2 * Copyright (c) 2008 The FreeBSD Foundation
3 * Copyright (c) 2009-2010 Bjoern A. Zeeb <bz@FreeBSD.org>
6 * This software was developed by CK Software GmbH under sponsorship
7 * from the FreeBSD Foundation.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * A pair of virtual back-to-back connected ethernet like interfaces
33 * (``two interfaces with a virtual cross-over cable'').
35 * This is mostly intended to be used to provide connectivity between
36 * different virtual network stack instances.
39 * Things to re-think once we have more experience:
40 * - ifp->if_reassign function once we can test with vimage. Depending on
41 * how if_vmove() is going to be improved.
42 * - Real random etheraddrs that are checked to be uniquish; we would need
43 * to re-do them in case we move the interface between network stacks
44 * in a private if_reassign function.
45 * In case we bridge to a real interface/network or between indepedent
46 * epairs on multiple stacks/machines, we may need this.
47 * For now let the user handle that case.
50 #include <sys/cdefs.h>
51 __FBSDID("$FreeBSD$");
53 #include <sys/param.h>
54 #include <sys/kernel.h>
56 #include <sys/module.h>
57 #include <sys/refcount.h>
58 #include <sys/queue.h>
60 #include <sys/socket.h>
61 #include <sys/sockio.h>
62 #include <sys/sysctl.h>
63 #include <sys/types.h>
66 #include <net/ethernet.h>
68 #include <net/if_clone.h>
69 #include <net/if_var.h>
70 #include <net/if_types.h>
71 #include <net/netisr.h>
74 #define EPAIRNAME "epair"
76 SYSCTL_DECL(_net_link);
77 SYSCTL_NODE(_net_link, OID_AUTO, epair, CTLFLAG_RW, 0, "epair sysctl");
80 static int epair_debug = 0;
81 SYSCTL_INT(_net_link_epair, OID_AUTO, epair_debug, CTLFLAG_RW,
82 &epair_debug, 0, "if_epair(4) debugging.");
83 #define DPRINTF(fmt, arg...) \
85 printf("[%s:%d] " fmt, __func__, __LINE__, ##arg)
87 #define DPRINTF(fmt, arg...)
90 static void epair_nh_sintr(struct mbuf *);
91 static struct mbuf *epair_nh_m2cpuid(struct mbuf *, uintptr_t, u_int *);
92 static void epair_nh_drainedcpu(u_int);
94 static void epair_start_locked(struct ifnet *);
96 static int epair_clone_match(struct if_clone *, const char *);
97 static int epair_clone_create(struct if_clone *, char *, size_t, caddr_t);
98 static int epair_clone_destroy(struct if_clone *, struct ifnet *);
100 /* Netisr realted definitions and sysctl. */
101 static struct netisr_handler epair_nh = {
102 .nh_name = EPAIRNAME,
103 .nh_proto = NETISR_EPAIR,
104 .nh_policy = NETISR_POLICY_CPU,
105 .nh_handler = epair_nh_sintr,
106 .nh_m2cpuid = epair_nh_m2cpuid,
107 .nh_drainedcpu = epair_nh_drainedcpu,
111 sysctl_epair_netisr_maxqlen(SYSCTL_HANDLER_ARGS)
115 netisr_getqlimit(&epair_nh, &qlimit);
116 error = sysctl_handle_int(oidp, &qlimit, 0, req);
117 if (error || !req->newptr)
121 return (netisr_setqlimit(&epair_nh, qlimit));
123 SYSCTL_PROC(_net_link_epair, OID_AUTO, netisr_maxqlen, CTLTYPE_INT|CTLFLAG_RW,
124 0, 0, sysctl_epair_netisr_maxqlen, "I",
125 "Maximum if_epair(4) netisr \"hw\" queue length");
128 struct ifnet *ifp; /* This ifp. */
129 struct ifnet *oifp; /* other ifp of pair. */
130 u_int refcount; /* # of mbufs in flight. */
131 u_int cpuid; /* CPU ID assigned upon creation. */
132 void (*if_qflush)(struct ifnet *);
133 /* Original if_qflush routine. */
137 * Per-CPU list of ifps with data in the ifq that needs to be flushed
138 * to the netisr ``hw'' queue before we allow any further direct queuing
139 * to the ``hw'' queue.
