FreeBSD/Linux Kernel Cross Reference
sys/net/if_epair.c
1 /*-
2 * Copyright (c) 2008 The FreeBSD Foundation
3 * Copyright (c) 2009-2010 Bjoern A. Zeeb <bz@FreeBSD.org>
4 * All rights reserved.
5 *
6 * This software was developed by CK Software GmbH under sponsorship
7 * from the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
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.
17 *
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
28 * SUCH DAMAGE.
29 */
30
31 /*
32 * A pair of virtual back-to-back connected ethernet like interfaces
33 * (``two interfaces with a virtual cross-over cable'').
34 *
35 * This is mostly intended to be used to provide connectivity between
36 * different virtual network stack instances.
37 */
38 /*
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.
48 */
49
50 #include <sys/cdefs.h>
51 __FBSDID("$FreeBSD: releng/10.1/sys/net/if_epair.c 241677 2012-10-18 09:57:56Z glebius $");
52
53 #include <sys/param.h>
54 #include <sys/kernel.h>
55 #include <sys/mbuf.h>
56 #include <sys/module.h>
57 #include <sys/refcount.h>
58 #include <sys/queue.h>
59 #include <sys/smp.h>
60 #include <sys/socket.h>
61 #include <sys/sockio.h>
62 #include <sys/sysctl.h>
63 #include <sys/types.h>
64
65 #include <net/bpf.h>
66 #include <net/ethernet.h>
67 #include <net/if.h>
68 #include <net/if_clone.h>
69 #include <net/if_media.h>
70 #include <net/if_var.h>
71 #include <net/if_types.h>
72 #include <net/netisr.h>
73 #include <net/vnet.h>
74
75 SYSCTL_DECL(_net_link);
76 static SYSCTL_NODE(_net_link, OID_AUTO, epair, CTLFLAG_RW, 0, "epair sysctl");
77
78 #ifdef EPAIR_DEBUG
79 static int epair_debug = 0;
80 SYSCTL_INT(_net_link_epair, OID_AUTO, epair_debug, CTLFLAG_RW,
81 &epair_debug, 0, "if_epair(4) debugging.");
82 #define DPRINTF(fmt, arg...) \
83 if (epair_debug) \
84 printf("[%s:%d] " fmt, __func__, __LINE__, ##arg)
85 #else
86 #define DPRINTF(fmt, arg...)
87 #endif
88
89 static void epair_nh_sintr(struct mbuf *);
90 static struct mbuf *epair_nh_m2cpuid(struct mbuf *, uintptr_t, u_int *);
91 static void epair_nh_drainedcpu(u_int);
92
93 static void epair_start_locked(struct ifnet *);
94 static int epair_media_change(struct ifnet *);
95 static void epair_media_status(struct ifnet *, struct ifmediareq *);
96
97 static int epair_clone_match(struct if_clone *, const char *);
98 static int epair_clone_create(struct if_clone *, char *, size_t, caddr_t);
99 static int epair_clone_destroy(struct if_clone *, struct ifnet *);
100
101 static const char epairname[] = "epair";
102
103 /* Netisr realted definitions and sysctl. */
104 static struct netisr_handler epair_nh = {
105 .nh_name = epairname,
106 .nh_proto = NETISR_EPAIR,
107 .nh_policy = NETISR_POLICY_CPU,
108 .nh_handler = epair_nh_sintr,
109 .nh_m2cpuid = epair_nh_m2cpuid,
110 .nh_drainedcpu = epair_nh_drainedcpu,
111 };
112
113 static int
114 sysctl_epair_netisr_maxqlen(SYSCTL_HANDLER_ARGS)
115 {
116 int error, qlimit;
117
118 netisr_getqlimit(&epair_nh, &qlimit);
119 error = sysctl_handle_int(oidp, &qlimit, 0, req);
120 if (error || !req->newptr)
121 return (error);
122 if (qlimit < 1)
123 return (EINVAL);
124 return (netisr_setqlimit(&epair_nh, qlimit));
125 }
126 SYSCTL_PROC(_net_link_epair, OID_AUTO, netisr_maxqlen, CTLTYPE_INT|CTLFLAG_RW,
127 0, 0, sysctl_epair_netisr_maxqlen, "I",
128 "Maximum if_epair(4) netisr \"hw\" queue length");
129
130 struct epair_softc {
131 struct ifnet *ifp; /* This ifp. */
132 struct ifnet *oifp; /* other ifp of pair. */
133 struct ifmedia media; /* Media config (fake). */
134 u_int refcount; /* # of mbufs in flight. */
135 u_int cpuid; /* CPU ID assigned upon creation. */
136 void (*if_qflush)(struct ifnet *);
137 /* Original if_qflush routine. */
138 };
139
140 /*
141 * Per-CPU list of ifps with data in the ifq that needs to be flushed
142 * to the netisr ``hw'' queue before we allow any further direct queuing
143 * to the ``hw'' queue.
