On Wed, May 20, 2020 at 08:00:25PM -0300, Marcelo Ricardo Leitner wrote:

quoted

+	if (err)
+		return err;
+
+	lock_sock(sk);
+	err = sctp_do_bind(sk, (union sctp_addr *)addr, af->sockaddr_len);
+	if (!err)
+		err = sctp_send_asconf_add_ip(sk, addr, 1);

Some problems here.
- addr may contain a list of addresses
- the addresses, then, are not being validated
- sctp_do_bind may fail, on which it requires some undoing
  (like sctp_bindx_add does)
- code duplication with sctp_setsockopt_bindx.

sctp_do_bind and thus this function only support a single address, as
that is the only thing that the DLM code requires.  I could move the
user copy out of sctp_setsockopt_bindx and reuse that, but it is a
rather rcane API.

This patch will conflict with David's one,
[PATCH net-next] sctp: Pull the user copies out of the individual sockopt functions.

Do you have a link?  A quick google search just finds your mail that
I'm replying to.

(I'll finish reviewing it in the sequence)

AFAICT, this patch could reuse/build on his work in there. The goal is
pretty much the same and would avoid the issues above.

This patch could, then, point the new bind_add proto op to the updated
sctp_setsockopt_bindx almost directly.

Question then is: dlm never removes an addr from the bind list. Do we
want to add ops for both? Or one that handles both operations?
Anyhow, having the add operation but not the del seems very weird to
me.

We generally only add operations for things that we actually use.
bind_del is another logical op, but we can trivially add that when we
need it.