From patchwork Fri Nov 13 01:58:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Dike X-Patchwork-Id: 1399498 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=akamai.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; secure) header.d=akamai.com header.i=@akamai.com header.a=rsa-sha256 header.s=jan2016.eng header.b=el8gCKYZ; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4CXM8q0lrVz9sTK for ; Fri, 13 Nov 2020 12:59:23 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726274AbgKMB7V (ORCPT ); Thu, 12 Nov 2020 20:59:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53604 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726148AbgKMB7U (ORCPT ); Thu, 12 Nov 2020 20:59:20 -0500 Received: from mx0b-00190b01.pphosted.com (mx0b-00190b01.pphosted.com [IPv6:2620:100:9005:57f::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A83C9C0613D1 for ; Thu, 12 Nov 2020 17:59:20 -0800 (PST) Received: from pps.filterd (m0050102.ppops.net [127.0.0.1]) by m0050102.ppops.net-00190b01. (8.16.0.42/8.16.0.42) with SMTP id 0AD1u2fs016093; Fri, 13 Nov 2020 01:59:18 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=akamai.com; h=from : to : cc : subject : date : message-id : mime-version : content-type; s=jan2016.eng; bh=E0IOFf/02M+fvgGyenLXqNoaKi5gJPr8OgLfSkn1D4s=; b=el8gCKYZs6uAwloo8rFtw3By9HIKvIqboR33dc15Jw5oau2M5cBta4NIsqI/H47/WdVP S6D7eipIwhStWTm1m4OHFbNYi0HsYxRA6ybSqoGDrVnD4t/K1oUgWesE0HlRVZ/xYnRT 5xcpZITmY/uWgmpiO/ZUQSxPjfqRRih9nLgP4J9TL4Gdc9AkA998FJ1P6T3mvDZSn2uf NzULgzHBOLpVAFw2h3rcZ9dsLe04lOK21Zvkdv7R0iVY7HbNRkX1fUMKg08lV9FByCBl 6LDYD+A7LbGLmvI/ds+yg6LOVFzvx5bTe+ClRs4lYmAA2SZIu7Pe3RLS6TRE+9noFios TA== Received: from prod-mail-ppoint1 (prod-mail-ppoint1.akamai.com [184.51.33.18] (may be forged)) by m0050102.ppops.net-00190b01. with ESMTP id 34nhhvex3r-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 13 Nov 2020 01:59:17 +0000 Received: from pps.filterd (prod-mail-ppoint1.akamai.com [127.0.0.1]) by prod-mail-ppoint1.akamai.com (8.16.0.42/8.16.0.42) with SMTP id 0AD1nrdc027956; Thu, 12 Nov 2020 20:59:17 -0500 Received: from email.msg.corp.akamai.com ([172.27.123.33]) by prod-mail-ppoint1.akamai.com with ESMTP id 34nqt3ktca-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT); Thu, 12 Nov 2020 20:59:17 -0500 Received: from USMA1EX-CAS2.msg.corp.akamai.com (172.27.123.31) by usma1ex-dag3mb4.msg.corp.akamai.com (172.27.123.56) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 12 Nov 2020 20:59:16 -0500 Received: from bos-lp1yy.kendall.corp.akamai.com (172.28.3.205) by USMA1EX-CAS2.msg.corp.akamai.com (172.27.123.31) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Thu, 12 Nov 2020 20:59:16 -0500 Received: by bos-lp1yy.kendall.corp.akamai.com (Postfix, from userid 45189) id 9300C15F7E0; Thu, 12 Nov 2020 20:58:20 -0500 (EST) From: Jeff Dike To: CC: David Ahern , Jakub Kicinski , Jeff Dike Subject: [PATCH net V4] Exempt multicast addresses from five-second neighbor lifetime Date: Thu, 12 Nov 2020 20:58:15 -0500 Message-ID: <20201113015815.31397-1-jdike@akamai.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.312,18.0.737 definitions=2020-11-12_16:2020-11-12,2020-11-12 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 bulkscore=0 adultscore=0 phishscore=0 suspectscore=1 mlxscore=0 malwarescore=0 mlxlogscore=990 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011130008 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.312,18.0.737 definitions=2020-11-12_16:2020-11-12,2020-11-12 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 clxscore=1015 mlxlogscore=967 malwarescore=0 priorityscore=1501 mlxscore=0 suspectscore=1 adultscore=0 lowpriorityscore=0 phishscore=0 impostorscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011130009 X-Agari-Authentication-Results: mx.akamai.com; spf=${SPFResult} (sender IP is 