From owner-freebsd-net@FreeBSD.ORG Fri Jul 22 11:21:30 2011 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E595B1065672 for ; Fri, 22 Jul 2011 11:21:30 +0000 (UTC) (envelope-from vladimir.budnev@gmail.com) Received: from mail-vx0-f182.google.com (mail-vx0-f182.google.com [209.85.220.182]) by mx1.freebsd.org (Postfix) with ESMTP id A2E278FC0C for ; Fri, 22 Jul 2011 11:21:30 +0000 (UTC) Received: by vxg33 with SMTP id 33so2101637vxg.13 for ; Fri, 22 Jul 2011 04:21:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; bh=hb7nyDUo5U7Xjxw54KcSxDzBTWIyxjCOoX70JSulOIc=; b=hgBlwSvgsoiPEgOmgIPwJBebOZlxdZjazFd/3dpoC9ce2ledbm9MJ8u2+dkUmVHvTN u4RKMY4cz2uiw1d9aw/H1HY5nrHmGg3CxNgnu9X/4/O/BBWhI2RKS3pEP5anQOYim6id coZ834/OaXsI+65VJBsBXxWLsLN2KEXbNUtkE= MIME-Version: 1.0 Received: by 10.52.173.45 with SMTP id bh13mr1406691vdc.3.1311333689786; Fri, 22 Jul 2011 04:21:29 -0700 (PDT) Received: by 10.220.178.129 with HTTP; Fri, 22 Jul 2011 04:21:29 -0700 (PDT) Date: Fri, 22 Jul 2011 15:21:29 +0400 Message-ID: From: Vladimir Budnev To: freebsd-net@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Subject: What does define COMMENT_ONLY mean? X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 22 Jul 2011 11:21:31 -0000 Hello! What does this define COMMENT_ONLY mean and what for it is used? Iv met such one in if_arp.h source in freebsd kernel, but cant get such strange if in arp header structure. -----------------------------------example struct arphdr { <...> /* * The remaining fields are variable in size, * according to the sizes above. */ #ifdef COMMENT_ONLY u_char ar_sha[]; /* sender hardware address */ u_char ar_spa[]; /* sender protocol address */ u_char ar_tha[]; /* target hardware address */ u_char ar_tpa[]; /* target protocol address */ #endif };