From patchwork Wed Sep 2 14:52:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 1355856 X-Patchwork-Delegate: pablo@netfilter.org Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.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=netfilter-devel-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=netfilter.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BhRlv25Wpz9sTv for ; Thu, 3 Sep 2020 00:54:03 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726922AbgIBOx0 (ORCPT ); Wed, 2 Sep 2020 10:53:26 -0400 Received: from correo.us.es ([193.147.175.20]:44222 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726406AbgIBOwL (ORCPT ); Wed, 2 Sep 2020 10:52:11 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id DD42E1878A0 for ; Wed, 2 Sep 2020 16:52:09 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id CCEEADA704 for ; Wed, 2 Sep 2020 16:52:09 +0200 (CEST) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id C0E98DA73D; Wed, 2 Sep 2020 16:52:09 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on antivirus1-rhel7.int X-Spam-Level: X-Spam-Status: No, score=-108.2 required=7.5 tests=ALL_TRUSTED,BAYES_50, SMTPAUTH_US2,USER_IN_WELCOMELIST,USER_IN_WHITELIST autolearn=disabled version=3.4.1 Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 82577DA704; Wed, 2 Sep 2020 16:52:07 +0200 (CEST) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Wed, 02 Sep 2020 16:52:07 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from localhost.localdomain (unknown [90.77.255.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: pneira@us.es) by entrada.int (Postfix) with ESMTPSA id 5FC7E42EF42C; Wed, 2 Sep 2020 16:52:07 +0200 (CEST) X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: phil@nwl.cc, eric@garver.life Subject: [PATCH nf,v2] netfilter: nf_tables: coalesce multiple notifications into one skbuff Date: Wed, 2 Sep 2020 16:52:02 +0200 Message-Id: <20200902145202.6822-1-pablo@netfilter.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-Virus-Scanned: ClamAV using ClamSMTP Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On x86_64, each notification results in one skbuff allocation which consumes at least 768 bytes due to the skbuff overhead. This patch coalesces several notifications into one single skbuff, so each notification consumes at least ~211 bytes, that ~3.5 times less memory consumption. As a result, this is reducing the chances to exhaust the netlink socket receive buffer. Rule of thumb is that each notification batch only contains netlink messages whose report flag is the same, nfnetlink_send() requires this to do appropriately delivery to userspace, either via unicast (echo mode) or multicast (monitor mode). The skbuff control buffer is used to annotate the report flag for later handling at the new coalescing routine. The batch skbuff notification size is NLMSG_GOODSIZE, using a larger skbuff would allow for more socket receiver buffer savings (to amortize the cost of the skbuff even more), however, going over that size might break userspace applications, so let's be conservative and stick to NLMSG_GOODSIZE. Reported-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso --- v2: len = NLMSG_GOODSIZE - skb->len; reported by Phil Sutter. include/net/netns/nftables.h | 1 + net/netfilter/nf_tables_api.c | 71 ++++++++++++++++++++++++++++------- 2 files changed, 59 insertions(+), 13 deletions(-) diff --git a/include/net/netns/nftables.h b/include/net/netns/nftables.h index a1a8d45adb42..6c0806bd8d1e 100644 --- a/include/net/netns/nftables.h +++ b/include/net/netns/nftables.h @@ -8,6 +8,7 @@ struct netns_nftables { struct list_head tables; struct list_head commit_list; struct list_head module_list; + struct list_head notify_list; struct mutex commit_mutex; unsigned int base_seq; u8 gencursor; diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index b7dc1cbf40ea..a5a444650c91 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -684,6 +684,18 @@ static int nf_tables_fill_table_info(struct sk_buff *skb, struct net *net, return -1; } +struct nftnl_skb_parms { + bool report; +}; +#define NFT_CB(skb) (*(struct nftnl_skb_parms*)&((skb)->cb)) + +static void nft_notify_enqueue(struct sk_buff *skb, bool report, + struct list_head *notify_list) +{ + NFT_CB(skb).report = report; + list_add_tail(&skb->list, notify_list); +} + static void nf_tables_table_notify(const