144 */
145 struct epair_ifp_drain {
146 STAILQ_ENTRY(epair_ifp_drain) ifp_next;
147 struct ifnet *ifp;
148 };
149 STAILQ_HEAD(eid_list, epair_ifp_drain);
150
151 #define EPAIR_LOCK_INIT(dpcpu) mtx_init(&(dpcpu)->if_epair_mtx, \
152 "if_epair", NULL, MTX_DEF)
153 #define EPAIR_LOCK_DESTROY(dpcpu) mtx_destroy(&(dpcpu)->if_epair_mtx)
154 #define EPAIR_LOCK_ASSERT(dpcpu) mtx_assert(&(dpcpu)->if_epair_mtx, \
155 MA_OWNED)
156 #define EPAIR_LOCK(dpcpu) mtx_lock(&(dpcpu)->if_epair_mtx)
157 #define EPAIR_UNLOCK(dpcpu) mtx_unlock(&(dpcpu)->if_epair_mtx)
158
159 #ifdef INVARIANTS
160 #define EPAIR_REFCOUNT_INIT(r, v) refcount_init((r), (v))
161 #define EPAIR_REFCOUNT_AQUIRE(r) refcount_acquire((r))
162 #define EPAIR_REFCOUNT_RELEASE(r) refcount_release((r))
163 #define EPAIR_REFCOUNT_ASSERT(a, p) KASSERT(a, p)
164 #else
165 #define EPAIR_REFCOUNT_INIT(r, v)
166 #define EPAIR_REFCOUNT_AQUIRE(r)
167 #define EPAIR_REFCOUNT_RELEASE(r)
168 #define EPAIR_REFCOUNT_ASSERT(a, p)
169 #endif
170
171 static MALLOC_DEFINE(M_EPAIR, epairname,
172 "Pair of virtual cross-over connected Ethernet-like interfaces");
173
174 static struct if_clone *epair_cloner;
175
176 /*
177 * DPCPU area and functions.
178 */
179 struct epair_dpcpu {
180 struct mtx if_epair_mtx; /* Per-CPU locking. */
181 int epair_drv_flags; /* Per-CPU ``hw'' drv flags. */
182 struct eid_list epair_ifp_drain_list; /* Per-CPU list of ifps with
183 * data in the ifq. */
184 };
185 DPCPU_DEFINE(struct epair_dpcpu, epair_dpcpu);
186
187 static void
188 epair_dpcpu_init(void)
189 {
190 struct epair_dpcpu *epair_dpcpu;
191 struct eid_list *s;
192 u_int cpuid;
193
194 CPU_FOREACH(cpuid) {
195 epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
196
197 /* Initialize per-cpu lock. */
198 EPAIR_LOCK_INIT(epair_dpcpu);
199
200 /* Driver flags are per-cpu as are our netisr "hw" queues. */
201 epair_dpcpu->epair_drv_flags = 0;
202
203 /*
204 * Initialize per-cpu drain list.
205 * Manually do what STAILQ_HEAD_INITIALIZER would do.
206 */
207 s = &epair_dpcpu->epair_ifp_drain_list;
208 s->stqh_first = NULL;
209 s->stqh_last = &s->stqh_first;
210 }
211 }
212
213 static void
214 epair_dpcpu_detach(void)
215 {
216 struct epair_dpcpu *epair_dpcpu;
217 u_int cpuid;
218
219 CPU_FOREACH(cpuid) {
220 epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
221
222 /* Destroy per-cpu lock. */
223 EPAIR_LOCK_DESTROY(epair_dpcpu);
224 }
225 }
226
227 /*
228 * Helper functions.
229 */
230 static u_int
231 cpuid_from_ifp(struct ifnet *ifp)
232 {
233 struct epair_softc *sc;
234
235 if (ifp == NULL)
236 return (0);
237 sc = ifp->if_softc;
238
239 return (sc->cpuid);
240 }
241
242 /*
243 * Netisr handler functions.
