From patchwork Sat Nov 7 19:38:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Fastabend X-Patchwork-Id: 322146 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=-9.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 2EA18C388F7 for ; Sat, 7 Nov 2020 19:38:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6BD921707 for ; Sat, 7 Nov 2020 19:38:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="g5J8Dz/H" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728651AbgKGTi3 (ORCPT ); Sat, 7 Nov 2020 14:38:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32890 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725836AbgKGTi2 (ORCPT ); Sat, 7 Nov 2020 14:38:28 -0500 Received: from mail-oi1-x244.google.com (mail-oi1-x244.google.com [IPv6:2607:f8b0:4864:20::244]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C62B1C0613CF; Sat, 7 Nov 2020 11:38:28 -0800 (PST) Received: by mail-oi1-x244.google.com with SMTP id t16so5389391oie.11; Sat, 07 Nov 2020 11:38:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:from:to:cc:date:message-id:in-reply-to:references :user-agent:mime-version:content-transfer-encoding; bh=lu8xFLzKq5EcwF/rmpzYgaF3GRt/mG2wCMUgnyFW2F4=; b=g5J8Dz/HsGZtjd0AFilkNvenRhKE/uv0CLpDugjcbQKLK8o3WKw5ow7SpIhN6lvu3C ZuUcxmqC0D7k7vPpEGQsSn3axH2mnycVFxW+29tIAkeH1UWLTsxTUwseVLXunKqUM5AK bdUng6sV/8hwrFTGB4eV6knoOmU6YwLDQdtYgq0SNOInPO5hTC4FfK7I8sKKvHvdvTLT 9ncFd1C6rM718vYKb5SfvZnDtUc3pQAJBrAn3wjtgr7Q7mX26VxW+49ie+gGxQr6kos+ UKzbrASiDVCDdDWXnmJDOE7LwL0XvnIKd4cQ0e5rzGhHQtS+UI7jdt6NMsPioNIOWOqE K64A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:date:message-id:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=lu8xFLzKq5EcwF/rmpzYgaF3GRt/mG2wCMUgnyFW2F4=; b=D72o1ApxNLrpkxV6S7w2NKGyAoIBKpMqvA0/Xbl0/RjFcgmtzSMCED6PKW7PoOIZLv Oj5y7XMh7xUrhvesti3sPjkrEuIK8ZjAZfvlj/WiOWCqjY12RsxcUndGMzjJSR/uYbdb AhDC8p5JbYv7k+znvYmx11kSGgA2q7aeCnvjr2VJlwi03DWMfCIcWIFOqHUU4bZ5j5Xr joNmjiIjhoSSoBJ+i0n26EMCuGyqnA3JSYHgX4070x501w89PG/qgvStZVHcKQaMS3mx R0b5Rswap12qnG4FWo4ZAPvwAsNye05+HVjnAleh5Hmi+RGN1tsZ12CP1uS83uhhlI6N DS9Q== X-Gm-Message-State: AOAM53237m42zgRiffH3zwzh1NxQGn5Ei2FNCr+uCSViKicdWiHxUzrj EwcJGkN0MXx1Vao5BGFLoj4= X-Google-Smtp-Source: ABdhPJy7qPlnp5/EvqHFs1UtAVy5avBgFP1x8B47wxkipA/CHg7aiTtRnKD53ItrFJAaUZOT/0FQ6A== X-Received: by 2002:aca:c70b:: with SMTP id x11mr4979894oif.58.1604777908240; Sat, 07 Nov 2020 11:38:28 -0800 (PST) Received: from [127.0.1.1] ([184.63.162.180]) by smtp.gmail.com with ESMTPSA id w70sm1235588oiw.29.2020.11.07.11.38.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 07 Nov 2020 11:38:27 -0800 (PST) Subject: [bpf PATCH 2/5] bpf, sockmap: Ensure SO_RCVBUF memory is observed on ingress redirect From: John Fastabend To: ast@kernel.org, daniel@iogearbox.net, jakub@cloudflare.com Cc: john.fastabend@gmail.com, bpf@vger.kernel.org, netdev@vger.kernel.org Date: Sat, 07 Nov 2020 11:38:15 -0800 Message-ID: <160477789531.608263.11406385279476664711.stgit@john-XPS-13-9370> In-Reply-To: <160477770483.608263.6057216691957042088.stgit@john-XPS-13-9370> References: <160477770483.608263.6057216691957042088.stgit@john-XPS-13-9370> User-Agent: StGit/0.23-36-gc01b MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Fix sockmap sk_skb programs so that they observe sk_rcvbuf limits. This allows users to tune SO_RCVBUF and sockmap will honor them. We can refactor the if(charge) case out in later patches. But, keep this fix to the point. Fixes: 51199405f9672 ("bpf: skb_verdict, support SK_PASS on RX BPF path") Suggested-by: Jakub Sitnicki Signed-off-by: John Fastabend --- net/core/skmsg.c | 20 ++++++++++++++++---- net/ipv4/tcp_bpf.c | 3 ++- 2 files changed, 18 insertions(+), 5 deletions(-) diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 654182ecf87b..fe44280c033e 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -170,10 +170,12 @@ static int sk_msg_free_elem(struct sock *sk, struct sk_msg *msg, u32 i, struct scatterlist *sge = sk_msg_elem(msg, i); u32 len = sge->length; - if (charge) - sk_mem_uncharge(sk, len); - if (!msg->skb) + /* When the skb owns the memory we free it from consume_skb path. */ + if (!msg->skb) { + if (charge) + sk_mem_uncharge(sk, len); put_page(sg_page(sge)); + } memset(sge, 0, sizeof(*sge)); return len; } @@ -403,6 +405,9 @@ static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb) int copied = 0, num_sge; struct sk_msg *msg; + if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) + return -EAGAIN; + msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_ATOMIC); if (unlikely(!msg)) return -EAGAIN; @@ -418,7 +423,14 @@ static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb) return num_sge; } - sk_mem_charge(sk, skb->len); + /* This will transition ownership of the data from the socket where + * the BPF program was run initiating the redirect to the socket + * we will eventually receive this data on. The data will be released + * from skb_consume found in __tcp_bpf_recvmsg() after its been copied + * into user buffers. + */ + skb_set_owner_r(skb, sk); + copied = skb->len; msg->sg.start = 0; msg->sg.size = copied; diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index 3709d679436e..30802fa99aa1 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -46,7 +46,8 @@ int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock, if (likely(!peek)) { sge->offset += copy; sge->length -= copy; - sk_mem_uncharge(sk, copy); + if (!msg_rx->skb) + sk_mem_uncharge(sk, copy); msg_rx->sg.size -= copy; if (!sge->length) {