The branch main has been updated by glebius: URL: https://cgit.FreeBSD.org/src/commit/?id=713b57c414b789fd6c3eb2ce7ecb682b6cb4ba30
commit 713b57c414b789fd6c3eb2ce7ecb682b6cb4ba30 Author: Gleb Smirnoff <[email protected]> AuthorDate: 2025-12-18 16:47:31 +0000 Commit: Gleb Smirnoff <[email protected]> CommitDate: 2025-12-18 19:15:53 +0000 net: split ifnet_arrival_event into two events Run the original ifnet_arrival_event before linking the interface. Otherwise there is a race window when interface is already visible, but not all of the protocols have completed their attach. Provide a new event handler ifnet_attached_event, that is executed when the inteface is fully visible. Use it in route(4) socket and netlink(4) to announce new interface to the userland. Properly document the ifnet events in if_var.h. Reviewed by: zlei, melifaro Differential Revision: https://reviews.freebsd.org/D54085 --- sys/net/if.c | 5 ++--- sys/net/if_var.h | 23 +++++++++++++++++------ sys/net/rtsock.c | 4 ++-- sys/netlink/route/iface.c | 2 +- 4 files changed, 22 insertions(+), 12 deletions(-) diff --git a/sys/net/if.c b/sys/net/if.c index d7c6b22821e2..b603c72bd106 100644 --- a/sys/net/if.c +++ b/sys/net/if.c @@ -932,10 +932,9 @@ if_attach_internal(struct ifnet *ifp, bool vmove) if (domain_init_status >= 2) if_attachdomain1(ifp); - - if_link_ifnet(ifp); - EVENTHANDLER_INVOKE(ifnet_arrival_event, ifp); + if_link_ifnet(ifp); + EVENTHANDLER_INVOKE(ifnet_attached_event, ifp); if (IS_DEFAULT_VNET(curvnet)) devctl_notify("IFNET", ifp->if_xname, "ATTACH", NULL); } diff --git a/sys/net/if_var.h b/sys/net/if_var.h index b717e879815b..cbc4969918ba 100644 --- a/sys/net/if_var.h +++ b/sys/net/if_var.h @@ -358,12 +358,23 @@ typedef void (*ifaddr_event_ext_handler_t)(void *, if_t, struct ifaddr *, int); EVENTHANDLER_DECLARE(ifaddr_event_ext, ifaddr_event_ext_handler_t); #define IFADDR_EVENT_ADD 0 #define IFADDR_EVENT_DEL 1 -/* new interface arrival event */ -typedef void (*ifnet_arrival_event_handler_t)(void *, if_t); -EVENTHANDLER_DECLARE(ifnet_arrival_event, ifnet_arrival_event_handler_t); -/* interface departure event */ -typedef void (*ifnet_departure_event_handler_t)(void *, if_t); -EVENTHANDLER_DECLARE(ifnet_departure_event, ifnet_departure_event_handler_t); + +/* + * Interface arrival & departure events. + * The ifnet_arrival_event is executed before the is yet globally visible. + * Protocols shall use this event to attach themselves. Protocols shall not + * expect other protocols to be fully attached. + * The ifnet_attached_event is executed after the interface is attached to all + * protocols, is globally visible and fully functional. + * The ifnet_departure_event is complementary to ifnet_arrival_event. The + * interface is no longer globally visible, protocols may detach. + * XXXGL: immediate memory reclamation may not be safe in ifnet_departure_event. + */ +typedef void (*ifnet_event_handler_t)(void *, if_t); +EVENTHANDLER_DECLARE(ifnet_arrival_event, ifnet_event_handler_t); +EVENTHANDLER_DECLARE(ifnet_attached_event, ifnet_event_handler_t); +EVENTHANDLER_DECLARE(ifnet_departure_event, ifnet_event_handler_t); + /* Interface link state change event */ typedef void (*ifnet_link_event_handler_t)(void *, if_t, int); EVENTHANDLER_DECLARE(ifnet_link_event, ifnet_link_event_handler_t); diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c index be858428bb3e..82af92545b79 100644 --- a/sys/net/rtsock.c +++ b/sys/net/rtsock.c @@ -317,11 +317,11 @@ rtsock_init(void *dummy __unused) SYSINIT(rtsock_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, rtsock_init, NULL); static void -rts_handle_ifnet_arrival(void *arg __unused, struct ifnet *ifp) +rts_ifnet_attached(void *arg __unused, struct ifnet *ifp) { rt_ifannouncemsg(ifp, IFAN_ARRIVAL); } -EVENTHANDLER_DEFINE(ifnet_arrival_event, rts_handle_ifnet_arrival, NULL, 0); +EVENTHANDLER_DEFINE(ifnet_attached_event, rts_ifnet_attached, NULL, 0); static void rts_handle_ifnet_departure(void *arg __unused, struct ifnet *ifp) diff --git a/sys/netlink/route/iface.c b/sys/netlink/route/iface.c index 70ec5e688c57..29a9a89fd20c 100644 --- a/sys/netlink/route/iface.c +++ b/sys/netlink/route/iface.c @@ -1508,7 +1508,7 @@ void rtnl_ifaces_init(void) { ifattach_event = EVENTHANDLER_REGISTER( - ifnet_arrival_event, rtnl_handle_ifattach, NULL, + ifnet_attached_event, rtnl_handle_ifattach, NULL, EVENTHANDLER_PRI_ANY); ifdetach_event = EVENTHANDLER_REGISTER( ifnet_departure_event, rtnl_handle_ifdetach, NULL,
