From patchwork Mon Jan 7 12:11:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Taehee Yoo X-Patchwork-Id: 1021283 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="QjMn5xK1"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43YDl93MBVz9sN1 for ; Mon, 7 Jan 2019 23:11:33 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726893AbfAGMLT (ORCPT ); Mon, 7 Jan 2019 07:11:19 -0500 Received: from mail-pf1-f193.google.com ([209.85.210.193]:32925 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726485AbfAGMLT (ORCPT ); Mon, 7 Jan 2019 07:11:19 -0500 Received: by mail-pf1-f193.google.com with SMTP id c123so83375pfb.0; Mon, 07 Jan 2019 04:11:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=MpvPXvIifufe+uDDCsa2UqAYZWkhMO+OlIK179a13b0=; b=QjMn5xK1bcIDMygfoVhyKutstONy9YcGjUh961V07+OfFF69tc5e72LjMDcUdom1qC GvHbP2Jg0dRdkOKtAKL055u3DQDPjcHyqfZwzTPMA4mPLioXH/EETvpor3D5ruYXyco2 6+GMxOKLNjq0EiHpUjj81ylzQWdnXRQ0Jg2FTsw5dN1mLaI+IsZFJa40xKA2f091yrG1 A4o5aDNOQE9dAepcXNIUiUkyGr40b0aR56kd7L55tXqgzLRgtTfLETFDQ3QCc08M+r/t L/ljCJxugh2+9kZhstE1HYUfoZmkFOhHGp2dDC2uza3VFHlcKS6a3MoR80HbzoaLLf+D /qKg== 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; bh=MpvPXvIifufe+uDDCsa2UqAYZWkhMO+OlIK179a13b0=; b=EFSIMOd0bVu7YE1qQFGcG5XuZQxwwN3kp7Ih7/26tzHUDZbCQRcolwPas8oDW/ALAV kWQS6abmcNBaceCU7Mndjow9+GXDImdXDsd4DKoL+UgOJoTLjFnSnaxiiQ69vxT6hh0D e6Nc/qp+Ody1qWXWEm7XC92lfUbu8wZWtsBiLrkMkUlLq//7Q7ijl3R/0Rb5NPJo8TpD B4EB08Pj3MRaN4BnY7oVZivPQB40VknVVI8NYA33DDF2A5QMOO137gqeAbcAC5V80acU ZNcavLmTlJIH82Yd/+DqyEw1MbbFPzgOWYjHZv7KRjMJt1zJ4vFaRDzeyStml1i1iK5H fVsg== X-Gm-Message-State: AJcUukfYS21Ft12itAmI/hpyo7XIHmildT2XkL3UT3iV+GoX/eNLPl3s cL3wUp65GXOO1geE5I/8kSs= X-Google-Smtp-Source: ALg8bN4LtwOXkWW+8/1Gz+FBl/QCdxKel9wqj+R+Hucb+9bTs6ElwD3DynDz26ERhqHWn+UnCD12Iw== X-Received: by 2002:a63:ee4c:: with SMTP id n12mr10403087pgk.21.1546863077993; Mon, 07 Jan 2019 04:11:17 -0800 (PST) Received: from ap-To-be-filled-by-O-E-M.8.8.8.8 ([14.33.120.60]) by smtp.gmail.com with ESMTPSA id m3sm109476941pff.173.2019.01.07.04.11.15 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 07 Jan 2019 04:11:17 -0800 (PST) From: Taehee Yoo To: davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, daniel@iogearbox.net, ast@kernel.org, mcgrof@kernel.org Cc: ap420073@gmail.com Subject: [PATCH net v3 3/4] net: bpfilter: restart bpfilter_umh when error occurred Date: Mon, 7 Jan 2019 21:11:10 +0900 Message-Id: <20190107121110.13725-1-ap420073@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The bpfilter_umh will be stopped via __stop_umh() when the bpfilter error occurred. The bpfilter_umh() couldn't start again because there is no restart routine. The section of the bpfilter_umh_{start/end} is no longer .init.rodata because these area should be reused in the restart routine. hence the section name is changed to .bpfilter_umh. The bpfilter_ops->start() is restart callback. it will be called when bpfilter_umh is stopped. The stop bit means bpfilter_umh is stopped. this bit is set by both start and stop routine. Before this patch, Test commands: $ iptables -vnL $ kill -9 $ iptables -vnL [ 480.045136] bpfilter: write fail -32 $ iptables -vnL All iptables commands will fail. After this patch, Test commands: $ iptables -vnL $ kill -9 $ iptables -vnL $ iptables -vnL Now, all iptables commands will work. Fixes: d2ba09c17a06 ("net: add skeleton of bpfilter kernel module") Signed-off-by: Taehee Yoo --- include/linux/bpfilter.h | 2 ++ net/bpfilter/bpfilter_kern.c | 35 +++++++++++++++++++++++--------- net/bpfilter/bpfilter_umh_blob.S | 2 +- net/ipv4/bpfilter/sockopt.c | 11 +++++++++- 4 files changed, 38 insertions(+), 12 deletions(-) diff --git a/include/linux/bpfilter.h b/include/linux/bpfilter.h index 70ffeed280e9..8ebcbdd70bdc 100644 --- a/include/linux/bpfilter.h +++ b/include/linux/bpfilter.h @@ -15,6 +15,8 @@ struct bpfilter_umh_ops { int (*sockopt)(struct sock *sk, int optname, char __user *optval, unsigned int optlen, bool is_set); + int (*start)(void); + bool stop; }; extern struct bpfilter_umh_ops bpfilter_ops; #endif diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c index a68940b74c01..33d6b159ba88 100644 --- a/net/bpfilter/bpfilter_kern.c +++ b/net/bpfilter/bpfilter_kern.c @@ -16,13 +16,14 @@ extern char bpfilter_umh_end; /* since ip_getsockopt() can run in parallel, serialize access to umh */ static DEFINE_MUTEX(bpfilter_lock); -static void shutdown_umh(struct umh_info *info) +static void shutdown_umh(void) { struct task_struct *tsk; - if (!info->pid) + if (bpfilter_ops.stop) return; - tsk = get_pid_task(find_vpid(info->pid), PIDTYPE_PID); + + tsk = get_pid_task(find_vpid(bpfilter_ops.info.pid), PIDTYPE_PID); if (tsk) { force_sig(SIGKILL, tsk); put_task_struct(tsk); @@ -31,10 +32,8 @@ static void shutdown_umh(struct umh_info *info) static void __stop_umh(void) { - if (IS_ENABLED(CONFIG_INET)) { - bpfilter_ops.sockopt = NULL; - shutdown_umh(&bpfilter_ops.info); - } + if (IS_ENABLED(CONFIG_INET)) + shutdown_umh(); } static void stop_umh(void) @@ -85,7 +84,7 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname, return ret; } -static int __init load_umh(void) +static int start_umh(void) { int err; @@ -95,6 +94,7 @@ static int __init load_umh(void) &bpfilter_ops.info); if (err) return err; + bpfilter_ops.stop = false; pr_info("Loaded bpfilter_umh pid %d\n", bpfilter_ops.info.pid); /* health check that usermode process started correctly */ @@ -102,14 +102,29 @@ static int __init load_umh(void) stop_umh(); return -EFAULT; } - if (IS_ENABLED(CONFIG_INET)) - bpfilter_ops.sockopt = &__bpfilter_process_sockopt; return 0; } +static int __init load_umh(void) +{ + int err; + + err = start_umh(); + if (!err && IS_ENABLED(CONFIG_INET)) { + bpfilter_ops.sockopt = &__bpfilter_process_sockopt; + bpfilter_ops.start = &start_umh; + } + + return err; +} + static void __exit fini_umh(void) { + if (IS_ENABLED(CONFIG_INET)) { + bpfilter_ops.start = NULL; + bpfilter_ops.sockopt = NULL; + } stop_umh(); } module_init(load_umh); diff --git a/net/bpfilter/bpfilter_umh_blob.S b/net/bpfilter/bpfilter_umh_blob.S index 40311d10d2f2..7f1c521dcc2f 100644 --- a/net/bpfilter/bpfilter_umh_blob.S +++ b/net/bpfilter/bpfilter_umh_blob.S @@ -1,5 +1,5 @@ /* SPDX-License-Identifier: GPL-2.0 */ - .section .init.rodata, "a" + .section .bpfilter_umh, "a" .global bpfilter_umh_start bpfilter_umh_start: .incbin "net/bpfilter/bpfilter_umh" diff --git a/net/ipv4/bpfilter/sockopt.c b/net/ipv4/bpfilter/sockopt.c index c326cfbc0f62..de84ede4e765 100644 --- a/net/ipv4/bpfilter/sockopt.c +++ b/net/ipv4/bpfilter/sockopt.c @@ -14,6 +14,7 @@ EXPORT_SYMBOL_GPL(bpfilter_ops); static void bpfilter_umh_cleanup(struct umh_info *info) { + bpfilter_ops.stop = true; fput(info->pipe_to_umh); fput(info->pipe_from_umh); info->pid = 0; @@ -23,14 +24,21 @@ static int bpfilter_mbox_request(struct sock *sk, int optname, char __user *optval, unsigned int optlen, bool is_set) { + int err; + if (!bpfilter_ops.sockopt) { - int err = request_module("bpfilter"); + err = request_module("bpfilter"); if (err) return err; if (!bpfilter_ops.sockopt) return -ECHILD; } + if (bpfilter_ops.stop) { + err = bpfilter_ops.start(); + if (err) + return err; + } return bpfilter_ops.sockopt(sk, optname, optval, optlen, is_set); } @@ -53,6 +61,7 @@ int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval, static int __init bpfilter_sockopt_init(void) { + bpfilter_ops.stop = true; bpfilter_ops.info.cmdline = "bpfilter_umh"; bpfilter_ops.info.cleanup = &bpfilter_umh_cleanup;