ping...
On Tue, Jul 05, 2022 at 09:15:48PM +0300, Vitaliy Makkoveev wrote:
> pppoe_timeout() and pppoe_clone_destroy() are both executed with kernel
> lock held, but they are not serialized because pppoe_timeout() has the
> sleep point provided by netlock. We should use timeout_del_barrier(9) to
> ensure pppoe_timeout() finished. Also pppoe_timeout() could be
> rescheduled if the interface state `sc_state' is PPPOE_STATE_PADI_SENT
> or PPPOE_STATE_PADR_SENT. The interface could be destroyed in any
> connection state, so introduce new PPPOE_STATE_DYING state and use it to
> prevent timeout rescheduling.
>
> Do sppp_detach() after if_detach(). It destroys some `ifp' data, so it
> should be called after the interface was unlinked from the stack.
>
> Also do sppp_attach() before if_attach() call because initializes and
> setups `ifp' data.
>
> ok?
>
> Index: sys/net/if_pppoe.c
> ===================================================================
> RCS file: /cvs/src/sys/net/if_pppoe.c,v
> retrieving revision 1.81
> diff -u -p -r1.81 if_pppoe.c
> --- sys/net/if_pppoe.c 29 Jun 2022 09:08:07 -0000 1.81
> +++ sys/net/if_pppoe.c 5 Jul 2022 17:39:44 -0000
> @@ -242,9 +242,9 @@ pppoe_clone_create(struct if_clone *ifc,
> /* init timer for interface watchdog */
> timeout_set_proc(&sc->sc_timeout, pppoe_timeout, sc);
>
> + sppp_attach(&sc->sc_sppp.pp_if);
> if_attach(&sc->sc_sppp.pp_if);
> if_alloc_sadl(&sc->sc_sppp.pp_if);
> - sppp_attach(&sc->sc_sppp.pp_if);
> #if NBPFILTER > 0
> bpfattach(&sc->sc_sppp.pp_if.if_bpf, &sc->sc_sppp.pp_if, DLT_PPP_ETHER,
> 0);
> #endif
> @@ -269,13 +269,14 @@ pppoe_clone_destroy(struct ifnet *ifp)
> struct pppoe_softc *sc = ifp->if_softc;
>
> NET_LOCK();
> + sc->sc_state = PPPOE_STATE_DYING;
> LIST_REMOVE(sc, sc_list);
> NET_UNLOCK();
>
> - timeout_del(&sc->sc_timeout);
> -
> - sppp_detach(&sc->sc_sppp.pp_if);
> if_detach(ifp);
> + sppp_detach(&sc->sc_sppp.pp_if);
> +
> + timeout_del_barrier(&sc->sc_timeout);
>
> if (sc->sc_concentrator_name)
> free(sc->sc_concentrator_name, M_DEVBUF,
> Index: sys/net/if_pppoe.h
> ===================================================================
> RCS file: /cvs/src/sys/net/if_pppoe.h,v
> retrieving revision 1.8
> diff -u -p -r1.8 if_pppoe.h
> --- sys/net/if_pppoe.h 29 Jun 2022 09:08:07 -0000 1.8
> +++ sys/net/if_pppoe.h 5 Jul 2022 17:39:44 -0000
> @@ -49,6 +49,7 @@ struct pppoediscparms {
> #define PPPOE_STATE_PADR_SENT 2
> #define PPPOE_STATE_SESSION 3
> #define PPPOE_STATE_CLOSING 4
> +#define PPPOE_STATE_DYING 5
> /* passive */
> #define PPPOE_STATE_PADO_SENT 1
>
>
