From patchwork Sun Mar 7 20:10:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gert Doering X-Patchwork-Id: 1609 Return-Path: Delivered-To: patchwork@openvpn.net Delivered-To: patchwork@openvpn.net Received: from director12.mail.ord1d.rsapps.net ([172.30.191.6]) by backend30.mail.ord1d.rsapps.net with LMTP id 0BCJHS3ORWA3KwAAIUCqbw (envelope-from ) for ; Mon, 08 Mar 2021 02:11:41 -0500 Received: from proxy2.mail.ord1d.rsapps.net ([172.30.191.6]) by director12.mail.ord1d.rsapps.net with LMTP id QOd+HS3ORWDaSQAAIasKDg (envelope-from ) for ; Mon, 08 Mar 2021 02:11:41 -0500 Received: from smtp9.gate.ord1c ([172.30.191.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) by proxy2.mail.ord1d.rsapps.net with LMTPS id YE3+HC3ORWCmbAAAfawv4w (envelope-from ) for ; Mon, 08 Mar 2021 02:11:41 -0500 X-Spam-Threshold: 95 X-Spam-Score: 0 X-Spam-Flag: NO X-Virus-Scanned: OK X-Orig-To: openvpnslackdevel@openvpn.net X-Originating-Ip: [216.105.38.7] Authentication-Results: smtp9.gate.ord1c.rsapps.net; iprev=pass policy.iprev="216.105.38.7"; spf=pass smtp.mailfrom="openvpn-devel-bounces@lists.sourceforge.net" smtp.helo="lists.sourceforge.net"; dkim=fail (signature verification failed) header.d=sourceforge.net; dkim=fail (signature verification failed) header.d=sf.net; dmarc=none (p=nil; dis=none) header.from=greenie.muc.de X-Suspicious-Flag: YES X-Classification-ID: 8256355c-7fdd-11eb-a871-0026b95bddb7-1-1 Received: from [216.105.38.7] ([216.105.38.7:59292] helo=lists.sourceforge.net) by smtp9.gate.ord1c.rsapps.net (envelope-from ) (ecelerity 4.2.38.62370 r(:)) with ESMTPS (cipher=DHE-RSA-AES256-GCM-SHA384) id 1F/CB-07022-42EC5406; Mon, 08 Mar 2021 02:11:32 -0500 Received: from [127.0.0.1] (helo=sfs-ml-2.v29.lw.sourceforge.com) by sfs-ml-2.v29.lw.sourceforge.com with esmtp (Exim 4.90_1) (envelope-from ) id 1lJA2M-0005cZ-48; Mon, 08 Mar 2021 07:10:42 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-2.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lJA2K-0005cM-6q for openvpn-devel@lists.sourceforge.net; Mon, 08 Mar 2021 07:10:40 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-Id:Date:Subject:To:From:Sender:Reply-To:Cc:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=wDyXpLyqB3zN4OaMV0Wmz+fT9wcDYa9ffc3wUsy6p9w=; b=nWeUmfP6wrmA5/DWOBMFFdF9/Q fn56TsrHgw/aTvViKWZEuA5rIoYuYuCSHj+/XrWI8tJ1zJXM1iKe/zPP31ou4EWGzUqPUZUM9bjy5 8TKsFSNU3M6DcJuz/K8D6uxBYKYbzrPSFowZA2fcueX8RLn83L+12dcU7taX++lVzh2Q=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-Id: Date:Subject:To:From:Sender:Reply-To:Cc:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=wDyXpLyqB3zN4OaMV0Wmz+fT9wcDYa9ffc3wUsy6p9w=; b=UI4DJncGV+88UMWpAeXtttIHtL D79W0/s2o8+HqYT9ZW64h2HVSShnQx2cSJzq5MVFQnhPekbtSh+lvuK6Zv6ujDDXEn9IGiWHTJ6Vf THttK1lRYhsDWX/OqDSy4qqVC7G7bbu+/WRGRw/fffknpnS2Lzs9LFrStG9OdsLUlihg=; Received: from dhcp-174.greenie.muc.de ([193.149.48.174] helo=blue.greenie.muc.de) by sfi-mx-1.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92.2) id 1lJA2D-000aJU-7N for openvpn-devel@lists.sourceforge.net; Mon, 08 Mar 2021 07:10:40 +0000 Received: from blue.greenie.muc.de (localhost [127.0.0.1]) by blue.greenie.muc.de (8.15.2/8.14.9) with ESMTP id 1287AOgR018317 for ; Mon, 8 Mar 2021 08:10:26 +0100 Received: (from gert@localhost) by blue.greenie.muc.de (8.15.2/8.14.9/Submit) id 1287AOjw018316 for openvpn-devel@lists.sourceforge.net; Mon, 8 Mar 2021 08:10:24 +0100 From: Gert Doering To: openvpn-devel@lists.sourceforge.net Date: Mon, 8 Mar 2021 08:10:23 +0100 Message-Id: <20210308071023.18269-1-gert@greenie.muc.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210307161547.25130-1-gert@greenie.muc.de> References: <20210307161547.25130-1-gert@greenie.muc.de> MIME-Version: 1.0 X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.0 SPF_PASS SPF: sender matches SPF record X-Headers-End: 1lJA2D-000aJU-7N Subject: [Openvpn-devel] [PATCH v2] Require at least 100MB of mlock()-able memory if --mlock is used. X-BeenThere: openvpn-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: openvpn-devel-bounces@lists.sourceforge.net X-getmail-retrieved-from-mailbox: Inbox If --mlock is used, the amount of memory OpenVPN can use is guarded by the RLIMIT_MEMLOCK value (see mlockall(2)). The OS default for this is usually 64 Kbyte, which is enough for OpenVPN to initialize, but as soon as the first TLS handshake comes it, OpenVPN will crash due to "ouf of memory", and might even end up in a crash loop. Steady-state OpenVPN requires between 8 MB and 30-50 MB (servers with many concurrent clients) of memory. TLS renegotiation with EC keys requires up to 90 MB of transient memory. So: with this patch, we check if getrlimit() is available, and if yes, log the amount of mlock'able memory. If the amount is below 100 MB, which is an arbitrary value "large enough for most smaller deployments", we try to increase the limits to 100 MB, and abort if this fails. v2: change arbitrary number to 100 MB, introduce #define for it not only check but also increase with setrlimit() uncrustify fixes Trac: #1390 Signed-off-by: Gert Doering Acked-by: selva.nair@gmail.com Signed-off-by: Gert Doering <gert@greenie.muc.de>
--- configure.ac | 2 +- doc/man-sections/generic-options.rst | 7 +++++++ src/openvpn/platform.c | 29 ++++++++++++++++++++++++++++ src/openvpn/platform.h | 4 ++++ 4 files changed, 41 insertions(+), 1 deletion(-) diff --git a/configure.ac b/configure.ac index 1ab8fe59..c65df3e2 100644 --- a/configure.ac +++ b/configure.ac @@ -645,7 +645,7 @@ AC_FUNC_FORK AC_CHECK_FUNCS([ \ daemon chroot getpwnam setuid nice system getpid dup dup2 \ - getpass syslog openlog mlockall getgrnam setgid \ + getpass syslog openlog mlockall getrlimit getgrnam setgid \ setgroups stat flock readv writev time gettimeofday \ ctime memset vsnprintf strdup \ setsid chdir putenv getpeername unlink \ diff --git a/doc/man-sections/generic-options.rst b/doc/man-sections/generic-options.rst index d5f08839..c026529e 100644 --- a/doc/man-sections/generic-options.rst +++ b/doc/man-sections/generic-options.rst @@ -237,6 +237,13 @@ which mode OpenVPN is configured as. likely fail. The limit can be increased using ulimit or systemd directives depending on how OpenVPN is started. + If the platform has the getrlimit(2) system call, OpenVPN will check + for the amount of mlock-able memory before calling mlockall(2), and + tries to increase the limit to 100 MB if less than this is configured. + 100 Mb is somewhat arbitrary - it is enough for a moderately-sized + OpenVPN deployment, but the memory usage might go beyond that if the + number of concurrent clients is high. + --nice n Change process priority after initialization (``n`` greater than 0 is lower priority, ``n`` less than zero is higher priority). diff --git a/src/openvpn/platform.c b/src/openvpn/platform.c index ef688c23..dfbf50c0 100644 --- a/src/openvpn/platform.c +++ b/src/openvpn/platform.c @@ -193,6 +193,35 @@ void platform_mlockall(bool print_msg) { #ifdef HAVE_MLOCKALL + +#ifdef HAVE_GETRLIMIT +#define MIN_LOCKED_MEM_MB 100 + struct rlimit rl; + if (getrlimit(RLIMIT_MEMLOCK, &rl) < 0) + { + msg(M_WARN | M_ERRNO, "WARNING: getrlimit(RLIMIT_MEMLOCK) failed"); + } + else + { + msg(M_INFO, "mlock: MEMLOCK limit: soft=%ld KB, hard=%ld KB", + ((long int) rl.rlim_cur) / 1024, ((long int) rl.rlim_max) / 1024); + if (rl.rlim_cur < MIN_LOCKED_MEM_MB*1024*1024) + { + msg(M_INFO, "mlock: RLIMIT_MEMLOCK < %d MB, increase limit", + MIN_LOCKED_MEM_MB); + rl.rlim_cur = MIN_LOCKED_MEM_MB*1024*1024; + if (rl.rlim_max < rl.rlim_cur) + { + rl.rlim_max = rl.rlim_cur; + } + if (setrlimit(RLIMIT_MEMLOCK, &rl) < 0) + { + msg(M_FATAL | M_ERRNO, "ERROR: setrlimit() failed"); + } + } + } +#endif + if (mlockall(MCL_CURRENT | MCL_FUTURE)) { msg(M_WARN | M_ERRNO, "WARNING: mlockall call failed"); diff --git a/src/openvpn/platform.h b/src/openvpn/platform.h index 01f3200c..02c23e38 100644 --- a/src/openvpn/platform.h +++ b/src/openvpn/platform.h @@ -48,6 +48,10 @@ #include #endif +#ifdef HAVE_GETRLIMIT +#include +#endif + #include "basic.h" #include "buffer.h"