABORTED/ XDP_DROP actions. We also return 0 even if devmap program drops the packet, as semantically redirect has already succeeded and the devmap prog is the last point before TX of the packet to device where it can deliver a verdict on the packet. This also means it must take care of freeing the skb, as xdp_do_generic_redirect callers only do that in case an error is returned. Since devmap entry prog is supported, remove the check in generic_xdp_install entirely. Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Kumar Kartikeya Dwivedi --- include/linux/bpf.h | 1 - kernel/bpf/devmap.c | 49 ++++++++++++++++++++++++++++++++++++--------- net/core/dev.c | 18 ----------------- 3 files changed, 39 insertions(+), 29 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 095aaa104c56..4afbff308ca3 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1508,7 +1508,6 @@ int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb, int dev_map_redirect_multi(struct net_device *dev, struct sk_buff *skb, struct bpf_prog *xdp_prog, struct bpf_map *map, bool exclude_ingress); -bool dev_map_can_have_prog(struct bpf_map *map); void __cpu_map_flush(void); int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_buff *xdp, diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 2a75e6c2d27d..49f03e8e5561 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -318,16 +318,6 @@ static int dev_map_hash_get_next_key(struct bpf_map *map, void *key, return -ENOENT; } -bool dev_map_can_have_prog(struct bpf_map *map) -{ - if ((map->map_type == BPF_MAP_TYPE_DEVMAP || - map->map_type == BPF_MAP_TYPE_DEVMAP_HASH) && - map->value_size != offsetofend(struct bpf_devmap_val, ifindex)) - return true; - - return false; -} - static int dev_map_bpf_prog_run(struct bpf_prog *xdp_prog, struct xdp_frame **frames, int n, struct net_device *dev) @@ -499,6 +489,37 @@ static inline int __xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp, return 0; } +static u32 dev_map_bpf_prog_run_skb(struct sk_buff *skb, struct bpf_dtab_netdev *dst) +{ + struct xdp_txq_info txq = { .dev = dst->dev }; + struct xdp_buff xdp; + u32 act; + + if (!dst->xdp_prog) + return XDP_PASS; + + __skb_pull(skb, skb->mac_len); + xdp.txq = &txq; + + act = bpf_prog_run_generic_xdp(skb, &xdp, dst->xdp_prog); + switch (act) { + case XDP_PASS: + __skb_push(skb, skb->mac_len); + break; + default: + bpf_warn_invalid_xdp_action(act); + fallthrough; + case XDP_ABORTED: + trace_xdp_exception(dst->dev, dst->xdp_prog, act); + fallthrough; + case XDP_DROP: + kfree_skb(skb); + break; + } + + return act; +} + int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp, struct net_device *dev_rx) { @@ -614,6 +635,14 @@ int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb, err = xdp_ok_fwd_dev(dst->dev, skb->len); if (unlikely(err)) return err; + + /* Redirect has already succeeded semantically at this point, so we just + * return 0 even if packet is dropped. Helper below takes care of + * freeing skb. + */ + if (dev_map_bpf_prog_run_skb(skb, dst) != XDP_PASS) + return 0; + skb->dev = dst->dev; generic_xdp_tx(skb, xdp_prog); diff --git a/net/core/dev.c b/net/core/dev.c index 8521936414f2..c674fe191e8a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5656,24 +5656,6 @@ static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp) struct bpf_prog *new = xdp->prog; int ret = 0; - if (new) { - u32 i; - - mutex_lock(&new->aux->used_maps_mutex); - - /* generic XDP does not work with DEVMAPs that can - * have a bpf_prog installed on an entry - */ - for (i = 0; i < new->aux->used_map_cnt; i++) { - if (dev_map_can_have_prog(new->aux->used_maps[i])) { - mutex_unlock(&new->aux->used_maps_mutex); - return -EINVAL; - } - } - - mutex_unlock(&new->aux->used_maps_mutex); - } - switch (xdp->command) { case XDP_SETUP_PROG: rcu_assign_pointer(dev->xdp_prog, new);