struct nft_ctx *ctx, int event) { struct sk_buff *skb; @@ -715,8 +727,7 @@ static void nf_tables_table_notify(const struct nft_ctx *ctx, int event) goto err; } - nfnetlink_send(skb, ctx->net, ctx->portid, NFNLGRP_NFTABLES, - ctx->report, GFP_KERNEL); + nft_notify_enqueue(skb, ctx->report, &ctx->net->nft.notify_list); return; err: nfnetlink_set_err(ctx->net, ctx->portid, NFNLGRP_NFTABLES, -ENOBUFS); @@ -1468,8 +1479,7 @@ static void nf_tables_chain_notify(const struct nft_ctx *ctx, int event) goto err; } - nfnetlink_send(skb, ctx->net, ctx->portid, NFNLGRP_NFTABLES, - ctx->report, GFP_KERNEL); + nft_notify_enqueue(skb, ctx->report, &ctx->net->nft.notify_list); return; err: nfnetlink_set_err(ctx->net, ctx->portid, NFNLGRP_NFTABLES, -ENOBUFS); @@ -2807,8 +2817,7 @@ static void nf_tables_rule_notify(const struct nft_ctx *ctx, goto err; } - nfnetlink_send(skb, ctx->net, ctx->portid, NFNLGRP_NFTABLES, - ctx->report, GFP_KERNEL); + nft_notify_enqueue(skb, ctx->report, &ctx->net->nft.notify_list); return; err: nfnetlink_set_err(ctx->net, ctx->portid, NFNLGRP_NFTABLES, -ENOBUFS); @@ -3837,8 +3846,7 @@ static void nf_tables_set_notify(const struct nft_ctx *ctx, goto err; } - nfnetlink_send(skb, ctx->net, portid, NFNLGRP_NFTABLES, ctx->report, - gfp_flags); + nft_notify_enqueue(skb, ctx->report, &ctx->net->nft.notify_list); return; err: nfnetlink_set_err(ctx->net, portid, NFNLGRP_NFTABLES, -ENOBUFS); @@ -4959,8 +4967,7 @@ static void nf_tables_setelem_notify(const struct nft_ctx *ctx, goto err; } - nfnetlink_send(skb, net, portid, NFNLGRP_NFTABLES, ctx->report, - GFP_KERNEL); + nft_notify_enqueue(skb, ctx->report, &ctx->net->nft.notify_list); return; err: nfnetlink_set_err(net, portid, NFNLGRP_NFTABLES, -ENOBUFS); @@ -6275,7 +6282,7 @@ void nft_obj_notify(struct net *net, const struct nft_table *table, goto err; } - nfnetlink_send(skb, net, portid, NFNLGRP_NFTABLES, report, gfp); + nft_notify_enqueue(skb, report, &net->nft.notify_list); return; err: nfnetlink_set_err(net, portid, NFNLGRP_NFTABLES, -ENOBUFS); @@ -7085,8 +7092,7 @@ static void nf_tables_flowtable_notify(struct nft_ctx *ctx, goto err; } - nfnetlink_send(skb, ctx->net, ctx->portid, NFNLGRP_NFTABLES, - ctx->report, GFP_KERNEL); + nft_notify_enqueue(skb, ctx->report, &ctx->net->nft.notify_list); return; err: nfnetlink_set_err(ctx->net, ctx->portid, NFNLGRP_NFTABLES, -ENOBUFS); @@ -7695,6 +7701,42 @@ static void nf_tables_commit_release(struct net *net) mutex_unlock(&net->nft.commit_mutex); } +static void nft_commit_notify(struct net *net, u32 portid) +{ + struct sk_buff *batch_skb = NULL, *nskb, *skb; + unsigned char *data; + int len; + + list_for_each_entry_safe(skb, nskb, &net->nft.notify_list, list) { + if (!batch_skb) { +new_batch: + batch_skb = skb; + NFT_CB(batch_skb).report = NFT_CB(skb).report; + len = NLMSG_GOODSIZE - skb->len; + list_del(&skb->list); + continue; + } + len -= skb->len; + if (len > 0 && NFT_CB(skb).report == NFT_CB(batch_skb).report) { + data = skb_put(batch_skb, skb->len); + memcpy(data, skb->data, skb->len); + list_del(&skb->list); + kfree_skb(skb); + continue; + } + nfnetlink_send(batch_skb, net, portid, NFNLGRP_NFTABLES, + NFT_CB(batch_skb).report, GFP_KERNEL); + goto new_batch; + } + + if (batch_skb) { + nfnetlink_send(batch_skb, net, portid, NFNLGRP_NFTABLES, + NFT_CB(batch_skb).report, GFP_KERNEL); + } + + WARN_ON_ONCE(!list_empty(&net->nft.notify_list)); +} + static int nf_tables_commit(struct net *net, struct sk_buff *skb) { struct nft_trans *trans, *next; @@ -7897,6 +7939,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) } } + nft_commit_notify(net, NETLINK_CB(skb).portid); nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN); nf_tables_commit_release(net); @@ -8721,6 +8764,7 @@ static int __net_init nf_tables_init_net(struct net *net) INIT_LIST_HEAD(&net->nft.tables); INIT_LIST_HEAD(&net->nft.commit_list); INIT_LIST_HEAD(&net->nft.module_list); + INIT_LIST_HEAD(&net->nft.notify_list); mutex_init(&net->nft.commit_mutex); net->nft.base_seq = 1; net->nft.validate_state = NFT_VALIDATE_SKIP; @@ -8737,6 +8781,7 @@ static void __net_exit nf_tables_exit_net(struct net *net) mutex_unlock(&net->nft.commit_mutex); WARN_ON_ONCE(!list_empty(&net->nft.tables)); WARN_ON_ONCE(!list_empty(&net->nft.module_list)); + WARN_ON_ONCE(!list_empty(&net->nft.notify_list)); } static struct pernet_operations nf_tables_net_ops = {