On Wed, Oct 21, 2020 at 5:13 PM Michael Tuexen <tuexen@xxxxxxxxxxxxxx> wrote: > > > On 21. Oct 2020, at 06:16, Xin Long <lucien.xin@xxxxxxxxx> wrote: > > > > On Wed, Oct 21, 2020 at 5:23 AM Marcelo Ricardo Leitner > > <marcelo.leitner@xxxxxxxxx> wrote: > >> > >> On Tue, Oct 20, 2020 at 11:15:26PM +0200, Michael Tuexen wrote: > >>>> On 20. Oct 2020, at 23:11, Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx> wrote: > >>>> > >>>> On Tue, Oct 20, 2020 at 05:12:06PM +0800, Xin Long wrote: > >>>>> On Tue, Oct 20, 2020 at 6:15 AM Marcelo Ricardo Leitner > >>>>> <marcelo.leitner@xxxxxxxxx> wrote: > >>>>>> > >>>>>> On Mon, Oct 19, 2020 at 08:25:33PM +0800, Xin Long wrote: > >>>>>>> --- a/Documentation/networking/ip-sysctl.rst > >>>>>>> +++ b/Documentation/networking/ip-sysctl.rst > >>>>>>> @@ -2640,6 +2640,12 @@ addr_scope_policy - INTEGER > >>>>>>> > >>>>>>> Default: 1 > >>>>>>> > >>>>>>> +udp_port - INTEGER > >>>>>> > >>>>>> Need to be more verbose here, and also mention the RFC. > >>>>>> > >>>>>>> + The listening port for the local UDP tunneling sock. > >>>>>> , shared by all applications in the same net namespace. > >>>>>>> + UDP encapsulation will be disabled when it's set to 0. > >>>>>> > >>>>>> "Note, however, that setting just this is not enough to actually > >>>>>> use it. ..." > >>>>> When it's a client, yes, but when it's a server, the encap_port can > >>>>> be got from the incoming packet. > >>>>> > >>>>>> > >>>>>>> + > >>>>>>> + Default: 9899 > >>>>>>> + > >>>>>>> encap_port - INTEGER > >>>>>>> The default remote UDP encapsalution port. > >>>>>>> When UDP tunneling is enabled, this global value is used to set > >>>>>> > >>>>>> When is it enabled, which conditions are needed? Maybe it can be > >>>>>> explained only in the one above. > >>>>> Thanks! > >>>>> pls check if this one will be better: > >>>> > >>>> It is. Verbose enough now, thx. > >>>> (one other comment below) > >>>> > >>>>> > >>>>> udp_port - INTEGER > >>>>> > >>>>> The listening port for the local UDP tunneling sock. > >>>>> > >>>>> This UDP sock is used for processing the incoming UDP-encapsulated > >>>>> SCTP packets (from RFC6951), and shared by all applications in the > >>>>> same net namespace. This UDP sock will be closed when the value is > >>>>> set to 0. > >>>>> > >>>>> The value will also be used to set the src port of the UDP header > >>>>> for the outgoing UDP-encapsulated SCTP packets. For the dest port, > >>>>> please refer to 'encap_port' below. > >>>>> > >>>>> Default: 9899 > >>>> > >>>> I'm now wondering if this is the right default. I mean, it is the > >>>> standard port for it, yes, but at the same time, it means loading SCTP > >>>> module will steal/use that UDP port on all net namespaces and can lead > >>>> to conflicts with other apps. A more conservative approach here is to > >>>> document the standard port, but set the default to 0 and require the > >>>> user to set it in if it is expected to be used. > >>>> > >>>> Did FreeBSD enable it by default too? > >>> No. The default is 0, which means that the encapsulation is turned off. > >>> Setting this sysctl variable to a non-zero value enables the UDP tunneling > >>> with the given port. > >> > >> Thanks Michael. > >> Xin, then we should change this default value (and update the > >> documentation above accordingly, to still have the standard port # > >> readily available in there). > > OK, I misunderstood the RFC. > Does that RFC mandate that the feature is on by default? Can you point me to > that text? Not really. I was thinking that by leaving it to 9899 by default users don't need to know the port when want to use it, and yet I didn't want to add another sysctl member. :D > > Best regards > Michael > > > > I will remove the call to sctp_udp_sock_start/stop() from > > sctp_ctrlsock_init/exit(), and set the udp_port as 0 by default. > > > > Thanks. >