244 */
245 static void
246 epair_nh_sintr(struct mbuf *m)
247 {
248 struct ifnet *ifp;
249 struct epair_softc *sc;
250
251 ifp = m->m_pkthdr.rcvif;
252 (*ifp->if_input)(ifp, m);
253 sc = ifp->if_softc;
254 EPAIR_REFCOUNT_RELEASE(&sc->refcount);
255 EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
256 ("%s: ifp=%p sc->refcount not >= 1: %d",
257 __func__, ifp, sc->refcount));
258 DPRINTF("ifp=%p refcount=%u\n", ifp, sc->refcount);
259 }
260
261 static struct mbuf *
262 epair_nh_m2cpuid(struct mbuf *m, uintptr_t source, u_int *cpuid)
263 {
264
265 *cpuid = cpuid_from_ifp(m->m_pkthdr.rcvif);
266
267 return (m);
268 }
269
270 static void
271 epair_nh_drainedcpu(u_int cpuid)
272 {
273 struct epair_dpcpu *epair_dpcpu;
274 struct epair_ifp_drain *elm, *tvar;
275 struct ifnet *ifp;
276
277 epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
278 EPAIR_LOCK(epair_dpcpu);
279 /*
280 * Assume our "hw" queue and possibly ifq will be emptied
281 * again. In case we will overflow the "hw" queue while
282 * draining, epair_start_locked will set IFF_DRV_OACTIVE
283 * again and we will stop and return.
284 */
285 STAILQ_FOREACH_SAFE(elm, &epair_dpcpu->epair_ifp_drain_list,
286 ifp_next, tvar) {
287 ifp = elm->ifp;
288 epair_dpcpu->epair_drv_flags &= ~IFF_DRV_OACTIVE;
289 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
290 epair_start_locked(ifp);
291
292 IFQ_LOCK(&ifp->if_snd);
293 if (IFQ_IS_EMPTY(&ifp->if_snd)) {
294 struct epair_softc *sc;
295
296 STAILQ_REMOVE(&epair_dpcpu->epair_ifp_drain_list,
297 elm, epair_ifp_drain, ifp_next);
298 /* The cached ifp goes off the list. */
299 sc = ifp->if_softc;
300 EPAIR_REFCOUNT_RELEASE(&sc->refcount);
301 EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
302 ("%s: ifp=%p sc->refcount not >= 1: %d",
303 __func__, ifp, sc->refcount));
304 free(elm, M_EPAIR);
305 }
306 IFQ_UNLOCK(&ifp->if_snd);
307
308 if ((ifp->if_drv_flags & IFF_DRV_OACTIVE) != 0) {
309 /* Our "hw"q overflew again. */
310 epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE;
311 DPRINTF("hw queue length overflow at %u\n",
312 epair_nh.nh_qlimit);
313 break;
314 }
315 }
316 EPAIR_UNLOCK(epair_dpcpu);
317 }
318
319 /*
320 * Network interface (`if') related functions.
321 */
322 static void
323 epair_remove_ifp_from_draining(struct ifnet *ifp)
324 {
325 struct epair_dpcpu *epair_dpcpu;
326 struct epair_ifp_drain *elm, *tvar;
327 u_int cpuid;
328
329 CPU_FOREACH(cpuid) {
330 epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
331 EPAIR_LOCK(epair_dpcpu);
332 STAILQ_FOREACH_SAFE(elm, &epair_dpcpu->epair_ifp_drain_list,
333 ifp_next, tvar) {
334 if (ifp == elm->ifp) {
335 struct epair_softc *sc;
336
337 STAILQ_REMOVE(
338 &epair_dpcpu->epair_ifp_drain_list, elm,
339 epair_ifp_drain, ifp_next);
340 /* The cached ifp goes off the list. */
341 sc = ifp->if_softc;
342 EPAIR_REFCOUNT_RELEASE(&sc->refcount);
343 EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
344 ("%s: ifp=%p sc->refcount not >= 1: %d",
345 __func__, ifp, sc->refcount));
346 free(elm, M_EPAIR);
347 }
348 }
349 EPAIR_UNLOCK(epair_dpcpu);
350 }
351 }
352
353 static int
354 epair_add_ifp_for_draining(struct ifnet *ifp)
355 {
356 struct epair_dpcpu *epair_dpcpu;
357 struct epair_softc *sc;
358 struct epair_ifp_drain *elm = NULL;
359
360 sc = ifp->if_softc;
361 epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
362 EPAIR_LOCK_ASSERT(epair_dpcpu);
363 STAILQ_FOREACH(elm, &epair_dpcpu->epair_ifp_drain_list, ifp_next)
364 if (elm->ifp == ifp)
365 break;
366 /* If the ifp is there already, return success. */
367 if (elm != NULL)
368 return (0);
369
