Re: [PATCH v2 04/16] udp: Don't connect "forward" sockets for spliced flows

[David Gibson <david@gibson.dropbear.id.au>]

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On Fri, Nov 25, 2022 at 02:47:59AM +0100, Stefano Brivio wrote:
> Nit:
> 
> On Thu, 24 Nov 2022 12:16:47 +1100
> David Gibson <david@gibson.dropbear.id.au> wrote:
> 
> > Currently we connect() the socket we use to forward spliced UDP flows.
> > However, we now only ever use sendto() rather than send() on this socket
> > so there's not actually any need to connect it.  Don't do so.
> > 
> > Rename a number of things that referred to "connect" or "conn" since that
> > would now be misleading.
> > 
> > Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> > ---
> >  udp.c | 85 ++++++++++++++++++++++++-----------------------------------
> >  1 file changed, 35 insertions(+), 50 deletions(-)
> > 
> > diff --git a/udp.c b/udp.c
> > index 1e78da5..ed095ec 100644
> > --- a/udp.c
> > +++ b/udp.c
> > @@ -45,23 +45,20 @@
> >   *
> >   * - from init to namespace:
> >   *
> > - *   - forward direction: 127.0.0.1:5000 -> 127.0.0.1:80 in init from bound
> > - *     socket s, with epoll reference: index = 80, splice = UDP_TO_NS
> > + *   - forward direction: 127.0.0.1:5000 -> 127.0.0.1:80 in init from socket s,
> > + *     with epoll reference: index = 80, splice = UDP_TO_NS
> >   *     - if udp_splice_to_ns[V4][5000].target_sock:
> >   *       - send packet to udp_splice_to_ns[V4][5000].target_sock, with
> >   *         destination port 80
> >   *     - otherwise:
> >   *       - create new socket udp_splice_to_ns[V4][5000].target_sock
> >   *       - bind in namespace to 127.0.0.1:5000
> > - *       - connect in namespace to 127.0.0.1:80 (note: this destination port
> > - *         might be remapped to another port instead)
> >   *       - add to epoll with reference: index = 5000, splice: UDP_BACK_TO_INIT
> >   *       - set udp_splice_to_ns[V4][5000].orig_sock to s
> >   *     - update udp_splice_to_ns[V4][5000].ts with current time
> >   *
> > - *   - reverse direction: 127.0.0.1:80 -> 127.0.0.1:5000 in namespace from
> > - *     connected socket s, having epoll reference: index = 5000,
> > - *     splice = UDP_BACK_TO_INIT
> > + *   - reverse direction: 127.0.0.1:80 -> 127.0.0.1:5000 in namespace socket s,
> > + *     having epoll reference: index = 5000, splice = UDP_BACK_TO_INIT
> >   *     - if udp_splice_to_ns[V4][5000].orig_sock:
> >   *       - send to udp_splice_to_ns[V4][5000].orig_sock, with destination port
> >   *         5000
> > @@ -69,7 +66,7 @@
> >   *
> >   * - from namespace to init:
> >   *
> > - *   - forward direction: 127.0.0.1:2000 -> 127.0.0.1:22 in namespace from bound
> > + *   - forward direction: 127.0.0.1:2000 -> 127.0.0.1:22 in namespace from
> >   *     socket s, with epoll reference: index = 22, splice = UDP_TO_INIT
> >   *     - if udp4_splice_to_init[V4][2000].target_sock:
> >   *       - send packet to udp_splice_to_init[V4][2000].target_sock, with
> > @@ -77,14 +74,12 @@
> >   *     - otherwise:
> >   *       - create new socket udp_splice_to_init[V4][2000].target_sock
> >   *       - bind in init to 127.0.0.1:2000
> > - *       - connect in init to 127.0.0.1:22 (note: this destination port
> > - *         might be remapped to another port instead)
> >   *       - add to epoll with reference: index = 2000, splice = UDP_BACK_TO_NS
> >   *       - set udp_splice_to_init[V4][2000].orig_sock to s
> >   *     - update udp_splice_to_init[V4][2000].ts with current time
> >   *
> > - *   - reverse direction: 127.0.0.1:22 -> 127.0.0.1:2000 in init from connected
> > - *     socket s, having epoll reference: index = 2000, splice = UDP_BACK_TO_NS
> > + *   - reverse direction: 127.0.0.1:22 -> 127.0.0.1:2000 in init from socket s,
> > + *     having epoll reference: index = 2000, splice = UDP_BACK_TO_NS
> >   *   - if udp_splice_to_init[V4][2000].orig_sock:
> >   *     - send to udp_splice_to_init[V4][2000].orig_sock, with destination port
> >   *       2000
> > @@ -144,8 +139,7 @@ struct udp_tap_port {
> >   * @orig_sock:		Originating socket, bound to dest port in source ns of
> >   *			originating datagram
> >   * @target_sock:	Target socket, bound to source port of originating
> > - *			datagram in dest ns, connected to dest port of
> > - *			originating datagram in dest ns
> > + *			datagram in dest ns
> >   * @ts:			Activity timestamp
> >   */
> >  struct udp_splice_flow {
> > @@ -163,8 +157,8 @@ static struct udp_splice_flow udp_splice_to_init[IP_VERSIONS][NUM_PORTS];
> >  
> >  enum udp_act_type {
> >  	UDP_ACT_TAP,
> > -	UDP_ACT_NS_CONN,
> > -	UDP_ACT_INIT_CONN,
> > +	UDP_ACT_SPLICE_NS,
> > +	UDP_ACT_SPLICE_INIT,
> >  	UDP_ACT_TYPE_MAX,
> >  };
> >  
> > @@ -398,20 +392,19 @@ static void udp_sock6_iov_init(void)
> >  }
> >  
> >  /**
> > - * udp_splice_connect() - Create and connect socket for "spliced" binding
> > + * udp_splice_new() - Create and prepare socket for "spliced" binding
> >   * @c:		Execution context
> > - * @v6:		Set for IPv6 connections
> > + * @v6:		Set for IPv6 sockets
> >   * @bound_sock:	Originating bound socket
> >   * @src:	Source port of original connection, host order
> > - * @dst:	Destination port of original connection, host order
> >   * @splice:	UDP_BACK_TO_INIT from init, UDP_BACK_TO_NS from namespace
> >   *
> > - * Return: connected socket, negative error code on failure
> > + * Return: Prepared socket, negative error code on failure
> 
> prepared

Fixed.  Is there a particular rationale for capitalizing on the
parameters, but not the return description?

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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