[Dnsmasq-discuss] RA support in dnsmasq

[Gene Czarcinski]

On 11/25/2012 01:10 PM, Vladislav Grishenko wrote:
> Hi Gene,
> Instead of deprecating/turning-off logging by facility, it would be better
> to have ability to tune loglevel for each sysbsystem.
> Like following: where 0 means
> 	log-level=dhcp,dhcpv6,6,dns,7,ra,-1
>
> Best Regards, Vladislav Grishenko
Yes, that is indeed a good idea,

I have no intention of deprecating logging but I also do not want a 
large amount of information-less clutter in the syslog which may hide 
something that is important.  The "RTR-ADVERT" messages being issued 
every 3 to 5 seconds with separate messages for each virtual interface 
that is started is a bit much.

I have taken a look at the code and (I hope) I just do not understand 
how things are really working.

If log-dhcp is specified (command line or conf-file), OPT_LOG_OPTS is 
set.  A little grepping resulted in rfc3315.c and rfc2131.c as issuing 
messages with log6_packet() and log_packet() respectively. Sounds good, 
the test can be done in a central place.  But, looking more closely, the 
only thing OPT_LOG_OPTS does is determine the form of the syslog message 
... not if it is being issued.  And, of course, there are other calls to 
my_syslog() scattered throughout.

BTW, warning or at least error message should always be issued.  It is 
all the info massages that are becoming overwhelming.

Certainly there should be a lot of messages to support debugging and the 
code should always be compiled in.  But, when things are working well it 
is better to have most of those messages inhibited so that some warning 
or error message will be seen.

Gene
>
>
>> -----Original Message-----
>> From: dnsmasq-discuss-bounces at lists.thekelleys.org.uk [mailto:dnsmasq-
>> discuss-bounces at lists.thekelleys.org.uk] On Behalf Of Gene Czarcinski
>> Sent: Sunday, November 25, 2012 9:31 PM
>> To: dnsmasq-discuss at lists.thekelleys.org.uk
>> Subject: Re: [Dnsmasq-discuss] RA support in dnsmasq
>>
>> On 11/24/2012 11:20 AM, Gene Czarcinski wrote:
>>> OK, I am using both "ra-only" and "enable-ra" in a couple of libvirt
>>> dnsmasq instances.
>>>
>>> 1.  I am getting a lot of "clutter" in syslog.  How about using
>>> log-dhcp to also enable all of the "RTR-ADVERT" messages.  There are a
>>> lot of them but they really provide little if any useful information.
>>> That is, add:
>>>        if (option_bool(OPT_LOG_OPTS))
>>>
>>> 2.  I am getting a lot of RTR-ADVERT messages.  I know it is suppose
>>> to start off frequently but then slow up to a much less frequent
>>> period (intervals of seconds).  I thought this was a problem but then
>>> I looked into radvd and it also issues advertisements often so I
>>> assume things are working properly. However, I am concerned that all
>>> those syslog messages will lead others to suspect a problem where
>>> there is none.
>>>
>>> 3. Similar to radvd, should there be some dnsmasq parameters which are
>>> used to specify how often RAs will be issued?
>>>
>> OK, I am going to slightly increase the scope of this.  Simon, how
> receptive
>> are you to adding a "couple" of new options to enable/disable some
> logging.
>> 1. log-ra to enable RA logging which, by default, is disabled.  This would
> be its
>> own option and not related to log-dhcp.
>>
>> 2. log-dhcp-renew to enable the log messages about renewing DHCP
>> requests which would, by default, be disabled.
>>
>> The messages from both of these currently run as if they were disabled.
>> Since I am running/testing using dnsmasq's RA services, I first noticed
> all of
>> the RA related messages and would like them to be normally suppressed.
>>
>> Apparently other libvirt users noticed the dhcp-renew messages and don't
>> wish to see them either.
>>
>> If you are receptive, I will do the heavy lifting but I would like to see
> this in
>> 2.64 if there is possibly enough time.
>>
>> Gene
>>