370 elm = malloc(sizeof(struct epair_ifp_drain), M_EPAIR, M_NOWAIT|M_ZERO);
371 if (elm == NULL)
372 return (ENOMEM);
373
374 elm->ifp = ifp;
375 /* Add a reference for the ifp pointer on the list. */
376 EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
377 STAILQ_INSERT_TAIL(&epair_dpcpu->epair_ifp_drain_list, elm, ifp_next);
378
379 return (0);
380 }
381
382 static void
383 epair_start_locked(struct ifnet *ifp)
384 {
385 struct epair_dpcpu *epair_dpcpu;
386 struct mbuf *m;
387 struct epair_softc *sc;
388 struct ifnet *oifp;
389 int error;
390
391 DPRINTF("ifp=%p\n", ifp);
392 sc = ifp->if_softc;
393 epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
394 EPAIR_LOCK_ASSERT(epair_dpcpu);
395
396 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
397 return;
398 if ((ifp->if_flags & IFF_UP) == 0)
399 return;
400
401 /*
402 * We get patckets here from ether_output via if_handoff()
403 * and ned to put them into the input queue of the oifp
404 * and call oifp->if_input() via netisr/epair_sintr().
405 */
406 oifp = sc->oifp;
407 sc = oifp->if_softc;
408 for (;;) {
409 IFQ_DEQUEUE(&ifp->if_snd, m);
410 if (m == NULL)
411 break;
412 BPF_MTAP(ifp, m);
413
414 /*
415 * In case the outgoing interface is not usable,
416 * drop the packet.
417 */
418 if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
419 (oifp->if_flags & IFF_UP) ==0) {
420 ifp->if_oerrors++;
421 m_freem(m);
422 continue;
423 }
424 DPRINTF("packet %s -> %s\n", ifp->if_xname, oifp->if_xname);
425
426 /*
427 * Add a reference so the interface cannot go while the
428 * packet is in transit as we rely on rcvif to stay valid.
429 */
430 EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
431 m->m_pkthdr.rcvif = oifp;
432 CURVNET_SET_QUIET(oifp->if_vnet);
433 error = netisr_queue(NETISR_EPAIR, m);
434 CURVNET_RESTORE();
435 if (!error) {
436 ifp->if_opackets++;
437 /* Someone else received the packet. */
438 oifp->if_ipackets++;
439 } else {
440 /* The packet was freed already. */
441 epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE;
442 ifp->if_drv_flags |= IFF_DRV_OACTIVE;
443 (void) epair_add_ifp_for_draining(ifp);
444 ifp->if_oerrors++;
445 EPAIR_REFCOUNT_RELEASE(&sc->refcount);
446 EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
447 ("%s: ifp=%p sc->refcount not >= 1: %d",
448 __func__, oifp, sc->refcount));
449 }
450 }
451 }
452
453 static void
454 epair_start(struct ifnet *ifp)
455 {
456 struct epair_dpcpu *epair_dpcpu;
457
458 epair_dpcpu = DPCPU_ID_PTR(cpuid_from_ifp(ifp), epair_dpcpu);
459 EPAIR_LOCK(epair_dpcpu);
460 epair_start_locked(ifp);
461 EPAIR_UNLOCK(epair_dpcpu);
462 }
463
464 static int
465 epair_transmit_locked(struct ifnet *ifp, struct mbuf *m)
466 {
467 struct epair_dpcpu *epair_dpcpu;
468 struct epair_softc *sc;
469 struct ifnet *oifp;
470 int error, len;
471 short mflags;
472
473 DPRINTF("ifp=%p m=%p\n", ifp, m);
474 sc = ifp->if_softc;
475 epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
476 EPAIR_LOCK_ASSERT(epair_dpcpu);
477
478 if (m == NULL)
479 return (0);
480
481 /*
482 * We are not going to use the interface en/dequeue mechanism
483 * on the TX side. We are called from ether_output_frame()
484 * and will put the packet into the incoming queue of the
485 * other interface of our pair via the netsir.
486 */
487 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
488 m_freem(m);
489 return (ENXIO);
490 }
491 if ((ifp->if_flags & IFF_UP) == 0) {
492 m_freem(m);
493 return (ENETDOWN);
494 }
495
496 BPF_MTAP(ifp, m);
497
498 /*
499 * In case the outgoing interface is not usable,
500 * drop the packet.
