/*- * Copyright (c) 2008 The FreeBSD Foundation * Copyright (c) 2009-2010 Bjoern A. Zeeb * All rights reserved. * * This software was developed by CK Software GmbH under sponsorship * from the FreeBSD Foundation. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * A pair of virtual back-to-back connected ethernet like interfaces * (``two interfaces with a virtual cross-over cable''). * * This is mostly intended to be used to provide connectivity between * different virtual network stack instances. */ /* * Things to re-think once we have more experience: * - ifp->if_reassign function once we can test with vimage. Depending on * how if_vmove() is going to be improved. * - Real random etheraddrs that are checked to be uniquish; we would need * to re-do them in case we move the interface between network stacks * in a private if_reassign function. * In case we bridge to a real interface/network or between indepedent * epairs on multiple stacks/machines, we may need this. * For now let the user handle that case. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define EPAIRNAME "epair" SYSCTL_DECL(_net_link); SYSCTL_NODE(_net_link, OID_AUTO, epair, CTLFLAG_RW, 0, "epair sysctl"); #ifdef EPAIR_DEBUG static int epair_debug = 0; SYSCTL_XINT(_net_link_epair, OID_AUTO, epair_debug, CTLFLAG_RW, &epair_debug, 0, "if_epair(4) debugging."); #define DPRINTF(fmt, arg...) \ if (epair_debug) \ printf("[%s:%d] " fmt, __func__, __LINE__, ##arg) #else #define DPRINTF(fmt, arg...) #endif static void epair_nh_sintr(struct mbuf *); static struct mbuf *epair_nh_m2cpuid(struct mbuf *, uintptr_t, u_int *); static void epair_nh_drainedcpu(u_int); static void epair_start_locked(struct ifnet *); static int epair_clone_match(struct if_clone *, const char *); static int epair_clone_create(struct if_clone *, char *, size_t, caddr_t); static int epair_clone_destroy(struct if_clone *, struct ifnet *); /* Netisr realted definitions and sysctl. */ static struct netisr_handler epair_nh = { .nh_name = EPAIRNAME, .nh_proto = NETISR_EPAIR, .nh_policy = NETISR_POLICY_CPU, .nh_handler = epair_nh_sintr, .nh_m2cpuid = epair_nh_m2cpuid, .nh_drainedcpu = epair_nh_drainedcpu, }; static int sysctl_epair_netisr_maxqlen(SYSCTL_HANDLER_ARGS) { int error, qlimit; netisr_getqlimit(&epair_nh, &qlimit); error = sysctl_handle_int(oidp, &qlimit, 0, req); if (error || !req->newptr) return (error); if (qlimit < 1) return (EINVAL); return (netisr_setqlimit(&epair_nh, qlimit)); } SYSCTL_PROC(_net_link_epair, OID_AUTO, netisr_maxqlen, CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_epair_netisr_maxqlen, "I", "Maximum if_epair(4) netisr \"hw\" queue length"); struct epair_softc { struct ifnet *ifp; /* This ifp. */ struct ifnet *oifp; /* other ifp of pair. */ u_int refcount; /* # of mbufs in flight. */ u_int cpuid; /* CPU ID assigned upon creation. */ void (*if_qflush)(struct ifnet *); /* Original if_qflush routine. */ }; /* * Per-CPU list of ifps with data in the ifq that needs to be flushed * to the netisr ``hw'' queue before we allow any further direct queuing * to the ``hw'' queue. */ struct epair_ifp_drain { STAILQ_ENTRY(epair_ifp_drain) ifp_next; struct ifnet *ifp; }; STAILQ_HEAD(eid_list, epair_ifp_drain); #define