On Tue, Sep 08, 2020 at 09:21:08AM -0600, David Ahern wrote:
> On 9/8/20 3:10 AM, Ido Schimmel wrote:
> > From: Ido Schimmel <ido...@nvidia.com>
> >
> > Emit a notification in the nexthop notification chain when a new nexthop
> > is added (not replaced). The nexthop can either be a new group or a
> > single nexthop.
>
> Add a comment about why EVENT_REPLACE is generated on an 'added (not
> replaced)' event.
Reworded:
"
nexthop: Emit a notification when a nexthop is added
Emit a notification in the nexthop notification chain when a new nexthop
is added (not replaced). The nexthop can either be a new group or a
single nexthop.
The notification is sent after the nexthop is inserted into the
red-black tree, as listeners might need to callback into the nexthop
code with the nexthop ID in order to mark the nexthop as offloaded.
A 'REPLACE' notification is emitted instead of 'ADD' as the distinction
between the two is not important for in-kernel listeners. In case the
listener is not familiar with the encoded nexthop ID, it can simply
treat it as a new one. This is also consistent with the route offload
API.
Signed-off-by: Ido Schimmel <ido...@nvidia.com>
"
>
> >
> > The notification is sent after the nexthop is inserted into the
> > red-black tree, as listeners might need to callback into the nexthop
> > code with the nexthop ID in order to mark the nexthop as offloaded.
> >
> > Signed-off-by: Ido Schimmel <ido...@nvidia.com>
> > ---
> > include/net/nexthop.h | 3 ++-
> > net/ipv4/nexthop.c | 6 +++++-
> > 2 files changed, 7 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/net/nexthop.h b/include/net/nexthop.h
> > index 4147681e86d2..6431ff8cdb89 100644
> > --- a/include/net/nexthop.h
> > +++ b/include/net/nexthop.h
> > @@ -106,7 +106,8 @@ struct nexthop {
> >
> > enum nexthop_event_type {
> > NEXTHOP_EVENT_ADD,
>
> looks like the ADD event is not used and can be removed.
Right. I will remove it in a separate patch
>
> > - NEXTHOP_EVENT_DEL
> > + NEXTHOP_EVENT_DEL,
> > + NEXTHOP_EVENT_REPLACE,
> > };
> >
> > struct nh_notifier_single_info {
> > diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
> > index 71605c612458..1fa249facd46 100644
> > --- a/net/ipv4/nexthop.c
> > +++ b/net/ipv4/nexthop.c
> > @@ -1277,7 +1277,11 @@ static int insert_nexthop(struct net *net, struct
> > nexthop *new_nh,
> >
> > rb_link_node_rcu(&new_nh->rb_node, parent, pp);
> > rb_insert_color(&new_nh->rb_node, root);
> > - rc = 0;
> > +
> > + rc = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new_nh, extack);
> > + if (rc)
> > + rb_erase(&new_nh->rb_node, &net->nexthop.rb_root);
> > +
> > out:
> > if (!rc) {
> > nh_base_seq_inc(net);
> >
>