501 */
502 oifp = sc->oifp;
503 if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
504 (oifp->if_flags & IFF_UP) ==0) {
505 ifp->if_oerrors++;
506 m_freem(m);
507 return (0);
508 }
509 len = m->m_pkthdr.len;
510 mflags = m->m_flags;
511 DPRINTF("packet %s -> %s\n", ifp->if_xname, oifp->if_xname);
512
513 #ifdef ALTQ
514 /* Support ALTQ via the clasic if_start() path. */
515 IF_LOCK(&ifp->if_snd);
516 if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
517 ALTQ_ENQUEUE(&ifp->if_snd, m, NULL, error);
518 if (error)
519 ifp->if_snd.ifq_drops++;
520 IF_UNLOCK(&ifp->if_snd);
521 if (!error) {
522 ifp->if_obytes += len;
523 if (mflags & (M_BCAST|M_MCAST))
524 ifp->if_omcasts++;
525
526 if ((ifp->if_drv_flags & IFF_DRV_OACTIVE) == 0)
527 epair_start_locked(ifp);
528 else
529 (void)epair_add_ifp_for_draining(ifp);
530 }
531 return (error);
532 }
533 IF_UNLOCK(&ifp->if_snd);
534 #endif
535
536 if ((epair_dpcpu->epair_drv_flags & IFF_DRV_OACTIVE) != 0) {
537 /*
538 * Our hardware queue is full, try to fall back
539 * queuing to the ifq but do not call ifp->if_start.
540 * Either we are lucky or the packet is gone.
541 */
542 IFQ_ENQUEUE(&ifp->if_snd, m, error);
543 if (!error)
544 (void)epair_add_ifp_for_draining(ifp);
545 return (error);
546 }
547 sc = oifp->if_softc;
548 /*
549 * Add a reference so the interface cannot go while the
550 * packet is in transit as we rely on rcvif to stay valid.
551 */
552 EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
553 m->m_pkthdr.rcvif = oifp;
554 CURVNET_SET_QUIET(oifp->if_vnet);
555 error = netisr_queue(NETISR_EPAIR, m);
556 CURVNET_RESTORE();
557 if (!error) {
558 ifp->if_opackets++;
559 /*
560 * IFQ_HANDOFF_ADJ/ip_handoff() update statistics,
561 * but as we bypass all this we have to duplicate
562 * the logic another time.
563 */
564 ifp->if_obytes += len;
565 if (mflags & (M_BCAST|M_MCAST))
566 ifp->if_omcasts++;
567 /* Someone else received the packet. */
568 oifp->if_ipackets++;
569 } else {
570 /* The packet was freed already. */
571 epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE;
572 ifp->if_drv_flags |= IFF_DRV_OACTIVE;
573 ifp->if_oerrors++;
574 EPAIR_REFCOUNT_RELEASE(&sc->refcount);
575 EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
576 ("%s: ifp=%p sc->refcount not >= 1: %d",
577 __func__, oifp, sc->refcount));
578 }
579
580 return (error);
581 }
582
583 static int
584 epair_transmit(struct ifnet *ifp, struct mbuf *m)
585 {
586 struct epair_dpcpu *epair_dpcpu;
587 int error;
588
589 epair_dpcpu = DPCPU_ID_PTR(cpuid_from_ifp(ifp), epair_dpcpu);
590 EPAIR_LOCK(epair_dpcpu);
591 error = epair_transmit_locked(ifp, m);
592 EPAIR_UNLOCK(epair_dpcpu);
593 return (error);
594 }
595
596 static void
597 epair_qflush(struct ifnet *ifp)
598 {
599 struct epair_softc *sc;
600
601 sc = ifp->if_softc;
602 KASSERT(sc != NULL, ("%s: ifp=%p, epair_softc gone? sc=%p\n",
603 __func__, ifp, sc));
604 /*
605 * Remove this ifp from all backpointer lists. The interface will not
606 * usable for flushing anyway nor should it have anything to flush
607 * after if_qflush().