EPAIR_LOCK_INIT(dpcpu) mtx_init(&(dpcpu)->if_epair_mtx, \ "if_epair", NULL, MTX_DEF) #define EPAIR_LOCK_DESTROY(dpcpu) mtx_destroy(&(dpcpu)->if_epair_mtx) #define EPAIR_LOCK_ASSERT(dpcpu) mtx_assert(&(dpcpu)->if_epair_mtx, \ MA_OWNED) #define EPAIR_LOCK(dpcpu) mtx_lock(&(dpcpu)->if_epair_mtx) #define EPAIR_UNLOCK(dpcpu) mtx_unlock(&(dpcpu)->if_epair_mtx) #ifdef INVARIANTS #define EPAIR_REFCOUNT_INIT(r, v) refcount_init((r), (v)) #define EPAIR_REFCOUNT_AQUIRE(r) refcount_acquire((r)) #define EPAIR_REFCOUNT_RELEASE(r) refcount_release((r)) #define EPAIR_REFCOUNT_ASSERT(a, p) KASSERT(a, p) #else #define EPAIR_REFCOUNT_INIT(r, v) #define EPAIR_REFCOUNT_AQUIRE(r) #define EPAIR_REFCOUNT_RELEASE(r) #define EPAIR_REFCOUNT_ASSERT(a, p) #endif static MALLOC_DEFINE(M_EPAIR, EPAIRNAME, "Pair of virtual cross-over connected Ethernet-like interfaces"); static struct if_clone epair_cloner = IFC_CLONE_INITIALIZER( EPAIRNAME, NULL, IF_MAXUNIT, NULL, epair_clone_match, epair_clone_create, epair_clone_destroy); /* * DPCPU area and functions. */ struct epair_dpcpu { struct mtx if_epair_mtx; /* Per-CPU locking. */ int epair_drv_flags; /* Per-CPU ``hw'' drv flags. */ struct eid_list epair_ifp_drain_list; /* Per-CPU list of ifps with * data in the ifq. */ }; DPCPU_DEFINE(struct epair_dpcpu, epair_dpcpu); static void epair_dpcpu_init(void) { struct epair_dpcpu *epair_dpcpu; struct eid_list *s; u_int cpuid; CPU_FOREACH(cpuid) { epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu); /* Initialize per-cpu lock. */ EPAIR_LOCK_INIT(epair_dpcpu); /* Driver flags are per-cpu as are our netisr "hw" queues. */ epair_dpcpu->epair_drv_flags = 0; /* * Initialize per-cpu drain list. * Manually do what STAILQ_HEAD_INITIALIZER would do. */ s = &epair_dpcpu->epair_ifp_drain_list; s->stqh_first = NULL; s->stqh_last = &s->stqh_first; } } static void epair_dpcpu_detach(void) { struct epair_dpcpu *epair_dpcpu; u_int cpuid; CPU_FOREACH(cpuid) { epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu); /* Destroy per-cpu lock. */ EPAIR_LOCK_DESTROY(epair_dpcpu); } } /* * Helper functions. */ static u_int cpuid_from_ifp(struct ifnet *ifp) { struct epair_softc *sc; if (ifp == NULL) return (0); sc = ifp->if_softc; return (sc->cpuid); } /* * Netisr handler functions. */ static void epair_nh_sintr(struct mbuf *m) { struct ifnet *ifp; struct epair_softc *sc; ifp = m->m_pkthdr.rcvif; (*ifp->if_input)(ifp, m); sc = ifp->if_softc; EPAIR_REFCOUNT_RELEASE(&sc->refcount); EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1, ("%s: ifp=%p sc->refcount not >= 1: %d", __func__, ifp, sc->refcount)); DPRINTF("ifp=%p refcount=%u\n", ifp, sc->refcount); } static struct mbuf * epair_nh_m2cpuid(struct mbuf *m, uintptr_t source, u_int *cpuid) { *cpuid = cpuid_from_ifp(m->m_pkthdr.rcvif); return (m); } static void epair_nh_drainedcpu(u_int cpuid) { struct epair_dpcpu *epair_dpcpu; struct epair_ifp_drain *elm, *tvar; struct ifnet *ifp; epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu); EPAIR_LOCK(epair_dpcpu); /* * Assume our "hw" queue and possibly ifq will be emptied * again. In case we will overflow the "hw" queue while * draining, epair_start_locked will set IFF_DRV_OACTIVE * again and we will stop