Re: setting rcvbuf

[John Heffner <jheffner () psc edu>]

On Tue, 15 Jun 2004, Guy Harris wrote:

> On Jun 15, 2004, at 2:49 PM, John Heffner wrote:
>
> > I've found that on my linux machines, setting the rcvbuf on the packet
> > socket bigger helps to reduce drops at high rates.
> >
> > I implemented the following, though I'm not sure how this works on BSD
> > and
> > other UNIXes.
>
> It *doesn't* work on BSD, unfortunately - you can't set the buffer size
> after binding a network interface to a BPF device, and, as that's done
> at open time, you can't set the buffer size on an open pcap_t.
>
> The ultimate fix is probably to have a new open routine that takes the
> buffer size as an argument (but don't implement that - there's a bunch
> of other stuff for which we need a new open API, and we don't want to
> introduce one new API and then keep introducing new ones; I'm thinking
> of an API that takes an attribute/value list of open parameters, so we
> can add new parameters as needed without having to introduce a whole
> new API).
>
> A short-term fix would be to implement "pcap_setbuff()" routines for
> all platforms - but have, on platforms where you can't set it, either
> no-op routines or routines that return an error - and, when we have the
> new open routine, deprecate "pcap_setbuff()" in favor of the new open
> routine.


How about making an error non-fatal?

Thanks,
  -John


                if(UserBufferSize != 1000000)
                        if(pcap_setbuff(pd, UserBufferSize)==-1){
-                               error("%s", pcap_geterr(pd));
+                               warning("%s", pcap_geterr(pd));
                        }



+#ifndef WIN32
+       if (setsockopt(p->fd, SOL_SOCKET, SO_RCVBUF, &dim, sizeof (dim)) != 0) {
+               snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Unable to set buffer size.\n");
+               return -1;
+       }
+
+       return 0;
+#else

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