608 */
609 epair_remove_ifp_from_draining(ifp);
610
611 if (sc->if_qflush)
612 sc->if_qflush(ifp);
613 }
614
615 static int
616 epair_media_change(struct ifnet *ifp __unused)
617 {
618
619 /* Do nothing. */
620 return (0);
621 }
622
623 static void
624 epair_media_status(struct ifnet *ifp __unused, struct ifmediareq *imr)
625 {
626
627 imr->ifm_status = IFM_AVALID | IFM_ACTIVE;
628 imr->ifm_active = IFM_ETHER | IFM_10G_T | IFM_FDX;
629 }
630
631 static int
632 epair_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
633 {
634 struct epair_softc *sc;
635 struct ifreq *ifr;
636 int error;
637
638 ifr = (struct ifreq *)data;
639 switch (cmd) {
640 case SIOCSIFFLAGS:
641 case SIOCADDMULTI:
642 case SIOCDELMULTI:
643 error = 0;
644 break;
645
646 case SIOCSIFMEDIA:
647 case SIOCGIFMEDIA:
648 sc = ifp->if_softc;
649 error = ifmedia_ioctl(ifp, ifr, &sc->media, cmd);
650 break;
651
652 case SIOCSIFMTU:
653 /* We basically allow all kinds of MTUs. */
654 ifp->if_mtu = ifr->ifr_mtu;
655 error = 0;
656 break;
657
658 default:
659 /* Let the common ethernet handler process this. */
660 error = ether_ioctl(ifp, cmd, data);
661 break;
662 }
663
664 return (error);
665 }
666
667 static void
668 epair_init(void *dummy __unused)
669 {
670 }
671
672
673 /*
674 * Interface cloning functions.
675 * We use our private ones so that we can create/destroy our secondary
676 * device along with the primary one.
677 */
678 static int
679 epair_clone_match(struct if_clone *ifc, const char *name)
680 {
681 const char *cp;
682
683 DPRINTF("name='%s'\n", name);
684
685 /*
686 * Our base name is epair.
687 * Our interfaces will be named epair<n>[ab].
688 * So accept anything of the following list:
689 * - epair
690 * - epair<n>
691 * but not the epair<n>[ab] versions.
692 */
693 if (strncmp(epairname, name, sizeof(epairname)-1) != 0)
694 return (0);
695
696 for (cp = name + sizeof(epairname) - 1; *cp != '\0'; cp++) {
697 if (*cp < '' || *cp > '9')
698 return (0);
699 }
700
701 return (1);
702 }
703
704 static int
705 epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
706 {
707 struct epair_softc *sca, *scb;
708 struct ifnet *ifp;
709 char *dp;
710 int error, unit, wildcard;
711 uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */
712
713 /*
714 * We are abusing params to create our second interface.
715 * Actually we already created it and called if_clone_create()
716 * for it to do the official insertion procedure the moment we knew
717 * it cannot fail anymore. So just do attach it here.
718 */
719 if (params) {
720 scb = (struct epair_softc *)params;
721 ifp = scb->ifp;
722 /* Assign a hopefully unique, locally administered etheraddr. */
723 eaddr[0] = 0x02;
724 eaddr[3] = (ifp->if_index >> 8) & 0xff;
725 eaddr[4] = ifp->if_index & 0xff;
726 eaddr[5] = 0x0b;
727 ether_ifattach(ifp, eaddr);
728 /* Correctly set the name for the cloner list. */
729 strlcpy(name, scb->ifp->if_xname, len);
730 return (0);
731 }
732
733 /* Try to see if a special unit was requested. */
734 error = ifc_name2unit(name, &unit);
735 if (error != 0)
736 return (error);
737 wildcard = (unit < 0);
738
739 error = ifc_alloc_unit(ifc, &unit);
740 if (error != 0)
741 return (error);
742
743 /*
744 * If no unit had been given, we need to adjust the ifName.
745 * Also make sure there is space for our extra [ab] suffix.
746 */
747 for (dp = name; *dp != '\0'; dp++);
748 if (wildcard) {
749 error = snprintf(dp, len - (dp - name), "%d", unit);
750 if (error > len - (dp - name) - 1) {
751 /* ifName too long. */
752 ifc_free_unit(ifc, unit);
753 return (ENOSPC);
754 }
755 dp += error;
756 }
757 if (len - (dp - name) - 1 < 1) {
758 /* No space left for our [ab] suffix. */
759 ifc_free_unit(ifc, unit);
760 return (ENOSPC);
761 }
762 *dp = 'a';
763 /* Must not change dp so we can replace 'a' by 'b' later. */
764 *(dp+1) = '\0';
765
766 /* Allocate memory for both [ab] interfaces */
767 sca = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO);
768 EPAIR_REFCOUNT_INIT(&sca->refcount, 1);
769 sca->ifp = if_alloc(IFT_ETHER);
770 if (sca->ifp == NULL) {
771 free(sca, M_EPAIR);
772 ifc_free_unit(ifc, unit);
773 return (ENOSPC);
774 }
775
776 scb = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO);
777 EPAIR_REFCOUNT_INIT(&scb->refcount, 1);
778 scb->ifp = if_alloc(IFT_ETHER);
779 if (scb->ifp == NULL) {
780 free(scb, M_EPAIR);
781 if_free(sca->ifp);
782 free(sca, M_EPAIR);
783 ifc_free_unit(ifc, unit);
784 return (ENOSPC);
785 }
786
787 /*
788 * Cross-reference the interfaces so we will be able to free both.
