From owner-freebsd-net@FreeBSD.ORG Tue Jun 29 13:40:26 2004 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 77B7616A4CE for ; Tue, 29 Jun 2004 13:40:26 +0000 (GMT) Received: from mail.FreeBSD.org.cn (dns3.freebsd.org.cn [61.129.66.75]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2182B43D41 for ; Tue, 29 Jun 2004 13:40:25 +0000 (GMT) (envelope-from delphij@frontfree.net) Received: (qmail 65783 invoked by uid 0); 29 Jun 2004 13:39:03 -0000 Received: from unknown (HELO beastie.frontfree.net) (218.107.145.7) by mail.FreeBSD.org.cn with AES256-SHA encrypted SMTP; 29 Jun 2004 13:39:03 -0000 Received: from localhost (localhost.frontfree.net [127.0.0.1]) by beastie.frontfree.net (Postfix) with ESMTP id 91FA611743; Tue, 29 Jun 2004 21:40:09 +0800 (CST) Received: from beastie.frontfree.net ([127.0.0.1]) by localhost (beastie.frontfree.net [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 03008-10; Tue, 29 Jun 2004 21:40:09 +0800 (CST) Received: by beastie.frontfree.net (Postfix, from userid 1001) id 56CA71172F; Tue, 29 Jun 2004 21:40:08 +0800 (CST) Date: Tue, 29 Jun 2004 21:40:08 +0800 From: Xin LI To: David Malone Message-ID: <20040629134008.GA356@frontfree.net> References: <200406291413.ab33924@salmon.maths.tcd.ie> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="pWyiEgJYm5f9v55/" Content-Disposition: inline In-Reply-To: <200406291413.ab33924@salmon.maths.tcd.ie> User-Agent: Mutt/1.4.2.1i X-GPG-key-ID/Fingerprint: 0xCAEEB8C0 / 43B8 B703 B8DD 0231 B333 DC28 39FB 93A0 CAEE B8C0 X-GPG-Public-Key: http://www.delphij.net/delphij.asc X-Operating-System: FreeBSD beastie.frontfree.net 5.2-delphij FreeBSD 5.2-delphij #80: Thu Jun 24 17:30:33 CST 2004 delphij@beastie.frontfree.net:/usr/obj/usr/src/sys/BEASTIE i386 X-URL: http://www.delphij.net X-By: delphij@beastie.frontfree.net X-Location: Beijing, China X-Virus-Scanned: by amavisd-new at frontfree.net cc: freebsd-net@freebsd.org Subject: Re: RANDOM_IP_ID sysctl? X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.1 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, 29 Jun 2004 13:40:26 -0000 --pWyiEgJYm5f9v55/ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jun 29, 2004 at 02:13:38PM +0100, David Malone wrote: > It seems to me that RANDOM_IP_ID might be better as a sysctl rather > than a kernel option. Would anyone mind if I changed this? Wouldn't this cause a performance penality? IIRC htons() is currently a macro which is essentially a no-op, while ip_randomid() is a function call. Of course we can convert the call to a uniform hook-alike mechainism, however, given the frequency the function is called, this should be carefully considered. In addition, what's the apparant benefit making it a sysctl rather than being a kernel option? I think there is rarely a sysadmin to enable and disable this runtime. BTW. For security considerations I'd like to see if this is made default in GENERIC kernels :-) Cheers, --=20 Xin LI http://www.delphij.net/ See complete headers for GPG key and other information. --pWyiEgJYm5f9v55/ Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFA4XE4OfuToMruuMARAr77AKCA53P42ZvlM4KyDYVrC6xzX0DFPgCfayWp IKu2UxkwYh/SCPMtej4ZhWg= =/BZ7 -----END PGP SIGNATURE----- --pWyiEgJYm5f9v55/--