On Mon, Feb 03, 2020 at 03:36:58PM +0100, Andrea Mayer wrote: > before this patch, each SRv6 behavior specifies a set of required > attributes that must be provided by the userspace application when the > behavior is created. If an attribute is not supplied, the creation > operation fails. > As a workaround, if an attribute is not needed by a behavior, it requires > to be set by the userspace application to a conventional skip-value. The > kernel side, that processes the creation request of a behavior, reads the > supplied attribute values and checks if it has been set to the > conventional skip-value or not. Hence, each optional attribute must have a > conventional skip-value which is known a priori and shared between > userspace applications and kernel. > > Messy code and complicated tricks may arise from this approach. > On the other hand, this patch explicitly differentiates the required > mandatory attributes from the optional ones. Now, each behavior can declare > a set of required attributes and a set of optional ones. The behavior > creation fails in case a required attribute is missing, while it goes on > without generating any issue if an optional attribute is not supplied by > the userspace application. > > To properly combine the required and optional attributes, a new callback > function called destroy() is used for releasing resources that have been > acquired, during the parse() operation, by a given attribute. > However, the destroy() function is optional and if an attribute does not > require resources that have to be later released, the callback can be > omitted. > > Signed-off-by: Andrea Mayer <andrea.mayer@xxxxxxxxxxx> > --- > net/ipv6/seg6_local.c | 226 ++++++++++++++++++++++++++++++++++++------ > 1 file changed, 198 insertions(+), 28 deletions(-) > > diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c > index 85a5447a3e8d..480f1ab35221 100644 > --- a/net/ipv6/seg6_local.c > +++ b/net/ipv6/seg6_local.c > @@ -7,6 +7,13 @@ > * eBPF support: Mathieu Xhonneux <m.xhonneux@xxxxxxxxx> > */ > > +/* Changes: > + * > + * Andrea Mayer <andrea.mayer@xxxxxxxxxxx> > + * add support for optional attributes during behavior construction > + * > + */ The lines above look strange in 2020 when all of us are using git. Thanks
