Gur Stavi wrote: > >> @@ -1846,21 +1846,21 @@ static int fanout_add(struct sock *sk, struct > >> fanout_args *args) > >> err = -EINVAL; > >> > >> spin_lock(&po->bind_lock); > >> - if (packet_sock_flag(po, PACKET_SOCK_RUNNING) && > >> - match->type == type && > >> + if (match->type == type && > >> match->prot_hook.type == po->prot_hook.type && > >> match->prot_hook.dev == po->prot_hook.dev) { > > > > Remaining unaddressed issue is that the socket can now be added > > before being bound. See comment in v1. > > I extended the psock_fanout test with unbound fanout test. > > As far as I understand, the easiest way to verify bind is to test that > po->prot_hook.dev != NULL, since we are under a bind_lock anyway. > But perhaps a more readable and direct approach to test "bind" would be > to test po->ifindex != -1, as ifindex is commented as "bound device". > However, at the moment ifindex is not initialized to -1, I can add such > initialization, but perhaps I do not fully understand all the logic. > > Any preferences?
prot_hook.dev is not necessarily set if a packet socket is bound. It may be bound to any device. See dev_add_pack and ptype_head. prot_hook.type, on the other hand, must be set if bound and is only modified with the bind_lock held too. Well, and in packet_create. But setsockopt PACKET_FANOUT_ADD also succeeds in case bind() was not called explicitly first to bind to a specific device or change ptype.