789 */
790 sca->oifp = scb->ifp;
791 scb->oifp = sca->ifp;
792
793 /*
794 * Calculate the cpuid for netisr queueing based on the
795 * ifIndex of the interfaces. As long as we cannot configure
796 * this or use cpuset information easily we cannot guarantee
797 * cache locality but we can at least allow parallelism.
798 */
799 sca->cpuid =
800 netisr_get_cpuid(sca->ifp->if_index % netisr_get_cpucount());
801 scb->cpuid =
802 netisr_get_cpuid(scb->ifp->if_index % netisr_get_cpucount());
803
804 /* Finish initialization of interface <n>a. */
805 ifp = sca->ifp;
806 ifp->if_softc = sca;
807 strlcpy(ifp->if_xname, name, IFNAMSIZ);
808 ifp->if_dname = epairname;
809 ifp->if_dunit = unit;
810 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
811 ifp->if_capabilities = IFCAP_VLAN_MTU;
812 ifp->if_capenable = IFCAP_VLAN_MTU;
813 ifp->if_start = epair_start;
814 ifp->if_ioctl = epair_ioctl;
815 ifp->if_init = epair_init;
816 ifp->if_snd.ifq_maxlen = ifqmaxlen;
817 /* Assign a hopefully unique, locally administered etheraddr. */
818 eaddr[0] = 0x02;
819 eaddr[3] = (ifp->if_index >> 8) & 0xff;
820 eaddr[4] = ifp->if_index & 0xff;
821 eaddr[5] = 0x0a;
822 ether_ifattach(ifp, eaddr);
823 sca->if_qflush = ifp->if_qflush;
824 ifp->if_qflush = epair_qflush;
825 ifp->if_transmit = epair_transmit;
826 if_initbaudrate(ifp, IF_Gbps(10)); /* arbitrary maximum */
827
828 /* Swap the name and finish initialization of interface <n>b. */
829 *dp = 'b';
830
831 ifp = scb->ifp;
832 ifp->if_softc = scb;
833 strlcpy(ifp->if_xname, name, IFNAMSIZ);
834 ifp->if_dname = epairname;
835 ifp->if_dunit = unit;
836 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
837 ifp->if_capabilities = IFCAP_VLAN_MTU;
838 ifp->if_capenable = IFCAP_VLAN_MTU;
839 ifp->if_start = epair_start;
840 ifp->if_ioctl = epair_ioctl;
841 ifp->if_init = epair_init;
842 ifp->if_snd.ifq_maxlen = ifqmaxlen;
843 /* We need to play some tricks here for the second interface. */
844 strlcpy(name, epairname, len);
845 error = if_clone_create(name, len, (caddr_t)scb);
846 if (error)
847 panic("%s: if_clone_create() for our 2nd iface failed: %d",
848 __func__, error);
849 scb->if_qflush = ifp->if_qflush;
850 ifp->if_qflush = epair_qflush;
851 ifp->if_transmit = epair_transmit;
852 if_initbaudrate(ifp, IF_Gbps(10)); /* arbitrary maximum */
853
854 /*
855 * Restore name to <n>a as the ifp for this will go into the
856 * cloner list for the initial call.
