[Openvpn-devel] [PATCH] Fix "--dev null"

[Openvpn-devel] [PATCH] Fix "--dev null"

[Gert Doering]

To test whether a server is reachable and all the key handling is
right, openvpn can connect with "--dev null --ifconfig-noexec" to
avoid needing to the client with elevated privileges.

This was erroring out for no good reason (because the "set environment
variables appropriately" code didn't know if this is a tun or tap
device...) - treat --dev null as "tap", done.

Signed-off-by: Gert Doering <gert@...1296...>
---
 src/openvpn/tun.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
index 31585b32..12ce99d5 100644
--- a/src/openvpn/tun.c
+++ b/src/openvpn/tun.c
@@ -560,7 +560,9 @@ is_tun_p2p(const struct tuntap *tt)
 {
     bool tun = false;
 
-    if (tt->type == DEV_TYPE_TAP || (tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET))
+    if (tt->type == DEV_TYPE_TAP ||
+        (tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET) ||
+	tt->type == DEV_TYPE_NULL )
     {
         tun = false;
     }
-- 
2.11.1

Re: [Openvpn-devel] [PATCH] Fix "--dev null"

[@ 2017-02-24 14:32 UTC (permalink / raw)]

Hi,

On 24/02/2017 15:52, Gert Doering wrote:
> To test whether a server is reachable and all the key handling is
> right, openvpn can connect with "--dev null --ifconfig-noexec" to
> avoid needing to the client with elevated privileges.

There seems to be a typo here. Did you mean "to avoid needing to
_connect to_ the client with elevated privileges"?

> 
> This was erroring out for no good reason (because the "set environment
> variables appropriately" code didn't know if this is a tun or tap
> device...) - treat --dev null as "tap", done.
> 
> Signed-off-by: Gert Doering <gert@...1296...>
> ---
>  src/openvpn/tun.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
> index 31585b32..12ce99d5 100644
> --- a/src/openvpn/tun.c
> +++ b/src/openvpn/tun.c
> @@ -560,7 +560,9 @@ is_tun_p2p(const struct tuntap *tt)
>  {
>      bool tun = false;
>  
> -    if (tt->type == DEV_TYPE_TAP || (tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET))
> +    if (tt->type == DEV_TYPE_TAP ||
> +        (tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET) ||
> +	tt->type == DEV_TYPE_NULL )
>      {
>          tun = false;
>      }
> 


-- 
Samuli Seppänen
Community Manager
OpenVPN Technologies, Inc

irc freenode net: mattock

Re: [Openvpn-devel] [PATCH] Fix "--dev null"

[Gert Doering]

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Hi,

On Fri, Feb 24, 2017 at 04:32:14PM +0200, Samuli Seppänen wrote:
> On 24/02/2017 15:52, Gert Doering wrote:
> > To test whether a server is reachable and all the key handling is
> > right, openvpn can connect with "--dev null --ifconfig-noexec" to
> > avoid needing to the client with elevated privileges.
> 
> There seems to be a typo here. Did you mean "to avoid needing to
> _connect to_ the client with elevated privileges"?

Actually "to _run_ the client" - indeed.

gert
-- 
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Gert Doering - Munich, Germany                             gert@...1296...
fax: +49-89-35655025                        gert@...1297...

[-- Attachment #2: signature.asc --]
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Re: [Openvpn-devel] [PATCH] Fix "--dev null"

[Steffan Karger]

Hi,

On 24-02-17 14:52, Gert Doering wrote:
> To test whether a server is reachable and all the key handling is
> right, openvpn can connect with "--dev null --ifconfig-noexec" to
> avoid needing to the client with elevated privileges.
> 
> This was erroring out for no good reason (because the "set environment
> variables appropriately" code didn't know if this is a tun or tap
> device...) - treat --dev null as "tap", done.
> 
> Signed-off-by: Gert Doering <gert@...1296...>
> ---
>  src/openvpn/tun.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
> index 31585b32..12ce99d5 100644
> --- a/src/openvpn/tun.c
> +++ b/src/openvpn/tun.c
> @@ -560,7 +560,9 @@ is_tun_p2p(const struct tuntap *tt)
>  {
>      bool tun = false;
>  
> -    if (tt->type == DEV_TYPE_TAP || (tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET))
> +    if (tt->type == DEV_TYPE_TAP ||
> +        (tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET) ||
> +	tt->type == DEV_TYPE_NULL )
>      {
>          tun = false;
>      }
> 

Code makes sense.  Code-ACK.

Style-wise, we went for pos_arith=lead (Knuth style), so

x = first_condition
      && second_condition
      && third_condition

and this patch is trying to sneak a tab into the code! ;)

I'd be fine with you fixing the style on the fly when applying.

-Steffan

[Openvpn-devel] [PATCH applied] Re: Fix '--dev null'

[Gert Doering]

Patch has been applied to the master and release/2.4 branch.

As ordered, '||' have been moved to pos_arith=lead, and the tab 
has been extabinated.

commit 22c5381b71710ad0e1dbbccc1d5680fccb602311 (master)
commit 2085c1f3875b9c96ac739941712247b805677efa (release/2.4)
Author: Gert Doering
Date:   Fri Feb 24 14:52:22 2017 +0100

     Fix '--dev null'

     Signed-off-by: Gert Doering <gert@...1296...>
     Acked-by: Steffan Karger <steffan.karger@...1435...>
     Message-Id: <20170224135222.44640-1-gert@...1296...>
     URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg14186.html
     Signed-off-by: Gert Doering <gert@...1296...>


--
kind regards,

Gert Doering