diff --git a/sys/net/if_epair.c b/sys/net/if_epair.c index 89483db46337..d15939dfe48b 100644 --- a/sys/net/if_epair.c +++ b/sys/net/if_epair.c @@ -1,805 +1,806 @@ /*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 2008 The FreeBSD Foundation * Copyright (c) 2009-2021 Bjoern A. Zeeb * * 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. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include 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 *); static const char epairname[] = "epair"; #define RXRSIZE 4096 /* Probably overkill by 4-8x. */ static MALLOC_DEFINE(M_EPAIR, epairname, "Pair of virtual cross-over connected Ethernet-like interfaces"); VNET_DEFINE_STATIC(struct if_clone *, epair_cloner); #define V_epair_cloner VNET(epair_cloner) static unsigned int next_index = 0; #define EPAIR_LOCK_INIT() mtx_init(&epair_n_index_mtx, "epairidx", \ NULL, MTX_DEF) #define EPAIR_LOCK_DESTROY() mtx_destroy(&epair_n_index_mtx) #define EPAIR_LOCK() mtx_lock(&epair_n_index_mtx) #define EPAIR_UNLOCK() mtx_unlock(&epair_n_index_mtx) static void *swi_cookie[MAXCPU]; /* swi(9). */ static STAILQ_HEAD(, epair_softc) swi_sc[MAXCPU]; static struct mtx epair_n_index_mtx; struct epair_softc { struct ifnet *ifp; /* This ifp. */ struct ifnet *oifp; /* other ifp of pair. */ void *swi_cookie; /* swi(9). */ struct buf_ring *rxring[2]; volatile int ridx; /* 0 || 1 */ struct ifmedia media; /* Media config (fake). */ uint32_t cpuidx; STAILQ_ENTRY(epair_softc) entry; }; static void epair_clear_mbuf(struct mbuf *m) { /* Remove any CSUM_SND_TAG as ether_input will barf. */ if (m->m_pkthdr.csum_flags & CSUM_SND_TAG) { m_snd_tag_rele(m->m_pkthdr.snd_tag); m->m_pkthdr.snd_tag = NULL; m->m_pkthdr.csum_flags &= ~CSUM_SND_TAG; } m_tag_delete_nonpersistent(m); } static void epair_if_input(struct epair_softc *sc, int ridx) { struct epoch_tracker et; struct ifnet *ifp; struct mbuf *m; ifp = sc->ifp; NET_EPOCH_ENTER(et); do { m = buf_ring_dequeue_sc(sc->rxring[ridx]); if (m == NULL) break; MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0); (*ifp->if_input)(ifp, m); } while (1); NET_EPOCH_EXIT(et); } static void epair_sintr(struct epair_softc *sc) { int ridx, nidx; if_ref(sc->ifp); do { ridx = sc->ridx; nidx = (ridx == 0) ? 1 : 0; } while (!atomic_cmpset_int(&sc->ridx, ridx, nidx)); epair_if_input(sc, ridx); if_rele(sc->ifp); } static void epair_intr(void *arg) { struct epair_softc *sc; uint32_t cpuidx; cpuidx = (uintptr_t)arg; /* If this is a problem, this is a read-mostly situation. */ EPAIR_LOCK(); STAILQ_FOREACH(sc, &swi_sc[cpuidx], entry) { /* Do this lockless. */ if (buf_ring_empty(sc->rxring[sc->ridx])) continue; epair_sintr(sc); } EPAIR_UNLOCK(); return; } static int epair_menq(struct mbuf *m, struct epair_softc *osc) { struct ifnet *ifp, *oifp; int len, ret; int ridx; short mflags; bool was_empty; /* * I know this looks weird. We pass the "other sc" as we need that one * and can get both ifps from it as well. */ oifp = osc->ifp; ifp = osc->oifp; M_ASSERTPKTHDR(m); epair_clear_mbuf(m); if_setrcvif(m, oifp); M_SETFIB(m, oifp->if_fib); /* Save values as once the mbuf is queued, it's not ours anymore. */ len = m->m_pkthdr.len; mflags = m->m_flags; MPASS(m->m_nextpkt == NULL); MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0); ridx = atomic_load_int(&osc->ridx); was_empty = buf_ring_empty(osc->rxring[ridx]); ret = buf_ring_enqueue(osc->rxring[ridx], m); if (ret != 0) { /* Ring is full. */ m_freem(m); return (0); } if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); /* * IFQ_HANDOFF_ADJ/ip_handoff() update statistics, * but as we bypass all this we have to duplicate * the logic another time. */ if_inc_counter(ifp, IFCOUNTER_OBYTES, len); if (mflags & (M_BCAST|M_MCAST)) if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1); /* Someone else received the packet. */ if_inc_counter(oifp, IFCOUNTER_IPACKETS, 1); /* Kick the interrupt handler for the first packet. */ if (was_empty && osc->swi_cookie != NULL) swi_sched(osc->swi_cookie, 0); return (0); } static void epair_start(struct ifnet *ifp) { struct mbuf *m; struct epair_softc *sc; struct ifnet *oifp; /* * We get packets here from ether_output via if_handoff() * and need to put them into the input queue of the oifp * and will put the packet into the receive-queue (rxq) of the * other interface (oifp) of our pair. */ sc = ifp->if_softc; oifp = sc->oifp; sc = oifp->if_softc; for (;;) { IFQ_DEQUEUE(&ifp->if_snd, m); if (m == NULL) break; M_ASSERTPKTHDR(m); BPF_MTAP(ifp, m); /* In case either interface is not usable drop the packet. */ if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || (ifp->if_flags & IFF_UP) == 0 || (oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || (oifp->if_flags & IFF_UP) == 0) { m_freem(m); continue; } (void) epair_menq(m, sc); } } static int epair_transmit(struct ifnet *ifp, struct mbuf *m) { struct epair_softc *sc; struct ifnet *oifp; int error, len; short mflags; if (m == NULL) return (0); M_ASSERTPKTHDR(m); /* * 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 receive-queue (rxq) of the * other interface (oifp) of our pair. */ if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { m_freem(m); if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); return (ENXIO); } if ((ifp->if_flags & IFF_UP) == 0) { m_freem(m); if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); return (ENETDOWN); } BPF_MTAP(ifp, m); /* * In case the outgoing interface is not usable, * drop the packet. */ sc = ifp->if_softc; oifp = sc->oifp; if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || (oifp->if_flags & IFF_UP) == 0) { if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); m_freem(m); return (0); } len = m->m_pkthdr.len; mflags = m->m_flags; #ifdef ALTQ /* Support ALTQ via the classic 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) if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1); IF_UNLOCK(&ifp->if_snd); if (!error) { if_inc_counter(ifp, IFCOUNTER_OBYTES, len); if (mflags & (M_BCAST|M_MCAST)) if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1); epair_start(ifp); } return (error); } IF_UNLOCK(&ifp->if_snd); #endif error = epair_menq(m, oifp->if_softc); return (error); } static int epair_media_change(struct ifnet *ifp __unused) { /* Do nothing. */ return (0); } static void epair_media_status(struct ifnet *ifp __unused, struct ifmediareq *imr) { imr->ifm_status = IFM_AVALID | IFM_ACTIVE; imr->ifm_active = IFM_ETHER | IFM_10G_T | IFM_FDX; } static int epair_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) { struct epair_softc *sc; struct ifreq *ifr; int error; ifr = (struct ifreq *)data; switch (cmd) { case SIOCSIFFLAGS: case SIOCADDMULTI: case SIOCDELMULTI: error = 0; break; case SIOCSIFMEDIA: case SIOCGIFMEDIA: sc = ifp->if_softc; error = ifmedia_ioctl(ifp, ifr, &sc->media, cmd); 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; /* * 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 void epair_clone_add(struct if_clone *ifc, struct epair_softc *scb) { struct ifnet *ifp; uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */ ifp = scb->ifp; /* Copy epairNa etheraddr and change the last byte. */ memcpy(eaddr, scb->oifp->if_hw_addr, ETHER_ADDR_LEN); eaddr[5] = 0x0b; ether_ifattach(ifp, eaddr); if_clone_addif(ifc, ifp); } 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; uint64_t hostid; uint32_t key[3]; uint32_t hash; uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */ /* 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 = 