857 */
858 strlcpy(name, sca->ifp->if_xname, len);
859 DPRINTF("name='%s/%db' created sca=%p scb=%p\n", name, unit, sca, scb);
860
861 /* Initialise pseudo media types. */
862 ifmedia_init(&sca->media, 0, epair_media_change, epair_media_status);
863 ifmedia_add(&sca->media, IFM_ETHER | IFM_10G_T, 0, NULL);
864 ifmedia_set(&sca->media, IFM_ETHER | IFM_10G_T);
865 ifmedia_init(&scb->media, 0, epair_media_change, epair_media_status);
866 ifmedia_add(&scb->media, IFM_ETHER | IFM_10G_T, 0, NULL);
867 ifmedia_set(&scb->media, IFM_ETHER | IFM_10G_T);
868
869 /* Tell the world, that we are ready to rock. */
870 sca->ifp->if_drv_flags |= IFF_DRV_RUNNING;
871 scb->ifp->if_drv_flags |= IFF_DRV_RUNNING;
872 if_link_state_change(sca->ifp, LINK_STATE_UP);
873 if_link_state_change(scb->ifp, LINK_STATE_UP);
874
875 return (0);
876 }
877
878 static int
879 epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
880 {
881 struct ifnet *oifp;
882 struct epair_softc *sca, *scb;
883 int unit, error;
884
885 DPRINTF("ifp=%p\n", ifp);
886
887 /*
888 * In case we called into if_clone_destroyif() ourselves
889 * again to remove the second interface, the softc will be
890 * NULL. In that case so not do anything but return success.
891 */
892 if (ifp->if_softc == NULL)
893 return (0);
894
895 unit = ifp->if_dunit;
896 sca = ifp->if_softc;
897 oifp = sca->oifp;
898 scb = oifp->if_softc;
899
900 DPRINTF("ifp=%p oifp=%p\n", ifp, oifp);
901 if_link_state_change(ifp, LINK_STATE_DOWN);
902 if_link_state_change(oifp, LINK_STATE_DOWN);
903 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
904 oifp->if_drv_flags &= ~IFF_DRV_RUNNING;
905
906 /*
907 * Get rid of our second half. As the other of the two
908 * interfaces may reside in a different vnet, we need to
909 * switch before freeing them.
910 */
911 CURVNET_SET_QUIET(oifp->if_vnet);
912 ether_ifdetach(oifp);
913 /*
914 * Wait for all packets to be dispatched to if_input.
915 * The numbers can only go down as the interface is
916 * detached so there is no need to use atomics.
917 */
918 DPRINTF("scb refcnt=%u\n", scb->refcount);
919 EPAIR_REFCOUNT_ASSERT(scb->refcount == 1,
920 ("%s: ifp=%p scb->refcount!=1: %d", __func__, oifp, scb->refcount));
921 oifp->if_softc = NULL;
922 error = if_clone_destroyif(ifc, oifp);
923 if (error)
924 panic("%s: if_clone_destroyif() for our 2nd iface failed: %d",
925 __func__, error);
926 if_free(oifp);
927 ifmedia_removeall(&scb->media);
928 free(scb, M_EPAIR);
929 CURVNET_RESTORE();
930
931 ether_ifdetach(ifp);
932 /*
933 * Wait for all packets to be dispatched to if_input.
934 */
935 DPRINTF("sca refcnt=%u\n", sca->refcount);
936 EPAIR_REFCOUNT_ASSERT(sca->refcount == 1,
937 ("%s: ifp=%p sca->refcount!=1: %d", __func__, ifp, sca->refcount));
938 if_free(ifp);
939 ifmedia_removeall(&sca->media);
940 free(sca, M_EPAIR);
941 ifc_free_unit(ifc, unit);
942
943 return (0);
944 }
945
946 static int
947 epair_modevent(module_t mod, int type, void *data)
948 {
949 int qlimit;
950
951 switch (type) {
952 case MOD_LOAD:
953 /* For now limit us to one global mutex and one inq. */
954 epair_dpcpu_init();
955 epair_nh.nh_qlimit = 42 * ifqmaxlen; /* 42 shall be the number. */
956 if (TUNABLE_INT_FETCH("net.link.epair.netisr_maxqlen", &qlimit))
957 epair_nh.nh_qlimit = qlimit;
958 netisr_register(&epair_nh);
959 epair_cloner = if_clone_advanced(epairname, 0,
960 epair_clone_match, epair_clone_create, epair_clone_destroy);
961 if (bootverbose)
962 printf("%s initialized.\n", epairname);
963 break;
964 case MOD_UNLOAD:
965 if_clone_detach(epair_cloner);
966 netisr_unregister(&epair_nh);
967 epair_dpcpu_detach();
968 if (bootverbose)
969 printf("%s unloaded.\n", epairname);
970 break;
971 default:
972 return (EOPNOTSUPP);
973 }
974 return (0);
975 }
976
977 static moduledata_t epair_mod = {
978 "if_epair",
979 epair_modevent,
980 0
981 };
982
983 DECLARE_MODULE(if_epair, epair_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
984 MODULE_VERSION(if_epair, 1);
Cache object: 32fa137d897d3a09b1e04a3fbecceb75
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