141 struct epair_ifp_drain {
142 STAILQ_ENTRY(epair_ifp_drain) ifp_next;
145 STAILQ_HEAD(eid_list, epair_ifp_drain);
147 #define EPAIR_LOCK_INIT(dpcpu) mtx_init(&(dpcpu)->if_epair_mtx, \
148 "if_epair", NULL, MTX_DEF)
149 #define EPAIR_LOCK_DESTROY(dpcpu) mtx_destroy(&(dpcpu)->if_epair_mtx)
150 #define EPAIR_LOCK_ASSERT(dpcpu) mtx_assert(&(dpcpu)->if_epair_mtx, \
152 #define EPAIR_LOCK(dpcpu) mtx_lock(&(dpcpu)->if_epair_mtx)
153 #define EPAIR_UNLOCK(dpcpu) mtx_unlock(&(dpcpu)->if_epair_mtx)
156 #define EPAIR_REFCOUNT_INIT(r, v) refcount_init((r), (v))
157 #define EPAIR_REFCOUNT_AQUIRE(r) refcount_acquire((r))
158 #define EPAIR_REFCOUNT_RELEASE(r) refcount_release((r))
159 #define EPAIR_REFCOUNT_ASSERT(a, p) KASSERT(a, p)
161 #define EPAIR_REFCOUNT_INIT(r, v)
162 #define EPAIR_REFCOUNT_AQUIRE(r)
163 #define EPAIR_REFCOUNT_RELEASE(r)
164 #define EPAIR_REFCOUNT_ASSERT(a, p)
167 static MALLOC_DEFINE(M_EPAIR, EPAIRNAME,
168 "Pair of virtual cross-over connected Ethernet-like interfaces");
170 static struct if_clone epair_cloner = IFC_CLONE_INITIALIZER(
171 EPAIRNAME, NULL, IF_MAXUNIT,
172 NULL, epair_clone_match, epair_clone_create, epair_clone_destroy);
175 * DPCPU area and functions.
178 struct mtx if_epair_mtx; /* Per-CPU locking. */
179 int epair_drv_flags; /* Per-CPU ``hw'' drv flags. */
180 struct eid_list epair_ifp_drain_list; /* Per-CPU list of ifps with
181 * data in the ifq. */
183 DPCPU_DEFINE(struct epair_dpcpu, epair_dpcpu);
186 epair_dpcpu_init(void)
188 struct epair_dpcpu *epair_dpcpu;
193 epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
195 /* Initialize per-cpu lock. */
196 EPAIR_LOCK_INIT(epair_dpcpu);
198 /* Driver flags are per-cpu as are our netisr "hw" queues. */
199 epair_dpcpu->epair_drv_flags = 0;
202 * Initialize per-cpu drain list.
203 * Manually do what STAILQ_HEAD_INITIALIZER would do.
205 s = &epair_dpcpu->epair_ifp_drain_list;
206 s->stqh_first = NULL;
207 s->stqh_last = &s->stqh_first;
212 epair_dpcpu_detach(void)
214 struct epair_dpcpu *epair_dpcpu;
218 epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
220 /* Destroy per-cpu lock. */
221 EPAIR_LOCK_DESTROY(epair_dpcpu);
229 cpuid_from_ifp(struct ifnet *ifp)
231 struct epair_softc *sc;
241 * Netisr handler functions.
244 epair_nh_sintr(struct mbuf *m)
247 struct epair_softc *sc;
249 ifp = m->m_pkthdr.rcvif;
250 (*ifp->if_input)(ifp, m);
252 EPAIR_REFCOUNT_RELEASE(&sc->refcount);
253 EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
254 ("%s: ifp=%p sc->refcount not >= 1: %d",
255 __func__, ifp, sc->refcount));
256 DPRINTF("ifp=%p refcount=%u\n", ifp, sc->refcount);
260 epair_nh_m2cpuid(struct mbuf *m, uintptr_t source, u_int *cpuid)
263 *cpuid = cpuid_from_ifp(m->m_pkthdr.rcvif);
269 epair_nh_drainedcpu(u_int cpuid)
271 struct epair_dpcpu *epair_dpcpu;
272 struct epair_ifp_drain *elm, *tvar;
275 epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
276 EPAIR_LOCK(epair_dpcpu);
278 * Assume our "hw" queue and possibly ifq will be emptied
279 * again. In case we will overflow the "hw" queue while
280 * draining, epair_start_locked will set IFF_DRV_OACTIVE
281 * again and we will stop and return.
