On 2016/08/04 16:24, Roopa Prabhu wrote: > On 8/3/16, 7:11 PM, Toshiaki Makita wrote: >> Adding fdb entries pointing to the bridge device uses fdb_insert(), >> which lacks various checks and does not respect added_by_user flag. >> >> As a result, some inconsistent behavior can happen: >> * Adding temporary entries succeeds but results in permanent entries. > > IIRC this is not specific to fdb entries on the bridge device. all temp > fdb entries via iproute2 result in permanent entries. thats why 'dynamic' > was added. Sorry for confusing you, I meant "temp" (i.e., "static") of bridge fdb command. "temp", "dynamic" and "use" should not result in "permanent". >> * Same goes for "dynamic" and "use". > This patch seems to not allow dynamic and use entries > on the bridge device. I don't see a strong use-case to > allow them, but any reason you want to add the restriction now ? Because dynamic fdb entries pointing the bridge device cannot be created. So it is prohibited. I cannot find other appropriate behavior about this. Or are you suggesting local entries with aging supported or something like that? >> * Changing mac address of the bridge device causes deletion of >> user-added entries. > unless I am missing something, this does not seem to be related to the > external fdb entry on the bridge device. Yes this is related to manually-added fdb entries on the bridge device. When manual addition of fdb pointing the bridge device was introduced, we should have set added_by_user on adding the entry and modify br_fdb_change_mac_address() to respect the flag, but both were not done. > >> * Replacing existing entries looks successful from userspace but actually >> not, regardless of NLM_F_EXCL flag. > curious about this one. I will try it, but if you have an example that > will help. Before: # bridge fdb add 12:34:56:78:90:ab dev enp3s0 master # bridge fdb add 12:34:56:78:90:ab dev br0; echo $? 0 # bridge fdb show ... 12:34:56:78:90:ab dev enp3s0 master br0 permanent # bridge fdb replace 12:34:56:78:90:ab dev br0; echo $? 0 # bridge fdb show ... 12:34:56:78:90:ab dev enp3s0 master br0 permanent After: # bridge fdb add 12:34:56:78:90:ab dev enp3s0 master # bridge fdb add 12:34:56:78:90:ab dev br0; echo $? RTNETLINK answers: File exists 255 # bridge fdb replace 12:34:56:78:90:ab dev br0; echo $? 0 # bridge fdb show ... 12:34:56:78:90:ab dev br0 master br0 permanent -- Toshiaki Makita