and return. */ STAILQ_FOREACH_SAFE(elm, &epair_dpcpu->epair_ifp_drain_list, ifp_next, tvar) { ifp = elm->ifp; epair_dpcpu->epair_drv_flags &= ~IFF_DRV_OACTIVE; ifp->if_drv_flags &= ~IFF_DRV_OACTIVE; epair_start_locked(ifp); IFQ_LOCK(&ifp->if_snd); if (IFQ_IS_EMPTY(&ifp->if_snd)) { struct epair_softc *sc; STAILQ_REMOVE(&epair_dpcpu->epair_ifp_drain_list, elm, epair_ifp_drain, ifp_next); /* The cached ifp goes off the list. */ sc = ifp->if_softc; EPAIR_REFCOUNT_RELEASE(&sc->refcount); EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1, ("%s: ifp=%p sc->refcount not >= 1: %d", __func__, ifp, sc->refcount)); free(elm, M_EPAIR); } IFQ_UNLOCK(&ifp->if_snd); if ((ifp->if_drv_flags & IFF_DRV_OACTIVE) != 0) { /* Our "hw"q overflew again. */ epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE DPRINTF("hw queue length overflow at %u\n", epair_nh.nh_qlimit); break; } } EPAIR_UNLOCK(epair_dpcpu); } /* * Network interface (`if') related functions. */ static void epair_remove_ifp_from_draining(struct ifnet *ifp) { struct epair_dpcpu *epair_dpcpu; struct epair_ifp_drain *elm, *tvar; u_int cpuid; CPU_FOREACH(cpuid) { epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu); EPAIR_LOCK(epair_dpcpu); STAILQ_FOREACH_SAFE(elm, &epair_dpcpu->epair_ifp_drain_list, ifp_next, tvar) { if (ifp == elm->ifp) { struct epair_softc *sc; STAILQ_REMOVE( &epair_dpcpu->epair_ifp_drain_list, elm, epair_ifp_drain, ifp_next); /* The cached ifp goes off the list. */ sc = ifp->if_softc; EPAIR_REFCOUNT_RELEASE(&sc->refcount); EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1, ("%s: ifp=%p sc->refcount not >= 1: %d", __func__, ifp, sc->refcount)); free(elm, M_EPAIR); } } EPAIR_UNLOCK(epair_dpcpu); } } static int epair_add_ifp_for_draining(struct ifnet *ifp) { struct epair_dpcpu *epair_dpcpu; struct epair_softc *sc; struct epair_ifp_drain *elm = NULL; sc = ifp->if_softc; epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu); EPAIR_LOCK_ASSERT(epair_dpcpu); STAILQ_FOREACH(elm, &epair_dpcpu->epair_ifp_drain_list, ifp_next) if (elm->ifp == ifp) break; /* If the ifp is there already, return success. */ if (elm != NULL) return (0); elm = malloc(sizeof(struct epair_ifp_drain), M_EPAIR, M_NOWAIT|M_ZERO); if (elm == NULL) return (ENOMEM); elm->ifp = ifp; /* Add a reference for the ifp pointer on the list. */ EPAIR_REFCOUNT_AQUIRE(&sc->refcount); STAILQ_INSERT_TAIL(&epair_dpcpu->epair_ifp_drain_list, elm, ifp_next); return (0); } static void epair_start_locked(struct ifnet *ifp) { struct epair_dpcpu *epair_dpcpu; struct mbuf *m; struct epair_softc *sc; struct ifnet *oifp; int error; DPRINTF("ifp=%p\n", ifp); sc = ifp->if_softc; epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu); EPAIR_LOCK_ASSERT(epair_dpcpu); if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) return; if ((ifp->if_flags & IFF_UP) == 0) return; /* * We get patckets here from ether_output via if_handoff() * and ned to put them into the input queue of the oifp * and call oifp->if_input() via netisr/epair_sintr(). */ oifp = sc->oifp; sc = oifp->if_softc; for (;;) { IFQ_DEQUEUE(&ifp->if_snd, m); if (m == NULL) break; BPF_MTAP(ifp, m); /* * In case the outgoing interface is not usable, * drop the packet. */ if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || (oifp->if_flags & IFF_UP) ==0) { ifp->if_oerrors++; m_freem(m); continue; } DPRINTF("packet %s -> %s\n", ifp->if_xname, oifp->if_xname); /* * Add a reference so the interface cannot go while the * packet is in transit as we rely on rcvif to stay valid. */ EPAIR_REFCOUNT_AQUIRE(&sc->refcount); m->m_pkthdr.rcvif = oifp; CURVNET_SET_QUIET(oifp->if_vnet); error = netisr_queue(NETISR_EPAIR, m); CURVNET_RESTORE(); if (!error) { ifp->if_opackets++; /* Someone else received the packet. */ oifp->if_ipackets++; } else { /* The packet was freed already. */ epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE; ifp->if_drv_flags |= IFF_DRV_OACTIVE; (void) epair_add_ifp_for_draining(ifp); ifp->if_oerrors++; EPAIR_REFCOUNT_RELEASE(&sc->refcount); EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1, ("%s: ifp=%p sc->refcount not >= 1: %d", __func__, oifp, sc->refcount)); } } } static void epair_start(struct ifnet *ifp) { struct epair_dpcpu *epair_dpcpu; epair_dpcpu = DPCPU_ID_PTR(cpuid_from_ifp(ifp), epair_dpcpu); EPAIR_LOCK(epair_dpcpu); epair_start_locked(ifp); EPAIR_UNLOCK(epair_dpcpu); } static int epair_transmit_locked(struct ifnet *ifp, struct mbuf *m) { struct epair_dpcpu *epair_dpcpu; struct epair_softc *sc; struct ifnet *oifp; int error, len; short mflags; DPRINTF("ifp=%p m=%p\n", ifp, m); sc = ifp->if_softc; epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu); EPAIR_LOCK_ASSERT(epair_dpcpu); if (m == NULL) return (0); /* * We are not going to use the interface en/dequeue mechanism * on the TX side. We are called from ether_output_frame() * and will put the packet into the incoming queue of the * other interface of our pair via the netsir. */ if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { m_freem(m); return (ENXIO); } if ((ifp->if_flags & IFF_UP) == 0) { m_freem(m); return (ENETDOWN); } BPF_MTAP(ifp, m); /* * In case the outgoing interface is not usable, * drop the packet. */ oifp = sc->oifp; if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || (oifp->if_flags & IFF_UP) ==0) { ifp->if_oerrors++; m_freem(m); return (0); } len = m->m_pkthdr.len; mflags = m->m_flags; DPRINTF("packet %s -> %s\n", ifp->if_xname, oifp->if_xname); #ifdef ALTQ /* Support ALTQ via the clasic if_start() path. */ IF_LOCK(&ifp->if_snd); if (ALTQ_IS_ENABLED(&ifp->if_snd)) { ALTQ_ENQUEUE(&ifp->if_snd, m, NULL, error); if (error) ifp->if_snd.ifq_drops++; IF_UNLOCK(&ifp->if_snd); if (!error) { ifp->if_obytes += len; if (mflags & (M_BCAST|M_MCAST)) ifp->if_omcasts++; if ((ifp->if_drv_flags & IFF_DRV_OACTIVE) == 0) epair_start_locked(ifp); else (void)epair_add_ifp_for_draining(ifp); } return (error); } IF_UNLOCK(&ifp->if_snd); #endif if ((epair_dpcpu->epair_drv_flags & IFF_DRV_OACTIVE) != 0) { /* * Our hardware queue is full, try to fall back * queuing to the ifq but do not call ifp->if_start. * Either we are lucky or the packet is gone. */ IFQ_ENQUEUE(&ifp->if_snd, m, error); if (!error) (void)epair_add_ifp_for_draining(ifp); return (error); } sc = oifp->if_softc; /* * Add a reference so the interface cannot go while the * packet is in transit as we rely on rcvif to stay valid. */ EPAIR_REFCOUNT_AQUIRE(&sc->refcount); m->m_pkthdr.rcvif = oifp; CURVNET_SET_QUIET(oifp->if_vnet); error = netisr_queue(NETISR_EPAIR, m); CURVNET_RESTORE(); if (!error) { ifp->if_opackets++; /* * IFQ_HANDOFF_ADJ/ip_handoff() update statistics, * but as we bypass all this we have to duplicate * the logic another time. */ ifp->if_obytes += len; if (mflags & (M_BCAST|M_MCAST)) ifp->if_omcasts++; /* Someone else received the packet. */ oifp->if_ipackets++; } else { /* The packet was freed already. */ epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE; ifp->if_drv_flags |= IFF_DRV_OACTIVE; ifp->if_oerrors++; EPAIR_REFCOUNT_RELEASE(&sc->refcount); EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1, ("%s: ifp=%p sc->refcount not >= 1: %d", __func__, oifp, sc->refcount)); } return (error); } static int epair_transmit(struct ifnet *ifp, struct mbuf *m) { struct epair_dpcpu *epair_dpcpu; int error; epair_dpcpu = DPCPU_ID_PTR(cpuid_from_ifp(ifp), epair_dpcpu); EPAIR_LOCK(epair_dpcpu); error = epair_transmit_locked(ifp, m); EPAIR_UNLOCK(epair_dpcpu); return (error); } static void epair_qflush(struct ifnet *ifp) { struct epair_softc *sc; sc = ifp->if_softc; KASSERT(sc != NULL, ("%s: ifp=%p, epair_softc gone? sc=%p\n", __func__, ifp, sc)); /* * Remove this ifp from all backpointer lists. The interface will not * usable for flushing anyway nor should it have anything to flush * after if_qflush(). */ epair_remove_ifp_from_draining(ifp); if (sc->if_qflush) sc->if_qflush(ifp); } static int epair_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) { struct ifreq *ifr; int error; ifr = (struct ifreq *)data; switch (cmd) { case SIOCSIFFLAGS: case SIOCADDMULTI: case SIOCDELMULTI: error = 0; break; case SIOCSIFMTU: /* We basically allow all kinds of MTUs. */ ifp->if_mtu = ifr->ifr_mtu; error = 0; break; default: /* Let the common ethernet handler process this. */ error = ether_ioctl(ifp, cmd, data); break; } return (error); } static void epair_init(void *dummy __unused) { } /* * Interface cloning functions. * We use our private ones so that we can create/destroy our secondary * device along with the primary one. */ static int epair_clone_match(struct if_clone *ifc, const char *name) { const char *cp; DPRINTF("name='%s'\n", name); /* * Our base name is epair. * Our interfaces will be named epair[ab]. * So accept anything of the following list: * - epair * - epair * but not the epair[ab] versions. */ if (strncmp(EPAIRNAME, name, sizeof(EPAIRNAME)-1) != 0) return (0); for (cp = name + sizeof(EPAIRNAME) - 1; *cp != '\0'; cp++) { if (*cp < '0' || *cp > '9') return (0); } return (1); } static int epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) { struct epair_softc *sca, *scb; struct ifnet *ifp; char *dp; int error, unit, wildcard; uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */ /* * We are abusing params to create our second interface. * Actually we already created it and called if_clone_createif() * for it to do the official insertion procedure the moment we knew * it cannot fail anymore. So just do attach it here. */ if (params) { scb = (struct epair_softc *)params; ifp = scb->ifp; /* Assign a hopefully unique, locally administered etheraddr. */ eaddr[0] = 0x02; eaddr[3] = (ifp->if_index >> 8) & 0xff; eaddr[4] = ifp->if_index & 0xff; eaddr[5] = 0x0b; ether_ifattach(ifp, eaddr); /* Correctly set the name for the cloner list. */ strlcpy(name, scb->ifp->if_xname, len); return (0); } /* Try to see if a special unit was requested. */ error = ifc_name2unit(name, &unit); if (error != 0) return (error); wildcard = (unit < 0); error = ifc_alloc_unit(ifc, &unit); if (error != 0) return (error); /* * If no unit had been given, we need to adjust the ifName. * Also make sure there is space for our extra [ab] suffix. */ for (dp = name; *dp != '\0'; dp++); if (wildcard) { error = snprintf(dp, len - (dp - name), "%d", unit); if (error > len - (dp - name) - 1) { /* ifName too long. */ ifc_free_unit(ifc, unit); return (ENOSPC); } dp += error; } if (len - (dp - name) - 1 < 1) { /* No space left for our [ab] suffix. */ ifc_free_unit(ifc, unit); return (ENOSPC); } *dp = 'a'; /* Must not change dp so we can replace 'a' by 'b' later. */ *(dp+1) = '\0'; /* Allocate memory for both [ab] interfaces */ sca = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO); EPAIR_REFCOUNT_INIT(&sca->refcount, 1); sca->ifp = if_alloc(IFT_ETHER); if (sca->ifp == NULL) { free(sca, M_EPAIR); ifc_free_unit(ifc, unit); return (ENOSPC); } scb = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO); EPAIR_REFCOUNT_INIT(&scb->refcount, 1); scb->ifp = if_alloc(IFT_ETHER); if (scb->ifp == NULL) { free(scb, M_EPAIR); if_free(sca->ifp); free(sca, M_EPAIR); ifc_free_unit(ifc, unit); return (ENOSPC); } /* * Cross-reference the interfaces so we will be able to free both. */ sca->oifp = scb->ifp; scb->oifp = sca->ifp; /* * Calculate the cpuid for netisr queueing based on the * ifIndex of the interfaces. As long as we cannot configure * this or use cpuset information easily we cannot guarantee * cache locality but we can at least allow parallelism. */ sca->cpuid = netisr_get_cpuid(sca->ifp->if_index % netisr_get_cpucount()); scb->cpuid = netisr_get_cpuid(scb->ifp->if_index % netisr_get_cpucount()); /* Finish initialization of interface a. */ ifp = sca->ifp; ifp->if_softc = sca; strlcpy(ifp->if_xname, name, IFNAMSIZ); ifp->if_dname = ifc->ifc_name; ifp->if_dunit = unit; ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST; ifp->if_start = epair_start; ifp->if_ioctl = epair_ioctl; ifp->if_init = epair_init; ifp->if_snd.ifq_maxlen = ifqmaxlen; /* Assign a hopefully unique, locally administered etheraddr. */ eaddr[0] = 0x02; eaddr[3] = (ifp->if_index >> 8) & 0xff; eaddr[4] = ifp->if_index & 0xff; eaddr[5] = 0x0a; ether_ifattach(ifp, eaddr); sca->if_qflush = ifp->if_qflush; ifp->if_qflush = epair_qflush; ifp->if_transmit = epair_transmit; ifp->if_baudrate = IF_Gbps(10UL); /* arbitrary maximum */ /* Swap the name and finish initialization of interface b. */ *dp = 'b'; ifp = scb->ifp; ifp->if_softc = scb; strlcpy(ifp->if_xname, name, IFNAMSIZ); ifp->if_dname = ifc->ifc_name; ifp->if_dunit = unit; ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST; ifp->if_start = epair_start; ifp->if_ioctl = epair_ioctl; ifp->if_init = epair_init; ifp->if_snd.ifq_maxlen = ifqmaxlen; /* We need to play some tricks here for the second interface. */ strlcpy(name, EPAIRNAME, len); error = if_clone_create(name, len, (caddr_t)scb); if (error) panic("%s: if_clone_createif() for our 2nd iface failed: %d", __func__, error); scb->if_qflush = ifp->if_qflush; ifp->if_qflush = epair_qflush; ifp->if_transmit = epair_transmit; ifp->if_baudrate = IF_Gbps(10UL); /* arbitrary maximum */ /* * Restore name to a as the ifp for this will go into the * cloner list for the initial call. */ strlcpy(name, sca->ifp->if_xname, len); DPRINTF("name='%s/%db' created sca=%p scb=%p\n", name, unit, sca, scb); /* Tell the world, that we are ready to rock. */ sca->ifp->if_drv_flags |= IFF_DRV_RUNNING; scb->ifp->if_drv_flags |= IFF_DRV_RUNNING; if_link_state_change(sca->ifp, LINK_STATE_UP); if_link_state_change(scb->ifp, LINK_STATE_UP); return (0); } static int epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp) { struct ifnet *oifp; struct epair_softc *sca, *scb; int unit, error; DPRINTF("ifp=%p\n", ifp); /* * In case we called into if_clone_destroyif() ourselves * again to remove the second interface, the softc will be * NULL. In that case so not do anything but return success. */ if (ifp->if_softc == NULL) return (0); unit = ifp->if_dunit; sca = ifp->if_softc; oifp = sca->oifp; scb = oifp->if_softc; DPRINTF("ifp=%p oifp=%p\n", ifp, oifp); if_link_state_change(ifp, LINK_STATE_DOWN); if_link_state_change(oifp, LINK_STATE_DOWN); ifp->if_drv_flags &= ~IFF_DRV_RUNNING; oifp->if_drv_flags &= ~IFF_DRV_RUNNING; ether_ifdetach(oifp); ether_ifdetach(ifp); /* * Wait for all packets to be dispatched to if_input. * The numbers can only go down as the interfaces are * detached so there is no need to use atomics. */ DPRINTF("sca refcnt=%u scb refcnt=%u\n", sca->refcount, scb->refcount); EPAIR_REFCOUNT_ASSERT(sca->refcount == 1 && scb->refcount == 1, ("%s: ifp=%p sca->refcount!=1: %d || ifp=%p scb->refcount!=1: %d", __func__, ifp, sca->refcount, oifp, scb->refcount)); /* * Get rid of our second half. */ oifp->if_softc = NULL; error = if_clone_destroyif(ifc, oifp); if (error) panic("%s: if_clone_destroyif() for our 2nd iface failed: %d", __func__, error); /* * Finish cleaning up. Free them and release the unit. * As the other of the two interfaces my reside in a different vnet, * we need to switch before freeing them. */ CURVNET_SET_QUIET(oifp->if_vnet); if_free(oifp); CURVNET_RESTORE(); if_free(ifp); free(scb, M_EPAIR); free(sca, M_EPAIR); ifc_free_unit(ifc, unit); return (0); } static int epair_modevent(module_t mod, int type, void *data) { int qlimit; switch (type) { case MOD_LOAD: /* For now limit us to one global mutex and one inq. */ epair_dpcpu_init(); epair_nh.nh_qlimit = 42 * ifqmaxlen; /* 42 shall be the number. */ if (TUNABLE_INT_FETCH("net.link.epair.netisr_maxqlen", &qlimit)) epair_nh.nh_qlimit = qlimit; netisr_register(&epair_nh); if_clone_attach(&epair_cloner); if (bootverbose) printf("%s initialized.\n", EPAIRNAME); break; case MOD_UNLOAD: if_clone_detach(&epair_cloner); netisr_unregister(&epair_nh); epair_dpcpu_detach(); if (bootverbose) printf("%s unloaded.\n", EPAIRNAME); break; default: return (EOPNOTSUPP); } return (0); } static moduledata_t epair_mod = { "if_epair", epair_modevent, 0 }; DECLARE_MODULE(if_epair, epair_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); MODULE_VERSION(if_epair, 1);