On Jan 28, 2013, at 8:09 AM, John Baldwin wrote: > On Sunday, January 27, 2013 1:51:12 am Tim Kientzle wrote: >> >> On Jan 26, 2013, at 3:56 PM, Tim Kientzle wrote: >> >>> My next TODO items for this network driver is to implement >>> the SIOCADDMULTI and SIOCDELMULTI ioctls. >> >> DELMULTI seems trickier. ... >> ... it looks like I have no choice but to remove >> every multicast address from the controller and then >> re-insert all of the ones that are still valid. >> ... >> Is there a better approach? > > You should always reprogram the full table while holding if_maddr_rlock().
Thanks. That's ultimately what I did. I was able to dump the table from the controller to eyeball that the entries looked right but haven't yet done any testing beyond that. >> Would still appreciate any suggestions for how to test these. > > You can write a simple app to listen for UDP packets and have it join a > multicast group and have another machine on the same network write a packet > to > the multicast group. I tried this first, but the test program worked fine even without ADDMULTI/DELMULTI support. Watching tcpdump -e, it appears that IP4 multicast UDP uses broadcast at the Ethernet layer. > However, a simpler test is to toggle the sysctl to enable multicast ping > replies and to ping a multicast address from another machine after joining it > on the test machine using mutest. Ahhh…. I wasn't aware of these tools; I'll take a look. Thanks for the pointer! Tim _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
