From patchwork Sun Mar 1 10:54:39 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Farnsworth X-Patchwork-Id: 444717 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 B0BD9140182 for ; Sun, 1 Mar 2015 21:55:24 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751143AbbCAKyw (ORCPT ); Sun, 1 Mar 2015 05:54:52 -0500 Received: from logos.farnz.org.uk ([93.93.135.63]:53409 "EHLO logos.farnz.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750794AbbCAKyt (ORCPT ); Sun, 1 Mar 2015 05:54:49 -0500 Received: from hummingbird.visitors.farnz.org.uk ([81.187.250.204] helo=hummingbird.farnz.org.uk) by logos.farnz.org.uk with esmtpsa (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.84) (envelope-from ) id 1YS1WG-00037v-W3; Sun, 01 Mar 2015 10:54:45 +0000 From: Simon Farnsworth To: netdev@vger.kernel.org Cc: linux-ppp@vger.kernel.org, Michal Ostrowski , Simon Farnsworth Subject: [PATCH net-next v2] pppoe: Use workqueue to die properly when a PADT is received Date: Sun, 1 Mar 2015 10:54:39 +0000 Message-Id: <1425207279-4822-1-git-send-email-simon@farnz.org.uk> X-Mailer: git-send-email 2.1.0 X-Spam-Score: -1.0 (-) X-Spam-Report: Spam detection software, running on the system "logos.farnz.org.uk", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: When a PADT frame is received, the socket may not be in a good state to close down the PPP interface. The current implementation handles this by simply blocking all further PPP traffic, and hoping that the lack of traffic will trigger the user to investigate. [...] Content analysis details: (-1.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When a PADT frame is received, the socket may not be in a good state to close down the PPP interface. The current implementation handles this by simply blocking all further PPP traffic, and hoping that the lack of traffic will trigger the user to investigate. Use schedule_work to get to a process context from which we clear down the PPP interface, in a fashion analogous to hangup on a TTY-based PPP interface. This causes pppd to disconnect immediately, and allows tools to take immediate corrective action. Note that pppd's rp_pppoe.so plugin has code in it to disable the session when it disconnects; however, as a consequence of this patch, the session is already disabled before rp_pppoe.so is asked to disable the session. The result is a harmless error message: Failed to disconnect PPPoE socket: 114 Operation already in progress This message is safe to ignore, as long as the error is 114 Operation already in progress; in that specific case, it means that the PPPoE session has already been disabled before pppd tried to disable it. Signed-off-by: Simon Farnsworth Tested-by: Dan Williams Tested-by: Christoph Schulz --- Changes from v1: * Amend commit message to tell people about the harmless error from pppd * Add in Tested-by tags * Change subject to add net-next drivers/net/ppp/pppoe.c | 17 ++++++++++++++++- include/linux/if_pppox.h | 2 ++ 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c index d2408a5..9c97e9b 100644 --- a/drivers/net/ppp/pppoe.c +++ b/drivers/net/ppp/pppoe.c @@ -455,6 +455,18 @@ out: return NET_RX_DROP; } +static void pppoe_unbind_sock_work(struct work_struct *work) +{ + struct pppox_sock *po = container_of(work, struct pppox_sock, + proto.pppoe.padt_work); + struct sock *sk = sk_pppox(po); + + lock_sock(sk); + pppox_unbind_sock(sk); + release_sock(sk); + sock_put(sk); +} + /************************************************************************ * * Receive a PPPoE Discovery frame. @@ -500,7 +512,8 @@ static int pppoe_disc_rcv(struct sk_buff *skb, struct net_device *dev, } bh_unlock_sock(sk); - sock_put(sk); + if (!schedule_work(&po->proto.pppoe.padt_work)) + sock_put(sk); } abort: @@ -613,6 +626,8 @@ static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr, lock_sock(sk); + INIT_WORK(&po->proto.pppoe.padt_work, pppoe_unbind_sock_work); + error = -EINVAL; if (sp->sa_protocol != PX_PROTO_OE) goto end; diff --git a/include/linux/if_pppox.h b/include/linux/if_pppox.h index aff7ad8..66a7d76 100644 --- a/include/linux/if_pppox.h +++ b/include/linux/if_pppox.h @@ -19,6 +19,7 @@ #include #include #include +#include #include static inline struct pppoe_hdr *pppoe_hdr(const struct sk_buff *skb) @@ -32,6 +33,7 @@ struct pppoe_opt { struct pppoe_addr pa; /* what this socket is bound to*/ struct sockaddr_pppox relay; /* what socket data will be relayed to (PPPoE relaying) */ + struct work_struct padt_work;/* Work item for handling PADT */ }; struct pptp_opt {