Bug 69536

Summary:	[pptp] PPTP subsystem / ng_pptpgre wrecked!? [4.10]
Product:	Base System	Reporter:	Jochen Gensch <incmc>
Component:	kern	Assignee:	Archie Cobbs <archie>
Status:	Closed FIXED
Severity:	Affects Only Me
Priority:	Normal
Version:	Unspecified
Hardware:	Any
OS:	Any

Description Jochen Gensch 2004-07-24 15:40:25 UTC

I've been using 4.9 with mpd to establish my pptp connection. However
since upgrading to 4.10-RELEASE and also 4-STABLE I'm having serious
problems to establish a connection by mpd. It is mostly impossible to
get the link up. It seems like FreeBSD isn't aware of the GRE packets
coming back from my dial up gateway. When reading up on that on the
internet I found, that something might have been changed on ng_pptpgre
in 4.10-RELEASE an beyond. After donwgrading to 4.9 anything works fine again.

How-To-Repeat: Just use 4.10-RELEASE or newer in combination with mpd and try to
establish a pptp connection.

Comment 1 Gleb Smirnoff freebsd_committer

2004-09-05 11:10:28 UTC

Responsible Changed
From-To: freebsd-bugs->archie

Archie, could you please look at this PR? 

Seems like lowering timeout to one second causes problems for 
people who are doing PPTP over slow dialup. What about making 
this parameter configurable or change it to smth like say 3 
seconds?

Comment 2 Gleb Smirnoff freebsd_committer

2004-09-05 20:45:59 UTC

  Jochen,

can you try out this on 4.10 system: apply this patch to
ng_pptpgre.c, rebuild ng_pptpgre.ko, load it and check whether
problem is fixed.

--- ng_pptpgre.c        22 Nov 2003 15:28:16 -0000      1.2.2.14
+++ ng_pptpgre.c        5 Sep 2004 19:44:06 -0000
@@ -120,7 +120,7 @@
 #define PPTP_XMIT_WIN          16                      /* max xmit window */
 #define PPTP_MIN_RTT           (PPTP_TIME_SCALE / 10)  /* 100 milliseconds */
 #define PPTP_MIN_TIMEOUT       (PPTP_TIME_SCALE / 83)  /* 12 milliseconds */
-#define PPTP_MAX_TIMEOUT       (1 * PPTP_TIME_SCALE)   /* 1 second */
+#define PPTP_MAX_TIMEOUT       (3 * PPTP_TIME_SCALE)   /* 3 seconds */
 
 /* When we recieve a packet, we wait to see if there's an outgoing packet
    we can piggy-back the ACK off of. These parameters determine the mimimum

On Sun, Sep 05, 2004 at 02:04:53PM -0500, Archie Cobbs wrote:
A> > Seems like lowering timeout to one second causes problems for
A> > people who are doing PPTP over slow dialup. What about making
A> > this parameter configurable or change it to smth like say 3
A> > seconds?
A> 
A> Yes, guess that's what we need to do... the timeout is the only
A> change from 4.9 -> 4.10.. Gleb go ahead and change it to 3 seconds
A> if you want.
A> 
A> As a workaround in the mean time, you might try "set pptp disable windowing".

 Archie,

isn't this feature commited after 4.10-RELEASE, or I mistake?

----------------------------
revision 1.2.2.15
date: 2004/05/16 19:26:46;  author: archie;  state: Exp;  lines: +49 -35
MFC: Add 'enableWindowing' configuration knob to the ng_pptpgre(4) node.


-- 
Totus tuus, Glebius.
GLEBIUS-RIPN GLEB-RIPE

Comment 3 Jochen Gensch 2004-09-06 14:10:34 UTC

>   Jochen,
> 
> can you try out this on 4.10 system: apply this patch to
> ng_pptpgre.c, rebuild ng_pptpgre.ko, load it and check whether
> problem is fixed.

No I can't. This was a production system and I had to get it working again
very soon. So after a few days I switched back to 4.9, where this problem
does not occur. It is even worse, we had to change our dsl provider in the
meantime due to other issues. So I do not have a PPTP dial in possibility
any more because the new provider uses another technique... anyways let me
know, if can help someway else.

Jochen

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Comment 4 Gleb Smirnoff freebsd_committer

2004-09-06 21:39:35 UTC

State Changed
From-To: open->closed

We have increased timeout value to 3 seconds. This should help.