From patchwork Fri Oct 16 14:54:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Dike X-Patchwork-Id: 1383432 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=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=ElPE4rsD; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4CCVp02bQgz9sSG for ; Sat, 17 Oct 2020 02:44:40 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2410381AbgJPPoj (ORCPT ); Fri, 16 Oct 2020 11:44:39 -0400 Received: from mx0a-00190b01.pphosted.com ([67.231.149.131]:13582 "EHLO mx0a-00190b01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2408685AbgJPPoj (ORCPT ); Fri, 16 Oct 2020 11:44:39 -0400 X-Greylist: delayed 2946 seconds by postgrey-1.27 at vger.kernel.org; Fri, 16 Oct 2020 11:44:38 EDT Received: from pps.filterd (m0050095.ppops.net [127.0.0.1]) by m0050095.ppops.net-00190b01. (8.16.0.42/8.16.0.42) with SMTP id 09GEpkYe010529 for ; Fri, 16 Oct 2020 15:54:32 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=akamai.com; h=to : from : subject : message-id : date : mime-version : content-type : content-transfer-encoding; s=jan2016.eng; bh=l9JhK1EGNePbhS3jag/fArtMYNMN0/hBp5pJxkbnisc=; b=ElPE4rsDaLJkLXtk2uCfnD/vrVzsNo28KZxHT8Dnv+N7z3nFAFxg2brmkqCvoYUwdZzY InnM54i45L+dps/XI5oeQuUo5cBdnu4og9dFwjJLSOUt98DDv7RSAItkLY8wI/t1/Bz+ Ex2ipH8XMWoouaH5bk35KvIQL2ewFcocVzxYddsop1tZBd5HrXZNd/P+dImkxlcp/u2i GOTUiVkfSfbiZQSusROAetq2aepfDTOsA/1BrCU5YzJHvESpVA+lUTgrr45O06vvWJHl ppWhfdrHFCoFXU3vow3OHgYf88RcNp5zucUsqoQNBKZXPdNPO78gGnLXF4h+tXVG/kJu 1w== Received: from prod-mail-ppoint6 (prod-mail-ppoint6.akamai.com [184.51.33.61] (may be forged)) by m0050095.ppops.net-00190b01. with ESMTP id 3434x6k73p-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 16 Oct 2020 15:54:32 +0100 Received: from pps.filterd (prod-mail-ppoint6.akamai.com [127.0.0.1]) by prod-mail-ppoint6.akamai.com (8.16.0.42/8.16.0.42) with SMTP id 09GEoVWn001620 for ; Fri, 16 Oct 2020 10:54:30 -0400 Received: from prod-mail-relay10.akamai.com ([172.27.118.251]) by prod-mail-ppoint6.akamai.com with ESMTP id 34389xwp9a-1 for ; Fri, 16 Oct 2020 10:54:30 -0400 Received: from [0.0.0.0] (stag-ssh-gw01.bos01.corp.akamai.com [172.27.113.23]) by prod-mail-relay10.akamai.com (Postfix) with ESMTP id 95D103D39E for ; Fri, 16 Oct 2020 14:54:30 +0000 (GMT) To: netdev@vger.kernel.org From: Jeff Dike Subject: [RFC] Exempt multicast address from five-second neighbor lifetime Message-ID: <0d7a29d2-499f-70ab-ee6f-ced4c9305181@akamai.com> Date: Fri, 16 Oct 2020 10:54:30 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 Content-Language: en-US X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-10-16_07:2020-10-16,2020-10-16 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=943 adultscore=0 bulkscore=0 phishscore=0 mlxscore=0 suspectscore=1 spamscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010160113 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-10-16_07:2020-10-16,2020-10-16 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 bulkscore=0 suspectscore=1 adultscore=0 clxscore=1011 impostorscore=0 malwarescore=0 mlxlogscore=882 mlxscore=0 priorityscore=1501 spamscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010160113 X-Agari-Authentication-Results: mx.akamai.com; spf=${SPFResult} (sender IP is 184.51.33.61) smtp.mailfrom=jdike@akamai.com smtp.helo=prod-mail-ppoint6 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Commit 58956317c8de guarantees arp table entries a five-second lifetime. We have some apps which make heavy use of multicast, and these can cause the table to overflow by filling it with multicast addresses which can't be GC-ed until their five seconds are up. This patch allows multicast addresses to be thrown out before they've lived out their five seconds. Signed-off-by: Jeff Dike 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..110d6d408edc 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -79,6 +79,7 @@ #include #include #include +#define __UAPI_DEF_IN_CLASS 1 #include #include #include @@ -125,6 +126,7 @@ 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 +158,7 @@ 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 +931,10 @@ 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 IN_MULTICAST(htonl(*((u32 *) pkey))); +} /* * Receive an arp request from the device layer. diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 27f29b957ee7..b42c9314cc4e 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 (((struct in6_addr *) pkey)->in6_u.u6_addr8[0] & 0xf0) == 0xf0; +} + static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb) { struct inet6_dev *idev = __in6_dev_get(skb->dev);