From owner-freebsd-bugs@FreeBSD.ORG Wed Sep 9 06:10:01 2009 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D34991065679 for ; Wed, 9 Sep 2009 06:10:01 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 968B58FC08 for ; Wed, 9 Sep 2009 06:10:01 +0000 (UTC) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.14.3/8.14.3) with ESMTP id n896A1aM061418 for ; Wed, 9 Sep 2009 06:10:01 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.3/8.14.3/Submit) id n896A1Aq061417; Wed, 9 Sep 2009 06:10:01 GMT (envelope-from gnats) Resent-Date: Wed, 9 Sep 2009 06:10:01 GMT Resent-Message-Id: <200909090610.n896A1Aq061417@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-bugs@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, Gaurav Goel Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A884F1065709 for ; Wed, 9 Sep 2009 06:02:40 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (www.freebsd.org [IPv6:2001:4f8:fff6::21]) by mx1.freebsd.org (Postfix) with ESMTP id 974CF8FC21 for ; Wed, 9 Sep 2009 06:02:40 +0000 (UTC) Received: from www.freebsd.org (localhost [127.0.0.1]) by www.freebsd.org (8.14.3/8.14.3) with ESMTP id n8962eb4077256 for ; Wed, 9 Sep 2009 06:02:40 GMT (envelope-from nobody@www.freebsd.org) Received: (from nobody@localhost) by www.freebsd.org (8.14.3/8.14.3/Submit) id n8962eD5077255; Wed, 9 Sep 2009 06:02:40 GMT (envelope-from nobody) Message-Id: <200909090602.n8962eD5077255@www.freebsd.org> Date: Wed, 9 Sep 2009 06:02:40 GMT From: Gaurav Goel To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.1 Cc: Subject: misc/138652: TCP window scaling value X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Sep 2009 06:10:01 -0000 >Number: 138652 >Category: misc >Synopsis: TCP window scaling value >Confidential: no >Severity: non-critical >Priority: high >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Wed Sep 09 06:10:01 UTC 2009 >Closed-Date: >Last-Modified: >Originator: Gaurav Goel >Release: >Organization: MTree Software Pvt. Ltd. >Environment: >Description: I found in file "tcp_input.c-orig" located at location "usr/src/sys/netinet" at line number 511, "tp->request_r_scale" is incremented depending on condition. 16 bits are reserved for window and its value could be MAX 30 bits. In your if condition "TCP_MAXWIN << tp->request_r_scale < so->so_rcv.sb_hiwat", if I have "so->so_rcv.sb_hiwat" value to be 524286, then "tp->request_r_scale" is incremented four times but its value should be 3. Reason being, while shifting TCP_MAXWIN, 1st iteration 1111111111111111 < 1111111111111111110 [TRUE] increment once 2nd iteration 11111111111111110 < 1111111111111111110 [TRUE] increment again 3rd iteration 111111111111111100 < 1111111111111111110 [TRUE] increment once 4th iteration 1111111111111111000 < 1111111111111111110 [TRUE] increment again 5th iteration 11111111111111110000 < 1111111111111111110 [FALSE] The LSB are zeros, which should be one. Please tell me if I am wrong. >How-To-Repeat: >Fix: >Release-Note: >Audit-Trail: >Unformatted: