Subject: Re: TCP ECN diff
To: Hubert Feyrer <hubert@feyrer.de>
From: Rui Paulo <rpaulo@fnop.net>
List: tech-net
Date: 08/31/2006 20:32:46
On Aug 31, 2006, at 8:13 PM, Hubert Feyrer wrote:

>
>> +	if (TCP_ECN_ALLOWED(tp)) {
>> +		switch (iptos & IPTOS_ECN_MASK) {
>> +		case IPTOS_ECN_CE:
>> +			tp->t_flags |= TF_ECN_SND_ECE;
>> +			tcpstat.tcps_ecn_ce++;
>> +			break;
>> +		case IPTOS_ECN_ECT0:
>> +			tcpstat.tcps_ecn_ect++;
>> +			break;
>> +		case IPTOS_ECN_ECT1:
>> +			/* XXX: ignore for now -- rpaulo */
>> +			break;
>
> Would it make sense to print a message to the console that a  
> unsupported/not allowed option was used? FWIW, Solaris prints  
> something like this (for something IPv6 related):
>
> 	Jul 17 00:26:22 foo ip: [ID 976445 kern.notice] ip_option_process:  
> bad opt 0x5

According to the standard, no.

>
> I think there was no patch for sysctl.[13].

This is only the kernel patch.

> Also: should tcp(4) mention this?

Yes.


	-- Rui Paulo