From mboxrd@z Thu Jan 1 00:00:00 1970 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=-6.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=ham 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 755DCC32753 for ; Thu, 1 Aug 2019 07:15:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 33876214DA for ; Thu, 1 Aug 2019 07:15:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="OORIw4Ep" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730552AbfHAHPF (ORCPT ); Thu, 1 Aug 2019 03:15:05 -0400 Received: from mail-lj1-f194.google.com ([209.85.208.194]:43272 "EHLO mail-lj1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725283AbfHAHPE (ORCPT ); Thu, 1 Aug 2019 03:15:04 -0400 Received: by mail-lj1-f194.google.com with SMTP id y17so43729748ljk.10 for ; Thu, 01 Aug 2019 00:15:03 -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=XqjNTMdCoxg7mqOMzCamjYwRdrBEdNTjPXYyp8Ir2GI=; b=OORIw4EpWMna92eRsKeGffoxXQBJ2NFun/gqf6YoseaLgJHqUF95kz6sr/5PJ5d/EZ x9hwNhYc76Y0kfSftLKetkDSGKirlzUfVAo5c/Y10kHv0/7jHuGlb+uE8UUVXAkKatIi FYN8JvgYdGKyy/cn62LfKX6GsqffgI0AwdxH1/8rUPRmLKXyGjkJyknxCwrks6zJDWqG xGTRfe/5aFTwO9VskmbdKft/tdm5/QNy+Badm6VjxDbNuzNZ1wB7OXYQJweCo/WjfSZk dLj36xVLVYWqMsqHMMcbh+Jm4Os6g1Q6MKzPZ/xrEQ5qsZgD2YPPwgzR3pJPtUPNMMqr WXIw== 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=XqjNTMdCoxg7mqOMzCamjYwRdrBEdNTjPXYyp8Ir2GI=; b=P4JBsipzVsmjFZQZUycb0ZdMZ40A8ZcrDh608/BuGKwyBpMLnSxmeU5mtCVRZq43b/ 1bga6+ke6RL4QPlmDdE4YmvQhzMawyb/z4azKbISurI1hZ4MBJk7/2QSAq9vxSx1iKQS 9YWMXaxwPu70M17XDQYCcmiuy35kZUTkzLRA/bTs1yWodd7ytdCsfVU0IfZTZh1TTM3x tAa3RSHilfc5zI67zZK1dbHqrr0Q/sl0OvmdNQWKV+k031J91gQ1ub7LxY+4RWhJHNHZ TFvdGBmrzxumXMFZv3yF5ax/GovqdWQiQ7JaROdp9iPDf24ra9C5oAm5ybRO4iwxRWYa Tjdg== X-Gm-Message-State: APjAAAVKeHLxAcQP8Wq07zfL6nXu3ZCr3SaGTlpVcbxK57fRso4NfKHn Alm0+nyHICVxSGPD1PH/tIc= X-Google-Smtp-Source: APXvYqyDb8+aPKTKfHRTO3GsA7Jey8wi9mTCLCYl/7DHglzteyhjqyF9N8D5nOE9hYfFvFnDCkAfBQ== X-Received: by 2002:a2e:9192:: with SMTP id f18mr36879499ljg.52.1564643702975; Thu, 01 Aug 2019 00:15:02 -0700 (PDT) Received: from localhost.localdomain ([109.252.54.73]) by smtp.gmail.com with ESMTPSA id 63sm14654577ljs.84.2019.08.01.00.15.01 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 01 Aug 2019 00:15:02 -0700 (PDT) From: Denis Kenzior To: johannes@sipsolutions.net, linux-wireless@vger.kernel.org Cc: Denis Kenzior Subject: [RFCv1 2/2] nl80211: Don't split-dump for clients with large buffers Date: Thu, 1 Aug 2019 02:14:55 -0500 Message-Id: <20190801071455.4974-2-denkenz@gmail.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190801071455.4974-1-denkenz@gmail.com> References: <20190801071455.4974-1-denkenz@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org --- net/wireless/nl80211.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 6774072e836f..e1707cfd9076 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -2496,6 +2496,22 @@ static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb) rtnl_unlock(); return ret; } + + /* + * auto-detect support for large buffer sizes: af_netlink + * will allocate skbufs larger than 4096 in cases where + * it detects that the client receive buffer (given to + * recvmsg) is bigger. In such cases we can assume that + * performing split dumps is wasteful since the client + * can likely safely consume the entire un-split wiphy + * message in one go without the extra message header + * overhead. + */ + if (skb_tailroom(skb) > 4096) { + state->large_message = true; + state->split = false; + } + cb->args[0] = (long)state; } @@ -2529,6 +2545,7 @@ static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb) * We can then retry with the larger buffer. */ if ((ret == -ENOBUFS || ret == -EMSGSIZE) && + !state->large_message && !skb->len && !state->split && cb->min_dump_alloc < 4096) { cb->min_dump_alloc = 4096; -- 2.21.0