283 STAILQ_FOREACH_SAFE(elm, &epair_dpcpu->epair_ifp_drain_list,
286 epair_dpcpu->epair_drv_flags &= ~IFF_DRV_OACTIVE;
287 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
288 epair_start_locked(ifp);
290 IFQ_LOCK(&ifp->if_snd);
291 if (IFQ_IS_EMPTY(&ifp->if_snd)) {
292 struct epair_softc *sc;
294 STAILQ_REMOVE(&epair_dpcpu->epair_ifp_drain_list,
295 elm, epair_ifp_drain, ifp_next);
296 /* The cached ifp goes off the list. */
298 EPAIR_REFCOUNT_RELEASE(&sc->refcount);
299 EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
300 ("%s: ifp=%p sc->refcount not >= 1: %d",
301 __func__, ifp, sc->refcount));
304 IFQ_UNLOCK(&ifp->if_snd);
306 if ((ifp->if_drv_flags & IFF_DRV_OACTIVE) != 0) {
307 /* Our "hw"q overflew again. */
308 epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE;
309 DPRINTF("hw queue length overflow at %u\n",
314 EPAIR_UNLOCK(epair_dpcpu);
318 * Network interface (`if') related functions.
321 epair_remove_ifp_from_draining(struct ifnet *ifp)
323 struct epair_dpcpu *epair_dpcpu;
324 struct epair_ifp_drain *elm, *tvar;
328 epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
329 EPAIR_LOCK(epair_dpcpu);
330 STAILQ_FOREACH_SAFE(elm, &epair_dpcpu->epair_ifp_drain_list,
332 if (ifp == elm->ifp) {
333 struct epair_softc *sc;
336 &epair_dpcpu->epair_ifp_drain_list, elm,
337 epair_ifp_drain, ifp_next);
338 /* The cached ifp goes off the list. */
340 EPAIR_REFCOUNT_RELEASE(&sc->refcount);
341 EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
342 ("%s: ifp=%p sc->refcount not >= 1: %d",
343 __func__, ifp, sc->refcount));
347 EPAIR_UNLOCK(epair_dpcpu);
352 epair_add_ifp_for_draining(struct ifnet *ifp)
354 struct epair_dpcpu *epair_dpcpu;
355 struct epair_softc *sc;
356 struct epair_ifp_drain *elm = NULL;
359 epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
360 EPAIR_LOCK_ASSERT(epair_dpcpu);
361 STAILQ_FOREACH(elm, &epair_dpcpu->epair_ifp_drain_list, ifp_next)
364 /* If the ifp is there already, return success. */
368 elm = malloc(sizeof(struct epair_ifp_drain), M_EPAIR, M_NOWAIT|M_ZERO);
373 /* Add a reference for the ifp pointer on the list. */
374 EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
375 STAILQ_INSERT_TAIL(&epair_dpcpu->epair_ifp_drain_list, elm, ifp_next);
381 epair_start_locked(struct ifnet *ifp)
383 struct epair_dpcpu *epair_dpcpu;
385 struct epair_softc *sc;
389 DPRINTF("ifp=%p\n", ifp);
391 epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
392 EPAIR_LOCK_ASSERT(epair_dpcpu);
394 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
396 if ((ifp->if_flags & IFF_UP) == 0)
400 * We get patckets here from ether_output via if_handoff()
401 * and ned to put them into the input queue of the oifp
402 * and call oifp->if_input() via netisr/epair_sintr().
407 IFQ_DEQUEUE(&ifp->if_snd, m);
413 * In case the outgoing interface is not usable,
416 if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
417 (oifp->if_flags & IFF_UP) ==0) {
422 DPRINTF("packet %s -> %s\n", ifp->if_xname, oifp->if_xname);
425 * Add a reference so the interface cannot go while the
426 * packet is in transit as we rely on rcvif to stay valid.
