From patchwork Tue Jan 26 13:23:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ido Schimmel X-Patchwork-Id: 371191 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7CB52C433DB for ; Tue, 26 Jan 2021 14:27:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 50BA422DFB for ; Tue, 26 Jan 2021 14:27:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405869AbhAZO1p (ORCPT ); Tue, 26 Jan 2021 09:27:45 -0500 Received: from wout2-smtp.messagingengine.com ([64.147.123.25]:51585 "EHLO wout2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391710AbhAZN0I (ORCPT ); Tue, 26 Jan 2021 08:26:08 -0500 Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailout.west.internal (Postfix) with ESMTP id 97D819AF; Tue, 26 Jan 2021 08:24:33 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute5.internal (MEProxy); Tue, 26 Jan 2021 08:24:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:date:from :in-reply-to:message-id:mime-version:references:subject:to :x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm1; bh=8frFZwEXu5e5HgRPoUIoQ1qXcZtGMcP/vAqCuSVD2p0=; b=fdEUV04Y BU6m5lQEPl9gjeZzQep2CvcOl4gNuM/eVhal8NPFkVKKFM1ioGZmzyoCICQpV8s0 6IDrTDngLkMQq1XY/uJh5rwQc/jz+AdjRhvdiM0ifSfm5hzn3q7asfGfeJgPRNCN wj2k33mpOETKPHNKBSvLD6Gd3K8tXRcYD5VlhuUdvsLZak3W5xXOC9EpNEkUKXwd NGomNI6aHcE6qE94L+h/X9k0HQYxY3LwydwV4avVCBZCZGKqM4qZNDcGwGMMwYLG z50hKz17L6xCwXnBkqHTAlAQoJu/lSsK6WtAeiMaq8RsuM1UBIp+v9VdcWVnqwgq KgwItLCfpoMrVg== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrvdehgdehudcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecunecujfgurhephffvufffkffojghfggfgsedtkeertd ertddtnecuhfhrohhmpefkughoucfutghhihhmmhgvlhcuoehiughoshgthhesihguohhs tghhrdhorhhgqeenucggtffrrghtthgvrhhnpeduteeiveffffevleekleejffekhfekhe fgtdfftefhledvjefggfehgfevjeekhfenucfkphepkeegrddvvdelrdduheefrdeggeen ucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehiughosh gthhesihguohhstghhrdhorhhg X-ME-Proxy: Received: from shredder.mellanox.com (igld-84-229-153-44.inter.net.il [84.229.153.44]) by mail.messagingengine.com (Postfix) with ESMTPA id D3A931080057; Tue, 26 Jan 2021 08:24:30 -0500 (EST) From: Ido Schimmel To: netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, dsahern@gmail.com, amcohen@nvidia.com, roopa@nvidia.com, sharpd@nvidia.com, bpoirier@nvidia.com, mlxsw@nvidia.com, Ido Schimmel Subject: [PATCH net-next 08/10] net: ipv6: Emit notification when fib hardware flags are changed Date: Tue, 26 Jan 2021 15:23:09 +0200 Message-Id: <20210126132311.3061388-9-idosch@idosch.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210126132311.3061388-1-idosch@idosch.org> References: <20210126132311.3061388-1-idosch@idosch.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Amit Cohen After installing a route to the kernel, user space receives an acknowledgment, which means the route was installed in the kernel, but not necessarily in hardware. The asynchronous nature of route installation in hardware can lead to a routing daemon advertising a route before it was actually installed in hardware. This can result in packet loss or mis-routed packets until the route is installed in hardware. It is also possible for a route already installed in hardware to change its action and therefore its flags. For example, a host route that is trapping packets can be "promoted" to perform decapsulation following the installation of an IPinIP/VXLAN tunnel. Emit RTM_NEWROUTE notifications whenever RTM_F_OFFLOAD/RTM_F_TRAP flags are changed. The aim is to provide an indication to user-space (e.g., routing daemons) about the state of the route in hardware. Introduce a sysctl that controls this behavior. Keep the default value at 0 (i.e., do not emit notifications) for several reasons: - Multiple RTM_NEWROUTE notification per-route might confuse existing routing daemons. - Convergence reasons in routing daemons. - The extra notifications will negatively impact the insertion rate. - Not all users are interested in these notifications. Move fib6_info_hw_flags_set() to C file because it is no longer a short function. Signed-off-by: Amit Cohen Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Reviewed-by: David Ahern --- Documentation/networking/ip-sysctl.rst | 20 ++++++++++++ include/net/ip6_fib.h | 10 ++---- include/net/netns/ipv6.h | 1 + net/ipv6/af_inet6.c | 1 + net/ipv6/route.c | 44 ++++++++++++++++++++++++++ net/ipv6/sysctl_net_ipv6.c | 9 ++++++ 6 files changed, 77 insertions(+), 8 deletions(-) diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index 01927b36bbee..11f10b8f4a83 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst @@ -1795,6 +1795,26 @@ nexthop_compat_mode - BOOLEAN and extraneous notifications. Default: true (backward compat mode) +fib_notify_on_flag_change - INTEGER + Whether to emit RTM_NEWROUTE notifications whenever RTM_F_OFFLOAD/ + RTM_F_TRAP flags are changed. + + After installing a route to the kernel, user space receives an + acknowledgment, which means the route was installed in the kernel, + but not necessarily in hardware. + It is also possible for a route already installed in hardware to change + its action and therefore its flags. For example, a host route that is + trapping packets can be "promoted" to perform decapsulation following + the installation of an IPinIP/VXLAN tunnel. + The notifications will indicate to user-space the state of the route. + + Default: 0 (Do not emit notifications.) + + Possible values: + + - 0 - Do not emit notifications. + - 1 - Emit notifications. + IPv6 Fragmentation: ip6frag_high_thresh - INTEGER diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index cc189e668adf..1e262b23c68b 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -336,14 +336,6 @@ static inline void fib6_info_release(struct fib6_info *f6i) call_rcu(&f6i->rcu, fib6_info_destroy_rcu); } -static inline void -fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i, bool offload, - bool trap) -{ - f6i->offload = offload; - f6i->trap = trap; -} - enum fib6_walk_state { #ifdef CONFIG_IPV6_SUBTREES FWS_S, @@ -546,6 +538,8 @@ static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric) { return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric)); } +void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i, + bool offload, bool trap); #if IS_BUILTIN(CONFIG_IPV6) && defined(CONFIG_BPF_SYSCALL) struct bpf_iter__ipv6_route { diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h index 5ec054473d81..21c0debbd39e 100644 --- a/include/net/netns/ipv6.h +++ b/include/net/netns/ipv6.h @@ -51,6 +51,7 @@ struct netns_sysctl_ipv6 { int max_hbh_opts_len; int seg6_flowlabel; bool skip_notify_on_dev_down; + int fib_notify_on_flag_change; }; struct netns_ipv6 { diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index 8e9c3e9ea36e..0e9994e0ecd7 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -954,6 +954,7 @@ static int __net_init inet6_net_init(struct net *net) net->ipv6.sysctl.max_hbh_opts_cnt = IP6_DEFAULT_MAX_HBH_OPTS_CNT; net->ipv6.sysctl.max_dst_opts_len = IP6_DEFAULT_MAX_DST_OPTS_LEN; net->ipv6.sysctl.max_hbh_opts_len = IP6_DEFAULT_MAX_HBH_OPTS_LEN; + net->ipv6.sysctl.fib_notify_on_flag_change = 0; atomic_set(&net->ipv6.fib6_sernum, 1); err = ipv6_init_mibs(net); diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 188e114b29b4..dcf28240541d 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -6063,6 +6063,50 @@ void fib6_rt_update(struct net *net, struct fib6_info *rt, rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err); } +void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i, + bool offload, bool trap) +{ + struct sk_buff *skb; + int err; + + if (f6i->offload == offload && f6i->trap == trap) + return; + + f6i->offload = offload; + f6i->trap = trap; + + if (!rcu_access_pointer(f6i->fib6_node)) + /* The route was removed from the tree, do not send + * notfication. + */ + return; + + if (!net->ipv6.sysctl.fib_notify_on_flag_change) + return; + + skb = nlmsg_new(rt6_nlmsg_size(f6i), GFP_KERNEL); + if (!skb) { + err = -ENOBUFS; + goto errout; + } + + err = rt6_fill_node(net, skb, f6i, NULL, NULL, NULL, 0, RTM_NEWROUTE, 0, + 0, 0); + if (err < 0) { + /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */ + WARN_ON(err == -EMSGSIZE); + kfree_skb(skb); + goto errout; + } + + rtnl_notify(skb, net, 0, RTNLGRP_IPV6_ROUTE, NULL, GFP_KERNEL); + return; + +errout: + rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err); +} +EXPORT_SYMBOL(fib6_info_hw_flags_set); + static int ip6_route_dev_notify(struct notifier_block *this, unsigned long event, void *ptr) { diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c index 5b60a4bdd36a..392ef01e3366 100644 --- a/net/ipv6/sysctl_net_ipv6.c +++ b/net/ipv6/sysctl_net_ipv6.c @@ -160,6 +160,15 @@ static struct ctl_table ipv6_table_template[] = { .mode = 0644, .proc_handler = proc_dointvec }, + { + .procname = "fib_notify_on_flag_change", + .data = &init_net.ipv6.sysctl.fib_notify_on_flag_change, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, { } };