From owner-freebsd-net@FreeBSD.ORG Tue Jul 22 16:53:18 2014 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 5229A167; Tue, 22 Jul 2014 16:53:18 +0000 (UTC) Received: from mail-we0-x230.google.com (mail-we0-x230.google.com [IPv6:2a00:1450:400c:c03::230]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 9ADE42C0D; Tue, 22 Jul 2014 16:53:17 +0000 (UTC) Received: by mail-we0-f176.google.com with SMTP id q58so9392430wes.35 for ; Tue, 22 Jul 2014 09:53:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=iyrqJZVAU9U17MIR/6LlCHMPJsMQ4Z4BzdfC0cjKC7M=; b=TJgUSAkILXgDOwFRt8JWfO9tmaKP29PfElSR/Cfa8xff7lx+8yGDU2greg6SINd+Ve 5UkpRg3QOW11WlZumD38M70hsWX2+1nakVTqtUZ4tJFuYyaykvf11q4DdfmV04UcFJ/X h2BqTb1U/yGBtBMHF3/08qQNSCcwceqh1GrDjrsw7z84iu3+I2OOiWBiwjfK3I4fH9vp ksusNpZmJGvlFbAjUZxxZ/jc/7RI7yBBFoNdnWhTtLr+AB2R1BtXgUSyOtMOHdo4n8sJ yB1PViL+HZQSB2KNIclGjjApRClXfzqhR9lZV/diuXby4hv3tBSGTrj7Jca0oO0156RT m6KA== MIME-Version: 1.0 X-Received: by 10.194.133.1 with SMTP id oy1mr35760051wjb.87.1406047993441; Tue, 22 Jul 2014 09:53:13 -0700 (PDT) Sender: jinmei.tatuya@gmail.com Received: by 10.194.108.166 with HTTP; Tue, 22 Jul 2014 09:53:13 -0700 (PDT) In-Reply-To: <20140720090410.GA7990@mx.elandsys.com> References: <20140720090410.GA7990@mx.elandsys.com> Date: Tue, 22 Jul 2014 09:53:13 -0700 X-Google-Sender-Auth: EeCFxD1LgnwH9Zpmv6k6wV8-bJE Message-ID: Subject: Re: IPv6 nodeinfo default behaviour From: =?UTF-8?B?56We5piO6YGU5ZOJ?= To: Loganaden Velvindron Content-Type: text/plain; charset=UTF-8 Cc: FreeBSD Net , bz@freebsd.org, gnn@freebsd.org X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Jul 2014 16:53:18 -0000 At Sun, 20 Jul 2014 02:04:10 -0700, Loganaden Velvindron wrote: > Security Considerations > > This protocol shares the security issues of ICMPv6 that are > documented in the "Security Considerations" section of [5]. > > This protocol has the potential of revealing information useful to a > would-be attacker. An implementation of this protocol MUST have a > default configuration that refuses to answer queries from global- > scope [3] addresses. > > I suggest that we switch to 0 by default to be more RFC compliant. Are you referring to the value of '(V_)icmp6_nodeinfo'? If so, and to be compliant with the above MUST of the RFC, it doesn't seem to have to be 0; it only has to have the ICMP6_NODEINFO_GLOBALOK bit cleared: /* * Validate IPv6 source address. * The default configuration MUST be to refuse answering queries from * global-scope addresses according to RFC4602. * Notes: * - it's not very clear what "refuse" means; this implementation * simply drops it. * - it's not very easy to identify global-scope (unicast) addresses * since there are many prefixes for them. It should be safer * and in practice sufficient to check "all" but loopback and * link-local (note that site-local unicast was deprecated and * ULA is defined as global scope-wise) */ if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) goto bad; and the default value already seems to meet this condition: VNET_DEFINE(int, icmp6_nodeinfo) = (ICMP6_NODEINFO_FQDNOK|ICMP6_NODEINFO_NODEADDROK); -- JINMEI, Tatuya