428 EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
429 m->m_pkthdr.rcvif = oifp;
430 CURVNET_SET_QUIET(oifp->if_vnet);
431 error = netisr_queue(NETISR_EPAIR, m);
435 /* Someone else received the packet. */
438 /* The packet was freed already. */
439 epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE;
440 ifp->if_drv_flags |= IFF_DRV_OACTIVE;
441 (void) epair_add_ifp_for_draining(ifp);
443 EPAIR_REFCOUNT_RELEASE(&sc->refcount);
444 EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
445 ("%s: ifp=%p sc->refcount not >= 1: %d",
446 __func__, oifp, sc->refcount));
452 epair_start(struct ifnet *ifp)
454 struct epair_dpcpu *epair_dpcpu;
456 epair_dpcpu = DPCPU_ID_PTR(cpuid_from_ifp(ifp), epair_dpcpu);
457 EPAIR_LOCK(epair_dpcpu);
458 epair_start_locked(ifp);
459 EPAIR_UNLOCK(epair_dpcpu);
463 epair_transmit_locked(struct ifnet *ifp, struct mbuf *m)
465 struct epair_dpcpu *epair_dpcpu;
466 struct epair_softc *sc;
471 DPRINTF("ifp=%p m=%p\n", ifp, m);
473 epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
474 EPAIR_LOCK_ASSERT(epair_dpcpu);
480 * We are not going to use the interface en/dequeue mechanism
481 * on the TX side. We are called from ether_output_frame()
482 * and will put the packet into the incoming queue of the
483 * other interface of our pair via the netsir.
485 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
489 if ((ifp->if_flags & IFF_UP) == 0) {
497 * In case the outgoing interface is not usable,
501 if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
502 (oifp->if_flags & IFF_UP) ==0) {
507 len = m->m_pkthdr.len;
509 DPRINTF("packet %s -> %s\n", ifp->if_xname, oifp->if_xname);
512 /* Support ALTQ via the clasic if_start() path. */
513 IF_LOCK(&ifp->if_snd);
514 if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
515 ALTQ_ENQUEUE(&ifp->if_snd, m, NULL, error);
517 ifp->if_snd.ifq_drops++;
518 IF_UNLOCK(&ifp->if_snd);
520 ifp->if_obytes += len;
521 if (mflags & (M_BCAST|M_MCAST))
524 if ((ifp->if_drv_flags & IFF_DRV_OACTIVE) == 0)
525 epair_start_locked(ifp);
527 (void)epair_add_ifp_for_draining(ifp);
531 IF_UNLOCK(&ifp->if_snd);
534 if ((epair_dpcpu->epair_drv_flags & IFF_DRV_OACTIVE) != 0) {
536 * Our hardware queue is full, try to fall back
537 * queuing to the ifq but do not call ifp->if_start.
538 * Either we are lucky or the packet is gone.
540 IFQ_ENQUEUE(&ifp->if_snd, m, error);
542 (void)epair_add_ifp_for_draining(ifp);
547 * Add a reference so the interface cannot go while the
548 * packet is in transit as we rely on rcvif to stay valid.
550 EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
551 m->m_pkthdr.rcvif = oifp;
552 CURVNET_SET_QUIET(oifp->if_vnet);
553 error = netisr_queue(NETISR_EPAIR, m);
558 * IFQ_HANDOFF_ADJ/ip_handoff() update statistics,
559 * but as we bypass all this we have to duplicate
560 * the logic another time.
562 ifp->if_obytes += len;
563 if (mflags & (M_BCAST|M_MCAST))
565 /* Someone else received the packet. */
568 /* The packet was freed already. */
569 epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE;
570 ifp->if_drv_flags |= IFF_DRV_OACTIVE;
572 EPAIR_REFCOUNT_RELEASE(&sc->refcount);
573 EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
574 ("%s: ifp=%p sc->refcount not >= 1: %d",
575 __func__, oifp, sc->refcount));
582 epair_transmit(struct ifnet *ifp, struct mbuf *m)
584 struct epair_dpcpu *epair_dpcpu;
587 epair_dpcpu = DPCPU_ID_PTR(cpuid_from_ifp(ifp), epair_dpcpu);
588 EPAIR_LOCK(epair_dpcpu);
589 error = epair_transmit_locked(ifp, m);
590 EPAIR_UNLOCK(epair_dpcpu);
595 epair_qflush(struct ifnet *ifp)
597 struct epair_softc *sc;
600 KASSERT(sc != NULL, ("%s: ifp=%p, epair_softc gone? sc=%p\n",
603 * Remove this ifp from all backpointer lists. The interface will not
604 * usable for flushing anyway nor should it have anything to flush
607 epair_remove_ifp_from_draining(ifp);
614 epair_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
619 ifr = (struct ifreq *)data;
628 /* We basically allow all kinds of MTUs. */
629 ifp->if_mtu = ifr->ifr_mtu;
634 /* Let the common ethernet handler process this. */
635 error = ether_ioctl(ifp, cmd, data);
643 epair_init(void *dummy __unused)
649 * Interface cloning functions.