'b'; /* Must not change dp so we can replace 'a' by 'b' later. */ *(dp+1) = '\0'; /* Check if 'a' and 'b' interfaces already exist. */ if (ifunit(name) != NULL) return (EEXIST); *dp = 'a'; if (ifunit(name) != NULL) return (EEXIST); /* Allocate memory for both [ab] interfaces */ sca = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO); sca->ifp = if_alloc(IFT_ETHER); if (sca->ifp == NULL) { free(sca, M_EPAIR); ifc_free_unit(ifc, unit); return (ENOSPC); } sca->rxring[0] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK,NULL); sca->rxring[1] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK, NULL); scb = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO); 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); } scb->rxring[0] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK, NULL); scb->rxring[1] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK, NULL); /* * Cross-reference the interfaces so we will be able to free both. */ sca->oifp = scb->ifp; scb->oifp = sca->ifp; EPAIR_LOCK(); #ifdef SMP /* Get an approximate distribution. */ hash = next_index % mp_ncpus; #else hash = 0; #endif if (swi_cookie[hash] == NULL) { void *cookie; EPAIR_UNLOCK(); error = swi_add(NULL, epairname, epair_intr, (void *)(uintptr_t)hash, SWI_NET, INTR_MPSAFE, &cookie); if (error) { buf_ring_free(scb->rxring[0], M_EPAIR); buf_ring_free(scb->rxring[1], M_EPAIR); if_free(scb->ifp); free(scb, M_EPAIR); buf_ring_free(sca->rxring[0], M_EPAIR); buf_ring_free(sca->rxring[1], M_EPAIR); if_free(sca->ifp); free(sca, M_EPAIR); ifc_free_unit(ifc, unit); return (ENOSPC); } EPAIR_LOCK(); /* Recheck under lock even though a race is very unlikely. */ if (swi_cookie[hash] == NULL) { swi_cookie[hash] = cookie; } else { EPAIR_UNLOCK(); (void) swi_remove(cookie); EPAIR_LOCK(); } } sca->cpuidx = hash; STAILQ_INSERT_TAIL(&swi_sc[hash], sca, entry); sca->swi_cookie = swi_cookie[hash]; scb->cpuidx = hash; STAILQ_INSERT_TAIL(&swi_sc[hash], scb, entry); scb->swi_cookie = swi_cookie[hash]; EPAIR_UNLOCK(); /* Initialise pseudo media types. */ ifmedia_init(&sca->media, 0, epair_media_change, epair_media_status); ifmedia_add(&sca->media, IFM_ETHER | IFM_10G_T, 0, NULL); ifmedia_set(&sca->media, IFM_ETHER | IFM_10G_T); ifmedia_init(&scb->media, 0, epair_media_change, epair_media_status); ifmedia_add(&scb->media, IFM_ETHER | IFM_10G_T, 0, NULL); ifmedia_set(&scb->media, IFM_ETHER | IFM_10G_T); /* Finish initialization of interface a. */ ifp = sca->ifp; ifp->if_softc = sca; strlcpy(ifp->if_xname, name, IFNAMSIZ); ifp->if_dname = epairname; ifp->if_dunit = unit; ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST; ifp->if_flags |= IFF_KNOWSEPOCH; ifp->if_capabilities = IFCAP_VLAN_MTU; ifp->if_capenable = IFCAP_VLAN_MTU; ifp->if_start = epair_start; ifp->if_ioctl = epair_ioctl; ifp->if_init = epair_init; if_setsendqlen(ifp, ifqmaxlen); if_setsendqready(ifp); /* * Calculate the etheraddr hashing the hostid and the * interface index. The result would be hopefully unique. * Note that the "a" component of an epair instance may get moved * to a different VNET after creation. In that case its index * will be freed and the index can get reused by new epair instance. * Make sure we do not create same etheraddr again. */ getcredhostid(curthread->td_ucred, (unsigned long *)&hostid); if (hostid == 0) arc4rand(&hostid, sizeof(hostid), 0); EPAIR_LOCK(); if (ifp->if_index > next_index) next_index = ifp->if_index; else next_index++; key[0] = (uint32_t)next_index; EPAIR_UNLOCK(); key[1] = (uint32_t)(hostid & 0xffffffff); key[2] = (uint32_t)((hostid >> 32) & 0xfffffffff); hash = jenkins_hash32(key, 3, 0); eaddr[0] = 0x02; memcpy(&eaddr[1], &hash, 4); eaddr[5] = 0x0a; ether_ifattach(ifp, eaddr); ifp->if_baudrate = IF_Gbps(10); /* arbitrary