[ofa-general] [PATCH] IB/IPoIB: Don't let a bad muticast address in the join list stop subsequent joins

[Moni Shoua]

Roland Dreier wrote:

>  After this patch, do we end up with
> an IPoIB interface that's not a member of the all hosts multicast group?
> (That seems like it would lead to confusing breakage later)
> 
In my search for a solution to the issue with bonding I found the answer for this.
I checked what will be the affect of delaying the decision of what is the device type 
until first the slave comes. This causes arp_mc_map() to fail and the address is 
not added to the mc list. On the other hand, the IPoIO will be a member of all hosts 
because dev_open()) does that for any net device that it is called for (see below).

linux-ck8g:/root # ip m s dev ib0
16:     ib0
        link  00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:00:00:00:fb
        link  00:ff:ff:ff:ff:12:60:1b:ff:ff:00:00:00:00:00:01:ff:98:2f:c5
        link  00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:00:00:00:01 users 2
        link  00:ff:ff:ff:ff:12:60:1b:ff:ff:00:00:00:00:00:00:00:00:00:01 users 2
        inet  224.0.0.1
        inet6 ff02::1


However, there is a side affect. The bonding interface will be registered only to the inet 
address of all hosts but not to the link address. This is until dev_open is called again (see 
below again)

linux-ck8g:/root # ip m s dev bond0
18:     bond0
        link  00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:00:00:00:fb
        link  00:ff:ff:ff:ff:12:60:1b:ff:ff:00:00:00:00:00:01:ff:98:2f:c5
        inet  224.0.0.251
        inet  224.0.0.1
        inet6 ff02::1:ff98:2fc5
        inet6 ff02::1
linux-ck8g:/root # ifconfig bond0 down
linux-ck8g:/root # ifconfig bond0 up
linux-ck8g:/root # ip m s dev bond0
18:     bond0
        link  00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:00:00:00:fb
        link  00:ff:ff:ff:ff:12:60:1b:ff:ff:00:00:00:00:00:01:ff:98:2f:c5
        link  00:ff:ff:ff:ff:12:60:1b:ff:ff:00:00:00:00:00:00:00:00:00:01
        link  00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:00:00:00:01
        inet  224.0.0.251
        inet  224.0.0.1
        inet6 ff02::1:ff98:2fc5
        inet6 ff02::1
linux-ck8g:/root #                                                                        

I don't want to leave it like that but just for curiosity, it is bad that the
bond interface is not registered to the all hosts group if its slave is?

thanks