From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x2272nIMtsmYkG7XYFDNUj8sVp3jMjwpc9X7ks6Xmg9rv/qsUa++3GYj8BDw2PCvdsu9b/AvL ARC-Seal: i=1; a=rsa-sha256; t=1517256302; cv=none; d=google.com; s=arc-20160816; b=HOdza719MY43nPgQ2hj/1oxCYfCH+GJ6dPoUCOs4DoevMwXN2Jh9l6PP45vWzHO1sp Jicfr+jgzn3Fy/NJJfyH92FjaiVmaosoGj/18yeC3SKI0xUKrfaCtWjrFgsFm1a3Q0+t ZK8j+e2YeEHzWuhkJtaz6EcsiwXaO9QG50BAWPaN92XSzmQQ0L6s3rwyk5Ci/mOpM/OB nu3N31RPAXsoJIbkx8Tc5ND3e1nahMFab8JsOvLWcfNF5xJ9fo/t+HBj/CSFNNqgDOAM 6R83ArFPUC47FBu77o9uYbfHb7tWk/EEs/oqIAWDozE975xbPiIre3w2cv8TuP3twqGJ BI2Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=FZfENYYExH63/cDHGBadKG8Hv3iD64vLmb2s1HC+75I=; b=FVsBa9XdGGVcXWwEZKeqtWIBjiZWrGu4X3DNmjaLqDlEbzcZgis+ACf/U1vLHxnKo9 sUAN7r2w87AdbLM3Rd1n9petdpyIb19uXOMpPJje5T3OaxJ8XlPkGyWHwtQxsaITZxda yevqswC0w5ZhaiEIHgYOkr95bJqRPBADEHYVuo8UbLm/ecPOUGNGhgskVWSPTWW7wbjU 20O992AndUWn2SWT9ciH14MH9TP3ubgGkifuDQ535veOwGURw/pZnF8Dsed31zgrW62C bqZNsGoNvPCz4T/26IazDZ+0zXrkzwCM+1VM9MQd1LyViXvmutKPm7u6IspT2KrDQNai xJkg== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jim Westfall , "David S. Miller" Subject: [PATCH 4.14 24/71] ipv4: Make neigh lookup keys for loopback/point-to-point devices be INADDR_ANY Date: Mon, 29 Jan 2018 13:56:52 +0100 Message-Id: <20180129123828.886031503@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180129123827.271171825@linuxfoundation.org> References: <20180129123827.271171825@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1590958544277885244?= X-GMAIL-MSGID: =?utf-8?q?1590958544277885244?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jim Westfall [ Upstream commit cd9ff4de0107c65d69d02253bb25d6db93c3dbc1 ] Map all lookup neigh keys to INADDR_ANY for loopback/point-to-point devices to avoid making an entry for every remote ip the device needs to talk to. This used the be the old behavior but became broken in a263b3093641f (ipv4: Make neigh lookups directly in output packet path) and later removed in 0bb4087cbec0 (ipv4: Fix neigh lookup keying over loopback/point-to-point devices) because it was broken. Signed-off-by: Jim Westfall Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- include/net/arp.h | 3 +++ net/ipv4/arp.c | 7 ++++++- 2 files changed, 9 insertions(+), 1 deletion(-) --- a/include/net/arp.h +++ b/include/net/arp.h @@ -20,6 +20,9 @@ static inline u32 arp_hashfn(const void static inline struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key) { + if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) + key = INADDR_ANY; + return ___neigh_lookup_noref(&arp_tbl, neigh_key_eq32, arp_hashfn, &key, dev); } --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -223,11 +223,16 @@ static bool arp_key_eq(const struct neig static int arp_constructor(struct neighbour *neigh) { - __be32 addr = *(__be32 *)neigh->primary_key; + __be32 addr; struct net_device *dev = neigh->dev; struct in_device *in_dev; struct neigh_parms *parms; + u32 inaddr_any = INADDR_ANY; + if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) + memcpy(neigh->primary_key, &inaddr_any, arp_tbl.key_len); + + addr = *(__be32 *)neigh->primary_key; rcu_read_lock(); in_dev = __in_dev_get_rcu(dev); if (!in_dev) {