maximum */ ifp->if_transmit = epair_transmit; /* 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 = epairname; ifp->if_dunit = unit; ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST; + ifp->if_flags |= IFF_KNOWSEPOCH; ifp->if_capabilities = IFCAP_VLAN_MTU; ifp->if_capenable = IFCAP_VLAN_MTU; ifp->if_start = epair_start; ifp->if_ioctl = epair_ioctl; ifp->if_init = epair_init; if_setsendqlen(ifp, ifqmaxlen); if_setsendqready(ifp); /* We need to play some tricks here for the second interface. */ strlcpy(name, epairname, len); /* Correctly set the name for the cloner list. */ strlcpy(name, scb->ifp->if_xname, len); epair_clone_add(ifc, scb); ifp->if_baudrate = IF_Gbps(10); /* arbitrary maximum */ ifp->if_transmit = epair_transmit; /* * 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); /* Tell the world, that we are ready to rock. */ sca->ifp->if_drv_flags |= IFF_DRV_RUNNING; if_link_state_change(sca->ifp, LINK_STATE_UP); scb->ifp->if_drv_flags |= IFF_DRV_RUNNING; if_link_state_change(scb->ifp, LINK_STATE_UP); return (0); } static void epair_drain_rings(struct epair_softc *sc) { int ridx; struct mbuf *m; for (ridx = 0; ridx < 2; ridx++) { do { m = buf_ring_dequeue_sc(sc->rxring[ridx]); if (m == NULL) break; m_freem(m); } while (1); } } static int epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp) { struct ifnet *oifp; struct epair_softc *sca, *scb; int unit, error; /* * 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; /* Frist get the interfaces down and detached. */ if_link_state_change(ifp, LINK_STATE_DOWN); ifp->if_drv_flags &= ~IFF_DRV_RUNNING; if_link_state_change(oifp, LINK_STATE_DOWN); oifp->if_drv_flags &= ~IFF_DRV_RUNNING; ether_ifdetach(ifp); ether_ifdetach(oifp); /* Second stop interrupt handler. */ EPAIR_LOCK(); STAILQ_REMOVE(&swi_sc[sca->cpuidx], sca, epair_softc, entry); STAILQ_REMOVE(&swi_sc[scb->cpuidx], scb, epair_softc, entry); EPAIR_UNLOCK(); sca->swi_cookie = NULL; scb->swi_cookie = NULL; /* Third free any queued packets and all the resources. */ CURVNET_SET_QUIET(oifp->if_vnet); epair_drain_rings(scb); 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); if_free(oifp); ifmedia_removeall(&scb->media); buf_ring_free(scb->rxring[0], M_EPAIR); buf_ring_free(scb->rxring[1], M_EPAIR); free(scb, M_EPAIR); CURVNET_RESTORE(); epair_drain_rings(sca); if_free(ifp); ifmedia_removeall(&sca->media); buf_ring_free(sca->rxring[0], M_EPAIR); buf_ring_free(sca->rxring[1], M_EPAIR); free(sca, M_EPAIR); /* Last free the cloner unit. */ ifc_free_unit(ifc, unit); return (0); } static void vnet_epair_init(const void *unused __unused) { V_epair_cloner = if_clone_advanced(epairname, 0, epair_clone_match, epair_clone_create, epair_clone_destroy); } VNET_SYSINIT(vnet_epair_init, SI_SUB_PSEUDO, SI_ORDER_ANY, vnet_epair_init, NULL); static void vnet_epair_uninit(const void *unused __unused) { if_clone_detach(V_epair_cloner); } VNET_SYSUNINIT(vnet_epair_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY, vnet_epair_uninit, NULL); static int epair_modevent(module_t mod, int type, void *data) { int i; switch (type) { case MOD_LOAD: for (i = 0; i < MAXCPU; i++) { swi_cookie[i] = NULL; STAILQ_INIT(&swi_sc[i]); } EPAIR_LOCK_INIT(); if (bootverbose) printf("%s: %s initialized.\n", __func__, epairname); break; case MOD_UNLOAD: EPAIR_LOCK(); for (i = 0; i < MAXCPU; i++) { if (!STAILQ_EMPTY(&swi_sc[i])) { printf("%s: swi_sc[%d] active\n", __func__, i); EPAIR_UNLOCK(); return (EBUSY); } } EPAIR_UNLOCK(); for (i = 0; i < MAXCPU; i++) if (swi_cookie[i] != NULL) (void) swi_remove(swi_cookie[i]); EPAIR_LOCK_DESTROY(); if (bootverbose) printf("%s: %s unloaded.\n", __func__, 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_MIDDLE); MODULE_VERSION(if_epair, 3);