From owner-freebsd-net@FreeBSD.ORG Thu Jan 24 13:02:42 2013 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id C0A64B2B; Thu, 24 Jan 2013 13:02:42 +0000 (UTC) (envelope-from lstewart@freebsd.org) Received: from lauren.room52.net (lauren.room52.net [210.50.193.198]) by mx1.freebsd.org (Postfix) with ESMTP id 702256F0; Thu, 24 Jan 2013 13:02:42 +0000 (UTC) Received: from lstewart1.loshell.room52.net (ppp59-167-184-191.static.internode.on.net [59.167.184.191]) by lauren.room52.net (Postfix) with ESMTPSA id BE0A27E84A; Fri, 25 Jan 2013 00:02:34 +1100 (EST) Message-ID: <510130EA.4020700@freebsd.org> Date: Fri, 25 Jan 2013 00:02:34 +1100 From: Lawrence Stewart User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:13.0) Gecko/20120613 Thunderbird/13.0 MIME-Version: 1.0 To: John Baldwin Subject: Re: [PATCH] Don't imply TCP and UDP socket options are bitmasks References: <201301141550.13577.jhb@freebsd.org> <201301151416.07231.jhb@freebsd.org> <50FE5473.7000807@freebsd.org> <201301221528.18388.jhb@freebsd.org> In-Reply-To: <201301221528.18388.jhb@freebsd.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=0.0 required=5.0 tests=UNPARSEABLE_RELAY autolearn=unavailable version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on lauren.room52.net Cc: freebsd-net@freebsd.org X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 24 Jan 2013 13:02:42 -0000 On 01/23/13 07:28, John Baldwin wrote: > On Tuesday, January 22, 2013 3:57:23 am Lawrence Stewart wrote: >> On 01/16/13 06:16, John Baldwin wrote: >>> On Tuesday, January 15, 2013 3:49:33 am Lawrence Stewart wrote: >>>> On 01/15/13 07:50, John Baldwin wrote: >>>>> The constants used for TCP and UDP socket options (TCP_NODELAY, etc.) are >>>>> currently defined as hex values that are individual bits. However, socket >>>>> options are never masked together, they are used as a simple enumeration of >>>>> discrete values. Using a bitmask forces us to run out of bits and makes it >>>>> harder for vendors to try to use a high range of values for local custom >>>>> options (hoping that they never conflict with a new option value added in >>>>> stock FreeBSD). >>>> >>>> Yup. Should we be explicitly #defining the boundary between "bits >>>> reserved for FreeBSD" and "bits for private vendor use"? >>> >>> Oh, we could if you wanted. I'm using 0x1000 locally for both TCP and UDP, >>> but those are completely arbitrary values. Saner ones might be 0x8000000 if >>> we want to do that explicitly. We could perhaps just say that is true for all >>> socket option levels (that is, just define one SO_VENDOR constant or some such >>> but say it applies to all levels)? >> >> A single SO_VENDOR applied to all levels sounds good to me. > > Ok, how about this for wording: > > Index: sys/socket.h > =================================================================== > --- socket.h (revision 245742) > +++ socket.h (working copy) > @@ -143,6 +143,15 @@ typedef __uid_t uid_t; > #endif > > /* > + * Space reserved for new socket options added by third-party vendors. > + * This range applies to all socket option levels. New socket options > + * in FreeBSD should always use an option value less than SO_VENDOR. > + */ > +#if __BSD_VISIBLE > +#define SO_VENDOR 0x80000000 > +#endif > + > +/* > * Structure used for manipulating linger option. > */ > struct linger { Two thumbs up from me. We might also want to #define TCP_VENDOR SO_VENDOR /* FreeBSD TCP socket options must be numerically less than this. */ and so on in each file that defines option levels to provide some hint to people that SO_VENDOR exists? Maybe we don't need the define and just need to put the one line comment at the end of each set of options in each file where a particular level's options are specified. Cheers, Lawrence