Re: User-space bridge on Solaris?

[Ben Greear <greearb () candelatech com>]

Guy Harris wrote:
> On Sep 19, 2008, at 8:16 PM, Ben Greear wrote:
>
> > I noticed that pcap_setdirection doesn't appear to work on Solaris.
> >
> > Anyone know if it would be possible to get this functionality 
> > implemented?
>
> Libpcap runs atop DLPI in Solaris.  In my experience with at least one 
> version of Solaris, if you don't enable promiscuous mode, only packets 
> received by the host, not packets sent by the host, are delivered.  
> The downside is that, if you just want to capture traffic to and from 
> your machine, you can't do that by just turning promiscuous mode off 
> (and, at least on older versions of Solaris, you have to be root to 
> turn promiscuous mode on, even if you have permission to open the DLPI 
> device).  The upside is that, if your application doesn't need 
> promiscuous mode, and your application doesn't want to see outgoing 
> packets, you get that for free by not requesting promiscuous mode.
To be a bridge, you have to receive all traffic, so disabling PROMISC 
isn't really an option as far as I can tell.

I implemented a work-around where I keep a list of transmitted pkts and 
then walk it on receive and
discard any received that are in the tx-list.

But, that causes a lot of extra work, and in certain degenerate cases 
could cause improper ignoring of
a received packet.   I got it running at around 100Mbps with only 
sporadic drops,
but can easily push several times that with Linux on the same hardware 
(using the very easy to use
raw-packet socket API, not pcap).

Another thing:  I tried setting the time-out to 1ms in pcap_open_live, 
and it seems the fd
never became active for read as far as select was concerned until I set 
the system clock to 1ms
(echo set hires_ticks=1 >> /etc/system)

Thanks,
Ben


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Ben Greear <greearb () candelatech com> 
Candela Technologies Inc  http://www.candelatech.com


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