From patchwork Wed Jan 13 01:50:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Praveen Chaudhary X-Patchwork-Id: 12015563 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 71CD9C433DB for ; Wed, 13 Jan 2021 01:51:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 328192310A for ; Wed, 13 Jan 2021 01:51:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726621AbhAMBu6 (ORCPT ); Tue, 12 Jan 2021 20:50:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725775AbhAMBu6 (ORCPT ); Tue, 12 Jan 2021 20:50:58 -0500 Received: from mail-pg1-x529.google.com (mail-pg1-x529.google.com [IPv6:2607:f8b0:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1172DC0617A7; Tue, 12 Jan 2021 17:50:43 -0800 (PST) Received: by mail-pg1-x529.google.com with SMTP id 30so461067pgr.6; Tue, 12 Jan 2021 17:50:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=fbqsGjoLVVq6FNxNCF6yVrk1Niald3CmUkyqvJb3fMs=; b=SsDxIpal3DfM7gKOF2LGOXb4h3JMCd8f64xv9JchHWwJZxsYIC39Bata8y/PCZJi3u GvPjcgP0G762BdM1G31yTYeKlWzwaGGCScDXQgv8FsbasaPtICHQ4kiqBLTYFZiQAx3J JEoaER7BTeZwNgati4VQzvd8f6gqDWzLZ2csjM5+TbzT6ADsz2YB7McNQQBobZkXMUJK JStm4bdo7b/h3PCcTo/hP3dSCltbbMKIbWiUpYFU8rKGy+1LOAOKwmAC06sVRWUptlH3 jY+wSdtS1alUr32wT95ZcRO61EL09MODirefF01+49KmjUVmKbodKQpLlp7Ypv0jVR/X K+pQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=fbqsGjoLVVq6FNxNCF6yVrk1Niald3CmUkyqvJb3fMs=; b=d/Yzeqv22/D69mdqrTxgC94pY3etROrLn+4JCT3fpiifbyJAI2SwoCVg2xJIpkYF8F ewW52eazmFg9lsnJL1g1OQWelRp8FunxqNZkCJvN7ZIxfIvas5NWzNHaQlYSjkmbjRCS 2u5NM9qIeq2oLENi3tJpwAmiC9esn3ZXDfFt9HIGi/YNFGzya/nT6tpMHCvSgW79GtvG /HTSqHErygSHrMIGzfAp4EzbtK55F7KxpC35aWwaOD3glsQlPmLPE78zuhZms2CdyM+q P4vTWC2QLc4e3W0gYVMWWJWHoMPL4U1h7YUnuGiXv7rTxDVmQpVSDprVlYe1YenHgX7E oh2Q== X-Gm-Message-State: AOAM533GgcAvPO2vEmINTjF4ILEzMeF25bIUtCcyHiKBu3c11OVNp2aR 74cRQDD5RyP68eFTY82Z/Q== X-Google-Smtp-Source: ABdhPJxzPKMPG0HMuqiaeoRHDDxSbXmXzZ2toz1XVW4DYjn+gkzNbPaj/Xut2QL+NN106lUYsvS+3Q== X-Received: by 2002:a63:c441:: with SMTP id m1mr1896523pgg.353.1610502642631; Tue, 12 Jan 2021 17:50:42 -0800 (PST) Received: from localhost.localdomain ([216.52.21.4]) by smtp.gmail.com with ESMTPSA id a18sm388345pfg.107.2021.01.12.17.50.41 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 12 Jan 2021 17:50:42 -0800 (PST) From: Praveen Chaudhary X-Google-Original-From: Praveen Chaudhary To: davem@davemloft.net, kuba@kernel.org, corbet@lwn.net, kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org, netdev@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Zhenggen Xu Subject: [PATCH v1 net-next 1/1] Allow user to set metric on default route learned via Router Advertisement. Date: Tue, 12 Jan 2021 17:50:36 -0800 Message-Id: <20210113015036.17674-2-pchaudhary@linkedin.com> X-Mailer: git-send-email 2.29.0 In-Reply-To: <20210113015036.17674-1-pchaudhary@linkedin.com> References: <20210113015036.17674-1-pchaudhary@linkedin.