Re: [PATCH RFC] RDMA/CMA: Allocate PS_TCP ports from the host TCP port space.

Evgeniy Polyakov
2007-08-07T15:39:55Z

On Tue, Aug 07, 2007 at 10:06:29AM -0500, Steve Wise (swise@opengridcomputing.com) wrote:
> >On Tue, Aug 07, 2007 at 09:37:41AM -0500, Steve Wise
> >(swise@opengridcomputing.com) wrote:
> >>+static int cma_get_tcp_port(struct rdma_id_private *id_priv)
> >>+{
> >>+ int ret;
> >>+ struct socket *sock;
> >>+
> >>+ ret = sock_create_kern(AF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
> >>+ if (ret)
> >>+ return ret;
> >>+ ret = sock->ops->bind(sock,
> >>+ (struct socketaddr
> >>*)&id_priv->id.route.addr.src_addr,
> >>+ ip_addr_size(&id_priv->id.route.addr.src_addr));
> >
> >If get away from talks about broken offloading, this one will result in
> >the case, when usual network dataflow can enter private rdma land, i.e.
> >after bind succeeded this socket is accessible via any other network
> >device. Is it inteded?
> >And this is quite noticeble overhead per rdma connection, btw.
> >
>
> I'm not sure I understand your question? What do you mean by
> "accessible"? The intention is to _just_ reserve the addr/port.

Above RDMA ->bind() ends up with tcp_v4_get_port(), which will only add
socket into bhash, but it is only accessible for new sockets created for
listening connections or expilicit bind, network traffic checks only
listening and establised hashes, which are not affected by above change,
so it was false alarm from my side. It does allow to 'grab' a port and
forbid its possible reuse.

--
Evgeniy Polyakov