650 * We use our private ones so that we can create/destroy our secondary
651 * device along with the primary one.
654 epair_clone_match(struct if_clone *ifc, const char *name)
658 DPRINTF("name='%s'\n", name);
661 * Our base name is epair.
662 * Our interfaces will be named epair<n>[ab].
663 * So accept anything of the following list:
666 * but not the epair<n>[ab] versions.
668 if (strncmp(EPAIRNAME, name, sizeof(EPAIRNAME)-1) != 0)
671 for (cp = name + sizeof(EPAIRNAME) - 1; *cp != '\0'; cp++) {
672 if (*cp < '0' || *cp > '9')
680 epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
682 struct epair_softc *sca, *scb;
685 int error, unit, wildcard;
686 uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */
689 * We are abusing params to create our second interface.
690 * Actually we already created it and called if_clone_createif()
691 * for it to do the official insertion procedure the moment we knew
692 * it cannot fail anymore. So just do attach it here.
695 scb = (struct epair_softc *)params;
697 /* Assign a hopefully unique, locally administered etheraddr. */
699 eaddr[3] = (ifp->if_index >> 8) & 0xff;
700 eaddr[4] = ifp->if_index & 0xff;
702 ether_ifattach(ifp, eaddr);
703 /* Correctly set the name for the cloner list. */
704 strlcpy(name, scb->ifp->if_xname, len);
708 /* Try to see if a special unit was requested. */
709 error = ifc_name2unit(name, &unit);
712 wildcard = (unit < 0);
714 error = ifc_alloc_unit(ifc, &unit);
719 * If no unit had been given, we need to adjust the ifName.
720 * Also make sure there is space for our extra [ab] suffix.
722 for (dp = name; *dp != '\0'; dp++);
724 error = snprintf(dp, len - (dp - name), "%d", unit);
725 if (error > len - (dp - name) - 1) {
726 /* ifName too long. */
727 ifc_free_unit(ifc, unit);
732 if (len - (dp - name) - 1 < 1) {
733 /* No space left for our [ab] suffix. */
734 ifc_free_unit(ifc, unit);
738 /* Must not change dp so we can replace 'a' by 'b' later. */
741 /* Allocate memory for both [ab] interfaces */
742 sca = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO);
743 EPAIR_REFCOUNT_INIT(&sca->refcount, 1);
744 sca->ifp = if_alloc(IFT_ETHER);
745 if (sca->ifp == NULL) {
747 ifc_free_unit(ifc, unit);
751 scb = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO);
752 EPAIR_REFCOUNT_INIT(&scb->refcount, 1);
753 scb->ifp = if_alloc(IFT_ETHER);
754 if (scb->ifp == NULL) {
758 ifc_free_unit(ifc, unit);
763 * Cross-reference the interfaces so we will be able to free both.
765 sca->oifp = scb->ifp;
766 scb->oifp = sca->ifp;
769 * Calculate the cpuid for netisr queueing based on the
770 * ifIndex of the interfaces. As long as we cannot configure
771 * this or use cpuset information easily we cannot guarantee
772 * cache locality but we can at least allow parallelism.
