From owner-freebsd-bugs@FreeBSD.ORG Fri Mar 8 23:30:00 2013
Return-Path: <owner-freebsd-bugs@FreeBSD.ORG>
Delivered-To: freebsd-bugs@smarthost.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115])
by hub.freebsd.org (Postfix) with ESMTP id D8837DD4
for <freebsd-bugs@smarthost.ysv.freebsd.org>;
Fri, 8 Mar 2013 23:30:00 +0000 (UTC)
(envelope-from gnats@FreeBSD.org)
Received: from freefall.freebsd.org (freefall.freebsd.org
[IPv6:2001:1900:2254:206c::16:87])
by mx1.freebsd.org (Postfix) with ESMTP id BBB12F51
for <freebsd-bugs@smarthost.ysv.freebsd.org>;
Fri, 8 Mar 2013 23:30:00 +0000 (UTC)
Received: from freefall.freebsd.org (localhost [127.0.0.1])
by freefall.freebsd.org (8.14.6/8.14.6) with ESMTP id r28NU0jP079264
for <freebsd-bugs@freefall.freebsd.org>; Fri, 8 Mar 2013 23:30:00 GMT
(envelope-from gnats@freefall.freebsd.org)
Received: (from gnats@localhost)
by freefall.freebsd.org (8.14.6/8.14.6/Submit) id r28NU0E5079252;
Fri, 8 Mar 2013 23:30:00 GMT (envelope-from gnats)
Resent-Date: Fri, 8 Mar 2013 23:30:00 GMT
Resent-Message-Id: <201303082330.r28NU0E5079252@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,
Keith Reynolds <keith.reynolds@tidalscale.com>
Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115])
by hub.freebsd.org (Postfix) with ESMTP id 8927CDAB
for <freebsd-gnats-submit@FreeBSD.org>; Fri, 8 Mar 2013 23:26:16 +0000 (UTC)
(envelope-from nobody@FreeBSD.org)
Received: from red.freebsd.org (red.freebsd.org [IPv6:2001:4f8:fff6::22])
by mx1.freebsd.org (Postfix) with ESMTP id 622B4F3D
for <freebsd-gnats-submit@FreeBSD.org>; Fri, 8 Mar 2013 23:26:16 +0000 (UTC)
Received: from red.freebsd.org (localhost [127.0.0.1])
by red.freebsd.org (8.14.5/8.14.5) with ESMTP id r28NQFeC063318
for <freebsd-gnats-submit@FreeBSD.org>; Fri, 8 Mar 2013 23:26:15 GMT
(envelope-from nobody@red.freebsd.org)
Received: (from nobody@localhost)
by red.freebsd.org (8.14.5/8.14.5/Submit) id r28NQF69063317;
Fri, 8 Mar 2013 23:26:15 GMT (envelope-from nobody)
Message-Id: <201303082326.r28NQF69063317@red.freebsd.org>
Date: Fri, 8 Mar 2013 23:26:15 GMT
From: Keith Reynolds <keith.reynolds@tidalscale.com>
To: freebsd-gnats-submit@FreeBSD.org
X-Send-Pr-Version: www-3.1
Subject: misc/176771: user-mode netgraph node hangs when replying to control
message
X-BeenThere: freebsd-bugs@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: Bug reports <freebsd-bugs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-bugs>,
<mailto:freebsd-bugs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-bugs>
List-Post: <mailto:freebsd-bugs@freebsd.org>
List-Help: <mailto:freebsd-bugs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
<mailto:freebsd-bugs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 08 Mar 2013 23:30:00 -0000
>Number: 176771
>Category: misc
>Synopsis: user-mode netgraph node hangs when replying to control message
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Fri Mar 08 23:30:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator: Keith Reynolds
>Release: 10.0-CURRENT
>Organization:
TidalScale
>Environment:
FreeBSD ts_bhyve1.local 10.0-CURRENT FreeBSD 10.0-CURRENT #1 r245569: Tue Mar 5 14:24:01 PST 2013 root@ts_bhyve1.local:/usr/obj/usr/src/sys/TS amd64
>Description:
When a netgraph client calls NgSendReplyMsg() to reply to a netgraph control message that is marked as having a reply (msg->header.cmd & NGM_HASREPLY), the library blocks waiting for a reply that will never come, because the message that's being sent *IS* the reply. It doesn't account for the possibility that the user-mode client is replying to a netgraph control message rather than originating one.
>How-To-Repeat:
Write a user-mode netgraph client that responds to the NGM_GENERIC_COOKIE/NGM_TEXT_STATUS control message, which is marked as NGM_HASREPLY, and use "ngctl status <node_path>" to query it. The call to NgSendReplyMsg() will block until another control message comes in, which won't happen until you use ngctl to send another request.
>Fix:
See the attached patch to lib/libnetgraph/msg.c. The change checks msg->header.flags & NGF_RESP to determine if the message being sent is the expected reply before blocking to wait for one.
Patch attached with submission follows:
Index: msg.c
===================================================================
--- msg.c (revision 245569)
+++ msg.c (working copy)
@@ -234,7 +234,7 @@
}
/* Wait for reply if there should be one. */
- if (msg->header.cmd & NGM_HASREPLY) {
+ if (msg->header.cmd & NGM_HASREPLY && !(msg->header.flags & NGF_RESP)) {
struct pollfd rfds;
int n;
>Release-Note:
>Audit-Trail:
>Unformatted: