2009/4/15 Devon H. O'Dell <devon.od...@gmail.com> > > > I think #2 would be an easily testable and maybe more `correct' way to > do this in Plan 9. I think doing an implementation directly in the IP > path is easier, overall, but that's where my experience lies anyway. > Thanks, I'll try that.
> > > > Do you have any advices on how to capture packets and how to send them > out > > again after replacing src/dst addr and port? > > It's not quite that simple. At the simplest, when the packet goes out, > you have to keep a tab of the destination host / port and source host > / port. When a packet comes in, you look up the source host / port in > the hash table (hashed by dest host / port). You rewrite the packet. > You have to regenerate the packet checksum after rewriting it. You > send it back out. I know it's not that simple. But for the rewriting and keeping state stuff, I can look at the existing implementations of nat, i.e. natd for freebsd. The thing I need now is the stuff for capturing and sending packets using pkt interfaces. > > > Are there any ways of testing NAT in a virtual machine? Right now I'm > using > > vmware and it would be nice to be able to test it without setting up a > real > > machine with two Ethernet interfaces. > > Sure, configure a couple VMs with hostonly networking and set up their > IP addresses accordingly. > Nice, thanks. > > > -Patrick Kristiansen > > --dho > >