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org For IPv4, default route is learned via DHCPv4 and user is allowed to change metric using config etc/network/interfaces. But for IPv6, default route can be learned via RA, for which, currently a fixed metric value 1024 is used. Ideally, user should be able to configure metric on default route for IPv6 similar to IPv4. This fix adds sysctl for the same. Signed-off-by: Praveen Chaudhary Signed-off-by: Zhenggen Xu Changes in v1. --- 1.) Correct the call to rt6_add_dflt_router. --- --- Documentation/networking/ip-sysctl.rst | 18 ++++++++++++++++++ include/linux/ipv6.h | 1 + include/net/ip6_route.h | 3 ++- include/uapi/linux/ipv6.h | 1 + include/uapi/linux/sysctl.h | 1 + net/ipv6/addrconf.c | 10 ++++++++++ net/ipv6/ndisc.c | 14 ++++++++++---- net/ipv6/route.c | 5 +++-- 8 files changed, 46 insertions(+), 7 deletions(-) diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index dd2b12a32b73..384159081d91 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst @@ -1871,6 +1871,24 @@ accept_ra_defrtr - BOOLEAN - enabled if accept_ra is enabled. - disabled if accept_ra is disabled. +accept_ra_defrtr_metric - INTEGER + Route metric for default route learned in Router Advertisement. This + value will be assigned as metric for the route learned via IPv6 Router + Advertisement. + + Possible values are: + 0: + Use default value i.e. IP6_RT_PRIO_USER 1024. + 0xFFFFFFFF to -1: + -ve values represent high route metric, value will be treated as + unsigned value. This behaviour is inline with current IPv4 metric + shown with commands such as "route -n" or "ip route list". + 1 to 0x7FFFFFF: + +ve values will be used as is for route metric. + + Functional default: enabled if accept_ra_defrtr is enabled. + disabled if accept_ra_defrtr is disabled. + accept_ra_from_local - BOOLEAN Accept RA with source-address that is found on local machine if the RA is otherwise proper and able to be accepted. diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index dda61d150a13..19af90c77200 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -31,6 +31,7 @@ struct ipv6_devconf { __s32 max_desync_factor; __s32 max_addresses; __s32 accept_ra_defrtr; + __s32 accept_ra_defrtr_metric; __s32 accept_ra_min_hop_limit; __s32 accept_ra_pinfo; __s32 ignore_routes_with_linkdown; diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h index 2a5277758379..a470bdab2420 100644 --- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -174,7 +174,8 @@ struct fib6_info *rt6_get_dflt_router(struct net *net, struct net_device *dev); struct fib6_info *rt6_add_dflt_router(struct net *net, const struct in6_addr *gwaddr, - struct net_device *dev, unsigned int pref); + struct net_device *dev, unsigned int pref, + unsigned int defrtr_usr_metric); void rt6_purge_dflt_routers(struct net *net); diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h index 13e8751bf24a..945de5de5144 100644 --- a/include/uapi/linux/ipv6.h +++ b/include/uapi/linux/ipv6.h @@ -189,6 +189,7 @@ enum { DEVCONF_ACCEPT_RA_RT_INFO_MIN_PLEN, DEVCONF_NDISC_TCLASS, DEVCONF_RPL_SEG_ENABLED, + DEVCONF_ACCEPT_RA_DEFRTR_METRIC, DEVCONF_MAX }; diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h index 458179df9b27..5e79c196e33c 100644 --- a/include/uapi/linux/sysctl.h +++ b/include/uapi/linux/sysctl.h @@ -571,6 +571,7 @@ enum { NET_IPV6_ACCEPT_SOURCE_ROUTE=25, NET_IPV6_ACCEPT_RA_FROM_LOCAL=26, NET_IPV6_ACCEPT_RA_RT_INFO_MIN_PLEN=27, + NET_IPV6_ACCEPT_RA_DEFRTR_METRIC=28, __NET_IPV6_MAX }; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index eff2cacd5209..702ec4a33936 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -205,6 +205,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = { .max_desync_factor = MAX_DESYNC_FACTOR, .max_addresses = IPV6_MAX_ADDRESSES, .accept_ra_defrtr = 1, + .accept_ra_defrtr_metric = 0, .accept_ra_from_local = 0, .accept_ra_min_hop_limit= 1, .accept_ra_pinfo = 1, @@ -260,6 +261,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = { .max_desync_factor = MAX_DESYNC_FACTOR, .max_addresses = IPV6_MAX_ADDRESSES, .accept_ra_defrtr = 1, + .accept_ra_defrtr_metric = 0, .accept_ra_from_local = 0, .accept_ra_min_hop_limit= 1, .accept_ra_pinfo = 1, @@ -5475,6 +5477,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf, array[DEVCONF_MAX_DESYNC_FACTOR] = cnf->max_desync_factor; array[DEVCONF_MAX_ADDRESSES] = cnf->max_addresses; array[DEVCONF_ACCEPT_RA_DEFRTR] = cnf->accept_ra_defrtr; + array[DEVCONF_ACCEPT_RA_DEFRTR_METRIC] = cnf->accept_ra_defrtr_metric; array[DEVCONF_ACCEPT_RA_MIN_HOP_LIMIT] = cnf->accept_ra_min_hop_limit; array[DEVCONF_ACCEPT_RA_PINFO] = cnf->accept_ra_pinfo; #ifdef CONFIG_IPV6_ROUTER_PREF @@ -6667,6 +6670,13 @@ static const struct ctl_table addrconf_sysctl[] = { .mode = 0644, .proc_handler = proc_dointvec, }, + { + .procname = "accept_ra_defrtr_metric", + .data = &ipv6_devconf.accept_ra_defrtr_metric, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, { .procname = "accept_ra_min_hop_limit", .data = &ipv6_devconf.accept_ra_min_hop_limit, diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 76717478f173..96ab202e95f9 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -1180,6 +1180,7 @@ static void ndisc_router_discovery(struct sk_buff *skb) unsigned int pref = 0; __u32 old_if_flags; bool send_ifinfo_notify = false; + unsigned int defrtr_usr_metric = 0; __u8 *opt = (__u8 *)(ra_msg + 1); @@ -1303,18 +1304,23 @@ static void ndisc_router_discovery(struct sk_buff *skb) return; } } - if (rt && lifetime == 0) { + /* Set default route metric if specified by user */ + defrtr_usr_metric = in6_dev->cnf.accept_ra_defrtr_metric; + if (defrtr_usr_metric == 0) + defrtr_usr_metric = IP6_RT_PRIO_USER; + /* delete the route if lifetime is 0 or if metric needs change */ + if (rt && ((lifetime == 0) || (rt->fib6_metric != defrtr_usr_metric))) { ip6_del_rt(net, rt, false); rt = NULL; } - ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, for dev: %s\n", - rt, lifetime, skb->dev->name); + ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n", + rt, lifetime, defrtr_usr_metric, skb->dev->name); if (!rt && lifetime) { ND_PRINTK(3, info, "RA: adding default router\n"); rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr, - skb->dev, pref); + skb->dev, pref, defrtr_usr_metric); if (!rt) { ND_PRINTK(0, err, "RA: %s failed to add default route\n", diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 188e114b29b4..5f177ae97e42 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -4252,11 +4252,12 @@ struct fib6_info *rt6_get_dflt_router(struct net *net, struct fib6_info *rt6_add_dflt_router(struct net *net, const struct in6_addr *gwaddr, struct net_device *dev, - unsigned int pref) + unsigned int pref, + unsigned int defrtr_usr_metric) { struct fib6_config cfg = { .fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT, - .fc_metric = IP6_RT_PRIO_USER, + .fc_metric = defrtr_usr_metric ? defrtr_usr_metric : IP6_RT_PRIO_USER, .fc_ifindex = dev->ifindex, .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT | RTF_UP | RTF_EXPIRES | RTF_PREF(pref),