Re: [PATCH net-next v02 1/2] af_packet: allow fanout_add when socket is not RUNNING

...

@@ -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?

...

err = -ENOSPC;
if (refcount_read(&match->sk_ref) < match->max_num_members) {

• 	__dev_remove_pack(&po->prot_hook);
  

• /* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */
  WRITE_ONCE(po->fanout, match);
  
  po->rollover = rollover;
  rollover = NULL;
  refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
  

• 	__fanout_link(sk, po);
  

• 	if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) {
  

• 		__dev_remove_pack(&po->prot_hook);
  

• 		__fanout_link(sk, po);
  

• 	}
  err = 0;
  

  } }

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