Do not call ip_output() recursively in vxlan_start().

ip_output() currently needs the NET_LOCK() which is not held when an
interface is added to a pf(4) queue.

Fix an issue reported by Jason Tubnor, ok dlg@

diff --git a/sys/net/if_vxlan.c b/sys/net/if_vxlan.c
index 107f6a5..ad4139b 100644 (file)
--- a/sys/net/if_vxlan.c
+++ b/sys/net/if_vxlan.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_vxlan.c,v 1.65 2018/01/09 15:24:24 bluhm Exp $     */
+/*     $OpenBSD: if_vxlan.c,v 1.66 2018/01/22 09:05:06 mpi Exp $       */
 
 /*
  * Copyright (c) 2013 Reyk Floeter <reyk@openbsd.org>
@@ -73,6 +73,8 @@ struct vxlan_softc {
        int64_t                  sc_vnetid;
        u_int8_t                 sc_ttl;
 
+       struct task              sc_sendtask;
+
        LIST_ENTRY(vxlan_softc)  sc_entry;
 };
 
@@ -91,6 +93,7 @@ int    vxlan_output(struct ifnet *, struct mbuf *);
 void    vxlan_addr_change(void *);
 void    vxlan_if_change(void *);
 void    vxlan_link_change(void *);
+void    vxlan_send_dispatch(void *);
 
 int     vxlan_sockaddr_cmp(struct sockaddr *, struct sockaddr *);
 uint16_t vxlan_sockaddr_port(struct sockaddr *);
@@ -132,6 +135,7 @@ vxlan_clone_create(struct if_clone *ifc, int unit)
        sc->sc_imo.imo_max_memberships = IP_MIN_MEMBERSHIPS;
        sc->sc_dstport = htons(VXLAN_PORT);
        sc->sc_vnetid = VXLAN_VNI_UNSET;
+       task_set(&sc->sc_sendtask, vxlan_send_dispatch, sc);
 
        ifp = &sc->sc_ac.ac_if;
        snprintf(ifp->if_xname, sizeof ifp->if_xname, "vxlan%d", unit);
@@ -186,6 +190,10 @@ vxlan_clone_destroy(struct ifnet *ifp)
        ifmedia_delete_instance(&sc->sc_media, IFM_INST_ANY);
        ether_ifdetach(ifp);
        if_detach(ifp);
+
+       if (!task_del(net_tq(ifp->if_index), &sc->sc_sendtask))
+               taskq_barrier(net_tq(ifp->if_index));
+
        free(sc->sc_imo.imo_membership, M_IPMOPTS, 0);
        free(sc, M_DEVBUF, sizeof(*sc));
 
@@ -299,22 +307,44 @@ vxlan_multicast_join(struct ifnet *ifp, struct sockaddr *src,
 void
 vxlanstart(struct ifnet *ifp)
 {
+       struct vxlan_softc      *sc = (struct vxlan_softc *)ifp->if_softc;
+
+       task_add(net_tq(ifp->if_index), &sc->sc_sendtask);
+}
+
+void
+vxlan_send_dispatch(void *xsc)
+{
+       struct vxlan_softc      *sc = xsc;
+       struct ifnet            *ifp = &sc->sc_ac.ac_if;
        struct mbuf             *m;
+       struct mbuf_list         ml;
 
+       ml_init(&ml);
        for (;;) {
                IFQ_DEQUEUE(&ifp->if_snd, m);
                if (m == NULL)
-                       return;
+                       break;
 
 #if NBPFILTER > 0
                if (ifp->if_bpf)
                        bpf_mtap(ifp->if_bpf, m, BPF_DIRECTION_OUT);
 #endif
 
+               ml_enqueue(&ml, m);
+       }
+
+       if (ml_empty(&ml))
+               return;
+
+       NET_RLOCK();
+       while ((m = ml_dequeue(&ml)) != NULL) {
                vxlan_output(ifp, m);
        }
+       NET_RUNLOCK();
 }
 
+
 int
 vxlan_config(struct ifnet *ifp, struct sockaddr *src, struct sockaddr *dst)
 {