775 netisr_get_cpuid(sca->ifp->if_index % netisr_get_cpucount());
777 netisr_get_cpuid(scb->ifp->if_index % netisr_get_cpucount());
779 /* Finish initialization of interface <n>a. */
782 strlcpy(ifp->if_xname, name, IFNAMSIZ);
783 ifp->if_dname = ifc->ifc_name;
784 ifp->if_dunit = unit;
785 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
786 ifp->if_start = epair_start;
787 ifp->if_ioctl = epair_ioctl;
788 ifp->if_init = epair_init;
789 ifp->if_snd.ifq_maxlen = ifqmaxlen;
790 /* Assign a hopefully unique, locally administered etheraddr. */
792 eaddr[3] = (ifp->if_index >> 8) & 0xff;
793 eaddr[4] = ifp->if_index & 0xff;
795 ether_ifattach(ifp, eaddr);
796 sca->if_qflush = ifp->if_qflush;
797 ifp->if_qflush = epair_qflush;
798 ifp->if_transmit = epair_transmit;
799 ifp->if_baudrate = IF_Gbps(10UL); /* arbitrary maximum */
801 /* Swap the name and finish initialization of interface <n>b. */
806 strlcpy(ifp->if_xname, name, IFNAMSIZ);
807 ifp->if_dname = ifc->ifc_name;
808 ifp->if_dunit = unit;
809 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
810 ifp->if_start = epair_start;
811 ifp->if_ioctl = epair_ioctl;
812 ifp->if_init = epair_init;
813 ifp->if_snd.ifq_maxlen = ifqmaxlen;
814 /* We need to play some tricks here for the second interface. */
815 strlcpy(name, EPAIRNAME, len);
816 error = if_clone_create(name, len, (caddr_t)scb);
818 panic("%s: if_clone_createif() for our 2nd iface failed: %d",
820 scb->if_qflush = ifp->if_qflush;
821 ifp->if_qflush = epair_qflush;
822 ifp->if_transmit = epair_transmit;
823 ifp->if_baudrate = IF_Gbps(10UL); /* arbitrary maximum */
826 * Restore name to <n>a as the ifp for this will go into the
827 * cloner list for the initial call.
829 strlcpy(name, sca->ifp->if_xname, len);
830 DPRINTF("name='%s/%db' created sca=%p scb=%p\n", name, unit, sca, scb);
832 /* Tell the world, that we are ready to rock. */
833 sca->ifp->if_drv_flags |= IFF_DRV_RUNNING;
834 scb->ifp->if_drv_flags |= IFF_DRV_RUNNING;
835 if_link_state_change(sca->ifp, LINK_STATE_UP);
836 if_link_state_change(scb->ifp, LINK_STATE_UP);
842 epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
845 struct epair_softc *sca, *scb;
848 DPRINTF("ifp=%p\n", ifp);
851 * In case we called into if_clone_destroyif() ourselves
852 * again to remove the second interface, the softc will be
853 * NULL. In that case so not do anything but return success.
855 if (ifp->if_softc == NULL)
858 unit = ifp->if_dunit;
861 scb = oifp->if_softc;
863 DPRINTF("ifp=%p oifp=%p\n", ifp, oifp);
864 if_link_state_change(ifp, LINK_STATE_DOWN);
865 if_link_state_change(oifp, LINK_STATE_DOWN);
866 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
867 oifp->if_drv_flags &= ~IFF_DRV_RUNNING;
868 ether_ifdetach(oifp);
871 * Wait for all packets to be dispatched to if_input.
872 * The numbers can only go down as the interfaces are
873 * detached so there is no need to use atomics.
875 DPRINTF("sca refcnt=%u scb refcnt=%u\n", sca->refcount, scb->refcount);
876 EPAIR_REFCOUNT_ASSERT(sca->refcount == 1 && scb->refcount == 1,
877 ("%s: ifp=%p sca->refcount!=1: %d || ifp=%p scb->refcount!=1: %d",
878 __func__, ifp, sca->refcount, oifp, scb->refcount));
881 * Get rid of our second half.
883 oifp->if_softc = NULL;
884 error = if_clone_destroyif(ifc, oifp);
886 panic("%s: if_clone_destroyif() for our 2nd iface failed: %d",
890 * Finish cleaning up. Free them and release the unit.
891 * As the other of the two interfaces my reside in a different vnet,
892 * we need to switch before freeing them.
894 CURVNET_SET_QUIET(oifp->if_vnet);
900 ifc_free_unit(ifc, unit);
906 epair_modevent(module_t mod, int type, void *data)
912 /* For now limit us to one global mutex and one inq. */
914 epair_nh.nh_qlimit = 42 * ifqmaxlen; /* 42 shall be the number. */
915 if (TUNABLE_INT_FETCH("net.link.epair.netisr_maxqlen", &qlimit))
916 epair_nh.nh_qlimit = qlimit;
917 netisr_register(&epair_nh);
918 if_clone_attach(&epair_cloner);
920 printf("%s initialized.\n", EPAIRNAME);
923 if_clone_detach(&epair_cloner);
924 netisr_unregister(&epair_nh);
925 epair_dpcpu_detach();
927 printf("%s unloaded.\n", EPAIRNAME);
935 static moduledata_t epair_mod = {
941 DECLARE_MODULE(if_epair, epair_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
942 MODULE_VERSION(if_epair, 1);