[Openvpn-devel] [HACK/PATCH] Prioritize TCP ACKs

[Openvpn-devel] [HACK/PATCH] Prioritize TCP ACKs

[Nielsen]

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Here's a hack of a patch which puts nice TOS bits on TCP ACK packets.
This allows you to use pf or another firewall to prioritize the
resulting openvpn traffic in the way you normally do over asynchronous
connections.

Certaintly no need to put this in openvpn. Just figured someone else out
there might have run into the same problems.

Cheers,
Nate Nielsen
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diff -rU3 ../openvpn-2.0.orig/socket.h ./socket.h
--- ../openvpn-2.0.orig/socket.h	2005-04-10 21:43:58.000000000 -0600
+++ ./socket.h	2005-08-09 13:23:12.874844376 -0600
@@ -737,6 +737,14 @@
       struct openvpn_iphdr *iph = (struct openvpn_iphdr *) BPTR (ipbuf);
       ls->ptos = iph->tos;
       ls->ptos_defined = true;
+
+      if (iph->protocol == OPENVPN_IPPROTO_TCP)
+        {
+          struct openvpn_tcphdr *tcp = (struct openvpn_tcphdr *) (BPTR(ipbuf) + OPENVPN_IPH_GET_LEN (iph->version_len));
+	  if ((tcp->flags & (OPENVPN_TCPH_SYN_MASK | OPENVPN_TCPH_ACK_MASK)) == OPENVPN_TCPH_ACK_MASK && 
+	      iph->tot_len <= 80)
+		ls->ptos |= 0x10;
+	}
     }
 }
 

Re: [Openvpn-devel] [HACK/PATCH] Prioritize TCP ACKs

[Florian Weimer]

> Here's a hack of a patch which puts nice TOS bits on TCP ACK packets.
> This allows you to use pf or another firewall to prioritize the
> resulting openvpn traffic in the way you normally do over asynchronous
> connections.

I think you have to make those TOS values configurable because their
meaning is no longer standardized (or, more precisely, there are
several standards to choose from).

Re: [Openvpn-devel] [HACK/PATCH] Prioritize TCP ACKs

[Nate Nielsen]

Florian Weimer wrote:
>>Here's a hack of a patch which puts nice TOS bits on TCP ACK packets.
>>This allows you to use pf or another firewall to prioritize the
>>resulting openvpn traffic in the way you normally do over asynchronous
>>connections.
> 
> I think you have to make those TOS values configurable because their
> meaning is no longer standardized (or, more precisely, there are
> several standards to choose from).

It's a patch :) Completely customizeable. I doubt this code would (or
should) be included in openvpn as is.

Cheers,
Nate