Re: [PATCH net-next v3 3/3] selftest: net: test SO_PRIORITY ancillary data with cmsg_sender

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

Willem de Bruijn wrote:
> Anna Emese Nyiri wrote:
> > Extend cmsg_sender.c with a new option '-Q' to send SO_PRIORITY
> > ancillary data.
> > 
> > Add the `cmsg_so_priority.sh` script, which sets up two network  
> > namespaces (red and green) and uses the `cmsg_sender.c` program to  
> > send messages between them. The script sets packet priorities both  
> > via `setsockopt` and control messages (cmsg) and verifies whether  
> > packets are routed to the same queue based on priority settings.
> 
> qdisc. queue is a more generic term, generally referring to hw queues.
>  
> > Suggested-by: Ido Schimmel <idosch@idosch.org>
> > Signed-off-by: Anna Emese Nyiri <annaemesenyiri@gmail.com>
> > ---
> >  tools/testing/selftests/net/cmsg_sender.c     |  11 +-
> >  .../testing/selftests/net/cmsg_so_priority.sh | 115 ++++++++++++++++++
> >  2 files changed, 125 insertions(+), 1 deletion(-)
> >  create mode 100755 tools/testing/selftests/net/cmsg_so_priority.sh
>  
> > diff --git a/tools/testing/selftests/net/cmsg_so_priority.sh b/tools/testing/selftests/net/cmsg_so_priority.sh
> > new file mode 100755
> > index 000000000000..706d29b251e9
> > --- /dev/null
> > +++ b/tools/testing/selftests/net/cmsg_so_priority.sh
> > @@ -0,0 +1,115 @@
> > +#!/bin/bash
> 
> SPDX header
> 
> > +
> > +source lib.sh
> > +
> > +IP4=192.168.0.2/16
> > +TGT4=192.168.0.3/16
> > +TGT4_NO_MASK=192.168.0.3
> > +IP6=2001:db8::2/64
> > +TGT6=2001:db8::3/64
> > +TGT6_NO_MASK=2001:db8::3
> > +IP4BR=192.168.0.1/16
> > +IP6BR=2001:db8::1/64
> > +PORT=8080
> > +DELAY=400000
> > +QUEUE_NUM=4
> > +
> > +
> > +cleanup() {
> > +    ip netns del red 2>/dev/null
> > +    ip netns del green 2>/dev/null
> > +    ip link del br0 2>/dev/null
> > +    ip link del vethcab0 2>/dev/null
> > +    ip link del vethcab1 2>/dev/null
> > +}
> > +
> > +trap cleanup EXIT
> > +
> > +priority_values=($(seq 0 $((QUEUE_NUM - 1))))
> > +
> > +queue_config=""
> > +for ((i=0; i<$QUEUE_NUM; i++)); do
> > +    queue_config+=" 1@$i"
> > +done
> > +
> > +map_config=$(seq 0 $((QUEUE_NUM - 1)) | tr '\n' ' ')
> > +
> > +ip netns add red
> > +ip netns add green
> > +ip link add br0 type bridge
> > +ip link set br0 up
> 
> Is this bridge needed? Can this just use a veth pair as is.
> 
> More importantly, it would be great if we can deduplicate this kind of
> setup boilerplate across similar tests as much as possible.

As a matter of fact, similar to cmsg_so_mark, this test can probably
use a dummy netdevice, no need for a second namespace and dev.

cmsg_so_mark.sh is probably small enough that it is fine to copy that
and create a duplicate. As trying to extend it to cover both tests
will probably double it in size and will just be harder to follow.