On Thu, Feb 27, 2014 at 1:05 PM, Guy Harris <g...@alum.mit.edu> wrote:
> > On Feb 27, 2014, at 12:57 PM, Luigi Rizzo <ri...@iet.unipi.it> wrote: > > > this can be used to plumb things together. > > If you want to plumb things together, do you need libpcap? > the plumbing is done by netmap/vale/netmap pipes. libpcap is "only" a shim layer that can be used by tools that only speak libpcap so you do not need to recompile them. But it is a crucially important shim layer that gives you a lot of flexibility. > > Say you want to interconnect two VMs, > > Why would I use libpcap for that? > > > or a traffic generator and a firewall/ids/monitor > > that you want to test for performance, etc. > > But wouldn't I create a netmap pipe using something other than libpcap, > and only use libpcap if I want to watch the traffic on that pipe? > > I.e., what would be lost if, for example, libpcap only supported capturing > on existing netmap devices, and didn't support creating new ones on the fly? > Well you would lose the ability to connect to a VALE switch or a pipe (which only support dynamically created endpoints). Most importantly, you would need additional code to disable the functionality, because if you look at the pcap-netmap.c everything is handled in the nm_open() call. cheers luigi -- -----------------------------------------+------------------------------- Prof. Luigi RIZZO, ri...@iet.unipi.it . Dip. di Ing. dell'Informazione http://www.iet.unipi.it/~luigi/ . Universita` di Pisa TEL +39-050-2211611 . via Diotisalvi 2 Mobile +39-338-6809875 . 56122 PISA (Italy) -----------------------------------------+------------------------------- _______________________________________________ tcpdump-workers mailing list tcpdump-workers@lists.tcpdump.org https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers
