From patchwork Fri Jul 29 13:34:02 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Soheil Hassas Yeganeh X-Patchwork-Id: 654115 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3s18pF3y8Fz9s2G for ; Fri, 29 Jul 2016 23:34:13 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=uTu67Exp; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752518AbcG2NeH (ORCPT ); Fri, 29 Jul 2016 09:34:07 -0400 Received: from mail-qk0-f193.google.com ([209.85.220.193]:33359 "EHLO mail-qk0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751449AbcG2NeG (ORCPT ); Fri, 29 Jul 2016 09:34:06 -0400 Received: by mail-qk0-f193.google.com with SMTP id n202so7048729qke.0 for ; Fri, 29 Jul 2016 06:34:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=6FIb3jbxbgQ9E4RTkxCq0NmKWZuxefyf6x2TiRwwPZc=; b=uTu67ExpFrky7eHiiMmOj3y6aWAUDIy4TmgBAu0BoFXfuI11XJVT1D9E3AUOMy2CPZ MlsG720cZhnx7UFp+1okN29VTjxxjPU8nyXMFofOPaGfNlzVMvRTcpVF11Qu//ua+eph jAWgIfy1rdE56hKwxkUW/8hoD0BQL7orAZOQzRxt5+FtADoW0uUNtZcyV7cAkxGxarjy edC7IVp+6LnykTDjvAtXg2CqK5Jx3Mx3Fu2dBjjYKlOlhdUEzAHtfvHrzWHx7vlv15A8 P30SChs8rhyJBo8bDrsD/DSlstF5r5jSwUEuHxafSezwxV+J6MYmj4Eb+UFPjJ9Fd0I2 eaHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=6FIb3jbxbgQ9E4RTkxCq0NmKWZuxefyf6x2TiRwwPZc=; b=nIdK8Z2RgEB42LGFYyKkljQfzOZrzcFTec3+r6T/MnxyTw/4g/vuifVbymOqkO+19C wefwVQl4IQqt9hHPW2Mz0657O44c4X69XZfCppVggYcZDgPOB10HtXaQHBEca1MBAZZW 8X3eFvpxGqydO/ChJDtlPkxN1SunA9EqUCg3A7qDYbW5IMDzSQA8e/Os/PNBHCOrMdk1 S+Ak9nqE5mGgzTmdVrI9h+hdmrme5ro74A3WtPWD9VmFomr61WAs3fIzsV/NBjg4a/J0 PtWsBaZTSHECISDvs8m/03ga9y9SYQIG1unh0Q2r6LXyI6qV8VBS0rk4ak0KJeMQRyh8 nXQQ== X-Gm-Message-State: AEkoouuFF1JmS0JybF8N49vDJM1cyZJMbYhv1jrUMzic4q/L3El7mOcjQjl/IPHwQwFfYw== X-Received: by 10.55.98.205 with SMTP id w196mr50451552qkb.65.1469799244762; Fri, 29 Jul 2016 06:34:04 -0700 (PDT) Received: from soheil.nyc.corp.google.com ([100.101.230.57]) by smtp.gmail.com with ESMTPSA id j7sm10055554qkf.11.2016.07.29.06.34.04 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 29 Jul 2016 06:34:04 -0700 (PDT) From: Soheil Hassas Yeganeh To: davem@davemloft.net, netdev@vger.kernel.org Cc: edumazet@google.com, ycheng@google.com, ncardwell@google.com, Soheil Hassas Yeganeh Subject: [PATCH v2 net] tcp: consider recv buf for the initial window scale Date: Fri, 29 Jul 2016 09:34:02 -0400 Message-Id: <1469799242-28408-1-git-send-email-soheil.kdev@gmail.com> X-Mailer: git-send-email 2.8.0.rc3.226.g39d4020 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Soheil Hassas Yeganeh tcp_select_initial_window() intends to advertise a window scaling for the maximum possible window size. To do so, it considers the maximum of net.ipv4.tcp_rmem[2] and net.core.rmem_max as the only possible upper-bounds. However, users with CAP_NET_ADMIN can use SO_RCVBUFFORCE to set the socket's receive buffer size to values larger than net.ipv4.tcp_rmem[2] and net.core.rmem_max. Thus, SO_RCVBUFFORCE is effectively ignored by tcp_select_initial_window(). To fix this, consider the maximum of net.ipv4.tcp_rmem[2], net.core.rmem_max and socket's initial buffer space. Fixes: b0573dea1fb3 ("[NET]: Introduce SO_{SND,RCV}BUFFORCE socket options") Signed-off-by: Soheil Hassas Yeganeh Suggested-by: Neal Cardwell Acked-by: Neal Cardwell --- net/ipv4/tcp_output.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index b26aa87..bdaef7f 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -236,7 +236,8 @@ void tcp_select_initial_window(int __space, __u32 mss, /* Set window scaling on max possible window * See RFC1323 for an explanation of the limit to 14 */ - space = max_t(u32, sysctl_tcp_rmem[2], sysctl_rmem_max); + space = max_t(u32, space, sysctl_tcp_rmem[2]); + space = max_t(u32, space, sysctl_rmem_max); space = min_t(u32, space, *window_clamp); while (space > 65535 && (*rcv_wscale) < 14) { space >>= 1;