184.51.33.18) smtp.mailfrom=jdike@akamai.com smtp.helo=prod-mail-ppoint1 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Commit 58956317c8de ("neighbor: Improve garbage collection") guarantees neighbour table entries a five-second lifetime. Processes which make heavy use of multicast can fill the neighour table with multicast addresses in five seconds. At that point, neighbour entries can't be GC-ed because they aren't five seconds old yet, the kernel log starts to fill up with "neighbor table overflow!" messages, and sends start to fail. This patch allows multicast addresses to be thrown out before they've lived out their five seconds. This makes room for non-multicast addresses and makes messages to all addresses more reliable in these circumstances. Fixes: 58956317c8de ("neighbor: Improve garbage collection") Signed-off-by: Jeff Dike Reviewed-by: David Ahern --- include/net/neighbour.h | 1 + net/core/neighbour.c | 2 ++ net/ipv4/arp.c | 6 ++++++ net/ipv6/ndisc.c | 7 +++++++ 4 files changed, 16 insertions(+) diff --git a/include/net/neighbour.h b/include/net/neighbour.h index 81ee17594c32..22ced1381ede 100644 --- a/include/net/neighbour.h +++ b/include/net/neighbour.h @@ -204,6 +204,7 @@ struct neigh_table { int (*pconstructor)(struct pneigh_entry *); void (*pdestructor)(struct pneigh_entry *); void (*proxy_redo)(struct sk_buff *skb); + int (*is_multicast)(const void *pkey); bool (*allow_add)(const struct net_device *dev, struct netlink_ext_ack *extack); char *id; diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 8e39e28b0a8d..9500d28a43b0 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -235,6 +235,8 @@ static int neigh_forced_gc(struct neigh_table *tbl) write_lock(&n->lock); if ((n->nud_state == NUD_FAILED) || + (tbl->is_multicast && + tbl->is_multicast(n->primary_key)) || time_after(tref, n->updated)) remove = true; write_unlock(&n->lock); diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c index 687971d83b4e..922dd73e5740 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -125,6 +125,7 @@ static int arp_constructor(struct neighbour *neigh); static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); static void parp_redo(struct sk_buff *skb); +static int arp_is_multicast(const void *pkey); static const struct neigh_ops arp_generic_ops = { .family = AF_INET, @@ -156,6 +157,7 @@ struct neigh_table arp_tbl = { .key_eq = arp_key_eq, .constructor = arp_constructor, .proxy_redo = parp_redo, + .is_multicast = arp_is_multicast, .id = "arp_cache", .parms = { .tbl = &arp_tbl, @@ -928,6 +930,10 @@ static void parp_redo(struct sk_buff *skb) arp_process(dev_net(skb->dev), NULL, skb); } +static int arp_is_multicast(const void *pkey) +{ + return ipv4_is_multicast(*((__be32 *)pkey)); +} /* * Receive an arp request from the device layer. diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 27f29b957ee7..76717478f173 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -81,6 +81,7 @@ static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb); static int pndisc_constructor(struct pneigh_entry *n); static void pndisc_destructor(struct pneigh_entry *n); static void pndisc_redo(struct sk_buff *skb); +static int ndisc_is_multicast(const void *pkey); static const struct neigh_ops ndisc_generic_ops = { .family = AF_INET6, @@ -115,6 +116,7 @@ struct neigh_table nd_tbl = { .pconstructor = pndisc_constructor, .pdestructor = pndisc_destructor, .proxy_redo = pndisc_redo, + .is_multicast = ndisc_is_multicast, .allow_add = ndisc_allow_add, .id = "ndisc_cache", .parms = { @@ -1706,6 +1708,11 @@ static void pndisc_redo(struct sk_buff *skb) kfree_skb(skb); } +static int ndisc_is_multicast(const void *pkey) +{ + return ipv6_addr_is_multicast((struct in6_addr *)pkey); +} + static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb) { struct inet6_dev *idev = __in6_dev_get(skb->dev);