Re: libpcap on Mac Os X 10.6 Snow Leopard

[Marco De Angelis <thorar () yahoo com>]

Hi Guy.

Thanks so much for replying.

> The issue described in that message is fixed in 10.6.2.

That is good to know. I have 10.6.2, but I still experience problems

> These are both BPF issues; libpcap 1.0.0 didn't *introduce* them - 

I was just looking at my depedency, without being sure if I should investigate more for
a Snow Leopard bug or on the libpcap side.

> So what is the exact problem you're seeing?  What is the difference you see between Leopard and Snow Leopard? 
> (PF_PACKET sockets work differently from BPF, so differences between Linux and {Leopard,Snow
> Leopard,*BSD} are less interesting here.)-

The problem is that the packets are not delivered to the application. More specifically, 
it seems that libpcap captures them, but the pcap_dispatch (and pcap_loop as well) does 
not deliver packets to the pcap_handler. Packets seems to remain in the buffer and they 
get delivered only when the buffer is full. 

With a buffer of 128 bytes (which can hold only one packet), the packets are delivered to 
the application immediately. 
With a buffer of 1280 bytes, I get the packets delivered at groups of ten, only when the 
next ten are collected. Of course, that means also that the last group of packets would 
remain in the buffer and are never delivered.

The problem is, the same code is working perfectly on all other OSes. Can you suggest something
to try out?

> > I recompiled tcpdump 4.0.0 on my machine, and it works!
>
> On which machine?  The Snow Leopard machine?  If so, does the tcpdump 4.0.0 that comes with 
> Snow Leopard *not* work?

Tcpdump worked on Snow Leopard (the one that comes with the O.S.), and also the one I downloaded and 
recompiled. I recompiled it just to be sure that they didn't do some "trick" to make it work. 
Maybe I just don't trust the Authority :)

Regards,
Marco

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